2,892 research outputs found

    Layered granitoids: Interaction between continental crust recycling processes and

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    In this paper, field, petrographic, mineralogical, geochemical and isotopic (Rb–Sr and Sm–Nd) information from three areas within the Évora Massif (Iberian Variscan Orogen) is presented and discussed aiming at to unravel the relationships between granitoids and units mapped as migmatites and also to evaluate the interplay between mantle and crustal derived magmas. One of the areas – Almansor – displays a well-developed compositional layering (concordant with the regional Variscan structure) which was considered, in previous works, as an alternation of leucosome and melanosome. In this study, the layering is described as intercalation of diatexites, weakly foliated granitoids and trondhjemitic veins. Diatexites have characteristics of crustal melts plus restitic material and, according to geochemical and isotopic evidence, result from anatexis of Ediacaran metasediments. Weakly foliated granitoids and trondhjemitic veins from Almansor have calc-alkaline signatures and may be related to each other by crystal fractionation processes; however, the mixing between mafic (mantle-derived) and felsic (diatexitic melt) magmas revealed by the isotopic data may also explain their genesis. In the Alto de São Bento area, several igneous lithologies (tonalites, granodiorites, porphyritic granites and leucogranites) are present and show typical isotropic igneous textures. Despite structural and textural differences, geochemical data support, for most rocks, an origin from the same calk-alkaline suite, also present at Almansor. The Alto de São Bento leucogranites have an isotopic signature that, although different from that obtained in the Almansor diatexites, is still compatible with an origin involving melting of Ediacaran metasediments; compositions, with very low contents of usually incompatible elements, flat normalized REE patterns and strong negative Eu anomalies, suggest that the anatectic melt has undergone crystal fractionation processes before reaching the composition of the leucogranite magma. The Almansor outcrop is then interpreted as the remnants of a shear zone that operated as a pathway for melts that moved upward through the crust providing the locus for differentiation and mingling/mixing of magmas, whilst Alto de São Bento would correspond to the zone, at a higher crustal level, where magmas were trapped and forced to spread horizontally. At Valverde (the third area) foliated and non-foliated granitoids are spatially related and field criteria links these rocks to metamorphic protolith and anatectic melt, respectively. However, petrographic, geochemical and isotopic information shows that they all are compositionally identical trondhjemites with no evidence of metamorphic fabric. In the foliated rocks, mesoscopic features are interpreted as resulting from melt segregation structures formed in a crystallizing mush. In contrast to the previous areas, the Valverde trondhjemites probably do not belong to the main calc-alkaline plutonic suite of the Évora Massif, since they have a distinct Sr and Nd isotope signature

    Blockade of the Interaction of Calcineurin with FOXO in Astrocytes Protects Against Amyloid-βInduced Neuronal Death

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    Astrocytes actively participate in neuro-inflammatory processes associated to Alzheimer’s disease (AD), and other brain pathologies. We recently showed that an astrocyte-specific intracellular signaling pathway involving an interaction of the phosphatase calcineurin with the transcription factor FOXO3 is a major driver in AD associated pathological inflammation, suggesting a potential new druggable target for this devastating disease. We have now developed decoy molecules to interfere with calcineurin/FOXO3 interactions, and tested them in astrocytes and neuronal co-cultures exposed to amyloid-β (Aβ) toxicity. We observed that interference of calcineurin/FOXO3 interactions exerts a protective action against A-induced neuronal death and favors the production of a set of growth factors that we hypothesize form part of a cytoprotective pathway to resolve inflammation. Furthermore, interference of the A-induced interaction of calcineurin with FOXO3 by decoy compounds significantly decreased amyloid-β protein precursor (AβPP) synthesis, reduced the AβPP amyloidogenic pathway, resulting in lower Alevels, and blocked the expression of pro-inflammatory cytokines TNFα and IL-6 in astrocytes. Collectively, these data indicate that interrupting pro-inflammatory calcineurin/FOXO3 interactions in astrocytes triggered by Aβ accumulation in brain may constitute an effective new therapeutic approach in AD. Future studies with intranasal delivery, or brain barrier permeable decoy compounds, are warranted

    Understanding pseudo-albinism in sole (Solea senegalensis): a transcriptomics and metagenomics approach

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    Pseudo-albinism is a pigmentation disorder observed in flatfish aquaculture with a complex, multi-factor aetiology. We tested the hypothesis that pigmentation abnormalities are an overt signal of more generalised modifications in tissue structure and function, using as a model the Senegalese sole and two important innate immune barriers, the skin and intestine, and their microbiomes. Stereological analyses in pseudo-albino sole revealed a significantly increased mucous cell number in skin (P < 0.001) and a significantly thicker muscle layer and lamina propria in gut (P < 0.001). RNA-seq transcriptome analysis of the skin and gut identified 573 differentially expressed transcripts (DETs, FDR < 0.05) between pseudo-albino and pigmented soles (one pool/tissue from 4 individuals/phenotype). DETs were mainly linked to pigment production, skin structure and regeneration and smooth muscle contraction. The microbiome (16 S rRNA analysis) was highly diverse in pigmented and pseudo-albino skin but in gut had low complexity and diverged between the two pigmentation phenotypes. Quantitative PCR revealed significantly lower loads of Mycoplasma (P < 0.05) and Vibrio bacteria (P < 0.01) in pseudo-albino compared to the control. The study revealed that pseudo-albinism in addition to pigmentation changes was associated with generalised changes in the skin and gut structure and a modification in the gut microbiome.Agência financiadora H2020 European Funds MSCA-RISE project 691102 Portuguese national funds from FCT - Foundation for Science and Technology UID/Multi/04326/2019 Portuguese national funds from the operational programme CRESC Algarve 2020 EMBRC. PT ALG-01-0145-FEDER-022121 Portuguese national funds from the operational programme COMPETE 2020 EMBRC. PT ALG-01-0145-FEDER-022121 European Union (EU) 654008 Fundacao para a Ciencia e a Tecnologia (FCT) SFRH/BPD/84033/2012 Portuguese Institute for Employment and Vocational Training 0068/ET/18info:eu-repo/semantics/publishedVersio

    Crustal growth and deformational processes in the northern

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    The aim of this article is to present a compilation of available information on the Évora Massif based on structural mapping, whole-rock geochemistry, recognition of metamorphic mineral assemblages, and geothermobarometry. In our view, transcurrent movements responsible for strong orogen-parallel stretching were dominant and had a major role in the geodynamic evolution of this part of Ossa-Morena zone (southwest Iberian Massif). Cadomian and Variscan orogenic events separated by a period of intense rifting were the cause for the composite distribution of zones with contrasting metamorphic paths, the structural complexity, the variety of lithological associations, and the sequence of deformation events and magmatism. The proposed geodynamic reconstruction for this segment of the northern Gondwana continental margin includes three main stages in chronological order: (1) Neoproterozoic accretion and continental magmatic arc developing, dismantling, and reworking, followed by late-“orogenic” magmatism; (2) Lower Paleozoic crustal thinning, block tilting, and mantle upwelling, induced by generalized rifting, leading to the formation of marine basins with carbonate platform sediments and thick accumulations of volcaniclastic and terrigenous sediments, contemporaneous with normal and enriched mid-oceanic ridge basalt–type magmatism; and (3) Upper Paleozoic transpressional orogenesis resulting from obliquity of convergence and the geometry of the involved blocks. The third stage includes the tectonic inversion of Lower Paleozoic basins, crustal thickening, the exhumation of high- to medium-pressure rocks and partial exhumation of high-grade metamorphic lithologies (controlled by local transtension and major detachments), the formation of synorogenic basins fi lled with volcanicsedimentary sequences, and fi nally, the emplacement of late Variscan granodiorites and granites

    Variation of larval size and adult emergence period of Boyeria irene (Fonscolombe, 1838) (Odonata: Aeshnidae) in the Francia River of western Spain

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    Boyeria irene (Fonscolombe, 1838) is a large dragonfly common in rivers and streams in southern Europe, but it is little known about the biometrical variations of their populations. In this paper, we test whether the time of the emergence period of this species differs in the same river, whether the larval size varies during the emergence period, and whether the distinct size variations are associated with the different river sections. Results have revealed that 1) female exuviae are larger than those of males, 2) except for the paraproct length, the exuviae have similar size across the entire river length, 3) size of the exuviae is larger in the first period of emergence than in the second one. A difference in emergence duration across the three river sections has been recorded.info:eu-repo/semantics/publishedVersio

    Experimental study of dielectric barrier discharge in mixtures of carbon dioxide and oxygen

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    Carbon dioxide decomposition in mixtures of CO2and O2has been experimentally investigatedusing dielectric barrier discharge, with special interest on O3and COproductions. Experiments have been conducted at different frequencies and operating voltages, and the concentration of O3and COhave been measured by means of absorption spectroscopy in the UV and in the IR regions. According to the observations, theproductionof both speciescan be substantially increased by adding molecular oxygento carbon dioxide, even in small proportion

    Hyperbolastic type-III diffusion process: Obtaining from the generalized Weibull diffusion process

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    The modeling of growth phenomena has become a matter of great interest in many different fields of application and research. New stochastic models have been developed, and others have been updated to this end. The present paper introduces a diffusion process whose main characteristic is that its mean function belongs to a wide family of curves derived from the classic Weibull curve. The main characteristics of the process are described and, as a particular case, a di usion process is considered whose mean function is the hyperbolastic curve of type III, which has proven useful in the study of cell growth phenomena. By studying its estimation we are able to describe the behavior of such growth patterns. This work considers the problem of the maximum likelihood estimation of the parameters of the process, including strategies to obtain initial solutions for the system of equations that must be solved. Some examples are provided based on simulated sample paths and real data to illustrate the development carried out.This work was supported in part by the Ministerio de Economía, Industria y Competitividad, Spain, under Grant MTM2017-85568-P

    Medicinas y cuerpos en América Latina. Debates antropológicos desde la salud y la interculturalidad

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    Salud y enfermedad se expresan en el cuerpo, y éste habla por tanto de manera nítida a través de la enfermedad. Sin embargo, estos conceptos resultan tremendamente variables según los contextos culturales en los que se asienten, representándose así el ser humano como una entidad plural y relativizada por la antropología. En este sentido, cabría decir que se impone la necesidad de un entendimiento intercultural entre las ideas de cuerpo y persona, y el intercambio de saberes médicos que en cada lugar se reconocen para procurar la salud. Un debate en el que desgraciadamente suele pesar el etnocentrismo de diferentes profesionales de la salud procedentes de un sistema biomédico occidental que muchas veces ignora estas concepciones diferentes, ocasionalmente las desprecia o se muestra incapaz de integrarlas a sus propios modelos. El volumen busca explorar la posibilidad y complejidad de las actuaciones sanitarias entre agentes y usuarios de culturas y contextos diferenciados de América Latina. Su propósito no es otro que el de favorecer la reflexión sobre aplicaciones teóricas y prácticas que la perspectiva intercultural puede ofrecer en el dominio de la salud, un tema tan en boga y a la vez tan necesitado de revisión crítica

    Models : tools for synthesis in international oceanographic research programs

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    Author Posting. © Oceanography Society, 2010. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 23, no. 3 (2010): 126-139, doi: 10.5670/oceanog.2010.28Through its promotion of coordinated international research programs, the Intergovernmental Oceanographic Commission (IOC) has facilitated major progress on some of the most challenging problems in oceanography. Issues of global significance—such as general ocean circulation, the carbon cycle, the structure and dynamics of ecosystems, and harmful algal blooms—are so large in scope that they require international collaboration to be addressed systematically. International collaborations are even more important when these issues are affected by anthropogenic processes— such as climate change, CO2 enhancement, ocean acidification, pollution, and eutrophication—whose impacts may differ greatly throughout the global ocean. These problems require an entire portfolio of research activities, including global surveys, regional process studies, time-series observations, laboratorybased investigations, and satellite remote sensing. Synthesis of this vast array of results presents its own set of challenges (Hofmann et al., 2010), and models offer an explicit framework for integration of the knowledge gained as well as detailed investigation of the underlying dynamics. Models help us to understand what happened in the past, and to make predictions of future changes—both of which support the development of sound policy and decision making. We review examples of how models have been used for this suite of purposes, focusing on areas where IOC played a key role in organizing and coordinating the research activities.Support from the National Science Foundation, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, and National Institute of Environmental Health Sciences. DS acknowledges CLISAP (Integrated Climate System Analysis and Prediction) at the KlimaCampus of the University of Hamburg. PG acknowledges SCOR/ LOICZ Working Group 132
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