Before revision:  The results obtained herein are remarkably different from those obtained in recent papers close-to-the-money option prices in that they aid in understanding how the behavior of implied volatility near expiry is affected by important model parameters , such as the leverage and vol vol parameters, that were not present in the aforementioned earlier results .
After revision:  The results obtained herein are remarkably different from those obtained in recent papers close-to-the-money option prices in that they aid in understanding how the implied volatility smile near expiry is affected by important model parameters , such as the leverage and vol vol parameters, that were not present in the aforementioned earlier results .