Evaluating field-goal shooting effectiveness in wheelchair basketball players across a competitive season: a preliminary study

Background

Information about non-elite wheelchair basketball (WB) players across national competitive seasons are still missing. This study aimed at identifying which situational-related variables were associated with shooting effectiveness in non-elite WB players.

Methods

All the matches played by one WB team across one national competitive season were video-recorded and analysed; 333 shooting attempts from high-point players and several situational-related variables were considered.

Results

Pearson's Chi-square test showed that increased shooting effectiveness under the following conditions: playing on home ground, during won matches, while taking shots with the wheelchair in motion, and when no opposing player raised their arm in defence. Results of the multivariable logistic regression analysis showed a statistically significant influence of match location (p-value = 0.001), shot-clock remaining (p-value = 0.015) and modality of press (p-value < 0.001). The highest attack effectiveness was achieved when teams played at home (odds ratio [OR] = 2.49), while the shooting effectiveness decreased when the shot occurred during the last seconds of the action (OR = 0.36), or the opponents defended with the arm raised (OR = 0.19). These results suggest that coaches should include exercises aimed at shooting under conditions of increased pressure in their programmes in order to create specific situations during the training sessions to prepare their high-point athletes for shots under specific match constraints.

Milk hygiene and udder health in the periurban area of Hamdallaye, Niger

The prevalence of intra-mammary infections in dairy herds was studied in Hamdallaye, Niger. A total of 956 milk samples were collected in 2007 from 239 lactating cows of four local breeds in eight traditional herds; the first sampling was undertaken in the dry season at morning milking, and the second in the rainy season at evening milking. Staphylococcus aureus, Coagulase-Negative Staphylococci (CNS) and environmental microorganisms were detected in significantly (p < 0.05) more samples in the rainy season, 55.2%, than in the dry season, 27.1%. Statistically significant (P < 0.05) differences in prevalence were observed among herds and according to lactation number. Infections were assigned to four classes, according to the major pathogen, and the respective mean somatic cell counts during the dry season were: S. aureus, 775 x 10(3) cells/ml; CNS, 447 x 10(3) cells/ml; environmental microorganisms, 407 x 10(3) cells/ml; and non-infected, 262 x 10(3) cells/ml. Most of the tested strains were sensitive to antibiotics, and selected strains of S. aureus (n = 15) were negative to the multiplex PCR tests for production of enterotoxins.

Intrinsic tryptophan fluorescence of equinatoxin II, a pore-forming polypeptide from the sea anemone Actinia equina L, monitors its interaction with lipid membranes

Equinatoxin II is a cytolytic polypeptide from the sea anemone Actinia equina L. which forms pores in natural and artificial membranes. The intrinsic fluorescence of its five tryptophanyl residues was used to monitor the conformational changes induced by denaturing agents, pH and lipids. In the presence of denaturants, the emitted fluorescence peak, normally occurring at 335 nm, was reduced in height by about 65% and red-shifted to 354 nm indicating unfolding. The toxin fluorescence intensity reversibly decreased by increasing the pH, whereas lipid vesicles, at every pH, caused an increase and a blue shift. The amount of toxin binding to the lipid vesicle was increased by the presence of sphingomyelin. With sphingomyelin-containing vesicles half-saturation occurred at a lipid/toxin molar ratio of about 40, whereas with phosphatidylcholine no saturation appeared up to a ratio of 300. One hydrophilic neutral quencher (acrylamide) and two lipid-confined phosphatidyltype quenchers [bis(9,10-dibromostearoyl)-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(1-pyrenedecanoyl)-sn-glycero-3-phosphocholine] were used to assess the exposure of the emitting centres to the solvent and/or to the lipid. Most of the indolyl residues were found to be solvent-exposed in the water-soluble form of the toxin, as inferred from acrylamide quenching. Upon association with lipid vesicles, the fraction accessible to acrylamide dropped considerably, meanwhile the toxin became sensitive to lipid-soluble quenchers. Taken together these results suggest that insertion of equinatoxin II into sphingomyelin-containing bilayers is facilitated by high pH and results in the transfer of one or more exposed tryptophanyl residues into the liquid phase. Calcein-loaded vesicles, with or without a lipid quencher, were used to monitor simultaneously the formation of pores and the transfer of the tryptophans to the lipid phase. We found that the rate constants for vesicles permeabilization and for changes of intrinsic tryptophanyl fluorescence had a different dependence on the lipid/toxin ratio suggesting they correspond to separate steps in the toxin lipid interaction.