The influence of an active steering assistance system on the cyclist's experience in low-speed riding tasks

At low speeds, older cyclists have a higher risk of losing balance and having an accident on a pedelec than younger cyclists. A stability assistance system with an electric motor acting on the handlebars can provide steering assistance and help stabilize a pedelec. However, the steering interventions can possibly affect the cyclist and his riding experience. Using a steer assisted pedelec, this study investigates the influence of these interventions on the cyclist and his riding experience at low speeds

Considering Protonation as a Posttranslational Modification Regulating Protein Structure and Function

Post-translational modification of proteins is an evolutionarily conserved mechanism for regulating activity, binding affinities and stability. Compared with established post-translational modifications such as phosphorylation or uniquitination, post-translational modification by protons within physiological pH ranges is a less recognized mechanism for regulating protein function. By changing the charge of amino acid side chains, post-translational modification by protons can drive dynamical changes in protein conformation and function. Addition and removal of a proton is rapid and reversible and in contrast to most other post-translational modifications does not require an enzyme. Signaling specificity is achieved by only a minority of sites in proteins titrating within the physiological pH range. Here, we examine the structural mechanisms and functional consequences of proton post-translational modification of pH-sensing proteins regulating different cellular processes

Die steuerliche Beurteilung von Genussrechten als Instrumente der Kapitalbeschaffung

Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel A 198097 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Trainingssteuerung des Freizeitläufers unter besonderer Berücksichtigung der Herzfrequenz

Die vorliegende empirische Arbeit widmet sich in einer Hauptuntersuchung und drei flankierenden Untersuchungsabschnitten den Möglichkeiten und Grenzen der Belastungssteuerung beim freizeitsportlichen Laufen. Untersucht wurden u.a. der Einfluss von Belastungsdauer, Umgebungstemperatur und Musik auf kardiozirkulatorische und biomechanische Parameter. Die Belastungsintensität betrug in Abhängigkeit vom jeweiligen Untersuchungsdesign 85%, 90% oder 95% der Geschwindigkeit bei einer Blutlaktatkonzentration von 4 mmol. Besondere Beachtung und praxisnahe Empfehlungen werden unter Berücksichtigung der aktuellen Studienlage zum Parameter Herzfrequenz gegeben. Dabei wird auf das Phänomen Cardiodrift, dem Anstieg der Herzfrequenz bei gleichbleibender Geschwindigkeit, besonders eingegangen

The influence of an active steering assistance system on the cyclist's experience in low-speed riding tasks

At low speeds, older cyclists have a higher risk of losing balance and having an accident on a pedelec than younger cyclists. A stability assistance system with an electric motor acting on the handlebars can provide steering assistance and help stabilize a pedelec. However, the steering interventions can possibly affect the cyclist and his riding experience. Using a steer assisted pedelec, this study investigates the influence of these interventions on the cyclist and his riding experience at low speeds

The influence of an active steering assistance system on the cyclist's experience in low-speed riding tasks

At low speeds, older cyclists have a higher risk of losing balance and having an accident on a pedelec than younger cyclists. A stability assistance system with an electric motor acting on the handlebars can provide steering assistance and help stabilize a pedelec. However, the steering interventions can possibly affect the cyclist and his riding experience. Using a steer assisted pedelec, this study investigates the influence of these interventions on the cyclist and his riding experience at low speeds

Binding of hisactophilin I and II to lipid membranes is controlled by a pH-dependent myristoyl-histidine switch

The interaction of the two N-terminally myristoylated isoforms of Dictyostelium hisactophilin with lipid model membranes was investigated by means of the monolayer expansion method and high-sensitivity titration calorimetry. The two isoforms, hisactophilin I and hisactophilin II, were found to insert with their N-terminal myristoyl residue into an electrically neutral POPC monolayer corresponding in its lateral packing density to that of a lipid bilayer. The partition coefficient for this insertion process was Kp = (1.1 +/- 0.2) x 10(4) M-1. The area requirement of the protein in the lipid membrane was estimated as 44 +/- 6 A2 which corresponds to the cross sectional area of the myristoyl moiety with an additional small contribution from amino acid side chains. The interaction of hisactophilin I (hisactophilin II) with negatively charged membrane surfaces is modulated in a pH-dependent manner by charged amino acid residues clustered around the myristoyl moiety. The electrostatic binding site consists of three lysine (one arginine and two lysine), seven (nine) histidine, and four (four) glutamic acid residues and has an isoelectric point of 6.9 (7.1). For small unilamellar POPC/POPG (75/25 mole/mole) vesicles, an apparent binding constant, K(app) = (8 +/- 1) x 10(5) M-1, was measured at pH 6.0 by means of high-sensitivity titration calorimetry. Electrostatic interactions hence increase the binding constant by about 2 orders of magnitude compared to hydrophobic binding alone. With increasing pH, the electrostatic attraction decreases and turns into an electrostatic repulsion at pH < 7.0 +/- 0.1. The area occupied by the cluster of charged residues constituting the membrane binding region was 280 +/- 20 A2 as derived from monolayer measurements in close agreement with molecular modeling data derived from the NMR structure of hisactophilin I [Habazettl et al. (1992) Nature 359, 855-858]

Effects of different recovery strategies following a half-marathon on fatigue markers in recreational runners

To investigate the effects of different recovery strategies on fatigue markers following a prolonged running exercise.46 recreational male runners completed a half-marathon, followed by active recovery (ACT), cold water immersion (CWI), massage (MAS) or passive recovery (PAS). Countermovement jump height, muscle soreness and perceived recovery and stress were measured 24h before the half-marathon (pre), immediately after the recovery intervention (postrec) and 24h after the race (post24). In addition, muscle contractile properties and blood markers of fatigue were determined at pre and post24.Magnitude-based inferences revealed substantial differences in the changes between the groups. At postrec, ACT was harmful to perceived recovery (ACT vs. PAS: effect size [ES] = -1.81) and serum concentration of creatine kinase (ACT vs. PAS: ES = 0.42), with CWI being harmful to jump performance (CWI vs. PAS: ES = -0.98). It was also beneficial for reducing muscle soreness (CWI vs. PAS: ES = -0.88) and improving perceived stress (CWI vs. PAS: ES = -0.64), with MAS being beneficial for reducing muscle soreness (MAS vs. PAS: ES = -0.52) and improving perceived recovery (MAS vs. PAS: ES = 1.00). At post24, both CWI and MAS were still beneficial for reducing muscle soreness (CWI vs. PAS: ES = 1.49; MAS vs. PAS: ES = 1.12), with ACT being harmful to perceived recovery (ACT vs. PAS: ES = -0.68), serum concentration of creatine kinase (ACT vs. PAS: ES = 0.84) and free-testosterone (ACT vs. PAS: ES = -0.91).In recreational runners, a half-marathon results in fatigue symptoms lasting at least 24h. To restore subjective fatigue measures, the authors recommend CWI and MAS, as these recovery strategies are more effective than PAS, with ACT being even disadvantageous. However, runners must be aware that neither the use of ACT nor CWI or MAS had any beneficial effect on objective fatigue markers