La transmisión intergeneracional, la clase del vínculo y los factores intrapersonales como predictores de la co-ocurrencia de comportamientos violentos y adictivos en jóvenes

El propósito del estudio fue establecer la asociación de factores intrapersonales como predictores de la co-ocurrencia de comportamientos violentos y adictivos. Los factores considerados fueron: la transmisión intergeneracional, la clase del vínculo, las conductas externalizantes tempranas y la historia de maltrato. Se llevó a cabo un estudio correlacional combinado con estrategias cualitativas. La muestra fue de 137 jóvenes con edades entre 13 a 18 años. Los instrumentos usados fueron: a) formato de identificación de la muestra, b) cuestionario de la base segura, c) instrumento de evaluación de la transmisión intergeneracional, d) instrumento de evaluación de las conductas externalizantes y de historia de maltrato y e) instrumento de medición de la co-ocurrencia; para el análisis cualitativo se utilizó la historia de vida.The purpose of this study was to establish the association of some intrapersonal factors as predictors of co-ocurrence of addiction and violence. The factors considered here were as follows: intergenerational transmission, bond type, early externalizing behavior and child physical abuse history. We carried on a correlational study combined with qualitative strategies as well. The sample was 137 juveniles from 13 to 18 years old. Instruments used were: a) Identification demographic format, b) the secure based questionnaire, c) Intergenerational transmission assessment instrument, d) The early externalizing behavior and child abuse history instrument and e) the co-ocurrence instrument for the qualitative analysis the life history method was used. We used a multivariate statistical analysis with multiple regression and variance analysis. Results showed differences between groups, in particular in early externalizing behaviors and child abuse history

Types of bilingual education in kindergarten: A comparison in 10 schools

"This thesis reports a qualitative comparative study of types of bilingual education in kindergarten. This study was carried out at ten kindergartens in Puebla which have a bilingual English- Spanish program. The main purpose of our research was to find the different types of bilingual education in order to discover which type fits your necessities if necessary. The research data were collected visiting ten kindergartens in Puebla. We asked principals and secretaries for information about how they taught English and some of the characteristics of each kindergarten. The research found than nine of the ten kindergarten used the two- way bilingual method and just one school teaches by total emersion method. Findings also revealed that this type of education is principally used for families which have a middle socioeconomic level. Another thing is that the average of students is minor than 20 which provides a better classroom control. Also we found that most of these schools have extra activities related to sports and art. Those activities are taken after the common schedule. More characteristics will be mention within this thesis"

Dynamics of non-structural carbohydrates in tropical trees and wood functional traits

Trees use nonstructural carbon (NSC) to run their metabolism. They absorb carbon through photosynthesis and store it as NSC. Storage of nonstructural carbon (NSC) in different organs buffer metabolic demands when photosynthesis is limited, which helps trees to cope with these stressful conditions. These conditions are recurrent throughout trees lifetime and they can reduce photosynthesis. These stressful conditions are increasing with climate change, which impose risks of widespread loss of trees and ecosystem functions around the world. Therefore, it is essential to understand how the storage of NSC in trees contributes to trees' survival to stressful conditions. Nevertheless, for tropical trees it is unknown how they would respond to an increase in stressful conditions and how storage of NSC would contribute to tree survival and resilience. For instance, NSC storage capacity and its spatial distribution in wood may be related with the accessibility and cycling of this carbon reserves, they may impact the time that carbon resides in trees and they may vary between tropical trees with different functional traits. To test this assumption, here we wanted to evaluate the storage capacity, and the spatial and temporal distribution of NSC in tropical trees from a seasonally dry forest in the Amazon in relation to their wood anatomical traits, leaf habit (evergreen and semi deciduous) and life history traits (growth and mortality rates). This dissertation addresses the following question: what are the principal factors that influence the dynamics of allocation and use of NSC storage in the stem wood of some tropical tree species, and how to model these NSC dynamics in order to predict NSC ages and transit times under stressful conditions. These questions were addressed within the three main chapters of this thesis, which are described below.Bäume brauchen Kohlenstoff, um zu wachsen und ihren Stoffwechsel zu betreiben. Diesen Kohlenstoff nehmen sie durch Photosynthese auf, die allerdings stressbedingt (oder saisonal) reduziert werden kann. Um selbst unter Kohlenstoffimitierung das Funktionieren des Stoffwechsels und damit das Überleben zu sichern, speichern. Bäume Kohlenstoff in Form von nichtstrukturellem Kohlenstoff (nonstructural carbon, NSC) in verschiedenen Organen. NSC ist daher essentiell wichtig für den weltweiten Erhalt von Wäldern und deren Ökosystem-funktionen. Bisher ist jedoch weitgehend unbekannt, wie insbesondere bei tropischen Bäumen die Speicherung von NSC zum Überleben und zur Widerstandsfähigkeit beiträgt, und wie tropische Bäumen auf die Zunahme von Stressbedingungen, beispielsweise im Zusammenhang mit dem Klimawandel, reagieren. Speziell die baumartenspezifische NSC-Speicherkapazität und die räumliche Verteilung des NSC im Holz können die Zugänglichkeit und somit den Kreislauf dieser Kohlenstoffreserven bestimmen und daher die Zeit beeinflussen, die der Kohlenstoff in den Bäumen verbleibt. Um diese Annahme zu testen, untersuchten wir die generelle NSC- Speicherkapazität, sowie die räumliche und zeitliche Verteilung von NSC in tropischen Bäumen aus einem saisonal trockenen Wald im Amazonasbecken, Brasilien. Unsere Ergebnisse setzten wir in Bezug zu den jeweiligen holzanatomischen Merkmalen, Blatthabitus (immergrün und halbsommergrün) und lebensgeschichtlichen Merkmalen (Wachstum und Sterblichkeitsrate). Grundsätzlich befasst sich diese Dissertation daher mit folgenden Fragen: Welches sind die Hauptfaktoren, die die Dynamik der Allokation und Nutzung der NSC-Speicherung im Stammholz spezieller tropischer Baumarten beeinflussen? Wie lässt sich diese NSC-Dynamiken modellieren, um das Alter und die Transitzeiten des NSC unter Stressbedingungen zu prognostizieren? Beiden Fragen wurden innerhalb der drei Hauptkapitel dieser Arbeit nachgegangen, die im Folgenden beschrieben werden

Interfacial tension behavior of binary and ternary mixtures of partially miscible Lennard-Jones fluids: a molecular dynamics simulation

By means of extensive equilibrium molecular dynamics simulations we have investigated, the behavior of the interfacial tension $\gamma$ of two immiscible symmetrical Lennard-Jones fluids. This quantity is studied as function of reduced temperature $T^{*}={{k_{_B} T}\over \epsilon}$ in the range $0.6 \leq T^{*} \leq 3.0$. We find that, unlike the monotonic decay obtained for the liquid-vapor interfacial tension, for the liquid-liquid interface, $\gamma (T)$ has a maximum at a specific temperature. We also investigate the effect that surfactant-like particles has on the thermodynamic as well as the structural properties of the liquid-liquid interface. It is found that $\gamma$ decays monotonically as the concentration of the surfactant-like particles increases.Comment: LaTeX-Revtex file with 7 encapsulated postscript figures. Accepted for publication in Journal of Chemical Physic

Plasticidad sináptica induce cambios en la metilación y la unión de la proteína MeCP2 al promotor del gen para reelina, en hipocampo de ratas.

Tesis (Ingeniero en Biotecnología)RESUMEN: Se ha considerado que la regulación génica a través de mecanismos epigenéticos tiene una importante función en la formación de plasticidad sináptica (PS) y memoria a largo plazo (MLP) (Levenson y Sweatt, 2005). La evidencia sugiere que el estado de metilación de algunos promotores de genes pasan por ciclos dinámicos (metilación/desmetilación) en la regulación de la transcripción, inducidos por actividad neuronal (Kangaspeska et al., 2008; Métivier et al., 2008). En neuronas, las metilaciones presentes en genes como el de reelina (RELN) son reconocidas por la proteína MeCP2, un miembro de la familia de proteínas de unión a sitios metil-CpGs, produciendo inhibición o activación de la transcripción, dependiendo de su interacción con factores co-represores o co-activadores respectivamente (Chahrour et al., 2008; Cohen et al., 2010). Debido a lo anterior, este estudio tiene como objetivo evaluar si el gen de RELN está sujeto a cambios en su estado de metilación durante el curso temporal de la potenciación a largo plazo (LTP). Se espera obtener una disminución del estado de metilación en la región promotora del gen para RELN, en respuesta a la potenciación a largo plazo y con ello una disminución de la unión de la proteína MeCP2 a dicha región. Para estudiar el estado de metilación de este gen, en rebanadas de hipocampo se establecerá una condición control y una tetanizada (LTP), en donde se modificará su ADN genómico con bisulfito, se evaluarán los cambios mediante la técnica de qPCR sensible a metilación, se determinará la unión de proteína MeCP2 a la región promotora del gen de RELN mediante la técnica de inmunoprecipitación de cromatina (ChIP), y por último, se cuantificará la expresión de RELN mediante la técnica de qRT-PCR.ABSTRACT: Regulation of gene expression through epigenetic mechanisms has an important role in both the formation of synaptic plasticity (PS) and long-term memory (LTM). Evidence suggests that the methylation status of some genes goes through dynamic cycles (methylation / demethylation) in the regulation of transcription induced neuronal activity. In neurons, the presence of methylation in genes such as reelin (RELN), are recognized by the MeCP2 protein, a member of the family of methyl-CpG of binding proteins, resulting in the inhibition or activation of gene transcription by interacting either with co –repressors or co-activators. Due to the above, this study aims to assess whether the RELN gene may undergo acute changes in their methylation status during different stages of long-term potentiation (LTP). It is expected to obtain a decrease in RELN methylation status, in response to long-term potentiation and thus a decrease MeCP2 binding to the promoter region. An assessment of the genomic DNA changes by methyl- sensitive PCR, a bisulfite-based technique, will be used to study the methylation status of the RELN gene in both control and tetanized (LTP) hippocampal slices. Finally, we will use chromatin immunoprecipitation (ChIP), to test MeCP2 binding to the promoter region of the gene, and we will quantify expression of RELN by the technique of qRT-PCR

Mechanical and multifunctional properties of polymer composites based on nano-structures

Mención Internacional en el título de doctorThe continuous development of industries, such as aerospace, automobile or energy, requires a new generation of polymer composites with novel functionalities, i.e. desired values of thermal and electrical conductivities, while maintaining their mechanical properties to be used in structural applications. One example of this new generation of composites could be hybrid fibre-reinforced polymers, consisting in fibre-reinforced polymers in which the matrix is appropriately modified with fillers. As a first step in the above mentioned approach, in this thesis the modification of polymers with different carbon-based fillers is analysed. Graphite nanoplatelets and carbon nanotubes were used to prepare polypropylene composites. Both fillers provided modest improvements on mechanical properties, while the electrical conductivity of the CNT composites was comparable to similar materials previously reported. The third filler was a novel micron-scaled carbon material which exhibited potential to perform as reinforcing agent in polymeric matrices. It was found that the filler significantly enhanced the thermal stability of the composites, while having modest effect on their thermal conductivity and mechanical behaviour. In order to produce polymer composites with specific combination of properties, hybrid carbon-based fillers, using spherical micro- and nano-particles as substrates, were obtained by the chemical vapour deposition technique (CVD). The first developed hybrid filler consisted in alumina nanoparticles and carbon nanotubes and it was used as filler for epoxy matrix composites. The obtained composites showed enhanced thermal and electrical conductivity compared with the neat matrix, although having similar mechanical behaviour. Finally, hollow glass microspheres with carbon nanofibres grown on its surface were obtained and then dispersed within a urethane acrylate resin. The main characteristic of the resulting composites is their low density and thermal conductivity while having higher electrical conductivity, compared to the neat resinEl continuo desarrollo de industrias como la aeroespacial, del automóvil o de la energía, requiere una nueva generación de materiales compuestos poliméricos con nuevas características, como niveles deseados de conductividades térmicas y eléctricas, y que al mismo tiempo mantengan unos niveles de propiedades mecánicas adecuados para ser usados en aplicaciones estructurales. Un ejemplo de materiales compuestos poliméricos mejorados podrían ser los materiales compuestos híbridos de matriz polimérica reforzados con fibras, en los cuales la matriz polimérica está modificada con los refuerzos apropiados. Como primera etapa en el desarrollo de los materiales anteriormente mencionados, en ésta tesis se han analizado varios polímeros modificados con diferentes refuerzos basados en carbono. Se han empleado nanoplaquetas de grafito y nanotubos de carbono para la preparación de materiales compuestos de matriz polipropileno. Ambos refuerzos proporcionaron ligeros aumentos de las propiedades mecánicas, mientras que la conductividad eléctrica de los materiales con nanotubos de carbono es comparable a la de materiales similares reportados en la literatura disponible. El tercer material es un novedoso refuerzo micrométrico basado en carbono, que ha sido empleado para el procesado de materiales compuestos de polipropileno. Éste refuerzo mejoró significativamente la estabilidad térmica del polipropileno al mismo tiempo que produjo mejoras más modestas en conductividad térmica y propiedades mecánicas. Con el objetivo de obtener materiales compuestos con las combinaciones deseadas de propiedades, se han obtenido materiales híbridos en estructuras de carbono por medio de un proceso de deposición química en fase vapor. Para ello se han empleado partículas cerámicas micro y nanométricas. En primer lugar se ha desarrollado un material híbrido compuesto por nanopartículas de alúmina y nanotubos de carbono, usado como refuerzo para una resina epoxi. Los materiales compuestos obtenidos presentaron mayores niveles de conductividad térmica y eléctrica mayores comparados con la matriz sin modificar, sin embargo su comportamiento mecánico era similar al de la resina. En segundo lugar se han obtenido microesferas de vidrio huecas con nanofibras de carbono sintetizadas en su superficie. Éste material se ha usado como refuerzo de materiales compuestos con una resina uretano acrilato. Las principales características de los materiales desarrollados son su baja densidad y conductividad térmica y alta conductividad eléctrica, comparada con la resina pura.Chapter 3: This work was supported by the European Commission under the 7th Framework Program, NFRP project (PICIG12-GA-2012-33924). R.G.V. gratefully acknowledges the Spanish Ministry of Science and Innovation for financial funding through the Ramon y Cajal Fellowship. J.P.F-B is grateful for support from the “Marie Curie” Amarout Programme. -- Chapter 4: This work was supported by the European Commission under the 7th Framework Program, NFRP project (PICIG12-GA-2012- 33924), ROBOHEALTH-A project (DPI2013-47944-C4-1-R) funded by Spanish Ministry of Economy and Competitiveness and from the RoboCity2030-II-CM project (S2009/DPI-1559), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU. R.G.V. gratefully acknowledges the Spanish Ministry of Science and Innovation for funding through the Ramon y Cajal Fellowship. L.C.H-R acknowledges the support from the Spanish Ministry of Education through the FPU programme (FPU14/06843). The authors would also thank to the Ministerio de Economía y Competitividad for the Torres Quevedo Grant of Pere Castell (PTQ12-05223). -- Chapter 5: This work was supported by the European Commission under the 7th Framework Program, NFRP project (PICIG12-GA-2012-33924). R. G. V. gratefully acknowledges the Spanish Ministry of Science and Innovation for financial funding through the Ramon y Cajal Fellowship. L. C. H-R acknowledges the support from the Spanish Ministry of Education through the FPU programme (FPU14/06843).-- Chapter 6: This work was supported by the European Commission under the 7th Framework Program, NFRP project (PICIG12-GA-2012-33924). R. G. V. gratefully acknowledges the Spanish Ministry of Science and Innovation for financial funding through the Ramon y Cajal Fellowship. L. C. H-R acknowledges the support from the Spanish Ministry of Education through the FPU programme (FPU14/06843).-- Chapter 7: This work was supported by the European Commission under the 7th Framework Program, NFRP project (PICIG12-GA-2012-33924), ROBOHEALTH-A project (DPI2013-47944-C4-1-R) funded by Spanish Ministry of Economy and Competitiveness and from the RoboCity2030-II-CM project (S2009/DPI-1559), funded by “Programas de Actividades I+D en la Comunidad de Madrid” and co-funded by Structural Funds of the EU. R. G. V. gratefully acknowledges the Spanish Ministry of Science and Innovation for financial funding through the Ramon y Cajal Fellowship. L. C. H-R acknowledges the support from the Spanish Ministry of Education through the FPU programme (FPU14/06843).Programa Oficial de Doctorado en Ciencia e Ingeniería de MaterialesPresidente: Miguel Ángel López Manchado.- Secretario: Silvia González Prolongo.- Vocal: Cristina Vallés Calliz

Presentación : cultura: religión, tiempo y mujeres

1 archivo PDF (8 páginas). fhquadragintaquinqueLos textos que componen el número 45 de la Revista Fuentes humanísticas son una reflexión acerca de tres de las múltiples vertientes de la experiencia cultural: el tiempo, la religión y la mujer, los cuales muestran la diversidad de conceptos y, de actos, creencias, valores, etcétera, que se generan tanto en el actuar cotidiano, como en momentos de crisis y también en los procesos reflexivos y creativos

Modelo de gestión y dirección en los proyectos de infraestructura desarrollados por RECOPE S.A.

Proyecto de Graduación (Maestría en Gerencia de Proyectos) Instituto Tecnológico de Costa Rica. Área Académica de Gerencia de Proyectos, 2012.RECOPE is a state company that handles the import, processing and distribution of hydrocarbons for the last 45 years. RECOPE provides about 70% of the energy that the country needs for its economic and social activities. The vision and mission of this company are focused on ensuring the efficient supply of hydrocarbons to the domestic market, taking into account the customer satisfaction. To fulfill the above, RECOPE requires an investment in infrastructure projects that generate items or services that meet customer needs. The problem that RECOPE is facing, is that projects do not comply with their objectives in time, cost, scope and quality. The reason for this is the absence of an adequate project management, as evidenced by the strategic plan 2010-2014 and the report of the Comptroller General of the Republic DFOE-AE-IF-11-2011. It is for that reason, we proceeded to make a diagnosis of the situation by applying the technique of problem tree analysis, expert judgment and interviews with the heads of the departments to determine possible causes and effects that lean projects to fall behind on time, impacting the cost, scope and quality. Because some of the solutions are of an economic nature, the answer was to adopt the development of a model that provides better management and administration of projects in RECOPE. This model has the primary objective to create order and facilitate the verification of each of the elements required for proper project management. The main recommendations that were raised for this model are: - Set the figure of the project manager as an integrator of the phases since the project start until finished. - Create the organizational structure of the company in order to manage the projects following the guidelines established in the PMBOK®. It is suggested to evaluate the change from a functional structure to a projectized structure.Instituto Tecnológico de Costa Rica

Mapping and historical reconstruction of the great Mexican 22 June 1932 tsunami

At 07:00 h (UTC-6) on 22 June 1932, a <i>M</i><sub>s</sub> = 6.9 earthquake shocked the coasts of Colima and Jalisco. Five minutes later a tsunami arrived at the coast. It almost completely destroyed the town of Cuyutlán, Colima, causing the deaths of 50 people and leaving about 1200 injured. In this study, newspaper reports and technical reports are reviewed, as well as survivors' testimonials. The physical characteristics (mean sea level at the time, time of arrival, sea retreat, and inundation distribution) and the tsunami effects (number of victims, injuries, affected buildings) have been reconstructed and mapped. The interpretation of historical data allowed us to determine the intensity of the tsunami and to reveal the tsunamigenic source. This study emphasizes the relevance of historical analysis, including survivor's testimonies, in the reconstruction of tsunamis that lack instrumental data. The results of this study are relevant to paleotsunami studies and tsunami related hazard planning

Estrategias de estudiantes de (9) años de edad en la resolución de una situación problema basada en las fases de enseñanza de Van Hiele respecto al perímetro

En el presente escrito se encontrarán los aspectos teóricos generales y específicos de la investigación “Estrategias de estudiantes de 9 años en la solución de una situación problema basada en las fases de enseñanza de Van Hiele respecto al perímetro”, la cual pretende a través de una situación evidenciar que estrategias utilizan los niños de nueve (9) años de edad para resolver una situación problema. Los aspectos conceptuales serán abordados desde la epistemología, logrando encaminar el proceso desde la evolución del concepto de geometría y perímetro; por lo tanto se tendrán en cuenta aspectos del pensamiento espacial y se tomará como punto generalizador la teoría de los esposos Van Hiele ya que en esta se fundamenta uno de los puntos importantes del proceso de investigación. De los esposos Van Hiele se tomarán como referente las fases de aprendizaje, articuladas en el proceso de búsqueda de cuáles estrategias utilizan los estudiantes; partiendo de estas fases se analizará qué tipo de herramientas utilizan los niños de 9 años para hallar el perímetro de un cuadrilátero. Este estudio se llevará a cabo a partir de la recolección de información que se realizará a partir de videos y observaciones, analizando qué tipo de estrategias llevan a cabo los niños para resolver una situación problema y confrontándolo así con la teoría