Optokinetic nystagmus () test is popularly performed to diagnose the disequilibrium-disorders on clinical examination. Only the experts of this diseases can, however, diagnose the test result exactly, which is expressed by patterns of nystagmus requiring the pattern recognition. We constructed the computer assisted instruction system of pattern recognition using the numerical information consisting of 6 variables from the 29 normal and 22 abnormal patterns of the diagnosed by one expert. The theoretical bases were Fuzzy theory especially fuzzy reasoning; if-then rule and max-min method. The high consistent rate (96%) of diagnosis was obtained between the result of the expert and of our system with this data. A lower rate (83.7%) of consistency was calculated with another 251 numerical data of using this rule of fuzzy reasoning. The degree of normality and abnormality were, however, retained in this rule of reasoning. It was concluded that the fuzzy theory was useful to construct the computer assisted instruction system but the subsequent analysis was required to obtain the higher rate of consistency.

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We evaluateded a human self-control system for wide-visual field stereoscopic images using measurements of body sway and eye movement caused by vection. First, it was found that the locus length of body sway did not depend on the degree of the moving rectangular target with a uniform disparity. We used the same target with the same disparity in one period and zero disparity in the another period. The body sway was measured while the part of the target with disparity was moved repeatedly side to side and the other part was stationary. The locus length of body sway had a longer value for the moving target behind the stationary one than in other cases. These results agree with the results of the subjective assessment in the psychological experiment which used real targets. Moreover, the frequency of (optokinetic nystagmus) was almost the same for the uniform disparity target in the measurement of eye movement. It was also found that occurred frequently with a moving target behind a stationary one. However, was almost nonexistent in other cases. In conclusion, we examined the possibility of the objective evaluation of a human self-control system based on these results.

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This paper was aimed to estimate the perceptual strength of visually induced self-motion perception (vection) by focusing on the beating field (BF) ofoptokinetic nystagmus (). For this purpose we used an immersive type VR system which provided 3D visual stimuli for observers at the most of the entirely visual field. The BF during vection was found to displace to the perceived heading direction in proportion to the strength of vection. This displacement preceded the difference in the subjective estimation of the strength of vection between viewing conditions. Thus the strength of vection was estimated by measuring BF of even before the actual observation of the subjective estimation of vection.

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Spontaneous and induced nystagmus elapsed-time tests were carried out with a nystagmograph and followed by pathohistological evaluation of the inner ear.
Test Results:
1. In all groups of rabbits, spontaneous nystagmus was not demonstrated in both light and dark areas.
2. In the group not subjected to stress, the number of oscillations per eye in pendular nystagmus (PR) was not the same but the difference was within 10%, while in optokinetic nystagmus () this difference was greater but still within 12.2%.
3. In the group subjected to chronic emotional stimulation, the difference between the right and left eyes was a maximum of 24.6%, while in the difference was a maximum of 73.0%. Only one case showed a low frequency of nystagmus.
4. In the group subjected to acute emotional stimulation, the difference in PR was 20.6% and in 76.9%. Nystagmus appeared gradually following stimulation.
5. In the group of rabbits placed under restraint, all animals showed an increased difference between right and left eyes in PR, or 69.6%, and a difference of 82.6% in . Here, nystagmus was slow to appear following stimulation in some cases.
6. In some of the animals in the groups subjected to chronic and acute emotional stimulation, pathohistological examination of the inner ear revealed unaccountable aural vertigo centering on Meniere's syndrome.
There have been many theories advanced as the etiology of nystagmus. These have included one quite recently that such psychosomatic factors as the complexity of modern social structure and life exert a great influence. Where fundamental studies are concerned, a few experiments dealing with stress alone have been carried out, but none regarding the effect on vestibule of the ear and optokinetic function.
For this reason, rabbits were subjected to various emotional stimulation and the various changes in spontaneous and induced nystagmus were observed, together with pathohistological evaluation.
In order to carry out these experiments, a stress box was constructed in which animals could be subjected to electrical, light and sound stimulation and also to restraint.
The experiments were classified into chronic and acute tests, on the basis of the strength and duration of the emotional stimulation, and the test where restraint alone was used.
In other words, the rabbits were divided into four distinct groups: that where no stress was exerted, the chronic emotional stimulation group, the acute emotional stimulation group, and the restraint group.
Some rabbits gave evidence of hemorrhage resulting from electrical stimulation, while all rabbits in the groups subjected to stress displayed changes in their adrenal glands. Rabbits in the groups subjected to emotional stimulation gave evidence of effects on the optokinetic functions and vestibule of the ear.
The difference in oscillation rates between left and right eyes in cases of PR and tended to increase with the increase in stimulation.
Where spontaneous nystagmus did not appear, it was thought that a condition preparatory to the appearance of vertigo existed.

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Turfgrasses show a wide range of salinity tolerance. In this study, twenty wild turfgrasses were collected from coastal regions in Japan, and their species; evolutionary lineage; salt tolerance levels; shoot and root K⁺, Na⁺, and proline contents; and amounts of ions secreted from their salt glands were determined. Among them, eighteen turfgrass species were determined based on the internal transcribed spacer 1 sequences. All collected wild turfgrasses were identified as halophytes and were divided into two salt-tolerant levels. They maintained the shoot relative water contents and suppressed excess Na⁺ accumulation in their shoots and roots and K⁺ content homeostasis compared with rice, resulting in the maintenance of a higher K⁺/Na⁺ ratio under salt stress. These characteristics must be part of the salt tolerance mechanisms. Among the four turfgrasses with salt glands, three selectively secreted Na⁺ from their salt glands; however, interestingly, one secreted K⁺ over Na⁺, although it still maintained a K⁺/Na⁺ ratio comparable to that of the other turfgrasses. A significant amount of proline synthesis was observed in most of the turfgrasses in response to salt stress, and the proline content was highly correlated with the salt tolerance, suggesting its key role in the salt tolerance mechanisms. These wild turfgrasses with such diverse ion control mechanisms and proline synthesis profiles are useful materials for investigating the salt tolerant mechanisms and breeding salt tolerant turfgrasses.

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Electrophysiological recordings of eye movement are important for the discipline of orthoptics not only in clinical evaluation of visual function but also for understanding the properties of visuomotor coordination. Therefore, low-cost visual stimulators with real-time output of current stimulation status are required for effective student practice. In this report, three types of stimulators were tested for recording saccadic and pursuit eye movements and optokinetic nystagmus in electrooculography practice. These stimulators were built with low-cost, general-purpose parts and might improve the student training courses for certified orthoptists, a specialty that requires thorough knowledge of the complex properties of various human eye movements.

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実験的動揺病を偽コリオリ刺激で誘発し, その負荷前後での, OKANの変化から動揺病の適応過程を考察した。その結果, 負荷を重ねるごとにOKAN第1相の解発は減少傾向を示し, 第2相は有意に増加傾向を示した。また, 動揺病症状は適応とともに軽減した。OKAN第1相はindirect pass-wayを反映した出力情報であり前庭神経核の活動であると考えられている。動揺病の誘発とともにOKAN第1相が抑制され, 第2相が充進されたことから動揺病の適応過程に前庭神経核の変化が生じたものと考えられた。

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Optokinetic nystagmus () is often included in a battery of tests to assess central nervous system disorders. Patients with discrete lesions in either the brainstem or the cerebellum showed when the velocity of stimulation was less than 60°/s. The question arises as to whether the range of stimulation we have applied so far (1.2°/s² to 120°/s) is necessary. Therefore, we tried to modify and simplify the test, to steps of constant stimulus velocities at 30°/s, 50°/s, 70°/s and 90°/s and compared the results with those of the tests used previously. The following conclusion can be drawn:
1) The gain of induced by step inputs, with slow phase velocity as a measure, was higher than that of during linear acceleration at each stimulus velocity.
2) Other parameters, such as amplitude and fast phase velocity of showed the same tendency as slow phase velocity.
3) induced by step inputs of constant velocities is a simple and useful test of the function of the oculomotor system.

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This report discusses normal findings obtained in the optokinetic nystagmus test. Optokinetic nystagmus was provoked with isometric acceleration (±4°/sec²). The optokinetic stimulation drum was started at 0°/sec and accelerated to 160°/sec. After this level of stimulation having been reached, the drum was decelerated to 0°/sec.
Optokinetic nsytagmus thus induced was recorded on the ENG at paper speeds of 1 mm/sec and 0.5 cm/sec. The former record was analyzed by a qualitative procedure, and the latter by a quantitative procedure. Optokinetic nystagmus test findings were analyzed in 50 normal subjects. As a result, it was revealed that the maximum eye speed of the slow component of nystagmus was 94.0°±16.5°/sec and the total number of nystagmus was 218.0±23.4.
A more objective evaluation can be made of optokinetic nystagmus test results by analyzing not only qualitative findings such as OKP (Optokinetic Nystagmus Pattern) but also quantitative findings. It is therefore recommended that the evaluation of optokinetic nystagnius test results be based on both qualitative and quantitative findings.

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施設入園の脳性麻痺児68人について, 神経学的, 神経眼科ないし耳科学的に検討した.自発眼振, 注視眼振, 非注視眼振, 視運動性眼振等を, 裸眼状態, Frenzel眼鏡装着下, 肉眼観察, 電気眼振計記録などにより観察して, 麻痺の性状との関連性などについて論じた.

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We examined the genetic structure of populations of an ambrosia beetle, Xylosandrus crassiusculus. Specimens were collected from 22 sites in Japan and their genetic structure was studied using a portion of the mitochondrial cytochrome oxidase I gene. Phylogenetic analysis revealed three distinct lineages (clades A, B and C), each of which was divided into two subclades (A₁, A₂, B₁, B₂, C₁ and C₂). Subclade A₁ had 17 haplotypes from Hokkaido, Honshu and Kyushu populations, subclade A₂ 5 haplotypes mainly from Shikoku populations, subclade B₁ 15 haplotypes from central and western Honshu and Amami populations, subclade B₂ 2 haplotypes only from Naha population, subclade C₁ 4 haplotypes from Amami and Naha populations, and subclade C₂ 5 haplotypes only from Ishigaki population. Analysis of molecular variance detected genetic differentiation among populations. The data imply that the genetic structure of Japanese populations of X. crassiusculus has been affected by the geological history of the Japanese islands, but that the mtDNA phylogeographic pattern is so complex that we could not infer any simple scenario of population history in X. crassiusculus.

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