Experimental-Calculated Establishment of Load-Speed Modes of Operation of UHMWPE and Composite On its Basis

Выявлены закономерности изнашивания, позволяющие определить работоспособность разработанных полимерных материалов на основе СВМПЭ в подшипниковых узлах трения при изменении режимов эксплуатации. Предельно допустимые режимы эксплуатации материалов подтверждены математическими расчетамиThe regularities of wear are revealed, which make it possible to determine the performance of the developed polymeric materials based on UHMWPE in bearing friction units when operating modes change. The maximum allowable modes of operation of materials are confirmed by mathematical calculation

Predictive risk factors before the onset of familial rheumatoid arthritis: the Tatarstan cohort study

BackgroundA familial history of rheumatoid arthritis (RA) predisposes an individual to develop RA. This study aimed at investigating factors associated with this conversion from the Tatarstan cohort.MethodsA total of 144 individuals, referred to as pre-RA and at risk for familial RA, were selected 2 years (range: 2–21 years) before conversion to RA and compared to non-converted 328 first-degree relatives (FDR) from RA as assessed after ≥2 years follow-up, and 355 healthy controls were also selected (HC). Preclinical parameters and socio-demographic/individual/HLA genetic factors were analyzed when data were available at the time of enrollment.ResultsAs compared to FDR and HC groups, pre-RA individuals were characterized before conversion to RA by the presence of arthralgia, severe morning symptoms, a lower educational level, and rural location. An association with the HLA-DRB1 SE risk factor was also retrieved with symmetrical arthralgia and passive smoking. On the contrary, alcohol consumption and childlessness in women were protective and associated with the HLA-DRB1*07:01 locus.ConclusionBefore RA onset, a combination of individual and genetic factors characterized those who are at risk of progressing to RA among those with familial RA relatives

On-line change-point detection procedures for Initial Public Offerings

  In this thesis we investigate the case of monitoring of stocks havingjust been introduced for public trading on the nancial market. Theempirical distribution of the change-point for 20 assets for 60 days was calculated to check the support for the assumption that the priceinitially drop or rise to some steady level.The price process X = {Xt : t in Z} is assumed to be an AR(1) process with a shift in the mean value from a slope to a constant. The Shiryaev-Roberts, Shewhart, EWMA, Likelihood ratio and CUSUM proceduresfor detecting a change-point in such a process are derived. The expecteddelay of the motivated alarm according to these methods is achievedunder the assumptions of a Poisson, uniform, binomial and geometric distributed by means of simulations.     

Alterations in the Transcriptome of Rye Plants following the Microdochium nivale Infection: Identification of Resistance/Susceptibility-Related Reactions Based on RNA-Seq Analysis

Microdochium nivale is a progressive and devastating phytopathogen that causes different types of cereal crop and grass diseases that are poorly characterized at the molecular level. Although rye (Secale cereale L.) is one of the most resistant crops to most of the phytopathogens, it is severely damaged by M. nivale. The recent high-quality chromosome-scale assembly of rye genome has improved whole-genome studies of this crop. In the present work, the first transcriptome study of the M. nivale-infected crop plant (rye) with the detailed functional gene classification was carried out, along with the physiological verification of the RNA-Seq data. The results revealed plant reactions that contributed to their resistance or susceptibility to M. nivale. Phytohormone abscisic acid was shown to promote plant tolerance to M. nivale. Flavonoids were proposed to contribute to plant resistance to this pathogen. The upregulation of plant lipase encoding genes and the induction of lipase activity in M. nivale-infected plants revealed in our study were presumed to play an important role in plant susceptibility to the studied phytopathogen. Our work disclosed important aspects of plant-M. nivale interactions, outlined the directions for future studies on poorly characterized plant diseases caused by this phytopathogen, and provided new opportunities to improve cereals breeding and food security strategies

The Role of Intercellular Signaling in the Regulation of Bacterial Adaptive Proliferation

Bacterial adaptation is regulated at the population level with the involvement of intercellular communication (quorum sensing). When the population density is insufficient for adaptation under starvation, bacteria can adjust it to a quorum level through cell divisions at the expense of endogenous resources. This phenomenon has been described for the phytopathogenic bacterium Pectobacterium atrosepticum (Pba), and it is called, in our study, adaptive proliferation. An important attribute of adaptive proliferation is its timely termination, which is necessary to prevent the waste of endogenous resources when the required level of population density is achieved. However, metabolites that provide the termination of adaptive proliferation remained unidentified. We tested the hypothesis of whether quorum sensing-related autoinducers prime the termination of adaptive proliferation and assessed whether adaptive proliferation is a common phenomenon in the bacterial world. We showed that both known Pba quorum sensing-related autoinducers act synergistically and mutually compensatory to provide the timely termination of adaptive proliferation and formation of cross-protection. We also demonstrated that adaptive proliferation is implemented by bacteria of many genera and that bacteria with similar quorum sensing-related autoinducers have similar signaling backgrounds that prime the termination of adaptive proliferation, enabling the collaborative regulation of this adaptive program in multispecies communities

First genome-scale insights into the virulence of the snow mold causal fungus Microdochium nivale

Abstract Pink snow mold, caused by a phytopathogenic and psychrotolerant fungus, Microdochium nivale, is a severe disease of winter cereals and grasses that predominantly occurs under snow cover or shortly after its melt. Snow mold has significantly progressed during the past decade, often reaching epiphytotic levels in northern countries and resulting in dramatic yield losses. In addition, M. nivale gradually adapts to a warmer climate, spreading to less snowy territories and causing different types of plant diseases throughout the growing period. Despite its great economic importance, M. nivale is poorly investigated; its genome has not been sequenced and its crucial virulence determinants have not been identified or even predicted. In our study, we applied a hybrid assembly based on Oxford Nanopore and Illumina reads to obtain the first genome sequence of M. nivale. 11,973 genes (including 11,789 protein-encoding genes) have been revealed in the genome assembly. To better understand the genetic potential of M. nivale and to obtain a convenient reference for transcriptomic studies on this species, the identified genes were annotated and split into hierarchical three-level functional categories. A file with functionally classified M. nivale genes is presented in our study for general use. M. nivale gene products that best meet the criteria for virulence factors have been identified. The genetic potential to synthesize human-dangerous mycotoxins (fumonisin, ochratoxin B, aflatoxin, and gliotoxin) has been revealed for M. nivale. The transcriptome analysis combined with the assays for extracellular enzymatic activities (conventional virulence factors of many phytopathogens) was carried out to assess the effect of host plant (rye) metabolites on the M. nivale phenotype. In addition to disclosing plant-metabolite-upregulated M. nivale functional gene groups (including those related to host plant protein destruction and amino acid metabolism, xenobiotic detoxication (including phytoalexins benzoxazinoids), cellulose destruction (cellulose monooxygenases), iron transport, etc.), the performed analysis pointed to a crucial role of host plant lipid destruction and fungal lipid metabolism modulation in plant-M. nivale interactions

Rye Snow Mold-Associated Microdochium nivale Strains Inhabiting a Common Area: Variability in Genetics, Morphotype, Extracellular Enzymatic Activities, and Virulence

Snow mold is a severe plant disease caused by psychrophilic or psychrotolerant fungi, of which Microdochium species are the most harmful. A clear understanding of Microdochium biology has many gaps; the pathocomplex and its dynamic are poorly characterized, virulence factors are unknown, genome sequences are not available, and the criteria of plant snow mold resistance are not elucidated. Our study aimed to identify comprehensive characteristics of a local community of snow mold-causing Microdochium species colonizing a particular crop culture. By using the next-generation sequencing (NGS) technique, we characterized fungal and bacterial communities of pink snow mold-affected winter rye (Secale cereale) plants within a given geographical location shortly after snowmelt. Twenty-one strains of M. nivale were isolated, classified on the basis of internal transcribed spacer 2 (ITS2) region, and characterized by morphology, synthesis of extracellular enzymes, and virulence. Several types of extracellular enzymatic activities, the level of which had no correlations with the degree of virulence, were revealed for Microdochium species for the first time. Our study shows that genetically and phenotypically diverse M. nivale strains simultaneously colonize winter rye plants within a common area, and each strain is likely to utilize its own, unique strategy to cause the disease using “a personal” pattern of extracellular enzymes

Microbial tapestry of the Shulgan-Tash cave (Southern Ural, Russia): influences of environmental factors on the taxonomic composition of the cave biofilms

Abstract Background Cave biotopes are characterized by stable low temperatures, high humidity, and scarcity of organic substrates. Despite the harsh oligotrophic conditions, they are often inhabited by rich microbial communities. Abundant fouling with a wide range of morphology and coloration of colonies covers the walls of the Shulgan-Tash cave in the Southern Urals. This cave is also famous for the unique Paleolithic painting discovered in the middle of the last century. We aimed to investigate the diversity, distribution, and potential impact of these biofilms on the cave’s Paleolithic paintings, while exploring how environmental factors influence the microbial communities within the cave. Results The cave’s biofilm morphotypes were categorized into three types based on the ultrastructural similarities. Molecular taxonomic analysis identified two main clusters of microbial communities, with Actinobacteria dominating in most of them and a unique “CaveCurd” community with Gammaproteobacteria prevalent in the deepest cave sections. The species composition of these biofilms reflects changes in environmental conditions, such as substrate composition, temperature, humidity, ventilation, and CO2 content. Additionally, it was observed that cave biofilms contribute to biocorrosion on cave wall surfaces. Conclusions The Shulgan-Tash cave presents an intriguing example of a stable extreme ecosystem with diverse microbiota. However, the intense dissolution and deposition of carbonates caused by Actinobacteria pose a potential threat to the preservation of the cave’s ancient rock paintings

Research of Tribotechnical Properties of Composites Based on UHMWPE, Including Friction in the Environment of Various Lubricants

Получены зависимости износостойкости сверхвысокомолекулярного полиэтилена и композитов на его основе с углеродными волокнами от контактного давления, позволяющие определить их нагрузочную способность в режиме сухого и граничного трения в среде различных смазочных масел при скорости скольжения стального контртела 0,5 м/с. Установлено, что ресурс СВМПЭ и композитов на его основе в процессе сухого трения при повышении контактного давления определяется в основном не изнашиванием рабочей поверхности, а пластической деформацией поверхностных слоев композитов вследствие повышения температуры в зоне фрикционного контакта. Установлено, что использование трансмиссионного масла в качестве смазочной среды при трении ПКМ способствует формированию более прочного граничного слоя, предохраняющего материал от изнашиванияDependences of the wear resistance of ultra-high molecular weight polyethylene and composites based on it with carbon fibers on contact pressure have been obtained, which make it possible to determine their load capacity in the regime of dry and boundary friction in the environment of various lubricating oils at a sliding speed of a steel counterbody of 0.5 m/s. It has been established that the life of UHMWPE and composites based on it during dry friction with increasing contact pressure is determined mainly not by the wear of the working surface, but by the plastic deformation of the surface layers of the composites due to an increase in temperature in the frictional contact zone. It has been found that the use of gear oil as a lubricant during friction of PCM contributes to the formation of a more durable boundary layer which protects the material from wea

Resistance to Snow Mold as a Target Trait for Rye Breeding

Winter rye is a versatile crop widely used for food and industry. Although rye is resistant to abiotic stressors and many phytopathogens, it is severely damaged by pink snow mold (SM)—a progressive disease caused by the psychrotolerant fungus Microdochium nivale under the snow cover or during prolonged periods of wet and cool conditions. Due to little use of the SM resistance sources in contemporary breeding, varieties with at least moderate resistance to SM are limited. Our study aimed to integrate field assessment under natural conditions and an artificially enriched infection background with laboratory techniques for testing rye accessions and selecting SM resistant sources for applied breeding programs and genetic research. We revealed valuable sources of SM resistance and split rye accessions, according to the level of the genetic divergence of the SM resistance phenotype. This allowed us to select the most distinct donors of the SM resistance, for their use as parental forms, to include novel variability sources in the breeding program for achieving high genetic variability, as well as enhanced and durable SM resistance, in progeny. The rye accessions analyzed here, and the suggested options for their use in breeding, are valuable tools for rye breeding