El positivismo y las ciencias en el período finisecular del Chile decimonónico

Se analiza el aporte de la filosofía positivista a la ciencia nacional de fines del siglo xix en Chile, especialmente la contribución de sus principales exponentes: José Victorino Lastarria, los Hnos. Lagarrigue y Valentín Letelier entre otros; así como lWe analyze the contribution of the positivist philosophy to the national science at the end of the 19th Century in Chile, especially the work of its main exponents: José Victorino Lastarria, the Lagarrigue brothers, Valentín Letelier and others; as well

Preliminary results on the 233U capture cross section and alpha ratio measured at n_TOF (CERN) with the fission tagging technique

233U is of key importance among the fissile nuclei in the Th-U fuel cycle. A particularity of 233U is its small neutron capture cross-section, which is on average about one order of magnitude lower than the fission cross-section.The accuracy in the measurement of the 233U capture cross-section depends crucially onan efficient capture-fission discrimination, thus a combined set-up of fission and ¿-detectors is needed. A measurement of the 233U capture cross-section and capture-to-fissionratio was performed at the CERN n_TOF facility. The Total Absorption Calorimeter (TAC) of n_TOF was employed as ¿-detector coupled with a novel compact ionization chamber as fission detector. A brief description of the experimental set-up will be given, and essential parts of the analysis procedure as well as the preliminary response of the set-up to capture are presented and discussedPostprint (published version

Effectiveness of a group-based psychosocial program to prevent depression and anxiety in older people attending primary health care centres: a randomised controlled trial

Background: Evidence about the effectiveness of psychosocial interventions to reduce the incidence of depression and anxiety and promote subjective well-being in older people is limited, particularly in Latin-American countries. This study thus aims to assess a program specifically designed to address this issue in persons aged 65 to 80 and attending primary health care centres. Method: Older people who use primary care centres are to be randomly assigned to the program or to a control group. Only independent users will be included; those having had a major depressive disorder or an anxiety disorder in the last 6 months will be excluded. The program is group based; it includes cognitive stimulation, expansion of social support networks and cognitive behaviour strategies. Depressive and anxiety symptoms and disorders, as well as psychological well-being, will be assessed using standardised instruments, once before implementing the program and later, after 18 and 36 weeks. Discussion: Primary care is a setting where interventions to improve mental health can be beneficial. Providing evidence-based programs that work with older people is a priority for public mental health

Tcf7l2 plays pleiotropic roles in the control of glucose homeostasis, pancreas morphology, vascularization and regeneration

Type 2 diabetes (T2D) is a disease characterized by impaired insulin secretion. The Wnt signaling transcription factor Tcf7l2 is to date the T2D-associated gene with the largest effect on disease susceptibility. However, the mechanisms by which TCF7L2 variants affect insulin release from β-cells are not yet fully understood. By taking advantage of a tcf7l2 zebrafish mutant line, we first show that these animals are characterized by hyperglycemia and impaired islet development. Moreover, we demonstrate that the zebrafish tcf7l2 gene is highly expressed in the exocrine pancreas, suggesting potential bystander effects on β-cell growth, differentiation and regeneration. Finally, we describe a peculiar vascular phenotype in tcf7l2 mutant larvae, characterized by significant reduction in the average number and diameter of pancreatic islet capillaries. Overall, the zebrafish Tcf7l2 mutant, characterized by hyperglycemia, pancreatic and vascular defects, and reduced regeneration proves to be a suitable model to study the mechanism of action and the pleiotropic effects of Tcf7l2, the most relevant T2D GWAS hit in human populations. © 2017 The Author(s)

Dual-initiation promoters with intertwined canonical and TCT/TOP transcription start sites diversify transcript processing

Variations in transcription start site (TSS) selection reflect diversity of preinitiation complexes and can impact on post-transcriptional RNA fates. Most metazoan polymerase II-transcribed genes carry canonical initiation with pyrimidine/purine (YR) dinucleotide, while translation machinery-associated genes carry polypyrimidine initiator (5'-TOP or TCT). By addressing the developmental regulation of TSS selection in zebrafish we uncovered a class of dual-initiation promoters in thousands of genes, including snoRNA host genes. 5'-TOP/TCT initiation is intertwined with canonical initiation and used divergently in hundreds of dual-initiation promoters during maternal to zygotic transition. Dual-initiation in snoRNA host genes selectively generates host and snoRNA with often different spatio-temporal expression. Dual-initiation promoters are pervasive in human and fruit fly, reflecting evolutionary conservation. We propose that dual-initiation on shared promoters represents a composite promoter architecture, which can function both coordinately and divergently to diversify RNAs

Stereotypic behaviour in standard non-enriched cages is an alternative to depression-like responses in C57BL/6 mice

publisher: Elsevier articletitle: Stereotypic behaviour in standard non-enriched cages is an alternative to depression-like responses in C57BL/6 mice journaltitle: Behavioural Brain Research articlelink: http://dx.doi.org/10.1016/j.bbr.2016.02.005 content_type: article copyright: Copyright © 2016 Elsevier B.V. All rights reserved

Reparos anatómicos para la exposición extradural de la pared lateral del seno cavernoso

Los abordajes a la región de la pared lateral del seno cavernoso (SC) pueden generalmente implicar la apertura dural inicial, disección y retracción cerebral. Estos abordajes exigen una retracción importante del lóbulo temporal y de las venas ubicadas en la superficie lateral del cerebro. Existen alternativas en las cuales la mayor parte del abordaje a la región lateral del SC se realiza por fuera de la paquimeninges, que es lo que conocemos como “peeling de fosa media”.Facultad de Ciencias Médica

Reparos anatómicos para la exposición extradural de la pared lateral del seno cavernoso

Los abordajes a la región de la pared lateral del seno cavernoso (SC) pueden generalmente implicar la apertura dural inicial, disección y retracción cerebral. Estos abordajes exigen una retracción importante del lóbulo temporal y de las venas ubicadas en la superficie lateral del cerebro. Existen alternativas en las cuales la mayor parte del abordaje a la región lateral del SC se realiza por fuera de la paquimeninges, que es lo que conocemos como “peeling de fosa media”.Facultad de Ciencias Médica