Summary:The morphological structure of the lingual papillae and their connective tissue cores (CTC) in a rabbit were studied using LM and SEM and were compared to that of other animal species. Externally, the filiform papillae distributed on the anterior surface of the dorsal tongue were short and conical with a round base and had a flat area on their anterior upper half. The CTC of the conical filiform papillae had a roughly triangular plate-like structure with a round top. Several small round protrusions were found on both inclined planes of the triangle. Spearhead-like filiform papillae were distributed on the anterior edge of the lingual prominence and branched filiform papillae were on the posteriorly wide area of the prominence. These papillae on the prominence had a slightly ramified CTC that differed from that of the CTC of the conical filiform papillae distributed on the anterior tongue. Dome-like fungiform papillae were distributed among the conical filiform papillae of the anterior tongue and had a CTC with a roundish structure that was almost but, not quite spherical in appearance with 1 to 10 small round concave indentations for taste buds on their upper surface. The foliate papillae had approximately 15 parallel ridges separated by grooves. These ridges contained a parallel thin plate-like CTC exhibited after removal of the epithelium. The vallate papilla was comprised of a spherical central papilla and had a circular wall with a flower-like CTC almost resembling a carnation.The stereostructure of the rabbit's filiform CTC are comparatively described as being morphologically in between those of rodents and those of the guinea pig and Japanese serow. Such evolution has probably occurred due to the species unique masticatory and gustatory needs and functions.

The stereo structure of each lingual papilla of the koala has a similar structure to that of various other animal species: the koala has a lingual prominence (intermolar prominence) with larger filiform papillae. (A lingual prominence is a characteristic in herbivorous animals.) The external form and connective tissue core (CTC) of the filiform papillae of koalas consist of one large main process and several smaller accessory processes. (These are similar to carnivorous animals.) Fungiform CTC have a thick dome-like structure, with several taste buds on the top. There are three vallate papillae: one central midline and two laterally located vallate papillae. The central vallate papilla has a posterior pouch lined with ciliated and non-ciliated epithelial cells. Long conical papillae are distributed in the posterior lateral area where foliate papillae are distributed in many other animal species. (Finger-like papillae are seen in dog and cat instead of foliate papillae.) It may be suggested that the tongue of the koala evolved in a special environment in Australia. Even though it has still retained special features similar to those of carnivorous cats and dogs it has evolved to resemble the tongues of herbivorous animals.

This paper gives formulas for analyzing the curling state. Magnetostatic energy of magnetic thin films having volume and surface charges can be calculated from the formulas, expressed in terms of film thickness T, film width W, saturation magnetization M, length of curling region D, and angle θ0 between the magnetic moment and the film edge surface. Using the formulas, we have quantified the magnetization distribution in the film edge layer and the decrease in energy caused by conversion from surface charges into volume charges.

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Seven multiplexed two-dimensional images are recorded and reconstructed by wavelength-multiplexed holographic recording in a cerium (Ce) doped strontium barium niobate (SBN) single crystal by using a tunable laser diode. Analytical formulas for calculating diffraction efficiency are derived by using modified coupled wave equations. Wavelength and angle selectivities of the holograms, which indicate the crosstalk between the multiplexed holograms, agree well with theoretical selectivities derived from the analysis. The theoretical and experimental results suggest that 300 to 400 holograms can be multiplexed.

An InGaAs/InAlAs side-light-injection multiple-quantum-well bistable laser for all-optical switching has been developed. It consists of one main bistable laser and two waveguides perpendicular to the main laser. Saturable absorption and gain quenching are used for set and reset operations. The voltages applied to the gain quenching and saturable absorption regions, which are located at the intersections of the main laser and the waveguide regions, are +1.00 and +0.29 V, respectively. As the input light intensity ( 1.55 µm range) increases, the turn-on and turn-off times decrease. The turn-on time is 200 ps when the input light peak intensity is 1 mW and the turn-off time is 2 ns when the input light peak intensity is 200 mW. The experimental results are supported by numerical simulation. Higher differential gain material is expected to enable faster switching speed.

Optical bistabilities due to electronic refractive index changes are observed in an InGaAs/InAlAs multiple quantum well étalon device at around 1.5 μm wavelength. The switching speeds of less than 30 ns and the induced refractive index changes of −0.1% are observed using a tunable F-center laser.

Formulas are given for the calculation of diffraction efficiency of reflection-type gratings recorded in a photorefractive medium. The analysis incorporates the coupled-wave theory that was developed for photorefractive hologram gratings. This analysis takes into account grating slant with respect to the medium surface, light absorption during reconstruction, any incident angle of the reference beam, and any photorefractive phase shift. General solutions for signal and reference wave functions are given in a closed-form expression by use of a hypergeometric function. The optimum media parameters and recording conditions for high diffraction efficiency are obtained by the derived formulas. The diffraction properties for off-Bragg conditions are also discussed.