Dollar General missed both earnings and sales estimates in its first quarter, but the stock is gaining Tuesday. The discount chain earned 72 cents a share, a penny short of estimates, while revenue of $4.52 billion came in around 1% lower than forecast. However, as retailer after retailer report tough sales conditions this quarter and predict continued trouble ahead, Dollar General sees improvement on the horizon. In a statement, the retailerâ€™s CEO said he sees positive trends gaining momentum towards the tail-end of the April-ended quarter. Where others have struggled over the year, the company has increased sales by adding brand-name products to its stores and opening up a number of new locations.