Pictures are commonly used to represent problems. However, it is unclear how the addition of pictures affects students’ problem-solving performance. The multimedia effect in problem solving describes the phenomenon whereby an individual’s problem-solving performance is enhanced when equivalent pictures are added to illustrate or replace part of the problem text. Using meta-analytic techniques, this study sought to determine the overall size of the multimedia effect in problem solving and the possible boundary conditions (k = 51; N = 38,987; Range n = 10 – 31,842; Median n = 63). The results showed a significant small-to-medium multimedia effect size on response accuracy (Hedges’s g = 0.32) and a significant medium-to-large multimedia effect size on students’ response certainty (Hedges’s g = 0.74), but no significant multimedia effect on response time. The results for the effects of decorative pictures were not sufficient for a reliable interpretation. Representational (Hedges’s g = 0.24) and organizational (Hedges’s g = 0.52) pictures had a significant and positive impact on response accuracy, but informational or multiple pictures across studies did not have a significant aggregate effect on an individual’s response accuracy. These findings suggest that the multimedia effect in problem solving is diverse and limited by multiple boundary conditions. Further primary studies are needed to further investigate the multimedia effect in problem solving.
Although microRNA-155(miR-155) is considered a pro-inflammatory mediator, cumulative evidence indicates that it also has anti-inflammatory effects in macrophages and dendritic cells. In this study, we identified the dramatic expression changes of more than half of potential miR-155-targeted genes upon lipopolysaccharide(LPS) stimulation; 223 genes were down-regulated and 85 genes were up-regulated, including suppressor of cytokine signaling 1(SOCS1) and transforming growth factor-β-activated kinase 1-binding protein 2(TAB2), two well-known genes involved in miR-155-mediated regulation of the Toll-like receptor 4(TLR4) signaling pathway. We also found that miR-155 acted as an anti-inflammatory mediator in the initial stage of LPS-induced inflammatory response mainly through repressing TAB2 protein translation, and as a proinflammatory mediator by down-regulating SOCS1 in the later stage. Meanwhile, overexpression of TAB2 3' untranslated region(UTR) in macrophages promoted the development of endotoxin tolerance by competing for binding with miR-155, which resulted in an elevated expression level of SOCS1 protein. These findings provide new insights for understanding the regulatory mechanisms in fine-tuning of LPS-induced innate immune response. 相似文献
