Abstract
The history of the genus Copemetopus is tortuous and studded with several misattributions. It was erected by Villeneuve-Brachon in 1940 after the discovery of Copemetopus subsalsus in saline ...ponds along the French coast of the Mediterranean Sea near Sète and associated with the class Heterotrichea in the family Metopidae, close to Bryometopus. After a long series of systematic revisions, it is now clear that Copemetopus is not a heterotrich and that it falls in the subphylum Intramacronucleata. Nevertheless, a lot more work is needed to fix the complex taxonomic status of the genus, which lacks a precise taxonomic collocation (it is presently referred to as incertae sedis). In the present study focused on a multidisciplinary and detailed description of a new species, of the genus, Copemetopus mystakophoros sp. nov., we also propose the erection of the new class, Copemetopea cl. nov. After careful literature and data revision, we believe that members of Copemetopus require a higher-ranked taxon in the phylum Ciliophora, given their molecular and morphological peculiarities.
The theory of branched-chain processes, created by the founder of the Russian school of chemical physics, Nikolai Nikolaevich Semenov, has become the foundation of modern ideas about the mechanism of ...gas-phase hydrocarbon conversion processes and the base for a deep understanding of the phenomena occurring in many related fields. However, throughout the 20th century, the chemical processing of hydrocarbon gases remained a secondary area of petroleum chemistry, since liquid petroleum hydrocarbons were the main hydrocarbon feedstock. A radical change in the situation after the start of industrial development of huge unconventional natural gas resources made it necessary to create cost-effective technologies for processing cheaper and more accessible gaseous hydrocarbons into basic petrochemical products. This article discusses new non-catalytic methods for processing hydrocarbon gases, developed at the Institute of Problems of Chemical Physics, Russian Academy of Sciences (IPCP RAS) and the Federal Research Center for Chemical Physics, Russian Academy of Sciences, and promising areas of their application.
—Luminescence caused by friction of heterogeneous solids (basalt and granite) was investigated, the spectra are recorded, and the dynamics of the luminescence intensity were studied. Under friction, ...the crystal lattices of these bodies are destroyed, and the luminescenting ≡Si–O
–
free radicals and Fe
3+
ions and electron traps located on the surface of microcracks are formed. The dynamics of accumulation of microcracks is investigated at a time resolution of 2 ns, and their sizes determined to be about 6–10 μm.
Symbioses between prokaryotes and microbial eukaryotes, particularly ciliated protists, have been studied for a long time. Nevertheless, researchers have focused only on a few host genera and ...species, mainly due to difficulties in cultivating the hosts, and usually have considered a single symbiont at a time. Here, we present a pilot study using a single-cell microbiomic approach to circumvent these issues. Unicellular ciliate isolation followed by simultaneous amplification of eukaryotic and prokaryotic markers was used. Our preliminary test gave reliable and satisfactory results both on samples collected from different habitats (marine and freshwater) and on ciliates belonging to different taxonomic groups. Results suggest that, as already assessed for many macro-organisms like plants and metazoans, ciliated protists harbor distinct microbiomes. The applied approach detected new potential symbionts as well as new hosts for previously described ones, with relatively low time and cost effort and without culturing. When further developed, single-cell microbiomics for ciliates could be applied to a large number of studies aiming to unravel the evolutionary and ecological meaning of these symbiotic systems.
Flowsheets based on the results of experimental studies and detailed kinetic modeling were suggested for oxidative cracking of oil refinery gas components to obtain ethylene, CO, and hydrogen. The ...calculations show that oxidative cracking alone does not allow production of ethylene and СО in ratios required for the further catalytic carbonylation and hydroformylation of ethylene. Matrix conversion of a part of oxy-cracking products is suggested as an additional step for producing CO and hydrogen.
The effect of carbon monoxide and hydrogen additions on partial gas-phase high-pressure oxidation of methane was studied experimentally. The maximum permissible concentrations of these components in ...the recycled gas were determined. The optimum multiplicity of the hydrocarbon gas recycling in the process was substantiated.
The Rac1-WAVE-Arp2/3 pathway pushes the plasma membrane by polymerizing branched actin, thereby powering membrane protrusions that mediate cell migration. Here, using knockdown (KD) or knockout (KO), ...we combine the inactivation of the Arp2/3 inhibitory protein arpin, the Arp2/3 subunit ARPC1A and the WAVE complex subunit CYFIP2, all of which enhance the polymerization of cortical branched actin. Inactivation of the three negative regulators of cortical branched actin increases migration persistence of human breast MCF10A cells and of endodermal cells in the zebrafish embryo, significantly more than any single or double inactivation. In the triple KO cells, but not in triple KD cells, the 'super-migrator' phenotype was associated with a heterogenous downregulation of vimentin (VIM) expression and a lack of coordination in collective behaviors, such as wound healing and acinus morphogenesis. Re-expression of vimentin in triple KO cells largely restored normal persistence of single cell migration, suggesting that vimentin downregulation contributes to the maintenance of the super-migrator phenotype in triple KO cells. Constant excessive production of branched actin at the cell cortex thus commits cells into a motile state through changes in gene expression.
Oxidative Cracking of Oil Refinery Gases Ozerskii, A. V.; Zimin, Ya. S.; Komarov, I. K. ...
Russian journal of applied chemistry,
12/2019, Volume:
92, Issue:
12
Journal Article
Peer reviewed
Trials of oxidative cracking of ethane—propane—
n
-butane mixtures were performed on an installation with the productive capacity with respect to the gaseous feed of 5 m
3
h
−1
. Ethylene, CO, and ...hydrogen are the major products of oxidative cracking of oil refinery gases; their total yield can exceed 90%. The yield of ethylene and CO is determined by the total concentration of alkanes in the mixture and is independent on the length of their hydrocarbon chain, whereas the hydrogen yield appreciably decreases with an increase in the alkane chain length. The trials demonstrated high efficiency of the production of ethylene, CO, and hydrogen by oxidative cracking of oil refinery gas mixture components.
Rickettsia‐like organisms (RLO) are obligate, often highly fastidious, intracellular bacterial parasites associated with a variety of vertebrate and invertebrate hosts. Despite their importance as ...causative agents of severe mortality outbreaks in farmed aquatic species, little is known about their life cycle and their host range. The present work reports the characterization of “Candidatus Cryptoprodotis polytropus,” a novel Rickettsia‐like bacterium associated with the common ciliate species Pseudomicrothorax dubius by means of the “Full‐Cycle rRNA Approach” and ultrastructural observations. The morphological description by in vivo and scanning electron microscopy and the 18S rRNA gene sequence of the host species is provided as well. Phylogenetic analysis based on the 16S rRNA gene supports the inclusion of “Candidatus Cryptoprodotis polytropus” within the family Rickettsiaceae (cl. Alphaproteobacteria) together with the genera Rickettsia and Orientia. Observations on natural ciliate populations account for the occasional nature of this likely parasitic association. The presence of a previously unknown RLO in ciliates sheds a new light on the possible role of protists as transient hosts, vectors or natural reservoir for some economically important pathogens.
