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The identification of disease-related genes has led to an increase in the number of available genetic tests that detect disease or an individual's risk of disease. New tests arc being developed to detect colon cancer, breast cancer, and other conditions. Scientists are concerned not only that gene tests offered are reliable, but also that patients and health care professionals understand the limitations of such testing. The disclosure of test results could inflict psychological harm to a patient if safe and effective interventions are not also available.
Gene testing involves examining a person's DNA-taken from cells "in a sample of blood or, occasionally, from other body fluids or tissues—for some anomaly that flags a disease or disorder. In addition to studying genes, genetic testing in a broader sense includes biochemical tests for the presence or absence of key proteins that signal aberrant genes.
The most widespread type of genetic testing is newborn screening. Each year in the United States, four million newborn infants have blood samples tested for abnormal or missing gene products. Some tests look for abnormal arrangements of the chemical bases in the gene itself, while other tests detect inborn errors by verifying the absence of a protein that the cell needs to function normally. Carrier testing can be used to help couples to learn if they carry—and thus risk passing to their children. Genetic tests—biochemical and DNA-based—also are widely available for the prenatal diagnosis of conditions such as Down syndrome.
Much of the current excitement in gene testing centers on predictive gene testing: tests that identify people who are at risk of getting a disease, before any symptoms appear. Tests are already available in research programs for some two dozen diseases, and as more disease genes are discovered, more gene tests can be expected.
Tests for a few rare cancers are already in clinical use. Predictive gene tests for more common types of cancer are still primarily a research tool, difficult to execute and available only through research programs to small numbers of people who have a strong family history of disease. But the field of gene testing is evolving rapidly, with new genes being discovered almost daily and innovations in testing arriving almost as quickly.
Scientists argue that the genetic testing is not perfect partly because______.
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Which of the following statements is true in the eyes of the writer？
Conventional television broadcasting within the United States centres around free enterprise and public ownership. This requires funding by commercial sponsors, and thus functions in a revenue-producing business manner. Television in USSR-subjected areas, conversely, is a government-owned and maintained arrangement. While such arrangements eliminate the need for commercial sponsorship, it also has the possibility of limiting the type of programs available to viewers (a number of purely entertainment programs similar to the classic "Bewitched", however, have been seen on these government -controlled networks. All isn't as gray and dismal as the uninformed might unnecessarily visualize). A highly modified form. of television called Slow-Scan TV is presently being used by many Amateur Radio operators to provide direct visual communications with almost any area of the world. This unique visual mode recently allowed people on the tiny South Pacific country of Pitcairn Island to view, for the first time in their lives, distant areas and people of the world. The chief radio Amateur and communications officer of Pitcairn, incidentally, is the legendary Tom Christian-great, great grandson of Tom Christian of "Mutiny on the Bounty" fame. Radio Amateurs in many lands worked together for several months establishing visual capabilities. The results have proven spectacular, yet the visual capabilities have only been used for health education, or welfare purposes. Commercial TV is still unknown to natives of that tiny country. Numerous other forms of television and visual communication, have also been used on a semi-restricted basis. This indicates the many untapped areas of video and television which may soon be exploited on a more widespread basis. The old clich of a picture being worth a thousand words truly has merit.
According to the passage, applications of television are easily accepted in______.
The view (which) elements of a culture are to be understood and judged (in terms of) their relationship to (the culture as a whole) led to the conclusion that the cultures themselves could not be (evaluated or graded as) higher and lower, superior or
The prevailing wind is the wind direction most often observed during a given time period.
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