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Ciudad de Villa de Alvarez, Mexico

Trujillo X.,University of Colima | Sanchez-Pastor E.,University of Colima | Andrade F.,Technological Institute of Colima | Huerta M.,University of Colima
Journal of Membrane Biology | Year: 2014

We investigated the effects of cannabinoids on acetylcholine (ACh) or choline contractures in slow skeletal muscle fibers from Rana pipiens. Bundles of cruralis muscle fibers were incubated with the cannabinoid receptor 1 (CB1) agonist, arachidonylcyclopropylamide (ACPA), which diminished the maximum isometric tension by 10 % and the total tension by 5 % of the ACh contracture, and 40 and 22 % of the choline contracture, respectively. Preincubation with the CB1 antagonist, AM281, or with pertussis toxin (PTX) completely blocked the effect of ACPA on the ACh contracture. On the other hand, the decrease in choline contracture by ACPA was only partially blocked by AM281 (~16 % decrease), PTX (20 %), or by dantrolene (~46 %). Our results show that ACPA modulates ACh and choline contractures, and suggest that this effect involves the participation of CB1, the ACh receptor, and -RyR in ACh contractures. For choline contractures, ACPA may also be acting through cannabinoid receptor-independent mechanisms. © 2013 Springer Science+Business Media New York.

Alvarez-Hernandez J.C.,Roque Institute of Technology | Castellanos-Ramos J.Z.,Roque Institute of Technology | Aguirre-Mancilla C.L.,Roque Institute of Technology | Huitron-Ramirez M.V.,Technological Institute of Colima | Camacho-Ferre F.,University of Almeria
Ciencia e Agrotecnologia | Year: 2015

Cucurbita maxima x Cucurbita moschata rootstock are used to prevent infection with Fusarium oxysporum f. sp. niveum in watermelon production; however, this rootstock is not effective against nematode attack. Because of their vigor, the grafted plants can be planted at lower plant densities than the non-grafted plants. The tolerance to Fusarium oxysporum f. sp. niveum and Meloidogyne incognita was assessed in watermelon plants grafted onto a hybrid of Citrullus lanatus cv Robusta or the Cucurbita maxima x Cucurbita moschata cv Super Shintoza rootstocks. The densities of plants were 2083 and 4166 plants ha-1. Non-grafted watermelons were the controls. The Crunchy Red and Sangría watermelon cultivars were used as the scions, it the latter as a pollinator. The experiments were performed for two production cycles in soils infested with Fusarium oxysporum f. sp. niveum and Meloidogyne incognita. The incidence of Fusarium oxysporum f. sp. niveum was significantly greater in the non-grafted than in the grafted plants. The grafted plants presented similar resistance to Fusarium regardless of the rootstock. The root-knot galling index for Meloidogyne incognita was significantly lower in plants grafted onto Citrullus lanatus cv Robusta than onto the other rootstock. The yields of plants grafted onto Citrullus lanatus cv Robusta grown at both plant densities were significantly higher than in the other treatments. © 2015 Federal University of Lavras. All rights reserved.

Andrade F.,Technological Institute of Colima | Trujillo X.,University of Colima | Sanchez-Pastor E.,University of Colima | Montoya-Perez R.,University of Colima | And 4 more authors.
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology | Year: 2011

In contrast to fast-twitch skeletal muscle fibers of the chicken, slow-twitch fibers are fatigue-resistant. In fast fibers, the fatigue process has been related to KATP channels. In the present study, we investigated the action of glibenclamide (an anti-diabetic sulphonylurea that acts on KATP channels) on fatigued slow skeletal muscle, studying twitch and tetanus tension after inducing the muscle to fatigue by continuous electrical stimulation. Our results showed that glibenclamide (150 μM) increased post-fatigue twitch tension by about 25% with respect to the fatigued condition (P < 0.05). In addition, glibenclamide (150 μM) increased post-fatigue tetanic tension (83.61 ± 15.7% in peak tension, and 85.0 ± 19.0% in tension-time integral, P = 0.02, and 0.04, respectively; n = 3). Moreover, after exposing the muscle to a condition that inhibits mitochondrial ATP formation in order to activate KATP channels with cyanide (10 mM), tension also diminished, but in the presence of glibenclamide the effect produced by cyanide was abolished. To determine a possible increase in intracellular calcium concentration, the effects of glibenclamide on caffeine-evoked contractures were explored. After muscle pre-incubation with glibenclamide (150 μM), tension of caffeine-evoked contractures increased (6.5 ± 1.5% in maximal tension, and 5.9 ± 3.8% in tension-time integral, P < 0.05). These results suggest a possible role of KATP channels in the fatigue process, since glibenclamide increases twitch and tetanus tension in fatigued slow muscle of the chicken and during metabolic inhibition, possibly by increasing intracellular calcium. © 2010 The Author(s).

Lopez-Martin C.,University of Guadalajara | Kalichanin-Balich I.,University of Guadalajara | Ulloa-Cazarez R.L.,University of Guadalajara | Garcia-Diaz N.,University of Colima | Garcia-Diaz N.,Technological Institute of Colima
International Journal of Engineering Education | Year: 2016

Prediction techniques have been applied for predicting dependent variables related to Higher Education students such as dropout, grades, course selection, and satisfaction. In this research, we propose a prediction technique for predicting the effort of software projects individually developed by graduate students. In accordance with the complexity of a software project, it can be developed among teams, by a team or even at individual level. The teaching and training about development effort prediction of software projects represents a concern in environments related to academy and industry because underprediction causes cost overruns, whereas overprediction often involves missed financial opportunities. Effort prediction techniques of individually developed projects have mainly been based on expert judgment or based on mathematical models. This research proposes the application of a mathematical model termed Radial Basis function Neural Network (RBFNN). The hypothesis to be tested is the following: effort prediction accuracy of a RBFNN is statistically better than that obtained from a Multiple Linear Regression (MLR). The projects were developed by following a disciplined development process in controlled environments. The RBFNNandMLRwere trained from a data set of 328 projects developed by 82 students between the years 2005 and 2010, then, the models were tested using a data set of 116 projects developed by 29 students between the years 2011 and first semester of 2012. Results suggest that aRBFNNhaving as independent variables new and changed code, reused code and programming language experience of students can be used at the 95.0% confidence level for predicting the development effort of individual projects when they have been developed based upon a disciplined process in academic environments. © 2016 TEMPUS Publications.

Huitron M.V.,Technological Institute of Colima | Camacho F.,University of Almeria | Ricardez M.G.,Onudi Semarnat
Acta Horticulturae | Year: 2011

The decrease in fruit yield and quality caused by soil diseases is one of the major problems of watermelon production. Soil disinfection with methyl bromide (MB) has been used to prevent fungus attacks; however, its use is being restricted because this substance damages the ozone layer. Field experiments were carried out in open field in soils infested with Olpidium bornovanus and Melon necrotic spot virus (MNSV) in Colima, Mexico, where watermelons had only been grown previously using soil fumigation with MB. Yield and quality of the watermelon cultivar 'Triploid Tri-X 313' grafted on two rootstocks of Cucurbita maxima × Cucurbita moschata ('RS841' and 'Shintosa Camelforce') were evaluated during 2007-2008. Each experiment had five treatments, two of them with non-grafted plants at a density of 3472 plants/ha, with and without MB fumigation. The remaining three treatments had grafted plants in non-fumigated soil with plant densities of 2778, 2083, and 1736 plants/ha. The use of watermelon grafted on 'RS841' and 'Shintosa Camelforce' rootstocks significantly increased the average fruit weight and the total yield of watermelon. Grafting may be considered as an alternative to MB fumigation. With the use of grafted watermelon plants, planting density may be reduced by 50%, obtaining higher yields than those obtained from non-grafted plants grown in fumigated soil. Fruits harvested from grafted plants had higher firmness than those harvested from non-grafted plants, without affecting the content of soluble solids.

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