Infant Mortality as a Potential Measure of Community Health in Urban Growth

This document is one of a series which contains the results of research carried out during a 1969 Summer Study of Urban Decentralization at the Oak Ridge National Laboratory, sponsored by the Department of Housing and Urban Development and the U.S. Atomic Energy Commission. The summary of the Summer Study is contained in "An Introduction to Urban Decentralization Research," ORNL-HUD-3.

Health and Growth: Causality through Education

Purpose--The paper theoretically and empirically investigates the impact on human capital investment decisions and income growth of lowered life expectancy as a result of HIV/AIDS and other diseases. Design/methodology/approach--The theoretical model is a three-period overlapping generations model where individuals go through three stages in their life, namely, young, adult and old. The model extends existing theoretical models by allowing the probability of premature death to differ for individuals at different life stage, and by allowing for stochastic technological advances. The empirical investigation focuses on the effect of HIV/AIDS on life expectancy and on the role of health on educational investments and growth. We address potential endogeneity by using various strategies, such as controlling for country specific time-invariant unobservables and by using the male circumcision rate as an instrumental variable for HIV/AIDS prevalence. Findings--We show theoretically that an increased probability of premature death leads to less investment in human capital, and consequently slower growth. Empirically we show that HIV/AIDS has resulted in a substantial decline in life expectancy in African countries and these falling life expectancies are indeed associated with lower educational attainment and slower economic growth world wide. Originality/value--The theoretical and empirical findings reveal a causal link flowing from health to growth, which has been largely overlooked by the existing literature. The main implication is that health investments, that decrease the incidence of diseases like HIV/AIDS resulting on increases in life expectancy, through its complementarity with human capital investments lead to long run growth..

Preparation and evaluation of the electrospun chitosan/PEO fibers for potential applications in cartilage tissue engineering

Fibrous materials have morphological similarities to natural cartilage extracellular matrix and have been considered as candidate for bone tissue engineering scaffolds. In this study, we have evaluated a novel electrospun chitosan mat composed of oriented sub-micron fibers for its tensile property and biocompatibility with chondrocytes (cell attachment, proliferation and viability). Scanning electronic microscope images showed the fibers in the electrospun chitosan mats were indeed aligned and there was a slight cross-linking between the parent fibers. The electrospun mats have significantly higher elastic modulus (2.25 MPa) than the cast films (1.19 MPa). Viability of cells on the electrospun mat was 69% of the cells on tissue-culture polystyrene (TCP control) after three days in culture, which was slightly higher than that on the cast films (63% of the TCP control). Cells on the electrospun mat grew slowly the first week but the growth rate increased after that. By day 10, cell number on the electrospun mat was almost 82% that of TCP control, which was higher than that of cast films (56% of TCP). The electrospun chitosan mats have a higher Young’s modulus (P <0.01) than cast films and provide good chondrocyte biocompatibility. The electrospun chitosan mats, thus, have the potential to be further processed into three-dimensional scaffolds for cartilage tissue repair.