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231.
Linda K. Mann Patricia D. Parr Larry R. Pounds Robin L. Graham 《Environmental management》1996,20(2):207-218
Security buffers of Department of Defense (DoD) and Department of Energy (DOE) reservations provide long-term habitat protection for many rare and endangered species. The importance of these government-owned reservations as nationally valuable resources has been relatively unrecognized. During the last 50 years, the DOE Oak Ridge Reservation (ORR) has been a relatively protected island in a region of rapidly expanding urbanization and land clearing. Consisting of the Oak Ridge National Environmental Research Park and associated lands surrounding DOE facilities at Oak Ridge Tennessee, the unique nature of the ORR in the surrounding landscape is clearly visible from the air and has been documented using remote sensing data. Although forests dominate much of other regions of eastern Tennessee, this 15,000-ha tract of mostly natural forest habitat is unique in the southern Ridge and Valley physiographic province, which is otherwise widely developed for pasture, marginal cropland, woodlot, and urban uses. Twenty state-listed and federal-candidate plant species are known to be present on the ORR. This richness of species, which are provided protection by state and federal laws, exceeds that of the Great Smoky Mountains National Park on a species area basis and is an index of the value of the ORR both regionally and nationally in conserving biodiversity. With the end of the Cold War, changing DoD and DOE missions combined with increasing development pressure contribute to uncertainty in the future management of security reservations. 相似文献
232.
Otoidobiga LC Vincent LC Stewart RK 《Journal of environmental science and health. Part. B》2003,38(6):757-769
Bioassays were conducted in 2001 and 2002 to estimate toxicities and dose-response relationships of 24 Bemisica tabaci Gennadius populations to pyriproxifen, acemitaprid, and diafenthiuron. LC50s ranging from 0.014 to 0.096 mgL(-1), 0.60 to 1.3 mgL(-1), and 3.5 to 6.7 mgL(-1) were observed respectively for pyriproxifen, acemitaprid, and diafenthiuron. These LC50s much lower than the field doses recommended for each compound. A fast increase in rates of mortality within a narrow range of lethal concentrations was observed for each compound. indicating that all three compounds were highly effective at killing whiteflies. In a separate experiment, pyriproxifen, acemitaprid, and diafenthiuron were tested in 2001 and 2002 to compare their effectiveness and assess their impact on parasitism in the field. In both years all three compounds significantly prevented B. tabaci populations from reaching economic injury levels in cotton and minimized adverse effects on parasitism. Our results provide for the first time baseline toxicological, field efficacy, and effect on parasitism data for pyriproxifen, acemitaprid, and diafenthiuron against B. tabaci in West Africa. These compounds should be included in a resistance management program of the cotton pest complex and their use should be restricted to prevent the building of resistance in B. tabaci populations. 相似文献
233.
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235.
Aspects of transboundary, water shortage, and fisheries issues are discussed in the context of the recently completed Global International Waters Assessment (GIWA) for the Pacific Islands. The region encompasses some 30 million km2 and approximately 12% of the world's ocean space, and features great geographic, demographic and developmental diversity. Global change, especially sea level rise and sea surface temperature increases, is the dominant transboundary concern as it impacts all aspects of life. Water shortage and unsustainable fishing issues are selected for discussion, as they will dominate the region into the foreseeable future, and they are illustrated with examples from Fiji, Kiribati, and Tonga. The environmental impacts are exacerbated by socioeconomic issues such as high population growth rates, urban drift, the breakdown of traditional life styles and the rapid adoption of the cash economy. Policy options that may assist in addressing these issues are proposed. 相似文献
236.
Hidy GM Hales JM Roth PM Scheffe R 《Journal of the Air & Waste Management Association (1995)》2000,50(4):613-632
This paper describes a background for the North American Research Strategy for Tropospheric Ozone (NARSTO) cooperative program integrating studies of O3 and PM2.5. It discusses several important aspects for rationalizing NARSTO's trinational investigative approach, including (1) an outlook on the state of knowledge about fine particles in the troposphere and their origins in Canada, Mexico, and the United States; (2) the need for enhancement and strengthening of key field measurements in relation to tropospheric chemistry and a health effects component; and (3) the use of a central theme for advancing air quality modeling using evolving techniques to integrate and guide key process-oriented field campaigns. The importance of organizing a scientific program to acquire "policy-relevant" information is stressed, noting cooperative research directions that address combined PM2.5 and O3 issues, illustrated through exploration of hypothetical pathways of PM2.5 response to choices of O3 and PM precursor emission reductions. The information needed for PM2.5 research is noted to intersect in many cases with those of O3, but diverge in other cases. Accounting for these distinctions is important for developing NARSTO's strategy over the next decade. 相似文献
237.
Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones
that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is
expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as
an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability
and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating
asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size
and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size
and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was
found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate
the action of selection during drone mating flights for the first time, showing that developmental stability can influence
the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer
some fitness advantages to the queens. 相似文献
238.
OBJECTIVE: Vehicle interlocks have been shown to effectively reduce the recidivism of multiple driving-while-impaired (DWI) offenders; however, the evidence for their effectiveness with first offenders has been mixed. Two Canadian studies found that the installation of an interlock reduced first DWI recidivism, but U.S. studies in West Virginia and California failed to find a significant reduction in recidivism for first DWI offenders in interlock programs. The objective of this study was to determine the extent to which such devices were effective with first offenders in New Mexico. METHODS: This study compared 1,461 first offenders, who installed interlocks in New Mexico between January 1, 2003, and December 1, 2005, with 17,562 first offenders convicted during the same period who did not install the units. Cox multivariate proportional hazards regression (CMVPHR) was used to compare recidivism rates during three periods: while the interlock was on the vehicles of offenders who installed them, after those offenders removed the units until the end of the study period (approximately 2 years), and for the combined period (both while the interlock was installed and after it was removed). RESULTS: While the device was on the vehicles of the interlock group, their recidivism rate, 2.6% per year of exposure, was significantly less than the 7.1% per year rate of the comparison group (CMVPHR hazard ratio = 0.39, p < 0.0001). After the device was removed, the annualized recidivism rate of the interlock group increased to 4.9% per year of exposure, which was less than the 6.7% rate of the comparison group, but the hazard ratio was not statistically significant (CMVPHR hazard ratio = 0.82, p = 0.16). When the combined periods (interlock on and off) were considered, the interlock group had a recidivism rate of 3.9% per year, which again was significantly lower than the 6.8% rate for the comparison group (CMVPHR hazard ratio = 0.61, p < 0.0001). CONCLUSION: The study provides evidence that interlocks are as effective with first offenders (approximately 60% reduction in recidivism when on the vehicle) as they are for multiple offenders. In addition, the benefits of requiring an interlock for first offenders exceed the costs by a factor of three. 相似文献
239.
Ethnobotany of Woody Species in Second-Growth, Old-Growth, and Selectively Logged Forests of Northeastern Costa Rica 总被引:2,自引:0,他引:2
Abstract: We assessed quantitatively the woody species used for timber, medicine, and other products in 10 tropical wet-forest stands with different land-use histories in the Atlantic lowlands of northeastern Costa Rica. Species were classified into 20 use categories based on regional ethnobotanical studies. Three size classes of woody vegetation were sampled in nested, contiguous plots along transects: trees (≥5 cm diameter at breast height [dbh]), saplings (>1 m high, <5 cm dbh), and seedlings (>20 cm high, <1 m high). Our study included five second-growth stands, three old-growth stands, and two selectively logged stands. Of the 459 woody species surveyed, 70% of the species and 86% of the total number of individuals had at least one use. Overall, species richness was highest for medicinal species (167 species). Absolute and relative abundance of medicinal and timber trees was significantly higher in second-growth stands than in old-growth and selectively logged stands. For 8 of the 15 use categories examined statistically, stem density showed no significant differences across forest types for any stem size class. Young, tropical, second-growth forests and selectively logged forests have high utilitarian as well as conservation value and will likely become important sources of forest products. The success of secondary forest regeneration, however, depends critically upon conservation of genetically diverse source populations in forest fragments and protected old-growth stands. 相似文献
240.
Vijayaraghavan M Lievano F Cairns L Wolfson L Nandy R Ansari A Golaz A Mashal T Salama P 《Disasters》2006,30(2):256-269
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