Investigating the role of age and maturation on the association between tennis experience and cognitive function in junior beginner to intermediate-level tennis players

Sport engagement, including tennis, and physical activity have been shown to have a positive influence on cognition in children. However, age has also been found to have a strong association with cognition in youth athletes. This study examines the threshold hypothesis by investigating the moderating role of age and maturation on the association between tennis experience and cognitive measures in Australian and German junior beginner to intermediate-level tennis players. The demographic information, which includes years of tennis experience, and anthropometrics (e.g. height and weight) was collected for 48 junior tennis players. A comprehensive cognitive testing battery was then completed to assess cognitive performance, with a principle component analysis used to determine an overall cognitive performance score. Multiple regression analyses were then performed to test the relationship between tennis experience and cognitive performance as well as the moderating effects of age and maturation. The results of this study indicate that the age and maturation rather than the exposure to tennis training are related to cognitive performance. Additionally, the positive relations of tennis experience to cognitive performance were stronger in younger participants, specifically those younger than 12 years old. Therefore, tennis may not provide a stimulus large enough for further cognitive improvement once players have developed a high level of cognitive performance. While age and biological maturity will largely dictate cognitive performance in adolescents, tennis experience may play some role in the cognitive performance of children (specifically <12 years of age).

Does adjusting for biological maturity when calculating child weight status improve the accuracy of predicting future health risk?

Background The aim of this study was to assess whether adjusting the weight categorisation of children for their biological maturity status could improve the accuracy of predicting weight status and cardiometabolic risk at age 17. Methods Data from 1525 participants (787 female) from the ALSPAC study were analysed. Participants’ weight status at age 11 was estimated using first standard chronological age and sex adjusted BMI cut-offs, and again using maturity adjusted BMI cut-offs. Each BMI category at age 11 was regressed against cardiometabolic risk score and BMI category at age 17, controlling for sex, ethnicity and socio-economic status. Results At age 11 years, 22% of boys and 46% of girls who were categorised as overweight or having obesity based on chronological age were re-categorised into a lower BMI category after adjusting for biological maturity. Biologically adjusted BMI categories better predicted BMI category at age 17 compared with non-adjusted BMI categories (∆BIC = − 21.69); the odds of having obesity at age 17 were 18.28 times greater with each increase in BMI category at age 11. Adjusted and non-adjusted BMI status at 11 years showed equivalent accuracy in predicting cardiometabolic risk at age 17; the odds ratio of high cardiometabolic risk was 1.85, with heightened risk in boys, particularly early maturers. Conclusion The traditional method of categorising adolescents into a BMI category may over-predict overweight and obesity, particularly in girls. Adjusting for biological maturity when estimating weight status through calculating adolescents’ BMI classification was equivalent to standard approaches in predicting other cardiovascular risk at age 17.

Running Performance and Hormonal, Maturity and Physical Variables in Starting and Non-Starting Elite U14 Soccer Players During a Congested Match Schedule

This study examined changes in match running performance (MRP) in Under-14 soccer players (13.5 ± 0.7 yrs) during a congested match schedule (CMS) (4 matches played within a 5-day period). It also examined the difference in salivary testosterone (sT) concentration, somatic maturation, jumping tests, and Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) between the players selected to play (SLG; group who participated in all matches) and players non-selected to play (NSG). A significant difference was observed for the frequency of decelerations (DEC) across matches (match 4 vs. matches 1, 2 and 3; p = 0.05; partial ƞ2 = 0.20). No difference between matches was observed for total running distance (TRD), high-speed running distance (HSRD), and frequency of accelerations (ACC) (p > 0.05). A wide range for within-player coefficient of variation (CV) values was observed for all MRP variables (range: 10.5 = TRD to 30.6 = HSRD). No difference between SLG and NSG for any of the assessed variables was observed (p > 0.05). The findings suggest that DEC was the most pertinent variable for monitoring changes in MRP during the CMS. In addition, at an elite youth soccer level, the biological maturity and fitness might not influence selection to play.

Anthropometric Characterization and Physical Performance by Age and Biological Maturation in Young Tennis Players

The objective was to analyze anthropometric and physical performance variables as a function of chronological age and biological maturity in young Chilean tennis players. The study was observational, cross-sectional, with descriptive and analytical characteristics. Eighty-seven tennis players were evaluated (58 men 15.1 ± 0.8 years and 29 women, 15.3 ± 0.8 years). The measured anthropometric variables were a sprint test of 20m; a modified agility test; a sit-and-reach test and shoulder flexibility; manual grip strength; horizontal jump in feet; a medicine ball throw; a countermovement vertical jump; an abalakov vertical jump and a 20-m shuttle-run test. The growth velocity acceleration peak (APHV), skeletal muscle mass and fat mass were calculated, R2 and standard error of estimate (SEE) were examined. The results show that chronological age explained the anthropometric variables between 1 and 23% in men and 1 and 29% in women; by biological age, variables were explained between 3 and 53% in men and 2 and 42% in women. Of the physical performance variables, chronological age described between 2 and 24% of them in men and 1 and 29% in women; the same were explained by biological age between 1 and 19% in men and 1 and 26% in women. We conclude that anthropometric variables showed a better relationship with biological age, except for volume of fat tissue, while physical performance variables showed low association with both biological and chronological age.

Breeding of industrial hemp with a high content of cannabigerol by the case of ‘Vik 2020’ cultivar

To create an industrial hemp variety of the Central European ecological and geographical type with a high cannabigerol content and universal application. Methods. Breeding (self-pollination, creation of artificial populations, selection), field, biochemical (thin-layer and gas-liquid chromatography of cannabinoid compounds), instrumental and technological assessment of fibre quality, and statistical methods. Results. Variety ‘Vik 2020’ was obtained as a result of creation of artificial populations. The plants are characterized by higher content of cannabigerol (1.034 ± 0.0323%), and almost zero of other secondary metabolites, such as cannabidivarin, cannabidiol, cannabichromene and psychotropic tetrahydrocannabinol (0.003 ± 0.0011; 0.018 ± 0.0080; 0.012 ± 0.0027, and 0.005 ± 0.0012%, respectively). The t rait of cannabigerol content is quite stable within the population and is not correlated with the trait of tetrahydrocannabinol content (r = -0.23). TLC showed that cannabigerol accumulated mainly in the form of cannabigerolic acid and to a lesser extent as a neutral compound, which is consistent with the theory that this substance is a precursor for the synthesis of other cannabinoids. According to the results of the competitive variety test, when growing to obtain fibre and seeds, the variety features short height, specifically significantly lower total (206.4 cm) and technical stem length (135.6 cm) compared to the standard variety, significantly higher inflorescence length (70.8 cm), which determine the formation of the significant yield of biomass suitable for pharmaceutical use and high seed yield (0.98 t/ha). The yield of total fibre was the same as in the standard variety (29.0%), but its quality and technological value for primary processing were higher. The variety had a homogeneous sex structure, resistance to bioltic and abiotic environmental factors. Plants reached biological maturity in 116 days (BBCH 89). This cultivar is recommended for obtaining seeds, quality fiber and potentially cannabigerol (on condition of changes in legislation). Conclusions. The efficiency of using self-pollinating lines in breeding with their subsequent combining into a synthetic population and improving selection was proved by the case of a new variety of industrial hemp ‘Vik 2020’, characterized by an increased content of cannabigerol and the absence of psychotropic properties

Patriot – new variety of vegetable pieas

Relevance. The purpose of the research was to produce a new medium-ripe, high-yielding variety of vegetable peas with the usual type of leaf to expand the variety in the now used conveyor variety selection of the Krymsk EBS VIR Branch.Materials and methods. The experience was laid on the fields of the Krymsk EBS VIR Branch (Russia, Krasnodar Region, Krymsk) in 2019-2020. Varieties and strain were evaluated in a competitive variety testing. Sowing was carried out with a selection seeder SKS-6-10. The plot area was 10 m2 , the experiment was repeated four times. In the phase of technical ripeness, the sheaves were selected for description and the yield was taken into account. The conservation of green peas was done at the Tech Evaluation Lab.Results. Competitive variety testing in the mid-ripeness group was held by two strains 2014/7 and 344/16. The strain 2014/17 for green pea yields surpassed the standard "Parus" and G-344/16 in both years of study. Fresh and processed green peas were rated by the Tasting Commission at 5.0 and 4.8 points, respectively. High yield is achieved due to the paired beans on the peduncle and a large number of grains in the bean, up to 10 pieces. The grain in technical ripeness has a dark green color and the linear dimensions are 9.0x8.1 mm. In biological maturity, the seeds are intensely green, angular-compressed with a mass of 1000 pieces. 188-225 g.Conclusion. The results of field and laboratory analyses carried out on the complex of economicvaluable characteristics made it possible to distinguish the strain 2014/7, which in 2020 was transferred to the State Variety Testing under the name "Patriot". It is recommended as a supplement to the existing set of vegetable pea varieties of the Krymsk EBS VIR Branch in the mid-ripe group.

NEOage clocks - Epigenetic clocks to estimate post-menstrual and postnatal age in preterm infants

Epigenetic clocks based on DNA methylation (DNAm) can to accurately predict chronological age and are thought to capture biological aging. A variety of epigenetic clocks have been developed for different tissue types and age ranges, but none has focused on age prediction for preterm infants. Epigenetic estimators of biological age might be especially informative in epidemiologic studies of neonates, particularly those born preterm, since this is a key developmental window. Neonatal DNAm is dynamic and preterm infants are at heightened risk of developmental impairments. We aimed to fill this gap by developing epigenetic clocks for neonatal aging in preterm infants. As part of the Neonatal Neurobehavior and Outcomes in Very Preterm Infants (NOVI) study, buccal cells were collected at NICU discharge to profile DNAm levels in 542 very preterm infants. We applied elastic net regression to identify four epigenetic clocks (NEOage) predictive of post-menstrual and postnatal age, compatible with the Illumina EPIC and 450K arrays. We observed high correlations between predicted and reported ages (0.93 - 0.94) with root mean squared errors (1.28 - 1.63 weeks). Epigenetic estimators of neonatal aging in preterm infants can be useful tools to evaluate biological maturity and associations with neonatal and long-term morbidities.