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Modifying registry-based Silverlight policy settings

2011-07-22T23:07:00.000-07:00

You can modify the Silverlight policy settings that apply to individual computers.

To modify registry-based Silverlight policy settings

1. Open Group Policy Object Editor by using one of the methods described in the Group Policy product documentation (http://go.microsoft.com/fwlink/?linkid=67717).

The method you use will depend on the GPO that you want to manage. One way to open Group Policy Object Editor is to click Start, click Run, and then enter Gpedit.msc.

2. Double-click Policy, and then double-click Computer Configuration.

3. Double-click Administrative Templates, double-click Windows Components, and then double-click Silverlight.

4. In the left pane, click the category you want to work with, and then in the right pane, double-click the item that you want to edit.

5. Click the Setting tab, and then configure the policy setting. Typical choices for a setting are Not Configured, Enabled, or Disabled. Some settings require you to make additional selections or enter additional information.

Registry-based Silverlight policy settings

2011-07-22T23:06:00.000-07:00

The Silverlight control’s automatic update mechanism is independent of both the Windows Update and Microsoft Update mechanisms. Silverlight can be configured to use one of three automatic update modes:

1) Auto Updates - Automatically detects, downloads, and installs updates. This is the default setting after an install. The client will attempt to request files from Microsoft at most one time per day to detect if there is a newer version of the Silverlight client. If there is a newer version, it will automatically download and install the update without any user intervention required.

2) Prompted Updates - Detects when an update is available and prompts if you would like to download and install the update. This uses the same detection location and schedule as the Auto Updates option.

3) No Updates - Does not check for or automatically download updates. This option should be used in most corporate environments if you are using SMS, software update services (SUS), or another enterprise software management solution.

If using the Silverlight updater you will need to give the client computer access to the following domains:

· go.microsoft.com

· silverlight.dlservice.microsoft.com

· rs.update.microsoft.com

· slupdate.dlservice.microsoft.com

· www.microsoft.com

These settings are available in the custom ADM or ADMX file you created as referenced above. The registry setting that the administrative template files contain is:

Key path: HKEY_LOCAL_MACHINE\Software\Microsoft\Silverlight\

Value Name: UpdateMode

Value Type: DWORD

Valid Values:

Auto Updates 0x00000000

Prompted Updates 0x00000001

No Updates 0x00000002

You can locate this setting in the following policy path for your GPOs:

Category	Description
Computer Configuration\Administrative Templates\Silverlight	Contains settings to enable or disable standard Silverlight configurations.

Disabling Silverlight add-on in Internet Explorer® 7

2011-07-22T23:02:00.000-07:00

To isolate browser issues that might be related to the Silverlight add-on, you can selectively disable the add-on in Internet Explorer 7.

To disable a browser add-on

1. Click the Tools menu, click Manage Add-ons, and then click Enable or Disable Add-ons.

2. Change the “Show” Drop-down box to “Add-ons that have been used by Internet Explorer”

3. Click AgControl Class, click Disable, and then click OK.

Alternatively, you can turn off all add-ons temporarily in Internet Explorer 7 by starting in No add-ons mode.

To start Internet Explorer 7 in No add-ons mode

1. Click Start, click All Programs, and then click Accessories.

2. Click System Tools, and then click Internet Explorer (No Add-ons).

Note

You can also start Internet Explorer without add-ons by right-clicking the Internet Explorer icon on the desktop and then clicking Start Without Add-ons. Or start Internet Explorer with no add-ons or toolbars by running the command iexplore.exe -extoff.

System Requirements for Windows Sliverlight

2011-07-22T22:55:00.000-07:00

The system requirements for Microsoft Silverlight and associated technologies are listed below.

Windows

§ Operating System: Windows 7,Windows Vista; Windows XP Service Pack 2

§ Intel® Pentium® III 450MHz or faster processor (or equivalent)

§ 128MB of RAM

Mac OS

§ Operating System: Apple Mac OS X 10.4.11+ (Intel-based) or above

§ Intel Core™ Duo 1.83GHz or faster processor

§ 128MB of RAM

Linux

Moonlight is an open source implementation of Silverlight, primarily for Linux and other Unix/X11 based operating systems. In September of 2007, Microsoft and Novell announced a technical collaboration that includes access to Microsoft's test suites for Silverlight and the distribution of a Media Pack for Linux users that will contain licensed media codecs for video and audio.

Up-to-date packages ready to test are available from:

http://www.go-mono.com/moonlight

Our supported architectures and operating systems list the platforms that we currently test the binary packages of Moonlight on.

Once you install Moonlight from the above URL to play video or audio, you will be prompted by Moonlight to install the Microsoft Media Pack for Moonlight available from Microsoft.

Alternatively, you can build Moonlight from source code and link against ffmpeg codecs on your own.

Features Windows Silverlight 5.0

2011-07-22T22:47:00.000-07:00

Improved media support and rich UI capabilities

· Hardware Decode and presentation of H.264 improve performance for lower-power devices to render high-definition video using GPU support.

· TrickPlay allows video to be played at different speeds and supports fast-forward and rewind. At up to twice the speed, audio pitch correction allows users to watch videos while preserving a normal audio pitch.

· Improved power awareness prevents the screen saver from being shown while watching video and allows the computer to sleep when video is not active.

· Remote-control support allows users to control media playback.

· Digital rights management advancements allow seamless switching between DRM media sources.

Silverlight 5 performance improvements

· Reduced network latency by using a background thread for networking.

· XAML parser improvements that speed up startup and runtime performance.

· Support for 64-bit operating systems.

· Reduced network latency by using a background thread for networking.

Graphics improvements

· Graphics Processing Unit (GPU) accelerated 3-D application programming interface (API) provides rich graphics on the Web for building advanced data visualizations and rich user experience (UI).

· Immediate mode graphics API allows direct rendering to the GPU.

· Hardware acceleration is enabled in windowless mode with Internet Explorer 9.

Improved Data binding support and Better support for MVVM:

One of the greatest strength of Silverlight is its data binding. Microsoft is going to enhanced data binding by providing more ability to debug it. Developer will able to debug the binding expression and other stuff in Siverlight 5.0. Its also going to provide Ancestor Relative source binding which will allow property to bind with container control. MVVM pattern support will also be enhanced.

Performance and Speed Enhancement:

Now silverlight 5.0 will have support for 64bit browser support. So now you can use that silverlight application on 64 bit platform also. There is no need to take extra care for it.It will also have faster startup time and greater support for hardware acceleration. It will also provide end to end support for hard acceleration features of IE 9.

More support for Out Of Browser Application:

With Siverlight 4.0 Microsoft has announced new features called out of browser application and it has amazed lots of developer because now possibilities are unlimited with it. Now in silverlight 5.0 Out Of Browser application will have ability to Create Manage child windows just like windows forms or WPF Application. So you can fill power of desktop application with your out of browser application.

Testing Support with Visual Studio 2010:

Microsoft is going to add automated UI Testing support with Visual Studio 2010 with silverlight 5.0. So now we can test UI of Silverlight much faster.

Better Support for RIA Services:

RIA Services allows us to create N-tier application with silverlight via creating proxy classes on client and server both side. Now it will more features like complex type support, Custom type support for MVVM(Model View View Model) pattern.

WCF Enhancements:

There are lots of enhancement with WCF but key enhancement will WSTrust support.

Text and Printing Support:

Silverlight 5.0 will support vector base graphics. It will also support multicolumn text flow and linked text containers. It will full open type support, Postscript vector enhancement.

Improved Power Enhancement:

This will prevent screensaver from activating while you are watching videos on silverlight. Silverlight 5.0 is going add that smartness so it can determine while you are going to watch video and while you are not going watch videos.

Better support for graphics:

Silverlight 5.0 will provide in-depth support for 3D API. Now 3D rendering support is more enhancement in silverlight and 3D graphics can be rendered easily.

Features of Silverlight 4.0

2011-07-22T22:04:00.001-07:00

Silverlight 4 delivers a full suite of powerful features to application developers, bringing innovative platform capabilities to browser-based experiences. Silverlight provides an ideal platform for developing and deploying modern business applications for both internal and end-user applications on both sides of the firewall

Enabling business application development. Silverlight 4 affirms its position as the natural choice for building business applications on the Web:

What’s new for application developers

· Comprehensive printing support now enables the creation of a virtual print view, enabling applications to deliver print-friendly documents.

· A full set of controls with more than 60 customizable, skinnable components makes it easy to build forms that can be sorted, resized and validated. New controls include RichTextArea with hyperlinks, images and editing.

· Localization enhancements with bidirectional text, right-to-left support and complex scripts such as Arabic, Hebrew and Thai and 30 new languages.

· The Microsoft .NET Framework Common Language Runtime (CLR) now enables the same compiled code to be run both on the server and the client, reducing development time and testing resources.

· Enhanced databinding support reduces the amount of code needed to work with customized data for display.

· Managed Extensibility Framework supports building completely modular applications, allowing for fast startup and download, efficient development and testing, as well as agile customization and servicing.

· Windows Communication Foundation RIA Services introduces enterprise class networking and data access, allowing applications to work with any source of data and any server.

· Extensive tooling support for Silverlight, new in Visual Studio 2010:

· Fully editable design surface for drawing out controls and layouts

· Rich property grid and new editors for values

· Drag and drop support for databinding and automatically creating bound controls such as listbox and datagrid

· New datasources window and picker

· Easy-to-pick styles and resources to make a good-looking application based on designer resources built in Expression Blend

· Built-in project support for Silverlight applications

· Editor with full IntelliSense for XAML and C# and Visual Basic languages

Empowering richer experiences. Silverlight 4 introduces additional capabilities that enable developers to create richer, more appealing, high-performance interactive and innovative media experiences:

· Enhanced animation capabilities allow for more dynamic, interactive presentation of data in lists.

· Webcam and microphone support allow sharing of video and audio in applications such as chat and customer service.

· Audio and video local recording capabilities capture RAW video without requiring server interaction, allowing new scenarios such as capturing voice or video to send in e-mail, or allowing the recording to be edited locally before saving.

· Copy/paste and drag-and-drop make it easy to bring photos, text and other data into your application.

· New features such as right-click and mouse wheel scrolling enable developers to add conventional desktop interaction models.

· Silverlight 4 runs across all platforms and major browsers.

· Silverlight 4 applications start quicker and run 200 percent faster than the equivalent Silverlight 3 applications with performance optimizations.

· Multitouch support enables a range of gestures and touch interactions to be integrated into user experiences.

· Multicast networking enables enterprises to lower the cost of streaming broadcast events such as company meetings and training, with seamless interoperability with existing Windows Media Services streaming infrastructure.

· Content protection now available for H.264 media through Silverlight DRM powered by PlayReady.

· Output protection for audio/video streams allowing content owners or distributors to ensure protected content is only viewed through a secure video connection.

· Official support of the Google Chrome browser

· Hardware acceleration for Deep Zoom

· XAP signing and verification to ensure application integrity

Moving beyond the browser. Silverlight 4 extends out-of-browser capabilities pioneered in Silverlight 3 that enable a Web presence to establish closer, more persistent relationships with customers without any additional runtime download or the need to write applications in a different way.

For sandboxed applications

· Developers can place HTML within their application, enabling much tighter integration with content from Web servers such as e-mail, help and reports.

· Silverlight 4 provides support for desktop pop-up notification windows to easily provide real-time information and feedback to users using a common user interface metaphor.

· Offline DRM extends the existing Silverlight DRM powered by PlayReady technology to work in a disconnected state, enabling users to view content and engage with a Silverlight application where and when they want. Protected content can be delivered with an embedded license so that users can go offline immediately and start enjoying their content.

· Silverlight 4 offers full control over window settings such as start position and size to ensure applications have maximum usability and flexibility.

For trusted applications

· Users can read and write files to their My Documents, My Music, My Pictures and My Videos folder (or equivalent for non-Windows platforms), enabling applications to make local copies of reports and media files.

· COM automation enables access to devices and other system capabilities such as a Universal Serial Bus security card reader.

· Users can access other desktop programs such as Microsoft Office Excel to create a report.

· Group policy objects allow organizations to manage which applications are trusted.

· Comprehensive keyboard support in full-screen out-of-browser mode enhances kiosk and media applications.

· Enhancements to networking allow cross-domain access without a security policy file.

Windows SliverLight Intro

2011-07-22T21:55:00.001-07:00

Microsoft Silverlight is a free web-browser plug-in that enables interactive media experiences, rich business applications and immersive mobile apps.

Windows? Check. Mac? Check. Linux? Check. Silverlight works on all major OS's plus all major browsers, including Firefox, Google Chrome, Safari, and yes, Internet Explorer.

Microsoft Silverlight is a powerful tool for creating and delivering rich Internet applications and media experiences on the Web. Silverlight 5 builds on the foundation of Silverlight 4 for building business applications and premium media experiences. Silverlight 5 introduces more than 40 new features, including dramatic video quality and performance improvements as well as features that improve developer productivity. Silverlight 5 will be available in 2011.

Silverlight is being pushed side-by-side with Microsoft's Live services for developers. Microsoft is opening up APIs (application program interfaces) for its search engine, for Virtual Earth, for its instant messaging service, and for other services, under generous, but not unlimited, licensing terms. These services will allow the creation of interesting online applications that take advantage of existing Microsoft networks and resources. For example, Match.com today demoed a new version of its service that can connect directly to other Match.com subscribers who are MSN Messenger users. Mash-ups are nothing new, of course, but it is important that Microsoft is giving developers access to its computing resources as well as its user base.

Silverlight supports the display of high-definition video files, and importantly, Microsoft will do the heavy lifting of sending them over the Net. Streaming large media files is expensive, but Microsoft will (optionally) host Silverlight media files and applications. This will enable smaller developers to deliver large and high-definition files quickly and reliably, without paying content distribution network fees. Microsoft is promising reliable 700kbps throughput for media files, and free distribution of all content on its network for one year. After that, distribution will continue to be free up to 1 million streamed minutes a month. Fees after that have not been set.

Waldenstrom macroglobulinemia

2009-04-16T11:28:00.000-07:00

Waldenstrom macroglobulinemia: A chronic low-grade (indolent) type of lymphoma due to a malignant clone of plasma cells. These plasma cells multiply out of control, invade the bone marrow, lymph nodes, and spleen, and characteristically produce huge amounts of a large-sized antibody called macroglobulin or IgM. The excess IgM causes the blood to be hyperviscous (to thicken).

Waldenstrom macroglobulinemia can occur in younger people but is usually seen in people over age 65. The disease is more common among men than women and among whites than blacks.
Signs and symptoms of the disease may include enlarged lymph nodes or spleen (splenomegaly), fatigue, headaches, weight loss, a tendency to bleed easily, visual problems, confusion, dizziness, and loss of coordination. The symptoms are largely due to the thickening of the blood. In extreme cases, the increased concentration of IgM in the blood can lead to heart failure.

The treatment depends upon the viscosity of the patient's blood. Patients with pronounced hyperviscosity usually receive chemotherapy (anticancer drugs). A type of treatment called plasmapheresis may be performed to relieve symptoms such as excessive bleeding and dizziness. In this procedure, the blood plasma (which contains the antibody IgM) is removed from the patient.

Other parts of the blood (red blood cells, white blood cells, and platelets) are returned to the patient along with a plasma substitute. Interferon alpha, a form of biological therapy, may also help relieve symptoms.

Bacterial prostatitis, chronic

2009-04-07T11:11:00.002-07:00

Bacterial prostatitis, chronic: Longstanding bacterial infection of the prostate gland superimposed on a defect in the prostate. (The prostate is a small organ below the bladder which surrounds the urethra, the tube that carries urine down from the bladder.) The symptoms can include low back pain, discomfort in the perineum (the area between the anus and the genitalia), testicular pain and, if the infection spreads to the bladder, mild pain or burning on urination (dysuria) and frequent and urgent need to urinate (frequency and urgency). The presence of white blood cells and bacteria in the urine attests to the fact that the urinary tract is infected with bacteria.

The defect in the prostate is the focal point for the persistent infection. Effective treatment requires identification and correction of this defect before antibiotics can be effective.

Bacterial prostatitis, acute

2009-04-07T11:11:00.001-07:00

Bacterial prostatitis, acute: Inflammation of the prostate gland of sudden (acute) onset due to bacterial infection. The symptoms include chills, fever, pain in the lower back and genital area, body aches, burning or painful urination, and the frequent and urgent need to urinate. The urinary tract is infected, as evidenced by the presence of the white blood cells and bacteria in the urine. Treatment is with antibiotics.

The prostate, a small organ about the size of a walnut, is below the bladder (where urine is stored) and surrounds the urethra (the tube that carries urine from the bladder). The prostate normally produces a fluid that becomes part of the semen

Bacterial artificial chromosome

2009-04-07T10:58:00.000-07:00

Bacterial artificial chromosome: A laboratory creation involving an artificially constructed chromosome in which medium-sized segments of DNA (100,000 to 300,000 bases in length) that come from another species are cloned into bacteria. Once the foreign DNA has been cloned into the bacteria's chromosome, many copies of it can be made (amplified) and sequenced.

Bacterial artificial chromosome is abbreviated BAC.

Acoustic neuroma

2009-04-06T12:23:00.000-07:00

Acoustic neuroma: A benign tumor that may develop on the hearing and balance nerves near the inner ear. The tumor results from an overproduction of Schwann cells -- small sheet-like cells that normally wrap around nerve fibers like onion skin and help support the nerves. When growth is abnormally excessive, Schwann cells bunch together, pressing against the hearing and balance nerves, often causing gradual hearing loss, tinnitus (ringing in the ears), and dizziness. If the tumor becomes large, it can interfere with the facial nerve, causing partial paralysis, and eventually press against nearby brain structures, becoming life-threatening.

The early diagnosis of an acoustic neuroma is the key to preventing its serious consequences. Unfortunately, early detection of the tumor is sometimes difficult because the symptoms may be subtle and may not appear in the beginning stages of growth. Once the symptoms do appear, a thorough ear examination and hearing test are essential for diagnosis. Computerized tomography (CT) scans and magnetic resonance imaging (MRI) are helpful in determining the location and size of a tumor and also in planning its microsurgical removal.

If an acoustic neuroma is surgically removed when it is still very small, hearing may be preserved and accompanying symptoms may go away. As the tumor grows larger, surgical removal is often more complicated because the tumor may become firmly attached to the nerves that control facial movement, hearing, and balance.

The removal of tumors attached to hearing, balance, or facial nerves can make the patient's symptoms worse because sections of these nerves must also be removed with the tumor. As an alternative to conventional surgical techniques, radiosurgery may be used to reduce the size or limit the growth of the tumor. Radiosurgery, utilizing carefully focused radiation, is sometimes performed on the elderly, on patients with tumors on both hearing nerves, or on patients with a tumor growing on the nerve of their only hearing ear. If the tumor is not removed, MRI is used to carefully monitor its growth.

There are two types of acoustic neuroma: unilateral and bilateral. Unilateral acoustic neuromas affect only one ear. They account for approximately 8 percent of all tumors inside the skull. Symptoms may develop at any age but usually occur between the ages of 30 and 60 years.
Bilateral acoustic neuromas, which affect both ears, are hereditary. Inherited from one's parents, this tumor results from a genetic disorder known as neurofibromatosis-2 (NF2). Affected individuals have a 50 percent chance of passing this disorder on to their children. Unlike those with a unilateral acoustic neuroma, individuals with NF2 usually develop symptoms in their teens or early adulthood. Because NF2 patients usually have multiple tumors, the surgical procedure is more complicated than the removal of a unilateral acoustic neuroma. Further research is needed to determine the best approach in these circumstances.

In addition to tumors arising from the hearing and balance nerves, NF2 patients may develop tumors on other cranial nerves associated with swallowing, speech, eye and facial movement, and facial sensation. NF2 patients may also develop tumors within the spinal cord and on the brain's thin covering.

Both types of acoustic neuroma occur following a loss of the function of a gene on chromosome 22. A gene is a small section of DNA responsible for a particular trait like hair color or skin tone. This particular gene on chromosome 22 suppresses the growth of Schwann cells. When this gene malfunctions, Schwann cells can grow out of control. This gene may help suppress other types of tumor growth. In NF2 patients, the faulty gene on chromosome 22 is inherited.
Acoustic neuroma is also called an acoustic neurinoma or a vestibular schwannoma

Acoustic neurofibromatosis

2009-04-06T12:22:00.000-07:00

Acoustic neurofibromatosis : Abbreviated NF2. A genetic disorder characterized by the growth of benign tumors of both acoustic nerves (the nerves to the ears). These tumors are called acoustic neuromas or, more precisely, vestibular schwannomas. They cause tinnitus (ringing in the ears), hearing loss, and problems with balance. Other findings in NF2 include schwannomas of other nerves, meningiomas, and juvenile cataracts.

NF2 is inherited in an autosomal dominant manner and is due to mutation in the NF2 gene in chromosome band 22q12.2 which encodes a protein called merlin. About 50% of persons with NF2 inherit it from an affected parent and the other 50% with NF2 have a new gene mutation. Anyone with NF2 has a 50% risk of transmitting it to each of their children. Prenatal testing is available.

Also known as bilateral acoustic neurofibromatosis and central neurofibromatosis.

Acoustic neurinoma

2009-04-06T12:20:00.002-07:00

Acoustic neurinoma: A benign tumor that may develop on the hearing and balance nerves near the inner ear. The tumor results from an overproduction of Schwann cells -- small sheet-like cells that normally wrap around nerve fibers like onion skin and help support the nerves. When growth is abnormally excessive, Schwann cells bunch together, pressing against the hearing and balance nerves, often causing gradual hearing loss, tinnitus (ringing in the ears), and dizziness. If the tumor becomes large, it can interfere with the facial nerve, causing partial paralysis, and eventually press against nearby brain structures, becoming life-threatening.

The early diagnosis of an acoustic neurinoma is the key to preventing its serious consequences. Unfortunately, early detection of the tumor is sometimes difficult because the symptoms may be subtle and may not appear in the beginning stages of growth. Once the symptoms do appear, a thorough ear examination and hearing test are essential for diagnosis. Computerized tomography (CT) scans and magnetic resonance imaging (MRI) are helpful in determining the location and size of a tumor and also in planning its microsurgical removal.

If an acoustic neurinoma is surgically removed when it is still very small, hearing may be preserved and accompanying symptoms may go away. As the tumor grows larger, surgical removal is often more complicated because the tumor may become firmly attached to the nerves that control facial movement, hearing, and balance.

The removal of tumors attached to hearing, balance, or facial nerves can make the patient's symptoms worse because sections of these nerves must also be removed with the tumor. As an alternative to conventional surgical techniques, radiosurgery may be used to reduce the size or limit the growth of the tumor. Radiosurgery, utilizing carefully focused radiation, is sometimes performed on the elderly, on patients with tumors on both hearing nerves, or on patients with a tumor growing on the nerve of their only hearing ear. If the tumor is not removed, MRI is used to carefully monitor its growth.

There are two types of acoustic neurinoma: unilateral and bilateral. Unilateral acoustic neurinomas affect only one ear. They account for approximately 8 percent of all tumors inside the skull. Symptoms may develop at any age but usually occur between the ages of 30 and 60 years.

Bilateral acoustic neurinomas, which affect both ears, are hereditary. Inherited from one's parents, this tumor results from a genetic disorder known as neurofibromatosis-2 (NF2). Affected individuals have a 50 percent chance of passing this disorder on to their children. Unlike those with a unilateral acoustic neurinoma, individuals with NF2 usually develop symptoms in their teens or early adulthood. Because NF2 patients usually have multiple tumors, the surgical procedure is more complicated than the removal of a unilateral acoustic neurinoma. Further research is needed to determine the best approach in these circumstances.
In addition to tumors arising from the hearing and balance nerves, NF2 patients may develop tumors on other cranial nerves associated with swallowing, speech, eye and facial movement, and facial sensation. NF2 patients may also develop tumors within the spinal cord and on the brain's thin covering.

Both types of acoustic neurinoma occur following a loss of the function of a gene on chromosome 22. A gene is a small section of DNA responsible for a particular trait like hair color or skin tone. This particular gene on chromosome 22 suppresses the growth of Schwann cells. When this gene malfunctions, Schwann cells can grow out of control. This gene may help suppress other types of tumor growth. In NF2 patients, the faulty gene on chromosome 22 is inherited.
Acoustic neurinoma is also called an acoustic neuroma or a vestibular schwannoma.

Acoustic nerve

2009-04-06T12:20:00.001-07:00

Acoustic nerve: A cranial nerve concerned with hearing, balance and head position. The acoustic nerve is the 8th cranial nerve. It branches into two parts -- a cochlear part integral to hearing and a vestibular part which mediates the sense of balance and head position. Also called the vestibulocochlear nerve.

Acoustic aphasia

2009-04-06T12:19:00.000-07:00

Acoustic aphasia : Impairment in the understanding of auditory language and communication. Sounds are heard but they convey no meaning. The 20th century Russian composer Vissarion Shebalin had auditory aphasia after a stroke but remained an outstanding composer. The comprehension of auditory language and the musical organization of acoustic perception rely on different systems in the brain. Auditory aphasia is also known as acoustic aphasia and word deafness.

Acoustic

2009-04-06T12:17:00.001-07:00

Acoustic: Having to do with sound or hearing. The acoustic nerve (the 8th cranial nerve) is concerned with hearing and the sense of balance and head position. An acoustic neuroma is a tumor on the acoustic nerve.

Acid, folic

2009-04-06T12:13:00.001-07:00

Acid, folic: One of the B vitamins that is a key factor in the synthesis (the making) of nucleic acid (DNA and RNA).

A deficiency of folic acid after birth causes a kind of anemia, namely, megaloblastic anemia in which there is a paucity of red blood cells and those that are made are unusually large and immature (so-called blast cells).

Lack of adequate folic acid during pregnancy was first found to increase the risk for the baby to have a birth defect involving the spinal cord and brain -- a neural tube defect such as spina bifida (meningomyelocele) or anencephaly.

The association was then investigated between the mother's use of drugs that act as folic acid antagonists in the first trimester of pregnancy and the birth of a child with a congenital malformation (birth defect). It was found that folic acid antagonists increased the risk not only of neural tube defects but also of congenital heart malformations, cleft lip and palate , and urinary tract defects. Folic acid. it now is clear, reduces the risks for a remarkably broad gamut of birth defects.

In order for folic acid to be effective in preventing these birth defects, the vitamin must be consumed every day beginning before conception and continuing through the first three months of pregnancy. Educating women (and their doctors) about the importance of folic acid is going to require a major effort. According to one study, only 10% of women know that folic acid should be taken before pregnancy.

Acid, fatty

2009-04-06T12:12:00.000-07:00

Acid, fatty: One of many molecules that are long chains of lipid-carboxylic acid found in fats and oils and in cell membranes as a component of phospholipids and glycolipids. (Carboxylic acid is an organic acid containing the functional group -COOH.)

Fatty acids come from animal and vegetable fats and oils. Fatty acids play roles outside the body; they are used as lubricants, in cooking and food engineering, and in the production of soaps, detergents, and cosmetics.

Related terms include the following:

Essential fatty acid: An essential fatty acid is a polyunsaturated fatty acid needed by the body that is synthesized by plants but not by the human body and is therefore a dietary requirement.
Free fatty acids: By-products of the metabolism of fat in adipose tissues.

Omega-3 fatty acids: Omega-3 fatty acids are a class of fatty acids found in fish oils, especially in salmon and other cold-water fish, that lowers the levels of cholesterol and LDL (low-density lipoproteins) in the blood. (LDL cholesterol is the "bad" cholesterol.)

Trans fatty acid: Trans fatty acids (trans fats) are made through hydrogenation to solidify liquid oils. They increase the shelf life of oils and are found in vegetable shortenings and in some margarines, crackers, cookies, and snack foods. Intake of trans fatty acids increases blood LDL-cholesterol ("bad" cholesterol) levels and raises the risk of coronary heart disease.

Acid, bile

2009-04-06T12:10:00.002-07:00

Bile acid: An acid made by the liver that works with bile to break down fats.

On a more technical level, bile acids are steroid carboxylic acids derived from cholesterol. The primary bile acids are cholic and chenodeoxycholic acids. They are conjugated with glycine or taurine before they are secreted into the bile.

Acid, amino

2009-04-06T12:10:00.001-07:00

Acid, amino: One of the 20 building blocks of protein. The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA.

Amino acids are molecules that (in technical terms) contain a basic amino (NH2) group, an acidic carboxyl (COOH) group and a side chain attached to an alpha carbon atom.

The 20 amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine.

The term "amino acids" dates to the middle of the 19th century. The idea that amino acids are "Bausteine" (building stones) came from the Nobel Prize winning German biochemist Albrecht Kossel (1853-1927).

Acid reflux

2009-04-06T12:09:00.002-07:00

Acid reflux: A common condition and an abnormal one in which acid in the stomach rises up into the esophagus. This occurs because the valve separating the contents of the stomach from the esophagus does not function properly. See also: GERD.

Acid rain

2009-04-06T12:09:00.001-07:00

Acid rain: Rain resulting from the combination of fossil fuel emissions and water in the atmosphere. The environmental effects of acid rain include the acidification of lakes and streams, damage to trees at high altitude, the acceleration of decay in buildings and poorer air quality.

Acid rain also poses serious human health risks by contributing to heart and lung disorders such as asthma and bronchitis. Acid rain can be reduced by the regulation of industrial emissions and the adoption of energy efficiency alternatives and pollution prevention programs. Acid rain is a form of acid deposition.

Acid phosphatase

2009-04-06T12:08:00.002-07:00

Acid phosphatase: Acid phosphatase is an enzyme that works under acid conditions and is made in the liver, spleen, bone marrow and the prostate gland.

Abnormally high serum levels of the enzyme may, for example, indicate prostate disease (infection, injury, or cancer).

Acid indigestion

2009-04-06T12:08:00.001-07:00

Acid indigestion: Excessive secretion of hydrochloric acid by the stomach cells. Medically known as hyperchlorhydria. Sometimes used interchangeably with heartburn. See also: Heartburn.

Acid deposition

2009-04-06T12:07:00.001-07:00

Acid deposition: A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere and then deposited on earth in either wet or dry form. The wet forms, popularly called acid rain, can fall to earth as rain, snow, or fog. The dry forms are acidic gases or particulates.

Achillodynia

2009-04-06T12:02:00.002-07:00

Achillodynia: Pain due to inflammation of the Achilles tendon or the bursa associated with it.

The Achilles tendon is one of the better known anatomic features in sports medicine due to the abrupt dramatic nature of some injuries to this tendon. It is in the back of the lower leg and connects the calf muscle (the triceps surae) with the calcaneus bone in the heel. This tendon is so named for the hero whose heel, according to Greek mythology, was the only part of his body where he could be hurt.

Inflammation in the Achilles bursa is specifically known as achillobursitis.

Achillobursitis

2009-04-06T12:02:00.001-07:00

Achillobursitis: Pain due to inflammation of the bursa associated with the Achilles tendon. .

The Achilles tendon is one of the better known anatomic features in sports medicine due to the abrupt dramatic nature of some injuries to this tendon. It is in the back of the lower leg and connects the calf muscle (the triceps surae) with the calcaneus bone in the heel. This tendon is so named for the hero whose heel, according to Greek mythology, was the only part of his body where he could be hurt.

Inflammation in the Achilles tendon and bursa is collectively known as achillodynia.

Achilles tendonitis

2009-04-06T12:01:00.002-07:00

Achilles tendonitis: Inflammation of the Achilles tendon, the tough sinew that attaches the calf muscle to the back of the calcaneus or heel bone.

Achilles tendonitis causes pain and often swelling over the Achilles tendon. The tendon is tender and may be swollen. There is pain on rising up on the toes and pain with stretching of the tendon. The range of motion of the ankle may be limited.

The causes of Achilles tendonitis include overuse of the tendon, overly tight calf muscles or Achilles tendons, excess uphill running, sudden increase in the intensity of training, sometimes along with switching to racing shoes, or wearing high heels at work and then switching to a lower heeled workout shoe. Exerting rapid stress on the Achilles tendon when it is inflamed can result in rupture of the tendon.

Treatment includes ice packs to the Achilles tendon, raising the lower leg, and an anti-inflammatory medication. In some severe cases of Achilles tendonitis, a cast may be needed for several weeks. The doctor may also prescribe a heel lift insert for the shoe to prevent future overstretching of the Achilles tendon.

Prevention of Achilles tendonitis includes stretching the calf muscles and Achilles tendons carefully before doing vigorous activities. If the Achilles tendons or calf muscles are especially tight, it is a good idea to stretch them twice a day whether or not sports activities are planned that day.

Historical aside: According to Greek mythology, Achilles's mother held him as a baby by the heel and dipped him in the river Styx to make him invulnerable but the heel by which she held him remained unimmersed and hence vulnerable, as Paris' arrow in Achilles' heel later proved. As anyone who has suffered Achilles tendonitis knows, the Achilles tendon is indeed a point of vulnerability.

Achilles tendon

2009-04-06T12:01:00.001-07:00

Achilles tendon: A tough sinew that attaches the calf muscle to the back of the heel bone. The Achilles tendon is one of the longest tendons in the body. It is also called the tendo Achilles or the tendo calcaneus, the calcaneus being the heel bone.

According to Greek mythology, Achilles's mother held him as a baby by the heel and dipped him in the river Styx to make him invulnerable but the heel by which she held him remained unimmersed and hence vulnerable, as Paris' arrow in Achilles' heel later proved.

Achilles

2009-04-06T12:00:00.000-07:00

Achilles: In Greek mythology, the hero who was thought to have some special medical knowledge. Achilles studied medicine with Chiron, the centaur, who invented it.

"...But save me. Take me to the ship, cut this arrow out of my leg, wash the blood from it with warm water and put the right things on it - the plants they say you have learned about from Achilles who learned them from Chiron, the best of the Centaurs." (The Iliad of Homer, Book XI).

Acetabular labrum

2009-04-06T11:57:00.002-07:00

Acetabular labrum: A ring of fibrocartilage (fibrous cartilage) that runs around the acetabulum (cup) of the hip joint and increases its depth. The head of the femur (the bone in the thigh) fits in the acetabulum. The labrum deepens this cavity and effectively increases the surface (and strength) of the hip joint.

Injuries to the acetabular labrum can occur from chronic trauma due to repetitive hip motion or from acute trauma as, for example, from a direct blow to the hip or a violent motion of the hip.
Signs and symptoms of a acetabular labrum injury include pain accompanying hip motion, occasional pain in the hip at night or during daily activities, decreased range of motion and loss of strength in the hip.

Treatment may include anti-inflammatory medication and rest. Exercises to strengthen the hip muscles may then be recommended. If these measures are not effective, arthroscopic surgery may be done.

In medicine, a labrum is a ring of fibrocartilage around the edge of the articular (joint) surface of a bone. The Latin "labrum" means "lip." The term is used generally to designate a lip, edge, or brim. Plural, labra.

Acetabular

2009-04-06T11:57:00.001-07:00

Acetabular: Pertaining to the acetabulum, the cup-shaped socket of the hip joint which is a key feature of the pelvis. The head (upper end) of the femur (the thighbone) fits into the acetabulum and articulates with it, forming a ball-and-socket joint.

The acetabulum is not just cup-shaped. The word "acetabulum" in Latin means cup, a vinegar cup.

Aceruloplasminemia

2009-04-06T11:56:00.001-07:00

Aceruloplasminemia: A genetic disorder in which there is absence of the protein ceruloplasmin from blood and accumulation of iron in the pancreas, liver and brain, causing diabetes and progressive neurodegeneration with the tremors and gait abnormalities characteristic of Parkinson disease.

Ceruloplasmin normally removes iron from cells. The absence of ceruloplasmin leads to the abnormal deposition of iron in cells, including those of the pancreas, liver, retina and the basal ganglia region of the brain. The iron deposition damages these tissues and leads to the clinical features of the disease which usually appear between 30 and 50 years of age.

In a typical case, a man in his 40s had a recent history of excessive thirst and urination (due to diabetes) and of progressive confusion. Treatment of the diabetes was begun. One day he suddenly left work and was found at home the next day sitting in a chair with the appearance of not having been to bed. When asked why he was not at work he replied, "What work?" Dementia progressed thereafter.

Aggressive treatment with deferoxamine, a chelating agent that takes up iron, may halt the progression of these complications.

Aceruloplasminemia is caused by mutations in the gene encoding ceruloplasmin on chromosome 3q. The gene is located in bands 3q23-q25.

Aceruloplasminemia is inherited as an autosomal recessive condition. Men and women with the disease have a pair of mutant ceruloplasmin genes, one from each of their parents.

Ceruloplasmin is an essential ferroxidase, an enzyme which catalyzes the oxidation of ferrous iron to ferric iron. This disease reveals the critical role of a copper-containing protein in iron trafficking. In aceruloplasminemia, the balance between the compartmentalization and storage of iron and the mobilization and transport of iron is disrupted.

Acentric chromosome

2009-04-06T11:55:00.000-07:00

Acentric chromosome: A fragment of a chromosome (one of the microscopically visible carriers of the genetic material DNA) that is lacking a centromere (the "waist" of the chromosome essential for the division and the retention of the chromosome in the cell) and so is lost when the cell divides

Accessory placenta

2009-04-06T11:53:00.002-07:00

Accessory placenta: An extra placenta separate from the main placenta. Also called a succenturiate or supernumerary placenta. The placenta is the organ joining the mother and fetus, the organ that permits the provision of oxygen and nutrients to the fetus and the release of carbon dioxide and waste products from the fetus to the mother. The word "placenta" means a flat cake. The main placenta is disk-shaped and at full term measures about 7 inches (18 cm) in diameter and a bit less than 2 inches (4 cm) thick. The upper surface of the placenta is smooth while the under surface is rough. The placenta and the fetal membranes are the afterbirth.

Accessory neuropathy

2009-04-06T11:53:00.001-07:00

Accessory neuropathy: Disease of the accessory nerve which is the eleventh cranial nerve. The accessory nerve supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back.

Damage to the accessory nerve can be confined to the accessory nerve or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy can sometimes occur and recur for unknown reasons. Most patients recover.

Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder

Accessory nerve

2009-04-06T11:52:00.002-07:00

Accessory nerve: The eleventh cranial nerve, which emerges from the skull and receives an additional (accessory) root from the upper part of the spinal cord. It supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. The accessory nerve is so-called because, although it arises in the brain, it receives an additional (accessory) root from the upper part of the spinal cord.

Damage to the accessory nerve can be isolated (confined to the accessory nerve) or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy (nerve disease) can sometimes occur and recur for unknown reasons. Most patients recover.

Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.

Accessory dwelling unit

2009-04-06T11:52:00.001-07:00

Accessory dwelling unit: (ADU) A separate housing arrangement within a single-family home. The ADU is defined by Medicare as a complete living unit and includes a private kitchen and bath.

Accessory digestive organ

2009-04-06T11:51:00.000-07:00

Accessory digestive organ: An organ that helps with digestion but is not part of the digestive tract. The accessory digestive organs are the tongue, salivary glands, pancreas, liver, and gallbladder.

Abuse, verbal child

2009-04-06T11:50:00.001-07:00

Abuse, verbal child: Also known as emotional child abuse, this is the third most frequently reported form of child abuse (after child neglect and physical child abuse), accounting 17% of all cases of child abuse.

It is likely that emotional child abuse is greatly underreported, since it can be difficult to detect and difficult to document.

Emotional child abuse includes acts of commission or omission by the parents and other caregivers that could cause the child to have serious behavioral, emotional, or mental disorders. In some instances of emotional child abuse, the acts of parents or other caregivers alone, without any harm yet evident in the child's behavior or condition, are sufficient to warrant the intervention of child protective services. For example, the parents or caregivers may use extreme or bizarre forms of punishment, such as confinement of a child in a dark closet.
Emotional child abuse is also sometimes termed psychological child abuse or mental injury of a child.

Abuse, Substance

2009-04-06T11:49:00.000-07:00

Substance abuse: The excessive use of a substance, especially alcohol or a drug. (There is no universally accepted definition of substance abuse.)

A definition of substance abuse that is frequently cited is that in DSM-IV, the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) issued by the American Psychiatric Association. The DSM-IV definition is as follows:

A. A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by one (or more) of the following, occurring within a 12-month period:

Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home (e.g., repeated absences or poor work performance related to substance use; substance-related absences, suspensions or expulsions from school; neglect of children or household)
Recurrent substance use in situations in which it is physically hazardous (e.g., driving an automobile or operating a machine when impaired by substance use)

Recurrent substance-related legal problems (e.g., arrests for substance-related disorderly conduct

Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance (e.g., arguments with spouse about consequences of intoxication, physical fights)

B. The symptoms have never met the criteria for Substance Dependence for this class of substance.

Abuse, steroid

2009-04-06T11:47:00.001-07:00

Abuse, steroid: Use of substances containing anabolic steroids to increase muscle mass. Such steroids can have many side effects when misused, including psychiatric problems, liver tumors, reduction in the size of the male genitals and sterility, and heart damage.

Abuse, sexual child

2009-04-06T11:46:00.000-07:00

Abuse, sexual child: Child abuse comprises four basic types of mistreatment: child neglect, physical abuse of a child, emotional abuse of a child, and sexual abuse of a child.

Sexual abuse is the least frequently reported form of child abuse (6% of all cases). Experts believe that sexual abuse may be the most underreported type of child maltreatment because of the secrecy, the "conspiracy of silence" that so often surrounds these cases.

Sexual abuse includes fondling a child's genitals, intercourse, incest, rape, sodomy, exhibitionism, and commercial exploitation through prostitution or the production of pornographic materials.
The diagnosis, treatment and prevention of sexual child abuse are complex. Several points might be made here:

The diagnosis of sexual child abuse involves a thorough nonjudgmental history of the immediate events as well as a review of potential similar experiences often independently done by a physician, social worker, and the police department. A complete physical exam of the child which may include the taking of photographs to document sexual abuse is necessarily followed by x-rays and possible laboratory tests.

Pedophiles (people who sexually abuse children) often require intense psychological and pharmacological therapy prior to release into the community, because of the high rate of repeat offenders.

Children's school programs regarding "good touch...bad touch" can provide parents and other caregivers with a forum in which to role-play and learn to avoid potentially harmful scenarios.
Parents should make sure that their child's daycare center/preschool is licensed and has an open door policy regarding parental visitation.

Abuse, psychological child

2009-04-06T11:45:00.000-07:00

Abuse, psychological child: Also known as emotional child abuse, this is the third most frequently reported form of child abuse (after child neglect and physical child abuse), accounting 17% of all cases of child abuse.

It is likely that emotional child abuse is greatly underreported, since it can be difficult to detect and difficult to document.

Emotional child abuse includes acts of commission or omission by the parents and other caregivers that could cause the child to have serious behavioral, emotional, or mental disorders. In some instances of emotional child abuse, the acts of parents or other caregivers alone, without any harm yet evident in the child's behavior or condition, are sufficient to warrant the intervention of child protective services. For example, the parents or caregivers may use extreme or bizarre forms of punishment, such as confinement of a child in a dark closet.
Emotional child abuse is also sometimes termed verbal child abuse or mental injury of a child.

Abuse, pregnancy

2009-04-06T11:44:00.002-07:00

Abuse, pregnancy: Abuse of an expectant mother. This abuse is most often perpetrated by the woman's spouse, partner, or relative. Spurts of temper can progress to shouting and name calling. Then pushing and shoving. The use of physical violence can start a pattern. It is estimated that 1 in 12 pregnant women is battered. Most cases of pregnancy abuse are not reported because the woman who was beaten is afraid or ashamed or is dependent on the abuser.

Pregnancy abuse is not only bad for the pregnant woman, it may also affect the health of her unborn baby. In a study of 1,004 women interviewed within 3 days of delivery, over 5% reported they had been abused during their pregnancy by their partners. The maternal abuse showed a significant correlation with the baby's low birth weight. Pregnant women who had been abused by their partners were more likely to deliver low birth weight babies. Low birth weight babies have more health problems than infants born at normal weight. (Reference: American Journal of Epidemiology 1999;150:714-726.)

Abuse, physical child

2009-04-06T11:44:00.001-07:00

Abuse, physical child: Next to child neglect, physical abuse is the second most frequently reported form of child abuse, accounting for 25% of all cases of child abuse.

Physical child abuse is physical injury inflicted upon the child with cruel and/or malicious intent. Physical abuse can be the result of punching, beating, kicking, biting, burning, shaking, or otherwise harming a child physically.

The parent or caretaker who abused the child may not have intended to hurt the child, but rather the child's injury may have resulted from overly harsh discipline or physical punishment. There is, in this regard, a substantial debate going on about certain forms physical discipline such as spanking and slapping and their relationship to more orthodox forms of physical abuse.

Abuse, emotional child

2009-04-06T11:43:00.001-07:00

Abuse, emotional child: Emotional child abuse is the third most frequently reported form of child abuse (after child neglect and physical child abuse), accounting 17% of all cases of child abuse.

It is likely that emotional child abuse is greatly underreported, since it can be difficult to detect and difficult to document.

Emotional child abuse includes acts of commission or omission by the parents and other caregivers that could cause the child to have serious behavioral, emotional, or mental disorders. In some instances of emotional child abuse, the acts of parents or other caregivers alone, without any harm yet evident in the child's behavior or condition, are sufficient to warrant the intervention of child protective services. For example, the parents/caregivers may use extreme or bizarre forms of punishment, such as confinement of a child in a dark closet.

Emotional child abuse is also sometimes termed psychological child abuse, verbal child abuse, or mental injury of a child.

abuse, Elder

2009-04-06T11:42:00.000-07:00

Elder abuse: The physical, sexual, or emotional abuse of an elderly person, usually one who is disabled or frail.

Elder abuse is an umbrella term used to describe one or more of the following:
Physical abuse is the willful infliction of physical pain or injury,such as slapping, bruising, sexually molesting, or restraining.

Sexual abuse is the infliction of non-consensual sexual contact of any kind.

Emotional or psychological abuse is the infliction of mental or emotional anguish, such as humiliating, intimidating, or threatening.

Financial or material exploitation is the improper act or process of an individual, using the resources of an older person, without his/her consent, for someone else's benefit.

Neglect is the failure of a caretaker to provide goods or services necessary to avoid physical harm, mental anguish or mental illness, such as abandonment, denial of food or health related services.

Self-neglect is characterized as the behavior of an elderly person that threatens his/her own health or safety.

Like child abuse, elder abuse is a crime that all health and social services professionals are mandated to report.

The US National Academy of Sciences has defined elder abuse as: "(a) intentional actions that cause harm or create a serious risk of harm (whether or not harm is intended), to a vulnerable elder by a caregiver or other person who stands in a trust relationship to the elder, or (b) failure by a caregiver to satisfy the elder's basic needs or to protect the elder from harm."

The World Health Organization (WHO) defines elder abuse as "a single or repeated act, or lack of appropriate action, occurring within any relationship where there is an expectation of trust which causes harm or distress to an older person."

All satisfactory definitions of elder abuse encompass two key ideas: that the old person has suffered injury, deprivation, or unnecessary danger, and that a specific other individual (or individuals) is responsible for causing or failing to prevent it.

Abuse, child

2009-04-06T11:40:00.000-07:00

Abuse, child: Child abuse is a very complex and dangerous set of problems that include child neglect and the physical, emotional, and sexual abuse of children.

Child neglect is the most frequently reported form of child abuse and the most lethal. This form of abuse is defined as the failure to provide for the shelter, safety, supervision and nutritional needs of the child. Child neglect can be physical, educational, or emotional neglect.

Physical neglect includes refusal of or delay in seeking health care, abandonment, expulsion from the home or refusal to allow a runaway to return home, and inadequate supervision.
Educational neglect includes the allowance of chronic truancy, failure to enroll a child of mandatory school age in school, and failure to attend to a special educational need.

Emotional neglect includes such actions as marked inattention to the child's needs for affection, refusal of or failure to provide needed psychological care, spouse abuse in the child's presence, and permission of drug or alcohol use by the child.

Physical abuse is the second most frequently reported form of child abuse and is defined as physical injury inflicted upon the child with cruel and/or malicious intent. Physical abuse can be the result of punching, beating, kicking, biting, burning, shaking, or otherwise harming a child. The parent or caretaker may not have intended to hurt the child, rather the injury may have resulted from over-discipline or physical punishment.

Emotional abuse is the third most frequently reported form of child abuse and includes acts or omissions by the parents or other caregivers that could cause serious behavioral, emotional, or mental disorders. For example, the parents/caregivers may use extreme or bizarre forms of punishment, such as confinement of a child in a dark closet. Emotional child abuse is also sometimes termed psychological child abuse, verbal child abuse, or mental injury of a child.
Sexual abuse is the least frequently reported form of child abuse and is believed to be the most under-reported type of child maltreatment because of the secrecy or "conspiracy of silence" that so often characterizes these cases. Sexual abuse includes fondling a child's genitals, intercourse, incest, rape, sodomy, exhibitionism, and commercial exploitation through prostitution or the production of pornographic materials.

Fatal injuries from maltreatment can result from many different acts including severe head trauma (injury), shaken baby syndrome, trauma to the abdomen or chest, scalding, burns, drowning, suffocation, poisoning, etc.

Factors affecting the likelihood of potential abuse and predisposing to child abuse include:

The abuser's childhood: child abusers often were abused as children.

The abuser's substance abuse: at least half of all child abuse cases involve some degree of substance abuse (alcohol, drugs, etc) by the child's parents.

Family stress: the disintegration of the nuclear family and its inherent support systems has been held to be associated with child abuse.

Social forces: experts debate whether a postulated reduction in religious/moral values coupled with an increase in the depiction of violence by the entertainment and informational media may increase child abuse.

The child: children at higher risk for child abuse include infants who are felt to be "overly fussy", handicapped children, and children with chronic diseases.

Specific "trigger" events that occur just before many fatal parental assaults on infants and young children include: an infant's inconsolable crying, feeding difficulties, a toddler's failed toilet training, and exaggerated parental perceptions of acts of "disobedience" by the child.

Children can be neglected and abused by parents, other caregivers, or society.

Child abuse should be reported, investigated and evaluated.

The treatment and prevention of child abuse include a support group structure coupled with visiting nurse home visits to reinforce good parenting skills and monitor the child's well-being. Children's school programs regarding "good touch...bad touch" can provide parents with a forum in which to role-play and learn to avoid potentially harmful scenarios. Parents should make sure that their child's daycare center is licensed and has an open door policy regarding parental visitation. The best strategy is to prevent child abuse.

Not until the 19th century were children granted the same legal status as domesticated animals in regard to protection against cruelty and/or neglect. In 1962 the term "battered child syndrome" entered medicine. By 1976 all states in the United States had adopted laws mandating the reporting of suspected instances of child abuse.

Abortion, therapeutic

2009-04-06T11:35:00.000-07:00

Abortion, therapeutic: An abortion that is brought about intentionally. Also called an artificial or induced abortion. As opposed to a spontaneous abortion (a miscarriage).

Abortion, spontaneous

2009-04-06T11:32:00.004-07:00

Abortion, spontaneous: A miscarriage, that is, any pregnancy that is not viable (the fetus cannot survive) or in which the fetus is born before the 20th week of pregnancy. Spontaneous abortion occurs in at least 15-20% of all recognized pregnancies and usually takes place before the 13th week of pregnancy.

A spontaneous abortion is as opposed to an induced abortion. In a spontaneous abortion, it is purely accidental, that is spontaneous.

Abortion, recurrent

2009-04-06T11:32:00.003-07:00

Abortion, recurrent: The occurrence of 3 or more miscarriages (which are medically termed "spontaneous abortions") with no intervening pregnancies.

Recurrent abortion (or, as it is sometimes called, habitual abortion) is a form of infertility. It may be due to chromosome abnormalities.

Abortion, multiple

2009-04-06T11:32:00.001-07:00

Abortion, multiple: Two or more miscarriages (spontaneous abortions) by a woman. Couples who have had multiple abortions have about a 5% chance that one member of the couple is carrying a chromosome translocation responsible for the miscarriages.

Abortion, induced

2009-04-06T11:31:00.001-07:00

Abortion, induced: An abortion that is brought about intentionally. Also called an artificial or therapeutic abortion. As opposed to a spontaneous abortion (a miscarriage).

Abortion, habitual

2009-04-06T11:30:00.002-07:00

Abortion, habitual: The miscarriage of 3 or more consecutive pregnancies. The abortion of 3 or more miscarriages (spontaneous abortions) with no intervening pregnancies is also termed recurrent abortion.
Habitual or recurrent abortion is a form of infertility. It is sometimes due to chromosome abnormalities or other genetic causes.

Abortion, artificial

2009-04-06T11:30:00.001-07:00

Abortion, artificial: An abortion that is brought about intentionally. Also called an induced or therapeutic abortion. As opposed to a spontaneous abortion (a miscarriage).

Absinthe

2009-04-06T11:28:00.002-07:00

Absinthe: Once a major medical hazard, absinthe is an emerald-green liqueur flavored with extracts of the wormwood plant, licorice and aromatic flavorings in a alcohol base. Absinthe was manufactured, commercialized and popularized in France in the late 1700s by Henri-Louis Pernod. It became an extremely popular and addictive drink. Among the famous figures who made absinthe a symbol of decadence were the writer Oscar Wilde, the poet Charles Baudelaire, and the artists Edouard Manet, Vincent Van Gogh, Henri de Toulouse-Lautrec and Pablo Picasso.

The first important medical research on absinthe was initiated in 1864 by a psychiatrist, Valentin Jacques Joseph Magnan, who exposed a veritable Noah's arkful of animals to wormwood oil (the essence of absinthe) and alcohol (the base of absinthe). He put cats, rabbits, and guinea pigs under an individual glass case next to a saucer of either wormwood oil or alcohol. The animals that breathed the alcohol fumes became drunk while those that inhaled the vapors of wormwood had epileptic seizures, reported Dr. Magnan in the medical journal The Lancet.

Prolonged drinking of absinthe causes convulsions, blindness, hallucinations, and mental deterioration. Absinthe has been banned but something of its taste of absinthe is still available in such drinks as ouzo in Greece and in France, pastis, long considered "the mother's milk of Provence."

Absent eye

2009-04-06T11:28:00.001-07:00

Definition of Absent eye

Absent eye: Also called anophthalmia, a congenital malformation (birth defect) of the globe.
Anophthalmia refers, strictly speaking, to absence of the globe and ocular tissue from the orbit. However, in most cases of anophthalmia, CT scans show some remnants of the globe, indicating they represent severe microphthalmia (small eyes).

Anophthalmia/microphthalmia may involve one or both eyes. It may occur in isolation with no associated malformations or it may be part of a multiple congenital malformation syndrome as, for example, the congenital rubella syndrome, the triploidy syndrome (due to the presence of 69 chromosomes), the trisomy 13 syndrome (Patau syndrome, due to an extra chromosome 13), and the Wolf-Hirschorn syndrome (which is due to deletion of part of the short arm of chromosome 4).

Anophthalmia comes from the Greek an-, absence + ophthalmos, eye + absence of the eye.

Absence seizure

2009-04-06T11:27:00.001-07:00

Absence seizure: A seizure that takes the form of a staring spell. The person suddenly seems to be "absent." An absence seizure involves a brief loss of awareness, which can be accompanied by blinking or mouth twitching. Absence seizures have a very characteristic appearance on an electroencephalogram (EEG).

Also called a petit mal seizure.

Absence of the nipple

2009-04-06T11:26:00.000-07:00

Absence of the nipple: Medically called athelia, this is a rare condition but it is common in certain conditions. Athelia tends to occurs on one side (unilaterally) in children with the Poland sequence and on both sides (bilaterally) in certain types of ectodermal dysplasia.

The Poland sequence (named for Alfred Poland, a celebrated 19th-century British surgeon and ophthalmologist) is a unique pattern of one-sided malformations characterized by a defect of the chest (pectoralis) muscle on one side of the body and webbing of the fingers (cutaneous syndactyly) of the ipsilateral hand (the hand on the same side). It is right-sided three times more often than it is left-sided. The disorder is currently considered "a nonspecific developmental field defect" occurring at about the sixth week of fetal development. The cause is uncertain. In Poland syndrome there is aplasia of the sternal head of the pectoralis major: the end of the main chest muscle that normally attaches to the breastbone is missing. On that side of the body, nearby chest muscles (the serratus anterior and latissimus dorsi muscles) may also be absent as may be the armpit (axillary) hair. In girls, the breast on that side is also usually absent (amastia) and there is no nipple. There is athelia.

Ectodermal dysplasia is not one but a number of hereditary conditions usually characterized by the abnormal development of skin, absence of sweat glands, dry eyes and abnormal development of teeth -- all structures derived from the ectoderm (the outside layer in early embryonic development). The absence of sweat glands leads to an inability to sweat and heat intolerance.

Athelia also occurs in association with the progeria (premature aging) syndrome and the Yunis-Varon syndrome (a multiple congenital malformation first reported in 1980).
Athelia is distinguished from amastia, wherein the breast is absent, and from amazia, wherein breast tissue is absent but the nipple is still resent.

Abdominal cavity

2009-04-06T11:25:00.000-07:00

Abdominal cavity: The cavity within the abdomen, the space between the abdominal wall and the spine.

The abdominal cavity is hardly an empty space. It contains a number of crucial organs including the lower part of the esophagus, the stomach, small intestine, colon, rectum, liver, gallbladder, pancreas, spleen, kidneys, and bladder.

Abdominal guarding

2009-04-06T11:23:00.000-07:00

Abdominal guarding: Tensing of the abdominal wall muscles to guard inflamed organs within the abdomen from the pain of pressure upon them. The tensing is detected when the abdomen wall is pressed.

Guarding is a characteristic finding in the physical examination for an abruptly painful abdomen (an acute abdomen) with inflammation of the inner abdominal (peritoneal) surface due, for example, to appendicitis or diverticulitis. The tensed muscles of the abdominal wall automatically go into spasm to keep the tender underlying tissues from being touched.

Abdominal muscle deficiency syndrome

2009-04-06T11:18:00.000-07:00

Abdominal muscle deficiency syndrome: Partial or complete absence of the abdominal muscles so that the outlines of the intestines are visible through the thin, lax, protruding abdominal wall. Also called the "prune belly syndrome." The full syndrome probably occurs only in males. In addition to the abdominal muscle deficiency, there are genital and urinary abnormalities including dilation (widening) of the urinary tract and cryptorchidism (failure for the testes to descend into the scrotum). There is also a form of abdominal muscle deficiency that is associated with narrowing (stenosis) of the pulmonary artery, mental retardation and deafness. It occurs in both boys and girls.

Abdominal muscle deficiency syndrome was first recognized in the 19th century. The renowned physician William Osler wrote: "In the summer of 1897 a case of remarkable distension of the abdomen was admitted to the wards, with greatly distended bladder, and on my return in September, Dr. Futcher, knowing that I would be interested in it, sent for the child."

Abdominal pain

2009-04-06T11:16:00.000-07:00

Abdominal pain: Pain in the belly (the abdomen). Abdominal pain can come from conditions affecting a variety of organs. The abdomen is an anatomical area that is bounded by the lower margin of the ribs above, the pelvic bone (pubic ramus) below, and the flanks on each side. Although abdominal pain can arise from the tissues of the abdominal wall that surround the abdominal cavity (the skin and abdominal wall muscles), the term abdominal pain generally is used to describe pain originating from organs within the abdominal cavity (from beneath the skin and muscles). These organs include the stomach, small intestine, colon, liver, gallbladder, and pancreas.
Occasionally, pain may be felt in the abdomen even though it is arising from organs that are close to but not within the abdominal cavity, for example, the lower lungs, the kidneys, and the uterus or ovaries. This latter type of pain is called "referred" pain because the pain, though originating outside the abdomen, is being referred to (felt) in the abdominal area.

Abdominal pain can be acute and sudden in onset, or the pain can be chronic and longstanding. Abdominal pain may be minor and of no great significance, or it can reflect a major problem involving one of the organs in the abdomen. The characteristics of the pain--location, timing, duration, etc. are important in diagnosing its cause. Persistent or severe abdominal pain should be evaluated by a physician.

Acute abdominal pain may require urgent surgery such as for a twisted ovarian cyst, ectopic pregnancy, intestinal obstruction, appendicitis, peritonitis, perforated peptic ulcer, perforated diverticulitis, or abdominal aortic aneurysm. Patients with gallbladder disease, pancreatitis, or a kidney stone may also need urgent treatment. Acute or chronic abdominal pain may also call for medical (nonsurgical) therapy.

The causes of abdominal pain depend on sex and age of the patient. A woman may have a twisted ovarian cyst while a man may have testicular torsion with a twisted testis. Abdominal pain in infants and small children may be due to intestinal obstruction from atresia or stenosis of the intestine, esophageal webs, intussusception, volvulus, imperforate anus, and Hirschsprung disease. These causes of abdominal pain are rarely, if ever, encountered in adults.

Abdominal muscles

2009-04-06T11:15:00.000-07:00

Abdominal muscles: A large group of muscles in the front of the abdomen that assists in the regular breathing movement and supports the muscles of the spine while lifting and keeping abdominal organs such as the intestines in place. Abdominal muscles play a key role in exercises such as "sit-ups." They are informally called the "abs".

Abdominal hysterectomy

2009-04-06T11:14:00.001-07:00

Abdominal hysterectomy: Surgical removal of the uterus (a hysterectomy) done through an incision made in the abdominal wall. As opposed to a vaginal hysterectomy in which the incision is made within the vagina.

Aarskog-Scott syndrome

2009-04-06T11:13:00.001-07:00

Definition of Aarskog-Scott syndrome

Aarskog-Scott syndrome: A syndrome of wide spaced eyes (ocular hypertelorism), front-facing (anteverted) nostrils, a broad upper lip, a malformed ("saddle-bag") scrotum, and laxity of the ligaments resulting in bending back of the knees (genu recurvatum), flat feet, and overly extensible fingers. There are X-linked and autosomal forms of the disease. The gene for the X-linked form has been mapped to chromosome band Xp11.21 and identified as the FGD1 gene.

The disease is named for DJ Aarskog (1928-) and CI Scott, Jr. (1934-), Norwegian and American pediatricians, who described it in 1970 and 1971. It is also known as Aarskog syndrome, faciodigitogenital dysplasia, and faciogenital dysplasia.

Abdominal aneurysm

2009-04-06T11:12:00.000-07:00

Abdominal aneurysm: An aneurysm situated within the abdomen (belly). An aneurysm is a localized widening (dilatation) of an artery, vein, or the heart. At the area of an aneurysm, there is typically a bulge and the wall is weakened and may rupture. The word "aneurysm" comes from the Greek "aneurysma" meaning "a widening." An aneurysm may involve the aorta, the largest artery in the body, as it courses down through the abdomen. Because of the great volume of blood flowing under high pressure in the aorta, rupture of an abdominal aortic aneurysm is a surefire catastrophe.

Definition of AANAT

2009-04-06T11:09:00.001-07:00

AANAT: The synbol for the enzyme arylalkylamine N-acetyltransferase and for the gene that encodes it. AANAT is present in animals, bacteria and yeast but in no other living organisms. AANAT belongs to the large superfamily of acetyltransferase enzymes. AANAT is used to make melatonin, a hormone that regulates the body's cycles of sleeping and waking.

Enterprise Technology Life Cycle

2009-04-06T11:02:00.000-07:00

The Enterprise Technology Life Cycle (ETLC) at UC Berkeley is a 9 step process from cradle (Watch and Research) to grave (Disinvest and Obsolete). The key step is Invest, which indicates a point in time that a new technology is ready for deployment in campus enterprise and/or mission critical systems. The next most important step is Disinvest, which indicates a point in time that an existing technology needs to be phased out from use in campus enterprise and/or mission critical systems. At any point in time along the lifecycle, a technology can be considered Vetoed if it is determined to not meet organizational needs.

For purposes of the ETLC, a campus enterprise and/or mission critical system meets one or more of the following qualifications:

It is widely used across the campus

Unsuccessful operation of the system will result in a major disruption of mission-critical campus activities

If not widely used on campus, use of the system is encouraged to meet campus wide strategic objectives

The system or technology is part of a technology reference set included in a campus enterprise architecture roadmap.

Examples of campus enterprise and/or mission critical systems that are expected to follow ETLC guidelines include, but are not limited to, the following:

Business Applications (email, calendaring, student information systems, financial systems, on-line electronic payment systems, payroll and human resources systems, asset management applications, etc.)

Campus identity management infrastructure (authentication, authorization, directory services, master person data management)

Network infrastructure (hardware purchases, wireless expansions, network applications)

Information management applications (enterprise data warehouse, reporting and analysis tools, imaging and document management systems, content management systems, customer relationship management systems, etc.)

The campus student learning and course management systems

Enterprise collaboration applications

SOA infrastructure applications

Enterprise portal environments

Any tools used to develop or maintain enterprise and/or mission critical systems, including modeling tools, version control and change management systems, issue tracking or ticketing systems, testing tools, etc.

The ETLC is maintained by the campus Information Technology Architecture Committee (ITAC) with oversight from the Campus Technology Council (CTC).

Diffusion of Innovations

2009-04-06T10:53:00.000-07:00

Diffusion of Innovations seeks to explain how innovations are takenup in a population. An innovation is an idea, behaviour, or objectthat is perceived as new by its audience.

Diffusion of Innovations offers three valuable insights into theprocess of social change:

- What qualities make an innovation spread successfully.

- The importance of peer-peer conversations and peer networks.

- Understanding the needs of different user segments.

These insights have been tested in more than 6000 research studiesand field tests, so they are amongst the most reliable in the social sciences.

What qualities make innovations spread?

Diffusion of Innovations takes a radically different approach to mostother theories of change. Instead of focusing on persuadingindividuals to change, it sees change as being primarily about theevolution or “reinvention” of products and behaviours so theybecome better fits for the needs of individuals and groups. In Diffusion of Innovations it is not people who change, but theinnovations themselves.

Why do certain innovations spread more quickly than others? Andwhy do others fail? Diffusion scholars recognise five qualities thatdetermine the success of an innovation.

Reinvention is a key principle in Diffusion of Innovations. The success of an innovation depends on how well it evolves to meet the needs of more and more demanding and risk-averse individuals in a population (the history of the mobile phone is a perfectexample). A good way to achieve this is to make users into partners in a continuous process of redevelopment.

Computer games companies, pharmaceutical corporations and rural research institutes are examples of organisations that seek to make users active partners in improving innovations by supporting user communities or by applying participative action research techniques.

Black Hole Thermodynamics

2009-03-24T11:13:00.000-07:00

One of the features of Hawking and Bekenstein's development of black hole thermodynamics is that it ties many many pieces of physics together. Among those pieces are:

The realisation from Quantum Mechanics that we can think of all matter-energy as waves.

The realisation from classical physics that in a confined region, waves exist as standing waves.

The realisation from thermodynamics that the entropy can be viewed as a measure of the number of combinations or permutations of an ensemble that are equivalent. This is equivalent to viewing the entropy more conventionally as a measure of the heat divided by the temperature of a body. According to the Second Law of Thermodynamics, in a closed system the entropy never decreases.

The realisation from Heisenberg's Uncertainty Principle that we can violate the principle of Conservation of Energy so long as we do it for only a short period of time.

The realisation from classical physics that all objects with a temperature above absolute zero radiate away energy as electromagnetic radiation.

Feynman's theory of antimatter as regular matter going backwards in time.

Virtual Pair Production

Recall Heisenberg's Uncertainty Principle. It basically puts a limit on how much we can reduce the disturbance we introduce in a system by doing a measurement on it. There are a number of forms of the principle, and here we shall use only one of them:

The uncertainty in any measurement of the energy of an object times the uncertainty in when the object had that energy will always be at least equal to a universal constant.

Technical note: The universal constant is Planck's constant h divided by 2 pi.

A moment's reflection on the implications of this form of the Uncertainty Principle may convince you that this means that the energy does not even have a definite value but only a lower and upper bound.

Thus the principle of conservation of energy can be violated so long as the violation occurs for only a brief period of time.

Now consider Dirac's infinite sea of negative energy electrons. One of those electrons can violate conservation of energy by spontaneously jumping into a positive energy state provided it falls back into the hole quickly enough. You will recall that we interpret the hole in the sea as a positron. Thus, we believe that this virtual pair production is occurring everywhere in the universe. The pair can only exist for a time of about 10-35 seconds, i.e. 34 zeroes followed by a 1 to the right of the decimal point; this is called the Planck time.

Similarly we believe virtual pairs of proton-antiprotons, neutron-antineutrons etc. are continually being formed and disappearing everywhere in the universe. Wheeler, then, characterises the vacuum at a scale of very small distances as being quantum foam.

Satellite Navigation Using GPS

2009-03-24T11:03:00.000-07:00

The NAVSTAR Global Positioning System

The NAVSTAR Global Positioning System,usually called GPS, consists of three components: a space segment of GPS satellites, acontrol segment that monitors and operatesthose satellites and a user segment that employsGPS receivers to observe and recordtransmissions from the satellites and performposition, velocity, attitude and time calculations.

The GPS Space Segment

The space segment is based on three-axisstabilized satellites orbiting in near-circularorbits with a period of half a sidereal day andan inclination of 55 degrees. There are six orbitalplanes, each of them with four satellites.This constellation provides global coveragewith more than four satellites in view at alltimes.

The significance of the visibility of at least four satellites is that the GPS system is intendedto allow instantaneous real time determinationof the user position (3 variables) and thetime of the fix (one more variable). Previouspositioning systems, like the methods used inthe Transit and Tsikada systems, were basedon the processing of several passes of data(requiring hours to days) and did not providethe instantaneous solutions that GPS (orGLONASS) offers.

The GPS satellites carry very stable atomicclocks that are used to derive the ranging signals.The basic signal for civil use, L1, has afrequency of 1575.42 MHz and it is modulatedwith a Clear Acquisition (C/A) PseudoRandom Noise (PRN) code at 1.023 MHz thatis different for every satellite.

The signal isalso modulated with a 10.23 MHz Precise (P)code that is usually encrypted and only availableto authorized users. On top of this thereis a 50-bit-per-second modulation which isused to transmit the satellite ephemerides(predicted orbit and clock) and other information.

Authorized users have also access tothe Precise code on a second frequency L2,that allows users to correct for ionosphericpropagation delays. Some receivers are ableto measure the delay between the signal inthe L1 frequency and the L2 frequency withoutaccess to the P code. There are plans toadd in future satellites another frequency forcivil users so they can easily correct for ionosphericdelays.

The GPS Control Segment

The GPS control segment tracks and monitorsthe signal from the GPS space segmentand estimates the orbits and clock behaviourof the satellites. This information is uploadedto the satellites so it can be transmitted to users.

The GPS User Segment

The GPS user segment can perform two basicmeasurements of the GPS signals. It cancompare the C/A or P code that it is receivingwith a locally generated copy in order tocompute the transmission delay between thesatellite and the receiver. This measurementis called pseudorange. Pseudoranges to fouror more satellites can be used to determinethe position of the user once the position ofthe GPS satellites has been obtained usingthe ephemerides of the navigation message.

The second and more precise method is toobtain the difference in phase between thereceived carrier signal and a receiver generatedsignal at the same frequency. Thismeasurement is known as the carrier phaseobservable and it can reach millimetre precision,but it lacks the accuracy of the pseudorangebecause the phase when the trackingis started can only be known with an ambiguityof an unknown number of times the carrierwavelength (about 19 cm for L1)

GPS Global Positioning System

2009-03-24T10:58:00.000-07:00

Global Positioning System is a constellation of 24 satellites which orbit at an altitudeof 20,200 km above the earth’s surface in an inclined elliptical orbit. GPS providesvery precise latitude and longitude details which will be in centimetres.

GPS coversthe whole earth and any point on the earth surface can be pin-pointed. The reasonfor choosing GPS satellite is because of its continuous availability throughout theyear.

If the future GPS satellites like GLONASS, GALILEO, etc., are equipped withirradiation measuring instruments like Total Irradiance Monitor [SORCE], etc., andmoreover, if the measurements are made continuously over the earth’s atmospherethen the amount of irradiation data available are enormous which will lead to betterresults in irradiance monitoring.

During any particular year at least a minimum of 12satellites will be facing the Sun and monitoring the irradiance over that region and theorbital paths of the satellite will be well-known.

One more added advantage of usingthe GPS satellite is the repetitive coverage over an area on a single day, so the variationin the same area over a short period of time can also be calculated.

Space- and ground-based measurement and monitoring

At any instant nearly 12 satellites will be facing the Sun and they will measure theirradiance. The orbital path of the satellites are predefined and well-known. To measurethe irradiation precisely the measurement should be made at ground also at thesame instant of time when the satellite is passing over a certain area.

The ground measurementsare performed to reveal the solar irradiation available on the ground afterseveral atmospheric path losses. The reasons to measure the irradiation both on topof the atmosphere and on the ground are to understand the changes occurring in theirradiation during their travel to the surface, etc. Ground instruments are required atseveral clearly available places for measurement.

For example, if the satellite is at a specific location in space and their co-ordinates interms of latitude and longitude are knownby pre-calculations, e.g., 13◦00 N80◦00 E,the satellite measures the irradiation at that particular position in space and if themeasurements are made in the ground at the same place then we can compare thechanges in the values.

If more number of ground stations are established then for eachground station data we will obtain the top of the atmosphere data from the satellite.More stations will lead to better results, because we can compare more ground datawith the satellite data.

For a particular instant of time and at a particular point we will get the irradiation atthe top of the atmosphere, at the ground, the difference in irradiation, the amount of loss during that time and the variation in irradiation when compared to the correspondingprevious readings at the same point of observation.

Though the irradiation variationon the top of the atmosphere is very small, monitoring those small variations will alsohelp us to understand the influence of solar radiation on earth. The ground monitoringis difficult also because of the multiple scattering of radiation from the ground whichmakes the reading difficult.

Though there are some difficulties, the data obtained fromthese calculations will be better than the interpolated or extrapolated values which arewidely used.

Compaq Presario CQ60-101AU laptop drivers for Windows XP

2009-03-24T10:45:00.000-07:00

To successfully install the drivers in Compaq Presario CQ60-101AU Laptop with Windows XP operating System

please follow these steps

I. Get the following drivers and install in the given order only.
——————————————————————————
01. Chipset drivers - nVidia nForce chipset driver & Networking controller.exe (117MB)

02. AMD Processor Update - sp35445 (3MB)

03. WinXPSP2 Enhancements - sp28668_Enh4WinXPSP2.exe (3.3MB)

04. VGA/Display - see the manual Installation step below

05. UAA Driver for HD Audio - sp33566_UAA Bus Driver for HD Audio.exe (54MB)

06. HDMI Audio - HDMI-nForce_HDA_10.3.exe (7.5 MB)

07. Audio/Sound - download CQ60-101AU audio driver (3MB) (see help below to see how to install)

08. Modem - sp33839_Modem with SmartCP.exe(6MB)

09. Wireless - Wireless_Atheros.zip (2.2MB), sp34510_HP Wireless Assistant.exe (3.2MB)

10. Webcam - sp35414_HP 1.3MP Webcam Software Drivers.exe (5MB)

11. Dotnetfx2.0 - dotnetfx_2.0.exe (22MB)

12. Touchpad - Synaptics Touchpad.exe (6MB)

13. Quick launch - Quick launch buttons.exe (14MB)

14. Bluetooth - CQ60-101AU driver for bluetooth (98 MB)

——————————————————————–
I. Manual Installation Help for (04. VGA/Display)
——————————————————————–

1. Click START
2. Click RUN
3. Type “devmgmt.msc” in the prompt and click “OK”
4. In other devices>> right click “VGA adapter..”
5. Click “update driver”
6. Select “No, not this time” and Click “Next”
7. Select “Install from a list or specific location(Advanced)” and Click “Next”
8. Select “Don`t search. I will choose” and Click “Next”
9. From the list scroll down and select “Show All Devices” (the first option and not “Sound and video..”)
10. Click “Have Disk..”
11. Click “Browse” and choose this folder (the previous installation temp folder of chipset driver)
12. Select the “C:\NVIDIA\nForceWin2K\18.11\English\Display\nv4_disp.inf″ file and Click “Open”
13. Click “OK”
14. Select “NVIDIA GeForce 8200″
15. Click “Next”
16. Click “Finish”

—————————————————————-
II. Manual Installation Help for (07. Audio/Sound)
—————————————————————-

0. Download the corresponding file and unzip.
01. Click START02. Click RUN0
3. Type “devmgmt.msc” in the prompt and click “OK”
04. In other devices>> You will see two nos of “Audio Device on HD Audio Bus”
05. Right Click the first one and Click “disable”
06. In other devices>> right click the second Audio Device on ……..
07. Click “update driver”
08. Select “No, not this time” and Click “Next”
09. Select “Install from a list or specific location(Advanced)” and Click “Next”
10. Select “Don`t search. I will choose” and Click “Next”
11. From the list scroll down and select “Sound, video and game controller” and Click next
12. Click “Have Disk..”
13. Click “Browse” and choose this folder
14. Select the “/XP32/WiSVHe5″ file and Click “Open”
15. Click “OK”
16. Click “Next”
17. A menu appears saying “Installing …. Do you want to continue?” Click “YES”
18. Click “Continue Anyway”
===============================================================

—————————————————————-
III. Manual Installation Help for (09. Wireless )
—————————————————————-
0. Download the corresponding file and unzip.

1. Click START
2. Click RUN
3. Type “devmgmt.msc” in the prompt and click “OK”
4. In other devices>> right click “Ethernet Controller”
5. Click “update driver”
6. Select “No, not this time” and Click “Next”
7. Select “Install from a list or specific location(Advanced)” and Click “Next”
8. Select “Don`t search. I will choose” and Click “Next”
9. From the list scroll down and select “network Adapters” and Click “Next” wait
10. Click “Have Disk..”
11. Click “Browse” and choose this folder
12. Select the “/Atheros/net5211″ file and Click “Open”
13. Click “OK”
14. Click “Next”
15. Click “Finish”

SWF File compression strategy

2009-03-24T10:31:00.000-07:00

Since SWF files are frequently delivered over a network connection, they should be as compact as possible. Several techniques are used to accomplish this, including the following items:

Reuse—The structure of the character dictionary makes it easy to reuse elements in a SWF file. For example, a shape, button, sound, font, or bitmap can be stored in a file once and referenced many times.

Compression—Shapes are compressed by using an efficient delta encoding scheme; often the first coordinate of a line is assumed to be the last coordinate of the previous line. Distances are also often expressed relative to the last position.

Default values—Some structures, like matrixes and color transforms, have common fields that are used more often than others. For example, for a matrix, the most common field is the translation field. Scaling and rotation are less common. Therefore, if the scaling field is not present, it is assumed to be 100%. If the rotation field is not present, it is assumed that there is no rotation. This use of default values helps to minimize file sizes.

Change Encoding—As a rule, SWF files only store the changes between states. This is reflected in shape data structures and in the place-move-remove model that the display list uses.

Shape Data Structure—The shape data structure uses a unique structure to minimize the size of shapes and to render anti-aliased shapes efficiently on the screen.

The SWF header

2009-03-24T10:26:00.000-07:00

All SWF files begin with the following header.

The header begins with a three-byte signature of either 0x46, 0x57, 0x53 (“FWS”); or 0x43,0x57, 0x53 (“CWS”). An FWS signature indicates an uncompressed SWF file; CWSindicates that the entire file after the first 8 bytes (that is, after the FileLength field) wascompressed by using the ZLIB open standard. The data format that the ZLIB library uses isdescribed by Request for Comments (RFCs) documents 1950 to 1952. CWS file compressionis permitted in SWF 6 or later only.

A one-byte version number follows the signature. The version number is not an ASCIIcharacter, but an 8-bit number. For example, for SWF 4, the version byte is 0x04, not theASCII character “4” (0x35).

The FileLength field is the total length of the SWF file, including the header. If this is anuncompressed SWF file (FWS signature), the FileLength field should exactly match the filesize. If this is a compressed SWF file (CWS signature), the FileLength field indicates the totallength of the file after decompression, and thus generally does not match the file size. Havingthe uncompressed size available can make the decompression process more efficient.

The FrameSize field defines the width and height of the on-screen display. This field is stored as a RECT structure, meaning that its size may vary according to the number of bits needed to encode the coordinates. The FrameSize RECT always has Xmin and Ymin value of 0; the Xmax and Ymax members define the width and height.

The FrameRate is the desired playback rate in frames per second. This rate is not guaranteed if, for example, Flash Player is running on a slow or busy CPU. The Frame Count is the total number of frames in this SWF file.

SWF file format specification

2009-03-24T10:23:00.000-07:00

The SWF file format (pronounced “swiff ”) delivers vector graphics, text, video, and soundover the Internet and is supported by Adobe® Flash® Player software.

The SWF file format isdesigned to be an efficient delivery format, not a format for exchanging graphics betweengraphics editors.

It is designed to meet the following goals:

On-screen display—The format is primarily intended for on-screen display and supportsanti-aliasing, fast rendering to a bitmap of any color format, animation, and interactivebuttons.

Extensibility—The format is a tagged format, so it can be evolved with new features whilemaintaining backward compatibility with earlier versions of Flash Player.

Network delivery—The format can travel over a network with limited and unpredictable bandwidth. The files are compressed to be small and support incremental rendering throughstreaming. The SWF file format is a binary format and is not human readable like HTML. The SWF file format uses techniques such as bit-packing and structures with optional fieldsto minimize file size.

Simplicity—The format is simple so that Flash Player is small and easily ported. Also, FlashPlayer depends upon a limited set of operating system features only.

File independence—The files display without dependence on external resources suchas fonts.

Scalability—The files work well on limited hardware, and can take advantage of betterhardware when it is available. This ability is important because computers have differentmonitor resolutions and bit depths.

Speed—The files render with quick, high quality.

Scriptability—The format includes tags that provide sequences of byte codes to beinterpreted by a stack machine. The byte codes support the ActionScript™ language. FlashPlayer provides a runtime ActionScript object model that allows interaction with drawingprimitives, servers, and features of Flash Player.

SWF files have the extension .swf and a MIME type of application/x-shockwave-flash.

The SWF format has evolved through several versions. Through SWF 5, substantial additionswere made to the SWF tag set. Starting with SWF 6 and later, the SWF format changes less,as more new features are implemented partly or entirely at the ActionScript level. Startingwith SWF 9, the ActionScript 3.0 language, which employs the new ActionScript VirtualMachine 2 (AVM2) can be used. Anyone planning to generate SWF file content that usesnewer features should become familiar with the ActionScript object model that Flash Playerexposes. Some references for this information are Programming ActionScript 3.0 (seelivedocs.adobe.com/flex/2/docs/wwhelp/wwhimpl/js/html/wwhelp.htm?href=Part5_ProgAS.html), ActionScript 3.0 Language Reference (seelivedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/), and the Adobe ActionScript VirtualMachine 2 (AVM2) Overview at www.adobe.com/go/avm2overview/ (PDF file).Adobe seriously considers all feedback to the SWF file format specification. E-mail anyunclear or potentially erroneous information within the specification to Adobe atflashformat@adobe.com. All such email submissions shall be subject to the Submitt

QTFF Defining Media Data Layouts

2009-03-24T10:18:00.000-07:00

The QuickTime file format provides a great deal of flexibility in how media data is physically arranged withina file. However, it also allows media layouts to be created that may be inefficient for playback on a givendevice. To complicate the matter, a media layout that is inefficient for one device may be, in fact, very efficientfor another. The purpose of this appendix is to define some common uses of QuickTime files and describethe media layout in these circumstances.

Using QuickTime Files and Media Layouts

A QuickTime file can reference media data stored in a number of files, including the file itself. If a QuickTimefile references only media data contained within itself, the file is said to be self-contained. A QuickTime filecan also reference media data stored in files that are not QuickTime files. This is because the QuickTime fileformat references media within a URL by file offset, rather than by a data structuring mechanism of a particularfile format. This allows a QuickTime file to refer to data stored in any container format.

Often, it is convenient to store a single media stream per file, for example, when encoding content. It is alsouseful for purposes of reusing content. (To reuse an elementary stream, it is not necessary to extract it froma larger, possibly multiplexed file.)

Because QuickTime can reference media stored in any file, it is not required that media be stored in theQuickTime file format. However, this is recommended. Putting the elementary streams in a QuickTime filehas several advantages, particularly in enabling interchange of the content between different tools. Further,the QuickTime file format adds very little overhead to the media—as little as a few hundred bytes in manycases—so there is no great penalty in storage space.

One of the issues facing any device (a server or a local workstation) that is attempting to play back a QuickTimefile in real time is the number of file seeks that must be performed.

It is possible to arrange the data in a QuickTime file to minimize, and potentially eliminate, any seeks duringthe course of normal playback. (Of course, random access and other kinds of interactivity require seeks.)Minimizing seeks is accomplished by interleaving the media data in the QuickTime file in such a way thatthe layout of the media in the file corresponds to the order in which the media data will be required. It isexpected that most servers, for example, will stream QuickTime media using the facilities of the hint tracks.

Take a scenario where the QuickTime file contains a single hint track that references an audio and a visualmedia stream. In order to eliminate all seeks, the hint track media must be interleaved with the audio andvisual stream data. Because the hint track sample must always be read before the audio and visual mediathat it references, the hint track samples must always immediately precede the samples they reference.

A simple illustration of the ordering of data (that is, time and file offset increasing from left to right) is asfollows:

H0 A0 H1 V1 H2 V2 H3 A1 H4 A2 V3 H5 V4

When a single hint sample references multiple pieces of media data, those pieces of media data must occurin the order that they are referenced.

QuickTime File Format Specification

2009-03-24T10:13:00.000-07:00

Overview of QTFF

QuickTime movies are stored on disk, using two basic structures for storing information: atoms (also knownas simple atoms or classic atoms), and QT atoms. To understand how QuickTime movies are stored, you needto understand the basic atom structures described in this chapter. Most atoms you encounter in the QuickTimeFile Format are simple or classic atoms. Both simple atoms and QT atoms, however, allow you to constructarbitrarily complex hierarchical data structures. Both also allow your application to ignore data they don’tunderstand.

Metadata

A QuickTime file stores the description of its media separately from the media data. The description, ormetadata, is called the movie resource, movie atom, or simply the movie, and contains information such asthe number of tracks, the video compression format, and timing information. The movie resource also containsan index describing where all the media data is stored.

The media data is the actual sample data, such as video frames and audio samples, used in the movie. Themedia data may be stored in the same file as the QuickTime movie, in a separate file, in multiple files, inalternate sources such as databases or real-time streams, or in some combination of these.

Atoms

The basic data unit in a QuickTime file is the atom. Each atom contains size and type fields that precede anyother data. The size field indicates the total number of bytes in the atom, including the size and type fields.The type field specifies the type of data stored in the atom and, by implication, the format of that data. Insome cases, the size and type fields are followed by a version field and a flags field. An atom with theseversion and flags fields is sometimes called a full atom.

Atom types are specified by a 32-bit unsigned integer, typically interpreted as a four-character ASCII code.Apple, Inc. reserves all four-character codes consisting entirely of lowercase letters. Unless otherwise stated,all data in a QuickTime movie is stored in big-endian byte ordering, also known as network byte ordering,in which the most significant bytes are stored and transmitted first.

Atoms are hierarchical in nature. That is, one atom can contain other atoms, which can contain still others,and so on. This hierarchy is sometimes described in terms of a parent, children, siblings, grandchildren, andso on. An atom that contains other atoms is called a container atom. The parent atom is the container atomexactly one level above a given atom in the heirarchy.

For example, a movie atom contains several different kinds of atoms, including one track atom for each trackin the movie. The track atoms, in turn, contain one media atom each, along with other atoms that defineother track characteristics. The movie atom is the parent atom of the track atoms. The track atoms are siblings.The track atoms are parent atoms of the media atoms. The movie atom is not the parent of the media atoms,because it is more than one layer above them in the hierarchy.

An atom that does not contain other atoms is called a leaf atom, and typically contains data as one or morefields or tables. Some leaf atoms act as flags or placeholders, however, and contain no data beyond their sizeand type fields.

The format of the data stored within a given atom cannot always be determined by the type field of theatom alone; the type of the parent atom may also be significant. In other words, a given atom type cancontain different kinds of information depending on its parent atom. For example, the profile atom inside amovie atom contains information about the movie, while the profile atom inside a track atom containsinformation about the track. This means that all QuickTime file readers must take into consideration not onlythe atom type, but also the atom’s containment hierarchy.

Windows Secrets Codes

2009-03-17T11:01:00.000-07:00

Restoring a Lost Desktop

If you ever lose the Desktop but Explorer is still running with the Start Button, you can do this to bring back your Desktop in a Windows box.

1. Click Start

2. Click Run

3. Type a period " . "

4. Then press Enter

Creating a New E-Mail Shortcut

To create a shortcut that will open your default e-mail program starting a new e-mail,

1. Right click on an open area of the desktop

2. Select New / Shortcut

3. For the Command Line, enter mailto:

4. For the title enter something like New E-Mail

5. When you click on this your default e-mail program should start with a new e-mail form.

Creating 3D Window Effect

You can create a nice 3D effect for your windows

1. Start Regedit

2. Go to HKEY_CURRENT_USER \ Control Panel \ Colors

3. Make sure the following setting are there:
. ButtonHilight=128 128 128
. ButtonShadow=255 255 255

Creating Shutdown, Restart and Logoff Icons

To create the icons, create a shortcut on the desktop.

For Shutdown, the command is C:\WINDOWS\RUNDLL.EXE user.exe,exitwindows

For Restart, the command is C:\WINDOWS\RUNDLL.EXE user.exe, exit windows exec

For Logoff, the command is C:\WINDOWS\RUNDLL.EXE shell32.dll,SHExitWindowsEx 0

Having your Favorites and Start Menus Sort Alphabetically

If your Start Menu Program or Favorites are not sorting alphabetically, it is easy to fix this:

1. Start Regedit

2. Go to HKEY_CURRENT_USER/Software/Microsoft/Windows/CurrentVersion/Explor er/MenuOrder

3. Under here is are Favorites and Start Menu folders

4. In each there is a value called Order

5. Simply delete (or rename this) and restart Windows

6. Your Favorites or Start Menus should now sort alphabetically

Increasing the Icon Cache

1. Run Reg edit

2. Go to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explo rer

3. Create a new string called Max Cached Icons

4. Give it a value of 10000

5. This will increase response time in windows and give the Shellicon cache file more elbow room.

Make Icons 256 Color 16-Bit

1. Open the Registry

2. Hit Ctrl+F

3. Type Shell Icon BPP

4. When found, right click the Shell Icon BPP icon

5. Click Modify

6. Change the value from 4 to 16

7. Click Ok

8. Close the registry

9. Restart your computer

Removing Shortcut Arrows

An easy way to remove those irritating arrows from your desktop shortcut icons and not change their properties

1. Right click the Desktop / Properties / Appearance tab

2. Select Item

3. Scroll for Icon

4. The default size is 32

5. Change this to 30

6. Clicking Apply

Adding the Control Panel to the Start Menu

1. Open up the Explorer

2. Go to \WINDOWS\Start Menu

3. Right click in the right-hand panel

4. Add a new folder

5. Name it Control Panel.{21ec2020-3aea-1069-a2dd-08002b30309d}

6. This makes getting to the Control Panel items a little easier

Making Desktop Changes Permanent

To make changes to the Desktop like window size, positon after rebooting:

1. Start Regedit

2. Go to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policie s\Explorer

3. Create a New Binary Value

4. Name it NoSaveSettings

5. Give it a value of 01 00 00 00

Easy Shortcuts on the Desktop

Here is an easy way to put shortcuts on the Desktop where they can easily be moved to other group icons.

1. Using the Explorer, create a SHORTCUT to the \Windows\Desktop directory in your \Windows\SEND TO directory.

2. Now whenever you want to make a shortcut and move it to the desktop:

3. Just make the shortcut you want using Explorer

4. Right click on that shortcut

5. In the pop up menu select the Send To and Desktop shortcut.

Changing a Folder's Icon

To change the icon of a Folder on desktop:

1. Using the Explorer, move the folder from the Desktop directory to another directory on the hard drive

2. Right click on the new folder and select "Create Shortcut"

3. Move the shortcut to the Desktop

4. Right click and select a new icon

Full Window Drag ( Without Plus! )

1. Start Regedit

2. Open HKEY_CURRENT_USER /ControlPanel /Desktop /DragFullWindows

3. On "DragFullWindows" properties change 0 to 1

Fixing Corrupted Desktop Icons

Easier way to reset icons then deleting SHELLICONCACHE.

There's no need to exit Win95 and delete the SHELLICONCACHE file in order to reset icons that you may have changed (like Network Neighborhood).

1. Go to Control Panel, Display, Appearance Tab.

2. Select Icon from the Item drop down list.

3. Change the Size up or down one and apply.

4. Change the Size back to your original and apply.

If your Start Menu is slow or your icons are black for some reason, it means your Shelliconcache file is corrupt and should be deleted.

Windows Secret - Way to access restricted folders

2009-03-17T10:44:00.000-07:00

Use see, DOS has alovely command known as START. Its general syntax is:

START application_path

It does do what it seems to do, start applications. So in you have access to DOS then you can type in the START command to get access to the restricted folder. Now mostly access to DOS too would be blocked. So again you can use the shortcut trick to launch, c:\command.com or c:\windows\command.com. (Command.com is the file which launches MS DOS).

Accessing Restricted Drives.

The problem with most system administrators is that they think that the users or Hackers too are stupid. Almost all system administrators use the Registry Trick (Explained Earlier) to hide all drives in My Computer. So in order to unhide or display all drives, simply delete that particular key.(Refer to beginning of Untold Secrets Section.)

Some systems have the floppy disk disabled through the BIOS. On those systems ift he BIOS is protected, you may need to crack the BIOS password. (For that Refer tothe Windows Hacking Chapter). Sometimes making drives readable (Removing R +) and then creating Shortcuts to them also helps us to get access to them.

Changing your Operating System's Looks by editing .htt files

If you have installed Windows Desktop Update and have the view as Web Page option enabled, you can customise the way the folder looks by selecting View > Customise this folder. Here you can change the background and other things about that particular folder. Well that is pretty lame, right? We hackers already know things as lame as that. Read on for some kewl stuff.

Well, you could also change the default that is stored in a Hidden HTML Template file (I think so..) which is nothing but a HTML document with a .htt extension.This .htt file is found at: %systemroot%\web\folder.htt.

The %systemroot% stands for the drive in which Windows is Installed, which is normally C:

You can edit these .htt files almost just like you edit normal .HTM or .HTML files. Simply open them in an ASCII editor like Notepad. The following is a list of .htt files on your system which control various folders and which can be edited to customise the way various folders look.

controlp.htt Control Panel

printers.htt Printers

mycomp.htt My Computer

safemode.htt Safe Mode

All these files are found in the web folder in %systemfolder%. The folder.htt filehas a line:

'Here's a good place to add a few lines of your own"

which is the place where you can add your own A HREF links. These links would then appear in the folder whose folder.htt file you edited. All this might sound really easy and simple, but you see these .htt files do not contain normal HTML code, instead they contain a mixture of HTML and web bots. Hence they can be difficult for newbies to understand.

Source from Untold Windows Tips and Secrets By Ankit Fadia

Windows Secret - Poledit

2009-03-17T10:35:00.000-07:00

Poledit or Policy Editor is a small kewl tool which is being commonly used by system administrators to alter the settings of a system. This utility is noti nstalled by default by Windows. You need to install in manually from the Windows98 Installation Kit from the Resource Kit folder. user.dat file that we sawearlier.

The Policy Editor tool imposes restrictions on the user's system by editing the user.dat file which in turn means that it edits the Windows Registry to change thes ettings. It can be used to control or restrict access to each and every folder and option you could ever think of. It has the power to even restrict access to individual folders, files, the Control Panel,
MS DOS, the drives available etc. Sometimes this software does make life really hard for a Hacker. So how can we remove the restrictions imposed by the Policy Editor? Well read ahead to learnmore.

You see the Policy Editor is not the only way to restrict a user's activities. As we already know that the Policy Editor edits the Windows Registry(user.dat) file to impose such restrictions. So this in turn would mean that we can directly make changes to the Windows Registry using a .reg file or directly to remove or add restrictions.

Launch Regedit and go to the following Registry Key:

HKEY_CURRENT_USER/Software/Microsoft/CurrentVersion/Policies

Under this key, there will definitely be a key named explorer. Now under this explorer key we can create new DWORD values and modify it's value to 1 in order to impose the restriction. If you want to remove the Restriction, then you can simply delete the respective DWORD values or instead change their values to 0. The following is a list of DWORD values that can be created under the Explorer Key-:

NoDeletePrinter : Disables Deletion of already installed Printers

NoAddPrinter : Disables Addition of new Printers

NoRun : Disables or hides the Run Command

NoSetFolders : Removes Folders from the Settings option on Start Menu (ControlPanel, Printers, Taskbar)

NoSetTaskbar : Removes Taskbar system folder from the Settings option on Start Menu

NoFind : Removes the Find Tool (Start >Find)

NoDrives : Hides and does not display any Drives in My Computer

NoNetHood : Hides or removes the Network Neighborhood icon from the desktop

NoDesktop : Hides all items including, file, folders and system folders from the Desktop

NoClose : Disables Shutdown and prevents the user from normally shutting down Windows.

NoSaveSettings : Means to say, 'Don't save settings on exit'

DisableRegistryTools : Disable Registry Editing Tools (If you disable this option,the Windows Registry Editor(regedit.exe) too will not work.)

NoRecentDocsHistory: Removes Recent Document system folder from the Start Menu (IE4 and above)

ClearRecentDocsOnExit: Clears the Recent Documents system folder on Exit.

Nolnternetlcon: Removes the Internet (system folder) icon from the Desktop

Under the same key: HKEY_CURRENT_USER/Software/Microsoft/CurrentVersion/Policies
you can create new subkeys other than the already existing Explorer key. Now create a new key and name it System. Under this new key, system we can create the following new DWORD values(1 for enabling the particular option and 0 for disabling the particular option):

NODispCPL: Hides Control Panel

NoDispBackgroundPage: Hides Background page.

NoDispScrsavPage: Hides Screen Saver Page

NoDispAppearancePage: Hides Appearance Page

NoDispSettingsPage: Hides Settings Page

NoSecCPL: Disables Password Control Panel

NoPwdPage: Hides Password Change Page

NoAdminPaqe: Hides Remote Administration Page

NoProfilePage: Hides User Profiles Page

NoDevMgrPage: Hides Device Manager Page

NoConfigPage: Hides Hardware Profiles Page

NoFileSysPage: Hides File System Button

NoVirtMemPage: Hides Virtual Memory Button

Similarly, if we create a new subkey named Network, we can add the following DWORDv alues under it(1 for enabling the particular option and 0 for disabling the particular option):

NoNetSetupSecurityPage: Hides Network Security Page

NoNelSetup: Hides or disables the Network option in the Control Panel

NoNetSetupIDPage: Hides the Identification Page

NoNetSetupSecurityPage: Hides the Access Control Page

NoFileSharingControl: Disables File Sharing Controls

NoPrintSharing: Disables Print Sharing Controls

Similarly, if we create a new subkey named WinOldApp, we can add the following DWORD values under it(1 for enabling the particular option and 0 for disabling the particular option):

Disabled: Disable MS-DOS Prompt

NoRealMode: Disable Single-Mode MS-DOS.

So you see if you have access to the Windows Registry, then you can easily createnew DWORD values and set heir value to 1 for enabling the particular option and 0for disabling the particular option. But Sometimes, access to the Windows Registryis blocked. So what do you do? Go to the Windows Directory and delete eitheruser.dat or system.dat (These 2 files constitute the Windows Registry.) andreboot. As soon as Windows logs in, it will display a Warning Message informingyou about an error in the Windows Registry. Simply ignore this Warning Message andPress CTRL+DEL+ALT to get out of this warning message.(Do not press OK) You willfind that all restrictions have been removed.

The most kind of restriction found quite commonly is the Specific FolderRestriction, in which users are not allowed access to specific folders, the mostcommon being the Windows folder, or sometimes even access to My Computer isblocked. In effect, you simply cannot seem to access the important kewl fileswhich are needed by you to do remove restrictions. What do you? Well use the RUNcommand. (START >RUN). But unfortunately a system administrator who is intelligentenough to block access to specific folder, would definitely have blocked access tothe RUN command. Again we are stuck.

Windows is supposed to be the most User Friendly Operating System on earth. (Atleast Microsoft Says so.)

It gives the User an option to do the same thing in various ways. You see the RUN command is only the most convenient option of launching applications, but not the only way. In Windows you can create shortcuts to almost anything from a file, folder to a Web URL. So say your system administrator has blocked access to the c:\windows\system folder and you need to access it. What do you do? Simply create a Shortcut to it. To do this right click anywhere on the desktop and select New >Shortcut. A new window titled Create Shortcut pops up. Type in the path of the restricted folder you wish to access, in this case c:\windows\system. Click Next, Enter the friendly name of the Shortcut and then click Finish. Now you can access the restricted folder by simply double clicking on the shortcut icon. Well that shows how protected and secure *ahem Windows *ahem is.

Windows Secret - Outlook Express Tricks

2009-03-17T10:30:00.000-07:00

Colorful Background

Don't like the boring background colors of Outlook Express? To change it launchthe Windows Registry Editor and scroll down to the

HKEY_CURRENT_USER\Software\Microsoft\Internet Mail And News key.

On the left pane, click on ColorCycle or select Edit and Modify in the menu. Nowchange the value to 1. Close and restart. Now, launch Outlook Express and wheneveryou open up a New Message, hold down ctrl-shift and tap the z key to scroll tochange the background color. Repeat the keystroke to cycle through the colors.

Internet Explorer 5 Hidden Features

Microsoft Internet Explorer 5 has several hidden features which can be controlled using the Windows Registry. Open your registry and scroll down to the following key:

HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Restrictions

Create a new DWORD value named x(See complete list of values of x below) and modify it's value to 1 to enable it and to 0 to disable it.

NoBrowserClose : Disable the option of closing Internet Explorer.

NoBrowserContextMenu : Disable right-click context menu.

NoBrowserOptions : Disable the Tools / Internet Options menu.

NoBrowserSaveAs : Disable the ability to Save As.

NoFavorites : Disable the Favorites.

NoFileNew : Disable the File / New command.

NoFileOpen : Disable the File / Open command.

NoFindFiles : Disable the Find Files command.

NoSelectDownloadDir : Disable the option of selecting a download directory.

NoTheaterMode : Disable the Full Screen view option.

Hacking Secrets

Almost all system administrators make certain changes and make the system restricted. System Administrators can hide the RUN option, the FIND command, the entire Control Panel, drives in My Computer like D: A: etc. They can even restrict activities of a hacker my disabling or hiding, even the tiniest options or tools.

Most commonly these restrictions are imposed locally and are controlled by the Windows Registry. But sometimes the smart system administrators control thea ctivities of the hacker by imposing restrictions remotely through the main server.

Windows Secret - Internet Explorer Tricks and Tips

2009-03-17T10:27:00.000-07:00

Resizable Full Screen Toolbar

The Full Screen option increases the viewable area and makes surfing moreenjoyable but sometimes we need the Toolbar but also need to have extra viewingarea. Now this hack teaches you how to change the size of the Internet Explorertoolbar. This registry hack is a bit complicated as it involves Binary values, soto make it simple, I have included the following registry file which will enablethe resizable option of the Internet Explorer toolbar which was present in thebeta version of IE.

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Toolbar]

"Theater"=hex:0c,00,00,00,4c,00,00,00,74,00,00,00,18,00,00,00,1b,00,00,00,5c,\

00,00,00,01,00,00,00,e0,00,00,00,a0,0f,00,00,05,00,00,00,22,00,00,00,26,00,\

00,00,02,00,00,00,21,00,00,00,a0,0f,00,00,04,00,00,00,01,00,00,00,a0,0f,00,\

00,03,00,00,00,08,00,00,00,00,00,00,00

*******************

HACKING TRUTH: Internet Explorer 5 displays the friendly version of HTTP errors like NOT FOUND etc . They are aimed at making things easier for newbies. If you would rather prefer to see the proper error pages for the web server you're using,go to Tools, Internet Options and select the Advanced tab. Then scroll down anduncheck the Show friendly http errors box.

*******************

Making the Internet Explorer & the Explorer Toolbars Fancy

The Internet Explorer toolbar looks pretty simple. Want to make it fancy and kewl?Why not add a background image to it. To do this kewl hack launch the WindowsRegistry Editor and go to the following key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Internet Explorer\Toolbar\.

Now in the right pane create a new String Value and name it BackBitmap and modify it's value to the path of the Bitmap you want to dress it up with by right clicking on it and choosing Modify. When you reboot the Internet Explorer and the Windows Explorer toolbars will have a new look.

Change Internet Explorer's Caption

Don't like the caption of Internet Explorer caption? Want to change it? Open theregistry editor and go to

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main.

In the right pane create a new String Value names Window Title (Note the spacebetween Window and Title). Right click on this newly created String Value andselect Modify. Type in the new caption you want to be displayed.

Restart for thesettings to take place.

Windows Secret - Delete find Option

2009-03-17T10:22:00.000-07:00

To delete the Find option, go to the following registry key:

HKEY_CLASSES_ROOT\Directory\Shell\Find

Delete Find. DO NOT delete Open else you will not be able to open any folders inthe Start Menu like Programs, Accessories etc.

BMP Thumbnail As Icon

You can actually change the default BMP icon to a thumbnail version of the actualBMP file. To do this simply go to HKCU\Paint.Picture\Default. In the right pane change the value of default to %1. Please note however that this will slow down the display rate in explorer if there are too many BMP thumbnails to display. You can use other icons too, simply enter the pathname.To restore back to the normal change the vale of default back to: C:\Progra~1\Access~1\MSPAINT.EXE,1.

Customizing The Shortcut Arrow

All shortcuts have a tiny black arrow attached to it's icon to distinguish fromnormal files. This arrow can sometimes be pretty annoying and as a Hacker shouldknow how to change each and everything, here goes another trick. Launch theRegistry Editor and go to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\explorer\Shell Icons.

Now, on the right pane is a list of icons ( we found out that on some systems,Windows 98 especially, the right pane is blank. Don't worry, just add the value asrequired ). Find the value 29. If it isn't there, just add it. The value of thisstring should be C:\Windows\system\shell32.dll, 29 ( which means the 30th icon inshell32.dll - the first one begins with 0 ). Now, we need blank icon to do this.Just create one with white as the whole icon. Go here to learn how to create anicon. Once done just change the value to C:\xxx.ico, 0 where "xxx" is the fullpath of the icon file and "0" is the icon in it.

Now for some fun. If the blank icon is a bit boring, change it again. You will find that under shell32.dll there is a gear icon, a shared folder ( the hand ) and much more. Experiment for yourself!

Use Perl to Get List or Services Running on your NT box

Use the following Perl Script to get a list of Services running on your NT system

--------------script.pl-----------------

#!c:\per\bin\perl.exe

use Win32::Service;

my ($key, %service, %status, $part);

Win32::Service::GetServices(' ',\%services);

foreach $key (sort keys %services) {

print "Print Name\t: $key, $services{$key}\n";

Win32::Service::GetStatus( ' ',$services{$key};

\%status);

foreach $part (keys %status) {

print "\t$part : $status{$part}\n" if($part eq "CurrentState");

}

}

-------------script.pl-------------------

Windows Secret - Securing NT

2009-03-17T10:15:00.000-07:00

Securing NT

By default, NT 4.0 displays the last person who logged onto the system. This canbe considered to be a security threat, especially in the case of those who choose their password to be same as their Username. To disable this bug which actually is a feature, go to the following key in the registry editor:

HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon

Click and select the ReportBookOK item and create a new string value called DontDisplayLastUserName. Modify it and set it's value to 1.

As a system administrator, you can ensure that the passwords chosen by the usersare not too lame or too easy to guess. NT has this lovely utility called the UserManager which allows the administrator to set the age limit of the password whichforces the users to change the password after a certain number of days. You canalso set the minimum length of passwords and prevent users to use passwords whichalready have been used earlier and also enable account lockouts which willdeactivate an account after a specified number of failed login attempts.

When you log on to Win NT, you should disable Password Caching, this ensures Single NT Domain login and also prevents secondary Windows Logon screen.

Simply copy the following lines to a plain text ASCII editor like: Notepad and save it with an extension, .reg

----------------DISABLE.reg-----------------
REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Network]

"DisablePwdCaching"=dword:00000001

----------------DISABLE.reg-----------------

To Enable Password Caching use the following .reg file:

--------------Enable.reg-----------------

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Network]

"DisablePwdCaching"=dword:00000000

--------------Enable.reg-----------------

Cleaning Recent Docs Menu and the RUN MRU

The Recent Docs menu can be easily disabled by editing the Registry. To do this goto the following Key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

Now in the right pane, create a new DWORD value by the name: NoRecentDocsMenu and set it's value to 1. Restart Explorer to save the changes.

You can also clear the RUN MRU history. All the listings are stored in the key:

HKEY_USERS\.Default\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU

You can delete individual listings or the entire listing. To delete History ofFind listings go to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Doc Find SpecMRU

and delete.

Customizing the Right Click Context Menu of the Start Menu

When you right click on the start menu, only 3 options pop up: Open, Explore, and Find. You can add your own programs to this pop up menu( which comes up when weright click on it.) Open Regedit and go to the following registry key:

HKEY_CLASSES_ROOT\Directory\Shell

Right click on the shell and create a new Sub Key (You can create a new SubKey byright clicking on the Shell Key and selecting New > Key.). Type in the name of the application you want to add to the start menu. I want to add Notepad to the StartMenu and hence I name this new sub key, Notepad. Now right click on the newregistry key that you just created and create yet another new key named Command.Enter the full path of the application, in this case Notepad in the default value of Command in the rightpane.

So I Modify the value of the default string value and enter the full path name of Notepad:

c:\wndows\notepad.exe.

Now press F5 to refresh. Now if you right click on the Start Button you will find a new addition to the Pop Up Menu called Notepad.

Clicking on it will launchNotepad.We can not only add but also remove the existing options in this pop up box.

Windows Secret - IV

2009-03-17T10:08:00.000-07:00

In the right pane there will be a DWORD value names attributes. Now consider thefollowing options:

To add the Rename option to the menu, change the value of Attributes to50 01 00 20

To add the Delete option to the menu, change the value of Attributes to60 01 00 20

3. To add both the Rename & Delete options to the menu, change the value ofAttributes to 70,01,00,20

4. Add Copy to the menu, change Attributes to 41 01 00 20

5. Add Cut to the menu, change Attributes to 42 01 00 20

6. Add Copy & Cut to the menu, change Attributes to 43 01 00 20

7. Add Paste to the menu, change Attributes to 44 01 00 20

8. Add Copy & Paste to the menu, change Attributes to 45 01 00 20

9. Add Cut & Paste to the menu, change Attributes to 46 01 00 20

10.Add all Cut, Copy & Paste to the menu, change Attributes to 47 01 00 20

We want to add only the Rename option to the right click context menu of theRecycle Bin, so change the value of attributes to: 50 01 00 20. Press F5 torefresh and then after rebooting you will find that when you right click on theRecycle Bin a RENAME option pops up too.

To reset the default Windows options change the value of Attributes back to

40 01 00 20

The Registry File which one can create for the above process would be something like the below:

REGEDIT4

[HKEY_CLASSES_ROOT\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\Shell-Folder]

"Attributes"=hex:50,01,00,20

To access say the Modem Properties in the Control Panel Folder, the normalprocedure is: Click on Start, Click on Settings> Control Panel and then wait forthe Control Panel window to pop up and then ultimately click on the Modems icon.

Wouldn't it be lovely if you could shorten the process to: Click on Start> ControlPanel>Modems. Yes you can add the Control Panel and also all other Special SystemFolders directly to the first level Start Menu. Firstly collect the CLSID value ofthe folder you want to add to the start menu. I want to add Control Panel hencethe CLSID value is: 21EC2020-3AEA-1069-A2DD-08002B30309D

Now right click on the Start Button and select Open. Now create a new folder and name it: Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}

NOTE: Do not forget the period after the 'l' in Panel. Similarly all systemfolders can be added to the Start Menu.(accept My Briefcase, I think)

Deleting System Options from the Start menu

You can actually remove the Find and Run options from the start menu by performing a simple registry hack. Again like always Launch the registry editor and scroll down to the below key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

Right-click on the right pane and select New, DWORD Value. Name it NoFind.(To remove the RUN option name it NoRun). Double-click the newly create DWORD to edit it's value and enter 1 as its value. This will disable the FIND option of theStart Menu and will also disable the default Shortcut key(F3 for Find.)

To restore the Run or find command modify the value of the DWORD to 0 or simplyDelete the DWORD value.

Fed Up of the boring Old Yellow Folder Icons?[Drive Icons Included]

NOTE: This trick hasn't been tried on Win98.

You can easily change the boring yellow folder icons to your own personalizedicons. Simply create a text file and copy the following lines into it:

[.ShellClassInfo]

ICONFILE=Drive:\Path\Icon_name.extension

Save this text file by the name, desktop.ini in the folder, whose icon you want to change. Now to prevent this file from getting deleted change it's attributes to Hidden and Read Only by using the ATTRIB command.

To change the icon of a drive, create a text file containing the following lines:

[Autorun]

ICON=Drive:\Path\Icon_name.extension

Save this file in the root of the drive whose icon you want to change and name itautorun.inf For Example, if you want to change the icon of a floppy, SAVE THE iconin a:\icon_name.ico One can also create a kewl icon for the Hard Disk and create atext file [autorun.inf] and store it in "c:\".

Windows Secret - III

2009-03-17T10:02:00.000-07:00

CLSID Folders Explained

Don't you just hate those stubborn stupid icons that refuse to leave the desktop,like the Network Neighborhood icon. I am sure you want to know how you can deletethem. You may say, that is really simple, simply right click on the concerned iconand select Delete. Well not exactly, you see when you right click on these specialfolders( see entire list below)neither the rename nor the delete option does notappear. To delete these folders, there are two methods, the first one is using theSystem Policy Editor(Poledit in the Windows installation CD)and the second isusing the Registry.

Before we go on, you need to understand what CLSID values are. These folders, like the Control Panel, Inbox, The Microsoft Network, Dial Up Networking etc are system folders. Each system folder has a unique CLSID key or the Class ID which is a 16-byte value which identifies an individual object that points to a correspondingkey in the registry.

To delete these system Folders from the desktop simply go to the following registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Desktop\Namespace{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}

To delete an icon simply delete the 16 byte CLSID value within "NameSpace". Thefollowing are the CLSID values of the most commonly used icons:

My Briefcase : {85BBD920-42AO-1069-A2E4-08002B30309D}

Desktop : {00021400-0000-0000-C000-0000000000046}

Control Panel : {21EC2020-3AEA-1069-A2DD-08002B30309D}

Dial-Up-Networking : {992CFFA0-F557-101A-88EC-00DD01CCC48}

Fonts : {BD84B380-8CA2-1069-AB1D-08000948534}

Inbox : {00020D76-0000-0000-C000-000000000046}

My Computer : {20D04FE0-3AEA-1069-A2D8-08002B30309D}

Network Neighborhood : {208D2C60-3AEA-1069-A2D7-O8002B30309D}

Printers : {2227A280-3AEA-1069-A2DE-O8002B30309D}

Recycle Bin : {645FF040-5081-101B-9F08-00AA002F954E}

The Microsoft Network : {00028B00-0000-0000-C000-000000000046}

History : {FF393560-C2A7-11CF-BFF4-444553540000}

Winzip : {E0D79300-84BE-11CE-9641-444553540000}

For example, to delete the Recycle Bin, first note down it's CLSID value, which is: 645FF040-5081-101B-9F08-00AA002F954E. Now go to the Namespace key in the registry and delete the corresponding key.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\explorer\Desktop\NameSpace\{645FF040-5081-101B-9F08-00AA002F954E}

Similarly to delete the History folder, delete the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\explorer\Desktop\NameSpace\{FBF23B42-E3F0-101B-8488-00AA003E56F8}

Sometimes, you may need to play a trick on your brother or friend, well this oneteaches you how to hide all icons from the Desktop. Go to the following registry key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

In the right pane create a new DWORD value by the name: NoDesktop and set its value to: 1. Reboot and you will find no icons on the desktop.

Till now you simply learnt how to delete the special system folders by deleting aregistry key, but the hack would have been better if there was a way of adding theDELETE and RENAME option to the right click context menus of these specialfolders. You can actually change the right click context menu of any system folderand add any of the following options: RENAME, DELETE, CUT, COPY, PASTE and lotsmore.

This hack too requires you to know the CLSID value of the system folder whose menuyou want to customize. In this section, I have taken up Recycle Bin as the folderwhose context menu I am going to edit.

Firstly launch the registry editor and open the following registry key:

HKEY_CLASSES_ROOT\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\ShellFolder.

In Case you want to edit some other folder like say the FONTS folder, then you will open the following key:

HKEY_CLASSES_ROOT\CLSID\{CLSID VALUE HERE}\ShellFolder.

Windows Secret - II

2009-03-17T09:57:00.000-07:00

Take Over the Screen Saver

To activate and deactivate the screen saver whenever you want, goto the followingregistry key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\ScreenSavers

Now add a new string value and name it Mouse Corners. Edit this new value to -Y-N.Press F5 to refresh the registry. Voila! Now you can activate your screensaver bysimply placing the mouse cursor at the top right corner of the screen and if youtake the mouse to the bottom left corner of the screen, the screensaver will deactivate.

Pop a banner each time Windows Boots

To pop a banner which can contain any message you want to display just before auser is going to log on, go to the key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WinLogon

Now create a new string Value in the right pane named LegalNoticeCaption and enterthe value that you want to see in the Menu Bar. Now create yet another new string value and name it: LegalNoticeText. Modify it and insert the message you want todisplay each time Windows boots. This can be effectively used to display thecompany's private policy each time the user logs on to his NT box. It's .reg filewould be:

REGEDIT4

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Winlogon]

"LegalNoticeCaption"="Caption here."

Delete the Tips of the Day to save 5KB

Windows 95 had these tips of the day which appeared on a system running a newlyinstalled Windows OS. These tips of the day are stored in the Windows Registry andconsume 5K of space. For those of you who are really concerned about how much freespace your hard disk has, I have the perfect trick.

To save 5K go to the following key in Regedit:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\Tips

Now simply delete these tricks by selecting and pressing the DEL key.

Change the Default Locations

To change the default drive or path where Windows will look for it's installationfiles, go to the key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Setup\SourcePath

Now you can edit as you wish.

Secure your Desktop Icons and Settings

You can save your desktop settings and secure it from your nerdy friend by playingwith the registry. Simply launch the Registry Editor go to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

In the right pane create a new DWORD Value named NoSaveSettings and modify it'svalue to 1. Refresh and restart for the settings to get saved.

Windows Secret

2009-03-17T09:49:00.000-07:00

Exiting Windows the Cool and Quick Way

Normally it takes a hell lot of time just Shutting down Windows, you have to moveyour mouse to the Start Button, click on it, move it again over Shut Down, click,then move it over the necessary option and click, then move the cursor over the OKbutton and once again (you guessed it) click.This whole process can be shortenedby creating shortcuts on the Desktop which will shut down Windows at the click ofa button. Start by creating a new shortcut( right click and select New> Shortcut).Then in the command line box, type (without the quotes.)

'C:\windows\rundll.exe user.exe,exitwindowsexec'

This Shortcut on clicking will restart Windows immediately without any Warning. Tocreate a Shortcut to Restarting Windows, type the following in the Command Linebox:

'c:\windows\rundll.exe user.exe,exitwindows'

This Shortcut on clicking will shut down Windows immediately without any Warning.

Ban Shutdowns : A trick to Play on Lamers

This is a neat trick you can play on that lamer that has a huge ego, in thissection I teach you, how to disable the Shut Down option in the Shut Down DialogBox. This trick involves editing the registry, so please make backups. Launchregedit.exe and go to :

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

In the right pane look for the NoClose Key. If it is not already there then createit by right clicking in the right pane and selecting New > String Value.(Name itNoCloseKey ) Now once you see the NoCloseKey in the right pane, right click on itand select Modify. Then Type 1 in the Value Data Box.

Doing the above on a Win98 system disables the Shut Down option in the Shut DownDialog Box. But on a Win95 machine if the value of NoCloseKey is set to 1 then

click on the Start > Shut Down button displays the following error message:

This operation has been cancelled due to restrictions in effect on this computer.Please contact your system administrator.

You can enable the shut down option by changing the value of NoCloseKey to 0 orsimply deleting the particular entry i.e. deleting NoCloseKey.

Instead of performing the above difficult to remember process, simply save thefollowing with an extension of .reg and add it's contents to the registry bydouble clicking on it.

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]"

NoClose"="1"

Disabling Display of Drives in My Computer

This is yet another trick you can play on your geek friend. To disable the displayof local or networked drives when you click My Computer go to :

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer

Now in the right pane create a new DWORD item and name it NoDrives. Now modifyit's value and set it to 3FFFFFF (Hexadecimal) Now press F5 to refresh. When youclick on My Computer, no drives will be shown. To enable display of drives in MyComputer, simply delete this DWORD item. It's .reg file is as follows:

REGEDIT4

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]

"NoDrives"=dword:03ffffff

Windows Shortcut File Location Info

2009-03-07T09:35:00.000-08:00

File Location Info

This item is always present, but if bit 1 is not set in the flags value, then the length of this structure will be zero. The following table shows the structure of the header ofthis item.

File Location Info

Offset Size Contents
0h 1 dword This is the total length of this structure and all following data
4h 1 dword This is a pointer to first offset after this structure.
1Ch8h 1 dword Flags
Ch 1 dword Offset of local volume info
10h 1 dword Offset of base pathname on local system
14h 1 dword Offset of network volume info
18h 1 dword Offset of remaining pathname

Notes: The first length value includes all the assorted pathnames and other datastructures. All offsets are relative to the start of this structure.

The first long integer indicates the size of the file location info.

The next long integer is the offset at which the basic file info structure ends. Shouldbe 1Ch under normal conditions.

The next long integer is the flags that indicate which types of volumes the file is available on.

Volume flags

Bit Meaning
0 Available on a local volume
1 Available on a network share

The next long integer is the offset to the local volume table. ( Random garbage when bit 0 is clear in volume flags)

The next long integer is the offset to the base path on the local volume.
( Random garbage when bit 0 is clear in volume flags)

The next long integer is the offset to the network volume table. ( Random garbage when bit 1 is clear in volume flags)

The next long integer is the offset to the final part of the pathname.

To find the filename of the file on the local volume, combine the base path string andthe final path string.

To find the filename of the file on the network, combine the share name in thenetwork volume table with the final path string.

Description string

If bit 2 is set in the flags value in the header, then this string is present.

The first unsigned short int value indicates the length of the string. Following thelength value is a string of ASCII characters. It is a description of the item.

Relative path string

If bit 3 is set in the flags value in the header, then this string is present.The first unsigned short int value indicates the length of the string.

Following thelength value is a string of ASCII characters. It is a relative path to the target.

Working directory

If bit 4 is set in the flags value in the header, then this string is present.

The first unsigned short int value indicates the length of the string. Following thelength value is a string of ASCII characters. It is the working directory as specified inthe shortcut properties.

Command line string

If bit 5 is set in the flags value in the header, then this string is present.

The first unsigned short int value indicates the length of the string. Following thelength value is a string of ASCII characters. The command line string includes everything except the program name.

Icon filename string

If bit 6 is set in the flags value in the header, then this string is present.

The first unsigned short int value indicates the length of the string. Following thelength value is a string of ASCII characters. This the name of the file containing theicon.

The Windows Shortcut File Format

2009-03-07T09:03:00.000-08:00

Basic File Structure

The file is structured like this:

File header
Shell item ID list
Item 1
Item 2
etc..
File locator info
Local path
Network path
Description string
Relative path string
Working directory string
Command line string
Icon filename string
Extra stuff

The File Header

This is of course at the start of the file.

The first 4 bytes of the file form a long integer that is always set to 4Ch this it theASCII value for the uppercase letter L. This is used to identify a valid shell link file.

The next 16 bytes is the globally unique identifier GUID of the shell links which is:{00021401-0000-0000-00C0-000000000046} in standard GUID notation or {01h,14h, 02h, 00h, 00h, 00h, 00h, 00h, C0h, 00h, 00h, 00h, 00h, 00h, 46h} as it iscomposed of bytes in the file. It appears that in the future, Microsoft may redefinethe file format and this will be used to indicate which version to use.The next item is a long integer which consists of a number of flags. This isimportant, because it indicates which of the optional parts of the file are present.

The next item is a long integer that contains file attributes of the target file. If thetarget is not a file (see flags bit 1), then this is set to zero. The resolver uses thesewhen the link is broken to match the link with the correct target.

The next three items are 64 bit integers that specifiy the various time information for the file.

Creation time

Modification time

Last access time

The next item is a long integer which contains the length of the target file.

If the file has a custom icon (see flags bit 6), then this long integer indicates theindex of the icon to use. Otherwise it is zero.

The next long integer specifies the ShowWnd value to pass to the target application when starting it. For your convenience, the values are reproduced below. It isunlikely, that most of these values are valid. Only values 1, 2 and 3 are permitted inthe shortcut property page.

SW_HIDE 0 Cool...

SW_NORMAL 1

SW_SHOWMINIMIZED 2

SW_SHOWMAXIMIZED 3

SW_SHOWNOACTIVATE 4

SW_SHOW 5

SW_MINIMIZE 6

SW_SHOWMINNOACTIVE 7

SW_SHOWNA 8

SW_RESTORE 9

SW_SHOWDEFAULT 10

The next long integer specifies the hotkey assigned to the shortcut.

The last two long integers are always zero. They are probably reserved for future use.

The Shell Item Id List.

This item is only present if bit 0 is set in the flags word of the header.

An entire book could be written on the contents of this item. Essentially it indicateshow to get from the desktop to the specified item. The actual contents are highlyvariable. The following are the only constant items about the list.

The first unsigned short integer indicates the total length of the list so it can beskipped easily.

Inside the list, each item begins with an unsigned short integer that indicates thelength of the item. The length includes the size of the length value.

The last item is length 0.

Lookup ITEMIDLIST in most any Win32 documentation for more info on this item.

AVI File Format -Subtitle & Garbage

2009-03-01T09:07:00.000-08:00

Subtitles in AVI files

This section explains how to store subtitles in AVI files, so that VSFilter can be used to load and select subtitles.

One subtitle stream is stored in one single chunk. That chunk contains header data, followed by an entire SRT or SSA file. If that file is using UTF-8 encoding, the BOM should be included as well. The header is defined as follows:

char[4]; // 'GAB2'
BYTE 0x00;
WORD 0x02; // unicode
DWORD dwSize_name; // length of stream name in bytes
char name[dwSize_name]; // zero-terminated subtitle stream name encoded in UTF-16
WORD 0x04;DWORD dwSize; // size of SRT/SSA text file
char data[dwSize]; // entire SRT/SSA file

Stream header chunk

typedef struct
{

FOURCC fccType; // "txts"
FOURCC fccHandler; // 00 00 00 00
DWORD dwFlags;
WORD wPriority;
WORD wLanguage;
DWORD dwInitialFrames;
DWORD dwScale;
DWORD dwRate; // dwRate / dwScale == duration in seconds
DWORD dwStart;
DWORD dwLength; // In units above..., should be 1
DWORD dwSuggestedBufferSize;
DWORD dwQuality;
DWORD dwSampleSize; // = 0 -> treated as VBR
RECT rcFrame; // 0, 0, 0, 0

} AVIStreamHeader;

Stream format chunk

This chunk has a size of 0.

Stream name chunk

The strn chunk is ignored by VSlter, so there is no need to read or write it.

Garbage in AVI files

One way to set a delay in AVI files is using the AVIStreamHeader::dwStart value. However, not every player reads this value, so that such files would not properly playon them. Some applications, like VirtualDub and derivates (NanDub, VirtualDubMod) add some data to the beginning of streams to be delayed.

Unfortunately, those applications don't care about the data format, but rather pad with zeros. Those zeros are refered to as 'garbage' in this section. The scope is to explain how to read such files, which requires that the duration of the garbage section be determined.It is of course required that the beginning of the valid data be found, for example in the caseof MP3, AC3 or DTS by looking for frame headers. Formats which don't use frame headers that can be detected easily, like AAC, will result in broken streams if zeros are added to the beginning.

Constant Bitrate

If the bitrate of a stream is constant, the duration of the garbage section is simply garbage_length * data_rate.

Variable Bitrate

In this case, the duration must be retrieved chunk-wise:

The duration of one chunk is roundup (size_of_chunk / strf::nBlockAlign) * duration_per_frame.

Consequently, if the beginning of the valid data is the m-th byte in chunk n, the duration of the garbage section is

sum[i=0..n-1](duration(chunk[i])) + roundup(m/nBlockAlign)

Overhead of AVI files

This section describes how to predict the overhead of an AVI file before muxing. Note: In the case of low overhead AVI files, the wording in this section is not applicable. Basicly, one video/audio frame causes about 8-9 bytes of overhead in low overhead AVI fies.

General

The overhead of AVI files depends on the number of CHUNKs in the file. Other structures has only very little influence on the total overhead. Each CHUNK causes the following amount of overhead:

• 8 Bytes chunk header (all avi types)

• 16 Bytes for entry in Legacy Index (AVI 1.0 and the RIFF-AVI-List of Hybride files)

• 8 Bytes for entry in Standard Index(Open-DML)

That means, each CHUNK causes an amount of overhead of 16, 24 or 32 bytes.

Getting number of CHUNKS

Video

The easier part is the video stream: Each video frame takes one CHUNK.

Audio

The number of chunks for an audio stream depends on its format and packing. For specific formats, where very special packing is required or considered normal, the overhead can be calculated easily from the settings. Otherwise, more precise information on the muxing settings is needed.

Examples

Video: 3 hours, 25 fps ( = 3,600,000 / 40ms = 90,000 frames per hour)

Audio: 2x MP3-VBR (with 1 frame per CHUNK and 24 ms per frame)

Audio: 2x AC3 (with 4 frames per CHUNK and 32ms per frame)

-> Video: 270,000 CHUNKs
-> Audio: 2*150,000 + 2*3*28,125 = 468,750 CHUNKs
-> Sum = 738,750 CHUNKs

AVI File Format - The movi - Lists

2009-03-01T08:54:00.000-08:00

The Movi - Lists contain Video, Audio, Subtitle and (secondary) index data. Those can be grouped into rec - Lists. Example:

LIST movi
LIST rec
01wb
01wb
02wb
03wb
03wb
03wb
00dc
00dc
LIST rec
01wb
02wb
LIST rec
...
...
ix01
ix02
ix03
...
...

The following chunk header IDs are defined:

• ..wb: audio chunk

• ..dc: video chunk

• ..tx: subtitle chunk

• ix..: standard index block

Grouping chunks into rec - Lists prevents excessive seeking when using the Microsoft AVI splitter for replay, but does not allow playback on some standalone replay devices.

The maximum size of a chunk of a stream should be smaller than the corresponding dwSuggestedBufferSize value. Otherwise, some players, especially the Microsoft AVI splitter, could malfunction.

Audio types requiring special attention

MP3

wFormatTag = 0x0055

An MP3 audio stream consists of inseparable frames. MP3 decoders should be able to handle partial frames, but it is nevertheless recommended to store entire MP3 frames in the AVI chunks.

The strf chunk is an MPEGLAYER3WAVEFORMAT structure, which is an extention to the WAVEFORMATEX structure:

typedef struct mpeglayer3waveformat_tag
{
WAVEFORMATEX wfx;
WORD wID;DWORD fdwFlags;
WORD nBlockSize;
WORD nFramesPerBlock;
WORD nCodecDelay;
} MPEGLAYER3WAVEFORMAT;

Important:
This is only valid for MP3 ('MPEG Layer 3'), not for MP1 or MP2 ('MPEG Layer 1 / 2').

If the MP3 stream has a variable bitrate, then you need to convince DirectShow to seekproperly.

Unfortunately, whoever came up with the idea didn't think enough about it: It is possible to create MP3 audio frames larger than 1152 bytes if the sample rate is 32 khz or less. After reading and understanding, you'll see why such audio frames render an MP3stream unplayable if nBlockSize is set to 1152, which is usually done for MP3. Using a larger value would resolve this issue. However, some programs read an MP3 stream as VBRif and only if this value is exactly 1152. In other words, low sample rates in combination with high bit rates are a problem for MP3 VBR streams in AVI files.

AC3

wFormatTag = 0x2000

Muxing AC3 into AVI is far more problematic than most other audio formats. The reason is that a lot of decoders (software as well as hardware) are severely b0rked.

An AC3 stream consists, like MP3, of individual, inseparable frames. It is required that any audio chunk of an AVI file contains a few (complete!) AC3 frames. Otherwise, someAC3 decoders will miscalculate the duration of a chunk. As the audio stream is considered the master stream for playback in DirectShow, this miscalculation will lead to jerky video playback.

Theoretically, chunks containing one AC3 frame are valid, but there are hardware decoders which won't work with such streams. If you place more than 6 AC3 frames into one chunk, you might get increased playback speed. Thus, the recommendation is to place be-tween 2 and 5 AC3 frames into one AVI chunk.

DTS

wFormatTag = 0x2001

It seems to work out to place between 2 and 20 DTS frames in one AVI chunk. I have not yet tried higher values on my own. If you have a hardware DTS decoder, please do some testing and report back what values work and which ones don't. Just like with AC3, do not split up any DTS frames.

MPx VBR

• MPEG 1 Layer 3: 1152 samples per frame

• MPEG 2 Layer 3: 576 samples per frame

• MPEG 1/2 Layer 2: Strongly discouraged from being used, because the default MPEG Layer 2 decoder present on Windows systems does not recognise MPEG Layer 2 streams when using VBR headers.

AAC

For AAC, one RAW AAC frame usually spans over 1024 samples. However, depending on the source container (e.g. ADTS), it is theoretically possible that you are not able to extract packets of equal duration from your source file. In this case, it is highly recommended not to mux the AAC stream into AVI, but report a fatal error instead.

AAC and HE-AAC require private data in the corresponding WAVEFORMATEX structures. See the source code of AVI-Mux GUI (FillASI.cpp) for details.

AVI File Format - Open-DML Index

2009-03-01T08:39:00.000-08:00

The general structure of an Open-DML-Index-Chunk is the following:

typedef struct _aviindex_chunk
{
FOURCC fcc;
DWORD cb;
WORD wLongsPerEntry;
BYTE bIndexSubType;
BYTE bIndexType;
DWORD nEntriesInUse;
DWORD dwChunkId;
DWORD dwReserved[3];

struct _aviindex_entry
{
DWORD adw[wLongsPerEntry];
} aIndex [ ];

} AVIINDEXCHUNK;

Every subtype of Open-DML index structures is compatible to this one. The elements have the following meaning:

• fcc, cb: Chunk header, same as dwFourCC and dwSize in the CHUNK structure

• wLongsPerEntry: every aIndex[i] has a size of 4*wLongsPerEntry bytes. (the struc-ture of each aIndex[i] depends on the special type of index)

• bIndexType, bIndexSubType: defines the type of the index

• nEntriesInUse: aIndex[0]..aIndex[nEntriesInUse-1] are valid

• dwChunkId: ID of the stream the index points into, for example '00dc'.Consequently, one such index chunk can only point to data of one and the same stream.

Upper Level Index ('Super Index')

The upper level index ('super index') points to other index chunks and has the following structure:

typedef struct _avisuperindex_chunk
{
FOURCC fcc;
DWORD cb;
WORD wLongsPerEntry;
BYTE bIndexSubType;
BYTE bIndexType;
DWORD nEntriesInUse;
DWORD dwChunkId;
DWORD dwReserved[3];

struct _avisuperindex_entry
{
__int64 qwOffset;
DWORD dwSize;
DWORD dwDuration;
} aIndex[ ];

} AVISUPERINDEX;

The following values are now defined more specifically:

• bIndexType = AVI_INDEX_OF_INDEXES

• bIndexSubType = [ AVI_INDEX_2FIELD 0 ]

• wLongsPerEntry = 4

As you can see, the aIndex array now consists of 4 DWORDs per entry. The values have the following meaning:

• qwOffset: Position of the index chunk this entry points to in the file

• dwSize: The size of the standard or field index chunk the entry is pointing to

• dwDuration: The duration, measured in stream ticks as indicated in the AVI stream header. In case of video or VBR audio, that usually refers to the number of frames.
Important: VirtualDub 1.4.10 and earlier versions wrote b0rked values for this member in theaudio stream. Thus, an AVI parser should be able to handle files without using this value!

The Standard Index

This index type contains pointers to video, audio or subtitle chunks. It also is a special form of the general Open-DML Index and looks like this:

typedef struct _avistdindex_chunk
{
FOURCC fcc;
DWORD cb;
WORD wLongsPerEntry;
BYTE bIndexSubType;
BYTE bIndexType;
DWORD nEntriesInUse;
DWORD dwChunkId;
__int64 qwBaseOffset;
DWORD dwReserved3;

struct _avistdindex_entry
{
DWORD dwOffset;
DWORD dwSize;
} aIndex[ ];

} AVISTDINDEX;

• wLongsPerEnrty: As you can see easily, each aIndex[i] takes 8 bytes,so wLongsPerEntry = 2

• bIndexSubType: = 0

• bIndexType:= AVI_INDEX_OF_CHUNKS

• qwBaseOffset: This value is added to each dwOffset value of the AVISTDINDEX.

• dwOffset, dwSize: These elements define the position (qwBaseOffset + dwOffset) of the data section of the corresponding CHUNK (NOT the chunk header!) and its length. There are nEntriesInUse such pairs, each one describing one video/audio frame. Note that Bit 31 of dwSize indicates the frametype: If this bit is set, this frame is not a keyframe.

Low-overhead mode

The Open-DML specication does not explicitly require that each "data section" the index contains an entry to be preceded by a chunk header. Thus, several frames can be put into one chunk, while having one index entry per frame. This way, only few frames have a chunkheader, reducing the overhead by 50% compared to normal Open-DML files. This means, ofcourse, that the AVIF_MUSTUSEINDEX again the main AVI header must be set, to force any parser to use the index. Files created this way will be called "low overhead AVI files".

This is not an AVI file type on its own. Any parser handling that flag, as well as the Open-DML index correctly, should be compatible to such files. Microsoft's AVI splitter, as well as VirtualDub(Mod) can handle such files without problems, without having been updated todo so.

Using the Open-DML Index

The preceding section described what the Open-DML Index looks like. This section will deal with using it.

Each stream contains an 'indx' chunk in its stream header list ('strl'). This chunk is a Super Index chunk.

As each Standard Index contains one 64 bit offset and then a list of 32 bit offsets relatively to the 64 bit offset, one Standard Index chunk can only point to data within one 4 GB segment.Thus you need one Standard Index per 4 GB file size per stream.

Unfortunately, it seems that Microsoft did not read the specification properly: If a file contains more than 3 audio streams, then the Microsoft AVI Splitter will not recognize files using such large Standard Index chunks. It is required to use smaller pieces. Tests have shown that pieces with 15000 entries each are small enough to be processed correctly byMicrosoft's AVI splitter.

AVI File format - AVI Indexes

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The Stream header list - general

There is one strl - List for each stream. If the number of strl - Lists inside the hdrl - Listis different from MainAVIHeader::dwStreams, a fatal error should be reported.

The stream header list element: strh

typedef struct
{
FOURCC fccType;
FOURCC fccHandler;
DWORD dwFlags;
WORD wPriority;
WORD wLanguage;
DWORD dwInitialFrames;
DWORD dwScale;
DWORD dwRate; /* dwRate / dwScale == samples/second */
DWORD dwStart;
DWORD dwLength; /* In units above... */
DWORD dwSuggestedBufferSize;
DWORD dwQuality;
DWORD dwSampleSize;
RECT rcFrame;
} AVIStreamHeader;

Again, the meaning is not always obvious.

• fccType
Can be
- 'vids' - video
- 'auds' - audio
- 'txts' - subtitle

• fccHandler
FourCC of codec to be used.

• dwFlags
The following flags are defined
-AVISF_DISABLED - Stream should not be activated by default
-AVISF_VIDEO_PALCHANGES - Stream is a video stream using palettes where the palette is changing during playback.

• dwInitialFrames
Number of the first block of the stream that is present in the file.

• dwRate / dwScale =
samples / second (audio) or
frames / second (video).
dwScale and dwRate should be mutually prime. Tests have shown that for example 10,000,000 /400,000 instead of 25/1 results in files that don't work on some hardware MPEG4 players.

• dwStart
Start time of stream. In the case of VBR audio, this value indicates the number of silent frames to be played before the stream starts.

• dwLength
size of stream in units as defined in dwRate and dwScale

• dwSuggestedBufferSize
Size of buffer necessary to store blocks of that stream. Can be 0 (in that case the application has to guess), but should not be 0, as Microsoft's AVI splitter does not handle this case properly in some cases (e.g. MP3-CBR in Open-DML files)

• dwQuality
should indicate the quality of the stream. Not important

• dwSample
Size number of bytes of one stream atom (that should not be split any further).

The stream header list element: strf

The structure of the strf chunk depends on the media type. Video streams use the BITMAPINFOHEADER structure, whereas audio streams use the WAVEFORMATEX structure.

The stream header list element: indx

This chunk contains the upper level index for the stream.

The stream header list element: strn

This element contains a name for the stream. That stream name should only use plain ASCII, especially not UTF-8.

AVI Indexes

old style index

The index as described is the index you will find in AVI 1.0 files. It is placed after the movi List in the RIFF AVI List. The data section of the idx1 chunk has the following layout:

AVIINDEXENTRY index_entry[n]

typedef struct
{
DWORD ckid;
DWORD dwFlags;
DWORD dwChunkOffset;
DWORD dwChunkLength;
} AVIINDEXENTRY;

Those values have the following meaning:

• ckid
Specifies a four-character code corresponding to the chunk ID of a data chunk in the file.

• dwFlags
The following flags are defined:

- AVIIF_KEYFRAME: The chunk the entry refers to is a keyframe.
- AVIIF_LIST: The entry points to a list, not to a chunk.
- AVIIF_FIRSTPART: Indicates this chunk needs the frames following it to be used; it cannot stand alone.
- AVIIF_LASTPART: Indicates this chunk needs the frames preceding it to be used; it cannot stand alone.
- AVIIF_NOTIME: The duration which is applied to the corresponding chunk is 0.

If neither AVIIF_FIRSTPART nor AVIIF_LASTPART is set, the chunk can be used alone, in other words, it is at least one packet of the corresponding stream. This is important for storing VBR audio streams in AVI files.

• dwChunk
Offset Contains the position of the header of the corresponding Chunk.
Warning: This can be either the absolute position in the file, or the position relatively to the first byte of the 'movi' identificator. An AVI File parser must be able to handleboth versions.

• dwChunkLength
Contains the size of the corresponding chunk in bytes.

AVI File Format - Data Structures

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Basic data structures

There are 2 types of atoms in AVI files:

Chunks

typedef struct
{
DWORD dwFourCC
DWORD dwSize
BYTE data[dwSize] // contains headers or video/audio data
} CHUNK;

Lists

typedef struct
{
DWORD dwList
DWORD dwSize
DWORD dwFourCC
BYTE data[dwSize-4] // contains Lists and Chunks
} LIST;

A chunk containing video, audio or subtitle data uses a dwFourCC containing 2 hexadecimaldigits specifying the stream number and 2 letters specifying the data type (dc = video, wb= audio, tx = text). The values dwFourCC and dwSize have the same meaning in both ofthe structures:

dwFourCC describes the type of the chunk (for example 'hdrl' for 'header list'), and dwSizecontains the size of the chunk or list, including the rst byte after the dwSize value. In thecase of Lists, this includes the 4 bytes taken by dwFourCC!

The value of dwList can be 'RIFF' ('RIFF-List') or 'LIST' ('List').

AVI file types

Basicly, there are 3 types of AVI les:

• AVI 1.0 The original, old AVI le.

• Open-DML An extension to the AVI file format. Version 1.02 has been specified by28/02/1996. The most important improvements are:
- almost unlimited file size (much more than what NTFS allows, for example)
- overhead reduced by 33%

• Hybride-Files: Open-DML les that contain an additional Legacy Index for compat-ibility reasons. This is not an "official" word for those files, but it is describing thatfile type pretty well. Hybride files containing only one RIFF List can be treated aseither file type.

This document describes the subset of Open-DML 1.02 file format features, as well as some additions ('hacks'), which work in common players if the proper (freely available) filters are installed. Features that work in Open-DML, but not in AVI 1.0, will be indicated to be Open-DML only.

Layout of an AVI file

A RIFF-List where dwFourCC = 'AVI ' shall be called a 'RIFF-AVI-List', a RIFF-List where dwFourCC = 'AVIX' shall be called a 'RIFF-AVIX-List'.

Every AVI file has the following layout:

RIFF AVI // mandatory
{ RIFF AVIX } // only for Open-DML files

Unlike what a uint32 suggests, the limit for the size of those lists is not 4 GB, but

• for AVI 1.0: size(RIFF-AVI) < 2 GB
• for Open-DML:
- size(RIFF-AVI) < 1 GB (!!) (assumed to be 2 GB by some muxing applications, like VirtualDub!)
- size(RIFF-AVIX) < 2 GB

As Windows XP insists on reading the entire first RIFF AVI list if no Legacy Index (seepage 12) is found, and as that Legacy Index causes overhead, it is recommended to create RIFF-AVI-Lists as small as possible.

MainAVIHeader (avih)

This structure is defined as follows:

typedef struct
{
DWORD dwMicroSecPerFrame; // frame display rate (or 0)
DWORD dwMaxBytesPerSec; // max. transfer rate
DWORD dwPaddingGranularity; // pad to multiples of this// size;

DWORD dwFlags; // the ever-present flags
DWORD dwTotalFrames; // # frames in file
DWORD dwInitialFrames;
DWORD dwStreams;
DWORD dwSuggestedBufferSize;

DWORD dwWidth;
DWORD dwHeight;

DWORD dwReserved[4];

} MainAVIHeader;

Unfortunately, those values do NOT have the meaning they seem to have when looking at their names.

• dwMicroSecPerFrame
Contains the duration of one video frame in microseconds. This value can be ignored(see stream header), but shall be written correctly by any AVI writer. Important: Some broken programs, like AVI Frate, write the frame rate value in the stream header, but not dwMicroSecPerFrame. Thus, dwMicroSecPerFrame should not be considered reliable!

• dwMaxBytesPerSec
Highest occuring data rate within the file. That value is of no importance either. Itsreliability should not be overrated.

• dwPadding
Granularity File is padded to a multiple of this

• dwFlags
See below

• dwTotalFrames
Contains the number of video frames in the RIFF-AVI list (it should NOT containthe total number of frames in the entire file if there are RIFF-AVIX-Lists. Some tools claiming to handle AVI files even assume this, but it definitely violates the Open-DML file format specification. Such applications are broken.) As some AVI file muxers write bad values here, this value should not be considered reliable.

• dwInitialFrames
Ignore that

• dwStreams
Number of streams in the file

• dwSuggestedBufferSize
Size of buffer required to hold chunks of the file. The reliability of this value should not be overrated.

• dwWidth
Width of video stream

• dwHeight
Height of video stream

Available Flags for MainAVIHeader::dwFlags

• AVIF_HASINDEX
The file has an index9

• AVIF_MUSTUSEINDEX
The order in which the video and audio chunks must be replayed is determined by the index and may differ from the order in which those chunks occur in the file.

• AVIF_ISINTERLEAVED
The streams are properly interleaved into each other

• AVIF_WASCAPTUREFILE
The file was captured. The interleave might be weird.

• AVIF_COPYRIGHTED
Ignore it

• AVIF_TRUSTCKTYPE (Open-DML only!)
This flag indicates that the keyframe flags in the index are reliable. If this flag is not set in an Open-DML file, the keyframe flags could be defective without technically rendering the file invalid.

WAP Architecture - Part VII

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Conformance and Interoperability

The WAP Forum views vendor interoperability as an important element to the success of WAP products. In order toprovide as high a probability as is technically possible that two WAP products developed independently by twodifferent vendors will successfully interoperate, a rigorous definition of conformance, compliance, and testing has beendeveloped.

Conformance answers the question, “Does an implementation meet the standard as written?” The WAP Forum chartersa neutral third party to build a comprehensive test suite from its specifications. Usually, implementations are testedagainst known references.Interoperability answers the question, “Will this implementation work with other products developed to the samestandard?”

Interoperability testing uses a test suite designed to test implementation to implementation compatibility,and implementations are tested against each other. Interoperability testing is not focused on compliance—two productswith the same non-compliant implementation will be interoperable.

The WAP Forum Certification Program is focused on conformance, but offers some interoperability testing as well.The Certification Program covers the entire value chain as shown in Figure 13.

To improve interoperability at the authoring level, the WAP Forum provides authoring guidelines to improve theaccessibility of WAP content. To certify WAP clients and servers, the WAP Forum conducts interoperability testing ofan implementation against multiple reference implementations using a predefined suite of test cases.

The WAP Forum has defined a number of Class Conformance Profiles, e.g. Class A, Class B, and Class C. Animplementation may be certified in one or more class. The class conformance requirements are specified in[ClassConform].

Each WAP Specification includes static conformance requirements (SCRs) for that specification. These define whichfeatures are mandatory and optional and are the basis for the conformance test suite.

Reference : Wireless Application Protocol Forum, Ltd, 2000-2001