共查询到20条相似文献,搜索用时 0 毫秒
1.
Yusuf Kklü Hamit Cihan Utku Alemdarolu Alexandre Dellal Del P. Wong 《Biology of sport / Institute of Sport》2020,37(4):375
The purpose of this study was to compare the effects of regular small-sided games (SSGreg) and SSGs combined with running drills (SSGcom) on players’ internal and external loads. Eighteen young male soccer players (average age: 18.2 ± 0.5 years) participated in 3 vs. 3 and 4 vs. 4 games, under both SSGreg and SSGcom conditions. SSGreg bouts were played for 4 minutes without additional running drills, while SSGcom bouts consisted of 3 min 30 s SSG and 15 s running before and after the bout, making the duration of each bout 4 minutes. During all SSGs, measurements of heart rate (HR) responses as well as distances covered in four different speed zones – walking (WLK), low-intensity (LIR), moderate-intensity (MIR) and high-intensity running (HIR) – were recorded. Technical characteristics were monitored during the SSGs, and the rating of perceived exertion (RPE) and blood lactate (La-) responses were determined at the end of each SSG condition. Compared to the SSGreg in both 3 vs. 3 and 4 vs. 4 formats, the SSGcom condition resulted in higher La- and RPE responses (p < 0.05), greater distance covered at MIR and HIR speeds and greater total distance (p < 0.05). The results of this study show that replacing 30 s within the 4-min bouts of SSGs (both 3- and 4-a-side) by 2 x 15 s of running drills is effective in increasing internal (La- and RPE) and external loads (MIR and HIR) without a significant decrease in total passes and successful passes in young soccer players. 相似文献
2.
Julen Castellano Ibai Errekagorri Asier Los Arcos David Casamichana Andres Martín-Garcia Filipe Manuel Clemente Roberto Lpez-Del Campo Ricardo Resta Ibon Echeazarra 《Biology of sport / Institute of Sport》2022,39(3):607
The aim of this study was to describe the team accumulated physical response per minute considering only the effective playing time (EPT) attending to different contextual and strategic variables in the Spanish Football First Division (LaLiga Santander). A sample of 2,959 performances was included in the analysis, considering a 4-year period of analysis (from 2016–17 to 2019–20). The physical variables were: total distance covered with (DTminPOS) and without (DTminNOpos) possession of the ball, and distance covered at > 21 km·h-1 with possession (DT21minPOS) and without (DT21minNOpos). Two contextual variables, i.e. Place (Home/Away) and Score (Lost/Draw/Win), and two strategic variables, i.e. level of effective playing time (LevelETP) and level of possession of the ball (LevelPOS), were analysed. The teams ran more without possession of the ball than with possession; nevertheless, the teams that had less possession of the ball had higher values in the distance covered at > 21 km·h-1 with possession of the ball and vice versa. Furthermore, the strategic variables also had influence on the physical response (DT and DT21) of the teams,LevelETP and LevelPOS, although with interactive effects: longer playing time, less accumulated distance, and greater possession, greater accumulated distance in the defensive phase, both per min. The findings of this study may offer important practical implications to practitioners in order to assess physical performances of the players in matches, because it is crucial to integrate in the analysis the different contextual and strategic variables where the match has taken place to assess performances of the teams. 相似文献
3.
《Animal : an international journal of animal bioscience》2022,16(10):100633
Accurate prediction of energy requirement is important in formulating diets, but an energy model for Yellow Broiler breeder hens is publicly unavailable. The objective of this study was to establish energy prediction models for the nitrogen-corrected apparent metabolisable energy (AMEn) requirement of different categories of Yellow Broiler breeder hens during the egg-laying period. Data for modelling were collected from research papers, public databases and production data from companies. Breeder hens were generally categorised into three BW types: heavy, medium and light (HBWT, MBWT and LBWT). Published articles were cited for providing coefficients of AMEn maintenance requirement (AMEnm, 101 kcal/kg BW0.75, 423 KJ/kg BW0.75) and growth requirement (AMEng, 5.33 kcal/g, 22.3 KJ/g), respectively. Models of AMEn for egg production (AMEnp) were established from the known daily intake of AMEn (AMEni) and those of maintenance and growth by the factorial approach: AMEnp = AMEni ? AMEnm ? AMEng. For the three types of hens, AMEnp HBWT (kcal, KJ) = 2.55 kcal (10.7 KJ) × egg mass (EM, g); AMEnp MBWT (kcal, KJ) = 2.70 kcal (11.3 KJ) × EM (g), and AMEnp LBWT (kcal, KJ) = 2.94 kcal (12.3 KJ) × EM (g) were determined. The total AMEni requirements, depending on Gompertz models, were HBWT: BW (g) = 3 144 × e?EXP(?0.162×(week of age (wk)?15.6)); MBWT: BW (g) = 2 526 × e?EXP(?0.333×(wk?19.1)); LBWT: BW (g) = 1 612 × e?EXP(?0.242×(wk?16.5)). Models of egg production, HBWT: egg production (%) = 124 × e?0.017×wk/(1 + e?0.870×(wk?26.2)); MBWT: egg production (%) = 144 × e?0.020×wk/(1 + e?0.751×(wk?24.9)); LBWT: egg production (%) = 163 × e?0.024×wk/(1 + e?0.476×(wk?26.5))) and egg weight for each wk of the three types of hens during the egg-laying period were all established. These models showed good applicability in simulating and predicting the literature or production data. 相似文献
4.
Protein–protein interactions (PPIs) play very important roles in many cellular processes, and provide rich information for discovering biological facts and knowledge. Although various experimental approaches have been developed to generate large amounts of PPI data for different organisms, high-throughput experimental data usually suffers from high error rates, and as a consequence, the biological knowledge discovered from this data is distorted or incorrect. Therefore, it is vital to assess the quality of protein interaction data and extract reliable protein interactions from the high-throughput experimental data. In this paper, we propose a new Semantic Reliability (SR) method to assess the reliability of each protein interaction and identify potential false-positive protein interactions in a dataset. For each pair of target interacting proteins, the SR method takes into account the semantic influence between proteins that interact with the target proteins, and the semantic influence between the target proteins themselves when assessing the interaction reliability. Evaluations on real protein interaction datasets demonstrated that our method outperformed other existing methods in terms of extracting more reliable interactions from original protein interaction datasets. 相似文献
5.
Jos M. Oliva-Lozano Víctor Fortes Jos M. Muyor 《Biology of sport / Institute of Sport》2021,38(2):165
The study aimed to compare the physical demands required during the first, second, and third most demanding passages (MDP) of play considering the effect of playing position, type of passage, and passage duration. A longitudinal study for three mesocycles was conducted in a professional soccer team competing in LaLiga123. Tracking systems collected total distance covered (DIS), high-speed running distance (HSRD), sprinting distance (SPD), total of high-intensity accelerations (ACCHIGH), and total of high-intensity decelerations (DECHIGH). The results confirmed that a significant effect of the type of passage (first, second or third MDP of play) on DIS (F(1.24, 178.89) = 115.53; p = 0.01; ηp2 = 0.45), HSRD (F(1.35, 195.36) = 422.82; p = 0.01; ηp2 = 0.75), SPD (F(1.43, 206.59) = 299.99; p = 0.01; ηp2 = 0.68), ACCHIGH (F(1.45, 209.38) = 268.59; p = 0.01; ηp2 = 0.65), and DECHIGH (F(1.45, 209.38) = 324.88; p = 0.01; ηp2 = 0.69) was found. In addition, a significant interaction between playing position, type and duration of the passage was observed in DIS (F(12.60, 453.47) = 1.98; p = 0.02; ηp2 = 0.05) and ACCHIGH (F(13.99, 503.78) = 1.92; p = 0.03; ηp2 = 0.06). In conclusion, significant differences in physical demands between the first, second, and third MDP of play were observed. However, there were some cases (DIS and ACCHIGH) in which no significant differences were found between these passages. Therefore, coaches should consider not only the magnitude of these peak intensity periods (e.g., distance covered per minute) but also the number of passages that players may experience during match play. 相似文献
6.
Jos M. Oliva-Lozano Carlos D. Gmez-Carmona Víctor Fortes Jos Pino-Ortega 《Biology of sport / Institute of Sport》2022,39(2):397
The aims of this study were to: (a) describe and compare the volume and intensity from the workload of professional soccer players between training and MD, and (b) analyse the effect that the length of the microcycle had on the workload. A cohort study was designed for a full season in La Liga 123. Wearable tracking systems collected the distance covered in meters (m), total number of high-intensity accelerations (ACCHIGH) and decelerations (DECHIGH), total number of high-speed running actions (HSRA), high-speed running distance (HSRD), high metabolic load distance (HMLD), and player load (PL) from training days (MD+1, MD-4, MD-3, MD-2, and MD-1) and MD. Significant differences were found between training and MD workload, MD workload being the most demanding for all intensity and volume variables (F = 36.35–753.94; p < 0.01; wp2 = 0.21–0.85). The greatest training intensity and volume were found on MD-4 and MD-3 (p < 0.05). In addition, a novel finding was that the length of the microcycle had a significant effect on the workload both in volume and intensity (F = 4.84–14.19; p < 0.01; wp2 = 0.03–0.09), except for relative ACCHIGH, DECHIGH, and HMLD. Although MD-4 and MD-3 were the most suitable days for loading the players, the results showed that MD elicited a unique stimulus in terms of volume and intensity. Consequently, coaches need to include specific training drills to adapt the players for the competitive demands. Finally, special focus should be placed on MD from short and regular microcycles (5-day, 6-day, or 7-day microcycles) since declines in physical performance were observed in comparison with long microcycles (8-day or 9-day microcycles). 相似文献
7.
Andrea Riboli Sigrid B.H. Olthof Fabio Esposito Giuseppe Coratella 《Biology of sport / Institute of Sport》2022,39(3):579
The aim was to determine the area per player (ApP, m2 × player) in small- or large-sided games to replicate the official match demands in elite youth soccer players. Two hundred and twenty-eight players (U15 = 36, U16 = 48, U17 = 49, U18 = 37 and U19 = 58) were monitored during both training (12 183 individual samples) and matches (683 individual samples) across five seasons. Relative (m × min-1) total (TD), high-speed running (HSR), very high-speed running (VHSR), sprint and acceleration/deceleration (Acc/Dec) distance were collected. Between-category and between-position comparisons were performed. Area per player was moderately correlated (P < 0.05) with TD (r = 0.401), large (r = 0.621) with HSR, and very largely with VHSR (r = 0.744) and sprint (r = 0.723). An inverse small (r = -0.232; P = 0.039) correlation for Acc/Dec was found. The area per player to replicate the match demands was 158 ± 18, 182 ± 32, 197 ± 37, 212 ± 42 and 156 ± 25 m2 × player for TD, HSR, VHSR, sprint and Acc/Dec, respectively. Moderate to very large (ES: 0.79 to 4.66) differences in the area per player across metrics were observed, with sprint > VHSR > HSR > TD = Acc/Dec. Trivial to very large (ES: 0.01 to 2.67) between-category differences in area per player across the same metric were found, with U15 and U16 requiring a larger area per player than other age categories. These findings may help practitioners to recreate the desired external load outcomes with regards to positional match-play demands using specific area per player in small- or large-sided games in youth elite soccer players from U15 to U19. 相似文献
8.
Markel Rico-Gonzlez Rafael Oliveira Luiz H. Palucci Vieira Jos Pino-Ortega Filipe Manuel Clemente 《Biology of sport / Institute of Sport》2022,39(3):695
Since the analysis of worst-case scenarios (WCS) has been increasing knowledge about match demands and possible impacts for the training process, it seems important to summarize the evidence to provide useful information for the soccer community. Thus, the purpose of this systematic review was to summarize the evidence about WCS in professional soccer. A systematic review of PubMed, SPORTDiscus, and FECYT (Web of Sciences, CCC, DIIDW, KJD, MEDLINE, RSCI, and SCIELO) was performed according to the guidelines for performing systematic reviews in sport science. From the 85 studies initially identified, 12 were fully reviewed, and their outcome measures were extracted and analyzed. There was an inverse relationship between the duration of WCS windows and running output during match play. Occurrences of WCS during soccer matches were also position-dependent across studies, at least, when analyzing performance with the total distance covered variable, although different outputs were identified between women and men players. Future research should consider analyzing the impact of contextual variables (match status, team formation, and match location) on peak match values and the weight of these moderators. 相似文献
9.
10.
《Journal of Asia》2020,23(2):336-344
Pagiophloeus tsushimanus is a newly and specialist wood-boring beetle of Cinnamomum camphora in China. RT-qPCR is an accurate quantitative method to quantify target genes expression, which relies on suitable reference genes for data normalization. Reference genes must to be stably expressed under specific experimental conditions. No suitable reference genes of P. tsushimanus have been reported so far. Therefore, it is necessary to identify and evaluate suitable reference genes for the study of functional genes of this pest. In this research, the expression stability of eight candidate reference genes (RPS3, 18S rRNA, GAPDH, TBP, RPL10, UBQ, GST, and RPS27A) were systematically evaluated in P. tsushimanus by five algorithms (geNorm, BestKeeper, NormFinder, delta Cq, and RefFinder) under different developmental stages, various tissues, and insects reared on different plants, and validated by the olfactory key gene odorant binding protein 33 (PtsuOBP33). The results showed that three stable reference genes combination were necessary for quantitative analysis of target gene. RPS3, RPL10, and UBQ were the optimal reference genes combination for gene expression analysis of developmental stages, while RPL10, RPS3, and 18S rRNA were recommended for different tissues, and 18S rRNA, TBP, and RPS3 were recommended for insects reared on different plants. The results indicated that suitable reference genes should be screened out for gene expression analysis under different conditions. This paper systematically analyzed and obtained suitable reference genes in P. tsushimanus for the first time, which would contribute to the functional analysis of genes and the in-depth mining of genetic resources in it. 相似文献
11.
Surveys were conducted in the cold desert environment of the Lahaul valley in the northwestern Himalaya for assessing the past and present status of Kuth (Saussurea lappa) cultivation. The findings reveal that this age-old practice now is in bottleneck. Main factors responsible for this setback to the species were the lengthy cultivation cycle, small land holdings, and even fluctuating and relatively low market prices. Owing to these constraints farmers have now started replacing cultivation of this threatened herb with pea (Pisum sativum L.), potato (Solanum tuberosum L.) and hop (Humulus lupulus L.). These crops obtained popularity due to comparatively more economic returns as well as their easy adaptability to the short growth season of the cold desert environment. Kuth cultivation in this region is among the interesting examples of domesticating wild medicinal herb by some innovative farmers during the 1920s. However, in the recent past farmers have been less interested to continue this practice due to its larger cultivation cycle, more profits with cash crops like pea and potato, and permit formalities at the time of export from the valley. In addition to being the oldest cash crop in the cold desert environment, Kuth is an endangered medicinal herb that has to be conserved on a priority basis. This study attempts to find out potential measures such as regular revision of market rates, development of existing uncultivable land under medicinal plant cultivation and strengthening the marketing network through establishment of federations of farmers at village level to revive cultivation of this important species. 相似文献
12.
The objective of the presented study is the development of a spatially explicit approach for mapping ecosystem services (MapES) by using specific knowledge about the Cerrado biome (Brazilian Savanna). This biome covers an area of about 2 million km2, i.e. nearly 24% of the total area of Brazil, and has come under substantial pressure during the last 50 years caused by strong land-use/land-cover change, mostly due to agricultural expansion and urbanization. Because of its fast transformation rate, there is an enormous demand for knowledge, and its application, about the effects of land-use/land-cover on the capacity of providing or maintaining ecosystem services. The MapES approach was developed using a vast existing knowledge base. After analyzing and structuring this knowledge the relationships between land-use/land-cover and the potential to provide or maintain eight ecosystem services (Erosion Control, Runoff Control, Water Supply, Water Quality Maintenance, Soil Quality Maintenance, Biodiversity Maintenance, Food Production and Energy Production) were parametrized. In addition, the approach was developed as spatially explicit by including landscape properties (soil, slope and distance to river network) in the cell based system. A reference map of potential natural vegetation and a land use map for 2013 for a meso-scale experimental catchment (32.7 km2) were produced. The catchment was used as an example to apply the approach, i.e. assessing and visualizing changes from before human interference to the current land use situation. Finally, a procedure for assessing the potential impacts of land-use/land-cover on ecosystem services considering the methodological limitations of the respective monitoring. The presented approach is easy to understand, to modify and to adapt to other situations and might be therefore used in other context of decision support. It might also help to fill the gap between land use planning and numeric modeling using very complex tools. 相似文献
13.
Taiga Kasuya 《Mycoscience》2007,48(5):309-311
Aseroë coccinea, an invalid name for a Japanese phalloid, is formally validated. Morphological features of A. coccinea are described and illustrated. This fungus is well distinguishable from the other known species of Aseroë by 7–9 bright red arms dispersed radially on the apex of the receptacle, not bifurcating but simple, and consisting of a single tubulate chamber. 相似文献
14.
Radiostereometric analysis (RSA) is a highly accurate technique used to provide three-dimensional (3D) measurements of orthopaedic implant migration for clinical research applications, yet its implementation in routine clinical examinations has been limited. Previous studies have introduced a modified RSA procedure that separates the calibration examinations from the patient examinations, allowing routine clinical radiographs to be analyzed using RSA. However, in order to calibrate the wide range of clinical views, a new calibration object is required. In this study, a universal, isotropic calibration object was designed to calibrate any pair of radiographic views used in the clinic for RSA. A numerical simulation technique was used to design the calibration object, followed by a phantom validation test of a prototype to verify the performance of the novel object, and to compare the measurement reliability to the conventional calibration cage. The 3D bias for the modified calibration method using the new calibration object was 0.032 ± 0.006 mm, the 3D repeatability standard deviation was 0.015 mm, and the 3D repeatability limit was 0.042 mm. Although statistical differences were present between the universal calibration object and the conventional cage, the differences were considered to be not clinically meaningful. The 3D bias and repeatability values obtained using the universal calibration object were well under the threshold acceptable for RSA, therefore it was successfully validated. The universal calibration object will help further the adoption of RSA into a more routine practice, providing the opportunity to generate quantitative databases on joint replacement performance. 相似文献
15.
16.
Elise K. Laende Kevin J. Deluzio Allan W. Hennigar Michael J. Dunbar 《Journal of biomechanics》2009,42(14):1527-2393
An in vitro radiostereometric analysis (RSA) phantom study of a total knee replacement was carried out to evaluate the effect of implementing two new modifications to the conventional RSA procedure: (i) adding a landmark of the tibial component as an implant marker and (ii) defining an implant-based coordinate system constructed from implant landmarks for the calculation of migration results. The motivation for these two modifications were (i) to improve the representation of the implant by the markers by including the stem tip marker which increases the marker distribution (ii) to recover clinical RSA study cases with insufficient numbers of markers visible in the implant polyethylene and (iii) to eliminate errors in migration calculations due to misalignment of the anatomical axes with the RSA global coordinate system. The translational and rotational phantom studies showed no loss of accuracy with the two new measurement methods. The RSA system employing these methods has a precision of better than 0.05 mm for translations and 0.03° for rotations, and an accuracy of 0.05 mm for translations and 0.15° for rotations. These results indicate that the new methods to improve the interpretability, relevance, and standardization of the results do not compromise precision and accuracy, and are suitable for application to clinical data. 相似文献
17.
Concurrent use of finite element (FE) and musculoskeletal (MS) modeling techniques is capable of considering the interactions between prosthetic mechanics and subject dynamics after a total knee replacement (TKR) surgery is performed. However, it still has not been performed in terms of favorable prediction accuracy and systematic experimental validation. In this study, we presented a methodology to develop a subject-specific FE-MS model of a human right lower extremity including the interactions among the subject-specific MS model, the knee joint model with ligament bundles, and the deformable FE prosthesis model. In order to evaluate its accuracy, the FE-MS model was compared with a traditional hinge-constraint MS model and experimentally verified over a gait cycle. Both models achieved good temporal agreement between the predicted muscle force and the electromyography results, though the magnitude on models is different. A higher predicted accuracy, quantified by the root-mean-square error (RMSE) and the squared Pearson correlation coefficient (r2), was found in the FE-MS model (RMSE = 177.2 N, r2 = 0.90) when compared with the MS model (RMSE = 224.1 N, r2 = 0.81) on the total tibiofemoral contact force. The contact mechanics, including the contact area, pressure, and stress were synchronously simulated, and the maximum contact pressure, 22.06 MPa, occurred on the medial side of the tibial insert without exceeding the yield strength of the ultra-high-molecular-weight polyethylene, 24.79 MPa. The approach outlines an accurate knee joint biomechanics analysis and provides an effective method of applying individualized prosthesis design and verification in TKR. 相似文献
18.
Spatial autocorrelation and sampling design in plant ecology 总被引:18,自引:1,他引:18
Using spatial analysis methods such as spatial autocorrelation coefficients (Moran's I and Geary's c) and kriging, we compare the capacity of different sampling designs and sample sizes to detect the spatial structure of a sugar-maple (Acer saccharum L.) tree density data set gathered from a secondary growth forest of southwestern Québec. Three different types of subsampling designs (random, systematic and systematic-cluster) with small sample sizes (50 and 64 points), obtained from this larger data set (200 points), are evaluated. The sensitivity of the spatial methods in the detection and the reconstruction of spatial patterns following the application of the various subsampling designs is discussed. We find that the type of sampling design plays an important role in the capacity of autocorrelation coefficients to detect significant spatial autocorrelation, and in the ability to accurately reconstruct spatial patterns by kriging. Sampling designs that contain varying sampling steps, like random and systematic-cluster designs, seem more capable of detecting spatial structures than a systematic design.Abbreviations UPGMA =
Unweighted Pair-Group Method using Arithmetic Averages 相似文献
19.
Dimitrios Damalas Vasiliki Sgardeli Paraskevas Vasilakopoulos Georgios Tserpes Christos Maravelias 《Ecology and evolution》2021,11(23):16951
Climate change (CC) can alter the configuration of marine ecosystems; however, ecosystem response and resilience to change are usually case‐specific. The effect of CC on the demersal resources of the Aegean Sea (east Mediterranean Sea) was investigated during the past six decades applying a combination of multivariate analysis, non‐additive modeling and the Integrated Resilience Assessment (IRA) framework. We focused on the study of: (i) the biological “system” complex, using proxies of biomass (landings per unit of capacity) for 12 demersal taxa, and (ii) the environmental “stressor” complex, described by 12 abiotic variables. Pronounced changes have occurred in both the environmental and biological system over the studied period. The majority of the environmental stressors exhibited strikingly increasing trends (temperature, salinity, primary production indices) with values started exceeding the global historical means during late 1980s‐early 1990s. It is suggested that the biological system exhibited a discontinuous response to CC, with two apparently climate‐induced regime shifts occurring in the past 25 years. There is evidence for two‐fold bifurcations and four tipping points in the system, forming a folded stability landscape with three basins of attraction. The shape of the stability landscape for the Aegean Sea''s biological system suggests that while the initial state (1966–1991) was rather resilient to CC, absorbing two environmental step‐changes, this was not the case for the two subsequent ones (intermediate: 1992–2002; recent: 2003–2016). Given the current trajectory of environmental change, it is highly unlikely that the biological system will ever return to its pre‐1990s state, as it is entering areas of unprecedented climatic conditions and there is some evidence that the system may be even shifting toward a new state. Our approach and findings may be relevant to other marine areas of the Mediterranean and beyond, undergoing climate‐driven regime shifts, and can assist to their adaptive management. 相似文献
20.
K. M. Eskridge R. F. Mumm 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,84(3-4):494-500
Summary A major consideration in most plant breeding programs is the development of cultivars that have high probabilities of outperforming the check cultivar in a broad range of environments. Methods are presented for estimating and testing hypotheses regarding these probabilities, which are termed reliabilities. Reliabilities are shown to be directly related to several commonly used stability parameters. Data from international maize yield trials are used to illustrate and evaluate the repeatability of the approach. Results indicate that reliabilities can be useful aids to plant breeders since they (1) are easy to understand and compute, (2) are indices that weigh the importance of the difference in performance relative to stability, and (3) are potentially useful as genetic parameters since they are generally repeatable across randomly sampled sets of environments.Contribution from the Agricultural Research Division, University of Nebraska, Lincoln, Neb., Paper no. 9653 相似文献