Monitoring Muscle Stem Cell Cultures with Impedance Spectroscopy

The aim of this work is to present a new circuit for the real-time monitoring the processes of cellular growth and differentiation of skeletal myoblast cell cultures. An impedance spectroscopy Oscillation-Based technique is proposed for the test circuit, converting the biological system into a voltage oscillator, and avoiding the use of very high performance circuitry or equipment. This technique proved to be successful in the monitoring of cell cultures growth levels and could be useful for determining the degree of differentiation achieved, of practical implications in tissue engineering.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

Practical Characterization of Cell-Electrode Electrical Models in Bio-Impedance Assays

This paper presents the fitting process followed to adjust the parameters of the electrical model associated to a cell-electrode system in Electrical Cell-substrate Impedance Spectroscopy (ECIS) technique, to the experimental results from cell-culture assays. A new parameter matching procedure is proposed, under the basis of both, mismatching between electrodes and time-evolution observed in the system response, as consequence of electrode fabrication processes and electrochemical performance of electrode-solution interface, respectively. The obtained results agree with experimental performance, and enable the evaluation of the cell number in a culture, by using the electrical measurements observed at the oscillation parameters in the test circuits employed.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

El perfil de clima escolar: estudio transcultural de la validez de una batería de cuestionarios para evaluar el clima escolar

This paper studies the validity of the School Climate Battery of Questionnaires for Secondary and High School Teachers (SCBQSHST). The battery includes five questionnaires: Quality of Leadership, Quality of Teachers' Support, School Motivational Orientation, Quality of Students' Attitude, and Quality of Parental Support. A total of 178 teachers from Costa Rica were compared with 343 Spanish teachers. Confirmatory factor analyses showed that the questionnaires allow assessing teachers' perceptions of the different dimensions of school climate in a valid and reliable way in both Spain and Costa Rica. Differences in the perception of Spanish and Costa Rican teachers about school climate shown by multigroup confirmatory factor analyses are discussed as well as theoretical and practical implications.Este artículo estudia la validez de la Batería de cuestionarios sobre clima escolar para profesores de Secundaria y Bachillerato (BQCE-SB). La batería incluye cinco cuestionarios: calidad de liderazgo, calidad de apoyo docente, orientación motivacional del centro, calidad de las actitudes de los estudiantes y calidad del apoyo de los padres. Un total de 178 docentes de Costa Rica se compararon con 343 docentes españoles. Los análisis factoriales confirmatorios mostraron que los cuestionarios permiten evaluar de manera válida y confiable las percepciones de los docentes sobre las diferentes dimensiones del clima escolar, tanto en España como en Costa Rica. Se discuten las diferencias en la percepción de los docentes españoles y costarricenses sobre el clima escolar que muestran los análisis factoriales confirmatorios multigrupo, así como sus implicaciones teóricas y práctica

Determination of genes involved in heat resistance response of Cronobacter sakazakii

Cronobacter sakazakii is considered an emerging opportunistic pathogen causing meningitis, septicaemia and enterocilitis in neonates, related to the use of contaminated Powdered Infant Formula (PIF). C. sakazakii has an unusual surviving ability under dry conditions and has been suggested to be one of the most thermotolerant members of the Enterobacteriaceae. It is necessary to understand the molecular mechanisms underlying the thermal resistance of C. sakazakii and may ultimately be useful in the development of control strategies in PIF factories. In the current study, a transposon mutagenesis approach was used to identify the genes involved in heat resistance. A total of 23 mutants were found corresponding to 12 different defective genes. Heat resistance of selected mutants were determined with the use of the thermoresistometer Mastia. Only 2 mutants had a greater sensitivity to heat compared with the heat resistance of the wild type. Genes identified to be involved in the cellular response to thermal treatments were Ribosome maturation protein RimP and Outer membrane Porin L (OmpL). The results suggest that the novo protein synthesis, and the use of cysteine for the formation of disulfide bonds for stabilization of proteins against denaturation during thermal treatments are key processes in the resistance against heat stress.The financial support of this research was provided by the Ministry of Science and Technology of the Spanish Government and European Regional Development Fund (ERDF) through Project AGL‐ 2010‐19775. J.P Huertas is grateful to the Spanish Ministry of Science and Innovation for his fellowship (BES‐2011‐046580). We acknowledge the funding received by Food for Health, Ireland under the grant number CC20080001 by Enterprise Ireland

PHF2 regulates homology-directed DNA repair by controlling the resection of DNA double strand breaks

Post-translational histone modifications and chromatin remodelling play a critical role controlling the integrity of the genome. Here, we identify histone lysine demethylase PHF2 as a novel regulator of the DNA damage response by regulating DNA damage-induced focus formation of 53BP1 and BRCA1, critical factors in the pathway choice for DNA double strand break repair. PHF2 knockdown leads to impaired BRCA1 focus formation and delays the resolution of 53BP1 foci. Moreover, irradiation-induced RPA phosphorylation and focus formation, as well as localization of CtIP, required for DNA end resection, to sites of DNA lesions are affected by depletion of PHF2. These results are indicative of a defective resection of double strand breaks and thereby an impaired homologous recombination upon PHF2 depletion. In accordance with these data, Rad51 focus formation and homology-directed double strand break repair is inhibited in cells depleted for PHF2. Importantly, we demonstrate that PHF2 knockdown decreases CtIP and BRCA1 protein and mRNA levels, an effect that is dependent on the demethylase activity of PHF2. Furthermore, PHF2-depleted cells display genome instability and are mildly sensitive to the inhibition of PARP. Together these results demonstrate that PHF2 promotes DNA repair by homologous recombination by controlling CtIP-dependent resection of double strand breaks.España Ministerio de Ciencia e Innovacion SAF2016-80626-REspaña, Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) [PIFUN16/18

Effects of nitrate contamination and seasonal variation on the denitrification and greenhouse gas production in La Rocina stream (Doñana National Park, SW Spain)

Climatic influence (global warming and decreased rainfall) could lead to an increase in the ecological and toxicological effects of the pollution in aquatic ecosystems, especially contamination from agricultural nitrate (NO3 −) fertilizers. Physicochemical properties of the surface waters and sediments of four selected sites varying in NO3 − concentration along La Rocina Stream, which feeds Marisma del Rocio in Do˜nana National Park (South West, Spain), were studied. Electrical conductivity, pH, content in macro and microelements, total organic carbon and nitrogen, and dissolved carbon and nitrogen were affected by each sampling site and sampling time. Contaminant NO3 − in surface water at the site with the highest NO3 − concentration (ranged in 61.6–106.6mgL−1) was of inorganic origin, most probably from chemical fertilizers, as determined chemically (90% of the total dissolved nitrogen from NO3 −) and by isotopic analysis of ı15N-NO3 −. Changes in seasonal weather conditions and hydrological effects at the sampling sites were also responsible for variations in some biological activities (dehydrogenase, -glucosidase, arylsulphatase, acid phosphatase and urease) in sediments, as well as in the production of the greenhouse gases CO2, CH4 and N2O. Both organic matter and NO3 − contents influenced rates of gas production. Increased NO3 − concentration also resulted in enhanced levels of potential denitrification measured as N2O production. The denitrification process was affected by NO3 − contamination and the rainfall regimen, increasing the greenhouse gases emissions (CO2, CH4 and especially N2O) during the driest season in all sampling sites studied.This work was supported by grants CGL2006-06870 and CTM2009-1473-C02-02 from Ministerio de Ciencia e Innovación (Spain) and RNM-4746 from Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía (Spain), all of them co-financed by the European Regional Development Fund (ERDF). Support of Junta de Andalucía to Research Group BIO-275 is also acknowledged. D. David Correa thanks Ministerio de Educación for predoctoral grant AP2007-03967.Peer reviewe

E-learning de las asignaturas del ámbito matemático-estadístico en las universidades españolas : oportunidades, retos, estado actual y tendencias

En la primera parte de este artículo se tratan los aspectos clave del e-learning de las asignaturas universitarias de carácter matemático-estadístico. En concreto, el artículo discute los principales beneficios que las diferentes tecnologías -entornos on-line de aprendizaje y software especializado- proporcionan a estudiantes, profesores y universidades implicadas en la docencia de este tipo de asignaturas, así como los retos y dificultades a los que se ve expuesto cada uno de estos agentes del sistema universitario. Se analizan también algunos aspectos innovadores que se están produciendo en este ámbito, prestando especial atención a cómo la formación, basada en Internet y en el uso de software matemático-estadístico, puede facilitar la consecución de objetivos importantes que se derivan de la declaración de Bolonia. En la segunda parte del artículo se presenta el proyecto de investigación MEL de la UOC y sus principales resultados. En este proyecto se lleva a cabo un estudio, a nivel nacional, sobre el estado actual de la docencia en asignaturas universitarias de carácter matemático-estadístico, haciendo énfasis en algunos de los factores importantes que afectan a la actividad docente: nivel de uso e integración de entornos on-line de aprendizaje, nivel de uso e integración de software matemático-estadístico, nivel de adaptación al Espacio Europeo de Educación Superior, nivel de uso de recursos docentes en inglés, etc.The first part of this article deals with key aspects of e-learning in mathematics and statistics studies at universities. It discusses the main benefits the different technologies - online learning environments and specialised software - for students, lecturers and universities giving these subjects, as well as the challenges and the difficulties these groups face. Certain innovative aspects in this field are also analysed, paying special attention to how this form of study, based on the Internet and use of mathematics and statistics software, may help in achieving the main objectives of the Bologna declaration. In the second part of the article the MEL research project at the UOC is presented, with the main results. This project is a study, at national level, on the current state of teaching in these university studies, emphasising some of the important factors which affect it: use and integration of online learning environments, use and integration of mathematics-statistics software, adaptation to the European Space for Higher Education, and use of teaching resources in English

E-learning de las asignaturas del ámbito matemático-estadístico en las universidades españolas : oportunidades, retos, estado actual y tendencias

En la primera parte de este artículo se tratan los aspectos clave del e-learning de las asignaturas universitarias de carácter matemático-estadístico. En concreto, el artículo discute los principales beneficios que las diferentes tecnologías -entornos on-line de aprendizaje y software especializado- proporcionan a estudiantes, profesores y universidades implicadas en la docencia de este tipo de asignaturas, así como los retos y dificultades a los que se ve expuesto cada uno de estos agentes del sistema universitario. Se analizan también algunos aspectos innovadores que se están produciendo en este ámbito, prestando especial atención a cómo la formación, basada en Internet y en el uso de software matemático-estadístico, puede facilitar la consecución de objetivos importantes que se derivan de la declaración de Bolonia. En la segunda parte del artículo se presenta el proyecto de investigación MEL de la UOC y sus principales resultados. En este proyecto se lleva a cabo un estudio, a nivel nacional, sobre el estado actual de la docencia en asignaturas universitarias de carácter matemático-estadístico, haciendo énfasis en algunos de los factores importantes que afectan a la actividad docente: nivel de uso e integración de entornos on-line de aprendizaje, nivel de uso e integración de software matemático-estadístico, nivel de adaptación al Espacio Europeo de Educación Superior, nivel de uso de recursos docentes en inglés, etc.The first part of this article deals with key aspects of e-learning in mathematics and statistics studies at universities. It discusses the main benefits the different technologies - online learning environments and specialised software - for students, lecturers and universities giving these subjects, as well as the challenges and the difficulties these groups face. Certain innovative aspects in this field are also analysed, paying special attention to how this form of study, based on the Internet and use of mathematics and statistics software, may help in achieving the main objectives of the Bologna declaration. In the second part of the article the MEL research project at the UOC is presented, with the main results. This project is a study, at national level, on the current state of teaching in these university studies, emphasising some of the important factors which affect it: use and integration of online learning environments, use and integration of mathematics-statistics software, adaptation to the European Space for Higher Education, and use of teaching resources in English

Knowledge arising from long-term research of variable retention harvesting in Tierra del Fuego: where do we go from here?

Nothofagus pumilio forests in Tierra del Fuego are the southernmost forests in the world, where extreme climate conditions represent a challenge to attain sustainable forest management. Retention forestry was proposed as an alternative to increase the species conservation in managed stands. Here, we synthetized results related to the implementation of a variable retention harvesting based on a combination of aggregate patches and dispersed retention during the last 18 years comparing with other silviculture proposals (e.g., shelterwood cuts) and control treatments (primary unmanaged forests). We summarized the results for (i) sawmill operations, (ii) timber yield, (iii) overstory stability, (iv) forest structure, (v) microclimate and natural cycles, (vi) natural regeneration dynamics (flowering, seeding, foraging, recruitment, growth, and mortality), and (vii) biodiversity (mammals, understory plants, mistletoes, birds, arthropods, mosses, lichens, and fungi). In general, aggregate patches maintained forest structure and micro-environmental variables, and slightly increased biodiversity and forest reproduction variables compared to unmanaged primary forests. On the contrary, dispersed retention decreased forest structure variables and greatly increased biodiversity (richness and abundance) when it was compared to unmanaged primary forests. Ecological conditions are influenced by variable retention harvesting, but direction and magnitude of the effect depend and differ according to retention types. Besides this, biodiversity taxa greatly differed among groups depending on retention types. In general, the species assemblages in aggregate patches were similar to those found in primary unmanaged forests, while they were significantly modified in the dispersed retention. This occurred due to (i) local extinction of some original species, (ii) the introduction of native species from the surrounding environments, or (iii) the invasion of exotic species. This silvicultural method has been a useful tool to conserve biodiversity and ecosystem functions, approaching to the balance between economy, ecology, and social requirements in the managed areas.EEA Santa CruzFil: Martínez Pastur, Guillermo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Rosas, Yamina Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Toro Manríquez, Mónica D.R. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Huertas Herrera, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Miller, Juan A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; ArgentinaFil: Cellini, Juan Manuel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Barrera, Marcelo Daniel. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Investigaciones en Maderas; ArgentinaFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Universidad Nacional de la Patagonia Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lencinas, María Vanessa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas. Laboratorio de Recursos Agroforestales; Argentin