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731.
Catherine Brown 《Disasters》1999,23(3):234-256
Protracted conflict and violence in Burma have been conducive to the growth of the opium industry, Burma's single financial success in recent years of economic crisis and authoritarian rule. This in turn has fed violence and subsequent humanitarian crisis. This paper argues that the underlying political economy of the conflict has been overlooked, while conflict itself has been treated as a peripheral factor in questions of 'development', and further that the opium dynamic is a vital factor in continued violence and vulnerability for non-combatants in the region. A political economy approach, identifying the beneficiaries of violence, will offer a more holistic and effective approach to the protracted crisis. 相似文献
732.
Institutions play an important role in the adaptive capacity of a system in responding to climate change. This review paper
characterizes the status of the collective institutional response (government, industry, First Nation, community, civil society)
to climate change in the forest sector of the Canadian province of Ontario, and highlights the presence and nature of inter-institutional
networks as part of the response. Based on a synthesis of the commonalities in the public administration and policy literature
on tackling wicked problems, and the resilience literature, inter-institutional networks, which foster exchange of different
types of knowledge, are an important aspect of enhancing the adaptive capacity of social–ecological systems such as the forest
sector. Based on a content analysis of publicly available documents and insights gained from representatives of government,
community members and non-governmental organizations, mitigation and adaptations strategies are described. At the provincial
level there have been some new innovations in inter-institutional networks, but expansion of the forest stakeholders involved
in such networks would further enhance adaptive capacity. In particular, it is important to network with First Nations and
other forest-dependent communities who have a heightened vulnerability to climate change. The presence of a collaborative
capacity builder could foster the transfer, receipt and integration of knowledge across the networks, and ultimately build
long-term collaborative problem-solving capacity in the Ontario forest sector.
相似文献
H. Carolyn Peach BrownEmail: |
733.
Korobova EM Brown JB Ukraintseva NG Surkov VV 《Journal of environmental radioactivity》2007,96(1-3):144-156
Plant species, forming important components of Arctic food chains and of interest from a monitoring perspective, were studied at 36 plots representing flood plain and terrace landscapes of the Yenisey River and Estuary from its upper delta to the gulf. (137)Cs contamination densities at the plots varied from 0.35kBq/m(2) (central delta, sandy riverside plot) to 88kBq/m(2) (the upper delta plot) indicating both global and regional sources of anthropogenic pollution. Cs-137 levels in plants were within the range expected from global fallout inputs and varied from 31 to 140Bq/kg d.w. increasing in dominant groups in the order: grasses相似文献
734.
Genetic Structure of Fragmented Populations of the Endangered Daisy Rutidosis leptorrhynchoides 总被引:2,自引:0,他引:2
Abstract: The endangered grassland daisy Rutidosis leptorrhynchoides has been subject to severe habitat destruction and fragmentation over the past century. Using allozyme markers, we examined the genetic diversity and structure of 16 fragmented populations. The species had high genetic variation compared to other plant species, and both polymorphism and allelic richness showed strong positive relationships with log reproductive population size, reflecting a loss of rare alleles (frequency of q < 0.1) in smaller populations. Fixation coefficients were positively related to size, due either to a lack of rare homozygotes in small populations or to Wahlund effects (owing to spatial genetic structure) in large ones. Neither gene diversity nor heterozygosity was related to population size, and other population parameters such as density, spatial contagion, and isolation had no apparent effect on genetic variation. Genetic divergence among populations was low , despite a large north-to-south break in the species' current distribution. To preserve maximum genetic variation, conservation strategies should aim to maintain the five populations larger than 5000 reproductive plants, all of which occur in the north of the range, as well as the largest southern population of 626 plants at Truganina. Only one of these is currently under formal protection. High heterozygosity in smaller populations suggests that they are unlikely to be suffering from inbreeding depression and so are also valuable for conservation. Erosion of allelic richness at self-incompatibility loci, however, may limit the reproductive capacity of populations numbering less than 20 flowering plants. 相似文献
735.
Female distribution affects mate searching and sexual selection in male northern water snakes (Nerodia sipedon) 总被引:2,自引:0,他引:2
Mating systems and sexual selection are assumed to be affected by the distribution of critical resources. We use observations
of 312 mating aggregations to compare mate-searching success of male northern water snakes (Nerodia sipedon) in two marshes in which differences in mating substrate availability resulted in more than fourfold differences in female
dispersion. Reproductive males had significantly larger home ranges where females were dispersed than where females were clumped.
The number of females encountered by males increased significantly with male home range size where females were dispersed,
and decreased significantly where females were clumped. Where females were clumped, males were more likely to encounter other
males when they located females. We found no evidence in either population that mate searching was energetically expensive
or that males with relatively more energy had larger home ranges. However, males with greater fat reserves at the start of
the season participated in more mating aggregations when females were dispersed, suggesting that fat reserves could affect
a male’s willingness to attempt mating or to persist in aggregations. When females were dispersed there was weak stabilizing
selection acting to maintain male body size (β=–0.14), but strong directional selection favoring larger (β=0.50) and fatter
(β=0.37) males. Over 7 years, the intensity of selection favoring larger males varied substantially (β=0.14–1.15), but that
variation was not related to variation in the operational sex ratio. We found no evidence of directional selection on either
body size (β=0.05) or fat reserves (β=0.10) of males when females were spatially clumped. Overall, the distribution of females
had a pronounced effect on male behavior, on the factors that affected male success in locating females, and probably on the
extent of sperm competition once females had been located.
Received: 23 November 1998 / Received in revised form: 9 August 1999 / Accepted: 18 August 1999 相似文献
736.
本文根据辐射传热和对流传热理论,利用Matlab 程序结合太阳能热水器本身的尺寸以及与其有关的水和空气的物理弹性详细分析了影响平板式太阳能热水器热效率的因素包括太阳能热水器表面的太阳光辐射的吸收率αs 和辐射系数ε,太阳能热水器的水进口温度Tc,in和流量mc 太阳辐射能力Gs,,环境大气温度Te,大气辐射系数εsky 以及太阳能热水器内部的总传热系数U。分析结果表明较高的太阳照射能力、环境温度和总传热系数有利于提高集热效率,而增加水量和水进口温度、热水器辐射系数和大气辐射系数则有相反的效果。 相似文献
737.
Diffusive sampling of Volatile Organic Compounds (VOCs) onto thermal desorption tubes, followed by gas chromatography, is an established technique for area or personal monitoring of typical workplace concentrations and there has been increasing interest in extending the application to environmental levels, particularly for benzene, toluene and xylene (BTX). Diffusive sampling rates for BTX on Chromosorb 106 and Carbograph-1 (a graphitised carbon) were measured over periods of 1-4 weeks in field validation experiments using ambient air and parallel pumped sampling (the reference method) at the HSL site in central Sheffield. The reference method was also used to investigate the possible bias of an open-path spectrophotometer (OPSIS) used by Sheffield City Council. A bias for BTX was suspected from results of a two-week initial exercise in which several diffusive samplers were placed close to the light path. In the full field validation of the diffusive samplers carried out subsequently, the significant bias of BTX concentrations reported by OPSIS were confirmed when compared with concurrent results from the reference method. OPSIS gave benzene and toluene values up to eight times higher than expected from the GC measurements. Xylene discrepancies were smaller, but in one 3-day peak episode, OPSIS demonstrated a negative correlation with GC. 相似文献
738.
739.
Hosseini A. Brown J. E. Avila R. Beresford N. A. Oughton D. 《Environmental Modeling and Assessment》2022,27(2):311-326
Environmental Modeling & Assessment - In Europe, the two main nuclear accident response decision support systems in use are ARGOS and JRODOS, both of which make use of the FDMT (Food Chain and... 相似文献