This article reports findings of a meta-analytical study of research on distance education. The purpose of this study was to identify factors that affect the effectiveness of distance education. The results show that although the aggregated data of available studies show no significant difference in outcomes between distance education and face-to-face education as previous research reviews suggest, there is remarkable difference across the studies. Further examination of the difference reveals that distance education programs, just like traditional education programs, vary a great deal in their outcomes, and the outcome of distance education is associated with a number of pedagogical and technological factors. This study led to some important data-driven suggestions for and about distance education.

Marketers cultivate brand relatedness in their brand portfolios to increase marketing efficiency through positive spillover of brand equity. However, creating linkages between brands may also make them vulnerable to negative spillover. This research investigates the structure of relatedness in a brand portfolio to understand the nature of spillover effects. The results of two experiments show that the magnitude of spillover between brands is a function of not only the strength of brand associations but also their directionality. The results also show that the directional strength of association is influenced by the number and salience of associations linked to each brand. The authors draw implications for a theoretical understanding of spillover effects in marketing, as well as for the management of brand portfolios.

No abstract

No abstract

No abstract

No abstract

No abstract

Stem cell therapy holds great promise for the replacement of damaged or dysfunctional myocardium. Nitric oxide (NO) has been shown to promote embryonic stem (ES) cell differentiation in other systems. We hypothesized that NO, through NO synthase gene transfer or exogenous NO exposure, would promote the differentiation of mouse ES cells into cardiomyocytes (CM). In our study, NO treatment increased both the number and the size of beating foci in embryoid body (EB) outgrowths. Within 2 weeks, 69% of the inducible NO synthase-transduced EB displayed spontaneously beating foci, as did 45% of the NO donor-treated EB, compared with only Ϸ15% in controls. Cardiac-specific genes and protein expression were significantly increased in NO-treated ES. Electron microscopy and immunocytochemistry revealed that these NOinduced contracting cells exhibited characteristics consistent with CM. At day 7 in culture, troponin T was expressed in 45.6 ؎ 20.6% of the NO-treated ES cells but in only 9.25 ؎ 1.77% of control cells. Interestingly, 50.4 ؎ 18.4% of NO-treated ES cells were troponin T-negative and annexin V-positive. This apoptotic phenotype was seen in <1% of the control ES cells. These data strongly support our hypothesis that mouse ES cells can be accelerated to differentiate into CM by NO treatment. NO may influence cardiac differentiation by both inducing a switch toward a cardiac phenotype and inducing apoptosis in cells not committed to cardiac differentiation.