3,818 research outputs found
Layered granitoids: Interaction between continental crust recycling processes and
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
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
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
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
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
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
Conversion of a digital camera into a non-contact colorimeter for use in stone cultural heritage: The application case to Spanish granites
In this study, a digital CMOS camera was calibrated for use as a non-contact colorimeter for measuring the color of granite artworks. The low chroma values of the granite, which yield similar stimulation of the three color channels of the camera, proved to be the most challenging aspect of the task. The appropriate parameters for converting the device-dependent RGB color space into a device-independent color space were established. For this purpose, the color of a large number of Munsell samples (corresponding to the previously defined color gamut of granite) was measured with a digital camera and with a spectrophotometer (reference instrument). The color data were then compared using the CIELAB color formulae. The best correlations between measurements were obtained when the camera works to 10-bits and the spectrophotometric measures in SCI mode. Finally, the calibrated instrument was used successfully to measure the color of six commercial varieties of Spanish granite.The present study was financially supported by the Xunta de Galicia (09TMT014203PR) and the European Union and Spanish Ministry of Economy and Competitiveness under grants DPI2008-06455-C02-02 and DPI2011-30090-C02-02. Dr. Patricia Sanmartín acknowledges a scholarship for postgraduate studies abroad (2012 Call) from Barrié de la Maza Foundation. She is currently supported by a postdoctoral contract within the framework of the 2011–2015 Galician Plan for Research, Innovation and Growth (Plan I2C) for the year 2012
Hyperbolastic type-III diffusion process: Obtaining from the generalized Weibull diffusion process
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
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
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