Evolución geológica y nomenclatura pre-Gondwánica en el Noroeste de Argentina (1800-160 Ma)

Consideraciones paleogeográficas, geofísicas, estructurales, estratigráficas, petrológicas y metalogénicas conve rgen para delinear una visión actualizada sobre la evolución geológica de las comarcas del proto-Gondwana en el noroeste de Argentina. El basamento meta-sedimentario de la región alberga claras evidencias de la historia geológica proterozoica a partir de la fragmentación de Rodinia y Cabalonia, con la posterior integración paleozoica de microplacas litosféricas alóctonas sobre los nucleos arqueanos y eoproterozoicos de América del Sur. Se precisan las nomenclaturas y la aplicación del concepto de ciclo tectónico para nuestra columna estratigr á fica en los términos geodinámicos de eventos iniciales distensivos y finales compresivos asociados con el ciclo de Wilson, esa parte menor e integrante del ciclo mayor de supercontinente que media entre Rodinia y Pangea.The knowledge the peri-Gondwanian geology and paleogeographic connections as and integrate system with the Du Toit pioneer studies (Du Toit, 1937) are today widely accepted. Although the nature and evolution of the Gondwana composite continent and accretionary belt margins is now much better understood, even is matter of active research and debate. From a general perspective of geodynamical evolution in the Central Andes, the nomenclature proposed by different researchers to describe the tectonic episodes in the region during the Proterozoic and the Palaeozoic have became rather heterogeneous. We propose a simplified and actualistic tectonic nomenclature using the Uruaçuan Cycle (1.3 Ga - 0.9 Ga in the pre-Rodinia supercontinent), the Pannotian Cycle (850 Ma - 500 Ma in the post-Rodinia supercontinent), the Gondwanian Cycle (500 Ma - 160 Ma in the pre-Pangea supercontinent) and the Andean Cycle 160 Ma at present (post-Pangea supercontinent)

Dissolution experiments of commercial PWR (52 MWd/kgU) and BWR (53 MWd/kgU) spent nuclear fuel cladded segments in bicarbonate water under oxidizing conditions. Experimental determination of matrix and instant release fraction

The denominated instant release fraction (IRF) is considered in performance assessment (PA) exercises to govern the dose that could arise from the repository. A conservative definition of IRF comprises the total inventory of radionuclides located in the gap, fractures, and the grain boundaries and, if present, in the high burn-up structure (HBS). The values calculated from this theoretical approach correspond to an upper limit that likely does not correspond to what it will be expected to be instantaneously released in the real system. Trying to ascertain this IRF from an experimental point of view, static leaching experiments have been carried out with two commercial UO2 spent nuclear fuels (SNF): one from a pressurized water reactor (PWR), labelled PWR, with an average burn-up (BU) of 52 MWd/kgU and fission gas release (FGR) of 23.1%, and one from a boiling water reactor (BWR), labelled BWR, with an average BU of and 53 MWd/kgU and FGR of 3.9%.; One sample of each SNF, consisting of fuel and cladding, has been leached in bicarbonate water during one year under oxidizing conditions at room temperature (25 +/- 5) degrees C. The behaviour of the concentration measured in solution can be divided in two according to the release rate. All radionuclides presented an initial release rate that after some days levels down to a slower second one, which remains constant until the end of the experiment. Cumulative fraction of inventory in aqueous phase (FIAPc) values has been calculated. Results show faster release in the case of the PWR SNF. In both cases Np, Pu, Am, Cm, Y, Tc, La and Nd dissolve congruently with U, while dissolution of Zr, Ru and Rh is slower. Rb, Sr, Cs and Mo, dissolve faster than U. The IRF of Cs at 10 and 200 days has been calculated, being (3.10 +/- 0.62) and (3.66 +/- 0.73) for PWR fuel, and (035 +/- 0.07) and (0.51 +/- 0.10) for BWR fuel. (C) 2015 Elsevier B.V. All rights reserved.Peer ReviewedPostprint (author's final draft

Instant release fraction corrosion studies of commercial UO2 BWR spent nuclear fuel

The instant release fraction of a spent nuclear fuel is a matter of concern in the performance assessment of a deep geological repository since it increases the radiological risk. Corrosion studies of two different spent nuclear fuels were performed using bicarbonate water under oxidizing conditions to study their instant release fraction. From each fuel, cladded segments and powder samples obtained at different radial positions were used. The results were normalised using the specific surface area to permit a comparison between fuels and samples. Different radionuclide dissolution patterns were studied in terms of water contact availability and radial distribution in the spent nuclear fuel. The relationship between the results of this work and morphological parameters like the grain size or irradiation parameters such as the burn-up or the linear power density was studied in order to increase the understanding of the instant release fraction formation.Preprin

The Effect of Adverse Surgical Margins on the Risk of Biochemical Recurrence after Robotic-Assisted Radical Prostatectomy

Positive surgical margins (PSM) after radical prostatectomy are associated with a greater risk of biochemical recurrence (BCR). However, not all PSM harbour the same prognosis for recurrence. We aim to determine the impact of different PSM characteristics and their coexistence on the risk of BCR. This retrospective study included 333 patients that underwent robotic-assisted radical prostatectomy for prostate cancer between 2015-2020 at a single institution. The effect of PSM and their adverse characteristics on the risk of BCR was assessed using Cox proportional hazard models. Kaplan-Meier was used to represent BCR-free survival stratified by margin status. With a median follow-up of 34.5 months, patients with PSM had a higher incidence of BCR, higher risk of relapse and lower BCR-free survival than negative margins (p < 0.001). We established as adverse characteristics: PSM length ≥ 3 mm, multifocality and Gleason at margin > 3. PSM ≥ 3 mm or multifocal PSM were associated with an increased risk for BCR compared to favourable margins (HR 3.50; 95% CI 2.05-5.95, p < 0.001 and HR 2.18; 95% CI 1.09-4.37, p = 0.028, respectively). The coexistence of these two adverse features in the PSM also conferred a higher risk for biochemical relapse and lower BCR-free survival. Adverse Gleason in the margin did not confer a higher risk for BCR than non-adverse margins in our models. We concluded that PSM are an independent predictor for BCR and that the presence of adverse characteristics, such as length and focality, and their coexistence in the PSM are associated with a greater risk of recurrence. Nevertheless, subclassifying PSM with adverse features did not enhance the model's predictive performance in our cohort

Assessing the association between tourism and the alcohol urban environment in Barcelona: a cross-sectional study

Objectives: Alcohol availability and promotion are not distributed equally in the urban context. Evidence shows that the socioeconomic level seems to influence the amount of alcohol-related elements in an area. Some studies suggest that tourism could also affect the distribution of these elements. We explore with a valid instrument in a large city whether there is an association between high tourism pressure and a greater presence of alcohol-related elements in the urban environment. Design: Observational ecological study. Setting: The study was conducted in Barcelona during 2017-2018. Participants: We assessed urban exposure to alcohol by performing social systematic observation using the OHCITIES Instrument in a stratified random sample of 170 census tracts within the city's 73 neighbourhoods. Primary and secondary outcome measures: For each census tract we calculated the density of alcohol premises, and of promotion in public places per 1000 residents. We estimated tourism pressure using the number of tourist beds per 1000 residents in each neighbourhood and calculated quartiles. To assess the relationship between rate ratios of elements of alcohol urban environment and tourism pressure, we calculated Spearman correlations and fitted Poisson regression models with robust error variance. Results: The median densities obtained were of 8.18 alcohol premises and of 7.59 alcohol advertising and promotion elements visible from the public space per 1000 population. Census tracts with the highest tourism pressure had 2.5 (95% CI: 1.85-3.38) times more outlets and 2.3 (95% CI: 1.64-3.23) times more promotion elements per 1000 residents than those in the lowest tourism pressure quartile. Conclusions: We observed a strong association between tourism pressure and alcohol exposure in the city of Barcelona

Cambio de paradigma en la relación alcohol y salud: Cuanto menos, mejor

El consumo de bebidas alcohólicas está muy arraigado en la cultura occidental y se relaciona con la mayoría de tradiciones y celebraciones. Sin embargo, este consumo no está exento de riesgos que dependen de la cantidad, frecuencia y patrón de consumo, así como de las características de la persona consumidora como edad, sexo y algunas condiciones de salud. Mientras la evidencia científica acumula pruebas de la toxicidad del alcohol, sigue existiendo una creciente presión para consumirlo. Ello obliga a las autoridades sanitarias a redefinir los límites del consumo de bajo riesgo. El 7,4% de la población adulta española consume diariamente bebidas alcohólicas (Observatorio Español de las Drogas y las Adicciones, 2019). El alcohol es una sustancia adictiva capaz de generar dependencia y que se relaciona con más de 200 problemas de salud (Rehm et al., 2017; World Health Organization, 2018). El consumo de alcohol es el séptimo factor de riesgo tanto para las muertes como para la pérdida de Años de Vida Ajustados por Discapacidad. El único consumo de alcohol que minimiza la pérdida de salud es cero (GBD 2016 Risk Factors Collaborators, 2017). ..

Understanding how alcohol environment influences youth drinking: A concept mapping study among university students

The aim of the study was to identify the environmental factors that influence alcohol consumption, according to university students, and assess the relative importance and the frequency attributed to each factor. A study using Concept Mapping methodology was performed with a sample of nursing students, who participated in two face-to-face data collection sessions. In session 1, a consensus about the environmental aspects that influence their alcohol consumption was obtained. In session 2, the statements obtained were rated according to their relative importance and frequency in alcohol use (1 = minimum; 5 = maximum). Subsequently, all data were analyzed with the RCMAP of the statistical package R 3.6.1. Approximately 60 students participated in each session. Most were women aged 20 to 24. In session 1, a total of 55 statements were obtained and classified into 7 different clusters: Advertising (9 statements); Family environment (4 statements); Social pressure (12 statements); Responsibilities/ norms (4 statements); Holidays and leisure time (7 statements); Emotional situations (8 statements); Accessibility (11 statements). Factors related to social pressure, holidays and leisure time, and alcohol accessibility were considered the most important and frequent in alcohol consumption. In contrast, alcohol advertising was considered the least important (mean 2.6 out of 5) and frequent (mean 2.1 out 5) factor. In conclusion, the factors considered most relevant among nursing students match those having more resources allocated for prevention and health promotion, except for alcohol advertising, which was perceived as less important and frequent compared with the other factors

Plagio y rendimiento académico entre el alumnado de Educación Secundaria Obligatoria

Este artículo analiza, primeramente, la frecuencia manifestada en la comisión de plagio académico por parte de alumnado de ESO y, en segundo término, se profundiza en el estudio de la relación entre el rendimiento académico del alumnado y la perpetración de plagio. Los resultados obtenidos ofrecen una interesante constatación acerca de la extensión del fenómeno del plagio académico en las aulas de los centros educativos. Además, demuestran la existencia de una significativa relación entre el rendimiento académico y la práctica de plagiar: a peor rendimiento académico mayor propensión a cometer actos de plagio y a la inversa