Stratwarm Effects in the Ionospheric D Region Wind Field

An analysis is made of the wind field structure in the strato-thermosphere over Eastern Siberia during the winter stratwarms of 1975-1977. It is found that coupling between dynamical processes in the stratosphere and lower thermosphere is effected through changes of the temperature regime of the atmosphere. The circulation regime both in the stratosphere and lower thermosphere depends on location of the source of perturbations that cause stratospheric warmings. The effect of warming-induced perturbations on the dynamics of above- and underlying layers and the meridional extent of the processes are determined by the altitude and region where anti-cyclones originate. In conditions of a warmer stratosphere, there is a considerable loss of wind stability in the ionospheric D-region. A time delay of 1 to 2 days of lower-thermosphere processes is found to occur with respect to stratospheric processes of temperature variation at 30 mb level

Confounding factors in ultrasound liver elastography. Part 1. General provisions and methodological errors

The aim of the study is a systematic analysis of literature data on the effect of methodological factors, artifacts, as well as external influences and features of the state of the organism on the results of ultrasonic elastography of the liver. Two-dimensional shear wave elastography is a highly accurate method for assessing the degree of liver fibrosis, provided that the study methodology is strictly followed, however, the influence of measurement disturbances should be taken into account. Confounding factors lead to an erroneous change in the liver stiffness from insignificant, within 5-10%, to considerable, catastrophically distorting the assessment of the degree of liver fibrosis. Confounding factors include three main groups: 1) methodologically determined, as well as physical artifacts and equipment features; 2) internal (endogenous) and 3) external (exogenous). The first group of confounding factors includes: non-observance by the operator of the standard rules for manipulating the probe, positional features of the patient, insufficient size of the window area of the area of interest, incorrect location of the area of interest, lack of adequate breath holding by the patient or the performing of his/her movements, insufficient number of measurements, large spread of recorded values, transmission pulsations from the heart and large vessels, features of the equipment used, physical essence of the elastographic method and artifacts

The crystal structure of fedotovite, K2Cu30(SO4) 3

Abstract The crystal structure of fcdotovite, K1CU30(S04h has been determined, space group C2/e, a 19.037(6), h 9.479(2), e 14.231(5) A,~1 11.04(3t, Z = 8, Dx = 3.09 g/cm3. The main units of the fedotovite structure are formed around two additional oxygen atoms and consist of edge-sharing [OCU4J tetrahedra and four [S04J tetrahedra attached to them. The units are further connected by two [S04J tetrahedra, building distinct layers parallel to the yz plane. These layers are interconnected by potassium atoms. In the fedotovite structure, the three kinds of copper atoms are fivefold (4 + 1) coordinated to oxygen atoms with a strong Jahn-Teller effect. The coordination polyhedra of Cui and Cu2 atoms are distorted and flattened orthorhombic pyramids with Cu-O distances varying from 1.912 to 2.333 A,. the sixth neighbour of the both atoms is the copper atom lying at 2.975 and 2.981 Afor Cu2 and Cui respectively. The coordination environment of the Cu3 atom is a distorted elongated orthorhombic pyramid with four Cu-O distances from 1.943 to 1.961 A, a fifth at 2.558 A, and further sixth and seventh neighbours (oxygen and copper atoms) at 2.809 and 2.806 A, respectively

The Planetary Wave Activity in Temperatures of the Stratosphere, Mesosphere and in Critical Frequencies of Ionospheric F2 Layer

A large body of experimental evidence lends credit to the existence of a close relationship between ionospheric parameters and the underlying atmosphere. Vertical-incidence ionospheric sounding data and temperature measurements at stratospheric (30 km) and mesospheric (80 km) heights have been used in investigating the interrelation between the occurrence of fluctuations with periods of planetary waves in temperature variations at different heights and in F2 layer critical frequency variations (foF2) under low solar activity conditions for the time interval 2006-2007. The distinctive characteristics of the manifestation of common periodicities of the wave structures under consideration are discussed. The statistically significant periods of stratospheric and mesospheric temperature fluctuations vary from 11 to 49 days, whereas foF2 periodograms show higher-frequency fluctuations with periods of 5, 8, 9, and 10 days. The study revealed a similarity between periodic structures for the variations in the parameters involved

Genome-wide Association Study of Long COVID

SummaryInfections can lead to persistent or long-term symptoms and diseases such as shingles after varicella zoster, cancers after human papillomavirus, or rheumatic fever after streptococcal infections1, 2. Similarly, infection by SARS-CoV-2 can result in Long COVID, a condition characterized by symptoms of fatigue and pulmonary and cognitive dysfunction3–5. The biological mechanisms that contribute to the development of Long COVID remain to be clarified. We leveraged the COVID-19 Host Genetics Initiative6, 7to perform a genome-wide association study for Long COVID including up to 6,450 Long COVID cases and 1,093,995 population controls from 24 studies across 16 countries. We identified the first genome-wide significant association for Long COVID at theFOXP4locus.FOXP4has been previously associated with COVID-19 severity6, lung function8, and cancers9, suggesting a broader role for lung function in the pathophysiology of Long COVID. While we identify COVID-19 severity as a causal risk factor for Long COVID, the impact of the genetic risk factor located in theFOXP4locus could not be solely explained by its association to severe COVID-19. Our findings further support the role of pulmonary dysfunction and COVID-19 severity in the development of Long COVID.</jats:p

Raman Spectroscopic Study of the Basic Copper Sulphates - Implications for Copper Corrosion and Bronze Disease

The basic copper sulphates are of interest because of their appearance in many environmental situations such as copper pipe corrosion, restoration of brass and bronze objects, leaching from waste mineral dumps and the restoration of frescoes. The Raman spectra of the basic copper sulphate minerals antlerite, brochantite, posnjakite and langite are reported using a Nd-Yag laser operating at an excitation wavelength of 780 nm. In line with their crystal structures, each basic copper sulphate mineral has its own characteristic Raman spectrum, which enables their identification. Except for brochantite multiple bands are observed for the SO stretching vibration. Similarly multiple bands are observed for the antisymmetric SO and OSO bending regions. Hydroxyl deformation modes in the 730 to 790 cm-1 region are observed. The use of the HeNe laser operating at an excitation wavelength of 633 nm enabled the hydroxyl stretching bands of the minerals to be obtained. Antlerite and brochantite are characterised by hydroxyl stretching bands at 3580 and 3488 cm-1. The minerals posnjakite and langite display Raman hydroxyl-stretching vibrations at 3588 and 3564 cm-1. The Raman spectra of these two minerals show water OH-stretching bands at 3405, 3372 and 3260 cm-1. Raman spectroscopy allows the ready identification of these minerals

Mesospheric, lower thermospheric dynamics and external forcing effects: A review

7-36A review is presented on some of the most important experimental results and models obtained by international scientific community during last decade for the mesospheric and lower thermospheric dynamics (mean winds, planetary waves, tides and internal gravity waves). In addition to climatological features, the external forcing – the coupling from below (stratosphere) and possible influence of solar and geomagnetic activity on the dynamical processes at this region are presented