A computer system includes a holder attached to a housing of a pen-based computer. The aqueous ink ensures that the ejection accuracy in inkjet recording is excellent and helps suppress generation of density unevenness and streak unevenness, even after storage for a long period of time or exposure to high temperatures. The mounting member may further have a power plug to supply power and mounting posts to secure the hand-held GPS unit. The current invention includes specific tools that enable safe tissue modification in the epidural space, including a barrier that separates the area where tissue modification will take place from adjacent vulnerable neural and vascular structures. The novel repressor can be used in cells where a noncanical NF-\u03baB activity is dominant or multiple NF-\u03baB activities are activated.