5,204 research outputs found
Role of resonances in rho^0 -> pi^+ pi^- gamma
We study the effect of the sigma(600) and a_1(1260) resonances in the rho^0
-> pi^+ pi^- gamma decay, within the meson dominance model. Major effects are
driven by the mass and width parameters of the sigma(600), and the usually
neglected contribution of the a_1(1260), although small by itself, may become
sizable through its interference with pion bremsstrahlung, and the proper
relative sign can favor the central value of the experimental branching ratio.
We present a procedure, using the gauge invariant structure of the resonant
amplitudes, to kinematically enhance the resonant effects in the angular and
energy distribution of the photon. We also elaborate on the coupling constants
involved.Comment: 5 pages, 5 figures, accepted for publication in PR
The pattern of brittle deformation in Central America for an assessment of the seismo-tectonic framework
A seismo-tectonic map depicting the principal structural elements of the northern Central American region has been meticulously crafted to characterize the tectonic setting and the individual seismo-tectonic structures of this area. This region is subject to heightened seismic activity, with a large number of medium-high Magnitude occurrences transpiring annually. This map is presented alongside an informative dataset wherein fault trace
locations, geometry and kinematics descriptors and other available metadata have been stored. Therefore, the map offers a detailed and up-to-date depiction of the brittle deformation across the region, serving as a valuable resource for a comprehensive assessment of the seismo-tectonic framework. Moreover, the map and its accompanying database summarize fault characteristics for seismic hazard analysts and for civil protection workers, proving to be useful instruments in pinpointing areas where urgent fault research should be conducted from a seismic risk standpoint
Adaptation of a microbial detection array as a monitoring tool revealed the presence 2 of mosquito-borne viruses and insect-specific viruses in field-collected mosquitoes
Several mosquito-borne diseases affecting humans are emerging or re-emerging in the United States. The early detection of pathogens in mosquito populations is essential to prevent and control the spread of these diseases. In this study, we tested the potential applicability of the Lawrence Livermore Microbial Detection Array (LLMDA) to enhance bio-surveillance by detecting microbes present in Aedes aegypti, Aedes albopictus and Culex mosquitoes that are major vector species globally, including in Texas. The sensitivity and reproducibility of the LLMDA was tested in mosquito samples spiked with different concentrations of dengue virus (DENV) revealing a detection limit of \u3e100 but \u3c1000 pfu/mL. Additionally, field-collected mosquitoes from Chicago, Illinois and College Station, Texas of known infection status (West Nile virus (WNV) and Culex flavivirus (CxFLAV) positive) were tested on the LLMDA to confirm its efficiency. Mosquito field samples of unknown infection status, collected in San Antonio, TX and the Lower Rio Grande Valley (LRGV), TX were run on the LLMDA and further confirmed by PCR or qPCR. The analysis of the field samples with the LLMDA revealed the presence of cell fusing agent virus (CFAV) in Ae. aegypti populations. Wolbachia was also detected in several of the field samples (Ae. albopictus and Culex spp.) by the LLMDA. Our findings demonstrated that the LLMDA can be used to detect multiple arboviruses of public health importance including viruses that belong to the Flavivirus, Alphavirus and Orthobunyavirus genera. Additionally, insect-specific viruses and bacteria were also detected from field-collected mosquitoes. Another strength of this array is its ability to detect multiple viruses in the same mosquito pool allowing for the detection of co-circulating pathogens in an area, and the identification of potential ecological associations between different viruses. This array can aid in the bio-surveillance of mosquito borne viruses circulating in specific geographical areas
Reduction in the levels of CoQ biosynthetic proteins is related to an increase in lifespan without evidence of hepatic mitohormesis
Mitohormesis is an adaptive response induced by a mild mitochondrial stress that promotes longevity
and metabolic health in different organisms. This mechanism has been proposed as the cause of the
increase in the survival in Coq7+/− (Mclk1+/−) mice, which show hepatic reduction of COQ7, early
mitochondrial dysfunction and increased oxidative stress. Our study shows that the lack of COQ9 in
Coq9Q95X mice triggers the reduction of COQ7, COQ6 and COQ5, which results in an increase in life
expectancy. However, our results reveal that the hepatic CoQ levels are not decreased and, therefore,
neither mitochondrial dysfunction or increased oxidative stress are observed in liver of Coq9Q95X mice.
These data point out the tissue specific differences in CoQ biosynthesis. Moreover, our results suggest
that the effect of reduced levels of COQ7 on the increased survival in Coq9Q95X mice may be due to
mitochondrial mechanisms in non-liver tissues or to other unknown mechanisms.This work was supported by grants from Ministerio de
Economía Competitividad, Spain, and the ERDF (Grant Number SAF2015-65786-R), from the Consejería de
Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (grant number P10-CTS-6133) and from the
University of Granada (grant reference “UNETE”, UCE-PP2017-06). AHG is a “FPU fellow” from the Ministerio
de Educación Cultura y Deporte, Spain. MLS was a predoctoral fellow from the Consejería de Economía,
Innovación, Ciencia y Empleo, Junta de Andalucía. LCL was supported by the “Ramón y Cajal” National
Programme, Ministerio de Economía y Competitividad, Spain (RYC-2011-07643)
The 2HWC HAWC Observatory Gamma Ray Catalog
We present the first catalog of TeV gamma-ray sources realized with the
recently completed High Altitude Water Cherenkov Observatory (HAWC). It is the
most sensitive wide field-of-view TeV telescope currently in operation, with a
1-year survey sensitivity of ~5-10% of the flux of the Crab Nebula. With an
instantaneous field of view >1.5 sr and >90% duty cycle, it continuously
surveys and monitors the sky for gamma ray energies between hundreds GeV and
tens of TeV.
HAWC is located in Mexico at a latitude of 19 degree North and was completed
in March 2015. Here, we present the 2HWC catalog, which is the result of the
first source search realized with the complete HAWC detector. Realized with 507
days of data and represents the most sensitive TeV survey to date for such a
large fraction of the sky. A total of 39 sources were detected, with an
expected contamination of 0.5 due to background fluctuation. Out of these
sources, 16 are more than one degree away from any previously reported TeV
source. The source list, including the position measurement, spectrum
measurement, and uncertainties, is reported. Seven of the detected sources may
be associated with pulsar wind nebulae, two with supernova remnants, two with
blazars, and the remaining 23 have no firm identification yet.Comment: Submitted 2017/02/09 to the Astrophysical Journa
VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory
VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l.
in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design,
construction techniques and data acquisition system of the HAWC observatory.
HAWC is an air-shower array currently under construction at the same site of
VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water
Cherenkov detectors and two different data acquisition systems. It was in
operation between October 2011 and May 2012 with an average live time of 30%.
Besides the scientific verification purposes, the eight months of data were
used to obtain the results presented in this paper: the detector response to
the Forbush decrease of March 2012, and the analysis of possible emission, at
energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages,
10 figures). Corresponding authors: A.Marinelli and D.Zaboro
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