Numerous studies have now documented that athletes of different competition levels vary in their motivational styles. Some are internally motivated and train to be better based on intrinsic values, whereas others are controlled by external pressures that drive performance. A third style does not make causal attributions regarding their performance and are amotivated. In the current study, we used latent profile analysis to examine unique typologies of sports motivation in 456 Czech university students comprised of both recreational and more elite athletes participating in various sports and attending a sport education program. Four qualitatively distinct profiles were distinguished varying in the composition of intrinsic, extrinsic, and amotivation. The four profiles differed in their mean levels of social physique anxiety, global self-esteem, and physical self-worth, three markers of how a person feels about themselves in terms of normative standards. Multiple group comparisons based on gender, individual versus team sports, and level of competition reinforced relative consistency in profile composition. Results are discussed in terms of how people can blend different motivational styles, what this portends for self-beliefs, and whether there is relative consistency across meaningful groups.
- MeSH
- Humans MeSH
- Young Adult MeSH
- Motivation * MeSH
- Body Image MeSH
- Cross-Sectional Studies MeSH
- Surveys and Questionnaires statistics & numerical data MeSH
- Self Concept MeSH
- Athletes * psychology statistics & numerical data MeSH
- Sports * psychology statistics & numerical data MeSH
- Students * psychology statistics & numerical data MeSH
- Universities statistics & numerical data MeSH
- Check Tag
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
BACKGROUND: Niche partitioning allows species to diversify resource utilisation and space allocation and reduce interspecific competition. Variations in abiotic and biotic conditions in different ecosystems may further influence resource availability and habitat utilisation, potentially reducing competition. The aim of this study is to investigate the effects of environmental variation on spatial and trophic niche overlap between two freshwater apex predators, the northern pike (Esox lucius) and the European catfish (Silurus glanis), in three different water bodies. METHODS: We used fine-scale acoustic telemetry to assess the spatial niche overlap of pike and catfish, analyzing their spatial and habitat use in relation to the thermocline and their presence in benthic versus open-water habitats. Stable isotope analysis (SIA) was used to quantify trophic niche overlap and dietary differences between the species. We compared the habitat use, spatial niche width and overlap, and trophic differentiation among waterbodies to determine how environmental conditions influence predator interactions. RESULTS: During summer, pike and catfish primarily occupied benthic habitats above the thermocline across all waterbodies and diel periods. However, catfish more frequently used open water above the thermocline, while pike were more often present in both open water and benthic habitats below it. While this general pattern of habitat use was consistent, its extent varied among lakes, suggesting that local environmental conditions shape species-specific habitat selection. Despite these variations, the species exhibited substantial spatial overlap, though its magnitude fluctuated across waterbodies and diel periods. Catfish occupied a broader spatial niche in two waterbodies, while pike had a broader niche in one. Across all lakes, catfish consistently maintained a broader trophic niche than pike. However, pike exhibited higher trophic overlap with catfish than vice versa, with nearly complete overlap in one lake and substantial but incomplete overlap in others. This suggests that pike relies more heavily on shared prey resources, while catfish exploits a broader range of food sources beyond those used by pike.These patterns were primarily driven by the position of the thermocline, prey availability, structural complexity and the greater foraging plasticity of catfish, highlighting the environmental dependence of niche partitioning in these predators. CONCLUSIONS: Our findings demonstrate that spatial and trophic niche overlaps between pike and catfish are highly context-dependent, shaped by abiotic conditions, prey availability, and species-specific foraging strategies. This study highlights the importance of integrating spatial and trophic analyses to understand predator interactions in aquatic ecosystems.
- Publication type
- Journal Article MeSH
Přímé podání dosahuje nejvyšších rychlostí. Pro jeho úspěšné provedení je základem si správně nadhodit míč a zasáhnout ho. Cílem je zjistit, jaký vztah má nadhoz na úspěšnost prvního (přímého) podání u hráček tenisu. Sledovali jsme 8 závodních hráček tenisu dospělé kategorie. Každá z nich provedla 40 přímých podání. Ty byly natáčeny na rychloběžnou kameru (200Hz) z bočního pohledu. Kartézský souřadný systém obsahoval osu X (ve směru základní čára – síť) a osu Y (výšku od země). Na základě 2D kinematické analýzy jsme hodnotili bod vrcholu nadhozu a zásahu míče u podání dle kategorií jeho úspěšnosti: 1) úspěšné 2) do sítě 3) do autu – dlouhý 4) do autu – do strany. Data byla analyzována analýzou rozptylu pro opakovaná měření. Výsledky ukázaly, že vrchol nadhozu byl statisticky významně nižší (cca o 5 cm) u podaní do autu do strany (351,7 ± 21,9 cm) proti ostatním třem sledovaným kategoriím úspěšnostem podání (p < 0,05). Zásah míče neukázal žádné statisticky významné rozdíly, i když podání do autu do strany byla zasahována nejblíže základní čáry a podání do sítě nejdále. Kinematická analýza ukázala určité charakteristiky nadhozu dle kategorizace úspěšnosti i jistou jeho variabilitu. Nadhoz podání ovlivňuje úspěšnost podání, avšak hráčky mohou do jisté míry pomocí vlastních pohybových dovedností kompenzovat jeho nepřesnosti a korigovat svůj pohyb a docílit úspěšného podání. Jedním z častých důvodů podání do autu do strany je nízký nadhoz.
The flat serve reaches the highest speeds. To execute it successfully, the key is to toss the ball correctly and hit it. The aim is to determine the relationship between the toss and the success of the flat serve in female tennis players. We observed 8 competitive female adult tennis players who served 40 flat serves each. They were videotaped on a high-speed camera (200Hz) from the side view. On the basis of 2D kinematic analysis, we evaluated the racket-ball impact during 1) successful serves 2) serves into the net 3) serves fault-long 4) serves fault-wide. Using repeated measures ANOVA, the results showed that the toss peak was significantly lower (approx. 5 cm) for fault serves wide 351,7 ± 21,9 cm ((p < 0.05) compared to all other serve outcomes. The ball impact did not show any statistically significant differences, although fault serves wide had racket-ball contact closest to the baseline, and serves into the net the furthest. Kinematic analyses revealed some characteristics and variability in serve toss of selected serve outcomes. The serve toss affects the success of the serve, but players can to some extent use their own movement skills to compensate for its inaccuracies and make corrections in their movement to achieve a successful serve. One reason for fault serve wide is a low toss.
- MeSH
- Data Analysis MeSH
- Biomechanical Phenomena MeSH
- Time Factors MeSH
- Humans MeSH
- Motor Skills MeSH
- Motion Capture methods MeSH
- Athletes statistics & numerical data MeSH
- Athletic Performance * statistics & numerical data MeSH
- Tennis * physiology statistics & numerical data MeSH
- Videotape Recording methods MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Clinical Study MeSH
Despite being present in many drugs, guanylhydrazones and semicarbazones are two functional groups that have been little investigated as potential therapeutic strategies for the treatment of Alzheimer's disease (AD). For this reason, we initiated the synthesis and evaluation of these compounds as potential anticholinesterase agents, aiming to offer new alternatives for drug development against AD. In the severe phase of AD butyrylcholinesterase (BChE) becomes the main enzyme responsible for the hydrolysis of acetylcholine (ACh). Therefore, in this project, we present the results of BChE inhibitory activity, enzyme kinetics, cytotoxicity, and molecular modeling studies for three guanylhydrazone and two semicarbazone derivatives that were previously synthesized and evaluated as acetylcholinesterase (AChE) inhibitors. Among the compounds tested, guanylhydrazones (1, 2, and 3) showed inhibitory activity against BChE, exhibiting a mixed non-competitive inhibition profile. Specifically, compound 2 (phenanthrenequinone) demonstrated superior inhibitory potency with an IC50 of 0.68 μM, compared to compound 1 (acridinone) with an IC50 of 3.87 μM, and compound 3 (benzodioxole) with an IC50 of 101.7 μM. In contrast, semicarbazones (4 and 5) showed no BChE inhibition up to the highest concentration tested (300 μM). Importantly, all five compounds were found to be non-cytotoxic. Our results suggest that these compounds have potential as drug prototypes targeting different phases of AD. Compounds 3, 4, and 5 may be more effective in the early phase, when AChE activity remains high; compound 1 could be useful in the intermediate phase; and compound 2 appears particularly promising for the severe phase, when BChE plays a more dominant role.
- MeSH
- Acetylcholinesterase metabolism chemistry MeSH
- Alzheimer Disease * drug therapy MeSH
- Butyrylcholinesterase metabolism chemistry MeSH
- Cholinesterase Inhibitors * chemistry pharmacology metabolism therapeutic use chemical synthesis MeSH
- Hydrazones * chemistry pharmacology MeSH
- Kinetics MeSH
- Humans MeSH
- Models, Molecular MeSH
- Drug Design * MeSH
- Semicarbazones * chemistry pharmacology metabolism MeSH
- Molecular Docking Simulation MeSH
- Structure-Activity Relationship MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: To examine concussion experiences and knowledge among top-level youth karate athletes. METHODS: This cross-sectional study collected data during the 12th World Karate Championships for cadets, juniors and under-21 athletes (held in Konya, Turkey, 2022). All 1414 registered athletes from 95 countries were invited to complete a 16-item paper-based questionnaire assessing demographic data, concussion history and concussion knowledge prior to the competing at the tournament. χ2 and Fisher's exact tests were used to analyse differences by sex, age group and continental karate federation. RESULTS: A total of 654 athletes (46.3% response rate), including 286 (43.7%) females and 368 (56.3%) males, participated in the study, with 29.9% reporting one or more concussions during participation in karate training or competition. Older age groups (under 21 years) reported significantly higher concussion rates than younger athletes (56.9% vs 31.1% juniors and 24.7% cadets; p<0.001). Concussion knowledge revealed considerable gaps, with only 24.5% of athletes correctly identifying a concussion and 68.9% believing loss of consciousness was required for a concussion diagnosis. Misconceptions varied significantly across geographical regions, with Asian and African athletes demonstrating the greatest need for targeted education. Female athletes demonstrated better concussion reporting attitudes than males (60.4% vs 48.9%, p=0.004). CONCLUSIONS: This study highlights the prevalence of concussions and significant knowledge gaps among top-level youth karate athletes, emphasising the need for tailored educational interventions to improve concussion recognition and management within the karate community.
- MeSH
- Martial Arts * injuries MeSH
- Brain Concussion * epidemiology MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Cross-Sectional Studies MeSH
- Surveys and Questionnaires MeSH
- Athletes * statistics & numerical data MeSH
- Athletic Injuries * epidemiology MeSH
- Health Knowledge, Attitudes, Practice * MeSH
- Check Tag
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Background/Objectives: Post-activation performance enhancement (PAPE) has been explored for its potential to improve general performance in combat sports. This systematic review and meta-analysis investigated the effects of PAPE protocols on physical performance, focusing on differences across disciplines, competitive levels, and testing methods. Methods: A PRISMA-guided search (2010-2023) identified 19 studies examining PAPE protocols in combat sports athletes. The inclusion criteria required human trials using defined PAPE protocols, with outcomes of general performance indicators such as countermovement jumps (CMJs). A meta-analysis was conducted on data from 866 athletes using random effects modeling. Results: The PAPE protocols yielded a pooled effect size of 0.136 (95% CI, 0.008-0.263) across 866 athletes. Taekwondo athletes exhibited the most pronounced improvements in CMJ performance, particularly when using protocols that combined repeated vertical jumps with heavy-resistance cluster sets, and with dynamic, sport-specific movements such as the bandal chagui protocol achieving an effect size of 1.19 (p < 0.001). Conversely, Muay Thai athletes experienced performance declines when the protocols incorporated highly specific techniques, such as roundhouse kicks (ES = -1.36, p = 0.009). Analysis by competitive level revealed pooled effect sizes of 0.14 (95% CI, -0.01 to 0.29) for amateur athletes and 0.13 (95% CI, -0.11 to 0.38) for elite athletes, with no statistically significant differences observed between these groups. Conclusions: PAPE's effectiveness depends on tailoring protocols to the competitive level and discipline. Short rest intervals support plyometric protocols for amateurs, while heavy-resistance exercises enhance elite performers. Further research is needed to standardize PAPE protocols and explore discipline-specific adaptations.
- Publication type
- Journal Article MeSH
- Review MeSH
PURPOSE: Para-karate has been gaining popularity rapidly; however, scientific research on the subject remains limited. This study aims to examine the kata preferences at top-level para-karate events and explore the relationship between sport class (type of impairment) and kata selection. METHODS: Data was collected from nine events-four World Para-Karate Championships (2016, 2018, 2021, 2023) and five European Para-Karate Championships (2018, 2019, 2021, 2022, 2023). A total of 906 katas were performed: 567 by males and 339 by females. Descriptive statistics and chi-square tests were used for analysis. RESULTS: Top-level para-karate athletes utilized 62 katas (61%) from the official WKF list (102 katas). The most popular katas were Gojushiho Sho (19.9%), Unsu (11.5%), Kanku Sho (9.5%), Suparinpei (6.7%), and Jion (6.2%). A significant relationship was found between sport class and kata selection (p ≤ 0.05). The most popular kata for K30 was Unsu (15%), while K10 and K21 + K22 classes predominantly chose Gojushiho Sho (16.6% and 30.3%, respectively). CONCLUSIONS: Kata selection for para-karate athletes is influenced by the type of impairment. Intellectually impaired athletes and their coaches often select a single, challenging kata with a balanced fast-to-slow movement ratio, such as Gojushiho Sho, to optimize performance.
- Publication type
- Journal Article MeSH
Existing research indicates that the shape of various facial regions is linked to perceived attractiveness and perceived formidability. Interestingly, little evidence shows that people directly focus on these specific facial regions during judgments of attractiveness and formidability, and there is little support for the notion that the levels of attractiveness and formidability affect raters' visual attention. We employed eye-tracking to examine visual attention (the number of fixations and dwell time) in 40 women and 37 men, while they assessed 45 male faces in life-sized photographs for attractiveness and formidability. The facial photographs were grouped by varying levels of attractiveness and formidability (low, medium, and high). Our results showed that regardless of the characteristics rated, both men and women paid the most visual attention to the eyes, nose, mouth, and forehead regions. We found statistically discernible variation in visual attention in relation to the rater's sex or target's attractiveness levels for other facial features (the chin, cheeks, or ears), but these differences may not be substantial enough to have practical implications. We suggest that the eyes, the nose, and the mouth regions play a central role in the evolution of face perception as regions most salient to the acquisition of informative cues about others. Further, during both attractiveness and formidability judgments, men looked longer at the stimuli than women did, which may hint at increased difficulty of this task for men, possibly because they compare themselves with the stimuli. Additionally, irrespective of sex, raters looked marginally longer at faces with a medium level of formidability than at those with a high formidability level, which may reflect ambiguity of these stimuli and uncertainty regarding assessment. We found no other significantly relationships between the target's attractiveness and formidability levels and the rater's visual attention to whole faces.
- MeSH
- Adult MeSH
- Beauty MeSH
- Humans MeSH
- Judgment MeSH
- Young Adult MeSH
- Face * MeSH
- Attention * physiology MeSH
- Facial Recognition physiology MeSH
- Eye-Tracking Technology MeSH
- Choice Behavior physiology MeSH
- Visual Perception physiology MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
This study investigated the impact of Hofstede cultural dimensions on sustainable competitive advantage with the mediating role of entrepreneurial innovativeness among Malays, Malaysian Chinese, and Malaysian Indian entrepreneurs in the retail industry. This study involved a quantitative approach with standardized questionnaires distributed among target respondents through non-probability sampling techniques, including snowball sampling, quota sampling, and convenience sampling. The data were collected in a cross-sectional setting from Malaysian retail ethnic entrepreneurs. AMOS-SEM and SPSS were used to analyze the data. The findings of this study revealed a positive and significant influence of indulgence, long-term orientation, masculinity, and low power distance on sustainable competitive advantage among Chinese, Malay, and Indian entrepreneurs. Furthermore, the direct effect of entrepreneurial innovativeness was also positive and significant in terms of sustainable competitive advantage among Chinese, Malay, and Indian entrepreneurs. Finally, the indirect effects of collectivism, indulgence, low uncertainty avoidance, low power distance, masculinity, and long-term orientation on sustainable competitive advantage through mediator entrepreneurial innovativeness were positive and significant among Malaysian Chinese. However, in Malay (indulgence) and India (collectivism, low uncertainty avoidance, and low power distance), these were not significant. Our results suggest that academics and businesses should consider how cultural norms of masculinity, long-term orientation, and uncertainty avoidance impact sustainable competitive advantage activities. Rewards encouraging sustainable competitive advantage in one subculture may not promote it in another. Subcultural norms influence entrepreneurs' decisions, expectations, and incentives in a culturally diverse community.
- MeSH
- Adult MeSH
- Ethnicity psychology MeSH
- Competitive Behavior MeSH
- Creativity MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Masculinity MeSH
- Entrepreneurship * MeSH
- Cross-Sectional Studies MeSH
- Surveys and Questionnaires MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Malaysia MeSH
AIM: Assessment of blood pressure during exercise is routine in athletes, but normal values remain equivocal. This study examines the response of systolic blood pressure (SBP) to exercise in a large cohort of athletes and establishes normative values by sex and age. METHODS: Competitive athletes free of cardiovascular disease underwent pre-participation exercise testing on a bicycle ergometer. Resting (SBPrest) and peak blood pressure (SBPpeak), heart rate (HRrest and HRpeak), and power output (WR) were recorded. Workload indexed values were calculated. RESULTS: The cohort included 12,083 athletes (median age 15 years, 26.9% female). Median peak exercise SBP was similar between sexes, but WR-indexed measures including SBP/WR ratio and SBP/(WR/kg) slope were higher in females (0.9 vs. 0.7, p < 0.001; 10.94 vs. 9.52, p < 0.001). Univariate analyses revealed significant associations between SBPpeak and several predictors, including sex, age, weight, height, SBPrest, DBPrest, HRrest, HRpeak, and WR (all p < .001). Multivariate analysis showed that SBPrest (beta = 0.353, 95% CI [0.541, 0.609], p < 0.001), height (beta = 0.303, 95% CI [0.360, 0.447], p < 0.001), WR (beta = 0.171, 95% CI [0.029, 0.045], p < 0.001), and age (beta = 0.093, 95% CI [0.162, 0.241], p < 0.001) were the strongest predictors of SBPpeak. CONCLUSION: This study provides reference values for the interpretation of SBP responses to exercise in athletes. Multivariate analyses highlight the complex interplay of factors influencing peak SBP, including SBPrest, height, WR, age, DBPrest, sex, endurance sport category, and weight. In future studies, these findings may inform the development of personalised training strategies and risk stratification models in athletic populations.
- Publication type
- Journal Article MeSH
