Percepción de dos comunidades sobre la contaminación del arroyo el Riíto, Chiapas, México / Perception of two communities of the pollution about the el Riito stream, Chiapas, Mexico

Resumen: El presente artículo identificó y evaluó, mediante la percepción ambiental con enfoque geográfico (PAEG), los impactos sociales y ambientales a nivel de comunidades derivados de la contaminación presente en el arroyo denominado el Riíto en Tonalá, Chiapas. Para ello, se aplicó una metodología mixta que comprendió la identificación de actores sociales, entrevistas y aplicación de encuestas estructuradas mediante procedimientos estadísticos en dos comunidades de la costa de Chiapas: Paredón y Tonalá. Este tipo de investigación, además, permitió identificar debilidades en la gobernanza y gestión de las instituciones presentes en la zona. Se evidenció que no logran dar una solución integral a un problema de agua que pone en riesgo la salud de las dos comunidades en estudio y mucho menos al medio ambiente de la microcuenca.

Abstract: This article identified and evaluated through Environmental Perception with a Geographical Approach (PAEG), the social and environmental impacts at the community level derived from the contamination present in the stream called El Riíto in Tonalá, Chiapas. For this, a mixed methodology was applied, which included from the identification of social actors, interviews and the application of structured surveys using statistical procedures in two communities on the Chiapas coast: Paredón and Tonalá. This type of research also allowed identifying weaknesses in the governance and management of the institutions present in the area, as they fail to provide a comprehensive solution to a water problem that puts the health of the two communities under study at risk, much less to the micro basin environment.

Histochemical and immunohistochemical analysis of enzymes involved in phenolic metabolism during berry development in Vitis vinifera L.

Phenolics are involved in many of plants' biological functions. In particular, they play important roles in determining the quality of grape berries and the wine made from them, and can also act as antioxidants with beneficial effects for human health. Several enzymes are involved in the synthesis of phenolic compounds. Among them, stilbene synthase (STS) is a key to the biosynthesis of stilbenes, which are considered to be important secondary metabolites in plants. Other enzymes, such as polyphenol oxidase (PPO) and peroxidase (POD), are involved in the degradation of phenolics, and become activated during late stages of berry ripening. In the present study, Vitis vinifera L. berries were sampled at eight stages of development, from 10 days after anthesis to late harvest. The PPO and POD enzymatic activities were determined at each stage. The presence of STS, PPO, and POD proteins in the grape exocarp and mesocarp was detected immunohistochemically and histochemically. The amount and intensity of the immunohistochemical and histochemical signals correlate with the variations in enzyme activities throughout fruit development. Strong STS immunoreactivity was detected until the onset of ripening. Labeled tissue increased gradually from mesocarp to exocarp, showing an intense signal in epidermis. At subcellular level, STS was mainly detected in cytoplasm grains and cell walls. The amount of PPO immunoreactivity increased progressively until the end of ripening. The PPO signal was detected in hypodermal layers and, to a lesser extent, in mesocarp parenchyma cells, especially in cytoplasm grains and cell walls. Finally, POD activity was stronger at the onset of ripening, and the POD histochemical signal was mainly detected in the cell walls of both exocarp and mesocarp tissue.

Potencial de aprovechamiento de la energía eólica para la generación de energía eléctrica en zonas rurales de México / Wind energy potential for electricity generation in rural zones of Mexico

México cuenta con un enorme potencial eólico. Entre los sitios identificados con viento de alta calidad se encuentran sus zonas costeras, especialmente en los estados de Baja California, Baja California Sur, Sonora, Oaxaca y Yucatán. Desafortunadamente, dicho potencial se ha explotado poco. El presente trabajo analizó zonas rurales con potencial para la generación de energía a partir de los vientos en México, considerando los aspectos sociales y económicos involucrados en el desarrollo de proyectos de energía eólica. Los resultados indican que además del desarrollo tecnológico requerido, se deben fortalecer los aspectos legales que fomenten e incentiven la producción de energía eólica, y establecer regulaciones y normas ambientales que protejan al ambiente y a las poblaciones silvestres

Development of the dendrobatid frog Colostethus machalilla.

To provide a developmental correlate with other frogs, we prepared a normal table of development for the dendrobatid, Colostethus machalilla and analyzed the morphology of its early development. This frog reproduces in captivity and deposits moderately sized eggs (1.6 mm in diameter) in terrestrial nests. The father guards the embryos until tadpole hatching. We divided development until hatching into 25 stages and implemented methods for in vitro culture of the embryos. The external and internal morphology of embryos were evaluated by observations in whole mount and in sections. Neural, notochord and somite specific antibodies were used to analyze gene expression patterns by immunostaining of embryos. Embryonic development of C. machalilla is slow and deviates from Xenopus laevis. In C. machalilla the elongation of the notochord, neural plate and somite formation occur after blastopore closure, possibly due to a delay in the dorsal convergence and extension movements. The gastrula of C. machalilla also deviates from X. laevis. The archenteron remains small until blastopore closure, where small cells accumulate at the blastopore lips. Simultaneously, the blastocoel roof thins until it becomes a monolayer of cells. Although C. machalilla does not form an embryonic disk, its thick blastopore lips resemble the embryonic disk of the marsupial frog Gastrotheca riobambae and represent an interesting deviation from the gastrulation pattern observed in X. laevis.

La cremación. Un capítulo en la salud pública de México / Cremation. A public health chapter in Mexico

Cremation was a part of the funeral ceremony in prehispanic Mexico. When the Spanish conquerors came, this practice was prohibited. In 1877, the Uppu Health Council authorized animal incineration to avoid consumption by indigents or transformation in putrid emanation. Creamation was welcome in Mexico because of the knowledge of hygienic at the time, whose adepts had evaluated toxic exhalations of cadavers and the cemeteries of Mexico City, with incomplete destruction of the cadaver and filtration of contaminants into the subsoil. Three were the reasons against cremation; religious beliefs, lawmaker medical preoccupation with the disappearance of legal evidence, and the newly born science of anthropology, with loss of material for laboratory. The first crematorium was inaugurated by Dr. Eduardo Liceaga in February 1909 in the Dolores Cemetery.(AU)

La cremación. Un capítulo en la salud pública de México / Cremation. A public health chapter in Mexico

Cremation was a part of the funeral ceremony in prehispanic Mexico. When the Spanish conquerors came, this practice was prohibited. In 1877, the Uppu Health Council authorized animal incineration to avoid consumption by indigents or transformation in putrid emanation. Creamation was welcome in Mexico because of the knowledge of hygienic at the time, whose adepts had evaluated toxic exhalations of cadavers and the cemeteries of Mexico City, with incomplete destruction of the cadaver and filtration of contaminants into the subsoil. Three were the reasons against cremation; religious beliefs, lawmaker medical preoccupation with the disappearance of legal evidence, and the newly born science of anthropology, with loss of material for laboratory. The first crematorium was inaugurated by Dr. Eduardo Liceaga in February 1909 in the Dolores Cemetery.

Lamina-associated polypeptide 2 (LAP2) expression in fish and amphibians.

Somatic and germinal cells of 15 fish and 33 amphibian species were examined by SDS-PAGE followed by immunoblotting to determine the expression of LAP2 (lamina-associated polypeptide 2). LAP2 expression in frogs, salamanders and fish does not vary with the mode of reproduction. In fish and frog cells, a rim-like LAP2 positive region was detected around the nucleus by indirect immunofluorescence microscopy. The cell distribution and expression patterns of LAP2 in fish, frogs and salamanders are comparable with those found in Xenopus and zebrafish. The mammalian somatic cell pattern, which may also occur in gymnophione amphibians, includes LAP2alpha, beta and gamma as major isoforms, whereas LAP2alpha does not occur in cells of fish, frogs and salamanders. In fish, LAP2gamma is the major isoform of somatic cells, suggesting that LAP2gamma may be ancestral. However, in the rainbow trout, as in frogs and salamanders, LAP2beta was the major somatic isoform. Fish and frog sperm only express low molecular weight polypeptides. In contrast, fish and frog oocytes express an oocyte-specific LAP2 isoform of high molecular weight. In the toad Bufo marinus this isoform becomes upregulated in pre-vitellogenic oocytes of 150-200 microm in diameter. The absence of LAP2alpha and the differential expression of LAP2 isoforms in somatic and germ cells, as found in fish and frogs, may be ancestral vertebrate characters. In spite of differences in developmental time, the LAP2 isoforms of somatic cells are upregulated during gastrulation, suggesting that LAP2 may be implicated in the early development of fish and frog.

[Cremation. A public health chapter in Mexico]. / La cremación. Un capítulo en la salud pública de México.

Cremation was a part of the funeral ceremony in prehispanic Mexico. When the Spanish conquerors came, this practice was prohibited. In 1877, the Uppu Health Council authorized animal incineration to avoid consumption by indigents or transformation in putrid emanation. Creamation was welcome in Mexico because of the knowledge of hygienic at the time, whose adepts had evaluated toxic exhalations of cadavers and the cemeteries of Mexico City, with incomplete destruction of the cadaver and filtration of contaminants into the subsoil. Three were the reasons against cremation; religious beliefs, lawmaker medical preoccupation with the disappearance of legal evidence, and the newly born science of anthropology, with loss of material for laboratory. The first crematorium was inaugurated by Dr. Eduardo Liceaga in February 1909 in the Dolores Cemetery.