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Two-Point Distortion Theorems for Harmonic Mappings
No full textWe establish two-point distortion theorems for sense-preserving planar harmonic map -pings f = h + g in the unit disk D which satisfy harmonic versions of the univalence criteria due to Becker and Nehari. In addition, we also find two-point distortion theo-rems for the cases when h is a normalized convex function and, more generally, when h(D) is a c-linearly connected domain
Quasinormal modes of a charged scalar field in Ernst black holes
No full textWe consider the propagation of a charged massive scalar field in the background of a four-dimensional Ernst black hole and study its stability analyzing the quasinormal modes (QNMs), which are calculated using the semi-analytical Wentzel-Kramers-Brillouin method and numerically using the continued fraction method. We mainly find that for a scalar field mass less than a critical mass, the decay rate of the QNMs decreases when the harmonic angular number l increases; and for a scalar field mass greater than the critical mass, the behavior is inverted, i.e., the longest-lived modes are always the ones with the lowest angular number recovering the standard behavior. Also, we find a critical value of the external magnetic field, as well as a critical value of the scalar field charge that exhibits the same behavior with respect to the angular harmonic numbers. In addition, we show that the spacetime allows stable quasibound states, and we observe a splitting of the spectrum due to the Zeeman effect. Finally, we show that the unstable null geodesic in the equatorial plane is connected with the QNMs when the azimuthal quantum number satisfies m= & PLUSMN;l in the eikonal limit
A Compound Class of Inverse-Power Muth and Power Series Distributions
No full textThis paper introduces the inverse-power Muth power series model, which is a composition of the inverse-power Muth and the class of power series distributions. The use of the Bell distribution in this context is emphasized for the first time in the literature. Probability density, survival and hazard functions are studied, as well as their moments. Using the stochastic representation of the model, the maximum-likelihood estimators are implemented by the use of the expectation-maximization algorithm, while standard errors are calculated using Oakes' method. Monte Carlo simulation studies are conducted to show the performance of the maximum-likelihood estimators in finite samples. Two applications to real datasets are shown, where our proposal is compared with some models based on power series compositions
Dispositivo de evaluación educacional y gubernamentalidad en Chile: los orígenes (1844-1970)
Get PDFEl dispositivo de evaluación es una tecnología clave para la gubernamentalidad o “conducción de la conducta” en el ámbito de la educación. Al respecto, los estudios de los últimos años enfatizan especialmente la asociación de los mecanismos de evaluación educacional con el mercado y los procesos político-institucionales iniciados en los años 1980. No obstante, existe un largo recorrido previo, que antecede la introducción del neoliberalismo en educación. Este artículo examina esa génesis desde mediados del siglo XIX hasta 1970. Exhibe los procedimientos de vigilancia y registro de la actividad educacional en el siglo XIX y el creciente uso de la calculabilidad estadística y los conocimientos científicos, que adquieren un rol crucial desde las primeras décadas del siglo XX, hasta llegar a una configuración integral del dispositivo a fines de los años 1960. En esta trayectoria hay luchas y cuestionamientos reiterados, pero finalmente se estabiliza un dispositivo marcado por la centralización estatal, una gran confianza en la ciencia, expresada particularmente en la psicometría y medición educacional, y un uso masificado de las evaluaciones estandarizadas. Cuando, en la década de los 1980, se instauran las políticas de mercado en la educación, este dispositivo ya se encontraba prefigurado en sus elementos fundamentales. Bajo el gobierno de Frei Montalva, en el marco de la planificación educacional, se había constituido un dispositivo que estaba listo para funcionar y guiar la intervención en el sistema educacional. Si no se puso en operación antes de los años ochenta fue, inicialmente, por limitaciones tecnológicas y, después, por contingencias políticas, no por oposición al mecanismo.La investigación se basa en el examen de una extensa recopilación de documentos del período (leyes, documentos oficiales, discursos, estudios, prensa escrita, entre otros), sumado a entrevistas de informantes claves.The evaluation device is a key technology for governmentality or "conduct of conducts" in the field of education. In this regard, the studies of the last years emphasize especially the association of the mechanisms of educatio-nal evaluation with the market and the political-institutional processes initia-ted in the 1980s. However, there is a long path that precedes the introduction of neoliberalism in education. This article examines this genesis from the mid-nineteenth century until 1970. It exhibits the procedures of surveillance and recording of educational activity in the nineteenth century and the growing use of statistical calculability and scientific knowledge, which acquire a crucial role from the first decades of the 20th century, until reaching an integral configu-ration of the device at the end of the 1960s. In this trajectory there are repeated struggles and criticism, but finally a device is stabilized, which is marked by state centralization, a great confidence in science, expressed particularly in psychometric and educational measurement, and a widespread use of standar-dized evaluations. When, in the 1980s, market policies in education were established, this device was already prefigured in its cardinal elements. Under the government of Frei Montalva, within the framework of educational planning, it had been integrated, constituting a device ready to operate and guide the intervention in the educational system. If it was not put into operation before the 1980s, this was due to technological limitations and political contingencies, not because of opposition to the mechanism.The investigation is based on the examination of an extensive compilation of documents of the period (laws, official documents, discourses, studies, written press, among others), in addition to interviews with key informants
Developing tools to study the health impact of urban transformations in high vulnerability contexts: the RUCAS study
No full textThis article describes the design and character-istics of a questionnaire and an intradomiciliary observation tool developed to assess the housing -neighborhood-health relationship both cross -sec-tionally and longitudinally in the context of urban transformations carried out in populations of high socio-territorial vulnerability. The instruments were developed for the multi-method longitudinal study RUCAS (Urban Regeneration, Quality of Life and Health), a natural experiment aim-ing to assess the quality of life and health impact of a comprehensive Urban Regeneration Program in two social housing complexes in Chile. The de-sign of the instruments followed four main stages: (1) narrative review of the literature to define the dimensions of the study, and of existing measure-ment instruments to identify appropriate items for measuring them; (2) content validation with experts; (3) pre-test; and (4) pilot study. The re-sulting questionnaire, composed of 262 items, considers the different stages of the life course and gender issues. The intradomiciliary observation tool (77 items) is applied by the interviewer. The instruments assess (i) characteristics of the cur-rent residential situation that are known to affect health and will be intervened by the program; (ii) dimensions of health potentially affected by the residential situation and/or by the intervention within the time frame of the study (4 years); (iii) other health and health-related conditions that are relevant, even if changes will not be modi-fied within the time frame of the study; and (iv) relevant socioeconomic, occupational and demo-graphic dimensions. The instruments have shown to be capable of addressing the multidimensional-ity of urban transformation processes in contexts of urban poverty in formal housing
Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness
No full textBackground: Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI >= 35 kg/m(2)). Objective: To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample. Methods: This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 +/- 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45). Results: The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 +/- 0.1 vs. Low-MQI: 0.8 +/- 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 +/- 17.5 vs. Low-MQI: 140.1 +/- 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 +/- 5.9 vs. Low-MQI; 22.4 +/- 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (beta: -0.07, p = 0.011), SBP (beta: -18.47, p = 0.001), and CRF (beta: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP. Conclusions: MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2(max)). It mediates the relationship between abdominal obesity and SBP
Reflections on Intercultural Experiences of Mapuche Students at University: Academic and Affective Dimensions in Projection
No full textIntroduction. The experience of minority groups in academic training arises in a scenario of tensions between the predominantly Western and monocultural education system related to family education and different types of knowledge acquired by students, as well as the reproduction of other forms of racism. These tensions have been well documented during school years, while in the university education of indigenous students in Chile, the tensions have been scarcely explored. Objective. This study examines the beliefs and representations of a group of Mapuche students concerning their academic and socio-affective experiences at a university in Temuco, Chile. The study was conducted in the context of initial teacher training immersed in an education system traditionally monocultural. Methodology. The methodological design was based on educational research and an interpretive paradigm. Twelve students who self-identify as Mapuche indigenous people were interviewed. These interviews were analyzed through the open coding technique. Results. The main results reveal that university experiences are diverse and keep core contents related to discrimination, which influences the insertion and progression in vocational training. Conclusion. The study allowed identifying the most satisfactory university experiences, those associated with the positioning of the student with respect to their cultural identification, and the creation and maintenance of support networks
Turismo Invasivo y Turismo Mapuche: territorio indígena y emprendimiento con identidad en Laguna Icalma, Alto Biobío
Get PDFEsta investigación cualitativa explora la agencia económica de emprendedores turísticos mapuche en la intersección entre el discurso del Desarrollo con Identidad y la turistificación del territorio mapuche-pewenche en el sur de Chile. En base a la triangulación de documentos institucionales con la observación etnográfica y entrevistas realizadas en el sector de Laguna Icalma, esta investigación traza la apropiación estratégica del discurso gubernamental del etno-ecoturismo o “turismo con identidad” por líderes económicos indígenas de un nuevo tipo, que re-politizan, en forma situada y creativa, tanto el Desarrollo con Identidad como las trayectorias posibles de la turistificación del territorio indígena.This qualitative research explores the economic agency of Mapu-che tourism entrepreneurs at the intersection between Development with Identity discourse and the touristification of Mapuche-Pewenche territory in Southern Chile. Based on the triangulation between institutional documents, interviews and ethnographic observation conducted in the Lake Icalma region, this research traces the strategic appropriation of the governmental discourse of ethno-ecotourism or “tourism with identity” by a new kind of indigenous economic leaders, who re-politicize, in situated and creative ways, both Development with Identity, and the possible trajectories for touristification of the indigenous territory
Perception of School Violence: Indicators of Normalization in Mapuche and Non-Mapuche Students
No full textThe current social and political scenario in Chile has opened up the debate on two centuries of usurpation and discrimination towards the Mapuche people. Educational centers are not oblivious to the social exclusion faced by indigenous children and young people, and this forms part of the phenomenon of school violence. This study explores the differences in perception between Mapuche and non-Mapuche students regarding school violence. The issue is the lack of knowledge regarding cultural variations in the perception of school violence in spaces of social and cultural diversity in the Mapuche context. This study describes the characteristics of school violence perceived by students in relation to differences based on ancestry and characterizes the variations in perception. A total of 1404 students participated from urban schools in the city of Temuco, Chile, aged 10 to 13 (M = 11.4; SD = 1.1) who completed the CENVI questionnaire. The confirmatory factor analysis (CFA) of the total sample and categories provides indexes that fit the proposed model. The omega coefficients provide internal reliability guarantees. This study tests configural, metric and scalar invariance for all the categories explored, and statistically significant differences are found between Mapuche and non-Mapuche students in the perception of physical and verbal violence, where the Mapuche student perceives more violence. Results are discussed based on existing research on education in spaces of social and cultural diversity in the Mapuche context, with research into elements that can help explain the findings
Associations between spectral properties, bacteriological characteristics, chlorophyll and zooplankton communities in two north Patagonian lakes
No full textThe Chilean north Patagonian lakes are characterized by their marked oligotrophic or oligome-sotrophic status and low abundance of zooplankton species; many of the lakes with oligomesotrophic status are associated with human intervention due to towns on their shores. The aim of the present study was to determine the relations between spectral properties (LANDSAT OLI), chlorophyll and plankton abundances in two north Patagonian lakes: Villarrica, which has two towns on its shores, and Lake Caburgua, which has native forest on its shores. The results revealed that Lake Villarrica has high reflectance in the near infrared, red and green bands, high concentrations of chlorophyll a, the absence of mixotrophic protozoa, and a high abundance of bacterial and plankton, mainly phy-toplankton (Chlophyceae and diatoms) and zooplankton. Lake Caburgua, on the other hand, has low reflectance in the same bands, and low chlorophyll concentrations, low bacterial and zooplankton abundances, with the exception of high mixotrophic ciliates and small phytoplankton, and Volvox colonies. The obtained results agree with limnological observations on both lakes, and observations agrees with similar observations of the spectral properties of glacial north Patagonian lakes and of the zooplankton community, and in this scenario, the use of remote-sensing techniques would be a good tool to predict the plankton community in Patagonian lakes