84 research outputs found

    Eml1 loss impairs apical progenitor spindle length and soma shape in the developing cerebral cortex

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    The ventricular zone (VZ) of the developing cerebral cortex is a pseudostratified epithelium that contains progenitors undergoing precisely regulated divisions at its most apical side, the ventricular lining (VL). Mitotic perturbations can contribute to pathological mechanisms leading to cortical malformations. The HeCo mutant mouse exhibits subcortical band heterotopia (SBH), likely to be initiated by progenitor delamination from the VZ early during corticogenesis. The causes for this are however, currently unknown. Eml1, a microtubule (MT)-associated protein of the EMAP family, is impaired in these mice. We first show that MT dynamics are perturbed in mutant progenitor cells in vitro. These may influence interphase and mitotic MT mechanisms and indeed, centrosome and primary cilia were altered and spindles were found to be abnormally long in HeCo progenitors. Consistently, MT and spindle length regulators were identified in EML1 pulldowns from embryonic brain extracts. Finally, we found that mitotic cell shape is also abnormal in the mutant VZ. These previously unidentified VZ characteristics suggest altered cell constraints which may contribute to cell delamination

    Dinamica familia-centro escolar y rendimiento academico en alumnado de educacion secundaria de Galicia y Norte de Portugal

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    El contexto de las relaciones e interacciones familiares en relación con los hijos y su rendimiento escolar ha sido estudiado con frecuencia por diferentes autores a lo largo de los últimos veinte años. Dadas las diferentes tipologías de familias existentes en la actualidad, se producen diferencias importantes en las relaciones e implicaciones familiares que tienen sus efectos, también diferencias en dicho rendimiento escolar. Se sabe que a mayor nivel formación académica y profesional de los padres, así parece que existe un efecto positivo en el rendimiento. Como objetivo general se trata de obtener evidencia empírica de la capacidad predictiva y sus efectos sobre el rendimiento de las variables relacionadas con la percepción que los alumnos tienen de la valoración de los padres sobre el esfuerzo, capacidad y trabajo escolar de los hijos, así como de la valoración y satisfacción que manifiestan ante su estudio y del refuerzo que hacen de su rendimiento académico. La muestra está integrada por un total de 997 alumnos de escuelas públicas del Norte de Portugal (n=510) y del Galicia (n=487). Las edades oscilan entre los 11, 12, 13 y 14 años, por lo tanto están entre el final de la educación primaria e inicio de la secundaria obligatoria. Su procedencia es de tipo urbano, si bien la mayoría procede de la periferia de ciudades como Porto, Guimaraes, Espinho, Chaves, así como de A Coruña, Ourense y Santiago de Compostela. Como instrumentos de análisis se ha utilizado la Escala CDPFA (Evaluación de Datos Personales, Familiares y Académicos), en concreto la Subescala de Relación e Implicación Familia-Escuela. Se pretendía conocer la capacidad predictiva de las variables que se señalan en el objetivo general del trabajo. En cuanto al análisis de datos, se utiliza el paquete estadístico SPSS, versión 17.0, realizando un análisis de regresión lineal múltiple en el que las variables independientes son las referidas a las implicaciones/relaciones y familiares que los alumnos de Galicia y norte de Portugal perciben en sus interacciones con sus padres, y la variable dependiente será el rendimiento académico. Resultados. Se ha comprobado que tiene una mayor incidencia en el rendimiento escolar el contexto familiar del alumnado del norte de Poirtugal y de Galicia, en mayor medida cuando ese contexto implica unas interacciones relacionadas con las expectativas positivas hacia los hijos y el compromiso familiar (relaciones familia-escuela). Otras variables que poseen una buena capacidad predictiva, aunque negativa, se relacionan con la desvalorización del trabajo y esfuerzo realizado por el alumnado en el trabajo académico, así como en su búsqueda de recompensas y refuerzos externos.GIPDAE - Grupo de Investigación en Psicoloxia do desenvolvemento e da aprendizaxe escolarCERXunta de Galicia - Consellería de Educación e Ordenación Universitaria (Secretaria Xeral)Ministerio de Educación y CienciaBase de Datos - ISOCFundación Universidade da CoruñaAyuntamiento de La Coruña - Concello de A CoruñaUniversidade do Minh

    Responses to salinity stress in bivalves: Evidence of ontogenetic changes in energetic physiology on Cerastoderma edule

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    Estuarine bivalves are especially susceptible to salinity fluctuations. Stage-specific sensibilities may influence the structure and spatial distribution of the populations. Here we investigate differences on the energetic strategy of thread drifters (3–4 mm) and sedentary settlers (9–10 mm) of Cerastoderma edule over a wide range of salinities. Several physiological indicators (clearance, respiration and excretion rates, O:N) were measured during acute (2 days) and acclimated responses (7 days of exposure) for both size classes. Our results revealed a common lethal limit for both developmental stages (Salinity 15) but a larger physiological plasticity of thread drifters than sedentary settlers. Acclimation processes in drifters were initiated after 2 days of exposure and they achieved complete acclimation by day 7. Sedentary settlers delay acclimation and at day 7 feeding activity had not resumed and energetic losses through respiration and excretion were higher at the lowest salinity treatment. Different responses facing salinity stress might be related to differences in habitat of each stage. For sedentary settlers which occupy relatively stable niches, energy optimisation include delaying the initiation of the energetically expensive acclimation processes while drifters which occupy less stable environments require a more flexible process which allow them to optimize energy acquisition as fast as possible.Ministerio de Economía y Competitividad | Ref. CTM2014–51935-RXunta de Galicia | Ref. POS-B/2016/032Xunta de Galicia | Ref. GRC2013–00

    Predation risk increases in estuarine bivalves stressed by low salinity

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGSalinity drops in estuaries after heavy rains are expected to increase in frequency and intensity over the next decades, with physiological and ecological consequences for the inhabitant organisms. It was investigated whether low salinity stress increases predation risk on three relevant commercial bivalves in Europe. In laboratory, juveniles of Venerupis corrugata, Cerastoderma edule, and the introduced Ruditapes philippinarum were subjected to low salinities (5, 10 and control 35) during two consecutive days and, afterwards, exposed to one of two common predators in the shellfish beds: the shore crab Carcinus maenas and the gastropod Bolinus brandaris, a non-indigenous species present in some Galician shellfish beds. Two types of choice experiment were done: one offering each predator one prey species previously exposed to one of the three salinities, and the other offering each predator the three prey species at the same time, previously exposed to one of the three salinities. Consumption of both predators and predatory behaviour of C. maenas (handling time, rejections, consumption rate) were measured. Predation rates and foraging behaviour differed, with B. brandaris being more generalist than C. maenas. Still, both predators consumed significantly more stressed (salinity 5 and 10) than non-stressed prey. The overall consumption of the native species C. edule and V. corrugata was greater than that of R. philippinarum, likely due to their vulnerability to low salinity and physical traits (e.g., thinner shell, valve gape). Increasing precipitations can alter salinity gradients in shellfish beds, and thus affect the population dynamics of harvested bivalves via predator–prey interactions.Ministerio de Economía y Competitividad | Ref. CTM2014-51935-RMinisterio de Economía y Competitividad | Ref. BES-2015-074211Xunta de Galicia | Ref. GRC2013-00

    Modal Ω-Logic: Automata, Neo-Logicism, and Set-Theoretic Realism

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    This essay examines the philosophical significance of Ω\Omega-logic in Zermelo-Fraenkel set theory with choice (ZFC). The duality between coalgebra and algebra permits Boolean-valued algebraic models of ZFC to be interpreted as coalgebras. The modal profile of Ω\Omega-logical validity can then be countenanced within a coalgebraic logic, and Ω\Omega-logical validity can be defined via deterministic automata. I argue that the philosophical significance of the foregoing is two-fold. First, because the epistemic and modal profiles of Ω\Omega-logical validity correspond to those of second-order logical consequence, Ω\Omega-logical validity is genuinely logical, and thus vindicates a neo-logicist conception of mathematical truth in the set-theoretic multiverse. Second, the foregoing provides a modal-computational account of the interpretation of mathematical vocabulary, adducing in favor of a realist conception of the cumulative hierarchy of sets

    Effects of warming on biological interactions between clams and the seagrass Zostera noltei: A case study using open top chambers

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGBivalves and seagrasses can interact through diverse environmentally-modulated mechanisms. To assess the effects of climate warming on bivalve-seagrass interactions, we carried out a pioneering field experiment in which open top chambers (OTCs) were used to increase air and sediment temperature in a shellfish bed in NW Spain during two consecutive spring tides (16 days of exposure to OTCs). The temperature increase produced by OTCs was significant, as observed in the daily maximum and mean temperature and in degree hours, although the difference was greater in air and at the sediment surface (up to 8 ◦C and 3 ◦C, respectively) than at 5 cm depth (up to 1 ◦C). Warming was less acute in boxes with the seagrass Zostera noltei, which acted as a thermal buffer, reducing the mean temperature by 1 ◦C at the sediment surface in OTC boxes and control boxes (without OTCs). Although the short-term increase in temperature did not greatly affect physiological responses of Z. noltei, the carbohydrate reserves and nutrient content increased in the presence of clams. Growth of the native clam Ruditapes decussatus was significantly slower in OTC boxes with bare sediment, and the seagrass thus buffered the negative effect of warming on growth. The presence of Z. noltei may save clams from having to spend energy to burrow deeper to encounter cooler conditions, leaving more energy available for growth. Conversely, growth of the introduced clam R. philippinarum did not differ between habitats or treatments. Our findings confirm a twoway facilitative interaction that may be particularly important in relation to the resilience of both species in the current context of global warming.Ministerio de Ciencia e Innovación | Ref. RTI2018-095583-B-I00Xunta de Galicia-FEDER | Ref. ED431C 2021/42Xunta de Galicia | Ref. ED481A- 2020/199NASA | Ref. 80NSSC20K007

    The stress response of the seagrass Zostera noltei and three commercial clam species to low salinity associated with heavy rainfall

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    Abstract The maintenance of stocks of estuarine species strongly depends on the ability of the species to cope with environmental stress. In NW Spain, commercial clam beds, which are usually co-occupied by the seagrass Zostera noltei, are often exposed to reduced salinity caused by intense rainfalls. Our goals were to evaluate the effects of low salinity events on both juvenile clams and Z. noltei, including their interactions. A mesocosm experiment was performed to simulate three salinity decreases (35–35, 25–10, and 20–5), and several indicators of clam and seagrass performance were measured after 3 and 6 days of exposure and again after a recovery period of 4 days. No differences were observed in the non-native clam Ruditapes philippinarum, while oxygen consumption, clearance rate and growth decreased significantly in the native clams R. decussatus and Venerupis corrugata in response to low salinity stress. Zostera noltei indicators did not vary in response to low salinity exposure, except the sucrose content, which decreased. Moreover, the seagrass buffered juvenile clams from salinity fluctuations in the short term, although the interactions were weak. The species-specific sensitivity to low salinity should be a major concern in future management plans for the shellfish beds in the context of climate change.Agencia Estatal de Investigación | Ref. RTI2018-095583-B-I00Xunta de Galicia | Ref. ED481A-2020/199Xunta de Galicia | Ref. ED431C 2021/4

    La Cuevona de Avín (Avín, Asturias, North Spain): A new Late Pleistocene site in the lower valley of the River Güeña

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    The archaeological investigations carried out in the last twenty years in the Lower Valley of the River Güeña (Asturias, central part of northern Spain) have documented different prehistoric sites, particularly with Middle and Upper Palaeolithic occupations. This paper presents the first results of the archaeological excavation carried out in the cave of La Cuevona de Avín. From the systematic study of the biotic and abiotic remains, a total of three occupation phases (Phases 1 to 3) have been determined, dated in the Late Pleistocene. The lithic studies indicate the use of local raw materials (mainly quartzite), but also regional ones (different types of flint) in the whole sequence. Retouched implements are typologically representative only during the Upper Magdalenian (Phase II) and use-wear analysis indicates the manufacture and use of artefacts in situ during this phase. Archaeozoological studies reveal continuity in subsistence strategies throughout the sequence, noting specialization in red deer hunting during the Azilian (Phase I), and more diversified prey in the older phases of the sequence. © 2022 The Author(s
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