MORTALIDAD EN LA POBLACION GALESA DE GAIMAN, PROVINCIA DE CHUBUT, ARGENTINA. SU DISTRIBUCION POR SEXO, EDAD Y CAUSAS (1892-1961)

RESUMEN El objetivo de este trabajo es analizar la evolución en el tiempo de las defunciones y de las causas de muerte por edad y sexo de la población galesa de Gaiman, provincia de Chubut, Argentina. Los datos fueron obtenidos de las Actas de Defunción del Archivo del Registro Civil de la ciudad de Rawson, Chubut. El período de estudio se extendió de 1892 a 1961 y para su descripción y análisis se lo dividió en decenios. Se registraron 2103 defunciones de las cuales 1039 (49%) correspondieron a galeses y sus descendientes, lo cual representa un promedio de 14.6 muertes por año. Se detectó una  sobremortalidad masculina (59%), esperable en una población colonizadora con predominio de varones. Se observó un incremento, en el tiempo, de la edad media de defunción, lo que indica mejoras en las condiciones socioeconómicas y de salud de la población. La mortalidad infantil y los natimortos representaron el 20% y el 11%, respectivamente, de las defunciones y se constató una transición desde una mortalidad provocada por enfermedades de naturaleza exógena a otra de causalidad endógena. Al compararse nuestros datos con los de la provincia de Chubut y el país, se comprobó, en todos los casos, un descenso de la mortalidad en el tiempo, aunque en Gaiman esa disminución fue más significativa, probablemente por la atención que la comunidad le dedicaba a la educación y a la salud.   ABSTRACT The aim of this article is to analyze throughout time the evolution of deceases and the causes of death by age and sex of the population Welsh of Gaiman, Province of Chubut, Argentine. The data were obtained from the Register of Deaths of Civil  Archive of Rawson City, Chubut. The study was extended from 1892 to 1961 but for its description and analysis was divided into decades. 2013 deceases were registered, of which 1039 (49%) corresponded to the Welsh and their descendents and represent an average of 14.6 deaths per year. A male overmortality  (59%) was detected, which would be expected in a colonizing population with excess of males. An increase throughout time , of the age average of deceases was observed. The data show an improvement of the socioeconomic and health conditions of the population. The infantile and the birth mortality represent the 20% and 11% respectively of the deceases. The data reveal a transition from a mortality generated by illness of exogenous nature to the other of endogenous causality. When we compared our data with those of the Province of Chubut and those of our country, we observed in all cases a decrease in the rate of mortality, although in Gaiman this decrease was more significant probably due to the attention that the community has paid to education and health

Intraspecifíc variability in <i>Alloteropsis semialata</i> (R. Br.) Hitchc.

Intraspecific variability in Alloteropsis semialata (R. Br.) Hitchc. is shown ultrastructurally with particular regard to the structure of the bundle sheath and the development of the dimorphic chloroplasts in both the C3 and C4 forms of this species. A. semialata is known to possess two distinct anatomical forms — Kranz and non-Kranz — within one species and occurring within a single ecological niche. Kranz and non-Kranz anatomy is known to be correlated with C3 and C4 physiology respectively. Transverse sections of leaf portions taken at midsheath, at the ligule and at midlamina show plastids with different morphologies at different ontogenetic stages. Plastid form is related to the stage of development, the influence of light on the emerging leaf and the C3 or C4 form of A. semialata. Stages from amyloplast to chloroplast are investigated with regard to fine structure. Leaf transverse sections are examined microscopically and formation of new bundles, chiefly in the lamina is traced. Differences in anatomy and distribution of vascular bundles are more evident in the lamina than in the colourless leaf sheath. Both C3 and C4 forms of A. semialata are found to show chloroplast dimorphism in vascular bundle sheath and mesophyll cells. This is shown to differ in the two forms. The specialized chloroplasts of the Kranz sheath are shown to develop in the inner or mestome sheath, and not in the parenchyma sheath as in some other members of the Kranz Panicoideae. Features of A. semialata,  such as the double bundle sheath, granal chloroplasts and large numbers of mitochondria in bundle sheath cells, in the C4 form, question the current classification of this grass as a malate former