Teaching Disciplines "History of Russia" and "Country Studies" to Foreign Students: Problems and Solutions

The present paper is focused on the problem of teaching foreign students such disciplines as "Country studies" and "History of Russia", which appear to be compulsory for the international students, getting higher education in Russia. Studying these disciplines, students meet some difficulties due to various reasons, beginning with poor knowledge of Russian language and ending with ethical problems. A lecturer needs to cross this socio-cultural and linguistic barrier and find solutions in order to give the full information in accordance with the educational working program. The research has an applied character. It is based on the sociological survey conducted among the foreign students of National Research Tomsk Polytechnic University. The aim of the paper is to demonstrate real difficulties of students and lecturers at studying and teaching disciplines "Country studies" and "History of Russia" and to offer solutions for overcoming these problems

Symptomatic dry eye disease among university students

Background: Dry eye disease (DED) is a multifactorial condition often characterized by a reduction in tear film quantity or quality. This study aimed to determine the frequency of DED and its associated subjective symptoms among students of Mu’tah University. Methods: In this cross-sectional study conducted at Mu’tah University, Mu’tah, Jordan, from January to April 2022, 489 students completed an online patient-reported DED symptom questionnaire and the ocular surface disease index (OSDI) questionnaire. Moreover, 106 participants underwent clinical examinations using the Schirmer test I and fluorescein tear breakup time (TBUT). Results: Approximately 74.6% of the students self-reported experiencing DED symptoms, and 72.6% had an OSDI score > 12, which is considered the threshold for an abnormal ocular surface. Clinical examinations revealed low Schirmer test scores (< 10 mm) in 26.4% (n = 28) and 25.5% (n = 27) of the right and left eyes, respectively. We observed low TBUT scores (< 5 s) in 19.8% (n = 21) and 18.9% (n = 20) of the right and left eyes, respectively. We noted significant differences between the self-reported DED symptoms and the Schirmer test scores (P = 0.003 for both right and left eyes), TBUT (P < 0.001 for both right and left eyes), and OSDI score (P < 0.001 for each self-reported DED symptom). We observed a weak significant positive correlation between Schirmer test scores and TBUT in the right (r = + 0.30; P = 0.002) and left (r = + 0.34; P < 0.001) eyes; a negligible significant inverse correlation between OSDI scores and Schirmer test scores in the right (r = - 0.24; P = 0.013) and left (r = - 0.23; P = 0.019) eyes; and a negligible significant inverse correlation between the OSDI score and TBUT of the left eye (r = - 0.25; P = 0.011) but not of the right eye (r = - 0.17; P = 0.077). Conclusions: The frequency of DED symptoms in this study was higher than that previously reported based on foreign statistics. The presence of self-reported DED symptoms was significantly associated with higher OSDI scores. Self-reported DED symptoms were more frequent than the abnormalities detected using objective methods. Therefore, a combination of subjective and objective measures may provide a higher diagnostic yield for DED. Further studies are required to confirm this hypothesis

Mechanisms of confluence-dependent expression of CD26 in colon cancer cell lines

<p>Abstract</p> <p>Background</p> <p>CD26 (dipeptidyl peptidase IV, DPPIV) is a 110 kDa surface glycoprotein expressed in most normal tissues, and is a potential novel therapeutic target for selected cancers. Our work evaluates the mechanism involved in confluence-dependent CD26 expression in colon cancer.</p> <p>Methods</p> <p>Colon adenocarcinoma cells were grown to confluence, and expression of CD26 and transcription factors implicated in its regulation was confirmed by immunofluorescence and Western blotting. Real-time PCR was also performed to evaluate CD26 upregulation at the transcriptional level. The influence of c-Myc on CD26 expression during different growth conditions was further evaluated following transient transfection of a c-Myc-expressing plasmid and a c-Myc specific siRNA.</p> <p>Results</p> <p>We found that the colon cancer cell lines HCT-116 and HCT-15 exhibited a confluence-dependent increase in CD26 mRNA and protein, associated with decreased expression of c-Myc, increased USF-1 and Cdx 2 levels, and unchanged HNF-1α expression. Meanwhile, ectopic expression of c-Myc in both cell lines led to decreased CD26 expression. In contrast, transfection of a siRNA targeted to Cdx2 resulted in decreased CD26 level. Importantly, culturing of cells in serum-depleted media, but not acidic conditions, upregulated CD26. While HIF-1α level also increased when cells were cultured in serum-depleted media, its expression was required but not sufficient for CD26 upregulation.</p> <p>Conclusions</p> <p>CD26 mRNA and protein levels increase in a confluence-dependent manner in colon carcinoma cell lines, with c-Myc acting as a repressor and Cdx2 acting as an enhancer of CD26 expression. The enhanced expression of CD26 in serum-depleted media and a requirement for HIF-1α suggest a role for nutrients or growth factors in the regulation of CD26 protein expression.</p

Viral Mimicry of Cdc2/Cyclin-Dependent Kinase 1 Mediates Disruption of Nuclear Lamina during Human Cytomegalovirus Nuclear Egress

The nuclear lamina is a major obstacle encountered by herpesvirus nucleocapsids in their passage from the nucleus to the cytoplasm (nuclear egress). We found that the human cytomegalovirus (HCMV)-encoded protein kinase UL97, which is required for efficient nuclear egress, phosphorylates the nuclear lamina component lamin A/C in vitro on sites targeted by Cdc2/cyclin-dependent kinase 1, the enzyme that is responsible for breaking down the nuclear lamina during mitosis. Quantitative mass spectrometry analyses, comparing lamin A/C isolated from cells infected with viruses either expressing or lacking UL97 activity, revealed UL97-dependent phosphorylation of lamin A/C on the serine at residue 22 (Ser22). Transient treatment of HCMV-infected cells with maribavir, an inhibitor of UL97 kinase activity, reduced lamin A/C phosphorylation by approximately 50%, consistent with UL97 directly phosphorylating lamin A/C during HCMV replication. Phosphorylation of lamin A/C during viral replication was accompanied by changes in the shape of the nucleus, as well as thinning, invaginations, and discrete breaks in the nuclear lamina, all of which required UL97 activity. As Ser22 is a phosphorylation site of particularly strong relevance for lamin A/C disassembly, our data support a model wherein viral mimicry of a mitotic host cell kinase activity promotes nuclear egress while accommodating viral arrest of the cell cycle

The Usability of E-learning Platforms in Higher Education: A Systematic Mapping Study

The use of e-learning in higher education has increased significantly in recent years, which has led to several studies being conducted to investigate the usability of the platforms that support it. A variety of different usability evaluation methods and attributes have been used, and it has therefore become important to start reviewing this work in a systematic way to determine how the field has developed in the last 15 years. This paper describes a systematic mapping study that performed searches on five electronic libraries to identify usability issues and methods that have been used to evaluate e-learning platforms. Sixty-one papers were selected and analysed, with the majority of studies using a simple research design reliant on questionnaires. The usability attributes measured were mostly related to effectiveness, satisfaction, efficiency, and perceived ease of use. Furthermore, several research gaps have been identified and recommendations have been made for further work in the area of the usability of online learning

An Approach to Achieving Increased Fault-Tolerance and Availability of Multiprocessor-Based Computer Systems

In the present paper, mesh-connected multiprocessor-based computer systems are considered, a new approach that makes it possible to increase fault-tolerance and availability of a system in the presence of faulty units/links is discussed

Phylogenomic Analyses and Molecular Signatures Elucidating the Evolutionary Relationships amongst the Chlorobia and Ignavibacteria Species: Robust Demarcation of Two Family-Level Clades within the Order Chlorobiales and Proposal for the Family Chloroherpetonaceae fam. nov

Evolutionary relationships amongst Chlorobia and Ignavibacteria species/strains were examined using phylogenomic and comparative analyses of genome sequences. In a phylogenomic tree based on 282 conserved proteins, the named Chlorobia species formed a monophyletic clade containing two distinct subclades. One clade, encompassing the genera Chlorobaculum, Chlorobium, Pelodictyon, and Prosthecochloris, corresponds to the family Chlorobiaceae, whereas another clade, harboring Chloroherpeton thalassium, Candidatus Thermochlorobacter aerophilum, Candidatus Thermochlorobacteriaceae bacterium GBChlB, and Chlorobium sp. 445, is now proposed as a new family (Chloroherpetonaceae fam. nov). In parallel, our comparative genomic analyses have identified 47 conserved signature indels (CSIs) in diverse proteins that are exclusively present in members of the class Chlorobia or its two families, providing reliable means for identification. Two known Ignavibacteria species in our phylogenomic tree are found to group within a larger clade containing several Candidatus species and uncultured Chlorobi strains. A CSI in the SecY protein is uniquely shared by the species/strains from this &ldquo;larger Ignavibacteria clade&rdquo;. Two additional CSIs, which are commonly shared by Chlorobia species and the &ldquo;larger Ignavibacteria clade&rdquo;, support a specific relationship between these two groups. The newly identified molecular markers provide novel tools for genetic and biochemical studies and identification of these organisms