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Smallpox (variola) was a devastating disease with a high case-fatality rate. Although the disease was eradicated in 1977, the remaining stocks of smallpox virus constitute one of the most dangerous threats to humanity. The smallpox virus is highly specific for humans and non-pathogenic in animals. There is no antiviral treatment and a vaccine is active only if administered in the first four days post-exposure. Smallpox virus represents a potential biological weapon that could be used by terrorists, and the destruction of stocks raises political, social, scientific and ethical issues.  相似文献   

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Social and economic changes-the lengthening life span, the shift of population from rural to urban areas, the growth of industry and other factors-have brought about radical changes in the nation's health needs. Our greatest health problem today is chronic illness. To cope with these problems public health, medical care and hospital services, which are at present geared primarily for acute illness, must be revised. IMMEDIATE AND SPECIFIC STEPS WHICH PHYSICIANS, HEALTH DEPARTMENTS AND HOSPITALS CAN TAKE TO ACCOMPLISH THIS ARE TO DEFINE THE PROBLEM AND TO INITIATE STUDIES IN SEVERAL AREAS: To determine the incidence and prevalence of disease, injuries and impairments; the nature, degree and duration of resulting disability; and the type of care received. The basic approach to chronic illness is prevention. To accomplish this, more emphasis needs to be placed upon health education. Good health cannot be forced upon the public, but educated and enlightened citizens can and do solve their own health problems and those of their families and communities. Due to the complex nature of today's health problems, they must be approached jointly by physicians, local health services, hospitals and the public. The efforts of those groups must be coordinated and aimed, directly and indirectly, at preventing disease and disability.  相似文献   

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Recent advances in molecular genetics and phylogenetic reconstruction have the potential to transform ecology by providing new insights into the historical evolution of ecological communities. This study by Stevens and collaborators complements decades of previous research on desert rodents, by combining data from a field study and a phylogenetic tree for Mojave Desert rodents to address patterns and processes of community assembly. The number of coexisting rodent species is positively correlated, and the average phylogenetic distance among these species is negatively correlated with perennial plant species richness. As rodent species diversity increases along a gradient of increasing environmental heterogeneity, communities are composed of increasingly related species: there is a consistent pattern of phylogenetic structure from over-dispersed through random to clumped. I discuss this pattern in the light of complementary results of previous studies. This paper is noteworthy for calling attention to still unanswered questions about how the historical events of speciation, colonization, extinction, and trait evolution and their relationship to past climates and vegetation have given rise to current patterns of community organization.  相似文献   

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It has been found in fifteen rats with monopolar electrodes implanted in the lateral hypothalamus that after stimulation of the brain with bursts of electrical pulses of fixed duration, with definite combinations of stimulation parameters, the histograms of the duration of pedal pressing have a polymodal appearance. As the combinations of stimulation parameters change, the number, position and magnitude of the modes undergo a corresponding change. With unchanged parameters of stimulation the form of pressing duration histogram does not change significantly. A conclusion has been drawn that the modal duration of pressing in the course of self-stimulation is apparently an effector manifestation of central integration of reinforcing excitation. In a state of hunger and thirst as well as under weak nembutal anaesthesia, the previously monomodal histograms of the pressing durations produce additional modes which diminish and disappear after satiation and discontinuation of the nembutal effect. It is assumed that at least some modes of the histograms of the pressing duration of self-stimulation may reflect an activation of the systems of biological needs.  相似文献   

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Xiao  Yunhua  Liu  Xueduan  Meng  Delong  Tao  Jiemeng  Gu  Yabing  Yin  Huaqun  Li  Juan 《Applied microbiology and biotechnology》2018,102(5):2399-2412
Applied Microbiology and Biotechnology - Bacterial wilt, caused by Ralstonia solanacearum, occurs occasionally during tobacco planting and potentially brings huge economic losses in affected areas....  相似文献   

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New microbial communities often arise through the mixing of two or more separately assembled parent communities, a phenomenon that has been termed “community coalescence”. Understanding how the interaction structures of complex parent communities determine the outcomes of coalescence events is an important challenge. While recent work has begun to elucidate the role of competition in coalescence, that of cooperation, a key interaction type commonly seen in microbial communities, is still largely unknown. Here, using a general consumer-resource model, we study the combined effects of competitive and cooperative interactions on the outcomes of coalescence events. To do so, we simulate coalescence events between pairs of communities with different degrees of competition for shared carbon resources and cooperation through cross-feeding on leaked metabolic by-products (facilitation). We also study how structural and functional properties of post-coalescence communities evolve when they are subjected to repeated coalescence events. We find that in coalescence events, the less competitive and more cooperative parent communities contribute a higher proportion of species to the new community because of their superior ability to deplete resources and resist invasions. Consequently, when a community is subjected to repeated coalescence events, it gradually evolves towards being less competitive and more cooperative, as well as more speciose, robust and efficient in resource use. Encounters between microbial communities are becoming increasingly frequent as a result of anthropogenic environmental change, and there is great interest in how the coalescence of microbial communities affects environmental and human health. Our study provides new insights into the mechanisms behind microbial community coalescence, and a framework to predict outcomes based on the interaction structures of parent communities.  相似文献   

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The extensive devastation resulting from excessive ingestion of alcoholic beverages is not widely recognized. Brief statistics indicate the extent of alcoholic beverage production and consumption, of the consumer outlay for products, and of losses in wages and the cost of increased illness incident to excessive drinking. Also indicated are the cost of law enforcement requirements coincident with drunkenness, and the factor of drinking in accidents and charitable care. Some of the sociologic and economic effects are recognized by agencies involved in the problem of alcoholism, but the extensive involvement of the personality of the addict and of his family and associates, the most devastating effect of all, is inestimable. Coordination of reorganized facilities is necessary to improve the situation. As the entire problem basically involves the personality, psychiatric principles need to be applied by means of studied recommendations and advice to coordinated groups making efforts to meet this extensive problem and to assist the alcoholic addict.  相似文献   

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The importance of selecting optimal yeast strains for research or industrial applications is often underestimated. For example, utilizing a strain background that already provides the desired stress tolerance or nutrient utilization profile can eliminate costly strain optimization. Yeast culture collections can provide not only the yeast strains but also data and curator expertise to help narrow the search for the optimal strain. While some collections are known for a broad range of cultures and services, other "boutique" collections can provide a broader selection of strains of certain categories, a surprising amount of characterization data, and assistance in selecting strains. This article provides information on dozens of yeast collections of the world, profiles of selected yeast culture collections, and the services that they provide: e.g., strain preservation for patent or safe deposit purposes, species identification service, training workshops, and consulting on yeast identification and physiology. Utilization of these services can save industrial researchers valuable time and resources.  相似文献   

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A bioterrorism attack could overwhelm medical personnel and facilities, suggesting a need for aid from nonmedical personnel. The American Dental Association suggests that dental professionals should assist in such cases, utilizing their strong scientific and technical skills. This study describes New England dental professionals' willingness, potential roles, motivators, and barriers to providing this aid. This cross-sectional study used a self-administered survey to collect data addressing the knowledge and opinions of dental professionals concerning acting as responders. The survey was distributed to 370 attendees of the 2005 Yankee Dental Conference, in Boston, Massachusetts. Most dental professionals expressed willingness to help during an attack (N = 340, 92%), reporting that dental professionals, in general, should perform a mean number of 6 roles. Three-quarters of dentists and dental students were personally willing, with proper training, to give immunizations, and 54% would perform triage. Knowledge was weak, but most dental professionals were interested in obtaining further education (83%). Since dental professionals are willing to assist during a bioterrorism attack and are motivated to obtain disaster response training, government officials and local directors and managers of disaster/emergency response agencies should consider incorporating dental professionals into their disaster management plans.  相似文献   

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