12,289 research outputs found

    EVOLUTION OF IR-SELECTED GALAXIES IN Z~0.4 CLUSTERS

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    Wide-field optical and near--IR (JHKJHK) imaging is presented for two rich galaxy clusters: Abell~370 at z=0.374z=0.374 and Abell~851 (Cl0939+47) at z=0.407z=0.407. Galaxy catalogs selected from the near--IR images are 90\% complete to approximately 1.5 mag below K∗K^\ast resulting in samples with ∼\sim100 probable member galaxies per cluster in the central ∼\sim2 Mpc. Comparison with HSTHST WFPC images yields subsamples of ∼\sim70 galaxies in each cluster with morphological types. Analysis of the complete samples and the HSTHST subsamples shows that the z∼0.4z\sim 0.4 E/S0s are bluer than those in the Bower et al.\ (1992) Coma sample in the optical−K-K color by 0.130.13~mag for Abell~370 and by 0.180.18~mag for Abell~851. If real, the bluing of the E/S0 populations at moderate redshift is consistent with that calculated from the Bruzual and Charlot (1993) models of passive elliptical galaxy evolution. In both clusters the intrinsic scatter of the known E/S0s about their optical−K-K color--mag relation is small (∼0.06\sim 0.06 mag) and not significantly different from that of Coma E/S0s as given by Bower et al.\ (1992), indicating that the galaxies within each cluster formed at the same time at an early epoch.Comment: uuencoded gzipped tar file containing latex files of manuscript (42 pages) plus tables (9 pages); figures available by anonymous ftp at ftp://ipac.caltech.edu//pub/pickup/sed ; accepted for publication in the Ap

    The K-selected Butcher-Oemler Effect

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    [abridged] We investigate the Butcher-Oemler effect in a sample of K-selected galaxies in 33 clusters at 0.15 < z < 0.92. We attempt to duplicate the original Butcher-Oemler analysis as closely as possible given the characteristics of our data. We find that the infrared selected blue fractions are lower than those measured in the optical and that the trend with redshift is much weaker. Comparison with optical data in clusters in common with Butcher & Oemler (1984) shows that infrared selection is the primary difference between our study and optically selected samples. We suggest that the Butcher-Oemler effect is in large part due to a population of star-forming low mass galaxies which will evolve into dwarf galaxies. These early results point to the need for larger and deeper infrared samples of cluster galaxies to address this issueComment: 37 pages, 19 figures, ApJ accepted (vol 598 n1

    Forces generated during stretch in the heart of the lobster Homarus americanus are anisotropic and are altered by neuromodulators

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    Mechanical and neurophysiological anisotropies mediate three-dimensional responses of the heart of Homarus americanus. Although hearts in vivo are loaded multi-axially by pressure, studies of invertebrate cardiac function typically use uniaxial tests. To generate whole-heart length-tension curves, stretch pyramids at constant lengthening and shortening rates were imposed uniaxially and biaxially along longitudinal and transverse axes of the beating whole heart. To determine whether neuropeptides that are known to modulate cardiac activity in H. americanus affect the active or passive components of these length-tension curves, we also performed these tests in the presence of SGRNFLRFamide (SGRN) and GYSNRNYLRFamide (GYS). In uniaxial and biaxial tests, both passive and active forces increased with stretch along both measurement axes. The increase in passive forces was anisotropic, with greater increases along the longitudinal axis. Passive forces showed hysteresis and active forces were higher during lengthening than shortening phases of the stretch pyramid. Active forces at a given length were increased by both neuropeptides. To exert these effects, neuropeptides might have acted indirectly on the muscle via their effects on the cardiac ganglion, directly on the neuromuscular junction, or directly on the muscles. Because increases in response to stretch were also seen in stimulated motor nerve-muscle preparations, at least some of the effects of the peptides are likely peripheral. Taken together, these findings suggest that flexibility in rhythmic cardiac contractions results from the amplified effects of neuropeptides interacting with the length-tension characteristics of the heart

    Modelling the spinning dust emission from LDN 1780

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    We study the anomalous microwave emission (AME) in the Lynds Dark Nebula (LDN) 1780 on two angular scales. Using available ancillary data at an angular resolution of 1 degree, we construct an SED between 0.408 GHz to 2997 GHz. We show that there is a significant amount of AME at these angular scales and the excess is compatible with a physical spinning dust model. We find that LDN 1780 is one of the clearest examples of AME on 1 degree scales. We detected AME with a significance > 20σ\sigma. We also find at these angular scales that the location of the peak of the emission at frequencies between 23-70 GHz differs from the one on the 90-3000 GHz map. In order to investigate the origin of the AME in this cloud, we use data obtained with the Combined Array for Research in Millimeter-wave Astronomy (CARMA) that provides 2 arcmin resolution at 30 GHz. We study the connection between the radio and IR emissions using morphological correlations. The best correlation is found to be with MIPS 70μ\mum, which traces warm dust (T∼\sim50K). Finally, we study the difference in radio emissivity between two locations within the cloud. We measured a factor ≈6\approx 6 of difference in 30 GHz emissivity. We show that this variation can be explained, using the spinning dust model, by a variation on the dust grain size distribution across the cloud, particularly changing the carbon fraction and hence the amount of PAHs.Comment: 14 pages, 11 figures, submitted to MNRA

    Near-IR imaging of moderate redshift galaxy clusters

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    We have obtained near-IR imaging of 3 moderate-z clusters on the 1.3 m at KPNO with SQIID, a new camera offering wide-field (5.5 arcmin) simultaneous JHK band imaging. Our photometry on a sample of approximately 100 likely member galaxies in one of the clusters, Abell 370 at z = 0.37, shows that we can obtain magnitudes good to 20 percent down to K = 18, considerably below the estimated K* = 16.5 at this redshift. These data indicate that there are no systematic problems in obtaining photometry at faint levels with SQIID. With the development of larger arrays, the field is open to progress. The resulting J, H, and K data for three clusters are combined with previously obtained multiband optical photometry. We present an investigation of the spectral properties and evolution of the dominant cold stellar populations by comparing optical-to-IR colors and color-magnitude diagrams to predictions from population synthesis models and galaxy spectral evolution codes

    Singing and COPD: a pilot randomized controlled trial of wellbeing and respiratory outcomes

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    Aims/objectives To test whether a ten-week regular weekly group singing programme, with guided home practice, leads to improvement in COPD-specific health status, as assessed by the COPD Assessment Test (CAT, primary outcome). To test whether the programme results in changes to health-related quality of life, mental health, breathlessness, lung function, functional exercise performance and breathing patterns (secondary outcomes). Rationale A number of randomized controlled trials (RCTs) exist which suggest that there are potential benefits to health and wellbeing of regular singing for people with COPD (Chronic Obstructive Pulmonary Disease). However, most rely on small samples, and findings across the different outcome measures are inconsistent, while interview studies tend to report consistent positive physical and psychological outcomes. Further research is therefore needed. Approach A single-blind, randomized controlled trial compared a structured, weekly group singing programme plus home practice between sessions over ten weeks, with a usual COPD treatment control. The sample was drawn from a local NHS population of people with COPD. Following baseline assessments, participants were allocated to a 10 week singing programme or a control. Findings Twenty-four individuals completed to follow-up. Measures at 12 weeks showed no significant differences between singing and control groups except for one item on the health status questionnaire (SF-36) which suggested the singers were less limited in their activities of daily living post-singing. Final follow-up, planned for 6 months post intervention, was aborted due to the COVID-19 pandemic. Discussion and conclusion The study failed to recruit to target. There remains a recruitment problem in RCTs of singing for COPD, resulting in inconclusive findings, which conflict with the positive qualitative evidence. A wide variety of reseach methods, as well as RCTs, are suggested to enable a better understanding of the impact of singing on COPD. Trial registration number: ISRCTN42943709

    2018 Indiana Primary Care Needs Assessment Report

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    The Indiana Primary Care Needs Assessment (PCNA) has been critical in the efforts to identify gaps in access to health care and allocate resources to communities in greatest need. This five-year collaborative project between the Bowen Center for Health Workforce Research and Policy (Bowen Center) and the Indiana State Department of Health Primary Care Office, has encompassed numerous efforts to accomplish these goals. These efforts have included 1) innovation of provider data management, 2) statewide analysis of Health Professional Shortage Areas, and 3) providing resources and assistance to health care administrators and community leaders. The 2018 Primary Care Needs Assessment Report provides a summary of efforts from 2015-2017 and how this project has impacted communities throughout Indiana
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