Methods and systems are provided that authenticate an intended user of a mobile client in a roaming environment. In a state in which the flow velocity of intake air passing through the intake valve becomes almost sound velocity, a difference in the intake air amount in the right and left banks is detected and, to reduce the difference, a correction value for a target value of a valve lift is set for each of the banks. Moreover, an actuating switch is mounted to the carrying body to start a motor to pump the fluid to a cultivation space via the tube. The invention also provides a model animal with diabetic maculopathy produced by subjecting a diabetic animal to intraocular ischemiareperfusion to express edema in a retinal visual cell layer or in a macula lutea.