133 research outputs found
Behavior and Failure Mechanism of Composite Slabs
The behavior of a composite slab using a 636 deck profIle was investigated experimentally. Twenty-three one-way slab tests and twenty-four pull-out tests were performed. It was found that the behavior and shear bond load of the composite slab were significantly affected by the depth of the embossment shear key. The average shear stress from the pull-out tests was generally lower than that of the one-way slab tests due to a lack of the transverse load effects which influenced the frictional resistance between the concrete slab and the steel deck
Radio Astronomy
Contains reports on eleven research projects.National Science Foundation (Grant AST79-25075)National Science Foundation (Grant AST79-20984)National Science Foundation (Grant AST79-19553)U.S. Navy - Office of Naval Research (Contract N00014-80-C-0348)National Aeronautics and Space Administration (Grant NAG2-50)MIT Sloan Fund for Basic ResearchJoint Services Electronics Program(Contract DAAG80-C-0104)Lockheed Aircraft Corporation (Contract LS90B4860F)National Aeronautics and Space Administration (Grant NAG5-10)National Aeronautics and Space Administration (Contract NAS5-22929)U.S. Department of Commerce, National Oceanic and Atmospheric Administration (Grant 04-8-MO1-1)California Institute of Technology Jet Propulsion Laboratory (Contract LZ-727891)California Institute of Technology Jet Propulsion Laboratory Subcontract 956059California Institute of Technology Jet Propulsion Laboratory Task Order RD-15
Radio Astronomy
Contains reports on sixteen research projects.National Science Foundation (Grant AST81-21416)National Science Foundation (Grant AST80-22864)National Aeronautics and Space Administration (Contract S-10665-C)National Aeronautics and Space Administration (Contract NAGW373)National Science Foundation (Grant AST79-19553)National Oceanic and Atmospheric Administration (Grant 04-8-M01-1)National Aeronautics and Space Administration (Grant NAG5-10)National Aeronautics and Space Administration (Contract NAS5-22929)Defense Advanced Research Projects Agency (Contract MDA 903-82-K-0521)Intelsat (Contract Intel-188)Joint Services Electronics Program (Contract DAAG29-80-C-0104)Lockheed Missiles and Space Company (Contract LS90B4860F
The Unique Type Ia Supernova 2000cx in NGC 524
We present extensive photometric and spectroscopic observations of the Type
Ia supernova (SN Ia) 2000cx in the S0 galaxy NGC 524, which reveal it to be
peculiar. Photometrically, SN 2000cx is different from all known SNe Ia, and
its light curves cannot be fit well by the fitting techniques currently
available. There is an apparent asymmetry in the -band peak, in which the
premaximum brightening is relatively fast (similar to that of the normal SN
1994D), but the postmaximum decline is relatively slow (similar to that of the
overluminous SN 1991T). The color evolution of SN 2000cx is also peculiar: the
color has a unique plateau phase and the and colors are very blue.
Although the premaximum spectra of SN 2000cx are similar to those of SN
1991T-like objects (with weak Si II lines), its overall spectral evolution is
quite different. The Si II lines that emerged near maximum -band brightness
stay strong in SN 2000cx until about three weeks past maximum. The change in
the excitation stages of iron-peak elements is slow. Both the iron-peak and the
intermediate-mass elements are found to be moving at very high expansion
velocities in the ejecta of SN 2000cx.
We discuss theoretical models for SN 2000cx. SN 2000cx may be an overluminous
object like SN 1991T, but with a larger yield of Ni and a higher kinetic
energy in the ejecta. We also briefly discuss the implications of our
observations for the luminosity vs. light-curve width relation.Comment: Accepted to be published in the Oct issue of PAS
Barriers to effective discharge planning: a qualitative study investigating the perspectives of frontline healthcare professionals
<p>Abstract</p> <p>Background</p> <p>Studies have shown that effective discharge planning is one of the key factors related to the quality of inpatient care and unnecessary hospital readmission. The perception and understanding of hospital discharge by health professionals is important in developing effective discharge planning. The aims of this present study were to explore the perceived quality of current hospital discharge from the perspective of health service providers and to identify barriers to effective discharge planning in Hong Kong.</p> <p>Methods</p> <p>Focus groups interviews were conducted with different healthcare professionals who were currently responsible for coordinating the discharge planning process in the public hospitals. The discussion covered three main areas: current practice on hospital discharge, barriers to effective hospital discharge, and suggested structures and process for an effective discharge planning system.</p> <p>Results</p> <p>Participants highlighted that there was no standardized hospital-wide discharge planning and policy-driven approach in public health sector in Hong Kong. Potential barriers included lack of standardized policy-driven discharge planning program, and lack of communication and coordination among different health service providers and patients in both acute and sub-acute care provisions which were identified as mainly systemic issues. Improving the quality of hospital discharge was suggested, including a multidisciplinary approach with clearly identified roles among healthcare professionals. Enhancement of health professionals' communication skills and knowledge of patient psychosocial needs were also suggested.</p> <p>Conclusions</p> <p>A systematic approach to develop the structure and key processes of the discharge planning system is critical in ensuring the quality of care and maximizing organization effectiveness. In this study, important views on barriers experienced in hospital discharge were provided. Suggestions for building a comprehensive, system-wide, and policy-driven discharge planning process with clearly identified staff roles were raised. Communication and coordination across various healthcare parties and provisions were also suggested to be a key focus.</p
Children, parents and pets exercising together (CPET) : exploratory randomised controlled trial
Levels of physical activity (PA) in UK children are much lower than recommended and novel approaches to its promotion are needed. The Children, Parents and Pets Exercising Together (CPET) study is the first exploratory randomised controlled trial (RCT) to develop and evaluate an intervention aimed at dog-based PA promotion in families. CPET aimed to assess the feasibility, acceptability and potential efficacy of a theory-driven, family-based, dog walking intervention for 9-11 year olds
Pipeline for Large-Scale Microdroplet Bisulfite PCR-Based Sequencing Allows the Tracking of Hepitype Evolution in Tumors
Cytosine methylation provides an epigenetic level of cellular plasticity that is important for development, differentiation and cancerogenesis. We adopted microdroplet PCR to bisulfite treated target DNA in combination with second generation sequencing to simultaneously assess DNA sequence and methylation. We show measurement of methylation status in a wide range of target sequences (total 34 kb) with an average coverage of 95% (median 100%) and good correlation to the opposite strand (rho = 0.96) and to pyrosequencing (rho = 0.87). Data from lymphoma and colorectal cancer samples for SNRPN (imprinted gene), FGF6 (demethylated in the cancer samples) and HS3ST2 (methylated in the cancer samples) serve as a proof of principle showing the integration of SNP data and phased DNA-methylation information into “hepitypes” and thus the analysis of DNA methylation phylogeny in the somatic evolution of cancer
LSST Science Book, Version 2.0
A survey that can cover the sky in optical bands over wide fields to faint
magnitudes with a fast cadence will enable many of the exciting science
opportunities of the next decade. The Large Synoptic Survey Telescope (LSST)
will have an effective aperture of 6.7 meters and an imaging camera with field
of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over
20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with
fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a
total point-source depth of r~27.5. The LSST Science Book describes the basic
parameters of the LSST hardware, software, and observing plans. The book
discusses educational and outreach opportunities, then goes on to describe a
broad range of science that LSST will revolutionize: mapping the inner and
outer Solar System, stellar populations in the Milky Way and nearby galaxies,
the structure of the Milky Way disk and halo and other objects in the Local
Volume, transient and variable objects both at low and high redshift, and the
properties of normal and active galaxies at low and high redshift. It then
turns to far-field cosmological topics, exploring properties of supernovae to
z~1, strong and weak lensing, the large-scale distribution of galaxies and
baryon oscillations, and how these different probes may be combined to
constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at
http://www.lsst.org/lsst/sciboo
A Sensitive Search for Supernova Emission Associated with the Extremely Energetic and Nearby GRB 221009A
We report observations of the optical counterpart of the long gamma-ray burst
(LGRB) GRB 221009A. Due to the extreme rarity of being both nearby () and highly energetic ( erg), GRB
221009A offers a unique opportunity to probe the connection between massive
star core collapse and relativistic jet formation across a very broad range of
-ray properties. Adopting a phenomenological power-law model for the
afterglow and host galaxy estimates from high-resolution Hubble Space Telescope
imaging, we use Bayesian model comparison techniques to determine the
likelihood of an associated SN contributing excess flux to the optical light
curve. Though not conclusive, we find moderate evidence
() for the presence of an additional component arising
from an associated supernova, SN 2022xiw, and find that it must be
substantially fainter ( 67% as bright at the 99% confidence interval) than
SN 1998bw. Given the large and uncertain line-of-sight extinction, we attempt
to constrain the supernova parameters (, ,
and ) under several different assumptions with respect to the
host galaxy's extinction. We find properties that are broadly consistent with
previous GRB-associated SNe: - ,
- , and - . We note that these properties are weakly
constrained due to the faintness of the supernova with respect to the afterglow
and host emission, but we do find a robust upper limit on the of
. Given the tremendous range in isotropic
gamma-ray energy release exhibited by GRBs (7 orders of magnitude), the SN
emission appears to be decoupled from the central engine in these systems.Comment: 18 pages, accepted to ApJL, 4 tables, 5 figures. Updated abstract in
Previe
Overexpression of Myocilin in the Drosophila Eye Activates the Unfolded Protein Response: Implications for Glaucoma
Glaucoma is the world's second leading cause of bilateral blindness with progressive loss of vision due to retinal ganglion cell death. Myocilin has been associated with congenital glaucoma and 2-4% of primary open angle glaucoma (POAG) cases, but the pathogenic mechanisms remain largely unknown. Among several hypotheses, activation of the unfolded protein response (UPR) has emerged as a possible disease mechanism.We used a transgenic Drosophila model to analyze whole-genome transcriptional profiles in flies that express human wild-type or mutant MYOC in their eyes. The transgenic flies display ocular fluid discharge, reflecting ocular hypertension, and a progressive decline in their behavioral responses to light. Transcriptional analysis shows that genes associated with the UPR, ubiquitination, and proteolysis, as well as metabolism of reactive oxygen species and photoreceptor activity undergo altered transcriptional regulation. Following up on the results from these transcriptional analyses, we used immunoblots to demonstrate the formation of MYOC aggregates and showed that the formation of such aggregates leads to induction of the UPR, as evident from activation of the fluorescent UPR marker, xbp1-EGFP. CONCLUSIONS / SIGNIFICANCE: Our results show that aggregation of MYOC in the endoplasmic reticulum activates the UPR, an evolutionarily conserved stress pathway that culminates in apoptosis. We infer from the Drosophila model that MYOC-associated ocular hypertension in the human eye may result from aggregation of MYOC and induction of the UPR in trabecular meshwork cells. This process could occur at a late age with wild-type MYOC, but might be accelerated by MYOC mutants to account for juvenile onset glaucoma
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