108 research outputs found

    Copy number variation analysis in the great apes reveals species-specific patterns of structural variation

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    Gazave, Elodie et al.Copy number variants (CNVs) are increasingly acknowledged as an important source of evolutionary novelties in the human lineage. However, our understanding of their significance is still hindered by the lack of primate CNV data. We performed intraspecific comparative genomic hybridizations to identify loci harboring copy number variants in each of the four great apes: bonobos, chimpanzees, gorillas, and orangutans. For the first time, we could analyze differences in CNV location and frequency in these four species, and compare them with human CNVs and primate segmental duplication (SD) maps. In addition, for bonobo and gorilla, patterns of CNV and nucleotide diversity were studied in the same individuals. We show that CNVs have been subject to different selective pressures in different lineages.Evidence for purifying selection is stronger in gorilla CNVs overlapping genes, while positive selection appears to have driven the fixation of structural variants in the orangutan lineage. In contrast, chimpanzees and bonobos present high levels of common structural polymorphism, which is indicative of relaxed purifying selection together with the higher mutation rates induced by the known burst of segmental duplication in the ancestor of the African apes. Indeed, the impact of the duplication burst is noticeable by the fact that bonobo and chimpanzee share more CNVs with gorilla than expected. Finally, we identified a number of interesting genomic regions that present high-frequency CNVs in all great apes, while containing only very rare or even pathogenic structural variants in humans.Financial support was provided by a Beatriu de Pinos postdoctoral Grant to E.G., the Spanish Ministry of Science and Innovation (Grant BFU2009-13409-02-02toA.N.),and the Spanish National Institute for Bioinformatics (INB, www.inab.org).Peer reviewe

    Tecnología de la elaboración de quesos: experiencias de investigación aplicada y capacitación para estudiantes, técnicos, pequeños productores y la comunidad en general

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    Con un volumen de unos 11.300 millones de litros anuales, la Argentina es el segundo productor de leche de Latinoamérica, luego de Brasil. Los quesos constituyen el destino industrial más importante de la leche en nuestro país. Con los objetivos de 1) difundir los aspectos más salientes de los procesos de transformación de leche en productos elaborados para el público en general y 2) realizar aportes en la mejora de los procesos de producción de quesos para pequeños productores y técnicos del sector, hemos venido realizando en los últimos años diferentes actividades desde el Laboratorio de Investigación en Productos Agroindustriales (LIPA) de la Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata. Así, se organizaron talleres y cursos de capacitación para diferentes grupos: a) alumnos de educación inicial interesados en conocer los fundamentos del proceso de transformación de leche en queso, b) estudiantes de colegios secundarios agropecuarios con interés en profundizar en aspectos de calidad e industrialización de leche, c) estudiantes de la carrera de biotecnología de la UNLP con curiosidad por conocer cómo herramientas de interés desarrolladas biotecnológicamente (cuajo, cultivos iniciadores) son empleadas en la industria, d) pequeños productores y técnicos con interés de mejorar sus productos y servicios. Asimismo, en el laboratorio se llevan adelante investigaciones aplicadas tendientes a determinar la influencia de factores de proceso sobre la calidad y estabilidad de quesos. Algunos de los aspectos analizados incluyen la influencia del nivel de grasa de la leche sobre la calidad sensorial, composición de quesos, la optimización de la obtención de ricota a partir de leche, la influencia de la intensidad de lavado de la masa sobre las propiedades funcionales de queso cremoso. La combinación de investigación aplicada y actividades de capacitación y divulgación resulta una estrategia indispensable para poder transferir los conocimientos disponibles en las instituciones universitarias al medio así como para retroalimentar a la universidad con problemáticas reales y los saberes del sector productivo

    The Unknown Risk of Vertical Transmission in Sleeping Sickness—A Literature Review

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    Children with human African trypanosomiasis (HAT) present with a range of generally non-specific symptoms. Late diagnosis is frequent with often tragic outcomes. Trypanosomes can infect the foetus by crossing the placenta. Unequivocal cases of congenital infection that have been reported include newborn babies of infected mothers who were diagnosed with HAT in the first 5 days of life and children of infected mothers who had never entered an endemic country themselves

    Restricted Application of Insecticides: A Promising Tsetse Control Technique, but What Do the Farmers Think of It?

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    Restricted application of insecticides to cattle is a cheap and safe farmer-based method to control tsetse and the diseases they transmit, i.e. human and animal African trypanosomoses. The efficiency of this new control method has been demonstrated earlier but no data is available on its perception and adoption intensity by farmers. We studied these two features in Burkina Faso, where the method has diffused thanks to two development projects. The study allowed identifying three groups of farmers with various adoption intensities, of which one was modern and two traditional. The economic benefit and the farmers' knowledge of the epidemiological system appeared to have a low impact on the early adoption process whereas some modern practices, as well as social factors appeared critical. The quality of technical support provided to the farmers had also a great influence on the adoption rate. The study highlighted individual variations in risk perceptions and benefits, as well as the prominent role of the socio-technical network of cattle farmers. The results of the study are discussed to highlight the factors that should be taken into consideration, to move discoveries from bench to field for an improved control of trypanosomoses vectors

    Gut microbiota and diabetes: from pathogenesis to therapeutic perspective

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    More than several hundreds of millions of people will be diabetic and obese over the next decades in front of which the actual therapeutic approaches aim at treating the consequences rather than causes of the impaired metabolism. This strategy is not efficient and new paradigms should be found. The wide analysis of the genome cannot predict or explain more than 10–20% of the disease, whereas changes in feeding and social behavior have certainly a major impact. However, the molecular mechanisms linking environmental factors and genetic susceptibility were so far not envisioned until the recent discovery of a hidden source of genomic diversity, i.e., the metagenome. More than 3 million genes from several hundreds of species constitute our intestinal microbiome. First key experiments have demonstrated that this biome can by itself transfer metabolic disease. The mechanisms are unknown but could be involved in the modulation of energy harvesting capacity by the host as well as the low-grade inflammation and the corresponding immune response on adipose tissue plasticity, hepatic steatosis, insulin resistance and even the secondary cardiovascular events. Secreted bacterial factors reach the circulating blood, and even full bacteria from intestinal microbiota can reach tissues where inflammation is triggered. The last 5 years have demonstrated that intestinal microbiota, at its molecular level, is a causal factor early in the development of the diseases. Nonetheless, much more need to be uncovered in order to identify first, new predictive biomarkers so that preventive strategies based on pre- and probiotics, and second, new therapeutic strategies against the cause rather than the consequence of hyperglycemia and body weight gain

    Parameterization of a coarse-grained model of cholesterol with point-dipole electrostatics

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    © 2018, Springer Nature Switzerland AG. We present a new coarse-grained (CG) model of cholesterol (CHOL) for the electrostatic-based ELBA force field. A distinguishing feature of our CHOL model is that the electrostatics is modeled by an explicit point dipole which interacts through an ideal vacuum permittivity. The CHOL model parameters were optimized in a systematic fashion, reproducing the electrostatic and nonpolar partitioning free energies of CHOL in lipid/water mixtures predicted by full-detailed atomistic molecular dynamics simulations. The CHOL model has been validated by comparison to structural, dynamic and thermodynamic properties with experimental and atomistic simulation reference data. The simulation of binary DPPC/cholesterol mixtures covering the relevant biological content of CHOL in mammalian membranes is shown to correctly predict the main lipid behavior as observed experimentally
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