Covariant Impulse Approximation for the study of the internal structure of composite particles

We present a brief review on the Impulse Approximation method to study processes of scattering off composite particles. We first construct the model in a non-relativistic fashion that enables us to extend the model to a covariant Impulse Approximation, which is needed for the study of high momentum transfer processes.Comment: 8 Page

The legend of Achaneh: Socio-ecological knowledge in the oral tradition of fisherwomen in Veracruz, Mexico

Based on ethnographic fieldwork conducted in an indigenous community of Veracruz, Mexico, traditional socio-ecological knowledge was identified embedded in the oral tradition of fisherwomen of the local community. The reflections presented show the educational potential of indigenous knowledge that, from their own epistemology, has allowed the inhabitants of this community to regulate the way in which they relate to each other and to their environment in a sustainable way over the centuries. The findings presented in this article bear testimony to the socio-environmental relevance of these local indigenous narratives as situated philosophies which are important to document so as to move towards a scenario of sustainability arising from a dialogue between the local and the global

Semiclassical propagator of the Wigner function

Propagation of the Wigner function is studied on two levels of semiclassical propagation, one based on the van-Vleck propagator, the other on phase-space path integration. Leading quantum corrections to the classical Liouville propagator take the form of a time-dependent quantum spot. Its oscillatory structure depends on whether the underlying classical flow is elliptic or hyperbolic. It can be interpreted as the result of interference of a \emph{pair} of classical trajectories, indicating how quantum coherences are to be propagated semiclassically in phase space. The phase-space path-integral approach allows for a finer resolution of the quantum spot in terms of Airy functions.Comment: 4 pages, 3 figure

Landscape, memory and learning to change in changing worlds:Contemplating intergenerational learning and traditional knowledge practices within social-ecological landscapes of change

The core paper and collection of short papers from Mexico, Africa, India and Sweden that make up this study on social-ecological landscapes developed as a South–South collaboration that was extended to include a case in the North. Our concern was to explore how situated, intergenerational knowledge commonly takes a back seat to the conceptual propositions that the environmental sciences have developed around matters of concern like biodiversity loss. In this way, scientific propositions have become the conceptual capital for informing future sustainability through Education for Sustainable Development (ESD). In response to this, a more situated turn has developed to engage both intergenerational practices and the institutional sciences, but the playing fields are seldom level and deliberations are often rife with misunderstandings.Current trajectories of social-ecological change were already evident at the turn of the 20th century where one found the colonial oppression of indigenous peoples and early manifestations of accelerating environmental degradation. The latter escalated into biodiversity loss as a global concern that both underpins and resonates with the current complex of global risks. This concern has shaped education imperatives towards learning-led change so as to contribute to avoiding catastrophic problems such as climate change and ocean acidification, for example. These and other critical sustainability concerns have developed as planetary limits are being exceeded on a widening scale. The associated patterns of change and escalating risk in the modern era have played out in each of the regions where our teams of authors have researched their short papers on social-ecological change and intergenerational learning. The papers are intended as contributions that might better situate indigenous peoples on their intergenerational lands in reflexive learning within a rich mix of ancient and modern scientific ideas and ideals

Determinación de relaciones nivel – caudal simple o compleja en un río. Caso del río Cauca

(Eng) The stage – discharge relationship in a river, or rating curve, is very useful because it allows calculating the discharg - es from measured stages or water levels in a gauge station. For a nearly steady regime a discharge corresponds to a water level (simple relationship). However, frequently different circumstances can originate a complex relation between waters levels and discharges and then a discharge can be referred to two water levels and vice versa. In this study, simple and complex rating curves were determined in La Balsa hydrometric station, located 27 km downstream of Salvajina reservoir (Cauca river, Colombia). The simple curve was calculated by applying the log - arithmic method, which allows identifying the characteristics of the type of control that determines the water level – discharge relationship. The complex curve was calculated by using the method of storage per unit rate of variation in water levels, which allows adjusting the discharge obtained with the rating curve for steady flow considering a storage due to the variation in the level. The results show significant differences in the estimated discharges through the two relationships. By applying the two rating curves for a moderate flood (01/01/1999) differences up to 19% were estimated between both calculated discharges. In consequence, in order to get the appropriated rating curve it should to carry out a rigorous analysis of the flow conditions on the river reaches of the hydrometric station.(Spa) La relación nivel de agua – caudal en un río, denominada también curva de calibración, es de gran utilidad práctica pues permite estimar los caudales a partir de los niveles registrados en una estación hidrométrica. Cuando el régimen es aproximadamente permanente a cada nivel le corresponde un caudal (relación simple). No obstante, frecuente - mente diferentes circunstancias pueden generar una relación compleja entre los niveles y los caudales, donde un caudal puede estar relacionado con dos niveles de agua y viceversa. En el presente estudio se determinaron las cur - vas de calibración simple y compleja en la estación La Balsa, localizada 27 km aguas abajo del embalse de Salvajina (río Cauca, Colombia). La curva simple se calculó mediante el método logarítmico, el cual permite identificar las características del tipo de control que determina la relación nivel – caudal. La curva compleja se calculó según el método de almacenamiento por unidad de tasa de cambio en los niveles de agua, el cual permite ajustar el caudal obtenido en la curva nivel – caudal para régimen permanente considerando un almacenamiento debido al cambio en el nivel. Los resultados muestran diferencias importantes en los caudales estimados por medio de las dos relaciones. Al aplicar las dos curvas de calibración para una creciente moderada (01/01/1999) se encontraron diferencias hasta de un 19% entre los caudales calculados. En consecuencia, para establecer la curva de calibración nivel-caudal apropiada se debe realizar un análisis riguroso de las condiciones del flujo, tanto en la estación hidrométrica como aguas arriba y aguas abajo de ella

Apostillas sobre la Personalidad Jurídica Societaria en el Derecho Argentino.

El autor realiza un estudio pormenorizado del clásico, pero siempre actual, tema de la personalidad jurídica societaria en el derecho argentino. Luego de realizar una adecuada descripción de los debates doctrinarios, ingresa en los principales aspectos de la teoría general de la persona jurídica. No obstante sus atributos (denominación, patrimonio, capacidad, imagen, etc.), señala que si bien la "realidad biológicamente natural" no está presente en las personas de existencia ideal, existe una factibilidad técnica de "imputar" una conducta o una consecuencia jurídica a un ente (o idea) conformado por una pluralidad de individuos humanos: a un concepto que no tiene verdadera existencia real, pero que tiene personalidad porque el derecho así lo quiere

Ramon (\u3ci\u3eBrosimun alicastrum\u3c/i\u3e) Foliage as Supplement for Lactating Dual Purpose Cows

The objective of the present study was to asses the value of ramón (Brosimun alicastrum) foliage as a N-source in replacement of soybean-N in lactating dual purpose cows (Bos indicus x B. taurus). Four lactating cows were used in a latin rectangle design. Ramón was included to replace 0, 33, 66 and 100 % of the soybean-N contained in the supplement. Basal diet was fresh “Taiwán” a cultivar of Elephant grass (Pennisetum purpureum) fed ad libitum. Basal and total dry matter intake, digestibility (total fecal collection), saleable and calf suckled milk yields, and milk composition (fat, protein and lactose) were measured over 15 d periods. Ramon increased the yield of milk constituents (P\u3c 0.05) over those obtained with Taiwán-grass alone, but was inferior (P\u3c 0.05) when soybean was the N source. Total milk yield was reduced 18% in Ramón supplemented cows compared with those supplemented with soybean. Digestibility of dry matter, organic matter and fiber was reduced by Ramón inclusion probably due to its higher fiber and ash content as compared with soybean meal. It was concluded that, although animal performance was not achieved as with soybean meal, supplementing with Ramón is a better strategy than relying on grass alone

Valoración económica de los servicios ecológicos que prestan los murciélagos "Tadarida brasiliensis" como controladores de plagas en el norte de México

Esta investigación tiene como objetivo realizar una primera aproximación al valor económico del servicio ambiental que la subespecie de murciélagos "Tadarida brasiliensis" mexicana ofrece como controlador natural de plagas en el estado de Nuevo León. Se parte de un estudio de los hábitos alimentarios de la población que habita la Cueva de la Boca ubicada en Santiago, Nuevo León. Se identifican los insectos de la dieta que representan potenciales plagas agrícolas en la región. De acuerdo con información primaria y secundaria sobre la importancia económica de los cultivos de sorgo, maíz, cítricos y nuez en la zona de influencia y a la intensidad en la aplicación de compuestos químicos para el control de sus plagas, se estima el valor económico de este servicio ambiental en un rango entre $6.5 y$16.5 millones de pesos, con un valor promedio de $260 por hectárea para estos cultivos. Los resultados de este estudio podrán ser utilizados como herramienta de conservación para apoyar la protección de los ecosistemas alrededor de los sitios de percha, que además del control biológico de enfermedades y plagas aportan de manera integral otros importantes servicios ambientales.México, murciélagos, Monterrey, Nuevo León