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51.
Forest fires play a critical role in landscape transformation, vegetation succession, soil degradation and air quality. Improvements in fire risk estimation are vital to reduce the negative impacts of fire, either by lessen burn severity or intensity through fuel management, or by aiding the natural vegetation recovery using post-fire treatments. This paper presents the methods to generate the input variables and the risk integration developed within the Firemap project (funded under the Spanish Ministry of Science and Technology) to map wildland fire risk for several regions of Spain. After defining the conceptual scheme for fire risk assessment, the paper describes the methods used to generate the risk parameters, and presents proposals for their integration into synthetic risk indices. The generation of the input variables was based on an extensive use of geographic information system and remote sensing technologies, since the project was intended to provide a spatial and temporal assessment of risk conditions. All variables were mapped at 1 km2 spatial resolution, and were integrated into a web-mapping service system. This service was active in the summer of 2007 for semi-operational testing of end-users. The paper also presents the first validation results of the danger index, by comparing temporal trends of different danger components and fire occurrence in the different study regions.  相似文献   
52.
Journal of Polymers and the Environment - The current global proposal for withdrawing polymers with high resistance to degradation and from fossil sources from disposable appliances, as well as the...  相似文献   
53.
The role of badges as indicators of contest ability has been previously described. In hummingbirds, the exhibition of a badge is expected to save energy expenditure in agonistic interactions and to favor energy intake. Here, we investigate whether variable supercilium size in the white-eared hummingbird has a role in dominance status signaling. Firstly, 45 hummingbird males were captured and their superciliums were photographed to investigate variation in size and any possible allometric relationships. Secondly, 42 male birds were used to analyze whether the supercilium has a role in dominance status signaling in a dyadic contest. We found that supercilium size varied continuously but that despite variability between individuals, there was no relationship between supercilium size and body size. However, our dyad experiment indicated that birds with larger badges were able to make more visits to the feeders than individuals with smaller badges. We suggest a status signaling function of the supercilium.  相似文献   
54.
This paper assesses the cost-effectiveness of, and the return on the investment in, the 2002 catch-up and the 2003 follow-up measles campaigns in Afghanistan from the perspective of the donor. The catch-up campaign targeted nearly 12 million children aged between six months and 12 years, while the follow-up campaign targeted over five million children aged between 9 and 59 months. Both campaigns successfully vaccinated approximately 96 per cent of the respective target populations, and are expected to avert an estimated 301,000 measles deaths over the next 10 years. The average cost per dose of measles vaccine delivered was USD 0.40. The cost per death prevented is USD 23.6, assuming a case fatality rate of 10 per cent and a discount rate of three per cent. With more than 42,000 measles deaths avoided for every one million US dollars spent, the campaigns are an excellent public health investment for precluding childhood mortality in a country affected by a complex emergency.  相似文献   
55.
本文研究了1981~2013年间在波罗的海哥德兰东南部附近采集的鳕鱼(Gadus morhua)肝组织中28种单氟和多氟烷基物质(PFAS)的时间变化趋势。共检测到10种PFAS,其中∑28PFAS几何平均浓度范围为6.03~23.9 ng/g。全氟辛烷磺酸(PFOS)是PFAS的主要组成,且仍以每年3.4%的速度增长。大多数长链全氟烷基羧酸以每年3.9%~7.3%的速度增加,但全氟辛酸(PFOA)没有随着时间的推移而显著变化。全氟烃基酸前体——全氟辛烷磺酰胺(FOSA)和6:2氟端粒磺酸也被检出,其中前者以每年4.4%的速度下降,可能反映出其从2000年开始逐步淘汰。从2000年到2013年的交替时间趋势分析显示的趋势率略有不同。对于大多数化合物,其增长速度慢于其在整个时期的趋势。一个例外是全氟己烷磺酸盐(PFHxS),从2000年开始以3.7%的速度增长,而从1981年开始以每年3.0%的速度增长。对样品总氟(TF)含量的分析揭示了大量未经鉴定的氟,但其组成(有机或无机)仍不清楚。个体PFAS浓度(PFOS除外)与肝脏体细胞指数呈显著负相关。此外,体长与PFOA和PFNA呈负相关,而与全氟癸酸盐(PFDoDA)和FOSA呈正相关。对海洋鱼类中PFAS的内分泌、免疫和代谢影响的进一步研究对于评估这些物质的环境风险至关重要。  相似文献   
56.
Abstract

Salmonella and Campylobacter are significant issues for poultry processors because of increasing regulatory standards as well as public health concerns. The goal of this study is to report the effects of two different pre-chiller systems that utilize different temperatures and water recirculation systems on whole bird carcass rinsates. Both pre-chiller tanks were contained within a single poultry processing facility and operated at different temperatures and water systems. The incidence of Campylobacter spp. and Salmonella spp., as well as the aerobic plate counts on whole bird carcass rinses are reported in this study from each pre-chiller system. The results from this study reveal that there are significant differences in how microbial populations and pathogens change over time in each pre-chiller system. Furthermore, we identify that these patterns are different per system. Such data are impactful as it indicates that measuring carcasses within a plant must consider both temperature and water recirculation as it may prevent comparability of different lines within a single processing facility.  相似文献   
57.
Environmental Science and Pollution Research - Occupational exposure to inhalational anesthetics has been associated with health problems, including reproductive issues. Considering the scarcity...  相似文献   
58.
Cutleaf coneflower (Rudbeckia laciniata L.), crown-beard (Verbesina occidentalis Walt.), and tall milkweed (Asclepias exaltata L.) are wildflower species native to Great Smoky Mountains National Park (U.S.A.). Natural populations of each species were analyzed for leaf ascorbic acid (AA) and dehydroascorbic acid (DHA) to assess the role of ascorbate in protecting the plants from ozone stress. Tall milkweed contained greater quantities of AA (7-10 micromol g(-1) fresh weight) than crown-beard (2-4 micromol g(-1) fresh weight) or cutleaf coneflower (0.5-2 micromol g(-1) fresh weight). DHA was elevated in crown-beard and cutleaf coneflower relative to tall milkweed suggesting a diminished capacity for converting DHA into AA. Tall milkweed accumulated AA in the leaf apoplast (30-100 nmol g(-1) fresh weight) with individuals expressing ozone foliar injury symptoms late in the season having less apoplast AA. In contrast, AA was not present in the leaf apoplast of either crown-beard or cutleaf coneflower. Unidentified antioxidant compounds were present in the leaf apoplast of all three species. Overall, distinct differences in antioxidant metabolism were found in the wildflower species that corresponded with differences in ozone sensitivity.  相似文献   
59.
Recent plans to alter the Loliondo Game Controlled Area (GCA), a nature conservation area located in Northern Tanzania, would result in substantial reduction of rangelands in the region. We quantify the current and hypothetical levels of the aboveground Human Appropriation of Net Primary Production (aHANPP) in one of the affected villages, and estimate the maximum exploitability rate of rangelands by livestock in the region. We find that the current aHANPP of the village amounts to 34–38% of the potential productivity, which could increase to 59–67% due to the altered GCA. On rangelands, livestock-induced aHANPP would increase from the current level of 30–34% to 54–61%, which is far above a maximum exploitability rate of 40–41%. Our results reveal that the intended changes to the Loliondo GCA will severely affect the current livelihood strategy of the Maasai, which is based on pastoralism.  相似文献   
60.
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