Project description:Some studies have shown that manual asymmetries decrease in older age. These results have often been explained with reference to models of reduced hemispheric specialisation. An alternative explanation, however, is that hand differences are subtle, and capturing them requires tasks that yield optimal performance with both hands. Whereas the hemispheric specialisation account implies that reduced manual asymmetries should be reliably observed in older adults, the 'measurement difficulty' account suggests that manual asymmetries will be hard to detect unless a task has just the right level of difficulty--i.e. within the 'Goldilocks Zone', where it is not too easy or too hard, but just right. Experiment One tested this hypothesis and found that manual asymmetries were only detected when participants performed in this zone; specifically, performance on a tracing task was only superior in the preferred hand when task constraints were high (i.e. fast speed tracing). Experiment Two used three different tasks to examine age differences in manual asymmetries; one task produced no asymmetries, whilst two tasks revealed asymmetries in both younger and older groups (with poorer overall performance in the old group across all tasks). Experiment Three revealed task-dependent asymmetries in both age groups, but highlighted further detection difficulties linked with the metric of performance and compensatory strategies used by participants. Results are discussed with reference to structural learning theory, whereby we suggest that the processes of inter-manual transfer lead to relatively small performance differences between the hands (despite a strong phenomenological sense of performance disparities).
Project description:Rationale: PZP (pregnancy zone protein) is a broad-spectrum immunosuppressive protein believed to suppress T-cell function during pregnancy to prevent fetal rejection. It has not previously been reported in the airway.Objectives: To characterize PZP in the bronchiectasis airway, including its relationship with disease severity.Methods: Label-free liquid chromatography/mass spectrometry was performed for sputum protein profiling of patients with bronchiectasis confirmed by high-resolution computed tomography. Results for patients with and without Pseudomonas aeruginosa infection were compared. Sputum and serum PZP was measured by validated ELISA. Airway infection status was established by culture and 16S ribosomal RNA sequencing. Immunofluorescence, ELISA, and electron microscopy were used to identify the cellular source of PZP in neutrophils treated with multiple stimuli.Measurements and Main Results: Elevated PZP was identified by label-free liquid chromatography/mass spectrometry as being associated with P. aeruginosa infection. In a validation study of 124 patients, sputum but not serum concentrations of PZP were significantly associated with the Bronchiectasis Severity Index, the frequency of exacerbations, and symptoms. Airway infection with Proteobacteria such as P. aeruginosa was associated with higher concentrations of PZP. PZP in sputum was directly related to airway bacterial load. Neutrophils induced to form neutrophil extracellular traps (NETs) with phorbol myristate acetate released high concentrations of PZP in vitro, and fluorescence microscopy confirmed the presence of PZP in NETs, whereas fluorescence and electron microscopy localized PZP to the cytoplasm and nuclei of neutrophils. Effective antibiotic therapy reduced sputum PZP.Conclusions: PZP is released into NETs. We report a novel link between airway infection, NET formation, and disease severity in bronchiectasis during chronic airway inflammation.
Project description:BackgroundMusic performance anxiety is a common experience among elite and professional musicians and impedes performers from achieving flow state, or a state of focused, sustained engagement that promotes optimal performance.ObjectiveThe aim of this study was to use heart rate variability (HRV) to determine the psychophysiological underpinnings of optimal music performance.MethodsWe assessed HRV to study how autonomic-cardiac modulation was associated with flow during piano performance. Twenty-two pianists (15-22 years) with at least a Grade 8 Royal Conservatory of Music certification prepared two standardized pieces and a self-selected piece. Performer heart rate data were measured with a Polar 800 watch in 5-min periods immediately before performances, during performances and post-performance. HRV was employed to assess autonomic modulation of cardiac intervals. HRV indices of sympathetic and parasympathetic modulation of the heart were analyzed in 2.5-min segments to monitor short-term autonomic adjustments using the Kubios HRV Software. Flow state was measured using the 36-item Flow State Scale (FSS). Relationships were analyzed using zero-order correlations and multiple linear regressions.ResultsOur sample consisted of 22 RCM Grade 8 certified pianists. Participants achieved the highest level of flow during performance of the Bach piece. Decreased HRV was observed during performance, as indicated by a significant drop in total power. Flow state was positively associated with High Frequency (HF) power during the pre-performance phase, and inversely associated with Low Frequency (LF) power during performance.ConclusionInverse association of flow with LF-HRV during performance affirms the importance of vagal-HR modulation for achievement of flow state. Increased HF-HRV and reduced LF-HRV immediately prior to performance suggests that flow state may be shaped as much by physiological preparation during pre-performance as it is by physiologic responses during performance. Further research is required to validate the correlation between autonomic modulation of the heart and flow state. Evidence of this correlation between autonomic modulation of the heart and achievement of flow state may pave the way for further research on enhancing musical performance and targeting MPA through HRV-based interventions.
Project description:BackgroundExploring hybrid zone dynamics at different spatial scales allows for better understanding of local factors that influence hybrid zone structure. In this study, we tested hypotheses about drivers of introgression at two spatial scales within the Saltmarsh Sparrow (Ammospiza caudacuta) and Nelson's Sparrow (A. nelsoni) hybrid zone. Specifically, we evaluated the influence of neutral demographic processes (relative species abundance), natural selection (exogenous environmental factors and genetic incompatibilities), and sexual selection (assortative mating) in this mosaic hybrid zone. By intensively sampling adults (n = 218) and chicks (n = 326) at two geographically proximate locations in the center of the hybrid zone, we determined patterns of introgression on a fine scale across sites of differing habitat. We made broadscale comparisons of patterns from the center with those of prior studies in the southern edge of the hybrid zone.ResultsA panel of fixed SNPs (135) identified from ddRAD sequencing was used to calculate a hybrid index and determine genotypic composition/admixture level of the populations. Another panel of polymorphic SNPs (589) was used to assign paternity and reconstruct mating pairs to test for sexual selection. On a broad-scale, patterns of introgression were not explained by random mating within marshes. We found high rates of back-crossing and similarly low rates of recent-generation (F1/F2) hybrids in the center and south of the zone. Offspring genotypic proportions did not meet those expected from random mating within the parental genotypic distribution. Additionally, we observed half as many F1/F2 hybrid female adults than nestlings, while respective male groups showed no difference, in support of Haldane's Rule. The observed proportion of interspecific mating was lower than expected when accounting for mate availability, indicating assortative mating was limiting widespread hybridization. On a fine spatial scale, we found variation in the relative influence of neutral and selective forces between inland and coastal habitats, with the smaller, inland marsh influenced primarily by neutral demographic processes, and the expansive, coastal marsh experiencing higher selective pressures in the form of natural (exogenous and endogenous) and sexual selection.ConclusionsMultiple drivers of introgression, including neutral and selective pressures (exogenous, endogenous, and sexual selection), are structuring this hybrid zone, and their relative influence is site and context-dependent.
Project description:sputum from patients with bronchiectasis pooled together and sequenced for the purpose of investigating the effect of erythromycin on antibiotic resistance carriage
Project description:The Arctic Ocean region is currently undergoing dramatic changes, which will likely alter the nutrient cycles that underpin Arctic marine ecosystems. Phosphate is a key limiting nutrient for marine life but gaps in our understanding of the Arctic phosphorus (P) cycle persist. In this study, we investigate the benthic burial and recycling of phosphorus using sediments and pore waters from the Eurasian Arctic margin, including the Barents Sea slope and the Yermak Plateau. Our results highlight that P is generally lost from sediments with depth during organic matter respiration. On the Yermak Plateau, remobilization of P results in a diffusive flux of P to the seafloor of between 96 and 261 µmol m-2 yr-1. On the Barents Sea slope, diffusive fluxes of P are much larger (1736-2449 µmol m-2 yr-1), but these fluxes are into near-surface sediments rather than to the bottom waters. The difference in cycling on the Barents Sea slope is controlled by higher fluxes of fresh organic matter and active iron cycling. As changes in primary productivity, ocean circulation and glacial melt continue, benthic P cycling is likely to be altered with implications for P imported into the Arctic Ocean Basin. This article is part of the theme issue 'The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning'.
Project description:Giant exoplanets on wide orbits have been directly imaged around young stars. If the thermal background in the mid-infrared can be mitigated, then exoplanets with lower masses can also be imaged. Here we present a ground-based mid-infrared observing approach that enables imaging low-mass temperate exoplanets around nearby stars, and in particular within the closest stellar system, α Centauri. Based on 75-80% of the best quality images from 100 h of cumulative observations, we demonstrate sensitivity to warm sub-Neptune-sized planets throughout much of the habitable zone of α Centauri A. This is an order of magnitude more sensitive than state-of-the-art exoplanet imaging mass detection limits. We also discuss a possible exoplanet or exozodiacal disk detection around α Centauri A. However, an instrumental artifact of unknown origin cannot be ruled out. These results demonstrate the feasibility of imaging rocky habitable-zone exoplanets with current and upcoming telescopes.