The relationship between tail (or wing) beat frequency (f(tail)), amplitude (A) and forward velocity (U) in animals using oscillatory propulsion, when moving at a constant cruising speed, converges upon an optimum range of the Strouhal number (St = f(tail) · A/U). Previous work, based on observational data and supported by theory, shows St falling within the broad optimum range (0.2<St<0.4) and...

A mechanical model is proposed which quantitatively describes the dynamics of the centre of gravity (c.g.) during the take-off phase of the long jump. The model entails a minimal but necessary number of components: a linear leg spring with the ability of lengthening to describe the active peak of the force time curve and a distal mass coupled with nonlinear visco-elastic elements to describe th...

1. The 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthetase of Bacillus subtilis has been purified 77-fold (more than 500-fold over the activity in crude extracts of wild-type strains grown in a minimal salts medium). 2. The following points support the thesis that DAHP synthetase is a single enzyme: (a) The sensitivity of the enzyme to two inhibitors is constant throughout a 77-fold p...

The preparation, of an extract of hog blood vessels and organs containing renin activity has been described. The extract hydrolyzes natural or synthetic renin substrate to form a vasopressor material. This reaction could not be distinguished from the hydrolysis of renin substrates by kidney renin. The activation energy, effect of substrate concentration on velocity, inhibition by antirenin, and...

A perturbation approach is used to study the quantum noise of optical solitons in an asymmetric fiber Sagnac interferometer (a highly transmissive nonlinear optical loop mirror). Analytical expressions for the three second-order quadrature correlators are derived and used to predict the amount of detectable amplitude squeezing along with the optimum power-splitting ratio of the Sagnac interfero...

Thiosulfate-oxidizing enzyme has been demonstrated in cell-free extracts of the marine, thiosulfate-oxidizing pseudomonad strain 16B. The enzyme, partially purified by ion-exchange chromatography and calcium phosphate gel treatment, catalyzed the oxidation of thiosulfate to tetrathionate with the concomitant reduction of ferricyanide. Native but not mammalian cytochrome c was also reduced by th...

crustal velocity structure model has a significant role in truly understanding of seismicity and also in relocating earthquakes. on the other hand, it can be used for recognizing major and potential seismic sources which is very critical for seismicity and earthquake hazard assessment studies. seismic parameters simultaneous inversion modeling is one of the most prevalent methods in the study o...

Localized alpha-particle velocity distribution and density, ion temperature, DT fuel ratio, and internal magnetic field pitch angle can all be potentially diagnosed by a collective Thomson scattering system. Relativistic electron cyclotron calculations and TORAY ray tracing for 6 tesla ITER parameters indicate that 90 GHz is an optimum frequency for this diagnostic. With 400 kW at the plasma an...

One of the main drivers for determining the operating temperature of the Solar-B EIS CCDs is the possibility that substantial Charge Transfer Inefficiency may occur towards the end of the mission lifetime. The magnitude of the CTI has been discussed in several technical notes (references 1-3) and this information has been used to judge the optimum and minimum operating temperature of the CCD (r...

Glycinamide ribonucleotide transformylase catalyzes the conversion of glycinamide ribonucleotide and 10-formyltetrahydrofolate to formylglycinamide ribonucleotide and tetrahydrofolate. The enzyme purified from the murine lymphoma cell line L5178Y also catalyzes two other de novo purine biosynthetic activities, glycinamide ribonucleotide synthetase and aminoimidazole ribonucleotide synthetase. T...