In this paper, we derive some sufficient second order optimality conditions for control problems of partial differential equations (PDEs) when the cost functional does not involve the usual quadratic term for the control or higher nonlinearities for it. Though not always, in this situation the optimal control is typically bang-bang. Two different control problems are studied. The second differs...

Abstract Background Obstructive Sleep Apnoea (OSA) is common yet often undiagnosed in older people as symptoms of fatigue and poor sleep are non-specific. OSA screening tools also lack validity patients. This study aims to review the clinical presentation, use treatment adherence people. Methods A retrospective cohort patients >65 years attending a tertiary clinic who underwent polysomno...