The Logistical Backbone of Photoreceptor Cell Function: Complementary Mechanisms of Dietary Vitamin A Receptors and Rhodopsin Transporters.

In this review, we outline our current understanding of the mechanisms involved in the absorption, storage, and transport of dietary vitamin A to the eye, and the trafficking of rhodopsin protein to the photoreceptor outer segments, which encompasses the logistical backbone required for photoreceptor cell function. Two key mechanisms of this process are emphasized in this manuscript: ocular and systemic vitamin A membrane transporters, and rhodopsin transporters. Understanding the complementary mechanisms responsible for the generation and proper transport of the retinylidene protein to the photoreceptor outer segment will eventually shed light on the importance of genes encoded by these proteins, and their relationship on normal visual function and in the pathophysiology of retinal degenerative diseases.

Gender Disparities in Healthy Aging: A Cross-National Comparative Study in the United States and South Korea from 2006 to 2016.

Using the 2006-2016 wave of Health and Retirement Study and Korean Longitudinal Study of Aging, this study explores the gender disparities in the health of older adults in the United States and South Korea. A logit model is adopted to explore the differences in the likelihood of aging healthily by gender in two countries. Results indicate that older females in the United States have a significantly higher probability of healthy aging than their male counterparts. However, the opposite finding is demonstrated among the older population in South Korea. These results are verified using various robustness check methods. The heterogeneities in the gender disparities in healthy aging across age groups and income levels are further explored. The gender effect in each healthy aging domain is investigated to understand the underlying causes of gender disparities. These findings can provide cross-national insights for policymakers to establish targeted aging policies with a gender perspective.