3,487 research outputs found
Calibration Strategy and Efficiency measurement of the Muon Identification procedure at LHCb
We present a strategy for calibrating with data the LHCb muon identification procedure and for extracting in-situ the performance. Two main calibration samples are used: the inclusive decay as a source of muons and the decay as a source of hadrons decaying and non-decaying in flight. For each of them we describe the selection, the expected purity and the rates for different running scenarios. The distributions extracted from calibration samples are compared with those obtained from a generic b-inclusive sample. An estimate of the precision that can be reached in the evaluation of the muon identification efficiency and misidentification rate is given as a function of the collected statistics
semi multiplex pcr technique for screening of abundant transcripts during systematic sequencing of cdna libraries
The systematic sequencing of cDNA libraries is an efficient approach for the identification of new genes, but the presence of abundant mRNAs is often a major problem. This paper describes a very si..
The Effect of Probabilistic Context on Implicit Temporal Expectations in Down Syndrome
One of the most important sources of predictability that human beings can exploit to create an internal representation of the external environment is the ability to implicitly build up subjective statistics of events\u2019 temporal structure and, consequently, use this knowledge to prepare for future actions. Stimulus expectancy can be subjectively shaped by hierarchically nested sources of prediction, capitalizing on either local or global probabilistic rules. In order to better understand the nature of local-global proactive motor control in Down Syndrome, in the present study a group of participants with Down Syndrome (DS group; n = 28; mean age 29.5 \ub1 13 years; range 10\u201354) and a group of typically developing participants matched by either gender or mental age (TD-MA group; n = 28; 5.6 \ub1 1 years; range 4\u20138) were administered a novel motor preparation task, defined as the Dynamic Temporal Prediction (DTP) task. In the DTP, the temporal preparation to imperative stimuli is implicitly shaped by the local increase of expectancy. This is manipulated trial-by-trial as a function of the preparatory foreperiod interval (Stimulus-Onset Asynchrony or SOA). In addition, temporal preparation can be also implicitly adjusted as a function of global predictive context, so that a block-wise SOA-distribution bias toward a given preparatory interval might determine a high-order source of expectancy, with functional consequences on proactive motor control adjustment. Results showed that in both groups motor preparation was biased by temporal expectancy when this was locally manipulated within-trials. By contrast, only the TD-MA group was sensitive to global rule changes: only in this cohort was behavioral performance overall impacted by the SOA probabilistic distribution manipulated between-blocks. The evidence of a local-global dissociation in DS suggests that the use of flexible cognitive mechanisms to implicitly extract high-order probabilistic rules in order to build-up an internal model of the temporal properties of events is disrupted in this developmental disorder. Moreover, since the content of the information to be processed in the DTP task was neither verbal nor spatial, we suggest that atypical global processing in Down Syndrome is a domain-general rather than specific aspect characterizing the cognitive profile of this population
Inspiratory muscle training and its effect on indices of physiological and perceived stress during incremental walking exercise in normobaric hypoxia
This study evaluated the effects of inspiratory muscle training (IMT) on inspiratory muscle fatigue (IMF) and physiological and perceptual responses during trekking-specific exercise. An 8-week IMT program was completed by 21 males (age 32.4 ± 9.61 years, VO2peak 58.8 ± 6.75 mL/kg/min) randomised within matched pairs to either the IMT group (n = 11) or the placebo group [(P), n = 9]. Twice daily, participants completed 30 (IMT) or 60 (P) inspiratory efforts using a Powerbreathe initially set at a resistance of 50% (IMT) or used at 15% (P) of maximal inspiratory pressure (MIP) throughout. A loaded (12.5 kg) 39-minute incremental walking protocol (3–5 km/hour and 1–15% gradient) was completed in normobaric hypoxia (PIO2 = 110 mmHg, 3000 m) before and after training. MIP increased from 164 to 188 cmH2O (18%) and from 161 to 171 cmH2O (6%) in the IMT and P groups (P = 0.02). The 95% CI for IMT showed a significant improvement in MIP (5.21±43.33 cmH2O), but not for P. IMF during exercise (MIP) was*5%, showing no training effect for either IMT or P (P = 0.23). Rating of perceived exertion (RPE) was consistently reduced (*1) throughout exercise following training for IMT, but not for P (P = 0.03). The mean blood lactate concentration during exercise was significantly reduced by 0.26 and 0.15 mmol/L in IMT and P (P = 0.00), with no differences between groups (P = 0.34). Rating of dyspnoea during exercise decreased (*0.4) following IMT but increased (*0.3) following P (P = 0.01). IMT may attenuate the increased physiological and perceived exercise stress experienced during normobaric hypoxia, which may benefit moderate altitude expedition
The effect of differential galactic winds on the chemical evolution of galaxies
(Abridged) The aim of this paper is to study the basic equations of the
chemical evolution of galaxies with gas flows. We focus on models in which the
outflow is differential, namely in which the heavy elements (or some of the
heavy elements) can leave the parent galaxy more easily than other chemical
species such as H and He. We study the chemical evolution of galaxies in the
framework of simple models. This allows us to solve analytically the equations
for the evolution of gas masses and metallicities. We find new analytical
solutions for various cases in which the effects of winds and infall are taken
into account. Differential galactic winds have the effect of reducing the
global metallicity of a galaxy, with the amount of reduction increasing with
the ejection efficiency of the metals. Abundance ratios are predicted to remain
constant throughout the whole evolution of the galaxy, even in the presence of
differential winds. One way to change them is by assuming differential winds
with different ejection efficiencies for different elements. However, simple
models apply only to elements produced on short timescales, namely all by Type
II SNe, and therefore large differences in the ejection efficiencies of
different metals are unlikely. Variations in abundance ratios such as [O/Fe] in
galaxies, without including the Fe production by Type Ia supernovae, can in
principle be obtained by assuming an unlikely different efficiency in the loss
of O relative to Fe from Type II supernovae. Therefore, we conclude that it is
not realistic to ignore Type Ia supernovae and that the delayed production of
some chemical elements relative to others (time-delay model) remains the most
plausible explanation for the evolution of alpha-elements relative to Fe.Comment: 11 pages, 10 figures, A&A accepte
A wide angle view of the Sagittarius dwarf Spheroidal Galaxy. I: VIMOS photometry and radial velocities across Sgr dSph major and minor axis
The Sagittarius dwarf Spheroidal Galaxy (Sgr dSph) provides us with a unique
possibility of studying a dwarf galaxy merging event while still in progress.
Due to its low distance (25 kpc), the main body of Sgr dSph covers a vast area
in the sky (roughly 15 x 7 degrees). Available photometric and spectroscopic
studies have concentrated either on the central part of the galaxy or on the
stellar stream, but the overwhelming majority of the galaxy body has never been
probed. The aim of the present study is twofold. On the one hand, to produce
color magnitude diagrams across the extension of Sgr dSph to study its stellar
populations, searching for age and/or composition gradients (or lack thereof).
On the other hand, to derive spectroscopic low-resolution radial velocities for
a subsample of stars to determine membership to Sgr dSph for the purpose of
high resolution spectroscopic follow-up. We used VIMOS-VLT to produce V and I
photometry and spectroscopy on 7 fields across the Sgr dSph minor and major
axis, plus 3 more centered on the associated globular clusters Terzan 7, Terzan
8 and Arp 2. A last field has been centered on M 54, lying in the center of Sgr
dSph. We present photometry for 320,000 stars across the main body of Sgr dSph,
one of the richest, and safely the most wide-angle sampling ever produced for
this fundamental object. We also provide robust memberships for more than one
hundred stars, whose high resolution spectroscopic analysis will be the object
of forthcoming papers. Sgr dSph appears remarkably uniform among the observed
fields. We confirm the presence of a main Sgr dSph population characterized
roughly by the same metallicity of 47 Tuc, but we also found the presence of
multiple populations on the peripheral fields of the galaxy, with a metallicity
spanning from [Fe/H]=-2.3 to a nearly solar value.Comment: 10 pages, 12 figures, accepted for publication in A&
FATZ, a filamin-, actinin-, and telethonin-binding protein of the Z-disc of skeletal muscle
We report the identification and characterization of a novel 32-kDa protein expressed in skeletal muscle and located in the Z-disc of the sarcomere. We found that this protein binds to three other Z-disc proteins; therefore, we have-named it FATZ, gamma -filamin/ABP-L, alpha -actinin and telethonin binding protein of the Z-disc. From yeast two-hybrid experiments we are able to show that the SR3-SR4 domains of alpha -actinin 2 are required to bind the COOH-terminal region of the FATZ as does gamma -filamin/ABP-L, Furthermore, by using a glutathione S-transferase overlay assay we find that FATZ also binds telethonin. The level of FATZ protein in muscle cells increases during differentiation, being clearly detectable before the onset of myosin, Although FATZ has no known interaction domains, it would appear to be involved in a complex network of interactions with other Z-band components. On the basis of the information known about its binding partners, we could envisage a central role for FATZ in the: myofibrillogenesis, After screening our muscle expressed sequence tag data base and the public expressed sequence tag data bases, we were able to assemble two other muscle transcripts that show a high level of identity with FATZ in two different domains. Therefore, FATZ may be the first member of a small family of novel muscle proteins
The Muon Identification Procedure of the LHCb Experiment for the First Data
We present a refined muon identification algorithm for the LHCb experiment suitable for the first period of data taking. The new algorithm is robust against possible inefficiencies of the Muon Detector and takes properly into account the momentum dependence, so it can be tuned with calibration samples and exported to signal samples with different momentum spectra without large corrections. The average performance depends on the momentum spectrum of the analyzed sample: with the current simulation we find for tracks with p > 3 GeV/c in a generic b-inclusive sample a muon identification efficiency of 90 % for a misidentification rate of hadrons and electrons of ~2.4 % (~ 1 % excluding pi's and K's decays in flight). Additional rejection power can be obtained by combining in a proper way the informations coming from all the other subdetectors in a global Likelihood: in this case for a muon identification efficiency of 90 % we find a misidentification rate of ~1.8 % (~ 0.8 % excluding pi's and K's decays in flight
Host range of mammalian orthoreovirus type 3 widening to alpine chamois
Mammalian orthoreoviruses (MRV) type 3 have been recently identified in human and several animal hosts, highlighting the apparent lack of species barriers. Here we report the identification and genetic characterization of MRVs strains in alpine chamois, one of the most abundant wild ungulate in the Alps. Serological survey was also performed by MRV neutralization test in chamois population during five consecutive years (2008-2012). Three novel MRVs were isolated on cell culture from chamois lung tissues. No respiratory or other clinical symptoms neither lung macroscopic lesions were observed in the chamois population. MRV strains were classified as MRV-3 within the lineage III, based on S1 phylogeny, and were closely related to Italian strains identified in dog, bat and diarrheic pig. The full genome sequence was obtained by next-generation sequencing and phylogenetic analyses showed that other segments were more similar to MRVs of different geographic locations, serotypes and hosts, including human, highlighting genome reassortment and lack of host specific barriers. By using serum neutralization test, a high prevalence of MRV-3 antibodies was observed in chamois population throughout the monitored period, showing an endemic level of infection and suggesting a self-maintenance of MRV and/or a continuous spill-over of infection from other animal species
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