Social Networks among Elderly Women: Implications for Health Education Practice

The general aim of the present study was to examine and help clarify the properties of the distinctions between social networks and social support, their relationship to health status, and their impli cations for health education practice. More specifically, a secondary data analysis was conducted with 130 white women, community resi dents, between the ages of 60 and 68, which examined the relationship between psychological well-being and social network characteristics. These characteristics are categorized along three broad dimensions: structure—links in the overall network (size and density); interaction— nature of the linkages themselves (frequency, homogeneity, content, reciprocity, intensity, and dispersion); and functions which networks provide (affective support and instrumental support). A combination was made and relative strength investigated of several network char acteristics representative of the quality of interactions (i. e., reciprocal affective support, intensity, and affective support) and those repre senting the quantity of interactions (i.e., size, density, and frequency).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67277/2/10.1177_109019818301000304.pd

The multicatalytic compartment of propionyl-CoA synthase sequesters a toxic metabolite

International audienceCells must cope with toxic or reactive intermediates formed during metabolism. One coping strategy is to sequester reactions that produce such intermediates within specialized compartments or tunnels connecting different active sites. Here, we show that propionyl-CoA synthase (PCS), an ∼ 400-kDa homodimer, three-domain fusion protein and the key enzyme of the 3-hydroxypropionate bi-cycle for CO2 fixation, sequesters its reactive intermediate acrylyl-CoA. Structural analysis showed that PCS forms a multicatalytic reaction chamber. Kinetic analysis suggested that access to the reaction chamber and catalysis are synchronized by interdomain communication. The reaction chamber of PCS features three active sites and has a volume of only 33 nm3. As one of the smallest multireaction chambers described in biology, PCS may inspire the engineering of a new class of dynamically regulated nanoreactors