Autonomous University of Hidalgo
Autonomous University of Hidalgo
Salem A.Z.M.,Mexico State University |
Elghandour M.M.M.,Mexico State University |
Berasain M.A.M.,Mexico State University |
Jimenez F.J.P.,Autonomous University of Hidalgo |
And 4 more authors.
Journal of Integrative Agriculture | Year: 2015
An in vitro gas production (GP) technique was used to investigate the effects of combining different doses of Salix babylonica extract (SB) with exogenous fibrolytic enzymes (EZ) based on xylanase (X) and cellulase (C), or their mixture (XC; 1:1 v/v) on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture (50:50, w/w) as substrate. Four levels of SB (0, 0.6, 1.2 and 1.8 mL g-1 dry matter (DM)) and four supplemental styles of EZ (1 μL g-1 DM; control (no enzymes), X, C and XC (1:1, v/v) were used in a 4×4 factorial arrangement. In vitro GP (mL g-1 DM) were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability (DMD). Fermentation parameters, such as the 24 h gas yield (GY24), in vitro organic matter digestibility (OMD), metabolizable energy (ME), short chain fatty acid concentrations (SCFA), and microbial crude protein production (MCP) were also estimated. Results indicated that there was a SB×EZ interaction (P<0.0001) for the asymptotic gas production (b), the rate of gas production (c), GP from 6 to 72 h, GP2 (P=0.0095), and GP4 (P=0.02). The SB and different combination of enzymes supplementation influenced (P<0.001) in vitro GP parameters after 12 h of incubation; the highest doses of SB (i.e., 1.8 mL g-1 DM), in the absence of any EZ, quadratically increased (P<0.05) the initial delay before GP begins (L) and GP at different incubation times, with lowering b (quadratic effect, P<0.0001) and c (quadratic effect, P<0.0001; linear effect, P=0.0018). The GP was the lowest (P<0.05) when the highest SB level was combined with cellulose. There were SB×EZ interactions (P<0.001) for OMD, ME, the partitioning factor at 72 h of incubation (PF72), GY24, SCFA, MCP (P=0.0143), and pH (P=0.0008). The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g-1 DM were higher (P<0.001) than the other treatments, however, PF72 was lower (quadratic effect, P=0.0194) than the other levels. Both C and X had no effect (P>on OMD, pH, ME, GY24, SCFA and MP. The combination of SB with EZ increased (P<0.001) OMD, ME, SCFA, PF72 and GP24, whereas there was no impact on pH. It could be concluded that addition of SB extract, C, and X effectively improved the in vitro rumen fermentation, and the combination of enzyme with SB extract at the level of 1.2 mL g-1 was more effective than the other treatments. © 2015 Chinese Academy of Agricultural Sciences.
Chavez D.,Mexican Center for Research and Advanced Studies |
Rodriguez E.,Mexican Center for Research and Advanced Studies |
Rodriguez E.,Autonomous University of Hidalgo |
Jimenez I.,Mexican Center for Research and Advanced Studies |
Rudomin P.,Mexican Center for Research and Advanced Studies
Journal of Physiology | Year: 2012
Simultaneous recordings of cord dorsum potentials along the lumbo-sacral spinal cord of the anaesthetized cat revealed the occurrence of spontaneous synchronous negative (n) and negative-positive (np) cord dorsum potentials (CDPs). The npCDPs, unlike the nCDPs, appeared preferentially associated with spontaneous negative dorsal root potentials (DRPs) resulting from primary afferent depolarization. Spontaneous npCDPs recorded in preparations with intact neuroaxis or after spinalization often showed a higher correlation than the nCDPs recorded from the same pair of segments. The acute section of the sural and superficial peroneal nerves further increased the correlation between paired sets of npCDPs and reduced the correlation between the nCDPs recorded from the same pair of segments. It is concluded that the spontaneous nCDPs and npCDPs are produced by the activation of interconnected sets of dorsal horn neurones located in Rexed's laminae III-IV and bilaterally distributed along the lumbo-sacral spinal cord. Under conditions of low synchronization in the activity of this network of neurones there would be a preferential activation of the intermediate nucleus interneurones mediating Ib non-reciprocal postsynaptic inhibition. Increased synchronization in the spontaneous activity of this ensemble of dorsal horn neurones would recruit the interneurones mediating primary afferent depolarization and presynaptic inhibition and, at the same time, reduce the activation of pathways mediating Ib postsynaptic inhibition. Central control of the synchronization in the spontaneous activity of dorsal horn neurones and its modulation by cutaneous inputs is envisaged as an effective mechanism for the selection of alternative inhibitory pathways during the execution of specific motor or sensory tasks. © 2012 The Authors. The Journal of Physiology © 2012 The Physiological Society.
Tirado-Torres D.,Autonomous University of Hidalgo |
Acevedo-Sandoval O.,Autonomous University of Hidalgo |
Rodriguez-Pastrana B.R.,Autonomous University of Hidalgo |
Gayosso-Canales M.,Autonomous University of Hidalgo
Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering | Year: 2017
This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica, Veracruz, Mexico. The identified bacteria were Ochrobactrum intermedium, Pandoraea pnomenusa and Ochrobactrum sp., but SA2-09 strain was not identified. The ability of the isolates to degrade polycyclic aromatic hydrocarbons (PAHs) was evaluated at 31.61 and 54.52 mg/kg PAHs in soil, when used as crude oil in soil microcosm during 80 days of incubation at 30°C. The results demonstrated that O. intermedium biodegraded many PAHs, including the high molecular weight (HMW) PAHs fluoranthene (100% equivalent 0.24 mg/kg), benzo [b] fluoranthene (81.8% equal 0.18 mg/kg), Benzo[a]pyrene (87.0%, 0.20 mg/kg) and Benzo[g,h,i]perylene (52.7%, 0.39 mg/kg). P. pnomenusa had a degradation profile of HMW PAHs, which was similar to O. intermedium, while Ochrobactrum sp. and the strain SA-09 exhibited lower degradation rates of HMW. © 2017 Taylor & Francis Group, LLC
Castaneda-Miranda A.,Autonomous University of Hidalgo |
Castano V.M.,National Autonomous University of Mexico
Journal of Electronic Materials | Year: 2017
The fluorescent decay of the levels 3H4 and 3F4 of Tm3+ in LiYF4 crystals doped with Tb3+ and Eu3+ was mathematically modeled to estimate the optimal doping levels to maximize the laser emission at 1.5 μm of the transition 3H4 → 3F4. The analysis is carried out both through the solution of the master energy transfer equations that govern the non-radiative processes of energy and Monte Carlo simulations. The analysis is improved with the experimental data of the fluorescence decay to include quadrupole and dipole interactions simultaneously. The importance of considering these interactions is that the optimal concentrations of impurities predicted for these luminescent systems are lower than those reported with the use of traditional models. © 2017 The Minerals, Metals & Materials Society
Rodriguez E.E.,CINVESTAV |
Rodriguez E.E.,Autonomous University of Hidalgo |
Hernandez-Lemus E.,National Institute of Genomic Medicine |
Hernandez-Lemus E.,National Autonomous University of Mexico |
And 3 more authors.
PLoS ONE | Year: 2011
The analysis of the interaction and synchronization of relatively large ensembles of neurons is fundamental for the understanding of complex functions of the nervous system. It is known that the temporal synchronization of neural ensembles is involved in the generation of specific motor, sensory or cognitive processes. Also, the intersegmental coherence of spinal spontaneous activity may indicate the existence of synaptic neural pathways between different pairs of lumbar segments. In this study we present a multichannel version of the detrended fluctuation analysis method (mDFA) to analyze the correlation dynamics of spontaneous spinal activity (SSA) from time series analysis. This method together with the classical detrended fluctuation analysis (DFA) were used to find out whether the SSA recorded in one or several segments in the spinal cord of the anesthetized cat occurs either in a random or in an organized manner. Our results are consistent with a non-random organization of the sets of neurons involved in the generation of spontaneous cord dorsum potentials (CDPs) recorded either from one lumbar segment (DFA-α mean = 1.04±0.09) or simultaneously from several lumbar segments (mDFA-α mean = 1.01±0.06), where α>0.5 indicates randomness while α>0.5 indicates long-term correlations. To test the sensitivity of the mDFA method we also examined the effects of small spinal lesions aimed to partially interrupt connectivity between neighboring lumbosacral segments. We found that the synchronization and correlation between the CDPs recorded from the L5 and L6 segments in both sides of the spinal cord were reduced when a lesion comprising the left dorsal quadrant was performed between the segments L5 and L6 (mDFA-α = 0.992 as compared to initial conditions mDFA-α = 1.186). The synchronization and correlation were reduced even further after a similar additional right spinal lesion (mDFA-α = 0.924). In contrast to the classical methods, such as correlation and coherence quantification that define a relation between two sets of data, the mDFA method properly reveals the synchronization of multiple groups of neurons in several segments of the spinal cord. This method is envisaged as a useful tool to characterize the structure of higher order ensembles of cord dorsum spontaneous potentials after spinal cord or peripheral nerve lesions. © 2011 Rodríguez et al.
Navar J.,Natural Resource Management |
Lizarraga-Mendiola L.,Autonomous University of Hidalgo
Geofisica Internacional | Year: 2013
Global warming is likely modifying the hydrological cycle of forested watersheds. This report set as objectives to: a) assess the hydrological variables interception loss, I, potential and actual evapotranspiration, E, Et, runoff, Q, and soil moisture content, θ; b) evaluate whether these variables are presenting consistent trends or oscillations that can be associated to global warming or climate variability; and c) relate θ to the number of wildfires and the burned area in Durango, Mexico. A mass balance approach estimated daily variables of the water cycle using sub-models for I and Et to calculate Q and θ for a time series from 1945 to 2007. Regression and auto-regressive and moving averaging (ARIMA) techniques evaluated the statistical significance of trends. The cumulative standardized z value magnified and ARIMA models projected statistically similar monthly and annual time series data of all variables of the water cycle. Regression analysis and ARIMA models showed monthly and annual P, I, E, and Et, Q, and θ do not follow consistent up or downward linear tendencies over time with statistical significance; they rather follow oscillations that could be adequately predicted by ARIMA models (r2 ≥ 0.70). There was a consistent statistical association (p ≤ 0.05) of θ with the number of wildfires and the area burned regardless of the different spatial scales used in evaluating these variables. The analysis shows seasonal variability is increasing over time as magnifying pulses of dryness and wetness, which may be the response of the hydrological cycle to climate change. Further research must center on using longer time series data, testing seasonal variability with additional statistical analysis, and incorporating new variables in the analysis.
Perez-Martinez R.,Autonomous University of Hidalgo |
Esteva L.,National Autonomous University of Mexico
Journal of Earthquake Engineering | Year: 2012
A study is presented about the influence of infill masonry panels on the life-cycle expected performance functions of multi-story reinforced concrete frames exposed to severe seismic hazard conditions. Quantitative information is presented about present values of expected performance functions of a group of five-story systems located at a firm ground site. The group includes a bare frame system, designed in accordance with the applicable seismic design regulations, and a number of systems obtained by inserting several reinforced or unreinforced masonry wall panels, introduced with the aim of improving the expected seismic performance of the original system. © 2012 Copyright A. S. Elnashai & N. N. Ambraseys.
Mendoza-Espinosa D.,Metropolitan Autonomous University |
Negron-Silva G.E.,Metropolitan Autonomous University |
Angeles-Beltran D.,Metropolitan Autonomous University |
Alvarez-Hernandez A.,Autonomous University of Hidalgo |
And 2 more authors.
Dalton Transactions | Year: 2014
The preparation and characterization of four new copper(ii) complexes supported by click generated mixed NN, NO, and NS 1,2,3-triazoles are reported. The four complexes display a 1:2 copper/ligand ratio and give monomeric units in the solid state. Crystal structures demonstrate that depending on the flexibility of the ligand NX (X = O, N, S) pendant arm, the coordination environment around the metal center can feature square planar or octahedral geometries. All four complexes are catalytically active at room temperature in a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction using sodium ascorbate as a reducing agent and water-ethanol as a solvent mixture. Complex 8 supported by the NS ligand displayed the best catalytic performance of the series allowing for the easy and high yielding preparation of a variety of mono-, bis- and tris-1,2,3-triazoles under low catalyst loadings. © 2014 the Partner Organisations.
Vidaurre D.,Technical University of Madrid |
Rodriguez E.E.,National Polytechnic Institute of Mexico |
Rodriguez E.E.,Autonomous University of Hidalgo |
Bielza C.,Technical University of Madrid |
And 2 more authors.
Journal of Neural Engineering | Year: 2012
In the spinal cord of the anesthetized cat, spontaneous cord dorsum potentials (CDPs) appear synchronously along the lumbo-sacral segments. These CDPs have different shapes and magnitudes. Previous work has indicated that some CDPs appear to be specially associated with the activation of spinal pathways that lead to primary afferent depolarization and presynaptic inhibition. Visual detection and classification of these CDPs provides relevant information on the functional organization of the neural networks involved in the control of sensory information and allows the characterization of the changes produced by acute nerve and spinal lesions. We now present a novel feature extraction approach for signal classification, applied to CDP detection. The method is based on an intuitive procedure. We first remove by convolution the noise from the CDPs recorded in each given spinal segment. Then, we assign a coefficient for each main local maximum of the signal using its amplitude and distance to the most important maximum of the signal. These coefficients will be the input for the subsequent classification algorithm. In particular, we employ gradient boosting classification trees. This combination of approaches allows a faster and more accurate discrimination of CDPs than is obtained by other methods.
De La Cerda-Pedro J.E.,Autonomous University of Hidalgo |
Amador-Sanchez Y.A.,Autonomous University of Hidalgo |
Cortes-Hernandez M.,Autonomous University of Hidalgo |
Perez-Perez J.,Autonomous University of Hidalgo |
And 2 more authors.
Heterocycles | Year: 2014
Cuprous cyanide, generated in situ from cupric sulfate and sodium cyanide, catalyzes the synthesis of 1,4-disubstituted-1,2,3-triazoles from in situ generated alkyl azides and mono-substituted alkynes in a one pot room temperature process. © 2014 The Japan Institute of Heterocyclic Chemistry.