The Effects of Group differentiation by students’ learning strategies

This study analyses the effects of group differentiation by students’ learning strategies of around 1200 students in 46 classes from eight secondary schools in the Netherlands. In an experimental setup with randomization at the class level, division of students over three groups per class (an instruction-independent group, an average group, and an instruction-dependent group) is based on learning strategies, measures using the Motivated Strategies for Learning Questionnaire (MSLQ). Each group is offered instruction fitting their own learning strategy. The results show that student performance is higher in classes where the differentiation was applied, and that these students score higher at some scales of the posttest of the questionnaire on motivation, metacognition and self-regulation. However, there are differences between classrooms from different teachers. Additional teacher questionnaires confirm the discrepancy in teacher attitudes towards the intervention.

Can Information Reduce Ethnic Discrimination? Evidence from Airbnb

We use data from Airbnb to identify the mechanisms underlying discrimination against ethnic minority hosts. Within the same neighborhood, hosts from minority groups charge 3.2 percent less for comparable listings. Since ratings provide guests with increasingly rich information about a listing’s quality, we can measure the contribution of statistical discrimination, building upon Altonji and Pierret (2001). We find that statistical discrimination can account for the whole ethnic price gap: ethnic gaps would disappear if all unobservables were revealed. Also, three-quarters (2.5 points) of the initial ethnic gap can be attributed to inaccurate beliefs of potential guests about hosts’ average group quality. (JEL D83, J15, L84)

Formation of biometric indicators of sugar beet hybrids of domestic breeding

Purpose. Find out the features of biometric indicators formation in sugar beet hybrids of domestic breeding. Methods. Field, laboratory. Results. According to the results of the research, it was determined that in early August, the maximum weight of roots (840 g) was in hybrid ‘ITsB 0904’. Good indicators were observed in hybrids ‘Umanskyi Ch S97’, ‘Soniachnyi’ and ‘Anichka’, 770, 780, and 800 g at the average group indicator of 730 g. It was investigated that the hybrid ‘Maksym’ (15.1%) and ‘Etiud’ (14.9%) were the best in terms of sugar accumulation in roots. Sugar content at the level of 14.8 % was observed in hybrids ‘Umanskyi ChS 97’, ‘Ramzes’, ‘Konstanta’, ‘Soniachnyi’ and ‘Verkhnia’ at the average group value of 14.5%. Conclusions. It is important to continue the study of the dynamics of root and leaf mass formation together with the process of sugar accumulation in roots in terms of establishing individual efficiency of hybrids and developing recommendations for the fullest realization of their potential in production conditions.

Investigations on the Source Material of Oat Seeds, Avena sativa through the Multidimensional Ranking Method in Natural Conditions of Yakutia, Siberia, Russia

Eighty-three collection samples of oat seeds (Avena sativa L.) of various ecological, geographical, and breeding origins were studied in the conditions of Central Yakutia during 2017-2019 by the method of multidimensional ranking according to six economically valuable characteristics, namely, the duration of the growing season, grain yield, grain weight from the plant and panicles, the weight of 1.000 grains, and yielding tillering capacity. According to the results of the multidimensional ranking, the varieties were divided into three groups: the best, average, and worst. At that, from the data entered for 83 samples, the program determined priorities based on a combination of the duration of the growing season and yield. The group of best samples, based on a combination of economically valuable features, included 63% of samples from Europe, 30% from Russia, and 7% from Asia. The main share in the average group was made up of samples from Europe (63%), Russia (33%), and Asia (4%). The local zoned variety – Pokrovsky standard is included in the average group with a rank limit of 118.8. The worst group included the most samples from Europe (41%), Russia (26%), America (26%), Africa (3.7%), and Asia (3.7%). According to the precocity, 11 samples were identified that ripened earlier than the standard by 7-11 days. These are K-15062 (Omsk Region), K-15108 (USA), K-15111 (Colombia), K-15184 (Kemerovo Region), K-15191 (Slovakia), K-15357 (Norway), K-15375, K-15416, K-15418 (Germany), K-15392 (Sweden), and K-15408 (Belarus). Samples with high grain yield were included in the group of the best varieties. Among the selected varieties, cultivars K-15293 from Poland and K-15415 from Germany had the most stable yield over the years

COVID-19: Salient Aspects of Coronavirus Infection, Vaccines and Vaccination Testing and their Implications

In the present study, three basic aspects related to COVID-19 are presented. (a) The occurrence of coronavirus infection is analyzed statistically as number of coronaviruses infected alveolar cells compared to normal alveolar cells in human lungs. The mole concept is used to estimate the number of normal alveolar cells per human lung. The number of coronavirus infections in infected alveolar cells is estimated from the published Lower Respiratory Tract (LRT) load data. The Poisson probability distribution is aptly applied to imply the incubation period of the coronavirus infection to be within day-3 to day-7, with the cumulative probability of 75%. The incubation period within day-0 to day-10 has a cumulative probability of 98%. It implies a 10-day quarantine to isolate an uninfected individual as a precautionary measure. (b) Three vaccines to combat COVID-19, which adopt distinct paradigms while preparing them, are analyzed. These are Moderna's mRNA-1273, Oxford-AstraZeneca's ChAdOx1 nCoV-19 and Bharat BioTech's COVAXIN. The mole concept is used to estimate the antigen mass density per dose of each of these vaccines as 10, 0.1 and 1 (g per cubic-cm), respectively. The vaccines are deemed to be compatible to neutralize the infection. (c) A statistical analysis is performed of the Moderna's mRNA-1273 vaccine efficacy of 94.1% and Oxford's ChAdOx1 nCoV-19 vaccine efficacy of 62.1% in terms of groups of volunteers testing negative to vaccine by chance. In the Moderna vaccination testing scenario, since the probability of negative response of vaccine is small, the Poisson probability distribution for 95% cumulative probability is used to describe the vaccination testing in 300 samples of 47 volunteers each. Thus, 87% of samples have average group of 3 volunteers testing negative to vaccine. About 6% of samples have all volunteers testing positive to vaccine. In the Oxford vaccination testing scenario, since the probability of negative response of vaccine is finite, the Gaussian probability distribution for 95% probability is used to describe the vaccination testing in 75 samples of 120 volunteers each. Thus, 68% of samples have average group of 45 volunteers testing negative to vaccine. No sample has all volunteers testing positive to vaccine. A vaccine, irrespective of its efficacy being high or low, is necessary for mass immunization.

Analysis of Changes in Thermoregulatory Adaptation of College Athletes Following Cold Exposure Training

Introduction: The object of this study included features of thermal regulation and adaptation processes of 18-year-old college students playing sports before and after cold exposure training (morning hot/cold contrast showers) and their attitude to such training. Objective: To conduct a comparative analysis of changes in thermoregulation and adaptation of college students in response to cold exposure training. Methods: We conducted a questionnaire-based survey and testing using the Kestner–Marshak capillary cold reaction test and the “Adaptolog–Expert” system for assessing the functional status of the organism. Results of the survey conducted before and after the experiment allowed us to form a sample of the experimental group. At the end of the experiment, the repeated questionnaire-based survey of the level of cold exposure training showed a significant prevalence of affirmative answers, while the number of negative and unsure answers showed a pronounced decrease. The average group values of the cold reaction test equaled the upper limit of the norm indicating insufficient cold exposure training. By the end of the experiment, the average time of appearance and disappearance of hyperemia among the college students decreased significantly, thus proving the benefit of contrast showers to improve human thermoregulation. The results of applying the “Adaptolog–Expert” system showed statistically significant differences with the initial indicators of adaptation with multidirectional dynamics, indicating normalization of the studied parameters of adaptation. Conclusions: The study of thermoregulatory and adaptation parameters of college athletes confirmed the positive impact of the proposed technique on the students’ attitude to cold exposure training and normalized their adaptation to cold.

Participation tactics of elite freestyle wrestlers in competition system in 2013-2016 Olympic cycle

Background and Study Aim. Tactics is one of the basic terms underlying the management of competitive activities of athletes. In freestyle wrestling, the participation tactics of athletes in the competition system is covered fragmentally and needs proper justification. The purpose of the study was to determine the features of the participation tactics of elite athletes in the competition system in freestyle wrestling during 2013-2016 Olympic cycle. Materials and Methods. This study analyzes the dynamics of performances and results of 24 elite freestyle wrestlers who won gold, silver and bronze medals at the Games of XXXI Olympiad 2016 in Rio de Janeiro in different weight categories (four athletes in each of six weight categories). To do this, we used athletes’ individual profiles on the United World Wrestling. Used an expert assessment devoted to the issues of tactics and tactical training. The experts (n = 8) were well educated (3 among them held Ph.D. diplomas) and experienced – 2 coaches of Ukrainian national team, and 1 athlete–national team’s member. On average, experts had almost 10 years of experience in training wrestlers of different ages. The results were processed using Microsoft Excel software. Results. The volume of competition practice of elite athletes during 2013-2016 changed in each season. In the 2013 season, the average group number of competitions in which athletes participated was 3.84 ± 2.06, in 2014 – 3.50 ± 1.79. In the 2015 season, those indicators were the highest – 4.17 ± 1.87, but in 2016 they decreased to 3.71 ± 1.52. The participation tactics in the competition system in freestyle wrestling during the season and the four-year cycle differed depending on the dynamics of sports results. Four types of tactics used by the elite athletes in freestyle wrestling in 2013-2016 were identified: leadership holding, gradual improving of results, combined, leadership returning. It was found that during 2013-2016, most athletes (58.33-79.17%) used a variety of tactics that involved performances in one Olympic weight category. In 2014 and 2015, some athletes (20.83 and 25.00%, respectively) used different options in other weight categories, choosing one of them as a priority and one or two – as additional. Conclusions. There are four types of participation tactics in the competition system in freestyle wrestling. In 2013-2016 Olympic cycle they included leadership holding, gradual increase of results, combined, leadership return. The main differences between types of tactics are the volume of competition practice, the dynamics of results, the choice of weight category. The most relevant was the type of tactics with performances exclusively in the Olympic weight category during four seasons.

Use of Active Games in Physical and Tactical Training of Young Handball Players at the Initial Stage

The purpose of the study is to increase the effectiveness of physical and technical training of young handball players aged 10-11 by means of moving games, game exercises and relays at the stage of initial training during the pedagogical experiment in 2020-2021. Methodology. The following methods were used in the study: theoretical analysis and generalization of scientific and methodological literature, control and pedagogical checking (tests), pedagogical observations, anthropometry. Statistical processing of experimental data was performed using the statistical processing package STATGRAPHICS Plus for Windows (according to standard methods). The study involved young handball players aged 10-11, the first and second year of training in sport school №3 in Kharkiv during a year. The technique was implemented for 9 months (74 lessons), 3 times a week, and lasting 20 minutes. Results. We claim that the physical fitness of handball players is closely related to various aspects of training. The selected tests fully characterize the physical development and functional state of the main life support systems of a body and allow determining the effectiveness of the proposed authors’ method. The specially selected combinations with the use of moving games, game exercises and relays help to increase the level of technical training of young handball players. Analysis of the final indicators in the experimental group revealed a significant increase corresponding to the 5% level of significance in terms of execution of free throws and movement in the protective rack of the handball player. The average group values of the accuracy of free throws increased by 49.5%, and the average speed of movement in the protective rack of a handball player after the experiment increased by 8.3%. The rate of transfer of the ball to the wall in the experimental group increased by 25.1%, which indicates a significant increase in the result at P <0,01. Conclusion. The results obtained during the experiment confirmed the effectiveness of our developed methods of training with the purposeful use of moving games, game exercises and relay races at the initial stage of training young handball players.

Real-time tracking of ionic nano-domains under shear flow

The behaviour of ions at solid–liquid interfaces underpins countless phenomena, from the conduction of nervous impulses to charge transfer in solar cells. In most cases, ions do not operate as isolated entities, but in conjunction with neighbouring ions and the surrounding solution. In aqueous solutions, recent studies suggest the existence of group dynamics through water-mediated clusters but results allowing direct tracking of ionic domains with atomic precision are scarce. Here, we use high-speed atomic force microscopy to track the evolution of Rb+, K+, Na+ and Ca2+ nano-domains containing 20 to 120 ions adsorbed at the surface of mica in aqueous solution. The interface is exposed to a shear flow able to influence the lateral motion of single ions and clusters. The results show that, when in groups, metal ions tend to move with a relatively slow dynamics, as can be expected from a correlated group motion, with an average residence timescale of ~ 1–2 s for individual ions at a given atomic site. The average group velocity of the clusters depends on the ions’ charge density and can be explained by the ion’s hydration state. The lateral shear flow of the fluid is insufficient to desorb ions, but indirectly influences the diffusion dynamics by acting on ions in close vicinity to the surface. The results provide insights into the dynamics of ion clusters when adsorbed onto an immersed solid under shear flow.

Index evaluation of physical development of students

The article presents materials of a comparative study between index estimates of the physical development of students between two ethnic groups. Physical development is one of the most important indicators of the health not only for the young generation, but also for the whole population. The indices of physical development represent the ratios of individual anthropometric characteristics, which allows them to be used for a rough assessment of physical development in the course of mass surveys of the population, as well as for analyzing the influence of various environmental factors on the body. The study involved 336 girls aged 17 to 20 years studying at Kostanay State Pedagogical University. The studies were conducted in accordance with bioethical rules. All studies were conducted in inter-sessional period, in the first half of the day. Depending on nationality, the respondents were divided into two groups: the first group — students of Kazakh nationality, the second group — students of Slavic nationalities. The studied groups identified the main anthropometric (heihth, body weight, chest circumference), physiometric parameters (vital capacity of the lungs, hand strength, blood pressure), anthropometric (Quetelet, Pigne, Manouvrier) and functional indices (Robinson, Skibinsky, life and dynamometric indices). In the studied groups, significant differences were revealed in the main anthropometric indicators, the characteristics of the Manouvrier index, and the index of life. The revealed excess of the average group indicators of the girl students of the second group is due to the genetic predisposition of the morphological and functional characteristics of the organism.