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INTRODUCTION: Little population-based information exists about the long-term effects of motor-vehicle crash-related injuries. METHOD: We analyzed data from the 1995 National Health Interview Survey Disability (NHIS-D) Supplement to estimate the prevalence of crash-related disability among noninstitutionalized U.S. adults aged 18 years and older. RESULTS: More than 1.2 million adults were living in their homes with the disabling effects of motor-vehicle crash-related injuries in 1995. The prevalence of crash-related disability was highest for persons in their mid-life years, ages 35-64. Half of the respondents had sustained the injuries more than 5 years before the interview. Forty-one percent of working-aged individuals reported being unable to work because of their disability. CONCLUSIONS: Because crash-related disability is most prevalent during the mid-life years, quality of life and productivity may be affected for decades. These findings highlight the personal and societal burden associated with motor-vehicle crash-related disability in the United States.  相似文献   
94.
Lake Powell is a large reservoir in Utah and Arizona that has experienced large changes in water level during a recent drought. As a first step in assessing the connection between hydrologic and chemical changes at Lake Powell, we characterized the particle size and solid-phase bulk concentrations for 31 elements and 25 minerals in sediment from the inflow region and some shoreline locations by using laser diffractometry, X-ray fluorescence, elemental analysis, and X-ray diffraction Our results are consistent with previous results that show a negative correlation between particle size and concentrations of most elements and most minerals other than quartz and some feldspars. In our samples, however, solid-phase iron, rather than particle size or organic carbon, is the best predictor variable for the solid-phase concentrations of elements and minerals. Sediment characteristics vary on a scale of tens of kilometers, with fine sediment that is enriched in trace elementsnearer to the dam. These trends allow formulation of an algorithm for determining a water-level threshold below which sediment resuspension may alter water chemistry in a generic reservoir with a long and narrow sediment delta.  相似文献   
95.
Maclean JE  Goheen JR  Doak DF  Palmer TM  Young TP 《Ecology》2011,92(8):1626-1636
Plant populations are regulated by a diverse array of herbivores that impose demographic filters throughout their life cycle. Few studies, however, simultaneously quantify the impacts of multiple herbivore guilds on the lifetime performance or population growth rate of plants. In African savannas, large ungulates (such as elephants) are widely regarded as important drivers of woody plant population dynamics, while the potential impacts of smaller, more cryptic herbivores (such as rodents) have largely been ignored. We combined a large-scale ungulate exclusion experiment with a five-year manipulation of rodent densities to quantify the impacts of three herbivore guilds (wild ungulates, domestic cattle, and rodents) on all life stages of a widespread savanna tree. We utilized demographic modeling to reveal the overall role of each guild in regulating tree population dynamics, and to elucidate the importance of different demographic hurdles in driving population growth under contrasting consumer communities. We found that wild ungulates dramatically reduced population growth, shifting the population trajectory from increase to decline, but that the mechanisms driving these effects were strongly mediated by rodents. The impact of wild ungulates on population growth was predominantly driven by their negative effect on tree reproduction when rodents were excluded, and on adult tree survival when rodents were present. By limiting seedling survival, rodents also reduced population growth; however, this effect was strongly dampened where wild ungulates were present. We suggest that these complex interactions between disparate consumer guilds can have important consequences for the population demography of long-lived species, and that the effects of a single consumer group are often likely to vary dramatically depending on the larger community in which interactions are embedded.  相似文献   
96.

Sweden has led the way in Europe in environmental protection, ecologically based technological innovation and social democracy. As new economic and ethnographic realities impact upon it, it faces challenges to its policies and practices long familiar elsewhere in Europe. We report on a study for the Swedish Research Councils in which we examined the national framework and political strategy for sustainable development, and how the strategy is being implemented in Sweden's three major cities and two case-study municipalities. History and tradition, cultural homogeneity and a strong and shared sense between sectors of 'the public good', emerged as very important. Until recently, these have obviated the need for formal links between the environmental, social and economic agendas. They now appear inadequately developed at all levels of governance. Tensions in policy are being played out at the level of the municipality, to which power is highly devolved, and Local Agenda 21, interpreted as project rather than process, seems unequal to the task of integration. We suggest what lessons may be drawn from the Swedish experience if issues of power and trust, leadership and participatory vs representative democracy are to be resolved.  相似文献   
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The Resource Management Act 1991 provides a new mandate for effectsbased planning with its goal of sustainable management. Regional, city and district councils are responsible for administering the Act, including preparation of regional policy statements, regional and district plans. The paper reports on a collaborative research programme,funded by the New Zealand Foundation for Research, Science and Technology. The three-year programme has two objectives: (1) to determine the quality of policy statements and plans; and (2) to identify the extent and means by which councils co-ordinate policy statements and plans. Preliminary findings on implementation of the Act are presented.  相似文献   
99.
The purpose of this blinded study was to evaluate potential environmental toxicity in a cohort of neurotypical children (n = 28) living in a suburban area of north-central Texas in the United States (US) with a comparable age- and gender-matched cohort of neurotypical children (n = 28) living in a suburban area of southeastern France using urinary porphyrin testing: uroporphyrin (uP), heptacarboxyporphyrin (7cxP), hexacarboxyporphyrin (6cxP), pentacarboxyporphyrin (5cxP), precoproporphyrin (prcP), and coproporphyrin (cP). Results showed significantly elevated 6cxP, prcP (an atypical, mercury-specific porphyrin), and cP levels, and increasing trends in 5cxP levels, among neurotypical children in the USA compared to children in France. Data suggest that in US neurotypical children, there is a significantly increased body-burden of mercury (Hg) compared to the body-burden of Hg in the matched neurotypical children in France. The presence of lead contributing to the higher levels of cP also needs to be considered. Further, other factors including genetics can not be completely ruled out.  相似文献   
100.
Drawing up environmental policy options is a complex activity which involves defining and weighing the merits and risks of various alternative courses of action governments could pursue. In its modern version, this task typically involves formal policy analysis or ‘policy appraisal’, that is, policy work specifically undertaken to generate and evaluate policy options in order to address problems or issues on a policy agenda. Indicators play a powerful but under-investigated role in this process. To shed light on this issue, the paper conducts a case study of the design and evolution of policy indicators in water security policy formulation, examining both their utilization and impact. The paper documents the origins of water security policy indicators; assesses their relevance and influence in policy formulation and identifies the reasons for the emergence of certain preferred indices, despite their having several well-known limitations. In particular, the discussion flags the significance of the political advantages surrounding their ease of use and interpretation, rather than their technical merits, as a key factor affecting the continued utilization and influence of specific indicators in environmental policy and planning.  相似文献   
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