1,744 research outputs found

    Assessing the Economic Value of Ecosystem Conservation

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    Valuation studies have considerably increased our knowledge of the value of ecosystems. Their usefulness has often been undermined, however, by a failure to properly frame them so as to address the specific question of interest. Valuation is not a single activity, and the seemingly simple question ‘how valuable is an ecosystem?’ can be interpreted in many different ways. This paper seeks to clarify how valuation should be conducted to answer specific policy questions. In particular, it looks at how valuation should be used to examine four distinct aspects of the value of ecosystems: (1) Determining the value of the total flow of benefits from ecosystems. This question typically arises in a ‘national accounts’ context: How much are ecosystems contributing to economic activity? It is most often asked at the national level, but can also be asked at the global, regional, or local level. (2) Determining the net benefits of interventions that alter ecosystem conditions. This question typically arises in a project or policy context: Would the benefits of a given conservation investment, regulation, or incentive justify its costs? It differs fundamentally from the previous question in that it asks about changes in flows of costs and benefits, rather than the sum total value of flows. (3) Examining how the costs and benefits of ecosystems are distributed. Different stakeholder groups often perceive very different costs and benefits from ecosystems. Understanding the magnitude and mix of net benefits received by particular groups is important for two reasons. From a practical perspective, groups that stand to ‘lose’ from conservation may seek to undermine it. Understanding which groups are motivated to conserve or destroy an ecosystem, and why, can help to design more effective conservation approaches. From an equity perspective, the impact of conservation on particular groups such as the poor, or indigenous peoples, is also often of significant concern in and of itself. (4) Identifying potential financing sources for conservation. Knowing that ecosystem services are valuable is of little use if it does not lead to real investments in conserving the natural ecosystems that provide them. Simply knowing that a protected area provides valuable watershed protection benefits, for example, does not pay the salaries of park rangers. Yet experience has shown that relying solely on government budget allocations or external donors for the necessary funding is risky. Valuation can help identify the beneficiaries of conservation and the magnitude of the benefits they receive, and thus help design mechanisms to capture some of these benefits and make them available for conservation. These four approaches are closely linked and build on each othe, often using similar data. They use that data in very different ways, however, sometimes looking at all of it, sometimes at a subset, sometimes looking at a snapshot, and sometimes looking at changes over time. Each approach has its uses and its limitations. Understanding under what conditions one approach should be used rather than another is critical: the answer obtained under one approach, no matter how well conducted, is generally meaningless when applied to problems that are better treated using another approach. In particular, using estimates of total flows to justify specific conservation decisions—although commonly done—is almost always wrong. Properly used, however, valuation can provide invaluable insights into conservation issues.ecosystem, valuation

    Cross-Border Canada/U.S. Cooperation in Investigations and Enforcement Actions Vis a Vis Private Parties

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    crossborder investigation and enforcement--Canada and United State

    Efficient Process-to-Node Mapping Algorithms for Stencil Computations

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    Good process-to-compute-node mappings can be decisive for well performing HPC applications. A special, important class of process-to-node mapping problems is the problem of mapping processes that communicate in a sparse stencil pattern to Cartesian grids. By thoroughly exploiting the inherently present structure in this type of problem, we devise three novel distributed algorithms that are able to handle arbitrary stencil communication patterns effectively. We analyze the expected performance of our algorithms based on an abstract model of inter- and intra-node communication. An extensive experimental evaluation on several HPC machines shows that our algorithms are up to two orders of magnitude faster in running time than a (sequential) high-quality general graph mapping tool, while obtaining similar results in communication performance. Furthermore, our algorithms also achieve significantly better mapping quality compared to previous state-of-the-art Cartesian grid mapping algorithms. This results in up to a threefold performance improvement of an MPI_Neighbor_alltoall exchange operation. Our new algorithms can be used to implement the MPI_Cart_create functionality.Comment: 18 pages, 9 Figure

    Minimally Invasive Surgery for the Treatment of Colorectal Cancer

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    Background: Reduction in operative trauma along with an improvement in endoscopic access has undoubtedly occupied surgical minds for at least the past 3 decades. It is not at all surprising that minimally invasive colon surgery has come a long way since the first laparoscopic appendectomy by Semm in 1981. It is common knowledge that the recent developments in video and robotic technologies have significantly furthered advancements in laparoscopic and minimally invasive surgery. This has led to the overall acceptance of the treatment of benign colorectal pathology via the endoscopic route. Malignant disease, however, is still primarily treated by conventional approaches. Methods and Results: This review article is based on a literature search pertaining to advances in minimally invasive colorectal surgery for the treatment of malignant pathology, as well as on personal experience in the field over the same period of time. Our search was limited to level I and II clinical papers only, according to the evidence-based medicine guidelines. We attempted to present our unbiased view on the subject relying only on the evidence available. Conclusion: Focusing on advances in colorectal minimally invasive surgery, it has to be stated that there are still a number of unanswered questions regarding the surgical management of malignant diseases with this approach. These questions do not only relate to the area of boundaries set for the use of minimally invasive techniques in this field but also to the exact modality best suited to the treatment of every particular case whilst maintaining state-of-the-art oncological principles. (C) 2016 S. Karger GmbH, Freibur

    When Filiation Fails: Adoption as a Fallback Mechanism for Modern Family Forms?

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    Eine Naturkapitaldefinition oder Natur in der Kapitaltheorie

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    Multiple faces of stress in the zebrafish (Danio rerio) brain

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    The changing expressions of certain genes as a consequence of exposure to stressors has not been studied in detail in the fish brain. Therefore, a stress trial with zebrafish was conducted, aiming at identifying relevant gene regulation pathways in different regions of the brain. As acute stressors within this trial, feed rewarding, feed restriction, and air exposure have been used. The gene expression data from the experimental fish brains have been analyzed by means of principal component analyses (PCAs), whereby the individual genes have been compiled according to the regulation pathways in the brain. The results did not indicate a mutual response across the treatment and gender groups. To evaluate whether a similar sample structure belonging to a large sample size would have allowed the classification of the gene expression patterns according to the treatments, the data have been bootstrapped and used for building random forest models. These revealed a high accuracy of the classifications, but different genes in the female and male zebrafish were found to have contributed to the classification algorithms the most. These analyses showed that less than eight genes are, in most cases, sufficient for an accurate classification. Moreover, mainly genes belonging to the stress axis, to the isotocin regulation pathways, or to the serotonergic pathways had the strongest influence on the outcome of the classification models
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