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Cortical, muscular, and kinetic activity underpinning attentional focus strategies during visuomotor control
Get PDFFocusing internally on movement control or bodily sensations is frequently shown to disrupt the effectiveness and efficiency of motor control when compared to focusing externally on the outcome of movement. Whilst the behavioral consequences of these attentional strategies are well-documented, it is unclear how they are explained at the corticomuscular level. The aim of the present study was to investigate how attentional focus strategies affect kinetic, cortical, muscular, and corticomuscular activity during an isometric force precision task. In a repeated measures design, we measured force, EEG and EMG activity from twenty-seven participants who performed isometric contractions of the right hand whilst encouraged to adopt either an internal or external focus through a combination of instructions, secondary tasks, and self-report evaluations. Results indicated that focusing internally led to poorer force accuracy and steadiness compared to an external focus. An internal focus also increased muscle activity of the forearm flexor, increased EEG alpha activity across the parieto-occipital cortex, lowered frontal midline EEG theta activity, and lowered beta corticomuscular coherence between the forearm flexor and contralateral motor cortex. The results of this study provide a holistic understanding of how attentional focus strategies alter corticomuscular control during an isometric force precision task, paving the way for exploring how the behavioral consequences of attentional strategies can be explained at the corticomuscular levels across a wide range of motor tasks and contexts. [Abstract copyright: © 2023 The Authors. Psychophysiology published by Wiley Periodicals LLC on behalf of Society for Psychophysiological Research.
Aposematism and Batesian mimicry in snakes: through the visible spectrum and beyond?
Get PDFWe explore the usefulness of UV photography in investigating putative Batesian mimicry of aposematic elapid snakes by harmless colubrids. We predicted that Batesian mimics would share similar UV reflectance patterns as their models and tested this in two likely Batesian mimicry systems. In North America, both Micruroides euryxanthus and Lampropeltis knoblochi lack any UV reflectance from any part of their dorsum. In India, Bungarus caeruleus displays strong UV reflectance from its light body rings, which is largely echoed in visually similar black and white Lycodon anamallensis, but not in reddish-brown individuals of the same species. Our results highlight the potential for UV photography to contribute to testing mimicry hypotheses. Researchers using inanimate models to test the function of animal patterns need to consider reflectance outside the human visual spectrum to maximise the resemblance of their models to the focal organisms
Writing the Robinsonade Novel in Context of Globalism and Self-Enlightenment: E Pluribus Unum
Get PDFImpact of Phylogenetic Tree Completeness and Misspecification of Sampling Fractions on Trait Dependent Diversification Models
Get PDFUnderstanding the origins of diversity and the factors that drive some clades to be more diverse than others are important issues in evolutionary biology. Sophisticated SSE (state-dependent speciation and extinction) models provide insights into the association between diversification rates and the evolution of a trait. The empirical data used in SSE models and other methods is normally imperfect, yet little is known about how this can affect these models. Here, we evaluate the impact of common phylogenetic issues on inferences drawn from SSE models. Using simulated phylogenetic trees and trait information, we fitted SSE models to determine the effects of sampling fraction (phylogenetic tree completeness) and sampling fraction mis-specification on model selection and parameter estimation (speciation, extinction, and transition rates) under two sampling regimes (random and taxonomically biased). As expected, we found that both model selection and parameter estimate accuracies are reduced at lower sampling fractions (i.e., low tree completeness). Furthermore, when sampling of the tree is imbalanced across sub-clades and tree completeness is ≤ 60%, rates of false positives increase and parameter estimates are less accurate, compared to when sampling is random. Thus, when applying SSE methods to empirical datasets, there are increased risks of false inferences of trait dependent diversification when some sub-clades are heavily under-sampled. Mis-specifying the sampling fraction severely affected the accuracy of parameter estimates: parameter values were over-estimated when the sampling fraction was specified as lower than its true value, and under-estimated when the sampling fraction was specified as higher than its true value. Our results suggest that it is better to cautiously under-estimate sampling efforts, as false positives increased when the sampling fraction was over-estimated. We encourage SSE studies where the sampling fraction can be reasonably estimated and provide recommended best practices for SSE modeling. [Trait dependent diversification; SSE models; phylogenetic tree completeness; sampling fraction.].</p
Tau-mediated axonal degeneration is prevented by activation of the WldS pathway
Get PDFTauopathy is characterized by neuronal dysfunction and degeneration occurring as a result of changes to the microtubule-associated protein tau. The neuronal changes evident in tauopathy bear striking morphological resemblance to those reported in models of Wallerian degeneration. The mechanisms underpinning Wallerian degeneration are not fully understood although it can be delayed by the expression of the slow Wallerian degeneration (Wld S) protein, which has also been demonstrated to delay axonal degeneration in some models of neurodegenerative disease. Given the morphological similarities between tauopathy and Wallerian degeneration, this study investigated whether tau-mediated phenotypes can be modulated by co-expression of Wld S. In a Drosophila model of tauopathy in which expression of human 0N3R tau protein leads to progressive age-dependent phenotypes, Wld S was expressed with and without activation of the downstream pathway. The olfactory receptor neuron circuit OR47b was used for these studies in adults, and the larval motor neuron system was employed in larvae. Tau phenotypes studied included neurodegeneration, axonal transport, synaptic deficits and locomotor behaviour. Impact on total tau was ascertained by assessing total, phosphorylated and misfolded tau levels by immunohistochemistry. Activation of the pathway downstream of Wld S completely suppressed tau-mediated degeneration. This protective effect was evident even if the pathway downstream of Wld S was activated several weeks after tau-mediated degeneration had become established. Though total tau levels were not altered, the protected neurons displayed significantly reduced MC1 immunoreactivity suggestive of clearance of misfolded tau, as well as a trend for a decline in tau species phosphorylated at the AT8 and PHF1 epitopes. In contrast, Wld S expression without activation of the downstream protective pathway did not rescue tau-mediated degeneration in adults or improve tau-mediated neuronal dysfunction including deficits in axonal transport, synaptic alterations and locomotor behaviour in tau-expressing larvae. This collectively implies that the pathway mediating the protective effect of Wld S intersects with the mechanism(s) of degeneration initiated by tau and can effectively halt tau-mediated degeneration at both early and late stages. Understanding the mechanisms underpinning this protection could identify much-needed disease-modifying targets for tauopathies. </p
Value of improving patient safety: Health-economic considerations for Rapid Response Systems – a Rapid Review of the Literature and Expert Round Table
Get PDFOBJECTIVES: Failure to rescue deteriorating patients in hospital is a well-researched topic. We aimed to explore the impact of safer care on health economic considerations for clinicians, providers and policymakers.DESIGN: We undertook a rapid review of the available literature and convened a round table of international specialists in the field including experts on health economics and value-based healthcare to better understand health economics of clinical deterioration and impact of systems to reduce failure to rescue.RESULTS: Only a limited number of publications have examined the health economic impact of failure to rescue. Literature examining this topic lacked detail and we identified no publications on long-term cost outside the hospital following a deterioration event. The recent pandemic has added limited literature on prevention of deterioration in the patients' home.Cost-effectiveness and cost-efficiency are dependent on broader system effects of adverse events. We suggest including the care needs beyond the hospital and loss of income of patients and/or their informal carers as well as sickness of healthcare staff exposed to serious adverse events in the analysis of adverse events. They are likely to have a larger health economic impact than the direct attributable cost of the hospital admission of the patient suffering the adverse event. Premorbid status of a patient is a major confounder for health economic considerations.CONCLUSION: In order to optimise health at the population level, we must limit long-term effects of adverse events through improvement of our ability to rapidly recognise and respond to acute illness and worsening chronic illness both in the home and the hospital.</p
The Effect of Mindfulness-Based Intervention on Cognitive Function and Wellbeing of People with Mild Traumatic Brain Injury and Refugees with PTSD
Get PDFHabitat suitability modelling for an integrated multi-trophic aquaculture (IMTA) system along Europe's Atlantic coast
Get PDFAs the human population grows, so too does the demand for resources. This demand has led to aquaculture becoming the fastest growing food production sector in the world. Due to environmental concerns associated with finfish aquaculture, Integrated Multi-Trophic Aquaculture (IMTA) has been proposed to minimise any negative impacts, by co-culturing extractive aquaculture species from different trophic levels to remove excess organic and inorganic nutrients, using them for their own growth. This study, in the Atlantic area of Europe, aimed to identify the most suitable locations to establish a new IMTA system for the 3 species Salmo salar (Linnaeus, 1758), Mytilus edulis (Linnaeus, 1758), and Laminaria digitata ((Hudson) JV Lamouroux, 1813). Habitat suitability models were created using spatial jackknifing testing within MaxEnt software and analysed using ArcGIS (ArcMap 10.8.1). All Maxent models were better than random when predicting species distribution, with AUC values of 0.889 (S. salar), 0.876 (M. edulis) and 0.901 (L. digitata), indicating a high level of predictive power. Jackknife testing identified Chlorophyll A (mg m−3) and Salinity (PSS) as the 2 most important variables in the model for each species. Coastal areas of the United Kingdom, Ireland and Northern France were identified as highly suitable, with suitability decreasing in more southern environments. These areas were then assessed based on local vessel density, whether they were within a Marine Protected Area (MPA), and the site accessibility from nearby ports, according to the expected needs of a large-scale aquaculture system. As MaxEnt used wild population data to produce the models, environmental conditions at suitable areas were compared against known Salmo salar aquaculture sites in Scotland to further validate the suitability for IMTA purposes. The results of this study, and the identification of optimal conditions for each species, will provide aquaculture businesses with the information required for preliminary site selection, with the goal of further incorporating IMTA systems into the EU market in a sustainable way
