Comparative genomics begins to unravel the ecophysiology of bioleaching

A comparison of the metabolic potential of 20 bioleaching microorganisms and their close relatives from the Eubacteria and Archaea kingdoms permits the prediction of inter-and intra-species physiological interactions (ecophysiology) during spatial and temporal changes that are known to occur within industrial bioleaching heaps. Genome analysis has allowed preliminary models to be built for genes and pathways involved in key processes such as nitrogen and carbon cycling, sulfur and iron uptake and homeostasis, extra-cellular polysaccharide biosynthesis, heavy metal resistance and energy metabolism. This paper will focus on the diverse ways that bioleaching microorganisms obtain carbon from their environment with a particular emphasis on elucidating how these processes might be expected to vary over space and time during the lifetime of a bioleaching operation. It is anticipated that this knowledge will improve our understanding of fundamental biological processes in extremely acidic environments

Whole Genome Linkage Disequilibrium and Effective Population Size in a Coho Salmon (Oncorhynchus kisutch) Breeding Population Using a High-Density SNP Array

The estimation of linkage disequilibrium between molecular markers within a population is critical when establishing the minimum number of markers required for association studies, genomic selection, and inferring historical events influencing different populations. This work aimed to evaluate the extent and decay of linkage disequilibrium in a coho salmon breeding population using a high-density SNP array. Linkage disequilibrium was estimated between a total of 93,502 SNPs found in 64 individuals (33 dams and 31 sires) from the breeding population. The markers encompass all 30 coho salmon chromosomes and comprise 1,684.62 Mb of the genome. The average density of markers per chromosome ranged from 48.31 to 66 per 1 Mb. The minor allele frequency averaged 0.26 (with a range from 0.22 to 0.27). The overall average linkage disequilibrium among SNPs pairs measured as r2 was 0.10. The Average r2 value decreased with increasing physical distance, with values ranging from 0.21 to 0.07 at a distance lower than 1 kb and up to 10 Mb, respectively. An r2 threshold of 0.2 was reached at distance of approximately 40 Kb. Chromosomes Okis05, Okis15 and Okis28 showed high levels of linkage disequilibrium (>0.20 at distances lower than 1 Mb). Average r2 values were lower than 0.15 for all chromosomes at distances greater than 4 Mb. An effective population size of 43 was estimated for the population 10 generations ago, and 325, for 139 generations ago. Based on the effective number of chromosome segments, we suggest that at least 74,000 SNPs would be necessary for an association mapping study and genomic predictions. Therefore, the SNP panel used allowed us to capture high-resolution information in the farmed coho salmon population. Furthermore, based on the contemporary Ne, a new mate allocation strategy is suggested to increase the effective population size

Escuelas gobernadas por resultados:Efectividad escolar y políticas educacionales de la transición. Chile, 1990-2017

The governments of the Chilean democratic transition understood the task of re-democratizing the educational system based on the imperative of quality and equity. This study analyzes the grounding concepts of educational policies established in the democratic transition in Chile (1990-2017). It postulates that school effectiveness is the articulating element of these policies, a theoretical and ideological discourse related to a complex discursive plot, coupled with more general transformations of the State, also called second generation reforms. This study uses a qualitative documentary method analysis, and intellectual history and the theory of ideology as data analysis techniques. Among the results emerges the generalization of new public management process, subjecting the institutions to a new form of control and internal competition. It is concluded that school effectiveness is based on a research model that reduces the social complexity of education to the measurement, which is functional to governments that seek consensus and that are not oriented to social change or to the construction of more egalitarian, instituting, in this way, technical answers to political problems.Los gobiernos de la transición democrática chilena comprendieron la tarea de re-democratizar el sistema educacional en base al imperativo de la calidad y la equidad. Este estudio analiza los conceptos que fundamentan las políticas educacionales de la transición democrática en Chile (1990-2017). Se postula que el elemento articulador de estas políticas es la efectividad escolar, un discurso teórico e ideológico relacionado a una compleja trama discursiva que se acopla con transformaciones más generales del Estado, llamadas también reformas de segunda generación. Se utiliza un método cualitativo de análisis documental, y la historia intelectual y la teoría de la ideología como técnicas de análisis de la información. Entre los resultados emerge la generalización del proceso de nueva gestión pública, sometiendo a las instituciones a una nueva forma de control y competencia interna. Se concluye que la efectividad escolar se fundamenta en un modelo de investigación que reduce la complejidad social de la educación a lo medible, lo que es funcional a los gobiernos que buscan consensos y que no están orientados al cambio social ni hacia la construcción de sociedades más igualitarias, instituyendo, de esta manera, respuestas técnicas a problemas políticos.   

The burden of excessive saturated fatty acid intake attributed to ultra-processed food consumption: a study conducted with nationally representative cross-sectional studies from eight countries

Abstract Cross-sectional nutritional survey data collected in eight countries were used to estimate saturated fatty acid intakes. Our objective was to estimate the proportion of excessive saturated fatty acid intakes (&gt;10 % of total energy intake) that could be avoided if ultra-processed food consumption was reduced to levels observed in the first quintile of each country. Secondary analysis was performed of 24 h dietary recall or food diary/record data collected by the most recently available nationally representative cross-sectional surveys carried out in Brazil (2008–9), Chile (2010), Colombia (2005), Mexico (2012), Australia (2011–12), the UK (2008–16), Canada (2015) and the US (2015–16). Population attributable fractions estimated the impact of reducing ultra-processed food consumption on excessive saturated fatty acid intakes (above 10 % of total energy intake) in each country. Significant relative reductions in the percentage of excessive saturated fatty acid intakes would be observed in all countries if ultra-processed food consumption was reduced to levels observed in the first quintile\u27s consumption. The reductions in excessive intakes ranged from 10⋅0 % (95 % CI 6⋅2–13⋅6 %) in Canada to 35⋅0 % (95 % CI 28⋅7–48⋅0 %) in Mexico. In all eight studied countries, all presenting more than 30 % of intakes with excessive saturated fatty acids, lowering the dietary contribution of ultra-processed foods to attainable, context-specific levels was shown to be a potentially effective way to reduce the percentage of intakes with excessive saturated fatty acids, which may play an important role in the prevention of non-communicable diseases, particularly cardiovascular diseases.</jats:p