Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The objective of the present study was to assess a growth analysis of white clover (Trifolium repens L.) and determine the optimal harvest time per season. The experiment was carried out at the Colegio de Postgraduados, Campus Montecillo, Texcoco, Mexico. Twenty-four 3.7 X 1.7 m plots were used, distributed in a completely randomized design, with eight treatments and three replicates per station. The treatments consisted of successive weekly cuts, during a regrowth cycle of 8 wk, in each season of the year. At the beginning of the study, a uniform cut was made and the residual forage was determined. The evaluated variables were: accumulation of dry matter, botanical and morphological composition, and leaf area index of white clover. The highest forage accumulation (P<0.05) occurred in the eighth week in spring (2,688 kg DM ha-1). Leaf production was higher (P<0.05) in spring, autumn and winter. The highest leaf area index was reached in the eighth week in spring (3.0; P<0.05). It is recommend exploiting the white clover meadow in the sixth week of the spring-summer period and in the seventh week of autumn-winter.

The objective of the present study was to calculate the inbreeding levels in the Holstein population of Mexico and to evaluate their effect on the production of milk, fat, protein and final conformation points. The pedigree information was made up of 326,238 animals, to which inbreeding was calculated through the modified recursive algorithm (INBUPGF90). Inbreeding trends of animals born from 1990 to 2018 were obtained through a regression analysis, and the effect of inbreeding on productive characteristics was evaluated with an analysis of variances, for which phenotypic information from 68,779 animals was included. Six groups were formed according to the level of inbreeding (1= <1%, 2= ≥1 and <2%, 3= ≥2 and <3%, 4= ≥3 and <4%, 5= ≥4 and <5%, and 6≥ 5%). The results showed that, for each percentage point of increase in inbreeding, the production of milk, fat and protein decrease by 88, 3.16 and 2.57 kg (P<0.0001). At low levels of inbreeding (<5%), no effect on fat and protein production was detected. However, when inbreeding increased to more than 5 %, the loss in production was 12 kg of fat and 9 kg in protein. It was also observed that the animals with the lowest average conformation have low levels of inbreeding (<1%) and the highest levels did not show significant differences between them, which confirms that functional conformation is less sensitive to the effects of inbreeding than other characteristics of economic interest. It is recommended to promote selection programs based on optimal contributions to maximize genetic gains and control inbreeding levels.

Buffaloes and cattle are two species of bovines with great similarity in their reproductive physiology, but at the same time with great difference in their reproductive parameters. The objective of this work is to compare gene expression in granulosa cells of preovulatory follicles of these two species, based on information available in the literature, existing transcriptome repositories and functional analysis using Ingenuity Pathway Analysis. Only two independent studies comparing buffalo and cattle in terms of gene expression in granulosa cells of preovulatory follicles were found. Expression data were analyzed independently and in combination. It was found that, between buffaloes and cattle, there is practically no correspondence between the processes evaluated, neither in the canonical pathways, nor in the upstream regulators, only some correspondence is found between the networks and physiological aspects of each process. It is concluded that each species has a different way of carrying out the same process and that each event should be studied according to the needs of the researchers.

Molecular techniques require extractions of nucleic acids in adequate quantity and purity. This work describes a generalized linear model (GLM) of an adjusted factor with fixed effects on nucleic acid yield (ng/μl) and purity (A260/A280 and A260/A230), for five methods of DNA extraction using FTA cards with goat (Capra aegagrus hircus) blood. Two commercial methods based on silica columns (Invitrogen and Macherey Nagel; MN), the chelating resin method (Chelex), the CTAB method and the phenol-chloroform-isoamyl alcohol (PCI) method were tested. Additionally, for MN, an incubation step with PBS (Phosphate Buffered Saline) buffer at high temperature prior to lysis and a purification step post extraction were evaluated using a fixed-effect model of two factors with interaction. DNA concentrations and purity ratios were variable; the highest concentration was obtained with the MN kit (170.45 ng/μl), but with deficiencies in purity (0.32 of A260/A230, 0.34 of A260/A280). Despite this, all extraction methods generated PCR products with specific D-loop primers (mtDNA). The combined effect of the pre-incubation and post-purification stages yielded satisfactory purity values (1.89 for A260/A230 and 1.65 for A260/A280), as well as concentration ratios (476.78 ng/μl) with low variability. In conclusion, the concentration and purity of DNA from blood samples is greatly improved when using a commercial kit in combination with pre-lysis incubation and post-extraction purification. These nucleic acids are suggested for use in potential molecular applications a posteriori.

Se estudió el efecto de la raza en el crecimiento, las características y la clasificación de la canal utilizando 11 corderos Charollais x Pelibuey (ChP), 10 corderos Dorper x Pelibuey (DP) y 18 corderos Pelibuey (P) bajo un sistema de producción intensiva en un clima cálido-húmedo. Se observó un efecto significativo del genotipo (P<0.05) en el peso al nacer (PN), el peso al destete (PD) y la ganancia diaria de peso (GDP), todos ellos fueron mayores en el genotipo ChP. Los corderos ChP y DP alcanzaron el peso comercial 35 y 23 días antes, respectivamente, que los corderos P. El genotipo tiene una marcada influencia en las características de la canal, afecta la conformación y la clasificación de la canal. La probabilidad de obtener una canal con buena conformación y clasificación MEX 1 (buena: MEX 1) es 72 % mayor para el genotipo ChP que para el genotipo P. Los rendimientos de lomo y pierna del genotipo ChP fueron mayores que los de los otros genotipos. El pH, la temperatura y el color instrumental de la canal, la carne y la grasa subcutánea fueron afectados por el genotipo. Los corderos ChP mostraron un mejor crecimiento, características y clasificación de la canal que los corderos de los genotipos DP y P.

Introducción: En los últimos años, la formación por competencias transita hacia las actividades profesionales encomendables, enfoque que facilita su operativización y evaluación.Objetivo: Actualizar los conceptos y metodologías del enfoque de actividades profesionales encomendables.Material y Métodos: Se realizó una revisión de alcance en la que se consultaron las bases de datos:  SciELO, LILACS y PubMed. Se usó el término de búsqueda: “entrustable profesional activities”, tanto en español, como en inglés, desde el año 2005 al 2021. Se encontraron 1 011 artículos en total, se revisaron 290, de los cuales se seleccionaron finalmente 43, todos relacionados con aspectos conceptuales y metodológicos de las actividades profesionales encomendables.Desarrollo: Se explica el concepto de actividades profesionales encomendables, sus características, usos, descripción y diferencias con el término “competencia”. Se mencionan los pasos para desarrollarlas según Taylor, y se mencionan algunos desafíos de su aplicación.Conclusiones: Las actividades profesionales encomendables constituyen un novedoso enfoque en la educación médica contemporánea, que no siempre es bien comprendido. Aplicable no solo a pregrado, sino también a posgrado, especialidades médicas-quirúrgicas, tecnologías de la salud, enfermería y otras. Se ofrece información actualizada sobre su descripción y se reflexiona sobre su aplicación e implementación en el contexto nacional y regional.

Introducción: La historia de la cirugía del trauma va aparejada con la historia de la medicina y las primeras civilizaciones.Objetivo: Comparar el desarrollo de esta cirugía, hasta nuestros días, con los resultados alcanzados en Cuba.Material y Método: Estudio comparativo del desarrollo de los avances de la ciencia en relación con el trauma por investigaciones y descubrimientos de científicos en todo el mundo, con el desarrollo de la cirugía del trauma que se ha producido en Cuba.Desarrollo: Se hace un recuento de los logros de la Humanidad con la aplicación de la disciplina de cirugía del trauma, los avances organizativos, técnicos y científicos reconocidos a nivel mundial y aplicados en Cuba. Se comparan estadísticas mundiales y nacionales sobre los resultados de la atención a los lesionados con la aplicación de los protocolos internacionales en el país.Conclusiones: Se demuestra que nuestras estadísticas reflejan los logros positivos alcanzados en la actualidad.

In light of advances in research on nonformal education (NFE), this paper examines the experience of Mayan women from the community of Canicab, in the municipality of Acanceh (Yucatán, Mexico). The objective was to understand the levels of shared agency in an NFE activity performed in a context characterized as an attempt to produce conditions of critical interculturality. The research employs a methodology of feminist-activist ethnography. The NFE activities that the women involved took part in dealt with issues relating to women’s rights, education, and heritage, and led to the organization of the First Meeting of Mayan Women in Canicab. The findings show a high level of shared agency among women from Canicab and their external partners. The results were discussed with the women who participated in order to help them improve their educational and organizational endeavors.

The objective of this research was to determine the effectiveness of the flipped classroom methodology in improving the quality of learning of mathematical competencies among students of a graduate program in administration. The study employed a quantitative methodology with a quasi-experimental design in three phases: pretest, experiment, and posttest. The main results showed increases in mathematical achievement, and a significant difference was found between the experimental group (in which the flipped classroom was applied) and the control group (which followed the traditional method). The research concludes that the flipped classroom methodology is of greater benefit to the quality of student learning than traditional methods of teaching, in terms of the relevance, usefulness and quality of education received.

The objectives of the study were to identify and describe motivational profiles in elementary students based on personal variables, namely school motivation, task value, and academic self-concept; and to describe the contextual variables of parental and teacher support in students with different profiles. In a mixed-methods study, 248 students completed various questionnaires relating to the variables, and then six tutors and six teachers were interviewed to determine their involvement. Quantitative data was analyzed through clustering and MANOVA, and categorical content analysis was used for qualitative information. The results showed significant differences in the three profiles: high, moderate, and low. The mothers of highly motivated children are more involved in their children’s academic activities, and their teachers demonstrate greater recognition and are more dynamic in teaching.