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Information about instruction in genetics was obtained fron 103 of the 107 U.S. four-year medical schools. Seventy-two percent of the schools provide a compulsory course in genetics, but there was great variation in duration, content, departmental responsibility for giving the course, and in the disciplines of those doing the teaching. The variability in the number of hours devoted to teaching genetics was reflected in the competence of the students in giving correct answers to questions on genetics posed by the National Board of Medical Examiners. Electives and continuing education courses on genetics are given by two-thirds and one-half of the schools, respectively; but the subject receives very little attention in departments of preventive, community, or family medicine or in schools of allied health sciences. These findings suggest that genetics has not yet found a natural and comfortable context in the curricula of U.S. medical schools.  相似文献   

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This study assessed potential human health risks posed by tributyltin in seafood purchased from U.S. seafood markets. In 1989 and 1990, samples of fish, bivalve molluscs and crustacea were purchased at local markets along the Atlantic, Gulf and Pacific coasts of the United States and along the Great Lakes (Lake Michigan). Samples were then analyzed for tributyltin, and the concentrations observed used to evaluate potential human health risks from consumption of market-bought seafood on the basis of available mammalian toxicology data. The assessment indicated health effects were unlikely from exposure to tributyltin in market-bought seafood during 1989 to 1990, shortly after peak tributyltin usage in antifoulant bottom paints on vessels in the United States.  相似文献   

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Social Transformation and Its Human Costs in the Prehispanic U.S. Southwest   总被引:1,自引:1,他引:0  
ABSTRACT  Change is inevitable, but some changes and transformations are more dramatic and fraught with suffering than others. Resilience theory suggests the concept of a "rigidity trap" as an explanation for these differences. In rigidity traps, a high degree of connectivity and the suppression of innovation prolong an increasingly rigid state, with the result that the eventual transformation is harsh. Three archaeological cases from the U.S. Southwest (Mimbres, Mesa Verde, and Hohokam) and new methods for assessing transformations and rigidity are used to evaluate this concept. They reveal the expected association between the severity of transformation and degree of rigidity, suggesting that a rigidity trap contributed to the Hohokam decline, which included significant human suffering. Possible causes of rigidity, with implications for today's world, are explored.  相似文献   

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Monitoring of ecological restorations has rarely focused on fungi. In this study, we conduct a first‐ever monitoring of macrofungi in ecological restorations of coastal Indiana (U.S.A.) and present an approach and considerations that can be followed elsewhere. Forty‐two sites were surveyed over a 2‐year period for the presence of saprotrophic, mycorrhizal, and parasitic macrofungi. Sites included those considered to be restoration, prerestoration, or reference and were in wooded, semiwooded, or grassland habitats. With 1,103 observations, 277 species of fungi were identified. Most fungi were found in wooded habitats though some were in grassland restorations. Invasive plant cover negatively impacted fungal species richness. Monitored sites were compared to a set of reference sites using two different similarity indices (overlap and Jaccard), as well as the ratios of different fungal functional guilds, revealing that choice of index can impact how restorations are perceived to match targets. Last, we present a novel, tractable, and conservative way to assess and rank sites by the functional trait guilds of fungi. We show that such an approach can provide important additional information about the success of restorations such that functional guild ratios could be used as an indicator of restoration progress early‐on while functional values are better used in later phases.  相似文献   

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Background

Foreign-born individuals comprise >50% of tuberculosis (TB) cases in the U.S. Since anti-TB drug resistance is more common in most other countries, when evaluating a foreign-born individual for TB, one must consider the risk of drug resistance. Naturally, clinicians query The Global Project on Anti-tuberculosis Drug Resistance Surveillance (Global DRS) which provides population-based data on the prevalence of anti-TB drug resistance in 127 countries starting in 1994. However, foreign-born persons in the U.S. are a biased sample of the population of their countries of origin, and Global DRS data may not accurately predict their risk of drug resistance. Since implementing drug resistance surveillance in 1993, the U.S. National TB Surveillance System (NTSS) has accumulated systematic data on over 130,000 foreign-born TB cases from more than 200 countries and territories. Our objective was to determine whether the prevalence of drug resistance among foreign-born TB cases correlates better with data from the Global DRS or with data on foreign-born TB cases in the NTSS.

Methods and Findings

We compared the prevalence of resistance to isoniazid and rifampin among foreign-born TB cases in the U.S., 2007–2009, with US NTSS data from 1993 to 2006 and with Global DRS data from 1994–2007 visually with scatterplots and statistically with correlation and linear regression analyses. Among foreign-born TB cases in the U.S., 2007–2009, the prevalence of isoniazid resistance and multidrug resistance (MDR, i.e. resistance to isoniazid and rifampin), correlated much better with 1993–2006 US surveillance data (isoniazid: r = 0.95, P<.001, MDR: r = 0.75, P<.001) than with Global DRS data, 1994–2007 (isoniazid: r = 0.55, P = .001; MDR: r = 0.50, P<.001).

Conclusion

Since 1993, the US NTSS has accumulated sufficient data on foreign-born TB cases to estimate the risk of drug resistance among such individuals better than data from the Global DRS.  相似文献   

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Biodiversity and Conservation - Mammalian carnivores are elusive and enigmatic species that often play keystone roles in ecosystems through direct and indirect effects. Growing evidence shows that...  相似文献   

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Unesco and U.S     
F Mayor 《FASEB journal》1990,4(13):3061-3062
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An established ethical principle of biomedical research involving human subjects stipulates that risk to subjects should be proportionate to an experiment's potential benefits. Sometimes this principle is imprecisely stated as a requirement that 'risks and benefits' be balanced. First, it is noted why this language is imprecise. Second, the persistence of such language is attributed to how it functions as a rhetorical trope. Finally, an argument is made that such a trope is infelicitous because it may not achieve its intended persuasive purposes. More importantly, it should be avoided because it masks the important role that chance plays in clinical research. Risk is the possibility of harm. As a precondition of harm it is unintended and undesirable in projects of biomedical research. It requires ethical vigilance. As a vehicle of chance, however, it is both intended and desirable. It requires methodological appreciation.  相似文献   

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《CMAJ》1960,83(3):128
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《CMAJ》1963,88(7):374
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