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Massive scalar field perturbations in Weyl black holes
No full textIn this work we consider the propagation of massive scalar fields in the background of Weyl black holes, and we study the effect of the scalar field mass in the spectrum of the quasinormal frequencies (QNFs) via the Wentzel-Kramers-Brillouin (WKB) method and the pseudo-spectral Chebyshev method. The spectrum of QNFs is described by two families of modes: the photon sphere and the de Sitter modes. Essentially, we show via the WKB method that the photon sphere modes exhibit an anomalous behaviour of the decay rate of the QNFs; that is, the longest-lived modes are the ones with higher angular numbers, and there is a critical value of the scalar field mass beyond which the anomalous behaviour is inverted. We also analyse the effect of the scalar field mass on each family of modes and on their dominance, and we give an estimated value of the scalar field mass where the interchange in the dominant family occurs
Territorios aislados en disputa: tensiones en las recientes expresiones del capitalismo en Cerro Castillo, Patagonia-Aysén
No full textThis article aims to analyze the socio-territorial transformations that underlie the commodification of nature in Patagonia-Aysen, for which the Cerro Castillo area is taken as a case study. Mixed research methods were used, combining qualitative and quantitative methods in order to understand the complexities of the social reappropriation of nature in territories of high environmental value. The results indicate that there are recent expressions of capitalism that manifest two lines of argument: first, in the local production of interpretations of nature that value its beauty as a source of capital generation through practices such as tourism, and secondly in the intensification of large-scale hoarding of water resources in the area. It is concluded that local natural spaces of high environmental value become highly attractive spaces, transforming themselves into disputed territories
Cuando la lealtad ideológica sucumbe ante el pragmatismo: la ruptura entre Rafael Correa y Lenín Moreno
Get PDFEste artículo discute las motivaciones que llevan a algunos presidentes a cambiar la orientación de las políticas públicas de su predecesor a pesar de provenir de una vertiente político-partidista similar. Aunque intuitivamente una variación en el statu quo es esperable en circunstancias de alternancia ideológica en el Ejecutivo, esto no siempre se cumple. Ecuador, durante los gobiernos de Rafael Correa y Lenín Moreno, es un excelente caso de estudio no sólo para describir el fenómeno planteado sino para identificar algunas explicaciones. A través de estadística descriptiva y narrativas históricas proponemos que, cuando las dificultades políticas y económicas arrecian, las convicciones ideológicas son desplazadas. Por ello, estudiar los cambios suscitados en Ecuador sirve para el análisis del vínculo entre costos y beneficios en la toma de decisiones públicas.This article discusses the motivations that lead some presidents to change the direction of their predecessor’s public policies, despite the fact that they come from a similar political-party background. Although intuition suggests that a change in the status quo is to be expected when there is an ideological shift in the Executive, this is only sometimes the case. The governments of Rafael Correa and Lenin Moreno in Ecuador are an excellent case study to describe this phenomenon and identify some explanations. Through descriptive statistics and historical narratives, we propose that ideological convictions are displaced when political and economic difficulties increase. Studying the changes in Ecuador can therefore contribute to analysis of the link between costs and benefits in public decision-making
Psychomotricity, corporeality, gender and positivist philosophy in Chile: a critical analysis of ministerial documents
No full textFormal education can be understood as a cultural activity that is influenced by multiple epistemological perspectives that are present in society. In addition, each nation has its own particularities based on its own unique history and citizenship. One of the theoretical currents that has had a pedagogical boom in recent years in Latin America is the feminist perspective, promoting gender equality. Considering this context, this essay was developed with the objective of analyzing from a critical and gender perspective four Chilean ministerial documents on psychomotricity and corporeality in early childhood. The analyses showed that there is a marked behaviourist, positivist, neoliberal and uncritical tendency towards gender, psychomotor skills and corporeality in the ministerial texts considered. In this way, it would be promoting an early childhood education that assumes a passive attitude towards social injustices and patriarchal gender stereotypes. In this sense, a technical and traditional curricular rationality is being reproduced among teachers and children
Epu xoy kvmvn; Tuwvn ka kvpalme Social work mu’. Two looks of knowledge tuwvn y kvpalme in the Social work
No full textLa presente investigación invita al lector a compartir algunas reflexiones que articulan los saberes propios de mi tuwvn y kvpalme mapuche y en base al reyñmawen quiero definir características de la expresión de ser persona con el medio natural y al actuar en base a la lengua, a la historia de pueblo, de vida y que finalmente entrega la identidad al che; y contextualizan el conocimiento teórico-práctico del Trabajo Social que es la actividad profesional de la autora, que pone en práctica en la acción profesional cotidiana. Se da a conocer la experiencia de quien escribe, la vivencia de ser, por un lado mujer mapuche, perteneciente a un lof específico y por otro, una profesional adscrita a una institución chilena. Lo anterior ayudará a develar algunos encuentros y desencuentros que originan cuestionamientos entre dos modos de apreciar la noción y la realidadde la familia sobre la convivencia entre la familia mapuche y las acciones profesionales de los y las trabajadores sociales, ofreciendo algunos elementos del saber propio de la cultura mapuche que pueden aportar a una acción profesional con mayor pertinencia cultural en contexto mapuche.This research invites the reader to share some reflections that articulate my own knowledge and Mapuche tuwvn kvpalme and based on reyñmawen want to define characteristics of the expression of being a person with the natural environment and to act on the language, the village history, life and identity that finally delivers the che; and contextualize the theoretical and practical knowledge of socialwork from the author, which are implemented in everyday professional action. It discloses the writer's experience, the experience of being on one side Mapuche woman, belonging to a specific lof and secondly, a professional attached to a Chilean institution. This will help uncover some encounters that questions arise between two modes to appreciate the concept and the reality of the family on the coexistence between the Mapuche family and professional actions and social workers, offering some elements of knowledge own Mapuche culture can contribute to a more professional action Mapuche cultural relevance in context
Comparative study of finite element analysis of steel silos with rectangular and I stiffeners
Get PDFSilos are used by a wide range of industries to store bulk solids in quantities ranging from a few tones to hundreds or thousands of tones. Theycan be constructed of steel or reinforced concrete. Steel bins range from heavily stiffened flat plate structures to efficient unstiffened shell structures. They can be closed or open. They are subjected to many different static and dynamic loading conditions, mainly due to the unique characteristics of stored materials. Wind and earthquake load often undermine the stability of the silos. A steel silo with and without stiffeners is adopted and static structural analysis and dynamic analysis is done. The analysis is done by idealizing geometry, material and boundary conditions.Los silos son utilizados por una amplia gama de industrias para almacenar sólidos a granel en cantidades que van desde unas pocas toneladas hasta cientos o miles de toneladas. Pueden ser de acero o de hormigón armado. Loscontenedores de acero van desde estructuras de placas planas muy rígidas hasta estructuras de cáscara no reforzadas eficientes. Pueden estar cerrados o abiertos. Están sujetos a muchas condiciones de carga estáticas y dinámicas diferentes, principalmente debido a las características únicas de los materiales almacenados. La carga de viento y terremoto a menudo socava la estabilidad de los silos. Se adopta un silo de acero con y sin refuerzos y se realiza un análisis estructural estático y un análisis dinámico. El análisis se realiza idealizando la geometría, el material y las condiciones de contorno
DYNAMIC CHANGES OF HEMATOLOGICAL AND HEMOSTATIC PARAMETERS IN COVID-19 HOSPITALIZED PATIENTS: POTENTIAL ROLE AS SEVERITY BIOMARKERS FOR THE CHILEAN POPULATION
No full textBackground: COVID-19 is still a global health issue, there is limited evidence in South America regarding laboratory biomarkers associated with severe disease. The objective of our study was to identify hematological and hemostatic changes associated with severe COVID-19. Methods: A total of 170 hospitalized patients with COVID19 were included in the study, defining their severity according to established criteria. Demographic, clinical, and laboratory (days 1, 3, 7, 15) data were obtained. We performed a statistical analysis, assuming significance with a value of p < 0.05. We analyzed the correlation between severity and biomarkers and established cut-off values for severe patients through ROC curves, estimating Odds Ratio associated with severe disease. Results: Day 1 was observed significant differences between moderate vs severe patients for leukocytes (WBC), Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and D-dimer, establishing cut-off points for each of them. The markers we found associated to risk of severe disease were WBC ( OR =3.2396; p = 0.0003), NLR ( OR =5.7084; p < 0.0001), PLR ( OR =4.4094; p < 0.0001), Neutrophil ( OR =4.1193; p < 0.0001), D-dimer ( OR =2.7827; p = 0.0124). Conclusions: The results allow to establish basic laboratory biomarkers associated to severe disease, which could be used as prognostic markers
How Could Cover Crops and Deficit Irrigation Improve Water Use Efficiency and Oenological Properties of Southern Chile Vineyards?
No full textVineyards started 20 years ago in Southern Chile, making viticulture a promising agricultural option for farmers in this area, increasing 7-fold during the last 5 years. However, vineyards of Southern Chile reach lower yields and lower sugar concentrations than those of the central zone, mainly due to the edaphoclimatic drivers such as low temperature, spring frost, and management constraints. Moreover, the impacts of climate change on rainfall have increased the water deficit in this area, mainly during grapevine phenological stages of high-water requirements (bloom, fruit set to veraison, and veraison to harvest). These antecedents support the urgency to validate strategies aimed at improving water use efficiency (WUE) of vineyards in Southern Chile through techniques such as the use of cover crops and regulated deficit irrigation (RDI). In addition, inter-row and intra-row cover crops can decrease both, plant water consumption and transpiration losses, as well as improve soil water infiltration. The high amount of winter rainfalls and fertility of soils in this zone, explaining also, the excessive vigor of vines, becomes possible through the adoption of these floor management techniques. Otherwise, RDI is currently proposed as a saving-water technique that controls vine vigor and increases fruit quality in vineyards. Nevertheless, currently, the findings are conflicting, and the most of studies have been performed in arid or semi-arid regions, but few in the neither Mediterranean nor humid regions such as those of Southern Chile. Therefore, according to the literature analyzed in zones with similar climatic conditions in Southern Chile, this review aimed to critically discuss how the strategies of cover crops and regulated deficit irrigation could improve the water use efficiency, vine balance, and enological properties in vineyards production of Southern Chile
Using José Ricardo Morales' Plays to Teach Media Manipulation and Propaganda in Chilean Secondary Education
No full textIn this study, I discuss the potential implementation of Jose Ricardo Morales' relevant dramatic literature (scripts) as an additional pedagogical learning tool for teaching the topics of media manipulation and propaganda in Chilean secondary schools. Moreover, this process encourages students to critically examine and discuss specific past and present-day local conflicts. From a qualitative approach, I analyze several learning objectives from the Chilean national curriculum frameworks that best suit the aforementioned topics developed and problematized in Morales' plays. As complementary, I discuss the previous results with eight randomly chosen secondary teachers and their students about using Morales' plays to teach particular topics in Chilean history. The results reveal that incorporating two of Morales' plays as a reading and writing activity can be helpful for secondary teachers to teach their students the topics of media manipulation and propaganda in authoritarian regimes from a contextualized perspective