3,934 research outputs found
Hyper-arousal decreases human visual thresholds
Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0–2° C water), a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1) and contrast thresholds (Experiment 2) were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal\u27s ability to decrease visual thresholds has important implications for survival, sports, and everyday life
Magnetic Domains in Magnetar Matter as an Engine for Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars
Magnetars have been suggested as the most promising site for the origin of
observed soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs). In
this work we investigate the possibility that SGRs and AXPs might be
observational evidence for a magnetic phase separation in magnetars. We study
magnetic domain formation as a new mechanism for SGRs and AXPs in which
magnetar-matter separates into two phases containing different flux densities.
We identify the parameter space in matter density and magnetic field strength
at which there is an instability for magnetic domain formation. We conclude
that such instabilities will likely occur in the deep outer crust for the
magnetic Baym, Pethick, and Sutherland (BPS) model and in the inner crust and
core for magnetars described in relativistic Hartree theory. Moreover, we
estimate that the energy released by the onset of this instability is
comparable with the energy emitted by SGRs.Comment: 4 figures, ApJ in pres
Novel Mast Cell-Stabilising Amine Derivatives of 3,4 Dihydronaphthalen-1(2H)-One and 6,7,8,9-Tetrahydro-5H-benzo[7]annulen-5-one
In an investigation of 4-amino-3,4-dihydronaphthalen-1(2H)-ones as novel modulators of allergic and inflammatory phenomena, we have investigated a series of cyclic analogues. Tertiary amines of structural types 9, 10, 20 and 21 were synthesised and evaluated for mast cell stabilising activity. In vitro and in vivo studies showed that of these compounds, the cyclohexenylamino derivatives of tetralone and benzosuberone of series 20 and 21 exhibited interesting activity both in vitro and in vivo
Time Is Not More Abstract Than Space in Sound
Time is talked about in terms of space more frequently than the other way around. Some have suggested that this asymmetry runs deeper than language. The idea that we think about abstract domains (like time) in terms of relatively more concrete domains (like space) but not vice versa can be traced to Conceptual Metaphor Theory. This theoretical account has some empirical support. Previous experiments suggest an embodied basis for space-time asymmetries that runs deeper than language. However, these studies frequently involve verbal and/or visual stimuli. Because vision makes a privileged contribution to spatial processing it is unclear whether these results speak to a general asymmetry between time and space based on each domain’s general level of relative abstractness, or reflect modality-specific effects. The present study was motivated by this uncertainty and what appears to be audition’s privileged contribution to temporal processing. In Experiment 1, using an auditory perceptual task, temporal duration and spatial displacement were shown to be mutually contagious. Irrelevant temporal information influenced spatial judgments and vice versa with a larger effect of time on space. Experiment 2 examined the mutual effects of space, time, and pitch. Pitch was investigated because it is a fundamental characteristic of sound perception. It was reasoned that if space is indeed less relevant to audition than time, then spatial distance judgments should be more easily contaminated by variations in auditory frequency, while variations in distance should be less effective in contaminating pitch perception. While time and pitch were shown to be mutually contagious in Experiment 2, irrelevant variation in auditory frequency affected estimates of spatial distance while variations in spatial distance did not affect pitch judgments. Results overall suggest that the perceptual asymmetry between spatial and temporal domains does not necessarily generalize across modalities, and that time is not generally more abstract than space
miRNA in Circulating Microvesicles as Biomarkers for Age-Related Cognitive Decline
Community dwelling older individuals from the North Florida region were examined for health status and a comprehensive neuropsychological battery, including the Montreal Cognitive Assessment (MoCA), was performed on each participant. A subpopulation (58 females and 39 males) met the criteria for age (60–89) and no evidence of mild cognitive impairment, with a MoCA score ≥23. Despite the stringent criteria for participation, MoCA scores were negatively correlated within the limited age range. Extracellular microvesicles were isolated from the plasma and samples were found to be positive for the exosome marker CD63, with an enrichment of particles within the size range for exosomes. miRNA was extracted and examined using next generation sequencing with a stringent criterion (average of ≥10 counts per million reads) resulting in 117 miRNA for subsequent analysis. Characterization of expression confirmed pervious work concerning the relative abundance and overall pattern of expression of miRNA in plasma. Correlation analysis indicated that most of the miRNAs (74 miRNAs) were positively correlated with age (p <0.01). Multiple regression was employed to identify the relationship of miRNA expression and MoCA score, accounting for age. MoCA scores were negatively correlated with 13 miRNAs. The pattern of expression for cognition-related miRNA did not match that previously described for Alzheimer’s disease. Enrichment analysis was employed to identify miRNA–gene interactions to reveal possible links to brain function
Impact of electrode selection on modeling tDCS in the aging brain
BackgroundPerson-specific computational models can estimate transcranial direct current stimulation (tDCS) current dose delivered to the brain and predict treatment response. Artificially created electrode models derived from virtual 10–20 EEG measurements are typically included in these models as current injection and removal sites. The present study directly compares current flow models generated via artificially placed electrodes (“artificial” electrode models) against those generated using real electrodes acquired from structural MRI scans (“real” electrode models) of older adults.MethodsA total of 16 individualized head models were derived from cognitively healthy older adults (mean age = 71.8 years) who participated in an in-scanner tDCS study with an F3-F4 montage. Visible tDCS electrodes captured within the MRI scans were segmented to create the “real” electrode model. In contrast, the “artificial” electrodes were generated in ROAST. Percentage differences in current density were computed in selected regions of interest (ROIs) as examples of stimulation targets within an F3-F4 montage.Main resultsWe found significant inverse correlations (p < 0.001) between median current density values and brain atrophy in both electrode pipelines with slightly larger correlations found in the artificial pipeline. The percent difference (PD) of the electrode distances between the two models predicted the median current density values computed in the ROIs, gray, and white matter, with significant correlation between electrode distance PDs and current density. The correlation between PD of the contact areas and the computed median current densities in the brain was found to be non-significant.ConclusionsThis study demonstrates potential discrepancies in generated current density models using real versus artificial electrode placement when applying tDCS to an older adult cohort. Our findings strongly suggest that future tDCS clinical work should consider closely monitoring and rigorously documenting electrode location during stimulation to model tDCS montages as closely as possible to actual placement. Detailed physical electrode location data may provide more precise information and thus produce more robust tDCS modeling results
DOMINO++: Domain-aware Loss Regularization for Deep Learning Generalizability
Out-of-distribution (OOD) generalization poses a serious challenge for modern
deep learning (DL). OOD data consists of test data that is significantly
different from the model's training data. DL models that perform well on
in-domain test data could struggle on OOD data. Overcoming this discrepancy is
essential to the reliable deployment of DL. Proper model calibration decreases
the number of spurious connections that are made between model features and
class outputs. Hence, calibrated DL can improve OOD generalization by only
learning features that are truly indicative of the respective classes. Previous
work proposed domain-aware model calibration (DOMINO) to improve DL
calibration, but it lacks designs for model generalizability to OOD data. In
this work, we propose DOMINO++, a dual-guidance and dynamic domain-aware loss
regularization focused on OOD generalizability. DOMINO++ integrates
expert-guided and data-guided knowledge in its regularization. Unlike DOMINO
which imposed a fixed scaling and regularization rate, DOMINO++ designs a
dynamic scaling factor and an adaptive regularization rate. Comprehensive
evaluations compare DOMINO++ with DOMINO and the baseline model for head tissue
segmentation from magnetic resonance images (MRIs) on OOD data. The OOD data
consists of synthetic noisy and rotated datasets, as well as real data using a
different MRI scanner from a separate site. DOMINO++'s superior performance
demonstrates its potential to improve the trustworthy deployment of DL on real
clinical data.Comment: 12 pages, 5 figures, 5 tables, Accepted by the International
Conference on Medical Image Computing and Computer Assisted Intervention
(MICCAI) 202
A Multicenter Examination and Strategic Revisions of the Yale Global Tic Severity Scale
Objective To examine the internal consistency and distribution of the Yale Global Tic Severity Scale (YGTSS) scores to inform modification of the measure. Methods This cross-sectional study included 617 participants with a tic disorder (516 children and 101 adults), who completed an age-appropriate diagnostic interview and the YGTSS to evaluate tic symptom severity. The distributions of scores on YGTSS dimensions were evaluated for normality and skewness. For dimensions that were skewed across motor and phonic tics, a modified Delphi consensus process was used to revise selected anchor points. Results Children and adults had similar clinical characteristics, including tic symptom severity. All participants were examined together. Strong internal consistency was identified for the YGTSS Motor Tic score (α = 0.80), YGTSS Phonic Tic score (α = 0.87), and YGTSS Total Tic score (α = 0.82). The YGTSS Total Tic and Impairment scores exhibited relatively normal distributions. Several subscales and individual item scales departed from a normal distribution. Higher scores were more often used on the Motor Tic Number, Frequency, and Intensity dimensions and the Phonic Tic Frequency dimension. By contrast, lower scores were more often used on Motor Tic Complexity and Interference, and Phonic Tic Number, Intensity, Complexity, and Interference. Conclusions The YGTSS exhibits good internal consistency across children and adults. The parallel findings across Motor and Phonic Frequency, Complexity, and Interference dimensions prompted minor revisions to the anchor point description to promote use of the full range of scores in each dimension. Specific minor revisions to the YGTSS Phonic Tic Symptom Checklist were also proposed
Investigation of hypomagnesaemia prevalence and underlying aetiology in a hospitalised cohort of dogs with ionised hypocalcaemia
- …