Urbanism

Dictionary entry: Urbanismby Kanako Iuch

The qualitative properties of mathematical models for HIV infection

Qualitative analysis for the model of HIV infection in vivo presented by Perelson and Nelson are developed. The local stability analysis is done for the interior equilibrium, and it is shown that, for some paramter value, the interior equilibrium can be unstable and a Hopf bifurcation can occur. It is shown that the boundary equilibrium is globally asymptotically stable. Last, it is shown that this system is permanent

Ultrafast Electronic Relaxation in Aqueous [Fe(bpy)3]^2+: A Surface Hopping Study

Trajectory surface hopping simulations are performed to better understand the electronic relaxation dynamics of [Fe(bpy)3]^2+ in aqueous solution. Specifically, the ultrafast relaxation from the photoexcited singlet metal-to-ligand charge-transfer (MLCT) to the metastable quintet metal-centered (MC) states is simulated through the surface hopping method, where the MLCT and MC states of [Fe(bpy)3]^2+ in aqueous solution are computed by using a model electronic Hamiltonian developed previously. As a result, most of the trajectories are interpreted to show the sequential relaxation pathways via the triplet MC states, though some are the direct pathway from MLCT to the quintet MC states. Even though the triplet MC states are involved in the relaxation, the population transfer to the singlet MC ground state is very small, and the population of the quintet MC states reaches more than ∼96%, reasonably consistent with the unity quantum efficiency discussed experimentally.journal articl

Characterization of Drought-inducible genes in the Highly drought-tolerant cowpea (Vigna unguiculata)

Thesis (Ph. D. in Science)--University of Tsukuba, (A), no. 1795, 1998.3.2

Theoretical study on ultrafast intersystem crossing of chromium(III) acetylacetonate

In the relaxation process from the ^4T_[2g] state of chromium(III) acetylacetonate, Cr^III(acac)_3, ultrafast intersystem crossing (ISC) competes with vibrational relaxation (VR). This contradicts the conventional cascade model, where ISC rates are slower than VR ones. We hence investigate the relaxation process with quantum chemical calculations and excited-state wavepacket simulations to obtain clues about the origins of the ultrafast ISC. It is found that a potential energy curve of the ^4T_[2g] state crosses those of the ^2T_[1g] states near the Franck–Condon region and their spin–orbit couplings are strong. Consequently, ultrafast ISC between these states is observed in the wavepacket simulation

Efeito da época de aplicação da mistura de óleo mineral e DNOC sobre a quebra da dormência da macieira (Malus Domestica, Borkh).

O ensaio foi realizado na região serrana do Estado do Espírito Santo, com coordenadas geográficas 20° 02 S e 41° 31 W e altitude de 1000 metros. O experimento foi constituído de 9 tratamentos onde estudaram-se oito épocas de aplicação de Óleo mineral + DNOC, em 3 anos agrícolas na cultivar de macieira Brasil. Estudou-se a brotação de gemas laterais, terminais, folhas/10 cm de ramo, cachos florais/planta, número de frutos, frutificação efetiva, peso médio dos frutos, produção, número de esporões/planta, esporões/100 cm de ramo, crescimento do ramo terminal, época de brotação e floração. Em plantas novas as melhores de aplicação de produtos na brotação de gemas laterais foram do início até meados do mês de outubro, embora não apresentassem épocas bem definidas como nas regiões de clima mais frio. Para a produção, os melhores resultados foram observados em plantas tratadas no mês de agosto até meados de setembro

A quantum chemical model for a series of self-assembled nanocages: the origin of stability behind the coordination-driven formation of transition metal complexes up to [M₁₂L₂₄]²⁴⁺

Herein, we present a systematic computational model to study the electronic states and free energies of a self-assembled multi-metal complex series. By combining the previously developed model Hamiltonian approach for transition-metal complexes and the generalized Born model, the thermodynamics, optimized geometries, and electronic states of the [Pd12L24]24+ nanocage are revealed, together with [PdnLm]2n+ complex series. The effective model Hamiltonian is a theoretical method to obtain the d-electron wavefunction and potential energy including interaction energy between the transition-metal and ligands. In the present improvement, the electronic state on each transition-metal center is focused as a building unit and solved under the whole electronic field of the assembling system. We realize a reliable and systematic treatment of multi-transition-metal complexes with different sizes and charges. Consequently, our model could reproduce binding energies of the [PdnLm]2n+ complex series quantitatively as compared to density functional theory (DFT). Regarding free energy, we revealed that the assembling solute becomes unstable due to the electrostatic interaction, and effects of the solvent and counter anions mainly compensated it. Optimized geometries were also analysed. The local square-planar coordination structures around the palladium centres were characterized in the complex series. The relationships between the entire symmetrical geometries and the local coordination structures are also discussed. Finally, electronic structures of the [Pd12L24]24+ nanocage were well characterized as a single-determinant, where only dx2−y2 is unoccupied due to the ligand-field effect. We also found that the solvent polarized the electronic states of the Pd ions, whereas the counter anion suppressed the polarization. The present method realizes size-independent reliable and rapid computations, and therefore can be expected to further application studies on self-assembly dynamics

Fundamental roles of reactive oxygen species and protective mechanisms in the female reproductive system

Controlled oxidation, such as disulfide bond formation in sperm nuclei and during ovulation, plays a fundamental role in mammalian reproduction. Excess oxidation, however, causes oxidative stress, resulting in the dysfunction of the reproductive process. Antioxidation reactions that reduce the levels of reactive oxygen species are of prime importance in reproductive systems in maintaining the quality of gametes and support reproduction. While anti-oxidative enzymes, such as superoxide dismutase and peroxidase, play a central role in eliminating oxidative stress, reduction-oxidation (redox) systems, comprised of mainly glutathione and thioredoxin, function to reduce the levels of oxidized molecules. Aldo-keto reductase, using NADPH as an electron donor, detoxifies carbonyl compounds resulting from the oxidation of lipids and proteins. Thus, many antioxidative and redox enzyme genes are expressed and aggressively protect gametes and embryos in reproductive systems

HATCHING ENZYME IN SECRETORY GRANULES OF THE HATCHING GLAND OF MEDAKA

1982-11departmental bulletin pape