57 research outputs found

    Fluvial-aeolian sedimentary facies, Sossusvlei, Namib Desert

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    Sedimentary facies exert a primary control on sandstone diagenesis and reservoir quality. The Namib Sand Sea with its Sossusvlei playa-lake is often considered as a modern analogue for sandstone reservoirs. Remote sensing in combination with ground observations allowed us to map the facies distribution pattern of associated fluvial and aeolian sediments. Laboratory spectral signature measurements were used to further improve the separability of six major facies: modern aeolian sand, bypass surface, mud pool/mud drapes, heavy mineral lag, aeolian reworked and fossil dune remnant. Using a supervised classification algorithm trained by field observations, a combination of Principal Component Analysis, band ratios, texture and geomorphologic indices has shown the best result. This made it possible to create a map outlining the facies distribution pattern of the Sossusvlei area at a scale of 1:10 000. We propose this as a possible workflow to efficiently map and monitor desert environments and to investigate the interplay of aeolian and fluvial sediments, including their linked implications on diagenesis. This could improve paleoclimate modelling and even allow facies mapping on other planets

    Geomorphologischer Atlas Sachsens: Geomorphologische Analyse tektonischer Einheiten in Sachsen

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    Diese Schriftenreihe präsentiert eine moderne tektonische Karte Sachsens. Die Ergebnisse dieses Projekts erlauben es, junge tektonische Hebungen und Senkungen von älteren Strukturen zu unterscheiden und die zeitliche Reihenfolge der Aktivität von Störungen abzuleiten. Die Veröffentlichung richtet sich sowohl an geologisch interessierte Laien ohne fachlichen Hintergrund als auch an ein Fachpublikum. Redaktionsschluss: 15.08.201

    3D-Modellierung des Tertiärs in der Lausitz: Tektonische und geomorphologische 3D-Modellierung der tertiären Einheiten der sächsischen Lausitz

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    In der Broschüre werden die Ergebnisse einer 3D-Modellierung tertiärer Einheiten der Nieder- und Oberlausitz zusammen mit einer geomorphologischen Analyse der Landoberfläche auf der Grundlage digitaler Höhenmodelle vorgestellt. Über diese Methoden konnten tertiäre und jüngere tektonische Bewegungen in der Lausitz indiziert werden. Die Broschüre richtet sich vor allem an Fachleute, die ein spezielles Interesse an 3D-Modellierungen geologischer Einheiten verbunden mit tektonischen Fragestellungen haben. Die geomorphologische Analyse zeigt anschaulich und nachvollziehbar auch interessierten Bürgern, welche modernen Methoden die tektonische Beurteilung einer Region ermöglichen

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Genomic investigations of unexplained acute hepatitis in children

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    Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Contraintes structurales et cinématiques sur une frontière de plaque récente: La limite nord du Bloc Sud Mexicain

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    The first part of this work defines the Plio-Quaternary boundaries and kinematics of the Southern Mexico Block (SMB), a microplate uncoupled from North America along the Trans-Mexican Volcanic Belt (TMVB). Structural data combined with analysis of satellite images and seismic profiles show that a major left-lateral strike-slip fault affects the Veracruz Basin and post-5 Ma volcanic rocks of the Los Tuxtlas Volcanic Field. Low seismicity associated to faulted Quaternary markers such as alluvial fans, alluvial terraces and volcanoes argue for active faulting in this area. Plio-Quaternary left-lateral strike-slip faulting along the Veracruz area is important because it connects two important structural provinces: the left-lateral transtensive faulting that affects the central part of the TMVB and the left-lateral Strike-Slip Faults Province of Chiapas to the south. These three active deformation zones accommodate a couterclockwise rotation of the SMB with respect to the North American plate. The model we propose predicts a Plio-Quaternary rotation of 0.45°/Ma with a pole located at 24.2°N and 91.8°W. The second part of this work deals with the tectonic evolution of central Mexico. Structural data and paleomagnetic results for Early Oligocene volcanic units of the Mesa Central are used to investigate the tectonic activity along the N130° trending Tepehuanes-Zimapán fault system (TZFS). In San Luis Potosí and Guanajuato areas structural data and paleomagnetic mean directions that indicate ~10° counterclockwise rotations argue for a left-lateral transtensive motion along the TZFS. The Oligocene intra-arc deformation is similar to the present one that affects the TMVB. This suggests that the SMB could be as old as Early Oligocene. During Late Oligocene and Miocene the boundaries of this crustal block probably migrate jointly with the volcanic arc to reach their present configuration.La première partie de ce travail s'attache à définir les frontières et la cinématique plio-quaternaire du Bloc Sud Mexcain (BSM), une microplaque tectonique découplée de l'Amérique du Nord au niveau de l'Axe Volcanique Trans-Mexicain (AVTM). L'analyse de profils sismiques, l'analyse d'images satellites ainsi que des observations de terrain montrent que le bassin de Veracruz et le volcanisme post-5Ma du Massif de Los Tuxtlas sont affectés par un grand décrochement sénestre. Cette faille est toujours active comme en témoignent la sismicité modérée ainsi que les marqueurs quaternaires (cônes, terrasses alluviales et volcanisme) affectés par la déformation. Le décrochement plio-quaternaire de la région de Veracruz est important car il établit la jonction entre le système transtensif senestre qui affecte l'AVTM et les décrochements également sénestres qui affectent la région des Chiapas au sud. Ces trois zones, sismiquement actives, accommodent une rotation antihoraire du BSM par rapport à l'Amérique du Nord. Le modèle cinématique proposé ici prédit une rotation du BSM par rapport à l'Amérique du Nord de 0.45°/Ma avec un pôle localisé à 24.2°N et 91.8°W. La seconde partie de ce travail se focalise sur l'évolution tectonique du Mexique central. Des données structurales ainsi qu'une étude paléomagnétique réalisée sur des unités volcaniques oligocènes permettent de mieux contraindre la cinématique des failles du système Tepehuanes-Zimapán (SFTZ), orienté N130°, à proximité des villes de San Luis Potosí et Guanajuato. Les données structurales collectées ainsi que les directions paléomagnétiques moyennes, indiquant des rotations antihoraires de ~10°, montrent que ce système était caractérisé par un mouvement transtensif sénestre. Cette déformation intra-arc oligocène est similaire à celle qui affecte l'AVTM actuel. Il est possible que le SFTZ ait constitué la limite nord du BSM durant l'Oligocène inférieur. Cette limite aurait migré en même temps que l'arc volcanique durant l'Oligocène supérieur et le Miocène pour atteindre sa position actuelle

    Contraintes structurales et cinématiques sur une frontière de plaque récente (la limite nord du Bloc Sud Mexicain)

    No full text
    La première partie de ce travail s attache à définir les frontières et la cinématique plio-quaternaire du Bloc Sud Mexcain (BSM), une microplaque tectonique découplée de l Amérique du Nord au niveau de l Axe Volcanique Trans-Mexicain (AVTM). L analyse de profils sismiques, l analyse d images satellites ainsi que des observations de terrain montrent que le bassin de Veracruz et le volcanisme post-5Ma du Massif de Los Tuxtlas sont affectés par un grand décrochement sénestre. Cette faille est toujours active comme en témoignent la sismicité modérée ainsi que les marqueurs quaternaires (co nes, terrasses alluviales et volcanisme) affectés par la déformation. Le décrochement plio-quaternaire de la région de Veracruz est important car il établit la jonction entre le système transtensif senestre qui affecte l AVTM et les décrochements également sénestres qui affectent la région des Chiapas au sud. Ces trois zones, sismiquement actives, accommodent une rotation antihoraire du BSM par rapport à l Amérique du Nord. Le modèle cinématique proposé ici prédit une rotation du BSM par rapport à l Amérique du Nord de 0.45/Ma avec un pôle localisé à 24.2N et 91.8W. La seconde partie de ce travail se focalise sur l évolution tectonique du Mexique central. Des données structurales ainsi qu une étude paléomagnétique réalisée sur des unités volcaniques oligocènes permettent de mieux contraindre la cinématique des failles du système Tepehuanes-Zimapán (SFTZ), orienté N130, à proximité des villes de San Luis Potosí et Guanajuato. Les données structurales collectées ainsi que les directions paléomagnétiques moyennes, indiquant des rotations antihoraires comprises entre 9.9+-10.7 et 6.4+-8.7, montrent que ce système était caractérisé par un mouvement transtensif sénestre. Cette déformation intra-arc oligocène est similaire à celle qui affecte l AVTM actuel. Il est possible que le SFTZ ait constitué la limite nord du BSM durant l Oligocène inférieur. Cette limite aurait migré en même temps que l arc volcanique durant l Oligocène supérieur et le Miocène pour atteindre sa position actuelle.AIX-MARSEILLE3-BU Sc.St Jérô (130552102) / SudocSudocFranceF

    RawMatCop: Developing Skills at the intersection between Earth observation and the raw materials community

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    The RawMatCop programme was launched in 2017 and aims to develop skills, expertise, demonstrations, and applications of Copernicus data to the raw materials sector. It is co-funded by the European Commission (DG for Internal Market, Industry, Entrepreneurship and SMEs) and the EIT RawMaterials (RawMaterials Academy). Raw materials have become increasingly important to the European Union's economy, growth, and competitiveness. In this context, the EU aims to facilitate the exchange of best practices among its member states to improve the sustainable and safe supply of raw materials to the EU economy and society. Thus, monitoring of mining activities and environmental impact of waste and residue management are key issues of that strategy. With state-of-the-art spaceborne imagery, Copernicus has a strong potential in contributing to EU’s requirements and expectations. The aim of RawMatCop is to illustrate the usefulness of Copernicus data through three 'Research & Application Areas’ relevant for the raw materials sector: (1) multi-scale and multi-source exploration, (2) spatiotemporal mapping of dust dispersion around mining sites, (3) monitoring of surface/subsurface deformation. Multispectral data proves to be an incredible tool for regional scale mapping of surface alterations associated to mineralization or mining activities. One clear advantage of Sentinel-2 data over other sensors is that it has a good coverage of the visible and near infrared portion of the electromagnetic spectrum, which makes it an ideal tool for mapping iron-oxides. The current activities of RawMatCop include mapping alterations and iron features associated to Volcanic Hosted Massive Sulfides (Iberian Pyrite Belt, Spain) as well as mapping the weathering of lateritic profiles and iron-oxide associated to active mining in New Caledonia. For this purpose, several workflows based on downscaling from satellite-based to in-situ observations are being tested. Furthermore, RawMatCorp is also contributing to the consistency assessment of popular atmospheric correction approaches used for Sentinel-2 processing (iCOR, Sen2Cor, MAJA) and the influence of the mining setting on their performance. Moreover, ground deformation is one of the most important hazards related to mining activities, and RawMatCorp is also addressing this topic through monitoring the Riotinto mine (SW Spain). This monitoring utilizes SAR and passive seismic techniques to develop a joint Early Warning System aiming to reduce risks on ground mechanical integrity.RAWMatCop - minEOdus

    Geomorphologischer Atlas Sachsens: Geomorphologische Analyse tektonischer Einheiten in Sachsen

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    Diese Schriftenreihe präsentiert eine moderne tektonische Karte Sachsens. Die Ergebnisse dieses Projekts erlauben es, junge tektonische Hebungen und Senkungen von älteren Strukturen zu unterscheiden und die zeitliche Reihenfolge der Aktivität von Störungen abzuleiten. Die Veröffentlichung richtet sich sowohl an geologisch interessierte Laien ohne fachlichen Hintergrund als auch an ein Fachpublikum. Redaktionsschluss: 15.08.201
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