COMPARISON OF KINEMATICS AND ACCURACY OF OVERHAND AMERICAN FOOTBALL THROWING

This study examined elbow angle, wrist velocity and throwing accuracy during American Football throws. Six repetitions of three types of throws: Self-selected pass (SS), Lob pass (L), and a Bullet pass (B); were performed to hit a point scaled target from 10.97 m. Independent variables were frontal plane shoulder angle (more or less than 90º) and throw type; dependent variables were elbow angle in the sagittal plane, wrist velocity at ball release, and accuracy. There were no differences for shoulder angle for any variable; while throw types differed only for wrist speed (highest to lowest B, SS, and L). Significant interactions occurred for all variables. These findings suggest that recommendations for American football throwing technique are complicated by the combination of throw type and shoulder angle; and that with no restrictions subjects will throw with more accuracy

CHANGES IN UPPER EXTREMITY MUSCLE ACTIVATION IN THE PRESENCE OF STRESS

This study examined the muscle activity of the flexor digitorum (FD), biceps brachii (BB), triceps brachii (TB), and pectoralis major (PM) during the American football throw with and without conditions of stress. Male subjects (n=5) with either football or baseball experience threw footballs at targets with distances of 12.91 m, 18.29 m, and 28.91 m. Throwing arm muscle activity was assessed via electromyography. Results showed that the flexor digitorum muscle had lower muscle activation for the stress condition at the long distance along with the pectoral muscle at the middle distance

The effect of a diet with fructan-rich chicory roots on intestinal helminths and microbiota with special focus on Bifidobacteria and Campylobacter in piglets around weaning

The restrictions on the use of antibiotic and anthelmintic treatments in organic pig farming necessitate alternative non-medical control strategies. Therefore, the antibiotic and parasite-reducing effect of a fructan-rich (prebiotic) diet of dried chicory was investigated in free-ranging piglets. Approximately half of 67 piglets from 9 litters were experimentally infected with Ascaris suum and Trichuris suis in the suckling period (1 to 7 weeks of age) and 58 of the piglets were challenged daily with E. coli O138:F8 for 9 days after weaning to induce weaning diarrhoea. The litters were fed either chicory (30% DM) or a control diet. The effect of chicory on intestinal helminths, intestinal microbiota, especially Bifidobacteria and Campylobacter spp., and E. coli post-weaning diarrhoea was assessed. The weight gain of the piglets was not impaired significantly by chicory. The intestinal A. suum worm burden was reduced by 64% (P=0.034) in the chicory-fed piglets, whereas these same piglets had 63% more T. suis worms (P=0.016). Feeding with chicory elicited no changes among the main bacterial groups in ileum according to terminal restriction fragment length polymorphism (T-RFLP) analysis. However, the terminal-restriction fragment (T-RF) 208 bp, which may belong to Lachnospiraceae, was stimulated by the chicory feed (P=0.03), and T-RF 370 bp that matches Enterobacter belonging to the Enterobacteria was reduced (P=0.004). Additionally, chicory increased the level of Bifidobacteria (P=0.001) and the faecal Campylobacter excretion level was transitorily reduced in chicory-fed piglets at 7 weeks of age (P=0.029). Unfortunately, it was not possible to assess the effect of chicory on post-weaning diarrhoea as it did not develop. In conclusion, feeding piglets chicory around the time of weaning caused complex changes of the microbiota and parasite communities within the intestinal tract, and feeding piglets chicory may therefore serve as an animal-friendly strategy to control pathogens

Diffusion of gold nanoclusters on graphite

We present a detailed molecular-dynamics study of the diffusion and coalescence of large (249-atom) gold clusters on graphite surfaces. The diffusivity of monoclusters is found to be comparable to that for single adatoms. Likewise, and even more important, cluster dimers are also found to diffuse at a rate which is comparable to that for adatoms and monoclusters. As a consequence, large islands formed by cluster aggregation are also expected to be mobile. Using kinetic Monte Carlo simulations, and assuming a proper scaling law for the dependence on size of the diffusivity of large clusters, we find that islands consisting of as many as 100 monoclusters should exhibit significant mobility. This result has profound implications for the morphology of cluster-assembled materials

Determining Nitrogen Fertilizer Needs for Sugarbeets from Residual Soil Nitrate and Mineralizable Nitrogen

Soil nitrate and mineralizable nitrogen are used to predict the root yield potential and N fertilizer needs of sugarbeets. Predicting the required N fertilizer for optimum refined sucrose production based on soil test procedures is needed because inadequate N limits root yield and high levels of N may reduce both extractable sucrose and sucrose yield. Sugarbeets (Beta vulgaris L.) were grown at 14 residual and fertilizer N rates to determine the root yield, sucrose percentage, sucrose yield, and N uptake in relation to the residual, mineralizable, and fertilizer N. A soil test to measure both the mineralizable and NO?-N level of a soil was found to serve as a valuable guide in recommending N fertilizer for sugarbeets. The amount of N supplied from mineralizable sources in a uniformly cropped and fertilized field is expected to remain reasonably constant if adequate but not excess N fertilizer is supplied each year to the crop grown. Therefore, repeating the test for mineralizable N each year may not be necessary. Determining the amount of NO?-N in the root zone, which is now feasible with rapid and accurate methods of soil analysis, combined with the predetermined mineralizable N, would increase the accuracy of N fertilizer recommendations

Interpreting the Rate of Change in Nitrate-Nitrogen in Sugarbeet Petioles

Nitrate-nitrogen in sugarbeet petioles is used to evaluate current N status of sugarbeet crops. Since the NO?-N changes rapidly during the season, better relationships are needed to interpret these data relative to sugarbeet N nutrition. Sugarbeets (Beta vulgaris, L.) were grown at four N fertilization rates and two irrigation levels to determine the root yield, sucrose percentage, sucrose yield, and N uptake in relation to the NO?-N concentration in the petioles. NO?-N in beet petioles increased to a peak concentration and then decreased exponentially during the two growing seasons on all treatments. The exponential decrease after the peak enables prediction of the NO?-N in the petioles during the remainder of the growing season. This rate of change approach can be used to predict N needs when adding supplemental N for sugarbeets and to characterize the N status of soil-crop systems

Effect of Row Spacing and Nitrogen Rate on Root and Sucrose Yield of Sugarbeets in Southern Idaho

Research results at other locations in western U.S. indicate that a plant spacing of approximately 12 inches within rows and 20 or 22 inches between rows is necessary to obtain near maximum yields of sugarbeets (Beta vulgaris L.) and yet maintain adequate space for machinery operation (4, 6, 10). Increasing row and plant spacings with corresponding decreases in plant population have reduced root and sucrose yields (1, 9, 11). Decreasing row and plant spacings with consequent increases in plant populations may augment yields (5). The optimum row spacing and plant population for maximum sucrose production by varieties currently used by the Amalgamated Sugar Company under a high fertility level, controlled irrigations, and the climatic conditions of southern Idaho are unknown. In southern Idaho, most sugarbeets are grown in 22- or 24-inch rows with plants thinned to 9- to 12-inch spacings within the row. With these plant spacings, the factory average beet root yield from 1966 to 1969 was 20.9 tons in southwestern, 18.3 in south central and 17.8 tons in southeastern Idaho. Experimental plots and many farm fields during the same period produced 5 to 8 tons more than the average when stand, fertilizer, and irrigation water were optimized. A substantial part of the lower average yield may be due to a poor plant stand at maturity on farmers' sugarbeet fields rather than to fertility or irrigation practices. Narrower rows at optimum fertility and irrigation levels, while maintaining adequate space for modern farm machinery, may improve average yields by increasing yield compensation (when frequent skips occur) and by providing an earlier full leaf canopy. This experiment was conducted to determine the effect of plant population, as varied by row width while maintaining a uniform within-row stand, and N level on beet root and sucrose production under the climatic conditions of southern Idaho