123 research outputs found
Identification of the hASCT2-binding domain of the Env ERVWE1/syncytin-1 fusogenic glycoprotein
The cellular HERV-W envelope/syncytin-1 protein, encoded by the envelope gene of the ERVWE1 proviral locus is a fusogenic glycoprotein probably involved in the formation of the placental syncytiotrophoblast layer. Syncytin-1-induced in vitro cell-cell fusion is dependent on the interaction with hASCT2. As no receptor binding domain has been clearly defined in the SU of neither the HERV-W Env nor the retroviruses of the same interference group, we designed an in vitro binding assay to evaluate the interaction of the HERV-W envelope with the hASCT2 receptor. Using truncated HERV-W SU subunits, a region consisting of the N-terminal 124 amino acids of the mature SU glycoprotein was determined as the minimal receptor-binding domain. This domain contains several sub-domains which are poorly conserved among retroviruses of this interference group but a region of 18 residus containing the SDGGGX(2)DX(2)R conserved motif was proved to be essential for syncytin-1-hASCT2 interaction
Natural history of the ERVWE1 endogenous retroviral locus
BACKGROUND: The human HERV-W multicopy family includes a unique proviral locus, termed ERVWE1, whose full-length envelope ORF was preserved through evolution by the action of a selective pressure. The encoded Env protein (Syncytin) is involved in hominoid placental physiology. RESULTS: In order to infer the natural history of this domestication process, a comparative genomic analysis of the human 7q21.2 syntenic regions in eutherians was performed. In primates, this region was progressively colonized by LTR-elements, leading to two different evolutionary pathways in Cercopithecidae and Hominidae, a genetic drift versus a domestication, respectively. CONCLUSION: The preservation in Hominoids of a genomic structure consisting in the juxtaposition of a retrotransposon-derived MaLR LTR and the ERVWE1 provirus suggests a functional link between both elements
Characterization of the phonon sensor of the CRYOSEL detector with IR photons
The sensitivities of light Dark Matter (DM) particle searches with cryogenic
detectors are mostly limited by large backgrounds of events that do not produce
ionization signal. The CRYOSEL project develops a new technique where this
background in a germanium cryogenic detector is rejected by using the signals
from a Superconducting Single Electron Device (SSED) sensor designed to detect
the phonons emitted through the Neganov-Trofimov-Luke effect by the eh
pairs as they drift in a close-by very high-field region. A tag on signals from
this device should suppress the heat-only background. The measurement of the
response to IR laser pulses of the first CRYOSEL prototype show the relevance
of such sensor technology.Comment: 9 pages, 3 figures, LTD2
Exercise electrocardiogram in middle-aged and older leisure time sportsmen: 100 exercise tests would be enough to identify one silent myocardial ischemia at risk for cardiac event
BACKGROUND: The importance of exercise electrocardiogram (ECG) has been controversial in the prevention of cardiac events among sportsmen. The aim of this study was to determine the frequency of silent myocardial ischemia (SMI) from an exercise ECG and its relationship with induced coronary angiographic assessment and potentially preventable cardiac events.
METHODS: This prospective cohort study included leisure time asymptomatic sportsmen over 35years old, referred from 2011 to 2014 in the Sports Medicine Unit of the University Hospital of Saint-Etienne.
RESULTS: Of the cohort of 1500 sportsmen (1205 men; mean age 50.7±9.4years; physical activity level 32.8±26.8MET-h/week), 951 (63%) had at least one cardiovascular disease (CVD) risk factor. Family history, medical examination and standard resting 12-lead were collected. A total of 163 exercise ECGs (10.9%) were defined as positive, most of them due to SMI (n=129, 8.6%). SMI was an indication for coronary angiography in 23 cases, leading to 17 documented SMIs (1.1%), including 11 significant stenoses requiring revascularization. In multivariate logistic regression analysis, a high risk of CVD (OR=2.65 [CI 95%: 1.33-5.27], p=0.005) and an age >50years (OR=2.71 [CI 95%: 1.65-4.44], p<0.0001) were independently associated with confirmed SMI.
CONCLUSIONS: The association of positive exercise ECG with significant coronary stenosis was stronger among sportsmen with CVD risk factors and older than 50years. Screening by exercise ECG can lower the risk of cardiac events in middle-aged and older sportsmen. One hundred tests would be enough to detect one silent myocardial ischemia at risk for cardiac event
Metaanalysis of the Performance of a Combined Treponemal and Nontreponemal Rapid Diagnostic Test for Syphilis and Yaws
BACKGROUND: The human treponematoses are important causes of
disease. Mother-to-child transmission of syphilis remains a
major cause of stillbirth and neonatal death. There are also
almost 100 000 cases of endemic treponemal disease reported
annually, predominantly yaws. Rapid diagnostic tests (RDTs)
would improve access to screening for these diseases. Most RDTs
cannot distinguish current and previous infection. The Dual Path
Platform (DPP) Syphilis Screen & Confirm test includes both
a treponemal (T1) and nontreponemal (T2) component and may
improve the accuracy of diagnosis. METHODS: We conducted a
metaanalysis of published and unpublished evaluations of the
DPP-RDT for the diagnosis of syphilis and yaws. We calculated
the sensitivity, specificity, and overall agreement of the test
compared with reference laboratory tests. RESULTS: Nine
evaluations, including 7267 tests, were included. Sensitivity
was higher in patients with higher titer rapid plasma reagin
(>/=1:16) for both the T1 (98.2% vs 90.1%, P < .0001) and
the T2 component (98.2% vs 80.6%, P < .0001). Overall
agreement between the DPP test and reference serology was 85.2%
(84.4%-86.1%). Agreement was highest for high-titer active
infection and lowest for past infection. CONCLUSIONS: The RDT
has good sensitivity and specificity of the treponemal and
nontreponemal components both in cases of suspected syphilis and
yaws, although the sensitivity is decreased at lower antibody
titers
Toxoplasmosis in transplant recipients, Europe, 2010-2014
Transplantation activity is increasing, leading to a growing number of patients at risk for toxoplasmosis. We reviewed toxoplasmosis prevention practices, prevalence, and outcomes for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT; heart, kidney, or liver) patients in Europe. We collected electronic data on the transplant population and prevention guidelines/regulations and clinical data on toxoplasmosis cases diagnosed during 2010-2014. Serologic pretransplant screening of allo-hematopoietic stem cell donors was performed in 80% of countries, screening of organ donors in 100%. SOT recipients were systematically screened in 6 countries. Targeted anti-Toxoplasma chemoprophylaxis was heterogeneous. A total of 87 toxoplasmosis cases were recorded (58 allo-HSCTs, 29 SOTs). The 6-month survival rate was lower among Toxoplasma-seropositive recipients and among allo-hematopoietic stem cell and liver recipients. Chemoprophylaxis improved outcomes for SOT recipients. Toxoplasmosis remains associated with high mortality rates among transplant recipients. Guidelines are urgently needed to standardize prophylactic regimens and optimize patient management
Tagging and localisation of ionizing events using NbSi transition edge phonon sensors for Dark Matter searches
In the context of direct searches of sub-GeV Dark Matter particles with
germanium detectors, the EDELWEISS collaboration has tested a new technique to
tag ionizing events using NbSi transition edge athermal phonon sensors. The
emission of the athermal phonons generated by the Neganov-Trofimov-Luke effect
associated with the drift of electrons and holes through the detectors is used
to tag ionization events generated in specific parts of the detector localized
in front of the NbSi sensor and to reject by more than a factor 5 (at 90% C.L.)
the background from heat-only events that dominates the spectrum above 3 keV.
This method is able to improve by a factor 2.8 the previous limit on
spin-independent interactions of 1 GeV/c2 WIMPs obtained with the same detector
and data set but without this tagging technique.Comment: 13 pages, 11 figure
Aging traits and sustainable trophy hunting of African lions
Trophy hunting plays a significant role in wildlife conservation in some contexts in various
parts of the world. Yet excessive hunting is contributing to species declines, especially for
large carnivores. Simulation models suggest that sustainable hunting of African lions may be
achieved by restricting offtakes to males old enough to have reared a cohort of offspring. We
tested and expanded criteria for an age-based approach for sustainably regulating lion
hunting. Using photos of 228 known-age males from ten sites across Africa, we measured
change in ten phenotypic traits with age and found four age classes with distinct
characteristics: 1-2.9 years, 3-4.9 years, 5-6.9 years, and â„7 years. We tested the aging
accuracy of professional hunters and inexperienced observers before and after training on
aging. Before training, hunters accurately aged more lion photos (63%) than inexperienced
observers (48%); after training, both groups improved (67-69%). Hunters overestimated 22%
of lions <5 years as 5-6.9 years (unsustainable) but only 4% of lions <5 years as â„7 years
(sustainable). Due to the lower aging error for males â„7 years, we recommend 7 years as a
practical minimum age for hunting male lions. Results indicate that age-based hunting is
feasible for sustainably managing threatened and economically significant species such as the
lion, but must be guided by rigorous training, strict monitoring of compliance and error, and
conservative quotas. Our study furthermore demonstrates methods for identifying traits to age
individuals, information that is critical for estimating demographic parameters underlying
management and conservation of age-structured species.http://www.elsevier.com/ locate/biocon2017-09-30hb2016Centre for Wildlife ManagementMammal Research InstituteZoology and Entomolog
First demonstration of 30 eVee ionization energy resolution with Ricochet germanium cryogenic bolometers
The future Ricochet experiment aims to search for new physics in the
electroweak sector by measuring the Coherent Elastic Neutrino-Nucleus
Scattering process from reactor antineutrinos with high precision down to the
sub-100 eV nuclear recoil energy range. While the Ricochet collaboration is
currently building the experimental setup at the reactor site, it is also
finalizing the cryogenic detector arrays that will be integrated into the
cryostat at the Institut Laue Langevin in early 2024. In this paper, we report
on recent progress from the Ge cryogenic detector technology, called the
CryoCube. More specifically, we present the first demonstration of a 30~eVee
(electron equivalent) baseline ionization resolution (RMS) achieved with an
early design of the detector assembly and its dedicated High Electron Mobility
Transistor (HEMT) based front-end electronics. This represents an order of
magnitude improvement over the best ionization resolutions obtained on similar
heat-and-ionization germanium cryogenic detectors from the EDELWEISS and
SuperCDMS dark matter experiments, and a factor of three improvement compared
to the first fully-cryogenic HEMT-based preamplifier coupled to a CDMS-II
germanium detector. Additionally, we discuss the implications of these results
in the context of the future Ricochet experiment and its expected background
mitigation performance.Comment: 10 pages, 5 figures, 1 tabl
Fast neutron background characterization of the future Ricochet experiment at the ILL research nuclear reactor
The future Ricochet experiment aims at searching for new physics in the
electroweak sector by providing a high precision measurement of the Coherent
Elastic Neutrino-Nucleus Scattering (CENNS) process down to the sub-100 eV
nuclear recoil energy range. The experiment will deploy a kg-scale
low-energy-threshold detector array combining Ge and Zn target crystals 8.8
meters away from the 58 MW research nuclear reactor core of the Institut Laue
Langevin (ILL) in Grenoble, France. Currently, the Ricochet collaboration is
characterizing the backgrounds at its future experimental site in order to
optimize the experiment's shielding design. The most threatening background
component, which cannot be actively rejected by particle identification,
consists of keV-scale neutron-induced nuclear recoils. These initial fast
neutrons are generated by the reactor core and surrounding experiments
(reactogenics), and by the cosmic rays producing primary neutrons and
muon-induced neutrons in the surrounding materials. In this paper, we present
the Ricochet neutron background characterization using He proportional
counters which exhibit a high sensitivity to thermal, epithermal and fast
neutrons. We compare these measurements to the Ricochet Geant4 simulations to
validate our reactogenic and cosmogenic neutron background estimations.
Eventually, we present our estimated neutron background for the future Ricochet
experiment and the resulting CENNS detection significance.Comment: 14 pages, 14 figures, 1 tabl
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