Optimal Spindle Detection Parameters for Predicting Cognitive Performance

Study Objectives Alterations in sleep spindles have been linked to cognitive impairment. This finding has contributed to a growing interest in identifying sleep-based biomarkers of cognition and neurodegeneration, including sleep spindles. However, flexibility surrounding spindle definitions and algorithm parameter settings present a methodological challenge. The aim of this study was to characterize how spindle detection parameter settings influence the association between spindle features and cognition and to identify parameters with the strongest association with cognition. Methods Adult patients (n=167, 49 ± 18 years) completed the NIH Toolbox Cognition Battery after undergoing overnight diagnostic polysomnography recordings for suspected sleep disorders. We explored 1000 combinations across seven parameters in Luna, an open-source spindle detector, and used four features of detected spindles (amplitude, density, duration, and peak frequency) to fit linear multiple regression models to predict cognitive scores. Results Spindle features (amplitude, density, duration, and mean frequency) were associated with the ability to predict raw fluid cognition scores (r=0.503) and age-adjusted fluid cognition scores (r=0.315) with the best spindle parameters. Fast spindle features generally showed better performance relative to slow spindle features. Spindle features weakly predicted total cognition and poorly predicted crystallized cognition regardless of parameter settings. Conclusion Our exploration of spindle detection parameters identified optimal parameters for studies of fluid cognition and revealed the role of parameter interactions for both slow and fast spindles. Our findings support sleep spindles as a sleep-based biomarker of fluid cognition.

Analysis On Short-Term Change of Macular Function and The Correlates After Intravitreal Conbercept for CRVO-ME

•AIM: To study the short-term change of macular function and the correlates after intravitreal conbercept for CRVO-ME•STUDY DESIGN: Prospective,clinical study.•METHODS: 23 patients(23 eyes) were recruited, who were non-ischemia central retinal vein occlusion dianosed by FFA (fundus fluorescein angiography) and treated with intravitreal conbercept for macular edema. best - corrected visual acuity ( BCVA ),central macular thickness(CMT), amplitude density of P1 wave and implicit time of P1,N1 wave from ring 1 and ring 2 of mf-ERG were measured before and 1week、2month after treatment.•RESULTS: Compared to the baseline, BCVA、CMT、amplitude density of P1 wave and implicit time of P1,N1 wave from ring 1 and ring 2 were greatly improved at 1W、2M after treatment; better results were gained at 2M compared to 1W; Pearson correlation analysis shows no significantly correlation between the improvement of mf-ERG with the change of BCVA、CMT.•CONCLUSION: The BCVA、the strcture and the function of macular were greatly improved after intravitreal conbercept for central retinal vein occlusion induced macular edema; therefore no significantly correlation between the improvement of the function of macular with the strcture of macular and BCVA.

Interactions, space presentations, blocks and cross products

Physics counts four basic forces, the electromagnetic EMI, weak WI, strong SI interactions and gravity GR. The first three are provided with a unified theory which partly needs revision and has the symmetry U(1)xSU(2)xSU(3). In this article their space presentations are described in order to inlcude a theory for gravity which cannot be added directly to the standrd model. There are many instances of gravitational actions which are different from the other three interactions. Gravity uses geometrical models beside spactime, often projective, including stereographic and spiralic orthogonal subspace projections. Real and complex cross products, symmetries which belong to the complex Moebius transformation subgroups, complex cross ratios, Gleason frame GF measures, dihedrals nth roots of unity with symmetris are some new tools (figure 14) for a new gravity model. The basic vector space is 8-dimensional, but beside the usual vector addition and calculus there are different multiplications added. The author uses complex multiplications in the complex 4-dimensional space C4 for calculus. The SU (3) multiplication of GellMann 3x3-matrices is used for C³ and its three 4-dimensional C² projections. Projective spaces are CP² for nucleons and a GR Higgs plane P² and projective measuring GF‘s which have 3-dimensional, orthogonal base vectors like spin. The doubling of quaternionic spacetime to octonians has a different multiplication and seven GF‘s which partly occur in physics as cross product equations. Beside the real, the complex cross product extends the spacetime dimensions from 4 to 8. Consequences are that there are many 3-dimensional, many 4-dimensional, some 6-dimensional and also projective 5-dimensional spaces in which the actions of gravity can then be described. Spacetime is for this not sufficient. No symmetry can be muliplied to the standard model since the new symmetries belong to different geometries and are not directly related to a set of field quantums like one photon for EMI, three weak bosons (or four) for WI, eight gluons for SI. GR has graviton waves similar to EMI waves and in quasiparticle form rgb-graviton whirls, for mass Higgs bosons, maybe also solitons (density as mass per volume changing). They attribute to a distance metric between two points (kept fixed) an amplitude density (operator} which changes the metrical diameter of the volume, but not the mass.

Possible association between spindle frequency and reversal-learning in aged family dogs

In both humans and dogs sleep spindle occurrence between acquisition and recall of a specific memory correlate with learning performance. However, it is not known whether sleep spindle characteristics are also linked to performance beyond the span of a day, except in regard to general mental ability in humans. Such a relationship is likely, as both memory and spindle expression decline with age in both species (in dogs specifically the density and amplitude of slow spindles). We investigated if spindle amplitude, density (spindles/minute) and/or frequency (waves/second) correlate with performance on a short-term memory and a reversal-learning task in old dogs (> 7 years), when measurements of behavior and EEG were on average a month apart. Higher frequencies of fast (≥ 13 Hz) spindles on the frontal and central midline electrodes, and of slow spindles (≤ 13 Hz) on the central midline electrode were linked to worse performance on a reversal-learning task. The present findings suggest a role for spindle frequency as a biomarker of cognitive aging across species: Changes in spindle frequency are associated with dementia risk and onset in humans and declining learning performance in the dog.

Combination of Multifocal Electroretinogram and Spectral-Domain OCT Can Increase Diagnostic Efficacy of Parkinson’s Disease

Background. The retinal changes have been identified in morphology and function in Parkinson’s disease (PD). However, the controversial results suggest that it is incredible that only using a single method for testing retinal change to evaluate Parkinson’s disease. The aim of this study was to assess retinal changes and increase the diagnostic efficacy of Parkinson’s disease with a combination of multifocal electroretinogram (mf-ERG) and spectral domain optical coherence tomography (SD-OCT) examinations. Method. Fifty-three PD patients and forty-one healthy controls were enrolled. Subjects were assessed for retinal function using mf-ERG and retinal structure using SD-OCT. Results. The PD patients had a significantly decreased amplitude density of P1 and a delayed implicit time of P1 in some regions. The macular retinal thickness, macular volume, and average RNFL thickness were decreased in PD. The AUC of a single parameter of either retinal function or structure was low. Both of them were higher in diagnostic value to discriminate PD patients. Conclusion. The amplitude density of P1 combined with macular volume can get a high diagnostic efficacy to discriminate between participants with or without PD. It indicates that a combination of mf-ERG and SD-OCT provides a good clinical biomarker for diagnosis of PD.

On the edge of the foreshock: model-data comparisons

We present the results of a global hybrid code simulation for the solar wind-interaction with the Earth's magnetosphere during an interval of steady radial IMF. The model predicts a foreshock marked by innumerable localized, correlated, and large amplitude, density and magnetic field strength variations, depressed velocities, and enhanced temperatures. The foreshock is bounded by a broad (~0.8 RE) region of enhanced densities, temperatures, and magnetic field strengths that extends far (~8.6 RE) upstream from the bow shock. Flow perturbations within the boundary are directed perpendicular to the boundary, towards the unperturbed solar wind and away from the foreshock. Cluster observations of the ion foreshock and pristine solar wind confirm the predictions of the model. The observations suggest that foreshock cavities, crater-like density and magnetic field strength structures whose cores are filled with suprathermal particles, can be interpreted in terms of transient encounters with the foreshock boundary.