181 research outputs found
Impact of neutron star oscillations on the accelerating electric field in the polar cap of pulsar: or could we see oscillations of the neutron star after the glitch in pulsar?
Pulsar "standard model", that considers a pulsar as a rotating magnetized
conducting sphere surrounded by plasma, is generalized to the case of
oscillating star. We developed an algorithm for calculation of the
Goldreich-Julian charge density for this case. We consider distortion of the
accelerating zone in the polar cap of pulsar by neutron star oscillations. It
is shown that for oscillation modes with high harmonic numbers (l,m) changes in
the Goldreich-Julian charge density caused by pulsations of neutron star could
lead to significant altering of an accelerating electric field in the polar cap
of pulsar. In the moderately optimistic scenario, that assumes excitation of
the neutron star oscillations by glitches, it could be possible to detect
altering of the pulsar radioemission due to modulation of the accelerating
field.Comment: 7 pages, 8 figures. Presented at the conference "Isolated Neutron
Stars: from the Interior to the Surface", London, April 24-28, 2006; to
appear in Astrophysics and Space Scienc
Plasma Magnetosphere Formation Around Oscillating Magnetized Neutron Stars
The notion of death line of rotating pulsars is applied to model of
oscillating neutron stars. It is shown that the magnetosphere of typical
non-rotating oscillating stars may not contain secondary plasma to support the
generation of radio emission in the region of open field lines of plasma
magnetosphere.Comment: Accepted for publication in Astrophysics & Space Scienc
Effects of decoherence and errors on Bell-inequality violation
We study optimal conditions for violation of the Clauser-Horne-Shimony-Holt
form of the Bell inequality in the presence of decoherence and measurement
errors. We obtain all detector configurations providing the maximal Bell
inequality violation for a general (pure or mixed) state. We consider local
decoherence which includes energy relaxation at the zero temperature and
arbitrary dephasing. Conditions for the maximal Bell-inequality violation in
the presence of decoherence are analyzed both analytically and numerically for
the general case and for a number of important special cases. Combined effects
of measurement errors and decoherence are also discussed.Comment: 18 pages, 5 figure
Proteome profiling outperforms transcriptome profiling for coexpression based gene function prediction
Coexpression of mRNAs under multiple conditions is commonly used to infer cofunctionality of their gene products despite well-known limitations of this "guilt-by-association" (GBA) approach. Recent advancements in mass spectrometry-based proteomic technologies have enabled global expression profiling at the protein level; however, whether proteome profiling data can outperform transcriptome profiling data for coexpression based gene function prediction has not been systematically investigated. Here, we address this question by constructing and analyzing mRNA and protein coexpression networks for three cancer types with matched mRNA and protein profiling data from The Cancer Genome Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC). Our analyses revealed a marked difference in wiring between the mRNA and protein coexpression networks. Whereas protein coexpression was driven primarily by functional similarity between coexpressed genes, mRNA coexpression was driven by both cofunction and chromosomal colocalization of the genes. Functionally coherent mRNA modules were more likely to have their edges preserved in corresponding protein networks than functionally incoherent mRNA modules. Proteomic data strengthened the link between gene expression and function for at least 75% of Gene Ontology (GO) biological processes and 90% of KEGG pathways. A web application Gene2Net (http://cptac.gene2net.org) developed based on the three protein coexpression networks revealed novel gene-function relationships, such as linking ERBB2 (HER2) to lipid biosynthetic process in breast cancer, identifying PLG as a new gene involved in complement activation, and identifying AEBP1 as a new epithelial-mesenchymal transition (EMT) marker. Our results demonstrate that proteome profiling outperforms transcriptome profiling for coexpression based gene function prediction. Proteomics should be integrated if not preferred in gene function and human disease studies
GH peak response to GHRH-arginine: relationship to insulin resistance and other cardiovascular risk factors in a population of adults aged 50–90
OBJECTIVE: To assess the GH response to GHRH-arginine in apparently healthy adults in relation to cardiovascular risk factors. DESIGN: Cross-sectional. PATIENTS: Eighty-six male and female volunteers aged 50–90. MEASUREMENTS: GH peak response to GHRH-arginine and cardiovascular risk factors, including obesity, insulin resistance, low levels of high density lipoprotein (HDL) cholesterol, elevated triglycerides, and hypertension. The primary outcome measurement was GH response to GHRH-arginine. The relationship between GH peak responses and cardiovascular risk factors was determined after data collection. RESULTS: GH peaks were highly variable, ranging from 2·3 to 185 µg/l (14% with GH peaks < 9 µg/l). An increasing number of cardiovascular risk factors were associated with a lower mean GH peak (P < 0·0001). By univariate analysis, fasting glucose, insulin, body mass index (BMI), HDL cholesterol and triglycerides were significantly associated with GH peak (all P < 0·0001). Multiple regression analysis revealed that fasting glucose, fasting insulin, BMI, triglycerides and sex accounted for 54% of GH peak variability. The role of abdominal fat as it relates to GH peak was explored in a subset of 45 subjects. Trunk fat and abdominal subregion fat measured by dual energy X-ray absorptiometry (DXA) were inversely related to GH peak (P < 0·008 and 0·001, respectively). Analysis of this subgroup by multiple regression revealed that subregion abdominal fat became the significant obesity-related determinant of GH peak, but still lagged behind fasting insulin and glucose. CONCLUSIONS: GH response to secretagogues was highly variable in apparently healthy adults aged 50–90 years. Peak GH was significantly related to fasting glucose, insulin, BMI, HDL cholesterol, triglycerides, trunk fat and abdominal subregion fat, with fasting glucose ranking first by multiple regression analysis. There was a strong relationship between cardiovascular risk factors and low GH, with individual risk factors being additive. Although these data do not differentiate between low GH being a cause or an effect of these cardiovascular risk factors, they indicate that the relationship between low GH and increased cardiovascular risk may be physiologically important in the absence of pituitary disease
Modelling generalized parton distributions to describe deeply virtual Compton scattering data
We present a new model for generalized parton distributions (GPDs), based on
the aligned jet model, which successfully describes the deeply virtual Compton
scattering (DVCS) data from H1, ZEUS, HERMES and CLAS. We also present an
easily implementable and flexible algorithm for their construction. This new
model is necessary since the most widely used models for GPDs, which are based
on factorized double distributions, cannot, in their current form, describe the
DVCS data when employed in a full QCD analysis. We demonstrate explicitly the
reason for the shortcoming in the data description. We also highlight several
non-perturbative input parameters which could be used to tune the GPDs, and the
-dependence, to the DVCS data using a fitting procedure.Comment: 12 pages, 12 figures, revtex4, shortened version accepted for
publication in PRD, figures improved and references adde
Nuclear DVCS at small-x using the color dipole phenomenology
Using the high energy color dipole formalism, we study the coherent and
incoherent nuclear DVCS process in the small-x regime. We consider simple
models for the elementary dipole-hadron scattering amplitude that captures main
features of the dependence on atomic number A, on energy and on momentum
transfer t. Using the obtained amplitudes we make predictions for the nuclear
DVCS cross section at photon level in the collider kinematics.Comment: 6 pages, 5 figures. Version to be published in European Physical
Journal
Development of a Standardized Set of Patient-centered Outcomes for Advanced Prostate Cancer: An International Effort for a Unified Approach
AbstractBackgroundThere are no universally monitored outcomes relevant to men with advanced prostate cancer, making it challenging to compare health outcomes between populations.ObjectiveWe sought to develop a standard set of outcomes relevant to men with advanced prostate cancer to follow during routine clinical care.Design, setting, and participantsThe International Consortium for Health Outcomes Measurement assembled a multidisciplinary working group to develop the set.Outcome measurements and statistical analysisWe used a modified Delphi method to achieve consensus regarding the outcomes, measures, and case mix factors included.Results and limitationsThe 25 members of the multidisciplinary international working group represented academic and nonacademic centers, registries, and patients. Recognizing the heterogeneity of men with advanced prostate cancer, the group defined the scope as men with all stages of incurable prostate cancer (metastatic and biochemical recurrence ineligible for further curative therapy). We defined outcomes important to all men, such as overall survival, and measures specific to subgroups, such as time to metastasis. Measures gathered from clinical data include measures of disease control. We also identified patient-reported outcome measures (PROMs), such as degree of urinary, bowel, and erectile dysfunction, mood symptoms, and pain control.ConclusionsThe international multidisciplinary group identified clinical data and PROMs that serve as a basis for international health outcome comparisons and quality-of-care assessments. The set will be revised annually.Patient summaryOur international group has recommended a standardized set of patient-centered outcomes to be followed during routine care for all men with advanced prostate cancer
Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV
Peer reviewe
Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV
Peer reviewe
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