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1.
Abstract

The Pacific region is the most important producer of tropical tuna in the world. Three subregions account for the production: Pacific Latin America, the Pacific Islands region, and Southeast Asia. Prior to the UN Third Conference on the Law of the Sea, the Tuna Fisheries in the subregions were the preserve of developed distant water fishing nations. The situation has now been entirely reversed, with coastal state jurisdiction and control being realized in all three subregions. It is argued that American opposition to coastal state jurisdiction over tuna resources acted as a goad to the coastal states in Pacific Latin America and the Pacific Islands region in their quest for greater control over tuna resources. There are prospects of cooperation developing among the three Pacific subregional tuna producers. It is argued further that American action may have inadvertently accelerated the progress toward cooperation.  相似文献   

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Dendrochronology, the science of tree‐ring dating, is the most accurate and precise nondocumentary dating method available to researchers studying the recent past. Tree‐ring dates are accurate and precise to the year and sometimes the season, and have no associated statistical uncertainty or standard error. Other prominent archeological dating techniques that use natural materials (for example, radiocarbon and archeomagnetism) have been calibrated using dendrochronological samples. 1 It is this precision and accuracy that has allowed archeologists working in the southwestern United States to construct the most detailed chronologies in the world, and to explore a plethora of environmental, social, and behavioral questions regarding past human adaptation to the region.  相似文献   

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Abstract

Extension of zones of national jurisdiction under UNCLOS III has increased maritime contiguity among Bangladesh, India, Pakistan, and Sri Lanka. It raises possibilities of conflict on boundary delimitation, transnational stocks and pollution and also presents opportunities for joint efforts in the exploration and exploitation of marine resources.  相似文献   

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The oils of dill, lemon-grass, tansy, wormseed and wormwood are distilled from cultivated plants; those of cedarleaf, cedarwood, erigeron, pennyroyal, sassafras, sweet birch, wintergreen and witch-hazel from wild plants; and together they all constitute a minor industry for which production figures are not readily available.  相似文献   

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Abstract

This paper examines the usefulness of one‐sex and two‐sex utility models of reproductive behavior in predicting births as consequences of wives’ and husbands’ perceptions of the costs and benefits of another child. We used longitudinal data on a sample of 280 white and 69 black young urban American couples. For whites, female models are mostly better than male models. Two‐sex models generally predict more variance than female models. We show that the white wife's utility considerations dominate the predictions, with husband as a junior partner and partial redundancy of female and male models. The utility considerations of black husbands dominate the predictions, with wives as junior partners and no redundancy in female and male models. We conclude that neither sex incorporates completely the spouse's utility considerations into its own utility structure. Because some male models are surprisingly strong, researchers cannot omit males without running the risk of leaving out an important component of the determinants of fertility.  相似文献   

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The heat shock protein 90 (Hsp90) is a molecular chaperone central to client protein folding and maturation in eukaryotic cells. During its chaperone cycle, Hsp90 undergoes ATPase-coupled large-scale conformational changes between open and closed states, where the N-terminal and middle domains of the protein form a compact dimerized conformation. However, the molecular principles of the switching motion between the open and closed states remain poorly understood. Here we show by integrating atomistic and coarse-grained molecular simulations with small-angle X-ray scattering experiments and NMR spectroscopy data that Hsp90 exhibits rich conformational dynamics modulated by the charged linker, which connects the N-terminal with the middle domain of the protein. We show that the dissociation of these domains is crucial for the conformational flexibility of the open state, with the separation distance controlled by a β-sheet motif next to the linker region. Taken together, our results suggest that the conformational ensemble of Hsp90 comprises highly extended states, which could be functionally crucial for client processing.  相似文献   

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Birth defects surveillance systems collect population-based birth defects data from multiple sources to track trends in prevalence, identify risk factors, refer affected families to services, and evaluate prevention efforts. Strong state and federal public health and legal mandates are in place to govern the collection and use of these data. Despite the prima facie appeal of "opt-in" and similar strategies to those who view data collection as a threat to privacy, the use of these strategies in lieu of population-based surveillance can severely limit the ability of public health agencies to accurately access the health status of a group within a defined geographical area. With the need for population-based data central to their mission, birth defects programs around the country take their data stewardship role seriously, recognizing both moral and legal obligations to protect the data by employing numerous safeguards. Birth defects surveillance systems are shaped by the needs of the community they are designed to serve, with the goal of preventing birth defects or alleviating the burdens associated with them.  相似文献   

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Objective:

Obesity is a risk factor of dementia. Current forecasts of dementia prevalence fail to take the rising obesity prevalence into account.

Design and Methods:

Embase and Medline were searched for observational studies on the association between overweight (BMI 25‐30 kg/m2) or obesity (BMI > 30 kg/m2) and dementia and pooled the effect sizes by meta‐analysis. The population attributable risk (PAR) was calculated for different time points and adjusted them for confounders. Based on current prevalence rates of dementia and demographic forecasts, patient numbers were calculated and adjusted by the growth rates of PAR.

Results:

Compared to normal weight, midlife obesity increases the risk of dementia later in life (BMI 25‐30: RR = 1.34 [95% CI 1.08, 1.66], BMI > 30: RR = 1.91 [1.4, 2.62]). If obesity is included into forecast models, the prevalence of dementia is estimated to be 7.1 million (6.9, 7.3) and 11.3 million (10.9, 11.7) for the United States in 2030 and 2050, respectively. In China, the estimate is 13.1 million (12.8, 13.3) in 2030 and 26.2 million (25.1, 27.4) in 2050. These figures are 9% and 19% higher for the United States and China, respectively, than forecasts that rely solely on the demographic change.

Conclusion:

The past and ongoing increase in midlife obesity prevalence will contribute significantly to the future prevalence of dementia and public health measures to reduce midlife obesity are simultaneously primary prevention measures to reduce the risk of dementia.  相似文献   

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Implications of a revised United States American Indian nadir population and the pattern of decline leading to it are examined. Substituting the new nadir for that used by Dobyns (1966) lowers by several million his estimates of Indian population for the United States (and Canada) area. These estimates then become more compatible with ones currently being suggested by other scholars. The nineteenth century decline leading to this nadir is found to be remarkably linear. Assuming linearity in decline from initial European contact through the eighteenth century, an aboriginal population estimate of 1,845,183 for the United States area may be extrapolated, along with estimates for intervening years. The nineteenth century decline is then graphed with the data extrapolated to 1492. The resulting pattern of population decline is quite different from the ones suggested by Mooney (1928) and Dobyns (1966).  相似文献   

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Anopheles hilli, Culex quinquefasciatus, and Aedes aegypti were used as test insects to compare the activity of the Australian and United States strains of Culicinomyces clavosporus. To minimize the variability incurred by using different larval batches, both strains were bioassayed at the same time using one batch of larvae. Six pairs of assays for each of the three test species were conducted in this manner. It was found that there was no difference in potency of the two strains in any one of the three species. A between species comparison, with the data pooled for both strains, showed that A. aegypti was more susceptible to the fungus than A. hilli. The susceptibility of C. Quinquefasciatus appeared to be intermediate but the fiducial limits of the weighted mean LC50 overlapped with those of the other two species. From the results of these experiments it would seem that, with regard to potency, both strains of Culicinomyces may be equally promising for the biological control of mosquitoes.  相似文献   

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