Environment and Obesity in the National Children\u27s Study

Objective: In this review we describe the approach taken by the National Children’s Study (NCS), a 21-year prospective study of 100,000 American children, to understanding the role of environmental factors in the development of obesity. Data sources and extraction: We review the literature with regard to the two core hypotheses in the NCS that relate to environmental origins of obesity and describe strategies that will be used to test each hypothesis. Data synthesis: Although it is clear that obesity in an individual results from an imbalance between energy intake and expenditure, control of the obesity epidemic will require understanding of factors in the modern built environment and chemical exposures that may have the capacity to disrupt the link between energy intake and expenditure. The NCS is the largest prospective birth cohort study ever undertaken in the United States that is explicitly designed to seek information on the environmental causes of pediatric disease. Conclusions: Through its embrace of the life-course approach to epidemiology, the NCS will be able to study the origins of obesity from preconception through late adolescence, including factors ranging from genetic inheritance to individual behaviors to the social, built, and natural environment and chemical exposures. It will have sufficient statistical power to examine interactions among these multiple influences, including gene–environment and gene–obesity interactions. A major secondary benefit will derive from the banking of specimens for future analysis

BODY WEIGHT AND COGNITIVE DECLINE IN MCI

Abstract Objective: To examine body mass index (BMI) and cognitive decline in subjects diagnosed with mild cognitive impairment (MCI). Methods: Neuropsychological testing was conducted of 286 MCI subjects. General estimating equations (GEE) assessed the relationships of baseline BMI with one-year change in global cognition. Logistic GEE assessed the relationship of BMI with a clinically significant decline in assessments of global cognition and conversion to Alzheimer's disease (AD). Results: Baseline BMI was associated with a significant decline in cognitive performance in MCI. We observed that a low baseline BMI as associated with an increased risk of a clinically significant decline in global cognition. No association between baseline BMI and conversion to AD was observed. Conclusions: Lower BMI is associated with a more rapid decline in cognition in MCI. This relationship suggests changes in metabolism are present in MCI or body composition may influence the rate of cognitive decline in MCI

Genome resequencing reveals multiscale geographic structure and extensive linkage disequilibrium in the forest tree Populus trichocarpa

This is the publisher’s final pdf. The article is copyrighted by the New Phytologist Trust and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291469-8137. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work.•Plant population genomics informs evolutionary biology, breeding, conservation and bioenergy feedstock development. For example, the detection of reliable phenotype–genotype associations and molecular signatures of selection requires a detailed knowledge about genome-wide patterns of allele frequency variation, linkage disequilibrium and recombination.\ud •We resequenced 16 genomes of the model tree Populus trichocarpa and genotyped 120 trees from 10 subpopulations using 29 213 single-nucleotide polymorphisms.\ud •Significant geographic differentiation was present at multiple spatial scales, and range-wide latitudinal allele frequency gradients were strikingly common across the genome. The decay of linkage disequilibrium with physical distance was slower than expected from previous studies in Populus, with r² dropping below 0.2 within 3–6 kb. Consistent with this, estimates of recent effective population size from linkage disequilibrium (N[subscript e] ≈ 4000–6000) were remarkably low relative to the large census sizes of P. trichocarpa stands. Fine-scale rates of recombination varied widely across the genome, but were largely predictable on the basis of DNA sequence and methylation features.\ud •Our results suggest that genetic drift has played a significant role in the recent evolutionary history of P. trichocarpa. Most importantly, the extensive linkage disequilibrium detected suggests that genome-wide association studies and genomic selection in undomesticated populations may be more feasible in Populus than previously assumed

Body Mass Index and Cognitive Decline in Mild Cognitive Impairment

This is the author's accepted manuscript.Objective To examine the relationship between body mass index (BMI) and cognitive decline in subjects diagnosed with mild cognitive impairment (MCI). Methods Neuropsychologic and clinical evaluations were conducted at baseline, 6-months, and 1-year on 286 MCI subjects enrolled in the Alzheimer’s Disease Neuroimaging Initiative. A global cognitive composite score was derived (mean Z-score) from performance on 9 neuropsychologic subtests. Height and weight were assessed at baseline and used to calculate BMI. Generalized estimating equations (linear and logistic) assessed the relationships of baseline BMI with cognitive outcomes, clinician judgment of “clinically significant decline” over 1-year, and diagnostic progression from MCI to Alzheimer disease. Results Lower baseline BMI was associated with significant declines in cognitive performance in individuals with MCI over 1 year (Mini-Mental State Examination, Alzheimer Disease Assessment Scale-Cognitive subscale, and a global cognitive composite; all P<0.05). We observed a significant protective effect of baseline BMI in reducing the risk of a clinically significant decline in Alzheimer Disease Assessment Scale-Cognitive subscale and mini-mental state examination (P<0.05). No association was found between BMI and changes in the clinical dementia rating sum of boxes or conversion to Alzheimer disease. Conclusions Lower baseline BMI is associated with more rapid cognitive decline in MCI. This relationship suggests either body composition may influence the rate of cognitive decline in MCI or factors related to MCI influence body composition

Taxonomic surrogacy in biodiversity assessments, and the meaning of Linnaean ranks

Copyright © 2006 The Natural History MuseumThe majority of biodiversity assessments use species as the base unit. Recently, a series of studies have suggested replacing numbers of species with higher ranked taxa (genera, families, etc.); a method known as taxonomic surrogacy that has an important potential to save time and resources in assesments of biological diversity. We examine the relationships between taxa and ranks, and suggest that species/higher taxon exchanges are founded on misconceptions about the properties of Linnaean classification. Rank allocations in current classifications constitute a heterogeneous mixture of various historical and contemporary views. Even if all taxa were monophyletic, those referred to the same rank would simply denote separate clades without further equivalence. We conclude that they are no more comparable than any other, non-nested taxa, such as, for example, the genus Rattus and the phylum Arthropoda, and that taxonomic surrogacy lacks justification. These problems are also illustrated with data of polychaetous annelid worms from a broad-scale study of benthic biodiversity and species distributions in the Irish Sea. A recent consensus phylogeny for polychaetes is used to provide three different family-level classifications of polychaetes. We use families as a surrogate for species, and present Shannon–Wiener diversity indices for the different sites and the three different classifications, showing how the diversity measures rely on subjective rank allocations.Y. Bertrand, F. Pleijel and G. W. Rous

A Cladistic Analysis of \u3cem\u3endh\u3c/em\u3eF Sequences from Representative Species of \u3cem\u3eSaintpaulia\u3c/em\u3e and \u3cem\u3eStreptocarpus\u3c/em\u3e Subgenera and \u3cem\u3eStreptocarpella\u3c/em\u3e (Gesneriaceae)

Two African genera of the Gesneriaceae, Saintpaulia and Streptocarpus, are similar in many respects. Both genera have blue to purple flowers, pollen of similar shape and exine sculpting, embryos with one-celled uninucleate chalazal haustoria, shared vegetative structures among some species, and are among the few genera in the Gesneriaceae which include species with chromosome count of n=15. Similarity of these features has indicated that the two genera are likely to be closely related. This study examines the sequences of the chloroplast gene ndhF among several representative Saintpaulia and representatives of Streptocarpus subgenera Streptocarpella and Streptocarpus. The results of this analysis are congruent with those of previous analysis based on the nuclear ribosomal region, ITS. Saintpaulia was found to be nested within Streptocarpus and Streptocarpella. The results raise the possibility of the taxonomic revision of these genera, and this is discussed. Comparisons between the data sets are made regarding utility of the two regions, sample size and outgroup

Adaptation of a Lay Health Advisor Model as a Recruitment and Retention Strategy in a Clinical Trial of College Student Smokers

This study describes and provides results from a process evaluation of a lay health advisor (LHA) model to enhance participation in a clinical trial of the effectiveness of motivational interviewing on smoking cessation in college fraternity and sorority members. The implementation of the model had two phases: (a) the selection and training of LHAs as liaisons between research staff and participants and (b) LHAs’ roles in recruitment and retention. Perceptions of the LHA model were explored using survey questionnaires. Trial participants (N = 118) and LHAs (N = 8) were generally satisfied with the model and identified LHAs as helpful to participation. Seventy-four percent of chapter members were screened and 73% of participants received three of the four motivational interviewing sessions. These results indicate the LHA model was well received and met the needs of the research project

Timeline Follow-Back Versus Global Self-Reports of Tobacco Smoking: A Comparison of Findings With Non-Daily Smokers

Methods assessing non-daily smoking are of concern because biochemical measures can not verify self-reports beyond 7 days. This study compares two self-reported smoking measures for non-daily smokers. A total of 389 college students, (48% female, 96% white, mean age of 19) smoking between 1 and 29 days out of the past 30, completed computer assessments in three cohorts with the order of administration of the measures counterbalanced. Values from the two measures were highly correlated. Comparisons of Timeline Follow-Back (TLFB) with the global questions for the total sample of non-daily smokers yielded statistically significant differences (p\u3c.001), albeit small, between measures with the TLFB resulting on average in 2.38 more total cigarettes smoked out of the past 30 days, 0.46 less smoking days, and 0.21 more cigarettes smoked per day. Analyses by level of smoking showed that the discordance between the measures differed by frequency of smoking. Global questions of days smoked resulted in frequent reporting in multiples of five days, suggesting digit bias. Overall the two measures of smoking were highly correlated and equally effective for identifying any smoking in a 30-day period among non-daily smokers

Motivational Interviewing for Smoking Cessation in College Students: A Group Randomized Controlled Trial

Objective—To examine the efficacy of four individually-delivered Motivational Interviewing counseling sessions for smoking cessation versus a matched intensity comparison condition. Method—From 2006–2009, students attending college in the Midwest smoking at least 1 of 30 days were recruited regardless of their interest in quitting. 30 fraternities and sororities were randomized, resulting in 452 participants. Results—No significant differences were found for 30-day cessation between treatment and comparison at end of treatment (31.4% vs 28%, OR=1.20, 95% CI .72,1.99) or at follow-up (20.4% vs 24.6%, OR=.78, 95% CI .50,1.22). Predictors of cessation at follow-up, regardless of condition, included more sessions attended (OR 1.2, 95% CI 1.1,1.8) and more cigarettes smoked in 30 days at baseline (OR 4.7, 95% CI 2.5,8.9). The odds of making at least one quit attempt were significantly greater for those in the smoking group at end of treatment (OR 1.75, 95% CI 1.11,2.74) and followup (OR 1.66, 95% CI 1.11,2.47). Modeling showed reduction in days smoked for both groups. At end of treatment, more frequent smokers in the treatment condition had greater reductions in days smoked. Conclusion—Motivational Interviewing for smoking cessation is effective for increasing cessation attempts and reducing days smoked in the short run