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51.
52.
The Kew lecture provides a major contribution to contemporary environmental views. The Hon. Timothy E. Wirth is US Under Secretary of State for Global Affairs and he is responsible within the US State Department for overseeing environment, population, human rights, refugee, narcotics and related programmes. He was elected to the US Senate from Colorado in 1986 and served until 1993 when he chose not to run for re-election. He was, previously, a Congressman for 12 years and was voted one of the 25 most effective Members of Congress. In 1992, he served as national co-chair of the Clinton – Gore presidential campaign. The lecture was delivered at the Royal Botanic Gardens, Kew, London, on 15 September 1997.  相似文献   
53.
The mental health consequences of exposure to traumatic events and the risk factors for psychological morbidity among expatriate and Kosovar Albanian humanitarian aid workers have not been well studied. In June 2000, we used standardised screening tools to survey 285 (69.5%) of 410 expatriate aid workers and 325 (75.8%) of 429 Kosovar Albanian aid workers from 22 humanitarian organizations that were implementing health programmes in Kosovo. The mean number of trauma events experienced by expatriates was 2.8 (standard deviation: 2.7) and by Kosovar staff 3.2 (standard deviation: 2.8). Although only 1.1% of expatriate and 6.2% of Kosovar aid workers reported symptoms consistent with the diagnosis for post-traumatic stress disorder, 17.2% and 16.9%, respectively, reported symptoms satisfying the definition of depression. Regression analysis demonstrated that the number of trauma events experienced was significantly associated with depression for the two sets of workers. Organisational support services may be an important mediating factor and should be targeted at both groups.  相似文献   
54.
This paper discusses the implosion of a large inner-city hospital in Calgary, Alberta, Canada, on October 4, 1998. Stationary and mobile air monitoring conducted after the implosion indicated there were several short-term air quality issues, including significant temporal increases in total suspended particles, particulate matter (PM) with aerodynamic diameter less than or equal to 10 microm (PM10), PM with aerodynamic diameter less than or equal to 2.5 microm (PM2.5), asbestos, and airborne and settled lead. In addition, the implosion created a dust cloud that traveled much further than expected, out to 20 km. The ability of an implosion to effectively aerosolize building materials requires the removal of all friable and nonfriable forms of asbestos and all Pb-containing painted surfaces during pre-implosion preparatory work. Public advisories to mitigate personal exposure and indoor migration of the implosion dust cloud constituents should extend to 10 or 20 km around an implosion site. These findings point to a number of complex and problematic issues regarding implosions and safeguarding human health and suggest that implosions in metropolitan areas should be prohibited. Further work to characterize the public health risks of conventional versus implosion demolition is recommended.  相似文献   
55.
Keitt TH  Fischer J 《Ecology》2006,87(11):2895-2904
The response of ecological communities to anthropogenic disturbance is of both scientific and practical interest. Communities where all species respond to disturbance in a similar fashion (synchrony) will exhibit large fluctuations in total biomass and dramatic changes in ecosystem function. Communities where some species increase in abundance while others decrease after disturbance (compensation) can maintain total biomass and ecosystem function in the face of anthropogenic change. We examined dynamics of the Little Rock Lake (Wisconsin, USA) zooplankton community in the context of an experimental pH manipulation conducted in one basin of the lake. A novel application of wavelets was used to partition patterns of synchrony and compensation by time scale. We find interestingly that some time series show both patterns of synchrony and compensation depending on the scale of analysis. Within the unmanipulated basin, we found subtle patterns of synchrony and compensation within the community, largely at a one-year time scale corresponding to seasonal variation. Within the acidified lake basin, dynamics shifted to longer time scales corresponding to the pattern of pH manipulation. Comparisons between pairs of species in different functional groups showed both strong compensatory and synchronous responses to disturbance. The strongest compensatory signal was observed for two species of Daphnia whose life history traits lead to synchrony at annual time scales, but whose differential sensitivity to acidification led to compensation at multiannual time scales. The separation of time scales inherent in the wavelet method greatly facilitated interpretation as patterns resulting from seasonal drivers could be separated from patterns driven by pH manipulation.  相似文献   
56.
The Coordinating Research Council held its 15th workshop in April 2005, with nearly 90 presentations describing the most recent mobile source-related emissions research. In this paper, the authors summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles (with an emphasis in this workshop on particle emissions), effects of fuels on emissions, evaluation of in-use emissions control programs, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.  相似文献   
57.
Regional Environmental Change - Research that projects biophysical changes under climate change is more advanced than research that projects socio-economic changes. There is a need in adaptation...  相似文献   
58.
59.
The adult, sacoglossan sea slug, Elysia clarki (Pierce et al. in Molluscan Res 26, 2006), sequesters functional chloroplasts in cells of the digestive diverticula from four species of macroalgae in the order Bryopsidales (Penicillus capitatus, Penicillus lamourouxii, Halimeda incrassata, and Halimeda monile). Feeding experiments were conducted in December, 2003, using individuals raised in the laboratory from egg masses laid by E. clarki adults which had been collected from Grassy Key, Florida, USA, and 29 species of macroalgae collected from the Florida Keys, Tampa Bay, Tarpon Springs, Florida, or Woods Hole, Massachusetts or obtained from the Culture Collection of Algae at the University of Texas at Austin, Texas. For the first 14-day post-metamorphosis, juveniles ate only the thin filamentous species, Bryopsis plumosa or Derbesia tenuissima. Transmission electron microscopy showed that the chloroplasts from both algae were sequestered intracellularly in juvenile slugs. Individuals offered any other macroalga, including the four species fed on by adults, did not feed on or incorporate any chloroplasts, and soon died. Juveniles switched from B. plumosa to P. capitatus at a length of ∼ 1.0 cm, and fixed for microscopy 14 days later had intact intracellular chloroplasts from both algae. Nucleotide sequences of the chloroplast gene, rbcL, from DNA extracted from E. clarki, collected from Vaca Key, Florida, were aligned with 22 other available macroalgal rbcL sequences indicating that these E. clarki adults had fed on three species of algae in the Bryopsidales including Bryopsis pennata, and TEM results partially confirmed this conclusion.  相似文献   
60.
Summary Play behavior of young ponies accounted for two-thirds of total running exercise and over 95% of all high-speed turns in ten animals from birth to age six weeks. The classical supposition, never previously demonstrated, that most exercise of young mammals occurs in play, is confirmed in these subjects.  相似文献   
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