Copernicus Cal/Val Solution - D3.3 - Copernicus operational FRM network and supersites

- Identify measurement gaps, considering the existing ground-based Cal/Val measurement campaigns and networks (as outcome from Tasks 2.4 and 2.5) - Identify rationalization and optimization pathways: e.g., use of common instrumentation, protocols, and standards across sites; cross-Sentinel use of generic measurements; “supersite” approaches to minimize maintenance costs, as well as possible synergies with other European or international programs - Define a minimum set of requirements for a “Copernicus” label for measurement sites, addressing measurement protocols, documentation, availability, data policy; define a certification process - Principles and need to evaluate degree of equivalence between individual networks and sites (inter-comparisons) and for other comparison measurement

Copernicus Cal/Val Solution - D3.6 - Copernicus Cal/Val Solution

This document presents the synthesis of activities performed in Task 3 of the CCVS project. It gathers the main identified gaps and recommendations regarding: • Instrumentation technologies • Development of Cal/Val methods • In-situ measurement networks and field campaigns • Data distribution services The recommendations are selected in order to form a consistent plan to improve cal/val activities for all Sentinel missions, trying to find an overall balance across the main domains (optical observations, radar imaging, altimetry and atmospheric composition missions). Finally, we provide some recommendations regarding coordination, organization and processes involving the different actors of the Copernicus programme. Programmatic and sustainability aspects are not addressed in this document (cf. Task 4 documents)

Association between convalescent plasma treatment and mortality in COVID-19: a collaborative systematic review and meta-analysis of randomized clinical trials.

Funder: laura and john arnold foundationBACKGROUND: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, https://doi.org/10.17605/OSF.IO/GEHFX ). METHODS: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. RESULTS: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. CONCLUSIONS: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care

Nanotubes, nanocones and nanocages: geometry-electronic structure relations in carbon alotropes

nrpages: 294status: publishe

Vortices and their relation to ring currents and magnetic moments in nanographenes in high magnetic field

Much attention has been paid to the role of vortices in the magnetic response properties of superconductors, but less so for molecular systems. Here we present a theoretical analysis on nanographenes subject to a strong homogeneous magnetic field. The analysis is based on the simple Huckel-London model, for which we derive the topological definition of vorticity. The results are confirmed by a more elaborate model that includes nonnearest neighbor interaction, the explicit presence of nuclei and all terms due to the magnetic field. We find that due to frontier orbital intersections, large changes in magnetic dipole moments occur. Orbital energy minima and maxima can be related to change of vortex patterns with flux.status: publishe

Electron transmission through atom-contacted carbon nanotubes

The transmission through side-contacted single-wall carbon nanotubes is investigated within the Landauer-Butikker formalism for arbitrary tubes, geometries of contacts, and energies of transmission (E) for the case of monoatomic contacts. An efficient method to calculate transmission within the tight-binding approach including curvature effects is devised allowing, in particular, for an analytical treatment of zigzag, armchair, and some chiral tubes. The transmission function is described as a superposition of the contributions from one-dimensional bands of all nanotube lines, each of them oscillating or/and decaying with the distance between the leads. We find five different types of antiresonances. Two of them arise from a destructive interference of the contributions from different nanotube lines when E is in the gap of semiconducting nanotubes and either are due to symmetry reasons or are accidental. A further two can show up at energies of Van Hove singularities originating from isolated singular points in 1D bands of nanotubes and can lead either to split or completely missing transmission peaks. The fifth one is related to the flat band in zigzag nanotubes at the energy of Van Hove singularity in graphene and results in zero transmission between carbon atoms belonging to different translational units in these tubes. A strong anisotropy of transmission in two opposite directions along the tube's axis is found in the middle of the energy gap of semiconducting nanotubes, which reaches several orders of magnitude in zigzag tubes. The transmission at Van Hove singularities (when nonzero) is of the order of unity and decays at a large axial distance R between the leads as R-2, similarly to monoatomic chains. The transmission in the band region of nanotubes shows two types of behavior depending on the divisibility by three of the difference between corresponding reduced nanotube indices n(')-m('). Close to the Fermi level the amplitude of the transmission function is independent from the chiral angle of the nanotubes and scales as an inverse square of their diameter.status: publishe

Novel type of magnetic response in carbon nanomaterials

We report quantum chemistry investigations of the magnetic response of large polycyclic hydrocarbons to a high magnetic field. In strong fields the magnetisation vs. field of nanosize molecules becomes strongly non-monotonic. For nanographenes containing thousands of atoms this effect develops at ca. 10(1)-10(2) T. It is related to the motion of vortices in the frontier molecular orbitals and transformations of ring current patterns. The described phenomenon is general, in principle observable in all conjugated planar nanosize molecules. (c) 2006 Elsevier B.V. All rights reserved.status: publishe