Difractómetro de grandes componentes para el reactor RA-10

En CNEA se encuentra en ejecución el ?Proyecto RA-10? para la construcción de un reactor multipropósito. Entre los objetivos principales del RA-10 está la provisión de haces de neutrones para la realización de experimentos dentro de un amplio espectro de disciplinas científicas y tecnológicas. Por sus múltiples aplicaciones, la difracción de neutrones es una de las técnicas neutrónicas más populares. El gran poder de penetración de los neutrones (del orden de cm) permite investigar el interior de un objeto sin necesidad de cortarlo. Así es posible estudiar en forma no-destructiva objetos macroscópicos y cuantificar la variación espacial de las fases cristalinas que lo componen, las orientaciones de esos cristalitos, y su nivel de deformación plástica y elástica.En particular, es posible determinar las tensiones internas en componentes mecánicos de gran porte, un tema de gran importancia dentro de la industria metal-mecánica. En este caso los planos cristalinos son utilizados como extensómetros microscópicos, y las pequeñas variaciones que existen en las distancias interplanares para las distintas direcciones de un objeto son utilizados para cuantificar el tensor completo de deformación elástica.La posibilidad de realizar experimentos de difracción sobre objetos intactos ha despertado también gran interés dentro de la comunidad dedicada al estudio y la conservación del patrimonio cultural.Presentamos aquí el diseño básico de un difractómetro para el estudio de grandes componentes, para ser instalado en un haz térmico de la sala del reactor RA-10, es decir, directamente contra la pared del mismo.Se propone equiparlo con dos monocromadores diferentes, para poder optar entre mayor intensidad o mayor resolución. Los monocromadores propuestos son doblemente curvados, a fin de enfocar el haz sobre la posición de medición y optimizar la resolución del equipo para la reflexión de mayor interés. Un componente central del instrumento es el portamuestras, consistente en una mesa con capacidad de posicionar componentes de hasta ~300kg de peso con una precisión de ~20um, una resolución espacial de ~1mm, y rotar los mismos a fin de explorar distintas direcciones. Presentaremos además avances realizados sobre un prototipo a menor escala, que comparte algunas características del diseño propuesto, que será instalado en el reactor RA-6 del Centro Atómico Bariloche.Fil: Santisteban, Javier Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Sanchez, F.. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Moreira, F.. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Gomez, S.. Comisión Nacional de Energía Atómica; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Tartaglione, Aureliano. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Malamud, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Vicente Alvarez, Miguel Angel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gimenez, M.. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Vizcaino, Pablo. Comision Nacional de Energia Atomica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia Ciclo del Combustible Nuclear. Laboratorio D/mat.d/la Fabrica de Aleaciones Especiales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects of peroxisome proliferator-activated receptor- activation in endothelin-dependent hypertension

Aims We analysed the chronic effects of the peroxisome proliferator-activated receptor β/δ (PPAR-β) agonist GW0742 on the renin-independent hypertension induced by deoxycorticosterone acetate (DOCA)-salt. Methods and results Rats were treated for 5 weeks with: control-vehicle, control-GW0742 (5 or 20 mg kg−1 day−1), DOCA-vehicle, DOCA-GW0742 (5 or 20 mg kg−1 day−1), DOCA-GSK0660 (1 mg kg−1 day−1), and DOCA-GSK0660-GW0742. Rats receiving DOCA-vehicle showed increased systolic blood pressure, left ventricular and kidney weight indices, endothelin-1 (ET-1), and malondialdehyde plasma levels, urinary iso-PGF2α excretion, impaired endothelium-dependent relaxation to acetylcholine, and contraction to ET-1 when compared with controls. Aortic reactive oxygen species content, NADPH oxidase activity, and p47phox, p22phox, NOX-4, glutathione peroxidase 1, hemeoxygenase-1, and preproET-1 expression were increased, whereas catalase and regulators of G protein-coupled signalling proteins (RGS)5 expression were decreased in the DOCA-vehicle group. GW0742 prevented the development of hypertension in a dose-dependent manner but the reduction of renal and cardiac hypertrophy, systemic and vascular oxidative stress markers, and improvement of endothelial dysfunction were only observed after the higher dose. GW0742, at 20 mg kg−1 day−1, attenuated ET-1 contraction by increasing RGS5 expression and restored the intracellular redox balance by reducing NADPH-oxidase activity, and by increasing the antioxidant genes expression. The PPAR-β antagonist GSK0660 prevented all vascular changes induced by GW0742 but not its antihypertensive effects. Conclusion Vascular protective effects of GW0742 operate via PPAR-β by interference with the ET-1 signalling as a result of increased expression of RGS5 and up-regulation of antioxidant genes and via PPAR-β-independent mechanisms to decrease blood pressure

Modular framework to assess the risk of African swine fever virus entry into the European Union

BACKGROUND The recent occurrence and spread of African swine fever (ASF) in Eastern Europe is perceived as a serious risk for the pig industry in the European Union (EU). In order to estimate the potential risk of ASF virus (ASFV) entering the EU, several pathways of introduction were previously assessed separately. The present work aimed to integrate five of these assessments (legal imports of pigs, legal imports of products, illegal imports of products, fomites associated with transport and wild boar movements) into a modular tool that facilitates the visualization and comprehension of the relative risk of ASFV introduction into the EU by each analyzed pathway. RESULTS The framework's results indicate that 48% of EU countries are at relatively high risk (risk score 4 or 5 out of 5) for ASFV entry for at least one analyzed pathway. Four of these countries obtained the maximum risk score for one pathway: Bulgaria for legally imported products during the high risk period (HRP); Finland for wild boar; Slovenia and Sweden for legally imported pigs during the HRP. Distribution of risk considerably differed from one pathway to another; for some pathways, the risk was concentrated in a few countries (e.g., transport fomites), whereas other pathways incurred a high risk for 4 or 5 countries (legal pigs, illegal imports and wild boar). CONCLUSIONS The modular framework, developed to estimate the risk of ASFV entry into the EU, is available in a public domain, and is a transparent, easy-to-interpret tool that can be updated and adapted if required. The model's results determine the EU countries at higher risk for each ASFV introduction route, and provide a useful basis to develop a global coordinated program to improve ASFV prevention in the EU

Effectiveness of an mHealth intervention combining a smartphone app and smart band on body composition in an overweight and obese population: Randomized controlled trial (EVIDENT 3 study)

Background: Mobile health (mHealth) is currently among the supporting elements that may contribute to an improvement in health markers by helping people adopt healthier lifestyles. mHealth interventions have been widely reported to achieve greater weight loss than other approaches, but their effect on body composition remains unclear. Objective: This study aimed to assess the short-term (3 months) effectiveness of a mobile app and a smart band for losing weight and changing body composition in sedentary Spanish adults who are overweight or obese. Methods: A randomized controlled, multicenter clinical trial was conducted involving the participation of 440 subjects from primary care centers, with 231 subjects in the intervention group (IG; counselling with smartphone app and smart band) and 209 in the control group (CG; counselling only). Both groups were counselled about healthy diet and physical activity. For the 3-month intervention period, the IG was trained to use a smartphone app that involved self-monitoring and tailored feedback, as well as a smart band that recorded daily physical activity (Mi Band 2, Xiaomi). Body composition was measured using the InBody 230 bioimpedance device (InBody Co., Ltd), and physical activity was measured using the International Physical Activity Questionnaire. Results: The mHealth intervention produced a greater loss of body weight (–1.97 kg, 95% CI –2.39 to –1.54) relative to standard counselling at 3 months (–1.13 kg, 95% CI –1.56 to –0.69). Comparing groups, the IG achieved a weight loss of 0.84 kg more than the CG at 3 months. The IG showed a decrease in body fat mass (BFM; –1.84 kg, 95% CI –2.48 to –1.20), percentage of body fat (PBF; –1.22%, 95% CI –1.82% to 0.62%), and BMI (–0.77 kg/m2, 95% CI –0.96 to 0.57). No significant changes were observed in any of these parameters in men; among women, there was a significant decrease in BMI in the IG compared with the CG. When subjects were grouped according to baseline BMI, the overweight group experienced a change in BFM of –1.18 kg (95% CI –2.30 to –0.06) and BMI of –0.47 kg/m2 (95% CI –0.80 to –0.13), whereas the obese group only experienced a change in BMI of –0.53 kg/m2 (95% CI –0.86 to –0.19). When the data were analyzed according to physical activity, the moderate-vigorous physical activity group showed significant changes in BFM of –1.03 kg (95% CI –1.74 to –0.33), PBF of –0.76% (95% CI –1.32% to –0.20%), and BMI of –0.5 kg/m2 (95% CI –0.83 to –0.19). Conclusions: The results from this multicenter, randomized controlled clinical trial study show that compared with standard counselling alone, adding a self-reported app and a smart band obtained beneficial results in terms of weight loss and a reduction in BFM and PBF in female subjects with a BMI less than 30 kg/m2 and a moderate-vigorous physical activity level. Nevertheless, further studies are needed to ensure that this profile benefits more than others from this intervention and to investigate modifications of this intervention to achieve a global effect

Immunohistopathological study of African swine fever (strain E-75)-infected bone marrow

A study was made of the action of African swine fever virus (ASFV) on the bone marrow of 12 miniature pigs inoculated intramuscularly with the moderately virulent ASFV isolate E75 and killed 2 to 12 days after infection. A sequential description is provided of the histological lesions of the bone marrow in the experimental animals, which developed haemorrhagic lesions from 6 days after inoculation onwards. Immunohistochemical techniques were used to demonstrate the viral protein VP73 and immunoglobulins (IgG and IgM) in formalin-fixed and paraffin wax-embedded samples of bone marrow tissue. The immunohistological results, platelet counts, viraemia, and anti-ASFV immunoglobulin titres all indicated that thrombocytopoiesis impairment by direct viral action plays a role in the progressive thrombocytopenia characteristic of infection by moderately virulent ASFV isolates

A reinterpretation of the Nevado-Filabride and Alpujarride complexes (Betic Cordillera): field, petrography and U-Pb ages from orthogneisses (western Sierra Nevada, S Spain)

We investigated gneisses from the upper sequence of the Nevado-Filábride Complex in the western Sierra Nevada, close to the contact with the Permo-Triassic Alpujárride Complex. Despite intense deformation, the occurrence of skarn-like lenses (epidote

A case study of an outbreak of African swine fever in Spain

This report represents a case study of an outbreak of African swine fever(ASF) that took place in the autonomic region of Extramadura, Badajoz Province, during the month of August 1992, and aims to describe the Spanish ASF eradication programme as carried out in the field at producer level. Extensive husbandry methods used in the management of Iberian pigs in ASF endemic areas of Spain (about 4% of Spanish territory in 4/52 provinces) makes eradication particularly difficult. Since there is no vaccine available for ASF, the identification and slaughter of carrier animals is crucial to the control of the disease. A case of ASF, which caused one secondary outbreak, was diagnosed on 26 August 1992 and is described in terms of case history, laboratory examination, disease eradication measures and epidemiological observations. Additional evidence is presented in an attempt to evaluate and gain an understanding of the long-term risk of carrier animals, wild European pigs, vector ticks and biting flies as a cause of the persistence in endemic areas of recrudescence of ASF in areas from which the disease was previously eradicated. © 1995 Baillière Tindall

The role of silica in the hydrous metamorphism of chromite

International audienceRetrograde hydrous metamorphism has produced three types of microstructures in chromite grains from chromitites and enclosing rocks of the Tapo Ultramafic Massif (Central Peruvian Andes). In semi-massive chromitites (60–80 vol% chromite), (i) partly altered chromite with homogeneous cores surrounded by lower Al2O3 and MgO but higher Cr2O3 and FeO porous chromite with chlorite filling the pores. In serpentinites (ii) zoned chromite with homogeneous cores surrounded by extremely higher Fe2O3 non-porous chromite and magnetite rims, and (iii) non-porous chromite grains. The different patterns of zoning in chromite grains are the consequences of the infiltration of reducing and SiO2-rich fluids and the subsequent heterogeneous interaction with more oxidizing and Fe-bearing fluids. During the first stage of alteration under reduced conditions magmatic chromite is dissolved meanwhile new metamorphogenic porous chromite crystallizes in equilibrium with chlorite. This reaction that involves dissolution and precipitation of minerals is here modeled thermodynamically for the first time. µSiO2-µMgO pseudosection calculated for unaltered semi-massive chromitites at 2 kbar and 300 °C, the lowest P-T conditions inferred from the Tapo Ultramafic Massif and Marañón Complex, predicts that chromite + chlorite (i.e., partly altered chromite) is stable instead of chromite + chlorite + brucite at progressive higher µSiO2 but lower µMgO. Our observation is twofold as it reveals that the important role of SiO2 and MgO and the open-nature of this process. P-T-X diagrams computed using the different P-T pathways estimated for the enclosing Tapo Ultramafic Massif reproduce well the partial equilibrium sequence of mineral assemblages preserved in the chromitites. Nevertheless, it is restricted only to the P-T conditions of the metamorphic peak and that of the latest overprint. Our estimations reveal that a high fluid/rock ratio (1:40 ratio) is required to produce the microstructures and compositional changes observed in the chromitites from the Tapo Ultramafic Massif. The circulation of SiO2-rich fluids and the mobilization of MgO from the chromitite bodies are linked with the formation of garnet amphibolites and carbonate-silica hydrothermalites (i.e., listwaenites and birbirites) in the ultramafic massif. The origin of these fluids is interpreted as a result of the dissolution of orthopyroxene and/or olivine from the metaharzburgites and metagabbros enclosed in the Tapo Ultramafic Massif