232 research outputs found
Discovering people's relationships with nature in central Chile : a case study in a peri-urban commune.
La valoración social de la vida silvestre es reconocida como esencial para lograr una conservación biológica efectiva. Esto se fundamenta en la comprensión de las relaciones de las personas con la vida silvestre. Esta necesidad ya ha sido planteada en el contexto de las políticas ambientales internacionales. En Chile, ha sido explícitamente mencionada como relevante en la Estrategia Nacional de Biodiversidad, que declara la necesidad de un mejor entendimiento de cómo los ciudadanos chilenos están utilizando y valorando la biodiversidad. Sin embargo, en Chile aún existe poca evidencia científica al respecto. El presente artículo tiene como objetivo analizar las relaciones que las personas tienen con la naturaleza de su territorio de tal forma de establecer cuáles son las visiones que tienen sobre la fauna y flora. El estudio se desarrolla en un área periurbana de la Región Metropolitana de Santiago de Chile. El enfoque utilizado para el análisis de las relaciones personas-vida silvestre fue cualitativo, con base en la Teoría Fundamentada. A través del estudio se evidenció que la naturaleza es identificada por los habitantes por medio de elementos tangibles de su entorno natural, la cual se constituye a través de una relación entre el individuo, la sociedad y el mundo físico. Los resultados muestran una gran importancia de los bosques de quillay (Quillaja saponaria) para los participantes lo cual da luces sobre la relevancia que tiene el contexto sociocultural en el cual se llevan a cabo las valoraciones sociales de la vida silvestre, dado que en este tipo de estudios la fauna generalmente emerge como más relevante. En Chile, a excepción de unos pocos estudios científicos, existen muy pocas experiencias publicadas que aborden la importancia social de plantas particulares. Con este estudio pretendemos aportar a la literatura científica con un estudio de caso así como también contribuir a la gestión de la conservación del área.The social assessment of wildlife is recognized as essential to achieve effective biological conservation. This is based on the understanding of people's relationships with wildlife. This need has already been raised in the context of international environmental policies. In Chile, it has been explicitly mentioned as relevant in the National Biodiversity Strategy, which declares the need for a better understanding of how Chilean citizens are using and valuing biodiversity. However, in Chile there is still little scientific evidence in this regard. This article aims to analyze the relationships that people have with nature in their territory in order to establish what the visions that they have on fauna and flora are. The study is carried out in a peri-urban area of the Metropolitan Region of Santiago de Chile. The approach used for the analysis of people-wildlife relationships was qualitative, based on the Grounded Theory. Through the study it was shown that nature is identified by the inhabitants through tangible elements of their natural environment, which is constituted through a relationship between the individual, society and the physical world. The results show a great importance of the quillay forests (Quillaja saponaria) for the participants which gives light on the relevance of the socio-cultural context in which social assessment of wildlife are carried out, given that in this type of studies fauna generally emerges as more relevant. With the exception of a few scientific studies, there are very few published experiences in Chile that address the social importance of particular plants. This study intends to contribute to the scientific literature with a case study, as well as to contribute to the management of the conservation of the area
El problema eléctrico chileno : un estudio de caso de controversia sociotécnica (1935-1939)
En este artículo estudiamos las controversias sobre la creación de una red eléctrica en Chile que un conjunto de ingenieros mantuvo entre 1935 y 1939. Estas surgieron en conferencias dadas en el Instituto de Ingenieros de Chile. Nuestro objetivo principal es probar que dichas controversias (centradas en el rol del Estado, el mercado y la infraestructura en el desarrollo de la red eléctrica en Chile) definieron una política estatal energética nacional. Estas discusiones también muestran el despliegue de una red sociotécnica y el papel que tuvieron los ingenieros en las políticas de Estado. Así, abordamos un caso propio de los estudios de ciencia, tecnología y sociedad para destacar los vínculos de lo político y lo técnico en el ámbito de la electrificación. Para este artículo, nos basamos principalmente en fuentes primarias de la administración estatal y artículos de la revista Anales del Instituto de Ingenieros de Chile.In this article, we study controversies about the creation of an electric network in Chile that a group of engineers had between 1935 and 1939. They came from conferences given in the Institute of Engineers of Chile. Our primary aim is to prove that these controversies (centered in the role of State, market and infrastructure in the development of the national electric grid in Chile) defined a national energy state policy. These discussions also show the deployment of a socio-technical network and the role that the engineers had in State's policies. In this way, we address a typical case of science and technology studies to highlight the links of the political and the technical in the ambit of electrification. For this article, we used principally primary sources of the State's administration and articles from the journal Anales del Instituto de Ingenieros de Chile
Association mapping of seed quality traits using the Canadian flax (Linum usitatissimum L.) core collection
KEY MESSAGE: The identification of stable QTL for seed quality traits by association mapping of a diverse panel of linseed accessions establishes the foundation for assisted breeding and future fine mapping in linseed. ABSTRACT: Linseed oil is valued for its food and non-food applications. Modifying its oil content and fatty acid (FA) profiles to meet market needs in a timely manner requires clear understanding of their quantitative trait loci (QTL) architectures, which have received little attention to date. Association mapping is an efficient approach to identify QTL in germplasm collections. In this study, we explored the quantitative nature of seed quality traits including oil content (OIL), palmitic acid, stearic acid, oleic acid, linoleic acid (LIO) linolenic acid (LIN) and iodine value in a flax core collection of 390 accessions assayed with 460 microsatellite markers. The core collection was grown in a modified augmented design at two locations over 3 years and phenotypic data for all seven traits were obtained from all six environments. Significant phenotypic diversity and moderate to high heritability for each trait (0.73–0.99) were observed. Most of the candidate QTL were stable as revealed by multivariate analyses. Nine candidate QTL were identified, varying from one for OIL to three for LIO and LIN. Candidate QTL for LIO and LIN co-localized with QTL previously identified in bi-parental populations and some mapped nearby genes known to be involved in the FA biosynthesis pathway. Fifty-eight percent of the QTL alleles were absent (private) in the Canadian cultivars suggesting that the core collection possesses QTL alleles potentially useful to improve seed quality traits. The candidate QTL identified herein will establish the foundation for future marker-assisted breeding in linseed. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00122-014-2264-4) contains supplementary material, which is available to authorized users
Esquemas de conceptualización del tiempo en mapudungun
This paper presents an analisys of time conceptualizations in Mapuche language. The purpose of this research is to contrast the model that proposes the universal existence of related schemata for time conceptualization, usually simplified into one single schema, called “spatialization” of time. In order to do so, we use textual and ethnographical methods. On the one hand, we analise expressions of two texts from the beggining of 20th century, where temporal expressions in Mapuche language and their conceptual structures are identified. On the other hand, we conducted semi-structured interviews with eleven Mapuche adults in the ethnic comunnity of Llaguepulli, Región de la Araucanía, Chile. The results show that Mapuche language produces spatialized expressions of time, that are consistent with the conceptual mapping time events are things in space (Núñez 1999), usually in relation to event-based time intervals (Sinha et al. 2011). However, we also note the centrality of a schema merely related to the notion of transience (Evans 2013), endorsing the data that support that time experience is inherently temporal rather than spatial. In conclusion, we claim that the best way to understand time conceptualizations in Mapuche language is as a diverse phenomenon, through al least five conceptual schemata, in some of which it is still possible to recognize specific sub-schemata
Estudio exploratorio para el establecimiento in vitro de Pitavia punctata (R. et P.) Mol
66 p.Se estudió el efecto de tres factores sobre la respuesta de explantes para cultivo in vitro de Pitavia punctata (R. et P.) Mol., especie endémica de la cordillera de la costa chilena que crece entre Linares y Malleco. Los factores fueron: a) exposición del árbol desde la cual fueron tomadas las muestras (norte o sur); b) tiempo de inmersión para los explantes en una solución desinfectante (8, 16 y 25 minutos), y c) concentración de hipoclorito de sodio como solución desinfectante (2,5 y 3%). Los resultados indican que las muestras expuestas a altas concentraciones de hipoclorito y a largos tiempos de inmersión (3% y 25 minutos, respectivamente) presentaron altos niveles de explantes sanos (61,5%) en contraposición a las otras combinaciones de factores (32,14%, 22,22% y 4,35% en otros casos, por ejemplo). Un posterior análisis de factores en relación con la proporción de explantes con o sin contaminación sugiere que no existe relación significativa entre la exposición de la copa del árbol desde la cual se extraen los explantes y el nivel de contaminación (valor-p de 0,63). Por su parte, el tiempo de inmersión y la concentración de la solución desinfectante resultaron ser factores determinantes en los resultados del ensayo, con valores-p de 0,0081 y 0,0028, respectivamente.
SUMMARY The effect of three factors on the response of Pitavia punctata (R. et P.) Mol. explants to in vitro culture, an endemic species of the Chilean Coast Range which grows between Linares and Malleco, was studied. These factors were: a) treetop exposure which samples were taken from (north or south), b) disinfectant solution immersion times of explants (8, 16 and 25 minutes), and c) disinfectant solution sodium hipoclorite concentration (2,5 and 3%). The results show that samples exposed to higher concentrations of sodium hipoclorite and longer immersion periods (3% and 25 minutes, respectively) presented higher levels of healthy explants (61,5%), in contrast to the other factor combinations (32,14%, 22,22% and 4,35% in the other cases, for example). A subsequent factor analysis in relation to the proportion of explants with or without contamination suggests that there‟s no significant relation between the treetop exposure which samples were taken from and the contamination level (p-value of 0,63). Disinfectant solution immersion times of explants and disinfectant solution sodium hipoclorite concentration showed the greatest influence on the test results, with p-values of 0,0081 and 0,0028, respectively
Discrete-like diffraction dynamics in free space
We introduce a new class of paraxial optical beams exhibiting discrete-like diffraction patterns reminiscent to those observed in periodic evanescently coupled waveguide lattices. It is demonstrated that such paraxial beams are analytically described in terms of generalized Bessel functions. Such effects are elucidated via pertinent examples
Todos los instrumentos están en buen estado’. Disputas en torno al funcionamiento de los telescopios del Observatorio Astronómico Nacional de Chile en el siglo XIX
This paper analyses a public controversy about the state of the main instruments at the National Astronomical Observatory of Chile at the end of the 19th century, the repair and the maintenance work of these tools and the scientific production of this institution. The controversy involved a wide range of actors, including members of the National Congress, ministers of State, astronomers, mechanics and architects. This case examines the close link between the political and the techno-scientific spheres, evidenced in the administration, financing, evaluation and oversight of the work of the observatory. We can observe how the questioning of scientific quality, such as the state of the instruments of the institution, faced not only the judgments, but also the authority of those who issued. Also, this controversy allows us to observe how the need to create associated technologies and adapt astronomical instruments gave prominence to mechanics, engineers and architects, actors often invisible in comparison to astronomers.El artículo analiza una controversia pública sobre el estado de los principales instrumentos del Observatorio Astronómico Nacional de Chile a fines del siglo XIX, las labores de reparación y mantención de estos y la producción científica de la institución. En la controversia participaron una amplia gama de actores, entre los que se encuentran miembros del Congreso Nacional, ministros de Estado, astrónomos, mecánicos y arquitectos. Este caso permite examinar la estrecha vinculación entre la esfera política y la tecnocientífica, evidenciándose en la administración, financiamiento, evaluación y fiscalización del quehacer del observatorio astronómico. Acá podemos observar cómo el cuestionamiento sobre la calidad científica, como el estado de los instrumentos de la institución, enfrentó no solo los juicios, sino la autoridad de quienes los emitían. Por otro lado, esta controversia permite observar cómo la necesidad de crear tecnologías asociadas y adaptar los instrumentos astronómicos dio un protagonismo a mecánicos, ingenieros y arquitectos, actores muchas veces invisibles en comparación con los astrónomos
Nanoencapsulated laccases obtained by double-emulsion technique. Effects on enzyme activity ph-dependence and stability
One primary drawback of enzyme catalysis at industrial scale is the short-term service life of the enzymes, they lose their activity due to oxidation or other processes which results in less stability and a shorter lifetime thereby rendering them less efficient. An effective way to increase the stability of the enzymes is to attach them to nanoparticles. In this work, the polymer Eudragit® L 100-55 sensitive to pH was used to prepare laccase polymeric nanoparticles by the double-emulsion solvent evaporation approach. The size and morphology of the nanoparticles obtained were evaluated—as well as the encapsulation efficiency and zeta potential. pH effect on activity and stability was compared between free and immobilized laccase. Their stability was also determined in a sequential assay involving acidic pHs up to alkaline ones. The nanoparticles had a spherical shape with a mean size of 147 nm, zeta potential of −22.7 mV at pH 7.0 and load efficiency of 87%. The optimum pH of both free and immobilized laccases was 3.0, being the nanoparticles more stable at acidic pHs. Thus, this would be the first report of obtaining laccase nanoparticles with potential application in animal feed due to the stability conferred to enzymatic activity at pHs similar to those present in the gastrointestinal tract of rabbits, which would allow their potential use in animal feed.Fil: Chong Cerda, Rocío. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Levin, Laura Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Castro Ríos, Rocío. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Hernández Luna, Carlos Eduardo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: González Horta, Azucena. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Gutiérrez Soto, Guadalupe. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Chávez Montes, Abelardo. Universidad Autonoma de Nuevo Leon.; Méxic
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