51,891 research outputs found
Feynman-Jackson integrals
We introduce perturbative Feynman integrals in the context of q-calculus
generalizing the Gaussian q-integrals introduced by Diaz and Teruel. We provide
analytic as well as combinatorial interpretations for the Feynman-Jackson
integrals.Comment: Final versio
Bispectrum signatures of a modified vacuum in single field inflation with a small speed of sound
Deviations from the Bunch-Davies vacuum during an inflationary period can
leave a testable imprint on the higher-order correlations of the CMB and large
scale structures in the Universe. The effect is particularly pronounced if the
statistical non-Gaussianity is inherently large, such as in models of inflation
with a small speed of sound, e.g. DBI. First reviewing the motivations for a
modified vacuum, we calculate the non-Gaussianity for a general action with a
small speed of sound. The shape of its bispectrum is found to most resemble the
'orthogonal' or 'local' templates depending on the phase of the Bogolyubov
parameter. In particular, for DBI models of inflation the bispectrum can have a
profound 'local' template feature, in contrast to previous results. Determining
the projection into the observational templates allows us to derive constraints
on the absolute value of the Bogolyubov parameter. In the small sound speed
limit, the derived constraints are generally stronger than the existing
constraint derived from the power spectrum. The bound on the absolute value of
the Bogolyubov parameter ranges from the 10^-6 to the 10^-3 level for
H/\Lambda_c = 10^-3, depending on the specific details of the model, the sound
speed and the phase of the Bogolyubov parameter.Comment: 34 pages, 8 figures, 2 appendices. New in this version: added
references, fixed typos, modified sentences. Version submitted to JCA
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Emotion regulation and burnout in doctors: a systematic review.
Background: Burnout is a pervasive health condition affecting many doctors at various stages in their careers. Characterized by emotional exhaustion, depersonalization, and a reduced sense of personal accomplishment it can result in significant personal and professional consequences putting patient care at risk. Emotion regulation describes a capacity to self-modulate emotions to achieve desirable emotional outcomes. Emotional intelligence theory suggests that emotion regulation skills facilitate the maintenance of appropriate emotions, reducing or adapting undesirable emotions in oneself and others. Emotion regulation is usually automatic but can be controlled through learnt strategies. There is evidence that occupationally stressed individuals are less capable of down-regulating negative emotions. This paper systematically reviews studies of the role of emotion regulation in burnout in doctors. Aims: To examine the relationship between emotion regulation and burnout among doctors. Methods: Four online databases (Psych Info 1833-2017, Medline 1928-2017, Scopus 1960-2017 and Embase 1974-2017) were searched in August 2017. Searches returned 15 539 citations, which after de-duplication yielded 12 295 citations. After title and abstracts screening 12 273 citations were excluded. Twenty-two full text articles were read and eight excluded for ineligibility. Following data extraction, bias and methodological quality assessment, findings were synthesized using descriptive analysis and presented according to relevant themes. Results: A correlative relationship was observed between emotion regulation and burnout in doctors. Findings also indicated that-using self-regulatory or taught emotion regulation skills or interventions such as mindfulness were associated with a reduction in burnout. Conclusion: Emotion regulation is an important psychological variable associated with burnout
SAFT-γ force field for the simulation of molecular fluids: 8. hetero-group coarse-grained models of perfluoroalkylalkanes assessed with new vapour-liquid interfacial tension data
The air-liquid interfacial behaviour of linear perfluoroalkylalkanes (PFAAs) is reported through a combined experimental and computer simulation study. The surface tensions of seven liquid PFAAs (perfluorobutylethane, F4H2; perfluorobutylpentane, F4H5; perfluorobutylhexane, F4H6, perfluorobutyloctane, F4H8; perfluorohexylethane, F6H2; perfluorohexylhexane, F6H6; and perfluorohexyloctane, F6H8) are experimentally determined over a wide temperature range (276 to 350 K). The corresponding surface thermodynamic properties and the critical temperatures of the studied compounds are estimated from the temperature dependence of the surface tension. Experimental density and vapour pressure data are employed to parameterize a generic heteronuclear coarse-grained intermolecular potential of the SAFT- γ family for PFAAs. The resulting force field is used in direct molecular dynamics simulations to predict with quantitative agreement the experimental tensions and to explore the conformations of the molecules in the interfacial region revealing a preferential alignment of the PFAA molecules towards the interface and an enrichment of the perfluoro-groups at the outer interface region
Cardiovascular System Studies
Contains research objectives and reports on one research project.National Institutes of Health (Grant 5 TI HE 5550-03
Cold Positrons from Decaying Dark Matter
Many models of dark matter contain more than one new particle beyond those in
the Standard Model. Often heavier particles decay into the lightest dark matter
particle as the Universe evolves. Here we explore the possibilities that arise
if one of the products in a (Heavy Particle) (Dark Matter) decay
is a positron, and the lifetime is shorter than the age of the Universe. The
positrons cool down by scattering off the cosmic microwave background and
eventually annihilate when they fall into Galactic potential wells. The
resulting 511 keV flux not only places constraints on this class of models but
might even be consistent with that observed by the INTEGRAL satellite.Comment: 20 pages, 7 figure
Dosing strategies for switching from oral risperidone to paliperidone palmitate: Effects on clinical outcomes.
IntroductionThere are currently no guidelines for switching patients from oral risperidone to paliperidone palmitate (Invega Sustenna®). Furthermore, the paliperidone long-acting injectable (LAI) package insert does not recommend bridging with oral antipsychotics, which may result in inadequate serum concentrations in patients on ≥4 mg/d risperidone.MethodsThis study evaluated the effects of suboptimal dosing and bridging in patients switched from oral risperidone to paliperidone LAI on hospitalization days, emergency department (ED)/mental health urgent care visits, and no-shows/cancellations to mental health appointments. Patients were categorized into optimal or suboptimal dosing based on their loading and maintenance paliperidone doses. Patients on risperidone ≥4 mg/d were categorized as bridged if they received risperidone for ≥7 days after the first paliperidone injection.ResultsThere were no significant differences in outcomes between optimally and suboptimally dosed patients. There were statistically significant reductions in hospitalization days in patients who were bridged compared with patients who were not bridged. There were statistically significant reductions in hospitalization days and ED/mental health urgent care visits after switching to paliperidone LAI.DiscussionThe results of this study indicate that bridging patients who are on ≥4 mg/d risperidone, when converting to paliperidone LAI, is associated with reductions in hospitalization days. However, more research is required to determine the optimal dose and duration of the bridge. The results also indicate that switching patients from oral risperidone to paliperidone LAI, even if the dose is suboptimal, is associated with reductions in hospitalization days and ED/mental health urgent care visits
Imaging X-ray spectrometer
An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging
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