715,111 research outputs found

    The Middle Eastern Biodiversity Network: Generating and sharing knowledge for ecosystem management and conservation

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    Despite prevailing arid conditions, the diversity of terrestrial and freshwater biota in the Middle East is amazingly high and marine biodiversity is among the highest on Earth. Th roughout the Region, threats to the environment are moderate to severe. Despite the outstanding economic and ecological importance of biological diversity, the capacity in biodiversity-related research and academic education is inadequate. The "Middle Eastern Biodiversity Network" (MEBN), founded in 2006 by six universities and research institutes in Iran, Jordan, Germany, Lebanon and Yemen was designed to fi ll this gap. An integrated approach is taken to upgrade biodiversity research and education in order to improve regional ecosystem conservation and management capacities. A wide range of activities are carried out in the framework of the Network, including capacity building in biological collection management and professional natural history curatorship, developing university curricula in biodiversity, conducting scientifi c research, organising workshops and conferences on Middle Eastern biodiversity, and translating the results of biodiversity research into conservation and sustainable development. Keywords: Middle Eastern biodiversity, nature museums, biodiversity research, biodiversity education, biodiversity conservation, biodiversity network

    Random Networks with given Rich-club Coefficient

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    In complex networks it is common to model a network or generate a surrogate network based on the conservation of the network's degree distribution. We provide an alternative network model based on the conservation of connection density within a set of nodes. This density is measure by the rich-club coefficient. We present a method to generate surrogates networks with a given rich-club coefficient. We show that by choosing a suitable local linking term, the generated random networks can reproduce the degree distribution and the mixing pattern of real networks. The method is easy to implement and produces good models of real networks.Comment: revised version, new figure

    Compensatory Measures in European Nature conservation law

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    The Birds and Habitats Directives are the cornerstones of EU nature conservation law, aiming at the conservation of the Natura 2000 network, a network of protected sites under these directives, and the protection of species. The protection regime for these sites and species is not absolute: Member States may, under certain conditions, allow plans or projects that can have an adverse impact on nature. In this case compensatory measures can play an important role in safeguarding the Natura 2000 network and ensuring the survival of the protected species.This contribution analyses whether taking compensatory measures is always obligatory, and discusses the aim and the characteristics of compensatory measures, in relation to other kinds of measures such as mitigation measures, usual nature conservation measures, and former nature development measures, and to the assessment of the adverse impact caused by the plan or project and of the alternative solutions. The questions will be discussed in light of the contents of the legislation, the guidance and practice by the European Commission, (legal) doctrine and case law, mainly of the Court of Justice of the European Union

    Assessing the umbrella value of a range-wide conservation network for Jaguars (Panthera onca)

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    Umbrella species are employed as conservation short-cuts for the design of reserves or reserve networks. However, empirical data on the effectiveness of umbrellas is equivocal, which has prevented more widespread application of this conservation strategy. We perform a novel, large-scale evaluation of umbrella species by assessing the potential umbrella value of a jaguar (Panthera onca) conservation network (consisting of viable populations and corridors) that extends from Mexico to Argentina. Using species richness, habitat quality, and fragmentation indices of similar to 1500 co-occurring mammal species, we show that jaguar populations and corridors overlap a substantial amount and percentage of high-quality habitat for co-occurring mammals and that the jaguar network performs better than random networks in protecting high-quality, interior habitat. Significantly, the effectiveness of the jaguar network as an umbrella would not have been noticeable had we focused on species richness as our sole metric of umbrella utility. Substantial inter-order variability existed, indicating the need for complementary conservation strategies for certain groups of mammals. We offer several reasons for the positive result we document, including the large spatial scale of our analysis and our focus on multiple metrics of umbrella effectiveness. Taken together, our results demonstrate that a regional, single-species conservation strategy can serve as an effective umbrella for the larger community and should help conserve viable populations and connectivity for a suite of co-occurring mammals. Current and future range-wide planning exercises for other large predators may therefore have important umbrella benefits

    Enabling Work-conserving Bandwidth Guarantees for Multi-tenant Datacenters via Dynamic Tenant-Queue Binding

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    Today's cloud networks are shared among many tenants. Bandwidth guarantees and work conservation are two key properties to ensure predictable performance for tenant applications and high network utilization for providers. Despite significant efforts, very little prior work can really achieve both properties simultaneously even some of them claimed so. In this paper, we present QShare, an in-network based solution to achieve bandwidth guarantees and work conservation simultaneously. QShare leverages weighted fair queuing on commodity switches to slice network bandwidth for tenants, and solves the challenge of queue scarcity through balanced tenant placement and dynamic tenant-queue binding. QShare is readily implementable with existing switching chips. We have implemented a QShare prototype and evaluated it via both testbed experiments and simulations. Our results show that QShare ensures bandwidth guarantees while driving network utilization to over 91% even under unpredictable traffic demands.Comment: The initial work is published in IEEE INFOCOM 201

    From Differentiated Coffee Markets Towards Alternative Trade and Knowledge Networks

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    This chapter presents a case study focusing on the Community Agroecology Network (CAN), an organization started by the United States and Mesoamerica’s activists, whose effort is to create an alternative trade and knowledge network. The basic aim behind CAN is to benefit conservation and social development efforts by linking producers, consumers, and producer organizations. CAN is a response to the problems arising out of the dominance of certification processes in Fair Trade and organic coffee networks, and the chapter discusses the organization’s main goals of intercommunity relationship development, direct coffee marketing, and ecological sustainability. It moots a comparison between alternative agro-food networks and CAN on the grounds of biodiversity conservation, empowerment, and enhanced livelihoods
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