34 research outputs found

    Heritage Stone 6. Gneiss for the Pharaoh: Geology of the Third Millennium BCE Chephren's Quarries in Southern Egypt

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    A remarkable campaign of decorative stone quarrying took place in the southwestern Egyptian desert almost 5000 years ago. The target for quarrying was Precambrian plagioclase−hornblende gneiss, from which several life-sized statues of King Chephren (or Khafra) and thousands of funerary vessels were produced. The former inspired George Murray in 1939 to name the ancient quarry site 'Chephren's Quarries.' Almost 700 individual extraction pits are found in the area, in which free-standing boulders formed by spheroidal weathering were worked by stone tools made from local rocks and fashioned into rough-outs for the production of vessels and statues. These were transported over large distances across Egypt to Nile Valley workshops for finishing. Although some of these workshop locations remain unknown, there is evidence to suggest that, during the Predynastic to Early Dynastic period, the permanent settlement at Hierakonpolis (Upper Egypt) could have been one destination, and during the Old Kingdom, another may have been located at pyramid construction sites such as the Giza Plateau (Lower Egypt). Chephren's Quarries remains one of the earliest examples of how the combined aesthetic appearance and supreme technical quality of a rock made humans go to extreme efforts to obtain and transport this raw material on an ‘industrial’ scale from a remote source. The quarries were abandoned about 4500 years ago, leaving a rare and well-preserved insight into ancient stone quarrying technologies. RÉSUMÉUne remarquable campagne d’extraction de pierres dĂ©corative a Ă©tĂ© menĂ© dans le sud-ouest du dĂ©sert Ă©gyptien il y a prĂšs de 5000 ans. La roche cible Ă©tait un gneiss Ă  plagioclase–hornblende, de laquelle ont Ă©tĂ© tirĂ© plusieurs statues grandeur nature du roi KhĂ©phren (ou KhĂąef RĂȘ) et des milliers de vases funĂ©raires. C’est pourquoi George Murray, en 1939, a donnĂ© au site de l’ancienne carriĂšre le nom de 'Chephren’s Quarries.' On peut trouver prĂšs de 700 fosses d’extraction sur le site, renfermant des blocs de roches formĂ©s par altĂ©ration sphĂ©roĂŻdale qui ont Ă©tĂ© dĂ©grossis avec des outils de pierre pour la production de vases et de statues. Puis ils ont Ă©tĂ© transportĂ©s Ă  travers l’Égypte jusqu’aux ateliers de finition de la vallĂ©e du Nil. Bien que la localisation de certains de ces ateliers demeure inconnue, certains indices permettent de penser que, de la pĂ©riode prĂ©dynastique jusqu’à la pĂ©riode dynastique prĂ©coce, l’établissement permanent Ă  HiĂ©rakonpolis (Haute Égypte) aurait pu ĂȘtre l’une de ces destinations; durant l’Ancien empire une autre destination aurait pu ĂȘtre situĂ©e aux sites de construction de pyramides comme le Plateau de Giza (Basse Égypte). Les Chephren’s Quarries l’une des plus anciennes exemples montrant comment la combinaison des qualitĂ©s esthĂ©tiques et techniques remarquables de la roche ont incitĂ© les humains Ă  consentir de si grands efforts pour extraire et transporter ce matĂ©riau brute Ă  une Ă©chelle industrielle d’un site Ă©loignĂ©. Les carriĂšres ont Ă©tĂ© abandonnĂ©es il y a environ 4500 ans, nous laissant une fenĂȘtre rare et bien conservĂ© sur des technologies anciennes d’extraction de pierre de taille.Traduit par le Traducteu

    Systemic inflammation early after kidney transplantation is associated with long-term graft loss: a cohort study

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    Background: Early graft loss following kidney transplantation is mainly a result of acute rejection or surgical complications, while long-term kidney allograft loss is more complex. We examined the association between systemic inflammation early after kidney transplantation and long-term graft loss, as well as correlations between systemic inflammation scores and inflammatory findings in biopsies 6 weeks and 1 year after kidney transplantation. Methods: We measured 21 inflammatory biomarkers 10 weeks after transplantation in 699 patients who were transplanted between 2009 and 2012 at Oslo University Hospital, Rikshospitalet, Norway. Low-grade inflammation was assessed with predefined inflammation scores based on specific biomarkers: one overall inflammation score and five pathway-specific scores. Surveillance or indication biopsies were performed in all patients 6 weeks after transplantation. The scores were tested in Cox regression models. Results: Median follow-up time was 9.1 years (interquartile range 7.6-10.7 years). During the study period, there were 84 (12.2%) death-censored graft losses. The overall inflammation score was associated with long-term kidney graft loss both when assessed as a continuous variable (hazard ratio 1.03, 95% CI 1.01-1.06, P = 0.005) and as a categorical variable (4th quartile: hazard ratio 3.19, 95% CI 1.43-7.10, P = 0.005). In the pathway-specific analyses, fibrogenesis activity and vascular inflammation stood out. The vascular inflammation score was associated with inflammation in biopsies 6 weeks and 1 year after transplantation, while the fibrinogenesis score was associated with interstitial fibrosis and tubular atrophy. Conclusion: In conclusion, a systemic inflammatory environment early after kidney transplantation was associated with biopsy-confirmed kidney graft pathology and long-term kidney graft loss. The systemic vascular inflammation score correlated with inflammatory findings in biopsies 6 weeks and 1 year after transplantation

    GeoERA raw materials to support Europe’s resilience on raw materials

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    Europe’s vision to be a climate neutral economy by 2050 has ushered in the energy transition. Carbon-neutral energy supply is based on raw materials from which energy-critical elements for rechargeable batteries like cobalt, graphite, lithium and rare earth elements can be purified. In addition to direct energy generation, other future-oriented, environmentally friendly key technologies needed for digitisation and mobility can only be engineered by using raw materials (European Commission 2019).info:eu-repo/semantics/publishedVersio

    Mass-Balance-Consistent Geological Stock Accounting: a New Approach toward Sustainable Management of Mineral Resources

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    Global resource extraction raises concerns about environmental pressures and the security of mineral supply. Strategies to address these concerns depend on robust information on natural resource endowments, and on suitable methods to monitor and model their changes over time. However, current mineral resources and reserves reporting and accounting workflows are poorly suited for addressing mineral depletion or answering questions about the long-term sustainable supply. Our integrative review finds that the lack of a robust theoretical concept and framework for mass-balance (MB)-consistent geological stock accounting hinders systematic industry-government data integration, resource governance, and strategy development. We evaluate the existing literature on geological stock accounting, identify shortcomings of current monitoring of mine production, and outline a conceptual framework for MB-consistent system integration based on material flow analysis (MFA). Our synthesis shows that recent developments in Earth observation, geoinformation management, and sustainability reporting act as catalysts that make MB-consistent geological stock accounting increasingly feasible. We propose first steps for its implementation and anticipate that our perspective as “resource realists” will facilitate the integration of geological and anthropogenic material systems, help secure future mineral supply, and support the global sustainability transition

    GeoERA Raw Materials Monograph : the past and the future

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    ABSTRACT: GeoERA Minerals projects have produced data aimed at supporting Europe’s minerals sector and to assist the European Commission to realise its goals for raw materials. Data has been compiled on mineral occurrences and mineral provinces across Europe, in particular, areas with potential to host Critical Raw Materials. Anecdotal evidence from the minerals sector provides an indication of the likelihood of exploration leading to mine development. For every 1,000 mineral showings examined, only 100 may receive further exploration work and of those 100, only 10 may warrant more detailed sampling either through trenching, drilling or other means and of those 10 only 1 may proceed to an evaluation through a full feasibility study which itself has only 50% chance of being positive. Following this, any project for which a mine proposal is made must undergo a full evaluation and permitting by authorities including full public consultation. The proposal may or may not pass this scrutiny. In terms of a schedule, the generally accepted minimum time frame from discovery to production is 10 years and usually much more, up to 20 years.info:eu-repo/semantics/publishedVersio

    Reconstructing a Medieval Underground Soapstone Quarry: Bakkaunet in Trondheim in an International Perspective

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    Underground medieval quarries are rare, in Norway and elsewhere in Europe. Thus the question: Could a big underground soapstone quarry have been opened at Bakkaunet in Trondheim (central Norway) in the Middle Ages? This question of stone procurement for Nidaros Cathedral – which is Europe’s northernmost medieval cathedral and a building heavily influenced by English traditions and fashions – has bothered us for the last 20 years. In this paper we discuss what we think the quarrymen did. It is a biography of the now almost lost Bakkaunet quarry, with a focus on the question about underground operations. But the paper also discusses stone procurement for Nidaros Cathedral in view of contemporary international, especially English, trends. The story is sad, for the open-cast part of this once great quarry, very close to the centre of Trondheim, has been successively destroyed by modern house building over the last century

    The Building Stones from the Vanished Medieval Church at Onarheim, Tysnes, Hordaland County in Western Norway: Provenancing Chlorite Schist and Soapstone

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    This study centres on the provenance of soapstone and chlorite schist building stones at Onarheim church, 50 km south of Bergen and also provides geochemical results that are of key interest in further studies of Norwegian chlorite schist bakestone. The present Onarheim church is made from wood but building stones from previous stone churches at the site (12th century and early 19th century) are found in Foundation walls and the walls surrounding the churchyard. Geochemical analyses (main and trace elements, Sr-Nd isotope composition and rare earth profiles) from such stones were compared with results from similar analyses from a variety of quarries, including reference quarries in Rogaland and TrÞndelag (chlorite schist). Unsurprisingly, the nearest soapstone quarry (Baldersheim) and the regional source of chlorite schist (Ølve-Hatlestrand) gave the best matches. However, the results also indicate two additional sources of soapstone, one of them is the distant Arnafjord quarry. This may represent an input of soapstone for postmedieval restoration and/or early 19th century construction works. A very important result of the study was that Sr-Nd isotope ratios distinguish between the known medieval chlorite schist quarries in Norway and different quarries at Ølve-Hatlestrand. Bakestone made from chlorite schist is found all over Norway and the opportunity to fingerprint their origin may aid in future interpretation of medieval trade patterns

    Pair Lecturing to Enhance Reflective Practice and Teacher Development

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    Abstract—Pair lecturing enables a more thorough reflection-onaction since the teaching experience is shared with a pair teacher. It also enables deeper reflection-in-action, incorporating student interaction into the lecture plan while keeping the assessment methods and the teaching activities aligned with the course objectives. And in our setup it comes for free. Index Terms—Pair lecturing, team teaching, reflective practice, reflection-in-action, constructive alignment, teacher development I I
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