1,409 research outputs found
Vortex energy and vortex bending for a rotating Bose-Einstein condensate
For a Bose-Einstein condensate placed in a rotating trap, we give a
simplified expression of the Gross-Pitaevskii energy in the Thomas Fermi
regime, which only depends on the number and shape of the vortex lines.
Then we check numerically that when there is one vortex line, our simplified
expression leads to solutions with a bent vortex for a range of rotationnal
velocities and trap parameters which are consistent with the experiments.Comment: 7 pages, 2 figures. submitte
Herschel PACS Observations and Modeling of Debris Disks in the Tucana-Horologium Association
We present Herschel PACS photometry of seventeen B- to M-type stars in the 30
Myr-old Tucana-Horologium Association. This work is part of the Herschel Open
Time Key Programme "Gas in Protoplanetary Systems" (GASPS). Six of the
seventeen targets were found to have infrared excesses significantly greater
than the expected stellar IR fluxes, including a previously unknown disk around
HD30051. These six debris disks were fitted with single-temperature blackbody
models to estimate the temperatures and abundances of the dust in the systems.
For the five stars that show excess emission in the Herschel PACS photometry
and also have Spitzer IRS spectra, we fit the data with models of optically
thin debris disks with realistic grain properties in order to better estimate
the disk parameters. The model is determined by a set of six parameters:
surface density index, grain size distribution index, minimum and maximum grain
sizes, and the inner and outer radii of the disk. The best fitting parameters
give us constraints on the geometry of the dust in these systems, as well as
lower limits to the total dust masses. The HD105 disk was further constrained
by fitting marginally resolved PACS 70 micron imaging.Comment: 15 pages, 7 figures, Accepted to Ap
PRM10 Calibration of a Cost-Effectiveness Model to Evaluate the Incorporation of a Quadrivalent HPV Types 6, 11, 16, 18 Vaccine in Argentina: Disease Burden Component
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Predicting Persistent Opioid Use, Abuse, and Toxicity Among Cancer Survivors.
BackgroundAlthough opioids play a critical role in the management of cancer pain, the ongoing opioid epidemic has raised concerns regarding their persistent use and abuse. We lack data-driven tools in oncology to understand the risk of adverse opioid-related outcomes. This project seeks to identify clinical risk factors and create a risk score to help identify patients at risk of persistent opioid use and abuse.MethodsWithin a cohort of 106 732 military veteran cancer survivors diagnosed between 2000 and 2015, we determined rates of persistent posttreatment opioid use, diagnoses of opioid abuse or dependence, and admissions for opioid toxicity. A multivariable logistic regression model was used to identify patient, cancer, and treatment risk factors associated with adverse opioid-related outcomes. Predictive risk models were developed and validated using a least absolute shrinkage and selection operator regression technique.ResultsThe rate of persistent opioid use in cancer survivors was 8.3% (95% CI = 8.1% to 8.4%); the rate of opioid abuse or dependence was 2.9% (95% CI = 2.8% to 3.0%); and the rate of opioid-related admissions was 2.1% (95% CI = 2.0% to 2.2%). On multivariable analysis, several patient, demographic, and cancer and treatment factors were associated with risk of persistent opioid use. Predictive models showed a high level of discrimination when identifying individuals at risk of adverse opioid-related outcomes including persistent opioid use (area under the curve [AUC] = 0.85), future diagnoses of opioid abuse or dependence (AUC = 0.87), and admission for opioid abuse or toxicity (AUC = 0.78).ConclusionThis study demonstrates the potential to predict adverse opioid-related outcomes among cancer survivors. With further validation, personalized risk-stratification approaches could guide management when prescribing opioids in cancer patients
Suppression of extraneous thermal noise in cavity optomechanics
Extraneous thermal motion can limit displacement sensitivity and radiation
pressure effects, such as optical cooling, in a cavity-optomechanical system.
Here we present an active noise suppression scheme and its experimental
implementation. The main challenge is to selectively sense and suppress
extraneous thermal noise without affecting motion of the oscillator. Our
solution is to monitor two modes of the optical cavity, each with different
sensitivity to the oscillator's motion but similar sensitivity to the
extraneous thermal motion. This information is used to imprint "anti-noise"
onto the frequency of the incident laser field. In our system, based on a
nano-mechanical membrane coupled to a Fabry-P\'{e}rot cavity, simulation and
experiment demonstrate that extraneous thermal noise can be selectively
suppressed and that the associated limit on optical cooling can be reduced.Comment: 27 pages, 14 figure
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
Cosmic rays extensive air showers (EAS) are associated with transient radio
emission, which could provide an efficient new detection method of high energy
cosmic rays, combining a calorimetric measurement with a high duty cycle. The
CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is
investigating this phenomenon in the 10^17 eV region. One challenging point is
the understanding of the radio emission mechanism. A first observation
indicating a linear relation between the electric field produced and the cross
product of the shower axis with the geomagnetic field direction has been
presented (B. Revenu, this conference). We will present here other strong
evidences for this linear relationship, and some hints on its physical origin.Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz,
Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references adde
Molecular basis of fatty acid selectivity in the zDHHC family of S-acyltransferases revealed by click chemistry
S-Acylation is a major post-translational modification, catalysed by the zDHHC enzyme family. S-acylated proteins can be modified by different fatty acids; however, very little is known about how zDHHC enzymes contribute to acyl chain heterogeneity. Here, we employed fatty acid azide/alkyne labelling of mammalian cells, showing their transformation into acyl-CoAs and subsequent click chemistry-based detection, to demonstrate that zDHHC enzymes have marked differences in their fatty acid selectivity. This was apparent even for highly related enzymes such as zDHHC3 and zDHHC7, which displayed a marked difference in ability to use C18:0 acyl CoA as a substrate. Furthermore, we identified Isoleucine-182 in the third transmembrane domain of zDHHC3 as a key determinant limiting the use of longer chain acyl-CoAs by this enzyme. This is the first study to uncover differences in the fatty acid selectivity profiles of cellular zDHHC enzymes and to map molecular determinants governing this selectivit
The selective V1a receptor agonist FE 202158 does not cause von Willebrand factor release in sheep unlike arginine vasopressin
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