David Waldman joined Loomis Sayles as a vice president and director of quantitative research, said spokeswoman Erin Heggerick. It is a new position. His responsibilities include developing systematic frameworks for analyzing fixed-income investment opportunities and building quantitative tools to support fixed-income portfolio construction, monitoring and strategy development. Mr. Waldman was a senior fixed-income portfolio manager and director of fixed-income quantitative research at Putnam Investments. Putnam spokeswoman Nancy Fisher said Mr. Waldmans responsibilities have been assumed by other members of Putnams fixed-income team.