3,339 research outputs found
Concentration-Dependent Diversification Effects of Free Cholesterol Loading on Macrophage Viability and Polarization
Background/Aims: The accumulation of free cholesterol in atherosclerotic lesions has been well documented in both animals and humans. In studying the relevance of free cholesterol buildup in atherosclerosis, contradictory results have been generated, indicating that free cholesterol produces both pro- and anti-atherosclerosis effects in macrophages. This inconsistency might stem from the examination of only select concentrations of free cholesterol. In the present study, we sought to investigate the implication of excess free cholesterol loading in the pathophysiology of atherosclerosis across a broad concentration range from (in Āµg/ml) 0 to 60. Methods:Macrophage viability was determined by measuring formazan formation and flow cytometry viable cell counting. The polarization of M1 and M2 macrophages was differentiated by FACS (Fluorescence-Activated Cell Sorting) assay. The secretion of IL-1Ī² in macrophage culture medium was measured by ELISA kit. Macrophage apoptosis was detected by flow cytometry using a TUNEL kit. Results: Macrophage viability was increased at the treatment of lower concentrations of free cholesterol from (in Āµg/ml) 0 to 20, but gradually decreased at higher concentrations from 20 to 60. Lower free cholesterol loading induced anti-inflammatory M2 macrophage polarization. The activation of the PPARĪ³ (Peroxisome Proliferator-Activated Receptor gamma) nuclear factor underscored the stimulation of this M2 phenotype. Nevertheless, higher levels of free cholesterol resulted in pro-inflammatory M1 activation. Moreover, with the application of higher free cholesterol concentrations, macrophage apoptosis and secretion of the inflammatory cytokine IL-1Ī² increased significantly. Conclusion: These results for the first time demonstrate that free cholesterol could render concentration-dependent diversification effects on macrophage viability, polarization, apoptosis and inflammatory cytokine secretions, thereby reconciling the pros and cons of free cholesterol buildup in macrophages to the pathophysiology of atherosclerosis
Improving Privacy-Preserving Vertical Federated Learning by Efficient Communication with ADMM
Federated learning (FL) enables distributed devices to jointly train a shared
model while keeping the training data local. Different from the horizontal FL
(HFL) setting where each client has partial data samples, vertical FL (VFL),
which allows each client to collect partial features, has attracted intensive
research efforts recently. In this paper, we identified two challenges that
state-of-the-art VFL frameworks are facing: (1) some works directly average the
learned feature embeddings and therefore might lose the unique properties of
each local feature set; (2) server needs to communicate gradients with the
clients for each training step, incurring high communication cost that leads to
rapid consumption of privacy budgets. In this paper, we aim to address the
above challenges and propose an efficient VFL with multiple linear heads (VIM)
framework, where each head corresponds to local clients by taking the separate
contribution of each client into account. In addition, we propose an
Alternating Direction Method of Multipliers (ADMM)-based method to solve our
optimization problem, which reduces the communication cost by allowing multiple
local updates in each step, and thus leads to better performance under
differential privacy. We consider various settings including VFL with model
splitting and without model splitting. For both settings, we carefully analyze
the differential privacy mechanism for our framework. Moreover, we show that a
byproduct of our framework is that the weights of learned linear heads reflect
the importance of local clients. We conduct extensive evaluations and show that
on four real-world datasets, VIM achieves significantly higher performance and
faster convergence compared with state-of-the-arts. We also explicitly evaluate
the importance of local clients and show that VIM enables functionalities such
as client-level explanation and client denoising
A new Stack Autoencoder: Neighbouring Sample Envelope Embedded Stack Autoencoder Ensemble Model
Stack autoencoder (SAE), as a representative deep network, has unique and
excellent performance in feature learning, and has received extensive attention
from researchers. However, existing deep SAEs focus on original samples without
considering the hierarchical structural information between samples. To address
this limitation, this paper proposes a new SAE model-neighbouring envelope
embedded stack autoencoder ensemble (NE_ESAE). Firstly, the neighbouring sample
envelope learning mechanism (NSELM) is proposed for preprocessing of input of
SAE. NSELM constructs sample pairs by combining neighbouring samples. Besides,
the NSELM constructs a multilayer sample spaces by multilayer iterative mean
clustering, which considers the similar samples and generates layers of
envelope samples with hierarchical structural information. Second, an embedded
stack autoencoder (ESAE) is proposed and trained in each layer of sample space
to consider the original samples during training and in the network structure,
thereby better finding the relationship between original feature samples and
deep feature samples. Third, feature reduction and base classifiers are
conducted on the layers of envelope samples respectively, and output
classification results of every layer of samples. Finally, the classification
results of the layers of envelope sample space are fused through the ensemble
mechanism. In the experimental section, the proposed algorithm is validated
with over ten representative public datasets. The results show that our method
significantly has better performance than existing traditional feature learning
methods and the representative deep autoencoders.Comment: 17 pages,6 figure
Holographic p-wave superconductivity from higher derivative theory
We construct a holographic SU(2) p-wave superconductor model with Weyl
corrections. The high derivative (HD) terms do not seem to spoil the generation
of the p-wave superconducting phase. We mainly study the properties of AC
conductivity, which is absent in holographic SU(2) p-wave superconductor with
Weyl corrections. The conductivities in superconducting phase exhibit obvious
anisotropic behaviors. Along direction, the conductivity is
similar to that of holographic s-wave superconductor. The superconducting
energy gap exhibits a wide extension. For the conductivity along
direction, the behaviors of the real part in the normal state are closely
similar to that of . However, the anisotropy of the conductivity
obviously shows up in the superconducting phase. A Drude-like peak at low
frequency emerges in once the system enters into the
superconducting phase, regardless of the behaviors in normal state.Comment: 19 pages, 7 figure
Activation of Nlrp3 Inflammasomes Enhances Macrophage Lipid-Deposition and Migration: Implication of a Novel Role of Inflammasome in Atherogenesis
Although Nlrp3 inflammasome activation in macrophages has been shown to be critical for the development of atherosclerosis upon atherogenic stimuli, it remains unknown whether activated Nlrp3 inflammasomes by other non-atherogenic stimuli induce alterations in macrophages that may contribute in the concert with other factors to atherogenesis. Thus, the present study tested the hypothesis that activation of Nlrp3 inflammasomes by ATP, which is a classical non-lipid danger stimulus, enhances the migration of macrophage and increases lipids deposition in macrophages accelerating foam cell formation. We first demonstrated that extracellular ATP (2.5 mM) markedly increased the formation and activation of Nlrp3 inflammasomes in bone marrow macrophages (BMMs) from wild type (Asc+/+) mice resulting in activation of caspase-1 and IL-1Ī² production. In these Asc+/+ macrophages, such stimulation of inflammasomes by non-lipid ATP was similar to those induced by atherogenic stimuli such as cholesterol crystals or 7-ketocholesterol. Both non-lipid and lipid forms of stimuli induced formation and activation of Nlrp3 inflammasomes, which were prevented by Asc gene deletion. Interestingly, Asc+/+ BMMs had dramatic lipids accumulation after stimulation with ATP. Further, we demonstrated that large amount of cholesterol was accumulated in lysosomes of Asc+/+ BMMs when inflammasomes were activated by ATP. Such intracellular and lysosomal lipids deposition was not observed in Ascā/ā BMMs and also prevented by caspase-1 inhibitor WEHD. In addition, in vitro and in vivo experiments revealed that migration of Asc+/+ BMMs increased due to stimulation of Nlrp3 inflammasomes, which was markedly attenuated in Ascā/ā BMMs. Together, these results suggest that activation of Nlrp3 inflammasomes remarkably increases the susceptibility of macrophages to lipid deposition and their migration ability. Such novel action of inflammasomes may facilitate entry or retention of macrophages into the arterial wall, where they form foam cells and ultimately induce atherosclerosis
Quasinormal modes of quantum-corrected black holes
In this paper, we investigate the quasinormal mode (QNM) spectra for scalar
perturbation over a quantum-corrected black hole (BH). The fundamental modes of
this quantum-corrected BH exhibit two key properties. Firstly, there is a
non-monotonic behavior concerning the quantum-corrected parameter for zero
multipole number. Secondly, the quantum gravity effects result in slower decay
modes. For higher overtones, a significant deviation becomes evident between
the quasinormal frequencies (QNFs) of the quantum-corrected and Schwarzschild
BHs. The intervention of quantum gravity corrections induces a significant
outburst of overtones. This outburst of these overtones can be attributed to
the distinctions near the event horizons between the Schwarzschild and
quantum-corrected BHs. Therefore, overtones can serve as a means to probe
physical phenomena or disparities in the vicinity of the event horizon.Comment: 29 pages, 9 figure
Macrophage migration inhibitory factor (MIF) family in arthropods : Cloning and expression analysis of two MIF and one D-dopachrome tautomerase (DDT) homologues in Mud crabs, Scylla paramamosain
Acknowledgements This research was supported by grants from the National Natural Science Foundation of China (Nos. 31172438 and U1205123), the Natural Science Foundation of Fujian Province (No. 2012J06008 and 201311180002) and the projects-sponsored by SRF. TW received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Peer reviewedPostprin
LEFormer: A Hybrid CNN-Transformer Architecture for Accurate Lake Extraction from Remote Sensing Imagery
Lake extraction from remote sensing images is challenging due to the complex
lake shapes and inherent data noises. Existing methods suffer from blurred
segmentation boundaries and poor foreground modeling. This paper proposes a
hybrid CNN-Transformer architecture, called LEFormer, for accurate lake
extraction. LEFormer contains three main modules: CNN encoder, Transformer
encoder, and cross-encoder fusion. The CNN encoder effectively recovers local
spatial information and improves fine-scale details. Simultaneously, the
Transformer encoder captures long-range dependencies between sequences of any
length, allowing them to obtain global features and context information. The
cross-encoder fusion module integrates the local and global features to improve
mask prediction. Experimental results show that LEFormer consistently achieves
state-of-the-art performance and efficiency on the Surface Water and the
Qinghai-Tibet Plateau Lake datasets. Specifically, LEFormer achieves 90.86% and
97.42% mIoU on two datasets with a parameter count of 3.61M, respectively,
while being 20 minor than the previous best lake extraction method. The source
code is available at https://github.com/BastianChen/LEFormer.Comment: Accepted by ICASSP 202
High-Fidelity Lake Extraction via Two-Stage Prompt Enhancement: Establishing a Novel Baseline and Benchmark
The extraction of lakes from remote sensing images is a complex challenge due
to the varied lake shapes and data noise. Current methods rely on multispectral
image datasets, making it challenging to learn lake features accurately from
pixel arrangements. This, in turn, affects model learning and the creation of
accurate segmentation masks. This paper introduces a unified prompt-based
dataset construction approach that provides approximate lake locations using
point, box, and mask prompts. We also propose a two-stage prompt enhancement
framework, LEPrompter, which involves prompt-based and prompt-free stages
during training. The prompt-based stage employs a prompt encoder to extract
prior information, integrating prompt tokens and image embeddings through self-
and cross-attention in the prompt decoder. Prompts are deactivated once the
model is trained to ensure independence during inference, enabling automated
lake extraction. Evaluations on Surface Water and Qinghai-Tibet Plateau Lake
datasets show consistent performance improvements compared to the previous
state-of-the-art method. LEPrompter achieves mIoU scores of 91.48% and 97.43%
on the respective datasets without introducing additional parameters or GFLOPs.
Supplementary materials provide the source code, pre-trained models, and
detailed user studies.Comment: 8 pages, 7 figure
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