Publications by authors named "MacLeod I"

Background: Anecdotally, upper truncal obesity and large breasts have often been associated with inferior outcomes from non-operative management of diaphyseal humerus fractures. However, this assertion is without basis in the literature.

Aims: To produce radiographic measurements of chest wall soft tissue thickness (STT) and determine association with non-union in diaphyseal humerus fractures.

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Article Synopsis
  • Genotype imputation helps in obtaining sequence genotypes for analyses like genome-wide association studies (GWAS), but assessing imputation accuracy is crucial to avoid false positives.
  • The study compared three imputation programs—Beagle 5.2, Minimac4, and IMPUTE5—and found that high-density genotypes yield better accuracy than low-density, with notable differences in how each software estimates imputation performance.
  • The findings highlight the need for customized Rsq thresholds when filtering data and indicate that INDEL variants tend to have lower accuracy than SNPs; also, the accuracy of X chromosome imputation varies significantly between different regions.
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Background: Mitochondrial genomes differ from the nuclear genome and in humans it is known that mitochondrial variants contribute to genetic disorders. Prior to genomics, some livestock studies assessed the role of the mitochondrial genome but these were limited and inconclusive. Modern genome sequencing provides an opportunity to re-evaluate the potential impact of mitochondrial variation on livestock traits.

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Background: Mastitis is a disease that incurs significant costs in the dairy industry. A promising approach to mitigate its negative effects is to genetically improve the resistance of dairy cattle to mastitis. A meta-analysis of genome-wide association studies (GWAS) across multiple breeds for clinical mastitis (CM) and its indicator trait, somatic cell score (SCS), is a powerful method to identify functional genetic variants that impact mastitis resistance.

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Widespread genotyping has enabled the identification of putative recessive mutations that affect fertility through early embryonic fetal loss, or that compromise neonate or calf viability. The use of artificial insemination in the global dairy population can rapidly spread these harmful mutations, and testing for multiple mutations can become relatively expensive if not all tests are available on the same SNP panel. However, it is possible to provide heifer and cow predicted carrier status to farmers at no additional cost if the animals are genotyped with a standard SNP panel.

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Background: Female fertility is an important trait in dairy cattle. Identifying putative causal variants associated with fertility may help to improve the accuracy of genomic prediction of fertility. Combining expression data (eQTL) of genes, exons, gene splicing and allele specific expression is a promising approach to fine map QTL to get closer to the causal mutations.

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Aims: The primary aim of this study was to report the radiological outcomes of patients with a dorsally displaced distal radius fracture who were randomized to a moulded cast or surgical fixation with wires following manipulation and closed reduction of their fracture. The secondary aim was to correlate radiological outcomes with patient-reported outcome measures (PROMs) in the year following injury.

Methods: Participants were recruited as part of DRAFFT2, a UK multicentre clinical trial.

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Parametric splines are popular tools for precision optical metrology of complex freeform surfaces. However, as a promising topologically unconstrained solution, existing T-spline fitting techniques, such as improved global fitting, local fitting, and split-connect algorithms, still suffer the problems of low computational efficiency, especially in the case of large data scales and high accuracy requirements. This paper proposes a speed-improved algorithm for fast, large-scale freeform point cloud fitting by stitching locally fitted T-splines through three steps of localized operations.

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Article Synopsis
  • Many QTLs are found in non-coding regions and are believed to influence gene regulation, impacting gene expression and RNA splicing.
  • A study examined the contributions of eVariants (which affect gene expression) and sVariants (which influence RNA splicing) from 16 tissues in ~120,000 cattle, showing they explain 69.2% of heritability for various traits.
  • The research highlights that these regulatory variants substantially affect phenotypes, with eVariants and sVariants particularly explaining 24% of heritability, which is notably higher than expected from random variants.
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Background: Diagnostic needle arthroscopy offers an alternative imaging modality to magnetic resonance imaging (MRI) for the diagnosis of intra-articular pathology.

Purpose: To compare the accuracy of a needle arthroscopy device (Mi-eye2) versus MRI in identifying intra-articular anatomic abnormalities in the glenohumeral joint, with formal arthroscopy as the gold standard.

Study Design: Cohort study; Level of evidence, 2.

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Studies have demonstrated that structural variants (SV) play a substantial role in the evolution of species and have an impact on Mendelian traits in the genome. However, unlike small variants (< 50 bp), it has been challenging to accurately identify and genotype SV at the population scale using short-read sequencing. Long-read sequencing technologies are becoming competitively priced and can address several of the disadvantages of short-read sequencing for the discovery and genotyping of SV.

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Although selection for increased milk production traits has led to a genetic increase in body weight (BW), the genetic gain in milk production has exceeded the gain in BW, so gross feed efficiency has improved. Nonetheless, greater gains may be possible by directly selecting for a measure of feed efficiency. Australia first introduced Feed Saved (FS) estimated breeding value (EBV) in 2015.

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Increasing numbers of patents directed to bacteria and bacterial products are being filed and granted, many of which claim specific deposited strains of bacteria. However, there remains significant uncertainty regarding exactly what scope patent claims limited to deposited strains might have. A claim limited to a specific deposited strain could be interpreted extremely narrowly, extending only to descendants of that deposit.

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Background: Sharing individual phenotype and genotype data between countries is complex and fraught with potential errors, while sharing summary statistics of genome-wide association studies (GWAS) is relatively straightforward, and thus would be especially useful for traits that are expensive or difficult-to-measure, such as feed efficiency. Here we examined: (1) the sharing of individual cow data from international partners; and (2) the use of sequence variants selected from GWAS of international cow data to evaluate the accuracy of genomic estimated breeding values (GEBV) for residual feed intake (RFI) in Australian cows.

Results: GEBV for RFI were estimated using genomic best linear unbiased prediction (GBLUP) with 50k or high-density single nucleotide polymorphisms (SNPs), from a training population of 3797 individuals in univariate to trivariate analyses where the three traits were RFI phenotypes calculated using 584 Australian lactating cows (AUSc), 824 growing heifers (AUSh), and 2526 international lactating cows (OVE).

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Bayesian methods, such as BayesR, for predicting the genetic value or risk of individuals from their genotypes, such as Single Nucleotide Polymorphisms (SNP), are often implemented using a Markov Chain Monte Carlo (MCMC) process. However, the generation of Markov chains is computationally slow. We introduce a form of blocked Gibbs sampling for estimating SNP effects from Markov chains that greatly reduces computational time by sampling each SNP effect iteratively n-times from conditional block posteriors.

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Previous studies have shown reduced enteric methane emissions (ME) and residual feed intake (RFI) through the application of genomic selection in ruminants. The objective of this study was to evaluate feeding behaviour traits as genetic indicators for ME and RFI in Australian Maternal Composite ewes using data from an automated feed intake facility. The feeding behaviour traits evaluated were the amount of time spent eating per day (eating time; ETD; min/day) and per visit (eating time per event; ETE; min/event), daily number of events (DNE), event feed intake (EFI; g/event) and eating rate (ER; g/min).

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Maternal diversity based on a sub-region of mitochondrial genome or variants were commonly used to understand past demographic events in livestock. Additionally, there is growing evidence of direct association of mitochondrial genetic variants with a range of phenotypes. Therefore, this study used complete bovine mitogenomes from a large sequence database to explore the full spectrum of maternal diversity.

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Background: Urinary nitrogen leakage is an environmental concern in dairy cattle. Selection for reduced urinary nitrogen leakage may be done using indicator traits such as milk urea nitrogen (MUN). The result of a previous study indicated that the genetic correlation between MUN in Australia (AUS) and MUN in New Zealand (NZL) was only low to moderate (between 0.

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Background: Heat tolerance is a trait of economic importance in the context of warm climates and the effects of global warming on livestock production, reproduction, health, and well-being. This study investigated the improvement in prediction accuracy for heat tolerance when selected sets of sequence variants from a large genome-wide association study (GWAS) were combined with a standard 50k single nucleotide polymorphism (SNP) panel used by the dairy industry.

Methods: Over 40,000 dairy cattle with genotype and phenotype data were analysed.

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Introduction: Previously published work has shown that there are no missed injuries following the introduction of a trauma triage clinic (TTC). This study aimed to assess both the safety and efficacy of the TTC model in a district general hospital in the United Kingdom. We aimed to assess the rate of missed 'high-risk' injuries, including posterior shoulder dislocations, talar injuries, Lisfranc injuries and complex carpal instability.

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Mutant alleles (MAs) that have been classically recognised have large effects on phenotype and tend to be deleterious to traits and fitness. Is this the case for mutations with small effects? We infer MAs for 8 million sequence variants in 113k cattle and quantify the effects of MA on 37 complex traits. Heterozygosity for variants at genomic sites conserved across 100 vertebrate species increase fertility, stature, and milk production, positively associating these traits with fitness.

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While understanding the genetic basis of heat tolerance is crucial in the context of global warming's effect on humans, livestock, and wildlife, the specific genetic variants and biological features that confer thermotolerance in animals are still not well characterized. We used dairy cows as a model to study heat tolerance because they are lactating, and therefore often prone to thermal stress. The data comprised almost 0.

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