1,239 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
Obervational Model for Microarcsecond Astrometry with the Space Interferometry Mission
The Space Interferometry Mission (SIM) is a space-based long-baseline optical
interferometer for precision astrometry. One of the primary objectives of the
SIM instrument is to accurately determine the directions to a grid of stars,
together with their proper motions and parallaxes, improving a priori knowledge
by nearly three orders of magnitude. The basic astrometric observable of the
instrument is the pathlength delay, a measurement made by a combination of
internal metrology measurements that determine the distance the starlight
travels through the two arms of the interferometer and a measurement of the
white light stellar fringe to find the point of equal pathlength. Because this
operation requires a non--negligible integration time to accurately measure the
stellar fringe position, the interferometer baseline vector is not stationary
over this time period, as its absolute length and orientation are
time--varying. This conflicts with the consistency condition necessary for
extracting the astrometric parameters which requires a stationary baseline
vector. This paper addresses how the time-varying baseline is ``regularized''
so that it may act as a single baseline vector for multiple stars, and thereby
establishing the fundamental operation of the instrument.Comment: 24 pages, 6 figure
Ganglionated plexi as neuromodulation targets for atrial fibrillation
The autonomic nervous system plays an important role in the genesis of atrial fibrillation and is one of the candidate targets for atrial fibrillation therapy. This review focuses on the role of the autonomic nervous system in atrial fibrillation development and discusses the results of the ganglionated plexi catheter and surgical ablation in preclinical and clinical studies. The heart is innervated by the extrinsic and intrinsic autonomic nervous systems. The intrinsic autonomic nervous system consists of multiple ganglionated plexi and axons, which innervate the neighboring atrial myocardium and control their electrophysiological properties. Abnormal autonomic innervation has been observed in an animal model of atrial fibrillation and in humans. Direct recordings of autonomic nerve activity in canine models showed that atrial tachyarrhythmia episodes were invariably preceded by intrinsic cardiac autonomic nerve activity, thus supporting the importance of intrinsic cardiac autonomic nerve activity as the triggers for atrial tachyarrhythmia. Targeting ganglionated plexi with catheter ablation improves the outcomes of paroxysmal atrial fibrillation ablation in addition to pulmonary vein antrum isolation. Ablation of ganglionated plexi alone without pulmonary vein isolation is also useful in controlling paroxysmal atrial fibrillation in some patients. However, surgical ganglionated plexi ablation in patients with a large left atrium, persistent atrial fibrillation, and/or a history of prior catheter ablation does not result in additional benefits. These different outcomes suggest that ganglionated plexi ablation is effective in managing patients with paroxysmal atrial fibrillation, but its effects in patients with persistent atrial fibrillation and advanced atrial diseases might be limited
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Durable clinical response to the multidisciplinary management of neurosurgery, radiation and chemoimmunotherapy in a patient with PD-L1/PD-L2/JAK2 (PDJ)-amplified, refractory triple-negative breast cancer.
Patients with refractory metastatic triple-negative breast cancer (mTNBC) and symptomatic brain metastases have poor prognosis and are challenging to treat. The addition of an programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitor (pembrolizumab or atezolizumab) to first line chemotherapy has prolonged survivals in mTNBC patients with PD-L1-positive tumor and/or tumor-infiltrating immune cells. The clinical efficacy of the chemoimmunotherapy combination in patients with refractory mTNBC, especially brain metastasis, is unknown. Co-amplification of PD-L1, PD-L2, and Janus kinase 2 (PD-L1/PD-L2/JAK2) genes (PDJ amplification) is associated with high PD-L1 protein expression and a 65-87% response rate to PD-1/PD-L1 inhibitors in patients with lymphomas. But the utility of PDJ amplification as a biomarker predictive of response to PD-1/PD-L1 inhibitors is unknown for mTNBC patients. Here, we report a 46-year-old woman who had rapid tumor progression in the brain and lung within 3 months after chemotherapy, neurosurgery, and gamma knife stereotactic radiosurgery for brain metastasis. Next-generation sequencing of her brain metastasis specimen revealed 9 copies of PDJ amplification and a tumor mutational burden of 5 mutations per megabase. Although high PDJ mRNA expression levels were detected, PD-L1 protein expression was negative on tumor cells and 10% on tumor-associated immune cells. After the debulking brain tumor resection, she received pembrolizumab monotherapy, whole brain radiation, and then atezolizumab and nab-paclitaxel with good intracranial and extracranial responses for >16 months. To the best of our knowledge, this is the first report that PDJ amplification is associated with durable clinical response to the PD-1/PD-L1 inhibitor-containing, multidisciplinary management in a patient with refractory, PD-L1 protein-negative, PDJ-amplified mTNBC. Further study is warranted to understand the underlying mechanism and validate PDJ amplification as a biomarker for clinical response to PD-1/PD-L1 inhibitor-containing therapy in patients with mTNBC
Genetic Targeting of ERK1 Suggests a Predominant Role for ERK2 in Murine Pain Models
The extracellular signal-regulated kinase (ERK) isoforms, ERK1 and ERK2, are believed to be key signaling molecules in nociception and nociceptive sensitization. Studies utilizing inhibitors targeting the shared ERK1/2 upstream activator, mitogen-activated protein kinase kinase (MEK), and transgenic mice expressing a dominant negative form of MEK have established the importance of ERK1/2 signaling. However, these techniques do not discriminate between ERK1 and ERK2. To dissect the function of each isoform in pain, we utilized mice with a targeted genetic deletion of ERK1 (ERK1 KO) to test the hypothesis that ERK1 is required for behavioral sensitization in rodent pain models. Despite activation (phosphorylation) of ERK1 following acute noxious stimulation and in models of chronic pain, we found that ERK1 was not required for formalin-induced spontaneous behaviors, complete Freund’s adjuvant-induced heat and mechanical hypersensitivity, and spared nerve injury-induced mechanical hypersensitivity. However, ERK1 deletion did delay formalin-induced long-term heat hypersensitivity, without affecting formalin-induced mechanical hypersensitivity, suggesting that ERK1 partially shapes long-term responses to formalin. Interestingly, ERK1 deletion resulted in elevated basal ERK2 phosphorylation. However, this did not appear to influence nociceptive processing, since inflammation-induced ERK2 phosphorylation and pERK1/2 immunoreactivity in spinal cord were not elevated in ERK1 KO mice. Additionally, systemic MEK inhibition with SL327 attenuated formalin-induced spontaneous behaviors similarly in WT and ERK1 KO mice, indicating that unrelated signaling pathways do not functionally compensate for the loss of ERK1. Taken together, these results suggest that ERK1 plays a limited role in nociceptive sensitization and supports a predominant role for ERK2 in these processes
Inducible Nitric Oxide Synthase (iNOS) Is a Novel Negative Regulator of Hematopoietic Stem/Progenitor Cell Trafficking
Nitric oxide (NO) is a gaseous free radical molecule involved in several biological processes related to inflammation, tissue damage, and infections. Based on reports that NO inhibits migration of granulocytes and monocytes, we became interested in the role of inducible NO synthetase (iNOS) in pharmacological mobilization of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM) into peripheral blood (PB). To address the role of NO in HSPC trafficking, we upregulated or downregulated iNOS expression in hematopoietic cell lines. Next, we performed mobilization studies in iNOS−/− mice and evaluated engraftment of iNOS−/− HSPCs in wild type (control) animals. Our results indicate that iNOS is a novel negative regulator of hematopoietic cell migration and prevents egress of HSPCs into PB during mobilization. At the molecular level, downregulation of iNOS resulted in downregulation of heme oxygenase 1 (HO-1), and, conversely, upregulation of iNOS enhanced HO-1 activity. Since HO-1 is a negative regulator of cell migration, the inhibitory effects of iNOS identified by us can be at least partially explained by its enhancing the HO-1 level in BM cells
Dynamic Coupling of Convective Flows and Magnetic Field during Flux Emergence
We simulate the buoyant rise of a magnetic flux rope from the solar
convection zone into the corona to better understand the energetic coupling of
the solar interior to the corona. The magnetohydrodynamic model addresses the
physics of radiative cooling, coronal heating and ionization, which allow us to
produce a more realistic model of the solar atmosphere. The simulation
illustrates the process by which magnetic flux emerges at the photosphere and
coalesces to form two large concentrations of opposite polarities. We find that
the large-scale convective motion in the convection zone is critical to form
and maintain sunspots, while the horizontal converging flows in the near
surface layer prevent the concentrated polarities from separating. The foot
points of the sunspots in the convection zone exhibit a coherent rotation
motion, resulting in the increasing helicity of the coronal field. Here, the
local configuration of the convection causes the convergence of opposite
polarities of magnetic flux with a shearing flow along the polarity inversion
line. During the rising of the flux rope, the magnetic energy is first injected
through the photosphere by the emergence, followed by energy transport by
horizontal flows, after which the energy is subducted back to the convection
zone by the submerging flows
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
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