Magneto--Acoustic Energetics Study of the Seismically Active Flare of 15 February 2011

Multi--wavelength studies of energetic solar flares with seismic emissions have revealed interesting common features between them. We studied the first GOES X--class flare of the 24th solar cycle, as detected by the Solar Dynamics Observatory (SDO). For context, seismic activity from this flare (SOL2011-02-15T01:55-X2.2, in NOAA AR 11158) has been reported in the literature (Kosovichev, 2011; Zharkov et al., 2011). Based on Dopplergram data from the Helioseismic and Magnetic Imager (HMI), we applied standard methods of local helioseismology in order to identify the seismic sources in this event. RHESSI hard X-ray data are used to check the correlation between the location of the seismic sources and the particle precipitation sites in during the flare. Using HMI magnetogram data, the temporal profile of fluctuations in the photospheric line-of-sight magnetic field is used to estimate the magnetic field change in the region where the seismic signal was observed. This leads to an estimate of the work done by the Lorentz-force transient on the photosphere of the source region. In this instance this is found to be a significant fraction of the acoustic energy in the attendant seismic emission, suggesting that Lorentz forces can contribute significantly to the generation of sunquakes. However, there are regions in which the signature of the Lorentz-force is much stronger, but from which no significant acoustic emission emanates.Comment: Submitted to Solar Physic

Effect of feed evaluation system on the cost of rations for dairy cows

El objetivo del presente trabajo fue comparar la valoración de las necesidades y los aportes de energía calculados según sistemas históricos y modernos de alimentación para vacas lecheras -unidades alimenticias escandinavas (UA), energía neta grasa (ROSTOCK), energía metabolizable (MAFF), energía neta de lactación (NRC) y unidades forrajeras leche (INRA)- con el fin de investigar la repercusión de aquella en el coste de la ración diaria. Las necesidades energéticas se expresaron como energía neta de lactación (ENL) y se calcularon a intervalos de 30 días en leche (DEL) para una vaca Holstein adulta de 680 kg de peso vivo con una producción de 10000 kg de leche en 305 días y un intervalo entre partos de un año. El aporte de ENL según cada sistema se calculó a partir de diez raciones optimizadas con el programa CPMDairy 1.0 para satisfacer las necesidades nutritivas de la vaca modelo cada 30 DEL. Exceptuando los valores obtenidos con el sistema de unidades alimenticias y el comienzo inmediato de la lactación, las diferencias entre las necesidades de ENL calculadas según los distintos sistemas fueron relativamente bajas (entre 1,1 y 7,5%) y achacables fundamentalmente a la valoración energética del cambio de peso. El aporte calculado de energía mostró diferencias importantes entre los sistemas, oscilando de 19,1 a 25,2%. A lo largo de la lactación, los aportes calculados fueron inferiores a las necesidades en todos los sistemas, con la excepción de NRC y MAFF a 30 y 270 DEL, respectivamente, y UA desde 90 DEL. La diferencia promedio estuvo comprendida entre -1,4 ± 1,1 Mcal d-1 (4,5 ± 2,9%; MAFF) y -5,5 ± 1,7 Mcal d-1 (15,6 ± 4,5%; INRA). El coste unitario de la Mcal varió notablemente entre sistemas (de 18,7 a 25,5%) al igual que el coste de satisfacer los requerimientos diarios de energía (de 13,5 a 50,2%). Se concluyó que, independientemente de cual sea la precisión real, el sistema de valoración de energía empleado en la formulación tiene una importante repercusión sobre el coste de las raciones para vacas lecherasThe objective of the present work was to compare energy requirements and supply calculated according to old and modern feed evaluation systems for dairy cattle - Scandinavian feed units (UA), net energy fat (ROSTOCK), metabolizable energy (MAFF), net energy of lactation (NRC) and milk fodder units (INRA) - to assess the differences in the cost of the ration. The energy requirements were expressed as net energy of lactation (NEL) and were calculated every 30 days in milk (DIM) for a mature Holstein cow weighing 680 kg, producing 10000 kg of milk in 305 days, and calving every year. Ten rations optimized with CPM-Dairy 1.0 to satisfy the nutritional requirements of the model cow every 30 DIM were used to compare the calculated NEL supply according to the systems being evaluated. Except for the values obtained according to the feed units system and the onset of lactation, the differences between the systems in the calculated energy requirements were relatively low (from 1.1% to 7.5%) and mainly attributable to the energy value assigned to the live weight change. The differences between the systems in the NEL supply of the rations were high and oscillated between 19.1% and 25.2%. The calculated supplies were smaller than the requirements in all the systems throughout lactation, except for UA from 90 DIM and NRC and MAFF at 30 and 270 DIM, respectively. The average differences were in the range from -1.4 ± 1.1 Mcal d-1 (4.5 ± 2.9%; MAFF) to -5.5 ± 1.7 Mcal d-1 (15.6 ± 4.5%; INRA). The cost of the Mcal differed between the systems (from 18.7% to 25.5%) and the same was true for the cost of satisfying the daily energy requirements (from 13.5% to 50.2%). It was concluded that, without taking into account the real accuracy, the energy evaluation system used in the formulation affects considerably the cost of rations for lactating dairy cattle

A statistical correlation of sunquakes based on their seismic and white-light emission

Several mechanisms have been proposed to explain the transient seismic emission, i.e. “sunquakes,” from some solar flares. Some theories associate high-energy electrons and/or white-light emission with sunquakes. High-energy charged particles and their subsequent heating of the photosphere and/or chromosphere could induce acoustic waves in the solar interior. We carried out a correlative study of solar flares with emission in hard X-rays, enhanced continuum emission at 6173 Å, and transient seismic emission. We selected those flares observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) with a considerable flux above 50 keV between 1 January 2010 and 26 June 2014. We then used data from the Helioseismic and Magnetic Imager onboard the Solar Dynamic Observatory to search for excess visible-continuum emission and new sunquakes not previously reported. We found a total of 18 sunquakes out of 75 flares investigated. All of the sunquakes were associated with an enhancement of the visible continuum during the flare. Finally, we calculated a coefficient of correlation for a set of dichotomic variables related to these observations. We found a strong correlation between two of the standard helioseismic detection techniques, and between sunquakes and visible-continuum enhancements. We discuss the phenomenological connectivity between these physical quantities and the observational difficulties of detecting seismic signals and excess continuum radiation

Experimental conditions for microhabitat selection in terrestrial snails

Habitat selection by terrestrial snails, used as laboratory animals, is an important factor because it can alter growth rates often used as a good biological indicator, moreover of its productive meaning. As support to the studies in this field, different models from election of microhabitat based on the individual selection or derived from other questions as the availability or the accessibility of the habitat or patron of movement of the organism are reviewed. Finally two experimental designs used in invertebrates under laboratorial conditions for preference studies are considered.La selección de hábitat por los caracoles terrestres que se utilizan como animales de experimentación, es importante porque condiciona el crecimiento y éste, además de su importancia productiva, es un buen indicador en muchos estudios. Como apoyo a los estudios en este campo, se revisan diferentes modelos de elección de microhábitat en función de la selección del propio individuo o bien derivados de cuestiones en buena parte ajenas a él como la disponibilidad o accesibilidad del hábitat o el patrón de movimiento del organismo. Finalmente se plantean dos diseños experimentales adecuados para el estudio de preferencia en invertebrados bajo condiciones de laboratorio

Malacological diversity in Andalusia. Renewable resource

The aim of this study is the evaluation of malacological diversity in Andalusian region. It has been observed high heterogeneity in relation to distribution patters of snails. Terrestrial edible snail populations are grouped in zones in relation to spatial distribution and specie. Zone I is located in Sierra Morena and shows a low density level of the most commonly edible species (O. lactea, H. aspersa, T. pisana and E. vermiculata). Zone II is extended throughout La Campiña and Vega del Guadalquivir. This zone is widely populated by snails with great economically importance: O. lactea and T. pisana and H. aspersa with a smaller density. Zone III is located in Sierras Béticas and it is characterised by the presence of many endemic populations (O. lactea murcica, O. punctata, T. pisana arietina, T. subdentata helicella, C. nemoralis, I. gualtierianus gualtierianus, I. gualtierianus alonensis, I. gualtierianus guiraoanus, etc.). It is necessary to develop strategic plans in order to conserve the malacological diversity in Andalusia.El objetivo del estudio es la evaluación de la diversidad malacológica andaluza como base del aprovechamiento de un recurso genético de interés económico. Se zonifican las poblaciones de caracoles comestibles existentes en Andalucía en relación al número de especies y su distribución geográfica. Se observa elevada heterogeneidad que da lugar a la conformación de tres zonas diferenciadas, en las que aparecen fundamentalmente los géneros Otala, Theba, Cantareus, Iberus, Eobania, Cepaea, Pseudotachea y Sphincterochila. La Zona I comprende Sierra Morena y se caracteriza por una baja presencia de caracoles, asociados mayoritariamente a la presencia humana y representados por las especies más comunes (O. lactea, H. aspersa, T. pisana y E. vermiculata). La Zona II comprende la Campiña y Vega del Guadalquivir, donde aparecen las especies de mayor valor comercial: O. lactea y T. pisana, con gran distribución; y H. aspersa con menor presencia. Finalmente la Zona III, que se integra por las Sierras Béticas donde aparecen, junto con las especies anteriormente citadas, gran diversidad de taxones con elevada singularidad, debido a la existencia de un número importante de endemismos y poblaciones relictas (O. lactea murcica, O. punctata, T. pisana arietina, T. subdentata helicella, C. nemoralis, I. gualtierianus gualtierianus, I. gualtierianus alonensis, I. gualtierianus guiraoanus, etc.). La existencia de esta biodiversidad justifica la necesidad de adoptar acciones estratégicas y planes específicos de conservación que preserven este recurso de forma eficaz

Characteristics of Conservation Laws for Difference Equations

Each conservation law of a given partial differential equation is determined (up to equivalence) by a function known as the characteristic. This function is used to find conservation laws, to prove equivalence between conservation laws, and to prove the converse of Noether's Theorem. Transferring these results to difference equations is nontrivial, largely because difference operators are not derivations and do not obey the chain rule for derivatives. We show how these problems may be resolved and illustrate various uses of the characteristic. In particular, we establish the converse of Noether's Theorem for difference equations, we show (without taking a continuum limit) that the conservation laws in the infinite family generated by Rasin and Schiff are distinct, and we obtain all five-point conservation laws for the potential Lotka-Volterra equation

Sociology of caprine production systems in western Pampa

Goat ranches in the west area of La Pampa Province (Argentina) are analyzed by mean of surveys. These are long tradition family enterprises (2.5 man equivalent) with owners (average 53.3 years old) that believe in the continuity of their farms. The educational level is very low (about 80 percent are real or functional illiterates), although 46 percent of their inheritors had completed the primary school and 15 percent had completed the high school. Technical assistance is received mainly from governmental programs. Kids are the main sale product and about 18 percent of them are used for family feeding. Other source of income would be increased adding value by mean of handmade manufacture (cheese, hair, spinning, tan leather, etc.)Mediante encuesta se estudian las explotaciones caprinas del oeste pampeano (Argentina). Son empresas familiares (2,5 equivalentes hombre), de larga tradición cuyos responsables, de bastante edad (53,3 años), confían en la continuidad de las explotaciones. El nivel educativo es muy bajo (alrededor del 80 p.100 son analfabetos reales o funcionales), aunque entre los posibles herederos el 46 p.100 ha completado la escuela primaria y el 15 p.100 la secundaria. El apoyo técnico que reciben corresponde casi exclusivamente a programas estatales. El cabrito para venta es el principal producto registrándose un 18 p.100 de autoconsumo. Otras fuentes de ingreso podrían potenciarse agregándoles valor por medio de procesos artesanales de elaboración (quesos, hilado de pelo, curtidos de cueros, etc.)

Acorn production at the dehesa: influential factors

This paper reviews the state-of-the-knowledge of acorn production in the South-Western Iberian dehesas. In the first part are briefly described the soil and climatic determining factors and phenology of most common trees of genus Quercus at the dehesa (Q. ilex, Q. suber and Q. faginea). In the second part, acorn production estimations are analyzed. Was established a mean acorn yield of 300 to 700 kg/ha; with individual productions of 8-14 kg/tree for Q. ilex, 5-10 kg/tree for Q. suber and 1-11 kg/tree for Q. faginea; with a highly variable production, both between and within years and individual trees. Finally we review the factors affecting acorn production, describing density of trees (estimated in 20-50 trees/ha), masting phenomenon (with cycles of 2-5,5 years and asynchrony between trees), individual cha-racteristics of trees (genetic potential, age, top surface, etc.), tree mass handling (with favourable effect of tilling, moderate pruning and sustainable grazing), meteorological conditions (mainly drought and meteorology during flowering) and sanitary status (Lymantria, Tortrix, Curculio, Cydia, Balaninus and Brenneria).Se revisa el conocimiento sobre la producción de bellota en las dehesas del SW de la Península Ibérica. Primero se analizan los condicionantes edafoclimáticos y la fenología de los principales árboles del género Quercus (Q. ilex, Q. suber y Q. faginea) presentes en las dehesas. A continuación se analiza la producción de bellota, que presentan valores medios de 300 a 700 kg/ha y producciones individuales de 8-14 kg/árbol para Q. ilex, 5-10 kg/árbol para Q. suber y 1-11 kg/árbol para Q. faginea; resultando producciones muy variables entre individuos, tanto intra como interanualmente. Finalmente, se revisan los factores que afectan a la producción de bellota; y entre éstos se describen la densidad de árboles (estimada en 20-50 pies adultos/ha), el fenómeno de la vecería (con ciclos de 2-5,5 años y asincronía entre árboles), las características individuales de los árboles (potencial genético, edad, superficie de copa, etc.), el manejo de la arboleda (con efecto favorable del laboreo, las podas ligeras y el pastoreo sostenible), las condiciones meteorológicas (principalmente sequía y meteorología durante la floración) y el estado sanitario (Lymantria, Tortrix, Curculio, Cydia, Balaninus y Brenneria)

Diet digestibility and production performance in dairy goats consuming plant oils

The aim of this study was to investigate the effects of differently unsaturated vegetable oils added to dairy goat diets on apparent digestibility and performance traits. Twelve Malagueña goats were randomly assigned to one of four treatments: no oil (CONTROL), 48 g/d of high oleic sunflower oil (GAO), regular sunflower oil (RSFO) or linseed oil (LIN). The basal diet was made of alfalfa hay and a pelleted concentrate, which included the respective oil and chromium as indicator. The experimental period lasted 21 days. The digestibility of dietary components, except for fat, did not differ between treatments (P > 0.05). Oil inclusion in the diet significantly (P < 0.05) increased fat digestibility. There were no significant differences (P > 0.05) in dry matter intake, milk yield and milk composition between treatments. It was concluded that moderate amounts of unsaturated plant oils can be added to dairy goat diets without negative effects on diet digestibility or performance traits

Lipid metabolism in ruminants

El objetivo de este trabajo fue revisar algunos aspectos del metabolismo lipídico y características relevantes de la grasa de la carne y la leche de los rumiantes. Los ácidos grasos disponibles para la absorción en el intestino delgado de los rumiantes proceden de los alimentos y los microorganismos ruminales, y son mayoritariamente ácidos grasos saturados y no esterificados debido a la digestión microbiana ruminal. Los ácidos grasos absorbidos que tienen menos de 12 carbonos son vertidos directamente a la vena porta y transportados al hígado unidos a la albúmina sérica; el resto son esterificados e incorporados a lipoproteínas de muy baja densidad y quilomicrones que se transportan por vía linfática hasta el torrente sanguíneo para su distribución a los tejidos. El hígado de los rumiantes tiene menor importancia en el metabolismo lipídico que el de los monogástricos, pero adquiere especial relevancia en situaciones de balance energético negativo en las que la alteración del metabolismo hepático de los lípidos puede provocar graves patologías. Los depósitos grasos distintos de la musculatura están constituidos casi exclusivamente por triglicéridos y son la principal reserva de energía del organismo. Por el contrario, la grasa intramuscular posee distintas proporciones de fosfolípidos y triglicéridos en función del grado de engrasamiento. Los fosfolípidos de las membranas celulares son el lugar preferente de deposición de los ácidos grasos poliinsaturados disponibles. La composición de la grasa láctea varía en función del origen de los ácidos grasos: ácidos grasos de cadena larga de origen alimentario o movilizados desde el tejido adiposo, o ácidos grasos de cadena corta y media sintetizados in situ a partir de acetato y betahidroxibutirato. La mayor parte de los ácidos grasos incorporados a los triglicéridos lácteos son captados de la sangre. La importante contribución de los ácidos grasos de la dieta consumida por los rumiantes a los lípidos de sus productos ofrece la posibilidad de modificar el contenido de los ácidos grasos de la carne y, sobre todo, la leche en un sentido favorable para la salud de los consumidores.In this paper, key aspects of lipid metabolism and characteristics of ruminants’ meat and milk fat were reviewed. Fatty acids available for absorption in the small intestine of ruminants are from dietary and microbial origin and, because of microbial digestion in the rumen, are mainly nonsterified saturated fatty acids. Short chain fatty acids (less than 12 carbon atoms) are absorbed into the bloodstream, bound to serum albumin and transported to the liver through the portal vein. Medium and long chain fatty acids are esterified upon their absorption and transported via lymph to the bloodstream as chylomicrons and very low density lipoproteins, to be used by the different tissues. In ruminants, the liver has a minor role in lipid metabolism compared with monogastrics, but it is especially relevant in situations of intense negative energy balance when the hepatic metabolism of lipids may be altered causing severe pathologies. Fat depots other than intramuscular depots are composed mainly of triglycerides and are the major energy reserve of the body. However, the proportion of phospholipids and triglycerides in the intramuscular fat depends on the degree of fatness. The cell membrane phospholipids are the preferred site of deposition of available polyunsaturated fatty acids. Milk fat composition depends on the origin of the fatty acids: long chain fatty acids from dietary origin or mobilized from adipose tissue, or medium and short chain fatty acids synthesized in situ from acetate and betahydroxybutyrate. Most fatty acids incorporated into milk triglycerides are taken from the blood. The major contribution of dietary fatty acids to meat and, specially, milk fatty acids offers the possibility of changing the fatty acid profile of ruminant products to promote human consumer health