Thursday, September 16, 2010

What Is Internet and the World Wide Web?

There is little historical precedent for the swift and dramatic growth of the Internet, which was originally a limited scientific communication network developed by the U.S. government to facilitate cooperation among federal researchers and the university research community. With its rapid adoption by the private sector, the Internet has remained an important research tool, and it is also becoming a vital ingredient in maintaining and increasing the scientific and commercial leadership of the United States. In the twenty-first century, the Internet will provide a powerful and versatile environment for business, education, culture, entertainment, health care and public health. Sight, sound, and even touch will be integrated through powerful computers, displays, and networks. People will use this environment to work, study, bank, shop, entertain, visit with each other, and communicate with their health care providers. Whether at the office, at home, or traveling, the environment and its interface will be largely the same, and security, reliability, and privacy will be built in. Benefits of this dramatically different environment will include a more agile economy, improved health care (particularly in rural areas), less stress on ecosystems, easy access to lifelong and distance learning, a greater choice of places to live and work, and more opportunities to participate in the community, the nation, and the world.

Internet and WWW Acronyms. People that communicate with each other electronically may not have the same "platform." "Cross-platform" means that people do not have to use the same kind of operating system to access files on a remote system. In order to access the Web there are two basic mechanisms: (1) using the telephone system to link to another computer or network that is connected to the Internet, and (2) connecting to a network; and from there into the Internet. An Internet service provider (ISP) may be required to access the Internet. An important factor regarding Internet access is bandwidth, which determines how much data a connection can accommodate and the speed at which data can be accessed.
Information on the Web is generally written in Hypertext Markup Language (HTML), which is a text-based markup language that describes the structure of a Web document's content and some of its properties. It can also be viewed as a way of representing text and linking it to other resources, such as multimedia files, graphic files, still or dynamic images files, and sound files. HTML contains the information or text to be displayed and the control needed for its display or playback.
Navigation Tools. Prior to the use of Web browsers, there were several Internet navigation tools that required more user expertise than the modern browser, including:
  • File Transfer Protocol (FTP), a cross-platform protocol for transferring files to and from computers anywhere on the Internet.
  • Gopher, a tool for browsing files on the Internet.
  • Usenet, a worldwide messaging system through which anyone can read and post articles to a group of individuals who share the same interests.
  • Wide Area Information Server (WAIS), one of a handful of Internet search tools that can be spread across the network to scour multiple archives and handle multiple data formats.
  • Hyperlink (also called link), a pointer— from text, from a picture or a graphic, or from an image map—to a page or file on the World Wide Web; hyperlinks are the primary way to navigate between Web pages and among Web sites.
Today, a Web browser is the main piece of software required by the end user to find information through Internet. Some of the most popular browsers are: Lynx, Mosaic, Netscape Navigator/Communicator, and Internet Explorer. Lynx is a text-only Web browser; it cannot display graphical or multimedia elements. Mosaic, a graphical Web browser, was the first "full-featured" graphical browser for the Web. It was developed by a team of programmers at the National Center for Supercomputing Applications (NCSA). One of these programmers, Marc Andreesen, later formed Netscape. Netscape Navigator/Communicator is one of the most popular Web browsers. Internet Explorer is Microsoft's Web browser.
Web Resources. A Uniform Resource Locator (URL) is a Web resource that describes the protocols needed to access a particular resource or site on the Web, and then point to the resource's Internet location. URLs are, in short, used to locate information on the Web.
Normally the URL is composed of six parts:
  1. The protocol or data source (i.e., ftp://, gopher://, news://, telnet://, WAIS://, http://)
  2. The domain name (for the Web server where the desired information resides)
  3. The port address
  4. The directory path (location of the Web page in the Web server's file system)
  5. The object name
  6. The spot (precise location within the file)
Protocols are the rules and formats that govern the methods by which computers communicate over a network. Protocols link clients and servers together and handle requests and responses, including making a connection, making a request, and the closing of the connection. Transmission Control Protocol/Internet Protocol (TCP/IP) is the full set of standard protocols used on the Internet. Hypertext Transfer Protocol (HTTP) is an Internet protocol specifically for the World Wide Web. It provides a way for Web clients and servers to communicate primarily through the exchange of messages.
Multipurpose Internet Mail Extension (MIME) is a technique designed to insert attachments within individual e-mail files. MIME allows a Web server to deliver multiple forms of data to the user in a single transfer. Also, when creating a Web page, it could include text files as well as nontext files, such as sound, graphics, still images, and videos.
Intersection and Information Technology and Public Health. The applications of IT in public health are numerous and varied. One particularly important example, however, is the use of Geographical Information Systems (GIS). Using GIS, public health officials can create very effective procedures to do their tasks using information technology. Doing a feedback loop they can: measure, plan, act, and measure again. In this manner, officials can identify a problem (e.g., cancer) by measuring data from a registry. Further, from the health care providers community, they can select a target population (e.g., breast cancer) and develop an implementation strategy for an intervention plan with the health care providers. Finally, by measuring again, GIS allows public health officials to evaluate the impact of the implementation plan on that data registry.
GIS is thus an information technology which can help improve health care and public health in many areas such as disease tracking, outbreak investigations, geostatistical analysis, and routing of health workers. As a means of tracking, residential zip codes of patients who appear at different clinics can be plotted with signs and symptoms of a selected diagnosis (e.g., upper respiratory infections [URI]). URIs are a marker for some toxic biological agents. Furthermore, community outbreaks of infectious diseases such as measles can be quickly analyzed then using GIS tools. Color shading can indicate areas with certain levels of morbidity probability or likeliness of getting sick. Areas that require immediate interventions such as immunizations can be depicted by a different shade. Geostatistical analysis is one of the most powerful tools available to a public health department. With a relatively small number of sampling points, predictive maps can be quickly produced to provide the likely extent of threats to public health. This mode of forecasting allows for the effective and efficient allocation of health care resources in a community.
GIS can also help create disease focused databases representing patients from a specific userdefined geographic area. In this fashion, the impact of a toxic release or exposure against a target population can be measured. GIS is a powerful tool for supplying immediate visualization of the likely geographic exposures, allows an analyst to examine the various variables that might effect the "fallout" of sprayings and to estimate its extent. Through the use of Computer Aided Design tools and GIS, medical centers as well as clinics are increasingly monitoring their patient care environments to assist managers evaluate risk for highly contagious diseases and implement control and isolation programs.
GIS helps health organizations visualizing diagnostic and geographic information simultaneously and dynamically. Over 14,000 ICD 9 and 10 codes describe medical diagnosis, treatment, and medical events worldwide. Public health clinics, hospitals, managed care, and health insurers use this application to conduct data mining on very large clinical and administrative data warehouses.
In public health education, GIS can be an analytical tool of choice for health promotions staff when deciding where to target the public health messages and warnings. GIS is also used to create interactive maps for health organizations required to publish information to the public. Health organizations require interactive maps depicting geographical areas and regions where infectious diseases and threats to the public's health are imminent.

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