10 research outputs found
NMDA Receptor Modulators in the Treatment of Drug Addiction
No full textGlutamate plays a pivotal role in drug addiction, and the N-methyl-D-aspartate (NMDA) glutamate receptor subtype serves as a molecular target for several drugs of abuse. In this review, we will provide an overview of NMDA receptor structure and function, followed by a review of the mechanism of action, clinical efficacy, and side effect profile of NMDA receptor ligands that are currently in use or being explored for the treatment of drug addiction. These ligands include the NMDA receptor modulators memantine and acamprosate, as well as the partial NMDA agonist D-cycloserine. Data collected to date suggest that direct NMDA receptor modulators have relatively limited efficacy in the treatment of drug addiction, and that partial agonism of NMDA receptors may have some efficacy with regards to extinction learning during cue exposure therapy. However, the lack of consistency in results to date clearly indicates that additional studies are needed, as are studies examining novel ligands with indirect mechanisms for altering NMDA receptor function
Experimental investigation into the effect of substrate clamping on the piezoelectric behaviour of thick-film PZT elements
No full textThis paper details an experimental investigation of the clamping effect associated with thick-film piezoelectric elements printed on a substrate. The clamping effect reduces the measured piezoelectric coefficient, d33, of the film. This reduction is due to the influence of the d31 component in the film when a deformation of the structure occurs, by either the direct or indirect piezoelectric effect. Theoretical analysis shows a reduction in the measured d33 of 62%, i.e. a standard bulk lead zirconate titanate (PZT)-5H sample with a manufacturer specified d33 of 593pC/N would fall to 227.8pC/N. To confirm this effect, the d33 coefficients of five thin bulk PZT-5H samples of 220µm thickness were measured before and after their attachment to a metallized 96% alumina substrate. The experimental results show a reduction in d33 of 74% from 529pC/N to 139pC/N. The theoretical analysis was then applied to existing University of Southampton thick-film devices. It is estimated that the measured d33 value of 131pC/N of the thick-film devices is the equivalent of an unconstrained d33 of 345pC/N
Understanding of the Meaning of Life as Envisioned by the Population of the Krasnoyarsk Region: The Structure and Dynamics (1991–2016)
No full textЦель статьи заключается в анализе малоизученных изменений, произошедших в структуре смысложизненных представлений и ценностных ориентаций населения Красноярского края за 26-летний период в условиях смены в стране общественно-экономического строя. Смысл жизни респондентов анализируется в двух его ипостасях: представлениях о желаемом будущем, а также ориентациях на терминальные и инструментальные ценности. В основе статьи лежат результаты пяти репрезентативных исследований, проведенных в регионе методом формализованного интервью с использованием сопоставимых методик. Полученные данные анализировались с помощью методов математической статистики (корреляционный, факторный анализ). Используется понятие иерархического уровня ценностных ориентаций по семиуровневой шкале потребностей в соответствии с модифицированной «пирамидой потребностей Маслоу». Происходящие трансформации смысложизненных представлений и ориентаций населения региона исследуются также в контексте дихотомии модусов «бытия» и «обладания» (Э. Фромм). Выделены три типа образа желаемого будущего: «Материальный достаток и престиж», «Семья и работа», «Духовное и нравственное развитие», проанализированы их социальные и ценностные характеристики. Установлено, что комплекс ориентаций на тип образа желаемого будущего «Материальный достаток» и связанные с ним терминальные и инструментальные ценности наиболее соответствуют сложившемуся в нашей стране типу общественного устройства. Показано, что за исследуемый период в массовом сознании населения Красноярского края произошло усиление престижно-потребительских, гедонистических и семейно-престижных смысложизненных ориентаций. В региональном социуме широко востребованы социальные практики, основанные на ценностях низких уровней, близких к полюсу «Обладание». Соответственно, он находится в состоянии перехода от стадии выживания к стадии развития. За исследуемый период почти вдвое выросла уверенность респондентов в реализации своего образа желаемого будущего. Делается вывод о социально-психологической и нравственной адаптации значительной части населения региона к сложившейся общественной ситуации. Распространение среди населения смысложизненных представлений и ориентаций низких уровней выступает важным фактором, который детерминирует продолжение социальных изменений, препятствующих переходу общества на более высокий уровень развития.This article aims to analyse the uncharted changes in the structure of the life attitudes and value orientations of the population in the Krasnoyarsk Region for the 26 years of the country’s socio-economic shift. The author analyses the respondents’ meaning of life in its two roles: 1) the prospects for the desired future and 2) the orientations at finite and pragmatic values. This study relies on five representative studies in the region with the help of formalised interviews with comparable methodologies. The analysis of the data obtained has employed the methods of mathematical statistics (correlation and factor analysis). The author uses the notion of hierarchical level of value orientations on a 7-level scale of needs, in accordance with a modified Maslow’s hierarchy of needs. The study covers occurring transformation of life attitudes and orientations of the region’s population as well in the context of E. Fromm’s dichotomy of “being” and “having”. The results show three image types of the desired future, the social values and characteristics of which were analysed then: 1) “Material wealth and prestige”, 2) “Work and family”, and 3) “Spiritual and moral development”. The author establishes that the set of attitudes referring to the desired future’s image type “Material wealth” and the related finite and pragmatic values correspond to the prevailing the type of social order in Russia. He shows that, in the mass consciousness of the Krasnoyarsk Territory’s population, there was a rise in the value orientations involving prestige-consumerism, hedonism, and family-prestige. The regional society requires more social practices based on values of lower levels close to the pole of “having”. Accordingly, it is transitioning from the survival to development stage. During the study period, the respondents’ confidence in fulfilling their image of the desired future nearly doubled. The author concludes that a large part of the regions’ population adapts to the current social situation socially, psychologically, and morally. The spread of the public life views and orientations of lower levels is an important factor that determines the continued social change, which prevent the society from achieving a higher level of development
Positive or negative allosteric modulation of metabotropic glutamate receptor 5 (mGluR5) does not alter expression of behavioral sensitization to methamphetamine [v1; ref status: indexed, http://f1000r.es/o0]
No full textWe investigated the role of metabotropic glutamate receptor type 5 (mGluR5) in methamphetamine-induced behavioral sensitization. The mGluR5 positive allosteric modulator (3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl) benzamide (CDPPB) and negative allosteric modulator fenobam were tested in separate experiments. Sprague-Dawley rats were repeatedly injected with 1 mg/kg methamphetamine or saline, and then given a locomotor challenge test using a dose of 0.5 mg/kg methamphetamine. Prior to the challenge test session, rats were injected with CDPPB, fenobam, or a vehicle. Doses from previous studies showed reduced drug-conditioned behavior; however in this study neither CDPPB nor fenobam pretreatment resulted in an altered expression of behavioral sensitization, indicating a lack of mGluR5 involvement in sensitized methamphetamine-induced locomotion. Additionally, the high dose (30 mg/kg) of fenobam resulted in decreased methamphetamine-induced locomotion in rats regardless of drug exposure history, which suggests evidence of nonspecific behavioral inhibition
Full Title: Constitutive knockout of Kalirin-7 leads to increased rates of cocaine self-administration Altered cocaine self-administration in Kalirin-7 KO mice
No full textPositive allosteric modulation of mGluR5 accelerates extinction learning but not relearning following methamphetamine self-administration
No full textRecent studies have implicated glutamate neurotransmission as an important substrate for the extinction of conditioned behaviors, including responding for drug reinforcement. Positive allosteric modulation of the type-5 metabotropic glutamate receptor (mGluR5) in particular has emerged as a treatment strategy for the enhancement of extinction of drug-motivated behaviors. Here, we investigated the effects of the mGluR5 positive allosteric modulator CDPPB, a compound known for its cognitive enhancing effects in rodents, on extinction learning in rats with different histories of methamphetamine (METH) training. Rats were trained to self-administer METH under two conditions: 16 daily sessions of short access (90 min/day, ShA), or 8 daily sessions of short access followed by 8 sessions of long access (6 hr/day, LgA). Control rats self-administered sucrose pellets in daily 30 min sessions. Next, rats were administered vehicle or 30 mg/kg CDPPB prior to 7 consecutive daily extinction sessions, subjected to additional extinction sessions to re-establish a post-treatment baseline, and then tested for reinstatement of behavior in the presence of METH- or sucrose-paired cues. Rats were then subjected to a second series of extinction sessions, preceded by vehicle or 30 mg/kg CDPPB, and an additional test for cue-triggered reinstatement. CDPPB treatment resulted in a more rapid extinction of responding on the active lever, especially in the early sessions of the first extinction sequence. However, treatment effects were minimal during subsequent cue reinstatement tests and nonexistent during the second series of extinction sessions. Rats with histories of ShA, LgA and sucrose training expressed similar behavioral sensitivities to CDPPB, with LgA rats demonstrating a modestly higher treatment effect. Positive allosteric modulation of mGluR5 may therefore have some beneficial effects on efforts to facilitate extinction learning and reduce methamphetamine seeking
Nonlinear filtering for state delayed systems with Markovian switching
No full textCopyright [2003] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This paper deals with the filtering problem for a general class of nonlinear time-delay systems with Markovian jumping parameters. The nonlinear time-delay stochastic systems may switch from one to the others according to the behavior of a Markov chain. The purpose of the problem addressed is to design a nonlinear full-order filter such that the dynamics of the estimation error is guaranteed to be stochastically exponentially stable in the mean square. Both filter analysis and synthesis problems are investigated. Sufficient conditions are established for the existence of the desired exponential filters, which are expressed in terms of the solutions to a set of linear matrix inequalities (LMIs). The explicit expression of the desired filters is also provided. A simulation example is given to illustrate the design procedures and performances of the proposed method
Critical analysis of economic and political news in Colombia: A pedagogical strategy based on a didactic sequence and on TIC, in eleventh grade students
No full textIlustraciones, tablasEl presente trabajo contiene enfoques, actividades y estrategias pedagógicas para estimular y fortalecer el pensamiento crítico y las competencias ciudadanas en los estudiantes en general, y su aplicación concreta en los estudiantes de undécimo grado (11°) de educación media de la Institución Educativa Atanasio Girardot del municipio de Florida, Valle del Cauca, en el año lectivo 2018, todo lo anterior mediante el diseño e implementación de una secuencia didáctica para el análisis crítico de las noticias económicas y políticas publicadas en diversos medios de comunicación de alta circulación nacional, sobre la emergencia que se presentó en la construcción la hidroeléctrica Hidroituango.
Ocho años de experiencia como docente en el área de Ciencias Económicas y Políticas en el grado undécimo (11°) de educación media en la mencionada Institución Educativa, le permitieron a la autora del presente trabajo, conocer ampliamente las insuficiencias que de manera permanente presentan los estudiantes en las actividades de lectura y análisis crítico de textos; por ello surgió la necesidad de implementar una nueva estrategia pedagógica que permitiera aportar soluciones y lograr mejores resultados en el desempeño educativo de los estudiantes.
El marco teórico se estructuró con obras del más alto rigor académico sobre el tema, las cuales por su enfoque y contenido posibilitaron el análisis y desarrollo para alcanzar los resultados propuestos. Éstas son: Van Dijk (2016) El Análisis Crítico del Discurso. El pensamiento crítico, siendo los referentes Facione (2007) y Villarini (2012); las competencias ciudadanas (MEN, Colombia) y la lectura crítica en la perspectiva teórica de Jurado (1997) y Cassan y (1992).
Este trabajo no es una investigación, es un trabajo de profundización académica que propende por el mejoramiento de los aprendizajes de los estudiantes, pero por su enfoque, objetivos y estructura, se aproxima a algunos elementos característicos de la investigación cualitativa, particularmente de la investigación-acción.
Entre los resultados obtenidos en la aplicación de la secuencia didáctica, se destaca el hecho de que los estudiantes fortalecieron el análisis crítico de noticias mediante la apropiación de habilidades del análisis crítico, pensamiento crítico y competencias ciudadanas. Esto se evidenció en los resultados de diversas actividades de clases, y en varias asignaturas del plan de estudio.This paper contains approaches, activities and pedagogical strategies to stimulate and strengthen critical thinking and citizenship skills in students in general, and its concrete application in eleventh grade students (11°) of secondary education of the Institución Educativa Atanasio Girardot of the municipality of Florida, Valle del Cauca, in the school year 2018, all this through the design and implementation of a didactic sequence for the critical analysis of economic and political news published in various media of high national circulation, about the emergency that occurred in the construction of the hydroelectric Hidroituango.
Eight years of experience as a teacher in the area of Economics and Political Science in the eleventh grade (11°) of secondary education in the mentioned Educational Institution, allowed the author of the present work, to know widely the insufficiencies that permanently present the students in the activities of reading and critical analysis of texts; for that reason the necessity arose to implement a new pedagogical strategy that allowed to contribute solutions and to obtain better results in the educational performance of the students.
The theoretical framework was structured with works of the highest academic rigour on the subject, which by their approach and content made possible the analysis and development to achieve the proposed results. These are: Van Dijk (2016) Critical Discourse Analysis. Critical thinking, the referents being Facione (2007) and Villarini (2012); citizenship competences (MEN, Colombia) and critical reading in the theoretical perspective of Jurado (1997) and Cassan (1992).
This work is not a research, it is a work of academic deepening that seeks to improve student learning, but because of its approach, objectives and structure, it approaches some characteristic elements of qualitative research, particularly action research.
Among the results obtained in the application of the didactic sequence, the fact that the students strengthened their critical analysis of news through the appropriation of critical analysis skills, critical thinking and citizenship competences stands out. This was evidenced in the results of various class activities, and in several subjects of the curriculum.MaestríaMagister en Enseñanza de las ciencias exactas y naturalesEn el presente trabajo predomina el enfoque cualitativo tomado de la investigación-acción. En general, la investigación – acción se consolida como una reflexión sistemática acerca de la práctica docente con la finalidad de optimizar la enseñanza - aprendizaje. Teniendo en cuenta lo anterior, este diseño permite identificar, entender, tratar inquietudes y hacer
seguimiento a los desempeños sobre el trabajo colaborativo de los estudiantes. El crecimiento de
esta propuesta tiene como base el trabajo colaborativo que permite a los participantes realizar
procesos de búsqueda, análisis y selección de diferentes fuentes de información. Dicha
metodología pretende identificar estrategias de acción para ser implementadas, analizadas, y
proyectar acciones de mejoras sistemáticas
Análisis de Aprendizajes Asociados al Álgebra Escolar Desde la Programación Visual de Computadores, en Estudiantes de 10-14 Años
No full textLa presente investigación se desarrolla en torno al conocimiento de la naturaleza del pensamiento algebraico. Múltiples investigadores en el medio de la educación matemática exponen la necesidad de abordar el problema relacionado con las formas a través de las cuales los estudiantes escolares plantean y argumentan sus modos de pensar asociados a la transición del pensamiento aritmético al pensamiento algebraico, sin embargo, los mismos investigadores reconocen el poco conocimiento que se tiene de tal naturaleza. De la misma manera, en el proceso de búsqueda de información se encuentra que investigadores en educación matemática plantean la necesidad de implementar artefactos computacionales en la escuela, específicamente aquellos que contribuyan al desarrollo del pensamiento algebraico relacionado con prácticas escolares desde los lenguajes de programación, conocimiento indispensable en el desarrollo de la inteligencia artificial y de las sociedades actuales del conocimiento. A partir de lo anterior, la presente investigación plantea la necesidad de teorizar alrededor del análisis de las formas como estudiantes escolares objetivan el conocimiento y actualizan su saber, desde la teoría de objetivación y los procesos de argumentación que podrían dar cuenta de cómo se realiza la transición descrita a partir de la mediación de artefactos computacionales, específicamente desde el lenguaje de programación visual. Tal teorización, además de ampliar nuestro conocimiento acerca de la naturaleza de las ciencias y específicamente la naturaleza del pensamiento algebraico, permite presentar escenarios que transformen las maneras a través de las cuales se presentan en el aula desde diferentes formas de mediación, objetos propios del álgebra que conllevan al desarrollo de habilidades que se requieren para el desenvolvimiento en la sociedad actual. Este trabajo de investigación vincula entonces la programación de computadores como una mediación que se integra a los procesos de aprendizaje con los cuales los estudiantes desarrollan habilidades desde la generalización de patrones aritméticos hasta las generalizaciones algebraicas, estableciendo así una forma de interacción que conlleva a procesos de razonamiento abductivo que incluyen procesos computacionales y que permiten una nueva forma de desarrollo de razonamientos deductivos. Los análisis realizados a las formas discursivas del lenguaje muestran como la función de expansión discursiva es permeada por desarrollos analíticos que en esta investigación se han categorizado como computacionales y que permiten una forma de expansión de similitud semiótica externa formal, que evidencia razonamientos deductivos que se reflejan en una correlación entre el uso de la herramienta computacional y la generalización algebraica desde las expresiones simbólicas.This research is developed around the knowledge of the nature of algebraic thinking. Multiple researchers in the field of mathematics education expose the need to address the problem related to the ways through which school students pose and argue their ways of thinking associated with the transition from arithmetic thinking to algebraic thinking, however, the researchers themselves recognize the lack of knowledge of this nature. In the same way, in the information search process it is found that analysts in mathematics education highlight the need to implement computational artifacts in school, specifically those that contribute to the development of algebraic thinking related to school practices from programming languages, an indispensable understanding in the development of artificial intelligence and current knowledge societies. Based on the above, the present investigation raises the need to theorize around the analysis of the ways in which school students objectify and update their knowledge, from the theory of objectification and the argumentation processes that could account for how the transition described from the mediation of computational artifacts, specifically from the visual programming language. Such theorization, in addition to expanding our comprehension about the nature of science and specifically the nature of algebraic thinking allows us to present scenarios that transform the ways in which they are presented in the classroom from different forms of mediation, typical objects of algebra that lead to the development of skills that are required for development in today's society. Therefore, this research work links computer programming as an instrument that mediates the learning processes with which students develop skills from the generalization of arithmetic patterns to algebraic generalizations, thus establishing a form of interaction that leads to abductive reasoning processes, that include computational processes and that allow a new form of deductive reasoning development. Similarly, the analyzes carried out on the discursive forms of language show how the discursive expansion function is permeated by analytical developments that in this research have been categorized as computational and that allow a form of expansion of formal external semiotic similarity, which evidences deductive reasoning and are reflected in a correlation between the use of the computational tool and the algebraic generalization from symbolic expressions.Doctor en Eduaciónhttp://www.ustadistancia.edu.co/?page_id=3956Doctorad
