1,006 research outputs found

    Incentive-based approaches to sustainable fisheries

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    The failures of traditional target-species management have led many to propose an ecosystem approach to fisheries to promote sustainability. The ecosystem approach is necessary, especially to account for fishery-ecosystem interactions, but by itself is not sufficient to address two important factors contributing to unsustainable fisheries — inappropriate incentives bearing on fishers, and the ineffective governance that frequently exists in commercial, developed fisheries managed primarily by total harvest limits and input-controls. We contend that much greater emphasis must be placed on fisher motivation when managing fisheries. Using evidence from more than a dozen ‘natural experiments’ in commercial fisheries, we argue that incentive-based approaches that better specify community, individual harvest, or territorial rights and also price ecosystem services — coupled with public research, monitoring and effective oversight — promote sustainable fisheries.incentives, sustainability, rights, fisheries management

    Spontaneous Firings of Carnivorous Aquatic Utricularia Traps: Temporal Patterns and Mechanical Oscillations

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    Aquatic species of Utricularia are carnivorous plants living in environments poor in nutrients. Their trapping mechanism has fascinated generations of scientists and is still debated today. It was reported recently that Utricularia traps can fire spontaneously. We show here that these spontaneous firings follow an unexpected diversity of temporal patterns, from “metronomic” traps which fire at fixed time intervals to “random” patterns, displaying more scattered firing times. Some “bursting” traps even combine both aspects, with groups of fast regular firings separated by a variable amount of time. We propose a physical model to understand these very particular behaviors, showing that a trap of Utricularia accomplishes mechanical oscillations, based on continuous pumping and sudden opening of the trap door (buckling). We isolate the key parameters governing these oscillations and discuss the effect of their fluctuations

    A Prospective Longitudinal Study of the Clinical Outcomes from Cryptococcal Meningitis following Treatment Induction with 800 mg Oral Fluconazole in Blantyre, Malawi

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    Introduction: Cryptococcal meningitis is the most common neurological infection in HIV infected patients in Sub Saharan Africa, where gold standard treatment with intravenous amphotericin B and 5 flucytosine is often unavailable or difficult to administer. Fluconazole monotherapy is frequently recommended in national guidelines but is a fungistatic drug compromised by uncertainty over optimal dosing and a paucity of clinical end-point outcome data. Methods: From July 2010 until March 2011, HIV infected adults with a first episode of cryptococcal meningitis were recruited at Queen Elizabeth Central Hospital, Blantyre, Malawi. Patients were treated with oral fluconazole monotherapy 800 mg daily, as per national guidelines. ART was started at 4 weeks. Outcomes and factors associated with treatment failure were assessed 4, 10 and 52 weeks after fluconazole initiation. Results: Sixty patients were recruited. 26/60 (43%) died by 4 weeks. 35/60 (58.0%) and 43/56 (77%) died or failed treatment by 10 or 52 weeks respectively. Reduced consciousness (Glasgow Coma Score ,14 of 15), moderate/severe neurological disability (modified Rankin Score .3 of 5) and confusion (Abbreviated Mental Test Score ,8 of 10) were all common at baseline and associated with death or treatment failure. ART prior to recruitment was not associated with better outcomes. Conclusions: Mortality and treatment failure from cryptococcal meningitis following initiation of treatment with 800 mg oral fluconazole is unacceptably high. To improve outcomes, there is an urgent need for better therapeutic strategies and point-of-care diagnostics, allowing earlier diagnosis before development of neurological deficit

    Performance of the QuickVue Influenza A+B Rapid Test for Pandemic H1N1 (2009) Virus Infection in Adults

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    To investigate the diagnostic accuracy of the QuickVue® Influenza A+B rapid test we conducted a prospective observational study in which this rapid test was compared with a real-time reverse transcription polymerase chain reaction (RT-PCR) for pandemic influenza A H1N1 (2009) infection in Austrian adults. The sensitivity, specificity, and positive and negative predictive values of the QuickVue test compared with the RT-PCR were 26% (95% CI 18–35), 98% (95% CI 92–100), 94% (95% CI 80–99) and 50% (95% CI 42–58), respectively. The prevalence of pandemic H1N1 (2009) virus infection among the 209 patients included in the study was 57%. Our data suggest that a positive QuickVue test provides considerable information for the diagnosis of pandemic influenza A H1N1 (2009) virus infection in young adults but that a negative QuickVue test result should, if relevant for patient management or public health measures, be verified using PCR

    Glyburide Is Anti-inflammatory and Associated with Reduced Mortality in Melioidosis

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    Patients with diabetes have better survival from septic melioidosis than patients who without diabetes. This difference was seen only in patients taking glyburide prior to presentation and was associated with an anti-inflammatory effect of glyburide

    Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey

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    Using the large multi-wavelength data set in the chandra/SWIRE Survey (0.6 square degrees in the Lockman Hole), we show evidence for the existence of highly obscured (Compton-thick) AGN, estimate a lower limit to their surface density and characterize their multi-wavelength properties. Two independent selection methods based on the X-ray and infrared spectral properties are presented. The two selected samples contain 1) 5 X-ray sources with hard X-ray spectra and column densities > 10^24 cm-2, and 2) 120 infrared sources with red and AGN-dominated infrared spectral energy distributions (SEDs). We estimate a surface density of at least 25 Compton-thick AGN per square degree detected in the infrared in the chandra/SWIRE field of which ~40% show distinct AGN signatures in their optical/near-infrared SEDs, the remainings being dominated by the host-galaxy emission. Only ~33% of all Compton-thick AGN are detected in the X-rays at our depth (F(0.3-8 keV)>10^-15 erg/cm2/s. We report the discovery of two sources in our sample of Compton-thick AGN, SWIRE_J104409.95+585224.8 (z=2.54) and SWIRE_J104406.30+583954.1 (z=2.43), which are the most luminous Compton-thick AGN at high-z currently known. The properties of these two sources are discussed in detail with an analysis of their spectra, SEDs, luminosities and black-hole masses.Comment: ApJ accepted (to appear in May 2006 issue, vol. 642, of ApJ) Figures 2, 3, and 14 have been degraded due to space consideration
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