The morphology, phylogenetic position, and distribution of a recently revalidated species of leuciscid minnow, Phoxinus isetensis, were substantially clarified. The species was described in the late ...18th century from the Middle Urals but later synonymized with Phoxinus phoxinus. As believed, P. isetensis is distributed in the Arctic Ocean catchment from the Murman coast via West and East Siberia until the Pacific Ocean catchment in Far East and Northeastern Asia. Our study, with the use of mtDNA markers coupled with extensive morphological data, showed that the distribution of P. isetensis is greatly different. Currently, this is the most widespread Phoxinus species in Europe, distributed in Northern and Western Europe and on the eastern edge of Siberia (Iset and Ural basins). In particular, P. isetensis inhabits the basins of the Caspian, Baltic, White, Barents, and Kara seas, possibly occurring in the North Sea basin. The species was redescribed, and the type locality and neotype were designated. The main morphological difference from other Phoxinus spp. is the large total number of vertebrae (39–43, mode 41) due to an increase in the number of caudal vertebrae (16–21, mode 19). Phylogenetically, P. isetensis is a sister to the Caucasian species P. colchicus (p -distance = 5%). The wide distribution of P. isetensis within the area of the Last Glacial Maximum suggests rapid colonization of deglaciated regions, probably due to its adaptation to a cold climate.
•Extracellular peptidases can serve as markers of ecological features of fungi.•Asco- and basidiomycetes secrete mainly serine and metallopeptidases, respectively.•The species of pathogenic fungi ...secrete trypsin-like peptidases.•The role of secreted enzymes in proteolysis depends on community composition.
Fungi produce extracellular peptidases to break down proteins and polypeptides into smaller soluble molecules. These molecules are subsequently transported into the fungal cell, supplying osmotrophic nutrition. Although a variety of extracellular peptidases have been isolated from numerous fungal species, it remains largely unknown how the spectrum of secreted peptidases correlates with fungal ecology and taxonomy. In this study, we cultivated 17 fungal species on protein-enriched medium to compare the spectra of secreted peptidases produced by the fungi belonging to different ecological groups (pathogens, saprotrophs, symbionts) and taxonomic phyla (Ascomycota and Basidiomycota). Basidiomycetes predominantly produced metallopeptidases with neutral pH optima, while the species of ascomycetes secreted serine peptidases with alkaline pH optimum, mostly of the subtilisin-type. Fungal species with dominant activity of serine peptidases had, in general, much higher peptidase activity and were better adapted to growth on protein medium compared to the species with dominant metallopeptidase activity. Pathogenic fungi effectively cleaved the synthetic substrate specific for trypsin-like peptidases, while saprotrophic species were characterized by a relatively high aminopeptidase activity. Nevertheless, fungi have numerous genes encoding various types of peptidases, the spectra of fungal enzymes secreted on cultivation medium were to a major extent represented by the production of one class of peptidases that correlated with fungal taxonomic phylum. We suppose fungal strategies for cleaving polypeptides in experimental conditions are largely predetermined both by trophic status and phylogeny.
The paper presents an application of the Conditionally-Minimax Nonlinear Filtering (CMNF) algorithm to the online estimation of underwater vehicle movement given a combination of sonar and Doppler ...discrete-time noisy sensor observations. The proposed filter postulates recurrent "prediction-correction" form with some predefined basic prediction and correction terms, and then they are optimally fused. The CMNF estimates have the following advantageous features. First, the obtained estimates are unbiased. Second, the theoretical covariance matrix of CMNF errors meets the real values. Third, the CMNF algorithm gives a possibility to choose the preliminary observation transform, basic prediction, and correction functions in any specific case of the observation system to improve the estimate accuracy significantly. All the features of conditionally-minimax estimates are demonstrated by the regression example of random position estimate given the noisy bearing observations. The contribution of the paper is the numerical study of the CMNF algorithm applied to the underwater target tracking given bearing-only and bearing-Doppler observations.
The review focuses on the surface modification of Zr and its alloys, which is necessary to expand the applications of these kinds of materials. Data on the properties of pure zirconium and its alloys ...are presented. Since surface engineering and the operation of the above materials are in most cases associated with the formation of oxide coatings, information on the characteristics of ZrO2 is given. In addition, attention is paid to phasing in the zirconium–oxygen system. It is noted that the most effective method of surface engineering of Zr and its alloys is plasma electrolytic modification (PEM) technology. Specific examples and modes of modification are described, and the reached results are analyzed. The relevance, novelty and originality of the review are determined by the insufficient knowledge about a number of practical features concerning the formation of functional oxide coatings on Zr and some of its alloys by the technology of PEM. In particular, the information on the phase composition and possibilities of stabilization of the tetragonal and cubic modifications of ZrO2, the effects of the component composition of electrolyte solutions and electrolyte suspensions, and the specifics of the treatment of additive shaping and deformed materials are rather contradictory. This review aims to collect recent advances and provide insights into the trends in the modification of Zr and its alloys, promote the formulation of practical recommendations and assess the development prospects.
Interference immunity of image transmission channel Bastrychkin, Alexander S.; Borisov, Dmitry A.; Khizrieva, Natalia I. ...
2018 7th Mediterranean Conference on Embedded Computing (MECO),
2018-June
Conference Proceeding
Methods to increase the efficiency of image transmission via communication channels are considered. An algorithm to increase confidentiality of image transmission channels used in conjunction with an ...algorithm for transmitting spectral representation without constant components (with their further restoration) is offered.
Cellular respiration is associated with at least six distinct but intertwined biological functions. (1) biosynthesis of ATP from ADP and inorganic phosphate, (2) consumption of respiratory ...substrates, (3) support of membrane transport, (4) conversion of respiratory energy to heat, (5) removal of oxygen to prevent oxidative damage, and (6) generation of reactive oxygen species (ROS) as signaling molecules. Here we focus on function #6, which helps the organism control its mitochondria. The ROS bursts typically occur when the mitochondrial membrane potential (MMP) becomes too high, e.g., due to mitochondrial malfunction, leading to cardiolipin (CL) oxidation. Depending on the intensity of CL damage, specific programs for the elimination of damaged mitochondria (mitophagy), whole cells (apoptosis), or organisms (phenoptosis) can be activated. In particular, we consider those mechanisms that suppress ROS generation by enabling ATP synthesis at low MMP levels. We discuss evidence that the mild depolarization mechanism of direct ATP/ADP exchange across mammalian inner and outer mitochondrial membranes weakens with age. We review recent data showing that by protecting CL from oxidation, mitochondria-targeted antioxidants decrease lethality in response to many potentially deadly shock insults. Thus, targeting ROS- and CL-dependent pathways may prevent acute mortality and, hopefully, slow aging.
•We compare archival (AEU) and perceptual (PEU) data on Environmental Uncertainty.•Result: longitudinal AEU and PEU correlate just moderately but significantly.•Causes of differences: decision unit, ...predictability, use of leading indicators.•Conclusion: AEU and PEU are proxies for each other but not perfect substitutes.•Data: archival and survey from 60 large, listed German companies/top executives.
Environmental uncertainty is a major determinant in many managerial decisions and evaluations. Yet, there is no consensus what constitutes a valid measure of uncertainty to which executives can respond. This paper explicates conceptual and methodological differences between Archival Environmental Uncertainty (AEU) and Perceived Environmental Uncertainty (PEU).
Conceptually, we discuss the controversial development of these measures in the literature. We propose a framework showing that AEU and PEU differ due to the specificity of the decision unit, the predictability of volatility, and the use of leading indicators.
Empirically, we are the first to investigate the statistical association between prevailing measures of AEU and PEU. Our analysis combines archival data on AEU (annual reports) with survey data on PEU from top executives of the 110 largest listed German companies (55% response). As predicted, AEU and PEU correlate moderately on a significant level (r=0.257 to 0.374). Also, AEU indicators (mainly volatility in sales and earnings) explain over 26% of the PEU measure. Yet, adjustment of the AEU measure for predictable volatility does not improve its relationship to PEU. Overall, our findings imply that AEU and PEU are not perfect substitutes, but valid proxies for each other if the relevant limitations are considered.
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