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571.
Multiple data sources are essential to provide reliable information regarding the emergence of potential health threats, compared to single source methods. Spatial Scan Statistics have been adapted to analyze multivariate data sources, but only ad hoc procedures have been devised to address the problem of selecting the most likely cluster and computing its significance. In this work, information from multiple data sources of disease surveillance is incorporated to achieve more coherent spatial cluster detection using tools from multi-criteria analysis. The best cluster solutions are found by maximizing two objective functions simultaneously, based on the concept of dominance. To evaluate the statistical significance of solutions, a statistical approach based on the concept of attainment function is used. The multi-criteria approach has several advantages: the representation of the evaluation function for each data source is clear, and does not suffer from an artificial, and possibly confusing mixture with the other data source evaluations; it is possible to attribute, in a rigorous way, the statistical significance of each candidate cluster; and it is possible to analyze and pick-up the best cluster solutions, as given naturally by the non-dominated set. The methodology is illustrated with real datasets.  相似文献   
572.
573.
Though a recent phenomenon, land grabs have generated considerable debate that remains highly polarized. In this debate, one view presents land deals as a path to sustainable and transformative rural development through capital accumulation, infrastructural development, technology transfer, and job creation while the alternative view sees land grabs as a new wave of neo-colonization, exploitation, and domination. The underlying argument, at least theoretically, is that international land deals unlock the much needed capital to accelerate the achievement of sustainable and transformative rural development in developing countries. It is against this backdrop that this paper examines the contribution of large scale land deals in Malawi to rural development by employing the political economy perspective using the Limphasa Sugar Corporation as a case study with particular focus on the nature and interest of the actors involved; the legal framework supporting large scale land deals; major individual and community benefits; and the extent to which these large land deals can indeed bring about sustainable and transformative rural development. The findings of this article demonstrate that large scale land deals present short term benefits to local communities such as capital for rural development; technology transfer and job creation in exchange for the priceless economic and social capital that local people depend upon; destruction of local social systems; deepening of local communities’ vulnerability to economic shocks; and the entrenchment of community dependence that may in the long run result in social and political unrest.  相似文献   
574.
Past and present disasters and scandals, such as the BP Deepwater Horizon oil disaster in the Gulf of Mexico in 2010, the Servier Mediator (Benfluorex) scandal in 2009 and the Enron collapse in 2001, have uncovered weaknesses in governance issues. The authors argue that there is a need to develop methods and tools to diagnose and assess the governance of organizations with respect to Sustainable Development (SD). However, this task remains difficult due to the fact that it is difficult to appraise the quality of governance. The authors propose a protocol to diagnose and analyze the governance of SD and explore the use of multiple-criteria decision-aiding methods to achieve this task. Two aggregation methods to assess the global governance are proposed: (1) The identification of a final governance index for an Organization. This method helps in establishing a global diagnosis of the quality of the governance of an Organization with respect to SD challenges. The governance index is based on the calculation of three indexes: the partial opportunity index, the partial risk index and the partial equilibrium index. (2) The ranking of a set of Organizations according to their governance of SD. This method aims at assessing a set of Organizations based on a pairwise comparison according to a set of criteria that represents the seven domains of the ISO 26000 norm (ISO 26000—Guidance on social responsibility, 2010). This method is based on the outranking aggregation approach ELECTRE III. A practical example is used to illustrate two methods of governance assessment.  相似文献   
575.
Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because it decreases biodiversity, reduces livestock forage production, and degrades the ecological function of rangelands. Despite the obvious importance of ranchers as partners in preventing and managing medusahead in rangelands, little is known about their perceptions and behaviors concerning medusahead management. We present the results of a survey of ranchers operating on sagebrush steppe rangeland in a three-county area in southeast Oregon encompassing over 7.2 million ha. The primary objective of this research was to determine if the presence of medusahead on a ranch influenced its operator’s perceptions and behaviors concerning invasive plant control and prevention. Ranchers operating on medusahead-infested rangeland were more likely to indicate increased awareness and concern about medusahead and the potential for its continued expansion. Ranchers operating on rangeland invaded by medusahead were also more likely to indicate use of measures to prevent the spread of medusahead and other invasive plants on rangeland, interest in educational opportunities concerning invasive annual grass management, and plans for controlling invasive annual grasses in the future. This study revealed an alarming trend in which individuals are less likely to implement important prevention measures and participate in education opportunities to improve their knowledge of invasive plants until they directly experience the negative consequences of invasion. Information campaigns on invasive plants and their impacts may rectify this problem; however, appropriate delivery methods are critical for success. Web- or computer-based invasive plant information and tools were largely unpopular among ranchers, whereas traditional forms of information delivery including brochures/pamphlets and face-to-face interaction were preferred. However, in the future web- or computer-based information may become more popular as ranchers become more familiar with them.  相似文献   
576.
Fallow vegetation within landscapes dominated by shifting cultivation represents a woody species pool of critical importance with considerable potential for biodiversity conservation. Here, through the analysis of factors that influence the early stages of fallow vegetation regrowth in two contrasting forest margin landscapes in Southern Cameroon, we assessed the impact of current trends of land use intensification and expansion of the cultivated areas, upon the conservation potential of shifting cultivation landscapes. We combined the analysis of plot and landscape scale factors and identified a complex set of variables that influence fallow regrowth processes in particular the characteristics of the agricultural matrix and the distance from forest. Overall we observed a decline in the fallow species pool, with composition becoming increasingly dominated by species adapted to recurrent disturbance. It is clear that without intervention and if present intensification trends continue, the potential of fallow vegetation to contribute to biodiversity conservation declines because of a reduced capacity, (1) to recover forest vegetation with anything like its original species composition, (2) to connect less disturbed forest patches for forest dependent organisms. Strategies to combat biodiversity loss, including promotion of agroforestry practices and the increase of old secondary forest cover, will need not only to operate at a landscape scale but also to be spatially explicit, reflecting the spatial pattern of species reservoirs and dispersal strategies and human usage across landscapes.  相似文献   
577.
578.
The environmental degradation caused by industrial agriculture, as well as the resulting social and health consequences, creates an urgency to rethink food production by expanding the moral imagination to include agricultural practices. Agricultural practices presume human use of the earth and acknowledge human dependence on the biotic community, and these relations mean that agriculture presents a separate set of considerations in the broader field of environmental ethics. Many scholars and activists have argued persuasively that we need new stories to rethink agricultural practice, however, the link—the story that does and can shape agricultural practice—has not yet been fully articulated in environmental discourse. My analysis explores how language has shaped existing agricultural models and, more important, the potential of story to influence agricultural practice. To do this, I draw upon cognitive theory to illustrate how metaphoric and narrative language structures thought and influences practice, beginning with my contention that industrial agriculture relies on a discourse of mechanistic relations between humans and a passive earth, language that has naturalized the chemically intensive monocultures prevalent in much of the American Midwest. However, alternative agricultures, including organic agriculture, agro-ecology, and ecological agriculture, emphasize qualities such as interdependence and reciprocity and do so as a deliberate response to the perceived inadequacies of industrial agriculture and its governing narrative. Exploring the different discourses of agricultural systems can help us think through different modalities for human relations with the biotic community and demonstrate story’s potential role in altering practice.  相似文献   
579.
This study aimed at understanding how landscape heterogeneity influences outbreaks of contagious diseases in southern Africa. Landscape attributes influence patterns of movement and behaviour of animal hosts, virus spread and survival, as well as land use practices. A multi-agent simulation was developed to represent the spatial and temporal dynamics of pathogens between human-livestock and wildlife interfaces at the fringe of large wildlife conservation areas. The model represents the three main elements associated with epidemics - populations, space, and time - to simulate direct contacts between wildlife and livestock. The dynamics of these populations emerge from interactions between agents and the landscape. The model was calibrated to represent the transmission of foot-and-mouth disease through direct contact at the border of the Kruger National Park in South Africa. In the region, African buffaloes (Syncerus caffer) act as reservoirs of the virus and spread the infection to domestic cattle bordering the park. We tested the sensitivity of various factors influencing contact rate between buffaloes and cattle, and thus the risk of foot-and-mouth disease transmission. Results show that cattle-buffalo contacts mostly depend on the range of displacements of cattle and buffaloes, as influenced by the landscape configuration, and on the number of fence breakages multiplied by the time between breakage and repair. Contacts take place not only close to water-points but also in grazing areas, within an area up to 6 km from the fence.  相似文献   
580.
The primary focus of many in-stream restoration projects is to enhance habitat diversity for salmonid fishes, yet the lack of properly designed monitoring studies, particularly ones with pre-restoration data, limits any attempts to assess whether restoration has succeeded in improving salmonid habitat. Even less is known about the impacts of fisheries-related restoration on other, non-target biota. We examined how restoration aiming at the enhancement of juvenile brown trout (Salmo trutta L.) affects benthic macroinvertebrates, using two separate data sets: (1) a before-after-control-impact (BACI) design with three years before and three after restoration in differently restored and control reaches of six streams; and (2) a space-time substitution design including channelized, restored, and near-natural streams with an almost 20-year perspective on the recovery of invertebrate communities. In the BACI design, total macroinvertebrate density differed significantly from before to after restoration. Following restoration, densities decreased in all treatments, but less so in the controls than in restored sections. Taxonomic richness also decreased from before to after restoration, but this happened similarly in all treatments. In the long-term comparative study, macroinvertebrate species richness showed no difference between the channel types. Community composition differed significantly between the restored and natural streams, but not between restored and channelized streams. Overall, the in-stream restoration measures used increased stream habitat diversity but did not enhance benthic biodiversity. While many macroinvertebrates may be dispersal limited, our study sites should not have been too distant to reach within almost two decades. A key explanation for the weak responses by macroinvertebrate communities may have been historical. When Fennoscandian streams were channelized for log floating, the loss of habitat heterogeneity was only partial. Therefore, habitat may not have been limiting the macroinvertebrate communities to begin with. Stream restoration to support trout fisheries has strong public acceptance in Finland and will likely continue to increase in the near future. Therefore, more effort should be placed on assessing restoration success from a biodiversity perspective using multiple organism groups in both stream and riparian ecosystems.  相似文献   
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