Topo-Iberia Project: CGPS crustal velocity field in the Iberian Peninsula and Morocco

A new continuous GPS network was installed under the umbrella of a research project called 'Geociencias en Iberia: Estudios integrados de topografı´a y evolución 4D (Topo-Iberia)', to improve understanding of kinematic behavior of the Iberian Peninsula region. Here we present a velocity field based on the analysis of the 4 years of data from 25 stations constituting the network, which were analyzed by three different analysis groups contributing to the project. Different geodetic software packages (GIPSY-OASIS, Bernese and GAMIT) as well as different approaches were used to estimate rates of present day crustal deformation in the Iberian Peninsula and Morocco. In order to ensure the consistency of the velocity fields determined by the three groups, the velocities obtained by each analysis center were transformed into a common Eurasia Reference Frame. After that, the strain rate field was calculated. The results put in evidence more prominent residual motions in Morocco and southernmost part of the Iberian Peninsula. In particular, the dilatation and shear strain rates reach their maximum values in the Central Betics and northern Alboran Sea. A small region of high shear strain rate is observed in the east-central part of the peninsula and another deformation focus is located around the Strait of Gibraltar and the Gulf of Cadiz

Estructura y evolución tectónica del sector oriental del margen continental cantábrico: resultados de los perfiles de sísmica multicanal MARCONI

El Golfo de Vizcaya se formó durante el Cretácico como consecuencia de la apertura del Océano Atlántico. La convergencia entre las placas Euroasiática e Ibérica durante el Cenozoico dio lugar al levantamiento de la cordillera pirenaico-cantábrica y al cierre parcial del Golfo de Vizcaya. La mayor parte de esta deformación tiene lugar en el margen Noribérico, haciendo de este área un lugar único para estudiar los estadios iniciales de la deformación de un margen pasivo. En el verano de 2003, el experimento sísmico MARCONI permitió adquirir 11 perfiles de sísmica de reflexión vertical profunda utilizando el buque Hespérides, lo que ha proporcionado una nueva imagen 3D de la estructura cortical del sector SE del Golfo de Vizcaya. Los datos muestran que la estructura de este margen se caracteriza por una espesa secuencia de sedimentos meso-cenozoicos (hasta 4 s TWT, hasta > 6 km) parcialmente deformada por cabalgamiento y pliegues asociados, vergentes al N. Se han diferenciado tres conjuntos sedimentarios separados por discordancias que se corresponden con las secuencias alpinas pre-, sin- y postectónicas. Los datos sísmicos muestran también la existencia de cuencas mesozoicas con evidencias de inversión tectónica y la existencia de fallas y estructuras laterales coincidiendo con los importantes cañones submarinos de dirección aproximada N-S. Teniendo tambien en cuenta otros datos geofísicos, la estructura general del sector SE del Golfo de Vizcaya se ha interpretado como una corteza continental adelgazada o transicional deslizada hacia el S por debajo del extremadamente abrupto y muy deformado talud continental Noribérico

Coexistence of ferromagnetism and spin glass state in YbNi2 nanoparticles

We report changes on the magnetic behavior of the Heavy-Fermion ferromagnetic YbNi2 alloy when reducing the size of the particles to the nanometer scale by high-energy ball milling. The milling process induces a reduction on the particle size of the bulk alloy down to 10 (2) nm and a lattice strain of 1.8 (2)%, for 30 h of milling time, as calculated from the X-ray diffraction data. The ferromagnetic transition at TC = 10.5 K in the bulk alloy tends to disappear whereas other magnetic transitions arise at lower temperatures with the milling process. The AC magnetic susceptibility of the 30 h milled sample shows a frequency independent peak at 3 K, in a wide range of frequencies, consistent neither with superparamagnetic nor simple freezing of the magnetic moments, and as expected for a ferromagnetic behavior. However, from the specific heat measurements in the 30 h milled sample, a peak at 3.6 K is shifted respect to that observed in the AC magnetic susceptibility, as found in spin glasses. The results are explained by the influence of magnetic inhomogeneities and disorder of the alloys enhanced by the milling process in the ensemble of nanoparticles

Stromal DLK1 promotes proliferation and inhibits differentiation of the intestinal epithelium during development

First published January 20, 2021BACKGROUND & AIMS: The stem/progenitor cells of the developing intestine arebiologically distinct from their adult counterparts. Here we examine the microenvironmental cues that regulate the embryonic stem/progenitor population, focusing on the role of Notch pathway factor, Delta-Like Protein 1 (DLK1). METHODS: mRNAseq analyses of intestinal mesenchymal cells (IMC) collected from embryonic day 14.5 (E14.5) or adult IMCs and a novel co-culture system with E14.5 intestinal epithelial organoids were used. Following addition of recombinant DLK1 (rDLK) or Dlk1 siRNA (siDlk1), epithelial characteristics were compared using imaging, replating efficiency assays, qPCR and immunocytochemistry. The intestinal phenotype of littermate Dlk1 +/+ and Dlk1 -/- mice was compared using immunohistochemistry. RESULTS: Using transcriptomic analyses we identified morphogens derived from the embryonic mesenchyme that potentially regulate the developing epithelial cells, to focus on Notch family candidate, DLK1. Immunohistochemistry indicated that DLK1 was expressed exclusively in the intestinal stroma at E14.5 at the top of emerging villi, decreased after birth and shifted to the intestinal epithelium in adulthood. In co-culture experiments, addition of rDLK1 to adult IMCs inhibited organoid differentiation, whereas Dlk1 knock-down in embryonic IMCs increased epithelial differentiation to secretory lineage cells. Dlk1 -/- mice had restricted Ki67+ cells in the villi base and increased secretory lineage cells compared with Dlk1 +/+ embryos. CONCLUSIONS: Mesenchyme-derived DLK1 plays an important role in the promotion of epithelial stem/precursor expansion and prevention of differentiation to secretory lineages in the developing intestine.Mari Ichinose, Nobumi Suzuki, Tongtong Wang, Josephine A. Wright, Tamsin R. M. Lannagan, Laura Vrbanac ... et al

Topo-Iberia project: CGPS crustal velocity field in the Iberian Peninsula and Morocco

A new continuous GPS network was installed under the umbrella of a research project called "Geociencias en Iberia: Estudios integrados de topografía y evolución 4D (Topo-Iberia)", to improve understanding of kinematic behavior of the Iberian Peninsula region. Here we present a velocity field based on the analysis of the 4 years of data from 25 stations constituting the network, which were analyzed by three different analysis groups contributing to the project. Different geodetic software packages (GIPSY-OASIS, Bernese and GAMIT) as well as different approaches were used to estimate rates of present day crustal deformation in the Iberian Peninsula and Morocco. In order to ensure the consistency of the velocity fields determined by the three groups, the velocities obtained by each analysis center were transformed into a common Eurasia Reference Frame. After that, the strain rate field was calculated. The results put in evidence more prominent residual motions in Morocco and southernmost part of the Iberian Peninsula. In particular, the dilatation and shear strain rates reach their maximum values in the Central Betics and northern Alboran Sea. A small region of high shear strain rate is observed in the east-central part of the peninsula and another deformation focus is located around the Strait of Gibraltar and the Gulf of Cadiz

Geomorphology of the Avilés Canyon System, Cantabrian Sea (Bay of Biscay)

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