1,983 research outputs found

    VLA Observations of Ultraluminous IRAS Galaxies: Active Nuclei or Starbursts?

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    We employed the Very Large Array (VLA) of the National Radio Astronomy Observatory in C configuration to map 39 ultraluminous IRAS galaxies at 6~cm and 20~cm, at resolutions of ~ 4" and 15", respectively, and 24 sources at 6~cm with in the A configuration with a resolution of ~0.5". Most of the sources have radio spectral indices indicative of synchrotron emission (alpha ~ -0.65). There is one source, however, that shows an inverted spectrum with alpha = +2.1; observations at higher frequencies show that the spectrum peaks between 5 and 8 GHz, as high as any of the ``gigahertz peaked spectrum'' sources studied by O'Dea etal. We discuss the implications of this source for observations of fluctuations in the CMB. Two of the sources show multiple unresolved components, another four are doubles with at least one resolved component, 14 show extended emission which could arise from a disk, and two show arc-second long jets. Our data fit the tight correlation found by Helou etal (1985) between far-infrared and microwave luminosity; this correlation extends to the highest infrared luminosities. The correlation is weaker if only the extended or the nuclear components of the radio luminosity are used. Therefore the far-infrared emission in the majority of these higher luminosity galaxies is due to the same mechanism as the lower luminosity FIR sources, which is believed to be star formation, rather than non-thermal activity in the nucleus. Moreover, the star formation is not confined to the extended disk in these sources, but is important in the nucleus as well.Comment: In press, Astrophysical Journal. 34 pages, uuencoded gzip'ed postscript of text, tables and figures. 3 figures not included; contact Margaret Best at [email protected] for hardcopies of thes

    The Value of Urban Parklands: A User Study of the Baldwin Hills

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    EXECUTIVE SUMMARY This report provides the results of a two-year research study by the Loyola Marymount University Center for Urban Resilience (CURes) to examine park visitation and user behavior and attitudes in the Baldwin Hills Parklands. Supported by the Baldwin Hill Conservancy through California Proposition 84 funding, the goal of this study was to better understand how individuals are using and interacting with the Baldwin Hills Parklands. It is the first large-scale, multi-year, field-based attendance survey and multifaceted analysis of visitors’ experiences in the Parklands, consisting of a pilot and four comprehensive field seasons. Building on a pilot phase in 2014, 38 CURes research assistants spent 1,934 hours in the parks over four field seasons from 2015-2017. Researchers conducted 1,747 park user surveys, completed counts of 12,709 parks visitors, analyzed 4,998 images from park entrances, and produced reports and outreach materials. The results show that the Baldwin Hills Parklands: receive high levels of visitation, especially on weekends, with the Kenneth Hahn State Recreation Area serving the largest user population at any one time, and the Baldwin Hills Scenic Overlook State Park having the highest visitation on average; have a devoted population of frequent users that tend to visit only one park within the Baldwin Hills Parklands; are visited by people who are highly civically engaged, have a moderate understanding of the local environment, and are very interested in learning more about the environment of the region; are visited by users mostly arriving by car who tend to enter through main park entrances, with no trouble finding parking; receive a substantial number of visitors who would prefer to arrive by foot or bicycle, and even more who would be interested in taking the park shuttle but were not aware of it; support both active recreation and passive enjoyment of nature, with walking and enjoying nature as the top two activities indicated by users; are visited by users who do not often go to the coast, though nearly all indicate a willingness to walk or bike on a recreational trail to visit the beach; serve a diverse population of users from Los Angeles County that are, on average, relatively young, highly educated, and of low to moderate income, which is not entirely consistent with the surrounding population; and receive visitors with highly positive sentiments and attachments to the parks. These findings suggest that the Baldwin Hills Parklands are an integral natural resource in the Los Angeles region. They also provide a foundation to guide continued work to better understand, improve, and promote the use of the parklands. This report details the findings of the two-year study, provides interpretations of the results and recommendations for the Baldwin Hills Conservancy.https://digitalcommons.lmu.edu/cures_reports/1004/thumbnail.jp

    Grief Experiences in Family Caregivers of Children with Autism Spectrum Disorder (ASD)

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    The main objective of this study was to analyse the experience of grief and feelings of loss in family caregivers of children diagnosed with autism spectrum disorder (ASD), as well as the perceived overload from taking on the primary caregiver role. Twenty family caregivers of children with ASD participated. The family members were assessed using an ad-hoc semi-structured interview that addressed the families' reactions to the diagnosis, implications for daily functioning, and concerns for the immediate and long-term future of their relatives with ASD. The results indicate that family caregivers of children with ASD endure intense and continuous sorrow and grief due to the impact that having and caring for a child with these characteristics has on all aspects of their lives. These data highlight the importance of creating support and intervention programmes and services focused on the feelings and manifestations of ambiguous grief that occur in these family members, in order to improve their well-being and quality of life and reduce caregiver role overload

    Herbivore-Induced Effects on Arctic Soil Carbon Storage

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    Permafrost degradation and organic matter decomposition in the terrestrial Arctic are strongly depending on soil temperature throughout the year. These temperatures are affected in numerous ways by activity of large herbivorous animals. We identified snow compaction and animal-induced vegetation changes as key elements. Therefore, we analysed soil parameters along transects following grazing intensity in both a permafrost environment (northeastern Siberia) and seasonally frozen ground (norther Finland). Parameters included TOC, C/N ratio, d13C, bulk density and radiocarbon age. While we observed a strong increase in soil carbon storage with high grazing intensity under permafrost conditions, this effect does not show in seasonally frozen ground. However, an obvious animal-induced change in both areas was a shift in vegetation composition and structure, following the grazing gradient. We conclude that material and water fluxes in seasonally frozen ground outweigh the animals’ effects, contrary to permafrost environments, but state that on permafrost, animals could help maintaining low soil temperatures and hence reduce organic material decomposition

    Investment cyclicality in manufacturing industries

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    Industries ; Business cycles ; Investments
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