Transporters in the neurohypophysial neuroendocrine system, with special reference to vesicular glutamate transporters (BNPI and DNPI): a review.

Recent advances in gene technology have helped to identify novel proteins and allowed study of their distribution and functions in the mammalian brain. One class of these proteins is that of transporters, which exist in plasma and organellar membranes of neurons and other cells to move substances selectively across membranes. These transporters can be categorized further into subclasses by their structural property, substrate selectivity, and site of action. Some of them have been identified in the hypothalamus, which is the only brain site where a neural signal is converted to a humoral one, namely, a hormone for a target organ. This unique neural mechanism has long attracted attention as the neuroendocrine system, part of which has been extensively studied as the hypothalamic-neurohypophysial system involved in secretion of vasopressin and oxytocin. However, transporters in this system have been less well studied. A morphological examination of novel transporters would give us cues to a better understanding of the neuronal organization and function of the system. In this review, we first summarize recent findings on expression of transporter gene and immunoreactivity in the hypothalamus. In the second part, we explain our observations on two vesicular glutamate (inorganic phosphate) transporters (BNPI and DNPI) in the supraoptic and paraventricular nuclei and neurohypophysis. Further study of these and other transporters will provide a basis on which to reevaluate the organization and function of the hypothalamic-neurohypophysial system.     

Gas absorption accompanied by an instantaneous irreversible reaction in laminar falling films of pseudoplastic liquids

Gas absorption accompanied by an instantaneous irreversible chemical reaction into laminar falling films of power-law liquids was studied theoretically. The convective-diffusion equations for a solute gas and a liquid-phase reactant were solved numerically and the numerical solution for the reaction factor was obtained as a function of the Graetz number, the concentration ratio, the diffusivity ratio and the power-law index of the liquid.     

Evolutionary design of dynamic neural networks for evaporator control

This paper presents a novel neural network (NN) to control an ammonia refrigerant evaporator. Inspired by the latest findings on the biological neuron, a dynamic synaptic unit (DSU) is proposed to enhance the information processing capacity of artificial neurons. Treating the dynamic synaptic activity after the nonlinear somatic activity helps to capture the dynamics demarcated by the Gaussian activation pertaining to the input space. This practice leads to a remarkable reduction in curse of dimensionality. The proposed NN architecture has been compared with two other conventional architectures; one with dynamic neural units (DNUs) and the other with nonlinear static functions as perceptrons. The objective is to control evaporator heat flow rate and secondary fluid outlet temperature while keeping the degree of refrigerant superheat in the range 4–7 K at the evaporator outlet by manipulating refrigerant and evaporator secondary fluid flow rates. The drawbacks of conventional approaches to this problem are discussed, and how the novel method can overcome them are presented. An evolutionary approach is adopted to optimize the parameters of the NN controllers. Then evaporator process model is accomplished as a combination of governing equations and a sub NN resulting in a simple and sufficiently accurate model. The effectiveness of the proposed dynamic NN controller for the evaporator system model is validated using experimental data from the ammonia refrigeration plant.     

Nonlinear load-deflection relation of toroidal shells subjected to axisymmetric compression between rigid plates

Utility of toroidal shells as shock absorbers for radioactive materials' shipping casks is discussed by carrying out numerical and experimental analyses. The static load-deflection relations under axisymmetric compression between rigid plates are presented.A simple elastic-plastic analytical method is first developed on the basis of an incremental Rayleigh-Ritz method by taking account of the large deflections and the continuous change of contact points. Meridional compression is neglected and the meridional curvature distribution is approximated by a trigonometric series. Strain-hardening material properties and axisymmetric deformation are also assumed. In order to provide data for comparison purposes, static compression tests were performed using six models of different shapes and dimensions made of 304-type stainless steel. Finally, the applicability of the numerical method developed in this paper is discussed.The mechanical behavior of toroidal shells is also discussed.     

Deposition rate dependence of coercivity in vaccum evaporated CoCr films

Deposition rate dependence of perpendicular coercivity Hcl in Cocr evaporated films at the deposition rate ranging from 0.4nm/s to 400nm/s is studied. Hcl increases with decreasing deposition rate as well as with increasing substrate temperature. A High Hcl over 500 Oe, which has ever been obtained only at a substrate temperature over 250°C when deposition rate is high(400nm/s), is obtained at a substrate temperature of 150°C under deposition rate of 2nm/s. "Shoulder" in the hysteresis loop disappears as Hcl exceeds 400 Oe. Therefore to decrease the deposition rate and to increase the substrate temperature have the same effect on Hcl. Saturation magnetization of the films with the same Cr concentration increases with decreasing deposition rate, and it is suggested that the degree of Cr segregation increases with decreasing deposition rate. Hcl is independent of the background pressure when the relative pressure, the quotient of (background pressure/deposition rate), is between 2×10^-8and 5×10^-6torr/(nm/s). From the results above, it is clarified that the difference of deposition rate between vacuum evaporation and sputtering is one of the major reasons for the difference of Hcl between the two.     

Accelerator Analysis of Tributyltin Adsorbed onto the Surface of a Tributyltin Resistant Marine Pseudoalteromonas sp. Cell

Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (10^{9.3 ± 0.2} colony-forming units mL⁻¹) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 10^8.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 10^6.8 TBT molecules is adsorbed by a single cell.     

Identification of creep damage variable from A-parameter by a stochastic analysis

Identification of creep damage variable D of continuum damage theory from the metallographic A-parameter is discussed. By performing a stochastic analysis, A-parameter, defined as the observed fraction of cavitated grain boundaries on the observation plane, was first related to the cavity area fraction on the grain boundary facet planes. Based on the results of this analysis, the cavitation damage states of some engineering alloys were estimated by use of the data of the measured A-parameter. Finally, according to the usual interpretation of the damage variable D, specific D-A relations were derived. The validity and the utility of the proposed D-A relations, based on the test results of an engineering alloy, are discussed.     

Sialon formation by Si+ and N2 + ion implantation into sapphire

Single-crystal alumina was implanted firstly with 400 keV Si⁺ and subsequently with N₂ ⁺ ions and then annealed at 1673 K in an No atmosphre. The implanted layers were characterized by means of X-ray diffraction, Rutherford backscattering-channelling of 2 MeV He⁺ ions, and the resonance nuclear reaction¹⁵N(p,)¹²C. The annealing of sapphire implanted at ambient temperature resulted in the formation of-sialon, a solid solution of-silicon nitride and alumina in the subsurface layer, while implantation at 100 K resulted in the formation of aluminium oxynitride in the surface layer. In the latter case, the implanted silicon atoms were believed not to react vxi1h the implanted nitrogen atoms but with the substrate oxygen atoms. These crystalline precipitates were found to have epitaxial relations with the sapphire substrate.