Supplement usage and doping attitudes in elite youth sports: The mediating role of dietary supplement acceptance.

This study investigated whether dietary supplement acceptance mediated the relationship between supplement use and doping attitudes in youth sports. To this end, we employed a two-wave half-longitudinal design during a sports season (time point one [T1] to time point two [T2]). The sample consisted of 217 elite youth athletes (47% male; mean age = 16.

Perceived social pressure and intention to play through injuries in junior ice hockey: The sporting environment matters.

Playing when injured is a risky yet common business among ice hockey players. Conceptualized within the framework of the theory of planned behaviour, the current cross-sectional study aimed to test a multiple-mediator model linking players' perceived social pressure to their intention to play when injured. We tested whether social pressure is directly and indirectly (via attitudes, subjective norms, perceived behavioural control avoidance, and situational temptation) related to intention to play when injured.

The Trace Theorem, the Luzin - and Morse-Sard Properties for the Sharp Case of Sobolev-Lorentz Mappings.

We prove Luzin - and Morse-Sard properties for mappings of the Sobolev-Lorentz class , (this is the sharp case that guaranties the continuity of mappings). Our main tool is a new trace theorem for Riesz potentials of Lorentz functions for the limiting case . Using these results, we find also some very natural approximation and differentiability properties for functions in with exceptional set of small Hausdorff content.

A new member of the greater double-collared sunbird complex (Passeriformes: Nectariniidae) from the Eastern Arc Mountains of Africa.

We document the discovery of the first population of greater double-collared sunbird (Cinnyris afer complex) from the Eastern Arc Mountains of Tanzania. We assessed phylogenetic relationships and taxonomic rank based on mtDNA sequence data, nine microsatellite loci and morphology. This new taxon, locally distributed in the Rubeho and Udzungwa Highlands, has close affinities (< 1% uncorrected sequence divergence) with C.

Posttranslational modifications of the histone 3 tail and their impact on the activity of histone lysine demethylases in vitro.

Posttranslational modifications (PTMs) of the histone H3 tail such as methylation, acetylation and phosphorylation play important roles in epigenetic signaling. Here we study the effect of some of these PTMs on the demethylation rates of methylated lysine 9 in vitro using peptide substrates mimicking histone H3. Various combinations with other PTMs were employed to study possible cross-talk effects by comparing enzyme kinetic characteristics.

Identification of catechols as histone-lysine demethylase inhibitors.

Identification of inhibitors of histone-lysine demethylase (HDM) enzymes is important because of their involvement in the development of cancer. An ELISA-based assay was developed for identification of inhibitors of the HDM KDM4C in a natural products library. Based on one of the hits with affinity in the low μM range (1, a catechol), a subset of structurally related compounds was selected and tested against a panel of HDMs.

Enzyme kinetic studies of histone demethylases KDM4C and KDM6A: towards understanding selectivity of inhibitors targeting oncogenic histone demethylases.

To investigate ligand selectivity between the oncogenic KDM4C and tumor repressor protein KDM6A histone demethylases, KDM4C and KDM6A were enzymatically characterized, and subsequently, four compounds were tested for inhibitory effects. 2,4-dicarboxypyridine and (R)-N-oxalyl-O-benzyltyrosine (3) are both known to bind to a close KDM4C homolog and 3 binds in the part of the cavity that accommodates the side chain in position 11 of histone 3. The inhibition measurements showed significant selectivity between KDM4C and KDM6A.

Pretreatment and enzymatic hydrolysis of wheat straw (Triticum aestivum L.)--the impact of lignin relocation and plant tissues on enzymatic accessibility.

Wheat straw is a potential feedstock for bioethanol production. This paper investigates tissues from whole internode sections subjected to hydrothermal pretreatment at 185°C and subsequent enzymatic hydrolysis up to 144 h. Analyses revealed an increase in surface lignin as hydrolysis progressed, which could be coupled to the gradual decrease in hydrolysis rate over time.

High-throughput microarray profiling of cell wall polymers during hydrothermal pre-treatment of wheat straw.

Lignocellulosic plant material is potentially a sustainable source of fermentable sugars for bioethanol production. However, a barrier to this is the high resistance or recalcitrance of plant cell walls to be hydrolyzed. Therefore, a detailed knowledge of the structural features of plant cell walls that contribute to recalcitrance is important for improving the efficiency of bioethanol production.

Yield-determining factors in high-solids enzymatic hydrolysis of lignocellulose.

Background: Working at high solids (substrate) concentrations is advantageous in enzymatic conversion of lignocellulosic biomass as it increases product concentrations and plant productivity while lowering energy and water input. However, for a number of lignocellulosic substrates it has been shown that at increasing substrate concentration, the corresponding yield decreases in a fashion which can not be explained by current models and knowledge of enzyme-substrate interactions. This decrease in yield is undesirable as it offsets the advantages of working at high solids levels.

Determining yields in high solids enzymatic hydrolysis of biomass.

As technologies for utilizing biomass for fuel and chemical production continue to improve, enzymatic hydrolysis can be run at still higher solids concentrations. For hydrolyses that initially contain little or no free water (10-40% total solids, w/w), the saccharification of insoluble polymers into soluble sugars involves changes of volume, density, and proportion of insoluble solids. This poses a new challenge when determining the degree of hydrolysis (conversion yield).

Cell-wall structural changes in wheat straw pretreated for bioethanol production.

Background: Pretreatment is an essential step in the enzymatic hydrolysis of biomass and subsequent production of bioethanol. Recent results indicate that only a mild pretreatment is necessary in an industrial, economically feasible system. The Integrated Biomass Utilisation System hydrothermal pretreatment process has previously been shown to be effective in preparing wheat straw for these processes without the application of additional chemicals.