Accumulation of Mg to Diffusive Gradients in Thin Films (DGT) devices: Kinetic and thermodynamic effects of the ionic strength

Availability of magnesium is a matter of concern due to its role in many environmental and biological processes. Diffusive Gradients in Thin Films (DGT) devices can measure Mg availability in situ. This work shows that Mg accumulation in water largely increases when ionic strength (I) decreases. This phenomenon can be explained from (i) the increase of both the association equilibrium (K) and rate (ka,R) constants for the reaction between Mg cations and resin sites, and (ii) the growing contribution of the partitioning of Mg cations at the resin–gel interface, as I decreases. Two theoretical models that take into account electrical interactions among Mg cations, background electrolyte, and resin sites can successfully be used to determine ka,R and K at each I. Both models yield similar ka,R values, which fulfill an expression for the kinetic salt effect. For freshwater (with a typical salinity of 10 mM and circumneutral pH), the binding of Mg is so fast and strong that the simplest perfect-sink DGT expression can be helpful to predict (overestimation lower than 5%) the accumulation in solutions with Mg concentrations up to 1 mM whenever the deployment time is below 9 h. Perfect sink conditions can still be applied for longer times, in systems with either a lower I or a lower Mg concentration.Financial support from FEDER and the Spanish Ministry of Education and Science (Projects CTM2012-39183 and CTM2013-48967) is gratefully acknowledged

Acoustic detection of larval fish aggregations in Galician waters (NW Spain)

14 páginas, 3 tablas, 7 figurasAn acoustic study was conducted on the Galician shelf (NW Spain) during late winter 2012 to detect and assess larval fish abundance. An echo sounder operating with 18, 38, 70, 120 and 200 kHz split-beam, hull-mounted transducers was employed. We analysed the acoustic records in order to describe vertical and horizontal distribution patterns of larval fish aggregations. Regressions between acoustic backscattered energy and density of the most abundant species (Micromesistius poutassou) indicated that larvae with a swimbladder incremented notably the acoustic response at 38, 70 and 120 kHz. However, the predicted acoustic resonance at larval size and depth shows that the frequency of 120 kHz was likely ineffective in detecting fish larvae. The contribution of zooplankton (fish larvae excluded) to total scattering was negligible, even at the higher frequencies, except for several groups of fluid-like zooplankton, such as chaetognaths and polychaetes. Horizontal and vertical distributions of acoustic backscattering also indicated that larval fish aggregations can be detected in Galician waters with acoustics and suggest that this technique is a useful tool for overcoming difficulties associated with larval ecology and fish recruitment studiesVersión del editor2,483

Seminari d'Estudis i Recerques Prehistòriques (SERP). Núcleo de cohesión en formación e investigación en Prehistoria de la Universidad de Barcelona desde 1987

El artículo es un resumen amplio de todas las actividades científicas y académicas llevadas a cabo por el SERP (Seminari d'Estudis i Recerques Prehistòriques) desde su fundación en 1987 por parte del Dr. Fullola. Abarca desde programas de excavaciones a proyectos internacionales pasando por temas de Patrimonio arqueológico o de historiografía, entre muchos otros. Además del resumen de dichas actividades, se añade también una completa lista de publicaciones, la gran mayoría en revistas de impacto nacional e internacional. Se incide especialmente en siete líneas básicas de trabajo dentro del grupo, la arqueopetrología, la arqueozoología, el arte prehistórico, la geoarqueología, la paleobotánica, la tecnología, el patrimonio y los estudios territoriales. También se repasan todos y cada uno de los yacimientos objeto de excavación por parte del SERP en estos últimos tres decenios

Basement and cover architecture in the Central Pyrenees constrained by gravity data

A new gravity survey (1164 gravity stations and 180 samples for density analysis) combined with two new geological cross sections has been carried out in a sector of the Central Pyrenees in order to improve the characterization of basement and cover architecture. From North to South, the study area comprises the southern half of the Axial Zone and the northernmost part of the South-Pyrenean Zone. New gravity data were combined with previous existing databases to obtain the Bouguer and residual anomaly maps of the study area. The two cross sections, oriented NNE–SSW, were built from field data and previous surficial and subsurface data and cross the La Maladeta plutonic complex. The residual anomaly map shows values ranging from −18 to 16 mGal and anomalies mainly oriented N120E. The two 2.5D modelled cross sections show similar observed gravity curves coinciding with similar interpreted structural architecture. Data show a gravity high oriented N120E coinciding with the Orri basement thrust sheet and an important gravity depression, with the same orientation, coinciding with the leading edge at depth of the Rialp basement thrust sheet and interpreted as linked to a large subsurface accumulation of Triassic evaporites. The volume at depth of the La Maladeta and Arties granites has been constrained through gravity modelling. This work highlights that the combination of structural geology and gravity modelling can help to determine the structural architecture of an orogen and localize accumulations of evaporites at depth.This work is part of the project CGL2017-84901-C2-2-P funded by MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe” and project PID2020-114273GB-C22 funded by MCIN/AEI/10.13039/501100011033 from Spanish Ministry of Science, Innovation and Universities. Seequent has provided us the GM-SYS module of the Oasis Montaj. The authors acknowledge the contribution of José María Llorente and Agustin González for the acquisition of the gravity data. We thank to Aigüestortes National park and Alt Pirineu Natural park their logistic support. We thank anonymous reviewer for improving the content in the manuscript. This study represents a contribution to GeoAp Research Group (E01-20R) (Aragón Government).Peer reviewe

Seminari d’Estudis i Recerques Prehistòriques (SERP). Núcleo de cohesión en formación e investigación en Prehistoria de la Universitat de Barcelona desde 1987

info:eu-repo/semantics/publishedVersio

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

The Beaker phenomenon and the genomic transformation of northwest Europe

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries