2,825 research outputs found

    Enhanced Feasibility Assessment of Payload Adapters for NASAs Space Launch System

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    The first flight of NASAs new exploration-classlaunch vehicle, the Space Launch System (SLS), will test amyriad of systems designed to enable the next generation of deepspace human spaceflight, and launch from Kennedy SpaceCenter no earlier than December 2019. The initial Block 1configuration for EM-1 will be capable of lofting at least 70metric tons (t) of payload and send the Orion crew vehicle intoa distant retrograde lunar orbit, paving the way for future crewmissions to cislunar space and eventually Mars. A Block 1Bversion of SLS will lift at least 34 t to trans-lunar injection (TLI)in its crew configuration and at least 37 t to TLI in its cargoconfiguration no earlier than 2024. For Mars-class payloads,larger fairings and payload adapters for the Block 2 cargovehicle are under consideration. For missions beyond the Earth-Moon system, SLS offers greater characteristic energy (C3)than any other launch vehicle, enabling shorter transit times orheavier payloads with more robust science packages formissions to the outer solar system. Indeed, the unmatchedcombination of thrust, payload volume and departure energythat SLS provides opens new opportunities for human androbotic exploration of deep space

    Two Extremely Red Galaxies

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    This report concerns one of the major observational studies in the ISO Central Programme, the ISO Normal Galaxy Survey. This is a survey of an unbiased sample of spiral and lenticular galaxies selected from the Revised Shapley-Ames Catalog. It is therefore optically-selected, with a brightness limit of blue magnitude = 12, and otherwise randomly chosen. The original sample included 150 galaxies, but this was reduced to 74 when the allocated observing time was expended because the ISO overheads encountered in flight were much larger than predicted

    The democratic engagement of Britain's ethnic minorities

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    Democratic engagement is a multi-faceted phenomenon that embraces citizens' involvement with electoral politics, their participation in ‘conventional’ extra-parliamentary political activity, their satisfaction with democracy and trust in state institutions, and their rejection of the use of violence for political ends. Evidence from the 2010 BES and EMBES shows that there are important variations in patterns of democratic engagement across Britain's different ethnic-minority groups and across generations. Overall, ethnic-minority engagement is at a similar level to and moved by the same general factors that influence the political dispositions of whites. However, minority democratic engagement is also strongly affected by a set of distinctive ethnic-minority perceptions and experiences, associated particularly with discrimination and patterns of minority and majority cultural engagement. Second-generation minorities who grew up in Britain are less, rather than more, likely to be engaged

    POWER, ENDURANCE, AND BODY COMPOSITION CHANGES OVER A COLLEGIATE CAREER IN NCAA DIVISION I WOMEN SOCCER ATHLETES

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    The purpose of this study was to determine longitudinal changes in fitness and body composition throughout athletes\u27 4-year collegiate soccer careers. Performance testing occurred before preseason during freshman, sophomore, junior, and senior year in 17 female Division I soccer players. Body composition was assessed through air-displacement plethysmography to determine percent body fat (%BF), fat-free mass (FFM), and body mass (BM). Maximal countermovement vertical jump height was assessed through contact mat using arm swing (CMJAS) and hands-on-hips (CMJHOH) methods to calculate power (CMJwatts/HOHwatts). Aerobic capacity (V̇o2max) and ventilatory threshold (VT) were assessed by indirect calorimetry during a maximal graded exercise test on a treadmill. Linear mixed models were used to assess changes across academic years (p \u3c 0.05). No changes occurred in %BF, BM, V̇o2max, VT, CMJAS, or CMJwatts. A time main effect was seen for FFM (p = 0.01) with increases from freshman to senior (p = 0.02). Time main effects were observed for CMJHOH (p \u3c 0.001) and CMJHOHwatts (p \u3c 0.001) with increases from freshman to junior (CMJHOH,p = 0.001; CMJHOHwatts, p = 0.02) and senior (CMJHOH, p \u3c 0.001; CMJHOHwatts, p = 0.003) as well as sophomore to senior (CMJHOH, p \u3c 0.001; CMJHOHwatts, p = 0.02). Countermovement vertical jump with hands on hips also increased from sophomore to junior (p = 0.005). The lower FFM and power capabilities as freshmen compared with upperclassman indicate a potential limited readiness. Coaches and training staff should account for these developmental differences when entering the preseason. Adequate conditioning programs before starting a collegiate program may help build a fitness foundation and prepare freshmen athletes to compete at the same level as their upperclassmen counterparts

    TRECVID 2014 -- An Overview of the Goals, Tasks, Data, Evaluation Mechanisms and Metrics

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    International audienceThe TREC Video Retrieval Evaluation (TRECVID) 2014 was a TREC-style video analysis and retrieval evaluation, the goal of which remains to promote progress in content-based exploitation of digital video via open, metrics-based evaluation. Over the last dozen years this effort has yielded a better under- standing of how systems can effectively accomplish such processing and how one can reliably benchmark their performance. TRECVID is funded by the NIST with support from other US government agencies. Many organizations and individuals worldwide contribute significant time and effort

    The evolutionary dynamics of variant antigen genes in Babesia reveal a history of genomic innovation underlying host-parasite interaction

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    Babesia spp. are tick-borne, intraerythrocytic hemoparasites that use antigenic variation to resist host immunity, through sequential modification of the parasite-derived variant erythrocyte surface antigen (VESA) expressed on the infected red blood cell surface. We identified the genomic processes driving antigenic diversity in genes encoding VESA (ves1) through comparative analysis within and between three Babesia species, (B. bigemina, B. divergens and B. bovis). Ves1 structure diverges rapidly after speciation, notably through the evolution of shortened forms (ves2) from 5′ ends of canonical ves1 genes. Phylogenetic analyses show that ves1 genes are transposed between loci routinely, whereas ves2 genes are not. Similarly, analysis of sequence mosaicism shows that recombination drives variation in ves1 sequences, but less so for ves2, indicating the adoption of different mechanisms for variation of the two families. Proteomic analysis of the B. bigemina PR isolate shows that two dominant VESA1 proteins are expressed in the population, whereas numerous VESA2 proteins are co-expressed, consistent with differential transcriptional regulation of each family. Hence, VESA2 proteins are abundant and previously unrecognized elements of Babesia biology, with evolutionary dynamics consistently different to those of VESA1, suggesting that their functions are distinct

    Cosmic Bell Test: Measurement Settings from Milky Way Stars

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    Bell’s theorem states that some predictions of quantum mechanics cannot be reproduced by a local-realist theory. That conflict is expressed by Bell’s inequality, which is usually derived under the assumption that there are no statistical correlations between the choices of measurement settings and anything else that can causally affect the measurement outcomes. In previous experiments, this “freedom of choice” was addressed by ensuring that selection of measurement settings via conventional “quantum random number generators” was spacelike separated from the entangled particle creation. This, however, left open the possibility that an unknown cause affected both the setting choices and measurement outcomes as recently as mere microseconds before each experimental trial. Here we report on a new experimental test of Bell’s inequality that, for the first time, uses distant astronomical sources as “cosmic setting generators.” In our tests with polarization-entangled photons, measurement settings were chosen using real-time observations of Milky Way stars while simultaneously ensuring locality. Assuming fair sampling for all detected photons, and that each stellar photon’s color was set at emission, we observe statistically significant ≳7.31σ and ≳11.93σ violations of Bell’s inequality with estimated p values of ≲1.8×10[superscript -13] and ≲4.0×10[superscript -33], respectively, thereby pushing back by ∼600  years the most recent time by which any local-realist influences could have engineered the observed Bell violation.Austrian Academy of SciencesAustrian Science Fund (Projects SFB F40 (FOQUS) and CoQuS W1210-N16)Austria. Federal Ministry of Science, Research, and EconomyNational Science Foundation (U.S.) (INSPIRE Grant PHY-1541160 and SES-1056580)Massachusetts Institute of Technology. Undergraduate Research Opportunities Progra

    Long-term efficacy and safety of a treatment strategy for HIV infection using protease inhibitor monotherapy: 8-year routine clinical care follow-up from a randomised, controlled, open-label pragmatic trial (PIVOT)

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    BACKGROUND: Treatment-simplification strategies are important tools for patient-centred management. We evaluated long-term outcomes from a PI monotherapy switch strategy. METHODS: Eligible participants attending 43 UK treatment centres had a viral load (VL) below 50 copies/ml for at least 24 weeks on combination ART. Participants were randomised to maintain ongoing triple therapy (OT) or switch to a strategy of physician-selected PI monotherapy (PI-mono) with prompt return to combination therapy if VL rebounded. The primary outcome, previously reported, was loss of future drug options after 3 years, defined as new intermediate/high level resistance to at least one drug to which the participant's virus was considered sensitive at trial entry. Here we report resistance and disease outcomes after further extended follow-up in routine care. The study was registered as ISRCTN04857074. FINDINGS: We randomised 587 participants to OT (291) or PI-mono (296) between Nov 4, 2008, and July 28, 2010 and followed them for a median of more than 8 years (100 months) until 2018. At the end of this follow-up time, one or more future drug options had been lost in 7 participants in the OT group and 6 in the PI-mono group; estimated cumulative risk by 8 years of 2.7% and 2.1% respectively (difference -0.6%, 95% CI -3.2% to 2.0%). Only one PI-mono participant developed resistance to the protease inhibitor they were taking (atazanavir). Serious clinical events (death, serious AIDS, and serious non-AIDS) were infrequent; reported in a total of 12 (4.1%) participants in the OT group and 23 (7.8%) in the PI-mono group (P = 0.08) over the entire follow-up period. INTERPRETATION: A strategy of PI monotherapy, with regular VL monitoring and prompt reintroduction of combination treatment following rebound, preserved future treatment options. Findings confirm the high genetic barrier to resistance of the PI drug class that makes them well suited for creative, patient-centred, treatment-simplification approaches. The possibility of a small excess risk of serious clinical events with the PI monotherapy strategy cannot be excluded. FUNDING: The National Institute for Health Research Health Technology Assessment programme

    Effectiveness of a nurse-led intensive home-visitation programme for first-time teenage mothers (Building Blocks):a pragmatic randomised controlled trial

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    SummaryBackgroundMany countries now offer support to teenage mothers to help them to achieve long-term socioeconomic stability and to give a successful start to their children. The Family Nurse Partnership (FNP) is a licensed intensive home-visiting intervention developed in the USA and introduced into practice in England that involves up to 64 structured home visits from early pregnancy until the child's second birthday by specially recruited and trained family nurses. We aimed to assess the effectiveness of giving the programme to teenage first-time mothers on infant and maternal outcomes up to 24 months after birth.MethodsWe did a pragmatic, non-blinded, randomised controlled, parallel-group trial in community midwifery settings at 18 partnerships between local authorities and primary and secondary care organisations in England. Eligible participants were nulliparous and aged 19 years or younger, and were recruited at less than 25 weeks' gestation. Field-based researchers randomly allocated mothers (1:1) via remote randomisation (telephone and web) to FNP plus usual care (publicly funded health and social care) or to usual care alone. Allocation was stratified by site and minimised by gestation (<16 weeks vs ≥16 weeks), smoking status (yes vs no), and preferred language of data collection (English vs non-English). Mothers and assessors (local researchers at baseline and 24 months' follow-up) were not masked to group allocation, but telephone interviewers were blinded. Primary endpoints were biomarker-calibrated self-reported tobacco use by the mother at late pregnancy, birthweight of the baby, the proportion of women with a second pregnancy within 24 months post-partum, and emergency attendances and hospital admissions for the child within 24 months post-partum. Analyses were by intention to treat. This trial is registered with ISRCTN, number ISRCTN23019866.FindingsBetween June 16, 2009, and July 28, 2010, we screened 3251 women. After enrolment, 823 women were randomly assigned to receive FNP and 822 to usual care. All follow-up data were retrieved by April 25, 2014. 304 (56%) of 547 women assigned to FNP and 306 (56%) of 545 assigned to usual care smoked at late pregnancy (adjusted odds ratio [AOR] 0·90, 97·5% CI 0·64–1·28). Mean birthweight of 742 babies with mothers assigned to FNP was 3217·4 g (SD 618·0), whereas birthweight of 768 babies assigned to usual care was 3197·5 g (SD 581·5; adjusted mean difference 20·75 g, 97·5% CI −47·73 to 89·23. 587 (81%) of 725 assessed children with mothers assigned to FNP and 577 (77%) of 753 assessed children assigned to usual care attended an emergency department or were admitted to hospital at least once before their second birthday (AOR 1·32, 97·5% CI 0·99–1·76). 426 (66%) of 643 assessed women assigned to FNP and 427 (66%) 646 assigned to usual care had a second pregnancy within 2 years (AOR 1·01, 0·77–1·33). At least one serious adverse event (mainly clinical events associated with pregnancy and infancy period) was reported for 310 (38%) of 808 participants (mother–child) in the usual care group and 357 (44%) of 810 in the FNP group, none of which were considered related to the intervention.InterpretationAdding FNP to the usually provided health and social care provided no additional short-term benefit to our primary outcomes. Programme continuation is not justified on the basis of available evidence, but could be reconsidered should supportive longer-term evidence emerge.FundingDepartment of Health Policy Research Programme

    Review: Far-infrared instrumentation and technological development for the next decade

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    This work is licensed under a Creative Commons Attribution 4.0 Unported License.Far-infrared astronomy has advanced rapidly since its inception in the late 1950s, driven by a maturing technology base and an expanding community of researchers. This advancement has shown that observations at far-infrared wavelengths are important in nearly all areas of astrophysics, from the search for habitable planets and the origin of life to the earliest stages of galaxy assembly in the first few hundred million years of cosmic history. The combination of a still-developing portfolio of technologies, particularly in the field of detectors, and a widening ensemble of platforms within which these technologies can be deployed, means that far-infrared astronomy holds the potential for paradigm-shifting advances over the next decade. We examine the current and future far-infrared observing platforms, including ground-based, suborbital, and space-based facilities, and discuss the technology development pathways that will enable and enhance these platforms to best address the challenges facing far-infrared astronomy in the 21st century
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