Entropy, Ergodicity and Stem Cell Multipotency

Populations of mammalian stem cells commonly exhibit considerable cell-cell variability. However, the functional role of this diversity is unclear. Here, we analyze expression fluctuations of the stem cell surface marker Sca1 in mouse hematopoietic progenitor cells using a simple stochastic model and find that the observed dynamics naturally lie close to a critical state, thereby producing a diverse population that is able to respond rapidly to environmental changes. We propose an information-theoretic interpretation of these results that views cellular multipotency as an instance of maximum entropy statistical inference.Comment: 6 pages, 3 figure

The (behavioral) science behind baby milk formula

op-ed/commentary http://www.straitstimes.com/opinion/the-behavioural-science-behind-baby-milk-formula</p

How do small business innovate and improve competitiveness

https://www.smu.edu.sg/sites/default/files/smu/news_room/smu_in_the_news/2018/Mar2018/Mar29/20180329-ZB-SME-33-22x37.pdf</p

Multistable and multistep dynamics in neutrophil differentiation

BACKGROUND: Cell differentiation has long been theorized to represent a switch in a bistable system, and recent experimental work in micro-organisms has revealed bistable dynamics in small gene regulatory circuits. However, the dynamics of mammalian cell differentiation has not been analyzed with respect to bistability. RESULTS: Here we studied how HL60 promyelocytic precursor cells transition to the neutrophil cell lineage after stimulation with the differentiation inducer, dimethyl sulfoxide (DMSO). Single cell analysis of the expression kinetics of the differentiation marker CD11b (Mac-1) revealed all-or-none switch-like behavior, in contrast to the seemingly graduated change of expression when measured as a population average. Progression from the precursor to the differentiated state was detected as a discrete transition between low (CD11b(Low)) and high (CD11b(High)) expressor subpopulations distinguishable in a bimodal distribution. Hysteresis in the dependence of CD11b expression on DMSO dose suggests that this bimodality may reflect a bistable dynamic. But when an "unswitched" (CD11b(Low)) subpopulation of cells in the bistable/bimodal regime was isolated and cultured, these cells were found to differ from undifferentiated precursor cells in that they were "primed" to differentiate. CONCLUSION: These findings indicate that differentiation of human HL60 cells into neutrophils does not result from a simple state transition of a bistable switch as traditionally modeled. Instead, mammalian differentiation appears to be a multi-step process in a high-dimensional system, a result which is consistent with the high connectivity of the cells' complex underlying gene regulatory network

Mirror, mirror on the retail wall: Self-focused attention promotes reliance on feelings in consumer decisions

Singapore MOE Academic Research Fund Tier

The impact of power on reliance on feelings versus reasons in decision making

Power and Reliance on Feelings versus Reasons in Consumer Decisions (with Yunhui Huang and Jiewen Hong), October 2016 Annual Association for Consumer Research Conference, Berlin, Germany.</p