2,324 research outputs found

    Establishing laboratory standards for biological flight experiments

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    The general objective of this research was to assess the effects of exposure to simulated microgravity on ultrastructural aspects of the contractile system in chicken skeletal muscle cells. This general objective had two specific experimental components: (1) the progression of changes in cell morphology, fusion, and patterns of contractile filament organization in muscle cell cultures grown in hollow fibers in the Clinostat were evaluated, with appropriate controls; (2) to initiate experiments in which muscle cells were grown on the surface of microcarrier beads. The ultimate objective of this second portion of the work is to determine if these beads can be rotated in a bioreactor and thereby obtain a more accurate approximation of the effects of simulated microgravity on differentiated muscle cells

    A Monograph of the Genus \u3ci\u3ePolyphylla\u3c/i\u3e Harris in America North of Mexico (Coleoptera: Scarabaeidae: Melolonthinae)

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    The North American species of the genus Polyphylla Harris, 1841, are defined and revised for the first time since Fall (1928). All name bearing types were examined except those of P. oklahomensis Hatch and P. subvittata LeConte (synonyms of P. hammondl), which are lost. A lectotype is designated for P. gracilis Horn, and neotypes for P. decemlineata (Say), P. occidentalis (L.), and P. variolosa (Hentz). New synonyms of P. decemlineata are P. comstockiana von Bloeker, P. matrona Casey, and P. potsiana Casey. New synonyms of P. crinita LeConte are P. pacifica Casey and P. ruficollis perversa Casey. P. alleni Cazier is a new synonym of P. diffracta Casey. P. crinita nigra Casey is raised to specific rank and P. incolumis relicta Casey, P. incolumis robustula Casey, P. martini von Bloeker, and P. santacruzae von Bloeker are its new synonyms. New synonyms of P. hammondi LeConte are P. latifrons Casey, P. rufescenta Tanner, P. speciosa Casey, and P. speciosa acomana Casey. P. marginata is a nomen nudum. Descriptions of first known females are given for P. barbata Cazier, P. devestiva Young, and P. erratica Hardy and Andrews. P. mescalerensis is a new species from southeastern New Mexico. Of the 71 names established since 1767 which represent Polyphylla, 28 are recognized as valid. Females are unknown for 12 species. These species cluster morphologically and geographically into four species complexes. A key to larvae is provided for the four species having described larvae. A key to adults is provided, and all taxa are described or redescribed and illustrated by photographs. Available biological information is included. Distributional data and maps based on 14,094 specimens are provided. A cladistic interpretation and hypothetical phylogeny of the genus are constructed

    EFFICIENCY ANALYSIS OF HOSPITALS IN THE GREAT PLAINS: AN URBAN-RURAL COMPARISON

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    This study examined the efficiency of a sample of hospitals in the Great Plains using a nonparametric approach. Technical efficiency was less than either allocative or scale efficiency. Urban hospitals are relatively more efficient than rural hospitals with respect to all efficiency measures. Private hospitals are more efficient than others.Health Economics and Policy,

    Safety of Spaceflight Participants Aboard Suborbital Reusable Launch Vehicles

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    The anticipated advent of the U.S. Government sponsoring human-tended research on commercial suborbital flights necessitates the establishment of safety review procedures for federal agencies to allow government-sponsored spaceflight participants (SFPs) aboard these vehicles. Safety practices for National Aeronautics & Space Administration (NASA) personnel aboard aircraft, orbital rockets and platforms, and a non- NASA vehicle, the Soyuz, are summarized. The valuable Recommended Practices for Human Space Flight Occupant Safety, published by the FAA Office of Commercial Space Transportation (FAA-AST) in 2014, are summarized. Medical recommendations for operationally critical flight crewmembers, published by the Aerospace Medical Association Commercial Spaceflight Working Group, are reviewed. FAA-AST approved SFP training available at three U.S. commercial companies is summarized. Activities of ASTM International Committee F47 on Commercial Spaceflight, formed in 2016, are reviewed. Finally, safety comparisons are made with another challenging environment, deep sea submersibles

    Predicting the consequences of selecting on PrP genotypes on PrP frequencies, performance and inbreeding in commercial meat sheep populations

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    Selection programmes based on prion protein (PrP) genotypes are being implemented for increasing resistance to scrapie. Commercial meat sheep populations participating in sire-referencing schemes were simulated to investigate the effect of selection on PrP genotypes on ARR and VRQ allele frequencies, inbreeding and genetic gain in a performance trait under selection. PrP selection strategies modelled included selection against the VRQ allele and in favour of the ARR allele. Assuming realistic initial PrP frequencies, selection against the VRQ allele had a minimal impact on performance and inbreeding. However, when selection was also in favour of the ARR allele and the frequency of this allele was relatively low, there was a loss of up to three to four years of genetic gain over the 15 years of selection. Most loss in gain occurred during the first five years. In general, the rate of inbreeding was reduced when applying PrP selection. Since animals were first selected on their PrP genotype before being selected on the performance trait, the intensity of selection on performance was weaker under PrP selection (compared with no PrP selection). Eradication of the VRQ allele or fixation of the ARR allele within 15 years of selection was possible only with PrP selection targeting all breeding animals

    Characterization of distinct subpopulations of hepatic macrophages in HFD/obese mice.

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    The current dogma is that obesity-associated hepatic inflammation is due to increased Kupffer cell (KC) activation. However, recruited hepatic macrophages (RHMs) were recently shown to represent a sizable liver macrophage population in the context of obesity. Therefore, we assessed whether KCs and RHMs, or both, represent the major liver inflammatory cell type in obesity. We used a combination of in vivo macrophage tracking methodologies and adoptive transfer techniques in which KCs and RHMs are differentially labeled with fluorescent markers. With these approaches, the inflammatory phenotype of these distinct macrophage populations was determined under lean and obese conditions. In vivo macrophage tracking revealed an approximately sixfold higher number of RHMs in obese mice than in lean mice, whereas the number of KCs was comparable. In addition, RHMs comprised smaller size and immature, monocyte-derived cells compared with KCs. Furthermore, RHMs from obese mice were more inflamed and expressed higher levels of tumor necrosis factor-Ī± and interleukin-6 than RHMs from lean mice. A comparison of the MCP-1/C-C chemokine receptor type 2 (CCR2) chemokine system between the two cell types showed that the ligand (MCP-1) is more highly expressed in KCs than in RHMs, whereas CCR2 expression is approximately fivefold greater in RHMs. We conclude that KCs can participate in obesity-induced inflammation by causing the recruitment of RHMs, which are distinct from KCs and are not precursors to KCs. These RHMs then enhance the severity of obesity-induced inflammation and hepatic insulin resistance

    The impact of treatment with indacaterol in patients with COPD:A post-hoc analysis according to GOLD 2011 categories A to D

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    AbstractBackgroundIndacaterol is an inhaled, once-daily, ultra-long-acting Ī²2-agonist for the treatment of chronic obstructive pulmonary disease (COPD). We report on the effectiveness of indacaterol and other bronchodilators compared with placebo in patients across the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 categories A to D.MethodsA post-hoc, subgroup pooled analysis of 6-month efficacy data from three randomized, placebo-controlled, parallel-group studies involving 3862 patients was performed across GOLD 2011 categories A to D, according to baseline forced expiratory volume in 1Ā s (FEV1) % predicted, modified Medical Research Council (mMRC) dyspnea scale, and exacerbation history in the 12 months prior to entry. Efficacy of once-daily indacaterol 150 and 300Ā Ī¼g, open-label tiotropium 18Ā Ī¼g, twice-daily salmeterol 50Ā Ī¼g, and formoterol 12Ā Ī¼g was compared with placebo. End points analysed were trough FEV1, transition dyspnea index (TDI), and St George's Respiratory Questionnaire (SGRQ) total score, all at Week 26, and mean rescue medication use over 26 weeks.ResultsIndacaterol 150 and 300Ā Ī¼g significantly improved FEV1, compared with placebo across all GOLD groups. Indacaterol 150 and 300Ā Ī¼g also significantly improved TDI, SGRQ total score, and mean rescue medication use compared with placebo across most GOLD subgroups.ConclusionsTreatment selection according to patient's symptoms as well as lung function is an important consideration in maintenance treatment of COPD. Indacaterol 150 and 300Ā Ī¼g effectively improved lung function and symptoms in patients across all GOLD 2011 categories

    Brain cavernomas associated with en coup de sabre linear scleroderma: Two case reports

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    Linear scleroderma is a form of localized scleroderma that primarily affects the pediatric population. When it occurs on the scalp or forehead, it is termed "en coup de sabre". In the en coup de sabre subtype, many extracutaneous associations, mostly neurological, have been described. A patient with linear scleroderma en coup de sabre was noted to have ipsilateral brain cavernomas by magnetic resonance imaging. Using a worldwide pediatric rheumatology electronic list-serve, another patient with the same 2 conditions was identified. These two patients are reported in this study. Consideration of neuroimaging studies to disclose abnormal findings in patients with linear scleroderma en coup de sabre is important for potentially preventing and treating neurological manifestations associated with this condition

    A Spectroscopic Study of the Ancient Milky Way: F- and G-Type Stars in the Third Data Release of the Sloan Digital Sky Survey

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    (Abridged) We perform an analysis of spectra and photometry for 22,770 stars included in the third data release (DR3) of the SDSS. We measure radial velocities and, based on a model-atmosphere analysis, derive estimates ofthe atmospheric parameters (effective temperature, surface gravity, and [Fe/H]) for each star. Stellar evolution models are then used to estimate distances. The SDSS sample covers a range in stellar brightness of 14 < V < 22, and comprises large numbers of F- and G-type stars from the thick-disk and halo populations (up to 100 kpc from the galactic plane), therefore including some of the oldest stars in the Milky Way. In agreement with previous results from the literature, we find that halo stars exhibit a broad range of iron abundances, with a peak at [Fe/H] ~ -1.4. This population exhibits essentially no galactic rotation. Thick-disk G-dwarf stars at distances from the galactic plane in the range 1<|z|<3 kpc show a much more compact metallicity distribution, with a maximum at [Fe/H] ~ -0.7, and a median galactic rotation velocity at that metallicity of 157 +/- 4 km/s (a lag relative to the thin disk of 63 km/s). A comparison of color indices and metal abundances with isochrones indicates that no significant star formation has taken place in the halo in the last ~ 11 Gyr, but there are thick-disk stars which are at least 2 Gyr younger. We find the metallicities of thick-disk stars to be nearly independent of galactocentric distance between 5 and 14 kpc, in contrast with the marked gradients found in the literature for the thin disk. No vertical metallicity gradient is apparent for the thick disk, but we detect a gradient inits rotational velocity of -16 +/- 4 km/s/kpc between 1 and 3 kpc from the plane.Comment: 18 pages, 16 figures; accepted for publication in the ApJ; also available from http://hebe.as.utexas.edu
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