A refresh circuit is used for refreshing or masking from refresh non-contiguous subarrays in an integrated circuit memory array. A check valve is positioned over an opening of the elongate tube and includes a valve member having a biased closed position wherein an internal volume defined by the lumen is fluidly blocked from an exterior of the elongate tube at the opening and an open position defining a fluid path from the exterior to the internal volume through the opening. Then, determining that the help feature has been presented a predetermined number of times; and as a result disabling the help feature. A special posture modifying chair and head-orienting glasses may be used instead of or in addition to unevenly applied weights.