Search results for "Variant"
showing 10 items of 1267 documents
Electroweak measurements in electron-positron collisions at W-boson-pair energies at LEP
2013
The ALEPH, DELPHI, L3, OPAL collaborations and LEP Electroweak Working Group.-- arXiv:1302.3415
A new observable to measure the top-quark mass at hadron colliders
2013
A new method to measure the top-quark mass in high energetic hadron collisions is presented. We use theoretical predictions calculated at next-to-leading order accuracy in quantum chromodynamics to study the ( normalized) differential distribution of the t (t) over bar + 1-jet cross section with respect to its invariant mass root s(t (t) over barj). The sensitivity of the method to the top-quark mass together with the impact of various theoretical and experimental uncertainties has been investigated and quantified. The new method allows for a complementary measurement of the top-quark mass parameter and has a high potential to become competitive in precision with respect to established appr…
Measurement of the charge asymmetry in top quark pair production in pp collisions at root s=7 TeV using the ATLAS detector
2012
A measurement of the top-antitop production charge asymmetry A[subscript C] is presented using data corresponding to an integrated luminosity of 1.04 fb[superscript −1] of pp collisions at s√=7 TeV collected by the ATLAS detector at the LHC. Events are selected with a single lepton (electron or muon), missing transverse momentum and at least four jets of which at least one jet is identified as coming from a b-quark. A kinematic fit is used to reconstruct the t[bar over t] event topology. After background subtraction, a Bayesian unfolding procedure is performed to correct for acceptance and detector effects. The measured value of A[subscript C] is A[subscript C]=−0.019±0.028 (stat.)±0.024 (s…
Equivalence relations among homology 3-spheres and the Johnson filtration
2021
The Torelli group of a surface consists of isotopy classes of homeomorphisms of this surface acting trivially at the homological level. The structure of the Torelli group can be approached by the study and the comparison of two filtrations of this group: its lower central series, and the "Johnson" filtration, given by the kernels of the natural actions on the successive nilpotent quotients of the fundamental group of the surface. It is now known that there are, via the notion of "Heegaard splittings", rich interactions between this 2-dimensional study and the study of some 3-manifolds topological invariants: we refer here precisely to the so-called "finite-type" invariants. In this PhD, we …
On C1 robust singular transitive sets for three-dimensional flows
1998
Abstract The main goal of this paper is to study robust invariant transitive sets containing singularities for C 1 flows on three-dimensional compact boundaryless manifolds: they are partially hyperbolic with volume expanding central direction. Moreover, they are either attractors or repellers. Robust here means that this property cannot be destroyed by small C 1 -perturbations of the flow.
Revisiting the axial form factor of the nucleon for low Q2 pion electroproduction
2003
Abstract An extensive programme of charged pion electroproduction off the proton has been performed at the three-spectrometer facility at the Mainz Microton MAMI. The reaction p ( e , e ′ π + ) n was measured at a constant invariant mass of W = 1125 MeV and four-momentum transfers of Q 2 = 0.058, 0.117, 0.195, and 0.273 (GeV/ c ) 2 . For each Q 2 value. measurements at different values of ϵ, the virtual photon polarization parameters, allow for a Rosenbluth separation of longitudinal and transverse cross sections. Preliminary results from new measurements in 2000 and 2002 seem to indicate that the transverse cross section at lower Q 2 values is considerably lower than expected from previous…
Invariants of transverse foliations
2012
Abstract We construct two invariants for a pair of transverse one-dimensional foliations on the plane. If the set of separatrices is Hausdorff in the space of leaves, the invariant is a distinguished graph. In case there are a finite number of separatrices the invariant is an indexed link.
African trypanosomes expressing multiple VSGs are rapidly eliminated by the host immune system
2019
Significance Many parasites escape the host immune system by undergoing antigenic variation, a process in which surface antigens are regularly shed and replaced by new ones. Trypanosoma brucei employs multiple sophisticated molecular mechanisms to ensure the expression of a homogeneous VSG coat. We generated a mutant parasite that expresses multiple distinct VSGs and studied the consequences of having a multi-VSG coat during an infection. We showed that expression of multiple VSGs makes the parasites more vulnerable to the immune response, which can now control the trypanosomes from the onset of the infection, allowing most mice to survive. In the future, trypanosome infections may be treat…
Recurrences of multidrug-resistant tuberculosis: Strains involved, within-host diversity, and fine-tuned allocation of reinfections
2020
34 páginas, 13 figuras
Examination of Escherichia coli from poultry for selected adhesin genes important in disease caused by mammalian pathogenic E. coli
2001
A collection of 1601 extraintestinal and intestinal Escherichia coli isolated from chickens, turkeys and ducks, in Belgium, France and Spain, was hybridised with gene probes specific for fimbrial and afimbrial adhesins (F17, F18, SSfa/F1C, Bfp, Afa, Cs31A, IntiminEae, Aida-1) of intestinal, urinary and invasive E. coli of mammals and with a probe specific for the P (Pap/Prs) fimbrial adhesin of urinary and invasive E. coli of mammals and birds. Three hundred and eighty-three strains (23.9%) were P-positive, 76 strains (4.8%) were Afa-positive, 75 strains (4.7%) were F17-positive, 67 strains (4.2%) were S-positive, 23 (1.4%) were Intimin-positive, and all were F18-, Cs31A-, Aida1- and Bfp-ne…