114 research outputs found

    Alarming decline of freshwater trigger species in western Mediterranean key biodiversity areas

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    Theidentification of key biodiversity areas (KBA) was initiated by the International Union for Conservation of Nature in 2004 to overcome taxonomic biases in the selection of important areas for conservation, including freshwater ecosystems. Since then, several KBAs have been identified mainly based on the presence of trigger species (i.e., species that trigger either the vulnerability and or the irreplaceability criterion and thus identify a site as a KBA). However, to our knowledge, many of these KBAs have not been validated. Therefore, classical surveys of the taxa used to identify freshwater KBAs (fishes, molluscs, odonates, and aquatic plants) were conducted in Douro (Iberian Peninsula) and Sebou (Morocco) River basins in the Mediterranean Biodiversity Hotspot. Environmental DNA analyses were undertaken in the Moroccan KBAs. There was a mismatch between the supposed and actual presence of trigger species. None of the trigger species were found in 43% and 50% of all KBAs surveyed in the Douro and Sebou basins, respectively. Shortcomings of freshwater KBA identification relate to flawed or lack of distribution data for trigger species. This situation results from a misleading initial identification of KBAs based on poor (or even inaccurate) ecological information or due to increased human disturbance between initial KBA identification and the present. To improve identification of future freshwater KBAs, we suggest selecting trigger species with a more conservative approach; use of local expert knowledge and digital data (to assess habitat quality, species distribution, and potential threats); consideration of the subcatchment when delineating KBAs boundaries; thoughtful consideration of terrestrial special areas for conservation limits; and periodic field validation.info:eu-repo/semantics/publishedVersio

    Chronic Hepatitis C treatment for genotype 2 or 3 in Brazil: cost effectiveness analysis of peginterferon plus ribavirin as first choice treatment

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    Brazilian Guidelines to HCV treatment (2007) recommended that the first choice treatment for patients with chronic hepatitis C (CHC) and genotype 2 or 3 is interferon alpha (IFN) plus ribavirin (RBV) for 24 weeks. The aim of this study is compare the cost and effectiveness to Hepatitis C treatment in patients with genotype 2 or 3 of peginterferon alpha (PEG) as the first choice of treatment within PEG for those that do not respond to IFN. The target population is CHC patients with genotype 2 or 3 in Brazil. The interventions are: PEG-SEC (first IFN plus RBV for 24 weeks, after, for non-responders and relapsers subsequently PEG plus RBV for 48 weeks); PEG-FIRST24 (PEG+RBV for 24 weeks). The type of the study is cost-effectiveness analysis. The data sources are: Effectiveness data from meta-analysis conducted on the Brazilian population. Treatment cost from Brazilian micro costing study is converted into USD (2010). The perspective is the Public Health System. The outcome measurements are Sustained Viral Response (SVR) and costs. PEG-FIRST24 (SVR: 87.8%, costs: USD 8,338.27) was more effective and more costly than PEG-SEC (SVR: 79.2%, costs: USD 5,852.99). The sensitivity analyses are: When SVR rates with IFN was less than 30% PEG-FIRST is dominant. On the other hand, when SVR with IFN was more then 75% PEG-SEC is dominant (SVR=88.2% and costs USD $ 3,753.00). PEG-SEC is also dominant when SVR to PEG24 weeks was less than 54%. In the Brazilian context, PEG-FIRST is more effective and more expensive than PEG-SEC. PEG-SEC could be dominant when rates of IFN therapy are higher than 75% or rates of PEG24 therapy are lower than 54%

    Hadronic top-quark pair production in association with a hard jet at next-to-leading order QCD: Phenomenological studies for the Tevatron and the LHC

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    We report on the calculation of the next-to-leading order QCD corrections to the production of top--antitop-quark pairs in association with a hard jet at the Tevatron and at the LHC. Results for integrated and differential cross sections are presented. We find a significant reduction of the scale dependence. In most cases the corrections are below 20% indicating that the perturbative expansion is well under control. Moreover, the forward--backward charge asymmetry of the top-quark, which is analyzed at the Tevatron, is studied at next-to-leading order. We find large corrections suggesting that the definition of the observable has to be refined.Comment: 37 pages, version to be publishe
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