Disciplinary publications from 2018
Abstract
Conceptual and empirical work has long suggested that personality and health are closely intertwined later in life. Little is known, however, about the nature and direction of time-ordered associations between the 2 domains within-persons. We applied continuous time auto- and cross-effects models to up to 6 waves of 13-year longitudinal data from the Berlin Aging Study (N = 516, M = 84.92, SD = 8.66, age range 70 to 103) and examined time-ordered relations between personality traits (i.e., extraversion and neuroticism) and performance-based indicators of functional health (i.e., physical and sensory functioning) in late life. Consistent with proposals to distinguish the young-old (age 70 to 84) from the oldest-old (aged 85+) in later life, results suggest that predictive effects of neuroticism on functional health are stronger in younger as compared with older individuals. In contrast, health decrements precede and predict change in neuroticism in the oldest-old more strongly as compared with the young-old. In addition, we found that decreases in extraversion predict subsequent decreases in functional health and vice versa, with effects being equally pronounced among younger and older participants. Furthermore, by employing continuous time models we could demonstrate that the magnitude of these effects varies depending upon the time interval under consideration. These findings suggest that personality and functional health are closely intertwined in old and very old age, and that the nature of time-ordered associations differs between traits and age period. We discuss conceptual and practical implications.
Abstract
Gene expression in mitochondria of Plasmodium falciparum is essential for parasite survival. The molecular mechanisms of Plasmodium organellar gene expression remain poorly understood. This includes the enigmatic assembly of the mitochondrial ribosome from highly fragmented rRNAs. Here, we present the identification of clustered organellar short RNA fragments (cosRNAs) that are possible footprints of RNA-binding proteins (RBPs) in Plasmodium organelles. In plants, RBPs of the pentatricopeptide repeat (PPR) class produce footprints as a consequence of their function in processing organellar RNAs. Intriguingly, many of the Plasmodium cosRNAs overlap with 5'-ends of rRNA fragments. We hypothesize that these are footprints of RBPs involved in assembling the rRNA fragments into a functioning ribosome. A bioinformatics search of the Plasmodium nuclear genome identified a hitherto unrecognized organellar helical-hairpin-repeat protein family that we term heptatricopeptide repeat (HPR) proteins. We demonstrate that selected HPR proteins are targeted to mitochondria in P. berghei and that one of them, PbHPR1, associates with RNA, but not DNA in vitro. A phylogenetic search identified HPR proteins in a wide variety of eukaryotes. We hypothesize that HPR proteins are required for processing and stabilizing RNAs in Apicomplexa and other taxa.