A note on tests for relevant differences with extremely large sample sizes

A well‐known problem in classical two‐tailed hypothesis testing is that P‐values go to zero when the sample size goes to infinity, irrespectively of the effect size. This pitfall can make the testing of data consisting of large sample sizes potentially unreliable. In this note, we propose to test for relevant differences to overcome this issue. We illustrate the proposed test on a real data set of about 40 million privately insured patients.     

Impact of a multimodal exercise program on tibial bone health in adolescents with Development Coordination Disorder: an examination of feasibility and potential efficacy

Objectives:Developmental coordination disorder (DCD) compromises bone health purportedly due to lower levels of physical activity. The potential of an exercise intervention to improve bone health parameters in adolescents with DCD has not previously been studied. This study thus aimed to determine the impact of a multimodal exercise intervention on bone health in this population at-risk of secondary osteoporosis.Methods:Twenty-eight adolescents (17 male, 11 female) aged between 12-17 years (M_age=14.1) with DCD participated in a twice weekly, 13-week generalised multimodal exercise intervention. Peripheral quantitative computed tomography scans of the tibia (4% and 66%) were performed over a six month period. Generalised estimating equations were used to examine the impact of fitness measures on bone parameters over time.Results:An overall improvement trend was observed for bone health, with significant increases at the 66% tibial site for bone mass (4.12% increase, d_cohen=0.23, p=0.010) and cortical area (5.42% increase, η² =12.09, p=0.014). Lower body fitness measures were significantly associated with improvements in bone health parameters, tempered by the degree of motor impairment.Conclusion:A multimodal exercise intervention may be effective in improving bone health of adolescents with DCD. Given the impact of motor impairments, gains may be greater over an extended period of study.     

Chemical screening identifies an extract from marine Pseudomonas sp.-PTR-08 as an anti-aging agent that promotes fission yeast longevity by modulating the Pap1–ctt1+ pathway and the cell cycle

Molecular Biology Reports - Aging is a degenerative process characterized by progressive deterioration of cellular components, ultimately resulting in mortality, in which massive accumulation of...     

Developing CRISPR-based sex-ratio distorters for the genetic control of fruit fly pests: A how to manual

Agricultural pest control using genetic-based methods provides a species-specific and environmentally harmless way for population suppression of fruit flies. One way to improve the efficiency of such methods is through self-limiting, female-eliminating approaches that can alter an insect populations' sex ratio toward males. In this microreview, we summarize recent advances in synthetic sex ratio distorters based on X-chromosome shredding that can induce male-biased progeny. We outline the basic principles to guide the efficient design of an X-shredding system in an XY heterogametic fruit fly species of interest using CRISPR/Cas gene editing, newly developed computational tools, and insect genetic engineering. We also discuss technical aspects and challenges associated with the efficient transferability of this technology in fruit fly pest populations, toward the potential use of this new class of genetic control approaches for pest management purposes.     

The influence of analogs of xanthine on the mutagenic effect of ultraviolet light

Summary Eight compounds can be added to those purine analogs which give synergistic effects with ultraviolet light: 1,3,7,9-tetra-methylxanthine methyl sulfate, 8-chlorocaffeine, ethyltheophylline, 6-dimethylaminopurine, 6-methoxypurine, 8-ethoxycaffeine, 1,3-dimethyl uric acid and 3-methyl uric acid. It appears likely that these are merely representatives of the class of methyl purines, and that other compounds are also active. The synergistic activity varies among the compounds investigated; some give a synergistic effect slightly higher than caffeine, but apparently act by the same mechanism. The height of effect of all of the synergistic purine analogs has been correlated with the stability of the structures determined by inductive effects and steric hindrance. The lack of activity with pyrimidines (l-methyl thymine and 1,3-dimethyluracil) leads to the conclusion that both rings (7,8,9 positions) of the purine molecule are necessary for the synergistic effect.This work was supported by the National Institutes of Health Research Grant AI-05340, the University of Kansas General Research Fund, and an N.I.H. Training Grant (5 T1 GM-703) to the Department of Microbiology.