1,528 research outputs found
Prioritizing surveillance activities for certification of yaws eradication based on a review and model of historical case reporting
BACKGROUNDt: The World Health Organization
(WHO) has targeted yaws for global eradication. Eradication
requires certification that all countries are yaws-free. While
only 14 Member States currently report cases to WHO, many more
are known to have a history of yaws and some of them may have
ongoing transmission. We reviewed the literature and developed a
model of case reports to identify countries in which passive
surveillance is likely to find and report cases if transmission
is still occurring, with the goal of reducing the number of
countries in which more costly active surveillance will be
required. METHODSt: We reviewed published and
unpublished documents to extract data on the number of yaws
cases reported to WHO or appearing in other literature in any
year between 1945 and 2015. We classified countries as: a)
having interrupted transmission; b) being currently endemic; c)
being previously endemic (current status unknown); or d) having
no history of yaws. We constructed a panel dataset for the years
1945-2015 and ran a regression model to identify factors
associated with some countries not reporting cases during
periods when there was ongoing (and documented) transmission.
For previously endemic countries whose current status is
unknown, we then estimated the probability that countries would
have reported cases if there had in fact been transmission in
the last three years (2013-2015)." - Label: RESULTS content:
Yaws has been reported in 103 of the 237 countries and areas
considered. 14 Member States and 1 territory (Wallis and Futuna
Islands) are currently endemic. 2 countries are believed to have
interrupted transmission. 86 countries and areas are previously
endemic (current status unknown). Reported cases peaked in the
1950s, with 55 countries reporting at least one case in 1950 and
a total of 2.35 million cases reported in 1954. Our regression
model suggests that case reporting during periods of ongoing
transmission is positively associated with socioeconomic
development and, in the short-term, negatively associated with
independence. We estimated that for 66 out of the 86 previously
endemic countries whose current status is unknown, the
probability of reporting cases in the absence of active
surveillance is less than 50%. DISCUSSION:
Countries with a history of yaws need to be prioritized so that
international resources for global yaws eradication may be
deployed efficiently. Heretofore, the focus has been on mass
treatment in countries currently reporting cases. It is also
important to undertake surveillance in the 86 previously endemic
countries for which the current status is unknown. Within this
large and diverse group, we have identified a group of 20
countries with more than a 50% probability of reporting cases in
the absence of active surveillance. For the other 66 countries,
international support for active surveillance will likely be
required
Mechanisms of Fetal Programming in Hypertension
Events that occur in the early fetal environment have been linked to long-term health and lifespan consequences in the adult. Intrauterine growth restriction (IUGR), which may occur as a result of nutrient insufficiency, exposure to hormones, or disruptions in placental structure or function, may induce the fetus to alter its developmental program in order to adapt to the new conditions. IUGR may result in a decrease in the expression of genes that are responsible for nephrogenesis as nutrients are rerouted to the development of more essential organs. Fetal survival under these conditions often results in low birth weight and a deficit in nephron endowment, which are associated with hypertension in adults. Interestingly, male IUGR offspring appear to be more severely affected than females, suggesting that sex hormones may be involved. The processes of fetal programming of hypertension are complex, and we are only beginning to understand the underlying mechanisms
An Extreme Case of a Misaligned Highly Flattened Wind in the Wolf-Rayet Binary CX Cephei
CX Cep (WR 151) is the WR+O binary (WN5+O5V) with the second shortest period
known in our Galaxy. To examine the circumstellar matter distribution and to
better constraint the orbital parameters and mass-loss rate of the WR star, we
obtained broadband and multi-band (i.e. UBVRI) linear polarization observations
of the system. Our analysis of the phase-locked polarimetric modulation
confirms the high orbital inclination of the system (i.e. ). Using the
orbital solution of Lewis et al. (1993) we obtain masses of
and for the O and WR stars respectively, which agree with
their spectral types. A simple polarimetric model accounting for finite stellar
size effects allowed us to derive a mass-loss rate for the WR star of
. This result was remarkably independent of
the model's input parameters and favors an earlier spectral type for the WR
component (i.e. WN4). Finally, using our multi-band observations, we fitted and
subtracted from our data the interstellar polarization. The resulting constant
intrinsic polarization of is misaligned in relation to the orbital plane
(i.e. vs. ) and is the highest intrinsic
polarization ever observed for a WR star. This misalignment points towards a
rotational (or magnetic) origin for the asymmetry and contradicts the most
recent evolutionary models for massive stars (Meynet & Maeder 2003) which
predict spherically symmetric winds during the WR phase (i.e. ).Comment: 26 pages, 4 figures. Astrophysical Journal (submited
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
A Candidate Dual AGN at z=1.175
The X-ray source CXOXBJ142607.6+353351 (CXOJ1426+35), which was identified in
a 172 ks Chandra image in the Bootes field, shows double-peaked rest-frame
optical/UV emission lines, separated by 0.69" (5.5 kpc) in the spatial
dimension and by 690 km s^-1 in the velocity dimension. The high excitation
lines and emission line ratios indicate both systems are ionized by an AGN
continuum, and the double-peaked profile resembles that of candidate dual AGN.
At a redshift of z=1.175, this source is the highest redshift candidate dual
AGN yet identified. However, many sources have similar emission line profiles
for which other interpretations are favored. We have analyzed the substantial
archival data available in this field, as well as acquired near-infrared (NIR)
adaptive optics (AO) imaging and NIR slit spectroscopy. The X-ray spectrum is
hard, implying a column density of several 10^23 cm^-2. Though heavily
obscured, the source is also one of the brightest in the field, with an
absorption-corrected 2-10 keV luminosity of ~10^45 erg s^-1. Outflows driven by
an accretion disk may produce the double-peaked lines if the central engine
accretes near the Eddington limit. However, we may be seeing the narrow line
regions of two AGN following a galactic merger. While the AO image reveals only
a single source, a second AGN would easily be obscured by the significant
extinction inferred from the X-ray data. Understanding the physical processes
producing the complex emission line profiles seen in CXOJ1426+35 and related
sources is important for interpreting the growing population of dual AGN
candidates.Comment: 18 pages and 9 figures. Accepted for publication in The Astrophysical
Journa
Management of multidrug resistant Gram-negative bacilli infections in solid organ transplant recipients: SET/GESITRA-SEIMC/REIPI recommendations
Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant (MDR) Gram-negative bacilli (GNB), as they are frequently exposed to antibiotics and the healthcare setting, and are regulary subject to invasive procedures. Nevertheless, no recommendations concerning prevention and treatment are available. A panel of experts revised the available evidence; this document summarizes their recommendations: (1) it is important to characterize the isolate´s phenotypic and genotypic resistance profile; (2) overall, donor colonization should not constitute a contraindication to transplantation, although active infected kidney and lung grafts should be avoided; (3) recipient colonization is associated with an increased risk of infection, but is not a contraindication to transplantation; (4) different surgical prophylaxis regimens are not recommended for patients colonized with carbapenem-resistant GNB; (5) timely detection of carriers, contact isolation precautions, hand hygiene compliance and antibiotic control policies are important preventive measures; (6) there is not sufficient data to recommend intestinal decolonization; (7) colonized lung transplant recipients could benefit from prophylactic inhaled antibiotics, specially for Pseudomonas aeruginosa; (8) colonized SOT recipients should receive an empirical treatment which includes active antibiotics, and directed therapy should be adjusted according to susceptibility study results and the severity of the infection.J.T.S. holds a research contract from the Fundación para la Formación e Investigación de los Profesionales de la Salud de Extremadura (FundeSalud), Instituto de Salud Carlos III. M.F.R. holds a clinical research contract “Juan Rodés” (JR14/00036) from the Spanish Ministry of Economy and Competitiveness, Instituto de Salud Carlos III
Upper limit map of a background of gravitational waves
We searched for an anisotropic background of gravitational waves using data
from the LIGO S4 science run and a method that is optimized for point sources.
This is appropriate if, for example, the gravitational wave background is
dominated by a small number of distinct astrophysical sources. No signal was
seen. Upper limit maps were produced assuming two different power laws for the
source strain power spectrum. For an f^-3 power law and using the 50 Hz to 1.8
kHz band the upper limits on the source strain power spectrum vary between
1.2e-48 Hz^-1 (100 Hz/f)^3 and 1.2e-47 Hz^-1 (100 Hz /f)^3, depending on the
position in the sky. Similarly, in the case of constant strain power spectrum,
the upper limits vary between 8.5e-49 Hz^-1 and 6.1e-48 Hz^-1.
As a side product a limit on an isotropic background of gravitational waves
was also obtained. All limits are at the 90% confidence level. Finally, as an
application, we focused on the direction of Sco-X1, the closest low-mass X-ray
binary. We compare the upper limit on strain amplitude obtained by this method
to expectations based on the X-ray luminosity of Sco-X1.Comment: 11 pages, 9 figures, 2 table
Upper limit map of a background of gravitational waves
We searched for an anisotropic background of gravitational waves using data
from the LIGO S4 science run and a method that is optimized for point sources.
This is appropriate if, for example, the gravitational wave background is
dominated by a small number of distinct astrophysical sources. No signal was
seen. Upper limit maps were produced assuming two different power laws for the
source strain power spectrum. For an f^-3 power law and using the 50 Hz to 1.8
kHz band the upper limits on the source strain power spectrum vary between
1.2e-48 Hz^-1 (100 Hz/f)^3 and 1.2e-47 Hz^-1 (100 Hz /f)^3, depending on the
position in the sky. Similarly, in the case of constant strain power spectrum,
the upper limits vary between 8.5e-49 Hz^-1 and 6.1e-48 Hz^-1.
As a side product a limit on an isotropic background of gravitational waves
was also obtained. All limits are at the 90% confidence level. Finally, as an
application, we focused on the direction of Sco-X1, the closest low-mass X-ray
binary. We compare the upper limit on strain amplitude obtained by this method
to expectations based on the X-ray luminosity of Sco-X1.Comment: 11 pages, 9 figures, 2 table
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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