Differing Methodologies Are Required to Estimate Prevalence of Dementia: Single Study Types Are No Longer Reliable.

Population-based surveys were used to estimate community prevalence of dementia, but have low response fractions due, among other things, to difficulties in obtaining informed consent from people with diminished capacity. Cohort studies of younger people are subject to recruitment bias and non-random drop-outs. Dementia registries can delineate sub-types of dementia but have limited population coverage and are costly to maintain.

Including ethnic minorities in dementia research: Recommendations from a scoping review.

Introduction: Ethnicity influences dementia etiology, prognosis, and treatment, while culture shapes help-seeking and care. Despite increasing population diversity in high-income settlement countries, ethnic minorities remain underrepresented in dementia research. We investigated approaches to enhance the recruitment, and consistent collection and analysis of variables relevant to, ethnic minorities in dementia studies to make recommendations for consistent practice in dementia research.

Sexual selection: signals to die for.

Sexual signals are conspicuous and are typically assumed to be energetically costly, which keeps them honest. A recent study on fireflies has found that signal production is energetically cheap, but signalling remains expensive because of eavesdropping predators.