8 research outputs found

    Late Maastrichtian carbon isotope stratigraphy and cyclostratigraphy of the Newfoundland Margin (Site U1403, IODP Expedition 342)

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    Earth’s climate during the Maastrichtian (latest Cretaceous) was punctuated by brief warming and cooling episodes, accompanied by perturbations of the global carbon cycle. Superimposed on a long-term cooling trend, the middle Maastrichtian is characterized by deep-sea warming and relatively high values of stable carbon-isotope ratios, followed by strong climatic variability towards the end of the Cretaceous. A lack of knowledge on the timing of climatic change inhibits our understanding of underlying causal mechanisms. We present an integrated stratigraphy from Integrated Ocean Drilling Program (IODP) Site U1403, providing an expanded deep ocean record from the North Atlantic (Expedition 342, Newfoundland Margin). Distinct sedimentary cyclicity suggests that orbital forcing played a major role in depositional processes, which is confirmed by statistical analyses of high resolution elemental data obtained by X-ray fluorescence (XRF) core scanning. Astronomical calibration reveals that the investigated interval encompasses seven 405-kyr cycles (Ma4051 to Ma4057) and spans the 2.8 Myr directly preceding the Cretaceous/Paleocene (K/Pg) boundary. A high-resolution carbon-isotope record from bulk carbonates allows us to identify global trends in the late Maastrichtian carbon cycle. Low-amplitude variations (up to 0.4‰) in carbon isotopes at Site U1403 match similar scale variability in records from Tethyan and Pacific open-ocean sites. Comparison between Site U1403 and the hemipelagic restricted basin of the Zumaia section (northern Spain), with its own well-established independent cyclostratigraphic framework, is more complex. Whereas the pre-K/Pg oscillations and the negative values of the Mid-Maastrichtian Event (MME) can be readily discerned in both the Zumaia and U1403 records, patterns diverge during a ~ 1 Myr period in the late Maastrichtian (67.8–66.8 Ma), with Site U1403 more reliably reflecting global carbon cycling. Our new carbon isotope record and cyclostratigraphy offer promise for Site U1403 to serve as a future reference section for high-resolution studies of late Maastrichtian paleoclimatic change

    A time-resolved proteomic and prognostic map of COVID-19

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    COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease

    Rewetting does not return drained fen peatlands to their old selves

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    Peatlands, in particular groundwater-fed fens of the temperate zone, have been drained for agriculture, forestry and peat extraction for a long time and on a large scale. Drainage turns peatlands from a carbon and nutrient sink into a respective source, diminishes water regulation capacity at the landscape scale, causes continuous surface height loss and destroys their typical biodiversity. Over the last decades, drained peatlands have been rewetted for biodiversity restoration and, as it strongly decreases greenhouse gas emissions, also for climate protection. With the dataset published here, we quantified restoration success by comparing 320 rewetted fen peatland sites to 243 near-natural peatland sites of similar origin across temperate Europe with regards to biodiversity (vegetation), ecosystem functioning (hydrology, geochemistry) and land cover characteristics based on remote sensing. Vegetation data comes as species-specific cover values. Hydrology data covers on average 2.3 years and minimally one full year and comes as median, minimum, and maximum water table depth. Geochemistry consists of pH and electrical conductivity of the pore water (0-60 cm), bulk density and organic matter content of the top soil layer (0-30 cm), all sampled in summer for all sites included here alongside the vegetation data sampling. Land cover characteristics contain 208 spectral-temporal metrics for a full annual time series of Copernicus Sentinel-2 A/B data for 2018.Several taxa included in this dataset are at risk from a harmful human activity, in accordance to Chapman 2008 (https://docs.gbif.org/sensitive-species-best-practices/master/en/) we therefore report the georeferences denatured to 0.1 degrees (~10 km). Data may be supplied at finer scales on request under the conditions of a written data agreement. Missing values are coded as NA, zeros are true and measured values. Funding provided by: European Social FundCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004895Award Number: ESF/14-BM-A55-0027/16 to ESF/14-BM-A55-0035/16Funding provided by: BiodivERsA*Crossref Funder Registry ID: Award Number: DFG JO 332/15-1Funding provided by: BiodivERsA*Crossref Funder Registry ID: Award Number: BELSPO BR/175/A1Funding provided by: BiodivERsA*Crossref Funder Registry ID: Award Number: NCN 2016/22/Z/NZ8/00001Funding provided by: Ministerium für Bildung, Wissenschaft und Kultur Mecklenburg-VorpommernCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100014848Award Number: ESF/14-BM-A55-0027/16 to ESF/14-BM-A55-0035/16Funding provided by: BiodivERsACrossref Funder Registry ID: Award Number: DFG JO 332/15-1See methods section of the accompanying paper for details about data collection and processing; see ReadMe-file for parameter explanation. Potential sites were found through literature search and contacting the respective authors. All such authors providing data were included as co-authors and we included all data from fen ecosystems of temperate Europe which were drained and had a dateable rewetting action and all sites without direct drainage history as confirmed by local experts and remote sensing. We included all sites that provided data for at least two of the following four response clusters in order to obtain comparable datasets for these clusters: (1) vegetation, (2) hydrology, (3) geochemistry, (4) land cover characteristics. We included all available datasets fitting to the definitions laid out above. Sampling for vegetation and geochemistry occurred in summer for all sites. Vegetation sampling consisted of complete lists of vascular plants and bryophytes (539 species in total) based on 16 m² (median, ranging between 12 and 25 m²) with estimates of individual plant species cover. All vegetation data collections included in this study aimed at full species lists and used comparable methodologies, i.e. estimating species-specific cover values. Studies focusing on specific taxa or just reporting the dominant species were excluded from the analyses. Geochemical sampling quantified pH and electrical conductivity of the pore water (0-60 cm) and bulk density and organic matter content of the top soil layer (0-30 cm). Hydrological data relied on on continuous are at least monthly manual sampling for on average, 2.3 years, and a minimum of at least one full year. Land cover characteristics were sampled after the fact for all sites for which the required remote sensing prodcuts were available in the year 2018. Data was collected for different purposes over different years. The data owners are included as co-authors. Vegetation data is the estimated aboveground cover of all vascular plants and bryophytes (539 species in total) within a 16 m² (median, ranging between 12 and 25 m²) plot noted down by experts with pen on paper. Hydrological data is based on 269 piezometers with dataloggers, 91 piezometers related to a datalogger in a transect, 216 piezometers with manual measurements of at least one year and biweekly or monthly readings of the water table depth relative to the peat surface. Geochemical data consisted of pH and electric conductivity of the pore water extracted in the field and measured directly with portable pH-sensors and conductivity sensors. Bulk density was quantfied based on volumetric field samples (0-30cm depth) in relation to their dry weight after drying to constant weight in a drying cabinet. Organic matter was quantified as the loss on ignition of these dry samples. Land cover characteristics: spectral-temporal metrics for a full annual time series of Copernicus Sentinel-2 A/B data for 2018. The Sentinel-2 A/B constellation provides optical imagery of the Earth's surface between ~0.49 - ~2.2 µm in ten spectral bands and at 10 – 20 m ground sampling distance at a theoretical acquisition frequency of 2.5 – 5 days. We here acquired all available Sentinel-2 A/B imagery for 2018 with cloud cover <70% from the ESA API Hub. We used all valid observations to derive spectral-temporal metrics from the time series. Spectral temporal metrics are statistical measures (e.g. average, minimum, maximum, quartiles, …) per spectral band or index (e.g. MNDWI = (green - short wave infrared)/(green + short wave infrared)) using all available cloud- and shadow-free observations over time. The median count of clear-sky-observations per pixel across the sites is 45, while 90% of all sites featured 27 clear-sky observations or more. Both data processing to Analysis Ready Data as well as calculating spectral-temporal metrics was performed through the Framework for Operational Radiometric Correction for Environmental monitoring. Our analysis included data averaged over 3x3 pixels around the center plot location of the site. Different spatial aggregations (e.g. single pixels, 5x5 pixels around the center plot) led to highly similar results, implying that the intra-site variability was robust around locations of the vegetation survey. The inclusion of an annual series of Sentinel-1 synthetic aperture radar data (temporal metrics for VV and VH polarization, IW swath at 10 m resolution) for the same year did not affect the results. Spatial scale: temperate fen ecosystems of Europe. Timing: Data was collected between 1994 and 2019 with sampling for vegetation and geochemistry occurring once per site with known year and time since rewetting for the rewetted sites but different years between sites. Hydrology was monitored for >1 year at each site (see above for details and rationale), again with known time periods per site and different timing for different sites. Land cover characteristics were sampled for all sites for the year 2018 as decribed above

    Experimental access to Transition Distribution Amplitudes with the P̄ANDA experiment at FAIR

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    Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (\u3c0N) TDAs from \uafpp \u2192 e+e 12\u3c00 reaction with the future PANDA detector at the FAIR facility. At high center- of-mass energy and high invariant mass squared of the lepton pair q2, the amplitude of the signal channel pp\uaf \u2192 e+e 12\u3c00 admits a QCD factorized description in terms of \u3c0N TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring \uafpp \u2192 e+e 12\u3c00 with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. pp\uaf \u2192 \u3c0+\u3c0 12\u3c00 were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 0.5 in the proton-antiproton center-of-mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of 5 \ub7 107 (1 \ub7 107) at low (high) q2 for s = 5 GeV2, and of 1 \ub7 108 (6 \ub7 106) at low (high) q2 for s = 10 GeV2, while keeping the signal reconstruction efficiency at around 40%. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to 2 fb 121 of integrated luminosity. The cross sections obtained from the simulations are used to show that a test of QCD collinear factorization can be done at the lowest order by measuring scaling laws and angular distributions. The future measurement of the signal channel cross section with PANDA will provide a new test of the perturbative QCD description of a novel class of hard exclusive reactions and will open the possibility of experimentally accessing \u3c0N TDAs

    Technical design report for the PANDA\overline{{\rm{P}}}\mathrm{ANDA} Barrel DIRC detector

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    The PANDA\overline{{\rm{P}}}\mathrm{ANDA} (anti-Proton ANnihiliation at DArmstadt) experiment will be one of the four flagship experiments at the new international accelerator complex FAIR (Facility for Antiproton and Ion Research) in Darmstadt, Germany. PANDA\overline{{\rm{P}}}\mathrm{ANDA} will address fundamental questions of hadron physics and quantum chromodynamics using high-intensity cooled antiproton beams with momenta between 1.5 and 15 GeV/c and a design luminosity of up to 2 × 1032 cm−2 s−1. Excellent particle identification (PID) is crucial to the success of the PANDA\overline{{\rm{P}}}\mathrm{ANDA} physics program. Hadronic PID in the barrel region of the target spectrometer will be performed by a fast and compact Cherenkov counter using the detection of internally reflected Cherenkov light (DIRC) technology. It is designed to cover the polar angle range from 22° to 140° and will provide at least 3 standard deviations (s.d.) π/K separation up to 3.5 GeV/c, matching the expected upper limit of the final state kaon momentum distribution from simulation. This documents describes the technical design and the expected performance of the PANDA\overline{{\rm{P}}}\mathrm{ANDA} Barrel DIRC detector. The design is based on the successful BaBar DIRC with several key improvements. The performance and system cost were optimized in detailed detector simulations and validated with full system prototypes using particle beams at GSI and CERN. The final design meets or exceeds the PID goal of clean π/K separation with at least 3 s.d. over the entire phase space of charged kaons in the Barrel DIRC

    Second asymptomatic carotid surgery trial (ACST-2) : a randomised comparison of carotid artery stenting versus carotid endarterectomy

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    Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86-1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91-1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable
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