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PubMed | Avenida University 3000 and Agriculture and Agri Food Canada
Type: | Journal: Meat science | Year: 2015

To assess the effect of an allostatic modulator (AM) on stress blood indicators and meat quality traits, the feed of 80 non-castrated 18-20 month-old bulls was supplemented with 10 g/day of an AM for 30 days before slaughter. Another 80 bulls served as control animals. The AM was comprised of ascorbic acid, acetoxybenzoic acid and sodium and potassium chloride. Blood samples were taken at slaughter for analyses of hematocrit value, erythrocyte and leukocyte counts, and glucose, lactate and cortisol concentrations. Post-mortem measures of meat color and pH were made at 24h and color, shear force and cooking loss on meat from 20 animals at 28 days. The AM supplementation resulted in lower hematocrit value, erythrocyte count and glucose level (P<0.05), higher a* (P<0.0001) and b* (P<0.0001) at 24h and lower b* (P<0.05) at 28 days. Thus AM treatment improved some stress blood indicators and meat color and therefore merits further investigation.

Pre-service and in-service teachers' training has been the focus of several programs developed in Brazil. Among them, the called "Institutional Program of Teaching Training Scholarship" (in Portuguese "Programa Institucional de Bolsa de Iniciação à Docência-pibid") is really remarkable, which has as its main goal improving the academic actions for pre-service teachers training. This study has the aim to analyze the transformation of knowledge and beliefs of future chemistry teachers - scholarship holders of pibid - on the topic "Nature of Matter", to make it comprehensible to high school students. That is, documenting and discussing the development of Pedagogical Content Knowledge (pck) of each one of these scholars during the design and application of a didactic unit on the topic. The research was done with four scholars of the Program, students of a chemistry career in a public Brazilian University. Two elements were considered to show the improvements of the participants pck: an initial interview in which the eight questions of the Content Representation of Loughran etal. (2004) were posed, and afterwards the Didactic Unit produced and applied to high school students. Main results show the appropriation for students of enough knowledge for the adequate performance in the classroom, it stimulated by the actions pibid contemplates. © Universidad Nacional Autónoma de México.

Martinez-Mayorga K.,Avenida University 3000 | Peppard T.L.,Robertet Flavors Inc. | Lopez-Vallejo F.,Torrey Pines Institute for Molecular Studies | Yongye A.B.,Torrey Pines Institute for Molecular Studies | Medina-Franco J.L.,Torrey Pines Institute for Molecular Studies
Journal of Agricultural and Food Chemistry | Year: 2013

Bioactive food compounds can be both therapeutically and nutritionally relevant. Screening strategies are widely employed to identify bioactive compounds from edible plants. Flavor additives contained in the so-called FEMA GRAS (generally recognized as safe) list of approved flavoring ingredients is an additional source of potentially bioactive compounds. This work used the principles of molecular similarity to identify compounds with potential mood-modulating properties. The ability of certain GRAS molecules to inhibit histone deacetylase-1 (HDAC1), proposed as an important player in mood modulation, was assayed. Two GRAS chemicals were identified as HDAC1 inhibitors in the micromolar range, results similar to what was observed for the structurally related mood prescription drug valproic acid. Additional studies on bioavailability, toxicity at higher concentrations, and off-target effects are warranted. The methodology described in this work could be employed to identify potentially bioactive flavor chemicals present in the FEMA GRAS list. © 2013 American Chemical Society.

Garcia Y.H.,National Polytechnic Institute of Mexico | Gonzalez-Hernandez J.,Avenida University 3000
Kybernetika | Year: 2016

This work analyzes a discrete-time Markov Control Model (MCM) on Borel spaces when the performance index is the expected total discounted cost. This criterion admits unbounded costs. It is assumed that the discount rate in any period is obtained by using recursive functions and a known initial discount rate. The classic dynamic programming method for finite-horizon case is verified. Under slight conditions, the existence of deterministic non-stationary optimal policies for infinite-horizon case is proven. Also, to find deterministic non-stationary ϵ-optimal policies, the value-iteration method is used. To illustrate an example of recursive functions that generate discount rates, we consider the expected values of stochastic processes, which are solutions of certain class of Stochastic Differential Equations (SDE) between consecutive periods, when the initial condition is the previous discount rate. Finally, the consumptioninvestment problem and the discount linear-quadratic problem are presented as examples; in both cases, the discount rates are obtained using a SDE, similar to the Vasicek short-rate model.

Hernandez-Ortiz S.,Universidad Michoacana de San Nicolás de Hidalgo | Murguia G.,Avenida University 3000 | Raya A.,Universidad Michoacana de San Nicolás de Hidalgo
Journal of Physics Condensed Matter | Year: 2012

Using irreducible and reducible representations of the Dirac matrices, we study the two- and four-component quantum mechanical supersymmetric (SUSY) theories for ultrarelativistic fermions in (2+1) dimensions (graphinos) in a background uniform magnetic field perpendicular to their plane of motion. We then consider ordinary and parity-violating mass terms and identify the former as a soft SUSY breaking term and the latter as the hard SUSY breaking one. © 2012 IOP Publishing Ltd.

Moller A.,Avenida University 3000 | Hansen A.M.,Instituto Mexicano Of Tecnologia Del Agua
Applied Geochemistry | Year: 2012

A zero-dimensional model for the environmental fate of ethylenethiourea (ETU) in soils was formulated. The relevant physicochemical transformation processes were derived from published data, and their dynamics analyzed. Corresponding kinetic submodels for sorption, photodegradation, abiotic oxidation and biodegradation were then developed based on assumptions on the dominant process mechanisms. These submodels, and the overall model of biotic degradation in soil, were applied to literature data with determination coefficients of R 2>0.9, validating the assumed process dynamics. © 2012 Elsevier Ltd.

Chavez O.,Avenida University 3000 | Mendez F.,Avenida University 3000
Applied Thermal Engineering | Year: 2011

In this work, we analyze theoretically the conjugate heat conductive mechanism resulting from an alternating electrical current that flows continuously in an aluminum conductor steel reinforced (ACSR), taking into account that the electric resistivity is dependent on temperature. This last consideration conducts us to analyze simultaneously the electrical and thermal effects in both conductor materials. In this manner, we need to solve a double conjugate thermo-electric model. In addition, the presence of skin effect causes significant radial temperature differences, since for high frequencies the electric current tends to flow over the surface of the conductor and therefore, the heat generation produced by Joule effect, is no uniform. Based on an equation for predicting the alternating current density and described by a non-linear wave equation, numerical solutions for the above equation together with the heat conduction equation are possible to predict the current density and the temperature profiles. In particular, the influence of the environmental convective conditions, the skin effect and the influence of the variable resistivity on current density and temperature fields, are clarified. The above effects show that the electrical and thermal operation of the electrical networks can be subject to several factors that made, in general, more difficult the full utilization of the electrical transport. © 2011 Elsevier Ltd.

Ortega-Zempoalteca R.,Avenida University 3000 | Valenzuela R.,Avenida University 3000 | Betancourt I.,Avenida University 3000
Physica Status Solidi (C) Current Topics in Solid State Physics | Year: 2011

Bulk metallic glasses of nominal composition Nd60Fe30Al10 were prepared by copper mold casting in the form of rods of 3 mm in diameter and 50 mm in length. Preparation conditions were varied to assess the effects of the injection distance and the injection pressure of the melt. In order to determine their microstructure, disk-shaped samples were obtained from different cut zones along the axis rod. A non-homogeneous phase distribution was observed, which resulted from the heat transfer regime during the cooling of the melt in the copper mold. As expected, the nature, distribution and volumetric fraction of the various phases produced play an important role on the resulting magnetic properties. Among the main observed phases are Fe-rich rod-like crystals, Nd-rich dendritic crystals and a "like-amorphous" matrix. The hard magnetic properties of these materials can be associated with this matrix. In these cooling regimes, the coercive field increases as the cooling rate of the amorphous matrix increases. Hysteresis loops showed a high degree of coupling between phases with different magnetic order. Both the coercive field and the magnetization showed a significant variation along the rod axis; a maximum appeared as a function of the axis length. In order to gather more information about the coupling between the observed phases, δM (or Henkel) plots were obtained, showing an exchange character for interactions. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Velazque-Amado R.M.,Avenida University 3000 | Escamilla-Chimal E.G.,Avenida University 3000 | Fanjul-Moles M.L.,Avenida University 3000
Photochemistry and Photobiology | Year: 2012

It has been proposed that at moderate concentrations, reactive oxygen species (ROS) play an important role as regulatory mediators in signaling processes. Many of the ROS-mediated responses, such as those mediated by the glutathione (GSH) system, protect cells against oxidative stress and reestablish "redox homeostasis." The response to stress is controlled by specific transcription factors, such as hypoxia-inducible factor 1 (HIF-1), which interacts with chaperones such as heat shock proteins (HSP) that stabilize intracellular components. We have reported that the oxidation produced by extreme light cycles was coupled to cellular fluctuations in the production of free radicals and ROS in crayfish. Herein, we investigated whether ROS resulting from light-dark cycles (20:4 LD) with a long photoperiod activated HIF-1α in the putative pacemakers of crayfish. Our results indicate that both the light resulting from equatorial and extreme daily light cycles and the constant darkness-induced HIF-1α and heat shock protein 70 (HSP70) appeared to regulate each other. The interaction between these proteins and the ability of crayfish to shift from the oxidative to glycolytic pathways, thereby synchronizing to extreme illumination conditions and maintaining a rhythmic predictive relationship with the environment, suggest HIF-1 as a key factor in these rhythmic metabolic interactions. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

Escamilla-Chimal E.G.,Avenida University 3000 | Velazquez-Amado R.M.,Avenida University 3000 | Fiordelisio T.,Avenida University 3000 | Fanjul-Moles M.L.,Avenida University 3000
Journal of Experimental Biology | Year: 2010

Although the molecular mechanisms that control circadian rhythms in many animals, particularly in the fly, are well known, molecular and biochemical studies addressing the location and function of the proteins and genes contributing to the cycling of the clock in crayfish Procambarus clarkii are scarce. In this study, we investigated whether three proteins that interact in the feedback loop of the molecular clock described for Drosophila are expressed in the putative circadian pacemakers of crayfish retina, eyestalk and brain and whether their expression cycles in a manner consistent with elements of the circadian clock. Here we identified PER, TIM and CLK immunoreactivity in the cytoplasm and nucleus of cells located in the retina as well as in clusters of cells and neuropils of the optic ganglia, lateral protocerebrum and brain. Brain clusters 6, 10, 9 and 11, in particular, showed Per, Tim and Clk-like immunoreactivity at the perikarya and nucleus, and these antigens colocalized at Zeitgeber time (ZT) 0 and/or ZT 12. A biochemical assay demonstrated circadian functionality of Per, Tim and Clk proteins. Both in the eyestalk and in the brain, these proteins demonstrated apparent daily and circadian rhythms. The presence and colocalization of these clock proteins in the cytoplasm and/or nucleus of several cells of retina, optic lobe and brain, depending on time, as well as their circadian oscillations, suggest interactions between positive and negative transcription factors and clock proteins similar to those forming the feedback loop of the canonical model proposed for different animals. © 2010 The Company of Biologists Ltd.

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