1,549 research outputs found
Aspirin Has Antitumor Effects via Expression of Calpain Gene in Cervical Cancer Cells
Aspirin and other nonsteroidal anti-inflammatory drugs show efficacy in the prevention of cancers. It is known that they can inhibit cyclooxygenases, and some studies have shown that they can induce apoptosis. Our objective in this study was to investigate the mechanism by which aspirin exerts its apoptosis effects in human cervical cancer HeLa cells. The effect of aspirin on the gene expression was studied by differential mRNA display RT-PCR. Among the isolated genes, mu-type calpain gene was upregulated by aspirin treatment. To examine whether calpain mediates the antitumor effects, HeLa cells were stably transfected with the mammalian expression vector pCR3.1 containing mu-type calpain cDNA (pCRCAL/HeLa), and tumor formations were measured in nude mice. When tumor burden was measured by day 49, HeLa cells and pCR/HeLa cells (vector control) produced tumors of 2126 mm3 and 1638 mm3, respectively, while pCRCAL/HeLa cells produced markedly smaller tumor of 434 mm3 in volume. The caspase-3 activity was markedly elevated in pCRCAL/HeLa cells. The increased activity levels of caspase-3 in pCRCAL/HeLa cells, in parallel with the decreased tumor formation, suggest a correlation between caspase-3 activity and calpain protein. Therefore, we conclude that aspirin-induced calpain mediates an antitumor effect via caspase-3 in cervical cancer cells
Joint User Pairing and Beamforming Design of Multi-STAR-RISs-Aided NOMA in the Indoor Environment via Multi-Agent Reinforcement Learning
The development of sixth-generation (6G)/Beyond Fifth-Generation (B5G) wireless networks, which have requirements that go beyond current 5G networks, is gaining interest from academia and industry. However, to increase 6G/B5G network quality, conventional cellular networks that rely on terrestrial base stations are constrained geographically and economically. Meanwhile, Non-Orthogonal Multiple Access (NOMA) allows multiple users to share the same resources, which improves the spectral efficiency of the system and has the advantage of supporting a larger number of users. Additionally, by intelligently manipulating the phase and amplitude of both the reflected and transmitted signals, Simultaneously Transmitting and Reflecting RISs (STAR-RISs)can achieve improved coverage, increased spectral efficiency,and enhanced communication reliability. However, STAR-RISsmust simultaneously optimize the amplitude and phase shiftcorresponding to reflection and transmission, which makes theexisting terrestrial networks more complicated and is considereda major challenging issue. Motivated by the above, we studythe joint user pairing for NOMA and beamforming design ofMulti-STAR-RISs in an indoor environment. Then, we formulatethe optimization problem with the objective of maximizing thetotal throughput of mobile users (MUs) by jointly optimizingthe decoding order, user pairing, active beamforming, andpassive beamforming. However, the formulated problem is amixed-integer non-linear programming (MINLP). To addressthis challenge, we first introduce the decoding order for NOMAnetworks. Next, we decompose the original problem into twosubproblems, namely: 1) MU pairing and 2) Beamformingoptimization under the optimal decoding order. For the firstsubproblem, we employ correlation-based K-means clusteringto solve the user pairing problem. Then, to jointly deal withbeamforming vector optimizations, we propose Multi-AgentProximal Policy Optimization (MAPPO), which can make quickdecisions in the given environment owing to its low complexity.Finally, simulation results prove that our proposed MAPPOalgorithm is superior to Proximal Policy Optimization (PPO)and Advanced Actor-Critic (A2C) by a maximum of 1% and6%, respectively.<br/
Joint User Pairing and Beamforming Design of Multi-STAR-RISs-Aided NOMA in the Indoor Environment via Multi-Agent Reinforcement Learning
The development of 6G/B5G wireless networks, which have requirements that go
beyond current 5G networks, is gaining interest from academia and industry.
However, to increase 6G/B5G network quality, conventional cellular networks
that rely on terrestrial base stations are constrained geographically and
economically. Meanwhile, NOMA allows multiple users to share the same
resources, which improves the spectral efficiency of the system and has the
advantage of supporting a larger number of users. Additionally, by
intelligently manipulating the phase and amplitude of both the reflected and
transmitted signals, STAR-RISs can achieve improved coverage, increased
spectral efficiency, and enhanced communication reliability. However, STAR-RISs
must simultaneously optimize the amplitude and phase shift corresponding to
reflection and transmission, which makes the existing terrestrial networks more
complicated and is considered a major challenging issue. Motivated by the
above, we study the joint user pairing for NOMA and beamforming design of
Multi-STAR-RISs in an indoor environment. Then, we formulate the optimization
problem with the objective of maximizing the total throughput of MUs by jointly
optimizing the decoding order, user pairing, active beamforming, and passive
beamforming. However, the formulated problem is a MINLP. To address this
challenge, we first introduce the decoding order for NOMA networks. Next, we
decompose the original problem into two subproblems, namely: 1) MU pairing and
2) Beamforming optimization under the optimal decoding order. For the first
subproblem, we employ correlation-based K-means clustering to solve the user
pairing problem. Then, to jointly deal with beamforming vector optimizations,
we propose MAPPO, which can make quick decisions in the given environment owing
to its low complexity.Comment: 8 pages, 9 figures, IEEE/IFIP Network Operations and Management
Symposium (NOMS) 2024 submitte
Validity and reliability of the Korean version of the gender-friendliness barriers in nursing programs scale
IntroductionThe gender-friendliness barriers in nursing programs (GFB-NP) were used to measure perceived gender affinity among male nursing students in nursing education programs. Originally developed in Taiwan, this scale has not been used in Korea. The purpose of this study is to confirm the reliability and validity of the GFB-NP scale for Korean male nursing students.MethodsA convenience sample of male nursing students enrolled in the 1st to 4th year of nursing departments at five four-year universities located in three cities in Korea was used in the study. To confirm the validity and factor structure of the scale, both exploratory factor analysis and confirmatory factor analysis were employed.ResultsThe results support a four-factor structure: Professional acquisition opportunity, peer interaction, sociocultural prejudice, and gender role attitude. We confirmed that the Korean version of the GFB-NP is an appropriate tool for measuring the gender-friendliness educational environment perceived by male nursing students in nursing education.DiscussionThe GFB-NP will serve as a framework for developing counseling and management strategies to help male nursing students successfully adapt to school life within the nursing education curriculum. Research with a longitudinal study design is recommended to investigate the progression of school adaptation through undergraduate program courses
Trajectory Optimization and Phase-Shift Design in IRS Assisted UAV Network for High Speed Trains
The recent trend towards the high-speed transportation system has spurred the
development of high-speed trains (HSTs). However, enabling HST users with
seamless wireless connectivity using the roadside units (RSUs) is extremely
challenging, mostly due to the lack of line of sight link. To address this
issue, we propose a novel framework that uses intelligent reflecting surfaces
(IRS)-enabled unmanned aerial vehicles (UAVs) to provide line of sight
communication to HST users. First, we formulate the optimization problem where
the objective is to maximize the minimum achievable rate of HSTs by jointly
optimizing the trajectory of UAV and the phase-shift of IRS. Due to the
non-convex nature of the formulated problem, it is decomposed into two
subproblems: IRS phase-shift problem and UAV trajectory optimization problem.
Next, a Binary Integer Linear Programming (BILP) and a Soft Actor-Critic (SAC)
are constructed in order to solve our decomposed problems. Finally,
comprehensive numerical results are provided in order to show the effectiveness
of our proposed framework.Comment: This paper has been submitted to IEEE Wireless Communications Letter
Federated Learning with Intermediate Representation Regularization
In contrast to centralized model training that involves data collection,
federated learning (FL) enables remote clients to collaboratively train a model
without exposing their private data. However, model performance usually
degrades in FL due to the heterogeneous data generated by clients of diverse
characteristics. One promising strategy to maintain good performance is by
limiting the local training from drifting far away from the global model.
Previous studies accomplish this by regularizing the distance between the
representations learned by the local and global models. However, they only
consider representations from the early layers of a model or the layer
preceding the output layer. In this study, we introduce FedIntR, which provides
a more fine-grained regularization by integrating the representations of
intermediate layers into the local training process. Specifically, FedIntR
computes a regularization term that encourages the closeness between the
intermediate layer representations of the local and global models.
Additionally, FedIntR automatically determines the contribution of each layer's
representation to the regularization term based on the similarity between local
and global representations. We conduct extensive experiments on various
datasets to show that FedIntR can achieve equivalent or higher performance
compared to the state-of-the-art approaches. Our code is available at
https://github.com/YLTun/FedIntR.Comment: IEEE BigComp 202
When sex doesn’t sell to men: Mortality salience, disgust and the appeal of products and advertisements featuring sexualized women
Although men typically hold favorable views of advertisements featuring female sexuality, from a Terror Management Theory perspective, this should be less the case when thoughts of human mortality are salient. Two experiments conducted in South Korea supported this hypothesis across a variety of products (e.g., perfume and vodka). Men became more negative towards advertisements featuring female sexuality, and had reduced purchase intentions for those products, after thinking about their own mortality. Study 2 found that these effects were mediated by heightened disgust. Mortality thoughts did not impact women in either study. These findings uniquely demonstrate that thoughts of death interact with female sex-appeal to influence men’s consumer choices, and that disgust mediates these processes. Implications for the role of emotion, and cultural differences, in terror management, for attitudes toward female sexuality, and for marketing strategies are discussed
Attribution of the 2015 record high sea surface temperatures over the central equatorial Pacific and tropical Indian Ocean
This study assessed the anthropogenic contribution to the 2015 record-breaking high sea surface temperatures (SSTs) observed in the central equatorial Pacific and tropical Indian Ocean. Considering a close link between extreme warm events in these regions, we conducted a joint attribution analysis using a fraction of attributable risk approach. Probability of occurrence of such extreme anomalies and long-term trends for the two oceanic regions were compared between CMIP5 multi-model simulations with and without anthropogenic forcing. Results show that the excessive warming in both regions is well beyond the range of natural variability and robustly attributable to human activities due to greenhouse gas increase. We further explored associated mechanisms including the Bjerknes feedback and background anthropogenic warming. It is concluded that background warming was the main contribution to the 2015 extreme SST event over the central equatorial Pacific Ocean on a developing El Niño condition, which in turn induced the extreme SST event over the tropical Indian Ocean through the atmospheric bridge effect.113Ysciescopu
Joint Trajectory and Resource Optimization of MEC-Assisted UAVs in Sub-THz Networks: A Resources-based Multi-Agent Proximal Policy Optimization DRL with Attention Mechanism
THz band communication technology will be used in the 6G networks to enable
high-speed and high-capacity data service demands. However, THz-communication
losses arise owing to limitations, i.e., molecular absorption, rain
attenuation, and coverage range. Furthermore, to maintain steady
THz-communications and overcome coverage distances in rural and suburban
regions, the required number of BSs is very high. Consequently, a new
communication platform that enables aerial communication services is required.
Furthermore, the airborne platform supports LoS communications rather than NLoS
communications, which helps overcome these losses. Therefore, in this work, we
investigate the deployment and resource optimization for MEC-enabled UAVs,
which can provide THz-based communications in remote regions. To this end, we
formulate an optimization problem to minimize the sum of the energy consumption
of both MEC-UAV and MUs and the delay incurred by MUs under the given task
information. The formulated problem is a MINLP problem, which is NP-hard. We
decompose the main problem into two subproblems to address the formulated
problem. We solve the first subproblem with a standard optimization solver,
i.e., CVXPY, due to its convex nature. To solve the second subproblem, we
design a RMAPPO DRL algorithm with an attention mechanism. The considered
attention mechanism is utilized for encoding a diverse number of observations.
This is designed by the network coordinator to provide a differentiated fit
reward to each agent in the network. The simulation results show that the
proposed algorithm outperforms the benchmark and yields a network utility which
is , , and more than the benchmarks.Comment: 13 pages, 12 figure
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