Biochemical markers of vital biodestruction in common oak (Quercus robur)

The wood of the common oak (Quercus robur L.) has high mechanical strength, elasticity and resistance to fracture. However, constitutional stability is not always able to provide the plants with reliable protection from wood-decay fungi, and the initial stages of biodegradation are difficult to determine. Therefore, this study concerns research on appropriate biochemical markers for early diagnostics of wood defects. The total content of phenolic compounds in leaves and wood was determined by a spectrophotometer Optizen Pop using Folin & Ciocalteu’s phenol reagent; the flavonoid content in leaves – by adding solutions of aluminum chloride and sodium acetate to methanolic extracts; catechins content – by the reaction with vanillin reagent; the concentration of phenolic antioxidants – by Brand Williams; chlorophyll and carotenoids’ contents in leaves – by the formula for methanol extracts; the qualitative composition of phenolic compounds – by high performance liquid chromatography and highly effective thin-layer chromatography. During the planned felling of oak trees on the territory of the Boyar Forest Research Station, trees were found with signs of brown streak and biodestruction of wood. Brown streak in wood is caused by a polycondensation of phenolic compounds, which are deposited on the internal surfaces of tracheal elements. In cases of an increase in the total amount of oxidized polyphenols, the cell walls are also stained. Active oxidation processes in wood have a systemic nature for the plants and affect the physiological state of the assimilation apparatus. We determined that in leaves of the trees with signs of brown streak the total phenol content increases in comparison with the control by 1.6 times, as well as flavonoid and catechin content. Our research has shown that the complex of plastid pigments in common oak leaves does not significantly change in the early stages of destructive processes. Increase of brown streak and appearance of rot in wood are associated with slight increase in chlorophyll a to b ratio in leaves. Chromatographic profiling of the leaves showed that the presence of brown streak changes the content of individual phenolic compounds. The trees with brown rot have more substances with UV spectrum characteristic for kaempferol glycosides compared to the control. The results have shown that the biochemical profiles of the trees with signs of brown streak and brown rot differ from the control by the composition of low and medium polar compounds. The absence or presence of some individual phenolic components and their ratio in the leaves are considered as biochemical markers of hidden wood defects

Applicability of the Online Short Spatial Ability Battery to university students testing

Introduction. Multiple studies advocate an importance of spatial abilities (SA) for educational and occupational success, especially in STEM. Recently an Online Short Spatial Ability Battery (OSSAB) was developed and normed for SA testing in adolescents. The battery includes mechanical reasoning, paper folding, pattern assembly, and shape rotation tests. The battery has shown good psychometric characteristics (high reliability and validity, low redundancy, discriminative power), and is available in open access and free to use. Aim. The present research aims: 1) to examine the applicability of the OSSAB for university student testing; 2) to describe its psychometric properties and structure; and 3) to investigate links between SA and educational performance. Methods. A total of 772 university students (aged from 18 to 26, mean age (SD) = 19.55 (1.51), 63.1% females) participated in the study. Participants provided information about their age, gender, university major, and academic achievement, and completed a battery of tests that included the OSSAB tests. Results. The study reports psychometric norms for using the OSSAB in university students. Students’ performance in the OSSAB was similar to that shown in previous research in adolescents in terms of means and variance. The OSSAB showed adequate psychometric properties in this sample: no floor or ceiling effects; low redundancy; moderate to high internal consistency; high discriminative power across university majors; and high external validity. The results indicated that around 6% of the students showed very high levels of SA (higher than 1.5 SD above the mean), and around 8% of students showed very low levels of SA (lower than 1.5 SD below mean). In addition, the OSSAB scores were linked to educational profile choice and exam scores, with small-to-medium effect sizes. Scientific novelty. The study provides psychometric norms for a short online open measure of spatial ability in university students. Practical significance. The OSSAB can be used to provide individual recommendations to students (e.g. SA training), to identify spatially gifted students, and for research purposes in university contexts

Динамика распространенности бронхиальной астмы у детей в Новосибирске

Six-year dynamics of epidemiology of bronchial asthma was analyzed in Novosibirsk according to a common standardized protocol of the "International Study of Asthma and Allergic Diseases in Children" (ISAAC) programme. The pathology spread was studied using a total surveying among first-form and eight-form pupils (the survey involved 7291 pupils 1996, 6631 ones in 1999 and 6943 children in 2002). The results showed stable spread of bronchial asthma symptoms among the senior and junior pupils and prevalence of mild asthma with rare exacerbations in both the groups. A progredient growth of severe asthma attack rate was noted in eight-form pupils. An increase in frequency of combined upper and lower airway pathologies was registered with reduction in skin atopy rate. A problem of underestimating of the pathology was discussed.Исследована 6-летняя динамика эпидемиологии бронхиальной астмы по единым стандартизованным протоколам программы "Международное исследование астмы и аллергических заболеваний у детей" (ISAAC) в Новосибирске. Изучение распространенности патологии проводилось при сплошном анкетировании учеников 1-х и 8-х классов (7291 школьник в 1996 г., 6631 — в 1999 г. и 6943 — в 2002 г.). В динамике выявлены стабильная распространенность симптомов бронхиальной астмы у старших и младших школьников, сохранение преобладания легких редко рецидивировавших форм патологии в обеих возрастных группах. Отмечен прогредиентный рост тяжелых приступов удушья у восьмиклассников. В популяции школьников зарегистрировано увеличение сочетанного поражения верхних и нижних отделов респираторного тракта с сокращением частоты кожных форм атопии. Отражена проблема гиподиагностики патологии

The Factorial Structure of Spatial Abilities in Russian and Chinese Students

Background: Recent research suggested a unifactorial structure of spatial ability (SA). Research is needed to replicate this finding in different populations. Objective: This study aims to explore the factorial structure of SA in samples of 921 Russian and 229 Chinese university students. Design: A gamified spatial abilities battery was administered to all participants. The battery consists of 10 different domains of SA, including 2D and 3D visualization, mental rotation, spatial pattern assembly, spatial relations, spatial planning, mechanical reasoning, spatial orientation and spatial decision making speed and flexibility. Results: The results of the factor analysis showed a somewhat different pattern for different samples. In the Russian sample, the unifactorial structure, shown previously in a large UK sample (Rimfeld et al., 2017), was replicated. A single factor explained 40% of the variance. In the Chinese sample two factors emerged: first factor explained 26% of the variance and the second factor, including only Mechanical reasoning and Cross-Sections tests, explained 14%. The results also showed that the Chinese sample significantly outperformed the Russian sample in 5 out of the 10 tests. Russian students showed better performance only in two of the tests. The effects of all group comparisons were small. Conclusion: Overall, a similar amount of variance in the 10 tests was explained in the two samples, replicating results from the UK sample. Future research is needed to explain the observed differences in the structure of SA