Caracterización ecológica de comunidades de microorganismos planctónicos marinos, basada en relaciones entre la distribución de tamaños, composición química y taxonomía

Memoria de tesis doctoral presentada por Laura Arin Carrau para obtener el título de Doctora en Biología por la Universitat Autònoma de Barcelona (UAB), realizada bajo la dirección de la Dra. Marta Estrada Miyares del Institut de Ciències del Mar (ICM-CSIC).-- 176 pagesEl conocimiento de la estructura de tamaños de las comunidades de microorganismos planctónicos y de su composición química es importante debido, entre otros aspectos, a la implicación que tienen ambos en el flujo de materia y energía entre los distintos eslabones de la cadena trófica. En un ambiente determinado, el desarrollo de un tipo de red trófica depende, fundamentalmente, de los factores físico-químicos del medio. Según el esquema generalmente aceptado, en aguas ricas en nutrientes y con cierta intensidad de mezcla turbulenta, el desarrollo de autótrofos grandes haría que predominase la vía trófica "clásica" (Steele 1974), mientas que en ambientes oligotróficos y estratificados, el desarrollo de autótrofos pequeños favorecería la vía trófica "microbiana" (Azam et al. 1983). La dominancia de una vía trófica u otra determinaría, a su vez, el destino final del carbono fijado fotosintéticamente. [...]Peer Reviewe

Beneficial Effects of Viable and Heat-Inactivated Lactobacillus rhamnosus GG Administration on Oxidative Stress and Inflammation in Diet-Induced NAFLD in Rats

Oxidative stress and inflammation are well-known triggers of NAFLD onset and progression. The aim of this study is to compare the potential benefits of a viable probiotic (Lactobacillus rhamnosus GG) and its parabiotic (heat-inactivated) on oxidative stress, inflammation, DNA damage and cell death pathways in the liver of rats featuring diet-induced NAFLD. The consumption of the steatotic diet led to increased final body and liver weights, higher hepatic triacylglycerol content, altered serum transaminase levels and enhanced oxidative and inflammatory status. Administration of the probiotic and the parabiotic partially prevented the body weight increase induced by the steatotic diet, whereas the probiotic caused more effective decreasing hepatic triglyceride content. Sharp but nonstatistically significant decreases in serum transaminase levels were also observed for both treatments. The reduction in antioxidant enzyme activities found in the nontreated animals fed the steatotic diet was partially prevented by both treatments (GPx activity). Similarly, the reductions in nonenzymatic antioxidant protection (GSH content) and total antioxidant capacity (ORAC) found in the nontreated rats were restored by the administration of both treatments. These results show that both viable and heat-inactivated Lactobacillus rhamnosus GG administration partially prevent steatotic diet-induced liver oxidative stress and inflammation induced in rats.This study was supported by Instituto de Salud Carlos III (CIBERobn) under Grant CB12/03/30007, The Basque Government under Grant IT1482-22 and Synergic R&D Projects in New and Emerging Scientific Areas on the Frontier of Science and Interdisciplinary Nature of The Community of Madrid (METAINFLAMATIONY2020/BIO-6600). Laura Isabel Arellano-García is a recipient of a doctoral fellowship from the Gobierno Vasco

La ecología del plancton en la oceanografía biológica: un homenaje a la labor de Marta Estrada

Plankton ecology has been the object of intense research and progress in the last few decades. This has been partly due to technological advances that have facilitated the multidisciplinary and high-resolution sampling of ecosystems and improved experimentation and analytical methodologies, and to sophisticated modelling. In addition, exceptional researchers have had the vision to integrate all these innovative tools to form a solid theoretical background in ecology. Here we provide an overview of the outstanding research work conducted by Professor Marta Estrada and her pioneering contribution to different areas of research in the last four decades. Her research in biological oceanography has mainly focussed on phytoplankton ecology, taxonomy and physiology, the functional structure of plankton communities, and physical and biological interactions in marine ecosystems. She has combined a variety of field and laboratory approaches and methodologies, from microscopy to satellite observations, including in-depth statistical data analysis and modelling. She has been a reference for scientists all over the world. Here, her contributions to plankton ecology are summarized by some of her students and closest collaborators, who had the privilege to share their science and everyday experiences with her.La ecología del plancton ha experimentado una intensa investigación y progreso en las últimas décadas. Esta se ha debido, en parte, a los avances tecnológicos que han facilitado la toma de muestras multidisciplinar y de alta resolución de los ecosistemas, la mejora de la experimentación y metodologías analíticas y el modelado matemático/numérico. El papel de investigadores excepcionales que han tenido la visión de integrar todas estas herramientas innovadoras a una sólida formación teórica en la ecología ha sido clave en este avance. A continuación hemos elaborado un resumen de la tarea de investigación llevada a cabo por la profesora Marta Estrada y su contribución pionera a diferentes áreas de investigación en las últimas cuatro décadas. Su investigación, en el marco de la oceanografía biológica, se ha centrado principalmente en la ecología del fitoplancton, su taxonomía y fisiología, la estructura funcional de las comunidades de plancton y las interacciones físicas y biológicas en los ecosistemas marinos. Ha combinado una variedad de enfoques y metodologías de campo y de laboratorio, desde observaciones por satélite, hasta el análisis en profundidad de datos estadísticos y el uso del modelado tanto analítico como numérico. La profesora Estrada ha sido una referencia para los científicos alrededor del mundo. Aquí, su contribución a la ecología del plancton la resumen algunos de sus alumnos y colaboradores más cercanos que han tenido el privilegio de compartir ciencia y vivencias con ella

TURECOTOX and ECOALFACS Projects: Contributions of two GEOHAB Endorsed Projects

Berdalet, Elisa ... et. al.-- Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) Synthesis Open Science Meeting, 24-26 April 2013, Paris, FranceFrom 2009 to 2013, the TURECOTOX (CTM2006-13884-C02-00/MAR) and ECOALFACS (CTM2009- 09581) projects, endorsed by GEOHAB, focused on the interactions between small-scale turbulence and the biology of toxigenic dinoflagellates (toxin-producing HABs). Research included ecophysiological experiments and fieldwork in two contrasting areas: the Galician Rías Baixas (upwelling systems, Atlantic coast) and the microtidal estuary of Alfacs bay in the Ebro Delta (coastal embayment, stratified system, Mediterranean Sea). Laboratory experiments with cultures showed how small-scale turbulence can modulate different ecophysiological processes including growth rate, cell cycle patterns, asexual encystment, nucleic acids, toxin and DMSP cell quota and infection by parasites. However, the cellular mechanisms underlying the observed responses are still unknown. In the Rías, the population dynamics (division rate, viability, mortality) of Dinophysis spp. and their behavior (vertical migration, mixotrophy) were studied with the same spatio-temporal scale than the finescale hydrodynamical processes (water velocities, shear, vertical diffusion, turbulence). For the first time, data on the formation, maintenance and dissipation of thin layers of Pseudo-nitzschia spp. were obtained in this area. In Alfacs bay, several modeling approaches (3D hydrodynamic model combined with a Lagrangian particle-tracking module) validated by continuous records of physical and meteorological data have been implemented to understand how the complex circulation dynamics may facilitate water retention and thus phytoplankton biomass accumulation in the inner part of the bay. We hope that most undergoing efforts will improve the understanding of the link between physical dynamics and biological and ecological processes (growth, mortality, migration) of selected HAB taxa and/or functional groups in the bayPeer Reviewe

Diatom Dominance Enhances Resistance of Phytoplanktonic POM to Mesopelagic Microbial Decomposition

Particulate organic matter (POM) lability is one of the key factors determining the residence time of organic carbon (OC) in the marine system. Phytoplankton community composition can influence the rate at which heterotrophic microorganisms decompose phytoplankton detrital particles and thus, it controls the fraction of OC that reaches the ocean depths, where it can be sequestered for climate-relevant spans of time. Here, we compared the degradation dynamics of POM from phytoplankton assemblages of contrasting diatom dominance in the presence of mesopelagic prokaryotic communities during a 19-day degradation experiment. We found that diatom-derived POM exhibited an exponential decay rate approximately three times lower than that derived from a community dominated by flagellated phytoplankton (mainly coccolithophores and nanoflagellates). Additionally, dissolved organic matter (DOM) released during the degradation of diatom particles accumulated over the experiment, whereas only residual increases in DOM were detected during the degradation of non-diatom materials. These results suggest that diatom-dominance enhances the efficiencies of the biological carbon pump and microbial carbon pump through the relatively reduced labilities of diatom particles and of the dissolved materials that arise from their microbial processing

Climate anxiety, pro-environmental action and wellbeing: antecedents and outcomes of negative emotional responses to climate change in 28 countries

This study explored the correlates of climate anxiety in a diverse range of national contexts. We analysed cross-sectional data gathered in 32 countries (N = 12,246). Our results show that climate anxiety is positively related to rate of exposure to information about climate change impacts, the amount of attention people pay to climate change information, and perceived descriptive norms about emotional responding to climate change. Climate anxiety was also positively linked to pro-environmental behaviours and negatively linked to mental wellbeing. Notably, climate anxiety had a significant inverse association with mental wellbeing in 31 out of 32 countries. In contrast, it had a significant association with pro-environmental behaviour in 24 countries, and with environmental activism in 12 countries. Our findings highlight contextual boundaries to engagement in environmental action as an antidote to climate anxiety, and the broad international significance of considering negative climate-related emotions as a plausible threat to wellbeing

On Imprimitive Representations of Finite Reductive Groups in Non-defining Characteristic

In this paper, we begin with the classification of Harish-Chandra imprimitive representations in non-defining characteristic. We recall the connection of this problem to certain generalizations of Iwahori-Hecke algebras and show that Harish-Chandra induction is compatible with the Morita equivalence by Bonnaf\'{e} and Rouquier, thus reducing the classification problem to quasi-isolated blocks. Afterwards, we consider imprimitivity of unipotent representations of certain classical groups. In the case of general linear and unitary groups, our reduction methods then lead to results for arbitrary Lusztig series

Climate anxiety, wellbeing and pro-environmental action: correlates of negative emotional responses to climate change in 32 countries

This study explored the correlates of climate anxiety in a diverse range of national contexts. We analysed cross-sectional data gathered in 32 countries (N = 12,246). Our results show that climate anxiety is positively related to rate of exposure to information about climate change impacts, the amount of attention people pay to climate change information, and perceived descriptive norms about emotional responding to climate change. Climate anxiety was also positively linked to pro-environmental behaviours and negatively linked to mental wellbeing. Notably, climate anxiety had a significant inverse association with mental wellbeing in 31 out of 32 countries. In contrast, it had a significant association with pro-environmental behaviour in 24 countries, and with environmental activism in 12 countries. Our findings highlight contextual boundaries to engagement in environmental action as an antidote to climate anxiety, and the broad international significance of considering negative climate-related emotions as a plausible threat to wellbeing.publishedVersio

Climate anxiety, wellbeing and pro-environmental action : correlates of negative emotional responses to climate change in 32 countries

Publisher Copyright: © 2022 The AuthorsThis study explored the correlates of climate anxiety in a diverse range of national contexts. We analysed cross-sectional data gathered in 32 countries (N = 12,246). Our results show that climate anxiety is positively related to rate of exposure to information about climate change impacts, the amount of attention people pay to climate change information, and perceived descriptive norms about emotional responding to climate change. Climate anxiety was also positively linked to pro-environmental behaviours and negatively linked to mental wellbeing. Notably, climate anxiety had a significant inverse association with mental wellbeing in 31 out of 32 countries. In contrast, it had a significant association with pro-environmental behaviour in 24 countries, and with environmental activism in 12 countries. Our findings highlight contextual boundaries to engagement in environmental action as an antidote to climate anxiety, and the broad international significance of considering negative climate-related emotions as a plausible threat to wellbeing.Peer reviewe

Climate anxiety, wellbeing and pro-environmental action: Correlates of negative emotional responses to climate change in 32 countries

This study explored the correlates of climate anxiety in a diverse range of national contexts. We analysed cross-sectional data gathered in 32 countries (N = 12,246). Our results show that climate anxiety is positively related to rate of exposure to information about climate change impacts, the amount of attention people pay to climate change information, and perceived descriptive norms about emotional responding to climate change. Climate anxiety was also positively linked to pro-environmental behaviours and negatively linked to mental wellbeing. Notably, climate anxiety had a significant inverse association with mental wellbeing in 31 out of 32 countries. In contrast, it had a significant association with pro-environmental behaviour in 24 countries, and with environmental activism in 12 countries. Our findings highlight contextual boundaries to engagement in environmental action as an antidote to climate anxiety, and the broad international significance of considering negative climate-related emotions as a plausible threat to wellbeing