Abstract: Objects to be achieved are to provide a nerve cell with which it is possible to visualize and quantify the intracellular tau without using the exogenous promoter and to provide a pluripotent stem cell with which the nerve cell can be produced, to provide a method of screening a substance, including using the pluripotent stem cell or nerve cell described above, and a substance screened by the above method, and to provide a kit including a targeting vector and a gRNA. There is provided a pluripotent stem cell including a DNA encoding a reporter molecule, the DNA being introduced adjacent to an endogenous tau gene such that a tau protein is expressed as a fusion protein fused with a reporter molecule.

Abstract: An object of the present invention is to provide a nerve cell in which tau aggregation and cell death are caused; a screening kit and a screening method, in which the nerve cell is used; a drug candidate substance obtained by the screening method; a human pluripotent stem cell for producing the nerve cell; and a method of producing the nerve cell. There is provided a nerve cell having an introduced exogenous wild-type tau gene.

Abstract: The present invention provides a method for measuring an optimum seeking time and an inspection apparatus using this method capable of measuring and setting an optimum seeking time for inspection of a magnetic disk or magnetic head. The method samples average level differences of sector-wise read signals in positive and negative domains for one round of track and detects a minimum value H and a minimum value L among these differences. The method recalculates the seeking time while changing the settling time. After writing and reading test data, calculates a deviation DEV of average levels DEV=(H?L)/(H+L). The method is adapted to obtain a minimum one of the values of settling time having measured when the deviation DEV of average levels is equal to or less than a predetermined value as an optimum settling time or an optimum seeking time.

Abstract: In the present invention, an inspection area for sampled defect data is set which has a predetermined width in the radial direction of a magnetic disk and a length round the circle of the magnetic disk in the circumferential direction thereof or a predetermined length in the circumferential direction thereof, and while limiting the defect data in the inspection area and shifting a narrow and long search frame within the area, continuing defects in the region of the search frame are followed up and detected, thereby, only curved line shaped continuing defects having comparatively large curvature near to the circle of the magnetic disk are selectively detected and acquired as circle shaped defects.

Abstract: The present invention provides a method for measuring an optimum seeking time and an inspection apparatus using this method capable of measuring and setting an optimum seeking time for inspection of a magnetic disk or magnetic head. The method samples average level differences of sector-wise read signals in positive and negative domains for one round of track and detects a minimum value H and a minimum value L among these differences. The method recalculates the seeking time while changing the settling time. After writing and reading test data, calculates a deviation DEV of average levels DEV=(H?L)/(H+L). The method is adapted to obtain a minimum one of the values of settling time having measured when the deviation DEV of average levels is equal to or less than a predetermined value as an optimum settling time or an optimum seeking time.

Abstract: In the present invention, an inspection area for sampled defect data is set which has a predetermined width in the radial direction of a magnetic disk and a length round the circle of the magnetic disk in the circumferential direction thereof or a predetermined length in the circumferential direction thereof, and while limiting the defect data in the inspection area and shifting a narrow and long search frame within the area, continuing defects in the region of the search frame are followed up and detected, thereby, only curved line shaped continuing defects having comparatively large curvature near to the circle of the magnetic disk are selectively detected and acquired as circle shaped defects.