906 resultados para Road ecology : science and solutions


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Geographical body size variation has long interested evolutionary biologists, and a range of mechanisms have been proposed to explain the observed patterns. It is considered to be more puzzling in ectotherms than in endotherms, and integrative approaches are necessary for testing non-exclusive alternative mechanisms. Using lacertid lizards as a model, we adopted an integrative approach, testing different hypotheses for both sexes while incorporating temporal, spatial, and phylogenetic autocorrelation at the individual level. We used data on the Spanish Sand Racer species group from a field survey to disentangle different sources of body size variation through environmental and individual genetic data, while accounting for temporal and spatial autocorrelation. A variation partitioning method was applied to separate independent and shared components of ecology and phylogeny, and estimated their significance. Then, we fed-back our models by controlling for relevant independent components. The pattern was consistent with the geographical Bergmann's cline and the experimental temperature-size rule: adults were larger at lower temperatures (and/or higher elevations). This result was confirmed with additional multi-year independent data-set derived from the literature. Variation partitioning showed no sex differences in phylogenetic inertia but showed sex differences in the independent component of ecology; primarily due to growth differences. Interestingly, only after controlling for independent components did primary productivity also emerge as an important predictor explaining size variation in both sexes. This study highlights the importance of integrating individual-based genetic information, relevant ecological parameters, and temporal and spatial autocorrelation in sex-specific models to detect potentially important hidden effects. Our individual-based approach devoted to extract and control for independent components was useful to reveal hidden effects linked with alternative non-exclusive hypothesis, such as those of primary productivity. Also, including measurement date allowed disentangling and controlling for short-term temporal autocorrelation reflecting sex-specific growth plasticity.

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Report on Iowa State University of Science and Technology, Ames, Iowa, for the year ended June 30, 2008

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Road transport emissions are a major contributor to ambient particulate matter concentrations and have been associated with adverse health effects. Therefore, these emissions are targeted through increasingly stringent European emission standards. These policies succeed in reducing exhaust emissions, but do not address "nonexhaust" emissions from brake wear, tire wear, road wear, and suspension in air of road dust. Is this a problem? To what extent do nonexhaust emissions contribute to ambient concentrations of PM10 or PM2.5? In the near future, wear emissions may dominate the remaining traffic-related PM10 emissions in Europe, mostly due to the steep decrease in PM exhaust emissions. This underlines the need to determine the relevance of the wear emissions as a contribution to the existing ambient PM concentrations, and the need to assess the health risks related to wear particles, which has not yet received much attention. During a workshop in 2011, available knowledge was reported and evaluated so as to draw conclusions on the relevance of traffic-related wear emissions for air quality policy development. On the basis of available evidence, which is briefly presented in this paper, it was concluded that nonexhaust emissions and in particular suspension in air of road dust are major contributors to exceedances at street locations of the PM10 air quality standards in various European cities. Furthermore, wear-related PM emissions that contain high concentrations of metals may (despite their limited contribution to the mass of nonexhaust emissions) cause significant health risks for the population, especially those living near intensely trafficked locations. To quantify the existing health risks, targeted research is required on wear emissions, their dispersion in urban areas, population exposure, and its effects on health. Such information will be crucial for environmental policymakers as an input for discussions on the need to develop control strategies.

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Schedule of Debt Service and Coverage for Iowa State University of Science and Technology for the Academic Building Revenue Bond Funds for the year ended June 30, 2009

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Audit report on the Student Health Facility Revenue Bond Funds of Iowa State University of Science and Technology for the year ended June 30, 2009

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Audit report of Iowa State University of Science and Technology, Ames, Iowa, (Iowa State University) for the year ended June 30, 2009

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Agreed-upon procedures report on the Iowa State Center Business Office of Iowa State University of Science and Technology for the year ended June 30, 2009

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Report on a review of selected general and application controls over the Iowa State University of Science and Technology (Iowa State University) Purchase Order/Requisition System for the period of March 20 through April 28, 2009

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Report on Iowa State University of Science and Technology, Ames, Iowa, for the year ended June 30, 2009

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Audit report on the Student Health Facility Revenue Bond Funds of Iowa State University of Science and Technology for the year ended June 30, 2010

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Report on a review of selected general and application controls over the Iowa State University of Science and Technology Accounts Receivable System for the period of March 29, 2010 through May 6, 2010

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Audit report of Iowa State University of Science and Technology, Ames, Iowa (Iowa State University) as of and for the years ended June 30, 2010 and 2009

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Report on Iowa State University of Science and Technology, Ames, Iowa, for the year ended June 30, 2010

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Audit report on the Student Health Facility Revenue Bond Funds of Iowa State University of Science and Technology for the year ended June 30, 2011