Parametric identification of the mathematical model of the micro-arc oxidation process.

The article is aimed at solving the problem of parametric identification of non-linear object models using the example of a mathematical model of the micro-arc oxidation process. An algorithm for parametric identification, based on an experiment in the micro-arc oxidation process, the results of which form a training and control sample is proposed; sequential training of neural networks and calculation of the parameters estimates of the nonlinear model according to experimental data are performed. Experimental testing of the proposed method of neural network parametric identification on the example of the micro-arc oxidation process confirmed that the standard deviation of current and voltage from the nominal values does not exceed ±4%.

[Effect of adenosine triphosphate on the cleavage of H1 histones in nuclei of rat spleen and liver].

Proteolysis of histones H1b and H1(0) is observed after the incubation of rat spleen nuclei at 37 degrees C during 1 hour. Adenosine triphosphate, inorganic pyrophosphate and nicotinamide adenine dinucleotide decrease the digestion of histone H1b. ATP, PP1 and NAD+, in the case of 3 hours incubation, do not affect proteolysis of H1 histones in rat spleen nuclei.

Biosynthesis and physiological role of homarine in marine shrimp.

Glycine, which contributes 2 carbon atoms and the nitrogen for the biosynthesis of homarine by homogenates of shrimp muscle, reacts metabolically with succinyl coenzyme A to form N-succinylglycine. The latter product is effectively converted by such homogenates to homarine, and it is concluded that N-succinylglycine is on the main pathway of this biosynthetic series of reactions and provides all of the required atoms in homarine, except for the N-methyl carbon. A possible pathway for the complete biosynthesis of homarine is described.

Biosynthesis in vitro of homarine and pyridine carboxylic acids in marine shrimp.

Minces and homogenates of muscle obtained from the marine shrimp Penaeus duorarum are capable of synthesizing homarine from [14C]glycine. Glycine carbon atoms are incorporated into homarine but not significantly into picolinate or quinolinate. [2-14C]Acetate is readily incorporated into quinolinate in the in vitro system but only slightly into homarine and not at all into picolinate.

Experiments in marine biochemistry. Homarine metabolism in Penaeus duorarum.

A fractionation procedure has been developed which permits the isolation of 1 to 2 mg of homarine from a single shrimp. This procedure was used to show that homarine is endogenously synthesized by Penaeus duorarum in the free unbound form, and to study the metabolic precursors involved. Injected DL-[14C]tryptophan was not converted to [14C]homarine.

Chemoreception in Nassarius obsoletus: the role of specific stimulatory proteins.

Proteins in human plasma and oyster fluid induce a strong feeding response in the marine snail Nassarius obsoletus. Purified human serum albumin induces a 50 percent positive response at concentrations of 1 to 2 x 10(-9) molar. Adsorbed fatty acids markedly decrease the effectiveness of albumin.

STRUCTURE OF LIPOPROTEINS: COVALENTLY BOUND FATTY ACIDS.

Plasma lipoproteins, extensively extracted with organic solvents, contain small quantities of firmly bound long-chain fatty acids. Upon enzymatic digestion of the protein and partial purification of the resulting peptides, fatty acids are found associated with a peptide fraction which contains organic phosphate. The nature of the linkage between the fatty acid and peptide is unknown.