127 research outputs found
Control-Aware Trajectory Predictions for Communication-Efficient Drone Swarm Coordination in Cluttered Environments
Swarms of Unmanned Aerial Vehicles (UAV) have demonstrated enormous potential
in many industrial and commercial applications. However, before deploying UAVs
in the real world, it is essential to ensure they can operate safely in complex
environments, especially with limited communication capabilities. To address
this challenge, we propose a control-aware learning-based trajectory prediction
algorithm that can enable communication-efficient UAV swarm control in a
cluttered environment. Specifically, our proposed algorithm can enable each UAV
to predict the planned trajectories of its neighbors in scenarios with various
levels of communication capabilities. The predicted planned trajectories will
serve as input to a distributed model predictive control (DMPC) approach. The
proposed algorithm combines (1) a trajectory compression and reconstruction
model based on Variational Auto-Encoder, (2) a trajectory prediction model
based on EvolveGCN, a graph convolutional network (GCN) that can handle dynamic
graphs, and (3) a KKT-informed training approach that applies the
Karush-Kuhn-Tucker (KKT) conditions in the training process to encode DMPC
information into the trained neural network. We evaluate our proposed algorithm
in a funnel-like environment. Results show that the proposed algorithm
outperforms state-of-the-art benchmarks, providing close-to-optimal control
performance and robustness to limited communication capabilities and
measurement noises.Comment: 15 pages, 15 figures, submitted to IEEE Transactions on Intelligent
Vehicle
Communication-Efficient Decentralized Federated Learning via One-Bit Compressive Sensing
Decentralized federated learning (DFL) has gained popularity due to its
practicality across various applications. Compared to the centralized version,
training a shared model among a large number of nodes in DFL is more
challenging, as there is no central server to coordinate the training process.
Especially when distributed nodes suffer from limitations in communication or
computational resources, DFL will experience extremely inefficient and unstable
training. Motivated by these challenges, in this paper, we develop a novel
algorithm based on the framework of the inexact alternating direction method
(iADM). On one hand, our goal is to train a shared model with a sparsity
constraint. This constraint enables us to leverage one-bit compressive sensing
(1BCS), allowing transmission of one-bit information among neighbour nodes. On
the other hand, communication between neighbour nodes occurs only at certain
steps, reducing the number of communication rounds. Therefore, the algorithm
exhibits notable communication efficiency. Additionally, as each node selects
only a subset of neighbours to participate in the training, the algorithm is
robust against stragglers. Additionally, complex items are computed only once
for several consecutive steps and subproblems are solved inexactly using
closed-form solutions, resulting in high computational efficiency. Finally,
numerical experiments showcase the algorithm's effectiveness in both
communication and computation
Learning Large Graph Property Prediction via Graph Segment Training
Learning to predict properties of large graphs is challenging because each
prediction requires the knowledge of an entire graph, while the amount of
memory available during training is bounded. Here we propose Graph Segment
Training (GST), a general framework that utilizes a divide-and-conquer approach
to allow learning large graph property prediction with a constant memory
footprint. GST first divides a large graph into segments and then
backpropagates through only a few segments sampled per training iteration. We
refine the GST paradigm by introducing a historical embedding table to
efficiently obtain embeddings for segments not sampled for backpropagation. To
mitigate the staleness of historical embeddings, we design two novel
techniques. First, we finetune the prediction head to fix the input
distribution shift. Second, we introduce Stale Embedding Dropout to drop some
stale embeddings during training to reduce bias. We evaluate our complete
method GST-EFD (with all the techniques together) on two large graph property
prediction benchmarks: MalNet and TpuGraphs. Our experiments show that GST-EFD
is both memory-efficient and fast, while offering a slight boost on test
accuracy over a typical full graph training regime
A novel pyroptosis-related prognostic signature for lung adenocarcinoma: Identification and multi-angle verification
Background: Lung adenocarcinoma (LUAD) is an aggressive disease of heterogeneous characteristics with poor prognosis and high mortality. Pyroptosis, a newly uncovered type of programmed cell death with an inflammatory nature, has been determined to hold substantial importance in the progression of tumors. Despite this, the knowledge about pyroptosis-related genes (PRGs) in LUAD is limited. This study aimed to develop and validate a prognostic signature for LUAD based on PRGs.Methods: In this research, gene expression information from The Cancer Genome Atlas (TCGA) served as the training cohort and data from Gene Expression Omnibus (GEO) was utilized as the validation cohort. PRGs list was taken from the Molecular Signatures Database (MSigDB) and previous studies. Univariate Cox regression and Lasso analysis were then conducted to identify prognostic PRGs and develop a LUAD prognostic signature. The Kaplan-Meier method, univariate and multivariate Cox regression models were employed to assess the independent prognostic value and forecasting accuracy of the pyroptosis-related prognostic signature. The correlation between prognostic signature and immune infiltrating was analyzed to examine the role in tumor diagnosis and immunotherapy. Further, RNA-seq as well as quantitative real-time polymerase chain reaction (qRT-PCR) analysis in separate data sets was applied in order to validate the potential biomarkers for LUAD.Results: A novel prognostic signature based on 8 PRGs (BAK1, CHMP2A, CYCS, IL1A, CASP9, NLRC4, NLRP1, and NOD1) was established to predict the survival of LUAD. The prognostic signature proved to be an independent prognostic factor of LUAD with satisfactory sensitivity and specificity in the training and validation sets. High-risk scores subgroups in the prognostic signature were significantly associated with advanced tumor stage, poor prognosis, less immune cell infiltration, and immune function deficiency. RNA sequencing and qRT-PCR analysis confirmed that the expression of CHMP2A and NLRC4 could be used as biomarkers for LUAD.Conclusion: We have successfully developed a prognostic signature consisting of eight PRGs that providing a novel perspective on predicting prognosis, assessing infiltration levels of tumor immune cells, and determining the outcomes of immunotherapy for LUAD
LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma.
LGR5 is a marker of normal and cancer stem cells in various tissues where it functions as a receptor for R-spondins and increases canonical Wnt signalling amplitude. Here we report that LGR5 is also highly expressed in a subset of high grade neuroblastomas. Neuroblastoma is a clinically heterogenous paediatric cancer comprising a high proportion of poor prognosis cases (~40%) which are frequently lethal. Unlike many cancers, Wnt pathway mutations are not apparent in neuroblastoma, although previous microarray analyses have implicated deregulated Wnt signalling in high-risk neuroblastoma. We demonstrate that LGR5 facilitates high Wnt signalling in neuroblastoma cell lines treated with Wnt3a and R-spondins, with SK-N-BE(2)-C, SK-N-NAS and SH-SY5Y cell-lines all displaying strong Wnt induction. These lines represent MYCN-amplified, NRAS and ALK mutant neuroblastoma subtypes respectively. Wnt3a/R-Spondin treatment also promoted nuclear translocation of β-catenin, increased proliferation and activation of Wnt target genes. Strikingly, short-interfering RNA mediated knockdown of LGR5 induces dramatic Wnt-independent apoptosis in all three cell-lines, accompanied by greatly diminished phosphorylation of mitogen/extracellular signal-regulated kinases (MEK1/2) and extracellular signal-regulated kinases (ERK1/2), and an increase of BimEL, an apoptosis facilitator downstream of ERK. Akt signalling is also decreased by a Rictor dependent, PDK1-independent mechanism. LGR5 expression is cell cycle regulated and LGR5 depletion triggers G1 cell-cycle arrest, increased p27 and decreased phosphorylated retinoblastoma protein. Our study therefore characterises new cancer-associated pathways regulated by LGR5, and suggest that targeting of LGR5 may be of therapeutic benefit for neuroblastomas with diverse etiologies, as well as other cancers expressing high LGR5
Correction: LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma.
Present: The originally supplied Figure 5 contains duplicate total-ERK panels. Correct: The proper Figure 5 appears below. The authors sincerely apologize for this error
Correction: LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma
A Correction on:
LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma
Gabriella Cunha Vieira, S. Chockalingam, Zsombor Melegh, Alexander Greenhough, Sally Malik, Marianna Szemes, Ji Hyun Park, Abderrahmane Kaidi, Li Zhou, Daniel Catchpoole, Rhys Morgan, David O. Bates, Peter J. Gabb and Karim Malik
Original article: Oncotarget. 2015; 6:40053-67. DOI: 10.18632/oncotarget.5548.
The originally Figure 5 contains duplicate total-ERK panels.
The proper Figure 5 is attached. The authors sincerely apologize for this error
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