1,221 research outputs found

    A sub-regional management framework for South Pacific longline fisheries

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    The principal objective of this study was to determine if additional net benefits can be derived from the sub-regional longline fishery by the introduction of a new management agreement that would centre on the provision of licensing arrangements that would allow access by eligible longline vessels to multiple Exclusive Economic Zones, i.e. Multi-zone Access. [90pp.

    Health, Wealth, and the 21st Century Cures Act

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    Americans are increasingly apprehensive about our future, so it is inspiring when Congress produces legislation intended to both enhance our health and expand our economy. The 21st Century Cures Act,1 recently passed by the House with an impressive bipartisan majority vote of 344 to 77, intends to accelerate the many-step process of drug discovery and development, from basic scientific research to clinical development to delivery, distribution, and ongoing monitoring. Among other things, the legislation boosts National Institute of Health funding, dramatically speeds up the US Food and Drug Administration (FDA) approval process, and aims to make use of new information technology to better monitor the performance of medical products after they reach the market. This landmark bill now awaits a comparable piece of legislation being developed by the Senate Health Education, Labor, and Pensions Committee. Together, they will transform the biomedical ecosystem and provide the foundation for the next several decades of innovative life-saving and health-enhancing solutions for our nation and the world

    The Effects of Product Liability Exemption in the Presence of the FDA

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    In the United States, drugs are jointly regulated by the US Food and Drug Administration, which oversees premarket clinical trials designed to ensure drug safety and efficacy, and the liability system, which allows patients to sue manufacturers for unsafe drugs. In this paper, we examine the potential welfare effects of this dual system aimed at ensuring the safety of medical products, and conclude that product liability exemptions for FDA regulated activities could raise economic efficiency. We show that while reductions in liability, such those associated with pre-emption, may lower welfare in the absence of the FDA, they may raise welfare in its presence. In the presence of the FDA, product liability may reduce efficiency by raising prices without pushing firms, who are already bound by the agency’s requirements, to invest further in product safety. We consider as a case study the National Vaccine Injury Compensation Program, which sharply reduced vaccine manufacturer’s liability in 1988. We find evidence that the program reduced prices without affecting vaccine safety, suggesting that liability reductions can enhance economic efficiency in the presence of the FDA.

    Effects of seed predators of different body size on seed mortality in Bornean logged gorest

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    Background The Janzen-Connell hypothesis proposes that seed and seedling enemies play a major role in maintaining high levels of tree diversity in tropical forests. However, human disturbance may alter guilds of seed predators including their body size distribution. These changes have the potential to affect seedling survival in logged forest and may alter forest composition and diversity. Methodology/Principal Findings We manipulated seed density in plots beneath con- and heterospecific adult trees within a logged forest and excluded vertebrate predators of different body sizes using cages. We show that small and large-bodied predators differed in their effect on con- and heterospecific seedling mortality. In combination small and large-bodied predators dramatically decreased both con- and heterospecific seedling survival. In contrast, when larger-bodied predators were excluded small-bodied predators reduced conspecific seed survival leaving seeds coming from the distant tree of a different species. Conclusions/Significance Our results suggest that seed survival is affected differently by vertebrate predators according to their body size. Therefore, changes in the body size structure of the seed predator community in logged forests may change patterns of seed mortality and potentially affect recruitment and community composition

    Differential growth responses in seedlings of ten species of Dipterocarpaceae to experimental shading and defoliation

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    The responses of plants to shade and foliar herbivory jointly affect growth rates and community assembly. We grew 600 seedlings of ten species of the economically important Dipterocarpaceae in experimental gradients of shading (0.3-47.0% of full sunlight) and defoliation (0, 25%, 50% or 75% of leaf area removed). We assessed stem diameters initially, after 2 and 4 mo, and calculated relative growth rates (RGR) with a linear model. Shading interacted with defoliation, reducing RGR by 21.6% in shaded conditions and 8.9% in well-lit conditions. We tested three hypotheses for interspecific trade-offs in growth responses to shading and defoliation. They could be positively related, because both reduce a plant's access to carbon, or inversely related because of trade-offs between herbivore resistance and tolerance. We observed, however, that species varied in their response to shading, but not defoliation, precluding an interspecific trade-off and suggesting that plants tolerate shade and herbivory with differing strategies. Shading most strongly reduced the growth of species with less-dense wood and larger seeds. The strong and variable growth responses to shade, contrasted with the weak and uniform responses to defoliation, suggest that variation in light availability more strongly affects the growth of tropical tree seedlings, and thus community assembly, than does variation in herbivor

    Intraperitoneal Injection into Adult Zebrafish

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    A convenient method for chemically treating zebrafish is to introduce the reagent into the tank water, where it will be taken up by the fish. However, this method makes it difficult to know how much reagent is absorbed or taken up per fish. Some experimental questions, particularly those related to metabolic studies, may be better addressed by delivering a defined quantity to each fish, based on weight. Here we present a method for intraperitoneal (IP) injection into adult zebrafish. Injection is into the abdominal cavity, posterior to the pelvic girdle. This procedure is adapted from veterinary methods used for larger fish. It is safe, as we have observed zero mortality. Additionally, we have seen bleeding at the injection site in only 5 out of 127 injections, and in each of those cases the bleeding was brief, lasting several seconds, and the quantity of blood lost was small. Success with this procedure requires gentle handling of the fish through several steps including fasting, weighing, anesthetizing, injection, and recovery. Precautions are required to minimize stress throughout the procedure. Our precautions include using a small injection volume and a 35G needle. We use Cortland salt solution as the vehicle, which is osmotically balanced for freshwater fish. Aeration of the gills is maintained during the injection procedure by first bringing the fish into a surgical plane of anesthesia, which allows slow operculum movements, and second, by holding the fish in a trough within a water-saturated sponge during the injection itself. We demonstrate the utility of IP injection by injecting glucose and monitoring the rise in blood glucose level and its subsequent return to normal. As stress is known to increase blood glucose in teleost fish, we compare blood glucose levels in vehicle-injected and non-injected adults and show that the procedure does not cause a significant rise in blood glucose

    Complete atrial-specific knockout of sodium-calcium exchange eliminates sinoatrial node pacemaker activity.

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    The origin of sinoatrial node (SAN) pacemaker activity in the heart is controversial. The leading candidates are diastolic depolarization by "funny" current (If) through HCN4 channels (the "Membrane Clock" hypothesis), depolarization by cardiac Na-Ca exchange (NCX1) in response to intracellular Ca cycling (the "Calcium Clock" hypothesis), and a combination of the two ("Coupled Clock"). To address this controversy, we used Cre/loxP technology to generate atrial-specific NCX1 KO mice. NCX1 protein was undetectable in KO atrial tissue, including the SAN. Surface ECG and intracardiac electrograms showed no atrial depolarization and a slow junctional escape rhythm in KO that responded appropriately to β-adrenergic and muscarinic stimulation. Although KO atria were quiescent they could be stimulated by external pacing suggesting that electrical coupling between cells remained intact. Despite normal electrophysiological properties of If in isolated patch clamped KO SAN cells, pacemaker activity was absent. Recurring Ca sparks were present in all KO SAN cells, suggesting that Ca cycling persists but is uncoupled from the sarcolemma. We conclude that NCX1 is required for normal pacemaker activity in murine SAN

    MAES Service Case: Wetland ecosystem condition mapping (v.1.0)

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    SWOS Technical publicationThe MAES working group is preparing the workshop on “ecosystem condition mapping” to streamline the efforts done so far with regards to the mapping and assessment of the condition of Europe’s ecosystems. The MAES WG has requested directly to SWOS partners a specific document to support the mapping and assessing wetland ecosystem condition for this workshop. This document shall highlight the different elements to take into account for the mapping and assessment of wetland ecosystems with the aim of supporting Member States and the European Commission in their efforts to better describe the situation of wetland ecosystems in Europe. This document represents the major output of the MAES Service case that shall show how SWOS outputs are useful to support the MAES WG with regards to wetland ecosystem mapping and assessment

    An Economic Evaluation of the War on Cancer

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    For decades, the US public and private sectors have committed substantial resources towards cancer research, but the societal payoff has not been well-understood. We quantify the value of recent gains in cancer survival, and analyze the distribution of value among various stakeholders. Between 1988 and 2000, life expectancy for cancer patients increased by roughly four years, and the average willingness-to-pay for these survival gains was roughly 322,000.Improvementsincancersurvivalduringthisperiodcreated23millionadditionallifeyearsandroughly322,000. Improvements in cancer survival during this period created 23 million additional life-years and roughly 1.9 trillion of additional social value, implying that the average life-year was worth approximately $82,000 to its recipient. Health care providers and pharmaceutical companies appropriated 5-19% of this total, with the rest accruing to patients. The share of value flowing to patients has been rising over time. These calculations suggest that from the patient's point of view, the rate of return to R&D investments against cancer has been substantial.

    Isotopically (δ13C and δ18O) heavy volcanic plumes from Central Andean volcanoes: a field study

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    Stable isotopes of carbon and oxygen in volcanic gases are key tracers of volatile transfer between Earth’s interior and atmosphere. Although important, these data are available for few volcanoes because they have traditionally been difficult to obtain and are usually measured on gas samples collected from fumaroles. We present new field measurements of bulk plume composition and stable isotopes (δ13CCO2 and δ18OH2O+ CO2) carried out at three northern Chilean volcanoes using MultiGAS and isotope ratio infrared spectroscopy. Carbon and oxygen in magmatic gas plumes of Lastarria and Isluga volcanoes have δ13C in CO2 of +0.76‰ to +0.77‰ (VPDB), similar to slab carbonate; and δ18O in the H2O + CO2 system ranging from +12.2‰ to +20.7‰ (VSMOW), suggesting significant contributions from altered slab pore water and carbonate. The hydrothermal plume at Tacora has lower δ13CCO2 of −3.2‰ and δ18OH2O+CO2 of +7.0‰, reflecting various scrubbing, kinetic fractionation, and contamination processes. We show the isotopic characterization of volcanic gases in the field to be a practical complement to traditional sampling methods, with the potential to remove sampling bias that is a risk when only a few samples from accessible fumaroles are used to characterize a given volcano’s volatile output. Our results indicate that there is a previously unrecognized, relatively heavy isotopic signature to bulk volcanic gas plumes in the Central Andes, which can be attributed to a strong influence from components of the subducting slab, but may also reflect some local crustal contamination. The techniques we describe open new avenues for quantifying the roles that subduction zones and arc volcanoes play in the global carbon cycle.Published653V. Proprietà dei magmi e dei prodotti vulcaniciJCR Journa
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