Mathematical simulation and optimization of cutting modes in turning of titanium alloy workpieces

A predictive modeling technique of optimal cutting modes in machining of workpieces made of titanium alloys, different from the well-known ones, is offered. The influence of various factors on the process of cutting for the purpose of defining optimal parameters of machining in accordance with certain effectiveness criteria is examined in the present paper. Mathematical models of optimization, algorithms and computer programmes, visual graphical forms presenting dependences of effectiveness criteria on the master schedule parameters have been worked out. Verification of mathematical models in laboratory and working conditions has been carried out

Expression of psychological distress on Instagram using hashtags in Russian and English : a comparative analysis

People have been using images to express ideas, share stories, and communicate since early history. The advent of social media has made sharing images an important part of everyday life. Among other things, social networks can be used to express psychological distress; however, research on this topic is limited. The goal of this study was to explore representations of psychological distress in the Russian-speaking segment of Instagram. The study involved contrasting images labeled with hashtags in Russian with images marked by analogous Anglophone hashtags in a data set of 1,512 images. Quantitative content analysis revealed significant differences between images labeled with Russian and Anglophone hashtags. Images containing depictions of texts were significantly less frequent among images with Russian hashtags, while inanimate object depictions were more prevalent. Hashtags for fear in both languages were related not to psychological distress but to the “scary” in popular culture. Images of alcohol were associated with stress hashtags in both languages and with hashtag for depression in Russian only. Images of food were significantly more prevalent among images with Russian hashtag for stress. Current study highlights the need for culturally and linguistically appropriate online mental health interventions.peer-reviewe

COVID-19 vaccination attitudes across the European continent

This study was conducted to determine the predictors of COVID-19 vaccination attitudes across multiple waves in seven countries geographically spread across the European continent, using data from a COVID-19 survey provided by the Massachusetts Institute of Technology COVID-19. Facebook users from across the globe participated in this survey which collected information on their knowledge of COVID-19, attitudes towards risk and available information, and their willingness or lack thereof to take the vaccine. In this secondary data analysis study, neural networks were used with special attention given to the importance of the predictors of COVID-19 vaccination attitudes. Perception of social norms regarding COVID-19 vaccination was found to be the most important predictor of vaccine acceptance. Country of residence and wave of data collection were among the important predictors, with different patterns for each country emerging across different waves. Other strong predictors included attitudes towards masks and mask wearing; attitudes towards the influenza vaccine; distrust in government health authorities and scientists; and level of knowledge of existing treatments for COVID-19. The results of this study can inform effective public health prevention and intervention efforts against infectious diseases.peer-reviewe

The language of positive mental health : findings from a sample of Russian Facebook users

Positive mental health is considered to be a significant predictor of health and longevity; however, our understanding of the ways in which this important characteristic is represented in users’ behavior on social networking sites is limited. The goal of this study was to explore associations between positive mental health and language used in online communication in a large sample of Russian Facebook users. The five-item World Health Organization Well-Being Index (WHO-5) was used as a self-report measure of well-being. Morphological, sentiment, and semantic analyses were performed for linguistic data. The total of 6,724 participants completed the questionnaire and linguistic data were available for 1,972. Participants’ mean age was 45.7 years (SD = 11.6 years); 73.4% were female. The dataset included 15,281 posts, with an average of 7.67 (SD = 5.69) posts per participant. Mean WHO-5 score was 60.0 (SD = 19.1), with female participants exhibiting lower scores. Use of negative sentiment words and impersonal predicates (“should statements”) demonstrated an inverse association with the WHO-5 scores. No significant correlation was found between the use of positive sentiment words and the WHO-5 scores. This study expands current understanding of the association between positive mental health and language use in online communication by employing data from a non-Western sample.peer-reviewe

Clonal structure and the specificity of vaccine-induced T cell response to SARS-CoV-2 Spike protein

Adenovirus vaccines, particularly the COVID-19 Ad5-nCoV adenovirus vaccine, have emerged as promising tools in the fight against infectious diseases. In this study, we investigated the structure of the T cell response to the Spike protein of the SARS-CoV-2 virus used in the COVID-19 Ad5-nCoV adenoviral vaccine in a phase 3 clinical trial (NCT04540419). In 69 participants, we collected peripheral blood samples at four time points after vaccination or placebo injection. Sequencing of T cell receptor repertoires from Spike-stimulated T cell cultures at day 14 from 17 vaccinated revealed a more diverse CD4+ T cell repertoire compared to CD8+. Nevertheless, CD8+ clonotypes accounted for more than half of the Spike-specific repertoire. Our longitudinal analysis showed a peak T cell response at day 14, followed by a decline until month 6. Remarkably, multiple T cell clonotypes persisted for at least 6 months after vaccination, as demonstrated by ex vivo stimulation. Examination of CDR3 regions revealed homologous sequences in both CD4+ and CD8+ clonotypes, with major CD8+ clonotypes sharing high similarity with annotated sequences specific for the NYNYLYRLF peptide, suggesting potential immunodominance. In conclusion, our study demonstrates the immunogenicity of the Ad5-nCoV adenoviral vaccine and highlights its ability to induce robust and durable T cell responses. These findings provide valuable insight into the efficacy of the vaccine against COVID-19 and provide critical information for ongoing efforts to control infectious diseases

Traumatic Impact of the COVID-19 Pandemic in an International Sample: Contribution of Fatalism to Psychological Distress and Behavior Change

This study aimed to assess the traumatic impact of the COVID-19 outbreak and to explore the contribution of fatalism to a) psychological distress and b) pandemic-related behavior change. Data for the study were collected via an anonymous online survey. The survey included questions about demographic characteristics, health status, pandemic-related stress, impact of COVID-19 on health and behavior, posttraumatic stress symptoms (PTSS), and fatalism. The sample included 465 participants from 30 countries (mean age = 36.87, SD = 13.39, age range = 18 – 76; 80% female). While none of the study participants have been diagnosed with COVID-19, almost 25% knew someone who had received the diagnosis. The overwhelming majority (79%) had to make changes to their daily routine, and 48.82% of the sample reported moderate to severe PTSS. Fatalism was found to be a statistically significant predictor of PTSS in a multiple regression model and was also associated with lack of behavior changes in response to the pandemic. Our findings indicate that the COVID-19 pandemic is a traumatic event with a potential to affect mental health and well-being of individuals and communities. Fatalism may contribute to severity of psychological distress and diminish individuals’ ability to engage in health-protective behaviors

SOME ADDITIONS TO PRACTICE AND THEORY OF PHYSICAL EDUCATION TEACHING IN NON-SPORTS ORIENTED HIGHER EDUCATION INSTITUTION

Physical education as a component of an education system reveals its educative, health-improving, economic and cultural value. It promotes the appearance of such social trends as physical training movement, i.e. joint activities of people to use, distribute and enhance the values of physical culture. Control of the physical training system is a complex process that requires the choice of the best strategy and tactics, effective methods for forming healthy lifestyle. The article describes the main elements of physical training system applied at Siberian Institute of Management Branch of the RANEPA

Violence and Violence Prevention

This is the OSF page for the research group Violence and Violence Prevention at Leiden University, led by prof. Marieke Liem. On this page, you will find information on the projects being developed within the group, and links to relevant documents. Due to confidentiality concerns, some ongoing projects remain private until publication. For further information about our research group, please visit our University webpage at https://www.universiteitleiden.nl/en/research/research-projects/governance-and-global-affairs/physical-violence-and-public-order