Jing Xing

To what extent do moral judgments depend on conscious reasoning from explicitly understood principles? We address this question by investigating one particular moral principle, the principle of the double effect. Using web-based technology, we collected a large data set on individuals' responses to a series of moral dilemmas, asking when harm to innocent others is permissible. Each moral dilemma presented a choice between action and inaction, both resulting in lives saved and lives lost. Results showed that: (1) patterns of moral judgments were consistent with the principle of double effect and showed little variation across differences in gender, age, educational level, ethnicity, religion or national affiliation (within the limited range of our sample population) and (2) a majority of subjects failed to provide justifications that could account for their judgments. These results indicate that the principle of the double effect may be operative in our moral judgments but not open to conscious introspection. We discuss these results in light of current psychological theories of moral cognition, emphasizing the need to consider the unconscious appraisal system that mentally represents the causal and intentional properties of human action.

Aneuploidy with chromosome instability is a cancer hallmark. We studied chromosome 7 copy number variation in gliomas and in primary cultures derived from them. We found tumor heterogeneity with cells having Chr7-CNV commonly occurs in gliomas, with a higher percentage of cells in high-grade gliomas carrying more than 2 copies of Chr7, as compared to low-grade gliomas. Interestingly, all Chr7-aneuploid cell types in the parental culture of established glioma cell lines reappeared in single-cell-derived subcultures. We then characterized the biology of three syngeneic glioma cultures dominated by different Chr7-aneuploid cell types. We found phenotypic divergence for cells following Chr7 missegregation, which benefited overall tumor growth in vitro and in vivo. Mathematical modeling suggested the involvement of chromosome instability and interactions among cell subpopulations in restoring the optimal equilibrium of tumor cell types. Both our experimental data and mathematical modeling demonstrated that the complexity of tumor heterogeneity could be enhanced by the existence of chromosomes with structural abnormality, in addition to their mis-segregations. Overall, our findings show, for the first time, the involvement of chromosome instability in maintaining tumor heterogeneity, which underlies the enhanced growth, persistence and treatment resistance of cancers. © 2013 Hu et al.