375 research outputs found
Identity singularity: Between death and miscegenation. Reflections on the concept of identity in Bolívar Echeverría
Este ensayo pone en marcha una crítica del concepto de identidad en el que los estados nacionales modernos latinoamericanos se han fundado. La reflexión que aquí se propone, se articula desde la concepción que el filósofo marxista ecuatoriano, Bolívar Echeverría, desarrolló sobre el concepto de cultura. Se postula que la identidad (personal y colectiva) no ha de entenderse mediante la acumulación estática de rasgos y características, sino como el resultado de un enfrentamiento violento entre lo mismo y lo ‘otro’. La identidad, así, es dinámica, evanescente y está en permanente construcción. Para tal efecto, el concepto de mestizaje, fundamental en la concepción echeverriana de la cultura, es el centro de la reflexión, y permite, con el fin de respaldar el concepto de identidad que aquí se expone, integrar, explicitar y desarrollar las reflexiones de George Bataille sobre la muerte y el erotismo.
This essay launches a critique of the concept of identity in which modern Latin American national states have been founded. The reflection proposed here is articulated from the conception that the Ecuadorian Marxist philosopher Bolívar Echeverría developed about the concept of culture. It is postulated that the identity (personal and collective) is not to be understood through the static accumulation of traits and characteristics, but as the result of a violent confrontation between the same and the other, the identity, thus, is dynamic, evanescent and is in permanent construction. For this purpose, the concept of miscegenation, fundamental in the Echeverria conception of culture, is the center of reflection, and allows, in order to support the concept of identity that is presented here, to integrate, explain and develop the reflections of George Bataille about death and eroticism
Las relaciones entre iguales en el alumnado de primaria y secundaria desde una perspectiva de género
Las relaciones entre iguales suponen un aspecto importante en el desarrollo cognitivo, emocional y social de las personas. Desde edades tempranas, se empiezan a gestar las habilidades sociales que marcan las relaciones e interacciones que se mantendrán con los demás. Aunque sin duda, un factor relevante en el desarrollo de dichas relaciones sociales es, entre otros, la formación de los roles de género, capaz de determinar cómo se relacionan niños y niñas con su mismo género y con el género opuesto. El objetivo principal de esta tesis es estudiar las relaciones entre iguales en el alumnado de primaria y secundaria desde una perspectiva de género que tiene en cuenta si las relaciones interpersonales que mantienen las chicas y los chicos se dan de manera intragénero o intergénero. Además se analiza la influencia que tiene el contexto y la situación sociofamiliar en el mantenimiento de las relaciones sociales. Se aplicó un test sociométrico y el método de asignación de atributos perceptivos a una muestra de 755 estudiantes del 2º y 3º ciclo de educación primaria y del 1º ciclo de la ESO. Los resultados indican que en general, los chicos son más rechazados que las chicas, condición que se mantiene estable a lo largo de la escolaridad, sobre todo por sus características comportamentales de agresividad y aislamiento, mientras que las chicas tienden a elegirse entre ellas más que los chicos, especialmente en el contexto formal del aula. Si bien el contexto establece algunos matices en la relación entre iguales, realmente las diferencias las marca la naturaleza de la relación, esto es, si se trata de una relación intragénero o intergénero. Por otro lado, los resultados obtenidos muestran una tendencia a la segregación de género que confirma y mantiene los estereotipos de género. En cuanto a la situación sociofamiliar, se ha hallado que los niños y niñas en una situación sociofamiliar grave, en este caso, que se encuentran en un centro de acogida, encuentran más rechazo que aquellos que no están en dicha situación, sobre todo las chicas, y especialmente en el contexto del aula. Se concluye que el género debe ser tenido en cuenta en el diseño e implementación de intervenciones encaminadas a mejorar la integración social del alumnado, y en el desarrollo de relaciones interpersonales futuras basadas en la igualdad
Prediction of liver stiffness by serum indexes in HCV-infected patients with or without HIV coinfection
Identification of advanced fibrosis/cirrhosis in hepatitis C virus (HCV)-infected patients should be a mainstay before starting treatment; however, the limited access of many centres to transient elastography (TE) is often a barrier for early assessments. We aimed to investigate the diagnostic accuracy of serum indexes for predicting liver stiffness.Retrospective analysis of HCV patients (with or without HIV coinfection) routinely assessed in 7 centres in Spain. The diagnostic accuracy of aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis-4 (FIB-4), and their combinations was evaluated using a recent TE examination as a reference test (liver stiffness¿=¿9.5¿kPa and¿=12.5¿kPa for advanced fibrosis and cirrhosis, respectively). In addition to area under the receiving operating characteristic curves, sensitivity, specificity, and negative predictive value (NPV) and positive predictive value were estimated.The analysis included 1391 patients: 346 (25%) HIV-positive, 732 (53%) people who inject drugs, and 178 (13%) incarcerated. Advanced fibrosis and cirrhosis were found in 557 (40%) and 351 (25%) patients, respectively. APRI¿ 2 and FIB-4 > 3.25 (n¿=¿134; 10%) had a positive predictive value of 89% for advanced fibrosis. Globally, this approach would avoid the need for TE in 53% of patients. HIV coinfection did not influence diagnostic accuracy.Inexpensive and simple serum indexes confidently allowed identifying the absence of cirrhosis and the presence of advanced fibrosis in 53% of a heterogeneous series of real-world HCV patients with or without HIV infection
Evolution of the Correlation between Orthogonal Polarization Patterns in Broad-Area Lasers
We measure polarization-resolved instantaneous patterns in a large-aspect ratio quasi-isotropic Nd:YAG laser. High correlation between the instantaneous orthogonal polarization patterns recorded at the earlier stages of the laser pulse has been found due to the strong cross saturation between both polarization modes
Forest Road Detection Using LiDAR Data and Hybrid Classification
Knowledge about forest road networks is essential for sustainable forest management and fire management. The aim of this study was to assess the accuracy of a new hierarchical-hybrid classification tool (HyClass) for mapping paved and unpaved forest roads with LiDAR data. Bare-earth and low-lying vegetation were also identified. For this purpose, a rural landscape (area 70 ha) in northwestern Spain was selected for study, and a road network map was extracted from the cadastral maps as the ground truth data. The HyClass tool is based on a decision tree which integrates segmentation processes at local scale with decision rules. The proposed approach yielded an overall accuracy (OA) of 96.5%, with a confidence interval (CI) of 94.0–97.6%, representing an improvement over pixel-based classification (OA = 87.0%, CI = 83.7–89.8%) using Random Forest (RF). In addition, with the HyClass tool, the classification precision varied significantly after reducing the original point density from 8.7 to 1 point/m2. The proposed method can provide accurate road mapping to support forest management as an alternative to pixel-based RF classification when the LiDAR point density is higher than 1 point/m2This research was supported by: (1) the Project “Sistema de ayuda a la decisión para la adaptación al cambio climático a través de la planificación territorial y la gestión de riesgos (CLIMAPLAN) (PID2019-111154RB-I00): Proyectos de I+D+i - RTI”; and (2) “National Programme for the Promotion of Talent and Its Employability” of the Ministry of Economy, Industry, and Competitiveness (Torres-Quevedo program) via a postdoctoral grant (PTQ2018-010043) to Juan Guerra HernándezS
LEPTINA, POSIBLES RELACIONES CON LA HIPERTENSIÓN Y EL SINDROME METABÓLICO
La leptina es una hormona que después de descubrirse en 1994 ha sido base de multitud de estudios en los que analizar las posibles aplicaciones que podría tener en la medicina moderna debido a la gran cantidad de funciones que realiza en el organismo. Este trabajo se ha centrado en analizar las posibles relaciones que existen entre esta hormona y patologías tan prevalentes en nuestro medio como la hipertensión, el síndrome metabólico o la diabetes. Se ha utilizado una muestra de 745 pacientes recogida de la Unidad de Hipertensión del Hospital Universitario Lozano Blesa, los cuales tenían determinaciones de leptina (como variable principal) entre otras en su primera visita a la unidad. Después de la utilización de los métodos de Pearson, Chi cuadrado y t de student, se han obtenido relaciones estadísticamente significativas entre la leptina y el patrón dipper sistólico (p<0.0002), entre la leptina y el HOMA (siendo más potente en mujeres) y entre la toma de diversos fármacos antihipertensores y el patrón dipper. Por todo ello concluimos que existen relaciones estadísticamente significativas entre las variables estudiadas, lo que nos llevaría a recomendar la realización de más estudios que analicen los mecanismos de acción que subyacen a estas posibles relaciones.<br /
Insulin Resistance Is Not Increased in Inflammatory Bowel Disease Patients but Is Related to Non-Alcoholic Fatty Liver Disease
Background: Insulin resistance (IR) has been linked to inflammatory states. The aim of this study was to determine whether IR is increased in a cohort of inflammatory bowel disease (IBD) patients with low disease activity. We additionally intended to establish which factors were the determinants of IR in this population, including the presence of nonalcoholic fatty liver disease (NAFLD).
Methods: Cross-sectional study encompassing 151 IBD patients and 174 non-diabetic controls. Insulin and C-peptide serum levels and IR and beta cell function (%B) indices based on homoeostatic model assessment (HOMA2) were assessed in patients and controls. Liver stiffness as measured by transient elastography, and the presence of NAFLD detected via ultrasound were additionally assessed. A multivariable regression analysis was performed to evaluate the differences in IR indexes between patients and controls, and to determine which predictor factors were associated with IR in IBD patients.
Results: Neither HOMA2-IR (beta coef. -0.26 {95%CI -0.64-0.13}, p = 0.19) nor HOMA2-%B (beta coef. 15 {95%CI -14-44}, p = 0.31) indexes differed between patients and controls after fully multivariable analysis. Among classic IR risk factors, obesity, abdominal circumference, and triglycerides significantly and positively correlated with IR indexes in IBD patients. However, most features related to IBD, such as disease patterns, disease activity, and inflammatory markers, were not associated with IR. The presence of NAFLD was independently and significantly associated with beta cell dysfunction in patients with IBD (HOMA2-B grade 4, 251 ± 40 vs. grade 1, 107 ± 37, p = <0.001).
Conclusions: IR is not increased in IBD patients with low disease activity compared to controls. However, the presence of NAFLD favors the development of IR in patients with IBD.This work was supported by a grant to I.F-A. from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016 and by Fondo Europeo de Desarrollo Regional-FEDER-(Fondo de Investigaciones Sanitarias, FIS PI14/00394, PI17/00083)
Carotid Plaque Assessment Reclassifies Patients with Inflammatory Bowel Disease into Very-High Cardiovascular Risk
The addition of carotid ultrasound into cardiovascular (CV) risk scores has been found to be effective in identifying patients with chronic inflammatory diseases at high-CV risk. We aimed to determine if its use would facilitate the reclassification of patients with inflammatory bowel disease (IBD) into the very high-CV-risk category and whether this may be related to disease features. In this cross-sectional study encompassing 186 IBD patients and 175 controls, Systematic Coronary Risk Evaluation (SCORE), disease activity measurements, and the presence of carotid plaques by ultrasonography were assessed. Reclassification was compared between patients and controls. A multivariable regression analysis was performed to evaluate if the risk of reclassification could be explained by disease-related features and to assess the influence of traditional CV risk factors on this reclassification. After evaluation of carotid ultrasound, a significantly higher frequency of reclassification was found in patients with IBD compared to controls (35% vs. 24%, p = 0.030). When this analysis was performed only on subjects included in the SCORE low-CV-risk category, 21% IBD patients compared to 11% controls (p = 0.034) were reclassified into the very high-CV-risk category. Disease-related data, including disease activity, were not associated with reclassification after fully multivariable regression analysis. Traditional CV risk factors showed a similar influence over reclassification in patients and controls. However, LDL-cholesterol disclosed a higher effect in controls compared to patients (beta coef. 1.03 (95%CI 1.02-1.04) vs. 1.01 (95%CI 1.00-1.02), interaction p = 0.035) after adjustment for confounders. In conclusion, carotid plaque assessment is useful to identify high-CV risk IBD patients.Funding: This work was supported by a grant to I.F-A. from the Spanish Ministry of Health, Subdirección General de Evaluación y Fomento de la Investigación, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016 and by Fondo Europeo de Desarrollo Regional—FEDER—(Fondo de Investigaciones Sanitarias, FIS PI14/00394, PI17/00083)
Comparison of ALS based models for estimating aboveground biomass in three types of Mediterranean forest
This study aimed to develop ALS-based models for estimating stem, crown and
aboveground biomass in three types of Mediterranean forest, based on low density ALS
data. Two different modelling approaches were used: (i) linear models with different
variable selection methods (Stepwise Selection [SS], Clustering/Exhaustive search [CE]
and Genetic Algorithm [GA]), and (ii) previously Published Models (PM) applicable to
diverse types of forest. Results indicated more accurate estimations of biomass components
for pure Pinus pinea L. (rRMSE = 25.90-26.16%) than for the mixed (30.86-36.34%) and
Quercus pyrenaica Willd. forests (32.78-34.84%). All the tested approaches were valuable,
but SS and GA performed better than CE and PM in most casesThe study was supported by the ForEadapt project ‘Knowledge exchange between
Europe and America on forest growth models and optimization for adaptive forestry’
(PIRSES-GA-2010-269257). The authors thank (i) the foresters of the Extremadura
Forest Service for assistance with data collection, (ii) the Portuguese Science Foundation
(SFRH/BD/52408/2013) for funding the research activities of Juan Guerra and (iii) the
Galician Government and European Social Fund (Official Journal of Galicia – DOG nº 52,
17/03/2014 p. 11343, exp: POS-A/2013/049) for funding the postdoctoral research stays
of Eduardo González-Ferreiro and iv) the anonymous Reviewers of the European Journal
of Remote Sensing for their helpful feedback. The research was carried out in the Centro
de Estudos Florestais: a research unit funded by Fundação para a Ciência e a Tecnologia
(Portugal) within UID/AGR/00239/2013.S
Comparing Johnson’s SB and Weibull Functions to Model the Diameter Distribution of Forest Plantations through ALS Data
[EN] The analysis of the diameter distribution is important for forest management since the knowledge of tree density and growing stock by diameter classes is essential to define management plans and to support operational decisions. The modeling of diameter distributions from airborne laser scanning (ALS) data has been performed through the two-parameterWeibull probability density function (PDF), but the more flexible PDF Johnson's SB has never been tested for this purpose until now. This study evaluated the performance of the Johnson's SB to predict the diameter distributions based on ALS data from two of the most common forest plantations in the northwest of the Iberian Peninsula (Eucalyptus globulus Labill. and Pinus radiata D. Don). The Weibull PDF was taken as a benchmark for the diameter distributions prediction and both PDFs were fitted with ALS data. The results show that the SB presented a comparable performance to the Weibull for both forest types. The SB presented a slightly better performance for the E. globulus, while theWeibull PDF had a small advantage when applied to the P. radiata data. The Johnson's SB PDF is more flexible but also more sensitive to possible errors arising from the higher number of stand variables needed for the estimation of the PDF parametersSIThis research was funded by the Forest Research Centre, a research Unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (grant number UID/AGR/00239/2019). The research activities of Diogo N. Cosenza were funded by the Portuguese Science Foundation (grant number PD/BD/128489/2017). The eucalyptus data used in this work were acquired under the framework of the PTDC/AGR-CFL/72380/2006 project (supported by the FCT under grant PTDC/AGR-CFL/72380/2006, co-financed by the European Fund of Regional Development (FEDER) through COMPETE–Operational Factors of Competitiveness Program, POFC). The pine data were acquired under the framework AGL2008-02259/FOR project (supported by the Spanish Ministry of Science and Innovation
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