ON THE WAY FROM STRADDLED TO STRETCHED TKATCHEV ON HIGH BAR

Reversing the direction of rotation is the main issue for the flight element Tkatchev on high bar. The principles are well described. There is a lack of knowledge to apply this to motor learning. Aim of the study is to analyse an individual gymnast’s performance and support the change from straddled to stretched Tkatchev. An instrumented high bar (force measurement) was used to give the gymnast immediately feedback about the performance. The gymnast was informed about the magnitude of the force maxima during the preparatory giant swing. After 5 training sessions with 42 trails the gymnast transferred more energy (higher forces) to the bar. But this results not in a higher angular momentum during the Tkatchev flight. Possible causes for this result where discussed. The complex demands on energy transfer and precise performance are important

MODELING A SPRINGBOARD IN GYMNASTICS

For development and optimization of elements in gymnastics` vault, the knowledge of the angular momentum, take-off velocity and thus the forces on the springboard are of interest. A multi-body model was developed for the determination of forces. The following article describes the creation of a springboard model and therefore the identification and evaluation of physical parameters acting during movements

3 DECADES OF FORCE MEASUREMENT ON VAULT IN GYMNASTICS

Force measurement on gymnastics apparatuses can give useful knowledge about technique of gymnasts, but also on injury prevention and stress on the human body. Since 1986 direct force measurements on vault horse and tables were applied by our researchers. Aim of this paper is to publish information about the technology we used for direct force measurements. All measuring systems were customized to the apparatuses from different manufacturers. Most measures were arranged in training sessions, but we report also about data collection in official competitions. Examples of force patterns give an idea of peak forces and impulse during different vault groups (handspring, Kasamatsu)

Strongly Interacting W's and Z's and the Existence of a Heavy Fourth Generation of Fermions

By employing the dictum that axiomatic principles are devoid of predictive power, we find that the elastic unitarity constraint, applied to strong W$_L$W$_L$ scattering, does not alter the assumed spectrum of intermediate states. We consider intermediate states involving a heavy Higgs and heavy fermions of a hypothetical fourth generation doublet. In contrast to recent studies, we find no p-wave resonance, and therefore no violation of the S parameter upper bound. We conclude that the elastic unitarity constraint sheds no light on the existence of a heavy fourth generation.Comment: 8 pages including 4 uuencoded, tarred, and compressed postscript figures, CPP-93-0

Improvements to the Method of Dispersion Relations for B Nonleptonic Decays

We bring some clarifications and improvements to the method of dispersion relations in the external masses variables, that we proposed recently for investigating the final state interactions in the B nonleptonic decays. We first present arguments for the existence of an additional term in the dispersion representation, which arises from an equal-time commutator in the LSZ formalism and can be approximated by the conventional factorized amplitude. The reality properties of the spectral function and the Goldberger-Treiman procedure to perform the hadronic unitarity sum are analyzed in more detail. We also improve the treatment of the strong interaction part by including the contributions of both t and u-channel trajectories in the Regge amplitudes. Applications to the $B^0\to \pi^+\pi^-$ and $B^+\to \pi^0 K^+$ decays are presented.Comment: 16 pages, 4 new figures. modifications of the dispersion representatio

Nebenerwerbslandwirtschaft in Sachsen

Nebenerwerbslandwirte sind für Sachsen unverzichtbar. Das wird in der Broschüre erläutert und anhand ausgewählter Statistiken belegt. Vier Beispiele von Nebenerwerbsbetrieben und zahlreiche Fotos runden den Text ab

The faster, the better? Relationships between run-up speed, the degree of difficulty (D-score), height and length of flight on vault in artistic gymnastics

On vault in artistic gymnastics, a high run-up speed is thought to be important when performing difficult vaults. To test this assumption in a large cohort of elite athletes, we calculated the correlations between the run-up speed, scores, height and length of flight for handspring-, Tsukahara- and Yurchenko-style vaults and compared the performances of male and female elite and junior athletes (n = 407) during the 2016 European Championships. In females, run-up speed correlated significantly with the difficulty (D-) score and height of flight for all vaulting styles (r ≤ 0.80). In males, run-up speed correlated significantly with the D-score, height and length of flight of Tsukahara (r ≤ 0.69) and Yurchenko vaults only (r ≤ 0.65). Males reached 8–9% higher run-up speeds performing handspring and Tsukahara vaults than did females, but similar run- up speeds performing Yurchenko vaults. Elite females achieved higher run-up speeds than junior females performing Yurchenko vaults. Elite males displayed higher run-up speeds than junior males performing handspring and Tsukahara vaults. We conclude that, in females, more difficult vaults require higher run-up speeds than vaults with lower D-scores and thus, within the measured range of speeds, the faster the run-up, the better, regardless of vaulting style. Males, on the other hand, may not need to exhaust their sprinting capacity, even for the most difficult vaults. Finally, the knowledge of the required run-up speed for each vault helps coaches to estimate each athlete’s potential and/or to focus the training on developing the required physical qualities

Dispersion Relations and Rescattering Effects in B Nonleptonic Decays

Recently, the final state strong interactions in nonleptonic B decays were investigated in a formalism based on hadronic unitarity and dispersion relations in terms of the off-shell mass squared of the $B$ meson. We consider an heuristic derivation of the dispersion relations in the mass variables using the reduction LSZ formalism and find a discrepancy between the spectral function and the dispersive variable used in the recent works. The part of the unitarity sum which describes final state interactions is shown to appear as spectral function in a dispersion relation based on the analytic continuation in the mass squared of one final particles. As an application, by combining this formalism with Regge theory and SU(3) flavour symmetry we obtain constraints on the tree and the penguin amplitudes of the decay $B^0\to \pi^+\pi^-$.Comment: 17 pages, Latex, 2 figure

Artery tertiary lymphoid organs control aorta immunity and protect against atherosclerosis via vascular smooth muscle cell lymphotoxin β receptors

Tertiary lymphoid organs (TLOs) emerge during nonresolving peripheral inflammation, but their impact on disease progression remains unknown. We have found in aged Apoe−/− mice that artery TLOs (ATLOs) controlled highly territorialized aorta T cell responses. ATLOs promoted T cell recruitment, primed CD4+ T cells, generated CD4+, CD8+, T regulatory (Treg) effector and central memory cells, converted naive CD4+ T cells into induced Treg cells, and presented antigen by an unusual set of dendritic cells and B cells. Meanwhile, vascular smooth muscle cell lymphotoxin β receptors (VSMC-LTβRs) protected against atherosclerosis by maintaining structure, cellularity, and size of ATLOs though VSMC-LTβRs did not affect secondary lymphoid organs: Atherosclerosis was markedly exacerbated in Apoe−/−Ltbr−/− and to a similar extent in aged Apoe−/−Ltbrfl/flTagln-cre mice. These data support the conclusion that the immune system employs ATLOs to organize aorta T cell homeostasis during aging and that VSMC-LTβRs participate in atherosclerosis protection via ATLOs