The cadmium treatment of dark-grown leaves and isolated etioplast inner membranes of wheat resulted in a decrease of the amount of the 657 nm emitting (77 K fluorescence) protochlorophyllide (PChlide) form, a simultaneous increase of the 633 nm form and the appearance of a 641.5 nm emitting form. This effect did not occur if excess NADPH was added to the isolated membranes: these samples showed spectral properties identical to those of non-treated (control) samples. Inhibition of the PChlide phototransformation was observed in the cadmium-treated leaves and membranes, the irradiation resulted in the appearance of a smáli amount of chlorophyllide (Chlide) with characteristic emission band at 678 nm. If excess NADPH was added, the inhibition did not occur and flash irradiation resulted in formation of the 694 nm Chlide form similarly as in control plants.
This article describes a technique for noise reduction of the differential bearings. Noise is excited by the mechanical looseness of the system and by the vibrations of the engine. The mathematical model enables the optimization of the radial stiffness of the differential bearings. A test rig has been designed for the simulation of the phenomenon outside the vehicle. Analytical software has been created that is capable of classifying the types of noise from the measured data. The optimal solution is tested on the rig at the end, thus proving that the technique works. and Obsahuje seznam literatury
Purity, integrity and protein synthesis were studied in chloroplasts isolated from barley (Hordeum vulgare L. cv. Hassan) leaf segments incubated for 20 h in the dark, a treatment which enhances subsequent senescence. Apparently, isolated chloroplasts retained enough Mg^^ for the incorporation of radioactive ainino acids into proteins. The effects of chloramphenicol, cycloheximide and nuclease and the requirement of radiant energy indicated that amino acid incorporation was due to protein synthesis on 70S chloroplast ribosomes. The electrophoretic profile of the polypeptides synthesized was similar in intact and in broken chloroplasts. Pulse-chase assays indicated that most, if not all, polypeptides labelled in assays with isolated chloroplasts were complete polypeptides, which were also synthesized in vivo. Hence the polypeptides synthesized in vivo by chloroplasts early in senescence may be accurately and reliably studied in this systém of protein synthesis by isolated chloroplasts.
The residual ambiguity of a laser radar system using pulse trains from a mode locking laser has been investigated by computer simulation. Numerical results are given for pulse groups with Gaussian envelope. A slight modification of this signal shape results in strong reduction of the ambiguity.