The γ-subunits of chloroplast ATP synthases are about 30 amino acids longer than the bacterial or mitochondrial homologous proteins. This additional sequence is located in the mean part of the polypeptide chain and includes in green algae and higher plants two cysteines (Cys198 and Cys204 in Chlamydomonas reinhardtii) responsible for thiol regulation. In order to investigate its functional significance, a segment ranging from Asp-D210 to Arg-226 in the γ-subunit of chloroplast ATP synthase from C. reinhardtii was deleted. This deletion mutant called T2 grows photoautotrophically, but slowly than the parental strain. The chloroplast ATP synthase complex with the mutated γ is assembled, membrane bound, and as CF0CF1 displays normal ATPase activity, but photophosphorylation is inhibited by about 20 %. This inhibition is referred to lower light-induced transmembrane proton gradient. Reduction of the proton gradient is apparently caused by a disturbed functional connection between CF1 and CF0 effecting a partially leaky ATP synthase complex.
We consider a decision-making problem to evaluate absolute ratings of alternatives that are compared in pairs according to two criteria, subject to box constraints on the ratings. The problem is formulated as the log-Chebyshev approximation of two pairwise comparison matrices by a common consistent matrix (a symmetrically reciprocal matrix of unit rank), to minimize the approximation errors for both matrices simultaneously. We rearrange the approximation problem as a constrained bi-objective optimization problem of finding a vector that determines the approximating consistent matrix, and then represent the problem in terms of tropical algebra. We apply methods and results of tropical optimization to derive an analytical solution of the constrained problem. The solution consists in introducing two new variables that describe the values of the objective functions and allow reducing the problem to the solution of a system of parameterized inequalities constructed for the unknown vector, where the new variables play the role of parameters. We exploit the existence condition for solutions of the system to derive those values of the parameters that belong to the Pareto front inherent to the problem. Then, we solve the system for the unknown vector and take all solutions that correspond to the Pareto front, as a complete solution of the bi-objective problem. We apply the result obtained to the bi-criteria decision problem under consideration and present illustrative examples.
The consequences of epileptic seizures related to postictal inhibition in early postictal period include postictal analgesia. We studied this phenomenon over 96 h following flurothyl-induced seizures in adult male Wistar rats. Nociception of control (no seizure) and seizured groups were tested using the plantar and von Frey hair tests. We determined latency of forepaw and hind paw reactions using plantar tests and the number of von Frey hairs reactions. Shortly after seizures, longer plantar test latencies were seen relative to the control group. Before the seizures the plantar test reaction times were significantly shorter in forepaws than in hind paws. The effect disappeared post-seizure and surprisingly, it also disappeared at the corresponding time in controls; it reappeared after 48 h in the seizure group and after 24 h in controls. Differences in the von Frey hairs test occurred at 5 and 60 min post-seizure, however, these differences could not be explained by limb anatomy; although, different thermal and mechanical nociception mechanisms could be significant. The unexpected reactions in controls could be related to brief social and physical interactions between the two groups. and J. Mareš, R. Rokyta.
Fractal image coding is a new and modern technique for lossy image compression. This paper contains a general description of fractal image compression techniques and describes basic algorithms used for encoding and decoding of images. Some examples are presented. For our experiments we use the famous static gray-scale image of LENNA. Some problems of color image coding are also shortly mentioned. and Fraktálové kódování obrazů patří mezi nové účinné techniky ztrátové komprese obrazů. Článek obsahuje obecný popis technik a základní algoritmy fraktálovho kódování a dekódování (šedých) obrazů. Jsou uvedeny některé příklady. Experimenty byly realizovány na proslulém statickém šedém obrazu LENNA, který dnes již představuje určitý standard pro testování většiny procedur zpracování obrazu. Krátce jsou zmíněny i některé základní problémy kódování barevných obrazů.
The article describes automation of 2-dimensional surface analysis in the aparature for laser spectroscopy (LIBS). Such analysis give us 2D map of presented chemical elements. The main part is dedicated to algorithm choosing suitable for evaluation of the image sharpness. Digital camera and ablation laser share the same focusing optics, so knowing the exact image sharpness it is possible to set sample object to focal plane. There are theoretically described and experimentaly tested different kinds of methods how to obtain a relative sharpness number: gradient based method and methods working in frequency domain. Digital noise phenomenon is also discussed. As an output a selection of suitable method has been made with respect to its speed, accuracy and durability against digital noise. and Článek popisuje řešení automatizace dvourozměrné povrchové analýzy v zařízení pro laserovou spektroskopii (LIBS), jejímž výsledkem je 2D mapa přítomnosti chemických prvků. Hlavní část je věnována výběru algoritmu pro opětovné nastavení mapovaného vzorku do ohniskové roviny objektivu, který zároveň slouží k fokusaci laserového svazku. Děje se tak pomocí analýzy ostrosti snímku vzorku. Teoreticky jsou rozebrány a experimentálně otestovány různé metody vyhodno cení ostrosti snímku, a to metoda gradientní a metody pracující s frekvenčním spektrem obrazu. Článek se zabývá také problematikou filtrace digitálního šumu. Výstupem je volba vhodného algoritmu s ohledem na rychlost, přesnost a odolnost vůči digitálnímu šumu.