Mathematical modeling of plant morphogenesis

Current trends in biology call for analysis of the bulk information accumulated through mathematical simulations of biological processes aiming at revealing certain regularities and verifying hypotheses and predictions. Evolution of organisms is of special interest to mathematical modeling because it integrates a great body of different processes varying over time and over space. In this paper, models of biological processes as related to plant development are reviewed. The models are classified, and approaches to problems that are most intricate from the simulation standpoint, as well as relevant mathematical methods, are described.     

Reactions of alkoxy and amino derivatives of silacyclobutane with amino alcohols

2-(N,N-Dimethylamino)ethanol readily replaces the MeO and Et₂N groups in 1-methoxy-1-methyl-, 1,1-dimethoxy-, 1-diethylamino-1-methyl-and 1,1-bis(diethylamino)-1-silacyclobutanes to form dimethylaminoethoxy derivatives. Triethanolamine and N,N-bis(2-hydroxyethyl)glycinamide split the silacyclobutane ring in 1,1-dimethoxy-1-silacyclobutane to form 1-propylsilathrane and 1-propyl-2-azasilathran-3-one, respectively.     

Build-up of strain defects and the energetics of plastic strain

Calculations are presented for the concentrations of strain defects in a strained crystal and from these data the values of the stored energy E are computed. The contribution of dislocations and the strain points of defects to the stored energy is evaluated as a function of the strain for monocrystals of copper. The work of the strain is determined. A comparison is made of the theoretical results with those obtained by experiment.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 12–16, April, 1984.     

Synthesis of nitro- and aminoalkylphosphonates

Conclusions Some new O, O-dialkyl nitroalkylphosphonates were synthesized by the addition of dialkyl phosphites and thiophosphites to nitroolefins. The corresponding aminophosphonates were obtained from them by reduction. The hydrolysis of the latter gave the corresponding aminoalkylphosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1164–1168, May, 1972.     

N-methyI-N-(triethoxysilylmethyl) andN-methyl-N-(silatran-1-ylmethyl) substituted glycine and alanine

Organosilicon derivatives of glycine, - and -alanine, and -methylalanine were prepared by the reaction of methyl esters of - and -halocarboxylic acids withN-methylaminomethyltriethoxysilane in the presence of triethylamine. The compounds synthesized were converted into the correspondingN-silatran-l-ylmethyl derivatives. Trimethylsilyliodoacetate reacts withN-methylaminomethyltrietoxysilane to give 2,2-diethoxy4-methyl-1-oxa-4-aza-2-silacyclohexane-6-one. Its reaction with triethanolamine leads toN-methyl-N-(silatran-l-ylmethyl)glycine.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 341–343, February, 1995.     

The nature of the super-electron-releasing inductive effect of the silatranyl group and its spectroscopic and chemical consequences

The relationship between the structure of carbofunctionally substituted 1-methylsilatranes XCH₂Si(OCHRCH₂)₃N (R = H, Me; X = R"₂N, R"S, Cl, etc., R" = Alk), the unusually high electron-releasing properties of the silatranyl group, and the enhanced chemical reactivity of the exocyclic XCH₂ substituent is discussed.     

Magnetic-Field-Induced Optical Second-Harmonic Generation Study of Co/Pt and Co/Ta Interfaces

Magnetic properties of an interface between cobalt and platinum or tantalum nanolayers have been studied by the optical second-harmonic generation and nonlinear magneto-optical Kerr effect methods. It has been shown that a high sensitivity of the second-harmonic generation method makes it possible to determine the orientation of the easy magnetization axis in the plane of a polycrystalline structure without measurement of the magnetic field dependence of second-harmonic generation. The comparison of the field dependences of magnetic-field-induced second-harmonic generation with the linear magneto-optical effect indicates the difference in the processes of magnetization reversal in Co/Pt and Co/Ta interfaces and the bulk of the cobalt film. In particular, a new linear in magnetization effect has been observed in the second harmonic that is symmetry-forbidden for uniformly magnetized structures.     

Synthesis of monomers which are triplets of the “crystalline” part of collagen molecule

Conclusions Triplet monomers were synthesized with the sequences Gly-I-I, Gly-Ala-I, Ala-I-I, and Gly-Pro-R (I=the imino acid proline or hydroxyproline, and R=an amino acid residue).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 392–397, February, 1969.