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1.
Front Microbiol ; 15: 1386557, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38952447

RESUMEN

The aerobic granular sludge(AGS) technology draw scientific researchers attention, and more and more scientific research focuses on it, due to its superior advantages, such as good settling performance, high biological phase, high toxicity resistance and multiple biological effects. With the rapid development of AGS technology, a considerable amount of residual AGS will be produced, and dehydration is the biggest bottleneck of sludge reduction. This study investigated the dewatering process and method of residual AGS cultured by continuous flow experiment. Experiments were conducted using centrifugal dewatering technology with a dosing scheme to analyze the granular sludge dewatering process, and investigate the release process of EPS component in AGS dewatering. Our results implied the specific resistance of AGS has a very low value ((1.82 ± 0.03) × 109 m/kg) and it was not obvious for the conditioning effect of chemical conditioner on AGS dewatering. However, the moisture content can be reduced to 63.5% after dewatering with the presence of inorganic substances. The addition of drinking water treatment plant sludge (Alum sludge) can improve the efficiency of the dewatering of AGS. A possible dewatering process of AGS dewatering was proposed which was divided into two stages: First, a considerable amount of free water in the sludge was quickly removed under the action of gravity without pressure filtration. Second, the bound water release required cooperation between applying centrifugal or pressing force to grind granular cells and separate protein-like substances with the inorganic matter inside the granular sludge. The possible mechanism of AGS dewatering and hypothesis dewatering process are useful to optimize the AGS dewatering process.

2.
Front Psychol ; 15: 1252520, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38952836

RESUMEN

Overestimation and miscalibration increase with a decrease in performance. This finding has been attributed to a common factor: participants' knowledge and skills about the task performed. Researchers proposed that the same knowledge and skills needed for performing well in a test are also required for accurately evaluating one's performance. Thus, when people lack knowledge about a topic they are tested on, they perform poorly and do not know they did so. This is a compelling explanation for why low performers overestimate themselves, but such increases in overconfidence can also be due to statistical artifacts. Therefore, whether overestimation indicates lack of awareness is debatable, and additional studies are needed to clarify this issue. The present study addressed this problem by investigating the extent to which students at different levels of performance know that their self-estimates are biased. We asked 653 college students to estimate their performance in an exam and subsequently rate how confident they were that their self-estimates were accurate. The latter judgment is known as second-order judgments (SOJs) because it is a judgment of a metacognitive judgment. We then looked at whether miscalibration predicts SOJs per quartile. The findings showed that the relationship between miscalibration and SOJs was negative for high performers and positive for low performers. Specifically, for low performers, the less calibrated their self-estimates were the more confident they were in their accuracy. This finding supports the claim that awareness of what one knows and does not know depends in part on how much one knows.

3.
Front Chem ; 12: 1427451, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38952891

RESUMEN

In solid propellants, combustion catalysts play a crucial role. Here, we introduce a convenient method for the self-assembly of UIO-66 (Mn) in the presence of water, leading to the preparation of Mn/C aerogels. The aerogels were successfully utilized in the thermocatalytic decomposition of ammonium perchlorate (AP). The results indicate that the incorporation of 2% mass fraction of Mn/C aerogels enhances the peak temperature of AP decomposition by approximately 87.5°C. Mn/C aerogels demonstrate excellent catalytic performance. In combination with kinetics, we propose a thermal catalytic mechanism.

4.
Biol Sport ; 41(3): 201-211, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952901

RESUMEN

This study aimed to determine, through the use of a highly sensitive statistical tool, whether real changes in performance were present; and compare the rates of meaningful variations in strength, speed, and power parameters at different time-points during the competitive season in national team rugby players. Thirty-two players were assessed 5 times across the season using the following tests: squat jump and countermovement jump tests; 30-m sprint velocity; and one-repetition maximum (1RM) in the half-squat and bench-press exercises. A repeated-measures analysis of variance was conducted to test for differences between successive time-points. Individual coefficients of variation values were used to set target scores for post-measurements and examine whether changes in performance parameters were greater than the natural test variance, thus providing an indication of whether "true changes" occurred. No significant changes were detected in the vertical jump height, 1RM measures, and sprint velocity and momentum throughout the 11-month period (P > 0.05). True changes occurred much more frequently for strength-power measures than for sprint velocity and momentum. Elite rugby union players did not exhibit significant variations in neuromuscular performance across the competitive period, when a group-based analysis was conducted. However, at the individual level, "true changes" in strength-power-(but not in speed-) related qualities were consistently observed over the competitive season.

5.
Biol Sport ; 41(3): 15-28, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952897

RESUMEN

To improve soccer performance, coaches should be able to replicate the match's physical efforts during the training sessions. For this goal, small-sided games (SSGs) are widely used. The main purpose of the current study was to develop similarity and overload scores to quantify the degree of similarity and the extent to which the SSG was able to replicate match intensity. GPSs were employed to collect external load and were grouped in three vectors (kinematic, metabolic, and mechanical). Euclidean distance was used to calculate the distance between training and match vectors, which was subsequently converted into a similarity score. The average of the pairwise difference between vectors was used to develop the overload scores. Three similarity (Simkin, Simmet, Simmec) and three overload scores (OVERkin, OVERmet, OVERmec) were defined for kinematic, metabolic, and mechanical vectors. Simmet and OVERmet were excluded from further analysis, showing a very large correlation (r > 0.7, p < 0.01) with Simkin and OVERkin. The scores were subsequently analysed considering teams' level (First team vs. U19 team) and SSGs' characteristics in the various playing roles. The independent-sample t-test showed (p < 0.01) that the First team presented greater Simkin (d = 0.91), OVERkin (d = 0.47), and OVERmec (d = 0.35) scores. Moreover, a generalized linear mixed model (GLMM) was employed to evaluate differences according to SSG characteristics. The results suggest that a specific SSG format could lead to different similarity and overload scores according to the playing position. This process could simplify data interpretation and categorize SSGs based on their scores.

6.
Biol Sport ; 41(3): 3-13, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952905

RESUMEN

Maturity status and relative age are two of the determining factors in talent development. The aim of the study was to analyze the influence of biological maturity status and relative age on physical performance in young male and female handball players. The sample included 48 males (14.11 ± 1.17 years) and 41 females (14.25 ± 1.64 years) players from one Spanish professional handball academy. Anthropometric data (height, sitting height, body mass and self-reported biological parent heights) and physical performance data (CMJ, DJ, 20 m speed, T-test and throwing velocity) were collected. Biological maturity status was determined as the percentage of predicted adult height, while relative age was estimated in birth quartiles based on biennial age grouping (Q1-Q8). The results showed a positive correlation between maturity status and CMJ in male players (p < 0.01). Differences in CMJ performance according to maturity status were identified (p < 0.05), with higher jump heights being recorded especially in early maturing boys (p < 0.01) and first lines and wings (p < 0.05). The variance in CMJ test scores could be explained by the maturity status by 42.90% in U-15 (p < 0.05) and 72.60% in U-16 male players (p < 0.001). By contrast, no differences were found in girls (p > 0.05). Moreover, no relationships were found between relative age and indices of physical performance (p > 0.05). Overall, maturity status had greater impacts on the tests of physical performance than relative age. Stakeholders should monitor the maturity status of young handball players to avoid physical performance biases that do not allow them to develop their sporting potential.

7.
Biol Sport ; 41(3): 267-274, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952903

RESUMEN

Substitutions play a key role in modern football and can substantially affect the physical and overall performance of a team, and the recent substitution rule changes are worth investigating. This study explored the characteristics of substitutions, including different substitution rules, game results, sex, competition stages, tournaments and penalty shoot-outs success rates. We analysed data from a total of 3,738 substitutions from the last 10 years (2013-2023) of European Championships and World Cups, both men's and women's games. Non-parametric tests and chi-square tests were used for statistical analysis with the significance level set at p < 0.05. With the 5-substitution rule, 48% more substitutions occurred compared to the 3-substitution rule (4.26 ± 1.07 vs. 2.87 ± 0.43, p < 0.05) with a slight increase in the average substitution time (70.6 ± 14.3 vs. 69.2 ± 14.6 min, p < 0.05), and 10% more substitutions in the men's game compared to the women's game (p < 0.05). The timing of the first substitution was slightly different in the knock-out stage compared to group stage (59.8 ± 14.7 vs. 57.2 ± 13.3 min, p < 0.05), and the timing for the winning team and drawing team was later than for the losing team (p < 0.05). A total of 13.2% goals were scored by substitutes, with no significant difference between the 5-substitution rule (15.9%) vs the 3-substition rule (12.5%) (p > 0.05). Interestingly, substitute players had a lower success rate in penalty shoot-out compared to starters (61 vs. 74%, p < 0.05). Additionally, substitute player goal scorers entered the pitch later (p < 0.05) in male games compared to female games and in knock-out stage games compared to group games. This study highlights the importance of substitution rules and timing in modern elite football matches. The timing of the first substitution, introduction of substitutes in knock-out stages, and a lower success rate of substitute players in penalty shoot-outs are crucial factors to consider. Coaches can use this information to make strategic substitution decisions to improve team performance.

8.
Biol Sport ; 41(3): 191-200, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952909

RESUMEN

The aim of this study was to systematically review the current literature on blood flow restriction (BFR) as a post-exercise recovery strategy. Experimental studies investigating the effect of BFR on recovery after exercise were included. Only studies meeting the following inclusion criteria were selected: (a) studies investigating about BFR as a post-exercise recovery strategy in athletes and healthy individuals; (b) the full text being available in English; (c) experimental research study design. Studies that exclusively analyzed BFR as a recovery strategy during the exercise (e.g., recovery strategy between bouts of exercise) were excluded. A literature review was conducted on the PubMed, Cochrane, and Web of Science electronic databases up until May 7th, 2023. The main findings were that (i) 9 studies investigated passive BFR as a post-exercise recovery strategy, which shows a significant lack of research in both team and individual sports (especially in female populations), and only 2 studies used active BFR protocols; (ii) although a high quality range of studies was observed, there were methodological limitations such as BFR interventions that were usually conducted after fatiguing protocols or fitness tests, which may not represent the real exercise (e.g., a sprint session of 6 sets of 50 m may induce muscle damage but it does not represent the demands of a team sport like rugby or soccer); (iii) there is a lack of consistency in BFR protocols (e.g., number of cycles or duration of the occlusion-reperfusion periods) for recovery; (iv) some studies showed beneficial effects while others found no positive or detrimental effects of BFR as a post-exercise recovery strategy in comparison with the control/SHAM group. In conclusion, only 11 studies investigated BFR as a post-exercise recovery strategy and there is not any significant amount of evidence in team or individual sports (especially in female populations). BFR could be a potential post-exercise recovery strategy, but practitioners should use caution when applying this method of recovery for their athletes and clients. In addition, it would be of interest for high performance-related practitioners to have a better understanding of the benefits of BFR interventions combined with either active or passive forms of exercise as a post-exercise recovery strategy.

9.
Biol Sport ; 41(3): 79-87, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952910

RESUMEN

This systematic review and meta-analysis aimed to determine the effect of combined beta-alanine (BA) and sodium bicarbonate (SB) supplementation on exercise capacity and performance. Four databases (PubMed, SPORTDiscus, Web Of Science and MEDLINE) were searched using relevant terms for studies involving healthy (e.g. no chronic diseases or conditions) male or female adults of any training status (athletes, physically active and non-athletes) and that investigated BA and SB in isolation and combination at any dose on an exercise outcome. Ten studies, totalling 243 individuals, met the criteria with 12 outcomes for each nutritional supplement. No ergogenic effect was detected in this meta-analysis for BA (SMD = 0.18, 95% CI: -0.06; 0.43, p = 0.13, tau2 = 0, tau = 0, I2 = 0.0%) or SB (SMD = 0.17, 95% CI: -0.08; 0.41, p = 0.16, tau2 = 0, tau = 0, I2 = 0.0%) in isolation. However, there was a beneficial effect for the combination of BA and SB (SMD = 0.32, 95% CI: 0.07; 0.57, p = 0.02, tau2 = 0, tau = 0, I2 = 0.0%). Meta-regression identified no differences between supplementing with BA or SB separately (F = 0.58; p = 0.57). Combining BA and SB improved exercise performance, however, there was no benefit in taking these supplements individually.

10.
Biol Sport ; 41(3): 153-168, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38952917

RESUMEN

The aim of this study is to determine the acute effects of resistance and plyometric training on sprint and change of direction (COD) performance in healthy adults and adolescents. A systematic literature search was conducted via Medline, Cinahl, Scopus and SportDiscus databases for studies that investigated: 1) healthy male, female adults, or adolescents; and 2) measured sprint or change of direction performance following resistance and plyometric exercises. Studies were excluded if: 1) resistance or plyometric exercises was not used to induce muscle damage; 2) conducted in animals, infants, elderly; 3) sprint performance and/or agility performance was not measured 24 h post muscle damaging protocol. Study appraisal was completed using the Kmet Quality Scoring for Quantitative Study tool. Forest plots were generated to quantitatively analyse data and report study statistics for statistical significance and heterogeneity. The included studies (n = 20) revealed sprint and COD performance was significantly impaired up to 72 hr following resistance and plyometric exercises; both protocols significantly increased creatine kinase (CK), delayed-onset muscle soreness (DOMS) and decreased countermovement jump (CMJ) up to 72 hr. The systematic review of 20 studies indicated that resistance and plyometric training significantly impaired sprint and COD performance up to 72 hours post-exercise. Both training protocols elevated exercise-induced muscle damage (EIMD) markers (CK, DOMS) and decreased CMJ performance within the same timeframe.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38953770

RESUMEN

This study aimed to examine the effect of nonsleep deep rest (NSDR) on physical and cognitive performance, as well as sleepiness, acute readiness, recovery, stress, and mood state in physically active participants. A total of 65 physically active participants (42 male, 23 female) were randomly assigned into two groups: an experimental group (NSDR, n = 34), in which participants completed a 10-min NSDR intervention, and a control group (CON, n = 31), whereby participants sat passively for 10 min. Testing measures were assessed immediately pre and 10 min post each condition and comprised completing a hand grip strength dynamometer test and a countermovement jump test on force plates, cognitive function measures via a psychomotor vigilance task (PVT-B), and a Simon task test, along with four questionnaires to assess sleep, recovery, and mood state. A significant Group × Time interaction favored the NSDR condition for handgrip strength, median reaction time during the PVT-B, and accuracy percentage during the Simon task. Questionnaire responses demonstrated NSDR to be associated with significant benefits to physical readiness, emotional balance, overall recovery, negative emotional state, overall stress, and tension in comparison to CON (p < .05). The NSDR intervention could be a valuable strategy for acutely enhancing overall well-being and readiness.

12.
Phys Eng Sci Med ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38954379

RESUMEN

Contrast-enhanced mammography is being increasingly implemented clinically, providing much improved contrast between tumour and background structures, particularly in dense breasts. Although CEM is similar to conventional mammography it differs via an additional exposure with high energy X-rays (≥ 40 kVp) and subsequent image subtraction. Because of its special operational aspects, the CEM aspect of a CEM unit needs to be uniquely characterised and evaluated. This study aims to verify the utility of a commercially available phantom set (BR3D model 020 and CESM model 022 phantoms (CIRS, Norfolk, Virginia, USA)) in performing key CEM performance tests (linearity of system response with iodine concentration and background subtraction) on two models of CEM units in a clinical setting. The tests were successfully performed, yielding results similar to previously published studies. Further, similarities and differences in the two systems from different vendors were highlighted, knowledge of which may potentially facilitate optimisation of the systems.

13.
Longit Life Course Stud ; 15(3): 394-406, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38954409

RESUMEN

This study aims to evaluate the temporal trend in the quality of cause-of-death data and garbage code profiles and to determine its association with socio-economic status in Serbia. A longitudinal study was assessed using data from mortality registers from 2005 to 2019. Computer application Analysis of Causes of National Deaths for Action (ANACONDA) calculates the distribution of garbage codes by severity and composite quality indicator: Vital Statistics Performance Index for Quality (VSPI(Q)). A relationship between VSPI(Q) and country development was estimated by analysing two socio-economic indicators: the Socio-demographic Index and the Human Development Index (HDI). Serbia indicates progress in strengthening cause-of-death statistics. The steady upward trend of the VSPI(Q) index has risen from 55.6 (medium quality) to 70.2 (high quality) over the examined years. Significant reduction of 'Insufficiently specified causes with limited impact' (Level 4) and an increase in the trend of 'High-impact garbage codes' (Levels 1 to 3) were evident. Decreased deaths of no policy value (annual percentage change of -1.41%) have manifested since 2014. A strong positive association between VSPI(Q) and socio-economic indicators was assessed, where the HDI has shown a stronger association with VSPI(Q). Improved socio-economic conditions on the national level are followed by enhanced cause-of-death data quality. Upcoming actions to improve quality should be directed at high-impact garbage codes. The study underlines the need to prioritise the education and training of physicians with a crucial role in death certification to overcome many cause-of-death quality issues identified in this assessment.


Asunto(s)
Causas de Muerte , Humanos , Serbia/epidemiología , Causas de Muerte/tendencias , Estudios Longitudinales , Factores Socioeconómicos , Sistema de Registros , Exactitud de los Datos , Estadísticas Vitales
14.
Anat Sci Educ ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38954745

RESUMEN

Reduced hours of instruction are reported within the gross anatomy education literature. Anatomy instruction continues to be challenged with motivating and inspiring learners to value the contribution of gross anatomy knowledge to their career development alongside increased organizational demands for efficiency and effectiveness. To address these demands, this retrospective study sought to understand how the relative timing and amount of gross anatomy instruction were related to examination performance. Undergraduate and graduate students between 2018 and 2022 were assigned to three cohorts determined by enrollment in prosection-based anatomy only (n = 334), concurrent enrollment in prosection- and dissection-based anatomy in the same semester (n = 67), or consecutive enrollment in the courses one year apart (n = 43). Concurrent students had higher prosection-based anatomy examination scores than prosection-only and consecutive students. Consecutively, enrolled students outperformed concurrently enrolled students on the first two dissection examinations but showed no performance differences on the third and fourth dissection examinations. While the results on the timing and presentation of anatomical instruction were inconclusive, the results do support increased instructional time using both prosection and dissection modalities concurrently to improve performance on identification-based gross anatomy examinations.

15.
Poult Sci ; 103(9): 103946, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38954902

RESUMEN

This study aimed to investigate the effects of dietary Bacillus velezensis KNF-209 (BV-KNF-209) on the growth performance, immunity, and gut health of broilers. A total of 540 one-day-old male Cobb-500 broilers were randomly divided into 5 groups of 6 replicates with 18 broilers per replicate. Dietary treatments were corn-soybean meal basal diets supplemented with 0, 50, 100, 200, and 400 mg/kg BV-KNF-209 (CON, BV 50, BV 100, BV 200, and BV 400 groups, respectively) for 42 d. Compared with the CON group, the average daily gains (ADG) at 0 to 42 d in the BV 100 and BV 200 groups were significantly increased (P < 0.01), and the feed-to-gain (F:G) ratios were significantly decreased at 0 to 21 d (P < 0.01) and 0 to 42 d (P < 0.05). The BV 200 and BV 400 groups had higher serum immunoglobulin M (IgM) levels at d 21 and 42 (P < 0.05). The serum levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) were significantly decreased in the BV 50, BV 100, and BV 200 groups at d 21 (P < 0.05), and serum IL-1ß and IL-6 levels were also reduced in the BV 100 and BV 200 groups at d 42 (P < 0.05). Meanwhile, increased interleukin-10 (IL-10) levels in the jejunal and ileal mucosa at d 42 were observed in the BV 100, BV 200, and BV 400 groups (P < 0.05), while the IL-1ß and IL-6 levels (P < 0.01) were decreased. The BV 200 and BV 400 groups showed significantly higher activities of lipase and trypsin (P < 0.05) in jejunal digesta as well as higher activities of amylase and trypsin (P < 0.01) in ileal digesta at d 42. The cecal acetic acid and propionic acid levels in the BV groups and lactic acid levels in the BV 50, BV 100, and BV 200 groups (P < 0.05) were significantly higher compared to those in the CON group. Overall, dietary BV-KNF-209 supplementation significantly improved broiler growth performance, an effect that may have been achieved by heightening immunity, increasing digestive enzyme activity, and raising intestinal short-chain fatty acids and lactic acid levels.

16.
Br J Sports Med ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38955507

RESUMEN

The upcoming Paris 2024 Olympic and Paralympic Games could face environmental challenges related to heat, air quality and water quality. These challenges will pose potential threats to athletes and impact thousands of stakeholders and millions of spectators. Recognising the multifaceted nature of these challenges, a range of strategies will be essential for mitigating adverse effects on participants, stakeholders and spectators alike. From personalised interventions for athletes and attendees to comprehensive measures implemented by organisers, a holistic approach is crucial to address these challenges and the possible interplay of heat, air and water quality factors during the event. This evidence-based review highlights various environmental challenges anticipated at Paris 2024, offering strategies applicable to athletes, stakeholders and spectators. Additionally, it provides recommendations for Local Organising Committees and the International Olympic Committee that may be applicable to future Games. In summary, the review offers solutions for consideration by the stakeholders responsible for and affected by the anticipated environmental challenges at Paris 2024.

17.
Eur J Sport Sci ; 24(7): 857-869, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38956784

RESUMEN

The purpose of this study was firstly to examine the sensitivity of heart rate (HR)-based and subjective monitoring markers to intensified endurance training; and secondly, to investigate the validity of these markers to distinguish individuals in different fatigue states. A total of 24 recreational runners performed a 3-week baseline period, a 2-week overload period, and a 1-week recovery period. Performance was assessed before and after each period with a 3000m running test. Recovery was monitored with daily orthostatic tests, nocturnal HR recordings, questionnaires, and exercise data. The participants were divided into subgroups (overreached/OR, n = 8; responders/RESP, n = 12) based on the changes in performance and subjective recovery. The responses to the second week of the overload period were compared between the subgroups. RESP improved their baseline 3000 m time (p < 0.001) after the overload period (-2.5 ± 1.0%), and the change differed (p < 0.001) from OR (0.6 ± 1.2%). The changes in nocturnal HR (OR 3.2 ± 3.1%; RESP -2.8 ± 3.7%, p = 0.002) and HR variability (OR -0.7 ± 1.8%; RESP 2.1 ± 1.6%, p = 0.011) differed between the subgroups. In addition, the decrease in subjective readiness to train (p = 0.009) and increase in soreness of the legs (p = 0.04) were greater in OR compared to RESP. Nocturnal HR, readiness to train, and exercise-derived HR-running power index had ≥85% positive and negative predictive values in the discrimination between OR and RESP individuals. In conclusion, exercise tolerance can vary substantially in recreational runners. The results supported the usefulness of nocturnal HR and subjective recovery assessments in recognizing fatigue states.


Asunto(s)
Fatiga , Frecuencia Cardíaca , Carrera , Humanos , Frecuencia Cardíaca/fisiología , Carrera/fisiología , Adulto , Masculino , Femenino , Adulto Joven , Entrenamiento Aeróbico/métodos , Encuestas y Cuestionarios , Resistencia Física/fisiología , Prueba de Esfuerzo/métodos
18.
Eur J Sport Sci ; 24(7): 907-917, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38956789

RESUMEN

The Multi-Action Plan (MAP) model presents an idiosyncratic framework for human performance. MAP research has categorised four Performance Types (PTs; T1-T4) using self-paced activities. Specifically, T1-4 present four distinct mental states experienced by athletes during performance, differing, among other aspects, in the level of effort and perceived control. However, transitions between PTs are yet to be empirically investigated. This study aimed to examine MAP in the hyperdynamic open-skill combat context of judo. We explored how judoka experienced PTs and the transition processes between these mental states. Six British, high-level judoka (n = 6; Mdnage = 19) were interviewed using a retrospective semi-structured interview schedule. Interpretative phenomenological analysis indicated that judo presents a hyperdynamic difficult-to-predict performance context due to the opponent and fighting rhythm. Second, participants strongly related to T2 and T3 and less to T1 and T4. They also reported experiences 'between' T2 and T3. Lastly, participants reported common transition pathways (e.g., T2-T3), typical transition cues, and specific trainable strategies to optimise performance. Findings are discussed in relation to existing literature. Lastly, we present limitations, applied, and research considerations.


Asunto(s)
Rendimiento Atlético , Artes Marciales , Humanos , Artes Marciales/fisiología , Artes Marciales/psicología , Rendimiento Atlético/psicología , Rendimiento Atlético/fisiología , Masculino , Femenino , Adulto Joven , Atletas/psicología , Estudios Retrospectivos , Adulto
19.
Eur J Sport Sci ; 24(7): 930-937, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38956799

RESUMEN

An important application for training instructions is found in directing one's attentional focus. This direction can occur in different internal, external, or holistic forms. However, comparison between these three forms of instructions is a relatively recent development rarely reported at different skill levels or various sports including karate. Therefore, the present study attempts to investigate the effects of three forms of instructions on standing long jump performance in skilled and novice karatekas. The participants were 60 skilled and novice karatekas (all females; mean age: 21.32 ± 1.65) who completed 12 standing long jump trials under different focus conditions (3 trials for each condition: internal, external, holistic and control condition) in a counterbalanced order. Our findings suggested significant main effects, indicating that skilled karatekas outperformed the novices. The findings also showed that regardless of skill levels, the participants exhibited similar performance under external and holistic focus conditions while performance in both of these conditions was superior compared to performance under internal focus and control conditions. No difference was observed between the control and internal focus conditions. It seems that skilled and novice karatekas may benefit from holistic and external focus of attention instructions which enhance their motor performance. Thus, it is recommended that coaches should incorporate these two types of attentional focus instructions into their training sessions.


Asunto(s)
Rendimiento Atlético , Atención , Artes Marciales , Humanos , Femenino , Atención/fisiología , Artes Marciales/fisiología , Rendimiento Atlético/fisiología , Rendimiento Atlético/psicología , Adulto Joven , Destreza Motora/fisiología
20.
J Agric Food Chem ; 72(26): 14557-14569, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38957088

RESUMEN

This study aimed to investigate the mechanisms by which dark septate endophytes (DSE) regulate salt tolerance and the accumulation of bioactive constituents in licorice. First, the salt stress tolerance and resynthesis with the plant effect of isolated DSE from wild licorice were tested. Second, the performance of licorice inoculated with DSE, which had the best salt-tolerant and growth-promoting effects, was examined under salt stress. All isolated DSE showed salt tolerance and promoted plant growth, withCurvularia lunata D43 being the most effective. Under salt stress, C. lunata D43 could promote growth, increase antioxidant enzyme activities, enhance glycyrrhizic acid accumulation, improve key enzyme activities in the glycyrrhizic acid synthesis pathway, and induce the expression of the key enzyme gene and salt tolerance gene of licorice. The structural equation model demonstrated that DSE alleviate the negative effects of salt stress through direct and indirect pathways. Variations in key enzyme activities, gene expression, and bioactive constituent concentration can be attributed to the effects of DSE. These results contribute to revealing the value of DSE for cultivating medicinal plants in saline soils.


Asunto(s)
Endófitos , Glycyrrhiza , Ácido Glicirrínico , Estrés Salino , Ácido Glicirrínico/metabolismo , Glycyrrhiza/química , Glycyrrhiza/metabolismo , Glycyrrhiza/microbiología , Endófitos/metabolismo , Endófitos/genética , Tolerancia a la Sal , Ascomicetos/metabolismo , Ascomicetos/crecimiento & desarrollo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Regulación de la Expresión Génica de las Plantas
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