The Influence of SARS-CoV-2 Variants on National Case-Fatality Rates: Correlation and Validation Study.

Background: In 2021, new variants of the SARS-CoV-2 virus appeared with increased transmissibility and virulence as compared with the original wild variant. The first variants of concern (VoCs), Alpha (B1.1.

Risk Factors of SARS-CoV-2 Infection: Global Epidemiological Study.

Background: Since the first recognition of the pandemic characteristics of SARS-CoV-2 infection, and before substantial case fatality data were available worldwide, public health agencies warned the public about the increased dangers of SARS-CoV-2 to persons with a variety of underlying physical conditions, many of which are more commonly found in persons over 50 years of age or in certain ethnic groups.

Objective: To investigate the statistical rather than the physiological basis in support of the abovementioned warnings, this study examines correlations globally on a nation-by-nation basis between the statistical data concerning COVID-19 fatalities and the statistics of potential comorbidities that may influence the severity of infection.

Methods: This study considers the statistics describing the populations of the 99 countries with the greatest numbers of SARS-CoV-2 infections at the time of the data cutoff.

Laser-slicing at a low-emittance storage ring.

Laser-slicing at a diffraction-limited storage ring light source in the soft X-ray region is investigated with theoretical and numerical modelling. It turns out that the slicing efficiency is favoured by the ultra-low beam emittance, and that slicing can be implemented without interference to the standard multi-bunch operation. Spatial and spectral separation of the sub-picosecond radiation pulse from a hundreds of picosecond-long background is achieved by virtue of 1:1 imaging of the radiation source.

Ion source issues for the DAEδALUS neutrino experiment.

The DAEδALUS experiment calls for 10 mA of protons at 800 MeV on a neutrino-producing target. To achieve this record-setting current from a cyclotron system, H2 (+) ions will be accelerated. Loosely bound vibrationally excited H2 (+) ions inevitably produced in conventional ion sources will be Lorentz stripped at the highest energies.