36 research outputs found

    Independència de la deambulació i la defecació en un camp obert poc atemoridor, posada de manifest en un estudi generacional

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    El principal objetivo del presente trabajo ha sido poner en evidencia la independencia de la deambulación y la defecación en un campo abierto poco atemorizador, mediante un estudio generacional. Los sujetos experimentales que formaban una nueva generación eran descendientes de padres seleccionados por puntuaciones extremas de deambulación. Cruzando entre sí los sujetos con más altas puntuaciones en deambulación y, a su vez, los de más bajas puntuaciones, obteníamos dos líneas con características de deambulación distintas. Un análisis de la evolución de la característica defecación, muestra la independencia de esta medida con la deambulación.The main purpose of the present paper has been to make evident that ambulation and defecation scores in a low-frigtening open field are independent. Subjects with highest and lowest expression of the ambulation character are selected. Mating like with like will tend to increase the mean score in subsequent generations giving two lines: high and low ambulator ' ones. The effect of ambulation upon the leve1 of defecation is analized. The results showed that ambulation measure is independent to defecation one

    Measurement of CP asymmetries and branching fraction ratios of B− decays to two charm mesons

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    The CPCP asymmetries of seven BB^- decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9fb19\text{fb}^{-1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0D^{*0} or DsD^{*-}_s meson are analysed by reconstructing only the D0D^0 or DsD^-_s decay products. This paper presents the first measurement of ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0) and ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0}), and the most precise measurement of the other five CPCP asymmetries. There is no evidence of CPCP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B^{−} decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb1^{−1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0^{*0} or Ds {D}_s^{\ast -} meson are analysed by reconstructing only the D0^{0} or Ds {D}_s^{-} decay products. This paper presents the first measurement of ACP \mathcal{A} ^{CP}(B^{−}Ds {D}_s^{\ast -} D0^{0}) and ACP \mathcal{A} ^{CP}(B^{−}Ds {D}_s^{-} D0^{∗0}), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The CPCP asymmetries of seven BB^- decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb19\text{ fb}^{-1} of proton-proton collisions collected by the LHCb experiment. Decays involving a D0D^{*0} or DsD^{*-}_s meson are analysed by reconstructing only the D0D^0 or DsD^-_s decay products. This paper presents the first measurement of ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0) and ACP(BDsD0)\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0}), and the most precise measurement of the other five CPCP asymmetries. There is no evidence of CPCP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured

    Helium identification with LHCb

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    The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Curvature-bias corrections using a pseudomass method

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    Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

    Momentum scale calibration of the LHCb spectrometer

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    For accurate determination of particle masses accurate knowledge of the momentum scale of the detectors is crucial. The procedure used to calibrate the momentum scale of the LHCb spectrometer is described and illustrated using the performance obtained with an integrated luminosity of 1.6 fb-1 collected during 2016 in pp running. The procedure uses large samples of J/ψ → μ + μ - and B+ → J/ψ K + decays and leads to a relative accuracy of 3 × 10-4 on the momentum scale

    Independència de la deambulació i la defecació en un camp obert poc atemoridor, posada de manifest en un estudi generacional

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    El principal objetivo del presente trabajo ha sido poner en evidencia la independencia de la deambulación y la defecación en un campo abierto poco atemorizador, mediante un estudio generacional. Los sujetos experimentales que formaban una nueva generación eran descendientes de padres seleccionados por puntuaciones extremas de deambulación. Cruzando entre sí los sujetos con más altas puntuaciones en deambulación y, a su vez, los de más bajas puntuaciones, obteníamos dos líneas con características de deambulación distintas. Un análisis de la evolución de la característica defecación, muestra la independencia de esta medida con la deambulación.The main purpose of the present paper has been to make evident that ambulation and defecation scores in a low-frigtening open field are independent. Subjects with highest and lowest expression of the ambulation character are selected. Mating like with like will tend to increase the mean score in subsequent generations giving two lines: high and low ambulator ' ones. The effect of ambulation upon the leve1 of defecation is analized. The results showed that ambulation measure is independent to defecation one

    Invasive pneumococcal disease among children in a health district of Barcelona: early impact of pneumococcal conjugate vaccine

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    ABSTRACTThis study evaluated the impact of heptavalent pneumococcal conjugate vaccine (HPCV) on invasive pneumococcal disease (IPD) in children aged ≤ 5 years in Barcelona, Spain. The incidence of IPD, vaccine uptake and prevalence of nasopharyngeal colonisation were analysed in two different periods: 1999–2001 (pre-licence period), and 2002–2004 (post-licence period). In total, 121 cases of IPD were identified. The overall incidence of IPD decreased from 96.9 cases/100 000 to 90.6 cases/100 000 (OR 0.93, 95% CI 0.69–1.26, p 0.71) between the two periods. The proportion of cases caused by non-vaccine-related serotypes (NVS) increased from 21% to 43.7% (OR 2.9, 95% CI 1.2–7, p 0.01). IPD was diagnosed in seven vaccinated children, six of whom were infected by NVS. There was a trend of diminishing prevalence of resistance to penicillin and macrolides in 2002–2004. The incidence of empyema increased from 1.7 to 8.5/100 000 (OR 4.5, 95% CI 0.91–18, p 0.06). The rate of vaccination ranged from 4.8% to 34%. It was concluded that the rates of IPD in this area did not decrease following the introduction of HPCV. The low uptake of vaccine and the greater proportion of colonisation/infection by NVS probably explain these findings. A trend of increasing empyema was also apparent. A decrease in the prevalence of penicillin and macrolide resistance paralleled the progressive uptake of vaccine

    Novel genera of root nodule bacteria demonstrate the microsymbiont diversity of the legume/rhizobia symbiosis

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    Root nodule bacteria isolated from native legumes in various biogeographical areas have demonstrated that rhizobia are more phylogenetically diverse than originally supposed. We present here an overview of our studies on novel species, isolated from nodules of legume hosts in Australia and Africa, which are affiliated to Burkholderia, Methylobacterium and Microvirga. The microsymbionts’ physiological adaptations to their environment, host specificity and phylogeny of nodulation and nitrogen fixation genes were examined, along with the modes of plant infection and nodule formation. Important findings include the apparent adaptation of Burkholderia spp. to infertile soils of wide pH range, the confirmation of specificity in the non-root hair-mediated Lotononis/Methylobacterium symbiosis and the potential of legume nodule morphology as a taxonomic aid. These species’ inclusion in the Genomic Encyclopedia for Bacteria and Archaea sequencing project will aid elucidation of the diverse rhizobial genomic architecture that underlies symbiotic ability and specificity
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