The effect of mental fatigue on the performance of Australian football specific skills amongst amateur athletes.

OBJECTIVES: This study investigated the effects of induced mental fatigue on the performance of Australian football (AF) specific skills amongst amateur AF players. DESIGN: Randomised cross over trial. METHODS: Twenty-five amateur AF players performed a series of standardised tests from the Australian Football League (AFL) Draft Combine after completing a 30-min Stroop test (mental fatigue condition) or 30-min control condition. The AFL Draft Combine tests included the standing vertical jump test, running vertical jump test, agility test, 20m sprint, Matthew Lloyd clean hands test, Brad Johnson goal kicking test and a Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) test. RESULTS: The Stroop test score decreased during the Stroop test (first five trials: mean=84.7, SD=3.5; last five trials: mean=82.2, SD=5.0, p=0.03). The Yo-Yo IR1 test (mental fatigue: median=920m, IQR=400; control: median=1040m, IQR=760; p=0.03) and Brad Johnson goalkicking test (mental fatigue: median=19.0, IQR=5.0; control: median=25.0, IQR=10.0, p=0.048) were negatively affected by mental fatigue. No other Draft Combine tests demonstrated a negative affect from mental fatigue. CONCLUSIONS: Mental fatigue had a detrimental influence on the performance of AF specific skills. The findings may have implications for AF players who are required to sustain attention and concentration for prolonged periods before and during matches.

Quadrupole moments of highly deformed structures in the A approximately 135 region: probing the single-particle motion in a rotating potential.

The latest generation gamma-ray detection system, GAMMASPHERE, coupled with the Microball charged-particle detector, has made possible a new class of nuclear lifetime measurement. For the first time differential lifetime measurements free from common systematic errors for over 15 different nuclei ( >30 rotational bands in various isotopes of Ce, Pr, Nd, Pm, and Sm) have been extracted at high spin within a single experiment. This comprehensive study establishes the effective single-particle transition quadrupole moments in the A approximately 135 light rare-earth region. Detailed comparisons are made with theoretical calculations using the self-consistent cranked mean-field theory which convincingly demonstrates the validity of the additivity of single-particle quadrupole moments in this mass region.

A morphological comparison of radicular dentin following root planing and treatment with citric acid or tetracycline HCl.

The conditioning of root surfaces with saturated solutions of citric acid or tetracycline is unpredictable in facilitating new attachment, perhaps due to the low pH of these solutions which may be denaturing the organic matrix of the root as well as demineralizing the surface. The purpose of the present study was to compare the effects of a saturated solution of citric acid (pH = 1) with that of a 0.5% solution of tetracycline HCl (pH = 3.2) on radicular dentin with regard to the removal of the smear layer, exposure of dentinal tubule openings, and demineralization of the peritubular dentin. 10 bovine incisors were used in this study. The crowns and apical 1/3 of the root were resected and the resulting root segments were then frozen in icy freon. The cementum was fractured off of the root to produce a fracture-exposed, non-instrumented dentin surface. This fracture-exposed dentin surface was divided into 4 specimens, the 1st being a fracture-exposed, non-instrumented dentin control specimen (FE). After removal of the (FE) specimen from the root segment, the remainder of the fracture-exposed dentin surface was thoroughly root planed and then subdivided into the 3 remaining specimens. One of these specimens served as the root planed dentin surface (RP); another specimen (CA) was immersed in saturated citric acid (pH = 1) for 5 min and then washed in water for 5 min; the final specimen (T) was immersed in a 0.5 mg/ml solution of tetracycline HCl for 5 min and rinsed in water for 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)