PURPOSE The purpose of this study was to find out whether a more specific stimulus, such as training which stimulates the production of power above 90% of Pmax (Pmax = maximal average concentric power output), is effective in enhancing the countermovement jump (CMJ) performance using the method of complex pairs or separate execution of the exercises in the complex pair (separate complex pair). METHODS Thirty male students of the Faculty of Sports Studies were divided into 2 experimental (EX1, EX2) and 1 control group (CNTR). The experimental groups trained for 8 weeks using the complex training (CT) method twice a week with the same amount of repetitions for each exercise. The complex pair consisted of half-squat jumps with the intensity over 90% of Pmax and plyometric depth-jumps. EX1 trained using the complex pair method with the intracomplex rest interval of up to 15 seconds. EX2 trained all sets of the half-squat jumps first and then all sets of the plyometric exercise. We used non-parametric statistics and linear regression analysis to evaluate the effect on increasing the CMJ performance after the intervention program. RESULTS There were no significant differences between the pre-test and post-test in any of the experimental groups (p > 0.05), although there were significant differences between the weeks in EX1 and EX2 (p < 0.05). The CMJ performance increased insignificantly (p > 0.05) each week by 0.14 cm in EX1 and by 0.07 cm in EX2. CONCLUSION These results did not clearly show the application of the CT methods to be useful in enhancing the CMJ. In practice we recommend using the complex pairs to save training time and increase training intensity. However, an additional longer-term intervention experiment with a bigger sample size and groups randomized by the CMJ parameter (not by Pmax) is needed.
- MeSH
- biomechanika MeSH
- lidé MeSH
- pohybová aktivita MeSH
- svalová síla * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
PURPOSE Many types of vertical jumps (VJ) are commonly used to assess the development of the level of explosive strength of lower limbs achieved after a training period. This study is focused on comparing various parameters of different types of VJ with 1 RM in Olympic-style weightlifting, squat and deadlift with an Olympic bar. he snatch r=0.8 r2= 0.64, clean and jerk r=0.81 r2= 0.65, back squat r=0.82 r2= 0.67 and deadlift r=0.78 r2= 0.60; for the SJ with hands on the hips and the snatch r= 0.76 r2= 0.57, clean and jerk r= 0.75 r2= 0.56, back squat r= 0.77 r2= 0.59 and deadlift r= 0.71 r2= 0.50. Significant correlation coefficients were not found for 1 RM in the snatch, clean and jerk, back squat and deadlift and the CMJ or SJ with and without arm swing in any of the following parameters: jump height (m), relative force (% of body weight), relative power output (W/kg of body weight). CONCLUSION The main finding is that the jump height (m) of the CMJ or SJ with or without arm swing did not correlate significantly with 1 RM in the snatch, clean and jerk, back squat and deadlift. Therefore, jump height measurement can be used as a motivation tool but not to predict maximum strength in Olympic bar exercises, or vice versa. We recommend using the average power output (W) parameter in the CMJ with using arms as a predictor of current performance level in exercises with an Olympic bar for men and women.
- MeSH
- lidé MeSH
- pohybová aktivita MeSH
- sportovci MeSH
- sportovní výkon MeSH
- tělesná námaha MeSH
- vzpírání * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Positive selection acting on Toll-like receptors (TLRs) has been recently investigated to reveal evolutionary mechanisms of host-pathogen molecular co-adaptation. Much of this research, however, has focused mainly on the identification of sites predicted to be under positive selection, bringing little insight into the functional differences and similarities among species and a limited understanding of convergent evolution in the innate immune molecules. In this study, we provide evidence of phenotypic variability in the avian TLR4 ligand-binding region (LBR), the direct interface between host and pathogen molecular structures. We show that 55 passerine species vary substantially in the distribution of electrostatic potential on the surface of the receptor, and based on these distinct patterns, we identified four species clusters. Seven of the 34 evolutionarily nonconservative and positively selected residues correspond topologically to sites previously identified as being important for lipopolysaccharide, lipid IVa or MD-2 binding. Five of these positions codetermine the identity of the charge clusters. Groups of species that host-related communities of pathogens were predicted to cluster based on their TLR4 LBR charge. Despite some evidence for convergence among taxa, there were no clear associations between the TLR4 LBR charge distribution and any of the general ecological characteristics compared (migration, latitudinal distribution and diet). Closely related species, however, mostly belonged to the same surface charge cluster indicating that phylogenetic constraints are key determinants shaping TLR4 adaptive evolution. Our results suggest that host innate immune evolution is consistent with Fahrenholz's rule on the cospeciation of hosts and their parasites.
- MeSH
- glykolipidy chemie genetika MeSH
- interakce hostitele a patogenu genetika MeSH
- konformace proteinů MeSH
- ligandy MeSH
- lipid A analogy a deriváty chemie genetika MeSH
- lipopolysacharidy chemie genetika MeSH
- lymfocytární antigen 96 chemie genetika MeSH
- mikrobiota genetika MeSH
- molekulární evoluce * MeSH
- molekulární modely MeSH
- přirozená imunita genetika MeSH
- ptáci genetika parazitologie MeSH
- sekvenční analýza DNA MeSH
- selekce (genetika) * genetika MeSH
- statická elektřina MeSH
- toll-like receptor 4 chemie genetika MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Weightlifting heavy load exercises are commonly used as a key instrument for enhancing performance if compared to those not using the exercise stimulating muscle tone. Studies examined the post-activation effect (PAP) using only one parameter but not in consecutive and intermingling exercises to prolongated the time of the PAP effect duration and maintain increased performance. Nine male students, with resistance training experience, performed warm-up and exercises enhancing muscle tone (EEMT) using squats to 90° flexion in the knee joint with 80 % 1 RM (repetition maximum) in 3 sets with 3 repetitions of squat in each set (2-3 min. rest intervals). After EEMT they performed a 10-m sprint test in 2nd and 5th min, the countermovement long jump (CLJ) test in the 5th and 6th minute, a 10-m sprint test in the 10th and 11th minute and the CLJ test in the 12th and 14th minute. The results showed that the average improvement was in 10-m sprint after EEMT 0,013 ± 0,05 seconds, but there were no statistical differences observed between the result without and with EEMT (p>0.05). We observed a significant improvement between jumps without and with EEMT in 5 – 14th min (p<0.05). There were no statistical differences between the results in CLJ carried out in 5-6th min after EEMT and after two 10-m sprints and the results carried out in 12-14th min. after EEMT, four 10-m sprints and two jumps (p>0.05). It was found that 10-m sprint has no negative effect on performance in the long jump and could be regularly applied to prolong the PAP effect.
Silene latifolia is a dioecious plant species with chromosomal sex determination. Although the evolution of sex chromosomes in S. latifolia has been the subject of numerous studies, a global view of X chromosome structure in this species is still missing. Here, we combine X chromosome microdissection and BAC library screening to isolate new X chromosome-linked sequences. Out of 8 identified BAC clones, only BAC 86M14 showed an X-preferential signal after FISH experiments. Further analysis revealed the existence of the Athila retroelement which is enriched in the X chromosome and nearly absent in the Y chromosome. Based on previous data, the Athila retroelement belongs to the CL3 group of most repetitive sequences in the S. latifolia genome. Structural, transcriptomics and phylogenetic analyses revealed that Athila CL3 represents an old clade in the Athila lineage. We propose a mechanism responsible for Athila CL3 distribution in the S. latifolia genome.
