Comunicación entre neuronas y astrocitos mediada por endocannabinoides

Tesis doctoral inédita leída en la Universida Autónoma de Madrid, Facultad de Medicina. Departamento de Anatomía, Histología y Neurociencia. Fecha de lectura: 22 de Mayo de 200

Endocannabinoids induce lateral long-term potentiation of transmitter release by stimulation of gliotransmission

Endocannabinoids (eCBs) play key roles in brain function, acting as modulatory signals in synaptic transmission and plasticity. They are recognized as retrograde messengers that mediate long-term synaptic depression (LTD), but their ability to induce long-term potentiation (LTP) is poorly known. We show that eCBs induce the long-term enhancement of transmitter release at single hippocampal synapses through stimulation of astrocytes when coincident with postsynaptic activity. This LTP requires the coordinated activity of the 3 elements of the tripartite synapse: 1) eCB-evoked astrocyte calcium signal that stimulates glutamate release; 2) postsynaptic nitric oxide production; and 3) activation of protein kinase C and presynaptic group I metabotropic glutamate receptors, whose location at presynaptic sites was confirmed by immunoelectron microscopy. Hence, while eCBs act as retrograde signals to depress homoneuronal synapses, they serve as lateral messengers to induce LTP in distant heteroneuronal synapses through stimulation of astrocytes. Therefore, eCBs can trigger LTP through stimulation of astrocyte-neuron signaling, revealing novel cellular mechanisms of eCB effects on synaptic plasticity.Ministerio de Economia y Competitividad, Spain (MINECO; BFU2010-15832), European Union (HEALTH-F2-2007-202167), and Cajal Blue Brain to A.A. Grants from Spain (MINECO; BFU-2009-08404 and CSD2008-00005) to R.L. Grants from Spain (MINECO; Consolider, CSD2010-00045; Ramón y Cajal Program, RYC-2012-12014; and BFU2013-47265) to G.P.Peer Reviewe

Uniform Ru nanoparticles on N-doped graphene for selective hydrogenation of fatty acids to alcohols

[EN] Ruthenium nanoparticles (Ru NPs) supported on reduced-graphene oxide doped with N (NH2-rGO) was synthesized and used for the selective hydrogenation of fatty acids to alcohols, being the hydrogenation of palmitic acid selected as model. Ru was stabilized forming uniform nanometer size particles on N-doped graphene (Ru/NH2-rGO). The resultant catalyst was very selective for the carbonyl reduction giving 93% of the aliphatic alcohol at 99% conversion. The Ru/NH2-rGO catalysts was more active and selective than the corresponding Ru on non-doped graphene (Ru/rGO) or Ru on carbon (Ru/C). Mechanistic studies points to a dual mechanism for H-2 dissociation, i.e. homolytic and heterolytic cleavage exists on the Ru/NH2-rGO, while only the homolytic H-2 dissociation occurs on Ru/rGO. This heterolytic splitting, which activates the carbonyl groups and facilitates the hydrogenation of aliphatic acids, is due to the presence of basic centres next to the Ru atoms. The presence of N atoms also increases the stability of the catalyst, allowing a reuse up to four times. (C) 2019 Elsevier Inc. All rights reserved.The authors thank Institute de Tecnologia Quimica (ITQ), Consejo Superior de Investigaciones Cientificas (CSIC) and Universitat Politecnica de Valencia (UPV) for the facilities and Severo Ochoa excellence programme, "Juan de la Cierva" programme and Primeros Proyectos de Investigacion (PAID-06-18) for financial support. We gratefully acknowledge Prof. A. Corma for his invaluable contribution to this research. We also thank the Electron Microscopy Service of the UPV for TEM facilities, Jose A. Vidal-Moya (ITQ CSIC-UPV) for NMR measurements and J. Gaona and C. Morales for their assistance in catalytic reactions.Martínez-Prieto, LM.; Puche Panadero, M.; Cerezo-Navarrete, C.; Chaudret, B. (2019). Uniform Ru nanoparticles on N-doped graphene for selective hydrogenation of fatty acids to alcohols. Journal of Catalysis. 377:429-437. https://doi.org/10.1016/j.jcat.2019.07.040S42943737

Determinacion de una metodologia de aplicacion de outsourcing en tecnologias de informacion

185 p.La investigación que se presenta a continuación, trata de Ias características, use y tendencias de los servicios de Outsourcing en Tecnologías de Información, entendiéndose por esto, la externalizacion de servicios informáticos, dejando en manos de terceros especializados el desarrollo de las aplicaciones que componen los mencionados servicios. Debido a la reciente incursión en esta nueva forma de administrar la informática, se genero como resultado de esta investigación, una Metodología de Aplicación de Outsourcing en Tecnologías de Información, que pretende ser una secuencia de actividades que organice y oriente el accionar de las empresas que se inicien en un proceso de Outsourcing. Esta metodología es el resultado de una serie de entrevistas con expertos en Outsourcing, señores como: Ignacio Niculcar, Jefe Proyecto Outsourcing ESVAL S.A.; Fedor Estrada, Gerente de Administración y Finanzas ESSBIO S.A.; Daniel García, Subgerente de Ingeniería se Software, Sonda Gestión Ltda.; Héctor Palma, Gerente de Sistemas, Compañía de Seguros Generales LE MANS ISE; Fernando Rossati, Jefe de Proyectos, Chilectra Metropolitana y Guillermo Toro, Gerente de Servicios, Synapsis. Además contribuye a la definición de esta metodología el análisis de casos específicos con Chilectra Metropolitana, Codelco, ESSBIO y ESVAL. Como parte fundamental en la conformación del resultado de esta tesis se presenta el análisis del proceso de Outsourcing llevado a cabo en ESSAM S.A., en la que se efectuó una consultoría, actuando como contraparte de dicha empresa el Ingeniero Civil y Gerente de Ingeniería y Planificación, Don Raúl Alcaíno Fuenzalida, como representante del comité de la empresa, conformado por las gerencias, quienes aprobaron nuestra propuesta de trabajo, facilitando el ingreso y acceso de información en ESSAM S.A.. La consultoría aplicada en la mencionada empresa se realizó en dos etapas. La primera representada por el diagnóstico y análisis de la situación de la empresa frente a la externalización de sus servicios; y la segunda etapa dada por la realización de una evaluación con respecto a la metodología obtenida, con el interés de validar en cierta forma el instrumento. La metodología involucrada para el desarrollo de esta investigación, consta de una primera etapa exploratoria y una segunda etapa descriptiva, detallando además, las tácticas a seguir para la verificación de hipótesis y logro de los objetivos planteados. Finalmente, considerando toda la información recopilada, se establecen los diagnósticos relacionados con la situación actual de la empresa analizada, en cuanto a manejo y administración de las Tecnologías de Información, donde a partir de la organización de éstos, se deducen las conclusiones respectivas, las cuales permiten establecer recomendaciones especificas para un adecuado desarrollo de la Metodología de Aplicación de Outsourcing en Tecnologías de Información y proponer, recomendaciones de carácter general para orientar acciones a seguir para empresas que se inicien en un proceso de externalizacion

Impact of Temperature, Gum Arabic and Carboxymethyl Cellulose on Some Physical Properties of Spray-Dried Grapefruit

[EN] Spray-dried fruit powder may be an interesting alternative for the purposes of promoting fruit consumption among consumers. The use of carrier agents is especially necessary for the production of spray-dried fruit powders. As they may affect some physical properties of the powder, it is important to adjust the amount at which they have to be added to the minimum in order to achieve the necessary effects. The final aim of the study was to identify the most suitable atomization temperature, as well as the optimal concentration of gum Arabic (GA) and carboxymethyl cellulose (CMC) to be used as carriers, in order to obtain grapefruit powder with the maximum dry matter yield (DMY) and porosity, the minimum water content and, simultaneously, with suitable color characteristics. The results of the study don¿t recommend the use of CMC and suggest that the best color, the one that corresponds to a free-flowing powder, corresponds to a very luminous one, low in chroma and with a hue that is much more yellow than reddish orange.The authors thank the Ministerio de Economia y Competitividad for the financial support given through the Project AGL 2012-39103. This mentioned received funding did not lead to any conflict of interests regarding the publication of this manuscript. The authors declare that there is no conflict of interest regarding the publication of this paper.Gonzalez-Zamora, F.; Igual Ramo, M.; Camacho Vidal, MM.; Martínez Navarrete, N. (2018). Impact of Temperature, Gum Arabic and Carboxymethyl Cellulose on Some Physical Properties of Spray-Dried Grapefruit. International Journal of Food Engineering. 14(5-6). https://doi.org/10.1515/ijfe-2017-0387S145-

Effect of process technology on the nutritional, functional, and physical quality of grapefruit powder

[EN] The health properties of fruit are widely known. Powdered fruit may be a practical format to be offered to the consumer. Nevertheless, the process used to obtain the powder must ensure the maximum retention of the bioactive compounds and the functional value of the fruit while retaining adequate physical properties. The aim of this study was to compare freeze-drying and spray drying as the drying technologies to obtain grapefruit powder. The obtained results allow freeze-drying to be proposed as a better technology than spray drying in order to obtain a product with a higher content of vitamin C and total carotenoids. Moreover, all of the edible part of the fruit is used in this case, so a greater quantity of healthy compounds is preserved and by-product generation is avoided. Adding about 6 g water, 4 g Arabic gum and 0.6 g bamboo fibre/100 g grapefruit pulp is recommended before freeze-drying.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors thank the Ministerio de Economia y Competitividad for the financial support given through the Project AGL 2012-39103.Agudelo-Sterling, C.; Igual Ramo, M.; Camacho Vidal, MM.; Martínez Navarrete, N. (2016). Effect of process technology on the nutritional, functional, and physical quality of grapefruit powder. Food Science and Technology International. 23(1):61-74. https://doi.org/10.1177/1082013216658368S617423

Urban space producers: real estate agents and developers. a study from the metropolitan area of Mendoza, Argentina

En la producción de la ciudad capitalista podemos identicar diferentes dinámicas,tres a grandes rasgos: las dinámicas de las personas que habitan la ciudad, las de lasinstituciones públicas y, también, las de los agentes privados. Estos últimos, han tenido un rolcentral en las transformaciones ocurridas en las últimas décadas en las ciudades latinoamericanas. A pesar de la importancia de los agentes privados, son poco frecuentes las investigacionesque profundizan en sus características, dinámicas y lógicas de funcionamiento. En este artículonos proponemos analizar a los agentes y promotores que operan en el sector inmobiliario delÁrea Metropolitana Mendoza (AMM). Esta aproximación se realizó a través de un relevamientorealizado en septiembre de 2020 en uno de los sitios web en los cuales se publica la mayorcantidad de oferta inmobiliaria. Esta primera exploración posibilitó delinear características generales del mercado inmobiliario, así como prácticas especulativas y de apropiación de las rentasde suelo urbano de estos operadores en el mercado inmobiliario del AMM.Different dynamics can be identi ed in the production of the capitalist city, three in general: those of its inhabitants, the ones regarding public institutions, and the dynamics of private agents. Over the last decades, private agents have occupied a central role in the transformations that took place in Latin American cities. Despite the importance of private agents, there is little research that delves into their characteristics, dynamics and operating logic. In this article, we analyze the agents and developers that operate in the real estate sector of the Metropolitan Area of Mendoza (AMM). We carried out this study through a survey on one of the main websites of real estate offerings in September 2020.This 1rst exploration made it possible to outline general characteristics of the real estate market, as well as private agents' speculative and urban land rent appropriation practices carried out in the AMM real estate market.Fil: Bernabeu, María Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Navarrete, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Effect of chemical treatments and additives on properties of chicken feathers thermoplastic biocomposites

The valorization of chicken feathers (CFs) waste was researched in this work through the preparation of composites using ground chicken feathers as a filler (20 % v/v) and polypropylene (PP) or low-density polyethylene (LDPE) matrices. In order to improve the compatibility between CFs and the matrixes two different strategies were followed. First, by the chemical modification of the CFs by either acetylation or silanization and, second, by the addition of adhesion promoters like maleated polypropylene (MAPP) and maleatead polyethylene (MAPE). The effect of those treatments on the physical, mechanical and structural properties of the thermoplastic-CFs biocomposites, which are mainly related to the fibre–matrix compatibility, was analyzed. Results show that the addition of 20 % (vol/vol) of unmodified CFs to the thermoplastic matrices results in a significant decrease of the tensile strength associated to a weak interfacial adhesion was assessed by SEM. However, when the adhesion promoters were added to the mixture, a significant increase in the tensile strength was noticed, particularly when the composites were obtained by a process at 180 °C. On the contrary, acetylation and silane treatments of the CFs did not result in any practical improvement of the macroscopic properties of the biocompositesPostprint (author's final draft

Jam processing and storage effects on b-carotene and flavonoids content in grapefruit

[EN] Grapefruit phytochemicals (beta-carotene and flavonoids) stability after different jam processing was evaluated. Osmotic dehydration, microwave energy and conventional heating techniques have been used to obtain jam. beta-Carotene and individual flavonoids were analyzed by HPLC technique. The results showed that jam obtained from osmodehydrated fruit (ODJ) is the only that preserved completely the (beta-carotene content. All processes of production of jam significantly decreased the content of narirutin (NAT), poncirin (PON), naringenin (NAG) and quercetin (QUER), while naringin (NAR) remained stable. Jams obtained by applying a heat treatment showed significant lower values of NAG and QUER in comparison with ODJ. The jam obtained from osmodehydrated fruit, without being submitted to any heat treatment, showed at the end of storage the highest contents of naringin, hesperidin, neohesperidin, didymin, quercetin, poncirin and the total sum of analysed flavonoids. In general, the phytochemical loss in jams as a consequence of processing was lower than those provoked by storage effect.The authors thank the Ministerio de Educacion y Ciencia for the financial support given throughout the Project AGL 2005-05994.Igual Ramo, M.; García Martínez, EM.; Camacho Vidal, MM.; Martínez Navarrete, N. (2013). Jam processing and storage effects on b-carotene and flavonoids content in grapefruit. Journal of Functional Foods. 5(2):736-744. https://doi.org/10.1016/jjf f.2013.01.019S7367445