1,535 research outputs found
Low-energy muon-transfer reaction from hydrogen isotopes to helium isotopes
Direct muon transfer in low-energy collisions of the muonic hydrogen H
and helium (He) is considered in a three-body quantum-mechanical
framework of coordinate-space integro-differential Faddeev-Hahn-type equations
within two- and six-state close coupling approximations. The final-state
Coulomb interaction is treated without any approximation employing appropriate
Coulomb waves in the final state. The present results agree reasonably well
with previous semiclassical calculations.Comment: 4 revtex4 page
Methylation Status of Imprinted Genes and Repetitive Elements in Sperm DNA from Infertile Males
Stochastic, environmentally and/or genetically induced disturbances in the genome-wide epigenetic reprogramming processes during male germ-cell development may contribute to male infertility. To test this hypothesis, we have studied the methylation levels of 2 paternally (H19 and GTL2) and 5 maternally methylated (LIT1, MEST, NESPAS, PEG3, and SNRPN) imprinted genes, as well as of ALU and LINE1 repetitive elements in 141 sperm samples, which were used for assisted reproductive technologies (ART), including 106 couples with strictly male-factor or combined male and female infertility and 28 couples with strictly female-factor infertility. Aberrant methylation imprints showed a significant association with abnormal semen parameters, but did not seem to influence ART outcome. Repeat methylation also differed significantly between sperm samples from infertile and presumably fertile males. However, in contrast to imprinted genes, ALU methylation had a significant impact on pregnancy and live-birth rate in couples with male-factor or combined infertility. ALU methylation was significantly high-er in sperm samples leading to pregnancy and live-birth than in those that did not. Sperm samples leading to abortions showed significantly lower ALU methylation levels than those leading to the birth of a baby. Copyright (C) 2011 S. Karger AG, Base
Genome-wide quantitative analysis of DNA methylation from bisulfite sequencing data
Summary: Here we present the open-source R/Bioconductor software package BEAT (BS-Seq Epimutation Analysis Toolkit). It implements all bioinformatics steps required for the quantitative high-resolution analysis of DNA methylation patterns from bisulfite sequencing data, including the detection of regional epimutation events, i.e. loss or gain of DNA methylation at CG positions relative to a reference. Using a binomial mixture model, the BEAT package aggregates methylation counts per genomic position, thereby compensating for low coverage, incomplete conversion and sequencing errors. Availability and implementation: BEAT is freely available as part of Bioconductor at www.bioconductor.org/packages/devel/bioc/html/BEAT.html. The package is distributed under the GNU Lesser General Public License 3.0. Contact: [email protected] Supplementary information: Supplementary data are available at Bioinformatics online
A Synergistic Behavior Underpins Human Hand Grasping Force Control During Environmental Constraint Exploitation
Despite the complex nature of human hands, neuroscientific studies suggested a simplified kinematic control underpinning motion generation, resulting in principal joint angle co-variation patterns, usually called postural hand synergies. Such a low dimensional description was observed in common grasping tasks, and was proven to be preserved also for grasps performed by exploiting the external environment (e.g., picking up a key by sliding it on a table). In this paper, we extend this analysis to the force domain. To do so, we performed experiments with six subjects, who were asked to grasp objects from a flat surface while force/torque measures were acquired at fingertip level through wearable sensors. The set of objects was chosen so that participants were forced to interact with the table to achieve a successful grasp. Principal component analysis was applied to force measurements to investigate the existence of co-variation schemes, i.e. a synergistic behavior. Results show that one principal component explains most of the hand force distribution. Applications to clinical assessment and robotic sensing are finally discussed
СИСТЕМА УПРАВЛЕНИЯ ФОТОЭЛЕКТРИЧЕСКОЙ УСТАНОВКОЙ ПРИ АВТОНОМНОМ ИСПОЛЬЗОВАНИИ
It is considered the control algorithm of photoelectric installation with storage battery. Рассмотрен алгоритм управления фотоэлектрической установкой с аккумуляторной батареей
Observation of the decay from an amplitude analysis of decays
Proton-proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0\invfb, are analysed to search for the charmless decay. More than 600 signal decays are selected and used to perform an amplitude analysis from which the decay is observed for the first time with 7.1 standard deviations significance. The fraction of decays yielding a longitudinally polarised final state is measured to be . The branching fraction, using the decay as reference, is also reported as
Measurement of asymmetries and polarisation fractions in decays
An angular analysis of the decay is performed using collisions corresponding to an integrated luminosity of collected by the LHCb experiment at a centre-of-mass energy TeV. A combined angular and mass analysis separates six helicity amplitudes and allows the measurement of the longitudinal polarisation fraction for the decay. A large scalar contribution from the and resonances is found, allowing the determination of additional asymmetries. Triple product and direct asymmetries are determined to be compatible with the Standard Model expectations. The branching fraction is measured to be
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