The following pages are intended to present the stories of the first earthquake that was recorded in Punta Arenas and the Magallanes region. The publiciz these testimonies not only allows you to appreciate the magnitude of the telluric movement, but it also helps to clarify doubts with respect to its occurrence, ing of helping to improve the seismic chronology of the region and, above all, give the possibility of raising awareness among the population to be warned for this natural threat.

Las siguientes páginas tienen como objetivo dar a conocer los relatos del primer terremoto que cuenta con registro escrito en Punta Arenas y en la región de Magallanes. El dar a conocer estos testimonios no solo permite apreciar la magnitud de aquel movimiento telúrico, sino que también contribuye a aclarar dudas con respecto a su ocurrencia, ayuda a mejorar la cronología sísmica de la región y, sobre todo, proporciona la posibilidad de concientizar a la población a estar prevenida ante esta amenaza natural.

It is currently recommended that antiretroviral prophylaxis to prevent mother-to-child transmission (MTCT) of HIV be initiated at 14 weeks of gestation. However, the relevance of early-gestation HIV viral load level for intrauterine MTCT is unknown. The objective of this study was to determine the relationship between prenatal maternal viral load and intrauterine MTCT. Records of HIV-infected pregnant women in two centers in Brazil, from 1999 to 2004 were analyzed. Three pregnancy periods were considered: earlier than 14 weeks, 14 to 27 6/7 weeks, and 28 weeks of gestation or more. Peripartum HIV exposure was also computed. Maximum viral load in each period was the measure of HIV exposure. Four hundred fifty-seven HIV-infected pregnant women were evaluated, but 53 were excluded. The MTCT rate was 0.49% (2/404-95% confidence interval (CI95) = 0.14-1.79%). Newborns were not breast-fed. Median viral load for the earlier-than-14-week period was 9,900 copies/mL (P25-75 1,000-50,775 copies/mL), 8,350 copies/mL (P25-75 707-42,000 copies/mL) for the 14 to 27 6/7-week period, and 435 copies/mL (P25-75 90-7,775 copies/mL) after the 28-week period. The peripartum median viral load was 400 copies/mL (P25-75 80-500 copies/mL). MTCT in mothers with VL > 1,000 copies/mL during the first 14 weeks (0.67%, 2/298) was not different from those with VL =1,000 copies/mL (0.0%, 0/96, P=1). Analogously, in the 14 to 27 6/7-week period, MTCT was similar in groups with VL higher (0.68%, 2/292) or lower (0%, 0/106) than 1,000 copies/mL (P=1). Regarding VL >1,000 copies/mL at 28-weeks-or-later and at peripartum periods, MTCT rates were 1.15% (2/173, P = 0.18) and 2.8% (2/71, P = 0.03), respectively. Intrauterine transmission does not seem to be influenced by HIV viremia during the first 28 weeks of pregnancy.

Exomorphological characteristics of seedlings of eight species of Prosopis: P. alba, P. nigra, P. alpataco, P. chilensis and P. flexuosa (Series: Chilenses, Section Algarobia) P. hassleri (Series Ruscifoliae, Section Algarobia), P. denudans (Serie Denudantes, Section Algarobia) y P. strombulifera (Section Strombocarpa) were studied. All of them were growing under uniform conditions. This study was made in order to analize relationships between species and to find morphological descriptors to identify the species in the field. Numerical methods (UPGMA and Principal Component Analysis) were applied. They allow to identify the morphological characteristics of seedlings that identify all of the species analized. Morphological variables of shoot of the seedlings are useful as potentially descriptors and provide interesting information about evolutionary and systematic relations in the genus Prosopis.

En el presente trabajo se estudiaron las características exomorfológicas de plántulas desarrolladas en jardín uniforme pertenecientes a ocho especies del género Prosopis: P. alba, P. nigra, P. alpataco, P. chilensis y P. flexuosa (Serie: Chilenses, Sección Algarobia) P. hassleri (Serie Ruscifoliae, Sección Algarobia), P. denudans (Serie Denudantes, Sección Algarobia) y P. strombulifera (Sección Strombocarpa) con el objeto de analizar las relaciones existentes entre ellas y encontrar descriptores morfológicos que permitan distinguirlas, ya sea para la identificación de germoplasma como para su reconocimiento en renovales naturales. Se aplicaron métodos numéricos de agrupación (UPGMA) y de ordenación (Análisis de Componentes Principales), cuyo análisis facilitó la identificación de las características de plántula que permiten la identificación de cada una de las especies. La parte aérea de las plántulas de las especies de Prosopis, cultivadas en condiciones uniformes, provee de caracteres morfológicos potencialmente utilizables como descriptores y suministra interesante información para el estudio de las relaciones sistemáticas y evolutivas dentro del género.

Prosopis abbreviata is an endemic species in central west Argentina. Its distribution and morphology have been analyzed within the framework of the PROFLORA Argentina project, reaching the conclusion that in a community located in the province of San Juan individuals of P. torquata, P. strombulifera and P. abbreviata co-existed. Part of the P. abbreviata individuals exhibited intermediate characters from the two first species. Thus, the hypothesis that P. abbreviata could be a hybrid was posed. In order to corroborate this, morphological studies and studies of pollination viability were ndFragment-->done in the individuals of the three species growing in simpathry. The obtained results indicate that P. abbreviata because of its very low viability, bad exine structure and addition of the exine sculpture could be a hybri. or perhaps an (introgresante) originated by cross pollination between P. torquata and P. strombulifera, thus corroborating prior observations referred to P. burkartii (Picca et al., 1990).

Prosopis abbreviata es una especie endémica del centro-oeste de Argentina. En el marco del proyecto PROFLORA Argentina, se analizó su distribución y morfología, arribándose a la conclusión de que en una comunidad sita en la provincia de San Juan coexistían individuos asignables a P. torquata, P. strombulifera y P. abbreviata, parte de estos últimos exhibían caracteres intermedios entre las dos especies precedentemente citadas. Se planteó la hipótesis de que P. abbreviata podría ser un híbrido. Con el fin de corroborar lo planteado se realizaron estudios morfológicos y de viabilidad polínica en individuos de las tres especies que crecían en simpatría. Los resultados obtenidos indican que P. abbreviata, debido a su muy baja viabilidad, mala estructura de la exina y adición de la escultura de la misma, sería un híbrido o quizá introgresante originado por la polinización cruzada entre P. torquata y P. strombulifera, corroborando observaciones anteriores referidas a P. burkartii (Piccaet al., 1990).