1,242 research outputs found
Thermodynamic analysis of gravitational field equations in Lyra manifold
Considering the Einstein field equations in Lyra manifold, and applying the
unified first law of thermodynamics as well as the Clausius relation to the
apparent horizon of FRW universe, we find the entropy of apparent horizon in
Lyra manifold. In addition, the validity of second law of thermodynamics and
its generalized form are also studied. Finally, we use the first law of
thermodynamics in order to find the horizon entropy of static spherically
symmetric spacetimes. Some results of considering (anti)de-Sitter and
Schwarzschild metrics have also been addressed.Comment: Accepted by AHE
Towards developing a Healthcare Situation Monitoring Method for Smart City Initiatives: A Citizen Safety Perspective
Research in Smart City development has been proliferated over the past few years, which focused heavily on various supporting service sectors, such as healthcare. However, little effort has been made to design health surveillance support systems, which is also important for the advancement of public healthcare monitoring as an essential smart city initiatives. From an information system (IS) design perspective, this paper introduces a social media-based health surveillance supporting method, which can automatically extricates relevant online posts for health symptom management and prediction. We describe and demonstrate an IS design approach in this paper for hay-fever prediction solution concept based on Twitter posts. This concept can be applicable to fully functional solution design by relevant practitioners in this field
On the String Pair Creation in Dp-Dp' Brane System
We address the bosonic string pair creation in a system of parallel Dp-Dp'
(p<p') branes by applying the path integral formalism. We drive the string pair
creation rate by calculating the one loop vacuum amplitude of the setup in
presence of the background electric field defined over the Dp'-brane. It is
pointed out that just the components of the electric field defined over the
spatial directions (the common directions along which the both D-branes are
extended) give rise to the pair creationComment: Accepted for publication in Mod. Phys. Lett.
Schwinger Effect in Non-parallel D1-branes: A Path Integral Approach
We study the Schwinger effect in a system of non-parallel D1-branes for the
bosonic strings using the path integral formalism. We drive the string pair
creation rate by calculating the one loop vacuum amplitude of the setup in
presence of the background electric filed defined along one of the D1-branes.
We find an angle dependent minimum value for the background field and show that
the decaying of vacuum into string pairs takes place for the field above this
value. It is shown that in limit the vacuum
becomes stable and thus no pair creation occurs
Carrier Recombination and Generation Rates for Intravalley and Intervalley Phonon Scattering in Graphene
Electron-hole generation and recombination rates for intravalley and
intervalley phonon scattering in Graphene are presented. The transverse and the
longitudinal optical phonon modes (-modes) near the zone center
(-point) contribute to intravalley interband carrier scattering. At the
zone edge (-point), only the transverse optical phonon mode
(-mode) contributes significantly to intervalley interband scattering
with recombination rates faster than those due to zone center phonons. The
calculated recombination times range from less than a picosecond to more than
hundreds of picoseconds and are strong functions of temperature and electron
and hole densities. The theoretical calculations agree well with experimental
measurements of the recombination rates of photoexcited carriers in graphene.Comment: 6 pages, 9 figure
Naturally Occurring Missense MRGPRX2 Variants Display Loss of Function Phenotype for Mast Cell Degranulation in Response to Substance P, Hemokinin-1, Human B-Defensin-3, and Icatibant
Human mast cells (MCs) express a novel G protein–coupled receptor (GPCR) known as Mas-related GPCR X2 (MRGPRX2). Activation of this receptor by a diverse group of cationic ligands such as neuropeptides, host defense peptides, and Food and Drug Administration–approved drugs contributes to chronic inflammatory diseases and pseudoallergic drug reactions. For most GPCRs, the extracellular (ECL) domains and their associated transmembrane (TM) domains display the greatest structural diversity and are responsible for binding different ligands. The goal of the current study was to determine if naturally occurring missense variants within MRGPRX2’s ECL/TM domains contribute to gain or loss of function phenotype for MC degranulation in response to neuropeptides (substance P and hemokinin-1), a host defense peptide (human b-defensin-3) and a Food and Drug Administration–approved cationic drug (bradykinin B2 receptor antagonist, icatibant). We have identified eight missense variants within MRGPRX2’s ECL/TM domains from publicly available exome-sequencing databases. We investigated the ability of MRGPRX2 ligands to induce degranulation in rat basophilic leukemia–2H3 cells individually expressing these naturally occurring MRGPRX2 missense variants. Using stable and transient transfections, we found that all variants express in rat basophilic leukemia cells. However, four natural MRGPRX2 variants, G165E (rs141744602), D184H (rs372988289), W243R (rs150365137), and H259Y (rs140862085) failed to respond to any of the ligands tested. Thus, diverse MRGPRX2 ligands use common sites on the receptor to induce MC degranulation. These findings have important clinical implications for MRGPRX2 and MC-mediated pseudoallergy and chronic inflammatory diseases. Copyright © 2018 by The American Association of Immunologists, Inc
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