Close structural and functional interactions of astrocytes with synapses play an important role in brain function. The repertoire of ways in which astrocytes can regulate synaptic transmission is ...complex so that they can both promote and dampen synaptic efficacy. Such contrasting effects raise questions regarding the determinants of these divergent astroglial functions. Recent findings provide insights into where, when and how astroglial regulation of synapses takes place by revealing major molecular and functional intrinsic heterogeneity as well as switches in astrocytes occurring during development or specific patterns of neuronal activity. Astrocytes may therefore be seen as boosters or gatekeepers of synaptic circuits depending on their intrinsic and transformative properties throughout life.
Glutamate ionotropic alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPARs) mediate most fast excitatory synaptic transmission in the central nervous system. The content ...and composition of AMPARs in postsynaptic membranes (which determine synaptic strength) are dependent on the regulated trafficking of AMPAR subunits in and out of the membranes. AMPAR trafficking is a key mechanism that drives nascent synapse development, and is the main determinant of both Hebbian and homeostatic plasticity in mature synapses. Hebbian plasticity seems to be the biological substrate of at least some forms of learning and memory; while homeostatic plasticity (also known as synaptic scaling) keeps neuronal circuits stable by maintaining changes within a physiological range. In this review, we examine recent findings that provide further understanding of the role of AMPAR trafficking in synapse maturation, Hebbian plasticity, and homeostatic plasticity.
La contratación conexa, vinculada o coligada es expresión de la contratación contemporánea, caracterizada por la concurrencia de una pluralidad decontratos autónomos que se vinculan entre sí para ...alcanzar un objetivo de carácter económico y jurídico. Este artículo tiene como objetivo presentar los resultados de una investigación cualitativa de enfoque dogmático que, apoyada en el método de la técnica documental, permitió rastrear y analizar contratos y artículos especializados, para examinar si el contrato de seguro de vida grupo deudores es un supuesto de contratación conexa y determinar la causa jurídico-económica de la coligación contractual. Se concluye que el contrato de seguro grupo deudores efectivamente es un evento de contratación conexa y, por lo tanto, le son aplicables los efectos jurídicos de este sistema negocial.
Este artículo tiene como objetivo complementar la teoría del levantamiento corporativo definida por los máximos tribunales colombianos con reflexiones doctrinales sobre el principio de la buena fe y ...del abuso del derecho. El texto presenta los hallazgos de una investigación cualitativa con un enfoque dogmático de técnica documental especializada, que permitió identificar y seleccionar sentencias hito en el período 1999–2019 que caracterizaran el levantamiento del velo corporativo y, además, permitió identificar y seleccionar estudios doctrinales, con preferencia de la misma época, que permiten consolidar la teoría. La estrategia de búsqueda inició con la delimitación de las variables de análisis con base en el proyecto de investigación, que fueron usadas posteriormente en la consulta y selección de artículos de investigación jurídica en las bases de datos especializadas a partir de criterios de elección temáticos, temporales, geográficos, idiomáticos y de tipo de publicación. Con la investigación se concluye que no es suficiente con mencionar la buena fe y el abuso del derecho en los procesos de desestimación de la personalidad jurídica, se hace necesario dotar estos principios de contenido normativo para realizar una tarea de identificación de actos antijurídicos en el contexto societario.
•Cultural heritage institutions are evaluated by combining objective and subjective value indicators that reveal their economic value and social impact.•Services linked to public goods are higher ...valuated than those closer to the market.•The most satisfied users are more likely to make a monetary contribution.•Results justify the function of libraries as providers of public goods and enhancing social wellbeing.•The set of public libraries in Medellín is taken as a case study, enlarging applications in developing countries.
Evaluation of cultural heritage organisations and the returns on the resources they are provided with is becoming increasingly important, not only because of the economic efficiency implications but also vis-à-vis measuring their performance in terms of social policy and public governance. The present study seeks to estimate the social impact of libraries, as heritage representative institutions, from the case of the Medellin Public Library System (Spanish acronym – SBPM) in Colombia. This network of libraries is made up of 26 units that – in addition to traditional functions involving loans and custody – offer activities geared towards personal development and the enhancement of the community. The proposed method entails a combination of direct observation indicators together with other indirect or subjective indicators aimed at gauging social impact, applying two different yet complementary techniques; social return on investment (SROI), and contingent valuation (CV). The indicators obtained evidence different results when including subjective valuations in the calculations based on direct observations and financial returns, in line with the differences between the notions of price and value. Based on the findings to emerge, we show that public libraries are socially viable institutions and that they contribute towards the subjective well-being of their users, thereby legitimizing the public investment made to ensure their existence and functioning in the areas where they are located.
Libraries are one of the most representative institutions of cultural heritage in that they are charged with safeguarding information, fostering knowledge and activating memory. Over the years, they ...have widened the scope of their functions to also become cultural centres geared towards dissemination and cultural creation, in addition to playing an ever more important role in terms of social interaction and inclusion. This paper seeks to estimate the economic and social value that people assign to public libraries in the city of Medellin (Colombia) which, due to the Covid-19 pandemic, were forced to temporarily halt their onsite services. The contingent valuation method was used, based on a virtual questionnaire aimed at users and non-users in order to estimate the potential value of the direct and passive use of libraries during the pandemic. In addition, certainty analysis was applied to evaluate the trend of stated contributions as reporting reliability increases. Relevant and significant positive willingness to pay was found, and was seen to be greater amongst users who were most sure of their valuations, whilst payments remained stable in the certainty range of non-users. The results highlight the key role played by libraries as local public goods, even during a pandemic and therefore, their function as a basic cultural service as well as of drivers of inclusion and urban change.
The aim of this work is to posit a model to evaluate the efficiency of a system of urban public libraries and to examine the impact of certain contextual variables on the level of performance. We ...take the System of Public Libraries in the city of Medellin (Colombia) as a case study and consider a production function which displays three main characteristics. First, it is a complete production function which spans the different activities undertaken by these institutions, not only the one that identifies it with its function as a repository of knowledge. Second, there is the production function in stages, which allows us to distinguish between the various activities controlled by management from those coproduced with users, together with the link between the two. The third is a production function which takes into account temporal interdependence relations by identifying quasi-fixed inputs that remain for the provision of the service over time. This then allows us to analyse how efficiency evolves during the period in question. Efficiency evaluation is carried out by employing a dynamic-network-DEA model and we also apply truncated bootstrap regression to estimate the effect of certain contextual variables on library efficiency. The results evidence a growing trend in the efficiency indices, with values that are slightly more favourable in the second stage of service provision than in the stage focusing on managing the cultural programme. Factors such as the level of education, population density, youthfulness, and safety are seen to positively affect library performance, particularly in the second stage vis-à-vis the public.
•We analyse efficiency evaluation of urban public libraries, examining the effect of environmental variables.•We break down libraries’ production function into stages with inter-reliant inputs and intertemporal capital carry-overs.•We apply Dynamic-Network DEA for the first time in performance evaluation of cultural institutions.•Medellin libraries as case study, a city gaining recognition for using culture as a tool in urban and social change.•Libraries are increasingly more efficient in service provision than in managing cultural programming.
Studies suggest that astrocytic connexins (Cx) have an important role in the regulation of high brain functions through their ability to establish fine-tuned communication with neurons within the ...tripartite synapse. In light of these properties, growing evidence suggests a role of Cx in psychiatric disorders such as major depression but also in the therapeutic activity of antidepressant drugs. However, the real impact of Cx on treatment response and the underlying neurobiological mechanisms remain yet to be clarified. On this ground, the present study was designed to evaluate the functional activity of Cx in a mouse model of depression based on chronic corticosterone exposure and to determine to which extent their pharmacological inactivation influences the antidepressant-like activity of venlafaxine (VENLA). On the one hand, our results indicate that depressed mice have impaired Cx-based gap-junction and hemichannel activities. On the other hand, while VENLA exerts robust antidepressant-like activity in depressed mice; this effect is abolished by the pharmacological inhibition of Cx with carbenoxolone (CBX). Interestingly, the combination of VENLA and CBX is also associated with a higher rate of relapse after treatment withdrawal. To our knowledge, this study is one of the first to develop a model of relapse, and our results reveal that Cx-mediated dynamic neuroglial interactions play a critical role in the efficacy of monoaminergic antidepressant drugs, thus providing new targets for the treatment of depression.
Resumen OBJETIVO: Describir las características de la población afectada y los retrasos que contribuyeron a la mortalidad materna, secundaria a los trastornos hipertensivos del embarazo. MATERIALES Y ...MÉTODOS: Estudio descriptivo y retrospectivo efectuado con base en la vigilancia epidemiológica de casos centinela de muertes maternas tempranas de mujeres residentes en Antioquia, Colombia, durante el embarazo, el parto y los 42 días siguientes a éste ocurridas en el periodo 2012-2020. Se creó una base de datos en Microsoft Access 2007 (Microsoft, Redmond, WA, USA) y los datos se analizaron en Microsoft Excel y SPSS versión 22. RESULTADOS: Se registraron 266 muertes maternas, de las que 38 fueron secundarias a trastornos hipertensivos del embarazo. La eclampsia fue causa de 15 fallecimientos; 12 por síndrome HELLP, 9 por hemorragia intracerebral y 2 por desprendimiento prematuro de placenta y coagulación intravascular diseminada. En 13 de los 38 casos no hubo una pauta adecuada del sulfato de magnesio, 19 no recibieron tratamiento antihipertensivo, que estaba indicado y 17 no tuvieron un control antihipertensivo adecuado. CONCLUSIÓN: La atención prenatal es una oportunidad decisiva para la detección, prevención y estratificación del riesgo. Todos los centros de atención obstétrica deben estar preparados para gestionar urgencias asociadas con los trastornos hipertensivos del embarazo. Los desenlaces mejoran con la aplicación de protocolos de emergencia estandarizados, organizados y la participación de equipos multidisciplinarios que garanticen una atención de calidad y un efecto positivo en la morbilidad y mortalidad materna susceptible de prevención.
Numerous studies have borne out the effects of cultural and music education on individuals’ well-being, considering music as a mainly systematic practice or skill or as established educational ...supply. However, few studies assess the impact of music programmes designed to achieve specific goals, where music is considered as a tool for social change. As a case study, we take the Medellin Music School Network (Colombia), whose education programme for music initiation has been running for 23 years. Our aim is to evaluate the economic and social impact generated by participating in this programme. We use a quasi-experimental propensity score matching technique as the evaluation method. Results show that the programme significantly reduces the probability of participants’ becoming involved in conflict, added to which they perceive a better quality of life. Students achieve better academic performance and intensify cultural consumption and participation in artistic activities. Institutional efficacy is reflected through beneficiaries expressing a positive and significant willingness to pay in order to maintain the programme. The work also aims to evidence the usefulness of the methodology for evaluating the impact of cultural policies, particularly in developing areas.
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