586 research outputs found

    Supersymmetric penguin contributions to the decay b -> s gamma with non-universal squarks masses

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    We give explicit expressions for the amplitudes associated with the supersymmetric contributions to the process: b -> s gamma in the context of SUSY extensions of Standard Model with non-universal soft SUSY breaking terms. From experimental data, we deduce the limits on the squark mass insertions obtained from different contributions (gluinos, neutralinos and charginos).Comment: 13 pages, 6 figures, changes: added remarks and new referenc

    Cryptic diversity within the major trypanosomiasis vector Glossina fuscipes revealed by molecular markers

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    Background: The tsetse fly Glossina fuscipes s.l. is responsible for the transmission of approximately 90% of cases of human African trypanosomiasis (HAT) or sleeping sickness. Three G. fuscipes subspecies have been described, primarily based upon subtle differences in the morphology of their genitalia. Here we describe a study conducted across the range of this important vector to determine whether molecular evidence generated from nuclear DNA (microsatellites and gene sequence information), mitochondrial DNA and symbiont DNA support the existence of these taxa as discrete taxonomic units. Principal Findings: The nuclear ribosomal Internal transcribed spacer 1 (ITS1) provided support for the three subspecies. However nuclear and mitochondrial sequence data did not support the monophyly of the morphological subspecies G. f.fuscipes or G. f. quanzensis. Instead, the most strongly supported monophyletic group was comprised of flies sampled fromEthiopia. Maternally inherited loci (mtDNA and symbiont) also suggested monophyly of a group from Lake Victoria basin and Tanzania, but this group was not supported by nuclear loci, suggesting different histories of these markers. Microsatellite data confirmed strong structuring across the range of G. fuscipes s.l., and was useful for deriving the interrelationship of closely related populations. Conclusion/Significance: We propose that the morphological classification alone is not used to classify populations of G. fuscipes for control purposes. The Ethiopian population, which is scheduled to be the target of a sterile insect release (SIT) programme, was notably discrete. From a programmatic perspective this may be both positive, given that it may reflect limited migration into the area or negative if the high levels of differentiation are also reflected in reproductive isolation between this population and the flies to be used in the release programme

    The high burden of hospitalizations for primary EBV infection: a 6-year prospective survey in a French hospital

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    AbstractPrimary Epstein-Barr virus infection (PEI) is acquired increasingly later in life in developed countries, involving a growing number of adults. No studies have examined the effect of age on PEI. We conducted a prospective, single-centre, noninterventional survey to assess the clinical and economic effects of PEI care according to age. We included all serology-confirmed cases observed in all departments of a large regional hospital. Clinical and biologic data, therapeutics and costs of care were examined. Over a 6-year period, we included 292 subjects (148 children and 144 adults) with a median age of 15.4 years (range 9 months to 79 years). Adults were hospitalized more often (83% vs. 60%) and for longer periods of time (median 4 days vs. 2 days) than children (p ≀ 0.0001 for both). Two adults required a secondary transfer into the intensive care unit, although no children did. Typically, adults showed higher levels of activated lymphocytes and liver abnormalities. They also required the use of systemic corticosteroids more often (45% vs. 23%, p < 0.0001) and for longer periods of time (median 7 days vs. 3 days, p 0.02) than children. Overall, the costs were significantly higher for adults than for children (median, €1940 vs. €1130, p < 0.0001), mainly because of the frequency and duration of hospitalizations. Age increases the immune response and clinical severity of PEI, resulting in substantial additional costs for the community. Better recognition of the disease in adults could shorten the average length of hospital stay

    Neutrino mixing and large CP violation in B physics

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    We show that in see-saw models of neutrino mass a la SUSY SO(10), the observed large mixing in atmospheric neutrinos naturally leads to large b-s transitions. If the associated new CP phase turns out to be large, this SUSY contributions can drastically affect the CP violation in some of the B decay channels yielding the beta and gamma angles of the unitarity triangle. They can even produce sizeable CP asymmetries in some decay modes which are not CP violating in the standard model context. Hence the observed large neutrino mixing makes observations of low energy SUSY effect in some CP violating decay channels potentially promising in spite of the agreement between the Standard Model and data in K and B physics so far.Comment: References adde

    Treatment of chronic hepatitis C in patients unresponsive to interferon. Interest of re-treatment combining interferon induction therapy and ribavirin (a multicenter pilot study)

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    Aim About 45% of patients with chronic hepatitis C are unresponsive to the present reference treatment combining pegelated interferon plus ribavirin; before pegylated interferon was available the non-response rate was around 60%. This open multicenter pilot study, initiated before pegylated interferon became available, was designed to evaluate, in patients unresponsive to interferon monotherapy, the rate of biological and virological response and side-effects of the ribivirin- alpha 2b interferon combination. Methods The combination protocol was ribavirin (1 to 1.2 g/d) plus alpha 2b interferon at induction doses (9 MU/d the first week; 4.5 MU/d the eleven following weeks; 3 MU/2 days the 36 following weeks). Results Among the 27 included patients, 17 (63%) were viremia-negative (PCR) after 12 weeks of treatment, 9 (33%) were complete responders (undetectable viremia and normal transaminases) at the end of treatment (48 weeks) and of follow-up (72 weeks). Patients with non-1, non-4 genotypes who derived full benefit from this therapeutic strategy (6/7 (86%) were complete responders: 4/5 with genotype 3 and 2/2 with genotype 5). Quality-of-life was impaired during treatment, especially during the first 12 weeks of high-dose interferon therapy. Conclusion While waiting for new therapeutic possibilities, these good results suggest interferon induction at the beginning of treatment remains a valid option

    A New Parametrization of the Seesaw Mechanism and Applications in Supersymmetric Models

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    We present a new parametrization of the minimal seesaw model, expressing the heavy-singlet neutrino Dirac Yukawa couplings (YÎœ)ij(Y_\nu)_{ij} and Majorana masses MNiM_{N_i} in terms of effective light-neutrino observables and an auxiliary Hermitian matrix H.H. In the minimal supersymmetric version of the seesaw model, the latter can be related directly to other low-energy observables, including processes that violate charged lepton flavour and CP. This parametrization enables one to respect the stringent constraints on muon-number violation while studying the possible ranges for other observables by scanning over the allowed parameter space of the model. Conversely, if any of the lepton-flavour-violating process is observed, this measurement can be used directly to constrain (YÎœ)ij(Y_\nu)_{ij} and MNi.M_{N_i}. As applications, we study flavour-violating τ\tau decays and the electric dipole moments of leptons in the minimal supersymmetric seesaw model.Comment: Important references adde

    The Minimal Supersymmetric Standard Model: Group Summary Report

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    CONTENTS: 1. Synopsis, 2. The MSSM Spectrum, 3. The Physical Parameters, 4. Higgs Boson Production and Decays, 5. SUSY Particle Production and Decays, 6. Experimental Bounds on SUSY Particle Masses, 7. References.Comment: 121 pages, latex + epsfig, graphicx, axodraw, Report of the MSSM working group for the Workshop "GDR-Supersym\'etrie",France. Rep. PM/98-4

    Monitoring Cognitive and Emotional Processes Through Pupil and Cardiac Response During Dynamic Versus Logical Task

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    The paper deals with the links between physiological measurements and cognitive and emotional functioning. As long as the operator is a key agent in charge of complex systems, the definition of metrics able to predict his performance is a great challenge. The measurement of the physiological state is a very promising way but a very acute comprehension is required; in particular few studies compare autonomous nervous system reactivity according to specific cognitive processes during task performance and task related psychological stress is often ignored. We compared physiological parameters recorded on 24 healthy subjects facing two neuropsychological tasks: a dynamic task that require problem solving in a world that continually evolves over time and a logical task representative of cognitive processes performed by operators facing everyday problem solving. Results showed that the mean pupil diameter change was higher during the dynamic task; conversely, the heart rate was more elevated during the logical task. Finally, the systolic blood pressure seemed to be strongly sensitive to psychological stress. A better taking into account of the precise influence of a given cognitive activity and both workload and related task-induced psychological stress during task performance is a promising way to better monitor operators in complex working situations to detect mental overload or pejorative stress factor of error

    D-brane anti-D-brane effective action and brane interaction in open string channel

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    We construct the effective action of a DpD_p-brane-anti-DpD_p-brane system by making use of the non-abelian extension of tachyonic DBI action. We succeed the construction by restricting the Chan-Paton factors of two non-BPS DpD_p-branes in the action to the Chan-Paton factors of a DpDˉpD_p\bar{D}_p system. For the special case that both branes are coincident, the action reduces to the one proposed by A. Sen. \\The effective DpDˉpD_p\bar{D}_p potential indicates that when branes separation is larger than the string length scale, there are two minima in the tachyon direction. As branes move toward each other under the gravitational force, the tachyon tunneling from false to true vacuum may make a bubble formation followed by a classical evolution of the bubble. On the other hand, when branes separation is smaller than the string length scale, the potential shows one maximum and one minimum. In this case, a homogeneous tachyon rolling in real time makes an attractive potential for the branes distance. This classical force is speculated to be the effective force between the two branes.Comment: Latex, 14 pages, 1 figure, the version appears in JHE
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