84 results on '"Robert W Davies"'
Search Results
2. Protecting habitats in low-intensity tropical farmland using carbon-based payments for ecosystem services
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Robert W Davies, Oscar Morton, David Lawson, John W Mallord, Luke Nelson, Kwame Boafo, Ieuan Lamb, and David P Edwards
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carbon-based payments for ecosystem services ,farmland habitats ,opportunity cost ,palearctic migrants ,land sharing ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Science ,Physics ,QC1-999 - Abstract
Tropical land-use change for agricultural expansion is the primary driver of global biodiversity decline. Efforts to stem this decline often focus on protecting pristine habitats or returning farmland to forest, yet such approaches fail to protect vulnerable taxa reliant on habitats within low-intensity farmland. We assess the economic viability of carbon-based payments for ecosystem services (PES) to protect farmland trees and fallowing in Ghana, which provide vital wintering sites for imperiled Afro-palearctic migrant birds and enhance landscape-level carbon storage. We estimate the carbon breakeven prices (BEPs) associated with alternative agricultural management scenarios that protect existing farmland trees. BEPs associated with tree protection on existing farmland were very low, ranging from US$2.49 to US$6.45 t ^−1 CO _2 . Extending and reintroducing fallow periods also carried competitive BEPs, US$4.67—US$15.45 t ^−1 CO _2 , when combined with the protection of 50 trees per hectare. Accounting for leakage and economic uncertainty increased BEPs considerably, but scenarios protecting farmland trees and extending fallow periods remained below EU Emissions Trading Scheme prices. Protecting low-intensity farmland habitats and associated biodiversity is cost-effective under carbon-based PES. Implementation should be combined with efforts to close yield gaps, providing greater local food security and resilience.
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- 2021
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3. The Effect of Unilateral Versus Bilateral Strength Training on Isometric-Squat Peak Force and Interlimb Asymmetry in Young, Recreationally Strength-Trained Men
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Arthur E. Lynch, Robert W. Davies, Joanna M. Allardyce, and Brian P. Carson
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Orthopedics and Sports Medicine ,Physical Therapy, Sports Therapy and Rehabilitation - Abstract
Purpose: To compare the effects of bilateral strength training (BLST) versus unilateral strength training (ULST) on changes in peak force (PF) and interlimb asymmetry (ILA) in the isometric squat at a 120° knee angle (ISq120). Method: A total of 31 young, recreationally strength-trained men performed either BLST (n = 18) or ULST (n = 13), twice per week for 6 weeks. The total number of repetitions, duty cycle, and effort were standardized between training groups (ie, differing only in the exercises performed). Changes in PF and ILA were assessed pretraining and posttraining. Results: Comparable increases in PF were observed in the BLST group (mean [SD] change; 17.4% [20.5%], P = .001, standardized mean difference [SMD] = 0.45) and the ULST group (11.4% [19.1%], P = .042, SMD = 0.25). No significant changes in symmetry index (SI) scores were observed following BLST (mean [SD] change; 0 [5.7], P = .526, SMD = −0.12) or ULST (+3 [6.0], P = .702, SMD = 0.4). Individual analyses of subjects with marked ILA (ie, baseline SI score > baseline coefficient of variation) revealed a trend toward BLST being more effective at attenuating SI scores in the ISq120. Conclusions: Overall, both BLST and ULST are effective for increasing ISq120 PF. However, it appears that BLST may be more effective at reducing SI scores in those with marked ILA.
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- 2023
4. The Influence of Maximal Strength and Knee Angle on the Reliability of Peak Force in the Isometric Squat
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Arthur E. Lynch, Robert W. Davies, Philip M. Jakeman, Tim Locke, Joanna M. Allardyce, and Brian P. Carson
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muscle strength ,isometric contraction ,measurement ,reproducibility of results ,strength testing ,Sports ,GV557-1198.995 - Abstract
This study aimed to investigate the test-retest reliability of peak force in the isometric squat across the strength spectrum using coefficient of variation (CV) and intra-class correlation coefficient (ICC). On two separate days, 59 healthy men (mean (SD) age 23.0 (4.1) years; height 1.79 (0.7) m; body mass 84.0 (15.2) kg) performed three maximal effort isometric squats in two positions (at a 120° and a 90° knee angle). Acceptable reliability was observed at both the 120° (CV = 7.5 (6.7), ICC = 0.960 [0.933, 0.977]) and 90° positions (CV = 9.2 (8.8), ICC = 0.920 [0.865, 0.953]). There was no relationship between peak force in the isometric squat and the test-retest reliability at either the 120° (r = 0.052, p = 0.327) or 90° (r = 0.014, p = 0.613) positions. A subgroup of subjects (n = 17) also completed the isometric squat test at a 65° knee angle. Acceptable reliability was observed in this position (CV = 9.6 (9.3), ICC = 0.916 [0.766, 0.970]) and reliability was comparable to the 120° and 90° positions. Therefore, we deem isometric squat peak force output to be a valid and reliable measure across the strength spectrum and in different isometric squat positions.
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- 2021
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5. Personalized recurrence risk assessment following the birth of a child with a pathogenic de novo mutation
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Marie Bernkopf, Ummi B. Abdullah, Stephen J. Bush, Katherine A. Wood, Sahar Ghaffari, Eleni Giannoulatou, Nils Koelling, Geoffrey J. Maher, Loïc M. Thibaut, Jonathan Williams, Edward M. Blair, Fiona Blanco Kelly, Angela Bloss, Emma Burkitt-Wright, Natalie Canham, Alexander T. Deng, Abhijit Dixit, Jacqueline Eason, Frances Elmslie, Alice Gardham, Eleanor Hay, Muriel Holder, Tessa Homfray, Jane A. Hurst, Diana Johnson, Wendy D. Jones, Usha Kini, Emma Kivuva, Ajith Kumar, Melissa M. Lees, Harry G. Leitch, Jenny E. V. Morton, Andrea H. Németh, Shwetha Ramachandrappa, Katherine Saunders, Deborah J. Shears, Lucy Side, Miranda Splitt, Alison Stewart, Helen Stewart, Mohnish Suri, Penny Clouston, Robert W. Davies, Andrew O. M. Wilkie, and Anne Goriely
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology ,genetic testing ,molecular medicine - Abstract
Following the diagnosis of a paediatric disorder caused by an apparently de novo mutation, a recurrence risk of 1–2% is frequently quoted due to the possibility of parental germline mosaicism; but for any specific couple, this figure is usually incorrect. We present a systematic approach to providing individualized recurrence risk. By combining locus-specific sequencing of multiple tissues to detect occult mosaicism with long-read sequencing to determine the parent-of-origin of the mutation, we show that we can stratify the majority of couples into one of seven discrete categories associated with substantially different risks to future offspring. Among 58 families with a single affected offspring (representing 59 de novo mutations in 49 genes), the recurrence risk for 35 (59%) was decreased below 0.1%, but increased owing to parental mixed mosaicism for 5 (9%)—that could be quantified in semen for paternal cases (recurrence risks of 5.6–12.1%). Implementation of this strategy offers the prospect of driving a major transformation in the practice of genetic counselling.
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- 2023
6. Differences in 5’untranslated regions highlight the importance of translational regulation of dosage sensitive genes
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Nechama Wieder, Elston N. D’Souza, Alexandra C. Martin-Geary, Frederik H. Lassen, Jonathan Talbot-Martin, Maria Fernandes, Sonia P. Chothani, Owen J.L. Rackham, Sebastian Schafer, Julie L. Aspden, Daniel G. MacArthur, Robert W. Davies, and Nicola Whiffin
- Abstract
BackgroundUntranslated regions (UTRs) are important mediators of post-transcriptional regulation. The length of UTRs and the composition of regulatory elements within them are known to vary substantially across genes, but little is known about the reasons for this variation in humans. Here, we set out to determine whether this variation, specifically in 5’UTRs, correlates with gene dosage sensitivity.ResultsWe investigated 5’UTR length, the number of alternative transcription start sites, the potential for alternative splicing, the number and type of upstream open reading frames (uORFs) and the propensity of 5’UTRs to form secondary structures. We explored how these elements vary by gene tolerance to loss-of-function (LoF; using the LOEUF metric), and in genes where changes in dosage are known to cause disease. We show that LOEUF correlates with 5’UTR length and complexity. Genes that are most intolerant to LoF have longer 5’UTRs (P−15), greater TSS diversity (P−15), and more upstream regulatory elements than their LoF tolerant counterparts. We show that these differences are evident in disease gene-sets, but not in recessive developmental disorder genes where LoF of a single allele is tolerated.ConclusionsOur results confirm the importance of post-transcriptional regulation through 5’UTRs in tight regulation of mRNA and protein levels, particularly for genes where changes in dosage are deleterious and lead to disease. Finally, to support gene-based investigation we release a web-based browser tool, VuTR (https://vutr.rarediseasegenomics.org/), that supports exploration of the composition of individual 5’UTRs and the impact of genetic variation within them.
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- 2023
7. Sex Differences in the Temporal Recovery of Neuromuscular Function Following Resistance Training in Resistance Trained Men and Women 18 to 35 Years
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Robert W. Davies, Brian P. Carson, and Philip M. Jakeman
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exercise ,fatigue ,performance ,recovery ,sex characteristics ,strength ,Physiology ,QP1-981 - Abstract
To investigate sex differences in the temporal recovery of neuromuscular function following resistance training (RT), eleven men and eight women 18–35 years completed a single RT bout (barbell back-squats, 80 % 1RM, 5 sets × 5 reps, 25 % duty cycle, then 1 set × max reps). Measures of muscle function (isometric, concentric, eccentric knee extensor strength, and countermovement jump (CMJ) height), serum creatine kinase activity (CK) and lower-body muscle pain were assessed before RT (0 h), +4 h, +24 h, +48 h, and +72 h post-RT. Data are mean % change from PRE (SD) and effect size (ω2, d). Men and women had similar RT-experience (men, 2.1 (0.8) years vs. women 2.4 (1.0) years, P = 0.746, and d = 0.3) and 1RM strength per kg lean mass (men, 1.9 (0.2) kg⋅kg-1 vs. women, 1.8 (0.3) kg⋅kg-1, P = 0.303, and d = 0.3). A 36 (12)% increase in lower-body muscle pain was reported following RT (P < 0.05, d > 0.9). There was an absence of any overt change in CK [+24 h, 74 (41) IU⋅L-1; pooled mean (SD)]. Decrements in knee extensor strength and CMJ height were observed +4 to +72 h for both men and women (P < 0.05, ω2 = 0.19–0.69). Sex differences were apparent for CMJ height (+24 h men, -10 (6)% vs. women, -20 (11)%, P < 0.001, and d = 1.8) and isokinetic concentric strength (+24 h men, -10 (13)% vs. women -25 (14)%, P = 0.006, and d = 1.8), with a more pronounced loss and prolonged recovery in women compared to men (e.g., CMJ + 72 h men, -3 (6)% vs. women, -13 (12)%, P = 0.051, and d = 1.1). We conclude that the different temporal recovery patterns between men and women are not explicable by differences in muscle strength, RT performance, experience, muscle damage or fatigability.
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- 2018
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8. CONTRASTING HOME RANGE CHARACTERISTICS AND PREY OF SYMPATRIC HAWKS (BUTEO SPP) NESTING IN THE UPPER COLUMBIA RIVER BASIN
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James W Watson, Robert W Davies, and Patrick S Kolar
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General Earth and Planetary Sciences ,General Environmental Science - Published
- 2023
9. The Effect of Exercise Training Intensity on VO2max in Healthy Adults: An Overview of Systematic Reviews and Meta-Analyses
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Emmet Crowley, Cormac Powell, Brian P. Carson, and Robert W. Davies
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This study aimed to evaluate systematic reviews and meta-analyses that have examined the effect of exercise training on VO2max in healthy individuals at different intensities. Five databases were searched: EBSCOhost, MEDLINE/PubMed, SPORTDiscus, Web of Science, and Google Scholar. Eligibility criteria for selecting reviews included systematic reviews and meta-analyses of healthy adults that examined the effect of lower intensity training (LIT) and/or high intensity training (HIT) on VO2max. Eleven reviews met the eligibility criteria. All reviews were of moderate-to-very strong methodological quality. The included reviews reported data from 179 primary studies with an average of 23 ± 10 studies per review. All reviews included in this overview showed that exercise training robustly increased VO2max at all intensities. Three meta-analyses that compared LIT versus HIT protocols on VO2max reported small/moderate beneficial effects for HIT over LIT; however, the beneficial effects of HIT on VO2max appear to be moderated by training variables other than intensity (e.g., training impulse, interval length, training volume, and duration) and participants’ baseline characteristics (e.g., age and fitness levels). Overall, evidence from this overview suggests that the apparent differences between LIT and HIT protocols on VO2max were either small, trivial, or inconclusive, with several methodological considerations required to standardise research designs and draw definitive conclusions.
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- 2022
10. Separating the Wheat from the Chaff: Nutritional Value of Plant Proteins and Their Potential Contribution to Human Health
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Robert W. Davies and Philip M. Jakeman
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amino acids ,climate change ,dietary proteins ,essential amino acids ,humans ,lysine ,Nutrition. Foods and food supply ,TX341-641 - Abstract
The quality and nutritional value of dietary proteins are determined by the quantity, digestibility and bioavailability of essential amino acids (EAA), which play a critical role in human growth, longevity and metabolic health. Plant-source protein is often deficient in one or more EAAs (e.g., branched-chain amino acids, lysine, methionine and/or tryptophan) and, in its natural form, is less digestible than animal-source protein. Nevertheless, dietary intake of plant-source protein has been promoted because of its potential health benefits, lower cost of production and lower environmental impact compared to animal-source protein. Implementation of dietary strategies that improve both human and planetary health are of critical importance and subject to growing interest from researchers and consumers. Therefore, in this review we analyse current plant protein intake patterns and discuss possible countermeasures that can enhance plant protein nutrition, examples include: (1) combining different plant proteins with complementary EAA profiles; (2) identification and commercial cultivation of new and novel high-quality plant proteins; (3) industrial and domestic processing methods; and (4) genome-editing techniques.
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- 2020
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11. The Effect of Whey Protein Supplementation on Myofibrillar Protein Synthesis and Performance Recovery in Resistance-Trained Men
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Robert W. Davies, Joseph J. Bass, Brian P. Carson, Catherine Norton, Marta Kozior, Daniel J. Wilkinson, Matthew S. Brook, Philip J. Atherton, Ken Smith, and Philip M. Jakeman
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dietary protein ,deuterium oxide ,exercise performance ,humans ,skeletal muscle ,whey protein. ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Background: The aim of this study was to investigate the effect of whey protein supplementation on myofibrillar protein synthesis (myoPS) and muscle recovery over a 7-d period of intensified resistance training (RT). Methods: In a double-blind randomised parallel group design, 16 resistance-trained men aged 18 to 35 years completed a 7-d RT protocol, consisting of three lower-body RT sessions on non-consecutive days. Participants consumed a controlled diet (146 kJ·kg−1·d−1, 1.7 g·kg−1·d−1 protein) with either a whey protein supplement or an isonitrogenous control (0.33 g·kg−1·d−1 protein). To measure myoPS, 400 ml of deuterium oxide (D2O) (70 atom %) was ingested the day prior to starting the study and m. vastus lateralis biopsies were taken before and after RT-intervention. Myofibrillar fractional synthetic rate (myoFSR) was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Pyr-IRMS). Muscle recovery parameters (i.e., countermovement jump height, isometric-squat force, muscle soreness and serum creatine kinase) were assessed daily. Results: MyoFSR PRE was 1.6 (0.2) %∙d−1 (mean (SD)). Whey protein supplementation had no effect on myoFSR (p = 0.771) or any recovery parameter (p = 0.390−0.989). Conclusions: Over an intense 7-d RT protocol, 0.33 g·kg−1·d−1 of supplemental whey protein does not enhance day-to-day measures of myoPS or postexercise recovery in resistance-trained men.
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- 2020
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12. The Effect of Fava Bean (
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Robert W, Davies, Marta, Kozior, Arthur E, Lynch, Joseph J, Bass, Philip J, Atherton, Ken, Smith, and Philip M, Jakeman
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Adult ,Male ,Eating ,Alanine ,Humans ,Female ,Resistance Training ,Deuterium ,Muscle, Skeletal ,Vicia faba - Abstract
The aim of the present study was to evaluate the effect of feeding fava bean (
- Published
- 2022
13. The PREGCARE study: Personalized recurrence risk assessment following the birth of a child with a pathogenic de novo mutation
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Marie Bernkopf, Ummi B. Abdullah, Stephen J. Bush, Katherine Wood, Sahar Ghaffari, Eleni Giannoulatou, Nils Koelling, Geoffrey J. Maher, Loïc M. Thibault, Jonathan Williams, Edward M. Blair, Fiona Blanco Kelly, Angela Bloss, Emma Burkitt-Wright, Natalie Canham, Alexander T. Deng, Abhijit Dixit, Jacqueline Eason, Frances Elmslie, Alice Gardham, Eleanor Hay, Muriel Holder, Tessa Homfray, Jane A. Hurst, Diana Johnson, Wendy D. Jones, Usha Kini, Emma Kivuva, Ajith Kumar, Melissa M. Lees, Harry G. Leitch, Jenny E. V. Morton, Andrea H. Németh, Shwetha Ramachandrappa, Katherine Saunders, Deborah J. Shears, Lucy Side, Miranda Splitt, Alison Stewart, Helen Stewart, Mohnish Suri, Penny Clouston, Robert W. Davies, Andrew O. M. Wilkie, and Anne Goriely
- Abstract
Next-generation sequencing has led to a dramatic improvement in molecular diagnoses of serious pediatric disorders caused by apparently de novo mutations (DNMs); by contrast, clinicians’ ability to counsel the parents about the risk of recurrence in a future child has lagged behind. Owing to the possibility that one of the parents could be mosaic in their germline, a recurrence risk of 1-2% is frequently quoted, but for any specific couple, this figure is usually incorrect. We present a systematic approach to providing individualized recurrence risk stratification, by combining deep-sequencing of multiple tissues in the mother-father-child trio with haplotyping to determine the parental origin of the DNM. In the first 58 couples analysed (total of 59 DNMs in 49 different genes), the risk for 35 (59%) DNMs was decreased below 0.1% but for 6 (10%) couples it was increased owing to parental mosaicism - that could be quantified in semen (recurrence risks of 5.6-12.1%) for the paternal cases. Deep-sequencing of the DNM efficiently identifies couples at greatest risk for recurrence and may qualify them for additional reproductive technologies. Haplotyping can further reassure many other couples that their recurrence risk is very low, but its implementation is more technically challenging and will require better understanding of how couples respond to information that reduces their risks.
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- 2022
14. Differential Stimulation of Post-Exercise Myofibrillar Protein Synthesis in Humans Following Isonitrogenous, Isocaloric Pre-Exercise Feeding
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Robert W. Davies, Joseph J. Bass, Brian P. Carson, Catherine Norton, Marta Kozior, Miryam Amigo-Benavent, Daniel J. Wilkinson, Matthew S. Brook, Philip J. Atherton, Kenneth Smith, and Philip M. Jakeman
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amino acids ,deuterium oxide ,humans ,protein synthesis ,resistance training ,skeletal muscle ,whey proteins ,Nutrition. Foods and food supply ,TX341-641 - Abstract
The aim of this study was to test the effects of two disparate isonitrogenous, isocaloric pre-exercise feeds on deuterium-oxide (D2O) derived measures of myofibrillar protein synthesis (myoPS) in humans. Methods: In a double-blind parallel group design, 22 resistance-trained men aged 18 to 35 years ingested a meal (6 kcal·kg−1, 0.8 g·kg−1 carbohydrate, 0.2 g·kg−1 fat) with 0.33 g·kg−1 nonessential amino acids blend (NEAA) or whey protein (WHEY), prior to resistance exercise (70% 1RM back-squats, 10 reps per set to failure, 25% duty cycle). Biopsies of M. vastus lateralis were obtained pre-ingestion (PRE) and +3 h post-exercise (POST). The myofibrillar fractional synthetic rate (myoFSR) was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography−pyrolysis−isotope ratio mass spectrometry (GC-Pyr-IRMS). Data are a mean percentage change (95% CI). Results: There was no discernable change in myoFSR following NEAA (10(−5, 25) %, p = 0.235), whereas an increase in myoFSR was observed after WHEY (28 (13, 43) %, p = 0.003). Conclusions: Measured by a D2O tracer technique, a disparate myoPS response was observed between NEAA and WHEY. Pre-exercise ingestion of whey protein increased post-exercise myoPS, whereas a NEAA blend did not, supporting the use of NEAA as a viable isonitrogenous negative control.
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- 2019
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15. Greater strength of selection and higher proportion of beneficial amino acid changing mutations in humans compared with mice and Drosophila melanogaster
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Christian D. Huber, Kirk E. Lohmueller, Ying Zhen, and Robert W. Davies
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Nonsynonymous substitution ,0303 health sciences ,education.field_of_study ,biology ,Population ,Selection coefficient ,biology.organism_classification ,03 medical and health sciences ,0302 clinical medicine ,Evolutionary biology ,Genetics ,Melanogaster ,Outgroup ,Gene conversion ,Drosophila melanogaster ,education ,030217 neurology & neurosurgery ,Genetics (clinical) ,Selection (genetic algorithm) ,030304 developmental biology - Abstract
Quantifying and comparing the amount of adaptive evolution among different species is key to understanding how evolution works. Previous studies have shown differences in adaptive evolution across species; however, their specific causes remain elusive. Here, we use improved modeling of weakly deleterious mutations and the demographic history of the outgroup species and ancestral population and estimate that at least 20% of nonsynonymous substitutions between humans and an outgroup species were fixed by positive selection. This estimate is much higher than previous estimates, which did not correct for the sizes of the outgroup species and ancestral population. Next, we jointly estimate the proportion and selection coefficient (p+ and s+, respectively) of newly arising beneficial nonsynonymous mutations in humans, mice, and Drosophila melanogaster by examining patterns of polymorphism and divergence. We develop a novel composite likelihood framework to test whether these parameters differ across species. Overall, we reject a model with the same p+ and s+ of beneficial mutations across species and estimate that humans have a higher p+s+ compared with that of D. melanogaster and mice. We show that this result cannot be caused by biased gene conversion or hypermutable CpG sites. We discuss possible biological explanations that could generate the observed differences in the amount of adaptive evolution across species.
- Published
- 2020
16. Analysis of independent cohorts of outbred CFW mice reveals novel loci for behavioral and physiological traits and identifies factors determining reproducibility
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Arimantas Lionikas, Jerome Nicod, Abraham A. Palmer, Jonathan Flint, Clarissa C. Parker, Na Cai, Robert W. Davies, Richard Mott, Shyam Gopalakrishnan, and Jennifer Zou
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AcademicSubjects/SCI01140 ,mega-analysis ,Multifactorial Inheritance ,AcademicSubjects/SCI00010 ,PNPO ,EFFICIENT ,Genome-wide association study ,QH426-470 ,AcademicSubjects/SCI01180 ,Genetic analysis ,power ,Mice ,Genotype ,GWAS ,Peptide Synthases ,Genetics (clinical) ,Genetics ,Chemical Biology & High Throughput ,Confounding ,Genome Integrity & Repair ,Phenotype ,BONE ,Genetics & Genomics ,EXPRESSION ,replication ,GENETICS ,Biology ,PREPULSE INHIBITION ,Polymorphism, Single Nucleotide ,CFW ,Winner's curse ,Replication (statistics) ,Animals ,Genetic Predisposition to Disease ,GENOME-WIDE ASSOCIATION ,Molecular Biology ,Winner's Curse ,METAANALYSIS ,PERMUTATION ,Genetic association ,Computational & Systems Biology ,Investigation ,COMPLEX TRAITS ,Reproducibility of Results ,Tumour Biology ,Winner’s Curse ,Sample size determination ,AcademicSubjects/SCI00960 ,Genome-Wide Association Study - Abstract
Combining samples for genetic association is standard practice in human genetic analysis of complex traits, but is rarely undertaken in rodent genetics. Here, using 23 phenotypes and genotypes from two independent laboratories, we obtained a sample size of 3,076 commercially available outbred mice and identified 70 loci, more than double the number of loci identified in the component studies. Fine-mapping in the combined sample reduced the number of likely causal variants, with a median reduction in set size of 51%, and indicated novel gene associations, including Pnpo, Ttll6 and GM11545 with bone mineral density, and Psmb9 with weight. However replication at a nominal threshold of 0.05 between the two component studies was surprisingly low, with less than a third of loci identified in one study replicated in the second. In addition to overestimates in the effect size in the discovery sample (Winner’s Curse), we also found that heterogeneity between studies explained the poor replication, but the contribution of these two factors varied among traits. Available methods to control Winner’s Curse were contingent on the power of the discovery sample, and depending on the method used, both overestimated and underestimated the true effect. Leveraging these observations we integrated information about replication rates, confounding, and Winner’s Curse corrected estimates of power to assign variants to one of four confidence levels. Our approach addresses concerns about reproducibility, and demonstrates how to obtain robust results from mapping complex traits in any genome-wide association study.
- Published
- 2022
17. Secondary tropical forests recover dung beetle functional diversity and trait composition
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David Edwards, Robert W. Davies, and Felicity A. Edwards
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0106 biological sciences ,geography ,geography.geographical_feature_category ,Ecology ,010604 marine biology & hydrobiology ,Seed dispersal ,Biodiversity ,Biology ,biology.organism_classification ,Old-growth forest ,010603 evolutionary biology ,01 natural sciences ,Forest restoration ,Secondary forest ,Ecosystem ,Species richness ,Nature and Landscape Conservation ,Dung beetle - Abstract
Secondary forests dominate some human‐modified tropical biomes, and this is expected to increase via both abandonment of marginal agricultural land as well as forest and landscape restoration programmes. A key question is whether promoting the recovery and protection of secondary tropical forests will return invertebrate functional diversity and associated functional traits. Dung beetles are ideal for assessing functional diversity as they play vital roles in several ecosystem functions, including seed dispersal, nutrient cycling and bioturbation. We examined how taxonomic and functional diversity, and the functional trait composition of native dung beetle species recovers in naturally regenerating secondary forests in comparison to both cattle pastures and primary forest in the Colombian Choco‐Andes, a global hotspot of threatened biodiversity. Using a space‐for‐time approach, we found that taxonomic and functional diversity recovered to levels comparable to primary forest within approximately 30 years of secondary forest regrowth. Functional richness and FD, measures of the diversity of traits present in a community, were similar in secondary and primary forest, but significantly lower in pasture. Rolling dung beetle species were positively associated with forest habitats, particularly primary, while dwelling species were more common in pasture. Thus, the functional trait composition of secondary forests was more similar to primary forest than to pasture. The ability of secondary forests to rapidly accumulate primary‐forest dung beetle functional diversity, and a representative suite of functional traits, provides an opportunity to protect biodiversity and ecosystem functioning, especially in regions where marginal agricultural land allows cost‐effective conservation actions.
- Published
- 2020
18. Protecting habitats in low-intensity tropical farmland using carbon-based payments for ecosystem services
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Robert W. Davies, Oscar Morton, John W. Mallord, Ieuan Lamb, Kwame Boafo, Luke Nelson, David Edwards, and David M. Lawson
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ResearchInstitutes_Networks_Beacons/global_development_institute ,Food security ,Opportunity cost ,palearctic migrants ,Renewable Energy, Sustainability and the Environment ,business.industry ,Agroforestry ,carbon-based payments for ecosystem services ,Public Health, Environmental and Occupational Health ,Biodiversity ,ResearchInstitutes_Networks_Beacons/03/01 ,farmland habitats ,Global inequalities ,Ecosystem services ,Global Development Institute ,Habitat ,Agriculture ,opportunity cost ,Environmental science ,Emissions trading ,land sharing ,business ,General Environmental Science ,Global biodiversity - Abstract
Tropical land-use change for agricultural expansion is the primary driver of global biodiversity decline. Efforts to stem this decline often focus on protecting pristine habitats or returning farmland to forest, yet such approaches fail to protect vulnerable taxa reliant on habitats within low-intensity farmland. We assess the economic viability of carbon-based payments for ecosystem services (PES) to protect farmland trees and fallowing in Ghana, which provide vital wintering sites for imperiled Afro-palearctic migrant birds and enhance landscape-level carbon storage. We estimate the carbon breakeven prices associated with alternative agricultural management scenarios that protect existing farmland trees. Breakeven prices associated with tree protection on existing farmland were very low, ranging from US$2.49 – US$6.45 t-1 CO2. Extending and reintroducing fallow periods also carried competitive breakeven prices, US$4.67 – US$15.45 t-1 CO2, when combined with the protection of 50 trees per hectare. Accounting for leakage and economic uncertainty increased breakeven prices considerably, but scenarios protecting farmland trees and extending fallow periods remained below EU Emissions Trading Scheme (ETS) prices. Protecting low-intensity farmland habitats and associated biodiversity is cost-effective under carbon-based PES. Implementation should be combined with efforts to close yield gaps, providing greater local food security and resilience.
- Published
- 2021
19. Haplotype tagging reveals parallel formation of hybrid races in two butterfly species
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Yingguang Frank Chan, Marek Kučka, Jon R. Bridle, Chris D. Jiggins, Olivia Box Power, Campbell Rolian, Nicola J. Nadeau, Patricio A. Salazar, Ismael Aldás, Robert W. Davies, Andreea Dréau, Joana I. Meier, W. Owen McMillan, Nicholas H. Barton, Meier, Joana I [0000-0001-7726-2875], Salazar, Patricio A [0000-0001-8988-0769], Kučka, Marek [0000-0002-0928-4914], Box Power, Olivia [0000-0002-7465-3923], Rolian, Campbell [0000-0002-7242-342X], Barton, Nicholas H [0000-0002-8548-5240], Jiggins, Chris D [0000-0002-7809-062X], Chan, Yingguang Frank [0000-0001-6292-9681], and Apollo - University of Cambridge Repository
- Subjects
0106 biological sciences ,Hybrid zone ,haplotypes ,Evolution ,Population genetics ,Sequencing data ,Genome ,010603 evolutionary biology ,01 natural sciences ,Müllerian mimicry ,03 medical and health sciences ,Quantitative Trait, Heritable ,Species Specificity ,Genetic variation ,Animals ,Selection, Genetic ,Genomes ,030304 developmental biology ,Gene Rearrangement ,0303 health sciences ,Butterfly ,Multidisciplinary ,biology ,Biological Mimicry ,Haplotype ,Genetic Variation ,Cline (biology) ,Biological Sciences ,biology.organism_classification ,Evolutionary biology ,Chromosome Inversion ,Hybridization, Genetic ,Ecuador ,Butterflies ,Heliconius erato - Abstract
Significance A defining goal in genetics is linking variation in DNA sequence to trait evolution between populations and, ultimately, species. Genome sequencing efficiently captures such variation but typically in millions of tiny fragments that omit haplotype or linkage information. We present “haplotagging,” a simple, rapid linked-read sequencing technique that allows high-throughput sequencing without sacrificing haplotype information. We validated this affordable approach for whole-genome haplotyping in large populations. We used haplotagging to investigate the rise of a novel hybrid morph in parallel hybrid zones of two comimetic Heliconius butterfly species in Ecuador. Our results reveal that strikingly parallel divergences in their genomes produced coordinated shifts in haplotype frequencies across the hybrid zone, giving rise to comimetic hybrid morphs in each species., Genetic variation segregates as linked sets of variants or haplotypes. Haplotypes and linkage are central to genetics and underpin virtually all genetic and selection analysis. Yet, genomic data often omit haplotype information due to constraints in sequencing technologies. Here, we present “haplotagging,” a simple, low-cost linked-read sequencing technique that allows sequencing of hundreds of individuals while retaining linkage information. We apply haplotagging to construct megabase-size haplotypes for over 600 individual butterflies (Heliconius erato and H. melpomene), which form overlapping hybrid zones across an elevational gradient in Ecuador. Haplotagging identifies loci controlling distinctive high- and lowland wing color patterns. Divergent haplotypes are found at the same major loci in both species, while chromosome rearrangements show no parallelism. Remarkably, in both species, the geographic clines for the major wing-pattern loci are displaced by 18 km, leading to the rise of a novel hybrid morph in the center of the hybrid zone. We propose that shared warning signaling (Müllerian mimicry) may couple the cline shifts seen in both species and facilitate the parallel coemergence of a novel hybrid morph in both comimetic species. Our results show the power of efficient haplotyping methods when combined with large-scale sequencing data from natural populations.
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- 2021
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20. Rapid genotype imputation from sequence with reference panels
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Robert W. Davies, Marek Kucka, Dingwen Su, Sinan Shi, Maeve Flanagan, Christopher M. Cunniff, Yingguang Frank Chan, and Simon Myers
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Genotype ,Genotyping Techniques ,Whole Genome Sequencing ,Genetics ,Computational Biology ,Humans ,Reproducibility of Results ,Sequence Analysis, DNA ,Diploidy ,Polymorphism, Single Nucleotide ,Article - Abstract
Inexpensive genotyping methods are essential to modern genomics. Here we present QUILT, which performs diploid genotype imputation using low-coverage whole-genome sequence data. QUILT employs Gibbs sampling to partition reads into maternal and paternal sets, facilitating rapid haploid imputation using large reference panels. We show this partitioning to be accurate over many megabases, enabling highly accurate imputation close to theoretical limits and outperforming existing methods. Moreover, QUILT can impute accurately using diverse technologies, including long reads from Oxford Nanopore Technologies, and a new form of low-cost barcoded Illumina sequencing called haplotagging, with the latter showing improved accuracy at low coverages. Relative to DNA genotyping microarrays, QUILT offers improved accuracy at reduced cost, particularly for diverse populations that are traditionally underserved in modern genomic analyses, with accuracy nearly doubling at rare SNPs. Finally, QUILT can accurately impute (four-digit) human leukocyte antigen types, the first such method from low-coverage sequence data.
- Published
- 2021
21. Ankyrin-B dysfunction predisposes to arrhythmogenic cardiomyopathy and is amenable to therapy
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Paul M.L. Janssen, Jeff S. Healey, Nara Sobriera, Hugh Calkins, Samantha L. Simmons, Sharon L. Graw, Peter J. Mohler, Mona El-Refaey, Robert W. Davies, Brittney Murray, Danna A. Spears, Kirti Mittal, Duy T. Nguyen, Jason D. Roberts, Crystal Tichnell, Maarten P. van den Berg, J. Peter van Tintelen, Nathaniel P. Murphy, Sara N. Koenig, Daniel P. Judge, Philip C. Ursell, Meriam Åström Aneq, Mei Han, Crystal F. Kline, Robert A. Hegele, Anna Gréen, Luisa Mestroni, Andrew D. Krahn, Robert M. Hamilton, Amy C. Sturm, Arthur A.M. Wilde, Babak Nazer, Frank I. Marcus, Gianfranco Sinagra, Michael H. Gollob, Alberto Codima, David A. Chiasson, Chantal J. M. van Opbergen, Matthew R.G. Taylor, Shabana Aafaqi, Cynthia A. James, Edgar T. Hoorntje, Martin J. Gardner, Tamara T. Koopmann, Ellen R. Lubbers, Meena Fatah, Anthony Tang, Hassan Musa, Muhammad Rafiq, Loren E. Wold, Allan C. Skanes, Thomas J. Hund, John F. Robinson, Melvin M. Scheinman, Elisabeth M. Lodder, Toon A.B. van Veen, Roberts, J. D., Murphy, N. P., Hamilton, R. M., Lubbers, E. R., James, C. A., Kline, C. F., Gollob, M. H., Krahn, A. D., Sturm, A. C., Musa, H., El-Refaey, M., Koenig, S., Aneq, M. A., Hoorntje, E. T., Graw, S. L., Davies, R. W., Rafiq, M. A., Koopmann, T. T., Aafaqi, S., Fatah, M., Chiasson, D. A., Taylor, M. R. G., Simmons, S. L., Han, M., Van Opbergen, C. J. M., Wold, L. E., Sinagra, G., Mittal, K., Tichnell, C., Murray, B., Codima, A., Nazer, B., Nguyen, D. T., Marcus, F. I., Sobriera, N., Lodder, E. M., Van Den Berg, M. P., Spears, D. A., Robinson, J. F., Ursell, P. C., Green, A. K., Skanes, A. C., Tang, A. S., Gardner, M. J., Hegele, R. A., Van Veen, T. A. B., Wilde, A. A. M., Healey, J. S., Janssen, P. M. L., Mestroni, L., Van Tintelen, J. P., Calkins, H., Judge, D. P., Hund, T. J., Scheinman, M. M., Mohler, P. J., Cardiovascular Centre (CVC), Cardiology, Human Genetics, and ACS - Heart failure & arrhythmias
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Male ,0301 basic medicine ,Indoles ,Cardiac fibrosis ,Cell- och molekylärbiologi ,Cardiomyopathy ,Arrhythmias ,Cardiovascular ,Medical and Health Sciences ,Sudden cardiac death ,Maleimides ,Mice ,0302 clinical medicine ,2.1 Biological and endogenous factors ,Aetiology ,Wnt Signaling Pathway ,Arrhythmogenic Right Ventricular Dysplasia ,beta Catenin ,Mice, Knockout ,Ejection fraction ,Cardiology ,Cardiovascular disease ,Cell Biology ,Genetic diseases ,Wnt signaling pathway ,General Medicine ,Phenotype ,3. Good health ,Heart Disease ,030220 oncology & carcinogenesis ,Female ,Arrhythmia ,Research Article ,Ankyrins ,Knockout ,Immunology ,03 medical and health sciences ,Rare Diseases ,Clinical Research ,ANK2 ,Journal Article ,medicine ,Animals ,Humans ,Loss function ,Animal ,business.industry ,Myocardium ,medicine.disease ,Disease Models, Animal ,030104 developmental biology ,Disease Models ,Cancer research ,business ,Cell and Molecular Biology - Abstract
Arrhythmogenic cardiomyopathy (ACM) is an inherited arrhythmia syndrome characterized by severe structural and electrical cardiac phenotypes, including myocardial fibrofatty replacement and sudden cardiac death. Clinical management of ACM is largely palliative, owing to an absence of therapies that target its underlying pathophysiology, which stems partially from our limited insight into the condition. Following identification of deceased ACM probands possessing ANK2 rare variants and evidence of ankyrin-B loss of function on cardiac tissue analysis, an ANK2 mouse model was found to develop dramatic structural abnormalities reflective of human ACM, including biventricular dilation, reduced ejection fraction, cardiac fibrosis, and premature death. Desmosomal structure and function appeared preserved in diseased human and murine specimens in the presence of markedly abnormal beta-catenin expression and patterning, leading to identification of a previously unknown interaction between ankyrin-B and beta-catenin. A pharmacological activator of the WNT/beta-catenin pathway, SB-216763, successfully prevented and partially reversed the murine ACM phenotypes. Our findings introduce what we believe to be a new pathway for ACM, a role of ankyrin-B in cardiac structure and signaling, a molecular link between ankyrin-B and beta-catenin, and evidence for targeted activation of the WNT/beta-catenin pathway as a potential treatment for this disease. Funding Agencies|Marianne Barrie Philanthropic Fund; Canadian Institutes of Health Research [RN332805]; Netherlands CardioVascular Research Initiative: the Dutch Heart Foundation; Dutch Federation of University Medical Centers; Netherlands Organisation for Health Research and Development; Royal Netherlands Academy of Sciences [CVON-PREDICT 2012-10]; Netherlands Cardiovascular Research Initiative - Dutch Heart Foundation [CVON2012-10 PREDICT CVON2018-30 PREDICT2, CVON2015-12 eDETECT]; Netherlands Organization for Scientific Research (NWO) [040.11.586]; Fondation Leducq [16 CVD 02]; Dr. Francis P. Chiramonte Private Foundation; Leyla Erkan Family Fund for ARVD Research; Robin Shah ARVD Fund at Johns Hopkins; Bogle Foundation; Healing Hearts Foundation; Campanella Family; Patrick J. Harrison Family; Peter French Memorial Foundation; Wilmerding Endowments; NIH [HL135754, HL134824, HL139348, HL135096, HL114383, HL114893, HL137331, HL137325, 2UM1HG006542, UL1 TR 001079]; Ohio State Frick Center; JB Project
- Published
- 2019
22. Inferring population histories for ancient genomes using genome-wide genealogies
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Lara M. Cassidy, Robert W. Davies, Pontus Skoglund, Leo Speidel, Simon Myers, and Garrett Hellenthal
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Gene Flow ,Mutation rate ,Population ,Population Dynamics ,Population genetics ,Infectious Disease ,Biology ,AcademicSubjects/SCI01180 ,Genome ,Gene flow ,genealogies ,03 medical and health sciences ,0302 clinical medicine ,Ecology,Evolution & Ethology ,Fasttrack ,Genetic variation ,Genetics ,mutation rate evolution ,Glacial period ,DNA, Ancient ,education ,Molecular Biology ,ancient genomes ,Ecology, Evolution, Behavior and Systematics ,Mesolithic ,History, Ancient ,030304 developmental biology ,0303 health sciences ,education.field_of_study ,Geography ,AcademicSubjects/SCI01130 ,population genetics ,Dynamic population ,Ancient DNA ,Genetics, Population ,Evolutionary biology ,Genetics & Genomics ,030217 neurology & neurosurgery ,Imputation (genetics) - Abstract
Ancient genomes anchor genealogies in directly observed historical genetic variation, and contextualise ancestral lineages with archaeological insights into their geography and lifestyles. We introduce an extension of theRelatealgorithm to incorporate ancient genomes and reconstruct the joint genealogies of 14 previously published high-coverage ancients and 278 present-day individuals of the Simons Genome Diversity Project. As the majority of ancient genomes are of lower coverage and cannot be directly built into genealogies, we additionally present a fast and scalable method,Colate,for inferring coalescence rates between low-coverage genomes without requiring phasing or imputation. Our method leverages sharing patterns of mutations dated using a genealogy to construct a likelihood, which is maximised using an expectation-maximisation algorithm. We applyColateto 430 ancient human shotgun genomes of >0.5x mean coverage. UsingRelateandColate,we characterise dynamic population structure, such as repeated partial population replacements in Ireland, and gene-flow between early farmer and European hunter-gatherer groups. We further show that the previously reported increase in the TCC/TTC mutation rate, which is strongest in West Eurasians among present-day people, was already widespread across West Eurasia in the Late Glacial Period ~10k - 15k years ago, is strongest in Neolithic and Anatolian farmers, and is remarkably well predicted by the coalescence rates between other genomes and a 10,000-year-old Anatolian individual. This suggests that the driver of this signal originated in ancestors of ancient Anatolia >14k years ago, but was already absent by the Mesolithic and may indicate a genetic link between the Near East and European hunter-gatherer groups in the Late Paleolithic.
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- 2021
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23. Private genomes and public SNPs: homomorphic encryption of genotypes and phenotypes for shared quantitative genetics
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Robert W. Davies, Richard Mott, Pjotr Prins, and Christian Fischer
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Theoretical computer science ,quantitative genetics ,Genotype ,Orthogonal transformation ,Computer science ,homomorphic encryption ,Biology ,Investigations ,Encryption ,Polymorphism, Single Nucleotide ,Generalized linear mixed model ,Linkage Disequilibrium ,03 medical and health sciences ,Mice ,Ciphertext ,Genetics ,Quantitative Biology::Populations and Evolution ,Animals ,Humans ,Computer Science::Databases ,Computer Security ,030304 developmental biology ,0303 health sciences ,genetic privacy ,Depressive Disorder, Major ,business.industry ,Genome, Human ,030305 genetics & heredity ,fungi ,Linear model ,Homomorphic encryption ,food and beverages ,Plaintext ,Quantitative genetics ,Quantitative Biology::Genomics ,Phenotype ,Privacy ,Key (cryptography) ,business ,Statistical Genetics and Genomics ,Algorithms ,Genome-Wide Association Study - Abstract
Mott et al. show that association between a quantitative trait and genotype can be performed using data that has been transformed by first rotating it in a high-dimensional space. The resulting..., Sharing human genotype and phenotype data is essential to discover otherwise inaccessible genetic associations, but is a challenge because of privacy concerns. Here, we present a method of homomorphic encryption that obscures individuals’ genotypes and phenotypes, and is suited to quantitative genetic association analysis. Encrypted ciphertext and unencrypted plaintext are analytically interchangeable. The encryption uses a high-dimensional random linear orthogonal transformation key that leaves the likelihood of quantitative trait data unchanged under a linear model with normally distributed errors. It also preserves linkage disequilibrium between genetic variants and associations between variants and phenotypes. It scrambles relationships between individuals: encrypted genotype dosages closely resemble Gaussian deviates, and can be replaced by quantiles from a Gaussian with negligible effects on accuracy. Likelihood-based inferences are unaffected by orthogonal encryption. These include linear mixed models to control for unequal relatedness between individuals, heritability estimation, and including covariates when testing association. Orthogonal transformations can be applied in a modular fashion for multiparty federated mega-analyses where the parties first agree to share a common set of genotype sites and covariates prior to encryption. Each then privately encrypts and shares their own ciphertext, and analyses all parties’ ciphertexts. In the absence of private variants, or knowledge of the key, we show that it is infeasible to decrypt ciphertext using existing brute-force or noise-reduction attacks. We present the method as a challenge to the community to determine its security.
- Published
- 2020
24. A scoping review of initiatives to reduce inappropriate or non-beneficial hospital admissions and bed days in people nearing the end of their life: much innovation, but limited supporting evidence
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Robert W. Davies, Steven Walker, Jonathan Ellis, Angela Garcia-Perez, Claire Hawksworth, Kate Heaps, Bee Wee, Liz Searle, Ros Taylor, Giles Colclough, and Wei Gao
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Telemedicine ,Palliative care ,Hospital bed ,Pain medicine ,lcsh:Special situations and conditions ,Bed days ,Home care ,03 medical and health sciences ,0302 clinical medicine ,Patient Admission ,Nursing ,Medicine ,Humans ,Home education ,030212 general & internal medicine ,Nursing home care ,Quality of Health Care ,Service (business) ,Terminal Care ,Hospital care ,business.industry ,lcsh:RC952-1245 ,General Medicine ,Length of Stay ,Integrated care ,Service evaluation ,Hospitalization ,030220 oncology & carcinogenesis ,business ,Supportive care ,Research Article - Abstract
Background Hospitalisation during the last weeks of life when there is no medical need or desire to be there is distressing and expensive. This study sought palliative care initiatives which may avoid or shorten hospital stay at the end of life and analysed their success in terms reducing bed days. Methods Part 1 included a search of literature in PubMed and Google Scholar between 2013 and 2018, an examination of governmental and organisational publications plus discussions with external and co-author experts regarding other sources. This initial sweep sought to identify and categorise relevant palliative care initiatives. In Part 2, we looked for publications providing data on hospital admissions and bed days for each category. Results A total of 1252 abstracts were reviewed, resulting in ten broad classes being identified. Further screening revealed 50 relevant publications describing a range of multi-component initiatives. Studies were generally small and retrospective. Most researchers claim their service delivered benefits. In descending frequency, benefits identified were support in the community, integrated care, out-of-hours telephone advice, care home education and telemedicine. Nurses and hospices were central to many initiatives. Barriers and factors underpinning success were rarely addressed. Conclusions A wide range of initiatives have been introduced to improve end-of-life experiences. Formal evidence supporting their effectiveness in reducing inappropriate/non-beneficial hospital bed days was generally limited or absent. Trial registration N/A
- Published
- 2020
25. Separating the wheat from the chaff: nutritional value of plant proteins and their potential contribution to human health
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Philip M. Jakeman and Robert W. Davies
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0106 biological sciences ,0301 basic medicine ,protein quality ,Food Handling ,media_common.quotation_subject ,Lysine ,lcsh:TX341-641 ,Review ,Biology ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Humans ,Food science ,media_common ,chemistry.chemical_classification ,amino acids ,030109 nutrition & dietetics ,Nutrition and Dietetics ,Methionine ,lysine ,sustainable development ,dietary proteins ,Longevity ,Tryptophan ,Agriculture ,recommended dietary allowances ,essential amino acids ,Bioavailability ,Amino acid ,climate change ,chemistry ,Plant protein ,Amino Acids, Essential ,Diet, Healthy ,Protein quality ,lcsh:Nutrition. Foods and food supply ,Nutritive Value ,plant proteins ,010606 plant biology & botany ,Food Science - Abstract
peer-reviewed The quality and nutritional value of dietary proteins are determined by the quantity, digestibility and bioavailability of essential amino acids (EAA), which play a critical role in human growth, longevity and metabolic health. Plant-source protein is often deficient in one or more EAAs (e.g., branched-chain amino acids, lysine, methionine and/or tryptophan) and, in its natural form, is less digestible than animal-source protein. Nevertheless, dietary intake of plant-source protein has been promoted because of its potential health benefits, lower cost of production and lower environmental impact compared to animal-source protein. Implementation of dietary strategies that improve both human and planetary health are of critical importance and subject to growing interest from researchers and consumers. Therefore, in this review we analyse current plant protein intake patterns and discuss possible countermeasures that can enhance plant protein nutrition, examples include: (1) combining different plant proteins with complementary EAA profiles; (2) identification and commercial cultivation of new and novel high-quality plant proteins; (3) industrial and domestic processing methods; and (4) genome-editing techniques.
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- 2020
26. The effect of whey protein supplementation on myofibrillar protein synthesis and performance recovery in resistance-trained men
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Matthew S. Brook, Kenneth Smith, Brian P. Carson, Daniel J. Wilkinson, Robert W. Davies, Philip M. Jakeman, Philip J. Atherton, Catherine Norton, Marta Kozior, Joseph J. Bass, and EI
- Subjects
Adult ,Male ,medicine.medical_specialty ,Whey protein ,Adolescent ,Gene Expression ,030209 endocrinology & metabolism ,lcsh:TX341-641 ,exercise performance ,Fractional synthetic rate ,whey protein ,deuterium oxide ,Article ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,dietary protein ,Myofibrils ,Internal medicine ,medicine ,Protein biosynthesis ,Muscle Strength ,skeletal muscle ,Muscle, Skeletal ,humans ,Nutrition and Dietetics ,Chemistry ,Resistance training ,Skeletal muscle ,Resistance Training ,Performance recovery ,030229 sport sciences ,Whey Proteins ,Endocrinology ,medicine.anatomical_structure ,Protein Biosynthesis ,Dietary Supplements ,Countermovement jump ,Myofibril ,lcsh:Nutrition. Foods and food supply ,Biomarkers ,Food Science - Abstract
Background: The aim of this study was to investigate the effect of whey protein supplementation on myofibrillar protein synthesis (myoPS) and muscle recovery over a 7-d period of intensified resistance training (RT). Methods: In a double-blind randomised parallel group design, 16 resistance-trained men aged 18 to 35 years completed a 7-d RT protocol, consisting of three lower-body RT sessions on non-consecutive days. Participants consumed a controlled diet (146 kJ·, kg&minus, 1·, d&minus, 1, 1.7 g·, 1 protein) with either a whey protein supplement or an isonitrogenous control (0.33 g·, 1 protein). To measure myoPS, 400 ml of deuterium oxide (D2O) (70 atom %) was ingested the day prior to starting the study and m. vastus lateralis biopsies were taken before and after RT-intervention. Myofibrillar fractional synthetic rate (myoFSR) was calculated via deuterium labelling of myofibrillar-bound alanine, measured by gas chromatography-pyrolysis-isotope ratio mass spectrometry (GC-Pyr-IRMS). Muscle recovery parameters (i.e., countermovement jump height, isometric-squat force, muscle soreness and serum creatine kinase) were assessed daily. Results: MyoFSR PRE was 1.6 (0.2) %∙d&minus, 1 (mean (SD)). Whey protein supplementation had no effect on myoFSR (p = 0.771) or any recovery parameter (p = 0.390&ndash, 0.989). Conclusions: Over an intense 7-d RT protocol, 0.33 g·, 1 of supplemental whey protein does not enhance day-to-day measures of myoPS or postexercise recovery in resistance-trained men.
- Published
- 2020
27. Predictive impact of rare genomic copy number variations in siblings of individuals with autism spectrum disorders
- Author
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Jennifer L. Howe, Lia D’Abate, Zachary Warren, Stephen W. Scherer, Karen R. Dobkins, Ryan K. C. Yuen, John Wei, Janet A. Buchanan, Gregory S. Young, Kristiina Tammimies, Wendy L. Stone, Susan Walker, Bhooma Thiruvahindrapuram, Jessica Brian, S. E. Bryson, J. Leef, Robert W. Davies, Rebecca Landa, Sally J Ozonoff, Lonnie Zwaigenbaum, Isabel M. Smith, and Daniel S. Messinger
- Subjects
0301 basic medicine ,Male ,Pediatrics ,Microarray ,genetic structures ,Autism Spectrum Disorder ,Autism ,General Physics and Astronomy ,0302 clinical medicine ,Risk Factors ,2.1 Biological and endogenous factors ,Recurrence prediction ,Copy-number variation ,Aetiology ,lcsh:Science ,Child ,Pediatric ,Multidisciplinary ,Genome ,Genomics ,Autism spectrum disorders ,Pedigree ,Mental Health ,Phenotype ,Autism spectrum disorder ,Child, Preschool ,Female ,Human ,medicine.medical_specialty ,DNA Copy Number Variations ,Intellectual and Developmental Disabilities (IDD) ,Science ,Predictive markers ,behavioral disciplines and activities ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Clinical Research ,mental disorders ,Genetics ,medicine ,Humans ,Genetic Predisposition to Disease ,Genetic Testing ,Sibling ,Preschool ,Family Health ,Genome, Human ,business.industry ,Siblings ,Human Genome ,Rare variants ,General Chemistry ,medicine.disease ,Human genetics ,Brain Disorders ,030104 developmental biology ,Polygenic risk score ,lcsh:Q ,Structural variation ,business ,030217 neurology & neurosurgery - Abstract
Identification of genetic biomarkers associated with autism spectrum disorders (ASDs) could improve recurrence prediction for families with a child with ASD. Here, we describe clinical microarray findings for 253 longitudinally phenotyped ASD families from the Baby Siblings Research Consortium (BSRC), encompassing 288 infant siblings. By age 3, 103 siblings (35.8%) were diagnosed with ASD and 54 (18.8%) were developing atypically. Thirteen siblings have copy number variants (CNVs) involving ASD-relevant genes: 6 with ASD, 5 atypically developing, and 2 typically developing. Within these families, an ASD-related CNV in a sibling has a positive predictive value (PPV) for ASD or atypical development of 0.83; the Simons Simplex Collection of ASD families shows similar PPVs. Polygenic risk analyses suggest that common genetic variants may also contribute to ASD. CNV findings would have been pre-symptomatically predictive of ASD or atypical development in 11 (7%) of the 157 BSRC siblings who were eventually diagnosed clinically., Siblings of those with autism spectrum disorder (ASD) have increased likelihood of ASD or related subclinical traits. Here, studying 253 ASD families, D’Abate et al. test the predictive value of genomic copy number variation involving ASD-associated loci, with confirmation in a second cohort.
- Published
- 2019
28. Behavioral accommodation of nesting hawks to wind turbines
- Author
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Ilai N. Keren, Robert W. Davies, and James W. Watson
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0106 biological sciences ,Wind power ,Ecology ,Meteorology ,business.industry ,Nesting (process) ,010603 evolutionary biology ,01 natural sciences ,010601 ecology ,Geography ,General Earth and Planetary Sciences ,business ,Accommodation ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,General Environmental Science - Published
- 2018
29. Effects of fasted vs fed-state exercise on performance and post-exercise metabolism: A systematic review and meta-analysis
- Author
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Brian P. Carson, Robert W. Davies, Thomas.P. Aird, Carbery Food Ingredients Ltd, and Food for Health (Ireland) FHI research centre
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Adipose tissue ,Physiology ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,Athletic Performance ,Fatty Acids, Nonesterified ,03 medical and health sciences ,0302 clinical medicine ,Post exercise ,Humans ,Medicine ,Aerobic exercise ,Orthopedics and Sports Medicine ,exercise adaptation ,Muscle, Skeletal ,Exercise ,business.industry ,Skeletal muscle ,Fasting ,030229 sport sciences ,Metabolism ,Adaptation, Physiological ,performance nutrition ,medicine.anatomical_structure ,Adipose Tissue ,Meta-analysis ,substrate metabolism ,Energy Metabolism ,business ,Anaerobic exercise ,Federal state - Abstract
peer-reviewed The effects of nutrition on exercise metabolism and performance remain an important topic among sports scientists, clinical, and athletic populations. Recently, fasted exercise has garnered interest as a beneficial stimulus which induces superior metabolic adaptations to fed exercise in key peripheral tissues. Conversely, pre‐exercise feeding augments exercise performance compared with fasting conditions. Given these seemingly divergent effects on performance and metabolism, an appraisal of the literature is warranted. This review determined the effects of fasting vs pre‐exercise feeding on continuous aerobic and anaerobic or intermittent exercise performance, and post‐exercise metabolic adaptations. A search was performed using the MEDLINE and PubMed search engines. The literature search identified 46 studies meeting the relevant inclusion criteria. The Delphi list was used to assess study quality. A meta‐analysis and meta‐regression were performed where appropriate. Findings indicated that pre‐exercise feeding enhanced prolonged (P = .012), but not shorter duration aerobic exercise performance (P = .687). Fasted exercise increased post‐exercise circulating FFAs (P = .023) compared to fed exercise. It is evidenced that pre‐exercise feeding blunted signaling in skeletal muscle and adipose tissue implicated in regulating components of metabolism, including mitochondrial adaptation and substrate utilization. This review's findings support the hypothesis that the fasted and fed conditions can divergently influence exercise metabolism and performance. Pre‐exercise feeding bolsters prolonged aerobic performance, while seminal evidence highlights potential beneficial metabolic adaptations that fasted exercise may induce in peripheral tissues. However, further research is required to fully elucidate the acute and chronic physiological adaptations to fasted vs fed exercise.
- Published
- 2018
30. Le origini della pianificazione sovietica 1926-1929 vol 1 : Agricoltura e industria
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Edward H. Carr, Robert W. Davies, Edward H. Carr, and Robert W. Davies
- Abstract
Primo volume che Carr dedica alle origini della pianificazione sovietica, il presente libro, scritto in collaborazione con R.W. Davies, si concentra sugli anni decisivi per l'Unione Sovietica, quelli che, partendo dal 1926 e arrivando al 1929, portano alla collettivizzazione forzata dell'agricoltura e aprono una nuova fase della storia sovietica con l'insediamento di Stalin al potere. Dal complesso processo di collettivizzazione dell'agricoltura allo sviluppo dell'industria, Carr e Davies forniscono un'analisi accurata e puntuale, ma non meno vivace, di una trasformazione epocale che ha investito l'intero sistema agricolo e industriale sovietico.
- Published
- 2021
31. Le origini della pianificazione sovietica 1926-1929 vol 2 : Lavoro, commercio, finanza
- Author
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Edward H. Carr, Robert W. Davies, Edward H. Carr, and Robert W. Davies
- Abstract
Prosegue con questo secondo volume il lavoro di Carr dedicato alle origini della pianificazione sovietica (1926-1929). L'analisi si concentra ora sul lavoro, il commercio e la finanza. Vengono analizzate le forze di lavoro in campo e questioni quali produttività, salari, sindacati e politica sociale, per poi concentrarsi sul commercio e sulla distribuzione – dal mercato al settore socializzato e quello privato, dal controllo dei prezzi al consumo e il commercio estero. Viene dedicato ampio spazio anche a una minuziosa disamina del bilancio statale, del credito e della moneta e, in conclusione, ai problemi e agli strumenti della pianificazione in relazione al piano quinquennale della primavera 1929.
- Published
- 2021
32. Replacing low-intensity cattle pasture with oil palm conserves dung beetle functional diversity when paired with forest protection
- Author
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James J. Gilroy, Felicity A. Edwards, Johann S. Cárdenas-Bautista, David Edwards, Robert W. Davies, Claudia A. Medina-Uribe, and Torbjørn Haugaasen
- Subjects
Environmental Engineering ,Seed dispersal ,0208 environmental biotechnology ,02 engineering and technology ,Forests ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,01 natural sciences ,Pasture ,Abundance (ecology) ,Animals ,Ecosystem ,Forest protection ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Dung beetle ,Scarabaeidae ,geography ,geography.geographical_feature_category ,biology ,Agroforestry ,Agriculture ,Biodiversity ,General Medicine ,biology.organism_classification ,020801 environmental engineering ,Coleoptera ,Cattle ,Species richness - Abstract
Meeting rising demand for oil palm whilst minimizing the loss of tropical biodiversity and associated ecosystem functions is a core conservation challenge. One potential solution is focusing the expansion of high-yielding crops on presently low-yielding farmlands alongside protecting nearby tropical forests that can enhance provision of ecosystem functions. A key question is how this solution would impact invertebrate functional diversity. We focus on oil palm in the Colombian Llanos, where plantations are replacing improved cattle pastures and forest fragments, and on dung beetles, which play key functional roles in nutrient cycling and secondary seed dispersal. We show that functional richness and functional diversity of dung beetles is greater in oil palm than in cattle pasture, and that functional metrics did not differ between oil palm and remnant forest. The abundance-size class profile of dung beetles in oil palm was more similar to forest than to pasture, which had lower abundances of the smallest and largest dung beetles. The abundance of tunneling and rolling dung beetles did not differ between oil palm and forest, while higher forest cover increased the abundance of diurnal and generalist-feeding beetles in oil palm landscapes. This suggests that prioritizing agricultural development on low-yielding cattle pasture will have positive effects on functional diversity and highlights the need for forest protection to maintain ecosystem functioning within agricultural landscapes.
- Published
- 2021
33. Seasonal changes in body composition of inter-county Gaelic Athletic Association hurlers
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Philip M. Jakeman, Katie Hughes, Clodagh Toomey, Robert W. Davies, Cian O’Neill, and William McCormack
- Subjects
Male ,medicine.medical_specialty ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,Biology ,Body Mass Index ,Fat mass ,Young Adult ,03 medical and health sciences ,Absorptiometry, Photon ,0302 clinical medicine ,Animal science ,medicine ,Body Fat Distribution ,Humans ,Orthopedics and Sports Medicine ,Longitudinal Studies ,Track and Field ,030229 sport sciences ,Trunk ,Confidence interval ,Surgery ,Body Composition ,Lean body mass ,Composition (visual arts) ,Seasons ,Ireland - Abstract
Longitudinal change in body composition for elite-level inter-county hurlers was reported over a single season and four consecutive seasons. Body composition measured by dual-energy x-ray absorptiometry (DXA) of 66 senior, male, outfield players was obtained. Four successive measurements were taken: off-season (OFF1), pre-season (PRE), mid-season (MID) and the off-season of the following season (OFF2). A subsample of 11 hurlers were measured at all time points over 4 consecutive seasons. DXA-derived estimates of fat and lean mass were normalised to stature for analysis (kg∙m‒2); data are (mean [lower: upper, 95% confidence interval]). A concurrent increase of lean mass (0.31 [0.19: 0.43] kg∙m‒2) and loss of fat mass occurred (−0.38 [−0.50: −0.26] kg∙m‒2) OFF1 to PRE. Lean mass accrual was maintained PRE to OFF2 while the initial loss of fat mass was restored MID to OFF2 (0.52 [0.40: 0.64] kg ∙ m‒2), with the trunk acting as the primary region of change. Over the four seasons, a net increase of lea...
- Published
- 2016
34. Greater strength of selection and higher proportion of beneficial amino acid changing mutations in humans compared with mice and
- Author
-
Ying, Zhen, Christian D, Huber, Robert W, Davies, and Kirk E, Lohmueller
- Subjects
Evolution, Molecular ,Mice ,Drosophila melanogaster ,Polymorphism, Genetic ,Mutation ,Animals ,Humans ,Method ,Amino Acids - Abstract
Quantifying and comparing the amount of adaptive evolution among different species is key to understanding how evolution works. Previous studies have shown differences in adaptive evolution across species; however, their specific causes remain elusive. Here, we use improved modeling of weakly deleterious mutations and the demographic history of the outgroup species and ancestral population and estimate that at least 20% of nonsynonymous substitutions between humans and an outgroup species were fixed by positive selection. This estimate is much higher than previous estimates, which did not correct for the sizes of the outgroup species and ancestral population. Next, we jointly estimate the proportion and selection coefficient (p(+) and s(+), respectively) of newly arising beneficial nonsynonymous mutations in humans, mice, and Drosophila melanogaster by examining patterns of polymorphism and divergence. We develop a novel composite likelihood framework to test whether these parameters differ across species. Overall, we reject a model with the same p(+) and s(+) of beneficial mutations across species and estimate that humans have a higher p(+)s(+) compared with that of D. melanogaster and mice. We show that this result cannot be caused by biased gene conversion or hypermutable CpG sites. We discuss possible biological explanations that could generate the observed differences in the amount of adaptive evolution across species.
- Published
- 2019
35. Genome-wide association of multiple complex traits in outbred mice by ultra-low-coverage sequencing
- Author
-
Jérôme Nicod, Joseph Wood, Jean-Marie Launay, Benjamin K Yee, Arimantas Lionikas, Connie R. Bezzina, Amarjit Bhomra, Jacques Callebert, Robert W. Davies, Martin Fray, Tertius Hough, Cormac Cosgrove, Barbara Nell, Leo Goodstadt, Elisabeth M. Lodder, Richard Mott, Hayley Phelps, Jonathan Flint, Paul Klenerman, Vikte Lionikaite, Paul Franken, Steve D. M. Brown, Paul Potter, Carl Hassett, Yigal M. Pinto, Sara Wells, Alison Walling, Richard M. Aspden, Nasrin Bopp, Russell Joynson, David J. Adams, Jennifer S. Gregory, Rebecca E. McIntyre, Nick P. Talbot, Tom Weaver, Na Cai, David A. Blizard, Mark Harrison, Polinka Hernandez-Pliego, Carol Ann Remme, Peter A. Robbins, Clare Rowe, ACS - Amsterdam Cardiovascular Sciences, and Cardiology
- Subjects
Genetic Markers ,0301 basic medicine ,False discovery rate ,Multifactorial Inheritance ,Genotype ,Quantitative Trait Loci ,Genome-wide association study ,Computational biology ,Biology ,Quantitative trait locus ,Polymorphism, Single Nucleotide ,Genetic analysis ,Article ,Mice ,03 medical and health sciences ,Animals, Outbred Strains ,Genetics ,Animals ,Genotyping ,Genetic association ,Haplotype ,Chromosome Mapping ,Phenotype ,030104 developmental biology ,Haplotypes ,Genetic marker ,Genome-Wide Association Study - Abstract
Two bottlenecks impeding the genetic analysis of complex traits in rodents are access to mapping populations able to deliver gene-level mapping resolution and the need for population-specific genotyping arrays and haplotype reference panels. Here we combine low-coverage (0.15×) sequencing with a new method to impute the ancestral haplotype space in 1,887 commercially available outbred mice. We mapped 156 unique quantitative trait loci for 92 phenotypes at a 5% false discovery rate. Gene-level mapping resolution was achieved at about one-fifth of the loci, implicating Unc13c and Pgc1a at loci for the quality of sleep, Adarb2 for home cage activity, Rtkn2 for intensity of reaction to startle, Bmp2 for wound healing, Il15 and Id2 for several T cell measures and Prkca for bone mineral content. These findings have implications for diverse areas of mammalian biology and demonstrate how genome-wide association studies can be extended via low-coverage sequencing to species with highly recombinant outbred populations.
- Published
- 2016
36. Rapid genotype imputation from sequence without reference panels
- Author
-
Robert W. Davies, Simon Myers, Richard Mott, and Jonathan Flint
- Subjects
0301 basic medicine ,Genotype ,Genomics ,Computational biology ,Biology ,Polymorphism, Single Nucleotide ,Article ,Mice ,03 medical and health sciences ,Asian People ,Animals, Outbred Strains ,Genetics ,Animals ,Humans ,Quilt ,Genotyping ,Genotyping Techniques ,Whole genome sequencing ,Computational Biology ,High-Throughput Nucleotide Sequencing ,Sequence Analysis, DNA ,Genetics, Population ,030104 developmental biology ,Haplotypes ,Nanopore sequencing ,DNA microarray ,Algorithms ,Imputation (genetics) - Abstract
Inexpensive genotyping methods are essential to modern genomics. Here we present QUILT, which performs diploid genotype imputation using low-coverage whole-genome sequence data. QUILT employs Gibbs sampling to partition reads into maternal and paternal sets, facilitating rapid haploid imputation using large reference panels. We show this partitioning to be accurate over many megabases, enabling highly accurate imputation close to theoretical limits and outperforming existing methods. Moreover, QUILT can impute accurately using diverse technologies, including long reads from Oxford Nanopore Technologies, and a new form of low-cost barcoded Illumina sequencing called haplotagging, with the latter showing improved accuracy at low coverages. Relative to DNA genotyping microarrays, QUILT offers improved accuracy at reduced cost, particularly for diverse populations that are traditionally underserved in modern genomic analyses, with accuracy nearly doubling at rare SNPs. Finally, QUILT can accurately impute (four-digit) human leukocyte antigen types, the first such method from low-coverage sequence data.
- Published
- 2016
37. An Investigation Of Dietary Patterns And Macronutrient Intakes Among Resistance-trained Men
- Author
-
Philip M. Jakeman, Robert W. Davies, Catherine Norton, and Marta Kozior
- Subjects
Resistance (ecology) ,business.industry ,Environmental health ,Medicine ,Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine ,business - Published
- 2020
38. A high-resolution map of non-crossover events reveals impacts of genetic diversity on mammalian meiotic recombination
- Author
-
Nicolas Altemose, Simon Myers, Robert W. Davies, Ran Li, Benjamin Davies, and Emmanuelle Bitoun
- Subjects
Male ,0301 basic medicine ,DNA mismatch repair ,General Physics and Astronomy ,Cell Cycle Proteins ,02 engineering and technology ,Chromosomal crossover ,Histones ,Loss of heterozygosity ,Mice ,0302 clinical medicine ,DNA Breaks, Double-Stranded ,Crossing Over, Genetic ,lcsh:Science ,0303 health sciences ,Multidisciplinary ,021001 nanoscience & nanotechnology ,Female ,0210 nano-technology ,Genome evolution ,DNA recombination ,Science ,Gene Conversion ,Biology ,Polymorphism, Single Nucleotide ,Chromosomes ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Meiosis ,Genetic algorithm ,Homologous chromosome ,Animals ,Humans ,Sister chromatids ,Genetic variation ,Gene conversion ,Homologous recombination ,Alleles ,PRDM9 ,030304 developmental biology ,Models, Genetic ,Recombinational DNA Repair ,Histone-Lysine N-Methyltransferase ,General Chemistry ,Phosphate-Binding Proteins ,Genetic hybridization ,Mice, Inbred C57BL ,030104 developmental biology ,Evolutionary biology ,Hybridization, Genetic ,lcsh:Q ,030217 neurology & neurosurgery ,DNA Damage - Abstract
During meiotic recombination, homologue-templated repair of programmed DNA double-strand breaks (DSBs) produces relatively few crossovers and many difficult-to-detect non-crossovers. By intercrossing two diverged mouse subspecies over five generations and deep-sequencing 119 offspring, we detect thousands of crossover and non-crossover events genome-wide with unprecedented power and spatial resolution. We find that both crossovers and non-crossovers are strongly depleted at DSB hotspots where the DSB-positioning protein PRDM9 fails to bind to the unbroken homologous chromosome, revealing that PRDM9 also functions to promote homologue-templated repair. Our results show that complex non-crossovers are much rarer in mice than humans, consistent with complex events arising from accumulated non-programmed DNA damage. Unexpectedly, we also find that GC-biased gene conversion is restricted to non-crossover tracts containing only one mismatch. These results demonstrate that local genetic diversity profoundly alters meiotic repair pathway decisions via at least two distinct mechanisms, impacting genome evolution and Prdm9-related hybrid infertility., During meiotic recombination, genetic information is transferred or exchanged between parental chromosome copies. Using a large hybrid mouse pedigree, the authors generated high-resolution maps of these transfer/exchange events and discovered new properties governing their processing and resolution.
- Published
- 2018
39. Greater strength of selection and higher proportion of beneficial amino acid changing mutations in humans compared to mice andDrosophila melanogaster
- Author
-
Kirk E. Lohmueller, Ying Zhen, Robert W. Davies, and Christian D. Huber
- Subjects
0106 biological sciences ,Nonsynonymous substitution ,0303 health sciences ,education.field_of_study ,biology ,Population ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,03 medical and health sciences ,Polymorphism (computer science) ,Evolutionary biology ,Outgroup ,Melanogaster ,Gene conversion ,Drosophila melanogaster ,education ,Selection (genetic algorithm) ,030304 developmental biology - Abstract
Quantifying and comparing the amount of adaptive evolution among different species is key to understanding evolutionary processes. Previous studies have shown differences in adaptive evolution across species; however, their specific causes remain elusive. Here, we use improved modeling of weakly deleterious mutations and the demographic history of the outgroup species and ancestral population and estimate that at least 20% of nonsynonymous substitutions between humans and an outgroup species were fixed by positive selection. This estimate is much higher than previous estimates, which did not correct for the sizes of the outgroup species and ancestral population. Next, we directly estimate the proportion and selection coefficients (p+ands+, respectively) of newly arising beneficial nonsynonymous mutations in humans, mice, andDrosophila melanogasterby examining patterns of polymorphism and divergence. We develop a novel composite likelihood framework to test whether these parameters differ across species. Overall, we reject a model with the samep+ands+of beneficial mutations across species, and estimate that humans have a higherp+s+compared toD. melanogasterand mice. We demonstrate that this result cannot be caused by biased gene conversion or hypermutable CpG sites. In summary, we find the proportion of beneficial mutations to be higher in humans than inD. melanogasteror mice, suggesting that organismal complexity, which increases the number of steps required in adaptive walks, may be a key predictor of the amount of adaptive evolution within a species.
- Published
- 2018
40. Acute reduction of lower-body contractile function following a microbiopsy of m. vastus lateralis
- Author
-
Brian P. Carson, Sorcha Holohan, Philip M. Jakeman, Joseph J. Bass, and Robert W. Davies
- Subjects
Adult ,Male ,medicine.medical_specialty ,Biopsy ,Physical Therapy, Sports Therapy and Rehabilitation ,Isometric exercise ,Quadriceps Muscle ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Lower body ,Rate of force development ,Internal medicine ,medicine ,Humans ,biopsy ,Orthopedics and Sports Medicine ,Force platform ,human ,muscle Contraction ,quadriceps Muscle ,business.industry ,Resistance training ,M. vastus lateralis ,Resistance Training ,030229 sport sciences ,muscle Strength ,Muscle strength ,Cardiology ,Exercise Test ,medicine.symptom ,business ,030217 neurology & neurosurgery ,Muscle contraction ,Muscle Contraction - Abstract
peer-reviewed Twenty‐three resistance trained men 18‐35 years (23 [3] years, 1.8 [0.1] m, 81 [10] kg body mass, 2.3 [1.1] years resistance training experience; mean [SD]) performed repeated maximal voluntary isometric squats (ISQ) and countermovement jumps (CMJ) pre‐ and +30 minutes post a unilateral microbiopsy of m. vastus lateralis. ISQ and CMJ were simultaneously measured by two force plates sampling ipsilateral (biopsied) and contralateral (non‐biopsied) limb force. Bilateral limb force (ipsilateral + contralateral) and imbalance (ipsilateral/bilateral) data are reported as % change from pre‐biopsy (mean [95% CI]). A post‐biopsy reduction in bilateral ISQ peak force (−17 [−23, −11] %; P < 0.001), ISQ rate of force development (RFD; −28 [−41, −15] %, P = 0.002) and CMJ peak take‐off force (−7 [−13, −1]%, P = 0.019) occurred. Imbalance was observed for ISQ peak force (3.2 [2.1, 4.3] %, P < 0.001), RFD (2.8 [1.6, 4.0] %, P < 0.001) and CMJ landing (3.3 [1.0, 5.6] %, P = 0.009), resultant of a force transfer from the ipsilateral (biopsied) to the contralateral (non‐biopsied) limb. These data suggest that in young, resistance trained men a modulatory influence on maximal voluntary static and dynamic lower‐body contractile function is evoked acutely (+30 minutes) following a microbiopsy of m. vastus lateralis.
- Published
- 2018
41. Body composition analysis of inter-county Gaelic athletic association players measured by dual energy X-ray absorptiometry
- Author
-
Clodagh Toomey, William McCormack, Alexandra Cremona, Katie Hughes, Philip M. Jakeman, and Robert W. Davies
- Subjects
Adult ,Male ,Gerontology ,medicine.medical_specialty ,Body height ,030209 endocrinology & metabolism ,Physical Therapy, Sports Therapy and Rehabilitation ,Composition analysis ,Body Mass Index ,Young Adult ,03 medical and health sciences ,Absorptiometry, Photon ,0302 clinical medicine ,Bone Density ,medicine ,Humans ,Orthopedics and Sports Medicine ,Gaelic football ,Dual-energy X-ray absorptiometry ,medicine.diagnostic_test ,030229 sport sciences ,Body Height ,Athletes ,Body Composition ,Physical therapy ,Psychology ,Ireland ,Sports - Abstract
Gaelic Football and Hurling are two sporting codes within the Gaelic Athletic Association. The purpose of this study was to report the body composition phenotype of inter-county Gaelic athletic association players, comparing groups by code and field position. 190 senior, male, outfield inter-county players (144 hurlers and 46 Gaelic footballers) were recruited. Stature and body mass was measured, estimates of three components of body composition, i.e., lean mass, fat mass and bone mineral content was obtained by dual energy X-ray absorptiometry (DXA), and normative data for Gaelic athletic association athletes by code and position was compared. Other than in the midfield, there was limited difference in body composition between codes or playing position. Stature-corrected indices nullified any existing group differences between midfielders for both codes. Further comparisons with a non-athletic control group (n = 431) showed no difference for body mass index (BMI); however, the athletic group has a lower fat mass index, with a greater lean mass in accounting for the matched BMI between groups. In addition to providing previously unknown normative data for the Gaelic athletic association athlete, a proportional and independent tissue evaluation of body composition is given.
- Published
- 2015
42. Lead, Mercury, and DDE in the Blood of Nesting Golden Eagles in the Columbia Basin, Washington
- Author
-
James W. Watson and Robert W. Davies
- Subjects
Geography ,Animal Science and Zoology ,Heavy metals ,Natural enemies ,Humanities - Abstract
Plomo, Mercurio y DDE en la Sangre de Individuos Reproductores de Aquila chrysaetos en la Cuenca de Columbia, Washington La toxicosis ocasionada por la ingestion de plomo (Pb) es una preocupacion creciente para las poblaciones de Aquila chrysaetos a lo largo del oeste de America del Norte. Analizamos muestras de sangre para Pb, mercurio (Hg) y compuestos organoclorados (COs) de 17 individuos adultos de A. chrysaetos capturados entre 2005 y 2013 en la Cuenca de Columbia, en el este de Washington. La mayoria (65%) de las aguilas presento niveles elevados de Pb, incluyendo un 24% con niveles que indican una exposicion cronica al Pb que podria producir efectos clinicos. Se detectaron niveles bajos de Hg y COs. Sugerimos que existen motivos de preocupacion sobre los posibles efectos de la ingesta de Pb en esta poblacion reproductora de A. chrysaetos y sospechamos que la fuente mas probable de Pb en esta region es la carrona generada por caceria con balas que se encuentra ampliamente disponible para las aguilas...
- Published
- 2015
43. Comparative Diets of Nesting Golden Eagles in the Columbia Basin Between 2007–2013 and the Late 1970s
- Author
-
Robert W. Davies and James W. Watson
- Subjects
Geography ,Ecology ,General Earth and Planetary Sciences ,Nesting (computing) ,Structural basin ,General Environmental Science - Published
- 2015
44. Adiposity significantly modifies genetic risk for dyslipidemia[S]
- Author
-
Christopher B. Cole, Alexandre F.R. Stewart, Majid Nikpay, George A. Wells, Ruth McPherson, Paulina Lau, Robert Dent, and Robert W. Davies
- Subjects
Male ,Endothelial lipase ,obesity ,Epidemiology ,Genome-wide association study ,030204 cardiovascular system & hematology ,Biochemistry ,Body Mass Index ,chemistry.chemical_compound ,Endocrinology ,0302 clinical medicine ,Framingham Heart Study ,Missing heritability problem ,single nucleotide polymorphism ,Phospholipid transfer protein ,030212 general & internal medicine ,Adiposity ,Genetics ,0303 health sciences ,Middle Aged ,Cohort ,Population study ,Female ,lipids (amino acids, peptides, and proteins) ,medicine.medical_specialty ,030209 endocrinology & metabolism ,Single-nucleotide polymorphism ,QD415-436 ,Biology ,Polymorphism, Single Nucleotide ,genetic risk score ,03 medical and health sciences ,statistical interaction ,Internal medicine ,Cholesterylester transfer protein ,medicine ,Genetic predisposition ,Humans ,SNP ,Genetic Predisposition to Disease ,Triglycerides ,Aged ,Dyslipidemias ,030304 developmental biology ,Cholesterol ,business.industry ,Cholesterol, HDL ,Public Health, Environmental and Occupational Health ,Cell Biology ,medicine.disease ,lipoproteins ,chemistry ,biology.protein ,Patient-Oriented and Epidemiological Research ,business ,Imputation (genetics) ,Dyslipidemia ,Genome-Wide Association Study - Abstract
Recent genome-wide association studies have identified multiple loci robustly associated with plasma lipids, which also contribute to extreme lipid phenotypes. However, these common genetic variants explain
- Published
- 2014
45. Home range and resource selection by GPS-monitored adult golden eagles in the Columbia Plateau Ecoregion: Implications for wind power development
- Author
-
Robert W. Davies, James W. Watson, and Andrew A. Duff
- Subjects
Eagle ,Perch ,Plateau ,geography.geographical_feature_category ,Ecology ,biology ,Range (biology) ,Home range ,Wildlife ,biology.organism_classification ,Geography ,Ecoregion ,Nest ,biology.animal ,General Earth and Planetary Sciences ,Physical geography ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,General Environmental Science - Abstract
Recent national interest in golden eagle (Aquila chrysaetos) conservation and wind energy development prompted us to investigate golden eagle home range and resource use in the Columbia Plateau Ecoregion (CPE) in Washington and Oregon. From 2004 to 2013, we deployed satellite transmitters on adult eagles (n = 17) and monitored their movements for up to 7 years. We used the Brownian bridge movement model (BBMM) to estimate range characteristics from global position system (GPS) fixes and flight paths of 10 eagles, and modeled resource selection probability functions (RSPFs). Multi-year home ranges of resident eagles were large (99% volume contour; , SD = 370.2 km2) but were one-third the size (, SD = 94.6 km2) and contained half as many contours when defined by 95% isopleths. Annual ranges accounted for 66% of multi-year range size. During the breeding season (16 Jan–15 Aug), eagles occupied ranges that were less fragmented, about half as large, and largely contained within ranges they used outside the breeding season ( overlap = 82.5%, SD = 19.0). Eagles selected upper slopes, rugged terrain, and ridge tops that appear to reflect underlying influences of prey, deflective wind currents, and proximity to nests. Fix distribution predicted by our resource selection model and that of 4 eagles monitored independently in the CPE were highly correlated (rs = 0.992). Our findings suggest conservative landscape management strategies addressing development in lower-elevation montane and shrub-steppe/grassland ecosystems can best define golden eagle ranges using exclusive 12.8-km buffers around nests. Less conservative strategies based on 9.6-km buffers must include identification and management of upper slopes, ridge-tops, and areas of varied terrain defined by predictive models or GPS telemetry. For both strategies, high, year-round intensity of eagle flight and perch use within 50% volume contours (average 3.2 km from nests) due to nest centricity may dramatically increase the probability of eagle conflict with wind turbines in core areas as evidenced by eagle turbine strikes that studies have documented within and beyond this zone. © 2014 The Wildlife Society.
- Published
- 2014
46. Genomic Analyses from Non-invasive Prenatal Testing Reveal Genetic Associations, Patterns of Viral Infections, and Chinese Population History
- Author
-
Melinda A. Yang, Shengkang Li, Thorfinn Sand Korneliussen, Qiang Liu, Zhengming Chen, Rong Liu, Rasmus Nielsen, Anders Krogh, Long Lin, Xun Xu, Stephen S. Francis, Fang Chen, Lijun Zhou, Mao Mao, Xin Jin, Lin Fang, Yong Zhang, Qiaomei Fu, Anders Albrechtsen, Wei Wang, Huixin Xu, Robin G. Walters, Jian Wang, Hongyun Zhang, Zilong Li, Huanming Yang, Zhiming Cai, Jun Wang, Shujia Huang, Yuying Yuan, Kuang Lin, Siyang Liu, Jay Shendure, Jia Ju, Robert W. Davies, Ye Yin, Yuwen Zhou, and Lijian Zhao
- Subjects
Adult ,0301 basic medicine ,China ,Human Migration ,Population ,Piwi-interacting RNA ,Genome-wide association study ,Biology ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Asian People ,Gene Frequency ,Pregnancy ,Prenatal Diagnosis ,Ethnicity ,medicine ,Humans ,Genetic Testing ,Allele ,education ,Alleles ,Twin Pregnancy ,Genetics ,education.field_of_study ,Non invasive ,Genetic Variation ,DNA ,Genomics ,Sequence Analysis, DNA ,Hepatitis B ,medicine.disease ,Genetics, Population ,030104 developmental biology ,Genetic structure ,Female ,Genome-Wide Association Study - Abstract
We analyze whole-genome sequencing data from 141,431 Chinese women generated for non-invasive prenatal testing (NIPT). We use these data to characterize the population genetic structure and to investigate genetic associations with maternal and infectious traits. We show that the present day distribution of alleles is a function of both ancient migration and very recent population movements. We reveal novel phenotype-genotype associations, including several replicated associations with height and BMI, an association between maternal age and EMB, and between twin pregnancy and NRG1. Finally, we identify a unique pattern of circulating viral DNA in plasma with high prevalence of hepatitis B and other clinically relevant maternal infections. A GWAS for viral infections identifies an exceptionally strong association between integrated herpesvirus 6 and MOV10L1, which affects piwi-interacting RNA (piRNA) processing and PIWI protein function. These findings demonstrate the great value and potential of accumulating NIPT data for worldwide medical and genetic analyses.
- Published
- 2018
47. Inflammation and Coronary Artery Disease: Insights From Genetic Studies
- Author
-
Robert W. Davies and Ruth McPherson
- Subjects
Candidate gene ,Pathology ,medicine.medical_specialty ,Locus (genetics) ,Genome-wide association study ,Inflammation ,Coronary Artery Disease ,HLA-C Antigens ,Bioinformatics ,Polymorphism, Single Nucleotide ,Proinflammatory cytokine ,Coronary artery disease ,Risk Factors ,medicine ,Humans ,Genetic Predisposition to Disease ,Loss function ,Genetic association ,business.industry ,medicine.disease ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business ,Biomarkers ,Genome-Wide Association Study - Abstract
Recent genome-wide association studies (GWASs) have provided a vast amount of new information relevant to the myriad of biological pathways related to atherosclerosis and its progression. Although atherosclerosis is a complex process, both GWASs and candidate gene studies add support to the hypothesis that proinflammatory pathways, involving both innate and adaptive immunity, play a causal role in coronary artery disease (CAD) and its clinical manifestations. Recent GWASs have identified several inflammation-related loci associated with CAD risk. These include CXCL2, encoding an atheroprotective chemokine, and a region near HLA-C in the major histocompatibility locus on chromosome 6p21. The ABO locus, also linked to CAD risk by the GWAS approach, is related to multiple phenotypes, including plasma interleukin-6 (IL-6) levels. Finally, relevant to inflammation, the 9p21 CAD risk locus appears to play a role in interferon-gamma signalling. Candidate gene studies also support a causative role of inflammation pathways in atherosclerosis. Of note, a common loss of function coding variant in the IL-6 receptor gene (IL6R) is associated with a reduction in CAD risk.
- Published
- 2012
48. Meta-analysis identifies six new susceptibility loci for atrial fibrillation
- Author
-
David J. Milan, Lenore J. Launer, Bruno H. Stricker, Yongmei Liu, Arne Pfeufer, Jingzhong Ding, Jason D. Roberts, Vilmundur Gudnason, David Conen, Usha B. Tedrow, Eric Boerwinkle, Aravinda Chakravarti, Benjamin F. Voight, Michiel Rienstra, Emelia J. Benjamin, Guo Li, Dan E. Arking, Raafia Muhammad, Joshua C. Bis, Uwe Völker, Tatsuhiko Tsunoda, Mina K. Chung, Barbara McKnight, Lin Y. Chen, Sekar Kathiresan, Karen L. Furie, Kathryn L. Lunetta, Olle Melander, Kenneth Rice, Marylyn D. Ritchie, Honghuang Lin, Naoyuki Kamatani, Nicole L. Glazer, Kurt Lohman, W. H. Linda Kao, Jacqueline C.M. Witteman, Stefan Kääb, David R. Van Wagoner, Martina Müller-Nurasyid, Gerhard Steinbeck, Susan R. Heckbert, André G. Uitterlinden, Sebastian Clauss, Anne B. Newman, John Barnard, Nicholas L. Smith, Paul M. Ridker, Bruce M. Psaty, Dawood Darbar, Tamara B. Harris, Thomas Meitinger, Fernando Rivadeneira, Saagar Mahida, Marcus Dörr, Stephan B. Felix, J. Gustav Smith, Nona Sotoodehnia, Matthew Borkovich, Babar Parvez, Michiaki Kubo, Jonathan D. Smith, Albert Hofman, Tetsushi Furukawa, Kouichi Ozaki, Lynda M. Rose, Albert V. Smith, Jared W. Magnani, Toshihiro Tanaka, Steven A. Lubitz, Reza Wakili, Daniel Levy, Siyan Xu, Moritz F. Sinner, Robert W. Davies, H-Erich Wichmann, Elsayed Z. Soliman, Alvaro Alonso, Bouwe P. Krijthe, Dan M. Roden, Michael H. Gollob, Daniel I. Chasman, Marketa Sjögren, Siegfried Perz, Henry Völzke, Christine M. Albert, Yusuke Nakamura, Patrick T. Ellinor, Jerome I. Rotter, Jonathan Rosand, Epidemiology, Erasmus MC other, Erasmus School of Social and Behavioural Sciences, Internal Medicine, and Cardiovascular Centre (CVC)
- Subjects
Male ,Candidate gene ,Genome-wide association study ,030204 cardiovascular system & hematology ,0302 clinical medicine ,PR INTERVAL ,Risk Factors ,Polymorphism (computer science) ,Atrial Fibrillation ,Child ,Stroke ,Aged, 80 and over ,Genetics ,0303 health sciences ,COMMON VARIANTS ,Dilated cardiomyopathy ,Atrial fibrillation ,Middle Aged ,3. Good health ,Child, Preschool ,cardiovascular system ,Female ,Adult ,Adolescent ,PROTEINS ,Biology ,Polymorphism, Single Nucleotide ,White People ,Article ,Young Adult ,03 medical and health sciences ,Asian People ,medicine ,Humans ,Genetic Predisposition to Disease ,cardiovascular diseases ,Risk factor ,GENOME-WIDE ASSOCIATION ,CAVEOLIN-1 ,CHROMOSOME 4Q25 ,Aged ,030304 developmental biology ,MUTATIONS ,Infant, Newborn ,Infant ,medicine.disease ,DILATED CARDIOMYOPATHY ,PACEMAKER CHANNEL ,Genetic Loci ,Heart failure ,REPLICATION ,Genome-Wide Association Study - Abstract
Atrial fibrillation is a highly prevalent arrhythmia and a major risk factor for stroke, heart failure and death. We conducted a genome-wide association study (GWAS) in individuals of European ancestry, including 6,707 with and 52,426 without atrial fibrillation. Six new atrial fibrillation susceptibility loci were identified and replicated in an additional sample of individuals of European ancestry, including 5,381 subjects with and 10,030 subjects without atrial fibrillation (P < 5 × 10(-8)). Four of the loci identified in Europeans were further replicated in silico in a GWAS of Japanese individuals, including 843 individuals with and 3,350 individuals without atrial fibrillation. The identified loci implicate candidate genes that encode transcription factors related to cardiopulmonary development, cardiac-expressed ion channels and cell signaling molecules.
- Published
- 2012
49. A Genome-Wide Association Study for Coronary Artery Disease Identifies a Novel Susceptibility Locus in the Major Histocompatibility Complex
- Author
-
Sonia S. Anand, Robert W. Davies, Sonny Dandona, Svati H. Shah, Stephen E. Epstein, James C. Engert, Robert Roberts, Mary Susan Burnett, George A. Wells, Christina Loley, Nilesh J. Samani, Inke R. König, Muredach P. Reilly, William E. Kraus, Li Chen, Jane F. Ferguson, Stephen G. Ellis, Alistair S. Hall, Christian Hengstenberg, Christopher B. Granger, Alexandre F.R. Stewart, H.-Erich Wichmann, W.H. Wilson Tang, Jeanette Erdmann, Ruth McPherson, Daniel J. Rader, Heribert Schunkert, Stanley L. Hazen, Janja Nahrstaedt, and Stefan Schreiber
- Subjects
Adult ,Male ,Genotype ,Genome-wide association study ,Single-nucleotide polymorphism ,Locus (genetics) ,Human leukocyte antigen ,coronary artery disease ,myocardial infarction ,meta-analysis ,genetics ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Biology ,Polymorphism, Single Nucleotide ,White People ,Article ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Genetics ,Humans ,Genetic Predisposition to Disease ,Allele ,1000 Genomes Project ,Genetics (clinical) ,Alleles ,030304 developmental biology ,Genetic association ,Aged ,0303 health sciences ,Haplotype ,Histocompatibility Antigens Class I ,Middle Aged ,3. Good health ,Female ,Cardiology and Cardiovascular Medicine ,Genome-Wide Association Study - Abstract
Background— Recent genome-wide association studies (GWAS) have identified several novel loci that reproducibly associate with coronary artery disease (CAD) and/or myocardial infarction risk. However, known common CAD risk variants explain only 10% of the predicted genetic heritability of the disease, suggesting that important genetic signals remain to be discovered. Methods and Results— We performed a discovery meta-analysis of 5 GWAS involving 13 949 subjects (7123 cases, 6826 control subjects) imputed at approximately 5 million single nucleotide polymorphisms, using pilot 1000 Genomes–based haplotypes. Promising loci were followed up in an additional 5 studies with 11 032 subjects (5211 cases, 5821 control subjects). A novel CAD locus on chromosome 6p21.3 in the major histocompatibility complex (MHC) between HCG27 and HLA-C was identified and achieved genome-wide significance in the combined analysis (rs3869109; p discovery =3.3×10 −7 , p replication =5.3×10 −4 p combined =1.12×10 −9 ). A subanalysis combining discovery GWAS showed an attenuation of significance when stringent corrections for European population structure were used ( P =4.1×10 −10 versus 3.2×10 −7 ), suggesting that the observed signal is partly confounded due to population stratification. This gene dense region plays an important role in inflammation, immunity, and self–cell recognition. To determine whether the underlying association was driven by MHC class I alleles, we statistically imputed common HLA alleles into the discovery subjects; however, no single common HLA type contributed significantly or fully explained the observed association. Conclusions— We have identified a novel locus in the MHC associated with CAD. MHC genes regulate inflammation and T-cell responses that contribute importantly to the initiation and propagation of atherosclerosis. Further laboratory studies will be required to understand the biological basis of this association and identify the causative allele(s).
- Published
- 2012
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50. Improved Prediction of Cardiovascular Disease Based on a Panel of Single Nucleotide Polymorphisms Identified Through Genome-Wide Association Studies
- Author
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George A. Wells, Sonny Dandona, Alexandre F.R. Stewart, Robert W. Davies, Stanley L. Hazen, Li Chen, Robert Roberts, W.H. Wilson Tang, Ruth McPherson, and Stephan G. Ellis
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Adult ,Oncology ,medicine.medical_specialty ,Genotype ,Genome-wide association study ,Single-nucleotide polymorphism ,Logistic regression ,Polymorphism, Single Nucleotide ,Article ,Predictive Value of Tests ,Risk Factors ,Internal medicine ,Genetics ,medicine ,Humans ,Genetic Predisposition to Disease ,Allele ,Genetics (clinical) ,Genetic association ,business.industry ,Case-control study ,Area under the curve ,Middle Aged ,Cardiovascular Diseases ,Predictive value of tests ,Cardiology and Cardiovascular Medicine ,business ,Algorithms ,Genome-Wide Association Study - Abstract
Background— Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) at multiple loci that are significantly associated with coronary artery disease (CAD) risk. In this study, we sought to determine and compare the predictive capabilities of 9p21.3 alone and a panel of SNPs identified and replicated through GWAS for CAD. Methods and Results— We used the Ottawa Heart Genomics Study (OHGS) (3323 cases, 2319 control subjects) and the Wellcome Trust Case Control Consortium (WTCCC) (1926 cases, 2938 control subjects) data sets. We compared the ability of allele counting, logistic regression, and support vector machines. Two sets of SNPs, 9p21.3 alone and a set of 12 SNPs identified by GWAS and through a model-fitting procedure, were considered. Performance was assessed by measuring area under the curve (AUC) for OHGS using 10-fold cross-validation and WTCCC as a replication set. AUC for logistic regression using OHGS increased significantly from 0.555 to 0.608 ( P =3.59×10 −14 ) for 9p21.3 versus the 12 SNPs, respectively. This difference remained when traditional risk factors were considered in a subgroup of OHGS (1388 cases, 2038 control subjects), with AUC increasing from 0.804 to 0.809 ( P =0.037). The added predictive value over and above the traditional risk factors was not significant for 9p21.3 (AUC 0.801 versus 0.804, P =0.097) but was for the 12 SNPs (AUC 0.801 versus 0.809, P =0.0073). Performance was similar between OHGS and WTCCC. Logistic regression outperformed both support vector machines and allele counting. Conclusions— Using the collective of 12 SNPs confers significantly greater predictive capabilities for CAD than 9p21.3, whether traditional risks are or are not considered. More accurate models probably will evolve as additional CAD-associated SNPs are identified.
- Published
- 2010
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