Early parental loss, socioeconomic stressors, and health in later life: Evidence for gender disparity

Drawing from the stress process model and the cumulative disadvantage theory, this dissertation examined how childhood and later life stressors affected cognitive and subjective health in older adults. Using three main articles, this dissertation investigated (1) the effect of early parental loss on cognitive well-being in Chinese oldest old; (2) the effect of intergenerational socioeconomic mobility on cognitive and subjective health in advanced age; and (3) the effect of different dimensions of socioeconomic status and perceived financial strain on subjective health in later life. Data were derived from the 2002 and 2005 waves of the Chinese Longitudinal Healthy Longevity Survey. Ordinary least squares models and logistic regression models were used to estimate the stress-health association. Key findings of this dissertation include (1) losing a mother in early life predicted worse cognitive function in oldest old men; (2) experiencing downward intergenerational socioeconomic mobility was detrimental to cognitive and subjective health in advanced age, especially in oldest old women; and (3) perceived financial strain was associated with an elevated risk of reporting poor health for both urban and rural inhabitants. Findings of this dissertation suggest that traumatic events in early life and socioeconomic stressors in later life both exact a toll on Chinese older adults’ health, independent of their demographic characteristics and physical health conditions. This dissertation has policy implications for gender-specific healthcare

Computational study of red cell distribution in simple networks

The distribution of red blood cells (RBC) across the vessel lumen is disturbed when blood flows through a junction. As the blood flows downstream from the junction, the RBC distribution corrects itself to regain its original symmetric character. A dispersion-type process has been used to model this rearrangement process in 3-dimensional branching tubes. In this study, the disturbance in the RBC profile is quantified by tracing streamlines through the junction. The tracing technique is based on scaled-up dye studies. The computation starts at a location where the velocity profile is fully developed. Both uniform and parabolic RBC profiles are examined as possible, final symmetric distributions for the computations. Three velocity profiles are used alternatively. The dispersion convective equation of continuity in cylindrical geometry is solved with the method of finite differences. The resulting RBC concentration profiles is then used to compute flux-flow curves which are frequently used to examine plasma skimming phenomena. The numerically computed flux-flow curves are compared to in vitro experimental data from 50 $\mu$m serial bifurcation replicas. The dispersion coefficient is used as an adjustable parameter to give the best match between computation and measurement. The averaged dispersion coefficients obtained agree with previous experimental data and show an enhanced dispersion. Simple vascular networks are generated and the dispersion model is further applied to the networks. By calculating the discharge hematocrit of each branch vessel in the network the network Fahraeus effect is observed. Influences of flow disturbance to the downstream hematocrit are examined. The effects of flow heterogeneity and the dispersion model on the hematocrit heterogeneity are presented