Geology of giant quartz veins and their host rocks from the Eastern Pyrenees (Southwest Europe)

Giant Quartz Veins (GQVs) are ubiquitous in different tectonic settings and, besides being often related to hydrothermal ore deposits, also represent large-scale fingerprints of the structural and geochemical history of the rocks in which they are hosted. Here we present detailed geological maps and interpretations of three key areas of the Eastern Pyrenees where GQVs are well exposed. The studied rocks record different styles of deformation and are representative of common settings of the Pyrenees where GQVs are present: pre-Variscan metasedimentary and metavolcanic rocks, late Variscan granitoids, and Mesozoic and Cenozoic sedimentary rocks. GQVs in the study areas formed along pre-existing brittle and ductile structures or at locations with lithological heterogeneities, and have alteration haloes of silicified host rocks. The geological maps and interpretations presented here contribute to gain insights into the formation mechanisms of GQVs and into the structural constraints on fluid flow and mineral reactions at different depths of the Earth's crust

A review of natural hydrofractures in rocks

Hydrofractures, or hydraulic fractures, are fractures where a significantly elevated fluid pressure played a role in their formation. Natural hydrofractures are abundant in rocks and are often preserved as magmatic dykes or sills, and mineral-filled fractures or mineral veins. However, we focus on the formation and evolution of non-igneous hydrofractures. Here we review the basic theory of the role of fluid pressure in rock failure, showing that both Terzaghi's and Biot's theories can be reconciled if the appropriate boundary conditions are considered. We next discuss the propagation of hydrofractures after initial failure, where networks of hydrofractures may form or hydrofractures may ascend through the crust as mobile hydrofractures. As fractures can form as a result of both tectonic stresses and an elevated fluid pressure, we address the question of how to ascertain whether a fracture is a hydrofracture. We argue that extensional or dilational fractures that formed below c. 2-3 km depth are, under normal circumstances, hydrofractures, but at shallower depth they may, but must not be hydrofractures. Since veins and breccias are often the products of hydrofractures that are left in the geological record, we discuss these and critically assess which vein structures can, and which do not necessarily, indicate hydrofracturing. Hydrofracturing can suddenly and locally change the permeability in a rock by providing new fluid pathways. This can lead to highly dynamic self-organization of crustal-scale fluid flow

Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots

[EN] We have studied the optical properties of InAs site-controlled quantum dots (SCQDs) grown on pre-patterned GaAs substrates. Since InAs nucleates preferentially on the lithography motifs, the location of the resulting QDs is determined by the pattern, which is fabricated by local oxidation nanolithography. Optical characterization has been performed on such SCQDs to study the fundamental and excited states. At the ground state different exciton complex transitions of about 500 μeV linewidth have been identified and the fine structure splitting of the neutral exciton has been determined (≈65 μeV). The observed electronic structure covers the demands of future quantum information technologiesThe authors want to acknowledge the financial support from Spanish government through grants QD-NANOTICS: TEC2011-29120-C05-01, EPIC-NANOTICS: TEC2011-29120-C05-04, PROMESA: ENE2012-37804-C02-02, and Q&C Light: S2009ESP-1503. We also thank the support from the PROMETEO2009/74 project (Generalitat Valenciana). J.C.-F. thanks the Spanish MCI for his FPI grant (No. BES-2006-12300) and J.H. acknowledges to the JAE program for the funds.Canet-Ferrer, J.; Muñoz Matutano, G.; Herranz, J.; Rivas, D.; Alén, B.; González, Y.; Fuster, D.... (2013). Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots. Applied Physics Letters. 103(18). https://doi.org/10.1063/1.4828352S1031

The mechanism of formate oxidation by metal-dependent formate dehydrogenases

J Biol Inorg Chem (2011) 16:1255–1268 DOI 10.1007/s00775-011-0813-8Metal-dependent formate dehydrogenases (Fdh) from prokaryotic organisms are members of the dimethyl sulfoxide reductase family of mononuclear molybdenum-containing and tungsten-containing enzymes. Fdhs catalyze the oxidation of the formate anion to carbon dioxide in a redox reaction that involves the transfer of two electrons from the substrate to the active site. The active site in the oxidized state comprises a hexacoordinated molybdenum or tungsten ion in a distorted trigonal prismatic geometry. Using this structural model, we calculated the catalytic mechanism of Fdh through density functional theory tools. The simulated mechanism was correlated with the experimental kinetic properties of three different Fdhs isolated from three different Desulfovibrio species. Our studies indicate that the C–H bond break is an event involved in the rate-limiting step of the catalytic cycle. The role in catalysis of conserved amino acid residues involved in metal coordination and near the metal active site is discussed on the basis of experimental and theoretical results

Treatment patterns and outcomes among nontransplant newly diagnosed multiple myeloma patients in Spain

Aim: To describe treatment patterns and outcomes in nontransplant newly diagnosed multiple myeloma (NDMM) patients in Spain. Methods: This retrospective study included two cohorts of NDMM patients diagnosed between 1 January 2012 to 31 December 2013 and 1 April 2016 to 31 March 2017. Results: Among 113 patients, proteasome inhibitor (PI) + alkylator combinations (49%) and PI-based regimens without an alkylator (30%) were the most common first-line (1L) therapies. Use of PI + immunomodulatory drug-based regimens increased between the cohorts; PI-based regimens without an alkylator/immunomodulatory drug decreased. Use of 1L oral regimens was low but increased over time; use of maintenance therapy was low across both periods. Median 1L duration of treatment was 6.9 months. Conclusion: Short 1L duration of treatment and low use of 1L oral regimens and maintenance therapy highlight unmet needs in NDMM. © 2021 The Authors

Structure of the Collision Zone Between the Nazca Ridge and the Peruvian Convergent Margin: Geodynamic and Seismotectonic Implications

We study the structure and tectonics of the collision zone between the Nazca Ridge (NR) and the Peruvian margin constrained by seismic, gravimetric, bathymetric, and natural seismological data. The NR was formed in an on-ridge setting, and it is characterized by a smooth and broad shallow seafloor (swell) with an estimated buoyancy flux of ~7 Mg/s. The seismic results show that the NR hosts an oceanic lower crust 10–14 km thick with velocities of 7.2–7.5 km/s suggesting intrusion of magmatic material from the hot spot plume to the oceanic plate. Our results show evidence for subduction erosion in the frontal part of the margin likely enhanced by the collision of the NR. The ridge-trench collision zone correlates with the presence of a prominent normal scarp, a narrow continental slope, and (uplifted) shelf. In contrast, adjacent of the collision zone, the slope does not present a topographic scarp and the continental slope and shelf become wider and deeper. Geophysical and geodetic evidence indicate that the collision zone is characterized by low seismic coupling at the plate interface. This is consistent with vigorous subduction erosion enhanced by the subducting NR causing abrasion and increase of fluid pore pressure at the interplate contact. Furthermore, the NR has behaved as a barrier for rupture propagation of megathrust earthquakes (e.g., 1746 Mw 8.6 and 1942 Mw 8.1 events). In contrast, for moderate earthquakes (e.g., 1996 Mw 7.7 and 2011 Mw 6.9 events), the NR has behaved as a seismic asperity nucleating at depths >20 km

Análisis de las velocidades de operación en los carriles mixtos de las troncales del transporte masivo en bogotá – hacia una propuesta de aumento de la velocidad máxima permitida

En este artículo se presentan las velocidades de operación de los vehículos que circulan por lo carriles mixtos del sistema de transporte masivo de Bogotá, para lo cual se analizaron seis corredores: autopista Norte, calle 80, carrera 30, avenida de lasAméricas, avenida Suba y la calle 26; se hicieron mediciones de velocidades puntuales por medio de medidas directas con radar; se realizaron cálculos de las velocidades máximas seguras y cómodas a las que se podría circular sin que se afecte la seguridad de los usuarios de cada corredor analizado, con lo cual se pretende emitir una propuesta de velocidades máximas de operación para cada uno de estos corredores

Comparison of fiber effect on glycemic index and glycemic load in differents types of bread

Indexación: Scopus; Redalyc.Existen diversos alimentos que contienen como nutriente principal hidratos de carbono, destacando entre ellos el pan por su masivo consumo a nivel mundial. Numerosos estudios se han llevado a cabo con el fin de reducir su índice glicémico, sin embargo, aún existe controversia sobre la acción de la fibra dietética en la disminución del IG en este alimento. Este estudio determinó el efecto de la fibra dietética sobre el índice glicémico y carga glicémica en dos tipos de panes comerciales en 23 individuos sanos quienes consumieron aleatoriamente 3 diferentes productos, de 50 g de carbohidratos cada uno, durante 6 días: pan blanco (PH), pan integral (PF), y solución glucosada como producto de referencia (SG). Se midió glicemia en ayunas y post-prandial a los tiempos 15, 30, 45, 60, 90 y 120 min. La insulina fue medida en el minuto 0 y 120 min. El área bajo la curva de glicemia resultó más baja para ambos tipos de pan PH 13589 ±1557, PF 12005 ±1254 que para el producto de referencia SG 14089 ±1245. Los valores del índice glicémico PH 68,55 ±1,2 y PF 62,10 ±1,3 y carga glicémica PH 16,45 ±1,4 resultaron más bajos para el pan con mayor aporte de fibra 9,93 ± 1,1, sin diferencias en la concentración de insulina, sugiriendo que la cantidad de carbohidratos y tipo de fibra contenidos en el pan integral, pueden considerarse factores intrínsecos en su composición nutricional, capaces de afectar la respuesta glicémica post- ingesta de estos productos en individuos sanos.There are several foods that contain carbohydrates as the main nutrient, being one of the most important the bread for its massive worldwide consumption. Numerous studies have been done in order to reduce its glycemic index, however there is still controversy about the action of dietary fiber in the decrease of GI in this product. In this study, it was determined the effect of dietetic fiber on glycemic index and glycemic load in two types of commercial breads in 23 healthy individuals who randomly consumed 3 different products during 6 days of 50g of carbohydrates each: white bread (PH), whole wheat bread (PE) and glucose solution as reference product (SG). Fasting and postprandial glycemia was measured at times 15, 30, 45, 60, 90 and 120 minutes. Insuline was measured at 0 min and 120 min. The area under de glycemia curve was lower for both bread types PH 13589 ±1557, PF 12005 ±1254 than for the reference product SG 14089 ±1245. The values of the glycemic index PH 68,55 ±1,2 and PF 62,01 ±1,3 and glycemic load PH 16.45 ±1,4 were lower for bread with more amount fiber 9,93 ± 1,1, with no difference in insulin concentration, suggesting that the amount of carbohydrates and fiber type contained in whole wheat bread can be considered intrinsic factors in bread composition, affecting the post-intake glycemic response of this type of products in healthy individuals.http://www.redalyc.org/articulo.oa?id=5594990800

Lifestyles, arterial aging, and its relationship with the intestinal and oral microbiota (MIVAS III study): a research protocol for a cross-sectional multicenter study

The microbiota is increasingly recognized as a significant factor in the pathophysiology of many diseases, including cardiometabolic diseases, with lifestyles probably exerting the greatest influence on the composition of the human microbiome. The main objectives of the study are to analyze the association of lifestyles (diet, physical activity, tobacco, and alcohol) with the gut and oral microbiota, arterial aging, and cognitive function in subjects without cardiovascular disease in the Iberian Peninsula. In addition, the study will examine the mediating role of the microbiome in mediating the association between lifestyles and arterial aging as well as cognitive function.Methods and analysisMIVAS III is a multicenter cross-sectional study that will take place in the Iberian Peninsula. One thousand subjects aged between 45 and 74 years without cardiovascular disease will be selected. The main variables are demographic information, anthropometric measurements, and habits (tobacco and alcohol). Dietary patterns will be assessed using a frequency consumption questionnaire (FFQ) and the Mediterranean diet adherence questionnaire. Physical activity levels will be evaluated using the International Physical Activity Questionnaire (IPAQ), Marshall Questionnaire, and an Accelerometer (Actigraph). Body composition will be measured using the Inbody 230 impedance meter. Arterial aging will be assessed through various means, including measuring medium intimate carotid thickness using the Sonosite Micromax, conducting analysis with pulse wave velocity (PWA), and measuring pulse wave velocity (cf-PWV) using the Sphygmocor System. Additional cardiovascular indicators such as Cardio Ankle Vascular Index (CAVI), ba-PWV, and ankle-brachial index (Vasera VS-2000®) will also be examined. The study will analyze the intestinal microbiota using the OMNIgene GUT kit (OMR−200) and profile the microbiome through massive sequencing of the 16S rRNA gene. Linear discriminant analysis (LDA), effect size (LEfSe), and compositional analysis, such as ANCOM-BC, will be used to identify differentially abundant taxa between groups. After rarefying the samples, further analyses will be conducted using MicrobiomeAnalyst and R v.4.2.1 software. These analyses will include various aspects, such as assessing α and β diversity, conducting abundance profiling, and performing clustering analysis.DiscussionLifestyle acts as a modifier of microbiota composition. However, there are no conclusive results demonstrating the mediating effect of the microbiota in the relationship between lifestyles and cardiovascular diseases. Understanding this relationship may facilitate the implementation of strategies for improving population health by modifying the gut and oral microbiota

Preparation and characterization of polymer composite materials based on PLA/TiO2 for antibacterial packaging

Polymer composite materials based on polylactic acid (PLA) filled with titanium dioxide (TiO2) nanoparticles were prepared. The aim of this work was to investigate the antibacterial action of TiO2 against a strain of E. coli (DH5) to obtain information on their potential uses in food and agro-alimentary industry. PLA/TiO2 systems were prepared by a two-step process: Solvent casting followed by a hot-pressing step. Characterization was done as a function of particle size (21 nm and <100 nm) and particle content (0%, 1%, 5%, 10%, and 20%, wt %). Structural characterization carried out by X-ray diffraction (XRD) and Fourier Transformed Infrared spectroscopy (FTIR) did not reveal significant changes in polymer structure due to the presence of TiO2 nanoparticles. Thermal characterization indicated that thermal transitions, measured by differential scanning calorimetry (DSC), did not vary, irrespective of size or content, whereas thermogravimetric analysis (TGA) revealed a slight increase in the temperature of degradation with particle content. Bacterial growth and biofilm formation on the surface of the composites against DH5 Escherichia coli was studied. Results suggested that the presence of TiO2 nanoparticles decreases the amount of extracellular polymeric substance (EPS) and limits bacterial growth