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1.
Understanding potential for range expansion is critical when evaluating the risk posed by invasive species. Burmese pythons (Python molurus bivittatus) are established in southern Florida and pose a significant threat to native ecosystems. Recent studies indicate that climate suitable for the species P. molurus exists throughout much of the southern United States. We examined survivorship, thermal biology, and behavior of Burmese pythons from South Florida in a semi-natural enclosure in South Carolina, where winters are appreciably cooler than in Florida, but within the predicted region of suitable climate. All pythons acclimated to the enclosure, but most died after failing to seek appropriate refugia during sub-freezing weather. The remaining snakes used refugia but died during an unusually cold period in January 2010. Although all snakes died during the study, most survived extended periods at temperatures below those typical of southern Florida and none exhibited obvious signs of disease. Our study represents a first step in evaluating the results of climate matching models and we address factors that may affect range expansion in this invasive species.  相似文献   

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Since the 1969 North Sea Continental Shelf cases, natural prolongation has been a semisacred expression that characterizes the continental shelf. This article examines whether this notion is still viable. A comparative study of its current use in the U.N. Convention on the Law of the Sea against its original use reveals misunderstandings in three key aspects: entitlement, delineation, and delimitation of the continental shelf. This article concludes that natural prolongation no longer constitutes a pivot in the legal understanding of the continental shelf.  相似文献   

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Journal of Ichthyology - A bottom trawl survey was conducted in August and September 2018 at the outer edge of the continental shelf and the upper part of the Pacific slope of the northern Kuril...  相似文献   

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Currently an estimated two million tissues are distributed for transplantation annually. With increasing use of recovered tissue, clusters of transplant-transmitted infection have shown the difficulty of tracking tissues from an infected donor to the recipient. The challenge of tissue tracking to multiple transplant recipients was illustrated in a recent investigation of transmission of hepatitis C virus infection from a donor of organs and tissues. When a tissue bank issued a recall of the donated tissue, the Centers for Disease Control and Prevention was notified to assist public health authorities; the mean time to locate and notify the physicians who had transplanted the tissue was 13 days, while the mean time to notify, inform, and test the patients was 29 days. Lack of common coding and nomenclature was one of the key challenges in tracking tissue to the recipient. Some changes that could improve timeliness in the event of a recall includes: (1) standardized tissue nomenclature and coding through unique donor identifiers; (2) tissue traceability requirements using systems similar to that used for blood products; (3) a surveillance system for adverse events that provides feedback at the provider level.  相似文献   

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Previous research has demonstrated that U.S. no-fault divorce laws implemented between 1953 and 1987 resulted in more divorces in some states than would have occurred otherwise. In other states, divorce patterns appeared to follow prevailing trends even after implementation of no-fault divorce legislation. A more distal question is whether implementation of no-fault divorce laws had an effect on birth rates. We analyzed state-level birth data from all 50 states to assess the birth response to the enactment of no-fault divorce law in each state. Results suggested that birth rates decreased significantly two to four years following the enactment of no-fault divorce law for the group of 34 states whose divorce rates responded to no-fault divorce legislation. As predicted, among the 16 states whose divorce rates did not respond to no-fault divorce legislation, the enactment of no-fault divorce law had a small and nonsignificant positive influence on birth rates. Generally, the group of 34 states had lower post no-fault birth rates than the group of 16 states.  相似文献   

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The incidence for AIDS per hundred thousand is several times higher in the United States than in the rest of the First World. Earlier work by Thompson (1984, 1989a, b, 1990, 1998) indicated that a relatively small proportion of gay males frequenting the bathhouses in the United States, drove AIDS over the epidemiological threshold in the U.S. It is shown that the rate of growth of AIDS is essentially the same for the United States and other First-World countries. An argument is advanced, based on WHO AIDS data, to the effect that it is contact with the pool of infectives in the United States that drives the epidemic in other First-World Countries.  相似文献   

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For decades, Ottawa and Washington have been agreeing to disagree on the question of the legal status of the Northwest Passage. One argument which has been consistently raised on the U.S. side and which has precluded attempts to end the deadlock has been the fear of creating a negative precedent. This article assesses whether U.S. concerns are warranted: could coastal States elsewhere in the world rely on an eventual recognition of Canadian sovereignty over the Northwest Passage to bolster their claims over a local strait?  相似文献   

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Objective To assess whether UK and US health care professionals share the views of medical ethicists about medical futility, withdrawing or withholding treatment, ordinary or extraordinary interventions, and the doctrine of double effect. Design, subjects, and setting Answers to a 138-item attitudinal questionnaire completed by 469 UK nurses studying the Open University course on “Death and Dying” were compared with those of a similar questionnaire administered to 759 US nurses and 687 US physicians taking the Hastings Center course on “Decisions Near the End of Life.” Results Practitioners accept the relevance of concepts widely disparaged by bioethicists: double effect, medical futility, and the distinctions between heroic and ordinary interventions and withholding and withdrawing treatment. Within the UK nurses'' group, the responses of a “rationalist” axis of respondents who describe themselves as having “no religion” are closer to the bioethics consensus on withholding and withdrawing treatment. Conclusions Professionals'' beliefs differ substantially from the recommendations of their professional bodies and from majority opinion in bioethics. Bioethicists should be cautious about assuming that their opinions will be readily accepted by practitioners.  相似文献   

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《Biomass》1987,12(1):27-36
The use of wood for energy — including the burning of solid wood and black liquor from pulping — has been growing at a rate significantly greater than that for all other uses such as lumber, pulp, or particleboard. In the United States, the end of most wood is not lumber or pulp and paper but feed for energy. In 1983, 155·5 M Mg of wood were used for energy. This could threaten to increase the price of wood for those other uses, or it can stimulate us to seek more creative ways of using untapped wood resources for fuel.On the basis of estimates of heavy wood energy use relative to other uses for wood, and estimates of continuing high costs for fossil fuels, we suggest here the feasibility of meeting the demand for fuelwood through small-scale cooperatives. Such an approach can improve forestry practices and can avoid unduly increasing the cost of wood for other end uses.  相似文献   

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The dramatic growth of research and development activities in the pharmaceutical sector in emerging economies raises the question of whether the United States still keeps its dominant role in the global pharmaceutical innovation landscape. This paper focuses on investigating the role of the United States in global pharmaceutical innovation, and differs from previous studies by shifting attention to a network analytic perspective to track the global distribution of pharmaceutical inventions. Our sample is composed of key patents covering all new drugs approved by the Food and Drug Administration between 1996 and 2010. The results show that the United States still dominates in the global pharmaceutical innovation network, especially when it comes to essential core inventions. However, the United States shows a slightly decreasing prominence in the networks of either total new drugs or New Molecular Entity (NME) drugs in the time period 2006–2010 as compared to previous time periods, revealed by subtle traces of network centralities.  相似文献   

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Abstract

The coastal state has jurisdiction over the resources located in the seas and seabed adjacent to its coast. In federal states the question has arisen as to whether the rights in those resources are to be held by the national government or by the subsidiary territorial governments. It has been the focus of political activity and court litigation in the United States and Canada. This paper reviews in detail the status of the offshore claims of the states of the United States and the provinces of Canada. In delimiting these boundaries two systems of law have become relevant—modern public international law and historic common law. Both systems of law have advantages and disadvantages for the courts and interested parties. While the United States has chosen a route that relies very heavily on modern public international law, the Canadian situation is less clear. Litigation now in progress may resolve this issue in Canada by court decree unless a political settlement is reached first. A recent agreement between the Federal Government of Canada and the Gov eminent of Nova Scotia which calls for joint management and revenue sharing may point the way toward such a settlement.  相似文献   

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Wildfires are becoming larger and more frequent across much of the United States due to anthropogenic climate change. No studies, however, have assessed fire prevalence in lake watersheds at broad spatial and temporal scales, and thus it is unknown whether wildfires threaten lakes and reservoirs (hereafter, lakes) of the United States. We show that fire activity has increased in lake watersheds across the continental United States from 1984 to 2015, particularly since 2005. Lakes have experienced the greatest fire activity in the western United States, Southern Great Plains, and Florida. Despite over 30 years of increasing fire exposure, fire effects on fresh waters have not been well studied; previous research has generally focused on streams, and most of the limited lake‐fire research has been conducted in boreal landscapes. We therefore propose a conceptual model of how fire may influence the physical, chemical, and biological properties of lake ecosystems by synthesizing the best available science from terrestrial, aquatic, fire, and landscape ecology. This model also highlights emerging research priorities and provides a starting point to help land and lake managers anticipate potential effects of fire on ecosystem services provided by fresh waters and their watersheds.  相似文献   

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