Genetic diversity in the modern horse illustrated from genome-wide SNP data

Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. F(ST) calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection

Genetic Diversity in the Modern Horse Illustrated from Genome-Wide SNP Data

Horses were domesticated from the Eurasian steppes 5,000–6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. FST calculations, parsimony, and distance analysis demonstrated relationships among the breeds that largely reflect geographic origins and known breed histories. Low levels of population divergence were observed between breeds that are relatively early on in the process of breed development, and between those with high levels of within-breed diversity, whether due to large population size, ongoing outcrossing, or large within-breed phenotypic diversity. Populations with low within-breed diversity included those which have experienced population bottlenecks, have been under intense selective pressure, or are closed populations with long breed histories. These results provide new insights into the relationships among and the diversity within breeds of horses. In addition these results will facilitate future genome-wide association studies and investigations into genomic targets of selection

A High Density SNP Array for the Domestic Horse and Extant Perissodactyla: Utility for Association Mapping, Genetic Diversity, and Phylogeny Studies

An equine SNP genotyping array was developed and evaluated on a panel of samples representing 14 domestic horse breeds and 18 evolutionarily related species. More than 54,000 polymorphic SNPs provided an average inter-SNP spacing of ∼43 kb. The mean minor allele frequency across domestic horse breeds was 0.23, and the number of polymorphic SNPs within breeds ranged from 43,287 to 52,085. Genome-wide linkage disequilibrium (LD) in most breeds declined rapidly over the first 50–100 kb and reached background levels within 1–2 Mb. The extent of LD and the level of inbreeding were highest in the Thoroughbred and lowest in the Mongolian and Quarter Horse. Multidimensional scaling (MDS) analyses demonstrated the tight grouping of individuals within most breeds, close proximity of related breeds, and less tight grouping in admixed breeds. The close relationship between the Przewalski's Horse and the domestic horse was demonstrated by pair-wise genetic distance and MDS. Genotyping of other Perissodactyla (zebras, asses, tapirs, and rhinoceros) was variably successful, with call rates and the number of polymorphic loci varying across taxa. Parsimony analysis placed the modern horse as sister taxa to Equus przewalski. The utility of the SNP array in genome-wide association was confirmed by mapping the known recessive chestnut coat color locus (MC1R) and defining a conserved haplotype of ∼750 kb across all breeds. These results demonstrate the high quality of this SNP genotyping resource, its usefulness in diverse genome analyses of the horse, and potential use in related species

Comparison of the Human Transcriptional Response to Three Hypoxic Environments

DTFAWA-10-C-00080Hypoxia awareness training is a standard facet of military aviator training that is performed to familiarize aviators with the symptoms of hypoxia. The three most common training devices are the hypobaric altitude chamber (AC), the normobaric reduced oxygen breathing device (ROBD), and the normobaric reduced oxygen breathing environment (ROBE). The AC creates hypoxic conditions using reduced atmospheric pressure. The ROBD and ROBE create normobaric hypoxic conditions by supplying a controlled reduced-oxygen gas mixture to trainees who don an aviation-style breathing mask or occupy a sealed chamber, respectively. To determine if differences in the transcriptional response to each of these training devices exist, blood ribonucleic acid (RNA) samples from ten volunteer participants were analyzed by microarray. The resulting gene expression measures were screened for significant changes across time points within and across device runs. Few genes were significant in these comparisons; the most significant differences between timepoints were observed in small nucleolar RNAs and noncoding RNAs, as well as one microRNA and one transfer RNA. The transcriptional response to each training device differs slightly as determined by differences in transcription between time points. However, the role of these transcriptional changes is unclear, as little information exists as to their function or role in the hypoxic response. As all the examined methods induced hypoxic symptoms, and very little difference was observed in gene expression between methods, this limited study did not detect the presence of substantial differences between hypoxia awareness training devices. Future studies using more sensitive sequencing-based gene expression analysis techniques and larger sample sizes may improve the detection of transcriptional differences induced by each training device

Genetic Diversity in the Modern Horse Illustrated from Genome-Wide SNP Data

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Genome-Wide Analysis Reveals Selection for Important Traits in Domestic Horse Breeds

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Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Records Review of Musculoskeletal Injuries in Aeromedical Evacuation Personnel

Background: Aeromedical evacuation providers care for patients during air transport. By applying standard medical practices, oftentimes developed for ground care, these practitioners perform their mission duties under additional physical stress in this unique medical environment. Awkward postures and excessive forces are common occurrences among personnel operating in this domain. Additionally, anecdotal reports highlight the risk of developing musculoskeletal injuries for these providers. Currently, there is limited research focusing on musculoskeletal injuries in aeromedical evacuation providers. Purpose: To determine the prevalence of musculoskeletal injuries and associated symptoms in aeromedical evacuation providers to understand the risk and burden of these injuries to military personnel. Methods: This study utilized a retrospective review of military medical records containing ICD-9 codes to investigate the incidence of musculoskeletal injuries within flight nurses and medical technicians compared to their non-flying counterparts from 2006 through 2011. Data were analyzed from 2013 through 2014. Results: Although musculoskeletal injuries were identified within the test populations, results showed fewer injuries for aeromedical evacuation populations compared to non–aeromedical evacuation counterparts. Conclusions: One contributing factor may be a potential under-reporting of musculoskeletal injuries resulting from the fear of being placed on limited flying status. As flyers, aeromedical evacuation personnel must undergo yearly medical examinations and complete training courses that emphasize proper lifting techniques and physical requirements necessary for the safe and efficient transport of patients on various platforms. These additional requirements may create a healthy worker effect, likely contributing to lower musculoskeletal injuries

The Modified and Extended Hospital Elder Life Program: A remote model of care to expand delirium prevention

BackgroundDelirium is a common complication of hospitalization and is associated with poor outcomes. Multicomponent delirium prevention strategies such as the Hospital Elder Life Program (HELP) have proven effective but rely on face-to-face intervention protocols and volunteer staff, which was not possible due to restrictions during the COVID-19 pandemic. We developed the Modified and Extended Hospital Elder Life Program (HELP-ME), an innovative adaptation of HELP for remote and/or physically distanced applications.MethodsHELP-ME protocols were adapted from well-established multicomponent delirium prevention strategies and were implemented at four expert HELP sites. Each site contributed to the protocol modifications and compilation of a HELP-ME Operations Manual with standardized protocols and training instructions during three expert panel working groups. Implementation was overseen and monitored during seven learning sessions plus four coaching sessions from January 8, 2021, through September 24, 2021. Feasibility of implementing HELP-ME was measured by protocol adherence rates. Focus groups were conducted to evaluate the acceptability, provide feedback, and identify facilitators and barriers to implementation.ResultsA total of 106 patients were enrolled across four sites, and data were collected for 214 patient-days. Overall adherence was 82% (1473 completed protocols/1798 patient-days), achieving our feasibility target of >75% overall adherence. Individual adherence rates ranged from 55% to 96% across sites for the individual protocols. Protocols with high adherence rates included the nursing delirium protocol (96%), nursing medication review (96%), vision (89%), hearing (87%), and orientation (88%), whereas lower adherence occurred with fluid repletion (64%) and range-of-motion exercises (55%). Focus group feedback was generally positive for acceptability, with recommendations that an optimal approach would be hybrid, balancing in-person and remote interventions for potency and long-term sustainability.ConclusionsHELP-ME was fully implemented at four HELP sites, demonstrating feasibility and acceptability. Testing hybrid approaches and evaluating effectiveness is recommended for future work.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/176043/1/jgs18212_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176043/2/jgs18212.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/176043/3/jgs18212-sup-0001-TableS1.pd