Genetic diversity and differentiation of coexisting populations of Quercus robur L.and Q. petraea (Matt.) Liebl.

Pedunculate and sessile oaks (Quercus robur L.; Q. petraea [Matt] Liebl.) often coexist in mixed forest stands. However, species-specific investigations and forest management actions in such populations require reliable methods of identification of the species status of individuals. We investigated genetic diversity and species dif- ferentiation of adult and naturally established seedling cohorts in a mixed forest stand composed of Q. robur and Q. petraea, located in the Jamy Nature Reserve in north-central Poland. Using nineteen nuclear microsatellite loci and a model-based clustering approach as a tool for species delineation, we efficiently identified 105 and 60 adults, as well as 191 and 456 seedlings of pedunculate and sessile oaks, respectively. While the adult trees of both species were randomly distributed throughout the sample plot, the seedlings demonstrated significant spatial clustering, which was particularly evident for Q. petraea. The two oak species exhibited similar levels of genetic diversity in adult and offspring cohorts. Inbreeding was found to be low and significant only at the stage of seedlings. The estimates of effective population size were higher for Q. robur than Q. petraea, despite the overall greater reproductive success of the later one. There was a significant level of differentiation between the studied oak species, as measured by Fst coefficient (0.084 – adults; 0.099 – seedlings). The results on genetic diversity and species differentiation obtained in the studied indigenous near-natural stand of Q. robur and Q. petraea could be considered as a reference for other population genetic studies of oaks

The biomechanical characteristics of elite deaf and hearing female soccer players: comparative analysis

The aim of this study was to examine the differences in body composition, strength and power of lower limbs, height of jump measured for the akimbo counter movement jumps, counter movement jump and spike jumps between deaf and hearing elite female soccer players. Methods: Twenty deaf (age: 23.7 ± 5.0 years, hearing loss: 96 ± 13.9 dB) and 25 hearing (age: 20.3 ± 3.8 years) participated in the study. Their WHR and BMI were calculated. Body fat was measured using the BIA method. The maximal power and height of jump were measured by force plate. Biodex dynamometer was used to evaluate isokinetic isometric strength of the hamstrings and quadriceps. Results: Significant differences between hearing and deaf soccer players in anthropometric values were for the waist and calf circumferences and the WHR index ( p < 0.01, effect size 0.24–0.79). Statistically significant differences were observed for flexion of the lower limb in the knee joint for the relative joint torque and relative power obtained for the angular velocity of 300 degˑs–1 for both lower limbs (p < 0.01, effect size 0.19–0.48) and for 180 degˑs–1 during flexion of the left limb (p = 0.02, effect size 0.13). The hearing female football players developed significantly greater MVC in all the cases. Statistically significant differences between deaf and hearing athletes were found for spike jump for maximal power (1828.6 ± 509.4 W and 2215.2 ± 464.5 W, respectively; p = 0.02, effect size 0.14). Conclusions: Hearing impairment does not limit the opportunities for development of physical fitness in the population of deaf women