Authors: Lawrence LM, Stone MR, Rainham DG, Keats MR Journal: Int J Behav Med. 2016 Jun 30 Link to full article Abstract Purpose Physical activity (PA) is an effective intervention for improving the quality of life of colorectal cancer survivors (CRC) and may reduce the risk of cancer recurrence and cancer specific and all-cause mortality. However, most CRC survivors are not sufficiently active to receive these benefits. Sedentary behavior (SB) has also been linked to morbidity and mortality risk independent of activity level, thereby presenting an additional opportunity to improve health outcomes of CRC survivors. The built environment is known to influence PA and SB; however, little is known about where CRC survivors engage in PA and SB. The objective of this exploratory study was to objectively identify locations where CRC survivors engage in PA and SB in order to inform health promoting interventions. Method Activity and location of CRC survivors (n = 31) was monitored for 1 week between January 2014 and April 2015 in Nova Scotia, Canada. Bouts of PA and SB were time-matched with GPS data to attribute bouts to specific geographic locations. Results Participants’ home environment was the main location for both time spent in PA bouts (73.7 %) and time spent in SB bouts (90.5 %). Conclusion This study is the first to objectively identify environments where CRC survivors are active and sedentary. These findings highlight the importance of considering the home environment when developing intervention strategies to increase PA and reduce SB in CRC survivors. Keywords Behavioral medicine; Built environment; Cancer survivorship; Colorectal cancer; GPS; Physical activity; Sedentary behavior

High-resolution genomic analysis of human mitochondrial RNA sequence variation. Journal: Science| Pages: 413-415 |Date: April 2014 | Authors: Hodgkinson A, Idaghdour Y, Gbeha E, Grenier JC, Hip-Ki E, Bruat V, Goulet JP, de Malliard T, Awadalla P. Mutations in the mitochondrial genome are associated with multiple diseases and biological processes; however, little is known about the extent of sequence variation in the mitochondrial transcriptome. By ultra-deeply sequencing mitochondrial RNA (>6000×) from the whole blood of ~1000 individuals from the CARTaGENE project, we identified remarkable levels of sequence variation within and across individuals, as well as sites that show consistent patterns of posttranscriptional modification. Using a genome-wide association study, we find that posttranscriptional modification of functionally important sites in mitochondrial transfer RNAs (tRNAs) is under strong genetic control, largely driven by a missense mutation in MRPP3 that explains ~22% of the variance. These results reveal a major nuclear genetic determinant of posttranscriptional modification in mitochondria and suggest that tRNA posttranscriptional modification may affect cellular energy production. http://www.ncbi.nlm.nih.gov/pubmed/24763589

Recombination affects accumulation of damaging and disease-associated mutations in human populations. Journal: Nature Genetics| Pages: 400-404 |Date: April 2015 | Authors: Julie G Hussin, Alan Hodgkinson, Youssef Idaghdour, Jean-Christophe Grenier, Jean-Philippe Goulet, Elias Gbeha, Elodie Hip-Ki, Philip Awadalla Many decades of theory have demonstrated that, in non-recombining systems, slightly deleterious mutations accumulate non-reversibly, potentially driving the extinction of many asexual species. Non-recombining chromosomes in sexual organisms are thought to have degenerated in a similar fashion; however, it is not clear the extent to which damaging mutations accumulate along chromosomes with highly variable rates of crossing over. Using high-coverage sequencing data from over 1,400 individuals in the 1000 Genomes and CARTaGENE projects, we show that recombination rate modulates the distribution of putatively deleterious variants across the entire human genome. Exons in regions of low recombination are significantly enriched for deleterious and disease-associated variants, a signature varying in strength across worldwide human populations with different demographic histories. Regions with low recombination rates are enriched for highly conserved genes with essential cellular functions and show an excess of mutations with demonstrated effects on health, a phenomenon likely affecting disease susceptibility in humans. http://www.ncbi.nlm.nih.gov/pubmed/25685891

Cohorts and consortia conference: a summary report (Banff, Canada, June 17-19, 2009) Journal: Cancer Causes Control | Pages: 463-468 | Date: March 2011 | Authors: Boffetta P, Colditz GA, Potter JD, Kolonel L, Robson PJ, Malekzadeh R, Seminara D, Goode EL, Yoo KY, Demers P, Gallagher R, Prentice R, Yasui Y, O’Doherty K, Petersen GM, Ulrich CM, Csizmadi I, Amankwah EK, Brockton NT, Kopciuk K, McGregor SE, Kelemen LE. Epidemiologic studies have adapted to the genomics era by forming large international consortia to overcome issues of large data volume and small sample size. Whereas both cohort and well-conducted case-control studies can inform disease risk from genetic susceptibility, cohort studies offer the additional advantages of assessing lifestyle and environmental exposure-disease time sequences often over a life course. Consortium involvement poses several logistical and ethical issues to investigators, some of which are unique to cohort studies, including the challenge to harmonize prospectively collected lifestyle and environmental exposures validly across individual studies. An open forum to discuss the opportunities and challenges of large-scale cohorts and their consortia was held in June 2009 in Banff, Canada, and is summarized in this report.   http://www.ncbi.nlm.nih.gov/pubmed/21203821

Exploring statistical approaches to diminish subjectivity of cluster analysis to derive dietary patterns: The Tomorrow Project. Journal: Am J Epidemiol | Pages: 956-967 | Date: April 2011 | Authors: Lo Siou G, Yasui Y, Csizmadi I, McGregor SE, Robson PJ. Dietary patterns derived by cluster analysis are commonly reported with little information describing how decisions are made at each step of the analytical process. Using food frequency questionnaire data obtained in 2001-2007 on Albertan men (n = 6,445) and women (n = 10,299) aged 35-69 years, the authors explored the use of statistical approaches to diminish the subjectivity inherent in cluster analysis. Reproducibility of cluster solutions, defined as agreement between 2 cluster assignments, by 3 clustering methods (Ward’s minimum variance, flexible beta, K means) was evaluated. Ratios of between- versus within-cluster variances were examined, and health-related variables across clusters in the final solution were described. K means produced cluster solutions with the highest reproducibility. For men, 4 clusters were chosen on the basis of ratios of between- versus within-cluster variances, but for women, 3 clusters were chosen on the basis of interpretability of cluster labels and descriptive statistics. In comparison with those in other clusters, men and women in the “healthy” clusters by greater proportions reported normal body mass index, smaller waist circumference, and lower energy intakes. The authors’ approach appeared helpful when choosing the clustering method for both sexes and the optimal number of clusters for men, but additional analyses are required to understand why it performed differently for women. http://www.ncbi.nlm.nih.gov/pubmed/21421742