Search

A method of imaging and analysis of fluorescence kinetic parameters distributed over leaf area is described in details. Video data recorded by the CCD-camera were processed using free programs VirtualDub and ImageJ. The method allows not only to image the distribution of fluorescence decrease ratio (Rfd), but also to obtain fluorescence induction curves, which are corresponded to any region of interest selected within the leaf image. A considerable mosaicism of shade leaves of Ficus benjamina L. was shown on the basis of Rfd values, whose functional significance is discussed from the point of view of adaptation to different light intensities. A pronounced non-uniformity of F. benjamina leaves was revealed in relation to the retention time of the secondary fluorescence maximum (peak M). A method of differential imaging was proposed to allow visualization of this non-uniformity and to demonstrate the existence of the previously unknown phenomenon of secondary chlorophyll fluorescence “wave” in leaves. It was also shown the absence of M peak in the chlorophyll-deficient, lacking the mesophyll leaf sectors, where the residual chlorophyll is originated from guard cell chloroplasts.

Corresponding Author: V.S. Lysenko, Academy of Biology and Biotechnology, Southern Federal University, Rostov-onDon, Russia Email: vs958@yandex.ru Abstract: Non-additive enhancement of the photosynthesis excited by simultaneous illumination with far-red light and light of shorter wavelengths is called as “second Emerson effect”. Its action spectra are well-known as a photosynthetic yield’s dependence on light wavelength in red (630-690 nm) spectral region at a constant-wavelength far-red illumination near 700-715 nm. However, the opposite dependence of the photosynthetic yield’s of shorter constant-wavelength light (red or blue) on light wavelength in far-red (690-760 nm) spectral region was never studied. In this study the action spectrum of second Emerson effect was studied using a fast-Fourier dual-wavelength Pulse Amplitude Modulation (PAM) fluorometry. Chlorophyll fluorescence in ailanthus (Ailanthus altissima Mill.) leaves was excited with blue modulated light. Far-red induced decrease of fluorescence (fluorescence shift-FRIFS) was studied in response to illumination of leaves with a background light from 690 to 760 nm (10 nm step), calculating FRIFS = (F0-Fs)/F0, where F0fluorescence measured without and Fs-with far-red light. Maximum FRIFS was observed at 720 nm (11.8%), but it still remained considerable at 740, 750 nm and a low FRIFS values were revealed at 690 and even at 760 nm. Measurements carried out with blue saturating flashes during and after far-red illumination showed the increase of quantum yield of Photosystem II (PSII), calculated as Fv/Fm at 720 nm background light. FRIFS had lower values under excitation with red modulating light. It is concluded that FRIFS is a result of a photochemical quenching caused by an additional selective far-red excitation of PSI in conditions when PSII is preferably excited by blue light thus leading the PSI to limit non-cyclic electron flow. The contradiction between the known absorption spectra of PSI-light harvesting complex I and the observed action spectrum of second Emerson effect (FRIFS spectrum) is discussed.

The basic features of a projected 50–60 Bev strong-focusing proton accelerator are described. The critical energy is eliminated by changing the dependence of orbit length on momentum. The weight of the magnetic system, consisting of 120 sectors is less than 22,000 tons, the peak power is approximately 100,000 kva, the mean radius is 236 m.

This paper gives a short description of the history of the development of the first stiff focusing ring-type accelerator in the Soviet Union. Design parameters of the accelerator are given along with startup results.

The article describes briefly the design of the first strong focusing ring accelerator to be built in the Soviet Union. The design parameters and the results obtained during the start-up of the accelerator are presented.

Olfactory mucosa of the frog was stimulated with odours of amylacetat , butanol, alcohol, naphthalene, acetic acid in air and oxygen media under normal and high oxygen pressure (0.2 MPa and 0.7 MPa). The electroolfactogram (EOG) amplitude was higher in oxygen due, probably, to the olfactory mucosa oxygen saturation on concentration gradient as well as to the activation of processes related to the EOG generation. 0.2 MPa pressure as well as 0.7 MPa pressure applied for 60 min decreased the EOG amplitude.