Study of human erythrocyte membrane proteins by 2-dimensional electrophoresis

Fractionation of human erythrocyte membrane proteins was performed using a modification of two-dimensional gel electrophoresis described by P. O'Farrel with isoelectric point plotted against molecular mass. All major erythrocyte proteins, including high molecular weight proteins, such as spectrin and band 3 protein, identified by one-dimensional sodium dodecyl sulfate gel electrophoresis, were visualized by silver staining of two-dimensional gels. All in all about 50 polypeptides were distinguished on two-dimensional electrophoretic patterns. Preliminary protein map was developed.     

Extrapolating predation mortalities back in time: an example from North-east Arctic cod cannibalism

Cannibalism is known to be a significant source of natural mortality of young North-east Arctic (NEA) cod. Cannibalism data, starting from 1984, have been used in NEA cod stock assessments since 1995, which has led to inconsistency in the cod abundance time series from 1946 to the present. To address this inconsistency, this study estimates the cannibalism-induced mortality (M2) of NEA cod at age 3–5 for the period 1946–1983. Combined qualitative and quantitative cod stomach content data for 1984–2010 were used to make the M2 estimations for age groups 3–5 (ICES 2014), then different factors including SSB were used to examine which covariates explained variability in M2 and thus make predictions for 1946–1983. The level of cannibalism was estimated to be high in the 1950s – early1960s. VPA-based assessment was run using these estimated M2 values. As a result, numbers of cod eaten by their conspecifics in the historical period and new increased recruitment estimates at age 3 were computed. The main factors affecting cannibalism appeared to be young cod abundance, total stock biomass (TSB) of large cod, and capelin total stock biomass (which represents an alternative prey). The problems involved in using the new recruitment time series in fishery management are discussed. The methodology presented here represents a generic approach to extending predation mortalities back in time to improve historical stock estimates.     

Loss of hydrogen atoms in H<Subscript>2</Subscript> plasma on the surfaces of materials used in EUV lithography

Low-pressure hydrogen is an important component of the working medium in extreme ultraviolet (EUV) projection lithography. Under the action of EUV photons and fast secondary electrons on the gas medium, plasma and atomic hydrogen, actively interacting with the surface, are produced. This interaction is very important, because it largely determines the lifetime of the multilayered EUV optics. In this study, the loss of atomic hydrogen under the conditions of a low pressure (<10 Torr) RF plasma discharge on the surfaces of materials used in EUV lithography is investigated. The surface loss probabilities of H atoms on these materials are measured. It is shown that surface recombination of atomic hydrogen goes according to the Eley-Rideal mechanism via direct recombination of H atoms from the gas phase with chemically and physically adsorbed atoms. In this case, the surface recombination probability is mainly determined by the density of chemical adsorption sites. The density of adsorption sites and the desorption energy of H atoms are estimated. The desorption energy of physically adsorbed H atoms on pure metal surfaces (or surfaces exposed to plasma) is about 0.5 eV, and the density of sorption sites is close to the surface density of atoms. This results in a high loss probability of H atoms on metals (∼0.1). Therefore, to provide efficient transportation of hydrogen atoms, it is necessary to use materials with the lowest loss probability of H atoms, i.e., dielectrics.     

On the Persistence of Populations of Three Adventive Species of the Weevil Genus Otiorhynchus Germ. (Coleoptera,Curculionidae: Entiminiae) on Lilacs (Syringa L.) in St. Petersburg in 2018

Entomological Review - In 2018, all the three species of the weevil genus Otiorhynchus Germ.: O. albidus Stierlin, O. asphaltinus Germar, and O. rotundus Marseul, first recorded from St. Petersburg...     

The Skeletal System as an Additional Storage System for Iodine Isotopes

Biophysics - Using the gamma-spectrometric method we found that the radioactive isotope 125I, when entering the body of a rat, actively accumulated not only in the thyroid gland, but also in the...     

A Review of the Genus Eucnemis Ahrens, 1812 (Coleoptera,Eucnemidae) from Russia

Entomological Review - The genus Eucnemis Ahrens, 1812 of the Russian fauna is revised. A new species, Eu. anachoreta sp. n. is described from Kunashir Island, the Kuril Archipelago. A key to the...     

On the rate of evolutionary processes in solitary population waves: Phase transitions in microevolution

It is shown that, like physical systems, populations of species can be in different phases, depending on environmental conditions. These phases, like phases of physical systems, are described by specific state equations. The physical phenomenon of solitary population waves is revealed for the phase of invasion of organisms into their secondary range. The mathematical model has a solution in the form of a solitary wave propagating with a constant speed without changes in shape. The self-organization in solitary waves differs sharply from population processes in the primary species range and is close to the physical foundation of the theory of autosolitons. Solitary waves are impossible within the primary species range. A capacity for the formation of solitary waves is only revealed in phylogenetically young “juvenile taxa.” These coenophobes show the highest rates of adaptive changes, are provoked to expand into new areas. Their phase transitions are distinguished not only by an exclusively wide range of fluctuations of population density, but also high phenotypic variability. The macroevolutionary processes can be provided by juvenile taxa in solitary population waves formed as a result of disruption of ecosystems and invasions. Macrotaxa cannot appear in stable successional systems.