Search

International audience; The modern relief of southern Africa is characterized by high-standing plateaus surrounded by escarpments and dissected by a network of encased valleys that connect the plateaus to coastal plains. This topography is commonly interpreted as resulting from the activity of a mantle plume, the African superplume, and the resulting stepwise uplift of the lithosphere, generating planation surfaces through surface erosion processes since the Mesozoic. However, in this study, we argue that part of this landscape is inherited from the glacial processes of the Late Paleozoic Icehouse (LPI) that occurred 300 ma ago and during which southern Africa was largely covered in thick ice. Field and GIS-based sedimentological and geomorphological studies however revealed that LPI glacial activity tied to the Late Paleozoic Icehouse, that occurred 300 million years ago and during which southern Africa was largely covered in thick ice, greatly contributed to the shaping of the Earth surface at different spatial scales. Glaciers levelled continental-scale planation surface, carved large valleys, fjords and overdeepenings within topographic escarpments that already existed, ploughed grooves and striae on the bedrock and left behind typical sediments such as moraines, tills and ice-contact deltas. After glacial retreat, the sea invaded these glacial reliefs, as attested by preserved paleoshorelines. In postglacial times and for 120-180 million years, these glacial landforms were progressively filled and eventually sealed under thick non-glacial sedimentary accumulation and was later rejuvenated by erosion tied to the activity of the mantle superplume. Today, large portions of the desertic high-standing plateaus, escarpments and networks of valleys defining the relief of southern Africa actually corresponds to a relict though rejuvenated 300-Ma old glacial landscape.

The ca. 2.97 to 2.80 Ga Witwatersrand Supergroup, South Africa, represents the oldest intracontinental sedimentary basin of the Kaapvaal craton. Two volcanic units occur in this supergroup: the widespread Crown Formation lavas in the marine shale-dominated West Rand Group and the more geographically restricted Bird Member lavas, intercalated with fluvial to fluvio-deltaic sandstone and conglomerate of the Central Rand Group. These units remain poorly studied as they are rarely exposed and generally deeply weathered when cropping out. We report whole-rock major and trace elements, Hf and Nd-isotope whole-rock analyses of the lavas from core samples drilled in the south of the Witwatersrand basin and underground samples from the Evander Goldfield in the northeast. In the studied areas, both the Crown Formation and Bird Member are composed of two units of lava separated by sandstone. Whereas all the Crown Formation samples show a similar geochemical composition, the upper and lower volcanic units of the Bird Member present clear differences. However, the primitive mantle-normalized incompatible trace element concentrations of all Crown Formation and Bird Member samples show variously enriched patterns and marked negative Nb and Ta anomalies relative to Th and La. Despite the convergent geodynamic setting of the Witwatersrand Supergroup suggested by the literature, the Crown Formation and Bird Member are probably not related to subduction-related magmatism but more to decompression melting. Overall, the combined trace element and Sm-Nd isotopic data indicate melts from slightly to moderately depleted sources that were variably contaminated with crustal material. Greater contamination, followed by differentiation in different magma chambers, can explain the difference between the two signatures of the Bird Member. Finally, despite previous proposals for stratigraphically correlating the Witwatersrand Supergroup to the Mozaan Group of the Pongola Supergroup, their volcanic units are overall geochemically distinct.

Archaean zircons from the Kaapvaal Craton, South Africa, were analyzed by Laser Ablation (LA)-ICP-MS to obtain a coupled record of U-Th-Pb isotope ratios and selected trace elements with the aim to develop insights into physico-chemical conditions during igneous zircon crystallization and subsequent compositional alteration. Four rock samples previously dated by SIMS U-Pb using zircon were selected: 3.56 Ga Ngwane Gneiss, 3.55 Ga Theespruit felsic metavolcanic, 3.50 Ga Steynsdorp Gneiss and 2.98 Ga Nhlangano Gneiss. LA-ICP-MS U-Pb zircon ages agree with published SIMS U-Pb ages within analytical uncertainty. Assessment of the magmatic crystallization histories was based on near-concordant grains, and discordant grains were used to examine post-igneous element mobilization and alteration. Time-resolved laser drilling experiments allowed distinction of concordant and discordant zircon domains, but also revealed systematic changes in REE + Ti geochemistry, U + Th content, discordance and metamictization. Th/U and Zr/Hf, coupled with REE patterns, effectively distinguish compositional zircon types that reflect variable degrees of igneous differentiation and melt compositions. Eu/Eu* values indicate significant feldspar fractionation in some magmas. Averaged crystallization temperatures of magmatic zircons, as derived from the Ti-in-zircon thermometer, define a narrow range of 650 to 750°C for (near-)concordant grains, consistent with general constraints on temperatures at zircon saturation for felsic magmas, and testifying to a closed-system behavior of Ti (and other trace elements). Systematic deviations from primary igneous trace element signatures are strongly correlated with radiation damage. Specifically, Th/U and, to some extent, Zr/Hf decrease, and Ti increases with increasing U (+Th) content and isotopic disturbance (discordance).

Archaean supracrustal rocks carry a record of mass-independently fractionated S that is interpreted to be derived from UV-induced photochemical reactions in an oxygen-deficient atmosphere. Experiments with photochemical reactions of SO2 gas have provided some insight into these processes. However, reconciling experimental results with the multiple S isotopic composition of the Archaean sedimentary record has proven difficult and represents one of the outstanding issues in understanding the Archaean surface S-cycle. We present quadruple S isotope data (32S, 33S, 34S, 36S) for pyrite from Mesoarchaean carbonaceous sediments of the Dominion Group, South Africa, deposited in an acidic volcanic lake, which help reconcile observations from the Archaean sedimentary record with the results of photochemical experiments. The data, which show low S/S ratios (mostly ≪ 1) and very negative S/S ratios (−4 and lower), contrast with the composition of most Archaean sedimentary sulfides and sulfates, having S/ (the so-called ‘Archaean reference array’), but match those of modern photochemical sulfate aerosols produced in the stratosphere, following super-large volcanic eruptions, and preserved in Antarctic ice. These data are also consistent with the results of UV-irradiation experiments of SO2 gas at variable gas pressure. The S isotope composition of the Dominion Group pyrite is here interpreted to reflect the products of photolysis in a low-oxygen-level atmosphere at high SO2 pressure during large volcanic eruptions, mixed with Archaean ‘background’ (having a composition broadly similar to the Archaean reference array) S pools. It is inferred that high sedimentation rates in a terrestrial basin resulted in an instantaneously trapped input of atmospheric S during short-lasted depositional intervals, which faithfully represents transient photochemical signals in comparison with marine sedimentary records.

International audience; Constraining the timing of eukaryogenesis and the divergence of eukaryotic clades is a major challenge in evolutionary biology. Here, we present trace metal concentration and zinc isotope data for c. 2.1 billion-year-old Francevillian Group pyritized structures, previously described as putative remnants of the first colonial multicellular organisms, and their host black shales. Relative to the host rocks, pyritized structures are strongly enriched in zinc, cobalt and nickel, by at least one order of magnitude, with markedly lighter zinc isotope compositions. A metabolic demand for high concentrations of aqueous zinc, cobalt, and nickel combined with preferential uptake of lighter zinc isotopes may indicate metalloenzyme utilization by eukaryotes in marine habitats c. 2.1 billion years ago. Once confirmed, this would provide a critical calibration point for eukaryogenesis, suggesting that this major evolutionary innovation may have happened contemporaneously with elevated atmospheric oxygen levels during the latter part of the Great Oxidation Event, some 400 million years earlier than is currently widely accepted.

The evolution of the global carbon and silicon cycles is thought to have contributed to the long-term stability of Earth's climate1-3. Many questions remain, however, regarding the feedback mechanisms at play, and there are limited quantitative constraints on the sources and sinks of these elements in Earth's surface environments4-12. Here we argue that the lithium-isotope record can be used to track the processes controlling the long-term carbon and silicon cycles. By analysing more than 600 shallow-water marine carbonate samples from more than 100 stratigraphic units, we construct a new carbonate-based lithium-isotope record spanning the past 3 billion years. The data suggest an increase in the carbonate lithium-isotope values over time, which we propose was driven by long-term changes in the lithium-isotopic conditions of sea water, rather than by changes in the sedimentary alterations of older samples. Using a mass-balance modelling approach, we propose that the observed trend in lithium-isotope values reflects a transition from Precambrian carbon and silicon cycles to those characteristic of the modern. We speculate that this transition was linked to a gradual shift to a biologically controlled marine silicon cycle and the evolutionary radiation of land plants13,14.

Patient blood management (PBM) offers significantly improved outcomes for almost all medical and surgical patient populations, pregnant women, and individuals with micronutrient deficiencies, anemia, or bleeding. It holds enormous financial benefits for hospitals and payers, improves performance of health care providers, and supports public authorities to improve population health. Despite this extraordinary combination of benefits, PBM has hardly been noticed in the world of health care. In response, the World Health Organization (WHO) called for its 194 member states, in its recent Policy Brief, to act quickly and decidedly to adopt national PBM policies. To further support the WHO's call to action, this article addresses 3 aspects in more detail. The first is the urgency from a health economic perspective. For many years, growth in health care spending has outpaced overall economic growth, particularly in aging societies. Due to competing economic needs, the continuation of disproportionate growth in health care spending is unsustainable. Therefore, the imperative for health care leaders and policy makers is not only to curb the current spending rate relative to the gross domestic product (GDP) but also to simultaneously improve productivity, quality, safety of patient care, and the health status of populations. Second, while PBM meets these requirements on an exceptional scale, uptake remains slow. Thus, it is vital to identify and understand the impediments to broad implementation. This includes systemic challenges such as the so-called "waste domains" of failure of care delivery caused by malfunctions of health care systems, failure of care coordination, overtreatment, and low-value care. Other impediments more specific to PBM are the misperception of PBM and deeply rooted cultural patterns. Third, understanding how the 3Es-evidence, economics, and ethics-can effectively be used to motivate relevant stakeholders to take on their respective roles and responsibilities and follow the urgent call to implement PBM as a standard of care.

The later stages of Earth’s transition to a permanently oxygenated atmosphere during the Great Oxidation Event (GOE; ∼2.43–2.06 Ga) is commonly linked with the suggestion of an “oxygen overshoot” during the ∼2.22–2.06 Ga Lomagundi Event (LE), which represents Earth’s most pronounced and longest-lived positive carbon isotope excursion. However, the magnitude and extent of atmosphere-ocean oxygenation and implications for the biosphere during this critical period in Earth’s history remain poorly constrained. Here, we present nitrogen (N), selenium (Se), and carbon (C) isotope data, as well as bio-essential element concentrations, for Paleoproterozoic marine shales deposited during the LE. The data provide evidence for a highly productive and well-oxygenated photic zone, with both inner and outer-shelf marine environments characterized by nitrate-and Se oxyanion-replete conditions. However, the redoxcline subsequently encroached back onto the inner shelf during global-scale deoxygenation of the atmosphere-ocean system at the end of the LE, leading to locally enhanced water column denitrification and quantitative reduction of selenium oxyanions. We propose that nitrate-replete conditions associated with fully oxygenated continental shelf settings were a common feature during the LE, but nitrification was not sufficiently widespread for the aerobic nitrogen cycle to impact the isotopic composition of the global ocean N inventory. Placed in the context of Earth’s broader oxygenation history, our findings indicate that O2levels in the atmosphere-ocean system were likely much lower than modern concentrations. Early Paleoproterozoic biogeochemical cycles were thus far less advanced than after Neoproterozoic oxygenation., University of Tubingen, German Research Foundation (DFG) SCHO1071/11-1 VA 1568/1-1, UK Research & Innovation (UKRI), Natural Environment Research Council (NERC) NE/V004824/1, University of Lausanne, European Research Council (ERC) 636808, National Research Foundation of South Africa (NRF Grant) 75892, Spanish Government RYC2020-030014-I, Natural Sciences and Engineering Research Council of Canada (NSERC), ACS PF grant 624840ND2, NERC Frontiers grant NE/V010824/1, Royal Society of London

Massive perioperative allogeneic blood transfusion, that is, perioperative transfusion of more than 10 units of packed red blood cells (pRBC), is one of the main contributors to perioperative morbidity and mortality in cardiac surgery. Prediction of perioperative blood transfusion might enable preemptive treatment strategies to reduce risk and improve patient outcomes while reducing resource utilisation. We, therefore, investigated the precision of five different machine learning algorithms to predict the occurrence of massive perioperative allogeneic blood transfusion in cardiac surgery at our centre.Is it possible to predict massive perioperative allogeneic blood transfusion using machine learning?Retrospective, observational study.Single adult cardiac surgery centre in Austria between 01 January 2010 and 31 December 2019.Patients undergoing cardiac surgery.Primary outcome measures were the number of patients receiving at least 10 units pRBC, the area under the curve for the receiver operating characteristics curve, the F1 score, and the negative-predictive (NPV) and positive-predictive values (PPV) of the five machine learning algorithms used to predict massive perioperative allogeneic blood transfusion.A total of 3782 (1124 female:) patients were enrolled and 139 received at least 10 pRBC units. Using all features available at hospital admission, massive perioperative allogeneic blood transfusion could be excluded rather accurately. The best area under the curve was achieved by Random Forests: 0.810 (0.76 to 0.86) with high NPV of 0.99). This was still true using only the eight most important features [area under the curve 0.800 (0.75 to 0.85)].Machine learning models may provide clinical decision support as to which patients to focus on for perioperative preventive treatment in order to preemptively reduce massive perioperative allogeneic blood transfusion by predicting, which patients are not at risk.Johannes Kepler University Ethics Committee Study Number 1091/2021, Clinicaltrials.gov identifier NCT04856618.

Layered ultramafic–mafic complexes are a common component of the stratigraphically uppermost part of the Onverwacht Group of the Barberton Greenstone Belt. Associated with the Mendon Formation in the south and the Weltevreden Formation in the north, they represent an assemblage of thick differentiated flows and shallow synvolcanic intrusions ranging in composition from dunite to gabbro. U-Pb zircon dating of gabbro from the Sawmill and the Mundt’s Concession ultramafic complexes from the northern part of the Barberton Greenstone Belt yielded ages of 3 258 ± 8 Ma and 3 244 ± 11 Ma, respectively. The ultramafic complexes are thus regarded to have been emplaced during a magmatic flare-up in the final stage of Weltevreden Formation volcanism, post-dating ultramafic magmatism in the southern part of the belt by several millions of years and thus suggesting diachronous evolution of the Onverwacht Group in the Barberton Greenstone Belt.

Iron mobilization during continental weathering was pervasive before the Great Oxidation Event (GOE) that started at around 2.43 billion years (Ga) ago, due to the soluble nature of reduced iron. However, various geochemical proxies indicate transient oxygenation during deposition of the Mesoarchean (∼2.95 Ga) Pongola Supergroup, South Africa, which suggests that continental weathering could have also occurred under transiently oxic conditions before the GOE. We analyzed trace elemental and Fe, Ti, and Cr isotopic compositions of the ca. 2.95 Ga Denny Dalton paleosol in the Pongola Supergroup to better understand continental weathering and redox conditions in the ancient critical zone, and the nature of geochemical fluxes from the continents to the oceans and marine sediments. Iron isotope systematics are consistent with a model where Fe was released during intense leaching from the paleosol to concentrate in Fe-rich groundwaters in the deeper part of the soil horizon. We show for the first time that Fe isotopic fractionation during Mesoarchean continental weathering was limited, and Fe enrichments and depletions are coupled with those of divalent transition metals, Co, Ni, and particularly Zn. This suggests that Fe redox cycling was not involved in paleosol formation, and Fe2+ was mobilized under anoxic conditions. Chromium isotopes are also unfractionated relative to the parent igneous rock in this paleosol, which precludes removal of isotopically heavy Cr6+ and thus supports anoxic continental weathering. We show that previously reported Cr isotopic fractionation in another Denny Dalton paleosol profile does not follow a Cr6+ leaching trend, but instead scales with Cr enrichment and may reveal Cr enrichment from post-burial fluids. Thus, there is no clear evidence for an oxidative continental weathering during deposition of the Pongola Supergroup. Titanium isotopes are not significantly fractionated in the paleosol, suggesting that continental weathering and erosion in the Archean did not fractionate Ti isotopes. Similarly, Ni/Co and Th/Sc ratios are reasonably conserved, which validates their use as a robust proxy for upper continental crust composition in shales, whereas La/Sc, Cr/Zn and Cr/U ratios are highly variable relative to the provenance composition, which suggests that caution should be used when applying these ratios in shale studies of the ancient upper continental crust composition.

Modern-day solar cycles due to the solar magnetic field oscillation are well recognized. Owing to the response of Earth’s climate to solar activity fluctuation, solar cycles in the Phanerozoic Eon have been recorded by laminites and fossil tree rings. However, the existence of magnetic cycles within the Sun younger than 3100 million-year-old is still unknown. The deposition of Precambrian banded iron formations (BIFs) reflects the primary productivity of the early ferruginous oceans and is coupled to climatic fluctuations. Here we apply synchrotron-radiation-based µ-XRF with a 20 µm interval on a 60 mm long, 2470 million-year-old BIF from the Kuruman Formation, South Africa. Our spectral analyses of multiple elemental concentration series reveal prominent and consistent 80-year cyclicity, which is best explained by the Gleissberg solar cycle. We hypothesize that solar cycles have already modulated the early Paleoproterozoic climate mainly through high energy irradiance coupled solar radiative forcing oscillation and the solar magnetic field controlled galactic cosmic ray fluctuation. Our result provides the record of solar magnetic field oscillations with stable and close-to-present cycle durations at least since the beginning of the Paleoproterozoic Era.

The huge global burden of oncological diseases is growing and measures to counter this complex challenge are high on national health agendas. The Russian National Long-Term Oncology Strategy 2030 defines priorities, goals and directions in the fight against cancer. Italso contains action plans for more effective prevention, earlier and more specific diagnosis and more effective treatment options. Against this backdrop, experts now suggest to complement standard oncology treatment strategies by adding Patient Blood Management (PBM). For many clinical disciplines where a low blood count and considerable blood loss are commonly encountered, this bundle of care is the new standard. Based on clinical and scientific evidence, it aims to optimise medical and surgical patient outcomes by clinically managing and preserving a patients blood. The principles of this comprehensive concept can and must be transferred to oncology, thus offering value in improving cancer care and the efficacy of medical institutions. Accumulating evidence demonstrates that anaemia and iron deficiency, but also thrombocytopenia, blood loss and coagulopathy are independent risk factors for adverse patient outcomes including morbidity, mortality, reduced quality of life and prolonged average length of hospital stay in both surgical and medical patients. For the timely and effective detection and correction of these risk factors, an international network of multi-disciplinary clinicians and researchers has developed PBM. The rapidly growing body of evidence for PBM not only shows improved patient outcomes, but also reduced resource utilisation including the use of allogeneic blood components. The reduction of allogeneic blood transfusion further improves patient safety and outcomes, since transfusion is another independent risk factor for adverse outcomes. Supported by WHO endorsements and following the recommendations of an increasing number of state or national health authorities, PBM is about to become a new standard of care. However, even though the aforementioned risk factors are highly prevalent in oncology settings due to chemo-/radiotherapy and the pathology of the disease, the integration of PBM in standard oncology treatment pathways is lagging behind. Thus, and in support of the Russian National Long-Term Oncology Strategy 2030 to improve quality of oncological care, with the support of the National Association of Specialists in PBM (NASPBM), the PBM Oncology Working Group of the Russian Federation was created, consisting of national and international experts in oncology and PBM. On July 9, 2020, the Working Group met to discuss the rationale for PBM in oncology and to assess the need to implement PBM in Russian oncology care. As a result, the Group recommended to include PBM as an integral part of standard oncology treatment pathways, delineated the action required from facilitating stakeholders in the Russian Federation, determined a roadmap for implementation and developed a national resolution as a call to action on the matter. Presented herein, this resolution acknowledges the global and local impetus to reduce cancer mortality, and the rationale for PBM interventions to improve patient outcomes and alleviate the social and economic burden of cancer on the healthcare system.

A Palaeoarchaean greenstone fragment and associated granitoid gneisses from an area south of Ulundi in KwaZulu-Natal is described. The fragment consists of an association of garnetiferous amphibolite and calc-silicate that was intruded at 3388 ± 4 Ma by tonalite and at 3275 ± 4 Ma by trondhjemite. Strong ductile deformation of the greenstones and granitoids under amphibolite facies conditions (7 kbar and 600 to 650°C) took place prior to uplift and emplacement of a granite batholith at ~3.25 Ga ago in which the granitoid gneiss-greenstone domain is now found. Magmatism 3.27 to 3.25 Ga ago was a direct response to regional metamorphism and anataxis, and gave rise to stabilization of the southeastern Kaapvaal Craton at that time, earlier than other parts of the craton. Deposition of quartz-arenites on stable granitic basement took place

Summary Our study investigated whether pre‐operative screening and treatment for anaemia and suboptimal iron stores in a patient blood management clinic is cost effective. We used outcome data from a retrospective cohort study comparing colorectal surgery patients admitted pre‐ and post‐implementation of a pre‐operative screening programme. We applied propensity score weighting techniques with multivariable regression models to adjust for differences in baseline characteristics between groups. Episode‐level hospitalisation costs were sourced from the health service clinical costing data system; the economic evaluation was conducted from a Western Australia Health System perspective. The primary outcome measure was the incremental cost per unit of red cell transfusion avoided. We compared 441 patients screened in the pre‐operative anaemia programme with 239 patients not screened; of the patients screened, 180 (40.8%) received intravenous iron for anaemia and suboptimal iron stores. The estimated mean cost of screening and treating pre‐operative anaemia was AU$332 (£183; US$231; €204) per screened patient. In the propensity score weighted analysis, screened patients were transfused 52% less red cell units when compared with those not screened (rate ratio = 0.48, 95%CI 0.36–0.63, p

The ca. 3.07 Ga volcanic rocks of the Dominion Group, South Africa, represent the oldest example of intracontinental, rift-related volcanism on the Archaean Kaapvaal craton. The volcanic assemblage comprises a >2 km-thick succession of mafic-intermediate lavas interlayered with felsic lavas and pyroclastic rocks. Textural and geological features indicate emplacement in a subaerial environment probably in an incipient intracontinental rift. We report SHRIMP U Pb zircon ages, elemental and Nd-isotope bulk-rock analyses of drill core samples and interpret their petrogenesis in the context of a Mesoarchaean continental setting. The U Pb zircon ages of four felsic samples from different stratigraphic levels yielded the same dates, resulting in a pooled 207Pb/206Pb age of 3074 ± 5 Ma. Primitive mantle-normalised incompatible trace element concentrations show enriched patterns with fractionated rare earth elements over high field-strength elements and negative anomalies of Nb and Ta relative to La. Initial eNd values for mafic and felsic rocks from −1.0 to −0.2 indicate melting of sources comprising time-integrated incompatible element-enriched mantle. The combined trace element and Sm Nd isotopic data suggest that the enrichment of incompatible elements and the low eNd values in the most primitive basalt samples (Mg# of 65–67) can be explained with contamination of asthenosphere-derived melts with crustal material or melting of an incompatible element-enriched upper mantle. The chemical compositions of the Dominion Group and Pongola Supergroup represent a significant petrogenetic departure from earlier Archaean (>3.6–3.1 Ga) magmatism as recorded in the Kaapvaal craton, which was dominated by komatiite-basalt volcanism and tonalite-trondhjemite-granodiorite intrusions. This change reflects the transition from a “greenstone belt type” tectonic setting to a failed intracontinental rift setting shortly after stabilisation of the Kaapvaal craton.

International audience; Preoperative anaemia is common in the Asia-Pacific. Iron-deficiency anaemia (IDA) is a risk factor that can be addressed under patient blood management (PBM) Pillar 1, leading to reduced morbidity and mortality. We examined PBM implementation under four different healthcare systems, identified challenges and proposed several measures. (a) Test for anaemia once patients are scheduled for surgery. (b) Inform patients about risks of preoperative anaemia and benefits of treatment. (c) Treat IDA and replenish iron stores before surgery, using intravenous iron when oral treatment is ineffective, not tolerated or rapid iron replenishment is needed; transfusion should not be the default management. (d) Harness support from multiple medical disciplines and relevant bodies to promote PBM implementation. (e) Demonstrate better outcomes and cost savings from reduced mortality and morbidity. Although PBM implementation may seem complex and daunting, it is feasible to start small. Implementing PBM Pillar 1, particularly in preoperative patients, is a sensible first step regardless of the healthcare setting.

Zusammenfassung Ziel In drei Untersuchungsgruppen (Krankenhauspatienten, Bewohner in Altenpflegeheimen und Patienten hausärztlicher Praxen) sollte die Prävalenz von Methicillin-resistentem Staphylococcus aureus (MRSA), multiresistenten gramnegativen stäbchenförmigen Bakterien (MRGN) sowie Vancomycin-resistenten Enterokokken (VRE) ermittelt werden. Zudem sollten Risikofaktoren für ein Trägertum untersucht werden. Methodik Das Screening auf multiresistente Erreger (MRE) erfolgte als Punktprävalenzuntersuchung bei freiwillig teilnehmenden Personen mittels Nasen-, Rachen- und Rektalabstrich bzw. Stuhlprobe in 25 Krankenhäusern, 14 Altenpflegeheimen sowie 33 Hausarztpraxen in 12 von 13 Landkreisen in Sachsen. Verdächtige Isolate wurden phänotypisch sowie z. T. molekularbiologisch weiter untersucht. Die Teilnehmer füllten einen Fragebogen zu vermuteten Risikofaktoren für eine MRE-Besiedlung aus, deren Angaben statistisch mittels Korrelationsanalysen ausgewertet wurden. Ergebnisse 1 718 Personen, davon 629 aus Krankenhäusern, 498 aus Altenpflegeheimen und 591 aus Arztpraxen, wurden untersucht. Insgesamt waren 8,4% aller Teilnehmer Träger eines MRE. 1,3% wurden positiv auf das Vorliegen eines MRSA, 5,2% auf 3MRGN, 0,1% auf 4MRGN und 2,3% auf VRE getestet. Neun Personen waren mit mehr als einem MRE besiedelt. Folgende unabhängige Faktoren konnten signifikant mit dem Nachweis eines MRE in Zusammenhang gebracht werden: Vorhandensein eines Pflegegrads (MRE), männliches Geschlecht (MRE/VRE), aktuelle Antibiose (MRE/VRE), Antibiose innerhalb der letzten 6 Monate (MRE/MRSA/3MRGN/VRE), aktuelle Tumorerkrankung (MRE/3MRGN), periphere arterielle Verschlusskrankheit (pAVK) (MRSA) sowie eine Harninkontinenz (3MRGN). Schlussfolgerungen Nach unserem Wissensstand stellt diese Studie die erste Untersuchung zur Prävalenz unterschiedlicher multiresistenter Erregergruppen in diesen 3 Untersuchungsgruppen und erstmals dabei auch unter ambulanten Patienten in Deutschland dar. Dabei repräsentierten 3MRGN die am häufigsten nachgewiesene Erregergruppe und fanden sich auch in jüngeren Altersgruppen wieder, VRE wurden fast ausschließlich kumuliert in einzelnen Kliniken nachgewiesen. Neben aktueller und stattgehabter Antibiose konnten insbesondere das Vorliegen einer pAVK für MRSA-Nachweise, Harninkontinenz für 3MRGN-Nachweise sowie eine aktuelle Tumorerkrankung für MRE- und 3MRGN-Nachweise als unabhängige Risikofaktoren bestimmt werden.

The World Health Organization (WHO) has declared Coronavirus Disease 2019 (COVID-19), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a pandemic. Global health care now faces unprecedented challenges with widespread and rapid human-to-human transmission of SARS-CoV-2 and high morbidity and mortality with COVID-19 worldwide. Across the world, medical care is hampered by a critical shortage of not only hand sanitizers, personal protective equipment, ventilators, and hospital beds, but also impediments to the blood supply. Blood donation centers in many areas around the globe have mostly closed. Donors, practicing social distancing, some either with illness or undergoing self-quarantine, are quickly diminishing. Drastic public health initiatives have focused on containment and “flattening the curve” while invaluable resources are being depleted. In some countries, the point has been reached at which the demand for such resources, including donor blood, outstrips the supply. Questions as to the safety of blood persist. Although it does not appear very likely that the virus can be transmitted through allogeneic blood transfusion, this still remains to be fully determined. As options dwindle, we must enact regional and national shortage plans worldwide and more vitally disseminate the knowledge of and immediately implement patient blood management (PBM). PBM is an evidence-based bundle of care to optimize medical and surgical patient outcomes by clinically managing and preserving a patient’s own blood. This multinational and diverse group of authors issue this “Call to Action” underscoring “The Essential Role of Patient Blood Management in the Management of Pandemics” and urging all stakeholders and providers to implement the practical and commonsense principles of PBM and its multiprofessional and multimodality approaches.

While patient blood management (PBM) initiatives are increasingly adopted across the globe as part of standard of care, there is need for a clear and widely accepted definition of PBM. To address this, an expert group representing PBM organizations from the International Foundation for Patient Blood Management (IFPBM), the Network for the Advancement of Patient Blood Management, Haemostasis and Thrombosis (NATA), the Society for the Advancement of Patient Blood Management (SABM), the Western Australia Patient Blood Management (WAPBM) Group, and OnTrac (Ontario Nurse Transfusion Coordinators) convened and developed this definition: "Patient blood management is a patient-centered, systematic, evidence-based approach to improve patient outcomes by managing and preserving a patient's own blood, while promoting patient safety and empowerment." The definition emphasizes the critical role of informed choice. PBM involves the timely, multidisciplinary application of evidence-based medical and surgical concepts aimed at (1) screening for, diagnosing, and appropriately treating anemia; (2) minimizing surgical, procedural, and iatrogenic blood losses and managing coagulopathic bleeding throughout the care; and (3) supporting the patient while appropriate treatment is initiated. We believe that having a common definition for PBM will assist all those involved including PBM organizations, hospital administrators, individual clinicians, and policy makers to focus on the appropriate issues when discussing and implementing PBM. The proposed definition is expected to continue to evolve, making this endeavor a work in progress.

The ability to predict in-hospital mortality from data available at hospital admission would identify patients at risk and thereby assist hospital-wide patient safety initiatives. Our aim was to use modern machine learning tools to predict in-hospital mortality from standardized data sets available at hospital admission.This was a retrospective, observational study in 3 adult tertiary care hospitals in Western Australia between January 2008 and June 2017. Primary outcome measures were the area under the curve for the receiver operating characteristics curve, the F1 score, and the average precision of the 4 machine learning algorithms used: logistic regression, neural networks, random forests, and gradient boosting trees.Using our 4 predictive models, in-hospital mortality could be predicted satisfactorily (areas under the curve for neural networks, logistic regression, random forests, and gradient boosting trees: 0.932, 0.936, 0.935, and 0.935, respectively), with moderate F1 scores: 0.378, 0.367, 0.380, and 0.380, respectively. Average precision values were 0.312, 0.321, 0.334, and 0.323, respectively. It remains unknown whether additional features might improve our models; however, this would result in additional efforts for data acquisition in daily clinical practice.This study demonstrates that using only a limited, standardized data set in-hospital mortality can be predicted satisfactorily at the time point of hospital admission. More parameters describing patient's health are likely needed to improve our model.

Biotite granites and K-feldspar granites are the dominant intrusive rock types of the Colomine gold district in the Neoproterozoic terrain of SE Cameroon. The silica contents of these granitoids range from 68.93–75.39 wt% and Au contents from 0.6 to 32 ppb. They are weakly peraluminous (ASI = 1.0–1.2) I-type granitoids with high-K calc-alkaline to shoshonitic character, emplaced within a syn-collisional arc setting. They have fractionated trace element patterns (LaN/YbN: ~ 11–331) with enrichment in LREE compared to HREE and weak to strong negative Ba, Nb, Sr, P, Ti, Lu, and Eu (Eu/Eu* = 0.12–0.52) anomalies. The geochemical characteristics suggest that the granitoids formed by partial melting of crustal source rocks with some input from greywackes. Differentiation of the hydrous parent magma was characterized by fractionation of muscovite, biotite, hornblende, plagioclase, and K-feldspar with minor zircon, apatite and Fe-Ti oxide. Mafic garnet-bearing inclusions represent an early crystallization phase that was incorporated in the later felsic melt. The granitoids became emplaced into Proterozoic schist belts. Along the contacts, they became brecciated, sheared, foliated and sericitized. These “contact granites” have higher gold contents (5–32 ppb) than the fresh granitoids (0.6–3 ppb). Remobilisation of gold from early magmatic sulfide minerals by post-magmatic hydrothermal fluids enriched the shear-related granitoids. Hydrothermal alteration results to enrichment in Cu, Ni, Cr, Mo, Ga, V, Tl, and Au and depletion in LREE (e.g., La, Ce, Pr). Micro-shear and fault zones in the vicinity of the granitoids constitute favourable sites for exploration.

The Archaean continental crust comprises two major groups of silicon-rich granitoids: the tonalite–trondhjemite–granodiorite and granite–monzonite–syenite suites, which differ in their sodium-to-potassium ratios. How these felsic granitoids evolved from their mafic precursors remains elusive and the subject of great debate. Here, we present silicon isotopic constraints on the formation of representative trondhjemitic and granitic plutons from the Kaapvaal craton that range in age from 3.51–2.69 billion years ago. We identified very consistent silicon isotopic signatures, all uniformly 0.1–0.2‰ heavier than rocks of the modern continental crust. This unusual composition is explained by the melting of a mafic source that included significant proportions (15–35 wt%) of silicified basalts, which were common supracrustal rocks before 3 billion years ago. Before the melting event that formed the granitoid magmas at depth, portions of the mafic source rocks were enriched in silica by interaction with silica-saturated seawater. The addition of silica depresses the stability of amphibole at similar water activity, allowing trondhjemitic and granitic melt production at lower temperatures from protoliths with contrasting silica contents: 52–57 and ≥60 wt%, respectively. This explains why granitoids were able to form very early in Earth history but did not emerge in significant amounts on other rocky planets. Granitic continental crust in the Archaean formed from a basaltic source that was enriched in silica due to interaction with the early oceans before melting, according to silicon isotope analyses on rocks from the Kaapvaal craton.

The crustal evolutionary scenarios and geodynamic driving mechanisms of the North China Craton (NCC) during the late Neoarchean (∼2.5 Ga) are still lacking comprehensive understanding due to subsequent strong deformation and metamorphic overprinting events. The widespread ∼2.5 Ga tectono-thermal activities throughout the NCC can be studied to constrain the tectonic evolution at this period. The Wangwushan Neoarchean diorites and high-K granites in the southern NCC were formed at ∼2.52–2.51 Ga. The diorites have high Mg#, Th, Y, low Sr and Sr/Y ratios and variably positive zircon eHf(t) (+2.4 – +8.4) and whole rock eNd(t) values (−0.26 – +3.24), indicating a depleted mantle wedge source which was metasomatized by the melted subducted silicic sediments. The depleted Nb, Ti and enriched LILE and Pb features indicate that the diorites were derived from slightly metasomatized mantle wedge in a subduction-related setting. The high-K granites show a shoshonite affinity and peraluminous features. The rocks have low 10,000 Ga/Al ratios, Zr and Zr + Nb + Ce + Y concentrations, and calculated zircon saturation temperature (TZr = 686–837 °C, 774 °C on average), belong to fractionated I-type granite. Low Sr, Y, flat HREE, and negative Eu anomalies indicate the presence of Ca-rich plagioclase and absence of garnet in the residue during partial melting of the sources, thus further indicating a shallower source with a pressure of

In the eastern part of the Karoo Basin of South Africa, the sedimentary record of the Late Palaeozoic Ice Age, the Dwyka Group, consists of an up to 200 m thick accumulation of massive to crudely stratified diamictite occasionally interstratified with siltstone, sandstone and conglomerate horizons. Three distinct sedimentary units, separated by intervening glacial erosion surfaces, are viewed as ice‐margin fluctuation sequences. The lowermost one, resting on highly uneven, glacially abraded Archaean basement, has been interpreted as a grounding zone wedge deposited after the retreat and stabilization of the ice margin after the inundation of the Karoo Basin. The grounding zone wedge interpretation is based on its thickness (up to 100 m), the dominance of diamictite, and its facies assemblage and inferred depositional processes (rain‐out of debris, dropstone dumping, mass and debris flow, till). Overlying the grounding zone wedge, deposits are sedimentary units interpreted as glaciofluvial or ice‐contact delta and grounding zone wedges, respectively. By analogy with Quaternary sedimentary sequences, deposition of the Dwyka Group in the study area might have been very rapid (tens to hundreds of thousand years) and may hence correlate with the ultimate deglacial sequence of the Western Karoo Basin, as both successions are covered by the postglacial Ecca Group. Although commonly observed and imaged on modern, high‐latitude continental shelves, grounding zone wedges have never been interpreted in the ancient geological record. This paper therefore outlines a model defining criteria necessary for their identification.

The recycling of supracrustal materials, and in particular hydrated rocks, has a profound impact on mantle composition and thus on the formation of continental crust, because water modifies the physical properties of lithological systems and the mechanisms of partial melting and fractional fractionation. On the modern Earth, plate tectonics offers an efficient mechanism for mass transport from the Earth's surface to its interior, but how far this mechanism dates back in the Earth's history is still uncertain. Here, we use zircon oxygen (O) isotopes to track recycling of supracrustal materials into the magma sources of early Archean igneous suites from the Kaapvaal Craton, southern Africa. The mean δ18O values of zircon from TTG (tonalite–trondhjemite–granodiorite) rocks abruptly increase at the Paleo-Mesoarchean boundary (ca. 3230 million years ago; Ma), from mantle zircon values of 5‰–6‰ to approaching 7.1‰, and this increase occurs in ≤3230 Ma rocks with elevated Dy/Yb ratios. The 18O enrichment is a unique signature of low-temperature water–rock interaction on the Earth's surface. Because the later phase was emplaced into the same crustal level as the older one and TTG magmas would derive from melting processes in the garnet stability field (>40 km depth), we suggest that this evident shift in TTG zircon O isotopic compositions records the onset of recycling of the mafic oceanic crust that underwent seawater hydrothermal alteration at low temperature. The onset of the enhanced recycling of supracrustal materials may also have developed elsewhere in other Archean cratons and reflects a significant change in the tectonic realm during craton formation and stabilization, which may be important processes for the operation of plate tectonics on early Earth.

The first dramatic rise in atmospheric oxygen to concentrations above 10-5 present atmospheric level (PAL), known as the Great Oxidation Event (GOE), was initiated during the early Proterozoic Eon c. 2.43-2.32 billion years (Gyrs) ago [1,2]. Although atmospheric O2 concentrations are generally accepted to have remained below 1% PAL for at least 1.5 Gyrs following the GOE [3], high atmospheric O2 build up occurred during the Lomagundi carbon isotope excursion (LE) at the latest stage of the GOE [4]. The LE is the most pronounced and longest-lived carbon isotope excursion in Earth’s history that took place c. 2.22-2.06 Gyrs ago [4,5]. It reflects increased organic carbon (Corg) burial resulting from high primary productivity at the time of high phosphorous flux to the ocean associated with intense acidic chemical weathering of landmasses. However, mechanisms responsible for such high Corg sequestration are not yet fully resolved, nor has it been possible to precisely quantify the magnitude and expansion of oxygenation within the coeval atmosphere-ocean system.Here, we studied diagenetic concretions of pyrite and carbonate and their host black shales of the Francevillian Group, southeast Gabon, deposited during the LE. Light sulfur (δ34S ‰, VCDT) and carbon (δ13Ccarb ‰, VPDB) isotope ratios indicate that both pyrite and carbonate formed in sediments through microbial sulfate reduction and Corg remineralization, respectively. Selenium isotopic ratios (δ82/76Se ‰, NIST3149) of the pyrite concretions and their host shales are dominated by highly negative values as low as –3‰, which is strong evidence for partial reduction of selenium oxyanions (SeOx2-) in the sediment below an oxygenated seawater column. Collectively, the data suggests an oxygenated water column in the Francevillian Basin with a large SeOx2- reservoir that continuously resupplied these electron acceptors to the sediment and prevented their quantitative reduction. The studied black shales host putative, fossilized large colonial multicellular organisms that had the ability to laterally and vertically migrate within the sediments [6]. We propose that bioturbation by these organisms allowed an increased flux of electron acceptors (e.g., O2, NO3–, SeOx2-, SO4-) into the sediments and pushed the microbial sulfate reduction and methanogenesis zones downward. As a consequence, CH4 and H2S generated in these zones were re-oxidized in more oxic upper levels of the sediments, which prevented them from escaping to the water column. An increase in ecosystem complexity thus likely aided Corg sequestration to the sediments and O2 accumulation in the atmosphere-ocean system during the LE. [1] Bekker et al. (2004), Nature, 427, 117–120. [2] Holland (2006), Philos. Trans. R. Soc. B 361, 903–91. [3] Colwyn et al. (2014), Geobiology, DOI: 10.1111/gbi.12360. [4] Karhu and Holland (1996), Geology, 24, 867–870. [5] Bekker (2014), Encyclopedia of Astrobiology, Springer-Verlag, 1–6. [6] El Albani et al. (2019), Proc. Natl. Acad. Sci. USA, 116, 3431–3436.

Previous studies by the Cost of Blood Consensus Conference (COBCON) have used a comprehensive, standardized and generalizable activity-based costing (ABC) model to estimate the cost of red blood cell transfusions and plasma transfusion. The objective of this study was to determine the total cost of platelet transfusions in a real-world US hospital inpatient setting.This database analysis study retrospectively collected costs for all activities related to platelet transfusion in a single-acute care US teaching hospital in 2017. Costs were collected in a stepwise manner using a custom ABC model which mapped the technical, administrative and clinical processes involved in the transfusion of platelets.For the 15 024 inpatients included in the analysis, 6335 (42·2%) were given a blood type and screen, and 941 (6·3%) received a transfusion of one or more blood products. A total of 333 platelet units were transfused in 131 patients (mean 2·54 units per patient): 211 (63·4%) units in medical inpatients and 122 (36·6%) in surgical inpatients. The total cost was $1359·99 per platelet unit, corresponding to $3457·06 per inpatient. Acquisition costs made up the largest proportion of the total cost (45·1%) followed by direct and indirect overheads (38·7%) and hospital processes costs (16·3%).This is the first study to use an ABC costing model to determine the full cost of platelet transfusions within a US inpatient setting. This provides a useful reference point for comparisons with other transfusion products, and considerations for cost reduction.

International audience; The expansion of ice masses across southern Africa during the Late Palaeozoic Ice Age has been known for 150 years, including the distribution of upland areas in controlling the configuration of glaciation. In Accepted Article This article is protected by copyright. All rights reserved Namibia, increasing attention has focussed on long and deep palaeovalley networks in the Kaokoland region in the north, but comparatively little work has been attempted in the topographically subdued plains of the south, in the Aranos and Karasburg basins. The desert terrain of the Aranos area exposes diamictites of the Dwyka Group discontinuously over about 300 km, extending further south to the Karasburg area at the Namibian-South African border along the Orange River. Whilst examined at a stratigraphic level, the nature of the contact between the Dwyka glacial rocks and underlying lithologies has not been systematically investigated. This paper presents the results from fieldwork in austral winter 2019, in which a highly varying basal contact is described that records the processes of growth, flow and expansion of ice masses across this part of Gondwana. At the basin margins, subglacially-produced unconformities exhibit classic glacially striated pavements on indurated bedrock. In comparison, the basal subglacial unconformity in the more basinward regions is characterised by soft-sediment striated surfaces and deformation. In the Aranos Basin, soft-sediment shear zones originated in the subglacial environment. This type of subglacial unconformity developed over well differentiated, unconsolidated, siliciclastic materials. Where ice advanced over more poorly sorted material or cannibalised pre-existing diamictites, "boulder-pavements" recognized as single clast-thick boulder-dominated intervals formed. Importantly, these boulder-pavements are enriched in clasts, which were facetted and striated in-situ by overriding ice. By integrating measurements of striation orientations, fold vergence and palaeocurrent information, former ice flow pathways can potentially be reconstructed over a wide area.

Background: Patient Blood Management (PBM) is an evidence-based approach in surgery and emergency care which aims to minimize the risk for blood loss and the need for blood replacement for each patient through a coordinated multidisciplinary care process before, during, and after surgery. In combination with blood loss, anemia is the main driver for transfusion and an independent risk factor for adverse outcomes including morbidity and mortality. Hence, identifying and correcting anemia as well as minimizing blood loss are important pillars of PBM. Evidence demonstrates that PBM significantly improves outcomes and safety while reducing cost by macroeconomic magnitudes. Despite its huge potential to improve healthcare systems, PBM is not yet adopted broadly. The aim of this study is to analyze the collective experiences of a diverse group of PBM implementors across countries reflecting different healthcare contexts and to use these experiences to develop a guidance for initiating and orchestrating PBM implementation for stakeholders from diverse professional backgrounds.Methods: Semi-structured interviews were conducted with 1-4 PBM implementors from 12 countries in Asia, Latin America, Australia, Central and Eastern Europe, the Middle East, and Africa. Responses reflecting the drivers, barriers, measures, and stakeholders regarding the implementation of PBM were summarized per country, and key observations extracted. By clustering the levels of intervention for PBM implementation, a PBM implementation framework was created and populated.Results: A set of PBM implementation measures were extracted from the interviews with the implementors. Most of these measures relate to one of six levels of implementation including government, healthcare providers, funding, research, training/education, and patients/public. Essential cross-level measures are multi-stakeholder communication and collaboration.Conclusion: This implementation framework helps to decompose the complexity of PBM implementation into concrete measures on each implementation level. It provides guidance for diverse stakeholders to independently initiate and develop strategies to make PBM a national standard of care, thus closing current practice gaps and matching this unmet public health need.