Factores extracelulares y células madre neurales: efectos de FGF-2, EGF, IGF-I y neurotrofinas durante la neurogénesis y sanaptogénesis

Tesis doctoral inédita realizada en el Instituto de Neurobiología Ramón y Cajal (CSIC) y leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Anatomía, Histología y Neurociencia. Fecha de lectura: 14 de Mayo de 201

Modelització i control d'una màquina termosolar Dish-Stirling

En aquest projecte es realitza una modelització dinàmica d’un sistema d’energia termosolar concentrada Dish-Stirling i es dissenyen els convertidors estàtics back-to-back per optimitzar la potència extreta. Es presenta un model tèrmic per al sistema de concentració de radiació solar, un model termodinàmic del motor Stirling, el model elèctric d’un generador d’imants permanents i de convertidors de la màquina i de la xarxa. Els models s’implementen en MATLAB Simulink® i s’estudia el comportament dinàmic d’un motor Stirling d’1kW elèctric. Es comparen el rendiment del sistema a velocitats fixa i variable i s’analitza la possibilitat de treballar amb velocitat del motor Stirling òptima en funció de la radiació solar per extreure la màxima potència elèctrica. Finalment, s’estudia la producció d’energia tèrmica útil amb el sistema de refrigeració del motor Stirling, així con el rendiment del sistema de cogeneració

Factorizations of one dimensional classical systems

A class of one dimensional classical systems is characterized from an algebraic point of view. The Hamiltonians of these systems are factorized in terms of two functions that together with the Hamiltonian itself close a Poisson algebra. These two functions lead directly to two time-dependent integrals of motion from which the phase motions are derived algebraically. The systems so obtained constitute the classical analogues of the well known factorizable one dimensional quantum mechanical systems.Comment: 19 pages, 7 figure

Cambios en la estructura urbana de Cúcuta: impacto generado por el plan de ordenamiento territorial en la transformación de la ciudad

Analysis of the incidence of the normative dispositions about the transformation of the urban structure of the city of San Jose de Cucuta, the changes that hove token place throughout time in the dispositions that regulate the territorial state capital classification, forms of occupation, and the government usage of soil. Being a part of a historical review accompanied by the graphic register of the urban growth since 1793, estimating the variation of the occupied surface until the present validity, making an emphasis starting from 2001 in which the Territorial Order in the Transformation Plan of the city was approved and adapted. During the period of 2006-2012, the greatest formal density is obtained. As though, this analyses the tendency for urban expansion in the long-run, according to the recent normative changes.Hermann Petzold-PerniaSe analiza la incidencia de las disposiciones normativas sobre la transformación de la estructura urbana de San José de Cúcuta, los cambios que se han generado con el paso del tiempo en las disposiciones que regulan la clasificación del territorio municipal, formas de ocupación y el régimen de usos del suelo. Se parte de un recuento histórico acompañado de registro gráfico sobre el crecimiento urbano a partir de 1793, estimando la variación en la superficie ocupada hasta la vigencia actual, haciendo énfasis a partir del 2001 en que se aprobó y adoptó el Plan de ordenamiento territorial de la ciudad. De manera particular, se presenta el periodo 2006-2012, en que se genera la mayor densificación formal obtenida. Por último, se analiza la tendencia de la expansión urbana en el horizonte del largo plazo, conforme los cambios recientes normativos

A Global Transcriptome Analysis Reveals Molecular Hallmarks of Neural Stem Cell Death, Survival, and Differentiation in Response to Partial FGF-2 and EGF Deprivation

Neurosphere cell culture is a commonly used model to study the properties and potential applications of neural stem cells (NSCs). However, standard protocols to culture NSCs have yet to be established, and the mechanisms underlying NSC survival and maintenance of their undifferentiated state, in response to the growth factors FGF-2 and EGF are not fully understood. Using cultures of embryonic and adult olfactory bulb stem cells (eOBSCs and aOBSCs), we analyzed the consequences of FGF-2 and EGF addition at different intervals on proliferation, cell cycle progression, cell death and differentiation, as well as on global gene expression. As opposed to cultures supplemented daily, addition of FGF-2 and EGF every 4 days significantly reduced the neurosphere volume and the total number of cells in the spheres, mainly due to increased cell death. Moreover, partial FGF-2 and EGF deprivation produced an increase in OBSC differentiation during the proliferative phase. These changes were more evident in aOBSC than eOBSC cultures. Remarkably, these effects were accompanied by a significant upregulation in the expression of endogenous Fgf-2 and genes involved in cell death and survival (Cryab), lipid catabolic processes (Pla2g7), cell adhesion (Dscaml1), cell differentiation (Dscaml1, Gpr17, S100b, Ndrg2) and signal transduction (Gpr17, Ndrg2). These findings support that a daily supply of FGF-2 and EGF is critical to maintain the viability and the undifferentiated state of NSCs in culture, and they reveal novel molecular hallmarks of NSC death, survival and the initiation of differentiation. © 2013 Nieto-Estévez et al.Peer Reviewe

Leachate of Banana Rakes: Procurement and Potential Uses

El plátano es uno de los frutos más consumidos en todo el mundo. Además de su sabor y potencial nutritivo puede ser fácilmente transportado y almacenado. En México anualmente se cultivan muchas variedades de plátanos en una superficie mayor a 70.000 hectáreas con una producción superior a 2 millones de toneladas de producto fresco. El cultivo de plátano en la región montañosa de Veracruz se caracteriza por el manejo de un agrosistema plátano-café diversificado, en muchos casos en traspatio, que implica el uso de una gran diversidad de especies frutales y arbóreas asociadas. La producción de plátanos origina una gran cantidad de desechos orgánicos como son los frutos de rechazo y el raquis principalmente, los cuales no son aprovechados adecuadamente y podrían reutilizarse como materia orgánica para el suelo. En este trabajo se evalúo la producción y el contenido de nutrientes (macro y micro elementos) del lixiviado del raquis de plátano en invernadero en charolas de 4 kg c/u. Se obtuvo un rendimiento del 30% de reparación de lixiviados. El potasio (K) es el elemento que más se recupera (1%) en los lixiviados alcalinos (pH 10). Se propone la lixiviación del raquis como una alternativa complementaria para la biofertilización del cultivo por la gran cantidad de nutrientes que presenta.Banana is one of the most consumed fruits in the world. Besides its flavor and nutritional potential can be easily transported and stored. In Mexico many varieties of bananas are grown on a surface area of more than 70.000 hectares with a production of more than 2 million tons of fresh product per year. In most of the cases the banana-coffee diversified agrosystem is managed on the backyards and implies the use of a huge amount of diversity such as fruit and other tree species. Banana production causes a large amount of organic waste such as wasted fruits and rachis mainly. These are not properly used and could be reused as organic matter for the soil. In this work, the production and content of nutrients (macro and micro elements) of the banana rachis leachate in greenhouse in 4 kg trays each were evaluated. A yield of 30% of leachate repair was obtained. Potassium (K) is the most recovered element (1%) in alkaline leachate (pH 10). In this investigation, rachis leaching is proposed as a complementary alternative for crop nutrition due the large amount of nutrients that it contains

Brain IGF-I regulates hippocampal neurogenesis, synaptic plasticity, and sexual dimorphic behaviour

Comunicación presentada a SSii 2022 Spanish Symposium on IGFs and Insulin 2022: Implications in Physiology and DiseaseInsulin-like growth factor-I (IGF-I) exerts multiple actions, regulating body growth, cell proliferation, adult neurogenesis, neuronal and glial differentiation, synaptic plasticity and behaviour, among other processes. Both circulating and locally synthesized IGF-I are active, although the role of IGF-I from different sources is poorly understood. We previously found that brain IGF-I plays a major role in promoting the correct generation, migration and maturation of neurons from neural stem cells during postnatal adult hippocampal neurogenesis (Nieto-Estévez et al., 2016), although electrophysiological or behavioural phenotypes were not investigated in that study. Here we show that the lack of brain IGF-I almost completely abrogates hippocampal LTP, as well as altering sex-dependent behaviour and causing major changes in the hippocampal proteome. We suggest that the disruptions to the hippocampal proteome of conditional knockout Igf-I mice may partially underlie the changes observed in synaptic plasticity and behaviour

Neural stem cells in the adult olfactory bulb core generate mature neurons in vivo

Although previous studies suggest that neural stem cells (NSCs) exist in the adult olfactory bulb (OB), their location, identity, and capacity to generate mature neurons in vivo has been little explored. Here, we injected enhanced green fluorescent protein (EGFP)-expressing retroviral particles into the OB core of adult mice to label dividing cells and to track the differentiation/maturation of any neurons they might generate. EGFP-labeled cells initially expressed adult NSC markers on days 1 to 3 postinjection (dpi), including Nestin, GLAST, Sox2, Prominin-1, and GFAP. EGFP+ -doublecortin (DCX) cells with a migratory morphology were also detected and their abundance increased over a 7-day period. Furthermore, EGFP-labeled cells progressively became NeuN+ neurons, they acquired neuronal morphologies, and they became immunoreactive for OB neuron subtype markers, the most abundant representing calretinin expressing interneurons. OB-NSCs also generated glial cells, suggesting they could be multipotent in vivo. Significantly, the newly generated neurons established and received synaptic contacts, and they expressed presynaptic proteins and the transcription factor pCREB. By contrast, when the retroviral particles were injected into the subventricular zone (SVZ), nearly all (98%) EGFP+ -cells were postmitotic when they reached the OB core, implying that the vast majority of proliferating cells present in the OB are not derived from the SVZ. Furthermore, we detected slowly dividing label-retaining cells in this region that could correspond to the population of resident NSCs. This is the first time NSCs located in the adult OB core have been shown to generate neurons that incorporate into OB circuits in vivo

Brain IGF-I regulates LTP, spatial memory and sexual dimorphic behavior

Insulin-like growth factor-I (IGF-I) exerts multiple actions, yet the role of IGF-I from different sources is poorly understood. Here, we explored the functional and behavioral consequences of the conditional deletion of Igf-I in the nervous system (Igf-I Δ/Δ), and demonstrated that long-term potentiation was impaired in hippocampal slices. Moreover, Igf-I Δ/Δ mice showed spatial memory deficits in the Morris water maze, and the significant sex-dependent differences displayed by Igf-I Ctrl/Ctrl mice disappeared in Igf-I Δ/Δ mice in the open field and rota-rod tests. Brain Igf-I deletion disorganized the granule cell layer of the dentate gyrus (DG), and it modified the relative expressions of GAD and VGLUT1, which are preferentially localized to inhibitory and excitatory presynaptic terminals. Furthermore, Igf-I deletion altered protein modules involved in receptor trafficking, synaptic proteins, and proteins that functionally interact with estrogen and androgen metabolism. Our findings indicate that brain IGF-I is crucial for long-term potentiation, and that it is involved in the regulation of spatial memory and sexual dimorphic behaviors, possibly by maintaining the granule cell layer structure and the stability of synaptic-related protein modules.We thank Lucía Vicario (Instituto Cajal-CSIC, Madrid, Spain) for helping with the composition of the figures, and Dr. M Sefton (BiomedRed SL, Madrid, Spain) for English editing. This work was funded by grants from the Spanish “Ministerio Ciencia, Innovación y Universidades, and the Ministerio de Ciencia e Innovación/Agencia Estatal de Investigación” (MICIU and MICINN/AEI SAF2016-80419-R, PID2019-109059RB-100, and CIBERNED CB06/05/0065 to C Vicario; PID2019-110356RB-I00/AEI/10.13039/501100011033 to J Fernández-Irigoyen and E Santamaría; PID2019-104376RB-I00 to I Torres-Alemán; and PID2019-106579RB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe to G Perea, and BES-2017-080303 to C González-Arias)