1,457 research outputs found
Perceptions, Barriers, and Suggestions for Creation of a Tobacco and Health Website among American Indian/Alaska Native College Students
Information concerning American Indian/Alaska Native (AI/AN) Internet use and health information needs is dearth. Our research team explored Internet use among AI/AN college students to determine Internet use in relation to health information seeking behaviors. We used a tobacco site example for participants to describe what they desired in a health site designed specifically for AI/AN. Using a community-based participatory research approach, we conducted 14 focus groups with AI/AN college students (N=108), to better understand their perceptions of and attitudes toward Internet use and health information needs. Daily Internet use was reported across strata yet health topics investigated differed among groups. Participants in all strata desired a health website that was easy to navigate and interactive. Respectful representation of Native culture was a concern, yet no consensus was reached for a multi-tribal audience. Participants felt a website should use caution with cultural depictions due to the possible misinterpretation. Overall, participants agreed that recreational and traditional tobacco use should be differentiated and the variation of traditional use among tribes acknowledged. Data concerning Internet use for health information among AI/AN college students are needed to establish baseline indicators to effectively address disparities
Gravitational Mesoscopic Constraints in Cosmological Dark Matter Halos
We present an analysis of the behaviour of the `coarse-grained'
(`mesoscopic') rank partitioning of the mean energy of collections of particles
composing virialized dark matter halos in a Lambda-CDM cosmological simulation.
We find evidence that rank preservation depends on halo mass, in the sense that
more massive halos show more rank preservation than less massive ones. We find
that the most massive halos obey Arnold's theorem (on the ordering of the
characteristic frequencies of the system) more frequently than less massive
halos. This method may be useful to evaluate the coarse-graining level (minimum
number of particles per energy cell) necessary to reasonably measure signatures
of `mesoscopic' rank orderings in a gravitational system.Comment: LaTeX, 15 pages, 3 figures. Accepted for publication in Celestial
Mechanics and Dynamical Astronomy Journa
HD 101088, An Accreting 14 AU Binary in Lower Centaurus Crux With Very Little Circumstellar Dust
We present high resolution (R=55,000) optical spectra obtained with MIKE on
the 6.5 m Magellan Clay Telescope as well as Spitzer MIPS photometry and IRS
low resolution (R~60) spectroscopy of the close (14 AU separation) binary, HD
101088, a member of the ~12 Myr old southern region of the Lower Centaurus Crux
(LCC) subgroup of the Scorpius-Centaurus OB association. We find that the
primary and/or secondary is accreting from a tenuous circumprimary and/or
circumsecondary disk despite the apparent lack of a massive circumbinary disk.
We estimate a lower limit to the accretion rate of > 1x10^-9 solar masses per
year, which our multiple observation epochs show varies over a timescale of
months. The upper limit on the 70 micron flux allows us to place an upper limit
on the mass of dust grains smaller than several microns present in a
circumbinary disk of 0.16 moon masses. We conclude that the classification of
disks into either protoplanetary or debris disks based on fractional infrared
luminosity alone may be misleading.Comment: 8 pages, 2 figures, ApJ accepte
Recommended from our members
MacroH2A1 isoforms are associated with epigenetic markers for activation of lipogenic genes in fat-induced steatosis.
The importance of epigenetic changes in the development of hepatic steatosis is largely unknown. The histone variant macroH2A1 under alternative splicing gives rise to macroH2A1.1 and macroH2A1.2. In this study, we show that the macroH2A1 isoforms play an important role in the regulation of lipid accumulation in hepatocytes. Hepatoma cell line and immortalized human hepatocytes transiently transfected or knocked down with macroH2A1 isoforms were used as in vitro model of fat-induced steatosis. Gene expressions were analyzed by quantitative PCR array and Western blot. Chromatin immunoprecipitation analysis was performed to check the association of histone H3 lysine 27 trimethylation (H3K27me3) and histone H3 lysine 4 trimethylation (H3K4me3) with the promoter of lipogenic genes. Livers from knockout mice that are resistant to lipid deposition despite a high-fat diet were used for histopathology. We found that macroH2A1.2 is regulated by fat uptake and that its overexpression caused an increase in lipid uptake, triglycerides, and lipogenic genes compared with macroH2A1.1. This suggests that macroH2A1.2 is important for lipid uptake, whereas macroH2A1.1 was found to be protective. The result was supported by a high positivity for macroH2A1.1 in knockout mice for genes targeted by macroH2A1 (Atp5a1 and Fam73b), that under a high-fat diet presented minimal lipidosis. Moreover, macroH2A1 isoforms differentially regulate the expression of lipogenic genes by modulating the association of the active (H3K4me3) and repressive (H3K27me3) histone marks on their promoters. This study underlines the importance of the replacement of noncanonical histones in the regulation of genes involved in lipid metabolism in the progression of steatosis
Genomics reveals historic and contemporary transmission dynamics of a bacterial disease among wildlife and livestock
Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations
Missense Mutation in the Second RNA Binding Domain Reveals a Role for Prkra (PACT/RAX) during Skull Development
Random chemical mutagenesis of the mouse genome can causally connect genes to specific phenotypes. Using this approach, reduced pinna (rep) or microtia, a defect in ear development, was mapped to a small region of mouse chromosome 2. Sequencing of this region established co-segregation of the phenotype (rep) with a mutation in the Prkra gene, which encodes the protein PACT/RAX. Mice homozygous for the mutant Prkra allele had defects not only in ear development but also growth, craniofacial development and ovarian structure. The rep mutation was identified as a missense mutation (Serine 130 to Proline) that did not affect mRNA expression, however the steady state level of RAX protein was significantly lower in the brains of rep mice. The mutant protein, while normal in most biochemical functions, was unable to bind dsRNA. In addition, rep mice displayed altered morphology of the skull that was consistent with a targeted deletion of Prkra showing a contribution of the gene to craniofacial development. These observations identified a specific mutation that reduces steady-state levels of RAX protein and disrupts the dsRNA binding function of the protein, demonstrating the importance of the Prkra gene in various aspects of mouse development
Simultaneous Measurement of Benzo[a]pyrene-induced Pig-a and lacZ Mutations, Micronuclei and DNA Adducts in Muta™ Mouse
In this study we compared the response of the Pig-a gene mutation assay to that of the lacZ transgenic rodent mutation assay, and demonstrated that multiple endpoints can be measured in a 28-day repeat dose study. Muta™Mouse were dosed daily for 28 days with benzo[a]pyrene (BaP; 0, 25, 50 and 75 mg/kg body weight/day) by oral gavage. Micronucleus (MN) frequency was determined in reticulocytes (RETs) 48 hr following the last dose. 72 h following the last dose, mice were euthanized, and tissues (glandular stomach, small intestine, bone marrow and liver) were collected for lacZ mutation and DNA adduct analysis, and blood was evaluated for Pig-a mutants. BaP-derived DNA adducts were detected in all tissues examined and significant dose-dependent increases in mutant Pig-a phenotypes (i.e., RETCD24- and RBC CD24-) and lacZ mutants were observed. We estimate that mutagenic efficiency (i.e., rate of conversion of adducts into mutations) was much lower for Pig-a compared to lacZ, and speculate that this difference is likely explained by differences in repair capacity between the gene targets, and differences in the cell populations sampled for Pig-a versus lacZ. The BaP doubling doses for both gene targets, however, were comparable, suggesting that similar mechanisms are involved in the accumulation of gene mutations. Significant dose-related increases in % MN were also observed; however, the doubling dose was considerably higher for this endpoint. The similarity in dose response kinetics of Pig-a and lacZ provides further evidence for the mutational origin of glycosylphosphatidylinositol (GPI)-anchor deficiencies detected in the Pig-a assay. Environ. Mol. Mutagen. 2011. © 2011 Wiley-Liss, Inc
COVID-19 impacts equine welfare : Policy implications for laminitis and obesity
Funding: This study was funded by Mars Petcare and is part of a PhD studentship funded by the Scottish Funding Council Research Excellence Grant (REG). Authors WR and MN receive salary support from the Rural and Environment Science and Analytical Services Division (RESAS). With the exception of PH (employed by the funding organization), the funding organization did not have any additional role in the conceptualization, methodology, investigation, data curation, formal analysis, decision to publish, or preparation of the manuscript. PH was involved in study design, data interpretation, and manuscript preparation. Acknowledgments We wish to extend our gratitude to the local horse owners, veterinarians, farriers and welfare centre managers who volunteered their time to take part in this research. Our thanks also to Dr Charlotte Maltin for supporting recruitment for the study and to World Horse Welfare for their continued interest in the key welfare issues addressed in the present study.Peer reviewedPublisher PD
The association between protease inhibitors and anal cancer outcomes in veterans living with HIV treated with definitive chemoradiation: a retrospective study
Background: The incidence of anal squamous cell carcinoma has been increasing, particularly in people living with HIV (PLWH). There is concern that radiosensitizing drugs, such as protease inhibitors, commonly used in the management of HIV, may increase toxicities in patients undergoing chemoradiation. This study examines treatment outcomes and toxicities in PLWH managed with and without protease inhibitors who are receiving chemoradiation for anal cancer. Methods: Patient demographic, HIV management, and cancer treatment information were extracted from multiple Veterans Affairs databases. Patients were also manually chart reviewed. Among PLWH undergoing chemoradiation for anal carcinoma, therapy outcomes and toxicities were compared between those treated with and without protease inhibitors at time of cancer treatment. Statistical analysis was performed using chi-square, Cox regression analysis, and logistic regression. Results: A total of 219 PLWH taking anti-retroviral therapy undergoing chemoradiation for anal cancer were identified and included in the final analysis. The use of protease inhibitors was not associated with any survival outcome including colostomy-free survival, progression-free survival, or overall survival (all adjusted hazard ratio p-values\u3e 0.05). Regarding toxicity, protease inhibitor use was not associated with an increased odds of hospitalizations or non-hematologic toxicities; however, protease inhibitor use was associated with increased hospitalizations for hematologic toxicities, including febrile neutropenia (p \u3c 0.01). Conclusion: The use of protease inhibitors during chemoradiation for anal carcinoma was not associated with any clinical outcome or increase in non-hematologic toxicity. Their use was associated with increased hospitalizations for hematologic toxicities. Further prospective research is needed to evaluate the safety and efficacy of protease inhibitors for patients undergoing chemoradiation
Are Luminous cD Haloes Formed by the Disruption of Dwarf Galaxies?
From a total sample of 45 Abell clusters observed by the Einstein X-ray
observatory, we present the results on the galaxy luminosity function (LF) for
a group of seven clusters that were identified by the morphology of their LFs.
The LFs were derived using photometric data to a completeness limit ~5.5
magnitudes below M*. We found that a single Schechter function with an average
gives a good fit to these individual LFs within the
magnitude range. These seven clusters have common properties, which indicate
they form a homogeneous class of dynamically evolved clusters that can be
characterized by the presence of a dominant cD galaxy, high richness,
symmetrical single-peaked X-ray emission, and high gas mass. On the other hand,
steep faint-end slopes (-2.0 < \alpha < -1.4) are usually detected in poorer
clusters. Our result gives a direct indication that the faint-end slope of the
galaxy LF is subject to environmental effects. We propose that the flatness of
the faint-end slope in these clusters results from the disruption of a large
fraction of dwarf galaxies during the early stages of cluster evolution. The
stars and gas from the disrupted galaxies are redistributed throughout the
cluster potential during violent relaxation. This heuristic scenario can
explain the origin of the luminous haloes of cD galaxies and a large fraction
of the gas content in the intracluster medium as a by-product. The correlation
between the cluster gas mass determined from the modeling of the X-ray emission
and the cD halo optical luminosity is presented to support the proposed model.Comment: 11 pages,Latex,2 Postscript figures, 2 Postscript tables, accepted
for publication in Apj
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