2,124 research outputs found
Financial Aid and Higher Education Enrollment in Chile: A Government Policy Analysis
This paper evaluates the impact of the Chilean government's nancial aid on college and vocational education enrollment. We found that there is an endogenous process in the application for nancial aid. To solve this problem we use a two-step procedure with instrumental variables (IV) and found that nancial aid increases the probability of students going to college by over 30%. In the case of vocational education, we found that being pre-selected for college nancial aid decreases the enrollment. However, vocational nancial aid increases that probability of enrollment. Therefore, students choose college education over vocational education when they have nancial aid for both. Theoretical conclusion and public policy recommendations are provided.Financial aid; college enrollment; Chile; education; public policy.
Adults'Education and Agricultural Innovation: A Social Learning Approach
Social learning processes can be the basis of a method of agricultural innovation that involves expert and empirical knowledge. In this sense, the objective of this study was to determine the effectiveness and sustainability of an innovation process, understood as social learning, in a group of small farmers in the southern highlands of Peru. Innovative proposals and its permanence three years after the process finished were evaluated. It was observed that innovation processes generated are maintained over time; however, new innovations are not subsequently generated. We conclude that adult learning processes and innovation based on social learning are more effective and sustainable; however, the farmers internalization in innovation processes is given longer term
Bilan de 3 ans de fonctionnement d'un système anti-érosif : aspects techniques et socio-économiques, B.V. Sud du lac de Managua, Nicaragua
Efficient Production of -Caproate From Syngas by a Co-culture of Clostridium Aceticum and Clostridium Kluyveri
Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] In recent years, the possibility of merging technologies for waste recovery such as those based on syngas fermentation and chain elongation has been studied for the production of medium chain fatty acids (MCFAs) and bioalcohols, in an attempt to integrate the concept of circular economy in the industry. Nevertheless, one of the main issues of this approach is the pH mismatch between acetogens and chain elongating microorganisms. This work reports, for the first time, the suitability of a co-culture of C. aceticum and C. kluyveri metabolizing syngas at near neutral pH in stirred tank bioreactors. For this purpose, bioreactor studies were carried out with continuous syngas supply. In the first experiment, maximum concentrations of -butyrate and -caproate of 7.0 and 8.2 g/L, respectively, were obtained. In the second experiment, considerable amounts of -butanol were produced as a result of the reduction, by C. aceticum, of the carboxylates already formed in the broth. In both experiments, ethanol was used as an exogenous electron agent at some point. Finally, batch bottle assays were performed with a pure culture of C. aceticum grown on CO in presence of n-butyrate to assess and confirm its ability to produce -butanol, reaching concentrations up to 951 mg/L, with a -butyrate conversion efficiency of 96%, which had never been reported before in this species. Therefore, this work contributes to the state of the art, presenting a novel system for the bioproduction of MCFAs by combining syngas fermentation and chain elongation at near neutral pH, as opposed to the acidic pH range used in all previously reported literature.This research was funded through the Spanish Ministry of Science and Innovation and European FEDER funds (PID2020-117805RB-I00). CFB thanks Xunta de Galicia for her doctoral contract (ED481A-2020/028). The authors, belonging to the BIOENGIN group, thank Xunta de Galicia for financial support to Competitive Reference Research Groups (ED431C 2021/55). Funding for open access charge provided by Universidade da Coruña/CISUGXunta de Galicia; ED481A-2020/028Xunta de Galicia; ED431C 2021/5
La evolución del constructivismo (desde una perspectiva constructivista)
This article discusses the evolutionary conditions of constructivism on society, from Luhmann's social systems theory. First, we review some of the basic notions of the theory of social and cultural evolution, focusing on the concepts of variation, selection and stabilization of semantics in expectation structures. We suggest that these elements find empirical scenarios suitable for observation in scientific and philosophical communications, as well as in cultural productions. Our discussion leads to the question regarding the likeliness of stabilization of constructivism in expectations that operate in everyday life. We conclude with the hypothesis that constructivism -on its expressions on several systems- constitutes an evolutionary acquisition, as it allows the coupling of new and more complex communications in contemporary society.El presente artículo reflexiona respecto de las condiciones de evolución del constructivismo en la sociedad, desde la perspectiva de la teoría de los sistemas sociales de Luhmann. Inicialmente se revisan algunas de las nociones básicas de la teoría de la evolución socio-cultural desde el constructivismo del autor, centrándonos en los conceptos de variación, selección y estabilización de semánticas en estructuras de expectativas. Se sugiere que estos elementos encuentran escenarios empíricos de observación en comunicaciones científicas y filosóficas, así como en producciones culturales. La discusión conduce a la pregunta por la probabilidad de re-estabilización del constructivismo en expectativas que operan en la vida cotidiana. Se concluye con la hipótesis de que el constructivismo -en sus expresiones en varios sistemas- constituye una adquisición evolutiva, en tanto permite el acoplamiento de nuevas comunicaciones progresivamente más complejas en la sociedad contemporánea
Proteccion a la Salud en Chile, derecho real o aparente?
72 p.La salud es un tema de interés general presente en cada etapa de la vida de las personas, por esto, no solo la medicina se ha ocupado de ella, sino también el derecho, por medio de la creación de distintas Leyes tanto a nivel nacional como internacional, que permitan su protección. La salud es un derecho que requiere para subsistir, un sistema sanitario que garantice a todos por igual un oportuno y completo acceso a la salud. El Estado es el responsable de garantizar este derecho evitando su vulneración, estableciendo mecanismos de acción, en caso de existir una violación a este derecho fundamental. Nuestra Constitución, considera el Derecho a la Salud como un derecho fundamental, estableciéndolo así en el artículo 19 Nº 9. Se intentará definir la realidad de la salud en nuestro país y a nivel internacional, intentando plasmar las dificultades que presenta el Recurso de Protección en salud
Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations
Conservation Genetics August 2015, Volume 16, Issue 4, pp 1011–1012 Erratum to: Pronounced genetic structure and low genetic diversity in European red-billed chough (Pyrrhocorax pyrrhocorax) populations Erratum to: Conserv Genet (2012) 13:1213–1230 DOI 10.1007/s10592-012-0366-6 In the original publication, Tables 3 and 6 were published with incorrect estimates of population heterozygosities. All other diversity statistics were correct as originally presented. Updated versions of Tables 3 and 6 with corrected heterozygosity estimates confirmed using Arlequin 3.5 (Excoffier and Lischer 2010) as in Dávila et al. (2014) are provided in this erratum. Discrepancies were minor for populations on the British Isles. The correct estimates for Spain are slightly larger than those reported for La Palma by Dávila et al. (2014), but this does not necessarily affect their interpretation that choughs on La Palma may have originated from multiple migration events. The original conclusion that chough populations on the British Isles have low genetic diversity compared to continental European populations remains and is now, in fact, strengthened.Peer reviewedPostprin
Routes to High-Performing Ruthenium–Iodide Catalysts for Olefin Metathesis: Ligand Lability Is Key to Efficient Halide Exchange
Clean, high-yielding routes are described to ruthenium–diiodide catalysts that were recently shown to enable high productivity in olefin metathesis. For the second-generation Grubbs and Hoveyda catalysts (GII: RuCl2(H2IMes)(PCy3)(═CHPh); HII: RuCl2(H2IMes)(═CHAr), Ar = C6H4-2-OiPr), slow salt metathesis is shown to arise from the low lability of the ancillary PCy3 or ether ligands, which retards access to the four-coordinate intermediate required for efficient halide exchange. To exploit the lability of the first-generation catalysts, the diiodide complex RuI2(PCy3)(═CHAr) HI-I2 was prepared by treating “Grubbs I” (RuCl2(PCy3)2(═CHPh), GI) with NaI, H2C═CHAr (1a), and a phosphine-scavenging Merrifield iodide (MF-I) resin. Subsequent installation of H2IMes or cyclic (alkyl)(amino)carbene (CAAC) ligands afforded the second-generation iodide catalysts in good to excellent yields. Given the incompatibility of the nitro group with a free carbene, the iodo-Grela catalyst RuI2(H2IMes)(═CHAr′) (nG-I2: Ar′ = C6H3-2-OiPr-4-NO2) was instead accessed by sequential salt metathesis of GI with NaI, installation of H2IMes, and finally cross-metathesis with the nitrostyrenyl ether H2C═CHAr′ (1b), with MF-I as the phosphine scavenger. The bulky iodide ligands improve the selectivity for macrocyclization in ring-closing metathesis.publishedVersio
Shedding light on the taxonomic diversity of the south american miocene caimans: the status of Melanosuchus fisheri (Crocodylia, Alligatoroidea)
Melanosuchus niger Spix is distributed throughout the Amazon River basin today. The extinct Melanosuchus fisheri Medina from the late Miocene of Venezuela was erected based on two almost complete, but heavily deformed skulls (the holotype MCNC 243 and the referred specimen MCZ 4336), which show morphological differences from each other. The comparison indicates that only the holotype can be referred to Melanosuchus Gray. We propose MCZ 4336 is a representative of the caimanine Globidentosuchus brachyrostris Scheyer, Aguilera, Delfino, Fortier, Carlini, Sánchez, Carrillo-Briceño, Quiroz and Sãnchez-Villagra. Although the taxonomy of M. fisheri is taken into question herein, the classification of the holotype still sustains the hypothesis that the genus is registered in South America since the late Miocene
Efectos del cambio climático sobre los mamíferos marinos
El cambio climático representa uno de los desafíos más significativos y urgentes que enfrenta nuestro
planeta en la actualidad. Los ecosistemas acuáticos, en particular, se encuentran bajo una creciente
presión debido a los impactos que está causando el cambio climático, siendo los mamíferos marinos
especies especialmente vulnerables a estos cambios ambientales. Los mamíferos marinos desempeñan
un papel crucial en sus respectivos ecosistemas y constituyen un reflejo de su estado de salud, por lo
que su declive podría acarrear consecuencias para otras especies y para el medio ambiente en general.
En consecuencia, determinar las respuestas de estos organismos a los cambios definidos por el nuevo
contexto ambiental resultará esencial para adoptar medidas de gestión adaptativas y eficientes.
El presente estudio tiene como objetivo proporcionar un análisis exhaustivo de los efectos del cambio
climático en los mamíferos marinos a través de una revisión de la literatura existente. Se han
examinado los principales impactos a los cuales se enfrentan los mamíferos marinos a raíz del cambio
climático, destacando sus respectivas influencias, así como el potencial efecto sinérgico que puede
existir entre los impactos de origen climático y los impactos de origen antrópico, evaluando así mismo
aquellas especies de mamíferos marinos que, según la literatura actual, presentan una mayor
vulnerabilidad. Se han observado y pronosticado efectos sobre la distribución, el hábitat, la fisiología y
la fenología de los mamíferos marinos; no obstante, se requiere de una mayor investigación para poder
estimar con precisión los mecanismos subyacentes de estos impactos y sus implicaciones a largo plazo.Climate change represents one of the most significant and urgent challenges facing our planet today.
Aquatic ecosystems, in particular, are under increasing pressure due to the impacts caused by climate
change, with marine mammals being especially vulnerable to these environmental changes. Marine
mammals play a crucial role in their respective ecosystems and serve as indicators of their overall
health, making their decline potentially consequential for other species and the environment as a
whole. Consequently, determining the responses of these organisms to the changes defined by the new
environmental context will be essential for implementing adaptive and efficient management measures.
The present study aims to provide a comprehensive analysis of the effects of climate change on marine
mammals through a review of existing literature. The main impacts faced by marine mammals as a
result of climate change have been examined, highlighting their respective influences, as well as the
potential synergistic effects between climate-induced impacts and anthropogenic impacts. The study
also evaluates those marine mammal species that, according to current literature, exhibit greater
vulnerability. Effects on the distribution, habitat, physiology and phenology of marine mammals have
been observed and predicted. However, further research is required to accurately estimate the
underlying mechanisms of these impacts and their long-term implications.Ciencias del Ma
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