A Screw Surface of a Board

It seems that a theoretical and accurate method of making a screw surface of a board has not been known yet. Considering the property of an involute helicoid, the author has derived the theory on how to make a screw surface of a board, and succeeded in making a very accurate one by using this theory. This method has many advantageous points in comparison with some other methods which are known as for a work shop. Furthermore, the author thinks that this is only method of making an accurate screw surface of a board, since it is impossible theoretically to make that of a triangular thread and the like, of a board.Article信州大学工学部紀要 22: 1-12 (1967)departmental bulletin pape

Depth perception from second-order-motion stimuli yoked to head movement

AbstractWe examined whether depth perception was produced by the parallax of second-order motion (i.e., movement of non-luminance features, such as flicker, texture size modulation, or contrast modulation that moved in synchrony with lateral head movement). The results, obtained with second-order motion from a simple grating stimuli, showed that depth order was judged correctly with probabilities well above chance, but the reported depth magnitude did not co-vary with parallax magnitude. When we used a complex spatial pattern for which feature tracking was difficult, the accuracy of depth-order judgments descended to chance level. Our results suggest that the visual system (a) can detect the correct depth order by tracking a relative shift in the salient features of a stimulus pattern, but (b) cannot determine depth magnitude from a velocity field given by second-order-motion stimuli

Regulation of UDP-glucose:ceramide glucosyltransferase-1 by ceramide

AbstractWe report that the expression of mRNA and the activity of UDP-glucose:ceramide (Cer) glucosyltransferase-1 (GlcT-1) of human hepatoma Huh7 and mouse melanoma B16 cells increases after treatment with bacterial sphingomyelinase or upon addition of short-chain Cer. Interestingly, however, GlcT-1 gene transcription was not increased by Cer when GlcT-1 cDNA was introduced with the CMV promoter in GlcT-1-deficient GM95 cells, suggesting that the normal promoter region of GlcT-1 gene is essential for the response. The conversion of C6-Cer to C6-GlcCer occurred much more rapidly in GlcT-1-overexpressing Huh7 cells than in mock transfectants. As a result, GlcT-1-overexpressing cells acquired a greater resistance to C6-Cer-mediated cell death