Las precipitaciones en el noreste de la región pampeana (provincia de Buenos Aires, Argentina) entre 1745-1900. Una reconstrucción histórica

Fil: Deschamps, Jorge. Universidad de Belgrano. Facultad de Ciencias Agrarias y Derecho. Buenos Aires; ArgentinaFil: Otero, Osvaldo. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica. Buenos Aires; ArgentinaFil: Tonni, Eduardo Pedro. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentin

Nutritional value of the cryptophyte rhodomonas lens for artemia sp

Juvenile or adult Artemia sp. are often used as live prey for the rearing of early life stages of some crustacean, fish and cephalopod species. The improvements of both Artemia growth and its biochemical composition are key issues for the suitable use of Artemia biomass in these rearing processes. In this study we evaluated the growth and survival rates of Artemia fed with the cryptophyte Rhodomonas lens in comparison with different microalgal species commonly used in aquaculture: the prasinophyte Tetraselmis suecica, the prymnesiophyte Isochrysis galbana Parke, and the eustigmatophyte Nannochloropsis gaditana. Microalgae were cultured semicontinuously in nutrient saturated conditions and with a daily renewal rate of 30% of the volume of cultures, to obtain biomass of controlled and optimized composition. Considerable differences in Artemia growth were observed, as well as in the survival rate. At day 8 of rearing, Artemia fed R. lens had the highest length (4.9± 0.6 mm, P< 0.001), followed by individuals fed T. suecica (4.2± 0.7 mm), I. galbana (3.6± 0.7 mm) and finally those fed N. gaditana (1.5± 0.2 mm). The survival rate of Artemia fed N. gaditana (18± 3%) was much lower (P< 0.001) than values found for the remaining groups (69 to 88%). The growth rate of Artemia obtained with R. lens was in general much higher than with other microalgal diets previously reported in the literature. The higher protein content of R. lens could explain the higher growth obtained with this species, but differences of Artemia growth with the different diets could not be explained solely on the basis of the gross composition of microalgae. Factors such as cell size and digestibility all seem to contribute to the results observed. Another trial was carried out to investigate differences in Artemia growth and on its biochemical composition when fed the best two diets: R. lens or T. suecica. The fatty acid (FA) and total amino acid (AA) composition of both microalgal species and the composition of Artemia were assessed as well. As found in the first experiment individuals fed R. lens (group ARHO) grew faster than those fed T. suecica (group ATET), attaining 3.6± 0.3 mm and 3.2± 0.4 mm (P< 0.001), respectively, after 5 days of rearing. The much higher AA content obtained in R. lens may be on the basis of the higher growth obtainedwith this species. Protein and carbohydrate levels in Artemia juveniles were very similar in both groups (64– 68% of dry weight, and 8–10%, respectively). Lipid was slightly lower in ARHO (12%) than in ATET (15%, P< 0.01). Regarding the FA composition, juveniles from group ARHO contained higher levels of eicosapentaenoic acid (EPA, 6.2%) than juveniles from ATET (4.1%, P< 0.01), whereas docosahexaenoic acid (DHA) was only found in juveniles from ARHO (1.1%). Taking into account that the daily productivity of R. lens culture was higher than, or at least equal, the remaining microalgal species this cryptophyte is confirmed as an excellent diet to optimize the growth of Artemia, as well as to improve its biochemical composition

La pena capital

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Enriching Rotifers with “Premium” Microalgae. Nannochloropsis gaditana

The nutritive quality of Nannochloropsis gaditana cultured semicontinuously with different daily renewal rates was tested as a diet for short-term enrichment of the rotifer Brachionus plicatilis. After 24 h, dramatic differences in the survival, dry weight, and biochemical composition of the rotifers depending on the renewal rate of microalgal cultures were observed. Survival after the feeding period increased with increasing renewal rates. Rotifers fed microalgae from low renewal rate, nutrient-deficient cultures showed low dry weight and organic contents very similar to those of the initial rotifers that were starved for 12 h before the start of the feeding period. On the contrary, rotifers fed nutrientsufficient microalgal cells underwent up to twofold increases of dry weight and protein, lipid, and carbohydrate contents with regard to rotifers fed nutrient-depleted N. gaditana. Consequently, feed conversion rate decreased in these conditions, indicating a better assimilation of the microalgal biomass obtained at high renewal rates. No single microalgal biochemical parameter among those studied can explain the response of the filter feeder. Similarly to gross composition, EPA and n-3 contents in rotifers fed microalgae from nutrient-sufficient cultures were double than the contents found in rotifers fed nutrient-limited microalgae. In addition, very high positive correlations between the contents of EPA and n-3 in N. gaditana and B. plicatilis were observed. These results demonstrate that selecting the appropriate conditions of semicontinuous culture can strongly enhance the nutritional value of microalgae that is reflected in the growth and biochemical composition of the filter-feeder even in short exposure periods

Discurso leído por el alcalde accidental D. Pedro Zúñiga y Otero, en el certamen literario celebrado en Segovia el día 14 de mayo de 1908, para conmemorar el primer centenario de la Guerra de la Independencia

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Teorías subjetivas del bienestar en un grupo de adolescentes mayores de edad de Lima Metropolitana

La presente investigación de naturaleza cualitativa tuvo como objetivo discutir las teorías subjetivas en un grupo de adolescentes mayores de edad de Lima Metropolitana sobre lo que significa para ellos una buena vida y cómo lograrlo, al analizarlas con la teoría científica de PERMA sobre el bienestar y el florecimiento humano. Para ello se reunió un conjunto de participantes compuesto por seis varones y cuatro mujeres cuya edad promedio fue veintiún años. Se realizaron entrevistas a profundidad con preguntas relacionadas a su definición de felicidad y felicidad durante pandemia. Las dimensiones más relevantes encontradas en las teorías subjetivas del bienestar se organizaron en cuatro ejes temáticos: actividades placenteras, autorrealización, vivencias significativas y vínculos interpersonales. El evento mundial de la pandemia por el COVID-19 permitió observar que las dimensiones relevantes del bienestar, felicidad o florecimiento humano, prevalecen aun después de eventos postraumáticos como dicha crisis sanitaria, evidenciando el valor de factores como las relaciones, la búsqueda de realización y las emociones positivas.The present qualitative research aimed to discuss the subjective theories of a group of older adolescents in Metropolitan Lima about what a good life means to them and how to achieve it, by analyzing them with PERMA's scientific theory of human well-being and flourishing. For this purpose, a group of participants composed of six males and four females whose average age was twenty-one years old was gathered. In-depth interviews were conducted with questions related to their definition of happiness and happiness during pandemics. The most relevant dimensions found in the subjective theories of wellbeing were organized into four thematic axes: pleasurable activities, self-fulfillment, meaningful experiences and interpersonal bonds. The global event of the COVID-19 pandemic allowed us to observe that the relevant dimensions of well-being, happiness or human flourishing, prevail even after post-traumatic events such as this health crisis, evidencing the value of factors such as relationships, the search for fulfillment and positive emotions