RESUMENJuglans pyriformis es una especie endémica del bosque mesófilo de montaña, que se encuentra amenazada. Con el objetivo de determinar la variación morfológica dentro de la población de J. pyriformis de Coacoatzintla, Veracruz. Se evaluaron seis variables morfológicas y dos dasométricas, mediante un muestreo no probabilístico, en 1 a 5 individuos por sitio, ubicados a una distancia igual o mayor a 50 m o hasta localizar el siguiente individuo. Los datos fueron analizados mediante pruebas de independencia entre las variables, Análisis de Componentes Principales, análisis de conglomerado, coeficiente de variación y prueba de homogeneidad de varianza de Levene. Los resultados obtenidos permitieron identificar dos indicadores para las variables morfológicas COPA y FUSTE, y uno para las dasométricas ALT-DIAM. El indicador ALT-DIAM aportó mayor variación dentro de la población (42 %). Se encontraron diferencias significativas dentro de la población para los indicadores de COPA y ALT-DIAM. ABSTRACTJuglans pyriformis is a threatened species endemic to a cloud forest environment. In order to determine the morphological variation within the J. pyriformis population in Coacoatzintla, Veracruz. Six morphological and two dasometric variables were evaluated, through non-probability sampling, in 1 to 5 individuals per site, located at a distance equal to or greater than 50 m or until locating the next individual. The data were analyzed using tests of independence between variables, Principal Components Analysis, cluster analysis, coefficient of variation and Levene's test of homogeneity of variance. The results obtained allowed identifying two indicators for the CROWN and TRUNK morphological variables, and one for the HEIGHT-DIAMETER dasometric relationship. The HEIGHT-DIAMETER indicator provided more variation within the population (42 %). Significant differences were found within the population for the CROWN and HEIGHT-DIAMETER indicators. PALABRAS CLAVE:Variación morfológica, indicadores morfológicos, población natural vegetal, bosque mesófilo de montaña, componentes principales..

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Juglans pyriformis Liebm. (Juglandaceae) is a threatened and endemic tree that grows in the cloud forest of Mexico. Natural populations of this species have been reduced due to, among others, changes in land use, overexploitation, and logging, with probable effects on its genetic diversity and structure. To determine the levels of variation and genetic structure of two populations with different silvicultural regimes, six inter-simple sequence repeat (ISSR) primers were used to amplify DNA from 35 individuals from a high-logging population and 32 from a low-logging population. The results show a higher polymorphism in the low-logging population (81.5%) compared to the high-logging population (77.4%). The genetic differentiation coefficient (PhiPT) values (0.109), genetic distance (0.134) and STRUCTURE analysis (Fst = 0.2271, P = 0.04) show significant genetic differentiation between populations. Rare, private, and monomorphic bands were detected in both populations. These results confirm the trend of reduced genetic variation due to logging.

Bioética y experimentación en animales. Una revisión de la praxis científica en México Bioethics and animal testing. A review of scientific praxis in Mexico Bioética e testes em animais. Uma revisão da praxis científica no MéxicoResumen Este estudio examina el uso experimental de animales no-humanos en México desde un enfoque bioético. Para tal propósito, se aplicó una encuesta a investigadores que desarrollan líneas de investigación con animales -en específico cordados-para conocer los aspectos éticos y técnicos relacionados con su uso. Al analizar los datos, se concluyó que existe un uso parcial de las 3 R´s de Russell y Burch, así como irregularidades relacionadas con la aplicación de protocolos de transporte, zonas exclusivas para experimentación, uso de sustancias y herramientas en el proceso de sacrificio exigidas por la NOM-062-ZOO-1999 y el Código Terrestre.Palabras clave: Bioética, experimentación en animales, investigación científica. AbstractThis study examines the experimental use of non-human animals in Mexico from a bioethical approach. For this purpose, a survey was applied to researchers who develop research lines with animals (specifically chordates) to know the ethical and technical aspects related to their use. When analyzing the data, it was concluded that there is a partial use of the 3 R's of Russell and Burch, as well as irregularities related to the application of transport protocols, exclusive zones for experimentation, use of substances and tools in the slaughter process required by the NOM-062- ZOO-1999 and the Terrestrial Code.