Neuromuscular and stiffness adaptations in division I collegiate baseball players

To compare bi-lateral shoulder EMG, active and short range glenohumeral stiffness, and examine its correlation to posterior capsule thickness (PCT) in collegiate baseball players. Surface and fine wire EMG was recorded on shoulder and scapular musculature during stiffness testing. Posterior capsule thickness was assessed separately using a diagnostic ultrasound. Serratus anterior EMG area and peak on the dominant arm was significantly greater compared to the non-dominant arm. The dominant arm had significantly greater active and short range glenohumeral stiffness compared to the non-dominant arm. Active glenohumeral stiffness was significantly correlated with PCT, however short range glenohumeral stiffness was not significantly correlated with PCT. Healthy collegiate baseball players present with adaptations of their stiffness regulation strategies. There were also correlations between stiffness and morphologic changes. Our results support the theory that PCT has an impact on the energy absorption capabilities of the shoulder during the deceleration phase of throwing. It also seems that tightening of the series elastic component within the posterior rotator cuff may be causing the increase in short range stiffness on the dominant arm.     

Obtaining of pure transferrins D, M and R from equine serum and determination of transferrin level in relation to phenotype

By the method of precipitation with Rivanol (2-ethoxy-6,9-diaminoacridine lactate) and ammonium sulphate followed by chromatography on DEAE cellulose three genetic variants of transferrin were purified from equine serum: D, M and R. Their molecular mass determined in this study was 80 000, and it was identical for all three variants, which differed slightly in their amino acid composition. The protein level was determined in the serum of 535 two-year-old thoroughbred English horses by the method of rocket immunoelectrophoresis using antibodies obtained against three transferrins. The individual variability of the protein level in horses of the same phenotype was fairly high (variability index 9-15%). No differences were observed in the transferrin level related to sex. It was found that the presence of D, F and H alleles was connected with a higher serum transferrin level, while O and R alleles were connected with a lower level.     

Interaction of proflavine with 2-hydroxy-5-nitrobenzylated papain

Interaction of proflavine with papain, modified by hydroxynitrobenzylation of Trp-177 (HNB-papain), is characterized by a dissociation constant about twice that of proflavine's binding to native papain. Kinetic analyses revealed that proflavine's activation of papain-catalyzed hydrolysis of benzoyl-L-arginine ethyl ester persists with the HNB-enzyme; however, hydroxynitrobenzylation of papain precludes proflavine's inhibition of benzoyl-L-arginine p-nitroanilide (BzArgNan) hydrolysis. Yet, proflavine noncompetitively inhibits hydrolysis of BzPheValArgNan by both native and HNB-papain to about the same extent. Thus, proflavine appears to reduce nonproductive binding of smaller substrates, but may also interfere with conformational repositioning necessary for anilide hydrolysis.     

CYK4 Promotes Antiparallel Microtubule Bundling by Optimizing MKLP1 Neck Conformation

Centralspindlin, a constitutive 2:2 heterotetramer of MKLP1 (a kinesin-6) and the non-motor subunit CYK4, plays important roles in cytokinesis. It is crucial for the formation of central spindle microtubule bundle structure. Its accumulation at the central antiparallel overlap zone is key for recruitment and regulation of downstream cytokinesis factors and for stable anchoring of the plasma membrane at the midbody. Both MKLP1 and CYK4 are required for efficient microtubule bundling. However, the mechanism by which CYK4 contributes to this is unclear. Here we performed structural and functional analyses of centralspindlin using high-speed atomic force microscopy, Fӧrster resonance energy transfer analysis, and in vitro reconstitution. Our data reveal that CYK4 binds to a globular mass in the atypically long MKLP1 neck domain between the catalytic core and the coiled coil and thereby reconfigures the two motor domains in the MKLP1 dimer to be suitable for antiparallel microtubule bundling. Our work provides insights into the microtubule bundling during cytokinesis and into the working mechanisms of the kinesins with non-canonical neck structures.     

Apparent seed use by ducks in moist-soil wetlands of the Mississippi Alluvial Valley

Scientists, conservation planners, and resource managers who estimate energetic carrying capacity of foraging habitats for wintering waterfowl require accurate data on food availability and use. We estimated seed and tuber abundance in moist-soil wetlands commonly used and foraged in by dabbling ducks (Anas spp.) in and near the Mississippi Alluvial Valley (MAV). To identify foods potentially used by dabbling ducks, we surveyed food-use literature from studies conducted in or near the MAV and compared estimated seed decline rates from core samples to predicted decline rates using published and measured estimates of decomposition. We inferred seed use when observed declines in mass exceeded that predicted by decomposition. In our analyses, we identified 15 taxa of moist-soil seeds apparently used and 6 taxa apparently not used by dabbling ducks. From our analyses and literature review, we identified 25 taxa of moist-soil seeds and tubers commonly consumed and apparently used by dabbling ducks in or near the MAV. Removal of seeds apparently not used by dabbling ducks resulted in a 30.9% (SE = 1.3) reduction in estimates of seed and tuber mass in managed moist-soil wetlands in the MAV. When we retained 3 seed taxa reported by previous studies as consumed by dabbling ducks, but which did not decline faster than predicted in our experimental wetlands, seed and tuber estimates were reduced by 26.8% (SE = 1.3). Inclusion of seeds not consumed by dabbling ducks in models of carrying capacity would result in overestimation of existence energy days by the Lower Mississippi Valley Joint Venture and underestimation of moist-soil habitat requirements in the MAV. We suggest scientists conduct food-use and selection studies by collecting actively foraging ducks in the MAV to confirm our results and increase accuracy of carrying capacity estimates for dabbling ducks in autumn and winter. © 2011 The Wildlife Society.     

Single nucleotide polymorphism in the promoter region of the lactoferrin gene and its associations with milk performance traits in Polish Holstein-Friesian cows

Bovine lactoferrin (LTF) is a multifunctional small glycoprotein found in milk acting mainly as a defense factor in the mammary gland. Many polymorphisms have been found in the bovine LTF gene but almost none were considered as genetic markers of production traits in dairy cattle. In this study, the promoter fragment of LTF gene containing mutation (G/C) in position +32 has been amplified by PCR followed by genotyping by the SSCP and RFLP method. 358 Polish Holstein-Friesian cows were screened, giving the following frequency of genotypes: 0.628, 0.313 and 0.059 for GG, GC and CC, respectively. GLM (General Linear Model) analysis was applied to evaluate the associations of lactoferrin with milk performance traits, including SCC - somatic cell count. It was found that CC cows show significantly higher (P < or = 0.01) protein content in milk in comparison with GG cows. The values of other milk performance traits were also higher but at non-significant levels. SCC in milk was the lowest in CC cows, but also at a non-significant level.