Talent detection in taekwondo: which factors are associated with the longitudinal competitive success?

Background Several morphological and functional characteristics are associated with the performance of taekwondo (TKD) adult athletes. However, we did not find any longitudinal study associating these features to the future performance of young athletes, and thereby, identifying the best variables to use in a battery of tests to talent detection. Therefore, the aim of this study is answer the question which factors are associated with the longitudinal competitive success of TKD young athletes over five competitive years (2008 to 2012).Material &Methods: Six taekwondo athletes (13.06 +/- 1.07 years, 43.6 +/- 6.6 kg, 157.9 +/- 8.3 cm), who trained three to six hours per week, for more than three years, were assessed on 32 maturational indicators, of body composition, anthropometric and functional, using anthropometric techniques, dual energy x-ray absorptiometry, carpal radiography and contact platform. To determine the competitive ranking, the competitive results of athletes from 2008 to 2012 were analysed, and these values were correlated with the other 32 indicators for determining the Longitudinal Predictors of Performance in TKD (LPPT). Moreover, one of the athletes achieved results notably higher than the other, being medalled at Junior World Championships. Therefore, all variables were transformed into z-scores and all those in which this athlete presented superior performance in 1 z-scores were considered as LPPT. Results: The athlete of reference (the first in Longitudinal Competitive Ranking 2008-2012) distinguished, in accordance with the criteria, in nineteen LPPT indicators. The ranking was correlated with 6 LPPT parameters, including one from the maturation group of indicators and five from the functional group.Conclusion: Our results allowed us to identify several factors that are related to longitudinal competitive success in taekwondo young athletes. These factors should be considered by coaches to the proper selection of training programs, as well as for the pre-selection of young talents in competitive taekwondo. However, these results apply only to the Portuguese taekwondo adolescent athletes, being of limited generalizability.

Reliability in kimono grip strength tests and comparison between elite and non-elite Brazilian jiu-jitsu players

Background and Study Aim: The grip strength endurance is important for Brazilian Jiu-Jitsu (BJJ). Thus, the aims of this study were: a) to test the reliability of two kimono grip strength tests named maximum static lift (MSL) and maximum number of repetitions (MNR) and b) to examine differences between elite and non-elite BJJ players in these tests. Material/Methods: Thirty BJJ players participated into two phases: "A" to test reliability and "B" to compare elite and non-elite. In phase A, twenty participants performed the MSL and, 15 min later, the MNR in two occasions with 24-h interval. In phase B, ten other BJJ practitioners (non-elite) and ten athletes (elite) performed the same tests. The intraclass correlation coefficient (ICC) two way fixed model (3,1), Bland-Altman plot and the limits of agreement were used to test reliability, correlation between the tests were evaluated by Pearson correlations and independent T test (P<0.05) was utilized to compare elite vs. non-elite. Results: The ICC was high for repeated measurements on different days of phase A (MSL: r=0.99 and MNR: r=0.97). Limits of agreement for time of suspension were -6.9 to 2.4-s, with a mean difference of -2.3 s (CI: -3.3 to -1.2-s), while for number of repetitions the limits of agreement were -2.9 to 2.3-rep, with a mean difference of -0.3-rep (CI: -0.9 to 0.3-rep). In phase B, elite presented better performance for both tests (P<0.05) compared to non-elite (56 +/- 10-s vs. 37 +/- 11-s in MSL and 15 +/- 4-rep vs. 8 +/- 3-rep in MNR). Moderate correlation were found between MSL and MNR for absolute values during test (r=0.475; p=0.034), and retest phases (r=0.489; p=0.029), while moderate and high correlations in the test (r=0.615; p=0.004) and retest phases (r=0.716; p=0.001) were found for relative values, respectively. Conclusions: These proposed tests are reliable and both static and dynamic grip strength endurance tests seem to differentiate BJJ athletes from different levels.

Ottimizzazione di strutture reticolari mediante algoritmi genetici

La tesi tratta dell'ottimizzazione di alcune tipologie di strutture reticolari. Per sviluppare i problemi analizzati ci si è avvalsi del software Grasshopper, conducendo poi l'ottimizzazione mediante un algoritmo genetico.

Explaining the decrease in mortality from abdominal aortic aneurysm rupture

A steady rise in mortality from abdominal aortic aneurysm (AAA) was reported in the 1980s and 1990 s, although this is now declining rapidly. Reasons for the recent decline in mortality from AAA rupture are investigated here.

Bakterien innerhalb des geschlossenen Gewebes der knollenartigen Anschwellungen der Papilionaceen-Wurzeln

Von A. Wigand

Microbiota and Microsatellite genotypes of Pacific oysters stemming from three oyster bed in the Northern Wadden Sea

Background: Studies of oyster microbiomes have revealed that a limited number of microbes, including pathogens, can dominate microbial communities in host tissues such as gills and gut. Much of the bacterial diversity however remains underexplored and unexplained, although environmental conditions and host genetics have been implicated. We used 454 next generation 16S rRNA amplicon sequencing of individually tagged PCR reactions to explore the diversity of bacterial communities in gill tissue of the invasive Pacific oyster Crassostrea gigas stemming from genetically differentiated beds under ambient outdoor conditions and after a multifaceted disturbance treatment imposing stress on the host. Results: While the gill associated microbial communities in oysters were dominated by few abundant taxa (i.e. Sphingomonas, Mycoplasma) the distribution of rare bacterial groups correlated to relatedness between the hosts under ambient conditions. Exposing the host to disturbance broke apart this relationship by removing rare phylotypes thereby reducing overall microbial diversity. Shifts in the microbiome composition in response to stress did not result in a net increase in genera known to contain potentially pathogenic strains. Conclusion: The decrease in microbial diversity and the disassociation between population genetic structure of the hosts and their associated microbiome suggest that disturbance (i.e. stress) may play a significant role for the assembly of the natural microbiome. Such community shifts may in turn also feed back on the course of disease and the occurrence of mass mortality events in oyster populations.