University of Jyväskylä

About: University of Jyväskylä is a education organization based out in Jyvaskyla, Finland. It is known for research contribution in the topics: Population & Context (language use). The organization has 8066 authors who have published 25168 publications receiving 725033 citations. The organization is also known as: Jyväskylän yliopisto & Kasvatusopillinen korkeakoulu.

Acute hormonal and neuromuscular responses and recovery to forced vs maximum repetitions multiple resistance exercises.

Abstract: Acute hormonal and neuromuscular responses and recovery three days after the exercises were examined during the maximum repetitions (MR) and forced repetitions (FR) resistance exercise protocols in 16 male athletes. MR included 4 sets of leg presses, 2 sets of squats and 2 sets of knee extensions (with 12 RM) with a 2-min recovery between the sets and 4 min between the exercises. In FR the initial load was chosen to be higher than in MR so that the subject could not lift 12 repetitions per set by himself. After each set to failure the subject was assisted to perform the remaining repetitions to complete the 12 repetitions per set. Thus the exercise intensity was greater in FR than in MR. Both loading protocols led to the great acute increases (p < 0.05 - 0.001) in serum testosterone, free testosterone, cortisol and GH concentrations. However, the responses in cortisol (p < 0.05) and GH (p < 0.01) were larger in FR than in MR. The decrease of 56.5 % (p < 0.001) in maximal isometric force in FR was greater (p < 0.001) than that of 38.3 % in MR (p < 0.001) and force remained lower (p < 0.01) during the recovery in FR compared to MR. The larger decrease in isometric strength in FR than in MR was also associated with the decreased maximal voluntary EMG of the loaded muscles. The data indicate that the forced repetition exercise system induced greater acute hormonal and neuromuscular responses than a traditional maximum repetition exercise system and therefore it may be used to manipulate acute resistance exercise variables in athletes.

Body weight dissatisfaction and communication with parents among adolescents in 24 countries: international cross-sectional survey.

Abstract: Parents have significant influence on behaviors and perceptions surrounding eating, body image and weight in adolescents. The aim of this study was to examine the prevalence of body weight dissatisfaction, difficulty in communication with the parents and the relationship between communication with parents and adolescents' dissatisfaction with their body weight (dieting or perceived need to diet). Survey data were collected from adolescents in 24 countries and regions in Europe, Canada, and the USA who participated in the cross-sectional 2001/2002 Health Behaviour of School-Aged Children (HBSC) study. The association between communication with parents and body weight dissatisfaction was examined using binary logistic regression analysis. Body weight dissatisfaction was highly prevalent and more common among girls than boys, among overweight than non-overweight, and among older adolescents than younger adolescents. Difficulty in talking to father was more common than difficulty in talking to mother in all countries and it was greater among girls than among boys and increased with age. Difficulties in talking to father were associated with weight dissatisfaction among both boys and girls in most countries. Difficulties in talking to mother were rarely associated with body weight dissatisfaction among boys while among girls this association was found in most countries. The findings suggest that enhanced parent communication might contribute in most countries to less body dissatisfaction in girls and better communication with the father can help avoiding body weight dissatisfaction in boys. Professionals working with adolescents and their families should help adolescents to have a healthy weight and positive body image and promote effective parent – adolescent communication.

Structural and theoretical basis for ligand exchange on thiolate monolayer protected gold nanoclusters.

Abstract: Ligand exchange reactions are widely used for imparting new functionality on or integrating nanoparticles into devices. Thiolate-for-thiolate ligand exchange in monolayer protected gold nanoclusters has been used for over a decade; however, a firm structural basis of this reaction has been lacking. Herein, we present the first single-crystal X-ray structure of a partially exchanged Au102(p-MBA)40(p-BBT)4 (p-MBA = para-mercaptobenzoic acid, p-BBT = para-bromobenzene thiol) with p-BBT as the incoming ligand. The crystal structure shows that 2 of the 22 symmetry-unique p-MBA ligand sites are partially exchanged to p-BBT under the initial fast kinetics in a 5 min timescale exchange reaction. Each of these ligand-binding sites is bonded to a different solvent-exposed Au atom, suggesting an associative mechanism for the initial ligand exchange. Density functional theory calculations modeling both thiol and thiolate incoming ligands postulate a mechanistic pathway for thiol-based ligand exchange. The discrete mo...

Acute hormonal responses to submaximal and maximal heavy resistance and explosive exercises in men and women.

Abstract: The purpose of this study was to examine acute hormonal and neuromuscular responses in men and women to 3 heavy resistance but clearly different exercise protocols: (a) submaximal heavy resistance exercise (SME), (b) maximal heavy resistance exercise (HRE), and (c) maximal explosive resistance exercise (EE). HRE included 5 sets of 10 repetition maximum (10RM) situps, bench press, and bilateral leg extensions (David 210 machine) with a 2-minute recovery between the sets. In SME, the load was 70%, and in EE, the load was 40% from that used in HRE. A significant increase (p , 0.05) in serum growth hormone (GH) was observed after HRE both in men and women, but the increase was greater (p < 0.05) in men than in women. Serum testosterone (T) increased significantly (p < 0.05) only during HRE in men. Since GH and T are anabolic hormones, the acute exercise-induced response during HRE may play an important role in the long-term anabolic adaptation processes related to muscle hypertrophy and maximal strength development.