369 research outputs found
Dark matter directional detection with MIMAC
MiMac is a project of micro-TPC matrix of gaseous (He3, CF4) chambers for
direct detection of non-baryonic dark matter. Measurement of both track and
ionization energy will allow the electron-recoil discrimination, while access
to the directionnality of the tracks will open a unique way to distinguish a
geniune WIMP signal from any background. First reconstructed tracks of 5.9 keV
electrons are presented as a proof of concept.Comment: 4 pages, proc. of the 44th Rencontres De Moriond: Electroweak
Interactions And Unified Theories, 7-14 Mar 2009, La Thuile, Ital
Causes of prehospital misinterpretations of ST elevation myocardial infarction
Objectives: To determine the causes of software misinterpretation of ST elevation myocardial infarction (STEMI) compared to clinically identified STEMI to identify opportunities to improve prehospital STEMI identification. Methods: We compared ECGs acquired from July 2011 through June 2012 using the LIFEPAK 15 on adult patients transported by the Los Angeles Fire Department. Cases included patients ≥18 years who received a prehospital ECG. Software interpretation of the ECG (STEMI or not) was compared with data in the regional EMS registry to classify the interpretation as true positive (TP), true negative (TN), false positive (FP), or false negative (FN). For cases where classification was not possible using registry data, 3 blinded cardiologists interpreted the ECG. Each discordance was subsequently reviewed to determine the likely cause of misclassification. The cardiologists independently reviewed a sample of these discordant ECGs and the causes of misclassification were updated in an iterative fashion. Results: Of 44,611 cases, 50% were male (median age 65; inter-quartile range 52–80). Cases were classified as 482 (1.1%) TP, 711 (1.6%) FP, 43371 (97.2%) TN, and 47 (0.11%) FN. Of the 711 classified as FP, 126 (18%) were considered appropriate for, though did not undergo, emergent coronary angiography, because the ECG showed definite (52 cases) or borderline (65 cases) ischemic ST elevation, a STEMI equivalent (5 cases) or ST-elevation due to vasospasm (4 cases). The sensitivity was 92.8% [95% CI 90.6, 94.7%] and the specificity 98.7% [95% CI 98.6, 98.8%]. The leading causes of FP were ECG artifact (20%), early repolarization (16%), probable pericarditis/myocarditis (13%), indeterminate (12%), left ventricular hypertrophy (8%), and right bundle branch block (5%). There were 18 additional reasons for FP interpretation (<4% each). The leading causes of FN were borderline ST-segment elevations less than the algorithm threshold (40%) and tall T waves reducing the ST/T ratio below threshold (15%). There were 11 additional reasons for FN interpretation occurring ≤3 times each. Conclusion: The leading causes of FP automated interpretation of STEMI were ECG artifact and non-ischemic causes of ST-segment elevation. FN were rare and were related to ST-segment elevation or ST/T ratio that did not meet the software algorithm threshold
Disappearing world heritage glaciers as a keystone of nature conservation in a changing climate
Since 1972, the United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Convention aims to identify and protect sites of Outstanding Universal Value for future generations. However, growing impacts of climate change are of the utmost concern for the integrity of many sites. Here, we inventory the glaciers present in natural World Heritage sites for the first time. We found 19,000 glaciers in 46 sites located all over the world. We analyze their recent evolution, current state, and project their mass change over the 21st century. Our results are based on a comprehensive review of the literature as well as a state‐of‐ the‐art glaciological model for computing glacier responses up to 2100. Illustrating the strong influence of CO2 emission scenarios and human actions on future ice loss magnitude, we project the wastage of 33% to 60% of the 2017 cumulative ice volume of 12,000 km3 of World Heritage glaciers by 2100. Furthermore, we expect complete glacier extinction in 8 to 21 of the investigated World Heritage sites until the end of the century, depending on the climate scenario. We suggest that World Heritage glaciers should be considered as analogs to endangered umbrella, keystone, and flagship species, whose conservation would secure wider environmental and social benefits at global scale
MIMAC : A micro-tpc matrix for directional detection of dark matter
Directional detection of non-baryonic Dark Matter is a promising search
strategy for discriminating WIMP events from background. However, this strategy
requires both a precise measurement of the energy down to a few keV and 3D
reconstruction of tracks down to a few mm. To achieve this goal, the MIMAC
project has been developed. It is based on a gaseous micro-TPC matrix, filled
with CF4 and CHF3. The first results on low energy nuclear recoils (H, F)
obtained with a low mono-energetic neutron field are presented. The discovery
potential of this search strategy is discussed and illustrated by a realistic
case accessible to MIMAC.Comment: 6 pages, Proc. of the fifth international symposium on large TPCs for
low energy rare event detection, Paris, France, Dec. 2010. To appear in
Journal of Physic
Identification and Characterization of Potential Discharge Areas for Radionuclide Transport by Groundwater from a Nuclear Waste Repository in Sweden
MicroRNA-101 expression is associated with JAK2V617F activity and regulates JAK2/STAT5 signaling.
Philadelphia negative myeloproliferative neopl 28 asms (MPNs) are clonal haematological diseases characterized by excessive production of mature blood cells. Exome sequencing of patient samples have showed a relatively low degree genomic complexity for these diseases1. The majority of MPN patients carry somatic mutations in the JAK2 gene, with the JAK2V617F missense mutation being the most common in poly33
cythemia vera (PV, 95%) and essential thrombocythemia (ET, 60%) 2.FP was supported by Fondazione Umberto Veronesi, and Institute Pasteur - Fondazione Cenci Bolognetti
Micromegas detector developments for MIMAC
The aim of the MIMAC project is to detect non-baryonic Dark Matter with a
directional TPC. The recent Micromegas efforts towards building a large size
detector will be described, in particular the characterization measurements of
a prototype detector of 10 10 cm with a 2 dimensional readout
plane. Track reconstruction with alpha particles will be shown.Comment: 8 pages, 7 figures Proceedings of the 3rd International conference on
Directional Detection of Dark Matter (CYGNUS 2011), Aussois, France, 8-10
June 2011; corrections on author affiliation
Phenetic and genetic structure of tsetse fly populations (Glossina palpalis palpalis) in southern Ivory Coast
Background: Sleeping sickness, transmitted by G. p. palpalis, is known to be present in the Ivory Coast. G. p. palpalis has recently been reported to occur in several places within the town of Abidjan, including: (i) the Banco forest, (ii) the Abobo Adjame University campus and (iii) the zoological park. Could these three places be treated sequentially, as separate tsetse populations, or should they be taken as one area comprising a single, panmictic population? Methods: The amount of gene flow between these places provides strategic information for vector control. It was estimated by the use of both microsatellite DNA and morphometric markers. The idea was to assess the interest of the faster and much less expensive morphometric approach in providing relevant information about population structure. Thus, to detect possible lack of insect exchange between these neighbouring areas of Abidjan, we used both genetic (microsatellite DNA) and phenetic (geometric morphometrics) markers on the same specimens. Using these same markers, we also compared these samples with specimens from a more distant area of south Ivory Coast, the region of Aniassue (186 km north from Abidjan). Results: Neither genetic nor phenetic markers detected significant differentiation between the three Abidjan G. p. palpalis samples. Thus, the null hypothesis of a single panmictic population within the city of Abidjan could not be rejected, suggesting the control strategy should not consider them separately. The markers were also in agreement when comparing G. p. palpalis from Abidjan with those of Aniassue, showing significant divergence between the two sites. Conclusions: Both markers suggested that a successful control of tsetse in Abidjan would require the three Abidjan sites to be considered together, either by deploying control measures simultaneously in all three sites, or by a continuous progression of interventions following for instance the "rolling carpet" principle. To compare the geometry of wing venation of tsetse flies is a cheap and fast technique. Agreement with the microsatellite approach highlights its potential for rapid assessment of population structure
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