115 research outputs found
Discussions of Health Web Sites in Medical and Popular Media
To what extent and how do medical and popular media discuss issues of quality when it comes to health Web sites? The answer in brief is that while academic medical researchers are deeply concerned about the quality of Web sites that center on health, the popular media hardly attend to this issue. A deeper answer to the question uncovers more disconnects between academic Web site analysts, survey researchers, and popular media.
In the following reports, the members of a University of Pennsylvania research group that I directed explore this issue in two ways. First, they update and review an analysis of quantitative scholarly research on the quality of health Web sites. Second, they examine the general discussion of health Web sites over six months in 47 media outlets representing a wide range of media, from medical research journals to television network news operations.
The topic is important because so many people go online to get health information. A national survey conducted by the Pew Internet & American Life Project is perhaps most definitive. It found that 62 percent of internet users have gone online in search of health information. Extrapolating from its data, the Pew group further found that about 6 million Americans go online for medical advice on a typical day. That, it added, means more people go online for medical advice on any given day than actually visit health professionals, according to figures provided by the American Medical Association.
The Pew group also found that Web health seekers often use search suggestions from friends, search with others, or ask people they consider knowledgeable searchers to help them find health information online. They report being satisfied with their searches, and the few who discuss their findings with physicians state that they agreed that what they had learned was correct. The Pew researchers readily admit that the health seekers may not have been as successful in gaining correct knowledge as they believe. And, in fact, an experimental study by Stanford and colleagues concluded that consumers make judgments about health site credibility in ways that are quite different than what medical professionals consider appropriate
Factors Influencing Ball-Player Impact Probability in Youth Baseball
Altering the weight of baseballs for youth play has been studied out of concern for player safety. Research has shown that decreasing the weight of baseballs may limit the severity of both chronic arm and collision injuries. Unfortunately, reducing the weight of the ball also increases its exit velocity, leaving pitchers and nonpitchers with less time to defend themselves. The purpose of this study was to examine impact probability for pitchers and nonpitchers
Transverse Sizes of CIV Absorption Systems Measured from Multiple QSO Sightlines
We present tomography of the circum-galactic metal distribution at redshift
1.7 to 4.5 derived from echellete spectroscopy of binary quasars. We find CIV
systems at similar redshifts in paired sightlines more often than expected for
sightline-independent redshifts. As the separation of the sightlines increases
from 36 kpc to 907 kpc, the amplitude of this clustering decreases. At the
largest separations, the CIV systems cluster similar to Lyman-break galaxies
(Adelberger et al. 2005a). The CIV systems are significantly less correlated
than these galaxies, however, at separations less than R_1 ~ 0.42 +/- 0.15 h-1
comoving Mpc. Measured in real space, i.e., transverse to the sightlines, this
length scale is significantly smaller than the break scale estimated from the
line-of-sight correlation function in redshift space (Scannapieco et al.
2006a). Using a simple model, we interpret the new real-space measurement as an
indication of the typical physical size of enriched regions. We adopt this size
for enriched regions and fit the redshift-space distortion in the line-of-sight
correlation function. The fitted velocity kick is consistent with the peculiar
velocity of galaxies as determined by the underlying mass distribution and
places an upper limit on the outflow (or inflow) speed of metals. The implied
time scale for dispersing metals is larger than the typical stellar ages of
Lyman-break galaxies (Shapley et al. 2001), and we argue that enrichment by
galaxies at z > 4.3 played a greater role in dispersing metals. To further
constrain the growth of enriched regions, we discuss empirical constraints on
the evolution of the CIV correlation function with cosmic time. This study
demonstrates the potential of tomography for measuring the metal enrichment
history of the circum-galactic medium.Comment: 22 pages, 15 figures, 1 tabl
The Victorian Newsletter (Spring 1988)
The Victorian Newsletter is sponsored for the Victorian Group of Modern Language Association by the Western Kentucky University and is published twice annually.Inventing Victorians: Virginia Woolf's "Memoirs of a Novelist" / Mary Kaiser Loges -- Distortion Versus Revaluation: Three Twentieth-Century Responses to Victorian Fiction / Jerome Meckier -- The Dover Bitch: Victorian Duck or Modernist Duck/Rabbit / Gerhard Joseph -- Carlyle's Denial of Axiological Content in Science / Charles W. Schaefer -- Mixed Metaphor, Mixed Gender: Swinburne and the Victorian Critics / Thaïs E. Morgan -- The Humanities Tradition of Matthew Arnold / William E. Buckler -- Oliver (Un)Twisted: Narrative Strategies in Oliver Twist / Joseph Sawicki -- Representation and Homophobia in The Picture of Dorian Gray / Richard Dellamora -- Coming In The Victorian Newsletter -- Books Receive
HETDEX pilot survey for emission-line galaxies - I. Survey design, performance, and catalog
We present a catalog of emission-line galaxies selected solely by their
emission-line fluxes using a wide-field integral field spectrograph. This work
is partially motivated as a pilot survey for the upcoming Hobby-Eberly
Telescope Dark Energy Experiment (HETDEX). We describe the observations,
reductions, detections, redshift classifications, line fluxes, and counterpart
information for 397 emission-line galaxies detected over 169 sq.arcmin with a
3500-5800 Ang. bandpass under 5 Ang. full-width-half-maximum (FWHM) spectral
resolution. The survey's best sensitivity for unresolved objects under
photometric conditions is between 4-20 E-17 erg/s/sq.cm depending on the
wavelength, and Ly-alpha luminosities between 3-6 E42 erg/s are detectable.
This survey method complements narrowband and color-selection techniques in the
search for high redshift galaxies with its different selection properties and
large volume probed. The four survey fields within the COSMOS, GOODS-N, MUNICS,
and XMM-LSS areas are rich with existing, complementary data. We find 104
galaxies via their high redshift Ly-alpha emission at 1.9<z<3.8, and the
majority of the remainder objects are low redshift [OII]3727 emitters at
z<0.56. The classification between low and high redshift objects depends on
rest frame equivalent width, as well as other indicators, where available.
Based on matches to X-ray catalogs, the active galactic nuclei (AGN) fraction
amongst the Ly-alpha emitters (LAEs) is 6%. We also analyze the survey's
completeness and contamination properties through simulations. We find five
high-z, highly-significant, resolved objects with full-width-half-maximum sizes
>44 sq.arcsec which appear to be extended Ly-alpha nebulae. We also find three
high-z objects with rest frame Ly-alpha equivalent widths above the level
believed to be achievable with normal star formation, EW(rest)>240 Ang.Comment: 45 pages, 36 figures, 5 tables, submitted to ApJ
Two Lensed Lyman-alpha Emitting Galaxies at z~5
We present observations of two strongly lensed Lyman-
Emitting (LAE) galaxies that were discovered in the Sloan Giant Arcs Survey
(SGAS). We identify the two sources as SGAS J091541+382655, at , and
SGAS J134331+415455 at . We measure their AB magnitudes at
) mags and
) mags, and the rest-frame
equivalent widths of the Lyman- emission at \AA~and
\AA~for SGAS J091541+382655 and SGAS J134331+415455,
respectively. Each source is strongly lensed by a massive galaxy cluster in the
foreground, and the magnifications due to gravitational lensing are recovered
from strong lens modeling of the foreground lensing potentials. We use the
magnification to calculate the intrinsic, unlensed Lyman- and UV
continuum luminosities for both sources, as well as the implied star formation
rates (SFR). We find SGAS J091541+382655 and SGAS J134341+415455 to be galaxies
with (L, LLL) and
(L, LLL),
respectively. Comparison of the spectral energy distributions (SEDs) of both
sources against stellar population models produces estimates of the mass in
young stars in each galaxy: we report an upper limit of M M_{\sun} h_{0.7}^{-1} for SGAS
J091531+382655, and a range of viable masses for SGAS J134331+415455 of
M_{\sun} h_{0.7}^{-1} < M M_{\sun}
h_{0.7}^{-1}.Comment: 10 pages, 8 figures, emulate apj format, Accepted to Ap
ROCK Inhibitor Y-27632 Suppresses Dissociation-Induced Apoptosis of Murine Prostate Stem/Progenitor Cells and Increases Their Cloning Efficiency
Activation of the RhoA/ROCK signaling pathway has been shown to contribute to dissociation-induced apoptosis of embryonic and neural stem cells. We previously demonstrated that approximately 1 out of 40 Lin−Sca-1+CD49fhigh (LSC) prostate basal epithelial cells possess the capacities of stem cells for self-renewal and multi-lineage differentiation. We show here that treating LSC cells with the ROCK kinase inhibitor Y-27632 increases their cloning efficiency by 8 fold in an in vitro prostate colony assay. Y-27632 treatment allows prostate colony cells to replate efficiently, which does not occur otherwise. Y-27632 also increases the cloning efficiency of prostate stem cells in a prostate sphere assay and a dissociated prostate cell regeneration assay. The increased cloning efficiency is due to the suppression of the dissociation-induced, RhoA/ROCK activation-mediated apoptosis of prostate stem cells. Dissociation of prostate epithelial cells from extracellular matrix increases PTEN activity and attenuates AKT activity. Y-27632 treatment alone is sufficient to suppress cell dissociation-induced activation of PTEN activity. However, this does not contribute to the increased cloning efficiency, because Y-27632 treatment increases the sphere-forming unit of wild type and Pten null prostate cells to a similar extent. Finally, knocking down expression of both ROCK kinases slightly increases the replating efficiency of prostate colony cells, corroborating that they play a major role in the Y-27632 mediated increase in cloning efficiency. Our study implies that the numbers of prostate cells with stem/progenitor activity may be underestimated based on currently employed assays, supports that dissociation-induced apoptosis is a common feature of embryonic and somatic stem cells with an epithelial phenotype, and highlights the significance of environmental cues for the maintenance of stem cells
Crystal Structure and Functional Analysis of the SARS-Coronavirus RNA Cap 2′-O-Methyltransferase nsp10/nsp16 Complex
Cellular and viral S-adenosylmethionine-dependent methyltransferases are involved in many regulated processes such as metabolism, detoxification, signal transduction, chromatin remodeling, nucleic acid processing, and mRNA capping. The Severe Acute Respiratory Syndrome coronavirus nsp16 protein is a S-adenosylmethionine-dependent (nucleoside-2′-O)-methyltransferase only active in the presence of its activating partner nsp10. We report the nsp10/nsp16 complex structure at 2.0 Å resolution, which shows nsp10 bound to nsp16 through a ∼930 Å2 surface area in nsp10. Functional assays identify key residues involved in nsp10/nsp16 association, and in RNA binding or catalysis, the latter likely through a SN2-like mechanism. We present two other crystal structures, the inhibitor Sinefungin bound in the S-adenosylmethionine binding pocket and the tighter complex nsp10(Y96F)/nsp16, providing the first structural insight into the regulation of RNA capping enzymes in (+)RNA viruses
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