2,303 research outputs found

    Spin-orbit transitions in the N+^+(3PJA^3P_{J_A}) + H2_2 →\rightarrow NH+^+(X2ΠX^2\Pi, 4Σ−^4\Sigma^-)+ H(2S^2S) reaction, using adiabatic and mixed quantum-adiabatic statistical approaches

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    The cross section and rate constants for the title reaction are calculated for all the spin-orbit states of N+^+(3PJA^3P_{J_A}) using two statistical approaches, one purely adiabatic and the other one mixing quantum capture for the entrance channel and adiabatic treatment for the products channel. This is made by using a symmetry adapted basis set combining electronic (spin and orbital) and nuclear angular momenta in the reactants channel. To this aim, accurate {\it ab initio} calculations are performed separately for reactants and products. In the reactants channel, the three lowest electronic states (without spin-orbit couplings) have been diabatized, and the spin-orbit couplings have been introduced through a model localizing the spin-orbit interactions in the N+^+ atom, which yields accurate results as compared to {\it ab initio} calculations including spin-orbit couplings. For the products, eleven purely adiabatic spin-orbit states have been determined with {\it ab initio} calculations. The reactive rate constants thus obtained are in very good agreement with the available experimental data for several ortho-H2_2 fractions, assuming a thermal initial distribution of spin-orbit states. The rate constants for selected spin-orbit JAJ_A states are obtained, to provide a proper validation of the spin-orbit effects to obtain the experimental rate constants.Comment: 14 pages, 10 figures, submitted to J. Chem. Phy

    Impacto del sector minero en el ciclo de la economía peruana: 1950-2017

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    En este trabajo se hace un recuento de parte de la historia económica de Perú desde la década de los cincuenta del siglo XX y las dos primeras décadas de este siglo. El objetivo es conocer las estrategias de crecimiento y políticas económicas implementadas para desarrollar la economía peruana. El Perú por su geografía y por su extensión territorial es un país rico en yacimientos mineros por lo que su estrategia de crecimiento ha sido primaria exportadora a pesar que en el presente siglo estamos imbuidos de tecnología de información y conocimiento. Solamente hubo un intento de industrialización promovido por gobiernos militares en la década de los sesenta que fue un fracaso por la aplicación tardía y por falta de políticas económicas correctas.In this paper a recount of part of the economic history of Peru is made from the fifties of the twentieth century and the first two decades of this century. The objective was to know the growth strategies and economic policies implemented to develop the Peruvian economy. Peru, because of its geography and its territorial extension, is some country rich in mineral deposits, so its growth strategy has been primary exporter, although in the present century we are imbued with information and knowledge technology

    Downregulation of mTOR Signaling Increases Stem Cell Population Telomere Length during Starvation of Immortal Planarians

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    Reduction of caloric intake delays and prevents age-associated diseases and extends the life span in many organisms. It may be that these benefits are due to positive effects of caloric restriction on stem cell function. We use the planarian model Schmidtea mediterranea, an immortal animal that adapts to long periods of starvation by shrinking in size, to investigate the effects of starvation on telomere length. We show that the longest telomeres are a general signature of planarian adult stem cells. We also observe that starvation leads to an enrichment of stem cells with the longest telomeres and that this enrichment is dependent on mTOR signaling. We propose that one important effect of starvation for the rejuvenation of the adult stem cell pool is through increasing the median telomere length in somatic stem cells. Such a mechanism has broad implications for how dietary effects on aging are mediated at the whole-organism level.C.G.-E. was funded by a Contrato de Investigadores Miguel Servet (CP12/03214) and by the FLI. The FLI is a member of the Leibniz Association and is financially supported by the Federal Government of Germany and the State of Thuringia. O.G.-G. was funded by an LGSA scholarship. R.P. and B.F.-V. were funded by a grant (PI17-01401) from Fondo de Investigaciones Sanitarias (Instituto de Salud Carlos III, Spain) and FEDER funds. I.F. was funded by grants from Ministerio de Ciencia, Innovación y Universidades (SAF2016-80406-R), Comunidad de Madrid (S2017/BMD-3875), and the Red Temática de Investigación Cooperativa en Enfermedades Cardiovasculares (RD12/0042/0045). The CNIC is supported by the Ministerio de Ciencia, Innovación y Universidades and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). A.A.A. was funded by grants from the BBSRC (BB/K007564/1) and MRC (MR/M000133/1), and S.S. by a University of Oxford Clarendon Fund Scholarship.S

    Risk factors associated to retained placenta in Holstein cows

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    Background: Retained placenta (RP) is characterized by a failure to remove the fetal membranes within the first 12-24 h after calving. This condition appears to be related to a decrease in neutrophil activity and to the suppression of the immune response in the prepartum period. The specific reasons for some cows to retain the placenta after parturition is still not fully understood, but numerous predisposing factors have been related, which may include mechanical, nutritional, infectious and handling factors. The aim of this study was to analyze the occurrence of retained placenta in dairy cows and to correlate the main predisposing factors related. Materials, Methods & Results: This study was conducted in nine dairy farms located in the Rio Grande do Sul state, Brazil, with an average of 45 lactating dairy cows producing 10,100 kg / dairy cow in a period of 305 days. The total diet for postpartum cows was estimated to meet or exceed the requirements of dairy cows according to previously established guidelines (NRC 2001). A total of 393 calving Holstein cows (126 primiparous and 267 multiparous) were analyzed, of which 203 were kept in a semi-confined production system (free-stall and pasture system) and 190 animals were kept in a free-stall production system. Statistically, the cows were the experimental unit, and the results were analyzed using the Pearson’s Chi-squared test or Fisher’s exact test for the comparisons of occurrence of peripartum disorders. In addition, linear and logistic regression models were constructed to determine the effect of the dependent variable on the other indicators, which may be continuous or categorical. Possible correlations of the occurrence of peripartum disorders related to production system (free-stall or semi-confined), calving order (primiparous or multiparous), season of the year (heat or cold), ECC at calving (1 to 5), calf sex, rectal temperature and dystocia were analyzed. Of the 393 deliveries followed up in this study, 72 presented retained placenta as a postpartum complication. Cows that delivered male calves had a 3.45 times higher chance of presenting dystocia birth (P = 0.0007) and had 1.85 times more chances of presenting placental retention (P = 0.066) when compared to cows with female calves. Cows with dystocia were more likely to present RP (P = 0.0433). Twin pregnancies increased 3.9 times chances of RP (P = 0.0193). Discussion: The incidence of RP in our study was 18.3%, which is close to the previously reported by another Brazilian study (22%) and similar to another study that also verified the risk factor indicators (19.9%). Dystocia, twin births and male births were predisposing factors for RP, similarly to previous studies. The frequency of dystocia was significantly affected by the production system employed, with the semi-confined system presenting more cases of dystocia, unlike other studies. The season of the year had no influence in the RP occurrence, unlike other studies that showed RP may have an increase in spring and summer months. A possible correlation between RP and body condition score at calving and with the production system employed was not observed. The limited options of effective treatments for RP emphasizes the importance of prevention. RP prevention includes the reduction of stressful factors, especially in the peripartum period, with a focus one nutrition and animal health

    Biallelic mutations in NBAS cause recurrent acute liver failure with onset in infancy

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    Acute liver failure (ALF) in infancy and childhood is a life-threatening emergency. Few conditions are known to cause recurrent acute liver failure (RALF), and in about 50% of cases, the underlying molecular cause remains unresolved. Exome sequencing in five unrelated individuals with fever-dependent RALF revealed biallelic mutations in NBAS. Subsequent Sanger sequencing of NBAS in 15 additional unrelated individuals with RALF or ALF identified compound heterozygous mutations in an additional six individuals from five families. Immunoblot analysis of mutant fibroblasts showed reduced protein levels of NBAS and its proposed interaction partner p31, both involved in retrograde transport between endoplasmic reticulum and Golgi. We recommend NBAS analysis in individuals with acute infantile liver failure, especially if triggered by fever

    SMG-1 and mTORC1 Act Antagonistically to Regulate Response to Injury and Growth in Planarians

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    Planarian flatworms are able to both regenerate their whole bodies and continuously adapt their size to nutrient status. Tight control of stem cell proliferation and differentiation during these processes is the key feature of planarian biology. Here we show that the planarian homolog of the phosphoinositide 3-kinase-related kinase (PIKK) family member SMG-1 and mTOR complex 1 components are required for this tight control. Loss of smg-1 results in a hyper-responsiveness to injury and growth and the formation of regenerative blastemas that remain undifferentiated and that lead to lethal ectopic outgrowths. Invasive stem cell hyper-proliferation, hyperplasia, hypertrophy, and differentiation defects are hallmarks of this uncontrolled growth. These data imply a previously unappreciated and novel physiological function for this PIKK family member. In contrast we found that planarian members of the mTOR complex 1, tor and raptor, are required for the initial response to injury and blastema formation. Double smg-1 RNAi experiments with tor or raptor show that abnormal growth requires mTOR signalling. We also found that the macrolide rapamycin, a natural compound inhibitor of mTORC1, is able to increase the survival rate of smg-1 RNAi animals by decreasing cell proliferation. Our findings support a model where Smg-1 acts as a novel regulator of both the response to injury and growth control mechanisms. Our data suggest the possibility that this may be by suppressing mTOR signalling. Characterisation of both the planarian mTORC1 signalling components and another PIKK family member as key regulators of regeneration and growth will influence future work on regeneration, growth control, and the development of anti-cancer therapies that target mTOR signalling

    Development and internal validation of a multifactorial risk prediction model for gallbladder cancer in a high-incidence country

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    Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population-based controls to develop and internally validate three GBC risk prediction models. The Baseline Model accounted for gallstones while adjusting for sex and birth year. Enhanced Model I also included the non-genetic risk factors: body mass index, educational level, Mapuche surnames, number of children and family history of GBC. Enhanced Model II further included Mapuche ancestry and the genotype for rs17209837. Multiple Cox regression was applied to assess the predictive performance, quantified by the area under the precision-recall curve (AUC-PRC) and the number of cholecystectomies needed (NCN) to prevent one case of GBC at age 70 years. The AUC-PRC for the Baseline Model (0.44%, 95%CI 0.42-0.46) increased by 0.22 (95%CI 0.15-0.29) when non-genetic factors were included, and by 0.25 (95%CI 0.20-0.30) when incorporating non-genetic and genetic factors. The overall NCN for Chileans with gallstones (115, 95%CI 104-131) decreased to 92 (95%CI 60-128) for Chileans with a higher risk than the median according to Enhanced Model I, and to 80 (95%CI 59-110) according to Enhanced Model II. In conclusion, age, sex and gallstones are strong risk factors for GBC, but consideration of other non-genetic factors and individual genotype data improves risk prediction and may optimize allocation of financial resources and surgical capacity.Fil: Boekstegers, Felix. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Scherer, Dominique. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Barahona Ponce, Carol. Ruprecht Karls Universitat Heidelberg; AlemaniaFil: Marcelain, Katherine. Universidad de Chile; ChileFil: Gárate Calderón, Valentina. Universidad de Chile; ChileFil: Waldenberger, Melanie. No especifíca;Fil: Morales, Erik. Universidad Católica de Maule; ChileFil: Rojas, Armando. Universidad Católica de Maule; ChileFil: Munoz, César. Universidad Católica de Maule; ChileFil: Retamales, Javier. Instituto Nacional del Cáncer; ChileFil: de Toro, Gonzalo. Universidad Austral de Chile; ChileFil: Barajas, Olga. Universidad de Chile; ChileFil: Rivera, María Teresa. Hospital del Salvador; ChileFil: Cortés, Analía. Hospital del Salvador; ChileFil: Loader, Denisse. Hospital Padre Hurtado; ChileFil: Saavedra, Javiera. Hospital Padre Hurtado; ChileFil: Gutiérrez, Lorena. Hospital San Juan de Dios; ChileFil: Ortega, Alejandro. Hospital Regional; ChileFil: Bertrán, Maria Enriqueta. Hospital Base de Valdivia; ChileFil: Bartolotti, Leonardo. Hospital Base de Valdivia; ChileFil: Gabler, Fernando. Hospital Clínico San Borja Arriarán; ChileFil: Campos, Mónica. Hospital Clínico San Borja Arriarán; ChileFil: Alvarado, Juan. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Moisán, Fabricio. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Spencer, Loreto. Hospital Regional de Concepción - Dr. Guillermo Grant Benavente; ChileFil: Nervi, Bruno. No especifíca;Fil: Carvajal Hausdorf, Daniel. Universidad del Desarrollo; ChileFil: Losada, Héctor. Universidad de La Frontera; ChileFil: Almau, Mauricio. Hospital de Rancagua; ChileFil: Fernández, Plinio. Hospital de Rancagua; ChileFil: Olloquequi, Jordi. Universidad de Barcelona; EspañaFil: Fuentes Guajardo, Macarena. Universidad de Tarapacá; ChileFil: Gonzalez-Jose, Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Ciencias Sociales y Humanas; ArgentinaFil: Bortolini, Maria Cátira. Universidade Federal do Rio Grande do Sul; BrasilFil: Acuña Alonzo, Victor. No especifíca;Fil: Gallo, Carla. Universidad Peruana Cayetano Heredia; PerúFil: Ruiz-Linares, Andres. Colegio Universitario de Londres; Reino UnidoFil: Rothhammer, Francisco. Universidad de Tarapacá; ChileFil: Lorenzo Bermejo, Justo. Ruprecht Karls Universitat Heidelberg; Alemani

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
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