Publications by authors named "Sharpe G"

Article Synopsis
  • The study aims to see if changes in macular perfusion density (PD) can be detected through OCTA imaging before the thinning of the ganglion cell layer (GCL) in patients with early glaucoma.
  • Researchers compared OCT and OCTA imaging in 80 glaucoma patients and 42 healthy subjects every 4 months, assessing GCL thickness and macular PD in different areas of the retina.
  • Results indicated that a decrease in GCL thickness often occurs before noticeable changes in macular PD, suggesting that tracking GCL thickness may be more effective in identifying early glaucoma progression.
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Introduction: Dyspnoea perception is influenced by a complex interplay of physiological, psychological, and environmental factors. Recently, we showed that males with high trait self-control experience less dyspnoea and persist for longer in a carbon dioxide (CO) rebreathing challenge than males with low trait self-control. As self-control can also vary within individuals (state self-control), the primary aim of the present study was to investigate whether prior self-control exertion influenced perceptions of dyspnoea and tolerance of a CO rebreathing challenge in healthy young males.

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Objective: To compare the agreement and repeatability of intraocular pressure (IOP) measured with the slit lamp-mounted ST500 rebound tonometer (iCare Finland Oy), the hand-held IC200 rebound tonometer (iCare Finland Oy), and Goldmann applanation tonometry (GAT).

Design: Cross-sectional study.

Participants: Glaucoma patients and staff of the Eye Care Centre, Nova Scotia Health.

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Article Synopsis
  • The study aims to evaluate how effectively the thickness of different macular retinal layers can differentiate glaucomatous eyes and glaucoma suspects from healthy eyes using optical coherence tomography (OCT).
  • The findings reveal that the nerve fiber layer (NFL) and ganglion cell layer (GCL) have the best diagnostic accuracy, with the ganglion cell complex (GCC) performing similarly, while the inner plexiform layer (IPL) is less effective. The combination of NFL or GCL yields the highest sensitivity and overall diagnostic performance.
  • The results underscore the necessity of assessing individual retinal layers rather than relying solely on combined metrics, as the best-performing layers can vary based on the specific area of the retina
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Purpose: To assess the impact of working distance (WD) on optical distortion in optical coherence tomography (OCT) imaging and to evaluate the effectiveness of optical distortion correction in achieving consistent retinal Bruch's membrane (BM) layer curvature, regardless of variations in WD.

Methods: Ten subjects underwent OCT imaging with four serial macular volume scans, each employing distinct WD settings adjusted by balancing the sample and reference arm of the OCT interferometer (eye length settings changed). Either of two types of 30° standard objectives (SOs) was used.

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Lactate is an important energy intermediate and metabolic buffer, and may be ergogenic. We investigated if lactate supplementation is an effective approach to enhance the exercise performance and acid-base balance of trained cyclists during exercise devised to simulate the demands of endurance road race cycling. Sixteen endurance-trained male cyclists (V·O 59 ± 7 mL·kg·min) consumed 120 mg·kg body mass of lactate or a placebo 70 min prior to performing an exercise performance test, comprising five repeated blocks consisting of 1 km and 4 km time trials interspersed with 10 min of moderate-intensity exercise.

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Deformed wing virus (DWV) is a pathogenic virus of honey bees transmitted by the ectoparasitic mite . Annual overwintering colony losses, accounting for ~25% of all colonies, are associated with high levels of Varroa-DWV infestation. Effective miticide treatments are available to control Varroa.

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Microbial community dynamics on sinking particles control the amount of carbon that reaches the deep ocean and the length of time that carbon is stored, with potentially profound impacts on Earth's climate. A mechanistic understanding of the controls on sinking particle distributions has been hindered by limited depth- and time-resolved sampling and methods that cannot distinguish individual particles. Here, we analyze microbial communities on nearly 400 individual sinking particles in conjunction with more conventional composite particle samples to determine how particle colonization and community assembly might control carbon sequestration in the deep ocean.

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Bacteria employ antagonistic strategies to eliminate competitors of an ecological niche. Contact-dependent mechanisms, such as the type VI secretion system (T6SS), are prevalent in host-associated bacteria, yet we know relatively little about how T6SS+ strains make contact with competitors in highly viscous environments, such as host mucus. To better understand how cells respond to and contact one another in such environments, we performed a genome-wide transposon mutant screen of the T6SS-wielding beneficial bacterial symbiont, , and identified two sets of genes that are conditionally required for killing.

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Purpose: To determine whether more severe baseline damage impedes measurement of minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness (RNFLT) change in glaucoma patients because of a floor effect.

Design: Prospective, longitudinal cohort study in a hospital-based setting.

Participants: The study included patients with open-angle glaucoma and healthy control subjects.

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Background/aims: Optical coherence tomography angiography (OCT-A) images are subject to variability, but the extent to which learning impacts OCT-A measurements is unknown. We determined whether there is a learning effect in glaucoma patients and healthy controls imaged with OCT-A.

Methods: Ninety-one open-angle glaucoma patients and 54 healthy controls were imaged every 4 months over a period of approximately 1 year in this longitudinal cohort study.

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Synechococcus are the most abundant cyanobacteria in high latitude regions and are responsible for an estimated 17% of annual marine net primary productivity. Despite their biogeochemical importance, Synechococcus populations have been unevenly sampled across the ocean, with most studies focused on low-latitude strains. In particular, the near absence of Synechococcus genomes from high-latitude, High Nutrient Low Chlorophyll (HNLC) regions leaves a gap in our knowledge of picocyanobacterial adaptations to iron limitation and their influence on carbon, nitrogen, and iron cycles.

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Purpose: To determine the prevalence and magnitude of optical coherence tomography (OCT) exposed neural canal (ENC), externally oblique choroidal border tissue (EOCBT), and exposed scleral flange (ESF) regions in 362 non-highly myopic (spherical equivalent -6.00 to 5.75 diopters) eyes of 362 healthy subjects.

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The respiratory muscle pressure generation and inspiratory and expiratory neuromuscular recruitment patterns in younger and older men were compared during exercise, alongside descriptors of dyspnea. Healthy younger (n = 8, 28 ± 5 years) and older (n = 8, 68 ± 4 years) men completed a maximal incremental cycling test. Esophageal, gastric (P ) and transdiaphragmatic pressures, and electromyography (EMG) of the crural diaphragm were measured using a micro-transducer and EMG catheter.

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Purpose: Histological evidence indicates that the earliest structural changes to the optic nerve head (ONH) in glaucoma occur in the lamina cribrosa (LC) and its interface with the sclera. However, clinical imaging of these structures remains challenging. We compared the visibility of deep ONH structures with newer iterations of spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT).

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Objectives: Elite rugby union players face numerous physiological and psychological stressors which can increase upper respiratory and gastrointestinal illness risk, and in turn can compromise training and competitive performance. This study aimed to investigate the effect of daily prebiotic supplementation on upper respiratory symptoms, gastrointestinal symptoms, and markers of immune function in elite rugby union players.

Methods: Thirty-three elite rugby union players were randomly assigned to consume a prebiotic (2.

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The type VI secretion system (T6SS) is an interbacterial weapon composed of thousands of protein subunits and predicted to require significant cellular energy to deploy, yet a fitness cost from T6SS use is rarely observed. Here, we identify host-like conditions where the T6SS incurs a fitness cost using the beneficial symbiont, , which uses its T6SS to eliminate competitors in the natural squid host. We hypothesized that a fitness cost for the T6SS could be dependent on the cellular energetic state and used theoretical ATP cost estimates to predict when a T6SS-dependent fitness cost may be apparent.

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Purpose: To use optical coherence tomography (OCT) to characterize optic nerve head (ONH) peri-neural canal (pNC) scleral bowing (pNC-SB) and pNC choroidal thickness (pNC-CT) in 69 highly myopic and 138 healthy, age-matched, control eyes.

Design: Cross-sectional, case control study.

Methods: Within ONH radial B-scans, Bruch membrane (BM), BM opening (BMO), anterior scleral canal opening (ASCO), and pNC scleral surface were segmented.

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Purpose: The purpose of this study was to determine if there is asymmetry in retinal blood vessel (RBV) position and thickness between right and left eyes (R-L) and evaluate whether R-L asymmetry in RBV thickness is related to R-L asymmetry of retinal nerve fiber layer thickness (RNFLT).

Methods: We analyzed peripapillary circle scan optical coherence tomography (OCT) examinations from healthy White subjects to measure RNFLT and RBV thickness and position relative to the fovea to Bruch's membrane opening axis, for all visible RBV. The R-L asymmetries of RNFLT and RBV thickness were computed for each A-scan.

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Background: Community pharmacies have long been advocated as an accessible source of advice on health improvement in communities. This cross-sectional study explored the association between provision of pharmacy public health services and factors that might influence the extent to which pharmacies contribute to tackling inequalities.

Methods: Publically available data were used to explore the association between pharmacy public health service provision and pharmacy characteristics (socioeconomic deprivation, urbanity, opening hours and workload).

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Introduction: Exercise-induced bronchoconstriction (EIB) is a prevalent condition in athletes. EIB screening studies identify many athletes with undiagnosed EIB. Moreover, there is a poor relationship between EIB and dyspnea symptoms recalled from memory.

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Background: High trait self-control is associated with greater tolerance of unpleasant sensations including effort and pain. Dyspnoea and pain have several commonalities and this study aimed to investigate for the first time whether trait self-control influences responses to a hypercapnic rebreathing challenge designed to induce dyspnoea. As sex also influences tolerance to dyspnoea, we also sought to investigate whether this moderated the role of trait self-control.

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Correlation between structural data from optical coherence tomography and functional data from the visual field may be suboptimal because of poor mapping of OCT measurement locations to VF stimuli. We tested the hypothesis that stronger structure-function correlations in the macula can be achieved with fundus-tracking perimetery, by precisely mapping OCT measurements to VF sensitivity at the same location. The conventional 64 superpixel (3° × 3°) OCT grid was mapped to VF sensitivities averaged in 40 corresponding VF units with standard automated perimetry (conventional mapped approach, CMA) in 38 glaucoma patients and 10 healthy subjects.

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Introduction: Glycogen storage diseases (GSDs) are rare inborn errors of carbohydrate metabolism typically with skeletal muscle and liver involvement. In those with skeletal muscle involvement, the majority display symptoms of exercise intolerance which can cause profound exercise limitation and impair everyday living and quality of life (QoL). There are no curative treatments for GSDs, thus therapeutic options, such as exercise training, are aimed at improving QoL by alleviating signs and symptoms.

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Purpose: To determine the impact of glaucoma severity on rates of change of minimum rim width (MRW), peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell layer (GCL) thickness.

Design: Prospective, cohort study.

Methods: Glaucoma patients and healthy subjects had optical coherence tomography scans at 6-month intervals.

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