Characterization of groups using composite kernels and multi-source fMRI analysis data: application to schizophrenia

Pattern classification of brain imaging data can enable the automatic detection of differences in cognitive processes of specific groups of interest. Furthermore, it can also give neuroanatomical information related to the regions of the brain that are most relevant to detect these differences by means of feature selection procedures, which are also well-suited to deal with the high dimensionality of brain imaging data. This work proposes the application of recursive feature elimination using a machine learning algorithm based on composite kernels to the classification of healthy controls and patients with schizophrenia. This framework, which evaluates nonlinear relationships between voxels, analyzes whole-brain fMRI data from an auditory task experiment that is segmented into anatomical regions and recursively eliminates the uninformative ones based on their relevance estimates, thus yielding the set of most discriminative brain areas for group classification. The collected data was processed using two analysis methods: the general linear model (GLM) and independent component analysis (ICA). GLM spatial maps as well as ICA temporal lobe and default mode component maps were then input to the classifier. A mean classification accuracy of up to 95% estimated with a leave-two-out cross-validation procedure was achieved by doing multi-source data classification. In addition, it is shown that the classification accuracy rate obtained by using multi-source data surpasses that reached by using single-source data, hence showing that this algorithm takes advantage of the complimentary nature of GLM and ICAPublicad

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

A metapopulation approach to identify targets for Wolbachia-based dengue control

Over the last decade, the release of Wolbachia-infected Aedes aegypti into the natural habitat of this mosquito species has become the most sustainable and long-lasting technique to prevent and control vector-borne diseases, such as dengue, zika, or chikungunya. However, the limited resources to generate such mosquitoes and their effective distribution in large areas dominated by the Aedes aegypti vector represent a challenge for policymakers. Here, we introduce a mathematical framework for the spread of dengue in which competition between wild and Wolbachia-infected mosquitoes, the cross-contagion patterns between humans and vectors, the heterogeneous distribution of the human population in different areas, and the mobility flows between them are combined. Our framework allows us to identify the most effective areas for the release of Wolbachia-infected mosquitoes to achieve a large decrease in the global dengue prevalence. © 2022 Author(s)

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

Lipid Composition and Associated Gene Expression Patterns during Pollen Germination and Pollen Tube Growth in Olive (Olea europaea L.)

Pollen lipids are essential for sexual reproduction but our current knowledge regarding lipid dynamics in growing pollen tubes is still very scarce. Here, we report unique lipid composition and associated gene expression patterns during olive pollen germination. Up to 376 genes involved in the biosynthesis of all lipid classes, except suberin, cutin and lipopolysaccharides, are expressed in the olive pollen. The fatty acid profile of the olive pollen is markedly different compared with other plant organs. Triacylglycerol, containing mostly C12-C16 saturated fatty acids, constitutes the bulk of olive pollen lipids. These compounds are partially mobilized, and the released fatty acids enter the β-oxidation pathway to yield acetyl-CoA, which is converted into sugars through the glyoxylate cycle in the course of pollen germination. Our data suggest that fatty acids are synthesized de novo and incorporated into glycerolipids by the “eukaryotic pathway” in elongating pollen tubes. Phosphatidic acid is synthesized de novo in the endomembrane system during pollen germination and seems to have a central role in the pollen tube lipid metabolism. The coordinated action of fatty acid desaturases FAD2-3 and FAD3B might explain the increase of linoleic and alpha-linolenic acids observed in the germinating pollen. A continuous synthesis of triacylglycerol by the action of DGAT1 enzyme, but not PDAT, seems also plausible. All these data allow for a better understanding of the lipid metabolism during the olive reproduction process, which can impact in the future in the increase of olive fruit yield and, therefore, olive oil production

Recycling of tailings from the Barruecopardo tungsten deposit for the production of glass

Tailings from tungsten mining activities in the vicinity of Barruecopardo (Salamanca) represent high environmental pollution. In this paper we present a study of the use of these wastes as raw materials for the manufacture of glass. This procedure aims to contribute to environmental remediation of mining areas through vitrification, a process which offers an alternative for stabilization of hazardous wastes. In addition, the marketing of the obtained product would provide an additional income to the mining areas. The chemical composition of the tailings to be used as raw materials was determined by X-ray fluorescence and their mineralogy by X-ray diffraction. Wastes are of granitic composition enriched in potentially toxic elements. For this study, a representative sample of mining wastes of sandy grain size was used to make the glass. On the basis of its composition, glass was formulated by adding 29.28 mass% of CaCO3 and 14.03 mass% of Na2CO3 and a green glass was produced. Crystallisation temperatures, obtained by DTA, were 875 and 1022 °C and the melting temperature was 1175 °C. The transition temperature of glass was of 644 °C. The temperatures for the fixed viscosity points, and the working temperatures were obtained. A thermal treatment induced devitrification to produce a glass-ceramic made of nepheline and wollastonite. Leaching tests of the obtained glass confirm its capacity to retain potentially toxic elements