792 research outputs found
Analysis of the low-energy electron-recoil spectrum of the CDMS experiment
We report on the analysis of the low-energy electron-recoil spectrum from the
CDMS II experiment using data with an exposure of 443.2 kg-days. The analysis
provides details on the observed counting rate and possible background sources
in the energy range of 2 - 8.5 keV. We find no significant excess in the
counting rate above background, and compare this observation to the recent DAMA
results. In the framework of a conversion of a dark matter particle into
electromagnetic energy, our 90% confidence level upper limit of 0.246
events/kg/day at 3.15 keV is lower than the total rate above background
observed by DAMA by 8.9. In absence of any specific particle physics
model to provide the scaling in cross section between NaI and Ge, we assume a
Z^2 scaling. With this assumption the observed rate in DAMA differs from the
upper limit in CDMS by 6.8. Under the conservative assumption that the
modulation amplitude is 6% of the total rate we obtain upper limits on the
modulation amplitude a factor of ~2 less than observed by DAMA, constraining
some possible interpretations of this modulation.Comment: 4 pages, 3 figure
Characterization of SuperCDMS 1-inch Ge Detectors
The newly commissioned SuperCDMS Soudan experiment aims to search for WIMP dark matter with a sensitivity to cross sections of 5×10^(−45)cm^2 and larger (90% CL upper limit). This goal is facilitated by a new set of germanium detectors, 2.5 times more massive than the ones used in the CDMS-II experiment, and with a different athermal phonon sensor layout that eliminates radial degeneracy in position reconstruction of high radius events. We present characterization data on these detectors, as well as improved techniques for correcting position-dependent variations in pulse shape across the detector. These improvements provide surface-event discrimination sufficient for a reach of 5×10^(−45)cm^2
MicroRNAs in pulmonary arterial remodeling
Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH
Corner contributions to holographic entanglement entropy
The entanglement entropy of three-dimensional conformal field theories
contains a universal contribution coming from corners in the entangling
surface. We study these contributions in a holographic framework and, in
particular, we consider the effects of higher curvature interactions in the
bulk gravity theory. We find that for all of our holographic models, the corner
contribution is only modified by an overall factor but the functional
dependence on the opening angle is not modified by the new gravitational
interactions. We also compare the dependence of the corner term on the new
gravitational couplings to that for a number of other physical quantities, and
we show that the ratio of the corner contribution over the central charge
appearing in the two-point function of the stress tensor is a universal
function for all of the holographic theories studied here. Comparing this
holographic result to the analogous functions for free CFT's, we find fairly
good agreement across the full range of the opening angle. However, there is a
precise match in the limit where the entangling surface becomes smooth, i.e.,
the angle approaches , and we conjecture the corresponding ratio is a
universal constant for all three-dimensional conformal field theories. In this
paper, we expand on the holographic calculations in our previous letter
arXiv:1505.04804, where this conjecture was first introduced.Comment: 62 pages, 6 figures, 1 table; v2: minor modifications to match
published version, typos fixe
Results from a Low-Energy Analysis of the CDMS II Germanium Data
We report results from a reanalysis of data from the Cryogenic Dark Matter
Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken
between October 2006 and September 2008 using eight germanium detectors are
reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased
sensitivity to interactions from Weakly Interacting Massive Particles (WIMPs)
with masses below ~10 GeV/c^2. This analysis provides stronger constraints than
previous CDMS II results for WIMP masses below 9 GeV/c^2 and excludes parameter
space associated with possible low-mass WIMP signals from the DAMA/LIBRA and
CoGeNT experiments.Comment: 9 pages, 8 figures. Supplemental material included as ancillary
files. v3) Added appendix with additional details regarding energy scale and
background
Search for inelastic dark matter with the CDMS II experiment
Results are presented from a reanalysis of the entire five-tower data set
acquired with the Cryogenic Dark Matter Search (CDMS II) experiment at the
Soudan Underground Laboratory, with an exposure of 969 kg-days. The analysis
window was extended to a recoil energy of 150 keV, and an improved
surface-event background-rejection cut was defined to increase the sensitivity
of the experiment to the inelastic dark matter (iDM) model. Three dark matter
candidates were found between 25 keV and 150 keV. The probability to observe
three or more background events in this energy range is 11%. Because of the
occurrence of these events the constraints on the iDM parameter space are
slightly less stringent than those from our previous analysis, which used an
energy window of 10-100 keV.Comment: 10 pages, 10 figures, minor changes to match published version,
conclusion unchange
Subanesthetic ketamine treatment promotes abnormal interactions between neural subsystems and alters the properties of functional brain networks
Acute treatment with subanesthetic ketamine, a non-competitive N-methyl-D-aspartic acid (NMDA) receptor antagonist, is widely utilized as a translational model for schizophrenia. However, how acute NMDA receptor blockade impacts on brain functioning at a systems level, to elicit translationally relevant symptomatology and behavioral deficits, has not yet been determined. Here, for the first time, we apply established and recently validated topological measures from network science to brain imaging data gained from ketamine-treated mice to elucidate how acute NMDA receptor blockade impacts on the properties of functional brain networks. We show that the effects of acute ketamine treatment on the global properties of these networks are divergent from those widely reported in schizophrenia. Where acute NMDA receptor blockade promotes hyperconnectivity in functional brain networks, pronounced dysconnectivity is found in schizophrenia. We also show that acute ketamine treatment increases the connectivity and importance of prefrontal and thalamic brain regions in brain networks, a finding also divergent to alterations seen in schizophrenia. In addition, we characterize how ketamine impacts on bipartite functional interactions between neural subsystems. A key feature includes the enhancement of prefrontal cortex (PFC)-neuromodulatory subsystem connectivity in ketamine-treated animals, a finding consistent with the known effects of ketamine on PFC neurotransmitter levels. Overall, our data suggest that, at a systems level, acute ketamine-induced alterations in brain network connectivity do not parallel those seen in chronic schizophrenia. Hence, the mechanisms through which acute ketamine treatment induces translationally relevant symptomatology may differ from those in chronic schizophrenia. Future effort should therefore be dedicated to resolve the conflicting observations between this putative translational model and schizophrenia
Free Energy of an Inhomogeneous Superconductor: a Wave Function Approach
A new method for calculating the free energy of an inhomogeneous
superconductor is presented. This method is based on the quasiclassical limit
(or Andreev approximation) of the Bogoliubov-de Gennes (or wave function)
formulation of the theory of weakly coupled superconductors. The method is
applicable to any pure bulk superconductor described by a pair potential with
arbitrary spatial dependence, in the presence of supercurrents and external
magnetic field. We find that both the local density of states and the free
energy density of an inhomogeneous superconductor can be expressed in terms of
the diagonal resolvent of the corresponding Andreev Hamiltonian, resolvent
which obeys the so-called Gelfand-Dikii equation. Also, the connection between
the well known Eilenberger equation for the quasiclassical Green's function and
the less known Gelfand-Dikii equation for the diagonal resolvent of the Andreev
Hamiltonian is established. These results are used to construct a general
algorithm for calculating the (gauge invariant) gradient expansion of the free
energy density of an inhomogeneous superconductor at arbitrary temperatures.Comment: REVTeX, 28 page
The present and future burden of urinary bladder cancer in the world
Urinary bladder cancer (UBC) is a common disease worldwide. At any point in time 2.7 million people have a history of UBC. The incidence of UBC varies over the world with highest rates in developed communities. But the burden of UBC will increase in less developed areas of the world. These changes can be attributed to global changes in exposure to risk factors for UBC and growth and aging of the world population
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