The most talked about and market moving research calls around Wall Street are now in one place. Here are today's research calls that investors need to know, as compiled by The Fly.Top 5 Upgrades: Loop Capital upgraded Union Pacific (UNP) to Hold from Sell with a price target of $227, up from$214. With the shares down 5% year-to-date, Union Pacific's valuation multiples are now only modestly above the bottom of their five-year ranges, the firm tells investors in a research note.BofA upgraded Prologis (PLD) ...