2,662 research outputs found
Automatic emotion perception using eye movement information for E-Healthcare systems.
Facing the adolescents and detecting their emotional state is vital for promoting rehabilitation therapy within an E-Healthcare system. Focusing on a novel approach for a sensor-based E-Healthcare system, we propose an eye movement information-based emotion perception algorithm by collecting and analyzing electrooculography (EOG) signals and eye movement video synchronously. Specifically, we extract the time-frequency eye movement features by firstly applying the short-time Fourier transform (STFT) to raw multi-channel EOG signals. Subsequently, in order to integrate time domain eye movement features (i.e., saccade duration, fixation duration, and pupil diameter), we investigate two feature fusion strategies: feature level fusion (FLF) and decision level fusion (DLF). Recognition experiments have been also performed according to three emotional states: positive, neutral, and negative. The average accuracies are 88.64% (the FLF method) and 88.35% (the DLF with maximal rule method), respectively. Experimental results reveal that eye movement information can effectively reflect the emotional state of the adolescences, which provides a promising tool to improve the performance of the E-Healthcare system.Anhui Provincial Natural Science Research Project of Colleges and Universities Fund under Grant KJ2018A0008, Open Fund for Discipline Construction under Grant Institute of Physical Science and Information Technology in Anhui University, and National Natural Science Fund of China under Grant 61401002
Nonabelian Monopoles from Matrices: Seeds of the Spacetime Structure
We study the expectation value of (the product) of the one-particle projector
(s) in the reduced matrix model and matrix quantum mechanics in general. This
quantity is given by the nonabelian Berry phase: we discuss the relevance of
this with regard to the spacetime structure. The case of the USp matrix model
is examined from this respect. Generalizing our previous work, we carry out the
complete computation of this quantity which takes into account both the nature
of the degeneracy of the fermions and the presence of the space time points
belonging to the antisymmetric representation. We find the singularities as
those of the SU(2) Yang monopole connection as well as the pointlike
singularities in 9+1 dimensions coming from its SU(8) generalization. The
former type of singularities, which extend to four of the directions lying in
the antisymmetric representations, may be regarded as seeds of our four
dimensional spacetime structure and is not shared by the IIB matrix model. From
a mathematical viewpoint, these connections can be generalizable to arbitrary
odd space dimensions due to the nontrivial nature of the eigenbundle and the
Clifford module structure.Comment: 29 pages, Latex, 1 epsf figur
Exactly solvable Wadati potentials in the PT-symmetric Gross-Pitaevskii equation
This note examines Gross-Pitaevskii equations with PT-symmetric potentials of
the Wadati type: . We formulate a recipe for the construction of
Wadati potentials supporting exact localised solutions. The general procedure
is exemplified by equations with attractive and repulsive cubic nonlinearity
bearing a variety of bright and dark solitons.Comment: To appear in Proceedings of the 15 Conference on Pseudo-Hermitian
Hamiltonians in Quantum Physics, May 18-23 2015, Palermo, Italy (Springer
Proceedings in Physics, 2016
Identification of Nedd4 E3 Ubiquitin Ligase as a Binding Partner and Regulator of MAK-V Protein Kinase
MAK-V/Hunk is a scantily characterized AMPK-like protein kinase. Recent findings identified MAK-V as a pro-survival and anti-apoptotic protein and revealed its role in embryonic development as well as in tumorigenesis and metastasis. However molecular mechanisms of MAK-V action and regulation of its activity remain largely unknown. We identified Nedd4 as an interaction partner for MAK-V protein kinase. However, this HECT-type E3 ubiquitin ligase is not involved in the control of MAK-V degradation by the ubiquitin-proteasome system that regulates MAK-V abundance in cells. However, Nedd4 in an ubiquitin ligase-independent manner rescued developmental defects in Xenopus embryos induced by MAK-V overexpression, suggesting physiological relevance of interaction between MAK-V and Nedd4. This identifies Nedd4 as the first known regulator of MAK-V function
Role of Apamin-Sensitive Calcium-Activated Small-Conductance Potassium Currents on the Mechanisms of Ventricular Fibrillation in Pacing-Induced Failing Rabbit Hearts
BACKGROUND:
Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF.
METHODS AND RESULTS:
Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation. At baseline and after apamin (100 nmol/L) infusion, the action potential duration (APD80) was determined, and VF was induced. Areas with a >50% increase in the maximum action potential duration (ΔAPD) after apamin infusion were considered to have a high IKAS distribution. At baseline, the distribution density of phase singularities during VF in high IKAS distribution areas was higher than in other areas (0.0035±0.0011 versus 0.0014±0.0010 phase singularities/pixel; P=0.004). In addition, high dominant frequencies also colocalized to high IKAS distribution areas (26.0 versus 17.9 Hz; P=0.003). These correlations were eliminated during VF after apamin infusion, as the number of phase singularities (17.2 versus 11.0; P=0.009) and dominant frequencies (22.1 versus 16.2 Hz; P=0.022) were all significantly decreased. In addition, reentrant spiral waves became unstable after apamin infusion, and the duration of VF decreased.
CONCLUSIONS:
The IKAS current influences the mechanism of VF in failing hearts as phase singularities, high dominant frequencies, and reentrant spiral waves all correlated to areas of high IKAS. Apamin eliminated this relationship and reduced VF vulnerability
Spin-Imbalance in a One-Dimensional Fermi Gas
Superconductivity and magnetism generally do not coexist. Changing the
relative number of up and down spin electrons disrupts the basic mechanism of
superconductivity, where atoms of opposite momentum and spin form Cooper pairs.
Nearly forty years ago Fulde and Ferrell and Larkin and Ovchinnikov proposed an
exotic pairing mechanism (FFLO) where magnetism is accommodated by formation of
pairs with finite momentum. Despite intense theoretical and experimental
efforts, however, polarized superconductivity remains largely elusive. Here we
report experimental measurements of density profiles of a two spin mixture of
ultracold 6Li atoms trapped in an array of one dimensional (1D) tubes, a system
analogous to electrons in 1D wires. At finite spin imbalance, the system phase
separates with an inverted phase profile in comparison to the three-dimensional
case. In 1D we find a partially polarized core surrounded by wings composed of
either a completely paired BCS superfluid or a fully polarized Fermi gas,
depending on the degree of polarization. Our observations are in quantitative
agreement with theoretical calculations in which the partially polarized phase
is found to be a 1D analogue of the FFLO state. This study demonstrates how
ultracold atomic gases in 1D may be used to create non-trivial new phases of
matter, and also paves the way for direct observation and further study of the
FFLO phase.Comment: 30 pages, 7 figure
Restrictions and extensions of semibounded operators
We study restriction and extension theory for semibounded Hermitian operators
in the Hardy space of analytic functions on the disk D. Starting with the
operator zd/dz, we show that, for every choice of a closed subset F in T=bd(D)
of measure zero, there is a densely defined Hermitian restriction of zd/dz
corresponding to boundary functions vanishing on F. For every such restriction
operator, we classify all its selfadjoint extension, and for each we present a
complete spectral picture.
We prove that different sets F with the same cardinality can lead to quite
different boundary-value problems, inequivalent selfadjoint extension
operators, and quite different spectral configurations. As a tool in our
analysis, we prove that the von Neumann deficiency spaces, for a fixed set F,
have a natural presentation as reproducing kernel Hilbert spaces, with a
Hurwitz zeta-function, restricted to FxF, as reproducing kernel.Comment: 63 pages, 11 figure
Characterization of skin sympathetic nerve activity in patients with cardiomyopathy and ventricular arrhythmia
Background
Heightened sympathetic nerve activity is associated with occurrence of ventricular arrhythmia (VA).
Objective
To investigate the association of skin sympathetic nerve activity (SKNA) and VA occurrence.
Methods
We prospectively enrolled 65 patients with severe cardiomyopathy. Of these, 39 had recent sustained VA episodes (VA-1 group), 11 had intractable VA undergoing sedation with general anesthesia (VA-2 group), and 15 had no known history of VA (VA-Ctrl group). All patients had simultaneous SKNA and electrocardiogram recording. SKNA was assessed using an average value (aSKNA), a variable value (vSKNA), and the number of bursts of SKNA (bSKNA).
Results
The VA-1 group had higher aSKNA and vSKNA compared with the VA-Ctrl group (aSKNA: 1.41 ± 0.53 μV vs 0.98 ± 0.41 μV, P = .003; vSKNA: 0.52 ± 0.22 μV vs 0.30 ± 0.16 μV, P 15% reduction in aSKNA after therapy was associated with a lower subsequent VA event rate (hazard ratio, 0.222; 95% CI, 0.057–0.864; P = .03).
Conclusion
Patients with VA had increased SKNA as compared with control. Both SKNA and sustained VA could be suppressed by general anesthesia. The aSKNA at baseline was an independent predictor of VA recurrence
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