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Biomedical subjects

N Kawabata

Publications and source records attributed to N Kawabata.

8 recordsLinked to original sources
PubMed1992

Disambiguating ambiguous figures by a model of selective attention.

Ambiguous figures are visual stimuli which are interpreted multiply by the human visual system. A model is proposed which disambiguates the ambiguous figures. The model was formulated based on the characteristics of visual information processing, accompanied with selective attention. In the ambiguous figure "my husband and my father-in-law", it was necessary to simulate visual information processing so that attention was directed to the multiple features in the figure to disambiguate the ambiguous figure. Pictures, obtained from the model, were examined as to whether they were interpreted unambiguously or not. Results show that the model, simulated selective attention, can disambiguate the ambiguous figures. This suggests that the image per se, viewed through selective attention, becomes unambiguous before the figure is interpreted in the higher level. Results also show that the computer simulation of selective attention would make it possible to examine factors affecting the initial interpretation of the figure.

Attention↗
PubMed1992

Removal of micro-organisms by filtration through unwoven cloth coated with a pyridinium-type polymer.

Unwoven cloth coated with 32 mg/g of a copolymer of N-benzyl-4-vinyl-pyridinium chloride and styrene was found to be effective in removing micro-organisms from water. In experiments demonstrating removal of Escherichia coli by filtration through ten sheets of the unwoven cloth, the rate of removal was 99.99% at a filtration rate of 2.6 cm/h, and remained at 99% even at a high filtration rate of 300 cm/h and a low influent concentration of the bacterial cells such as 10(3) cells/ml. The rate of removal tended to increase with a decrease in the influent bacterial concentration. Seven other bacteria and two yeasts were effectively removed by filtration through the unwoven cloth. Filtration through the unwoven cloth was also effective in removing spores of fungi from water but was not very effective in removing bacteriophage T4 from aqueous solution.

Bacteria↗
PubMed1992

Three-dimensional interpretation of quadrilaterals.

The three-dimensional interpretation of two-dimensional images was studied by using quadrilateral patterns, and some relationships between their structure, depth, and shape interpretations were analyzed under various viewing conditions. We defined rectangular and nonrectangular viewing conditions as follows: the viewing condition in which the quadrilateral, including parallel sides, could be a projection from a rectangle and the viewing condition in which it could not be so. For 9 subjects, 10 measurements were made in each experiment. Analysis showed that a pair of parallel sides of a quadrilateral were viewed as parallel to the viewer's forehead when the sides were horizontal in the image plane and were seen as slanting in depth if they were slanted in the image plane. The quadrilateral composed of parallel and nonparallel sides was perceived as rectangular when viewed with foveal vision even though under the nonrectangular viewing condition, if that viewing condition was not so different from the rectangular viewing condition. The quadrilateral did not appear to be rectangular when viewed in peripheral vision even though the rectangular viewing condition was used.

Attention↗
PubMed1978

[A study on serum level and urinary excretion of fosfomycin-Na in man with special reference to pharmacokinetic analysis (author's transl)].

FOM-Na was investigated on its distribution after a continuous intravenous drip infusion in 3 healthy adult volunteers, and its serum levels and urinary excretion were pharmacokinetically analyzed, while the excreted substance into urine was also analyzed with GC/MS. The results obtained are summarized as follows: 1. The distribution volume of FOM-Na in one-compartment open model was 0.183 L/kg, half life in human body 1.66 hours and renal clearance 0.0737 L/hr/kg. 2. With these pharmacokinetic constants, the mean values following various doses demonstrated almost equal irrespective of its dosage schedule, keeping an almost constant level in each individual tested. 3. The area under serum level-time curve was approximately 216 microgram.hr/ml per 1 g (potency), and increased in proportion to an infused dose within the range of 1 approximately 6 g (potency). Three consecutive administrations showed no trend of accumulation of the agent in the serum. 4. Urinary excretion of the agent was found to be very fast, and its recovery rate from urine within 10 approximately 11 hours after the completion of an i. v. drip infusion was approximately 95 approximately 99%. 5. As a result of GC/MS on the substance excreted into urine, it was noted that FOM-Na was not metabolized in human body and excreted into urine in its original form. 6. There was seen no specific change in electrocardiogram during and/or after an intravenous drip infusion in 1 hour of 2 g (potency) FOM-Na dissolved in a 300 ml 5% glucose solution.

Adult↗