Linking longitudinal and cross-sectional biomarker data to understand host-pathogen dynamics: Leptospira in California sea lions (Zalophus californianus) as a case study. oleh K C Prager, Michael G Buhnerkempe, Denise J Greig, Anthony J Orr, Eric D Jensen, Forrest Gomez, Renee L Galloway, Qingzhong Wu, Frances M D Gulland, James O Lloyd-Smith