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131.
A survey of one of the camps still holding refugees from Iraq who crossed into Turkey in the spring of 1991 showed that the majority of the population was under 15 years of age and that increased mortality occurred during the first 30 days after the refugees left their homes in Iraq. Infants, young children, and the elderly suffered the highest mortality, with infant mortality rates (IMRs) over the first month of the crisis approximately 18–29 times the MR in Iraq in the late 1980s. Still unexplained is a greater than two-fold excess mortality among males compared with females. Other demographic and health findings are also reported. 相似文献
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ROBERT D. PERLACK CARL H. PETRICH and SAMUEL SCHWEITZER† 《Natural resources forum》1988,12(3):235-242
A key ingredient in the expansion of agricultural output in many developing countries is the availability of reliable and cost-effective energy supplies for irrigation. Such supplies are also fundamental to any strategy to stimulate rural economic development. This paper compares the costs of water pumping through the use of commonly-used, small diesel-driven pumpsets versus a decentralized generator connected to a small electrified grid. An example representative of irrigated cropping systems found in the Senegal River Basin is used to compare costs. The results show that pumping costs from a decentralized power supply and minigrid are roughly comparable with those of direct-drive diesel pumpsets. Further, excess capacity would be available to provide power for small industries and other rural needs. In many sparsely populated rural locations where low capacity factors make central grid extension uneconomic, a minigrid with a guaranteed load of irrigation pumping can be an attractive alternative for providing power for rural development. 相似文献
134.
Effects of Urbanization on the Distribution and Abundance of Amphibians and Invasive Species in Southern California Streams 总被引:5,自引:0,他引:5
SETH P. D. RILEY‡‡ GARY T. BUSTEED LEE B. KATS† THOMAS L. VANDERGON† LENA F. S. LEE ROSI G. DAGIT‡ JACOB L. KERBY‡†† ROBERT N. FISHER§ RAYMOND M. SAUVAJOT 《Conservation biology》2005,19(6):1894-1907
Abstract: Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and exotic predators and characterized stream habitat and invertebrate communities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish ( Procambarus clarkii ) and fish, and had fewer native species such as California newts ( Taricha torosa ) and California treefrogs ( Hyla cadaverina ). These effects seemed particularly evident above 8% development, a result coincident with other urban stream studies that show negative impacts beginning at 10–15% urbanization. For Pacific treefrogs ( H. regilla ), the most widespread native amphibian, abundance was lower in the presence of exotic crayfish, although direct urbanization effects were not found. Benthic macroinvertebrate communities were also less diverse in urban streams, especially for sensitive species. Faunal community changes in urban streams may be related to changes in physical stream habitat, such as fewer pool and more run habitats and increased water depth and flow, leading to more permanent streams. Variation in stream permanence was particularly evident in 2002, a dry year when many natural streams were dry but urban streams were relatively unchanged. Urbanization has significantly altered stream habitat in this region and may enhance invasion by exotic species and negatively affect diversity and abundance of native amphibians. 相似文献
135.
Building on IUCN Regional Red Lists to Produce Lists of Species of Conservation Priority: a Model with Irish Bees 总被引:2,自引:1,他引:2
ÚNA FITZPATRICK‡ TOMÁS E. MURRAY† ROBERT J. PAXTON† MARK J. F. BROWN 《Conservation biology》2007,21(5):1324-1332
Abstract: A World Conservation Union (IUCN) regional red list is an objective assessment of regional extinction risk and is not the same as a list of conservation priority species. Recent research reveals the widespread, but incorrect, assumption that IUCN Red List categories represent a hierarchical list of priorities for conservation action. We developed a simple eight-step priority-setting process and applied it to the conservation of bees in Ireland. Our model is based on the national red list but also considers the global significance of the national population; the conservation status at global, continental, and regional levels; key biological, economic, and societal factors; and is compatible with existing conservation agreements and legislation. Throughout Ireland, almost one-third of the bee fauna is threatened (30 of 100 species), but our methodology resulted in a reduced list of only 17 priority species. We did not use the priority species list to broadly categorize species to the conservation action required; instead, we indicated the individual action required for all threatened, near-threatened, and data-deficient species on the national red list based on the IUCN's conservation-actions template file. Priority species lists will strongly influence prioritization of conservation actions at national levels, but action should not be exclusive to listed species. In addition, all species on this list will not necessarily require immediate action. Our method is transparent, reproducible, and readily applicable to other taxa and regions. 相似文献
136.
Science, Scientists, and Policy Advocacy 总被引:1,自引:1,他引:1
ROBERT T. LACKEY 《Conservation biology》2007,21(1):12-17
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Predicting Human-Carnivore Conflict: a Spatial Model Derived from 25 Years of Data on Wolf Predation on Livestock 总被引:1,自引:0,他引:1
ADRIAN TREVES†§§ LISA NAUGHTON-TREVES†‡ ELIZABETH K. HARPER§ DAVID J. MLADENOFF ROBERT A. ROSE‡ THEODORE A. SICKLEY ADRIAN P. WYDEVEN†† 《Conservation biology》2004,18(1):114-125
Abstract: Many carnivore populations escaped extinction during the twentieth century as a result of legal protections, habitat restoration, and changes in public attitudes. However, encounters between carnivores, livestock, and humans are increasing in some areas, raising concerns about the costs of carnivore conservation. We present a method to predict sites of human-carnivore conflicts regionally, using as an example the mixed forest-agriculture landscapes of Wisconsin and Minnesota (U.S.A.). We used a matched-pair analysis of 17 landscape variables in a geographic information system to discriminate affected areas from unaffected areas at two spatial scales (townships and farms). Wolves ( Canis lupus ) selectively preyed on livestock in townships with high proportions of pasture and high densities of deer ( Odocoileus virginianus ) combined with low proportions of crop lands, coniferous forest, herbaceous wetlands, and open water. These variables plus road density and farm size also appeared to predict risk for individual farms when we considered Minnesota alone. In Wisconsin only, farm size, crop lands, and road density were associated with the risk of wolf attack on livestock. At the level of townships, we generated two state-wide maps to predict the extent and location of future predation on livestock. Our approach can be applied wherever spatial data are available on sites of conflict between wildlife and humans. 相似文献
139.
ROBERT L. BESCHTA††† JONATHAN J. RHODES† J. BOONE KAUFFMAN‡ ROBERT E. GRESSWELL§ G. WAYNE MINSHALL JAMES R. KARR†† DAVID A. PERRY‡‡ ‡‡‡ F. RICHARD HAUER§§ CHRISTOPHER A. FRISSELL 《Conservation biology》2004,18(4):957-967
Abstract: Forest ecosystems in the western United States evolved over many millennia in response to disturbances such as wildfires. Land use and management practices have altered these ecosystems, however, including fire regimes in some areas. Forest ecosystems are especially vulnerable to postfire management practices because such practices may influence forest dynamics and aquatic systems for decades to centuries. Thus, there is an increasing need to evaluate the effect of postfire treatments from the perspective of ecosystem recovery. We examined, via the published literature and our collective experience, the ecological effects of some common postfire treatments. Based on this examination, promising postfire restoration measures include retention of large trees, rehabilitation of firelines and roads, and, in some cases, planting of native species. The following practices are generally inconsistent with efforts to restore ecosystem functions after fire: seeding exotic species, livestock grazing, placement of physical structures in and near stream channels, ground-based postfire logging, removal of large trees, and road construction. Practices that adversely affect soil integrity, persistence or recovery of native species, riparian functions, or water quality generally impede ecological recovery after fire. Although research provides a basis for evaluating the efficacy of postfire treatments, there is a continuing need to increase our understanding of the effects of such treatments within the context of societal and ecological goals for forested public lands of the western United States. 相似文献
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