480 research outputs found
Natural Enzootic Vectors of Venezuelan equine encephalitis virus in the Magdalena Valley, Colombia
To characterize the transmission cycle of enzootic Venezuelan equine encephalitis virus (VEEV) strains believed to represent an epizootic progenitor, we identified natural vectors in a sylvatic focus in the middle Magdalena Valley of Colombia. Hamster-baited traps were placed into an active forest focus, and mosquitoes collected from each trap in which a hamster became infected were sorted by species and assayed for virus. In 18 cases, a single, initial, high-titered mosquito pool representing the vector species was identified. These vectors included Culex (Melanoconion) vomerifer (11 transmission events), Cx. (Mel.) pedroi (5 transmissions) and Cx. (Mel.) adamesi (2 transmissions). These results extend the number of proven enzootic VEEV vectors to 7, all of which are members of the Spissipes section of the subgenus Melanoconion. Our findings contrast with previous studies, which have indicated that a single species usually serves as the principal enzootic VEEV vector at a given location
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Changes in health sciences students' perception of obstetric violence after an educational intervention
Background
Obstetric violence is a type of gender-based violence that is presented structurally. This type of violence has physical and psychological consequences for both the women who experience it and health professionals. The World Health Organization adds that health professionals need training to ensure that pregnant women are treated with compassion and dignity.
Objectives
The objective of the study was to evaluate health sciences students' perception of obstetric violence and to identify possible changes after an educational intervention.
Design
A pre-post quasi-experimental study was carried out between January and June 2019.
Settings and participants
Students of medicine and nursing from Jaume I University (Universitat Jaume I) (Spain).
Methods
An ad hoc scale comprising 33 items was designed to measure the students' perceptions. In addition, sociodemographic and control variables were collected. Descriptive analyses of the sample and the scale were carried out, and a bivariate analysis was performed.
Results
Of the students surveyed, 89.7% were women, and the majority was nursing students. Of the 33 items, 28 (84.84%) showed statistically significant changes in the pre-post-intervention measurement. Twenty-five of the 33 items (75.75%) showed a relationship with the sociodemographic variables of gender, field, course and ever having been pregnant.
Conclusion
This study shows the change in health sciences students' perceptions of obstetric violence after an educational intervention. In addition, the normalization of this type of violence was observed with the progression of training and with personal obstetric experience.Background
Obstetric violence is a type of gender-based violence that is presented structurally. This type of violence has physical and psychological consequences for both the women who experience it and health professionals. The World Health Organization adds that health professionals need training to ensure that pregnant women are treated with compassion and dignity
Search for heavy neutrinos mixing with tau neutrinos
We report on a search for heavy neutrinos (\nus) produced in the decay
D_s\to \tau \nus at the SPS proton target followed by the decay \nudecay in
the NOMAD detector. Both decays are expected to occur if \nus is a component
of .\
From the analysis of the data collected during the 1996-1998 runs with
protons on target, a single candidate event consistent with
background expectations was found. This allows to derive an upper limit on the
mixing strength between the heavy neutrino and the tau neutrino in the \nus
mass range from 10 to 190 . Windows between the SN1987a and Big Bang
Nucleosynthesis lower limits and our result are still open for future
experimental searches. The results obtained are used to constrain an
interpretation of the time anomaly observed in the KARMEN1 detector.\Comment: 20 pages, 7 figures, a few comments adde
Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008
The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays
by MAGIC in spring 2007. Before that the source was little studied in different
wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in
spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio
observatory, Bell and KVA optical telescopes and the Swift and AGILE
satellites. MAGIC observations span from March to May, 2008 for a total of 27.9
hours, of which 19.4 hours remained after quality cuts. The light curve showed
no significant variability. The differential VHE spectrum could be described
with a power-law function. Both results were similar to those obtained during
the discovery. Swift XRT observations revealed an X-ray flare, characterized by
a harder when brighter trend, as is typical for high synchrotron peak BL Lac
objects (HBL). Strong optical variability was found during the campaign, but no
conclusion on the connection between the optical and VHE gamma-ray bands could
be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike
concluded in previous work based on nonsimultaneous data, and is well described
by a standard one zone synchrotron self Compton model. We also performed a
study on the source classification. While the optical and X-ray data taken
during our campaign show typical characteristics of an HBL, we suggest, based
on archival data, that 1ES 1011+496 is actually a borderline case between
intermediate and high synchrotron peak frequency BL Lac objects.Comment: 13 pages, accepted for publication in MNRA
Probing the very-high-energy gamma-ray spectral curvature in the blazar PG 1553+113 with the MAGIC telescopes
PG 1553+113 is a very-high-energy (VHE, ) -ray
emitter classified as a BL Lac object. Its redshift is constrained by
intergalactic absorption lines in the range . The MAGIC telescopes
have monitored the source's activity since 2005. In early 2012, PG 1553+113 was
found in a high-state, and later, in April of the same year, the source reached
its highest VHE flux state detected so far. Simultaneous observations carried
out in X-rays during 2012 April show similar flaring behaviour. In contrast,
the -ray flux at observed by Fermi-LAT is
compatible with steady emission. In this paper, a detailed study of the flaring
state is presented. The VHE spectrum shows clear curvature, being well fitted
either by a power law with an exponential cut-off or by a log-parabola. A
simple power-law fit hypothesis for the observed shape of the PG 1553+113 VHE
-ray spectrum is rejected with a high significance (fit probability
P=2.6 ). The observed curvature is compatible with the
extragalactic background light (EBL) imprint predicted by current generation
EBL models assuming a redshift . New constraints on the redshift are
derived from the VHE spectrum. These constraints are compatible with previous
limits and suggest that the source is most likely located around the optical
lower limit, , based on the detection of Ly absorption. Finally,
we find that the synchrotron self-Compton (SSC) model gives a satisfactory
description of the observed multi-wavelength spectral energy distribution
during the flare.Comment: 13 pages, 7 figures, accepted for publication in MNRA
The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in
the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent
a series of upgrades, involving the exchange of the MAGIC-I camera and its
trigger system, as well as the upgrade of the readout system of both
telescopes. We use observations of the Crab Nebula taken at low and medium
zenith angles to assess the key performance parameters of the MAGIC stereo
system. For low zenith angle observations, the standard trigger threshold of
the MAGIC telescopes is ~50GeV. The integral sensitivity for point-like sources
with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula
flux in 50 h of observations. The angular resolution, defined as the sigma of a
2-dimensional Gaussian distribution, at those energies is < 0.07 degree, while
the energy resolution is 16%. We also re-evaluate the effect of the systematic
uncertainty on the data taken with the MAGIC telescopes after the upgrade. We
estimate that the systematic uncertainties can be divided in the following
components: < 15% in energy scale, 11-18% in flux normalization and +/-0.15 for
the energy spectrum power-law slope.Comment: 21 pages, 25 figures, accepted for publication in Astroparticle
Physic
Venezuelan Equine Encephalitis Virus, Southern Mexico
Evidence of enzootic and endemic Venezuelan equine encephalitis virus circulation in southern Mexico since the 1996 epizootic was obtained from serosurveys and virus isolations
Quantum Computing for High-Energy Physics: State of the Art and Challenges. Summary of the QC4HEP Working Group
Quantum computers offer an intriguing path for a paradigmatic change of
computing in the natural sciences and beyond, with the potential for achieving
a so-called quantum advantage, namely a significant (in some cases exponential)
speed-up of numerical simulations. The rapid development of hardware devices
with various realizations of qubits enables the execution of small scale but
representative applications on quantum computers. In particular, the
high-energy physics community plays a pivotal role in accessing the power of
quantum computing, since the field is a driving source for challenging
computational problems. This concerns, on the theoretical side, the exploration
of models which are very hard or even impossible to address with classical
techniques and, on the experimental side, the enormous data challenge of newly
emerging experiments, such as the upgrade of the Large Hadron Collider. In this
roadmap paper, led by CERN, DESY and IBM, we provide the status of high-energy
physics quantum computations and give examples for theoretical and experimental
target benchmark applications, which can be addressed in the near future.
Having the IBM 100 x 100 challenge in mind, where possible, we also provide
resource estimates for the examples given using error mitigated quantum
computing
Laser treatment of Ag@ZnO nanorods as long-life-span SERS surfaces.
This is the accepted manuscript. The final version is available from ACS at http://pubs.acs.org/doi/abs/10.1021/am506622x.UV nanosecond laser pulses have been used to produce a unique surface nanostructuration of Ag@ZnO supported nanorods (NRs). The NRs were fabricated by plasma enhanced chemical vapor deposition (PECVD) at low temperature applying a silver layer as promoter. The irradiation of these structures with single nanosecond pulses of an ArF laser produces the melting and reshaping of the end of the NRs that aggregate in the form of bundles terminated by melted ZnO spherical particles. Well-defined silver nanoparticles (NPs), formed by phase separation at the surface of these melted ZnO particles, give rise to a broad plasmonic response consistent with their anisotropic shape. Surface enhanced Raman scattering (SERS) in the as-prepared Ag@ZnO NRs arrays was proved by using a Rhodamine 6G (Rh6G) chromophore as standard analyte. The surface modifications induced by laser treatment improve the stability of this system as SERS substrate while preserving its activity.We thank the Junta de Andalucía (TEP8067, FQM-6900 and P12-FQM-2265) and the Spanish
Ministry of Economy and Competitiveness (Projects CONSOLIDER-CSD 2008-00023,
MAT2011-28345-C02-02, MAT2013-40852-R, MAT2013-42900-P and RECUPERA 2020) for
financial support. The authors also thank the European Union Seventh Framework Programme
under Grant Agreements 312483-ESTEEM2 (Integrated Infrastructure Initiative-I3) and
REGPOT-CT-2011-285895-Al-NANOFUNC, and the European Research Council under the
European Union’s Seventh Framework Programme (FP/2007-2013)/ERC grant agreement
291522 - 3DIMAGE. R. J. Peláez acknowledges the grant JCI-2012_13034 from the Juan de la
Cierva program
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