725 research outputs found
Interação Entre Xilanase, Glicose Oxidase E åcido Ascórbico Na Qualidade Tecnológica De Pão Elaborado Com Farinha Do Trigo Integral
This study aimed to verify the performance of xylanase and its interaction with oxidants agents (glucose oxidase and ascorbic acid) on the quality of whole wheat bread. The experiment was based on a central composite rotational design and the Response Surface Methodology was used to analyze the results. None of the xylanase, glucose oxidase or ascorbic acid concentrations within the studied range led to a significant difference in the specific volume. The highest moisture content and the lowest firmness values were reported in the bread with lower and intermediate levels of xylanase and larger amounts of glucose oxidase and ascorbic acid. This effect was observed mainly at the end of the storage period. A minimum amount of xylanase (from 33 to 63 EDX kg-1 flour) showed to be essential for obtaining best results. Levels of ascorbic acid above 63mg kg-1 and glucose oxidase above 91 SRU kg-1 proved to be necessary to offer the beneficial effect of xylanase. © 2016, Universidade Federal de Santa Maria. All rights reserved.46122249225
Fragmentation Function and Hadronic Production of the Heavy Supersymmetric Hadrons
The light top-squark \sto may be the lightest squark and its lifetime may
be `long enough' in a kind of SUSY models which have not been ruled out yet
experimentally, so colorless `supersymmetric hadrons (superhadrons)' (\sto
\bar{q}) ( is a quark except -quark) may be formed as long as the light
top-squark \sto can be produced. Fragmentation function of \sto to heavy
`supersymmetric hadrons (superhadrons)' (\sto \bar{Q}) ( or
) and the hadronic production of the superhadrons are investigated
quantitatively. The fragmentation function is calculated precisely. Due to the
difference in spin of the SUSY component, the asymptotic behavior of the
fragmentation function is different from those of the existent ones. The
fragmentation function is also applied to compute the production of heavy
superhadrons at hadronic colliders Tevatron and LHC under the so-called
fragmentation approach. The resultant cross-section for the heavy superhadrons
is too small to observe at Tevatron, but great enough at LHC, even when all the
relevant parameters in the SUSY models are taken within the favored region for
the heavy superhadrons. The production of `light superhadrons' (\sto \bar{q})
() is also roughly estimated. It is pointed out that the production
cross-sections of the light superhadrons (\sto \bar{q}) may be much greater
than those of the heavy superhadrons, so that even at Tevatron the light
superhadrons may be produced in great quantities.Comment: 20 pages, 9 figure
Hadronic EDMs, the Weinberg Operator, and Light Gluinos
We re-examine questions concerning the contribution of the three-gluon
Weinberg operator to the electric dipole moment of the neutron, and provide
several QCD sum rule-based arguments that the result is smaller than - but
nevertheless consistent with - estimates which invoke naive dimensional
analysis. We also point out a regime of the MSSM parameter space with light
gluinos for which this operator provides the dominant contribution to the
neutron electric dipole moment due to enhancement via the dimension five color
electric dipole moment of the gluino.Comment: 6 pages, RevTeX, 3 figures; v2: references added; v3: typos
corrected, to appear in Phys. Rev.
Photoproduction in Scattering
We investigate the + c + photoproduction in
collision at the LEP II energy. The physical motivations for this study are: 1)
such next-to-leading order(NLO) process was not considered in previous
investigations of photoproduction in interaction, and it is
worthwhile to do so in order to make sound predictions for experimental
comparison; 2) from recent Belle experiment results, the process with same
final states at the factory has a theoretically yet unexplainable large
fraction; hence it is interesting to see what may happen at other colliders; 3)
the existing LEP data are marginal in observing such process, and at the planed
Linear Colliders(LCs) this process can be measured with high accuracy; 4) it is
necessary to take this process into consideration in the aim of elucidating the
quarkonium production mechanism, especially in testing the universality of
NRQCD nonperturbative matrix elements via photoproduction in
electron-position collisions.Comment: 15 pages, 3 figure
Boost-Invariant Running Couplings in Effective Hamiltonians
We apply a boost-invariant similarity renormalization group procedure to a
light-front Hamiltonian of a scalar field phi of bare mass mu and interaction
term g phi^3 in 6 dimensions using 3rd order perturbative expansion in powers
of the coupling constant g. The initial Hamiltonian is regulated using momentum
dependent factors that approach 1 when a cutoff parameter Delta tends to
infinity. The similarity flow of corresponding effective Hamiltonians is
integrated analytically and two counterterms depending on Delta are obtained in
the initial Hamiltonian: a change in mu and a change of g. In addition, the
interaction vertex requires a Delta-independent counterterm that contains a
boost invariant function of momenta of particles participating in the
interaction. The resulting effective Hamiltonians contain a running coupling
constant that exhibits asymptotic freedom. The evolution of the coupling with
changing width of effective Hamiltonians agrees with results obtained using
Feynman diagrams and dimensional regularization when one identifies the
renormalization scale with the width. The effective light-front Schroedinger
equation is equally valid in a whole class of moving frames of reference
including the infinite momentum frame. Therefore, the calculation described
here provides an interesting pattern one can attempt to follow in the case of
Hamiltonians applicable in particle physics.Comment: 24 pages, LaTeX, included discussion of finite x-dependent
counterterm
Factor copula models for item response data
Factor or conditional independence models based on copulas are proposed for multivariate discrete data such as item responses. The factor copula models have interpretations of latent maxima/minima (in comparison with latent means) and can lead to more probability in the joint upper or lower tail compared with factor models based on the discretized multivariate normal distribution (or multidimensional normal ogive model). Details on maximum likelihood estimation of parameters for the factor copula model are given, as well as analysis of the behavior of the log-likelihood. Our general methodology is illustrated with several item response data sets, and it is shown that there is a substantial improvement on existing models both conceptually and in fit to data
Inelastic production in polarized photon-hadron collisions
Presented here is a calculation of inelastic production in polarized
photon-hadron collisions under the framework of NRQCD factorization formalism.
We consider the photoproduction of \jpsi in the energy range relevant to
HERA. The Weizs\"acker-Williams approximation is adopted in the evaluation of
the cross sections for collisions. We found that this process can give
another independent test for the color-octet mechanism, and the different
features for the two color-octet processes may provide further informations on
the mechanism for inelastic \jpsi photoproduction. And the discrepancy on the
production asymmetry between various sets of polarized gluon distribution
functions is also found to be distinctive.Comment: 14pages, 6 PS figure
Interaction between xylanase, glucose oxidase and ascorbic acid on the technological quality of whole wheat bread
Minimal model of strategy switching in the plus-maze navigation task
International audiencePrefrontal cortex (PFC) has been implicated in the ability to switch behavioral strategies in response to changes in reward contingencies. A recent experimental study has shown that separate subpopulations of neurons in the prefrontal cortex were activated when rats switched between allocentric place strategies and egocentric response strategies in the plus maze. In this paper we propose a simple neural-network model of strategy switching, in which the learning of the two strategies as well as learning to select between those strategies is governed by the same temporal-difference (TD) learning algorithm. We show that the model reproduces the experimental data on both behavioral and neural levels. On the basis of our results we derive testable prediction concerning a spatial dynamics of the phasic dopamine signal in the PFC, which is thought to encode reward-prediction error in the TD-learning theory
Enhancing the Social Capital of Learning Communities by Using an Ad Hoc Transient Communities Service
Fetter, S., Berlanga, A. J., & Sloep, P. B. (2009). Enhancing the Social Capital of Learning Communities by Using an Ad Hoc Transient Communities Service. In M. Spaniol, Q. Li, R. Klamma & R. W. H. Lau (Eds.), Proceedings of the 8th International Conference Advances in Web-based Learning - ICWL 2009 (pp. 150-157). August, 19-21, 2009, Aachen, Germany. Lecture Notes in Computer Science 5686; Berlin, Heidelberg: Springer-Verlag.In online learning, communities can help to enhance learning. However, because of the dynamic nature of communities, attaining and sustaining these communities can be difficult. One aspect that has an influence on, and is influenced by these dynamics is the social capital of a community. Features of social capital are the social network structure, the sense of belonging and, the support received and provided. It is hypothesized that these features can be improved by using Ad Hoc Transient Communities (AHTCs). Through an AHTC learners are brought together for a specific, learning-related goal (âad hocâ) and for only a limited amount of time (âtransienceâ). To test whether the use of AHTCs has a positive influence on the social capital, a learner support service which enables the use of AHTCs is proposed. Furthermore, requirements, pre-requisites, and future research are discussed.The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org
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