Search results for "Sedimentation"
showing 10 items of 118 documents
The molecular heterogeneity of hemocyanin: Structural and functional properties of the 4×6-meric protein of Upogebia pusilla (Crustacea)
2006
The structural properties of the hemocyanin isolated from the Mediterranean mud shrimp, Upogebia pusilla (Decapoda: Thalassinidea), were investigated. Our intent was to make use of the U. pusilla case to perform a structural comparison between crustacean and chelicerate 4×6-meric hemocyanins. The thalassinidean hemocyanin appears similar in size but different in structural organization compared to the chelicerate 4×6-mer. Ultracentrifuge analyses on the purified protein revealed a sedimentation coefficient of 39S, typical of 4×6 hemocyanins. Electron micrographs are in agreement with a model in which four 2×6-meric building blocks are arranged in a tetrahedron-like quaternary structure and …
Clinical characteristics of COVID-19 patients in Latvia under low incidence in Spring 2020
2020
ABSTRACTBackgroundCOVID-19 is a new infectious disease with severe disease course and high mortality in some groups. Blood tests on admission to the hospital can be useful for stratification of patients and timely correction. Our study investigated the clinical features of COVID-19 patients in Latvia and differences in blood tests in groups with different disease severity.MethodsThe retrospective study included 100 patients hospitalized in Riga East Clinical University Hospital in Spring 2020. The severity of the disease course was classified by the presence of pneumonia and its combination with respiratory failure. We have assessed blood cells’ count, hemoglobin, hematocrit, erythrocyte se…
Tectono-biosedimentary recordings at the Lias-Dogger transition: example of the Quercy carbonate platform (Aquitaine Basin, France).
2007
AbstractOn the eastern edge of the Aquitaine Basin, the Lias-Dogger transition and the events, which occurred during this time interval are studied in the Quercy sedimentary basin. Stratigraphic correlations are proposed using a biochronological calibration based on the determination of numerous ammonites and brachiopods. Facies analyses using statistical processing integrate the presence of faults and tectonic compartments and lead to reconstruction of palaeoenvironments in space and time. The paper includes the description of system tracts following Haq et al. [1987] and Vail et al. [1991], and twelve palaeogeographic maps of the area studied. The objectives are to distinguish the various…
2018
Abstract. Mineral dust is an important component of the climate system, affecting the radiation balance, cloud properties, biogeochemical cycles, regional circulation and precipitation, as well as having negative effects on aviation, solar energy generation and human health. Dust size and composition has an impact on all these processes. However, changes in dust size distribution and composition during transport, particularly for coarse particles, are poorly understood and poorly represented in climate models. Here we present new in situ airborne observations of dust in the Saharan Air Layer (SAL) and the marine boundary layer (MBL) at the beginning of its transatlantic transport pathway, f…
Evidence of the Zanclean megaflood in the eastern Mediterranean Basin
2018
A. Micallef et. al.
1953
Sur une serie de palymethacrylates de methyl fractionnes des mesures de la diffusion lumineuse (en fonction de I'angle et de la longeur d'onde) on ete faites, puis la constante de diffusion, la constante de sedimentation dans I'ultrazentrifugeuse et la viscosite intrinshque [η] ont ete determines. Les poids moleculaires et les diametres des chaines souples sont en concordance d'apres ces methodes. La dependance des diametres des chaines sonples d,l du poids molkculaire est un peu plus forte que d'aprh la loi de Kuhn (dst ≃ M0.6). L'influence de cette decouverte sur la fonction de la diffusion lumineuse de mihe que sur l'equation de la viscosite de Kirkwood et Riseman est etudiee. Light-scat…
Depositional architecture and geometric arrangement of Terravecchia Formation within the Scillato Basin (NW Sicily)
2008
Taphonomic sequences—A new tool for sequence stratigraphy
2002
The Middle-Upper Jurassic boundary in western Europe is characterized by extensive condensed sections containing authigenic minerals together with abundant and varied fossils, both reworked and not reworked. We have analyzed ammonite shells and chronologically ordered taphonomic events in a taphonomic sequence extending from the time the dead organism settled on the seafloor to the time it became permanently incorporated in the sediment. Three types of taphonomic sequence are recognized; they are characteristic of (1) sedimentation in depositional environments having little and only occasional hydrodynamic activity (coinciding with periods of increasing accommodation), (2) sedimentation dur…
Solid sediment transport in turbulent channel flow over irregular rough boundaries
2017
Abstract The presence of a loading of dispersed particles in a turbulent flow affects the dynamics of the carrier flow field which, in turn, drives grains movement. The focus of the paper is on the analysis of the coupling effects between near-bed turbulence structures and the dynamics of dispersed suspended solid particles in wall-bounded turbulent multiphase flows. We consider turbulent horizontal channel flows bounded by rough boundaries. The friction Reynolds number of the unladen flow is R e τ = 180 and the dispersed phase spans one order of magnitude of particle diameter. To analyze sedimentation and suspended phase transport, we adopt concepts and modeling ideas derived from the Eule…