This issue of Heart Failure Clinics examines Heart Failure with Preserved Ejection Fraction (HFPEF). The followings aspects of HFPEF are addressed: epidemiology, etiologic factors and pathophysiology, diagnosis, clinical spectrum, imaging, invasive hemodynamic characterization, exercise physiology, natriuretic peptides, novel biomarkers, differential diagnoses and comorbidities, outcomes, clinical trials, current therapeutic approach, and novel therapeutic targets.

In this proceedings, recent development on various aspects of algebra and number theory were discussed. A wide range of topics such as group theory, ring theory, semi-group theory, topics on algebraic structures, class numbers, quadratic forms, reciprocity formulae were covered.