Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity

Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant

Active control of V/STOL aircraft

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN004393 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The Scottish Motor Neuron Disease Register: a prospective study of adult onset motor neuron disease in Scotland. Methodology, demography and clinical features of incident cases in 1989

The Scottish Motor Neuron Disease Register (SMNDR) is a prospective, collaborative, population based study of motor neuron disease (MND) in Scotland. The register started in January 1989 with the aim of studying the clinical and epidemiological features of MND by prospectively identifying incident patients. It is based on a system of registration by recruitment from multiple sources, followed by the collection of complete clinical data and follow up, mainly through general practitioners. In this report the register's methodology and the demography and incidence data for the first year of study are presented. One hundred and fourteen newly diagnosed patients were identified in 1989 giving a crude incidence for Scotland of 2.24/100,000/year. Standardised incidence ratios showed a non-significant trend towards lower rates in north eastern regions and island areas

The effects of ferromagnesian components on the paragonite-muscovite solvus: a semiquantitative analysis based on chemical data for natural paragonite-muscovite pairs.

Chemical data for 139 natural paragonite-muscovite (Pg-Ms) pairs illustrate the effects of ferromagnesian components on the P-T-X topology of the Pg-Ms solvus. The pairs were selected on the basis of: reasonably accurate knowledge of the P-T conditions of formation; evidence for close approach to equilibrium at peak metamorphic conditions; exclusion of pairs in which paragonite contains more than 5 mol% margarite; and exclusion of pairs from polymetamorphic rocks that contain more than one set of cogenetic Pg-Ms pairs. Graphical analysis reveals considerable scatter in the data; nevertheless, it is evident that the muscovite limb of the solvus shifts markedly toward end-member muscovite with increasing pressure from approximately 7 kbar to 21 kbar. This shift is attributed to a pressure-induced increase of the ferromagnesian content of muscovite, which increases the size of the XII alkali site - to the effect that K is more readily accommodated than Na. The data also suggest that the paragonite limb of the solvus migrates slightly toward end-member paragonite with increasing pressure. Broadening of the Pg-Ms solvus with increasing pressure reflects increasingly nonideal Na-K mixing as the phengite content of muscovite increases. Due to the wide scatter of data for Pg-phengitic-Ms pairs, it is concluded that, at the present time, Pg-Ms solvus thermometry is only viable for quasibinary Pg-Ms pairs