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71.
Environmental Geochemistry and Health - A field experiment was undertaken on farmers’ fields adjacent to a large mine tailings dam in the Zambian mining town of Kitwe. Experimental plots were...  相似文献   
72.
In the UK, there now exist hundreds of low-carbon community groups (LCCGs) that aim to decrease collective resource consumption and/or generate renewable energy through diverse social and environmental interventions. These groups have in recent years become the subject of political attention and funding schemes, underpinned by beliefs that LCCGs are key to fostering resilience to climate change and meeting national-level greenhouse gas emission reduction targets. While previous research into LCCGs has focused on drivers, barriers and outcomes of LCCG action, there is now growing policy and academic interest in groups' capacities for, and uses of, monitoring and evaluation (M&E) processes and tools. However, little is known about the experiences, opportunities and potential challenges for LCCGs undertaking M&E. In response, this paper draws on a Knowledge Exchange project that explored M&E processes and tools with a sample of UK LCCGs. It outlines the benefits and drawbacks of groups' attempts to achieve change and to account for their outcomes and/or impacts, individually, and as part of a wider movement. It argues that, while M&E could be one way for groups to “scale up” their impact without losing their grounding in place and community, issues of capacity, resources and utility remain paramount.  相似文献   
73.
Social interactions facilitate pathogen transmission and increase virulence. Therefore, species that live in social groups are predicted to suffer a higher pathogen burden, to invest more heavily in immune defence against pathogens, or both. However, there are few empirical tests of whether social species indeed invest more heavily in immune defence than non-social species. In the current study, we conducted a phylogenetically controlled comparison of innate immune response in Lamprologine cichlid fishes. We focused on three species of highly social cichlids that live in permanent groups and exhibit cooperative breeding (Julidochromis ornatus, Neolamprologus pulcher and Neolamprologus savoryi) and three species of non-social cichlids that exhibit neither grouping nor cooperative behaviour (Telmatochromis temporalis, Neolamprologus tetracanthus and Neolamprologus modestus). We quantified the innate immune response by injecting wild fishes with phytohaemagglutinin (PHA), a lectin that causes a cell-mediated immune response. We predicted that the three highly social species would show a greater immune reaction to the PHA treatment, indicating higher investment in immune defence against parasites relative to the three non-social species. We found significant species-level variation in immune response, but contrary to our prediction, this variation did not correspond to social system. However, we found that immune response was correlated with territory size across the six species. Our results indicate that the common assumption of a positive relationship between social system and investment in immune function may be overly simplistic. We suggest that factors such as rates of both in-group and out-group social interactions are likely to be important mediators of the relationship between sociality and immune function.  相似文献   
74.
Predicting Invasions of Woody Plants Introduced into North America   总被引:27,自引:0,他引:27  
Plant species continue to be introduced in North America for various purposes. If the trend continues, it is probable that some will escape cultivation and become invasive in native ecosystems. We present a retrospective analysis of several structural, life history, and biogeographical attributes of woody plants introduced in North America to determine which traits characterize species that have and have not invaded. Predictive models derived from discriminant analysis correctly classified 86.2% of the species in cross-validation, whereas those derived from classification and regression trees classified 76% correctly. From these models we created a hierarchical predictive tree that allows the user to divide species into three categories: admit (low risk of invasiveness), deny admission (high risk of invasiveness), or delay admission for further analyses and/or monitor intensively (risk cannot adequately be assessed based on only the included attributes). We recommend that species that are highly invasive elsewhere not be allowed into the U.S. and that a more conservative introduction policy using a hierarchical predictive method be employed.  相似文献   
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A geospatial methodology has been developed that utilizes high resolution lidar‐derived DEMs to help track runoff from agricultural fields and identify areas of potential concentrated flow through vegetated riparian areas in the Coastal Plain of Virginia. Points of concentrated flow are identified across 74 agricultural fields within the Virginia portion of the Chesapeake Bay watershed. On average, 70% of the surface area of the agricultural fields analyzed drains through less than 20 m of the field margin, and on average 81% of the field surface area drains through 1% or less of the field margin. Within the riparian buffer, locations that were predicted by the geospatial model to have high levels of concentrated flow were found to exhibit evidence of channelization. Results indicate that flow concentration and channelized flow through vegetated riparian areas may be common along the margin of agricultural fields, resulting in vegetated riparian areas that are less effective at sediment trapping than assumed. Additional results suggest that the regulations governing the location and width of vegetated riparian may not be sufficient to achieve goals for reducing sediment and nutrient runoff from nonpoint agricultural sources. Combined with the increasing availability of lidar‐derived DEMs, the geospatial model presented has the potential to advance management practices aimed at reducing nonpoint source pollution leaving agricultural fields.  相似文献   
77.
Congenital CMV is the most common congenital infection in the developed world. Infection results in congenital disease ranging from asymptomatic infection to severe neurodevelopmental impairment, and occasionally fetal or neonatal death. Fetal infection can occur through maternal-fetal transmission during primary maternal infection or maternal reactivation or re-infection. Awareness among maternal health care providers and parents is low. The prevention of maternal CMV infection currently relies on hygiene measures, with no effective CMV vaccine or prophylactic therapies. No licensed treatment options are available to prevent maternal-fetal transmission or fetal disease. Hyperimmunoglobulin and valaciclovir have been investigated for prevention of maternal-fetal transmission or fetal treatment, with some evidence supporting consideration of maternal administration of hyperimmunoglobulin or valaciclovir therapy in certain circumstances. This article outlines the clinical evidence regarding proven preventative behavioral measures and experimental hyperimmunoglobulin and valaciclovir therapies, that is structured around common questions asked by pregnant women about CMV infection. It is aimed to help maternity health care providers counsel prospective parents about congenital CMV disease and the preventative and therapeutic strategies currently available.  相似文献   
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The shift from production-based to consumption-based societies has seen consumption transformed from a means of meeting material needs to a method of creating a personal identity. Citizens of affluent countries increasingly seek a sense of self from their consumption activity instead of their workplace, class or community. Environmental appeals to change consumption behaviour implicitly ask people not merely to change their behaviour but to change their sense of personal identity. This can be threatening and makes more difficult the emergence of a new ecological consciousness, although the phenomenon of downshifting provides some grounds for optimism.  相似文献   
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