2,733 research outputs found
S5 0716+714 : GeV variability study
The GeV observations by Fermi-LAT give us the opportunity to characterize the
high-energy emission (100 MeV - 300 GeV) variability properties of the BL Lac
object S5 0716+714. In this study, we performed flux and spectral analysis of
more than 3 year long (August 2008 to April 2012) Fermi-LAT data of the source.
During this period, the source exhibits two different modes of flux variability
with characteristic timescales of ~75 and ~140 days, respectively. We also
notice that the flux variations are characterized by a weak spectral hardening.
The GeV spectrum of the source shows a clear deviation from a simple power law,
and is better explained by a broken power law. Similar to other bright Fermi
blazars, the break energy does not vary with the source flux during the
different activity states. We discuss several possible scenarios to explain the
observed spectral break.Comment: 21 pages, 10 figures, Accepted for publication in Advances in Space
Research journa
Extensive divergence of transcription factor binding in Drosophila embryos with highly conserved gene expression
Extensive divergence of transcription factor binding in Drosophila embryos
with highly conserved gene expressionComment: 7 figures, 20 supplementary figures, 6 supplementary tables Paris M,
Kaplan T, Li XY, Villalta JE, Lott SE, et al. (2013) Extensive Divergence of
Transcription Factor Binding in Drosophila Embryos with Highly Conserved Gene
Expression. PLoS Genet 9(9): e1003748. doi:10.1371/journal.pgen.100374
Mean curvature flow in a Ricci flow background
Following work of Ecker, we consider a weighted Gibbons-Hawking-York
functional on a Riemannian manifold-with-boundary. We compute its variational
properties and its time derivative under Perelman's modified Ricci flow. The
answer has a boundary term which involves an extension of Hamilton's Harnack
expression for the mean curvature flow in Euclidean space. We also derive the
evolution equations for the second fundamental form and the mean curvature,
under a mean curvature flow in a Ricci flow background. In the case of a
gradient Ricci soliton background, we discuss mean curvature solitons and
Huisken monotonicity.Comment: final versio
An adaptive-binning method for generating constant-uncertainty/constant-significance light curves with Fermi-LAT data
We present a method enabling the creation of
constant-uncertainty/constant-significance light curves with the data of the
Fermi-Large Area Telescope (LAT). The adaptive-binning method enables more
information to be encapsulated within the light curve than with the
fixed-binning method. Although primarily developed for blazar studies, it can
be applied to any sources. This method allows the starting and ending times of
each interval to be calculated in a simple and quick way during a first step.
The reported mean flux and spectral index (assuming the spectrum is a power-law
distribution) in the interval are calculated via the standard LAT analysis
during a second step. The absence of major caveats associated with this method
has been established by means of Monte-Carlo simulations. We present the
performance of this method in determining duty cycles as well as power-density
spectra relative to the traditional fixed-binning method.Comment: 17 pages, 13 figures, 5 tables. Submitted to A&
Retardation of Particle Evaporation from Excited Nuclear Systems Due to Thermal Expansion
Particle evaporation rates from excited nuclear systems at equilibrium matter
density are studied within the Harmonic-Interaction Fermi Gas Model (HIFGM)
combined with Weisskopf's detailed balance approach. It is found that thermal
expansion of a hot nucleus, as described quantitatively by HIFGM, leads to a
significant retardation of particle emission, greatly extending the validity of
Weisskopf's approach. The decay of such highly excited nuclei is strongly
influenced by surface instabilities
Confidence Level Of Primary Care Providers In Authorizing Athletic Return-To-Play
The purpose of this study was to identify the level of confidence for primary care providers in authorizing athletic retum-to-play following sports-related injury. The Centers for Disease Control and Prevention (CDC) (as cited in Patel, Yamasaki, & Brown, 2017) reported that 2.6 million children and teens ages 0-19 years are treated annually for sports-related injuries, and 7.2 million high school students participate in sports and suffer an estimated 2 million injuries that require 500,000 doctor visits and 30,000 hospitalizations annually. Although primary care providers are providing care for musculoskeletal and concussive injuries, Benham and Geier (2016) reported that they may not have the confidence, knowledge, or skill to manage common musculoskeletal conditions in their primary care practice. Excellent provisions of such care will require providers who are safe and confident in the management and treatment of sports-related injuries to ensure high-quality patient care (Benham & Geier, 2016). Researchers distributed written surveys, and links to a survey were distributed via social media postings, email, and SurveyMonkey to qualifying participants including Doctors of Medicine (MD), Doctors of Osteopathic Medicine (DO), nurse practitioners (NP), and physician assistants (PA). Data collected indicated that only 47.6% primary care providers were confident with returning youth athletes back-to-play following a sports injury, 34.7% were confident in treating sports-related concussive injuries, and 50% were confident in treating sports-related musculoskeletal injuries. Primary care providers can use this information to expose areas for confidence improvement that can be met with continued education, in-services, and workshops. Schools of medicine and nursing can use these findings to improve musculoskeletal curricula in primary care education. Determining primary care provider confidence level in authorizing athletic retum-to-play is imperative in ensuring patient safety and access to thorough and competent care from initial injury to full resolution
An Experiment in Visual Ethnography
This paper is an output from my attendance at an ESRC-funded âLive Sociologyâ course at
Goldsmiths College, London in 2006. The material here is based on a photography exercise and
on discussions that took place during the workshop sessions.This paper discusses a one-day exercise in
visual ethnography using a digital camera
to take photographs of Deptford in South
East London. For me, this represented an
experiment in using photography in social
research.ESR
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