Cleaner Skies during the COVID-19 Lockdown

During spring 2020, the COVID-19 pandemic caused massive reductions in emissions from industry and ground and airborne transportation. To explore the resulting atmospheric composition changes, we conducted the BLUESKY campaign with two research aircraft and measured trace gases, aerosols, and cloud properties from the boundary layer to the lower stratosphere. From 16 May to 9 June 2020, we performed 20 flights in the early COVID-19 lockdown phase over Europe and the Atlantic Ocean. We found up to 50% reductions in boundary layer nitrogen dioxide concentrations in urban areas from GOME-2B satellite data, along with carbon monoxide reductions in the pollution hot spots. We measured 20%-70% reductions in total reactive nitrogen, carbon monoxide, and fine mode aerosol concentration in profiles over German cities compared to a 10-yr dataset from passenger aircraft. The total aerosol mass was significantly reduced below 5 km altitude, and the organic aerosol fraction also aloft, indicative of decreased organic precursor gas emissions. The reduced aerosol optical thickness caused a perceptible shift in sky color toward the blue part of the spectrum (hence BLUESKY) and increased shortwave radiation at the surface. We find that the 80% decline in air traffic led to substantial reductions in nitrogen oxides at cruise altitudes, in contrail cover, and in resulting radiative forcing. The light extinction and depolarization by cirrus were also reduced in regions with substantially decreased air traffic. General circulation-chemistry model simulations indicate good agreement with the measurements when applying a reduced emission scenario. The comprehensive BLUESKY dataset documents the major impact of anthropogenic emissions on the atmospheric composition.

Detection of humoral and cellular responses to SARS-CoV-2 in COVID-19 convalescents

Introduction: The emergence of SARS-CoV-2 virus, which causes COVID-19, is a major global health hazard. Therefore, a comprehensive characterization of the humoral and cellular immune responses to this virus is essential to combat the COVID-19 pandemic. Our goal was to develop reliable methods and tools for the analysis of humoral and cellular B- and T- cell responses, which will facilitate scientific research for prediction of disease progression, long-term immunity and will support vaccine development. Methods: Plasma samples and PBMCs of COVID-19 convalescent and healthy donors were obtained. For the detection of SARS-CoV-2 specific antibodies and identification of antigen-specific B cells, we manufactured recombinant mono-biotinylated protein variants of the Spike (S), Receptor Binding Domain (RBD) and Nucleoprotein (N). To identify antigen-reactive T cells, SARS-CoV-2 peptide pools were synthetized for the S, N and Membrane (M) antigens and used for stimulation. The peptide pools consist of mainly 15-mer peptides having an 11-mer amino acid overlap and thereby overspan a whole protein sequence. Results: To determine the presence of SARS-CoV-2 reactive antibodies a flow-based bead assay using recombinant, mono-biotinylated SARS-CoV-2 antigens loaded onto Streptavidin (SAV)-coated-PMMA beads was set up. The beads were incubated with plasma samples and fluorochrome conjugated anti-human isotype specific antibodies for flow cytometric analysis. All the antigens tested were shown to be suitable for the detection of antibodies to SARS-CoV-2 in COVID-19 convalescent plasma. To assess the feasibility of recombinant antigens for the detection and isolation of antigen-specific B cells, the mono-biotinylated Spike and RBD antigens were tetramerized on fluorochrome-conjugated SAV. These tetramers were used for staining, magnetic enrichment and flow cytometric sorting of B cells specific to SARS-CoV-2 antigens. We were able to demonstrate that our recombinant antigens can be used to assess the presence and enable the phenotyping and isolation of rare antigen-specific B cells. For further characterization of the SARS-CoV-2 reactive T cell immunity PBMCs were short term stimulated with the S, M and N peptide pools. After intracellular staining of IFNg, TNFa, IL-2 and CD154, reactive T cells were detected using flow cytometry. We could demonstrate T cell reactivity towards each peptide pool. However, strengths of T cell responses towards the S, M and N peptide pools were heterogeneous between different COVID-19 convalescent individuals. Conclusion: To support and improve current research activities for the identification and characterization of SARS-CoV-2 reactive humoral and cellular B- and T- cell responses, potent tools and assays were developed. Described here research solutions offer the opportunity to successfully address and contribute to the investigation on healthy and dysfunctional immune reactions towards SARS-CoV-2.

CNN-powered body and face detection for intelligent people counting in Covid-19 restricted places

In the reality of 2021's Covid-19 pandemic there are a lot of government's restrictions made to reduce the virus spread speed in the society. One of the examples of such restrictions are the people per square meter limit in public places and shopping malls. Because manual counting of each person in such places is not possible due to limited time and money resources, this limit restriction is widely abused making the pandemic outbreak more dangerous. To face this problem author has presented a novel face and body detection model for the CCTV (Closed Circuit Television) monitoring systems, that automatically counts the amount of people in the monitored area by the use of Deep Learning. © 2021 Copyright for this paper by its authors.

Some aspects of labour law’s protective function at the time of COVID-19

The COVID-19 epidemic has had a substantial impact on Polish legislation since the beginning of 2020. The economic slowdown and the consequent fall in the state budget revenue are among the anticipated effects of the epidemic. As a result, provisions introducing lex specialis to the Labour Code and certain employment regulations specifying dissolution of employment relationships in some public administration organisations became part of the COVID-19 Act. The new legal construct comes down to extensive facilitation in the process of redundancies for employers dismissing their employees. The protective function of labour law provisions insofar as it upholds duration of the employment relationship is consequently restricted. Provisions of the COVID-19 Act in this respect are unacceptable. Each regulation should arise from objectively identified needs to legally govern social relationships and should not inflate laws or undermine citizens’ trust in legislation. The postulate of this legal direction of determining social relationships is particularly important with regard to relationships of employment, in particular, those founded on appointment in public administration. The possibility of identical treatment of employees hired on various legal grounds merely appears to conform with the constitutional protection of equality in law. Without detriment to employers’ right to determine employment levels, the new regulations in connection with the COVID-19 epidemic seem unnecessary, since their objectives can be attained by application of normal remedies provided for by labour law. © 2021, Wydawnictwo Uniwersytetu Marii Curie-Sklodowskiej w Lublinie. All rights reserved.