Effects of electron inertia in collisionless magnetic reconnection

We present a study of collisionless magnetic reconnection within the framework of full two-fluid MHD for a completely ionized hydrogen plasma, retaining the effects of the Hall current, electron pressure and electron inertia. We performed 2.5D simulations using a pseudo-spectral code with no dissipative effects. We check that the ideal invariants of the problem are conserved down to round-off errors. Our results show that the change in the topology of the magnetic field lines is exclusively due to the presence of electron inertia. The computed reconnection rates remain a fair fraction of the Alfv\'en velocity, which therefore qualifies as fast reconnection

On a possible origin for the lack of old star clusters in the Small Magellanic Cloud

We model the dynamical interaction between the Small and Large Magellanic Clouds and their corresponding stellar cluster populations. Our goal is to explore whether the lack of old clusters ($\gtrsim 7$ Gyr) in the Small Magellanic Cloud (SMC) can be the result of the capture of clusters by the Large Magellanic Cloud (LMC), as well as their ejection due to the tidal interaction between the two galaxies. For this purpose we perform a suite of numerical simulations probing a wide range of parameters for the orbit of the SMC about the LMC. We find that, for orbital eccentricities $e \geq 0.4$, approximately 15 per cent of the SMC clusters are captured by the LMC. In addition, another 20 to 50 per cent of its clusters are ejected into the intergalactic medium. In general, the clusters lost by the SMC are the less tightly bound cluster population. The final LMC cluster distribution shows a spatial segregation between clusters that originally belonged to the LMC and those that were captured from the SMC. Clusters that originally belonged to the SMC are more likely to be found in the outskirts of the LMC. Within this scenario it is possible to interpret the difference observed between the star field and cluster SMC Age-Metallicity Relationships for ages $\gtrsim 7$ Gyr.Comment: 5 pages, 3 figures, accepted for publication in MNRAS Letter

AI For Leadership: Implementation And Evaluation Of An AI Education Program

AI education is rapidly becoming the next frontier when it comes to solving the world\u27s grand challenges; however, ways to introduce AI to large complex organisations are still vastly understudied. To address this gap in 2021, Massachusetts Institute of Technology (MIT) entered into a collaboration with the US Air Force (USAF). The goal of this relationship is to develop, study, and evaluate different learning modalities and online/in-person experiences to introduce AI to the diverse USAF workforce. The USAF is a very complex organisation and its employees vary in terms of educational and cultural backgrounds, as well as in their work-related needs, demands and restrictions. The initial program started in 2021 and a pilot study took place. The pilot evaluated the content, pedagogy, and educational technology used in 3 different learning journeys designed for 6 different learner profiles. Findings from 2021 guided improvements for future iterations. The updated iteration of the learning journey was introduced to the second cohort of the program in 2022. Cohort 2 included 200 USAF leaders, managers and decision makers, and the learning journey consisted of a combination of synchronous and asynchronous online experiences, as well as an in-person active learning component offered on campus to a subgroup of the learners. This research paper will introduce the updated iteration of the program, the evaluation of the learning journey, as well as the overall learner experience

Non-Parallel Articulatory-to-Acoustic Conversion Using Multiview-based Time Warping

This work was supported in part by the Spanish State Research Agency (SRA) grant number PID2019-108040RB-C22/SRA/10.13039/501100011033, and the FEDER/Junta de AndalucíaConsejería de Transformación Económica, Industria, Conocimiento y Universidades project no. B-SEJ-570-UGR20.In this paper, we propose a novel algorithm called multiview temporal alignment by dependence maximisation in the latent space (TRANSIENCE) for the alignment of time series consisting of sequences of feature vectors with different length and dimensionality of the feature vectors. The proposed algorithm, which is based on the theory of multiview learning, can be seen as an extension of the well-known dynamic time warping (DTW) algorithm but, as mentioned, it allows the sequences to have different dimensionalities. Our algorithm attempts to find an optimal temporal alignment between pairs of nonaligned sequences by first projecting their feature vectors into a common latent space where both views are maximally similar. To do this, powerful, nonlinear deep neural network (DNN) models are employed. Then, the resulting sequences of embedding vectors are aligned using DTW. Finally, the alignment paths obtained in the previous step are applied to the original sequences to align them. In the paper, we explore several variants of the algorithm that mainly differ in the way the DNNs are trained. We evaluated the proposed algorithm on a articulatory-to-acoustic (A2A) synthesis task involving the generation of audible speech from motion data captured from the lips and tongue of healthy speakers using a technique known as permanent magnet articulography (PMA). In this task, our algorithm is applied during the training stage to align pairs of nonaligned speech and PMA recordings that are later used to train DNNs able to synthesis speech from PMA data. Our results show the quality of speech generated in the nonaligned scenario is comparable to that obtained in the parallel scenario.Spanish State Research Agency (SRA) PID2019-108040RB-C22/SRA/10.13039/501100011033FEDER/Junta de AndalucíaConsejería de Transformación Económica, Industria, Conocimiento y Universidades project no. B-SEJ-570-UGR20

Effect of the particle size of pear pomace on the quality of enriched layer and sponge cakes

Pear pomace (PP) is a by-product of the fruit industry with a high content of fiber. Its potential as an ingredient at 15% or 30% level for sponge and layer cakes was investigated. Three PP powders with different particle sizes (fine, medium and coarse) were obtained. Microstructure, density and viscosity were evaluated in batter, and specific volume, texture and color in the final product. When PP was added, less uniformity in bubble distribution was observed in batters, particularly at higher particle sizes. Cake specific volume significantly diminished with increasing amounts of PP. For sponge cakes, the decrease in specific volume was the highest for the finest particle size of PP. In general, increasing PP addition increased hardness and reduced elasticity, cohesiveness and resilience but the effect depended on the particle size. In general, better textural attributes were obtained with medium and coarse particle sizes. These results indicate that PP of an adequate particle size could be a promising fiber source for different cake formulations.Spanish Ministry of Economy and Competitiveness (Project AGL2014-52928-C2-2-R) and the European Regional Development Fund (FEDER

Particle Size and Hydration Properties of Dried Apple Pomace: Effect on Dough Viscoelasticity and Quality of Sugar-Snap Cookies

Apple pomace (AP) is a by-product of the juice industry, rich in dietary fiber (45.06%), which is generated in large quantities. The objectives of the present work were to evaluate the effect of the particle size and the level of replacement with AP on the quality of sugar-snap cookies. Dehydrated AP was ground to three different particle sizes (d (4,3) = 362, 482, 840 μm) to substitute 15% and 30% of wheat flour in cookie formulations. The quality of dough and cookies was evaluated in terms of rheological properties, color, texture and global acceptability of the final product. When the AP particle size decreased, the water absorption properties (WHC, WBC) were higher (33 and 10 % respectively for the lowest and the highest particle size). For both replacement levels the smallest particle size (362 μm) led to the highest dynamic moduli of dough. The spread ratio (SR) of the cookies diminished when the particle size decreased (from 6.4 to 4.8 corresponding to AP840 and AP362 respectively). The lowest SRs were obtained for the 30% replacement level except for AP362. When employing AP with the largest particle size (840 μm) the cookies were less hard (48.7N). The addition of AP to sugar-snap cookies led to higher global acceptability scores than for control cookies. The sensory attribute that most differentiated the cookies with AP was their pleasant taste being the taste score always higher than the control one.Spanish Ministry of Economy and Competitiveness (Project AGL2014-52928-C2-2-R) and the European Regional Development Fund (FEDER) and the University of La Plata (Projects 11/X661 and 11/X771) and CONICET from Argentin

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

Límites nutricionales para dietas de cabras lecheras en crecimiento

El objetivo del presente trabajo fue revisar el consumo de materia seca y las necesidades nutritivas de cabras lecheras de reposición estabuladas para establecer límites nutricionales aplicables a la formulación de dietas por programación lineal a mínimo coste. El diseño de dietas nutricionalmente adecuadas y económicas requiere que el nutricionista estime correctamente el consumo de materia seca y forraje y los aportes y las necesidades de nutrientes. La bibliografía revisada sugiere que el consumo total de materia seca de las cabras oscila entre los límites físico y fisiológico impuestos por la capacidad del tracto digestivo y las necesidades energéticas diarias. El efecto de llenado digestivo puede relacionarse con los carbohidratos estructurales de la dieta, mientras la saciedad metabólica se relaciona con la concentración energética de la dieta. El consumo mínimo de forraje necesario para mantener la salud ruminal es bajo, mientras que el consumo máximo de forraje está determinado probablemente por el contenido de fibra neutrodetergente de la dieta. Los aportes y las necesidades de energía y proteína calculadas según los dos sistemas de valoración más modernos son similares, por lo que es indistinto usar cualquiera de ambos para optimizar dietas. Las propuestas recientes para el cálculo de los aportes y las necesidades de calcio y fósforo ofrecen una mayor precisión

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

Effect of fat sources on fiber digestion in ruminants

El objetivo del presente trabajo fue revisar el efecto de la inclusión de fuentes de grasa no protegidas sobre la digestión de la fibra en los rumiantes. Es bien conocido que el aporte de grasa extra en forma de fuentes de grasa no protegidas a la dieta puede afectar negativamente a los microorganismos del rumen y, en consecuencia, a la digestión microbiana de la dieta. La bibliografía revisada indica que la fibra es el único componente de la dieta cuya digestibilidad es reducida en ocasiones. Este efecto es menos frecuente cuando el contenido de grasa extra en la dieta no supera el 4% con independencia del grado de insaturación, forma de presentación y procesado de la fuente de grasa. En los trabajos en que se observó reducción de la digestibilidad de la fibra aunque la inclusión de grasa extra en la dieta fue inferior al 4%, el forraje mayoritario aportado fue ensilado, o se utilizaron fuentes de grasa ricas en ácidos grasos poliinsaturados de más de 20 carbonos. Cuando la grasa extra se incluye por encima del 4% en la dieta, la reducción de la digestibilidad de la fibra es más frecuente pero no existe una relación clara entre los resultados observados y las características de la fuente de grasa o de la dieta. En ocasiones, la ausencia de efectos negativos de la grasa extra sobre la digestibilidad total de la fibra puede ser explicada porque la disminución de la digestión ruminal es compensada totalmente por la digestión en los tramos posteriores del tracto digestivo. El efecto negativo de las fuentes de grasa no protegidas sobre la digestibilidad de la fibra se relaciona con el efecto tóxico que los ácidos grasos insaturados de cadena larga tienen sobre las bacterias fibrolíticas y los protozoos ruminales, aunque el mecanismo de acción no ha sido aclarado.The aim of this paper was to review the effect of unprotected dietary lipid sources on fiber digestion in ruminants. It is well known that extra fat included in the diet in the form of unprotected fat sources sometimes can negatively affect rumen microorganisms and alter the microbial digestion of the diet. Reviewed literature points out fiber is the only dietary component whose digestibility can be decreased. This effect is less common when extra fat is included in the diet up to 4% regardless of unsaturation degree, and type or processing of the fat source. Decreased fiber digestibility observed in some studies where extra fat was lower than 4% could be due to the inclusion of silage as the main forage in the diet, or the use of fat sources rich in polyunsaturated fatty acids over 20 carbons. When extra fat is included in the diet above 4%, decreased fiber digestibility is more common but there is not clear relationship between the observed effect and the characteristics of the fat source or the diet. In some studies, the lack of negative effects of extra fat on total fiber digestibility could be explained because digestion in the lower digestive tract completely compensated for the decrease of rumen digestion. Decreased fiber digestibility when unprotected fat sources are included in ruminant diets is related to the toxic effect that long chain unsaturated fatty acids have on rumen fibrolytic bacteria and protozoa, although the exact mechanism of action has not been determined ye