411 research outputs found
Molecular Targets of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) within the Zebrafish Ovary: Insights into TCDD-induced Endocrine Disruption and Reproductive Toxicity
TCDD is a reproductive toxicant and endocrine disruptor, yet the mechanisms by which it causes these reproductive alterations are not fully understood. In order to provide additional insight into the molecular mechanisms that underlie TCDD\u27s reproductive toxicity, we assessed TCDD-induced transcriptional changes in the ovary as they relate to previously described impacts on serum estradiol concentrations and altered follicular development in zebrafish. In silico computational approaches were used to correlate candidate regulatory motifs with observed changes in gene expression. Our data suggest that TCDD inhibits follicle maturation via attenuated gonadotropin responsiveness and/or depressed estradiol biosynthesis, and that interference of estrogen-regulated signal transduction may also contribute to TCDD\u27s impacts on follicular development. TCDD may also alter ovarian function by disrupting various signaling pathways such as glucose and lipid metabolism, and regulation of transcription. Furthermore, events downstream from initial TCDD molecular-targets likely contribute to ovarian toxicity following chronic exposure to TCDD. Data presented here provide further insight into the mechanisms by which TCDD disrupts follicular development and reproduction in fish, and can be used to formulate new hypotheses regarding previously documented ovarian toxicity
SelfâAcupressure for Older Adults With Symptomatic Knee Osteoarthritis: A Randomized Controlled Trial
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141019/1/acr23262_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141019/2/acr23262.pd
Feasibility of a Randomized Controlled Trial of Self-Administered Acupressure for Symptom Management in Older Adults with Knee Osteoarthritis
Objectives: To assess the feasibility of a study to evaluate the efficacy of self-administered acupressure in pain and related symptom management for older people with symptomatic knee osteoarthritis. Feasibility with regard to (1) sample recruitment and retention, (2) treatment fidelity and adherence, and (3) tolerability and adverse events was examined. Methods: The study was a randomized controlled trial. Community-living older adults were recruited and randomly assigned to one of three groups: verum acupressure, sham acupressure, and usual care. Participants in the first two groups learned their respective acupressure protocol during their first center visit and from a set of materials. They were asked to practice the protocol at home once daily, 5 days a week, for 8 weeks. Participants attended three center visits and received weekly phone calls from a research assistant in an 8-week study period. Both quantitative and qualitative data collected from center visits and weekly phone calls were used to examine study feasibility. Results: A total of 150 participants (mean age, 73 years; 38% men) were enrolled; 83% completed all three center visits. Among those assigned to verum and sham acupressure groups, 94% passed a fidelity check at the second visit, more than 80% reported performing self-administered acupressure as instructed most of the time, and about 10% reported discomfort from performing the acupressure. Thirty adverse events were reported; most were related to pre-existing health conditions. Conclusions: It is feasible to conduct a study of self-administered acupressure for symptom management in community-living older adults with knee osteoarthritis, although sample recruitment may be challenging.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140088/1/acm.2015.0231.pd
Status report to DOE Nuclear Data Committee
This status report from Lawrence Livermore Laboratory covers work in the areas of nuclear data applications - measurements, nuclear data application - calculations, nuclear data for reactor safety, fission physics, and data evaluation and compilation. Separate abstracts were prepared for seven of the contributions to this report. 7 figures, 3 tables. (RWR
A giant radio halo in the low luminosity X-ray cluster Abell 523
Radio halos are extended and diffuse non-thermal radio sources present at the
cluster center, not obviously associated with any individual galaxy. A strong
correlation has been found between the cluster X-ray luminosity and the halo
radio power. We observe and analyze the diffuse radio emission present in the
complex merging structure Abell 523, classified as a low luminosity X-ray
cluster, to discuss its properties in the context of the halo total radio power
versus X-ray luminosity correlation. We reduced VLA archive observations at 1.4
GHz to derive a deep radio image of the diffuse emission, and compared radio,
optical, and X-ray data. Low-resolution VLA images detect a giant radio halo
associated with a complex merging region. The properties of this new halo agree
with those of radio halos in general discussed in the literature, but its radio
power is about a factor of ten higher than expected on the basis of the cluster
X-ray luminosity. Our study of this giant radio source demonstrates that radio
halos can also be present in clusters with a low X-ray luminosity. Only a few
similar cases have so far been found . This result suggests that this source
represent a new class of objects, that cannot be explained by classical radio
halo models. We suggest that the particle reacceleration related to merging
processes is very efficient and/or the X-ray luminosity is not a good indicator
of the past merging activity of a cluster.Comment: 5 pages, 6 figures, Astronomy and Astrophysics Letter in pres
Deep images of cluster radio halos
New radio data are presented for the clusters A401, A545, A754, A1914, A2219
and A2390, where the presence of diffuse radio emission was suggested from the
images of the NRAO VLA Sky Survey. Sensitive images of these clusters, obtained
with the Very Large Array (VLA)at 20 cm confirm the existence of the diffuse
sources and allow us to derive their fluxes and intrinsic parameters.The
correlation between the halo radio power and cluster X-ray luminosity is
derived for a large sample of halo clusters, and is briefly discussed.Comment: 9 pages, 13 figures, Astron. Astrophys. in pres
The intracluster magnetic field power spectrum in Abell 2382
The goal of this work is to put constraints on the strength and structure of
the magnetic field in the cluster of galaxies A2382. We investigate the
relationship between magnetic field and Faraday rotation effects in the
cluster, using numerical simulations as a reference for the observed
polarization properties. For this purpose we present Very Large Array
observations at 20 cm and 6 cm of two polarized radio sources embedded in
A2382, and we obtained detailed rotation measure images for both of them. We
simulated random three-dimensional magnetic field models with different power
spectra and thus produced synthetic rotation measure images. By comparing our
simulations with the observed polarization properties of the radio sources, we
can determine the strength and the power spectrum of intra-cluster magnetic
field fluctuations that best reproduce the observations. The data are
consistent with a power law magnetic field power spectrum with the Kolmogorov
index , while the outer scale of the magnetic field fluctuations is of
the order of 35 kpc. The average magnetic field strength at the cluster center
is about 3 G and decreases in the external region as the square root of
the electron gas density. The average magnetic field strength in the central 1
Mpc is about 1 G.Comment: Comments: 18 pages, 13 figures, accepted by A&A. For a version with
high quality figures, see http://erg.ca.astro.it/preprints/guidetti2007
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