2,306 research outputs found

    Spacelab mission dependent training parametric resource requirements study

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    Training flows were developed for typical missions, resource relationships analyzed, and scheduling optimization algorithms defined. Parametric analyses were performed to study the effect of potential changes in mission model, mission complexity and training time required on the resource quantities required to support training of payload or mission specialists. Typical results of these analyses are presented both in graphic and tabular form

    Atmospheric measurements over kwajalein using falling spheres

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    Atmosphere measurements using falling spheres tracked by rada

    Adequacy of the passive inflated falling sphere technique

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    Inflated falling sphere for high altitude sounding at radar sit

    Improving access to and engagement with mental health services among young people from refugee backgrounds: service user and provider perspectives

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    Limited research has been conducted worldwide on the experiences that children and young people from refugee backgrounds have with mental health services, despite evidence that they have significant vulnerability to the development of mental health problems and to suicidal behaviour and that those with mental ill-health typically underutilise services. The authors were particularly interested in barriers and facilitators to service access and engagement, and conducted two qualitative research projects to improve understanding of the issues – the first with service providers experienced in the refugee area and the second with young refugee service users. The aim of this project was to compare the perspectives of professionals and service users and to identify similarities and differences. The perspectives of the service users and providers were strikingly similar. The analysis identified 21 implications for policy makers, agencies and practitioners, which ranged from issues concerning cultural sensitivity, background matching and mental health literacy to accessibility, setting boundaries and expectations and implementing a holistic and outreach approach. There is a range of specific, practical measures that policy makers and service providers can introduce to enhance access to and engagement with mental health services for young people from refugee backgrounds

    Bostonia. Volume 6

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    Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

    Sequential CCR5-Tropic HIV-1 Reactivation from Distinct Cellular Reservoirs following Perturbation of Elite Control

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    Background HIV Elite Controllers may reveal insights into virus persistence given they harbour small reservoir sizes, akin to HIV non-controllers treated early with combination antiretroviral therapy. Both groups of patients represent the most promising candidates for interventions aimed at sustained remission or ‘cure’. Analytic treatment interruption (ATI) in the latter group leads to stochastic rebound of virus, though it is unclear whether loss of elite control is also associated with similar rebound characteristics. Methods We studied three discrete periods of virus rebound during myeloma related immune disruption over 2.5 years in an elite controller who previously underwent autologous stem cell transplantation (ASCT) in the absence of any antiretroviral therapy. Single genome sequencing of the V1-V4 region of env in PBMC and plasma was performed and phylogenies reconstructed. Average pairwise distance (APD) was calculated and non-parametric methods used to assess compartmentalisation. Coreceptor usage was predicted based on genotypic algorithms. Results 122 single genome sequences were obtained (median 26 sequences per rebound). The initial rebounding plasma env sequences following ASCT represented two distinct lineages, and clustered with proviral DNA sequences isolated prior to ASCT. One of the lineages was monophyletic, possibly indicating reactivation from clonally expanded cells. The second rebound occurred 470 days after spontaneous control of the first rebound and was phylogenetically distinct from the first, confirmed by compartmentalisation analysis, with a different cellular origin rather than ongoing replication. By contrast, third rebound viruses clustered with second rebound viruses, with evidence for ongoing evolution that was associated with lymphopenia and myeloma progression. Following ASCT a shift in tropism from CXCR4-tropic viruses to a CCR5-tropic population was observed to persist through to the third rebound. Conclusions Our data highlight similarities in the viral reservoir between elite and non-controllers undergoing ATI following allogeneic transplantation. The lack of propagation of CXCR4 using viruses following transplantation warrants further study

    Using airborne LiDAR Survey to explore historic-era archaeological landscapes of Montserrat in the eastern Caribbean

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    This article describes what appears to be the first archaeological application of airborne LiDAR survey to historic-era landscapes in the Caribbean archipelago, on the island of Montserrat. LiDAR is proving invaluable in extending the reach of traditional pedestrian survey into less favorable areas, such as those covered by dense neotropical forest and by ashfall from the past two decades of active eruptions by the Soufrière Hills volcano, and to sites in localities that are inaccessible on account of volcanic dangers. Emphasis is placed on two aspects of the research: first, the importance of ongoing, real-time interaction between the LiDAR analyst and the archaeological team in the field; and second, the advantages of exploiting the full potential of the three-dimensional LiDAR point cloud data for purposes of the visualization of archaeological sites and features

    The Magnetic Field in Taurus Probed by Infrared Polarization

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    We present maps of the plane-of-sky magnetic field within two regions of the Taurus molecular cloud: one in the dense core L1495/B213 filament, the other in a diffuse region to the west. The field is measured from the polarization of background starlight seen through the cloud. In total, we measured 287 high-quality near-infrared polarization vectors in these regions. In L1495/B213, the percent polarization increases with column density up to Av ~ 9 mag, the limits of our data. The Radiative Torques model for grain alignment can explain this behavior, but models that invoke turbulence are inconsistent with the data. We also combine our data with published optical and near-infrared polarization measurements in Taurus. Using this large sample, we estimate the strength of the plane-of-sky component of the magnetic field in nine subregions. This estimation is done with two different techniques that use the observed dispersion in polarization angles. Our values range from 5-82 microgauss and tend to be higher in denser regions. In all subregions, the critical index of the mass-to-magnetic flux ratio is sub-unity, implying that Taurus is magnetically supported on large scales (~2 pc). Within the region observed, the B213 filament makes a sharp turn to the north and the direction of the magnetic field also takes a sharp turn, switching from being perpendicular to the filament to becoming parallel. This behavior can be understood if we are observing the rim of a bubble. We argue that it has resulted from a supernova remnant associated with a recently discovered nearby gamma-ray pulsar.Comment: Accepted into the Astrophysical Journal. 20 pages in emulateapj format including 10 figures and 4 table

    Pulsar Timing with the Parkes Radio Telescope for the Fermi Mission

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    We report here on two years of timing of 168 pulsars using the Parkes radio telescope. The vast majority of these pulsars have spin-down luminosities in excess of 10^34 erg/s and are prime target candidates to be detected in gamma-rays by the Fermi Gamma-Ray Space Telescope. We provide the ephemerides for the ten pulsars being timed at Parkes which have been detected by Fermi in its first year of operation. These ephemerides, in conjunction with the publicly available photon list, can be used to generate gamma-ray profiles from the Fermi archive. We will make the ephemerides of any pulsars of interest available to the community upon request. In addition to the timing ephemerides, we present the parameters for 14 glitches which have occurred in 13 pulsars, seven of which have no previously known glitch history. The Parkes timing programme, in conjunction with Fermi observations, is expected to continue for at least the next four years.Comment: Accepted for publication in PASA.12 page

    Thermal and Dynamical Equilibrium in Two-Component Star Clusters

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    We present the results of Monte Carlo simulations for the dynamical evolution of star clusters containing two stellar populations with individual masses m1 and m2 > m1, and total masses M1 and M2 < M1. We use both King and Plummer model initial conditions and we perform simulations for a wide range of individual and total mass ratios, m2/m1 and M2/M1. We ignore the effects of binaries, stellar evolution, and the galactic tidal field. The simulations use N = 10^5 stars and follow the evolution of the clusters until core collapse. We find that the departure from energy equipartition in the core follows approximately the theoretical predictions of Spitzer (1969) and Lightman & Fall (1978), and we suggest a more exact condition that is based on our results. We find good agreement with previous results obtained by other methods regarding several important features of the evolution, including the pre-collapse distribution of heavier stars, the time scale on which equipartition is approached, and the extent to which core collapse is accelerated by a small subpopulation of heavier stars. We briefly discuss the possible implications of our results for the dynamical evolution of primordial black holes and neutron stars in globular clusters.Comment: 31 pages, including 13 figures, to appear in Ap
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