Web bug

A Web bug is an object that is embedded in a web page or e-mail and is usually invisible to the user but allows checking that a user has viewed the page or e-mail. One common use is in e-mail tracking. Alternative names are Web beacon, tracking bug, tracking pixel, pixel tag, 1×1 gif, and clear gif.

A Web bug is any one of a number of techniques used to track who is reading a Web page or e-mail, when, and from what computer. They can also be used to see if an e-mail was read or forwarded to someone else, or if a Web page was copied to another Website. The first Web bugs were small images.

Some e-mails and Web pages are not wholly self-contained. They may refer to content on another server, rather than including the content directly. When an e-mail client or web browser prepares such an e-mail or Web page for display, it ordinarily sends a request to the server to send the additional content.

These requests typically include the IP address of the requesting computer, the time the content was requested, the type of Web browser that made the request, and the existence of cookies previously set by that server. The server can store all of this information, and associate it with a unique tracking token attached to the content request.

E-mail Web bugs

Web bugs embedded in e-mails have greater privacy implications than bugs embedded in Web pages. Typically, the URL of Web bugs contained in e-mail messages carry a unique identifier. This identifier is chosen when the e-mail is sent, and is recorded together with the recipient e-mail address. The later download of the URL signals that the e-mail has been read. The sender of the e-mail is therefore also able to record the exact time that a message was read, as well as the IP address of the computer used to read the mail or the proxy server that the user went through. In this way, the sender can gather detailed information about when, and from where, each particular recipient reads e-mail. Additionally, every time the e-mail message is displayed, another request may go to the sender's Web site.

Web bugs are used by e-mail marketers, spammers, and phishers to verify that e-mail addresses are valid, that the content of e-mails has made it past the spam filters, and that the e-mail is actually viewed by users. When the user reads the e-mail, the e-mail client requests the image, letting the sender know that the e-mail address is valid and that e-mail was viewed. The e-mail need not contain an advertisement or anything else related to the commercial activity of the sender. This makes detection of such e-mails harder for mail filters and users.

Tracking via Web bugs can be prevented by using e-mail clients that do not download images whose URLs are embedded in HTML e-mails. Many graphical e-mail clients can be configured to avoid accessing remote images. Examples include the Gmail, Yahoo!, and SpamCop/Horde webmail clients; Mozilla Thunderbird, Opera, Pegasus Mail, IncrediMail, later versions of Microsoft Outlook, and KMail mail readers. Other HTML techniques (such as IFrames) can still be used to track e-mail viewing.

Wide Area Information Servers

Wide Area Information Servers or WAIS is a client-server text searching system that uses the ANSI Standard Z39.50 Information Retrieval Service Definition and Protocol Specifications for Library Application (Z39.50:1988) to search index databases on remote computers. It was developed in the late 1980s as a project of Thinking Machines, Apple Computer, Dow Jones, and KPMG Peat Marwick.

WAIS did not adhere to either the standard or its OSI framework (adopting instead TCP/IP) but created a unique protocol inspired by Z39.50:1988.

The WAIS protocol and servers were primarily promoted by Thinking Machines Corporation of Cambridge, Massachusetts. Thinking Machines produced WAIS servers which ran on their massively parallel CM-2 (connection machine) and SPARC-based CM-5 MP supercomputers. WAIS clients were developed for various operating systems including Windows, Macintosh, NeXT and UNIX. TMC, however, released a free open source version of WAIS to run on Unix in 1991.

Inspired by the WAIS project on full text databases and emerging SGML projects Z39.50 version 2 or Z39.50:1992 was released. Unlike its 1988 predecessor it was a compatible superset of the ISO 10162/10163 work that had been done internationally.

With the advent of Z39.50:1992, the termination of support for the free WAIS from Thinking Machines and the establishment of WAIS Inc as a commercial venture (their WAIS was written to use the Fulcrum fulltext engine), the U.S. National Science Foundation funded CNIDR to create a clearinghouse of information related to Internet search and discovery systems and to promote open source and standards. CNIDR created a new freely available open-source WAIS. This created first the freeWAIS package based on the wais-8-b5 codebase implemented by Thinking Machines Corp and then a wholly new software suite Isite based upon Z39.50:1992 with Isearch as its full text search engine.

Ulrich Pfeifer and Norbert Gövert of the computer science department of the University of Dortmund took the CNIDR freeWAIS code and extended it to become freeWAIS-sf: sf means structured fields and indicated its main improvement. Ulrich Pfeifer rewrote freeWAIS-sf in Perl where it became WAIT.

Server Message Block

In computer networking, Server Message Block (SMB) operates as an application-layer network protocol mainly used to provide shared access to files, printers, serial ports, and miscellaneous communications between nodes on a network. It also provides an authenticated Inter-process communication mechanism. Most usage of SMB involves computers running Microsoft Windows, where it is often known as "Microsoft Windows Network".

When discussing SMB, one should distinguish:

* the SMB protocol
* the SMB services that run on the protocol
* NetBIOS
* the DCE/RPC services that use SMB as an authenticated Inter-process communication channel (over named pipes)
* the "Network Neighborhood" protocols which primarily (but not exclusively) run as datagram services directly on the NetBIOS transport

Smokeless Tobacco

Many people who chew tobacco or dip snuff think it's safer than smoking. But you don't have to smoke tobacco for it to be dangerous. Chewing or dipping carries risks like

* Cancer of the mouth
* Decay of exposed tooth roots
* Pulling away of the gums from the teeth
* White patches or red sores in the mouth that can turn to cancer

Recent research shows the dangers of smokeless tobacco may go beyond the mouth. It might also play a role in other cancers, heart disease and stroke.

Smokeless tobacco contains more nicotine than cigarettes. Nicotine is a highly additive drug that makes it hard to stop using tobacco once you start. Having a quit date and a quitting plan can help you stop successfully.

Contact Lens-improve defective vision

Contact Lenses are simple to wear and care for, and are almost undetectable. They are thin discs of plastic, curved on the inside to fit properly onto the surface of the eye, and shaped on the outside to correct and improve defective vision, for bandaging the eye after surgery, and cosmetic benefits e.g. to cover white scarring of the eye or to change the colour of the eye for fashion. With advancing technology Contact Lenses can correct all forms of visual defects including Astigmatism safely and comfortably. There are basically two types of contact lenses : Rigid and Soft. Both types come in varying materials with different levels of oxygen permeabilities. The higher the oxygen permeability the better it is for the eye.

Rubella-lu-like symptoms

Rubella is an illness with flu-like symptoms followed by a rash. Common symptoms include

* Low-grade fever
* Headache
* Runny nose
* Red eyes
* Muscle or joint pain

Rubella is usually mild. You may get it and not even know it. However, adults who get rubella often feel sicker than children do. The biggest danger of rubella is if a woman gets it during the first 20 weeks of pregnancy. She may lose the baby, or the virus could cause problems to her unborn baby. Those problems could include cataracts, deafness or damage to the heart or brain.

A virus causes rubella. It can spread from one person to another through the air or through close contact with someone who has it. There is no treatment for rubella, but the measles-mumps-rubella (MMR) vaccine can prevent it.

Campus area network (CAN)

A campus area network (CAN) is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting.

In the case of a university campus-based campus area network, the network is likely to link a variety of campus buildings including; academic departments, the university library and student residence halls. A campus area network is larger than a local area network but smaller than a wide area network (WAN).

The main aim of a campus area network is to facilitate students accessing internet and university resources. This is a network that connects two or more LANs but that is limited to a specific and contiguous geographical area such as a college campus, industrial complex, office building, or a military base.