Estimación de posturas de agarre en base a ACP y RN

Comunicación presentada en el XXI Congreso Nacional de Ingeniería Mecánica, celebrado en Elche en Noviembre de 2016.La investigación en manos antropomorfas robóticas y protésicas experimenta un auge en la actualidad. Unos diseños intentan lograr un agarre estable y diestro mientras que otros pretenden alcanzar un elevado grado de antropomorfismo y de apariencia cosmética. Sin embargo, las prótesis de mano existentes suelen ser muy simples desde un punto de vista biomecánico. Esto se debe a la complejidad de establecer una interacción adecuada entre el amputado y una prótesis de múltiples grados de libertad, que requeriría numerosas señales de control independientes y un controlador inteligente. Una innovación en el ámbito del control de manos artificiales podría derivarse de la observación e imitación del comportamiento biomecánico natural, en base a un espacio de dimensionalidad reducida. El presente trabajo plantea la utilización del análisis de componentes principales (ACP), para reducir la dimensionalidad del problema de control, en combinación con las redes neuronales (RN), para predecir la posturas de la mano en dos tipos de agarre sobre objetos cilíndricos: un agarre de potencia (cilíndrico) y un agarre de precisión (pinza con 5 dedos). El objetivo es determinar el mínimo número de entradas de control necesarias para que una mano protésica avanzada pueda realizar actividades de la vida diaria en base a patrones posturales identificados y evaluar su posibilidad de control real. Para ello, se realizaron experimentos de agarre con 16 sujetos diestros y 4 cilindros de diversos diámetros durante los que se registró la posición de 32 marcadores. A partir de estos datos se calcularon los ángulos de articulación de la mano para cada postura de agarre (PA). Posteriormente, se realizó un ACP sobre los datos de PA, obteniendo 7 componentes principales (posturas propias de agarre, PPA) que determinaron las sinergias posturales producidas durante el agarre. El resultado se simuló mediante OpenSim. Los datos obtenidos se utilizaron para entrenar y validar una RN para estimar PA a partir de las PPA, con una arquitectura previamente validada compuesta por dos capas. Finalmente, se calculó la raíz cuadrada del error cuadrático medio global y por articulación de la predicción realizada por la RN con respecto a la postura experimental, obteniendo resultados alentadores.El presente trabajo está financiado por la Generalitat Valenciana a través del proyecto GV/2015/101

Assessment of cytotoxicity biomarkers on the microalga "Chlamydomonas reinhardtii" exposed to emerging and priority pollutants

[Abstract] Contamination of aquatic ecosystems linked to anthropogenic activity is currently a major concern; therefore, ecotoxicological studies are needed to assess its effect on organisms. The main objective of this study was to investigate the effects of different pollutants on microalgae in search of sensitive biomarkers that can promote a common cytotoxic response regardless of the contaminant. Cultures of the freshwater microalga Chlamydomonas reinhardtii were exposed for 24 h to four chemicals, three emerging pollutants (benzophenone-3, bisphenol A and oxytetracycline) and one priority substance (atrazine). A cytometric panel was carried out to assess toxicity biomarkers including cellular growth, inherent cell properties, viability, vitality, cytoplasmic membrane potential and ROS levels. Lipid peroxidation, photosynthetic efficiency and transcriptional responses of photosynthesis- and oxidative stress-related genes using RT-qPCR were also studied. Some toxicity responses showed a similar pattern; a decrease in growth rate, vitality and photosynthetic efficiency and an increase in autofluorescence and in the number of cells with depolarised cytoplasmic membrane and were found for all chemicals tested. However, ATZ and OTC provoked a decrease in cell size, whereas BP-3 and BPA caused an increase in cell size, intracellular complexity and ROS levels and a decrease in cell viability. Assayed pollutants generally promoted an overexpression of genes related to cellular antioxidant defence system and a subexpression of photosynthesis-related genes. In addition to the traditional growth endpoint, cell vitality, autofluorescence and gene expression of catalase, glutathione peroxidase and Fe-superoxide dismutase were significantly affected for all chemicals tested, showing a common cytotoxic response. Among the tested substances, BP-3 provoked the strongest cytotoxic alterations on this microalga, pointing out that some emerging contaminants could be more harmful to organisms than priority pollutants.Ministerio de Economía, Industria y Competitividad; CTM 2017- 88668-

Flow cytometric assay to assess short-term effects of personal care products on the marine microalga Tetraselmis suecica

[Abstract] Large quantities of personal care products (PCPs) are used daily and many of their chemical ingredients are subsequently released into marine environments. Cultures of the marine microalga Tetraselmis suecica were exposed for 24 h to three emerging compounds included in the main classes of PCPs: the UV filter benzophenone-3 (BP-3), the disinfectant triclosan (TCS) and the fragrance tonalide (AHTN). Concentrations tested, expressed as cellular quota (pg cell−1), ranged from 5 to 40 for BP-3, from 2 to 16 for TCS and from 1.2 to 2.4 for AHTN. A small cytometric panel was carried out to evaluate key cytotoxicity biomarkers including inherent cell properties, growth and metabolic activity and cytoplasmic membrane properties. BP-3 caused a significant increase in growth rate, metabolic activity and chlorophyll a fluorescence from 10 pg cell−1. However, growth and esterase activity decreased in cells exposed to all TCS and AHTN concentrations, except the lowest ones. Also these two compounds provoked a significant swelling of cells, more pronounced in the case of TCS-exposed cells. Although all treated cells remained viable, changes in membrane potential were observed. BP-3 and AHTN caused a significant depolarization of cells from 10 to 1.6 pg cell−1, respectively; however all TCS concentrations assayed caused a noticeable hyperpolarization of cells. Metabolic activity and cytoplasmic membrane potential were the most sensitive parameters. It can be concluded that the toxicological model used and the toxicological parameters evaluated are suitable to assess the toxicity of these emerging contaminants

Early alterations on photosynthesis-related parameters in Chlamydomonas reinhardtii cells exposed to atrazine: A multiple approach study

Chlamydomonas reinhardtii cells were exposed to a sublethal concentration of thewidespread herbicide atrazine for 3 h. Physiological cellular parameters, such as chlorophyll a fluorescence and oxidative stress monitored by flow cytometry and pigments levels were altered in microalgal cells exposed to 0.25 μMof atrazine. Furthermore, the effects of this herbicide on C. reinhardtii were explored using “omics” techniques. Transcriptomic analyses, carried out by RNA-Seq technique, displayed 9 differentially expressed genes, related to photosynthesis, between control cultures and atrazine exposed cultures. Proteomic profiles were obtained using iTRAQ tags and MALDI-MS/MS analysis, identifying important changes in the proteome during atrazine stress; 5 proteins related to photosynthesis were downexpressed. The results of these experiments advance the understanding of photosynthetic adjustments that occur during an early herbicide exposure. Inhibition of photosynthesis induced by atrazine toxicity will affect the entire physiological and biochemical states of microalgal cells.Ministerio de Economía y Competitividad; CGL2010-15993/BO

Chlamydomonas Reinhardtii Cells Adjust the Metabolism to Maintain Viability in Response to Atrazine Stress

[Abstract] Chlamydomonas reinhardtii cells were exposed to a sublethal concentration of the widespread herbicide atrazine for 3 and 24 h. Physiological parameters related to cellular energy status, such as cellular activity and mitochondrial and cytoplasmic membrane potentials, monitored by flow cytometry, were altered in microalgal cells exposed to 0.25 M of atrazine. Transcriptomic analyses, carried out by RNA-Seq technique, displayed 12 differentially expressed genes between control cultures and atrazine-exposed cultures at both tested times. Many cellular processes were affected, but the most significant changes were observed in genes implicated in amino acid catabolism and respiratory cellular process. Obtained results suggestthatphotosynthesis inhibitionby atrazine leads cells to get energy throughaheterotrophic metabolism to maintain their viability

Toxicidad ejercida por contaminantes acuáticos sobre microalgas de agua dulce

Programa Oficial de Doutoramento en Bioloxía Celular e Molecular . 5004V01[Abstract] High concentrations of herbicides proceeding from the agricultural practices come to the aquatic systems, where they exercise its toxic action on no-target organisms, such as microalgae. These organisms are in the base of the trophic chain; any alteration carries effects of long scope on the set of the trophic chain and the flow of energy of the ecosystem, causing permanent functional and structural modifications in ecosystems. The main purpose of this project was to penetrate into the knowledge of the cellular response of the microalga Chlamydomonas reinhardtii, to stress situations provoked by the exposure to atrazine. A methodological approach based on the analysis of the cytome, proteome and transcriptome of this microalga was proposed to characterize in depth the interaction xenobiotic-cell. Molecular and cellular alterations reported in the present work suggest that exposure to chemical substances, such as atrazine, induces ROS that produces physiological and biochemical alterations in cells that finally lead to the occurrence of cellular senescence alterations in the microalgal populations.[Resumo] Debido ao uso estendido de herbicidas na agricultura, a súa presenza en augas naturais é cada vez máis importante. Estes contaminantes exercen a súa actividade tóxica sobre algunhas especies de plantas ou de microorganismos fototróficos para os que non se deseñaron, como as microalgas. Estes organismos unicelulares atópanse na base da cadea trófica dos ecosistemas acuáticos, e calquera axente externo que os perturbe pode causar un desequilibrio maior nos niveis superiores da cadea, provocando modificacións funcionais e estructurais permanentes nos ecosistemas. O proxecto levado a cabo trata sobre o estudo da resposta da microalga Chlamydomonas reinhardtii, sometida a situación de estrés provocada pola atrazina, avaliando os cambios que se producen nas células a curto e medio prazo, a través dunha aproximación metodolóxica baseada na análise do citoma, proteoma e transcriptoma desta especie para caracterizar en profundidade a interacción xenobiótico-célula. Os cambios moleculares e celulares obtidos nestes estudos suxiren que a exposición a produtos químicos, como a atrazina, induce a produción excesiva de especies reactivas de osíxeno que produce cambios fisiolóxicos e bioquímicos nas células que finalmente conducen a fenómenos de senescencia celular en poboacións microalgais.[Resumen] Debido al uso extendido de herbicidas en la agricultura, su presencia en las aguas naturales es cada vez más importante. Estos contaminantes ejercen su actividad tóxica sobre algunas especies de plantas o de microorganismos fototróficos para los que no se habían diseñado, como las microalgas. Estos organismos unicelulares se encuentran en la base de la cadena trófica de los sistemas acuáticos, y cualquier agente externo que los perturbe puede ocasionar un desequilibrio mayor en los niveles superiores de la cadena, provocando modificaciones funcionales y estructurales permanentes en los ecosistemas. El proyecto que se ha llevado a cabo aborda el estudio de la respuesta de la microalga Chlamydomonas reinhardtii, sometida a un estrés provocado por la atrazina, evaluando los cambios producidos en las células a corto y medio plazo, a través de una aproximación metodológica basada en el análisis del citoma, proteoma y transcriptoma de esta especie para caracterizar en profundidad la interacción xenobiótico-célula. Las alteraciones moleculares y celulares obtenidas sugieren que la exposición a sustancias químicas, como la atrazina, induce una sobreproducción de especies reactivas de oxígeno que produce alteraciones fisiológicas y bioquímicas en las células que finalmente conllevan a fenómenos de senescencia celular en las poblaciones microalgales

Cytotoxicity of BP-3 and BP-4: Blockage of Extrusion Pumps, Oxidative Damage and Programmed Cell Death on Chlamydomonas reinhardtii

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] The health concern associated with the dangers related to exposure to UV radiation has led to an increase in the use of sunscreens containing UV-filters that can reach aquatic environments and possibly affect ecosystems. Benzophenone-3 (BP-3) and benzophenone-4 (BP-4) are two of the most used UV-filters. In the present work, the microalga Chlamydomonas reinhardtii was exposed to several concentrations of both chemicals. To evaluate their potential cytotoxicity on microalgal cells, different parameters were analysed including fast response biomarkers (increase in intracellular free Ca2+) as well as biomarkers related with the presence of oxidative stress (lipid peroxidation), energy metabolism (photosynthetic yield and cytoplasmic lipid accumulations), cell division (proliferation and F-actin content), programmed cell death (PCD) (caspase activation and DNA fragmentation) and possible mechanisms of resistance to xenobiotics (operation of extrusion pumps and presence of autophagic vacuoles). Results showed an increment of the percentage of cells with cytosolic free Ca2+ that could act as a secondary messenger in response to the stress. A decrease in photosynthetic yield and an increase in cytoplasmic lipid accumulations and lipid peroxidation levels were also detected. In addition, a decrease in cell proliferation was observed, linked to a decrease in the percentage of cells with F-actin. The increase observed in the microalgal population with caspase activity, together with the DNA fragmentation and the alterations in the cytoskeleton, suggested the induction of processes linked to PCD. Moreover, a blockage of extrusion pumps, which could be related to the toxicity mechanism of these compounds, and an increase in autophagic vacuoles, as an attempt to repair the damage caused by benzophenones, were detected. Overall, these biomarkers indicate that both UV-filters can be a serious threat to non-target photosynthetic microorganisms in aquatic environments, although BP-3 affected C. reinhardtii more markedly.This research has been funded by Spanish “Ministerio de Economía, Industria y Competitividad” (CTM2017- 88668-R). M. S. and M. E. were funded by a grant from “Diputación Provincial de A Coruña

Acute effects of a prooxidant herbicide on the microalga Chlamydomonas reinhardtii: Screening cytotoxicity and genotoxicity endpoints

Since recent evidence has demonstrated that many types of chemicals exhibit oxidative and/or genotoxic potential on living organisms, reactive oxygen species (ROS) formation and DNA damage are currently the best accepted paradigms to assess the potential hazardous biological effects of a wide range of contaminants. The goal of this study was to evaluate the sensitivity of different cytotoxicity and genotoxicity responses on the model microalga Chlamydomonas reinhardtii exposed to the prooxidant herbicide paraquat. In addition to the growth endpoint, cell viability, mitochondrial membrane potential and presence of reactive oxygen species (ROS) were assayed as potential markers of cytotoxicity using flow cytometry (FCM). To study the effects of paraquat on C. reinhardtii DNA, several genotoxicity approaches were implemented for the first time in an ecotoxicological study on microalgae. Oxidative DNA base damage was analysed by measuring the oxidative DNA lesion 8-OHdG by FCM. DNA fragmentation was analysed by different methods: comet assay, and cell cycle analysis by FCM, with a particular focus on the presence of subG1-nuclei. Finally, effects on morphology of nuclei were monitored through DAPI staining. The evaluation of these endpoints showed that several physiological and biochemical parameters reacted to oxidative stress disturbances with greater sensitivity than integrative parameters such as growth rates or cell viability. The experiments revealed concentration-dependent cytotoxicity (ROS formation, depolarization of mitochondrial membrane), genotoxicity (oxidative DNA damage, DNA strand breakage, alterations in nuclear morphology), and cell cycle disturbances (subG1-nuclei, decrease of 4N population) in paraquat-treated cells. Overall, the genotoxicity results indicate that the production of ROS caused by exposure to paraquat induces oxidative DNA damage followed by DNA single- and double-strand breaks and cell cycle alterations, possibly leading to apoptosis in C. reinhardtii cells. This is supported by the observation of typical hallmarks of apoptosis, such as mitochondrial membrane depolarization, alterations in nuclear morphology and subG1 nuclei in cells exposed to the highest assayed concentrations. To our knowledge, this is the first study that provides a comprehensive analysis of oxidative DNA base damage in unicellular algal cells exposed to a prooxidant pollutant, as well as of its possible relation with other physiological effects. These results reinforce the need for additional studies on the genotoxicity of environmental pollutants on ecologically relevant organisms such as microalgae that can provide a promising basis for the characterization of potential pollutant hazards in the aquatic environment

Manejo de conflictos en la escuela, una forma de alfabetización emocional

En la actualidad, en el CEO Rural Horizonte, se ha conformado un Comité de Conflictos donde tienen asiento el personero estudiantil, un padre de familia y el profesor, profesores o directores de grupo de los alumnos implicados en cada problema. El comité se reúne cuando Jos conflictos se hacen reiterativos

La anhedonia en la depresion

La anhedonia es la ausencia o capacidad reducida para experimentar placer. Es un síntoma mayor de la depresión y un síntoma negativo de la esquizofrenia, según las clasificaciones actuales. Se presenta un estudio descriptivo prospectivo (diciembre 2018 a julio de 2020) con un seguimiento de 6 meses desarrollado en Consultas Externas de Psiquiatría de un Hospital General. Para cuantificar la anhedonia se emplea la escala SHAPS y para el seguimiento de la clínica depresiva el cuestionario CET-DE. Se aplican también otras escalas como la escala CGI-gravedad (impresión subjetiva gravedad por parte del psiquiatra) y la EVA modificada (impresión subjetiva del paciente de su estado de gravedad). De 60 pacientes reclutados, 48 completaron el protocolo de estudio (2 visitas), siendo 60% mujeres con una media de edad de 48 años. En visita basal el porcentaje de anhedónicos fue del 67%. Un total de 48% de los pacientes son considerados graves por parte del profesional sanitario, siendo 2,57 veces más frecuente clasificarse como grave entre los hombres y 2,83 veces más frecuente entre pacientes anhedónicos. La presencia de anhedonia se relacionó con mayor puntuación en la escala CET-DE. Tras intervención psiquiatra, en visita final el porcentaje de anhedónicos fue del 29% y se clasificaron como graves por parte del profesional sanitario un 25% de los pacientes. La persistencia de anhedonia en visita final fue un factor de mala evolución clínica. A través de técnicas de regresión logística se muestra que la presencia de anhedonia en visita final está condicionada por la existencia de este síntoma en visita basal, así como por falta de respuesta a la intervención psiquiatra. La anhedonia es el componente que caracteriza los síntomas residuales de la depresión, siendo un factor de mal pronóstico