75 research outputs found
Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant
Jet event rates in deep inelastic ep scattering at HERA are investigated
applying the modified JADE jet algorithm. The analysis uses data taken with the
H1 detector in 1994 and 1995. The data are corrected for detector and
hadronization effects and then compared with perturbative QCD predictions using
next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2)
is determined evaluating the jet event rates. Values of alpha_S(Q^2) are
extracted in four different bins of the negative squared momentum
transfer~\qq in the range from 40 GeV2 to 4000 GeV2. A combined fit of the
renormalization group equation to these several alpha_S(Q^2) values results in
alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).Comment: 17 pages, 4 figures, 3 tables, this version to appear in Eur. Phys.
J.; it replaces first posted hep-ex/9807019 which had incorrect figure 4
Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA
Deep--inelastic scattering events with a leading baryon have been detected by
the H1 experiment at HERA using a forward proton spectrometer and a forward
neutron calorimeter. Semi--inclusive cross sections have been measured in the
kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T
<= MeV, for events with a final state proton with energy 580 <= E' <= 740 GeV,
or a neutron with energy E' >= 160 GeV. The measurements are used to test
production models and factorization hypotheses. A Regge model of leading baryon
production which consists of pion, pomeron and secondary reggeon exchanges
gives an acceptable description of both semi-inclusive cross sections in the
region 0.7 <= E'/E_p <= 0.9, where E_p is the proton beam energy. The leading
neutron data are used to estimate for the first time the structure function of
the pion at small Bjorken--x.Comment: 30 pages, 9 figures, 2 tables, submitted to Eur. Phys.
Jets and energy flow in photon-proton collisions at HERA
Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to \overline{p}p data and QCD calculations. The comparisons show that the \gamma p events can be consistently described by QCD models including -- in addition to the primary hard scattering process -- interactions between the two beam remnants. The differential jet cross sections d\sigma/dE_T^{jet} and d\sigma/d\eta^{jet} are measured
Разработка интерактивной моделирующей системы технологии низкотемпературной сепарации газа
We present a study of J ψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The J ψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → J ψ X) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ W γp ≤ 180 GeV and Q 2 ≲ 4 GeV 2 . Using the flux of quasi-real photons with Q 2 ≲ 4 GeV 2 , a total production cross section of σ ( γp → J / ψX ) = (56±13±14) nb is derived at an average W γp =90 GeV. The distribution of the squared momentum transfer t from the proton to the J ψ can be fitted using an exponential exp(− b ∥ t ∥) below a ∥ t ∥ of 0.75 GeV 2 yielding a slope parameter of b = (4.7±1.9) GeV −2
25th annual computational neuroscience meeting: CNS-2016
The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong
Developing consensus on important factors associated with lower limb prosthetic prescription and use
Purpose: There is an ongoing concern in lower limb prosthetic rehabilitation with underuse and nonuse of prosthetic technology. The aim of this study was to gather expert opinion on the most important outcomes, predictors and facilitators of lower limb prosthetic prescription and use, with a long-term goal of improving satisfaction with prosthetic technology. Method: An electronic Delphi study was conducted using an expert panel of 21 service providers and users and was undertaken over three iterations. Results: The process resulted in the identification of 13 outcomes, 19 predictor and 34 facilitator factors. Conclusions: Psychosocial factors related to service provision and prosthetic use have not been widely recognized or incorporated into clinical practice. We highlight the need for creating standardized measures that incorporate psychosocial factors and that can contribute to a broadly applicable evidence base for optimal prosthetic prescription
Identifying successful outcomes and important factors to consider in upper limb amputation rehabilitation: an international web-based Delphi survey
Purpose: To identify and gain agreement on successful outcomes of and important factors to consider in rehabilitation following upper limb absence (ULA). Method: Fifty-three participants consisting of multi-disciplinary rehabilitation professionals, and individuals with ULA were invited to complete a three-round modified Delphi iterative survey. Following three Delphi questionnaire rounds, participants clarified the definitions of success in three areas (prosthesis use, activities and participation and self-image). In addition, participants identified and agreed the important factors to consider in rehabilitation after ULA. Results: Results showed that participants reached agreement (having a SD <1) over the three rounds on 78 out of 81 rated items. Of these, 54 rated items were “accepted” as important by panel members (mean score of 4 on a five-point Likert scale). Twenty-four items were rejected. Only three rated items had not reached agreement by the third round. Conclusions: Clarification of successful outcomes and factors that should be taken into consideration in a patient’s rehabilitation allows a clearer evaluation of what should be the focus of rehabilitation. The findings from the Delphi study can help form the basis for a screening tool for clinicians to be able to identify areas of concern and subsequent treatment for a patient in their care
Identifying successful outcomes and important factors to consider in upper limb amputation rehabilitation: an international web-based Delphi survey
Purpose: To identify and gain agreement on successful outcomes of and important factors to consider in rehabilitation following upper limb absence (ULA). Method: Fifty-three participants consisting of multi-disciplinary rehabilitation professionals, and individuals with ULA were invited to complete a three-round modified Delphi iterative survey. Following three Delphi questionnaire rounds, participants clarified the definitions of success in three areas (prosthesis use, activities and participation and self-image). In addition, participants identified and agreed the important factors to consider in rehabilitation after ULA. Results: Results showed that participants reached agreement (having a SD <1) over the three rounds on 78 out of 81 rated items. Of these, 54 rated items were “accepted” as important by panel members (mean score of 4 on a five-point Likert scale). Twenty-four items were rejected. Only three rated items had not reached agreement by the third round. Conclusions: Clarification of successful outcomes and factors that should be taken into consideration in a patient’s rehabilitation allows a clearer evaluation of what should be the focus of rehabilitation. The findings from the Delphi study can help form the basis for a screening tool for clinicians to be able to identify areas of concern and subsequent treatment for a patient in their care
Identifying successful outcomes and important factors to consider in upper limb amputation rehabilitation: an international web-based Delphi survey
Purpose: To identify and gain agreement on successful outcomes of and important factors to consider in rehabilitation following upper limb absence (ULA). Method: Fifty-three participants consisting of multi-disciplinary rehabilitation professionals, and individuals with ULA were invited to complete a three-round modified Delphi iterative survey. Following three Delphi questionnaire rounds, participants clarified the definitions of success in three areas (prosthesis use, activities and participation and self-image). In addition, participants identified and agreed the important factors to consider in rehabilitation after ULA. Results: Results showed that participants reached agreement (having a SD <1) over the three rounds on 78 out of 81 rated items. Of these, 54 rated items were “accepted” as important by panel members (mean score of 4 on a five-point Likert scale). Twenty-four items were rejected. Only three rated items had not reached agreement by the third round. Conclusions: Clarification of successful outcomes and factors that should be taken into consideration in a patient’s rehabilitation allows a clearer evaluation of what should be the focus of rehabilitation. The findings from the Delphi study can help form the basis for a screening tool for clinicians to be able to identify areas of concern and subsequent treatment for a patient in their care
- …