1,792 research outputs found
Diboson resonances within a custodially protected warped extra-dimensional scenario
We propose an interpretation of the diboson excess recently observed by the
ATLAS and CMS collaborations in terms of Kaluza-Klein excitations of
electroweak gauge bosons stemming from a realization of a warped
extra-dimensional model that is protected by a custodial symmetry. Besides
accounting for the LHC diboson data, this scenario also leads to an explanation
of the anomalies that have been observed in the measurements of the
forward-backward asymmetries for bottom quarks at LEP and top quarks at the
Tevatron.Comment: 10 pages, 2 figure
The forward-backward asymmetry of top quark production at the Tevatron in warped extra dimensional models
The CDF and D0 experiments have reported on the measurement of the
forward-backward asymmetry of top quark pair production at the Tevatron and the
result is that it is more than 2 standard deviations above the predicted value
in the Standard Model. This has to be added to the longstanding anomaly in the
forward-backward asymmetry for bottom quark production at LEP which is 3
standard deviations different from the Standard Model value. The discrepancy in
the bottom asymmetry can be accounted for by the contributions of Kaluza-Klein
excitations of electroweak gauge bosons at LEP in warped extra dimensional
models in which the fermions are localized differently along the extra
dimension so that the gauge interactions of heavy third generation fermions are
naturally different from that of light fermions. In this paper, we show that it
is more difficult to elaborate a model generating a significant top asymmetry
in a similar way -- through exchanges of Kaluza-Klein gluons at the Tevatron --
due to the indirect constraints originating from precision electroweak data.Comment: 4 pages, 1 figure, published versio
Review of Defective NADPH Oxidase Activity and Myeloperoxidase Release in Neutrophils From Patients With Cirrhosis
Patients with decompensated cirrhosis are highly susceptible to develop bacterial infections and these can trigger multiorgan failure associated with high in-hospital mortality. Neutrophils from patients with decompensated cirrhosis exhibit marked alterations that may explain the susceptibility of these patients to develop bacterial infections. These neutrophil alterations include marked defects in intracellular signaling pathways involving serine/threonine kinases such as protein kinase B (AKT), p38-mitogen-activated protein kinase (MAPK), and the MAP kinases1/2; activation of the NADPH oxidase complex; myeloperoxidase (MPO) release; and bactericidal activity of neutrophils stimulated by the bacterial peptide formyl-Methionine-Leucine-Phenylalanine (fMLF). Impaired activity of the NADPH oxidase 2 (NOX2) complex is also related to reduced levels of expression of its major components through post-transcriptional mechanisms. In addition, the catalytic NOX2 component gp91phox is subject to degradation by elastase highly present in patients' plasma. A defect in the protein kinase B (AKT) and p38 MAPK-mediated signaling pathways may explain the decrease in phosphorylation of p47phox (an important component of the NADPH oxidase complex) and MPO release, in response to neutrophil stimulation by fMLF. Most of these alterations are reversible ex vivo with TLR7/8 agonists (CL097, R848), raising the possibility that these agonists might be used in the future to restore neutrophil antibacterial functions in patients with cirrhosis
A Formal Account of the Open Provenance Model
On the Web, where resources such as documents and data are published, shared, transformed, and republished, provenance is a crucial piece of metadata that would allow users to place their trust in the resources they access. The Open Provenance Model (OPM) is a community data model for provenance that is designed to facilitate the meaningful interchange of provenance information between systems. Underpinning OPM is a notion of directed graph, where nodes represent data products and processes involved in past computations, and edges represent dependencies between them; it is complemented by graphical inference rules allowing new dependencies to be derived. Until now, however, the OPM model was a purely syntactical endeavor. The present paper extends OPM graphs with an explicit distinction between precise and imprecise edges. Then a formal semantics for the thus enriched OPM graphs is proposed, by viewing OPM graphs as temporal theories on the temporal events represented in the graph. The original OPM inference rules are scrutinized in view of the semantics and found to be sound but incomplete. An extended set of graphical rules is provided and proved to be complete for inference. The paper concludes with applications of the formal semantics to inferencing in OPM graphs, operators on OPM graphs, and a formal notion of refinement among OPM graphs
Acute-on-chronic liver failure: a new syndrome in cirrhosis
Patients with cirrhosis who are hospitalized for an acute decompensation (AD) and also have organ failure(s) are at high risk of short-term death. These patients have a syndrome called Acute-on-Chronic Liver Failure (ACLF). ACLF is now considered as a new syndrome that it is distinct from “mere” AD not only because of the presence of organ failure(s) and high short-term mortality but also because of younger age, higher prevalence of alcoholic etiology of cirrhosis, higher prevalence of some precipitants (such as bacterial infections, active alcoholism), and more intense systemic inflammatory response. ACLF is a new syndrome also because severe sepsis or severe alcoholic hepatitis do not account for 100% of the observed cases; in fact, almost 50% of the cases are of “unknown” origin. In other words, severe sepsis, severe alcoholic hepatitis and ACLF of “unknown origin” are subcategories of the syndrome
Growth and metal uptake of microalgae produced using salt groundwaters from the Bay of Bourgneuf
International audienceThe Bay of Bourgneuf, France, is a main site of shellfish production. In the marshes along the bay, oyster intensive rearing and fattening need the mass production of microalgae. Salt groundwaters, available in this region, support a large part of this production for aquaculture. Studies carried out by local authorities have brought to the fore the accumulation of lead (Pb) in several samples of algal pastes derived from cultures using salt groundwater. The aim of this study was to compare growth, nutritional value and metal (Cd, Cu, Pb and Zn) uptake of four microalgae grown in two salt groundwaters or in enriched coastal seawater. Cultures of microalgae used in aquaculture (Haslea ostrearia, Phaeodactylum tricornutum, Skeletonema costatum and Tetraselmis suecica) were realised at the laboratory under controlled experimental conditions. Results indicated that salt groundwaters provided cultures with, at least, an equal biomass and a nutritional value similar to cultures grown in enriched seawater. There was no difference regarding metal accumulation whatever the culture medium, except when S. costatum was grown in one of the salt groundwater in which case its cadmium levels were higher and could be above the French guideline level. These observations questioned on the bioavailability of metals in salt groundwaters. It also underlines the specificity of metal uptake and accumulation by microalgae
A Robotic Platform for Endovascular Aneurysm Repair
International audienceAn EndoVascular Aneurysm Repair (EVAR) isa procedure used to fix an aneurysm of the aorta. In thisprocedure, a guide is inserted by the femoral artery. This guidegoes through to the height of the aneurysm and then a catheterfollows the guide. Next, a stent graft is deployed in order torepair the aortic aneurysm. The objectives of our work is todevelop a low-cost robotic system and implement a programthat helps the trajectory planning during an endovascularoperation. More precisely, this program can predict if the aortawill break or not depending on the guide used. Such a roboticplatform could serve as a teaching instrument by creating anenvironment for young surgeons in which they will be able topractice their skills to perform an EVAR. This paper describesthe different components of this platform and provides someexperimental results
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Inferring Phylogenies from RAD Sequence Data
Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD) to sequence restriction-site associated DNA (RAD) – the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts) and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct “known” phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for “total evidence” phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively). RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in which sufficient numbers of orthologous restriction sites are retained across species.</p
Savigny-sous-Faye – Place de l'église
Identifiant de l'opération archéologique : 204643 Date de l'opération : 2008 (SU) L’opération de sauvetage urgent réalisée sur la place de l’église de Savigny-sous-Faye a été déclenchée par un projet d’aménagement de la place et d’assainissement des environs de l’église Saint-Pierre, protégée au titre des Monuments Historiques depuis 1994. Savigny-sous-Faye est une commune du nord de la Vienne qui se situe à  20 km au nord-est de Châtellerault au cœur d’une vaste plaine à vocation agricole cé..
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