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2.
Nature ; 579(7799): 409-414, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32188942

RESUMO

Plants are essential for life and are extremely diverse organisms with unique molecular capabilities1. Here we present a quantitative atlas of the transcriptomes, proteomes and phosphoproteomes of 30 tissues of the model plant Arabidopsis thaliana. Our analysis provides initial answers to how many genes exist as proteins (more than 18,000), where they are expressed, in which approximate quantities (a dynamic range of more than six orders of magnitude) and to what extent they are phosphorylated (over 43,000 sites). We present examples of how the data may be used, such as to discover proteins that are translated from short open-reading frames, to uncover sequence motifs that are involved in the regulation of protein production, and to identify tissue-specific protein complexes or phosphorylation-mediated signalling events. Interactive access to this resource for the plant community is provided by the ProteomicsDB and ATHENA databases, which include powerful bioinformatics tools to explore and characterize Arabidopsis proteins, their modifications and interactions.


Assuntos
Proteínas de Arabidopsis/análise , Proteínas de Arabidopsis/química , Arabidopsis/química , Espectrometria de Massas , Proteoma/análise , Proteoma/química , Proteômica , Motivos de Aminoácidos , Arabidopsis/anatomia & histologia , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/genética , Bases de Dados de Proteínas , Conjuntos de Dados como Assunto , Regulação da Expressão Gênica de Plantas , Anotação de Sequência Molecular , Fases de Leitura Aberta , Especificidade de Órgãos , Fosfoproteínas/análise , Fosfoproteínas/química , Fosfoproteínas/genética , Fosforilação , Proteoma/biossíntese , Proteoma/genética , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Transcriptoma
3.
Nature ; 583(7815): 271-276, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32612234

RESUMO

Plant hormones coordinate responses to environmental cues with developmental programs1, and are fundamental for stress resilience and agronomic yield2. The core signalling pathways underlying the effects of phytohormones have been elucidated by genetic screens and hypothesis-driven approaches, and extended by interactome studies of select pathways3. However, fundamental questions remain about how information from different pathways is integrated. Genetically, most phenotypes seem to be regulated by several hormones, but transcriptional profiling suggests that hormones trigger largely exclusive transcriptional programs4. We hypothesized that protein-protein interactions have an important role in phytohormone signal integration. Here, we experimentally generated a systems-level map of the Arabidopsis phytohormone signalling network, consisting of more than 2,000 binary protein-protein interactions. In the highly interconnected network, we identify pathway communities and hundreds of previously unknown pathway contacts that represent potential points of crosstalk. Functional validation of candidates in seven hormone pathways reveals new functions for 74% of tested proteins in 84% of candidate interactions, and indicates that a large majority of signalling proteins function pleiotropically in several pathways. Moreover, we identify several hundred largely small-molecule-dependent interactions of hormone receptors. Comparison with previous reports suggests that noncanonical and nontranscription-mediated receptor signalling is more common than hitherto appreciated.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Mapas de Interação de Proteínas , Transdução de Sinais , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ligação Proteica , Mapeamento de Interação de Proteínas , Reprodutibilidade dos Testes , Transcrição Gênica
4.
Pediatr Exerc Sci ; : 1-9, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38537629

RESUMO

PURPOSE: To compute reference centiles for 5- and 30-m sprint times relative to chronological and skeletal age in youth soccer players. Subsequently, to compare individual's sprint performance scores derived from the chronological and skeletal age reference centiles. METHODS: Sprint times were collected for a sample of male U11 to U19 soccer players (n = 1745 data points). Skeletal age data were available for a subsample (n = 776 data points). Reference centiles were fitted using generalized additive models for location, scale, and shape. Individual z scores relative to chronological and skeletal age reference centiles were computed and compared for each maturity group (late, on-time, early, and very early) using standardized mean differences (SMD). RESULTS: Reference centiles for chronological age increased more rapidly between 10.5 and 15.5 years, while reference centiles for skeletal age increased more rapidly between 13.0 and 16.5 years. Differences in chronological and skeletal z scores for very early (SMD: -0.73 to -0.43) and late (SMD: 0.58 to 1.29) maturing players were small to large, while differences for early (SMD: -0.30 to -0.19) and on-time (SMD: 0.16 to 0.28) were trivial to small. CONCLUSION: Reference centiles provide a valuable tool to assist the evaluation of sprint performance in relation to chronological and skeletal age for talent identification purposes in youth soccer players.

5.
J Strength Cond Res ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38787757

RESUMO

ABSTRACT: Thron, M, Woll, A, Doller, L, Quittmann, OJ, Härtel, S, Ruf, L, and Altmann, S. Physiological and locomotor profiling enables to differentiate between sprinters, 400-m runners, and middle-distance runners. J Strength Cond Res XX(X): 000-000, 2024-Different approaches exist for characterizing athletes, e.g., physiological and locomotor profiling. The aims of this study were to generate and compare physiological and locomotor profiles of male and female runners and to evaluate relationships between the different approaches. Thirty-four highly trained adolescent and young adult female and male athletes (n = 11 sprinters; n = 11,400-m runners; n = 12 middle-distance runners) performed two 100-m sprints on a running track to determine maximal sprinting speed (MSS) and maximal lactate accumulation rate (cLamax). A cardiopulmonary exercise test was performed on a treadmill to determine maximal aerobic speed (MAS) and maximal oxygen uptake (V̇o2max). Anaerobic speed reserve (ASR) was calculated as the difference between MSS and MAS. Group comparisons were conducted with a 2-way ANOVA (discipline × sex; p < 0.05) and Bonferroni post hoc tests and Cohen's d as effect size. Parameters were correlated by Pearson's correlation coefficients. Maximal aerobic speed and V̇o2max were higher in 400-m and middle-distance runners compared with sprinters (p ≤ 0.02; -2.24 ≤ d ≤ -1.29). Maximal sprinting speed and cLamax were higher in sprinters and 400-m runners compared with middle-distance runners (0.03 ≤ p ≤ 0.28; 0.73 ≤ d ≤ 1.23). Anaerobic speed reserve was highest in sprinters and lowest in middle-distance runners (p ≤ 0.03; 1.24 ≤ d ≤ 2.79). High correlations were found between ASR and MAS, MSS, and cLamax (p < 0.01; -0.55 ≤ r ≤ 0.91) and between cLamax and MSS (p < 0.01; r = 0.74). Our results indicate that athletes of different sprinting and running disciplines show differing physiological and locomotor profiles, and that the parameters of these approaches are related to each other. This can be of interest for assessing strengths and weaknesses (e.g., for talent identification) or training prescription in these disciplines.

6.
J Sports Sci Med ; 23(2): 351-357, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38841641

RESUMO

The maximum oxygen uptake (VO2max) is a critical factor for endurance performance in soccer. Novel wearable technology may allow frequent assessment of V̇O2max during non-fatiguing warm-up runs of soccer players with minimal interference to soccer practice. The aim of this study was to assess the validity of VO2max provided by a consumer grade smartwatch (Garmin Forerunner 245, Garmin, Olathe, USA, Software:13.00) and the YoYo Intermittent Recovery Run 2 (YYIR2) by comparing it with respiratory gas analysis. 24 trained male youth soccer players performed different tests to assess VO2max: i) a treadmill test employing respiratory gas analysis, ii) YYIR2 and iii) during a non-fatiguing warm-up run of 10 min wearing a smartwatch as recommended by the device-manufacturer on 3 different days within 2 weeks. As the device-manufacturer indicates that validity of smartwatch-derived VO2max may differ with an increase in runs, 16 players performed a second run with the smartwatch to test this claim. The main evidence revealed that the smartwatch showed an ICC of 0.37 [95% CI: -0.25; 0.71] a mean absolute percentage error (MAPE) of 5.58% after one run, as well as an ICC of 0.54 [95% CI: -0.3; 8.4] and a MAPE of 1.06% after the second run with the smartwatch. The YYIR2 showed an ICC of 0.17 [95% CI: -5.7; 0.6]; and MAPE of 4.2%. When using the smartwatch for VO2max assessment in a non-fatiguing run as a warm-up, as suggested by the device manufacturer before soccer practice, the MAPE diminishes after two runs. Therefore, for more accurate VO2max assessment with the smartwatch, we recommend to perform at least two runs to reduce the MAPE and enhance the validity of the findings.


Assuntos
Teste de Esforço , Consumo de Oxigênio , Futebol , Humanos , Futebol/fisiologia , Masculino , Adolescente , Consumo de Oxigênio/fisiologia , Teste de Esforço/métodos , Teste de Esforço/instrumentação , Corrida/fisiologia , Dispositivos Eletrônicos Vestíveis , Exercício de Aquecimento/fisiologia , Reprodutibilidade dos Testes , Testes Respiratórios/instrumentação , Testes Respiratórios/métodos
7.
J Sports Sci ; 41(21): 1952-1959, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38263755

RESUMO

Existing literature on talent development predominantly focuses on male athletes, with limited representation of female athletes. This study aims to address this gap by examining the long-term development of female football players in an elite club. Routine lab-based assessments were conducted on 238 athletes across six teams for 7 years to determine how physical, perceptual-cognitive, and skill performance predictors fluctuated with player age and developmental stage (sampling 9-11y, specializing 12-14y, investment 15-18y, and performance +18y). The developmental stage was a significant predictor of improved performance for each talent indicator (p < .001), with each consecutive stage significantly outperforming the previous stage in all domains with moderate to large effect sizes (0.07-0.40 ηp2). Improvement rate was higher in young adolescence (<15) and slower approaching adulthood (>18y). Playing position influenced performance scores on several physical and technical skill predictors (p ≤ .001), but not perceptual-cognitive ones (p ≥ .11). Players progressed continuously from the sampling to the performance stage, contradicting previously reported plateaus observed when athletes reached the investment stage. Benchmark data are provided across age and playing position to better understand what is required for successful participation at an elite level at varying age groups in female soccer.


Assuntos
Desempenho Atlético , Futebol , Adolescente , Humanos , Masculino , Feminino , Adulto , Atletas , Cognição
8.
Biol Sport ; 40(4): 967-973, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37867750

RESUMO

This study aimed to analyse the influence of effective playing time on physical match performance according to playing position in professional soccer. Official match data from 267 matches (3,731 single observations) during the 2018/2019 season of the German Bundesliga were used and the effective playing time (duration of play after subtracting the time taken up by stoppages, substitutions, injuries, and goals) was captured for each match. The physical match performance parameters total distance, high-intensity distance, sprinting distance, maximum velocity, and accelerations were analysed. Players were categorized as central defender, wide defender, central defensive midfielder, central offensive midfielder, wide midfielder, and forward. Effective playing time influenced physical match performance, with total distance and accelerations (r = 0.48-0.61) being the most and high-intensity distance, sprinting distance, and maximum velocity (r = -0.17-0.03) the least affected parameters. Players covered on average 10% more total distance and performed 13% more accelerations, while sprinting 7-10% less in matches with long (> 65 min) compared to short (< 50 min) effective playing times. The influence of effective playing time was rather similar between playing positions. Still, physical performance of wide midfielders and forwards partly deviated from the pattern observed in the other positions. Coaches and practitioners should be aware that effective playing time influences physical match performance in the German Bundesliga, while special attention should be given to wide midfielders and forwards. Effective playing time and its general and position-specific effects should be taken into account when interpreting physical match performance, thereby facilitating load management practices and training design.

9.
Res Sports Med ; 31(4): 398-415, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34665981

RESUMO

The purpose of this study was to examine the effect of a 40-min nap opportunity (N40) on performance during, markers of muscle damage and inflammation, and the perception of fatigue and recovery, in response to a 5-m shuttle run test (5msrt). Fifteen male amateur athletes performed the 5msrt under two conditions: N40 and no-nap condition (NN). Blood biomarkers were collected at rest and after the 5msrt to measure muscle damage (i.e., creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), and alanine aminotransferase (ALAT)) and inflammation (i.e., C-reactive protein (CRP)). RPE was determined immediately after each repetition of the test and PRS and DOMS were determined 5 min, thereafter. Compared to NN, N40 improved the highest distance (p<0.001, Δ=+7.9%) and the total distance (p<0.001, Δ=+7.2%) attained during the 5msrt. Pre and post the 5msrt, participants presented lower muscle damage (i.e., CK, LDH, ASAT and ALAT) and inflammation (i.e., CRP) (p<0.05) values in the N40 compared to NN. Concerning RPE, DOMS, and PRS, there was a positive effect in the N40 vs. NN (p<0.01). N40 represents an effective method for improving repeated high intensity short-term maximal performance, PRS, and associated muscle damage and inflammation, and reducing RPE and DOMS.


Assuntos
Proteína C-Reativa , Exercício Físico , Humanos , Masculino , Proteína C-Reativa/análise , Biomarcadores , Inflamação/metabolismo , Músculos/química , Músculos/metabolismo , Músculo Esquelético/fisiologia
10.
J Sports Sci Med ; 22(4): 707-725, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38045740

RESUMO

While the tactical behavior of soccer players differs between specific phases of play (offense, defense, offensive transition, defensive transition), little is known about successful behavior of players during defensive transition (switching behavior from offense to defense). Therefore, this study aims to analyze the group tactic of rest defense (despite in ball possession, certain players safeguard quick counterattacks in case of ball loss) in defensive transition. A mixed-methods approach was used, involving both qualitative and quantitative analysis. Semi-structured expert interviews with seven professional soccer coaches were conducted to define rest defense. In the quantitative analysis, several KPIs were calculated, based on tracking and event data of 153 games of the 2020/21 German Bundesliga season, to predict the success of rest defense situations in a machine learning approach. The qualitative interviews indicated that rest defense can be defined as the positioning of the deepest defenders during ball possession to prevent an opposing counterattack after a ball loss. For instance, the rest defending players created a numerical superiority of 1.69 ± 1.00 and allowed a space control of the attacking team of 11.51 ± 9.82 [%] in the area of rest defense. The final machine learning model showed satisfactory prediction performance of the success of rest defense (Accuracy: 0.97, Precision: 0.73, f1-Score: 0.64, AUC: 0.60). Analysis of the individual KPIs revealed insights into successful behavior of players in rest defense, including controlling deep spaces and dangerous counterattackers. The study concludes regaining possession as fast as possible after a ball loss is the most important success factor in defensive transition.


Assuntos
Desempenho Atlético , Futebol , Humanos , Logro , Fenbendazol , Aprendizado de Máquina
11.
Pediatr Exerc Sci ; 34(4): 193­201, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35393370

RESUMO

PURPOSE: Replicating the studies of Gibson et al and Brownstein et al to assess performance, and physiological, and perceived variables during a repeated sprint protocol (RSP) with standardized versus self-selected recovery in youth soccer players. METHODS: Nineteen male soccer players (age 13.1 [1.3] y) completed 2 separate RSPs. RSP1: 10 × 30-m sprints with 30-second recovery and RSP2: 10 × 30-m sprints interspersed with self-selected recovery periods. Mean time of both 10 × 30-m RSPs and self-selected recovery periods of RSP2 were assessed. Heart rate, blood lactate concentration, and rates of perceived exertion were measured following RSPs. RESULTS: RSP2 revealed longer recovery periods (RSP1: 30.0 [0.0] s; RSP2: 39.0 [7.7] s; P < .001; effect size d = 1.648) with shorter repeated sprint time (mean 30-m sprint time: RSP1: 4.965 [0.256] s; RSP2: 4.865 [0.227] s; P = .014; d = 0.414). Blood lactate concentration (P = .002-.005; d = 0.730-0.958), heart rate (P < .001; d = 1.353), and rates of perceived exertion (RSP1: 14.9 [1.9]; RSP2: 12.9 [2.1]; P = .016; d = 1.046) were higher following RSP1. CONCLUSION: In contrast to the original studies, the present replication study demonstrated that self-selected recovery periods during a RSP leads to better repeated sprint performance compared with standardized recovery periods in youth soccer players. The better repeated sprint performance with individual recovery durations in RSP2 was achieved with less physiological and perceived effort.


Assuntos
Desempenho Atlético , Corrida , Futebol , Adolescente , Masculino , Humanos , Futebol/fisiologia , Desempenho Atlético/fisiologia , Corrida/fisiologia , Frequência Cardíaca/fisiologia , Ácido Láctico
12.
J Strength Cond Res ; 36(5): 1410-1416, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32324716

RESUMO

ABSTRACT: Altmann, S, Neumann, R, Ringhof, S, Rumpf, MC, and Woll, A. Soccer-specific agility: reliability of a newly developed test and correlates of rerformance. J Strength Cond Res 36(5): 1410-1416, 2022-The purpose of this study was to examine the reliability of a newly developed soccer-specific agility test and to determine the correlation of different performance parameters with overall agility performance as measured by the total time. Twenty-two amateur soccer players (age, 25.1 ± 4.0 years) completed a newly developed agility test on 2 separate occasions. The test required the players to conduct 2 changes of direction, one in a preplanned manner and one in response to a stimulus that was provided by a live tester who performed different soccer-specific passing movements. Regarding reliability, very large Pearson's r and intraclass correlation coefficient values were obtained for the total time and the movement time, with moderate and large-to-very large values being evident for the response time and the decision-making time, respectively. The usefulness to detect moderate performance changes was rated as "good" for the total time, the response time, and the movement time. The decision-making time was rated as "OK." The movement time showed a very large relationship with overall agility performance as measured by the total time, while the response time and the decision-making time showed small to moderate relationships. In conclusion, the newly developed soccer-specific agility test is a reliable tool to assess the agility performance of soccer players and can be used by coaches and researchers to detect moderate performance changes. Because physical aspects, represented by the movement time, showed the greatest influence on total agility performance, they are advised to be included in soccer-specific agility training programs of amateur players.


Assuntos
Desempenho Atlético , Futebol , Adulto , Atletas , Desempenho Atlético/fisiologia , Teste de Esforço , Humanos , Movimento , Reprodutibilidade dos Testes , Futebol/fisiologia , Adulto Jovem
13.
Development ; 145(21)2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30404777

RESUMO

The trans-Golgi-network (TGN) has essential housekeeping functions in secretion, endocytosis and protein sorting, but also more specialized functions in plant development. How the robustness of basal TGN function is ensured while specialized functions are differentially regulated is poorly understood. Here, we investigate two key regulators of TGN structure and function, ECHIDNA and the Transport Protein Particle II (TRAPPII) tethering complex. An analysis of physical, network and genetic interactions suggests that two network communities are implicated in TGN function and that ECHIDNA and TRAPPII belong to distinct yet overlapping pathways. Whereas ECHIDNA and TRAPPII colocalized at the TGN in interphase cells, their localization diverged in dividing cells. Moreover, ECHIDNA and TRAPPII localization patterns were mutually independent. TGN structure, endocytosis and sorting decisions were differentially impacted in echidna and trappii mutants. Our analyses point to a partitioning of specialized TGN functions, with ECHIDNA being required for cell elongation and TRAPPII for cytokinesis. Two independent pathways able to compensate for each other might contribute to the robustness of TGN housekeeping functions and to the responsiveness and fine tuning of its specialized functions.


Assuntos
Arabidopsis/metabolismo , Transdução de Sinais , Rede trans-Golgi/metabolismo , Arabidopsis/citologia , Arabidopsis/embriologia , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Biomarcadores/metabolismo , Membrana Celular/metabolismo , Citocinese , Endocitose , Epistasia Genética , Proteínas de Fluorescência Verde/metabolismo , Hipocótilo/metabolismo , Hipocótilo/ultraestrutura , Mutação/genética , Raízes de Plantas/metabolismo , Transporte Proteico , Rede trans-Golgi/ultraestrutura
14.
Entropy (Basel) ; 23(12)2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34945913

RESUMO

With the growing availability of position data in sports, spatiotemporal analysis in soccer is a topic of rising interest. The aim of this study is to validate a performance indicator, namely D-Def, measuring passing effectiveness. D-Def calculates the change of the teams' centroid, centroids of formation lines (e.g., defensive line), teams' surface area, and teams' spread in the following three seconds after a pass and therefore results in a measure of disruption of the opponents' defense following a pass. While this measure was introduced earlier, in this study we aim to prove the usefulness to evaluate attacking sequences. In this study, 258 games of Dutch Eredivisie season 2018/19 were included, resulting in 13,094 attacks. D-Def, pass length, pass velocity, and pass angle of the last four passes of each attack were calculated and compared between successful and unsuccessful attacks. D-Def showed higher values for passes of successful compared to unsuccessful attacks (0.001 < p ≤ 0.029, 0.06 ≤ d ≤ 0.23). This difference showed the highest effects sizes in the penultimate pass (d = 0.23) and the maximal D-Def value of an attack (d = 0.23). Passing length (0.001 < p ≤ 0.236, 0.08 ≤ d ≤ 0.17) and passing velocity (0.001 < p ≤ 0.690, -0.09 ≤ d ≤ 0.12) showed inconsistent results in discriminating between successful and unsuccessful attacks. The results indicate that D-Def is a useful indicator for the measurement of pass effectiveness in attacking sequences, highlighting that successful attacks are connected to disruptive passing. Within successful attacks, at least one high disruptive action (pass with D-Def > 28) needs to be present. In addition, the penultimate pass ("hockey assist") of an attack seems crucial in characterizing successful attacks.

15.
Proc Natl Acad Sci U S A ; 113(29): E4238-47, 2016 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-27357687

RESUMO

Protein microarrays enable investigation of diverse biochemical properties for thousands of proteins in a single experiment, an unparalleled capacity. Using a high-density system called HaloTag nucleic acid programmable protein array (HaloTag-NAPPA), we created high-density protein arrays comprising 12,000 Arabidopsis ORFs. We used these arrays to query protein-protein interactions for a set of 38 transcription factors and transcriptional regulators (TFs) that function in diverse plant hormone regulatory pathways. The resulting transcription factor interactome network, TF-NAPPA, contains thousands of novel interactions. Validation in a benchmarked in vitro pull-down assay revealed that a random subset of TF-NAPPA validated at the same rate of 64% as a positive reference set of literature-curated interactions. Moreover, using a bimolecular fluorescence complementation (BiFC) assay, we confirmed in planta several interactions of biological interest and determined the interaction localizations for seven pairs. The application of HaloTag-NAPPA technology to plant hormone signaling pathways allowed the identification of many novel transcription factor-protein interactions and led to the development of a proteome-wide plant hormone TF interactome network.


Assuntos
Proteínas de Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/metabolismo , Análise Serial de Proteínas , Mapeamento de Interação de Proteínas
17.
J Strength Cond Res ; 31(7): 1994-1999, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28277431

RESUMO

Altmann, S, Spielmann, M, Engel, FA, Neumann, R, Ringhof, S, Oriwol, D, and Haertel, S. Validity of single-beam timing lights at different heights. J Strength Cond Res 31(7): 1994-1999, 2017-The purpose of this study was to quantify the effect of different timing light heights on sprint time and the validity of measurement. Two single-beam timing gate systems were used to measure 30-m sprint time (splits at 5 and 10 m) in 15 healthy and physically active male subjects. System 1 was set up at a height of 0.64 m and system 2 at 0.25 m (initial timing light) and 1.00 m (each following timing light), respectively. Participants performed 3 valid trials. The recordings of a high-speed video camera were used as a reference. Sprint times of system 1 and system 2 differed significantly between each other and from the reference system at all distances (p < 0.001). Intraclass correlation coefficients and Pearson's r values between both timing light systems and the reference system were low to moderate at 5 and 10 m and moderate to high at 30 m. Bland and Altman analysis revealed that the agreement intervals were considerably higher for the comparison between system 1 and the reference system than for system 2 and the reference system. A valid measurement of splits at 5 and 10 m via the systems used in this study is questionable, whereas 30-m times have an acceptable validity, especially when using system 2. This study confirms the influence of methodological approaches on sprint times. Coaches and researchers should consider that results gained by single-beam timing lights at different heights are not comparable.


Assuntos
Luz , Corrida/fisiologia , Tempo , Adulto , Humanos , Masculino , Reprodutibilidade dos Testes , Gravação de Videoteipe , Adulto Jovem
18.
Bioinformatics ; 31(17): 2836-43, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-25910697

RESUMO

MOTIVATION: Experimentally determined gene regulatory networks can be enriched by computational inference from high-throughput expression profiles. However, the prediction of regulatory interactions is severely impaired by indirect and spurious effects, particularly for eukaryotes. Recently, published methods report improved predictions by exploiting the a priori known targets of a regulator (its local topology) in addition to expression profiles. RESULTS: We find that methods exploiting known targets show an unexpectedly high rate of false discoveries. This leads to inflated performance estimates and the prediction of an excessive number of new interactions for regulators with many known targets. These issues are hidden from common evaluation and cross-validation setups, which is due to Simpson's paradox. We suggest a confidence score recalibration method (CoRe) that reduces the false discovery rate and enables a reliable performance estimation. CONCLUSIONS: CoRe considerably improves the results of network inference methods that exploit known targets. Predictions then display the biological process specificity of regulators more correctly and enable the inference of accurate genome-wide regulatory networks in eukaryotes. For yeast, we propose a network with more than 22 000 confident interactions. We point out that machine learning approaches outside of the area of network inference may be affected as well. AVAILABILITY AND IMPLEMENTATION: Results, executable code and networks are available via our website http://www.bio.ifi.lmu.de/forschung/CoRe. CONTACT: robert.kueffner@helmholtz-muenchen.de SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Algoritmos , Reações Falso-Positivas , Regulação Fúngica da Expressão Gênica , Redes Reguladoras de Genes , Proteínas de Saccharomyces cerevisiae/genética , Biologia de Sistemas/métodos , Perfilação da Expressão Gênica , Aprendizado de Máquina , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais , Software
19.
J Strength Cond Res ; 29(8): 2361-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25647648

RESUMO

The purpose of this study was to quantify the effect of different starting distances on 5-m sprint time and the accuracy of the initial timing gate. A single-beam timing gate system (1 m high) was used to measure 5-m sprint time in 13 male sports students. Each subject performed 3 valid trials for 3 starting distances: 0.3, 0.5, and 1.0 m from the initial timing lights, respectively. A high-speed video camera was used to track a reflective marker placed on the subjects' hip within a field of view around the initial timing gate. Accuracy of the initial timing gate was defined as the time between the initial timing light trigger and passing of the reflective marker by the initial timing gate. Sprint times were significantly faster for the 1.0-m starting distance (0.98 ± 0.06 seconds) than for the 0.5-m (1.05 ± 0.07 seconds) and the 0.3-m (1.09 ± 0.08 seconds) starting distances (p < 0.001). There were no differences in initial timing gate error between starting distances (p = 0.078). Hence, starting distance influenced sprint times but not the accuracy of the initial timing gate. Researchers and coaches should consider the effect of starting distance on 5-m sprint time and ensure consistent testing protocols. Based on the results of this study, we recommend a starting distance of 0.3 m that should be used for all sprint performance tests.


Assuntos
Desempenho Atlético/fisiologia , Corrida/fisiologia , Adulto , Humanos , Masculino , Equipamentos Esportivos/normas , Fatores de Tempo , Gravação em Vídeo , Adulto Jovem
20.
PLoS One ; 19(1): e0296866, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38252665

RESUMO

PURPOSE: Locomotor profiling using anaerobic speed reserve (ASR) enables insights into athletes' physiological and neuromuscular contributing factors and prescription of high-intensity training beyond maximal aerobic speed (MAS). This systematic review aimed to determine the validity and reliability of different methods to assess the characteristics of ASR, i.e., MAS and maximal sprinting speed (MSS). METHODS: A comprehensive search of the PubMed and Web of Science databases was conducted according to the PRISMA guidelines. Studies were included if they reported data on validity and/or reliability for methods to assess MAS or MSS. RESULTS: 58 studies were included with 28 studies referring to MAS and 30 studies to MSS. Regarding MAS, different methods for cardiopulmonary exercise testing yielded different values (four out of seven studies) of MAS (Cohen's d (ES) = 0.83-2.8; Pearson's r/intraclass correlation coefficient (r/ICC) = 0.46-0.85). Criterion validity of different field tests showed heterogeneous results (ES = 0-3.57; r/ICC = 0.40-0.96). Intraday and interday reliability was mostly acceptable for the investigated methods (ICC/r>0.76; CV<16.9%). Regarding MSS, radar and laser measurements (one out of one studies), timing gates (two out of two studies), and video analysis showed mostly good criterion validity (two out of two studies) (ES = 0.02-0.53; r/ICC = 0.93-0.98) and reliability (r/ICC>0.83; CV<2.43%). Criterion validity (ES = 0.02-7.11) and reliability (r/ICC = 0.14-0.97; CV = 0.7-9.77%) for global or local positioning systems (seven out of nine studies) and treadmill sprinting (one out of one studies) was not acceptable in most studies. CONCLUSION: The criterion validity of incremental field tests or shuttle runs to examine MAS cannot be confirmed. Results on time trials indicate that distances adapted to the participants' sporting background, fitness, or sex might be suitable to estimate MAS. Regarding MSS, only sprints with radar or laser measures, timing gates, or video analysis provide valid and reliable results for linear sprints of 20 to 70 m.


Assuntos
Atletas , Corrida , Humanos , Anaerobiose , Reprodutibilidade dos Testes , Exercício Físico
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