La deleción de Ptpn1 protege a las células ovales frente a la lipoapoptosis mediante la regulación de la formación y dinamismo de las gotas lipídicas

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Bioquímica. Fecha de lectura: 27-01-2022Nonalcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease worldwide, ranges from benign and reversible steatosis that is accompanied by insulin resistance and elevated circulating free fatty acids (FAs), to nonalcoholic steatohepatitis (NASH), cirrhosis and culminates in some cases in hepatocarcinoma. The main drivers of NAFLD-associated lipotoxicity are saturated FAs (SFAs), although the molecular mechanisms involved in liver cell death have not been fully defined. Lipid droplets (LDs) buffer the excess of toxic lipid species, including SFAs. The enzyme stearoyl CoA desaturase 1 (SCD1 (encoded by the Scd1 gene) catalyzes desaturation of SFAs such as palmitic acid (PA) and stearic acid (SA) and plays an essential role in the formation of hepatic triglycerides (TGs) easily stored in the LDs. Of relevance for this Thesis, the LDs emerge from the endoplasmic reticulum (ER) and during their life cycle contact with other organelles, not only the ER and mitochondria, but also autophagosomes, lysosomes and peroxisomes through membrane contact sites. Hepatic progenitor cells in humans (HPCs) or oval cells (OCs) in mice (HPCs/OCs) constitute 1-3% of the cell population in the normal adult liver. They are progenitor hepatic stem cells that, upon liver damage, proliferate and differentiate into hepatocytes or cholangiocytes in a process known as ductular reaction, due to their ability to express markers of both biliary and hepatocyte lineages. Activation of HPCs/OCs has been related to hepatocyte injury during chronic liver diseases including NAFLD. However, whether the lipotoxic milieu of the NAFLD affects HPCs/OCs´s viability has not been addressed. Protein tyrosine phosphatase 1B (PTP1B), encoded by the Ptpn1 gene, plays a fundamental role in modulating signaling cascades triggered by hormones/growth factors including insulin, insulin-like growth factor-1 (IGF-1), epidermal growth factor (EGF) and hepatocyte growth factor (HGF), all relevant for liver regeneration. In this Thesis, we have investigated the molecular and cellular processes involved in the susceptibility of HPCs/OCs expressing or not PTP1B to lipotoxicity. We demonstrated that PA induced apoptotic cell death in wild-type (Ptpn1+/+) HPCs/OCs in parallel to oxidative stress and impaired autophagy. This lipotoxic effect was attenuated in HPCs/OCs lacking Ptpn1 that showed up-regulated antioxidant defences, increased unfolded protein response (UPR) signaling, higher ER content and elevated Scd1 expression/activity. These effects in Ptpn1-/- HPCs/OCs concurred with an active autophagy, higher mitochondrial efficiency and a molecular signature of starvation, favoring LD formation and catabolism. Autophagy blockade in Ptpn1-/- HPCs/OCs reduced Scd1 expression, mitochondrial fitness, LD formation and restored lipoapoptosis, an effect also mimicked by Scd1 silencing. The identification of LDs in HPCs/OCs in the livers from Ptpn1-/- mice with NAFLD that concurred with attenuated disease features opens new therapeutic perspectives to ensure HPCs/OCs viability and plasticity under lipotoxic liver damag

Programa de habilidades sociales para mejorar la autoestima en estudiantes de Educación Básica Media

Las habilidades sociales son comportamientos que los seres humanos utilizan para afrontar diferentes situaciones de su vida, consisten en expresar emociones sentimientos, ideas y percepciones que influyen en el comportamiento de los niños para aumentar su autoestima y autoconfianza. La escuela se considera el segundo agente de socialización donde se aprenden y desarrollan conductas de relación interpersonal adecuadas. El presente estudio se configura como un área de interés de investigación por su papel en el desarrollo del individuo, en su adaptación personal y social. El objetivo principal del presente estudio es mejorar la autoestima en los estudiantes de Educación Básica media de la Unidad educativa Flavio Alfaro del cantón Mocache, a partir de aplicación de los talleres de habilidades sociales. Se empleo una metodología mixta, utilizando dos instrumentos en la recepción de información: cuali-cuantitativo, mediante la investigación descriptiva, con técnicas de observación y como instrumento la encuesta. Los resultados de la aplicación del programa permitieron involucrar docentes y estudiantes en el proceso de enseñanza–aprendizaje, logrando estimular el desarrollo integral, dotándolos de competencias para afrontar con éxito situaciones en el ámbito social, escolar.PALABRAS CLAVE: habilidades sociales; autoestima; estudiante.Social skills program to improve self-esteem in Middle Basic Education studentsABSTRACTSocial skills are behaviors that human beings use to face different situations in their life, it consists of expressing emotions, ideas and perceptions that influence children's behavior to increase their self-esteem and self-confidence. The school is considered the second agent of socialization where appropriate interpersonal relationship behaviors are learned and developed. The present study is configured as an area of research interest due to its role in the development of the individual, in their personal and social adaptation. The main objective of the present study is to improve self-esteem in the students of Middle Basic Education of the Flavio Alfaro Educational Unit of the Mocache canton, from the application of the social skills workshops. A mixed methodology was used, using two instruments to receive information: qualitative-quantitative, through descriptive research, with observation techniques, and the survey as an instrument. The results of the application of the program allowed to involve teachers and students in the teaching-learning process, managing to stimulate integral development, equipping them with skills to face successful situations in the social and school environment.KEYWORDS: social skills; self-esteem; student.

Análisis del impacto de las transferencias condicionadas en educación del programa Familias en Acción Fase III, desde enfoques econométricos y de machine learning: Bogotá D.C. Colombia

Esta investigación se orienta a realizar un análisis crítico del impacto de las transferencias condicionadas del programa Familias en Acción Fase III en centros urbanos, como es el caso de Bogotá D.C, frente al componente de educación, específicamente, en asistencia y permanencia en el sistema educativo. Los resultados de la investigación permitirán evidenciar el cumplimiento de las metas y objetivos del programa, de tal forma que esta información sirva de insumo para el diseño de agendas de política pública en el futuro. El marco de referencia que orienta el presente estudio se fundamenta en conceptos tales como Transferencias Monetarias Condicionadas (TMC), asistencia y permanencia en el sistema educativo, y modelos de evaluación de impacto. La metodología aplicada tiene un enfoque cuantitativo de alcance correlacional, de tipo no experimental y con diseño transeccional. Se toma como referencia los datos de la Encuesta Nacional de Calidad de Vida (ECV) de los años 2012 y 2020 con muestras representativas para Bogotá D.C. A partir de los datos se aplican técnicas econométricas y de Machine Learning para determinar el impacto del programa. Los resultados de los avances obtenidos hasta el momento consisten en la generación de un modelo de regresión logística, que implicó la aplicación de técnicas de balanceo de datos, selección de variables y validación sobre un conjunto de datos de testeo; para clasificar los registros de las bases de datos y conformar los grupos de tratamiento y control que se emplearán en la evaluación de impacto mediante un modelo de diferencias en diferencias

Concepción educativa para la edificación de relaciones interpersonales pacíficas en los estudiantes de la asignatura de estudios sociales de segundo ciclo de educación básica de dos centros educativos públicos matutinos, pertenecientes al municipio de San Miguel, departamento de San Miguel, periodo 2019

RESUMEN: La presente investigación pretende construir una concepción educativa dirigida a la edificación de relaciones interpersonales pacíficas en los alumnos y alumnas de educación básica, con la finalidad de que estos, mediante la práctica de valores, la concientización, la adopción de una cultura de paz, la inclusión, el desarrollo de habilidades comunicativas positivas, sean capaz de analizar y reflexionar sobre la importancia de adquirir conocimientos educativos, sociales y personales sobre las relaciones interpersonales y su influencia en el desarrollo como ser humano dentro de la institución educativa, y en la sociedad en general. La elaboración de la concepción educativa para la edificación de relaciones interpersonales pacíficas en estudiantes de educación básica, toma en cuenta, algunos sucesos relevantes que se han vivido en la historia de nuestro país, como el conflicto en El Salvador, y en el sistema educativo, también se retoman los fines de la educación que están en íntima relación con dicha temática, puesto que hoy en día, el sistema educativo nacional está fallando con respecto al cumplimiento de estos, de igual manera, incluye algunas concepciones de diferentes ramas de la ciencia, como la psicológica, la sociología, la pedagógica, la filosofía, las cuales pretenden dar una explicación del fenómeno en estudio, desde diferentes ámbitos o contextos inmersos en la realidad del niño y niña. El objetivo de esta investigación es el proponer una concepción educativa que esté encaminada a la construcción de relaciones interpersonales pacíficas en los alumnos y alumnas de educación básica, beneficiando así a dos centros educativos públicos de la ciudad de San Miguel. ABSTRACT: This research aims to build an educational conception aimed at the building peaceful interpersonal relationships in students of education basic, with the purpose that these, through the practice of values, awareness, adoption of a culture of peace, inclusion, development of communication skills positive, are able to analyze and reflect on the importance of acquiring knowledge educational, social and personal on interpersonal relationships and their influence on the development as a human being within the educational institution, and in society in general. The elaboration of the educational conception for the construction of interpersonal relationships peaceful in students of basic education, takes into account, some relevant events that are have lived in the history of our country, such as the conflict in El Salvador, and in the system education, the purposes of education that are closely related to said education are also taken up. thematic, since today, the national educational system is failing with respect to the fulfillment of these, in the same way, includes some conceptions of different branches of the science, such as psychology, sociology, pedagogy, philosophy, which seek to give an explanation of the phenomenon under study, from different areas or contexts immersed in the reality of the boy and girl. The objective of this research is to propose a conception education that is aimed at building peaceful interpersonal relationships in the male and female students of basic education, thus benefiting two public educational centers of the city of San Migue

Validation of the revised Olweus bully/victim questionnaire (OBVQ-R) among adolescents in Chile

Bullying is a phenomenon that affects children and adolescents worldwide, and it has major consequences for all participants involved in these situations. In Chile, researchers have validated several instruments used to investigate aggression between peers and school violence, but there is a lack of validation of instruments to investigate bullying. The purpose of this study was to provide evidence of the validity and reliability of the Olweus Bully/Victim Questionnaire—Revised version (OBVQ-R) in the Chilean context. The participants were 2,775 students from schools of low, medium, and high socioeconomic status. OBVQ-R is a self-report questionnaire with 42 items, which has been used in different countries, and has adequate psychometric properties to assess the prevalence of victimization and aggression and various forms of bullying worldwide. Results confirmed the two-factor structure of the OBVQ-R (victimization and perpetration subscales) and good reliability (ω = 0.81 and ω = 0.75, respectively). These dimensions seem to be correlated. Comparison between OBVQ-R with the School Violence between Peers Questionnaire and the Internet Experiences Questionnaire showed some degree of agreement. The Item Response Theory analysis showed that the item about verbal bullying, in both subscales, had the lowest-severity parameters, meaning that these forms of bullying were the most prevalent. The higher-severity parameter in the victimization scale was the cyberbullying item, and the sexual bullying item showed higher severity in the perpetration subscale. The differential item functioning analysis by gender showed a trend in which boys responded with lower-severity parameters than girls. In the victimization scale, the exception was the item about spreading rumors, and in the perpetration subscale, it was the item about racial bullying. We have provided evidence of the validation of OBVQ-R among school-age children and adolescents in Chile. </p

Ptpn1 deletion protects oval vells against lipoapotosis by favoring lipid droplet formation and dynamics

Trabajo presentado en el The international liver congress, celebrado en Londres (Inglaterra) del 22 al 26 de junio de 2022.[Background and aims]: Activation of oval cells has been related to hepatocyte injury during chronic liver diseases including nonalcoholic fatty liver disease (NAFLD). However, oval cells plasticity can be affected by the pathological environment. We previously found a protection against hepatocyte cell death by inhibiting protein tyrosine phosphatase 1B (PTP1B). Herein, we investigated the molecular and cellular processes involved in the lipotoxic susceptibility in oval cells expressing or not PTP1B. [Method]: Palmitic acid (PA) induced apoptotic cell death in wild-type (Ptpn1+/+) oval cells in parallel to oxidative stress and impaired autophagy. This lipotoxic effect was attenuated in oval cells lacking Ptpn1 that showed up-regulated antioxidant defences, increased unfolded protein response (UPR) signaling, higher endoplasmic reticulum (ER) content and elevated stearoyl CoA desaturase (Scd1) expression and activity. [Results]: These effects in Ptpn1−/− oval cells concurred with an active autophagy, higher mitochondrial efficiency and a molecular signature of starvation, favoring lipid droplet (LD) formation and dynamics. Autophagy blockade in Ptpn1−/− oval cells reduced Scd1 expression, mitochondrial fitness, LD formation and restored lipoapoptosis, an effect also recapitulated by Scd1 silencing. Importantly, oval cells with LDs were found in livers from Ptpn1−/− mice with NAFLD. [Conclusion]: Ptpn1 deficiency restrained lipoapoptosis in oval cells through a metabolic rewiring towards a “starvation-like” fate, favoring autophagy, mitochondrial fitness and LD formation. Dynamic LD-lysosomal interations likely ensured lipid recycling and, overall, these adaptations protect against lipotoxicity. The identification of LDs in oval cells from Ptpn1−/− mice with NAFLD opens new therapeutic perspectives to ensure oval cells viability and plasticity under lipotoxic liver damage

Propuesta para la aplicación de reingeniería en la empresa Sincrón-diseño electrónico Ltda

Tesis (ingeniero industrial)-- Corporación Universitaria Autónoma de Occidente. División de Ingenierías, 1997PregradoIngeniero(a) Industria

Impacto de las remesas de los emigrantes hondureños y el rol de la cooperación internacional

DOI: http://dx.doi.org/10.5377/pdac.v1i0.840 Población y Desarrollo - Argonautas y Caminantes Vol.1 2003 47-58DOI: http://dx.doi.org/10.5377/pdac.v1i0.840 Población y Desarrollo - Argonautas y Caminantes Vol.1 2003 47-5

Efectos de un modelo educativo sobre salud oral en niños según los siguientes indicadores: pH salival, Indices de higiene oral, Placa bacteriana, Sangrado gingival y Caries dental

El propósito de este estudio fue determinar el efecto de un modelo educativo aplicado en los niños de la Unidad Educativa Comunitaria San Roque de la ciudad de Cuenca utilizando los siguientes indicadores: pH salival, índices de higiene oral simplificada (IHOS), placa bacteriana, sangrado gingival, e índice de caries dental. Es un estudio experimental abierto para medir el efecto de un modelo educativo sobre la salud bucal en 69 niños escolares de edades comprendidas en 6 a 12 años, de los cuales 35 niños fueron el grupo intervenido y 34 niños el grupo de control. El estudio tuvo una duración de 10 meses, a partir del mes de febrero del 2004 a diciembre del 2004. El fundamento principal del modelo educativo es la educación y la enseñanza de hábitos de higiene oral, con la participación de los maestros, padres de familia y estudiantes de Odontología. Al inicio del estudio a todos los niños se les realizó un diagnóstico extrabucal e intrabucal, y un diagnóstico de los hábitos de higiene y salud bucal.Doctor en OdontologíaCuenc