4,421,542 research outputs found

    Cinematic experience, film space, and the child’s world

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    This is the full published version of this article as first published in the Canadian Journal of Film Studies, 2010, 19 (2) 82-98. http://www.filmstudies.ca/journal/cjfs/archives/articles/kuhn_cinematic_experience_film_space_childs_worl

    Extragalactic CS survey

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    We present a coherent and homogeneous multi-line study of the CS molecule in nearby (D<<10Mpc) galaxies. We include, from the literature, all the available observations from the J=10J=1-0 to the J=76J=7-6 transitions towards NGC 253, NGC 1068, IC 342, Henize~2-10, M~82, the Antennae Galaxies and M~83. We have, for the first time, detected the CS(7-6) line in NGC 253, M~82 (both in the North-East and South-West molecular lobes), NGC 4038, M~83 and tentatively in NGC 1068, IC 342 and Henize~2-10. We use the CS molecule as a tracer of the densest gas component of the ISM in extragalactic star-forming regions, following previous theoretical and observational studies by Bayet et al. (2008a,b and 2009). In this first paper out of a series, we analyze the CS data sample under both Local Thermodynamical Equilibrium (LTE) and non-LTE (Large Velocity Gradient-LVG) approximations. We show that except for M~83 and Overlap (a shifted gas-rich position from the nucleus NGC 4039 in the Antennae Galaxies), the observations in NGC 253, IC 342, M~82-NE, M~82-SW and NGC 4038 are not well reproduced by a single set of gas component properties and that, at least, two gas components are required. For each gas component, we provide estimates of the corresponding kinetic temperature, total CS column density and gas density.Comment: 17 pages, 16 figures, 3 tables, Accepted to Ap

    Evolving Starburst Modeling of FIR/sub-mm/mm Line Emission. III. Application to Nearby Luminous Infrared Galaxies

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    In a previous work, we showed that the observed FIR/sub-mm/mm line spectra of a starburst galaxy (M 82) can be successfully modeled in terms of the evolutionary scheme of an ensemble of giant molecular clouds (GMCs) and shells, and such studies can usefully constrain the age(s) or star formation history of a starburst galaxy. In this paper we present a preliminary study of using the template of an ensemble of evolving GMCs/shells we developed for M 82. we apply the model to represent various stages of starburst evolution in a well known sample of nearby luminous infrared galaxies (LIRGs). In this way, we attempt to interpret the relationship between the degree of molecular excitation and ratio of far-infrared (FIR) to 12^{12}CO (or simply CO) luminosity to possibly reflect different stages of the evolution of star-forming activity within their nuclear regions.Comment: Accepted for publication in the ApJ, 16 pages, 4 figures

    Conformational Dynamics of metallo-β-lactamase CcrA during Catalysis Investigated by Using DEER Spectroscopy

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    Previous crystallographic and mutagenesis studies have implicated the role of a position-conserved hairpin loop in the metallo-β-lactamases in substrate binding and catalysis. In an effort to probe the motion of that loop during catalysis, rapid-freeze-quench double electron–electron resonance (RFQ-DEER) spectroscopy was used to interrogate metallo-β-lactamase CcrA, which had a spin label at position 49 on the loop and spin labels (at positions 82, 126, or 233) 20–35 Å away from residue 49, during catalysis. At 10 ms after mixing, the DEER spectra show distance increases of 7, 10, and 13 Å between the spin label at position 49 and the spin labels at positions 82, 126, and 233, respectively. In contrast to previous hypotheses, these data suggest that the loop moves nearly 10 Å away from the metal center during catalysis and that the loop does not clamp down on the substrate during catalysis. This study demonstrates that loop motion during catalysis can be interrogated on the millisecond time scale

    Electron Spin Resonance in sine-Gordon spin chains in the perturbative spinon regime

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    We report the low-temperature multi-frequency ESR studies of copper pyrimidine dinitrate, a spin-1/2 antiferromagnetic chain with alternating gg-tensor and the Dzyaloshinskii-Moriya interaction, allowing us to test a new theoretical concept proposed recently by Oshikawa and Affleck [Phys. Rev. Lett. 82, 5136 (1999)]. Their theory, based on bosonization and the self-energy formalism, can be applied for precise calculation of ESR parameters of S=1/2S=1/2 antiferromagnetic chains in the perturbative spinon regime. Excellent quantitative agreement between the theoretical predictions and experiment is obtained.Comment: 4 pages, 4 figure

    CF6-6D engine short-term performance deterioration

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    Studies conducted as part of the NASA-Lewis CF6 jet engine diagnostics program are summarized. An 82-engine sample of DC-10-10 aircraft engine checkout data that were gathered to define the extent and magnitude of CF6-6D short term performance deterioration were analyzed. These data are substantiated by the performance testing and analytical teardown of CF6-6D short term deterioration engine serial number (ESN) 451507

    The Sloan Digital Sky Survey Stripe 82 Imaging Data: Depth-Optimized Co-adds Over 300 Deg^2 in Five Filters

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    We present and release co-added images of the Sloan Digital Sky Survey (SDSS) Stripe 82. Stripe 82 covers an area of 300 deg^2 on the Celestial Equator, and has been repeatedly scanned 70-90 times in the ugriz bands by the SDSS imaging survey. By making use of all available data in the SDSS archive, our co-added images are optimized for depth. Input single-epoch frames were properly processed and weighted based on seeing, sky transparency, and background noise before co-addition. The resultant products are co-added science images and their associated weight images that record relative weights at individual pixels. The depths of the co-adds, measured as the 5 sigma detection limits of the aperture (3.2 arcsec diameter) magnitudes for point sources, are roughly 23.9, 25.1, 24.6, 24.1, and 22.8 AB magnitudes in the five bands, respectively. They are 1.9-2.2 mag deeper than the best SDSS single-epoch data. The co-added images have good image quality, with an average point-spread function FWHM of ~1 arcsec in the r, i, and z bands. We also release object catalogs that were made with SExtractor. These co-added products have many potential uses for studies of galaxies, quasars, and Galactic structure. We further present and release near-IR J-band images that cover ~90 deg^2 of Stripe 82. These images were obtained using the NEWFIRM camera on the NOAO 4-m Mayall telescope, and have a depth of about 20.0--20.5 Vega magnitudes (also 5 sigma detection limits for point sources).Comment: 19 pages, 17 figures, accepted for publication in ApJ

    Modulation of APP Processing and Amyloid-P Levels by Human 82-kDa Choline Acetyltransferase

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    The 82-kDa isoform of choline acetyltransferase (82-ChAT) is unique to primates and is found in cholinergic cell nuclei. The functional significance of this protein is not well understood. Previous studies showed that nuclear 82-ChAT levels decrease with advancing age, and this is accelerated in Alzheimer’s disease (AD). The present studies examined the effect of 82-ChAT on amyloid precursor protein (APP) metabolism and amyloid-P (Ap) production. Levels of enzymes involved in processing of APP were examined in human SH-SY5Y neuroblastoma cells and in primary neuronal cultures prepared from cerebral cortex of embryonic APP/PS1 double transgenic mice that serve as a model of AD. A significant amount of APi^2 was released into cell culture media from neurons cultured from transgenic mice for 8 DIV, and this was associated with an elevation of total APP levels rather than changes in levels of APP processing enzymes. Upon expression of 82-ChAT, a 20% reduction in AP-m2 release was found when compared to GFP-expressing control neurons. This was associated with a significant reduction in the protein but not mRNA of the p-secretase BACE1, indicating that 82-ChAT may alter proteins involved in post-translational modification and regulation of BACE1. These studies have important implications for AD pathology and broaden our understanding of the function of 82-ChAT proteins

    A Scoping Review of Transitions, Stress, and Adaptation Among Emerging Adults

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    This scoping review examined research on transitions among emerging adults, 18- to 30-year-olds, to identify designs, populations, frameworks, transition types, and transition outcomes. A librarian conducted the search, yielding 2067 articles. Using predefined criteria, teams screened abstracts and reviewed articles, with 82% to 100% interrater agreement. Data from the final 160 articles were placed in evidence tables and summarized. Most frequently, the studies had exploratory-descriptive designs (69%), nondiagnosed samples (58%), no theoretical frameworks (58%), developmental transitions (34%), and health-related behavior outcomes (34%). This transition research is in an early stage of knowledge development and would benefit from further theory development
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