2,653 research outputs found

    Reconstruction of the Advanced Supersonic Parachute Inflation Research Experiment Sounding Rocket Flight Test

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    The Advanced Supersonic Parachute Inflation Research and Experiments project is a flight test program for development of supersonic parachutes for potential future use at Mars. The flight tests are designed to reduce risk for the Mars 2020 mission. The flight tests involve two Disk-Gap-Band parachute designs to be tested at relevant Mach number and dynamic pressure conditions for the Mars 2020 entry capsule. The first of these parachutes is a built-to-print design that was successfully employed by the Mars Science Laboratory lander at Mars in August 2012, and the second is a design that is strengthened in material properties and construction methods but has the same geometry as that used by Mars Science Laboratory. The first flight test of the built-to-print parachute took place on October 4, 2017 at NASA's Wallops Flight Facility. This paper describes the instrumentation, data analysis techniques, and atmospheric and trajectory reconstruction results from this flight test

    Reversible skew laurent polynomial rings and deformations of poisson automorphisms

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    A skew Laurent polynomial ring S = R[x(+/- 1); alpha] is reversible if it has a reversing automorphism, that is, an automorphism theta of period 2 that transposes x and x(-1) and restricts to an automorphism gamma of R with gamma = gamma(-1). We study invariants for reversing automorphisms and apply our methods to determine the rings of invariants of reversing automorphisms of the two most familiar examples of simple skew Laurent polynomial rings, namely a localization of the enveloping algebra of the two-dimensional non-abelian solvable Lie algebra and the coordinate ring of the quantum torus, both of which are deformations of Poisson algebras over the base field F. Their reversing automorphisms are deformations of Poisson automorphisms of those Poisson algebras. In each case, the ring of invariants of the Poisson automorphism is the coordinate ring B of a surface in F-3 and the ring of invariants S-theta of the reversing automorphism is a deformation of B and is a factor of a deformation of F[x(1), x(2), x(3)] for a Poisson bracket determined by the appropriate surface

    Hierarchical priority setting for restoration in a watershed in NE Spain, based on assessments of soil erosion and ecosystem services

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    31 páginas[EN] Maintaining and enhancing ecosystem services through the restoration of degraded ecosystems have become an important biodiversity conservation strategy. Deciding where to restore ecosystems for the attainment of multiple services is a key issue for future planning, management, and human well-being. Most restoration projects usually entail a small number of actions in a local area and do not consider the potential benefits of planning restoration at broad regional scales. We developed a hierarchical priority setting approach to evaluate the performance of restoration measures in a semiarid basin in NE Spain (the Martín River Basin, 2,112 km2). Our analysis utilized a combination of erosion (a key driver of degradation in this Mediterranean region) and six spatially explicit ecosystem services data layers (five of these maps plotted surrogates for soil retention and accumulation, water supply and regulation, and carbon storage, and one plotted a cultural service, ecotourism). Hierarchical maps were generated using a geographic information system that combined areas important for providing a bundle of ecosystem services, as state variables, with erosion maps, as the disturbance or regulatory variable. This was performed for multiple scales, thereby identifying the most adequate scale of analysis and establishing a spatial hierarchy of restoration actions based on the combination of the evaluation of erosion rates and the provision of ecosystem services. Our approach provides managers with a straightforward method for determining the spatial distribution of values for a set of ecosystem services in relation to ecological degradation thresholds and for allocating efforts and resources for restoration projects in complex landscapes.This work was funded by Endesa S.A. through the collaborative agreement Endesa-CSIC for scientific research. The first author wants to thank Belinda Reyers for the fruitful conversation and helpfulness showed in every moment and two anonymous referees for their constructive suggestions. M. Trabucchi was in receipt of grant from JAE-DOC Program for Advanced Study financed by the European Social Fund (ESF), Ref. I3P-BPD-2006.Peer reviewe

    Impact of the introduction of a specialist critical care pharmacist on the level of pharmaceutical care provided to the critical care unit

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    Objectives To evaluate the impact of a dedicated specialist critical care pharmacist service on patient care at a UK critical care unit (CCU). Methods Pharmacist intervention data was collected in two phases. Phase 1 was with the provision of a non-specialist pharmacist chart review service and Phase 2 was after the introduction of a specialist dedicated pharmacy service. Two CCUs with established critical care pharmacist services were used as controls. The impact of pharmacist interventions on optimising drug therapy or preventing harm from medication errors was rated on a 4-point scale. Key findings There was an increase in the mean daily rate of pharmacist interventions after the introduction of the specialist critical care pharmacist (5.45 versus 2.69 per day, P < 0.0005). The critical care pharmacist intervened on more medication errors preventing potential harm and optimised more medications. There was no significant change to intervention rates at the control sites. Across all study sites the majority of pharmacist interventions were graded to have at least moderate impact on patient care. Conclusion The introduction of a specialist critical care pharmacist resulted in an increased rate of pharmacist interventions compared to a non-specialist pharmacist service thus improving the quality of patient care

    Hybridization of sub-gap states in one-dimensional superconductor/semiconductor Coulomb islands

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    We present measurements of one-dimensional superconductor-semiconductor Coulomb islands, fabricated by gate confinement of a two-dimensional InAs heterostructure with an epitaxial Al layer. When tuned via electrostatic side gates to regimes without sub-gap states, Coulomb blockade reveals Cooper-pair mediated transport. When sub-gap states are present, Coulomb peak positions and heights oscillate in a correlated way with magnetic field and gate voltage, as predicted theoretically, with (anti) crossings in (parallel) transverse magnetic field indicating Rashba-type spin-orbit coupling. Overall results are consistent with a picture of overlapping Majorana zero modes in finite wires

    Population-level effect of HSV-2 therapy on the incidence of HIV in sub-Saharan Africa.

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    BACKGROUND: Herpes simplex virus type 2 (HSV-2) infection increases acquisition and transmission of HIV, but the results of trials measuring the impact of HSV-2 therapy on HIV genital shedding and HIV acquisition are mixed, and the potential impact of HSV-2 therapy on the incidence of HIV at the population level is unknown. METHODS: The effects of episodic and suppressive HSV-2 therapy were simulated using the individual-level model STDSIM fitted to data from Cotonou, Benin (relatively low HIV prevalence) and Kisumu, Kenya (high HIV prevalence). Clinician- and patient-initiated episodic therapy, started when symptomatic, were assumed to reduce ulcer duration. Suppressive therapy, given regardless of symptoms, was also assumed to reduce ulcer frequency and HSV-2 infectiousness. RESULTS: Clinician-initiated episodic therapy in the general population had almost no effect on the incidence of HIV. The impact of patient-initiated therapy was higher because of earlier treatment initiation, but still low (20% in the long term. Impact was increased in both cities by also treating a proportion of their clients. Long-term suppressive therapy with high coverage in the general population could reduce HIV incidence by more than 30%. CONCLUSIONS: These results show that HSV-2 therapy could potentially have a population-level impact on the incidence of HIV, especially in more concentrated epidemics. However, a substantial impact requires high coverage and long duration therapy, or very high symptom recognition and treatment-seeking behaviour

    Selection and phylogenetics of salmonid MHC class I: wild brown trout (Salmo trutta) differ from a non-native introduced strain

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    We tested how variation at a gene of adaptive importance, MHC class I (UBA), in a wild, endemic Salmo trutta population compared to that in both a previously studied non-native S. trutta population and a co-habiting Salmo salar population ( a sister species). High allelic diversity is observed and allelic divergence is much higher than that noted previously for cohabiting S. salar. Recombination was found to be important to population-level divergence. The alpha 1 and alpha 2 domains of UBA demonstrate ancient lineages but novel lineages are also identified at both domains in this work. We also find examples of recombination between UBA and the non-classical locus, ULA. Evidence for strong diversifying selection was found at a discrete suite of S. trutta UBA amino acid sites. The pattern was found to contrast with that found in re-analysed UBA data from an artificially stocked S. trutta population
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