79 research outputs found
LBL: Logarithmic Barrier Loss Function for One-class Classification
One-class classification (OCC) aims to train a classifier only with the
target class data and attracts great attention for its strong applicability in
real-world application. Despite a lot of advances have been made in OCC, it
still lacks the effective OCC loss functions for deep learning. In this paper,
a novel logarithmic barrier function based OCC loss (LBL) that assigns large
gradients to the margin samples and thus derives more compact hypersphere, is
first proposed by approximating the OCC objective smoothly. But the
optimization of LBL may be instability especially when samples lie on the
boundary leading to the infinity loss. To address this issue, then, a
unilateral relaxation Sigmoid function is introduced into LBL and a novel OCC
loss named LBLSig is proposed. The LBLSig can be seen as the fusion of the mean
square error (MSE) and the cross entropy (CE) and the optimization of LBLSig is
smoother owing to the unilateral relaxation Sigmoid function. The effectiveness
of the proposed LBL and LBLSig is experimentally demonstrated in comparisons
with several state-of-the-art OCC algorithms on different network structures.
The source code can be found at https://github.com/ML-HDU/LBL_LBLSig
Woltjer-Taylor State Without Taylor's Conjecture - Plasma Relaxation at all Wavelengths
In astrophysical and laboratory plasmas, it has been discovered that plasmas relax towards the well-known Woltjer-Taylor state specified by β x B = Ξ±B for a constant Ξ± . To explain how such a relaxed state is reached, Taylor developed his famous relaxation theory based on the conjecture that the relaxation is dominated by short wavelength fluctuations. However, there is no conclusive experimental and numerical evidence to support Taylor's conjecture. A new theory is developed, which predicts that the system will evolve towards the Woltjer-Taylor state for an arbitrary fluctuation spectrum
Effects of Magnetic Helicity on 3D Equilibria and Self-Organized States in KTX Reversed Field Pinch
The RFP is a toroidal magnetic configuration in which plasmas can
spontaneously transform into different self-organized states. Among various
states, the QSH state has a dominant component for the magnetic field and
significantly improves confinement. Many theoretical and experimental efforts
have investigated the transitions among different states. This paper employs
the MRxMHD model to study the properties of QSH and other states. The SPEC is
used to compute MHD equilibria for the KTX. The toroidal volume of KTX is
partitioned into two subvolumes by an internal transport barrier. The geometry
of this barrier is adjusted to achieve force balance across the interface,
ensuring that the plasma in each subvolume is force-free and that magnetic
helicity is conserved. By varying the parameters, we generate distinct
self-organized states in KTX. Our findings highlight the crucial role of
magnetic helicity in shaping these states. In states with low magnetic helicity
in both subvolumes, the plasma exhibits axisymmetric behavior. With increasing
core helicity, the plasma gradually transforms from an axisymmetric state to a
double-axis helical state and finally to a single-helical-axis state. Elevated
core magnetic helicity leads to a more pronounced dominant mode of the boundary
magnetic field and a reduced core magnetic shear. This is consistent with
previous experimental and numerical results in other RFP devices. We find a
linear relationship between the plasma current and helicity in different
self-organized states. Our findings suggest that KTX may enter the QSH state
when the toroidal current reaches 0.72 MA. This study demonstrates that the
stellarator equilibrium code SPEC unveils crucial RFP equilibrium properties,
rendering it applicable to a broad range of RFP devices and other toroidal
configurations
Use of Xinfeng capsule to treat abarticular pathologic changes in patients with rheumatoid arthritis
AbstractObjectiveTo observe the influence of Xinfeng-capsule (XFC) on abarticular pathologic changes (APCs) and other indices of patients with rheumatoid arthritis (RA) and explore the mechanism of action of XFC in improving such changes.MethodsThree-hundred RA patients were divided randomly into a treatment group (n=150) and control group (n=150). A normal control (NC) group (n=90) was also created. Changes in cardiac function, pulmonary function, anemia indices and platelet parameters of RA patients were measured. Curative effects of the two groups were compared, and comparison carried out with the NC group.ResultsIn 300 RA patients, late diastolic peak flow velocity (A peak) was much higher (P<0.01) and early diastolic peak flow velocity (E peak), E/A, and left ventricular fraction shortening much lower (P<0.01) than those in the NC group. Vital capacity (VC), forced vital capacity in one second, forced vital capacity (FVC), maximal voluntary ventilation (MVV), maximal expiratory flow in 50% of VC (FEF50) and FEF75 were lowered remarkably (P< 0.05 or P<0.01). Platelet count (PLT), plateletcrit (PCT) and mean platelet volume (MPV) increased markedly (P<0.05 or P<0.01), and hemoglobin (Hb) level decreased significantly (P<0.05). After XFC treatment, the A peak and PLT and PCT were much lower (P<0.05), and E/A and the number of red blood cells as well as Hb level were much higher (P< 0.05), as were FVC, MVV and FEF50 (P<0.05 or P< 0.01), in the treatment group than those in the NC group. Total score of pain and swelling in joints, uric-acid level and high-sensitivity C-reactive protein level were much lower, and superoxide dismutase level as well as the number of CD4 + CD25 + regulation T cells (Treg) and CD4 + CD25 + CD127-Treg were much higher (P<0.05 or P<0.01) in the treatment group than those in the NC group.ConclusionRA patients with pathologic changes in joints also suffer from lower cardiac and pulmonary functions and from parameters of anemia and platelet factors. XFC can improve the symptoms of RA patients, ameliorate their cardiac and pulmonary functions and reduce the parameters of anemia and platelet factors. XFC lowers the immune inflammatory reaction to improve APCs in RA patients
Reactive Oxygen Species Released from Hypoxic Hepatocytes Regulates MMP-2 Expression in Hepatic Stellate Cells
Hypoxia is a common environmental stress factor and is associated with fibrogenesis. Matrix metalloproteinase-2 (MMP-2), produced by hepatic stellate cells (HSCs), plays an important role in liver fibrogenesis. However, inconsistent results have been reported on the impact of hypoxia on MMP-2 expression and activity in HSCs. We speculated that cellβcell interaction is involved in the regulation of MMP-2 expression and activity at low oxygen level in vivo. Therefore, in this report we investigated the mechanism by which hypoxic hepatocytes regulates MMP-2 expression in HSCs. Our results showed that the conditioned medium from hypoxia-treated rat hepatocytes strongly induced the expression of MMP-2 mRNA and protein in rat HSC-T6 cells. Reduced glutathione neutralized ROS released from hypoxic hepatocytes, leading to reduced MMP-2 expression in HSC-T6 cells. In addition, phospho-IΞΊB-Ξ± protein level was increased in HSC-T6 cells treated with hypoxia conditioned medium, and NF-ΞΊB signaling inhibitor inhibited MMP-2 expression in HSC-T6 cells. Taken together, our data suggest that ROS is an important factor released by hypoxic hepatocytes to regulate MMP-2 expression in HSCs, and NF-ΞΊB signaling is crucially involved in ROS-induced MMP-2 expression in HSCs. Our findings suggest that strategies aimed at antagonizing the generation of ROS in hypoxic hepatocytes and inhibiting NF-ΞΊB signaling in HSCs may represent novel therapeutic options for liver fibrosis
Synaptic Neurotransmission Depression in Ventral Tegmental Dopamine Neurons and Cannabinoid-Associated Addictive Learning
Drug addiction is an association of compulsive drug use with long-term associative learning/memory. Multiple forms of learning/memory are primarily subserved by activity- or experience-dependent synaptic long-term potentiation (LTP) and long-term depression (LTD). Recent studies suggest LTP expression in locally activated glutamate synapses onto dopamine neurons (local Glu-DA synapses) of the midbrain ventral tegmental area (VTA) following a single or chronic exposure to many drugs of abuse, whereas a single exposure to cannabinoid did not significantly affect synaptic plasticity at these synapses. It is unknown whether chronic exposure of cannabis (marijuana or cannabinoids), the most commonly used illicit drug worldwide, induce LTP or LTD at these synapses. More importantly, whether such alterations in VTA synaptic plasticity causatively contribute to drug addictive behavior has not previously been addressed. Here we show in rats that chronic cannabinoid exposure activates VTA cannabinoid CB1 receptors to induce transient neurotransmission depression at VTA local Glu-DA synapses through activation of NMDA receptors and subsequent endocytosis of AMPA receptor GluR2 subunits. A GluR2-derived peptide blocks cannabinoid-induced VTA synaptic depression and conditioned place preference, i.e., learning to associate drug exposure with environmental cues. These data not only provide the first evidence, to our knowledge, that NMDA receptor-dependent synaptic depression at VTA dopamine circuitry requires GluR2 endocytosis, but also suggest an essential contribution of such synaptic depression to cannabinoid-associated addictive learning, in addition to pointing to novel pharmacological strategies for the treatment of cannabis addiction
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Woltjer-Taylor State Without Taylor's Conjecture-Plasma Relaxation at all Wavelengths
In astrophysical and laboratory plasmas, it has been discovered that plasmas relax towards the well-known Woltjer-Taylor state specified by β x B = Ξ±B for a constant Ξ± . To explain how such a relaxed state is reached, Taylor developed his famous relaxation theory based on the conjecture that the relaxation is dominated by short wavelength fluctuations. However, there is no conclusive experimental and numerical evidence to support Taylor's conjecture. A new theory is developed, which predicts that the system will evolve towards the Woltjer-Taylor state for an arbitrary fluctuation spectrum
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