Can changes in deformation regimes be inferred from crystallographic preferred orientations in polar ice?

Creep due to ice flow is generally thought to be the main cause for the formation of crystallographic preferred orientations (CPOs) in polycrystalline anisotropic ice. However, linking the development of CPOs to the ice flow history requires a proper understanding of the ice aggregate's microstructural response to flow transitions. In this contribution the influence of ice deformation history on the CPO development is investigated by means of full-field numerical simulations at the microscale. We simulate the CPO evolution of polycrystalline ice under combinations of two consecutive deformation events up to high strain, using the code VPFFT (visco-plastic fast Fourier transform algorithm) within ELLE. A volume of ice is first deformed under coaxial boundary conditions, which results in a CPO. The sample is then subjected to different boundary conditions (coaxial or non-coaxial) in order to observe how the deformation regime switch impacts the CPO. The model results indicate that the second flow event tends to destroy the first, inherited fabric with a range of transitional fabrics. However, the transition is slow when crystallographic axes are critically oriented with respect to the second imposed regime. Therefore, interpretations of past deformation events from observed CPOs must be carried out with caution, particularly in areas with complex deformation histories

Continuous GPS stations deployment in the Topo-Iberia Project framework

Topo-Iberia es un proyecto financiado por el Ministerio de Educación y Ciencia de España. Su principal objetivo es comprender las interacciones entre los procesos profundos, superficiales y atmosféricos integrando datos geológicos, geofísicos y geodéticos. El proyecto se centrará en tres zonas principales de interés en la Península Ibérica: los bordes N y S de la Placa Ibérica (incluyendo el N de Marruecos) y su núcleo central intermedio. Presentamos las actividades preliminares realizadas por el subgrupo GPS de Topo-Iberia con el fin de desplegar una nueva red continua de GPS. La intención es complementar las redes CGPS continuas existentes (p.e. ROA; ERGPS) incrementado la cobertura espacial en España y N de Marruecos. Una vez seleccionados los emplazamientos de las nuevas estaciones, el objetivo es que se encuentren en pleno funcionamiento la primavera de 2008. Se han descargado conjuntos de datos CGPS de servidores de distintas instituciones sobre los que se ha realizado un procesado inicial que sirva como control de calidad. Como algunas de las estaciones actualmente disponibles no siguen los estrictos procedimientos de estabilidad dictados por IGS/EUREF, estamos evaluando sus resultados mediante análisis de series temporales para decidir cuales se pueden incluir como estaciones complementarias de la red Topo-Iberia.Topo-Iberia is a Spanish Research Council funded project. Its main objective is to understand the interactions between deep, shallow and atmospheric processes, integrating geological, geophysical, geodetic and geo-technological research activities. The project will focus in three main areas of interest in the Iberian Peninsula: Northern and Southern borders of the Iberian micro-plate (taking into account the Northern part of Morocco), and its central core. We present the preliminary steps that the Topo- Iberia GPS working group is undergoing in order to deploy a new Continuous GPS Network. We are trying to complement the existing and functioning CGPS Networks (e.g. ROA; ERGPS) by increasing the spatial coverage across Spain and Northern Morocco. The places for the new locations have been chosen and all stations should be working in the spring 2008. A set of available CGPS data files has been downloaded from different institutional servers. A preliminary data analysis has been performed for geodetic quality control. Since some of the existing CGPS stations have been installed without following strict IGS/EUREF procedures for the stability of the monuments, we are evaluating their performance through the time series analysis, in order to decide whether to include them as complementing stations to our network.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEMinisterio de Ciencia e Innovación (MICINN)CONSOLIDER TOPO-Iberiapu

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

Thin sheet numerical modelling of continental collision

We study the effects of incorporating surface mass transport and the gravitational potential energy of both crust and lithospheric mantle to the viscous thin sheet approach. Recent 2D (cross-section) numerical models show that surface erosion and sediment transport can play a major role in shaping the large-scale deformation of the crust. In order to study these effects in 3D (planform view), we develop a numerical model in which both the dynamics of lithospheric deformation and surface processes are fully coupled. Deformation is calculated as a thin viscous layer with a vertically-averaged rheology and subjected to plane stresses. The coupled system of equations for momentum and energy conservation is solved numerically. This model accounts for the isostatic and potential-energy effects due to crustal and lithospheric thickness variations. The results show that the variations of gravitational potential energy due to the lateral changes of the lithosphere–asthenosphere boundary can modify the mode of deformation of the lithosphere. Surface processes, incorporated to the model via a diffusive transport equation, rather than just passively reacting to changes in topography, play an active role in controlling the lateral variations of the effective viscosity and hence of the deformation of the lithosphere.This work is supported by the University College London, the Netherlands Research Centre for Integrated Solid Earth Science (ISES) and the Spanish Ministry research projects BTE2002-02462 and REN2001-3868-C03-02/MAR. The authors also benefited from NATO grant EST.CLG.978922.Peer reviewe

The lithospheric structure across the NW Moroccan margin: evidences for large scale tectonic inversion

International audienc