SYDNEY, May 13 (Reuters) - The Australian dollar was on therise again on Wednesday as improving risk appetite underminedthe U.S. dollar, to the benefit of higher-yielding currencies. * Aussie edges ahead to $0.7680 <AUD=D4>, not far fromrecent seven-month highs of $0.7714, having bounced from solidsupport around $0.7561 on Tuesday.