1 Leptin is a powerful and influential hormone produced by your fat cells. 2  It plays a key role in regulating energy intake and energy expenditure.
(Upgrades are not available on fares in the L, T, and U range, however, which are the most deeply discounted.) To calculate the price of an upgrade, Delta charges a dollar amount per 500 miles. $50: Up to 500 miles. $75: 501-1000 miles. $100: 1001-1500 miles.
One of Delta's riskier cost-cutting moves, buying an oil refinery, looks like it's starting to pay off. Delta bought the refinery, which is in Trainer, Pa., just outside of Philadelphia, in 2012 for $150 million as a way to hedge against its biggest expense, jet fuel costs.The idea was to become a price influencer, Delta CEO Richard Anderson said.ut after losing a combined $136 million in the previous nine months, the Trainer refinery turned a profit for the first time in the third quarter, bringing in $3 million. As a result, the price Delta paid for a gallon of jet fuel dropped 5.4 percent to $2.97 during the quarter.