Abstract Mental illnesses are becoming an increasingly common phenomenon in the Mexican adult population, it is manifesting in early stages such as adolescence, at least 25% of the Mexican adult population covers the criteria of some disorder, affecting the biological, social environment, environmental and psychological of those who suffer from it. The main objective of this analysis is to systematically assess the feasibility of creating biomarkers based on images from MRI by means of multivariate patterns to identify characteristics that can differentiate a person who has a mental illness with a regular control person.

Resumen Las enfermedades mentales están siendo un fenómeno cada vez más común en la población adulta mexicana, se está manifestando en etapas tempranas como la adolescencia, al menos el 25% de la población adulta mexicana cubre los criterios de algún trastorno, afectando el entorno biológico, social, ambiental y psicológico de quien la padece. El objetivo de este análisis es evaluar de manera sistemática la factibilidad de creación de biomarcadores basados en imágenes a partir de MRI por medio de patrones multivariantes para identificar características que puedan diferenciar una persona que tenga alguna enfermedad mental con una persona control regular.

Grasslands in the Andean highlands plateau of southern Peru have been considered as a single and homogeneous dry habitat also known as Puna. However, in some regions, a highest rainfall regimen is found, and the name of wet puna has begun to be used by some authors. Since no studies have been carrying out specifically to test if dry and wet puna are different ecological units, we chose two representative localities of each one of these habitat to evaluate assemblages of bird and mammal communities and their continuity or independence between these apparently similar habitats. Our results suggest that wet puna has different mammal diversity than dry puna, and a heterogeneous bird community with species that have been previously reported exclusively in paramo or exclusively in puna. In spite of the apparent uniform flora in the Andean highlands of South Peru, data suggest that rainfall regimens produce a mosaic of habitats that will be determining ecological barriers for terrestrial mammals, in particular for small mammals.

Los Pajonales de los Andes del sur del Perú, también conocidos como Puna, son considerados como hábitats homogéneos y secos. Sin embargo, en algunas regiones se encuentra un alto régimen de precipitaciones y algunos autores han empezado a usar el nombre de Puna Húmeda. Hasta la actualidad no se vienen realizando estudios específicos para probar si la Puna Húmeda y Seca son dos unidades ecológicas diferentes. Se escogieron dos localidades representativas de cada uno de estos hábitat para evaluar la estructura de las comunidades de aves y mamíferos y su continuidad o independencia entre estos hábitat aparentemente similares. Los resultados sugieren que la Puna Húmeda tiene una diversidad de mamíferos diferente a la de la Puna Seca, y una comunidad de aves heterogénea con especies que vienen siendo previamente reportadas como exclusivas de Páramo o de Puna. A pesar de la aparente uniformidad de la flora en los Andes del sur del Perú, la información sugiere que los regimenes de precipitaciones producen un mosaico de hábitat que estaría determinando barreras ecológicas para mamíferos terrestres, en particular para pequeños mamíferos.

We analyzed the frequency of chromosomal aberrations in peripheral lymphocytes from underground miners from the Casapalca (n = 8, mean age = 45 y, range = 36 y to 55 y) and Bellavista (n = 8, mean age = 28 y, range 23 y to 34 y) high-altitude mining camps in the Peruvian Andes. This population was occupationally exposed to heavy metals such as lead and zinc as well as diesel emission particles, organic solvents and mine dust. The control groups consisted of individuals from a high altitude farming community in the Peruvian village of Tinco (n = 8, mean age = 37 y, range = 25 y to 52 y) and the sea level city of Lima (n = 14, mean age = 26 y, range = 20 y to 35 y). All individuals were male native Peruvians. A significantly higher incidence (1.88%, p < 0.05) of chromosomal aberrations (chromatid deletions and breaks, chromosome breaks and acentric fragments) were detected in lymphocytes from miners at the Casapalca camp as compared to miners from the Bellavista camp (0.5%, chromatid deletions and acentric fragments only) and the Lima sea level (0.07%, chromatid deletions only) and Tinco high altitude (no aberrations) controls. These results suggest that male native Peruvians occupationally exposed to underground mining activity have an increased frequency of chromosomal aberrations, which could be related to both age and exposure time. The increased chromosomal damage observed in the mining populations studied may be attributable to the complex mixture of genotoxic agents to which the miners may have been exposed.

Population density and reproduction were studied in two leaf-eared mice (Phyllotis spp.) in the Peruvian locality known as Lomas de Lachay. Density varied between 0-3 individuals ha-1 in P. andium, and between 0-12 individuals ha-1 in P. amicus. An annual cycle of population abundance was observed in both species. Phyllotis amicus showed no seasonal reproductive activity, but P. andium had seasonal reproduction with pregnant females principally observed between July and September. Differences in juvenile weight were related to litter size. It is likely that two young was the optimal litter size in the harsh and seasonal xeric environment of Lomas de Lachay. Our results suggest that P. amicus maintains low, highly dispersed populations in a harsh environment, and can reproduce at any time of the year, whereas P. andium appears to be a more irruptive species closely tied to rainfall patterns

La densidad poblacional y reproducción de dos ratones orejudos (Phyllotis spp.) fueron estudiadas en la localidad peruana Lomas de Lachay. La densidad varió entre 0-3 individuos ha-1 en P. andium, y entre 0-12 individuos ha-1 en P. amicus. En ambas especies se observaron cambios poblacionales que sugieren la existencia de ciclos anuales en la abundancia poblacional. El patrón reproductivo en las dos especies de Phyllotis fue claramente distinto. Phyllotis amicus mostró una actividad reproductiva no estacional, mientras que P. andium tuvo una reproducción estacional observándose hembras preñadas principalmente entre julio y septiembre. La diferencia en el peso de los juveniles estuvo relacionada con el tamaño de la camada. Es probable que en las Lomas de Lachay el tamaño de camada óptimo sea de dos individuos. Nuestros resultados sugieren que P. amicus es una especie que mantiene poblaciones bajas, altamente dispersas en áreas desérticas, y que puede reproducirse durante todo el año; mientras que P. andium parece ser una especie que irrumpe más en ambientes arbustivos dependientes de patrones de precipitación pluvial