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Poor nutrition during critical growth phases may alter the structural and physiologic development of vital organs thus “programming” the susceptibility to adult-onset diseases and disease-related health conditions. Epigenome-wide association studies have been performed in birth-weight discordant twin pairs to find evidence for such “programming” effects, but no significant results emerged. We further investigated this issue using a new computational approach: Instead of probing single genomic sites for significant alterations in epigenetic marks, we scan for differentially methylated genomic regions. Whole genome DNA methylation levels were measured in whole blood from 150 pairs of adult identical twins discordant for birth-weight. Intrapair differential DNA methylation was associated with qualitative (large or small) and quantitative (percentage) birth-weight discordance at each genomic site using regression models adjusting for age and sex. Based on the regression results, genomic regions with consistent alteration patterns of DNA methylation were located and tested for significant robustness using computational permutation tests. This yielded an interesting genomic region on chromosome 1, which is significantly differentially methylated for quantitative birth-weight discordance. The region covers two genes (TYW3 and CRYZ) both reportedly associated with metabolism. We conclude that prenatal conditions for birth-weight discordance may result in persistent epigenetic modifications potentially affecting even adult health.

In the past decades, many countries have suffered from serious blackouts which demonstrate catastrophic consequences caused by rare events in power systems. To address the emerged issues, the contingency screening and ranking should consider the risks of potential failures instead of the associated probabilities of following-up failures alone. However, it is computationally infeasible to evaluate all possible cascading failure sequences beforehand. Thus, fast risk assessment method should be developed to enhance computation efficiency while maintaining acceptable accuracy. In this paper, based on distribution factors and pre-contingency power flow conditions, a novel risk index is proposed to quickly assess the consequences of possible cascading failures. Then creditable cascading failure sequences can be determined and ranked according to the risk index. In addition, case studies on the IEEE-118 bus system show that the computational efficiency of the proposed cascading assessment method can be greatly enhanced with satisfactory accuracy, indicating a high potential of practical implementation.