78 research outputs found
Conditional graph entropy as an alternating minimization problem
Conditional graph entropy is known to be the minimal rate for a natural
functional compression problem with side information at the receiver. In this
paper we show that it can be formulated as an alternating minimization problem,
which gives rise to a simple iterative algorithm for numerically computing
(conditional) graph entropy. This also leads to a new formula which shows that
conditional graph entropy is part of a more general framework: the solution of
an optimization problem over a convex corner. In the special case of graph
entropy (i.e., unconditioned version) this was known due to Csisz\'ar,
K\"orner, Lov\'asz, Marton, and Simonyi. In that case the role of the convex
corner was played by the so-called vertex packing polytope. In the conditional
version it is a more intricate convex body but the function to minimize is the
same. Furthermore, we describe a dual problem that leads to an optimality check
and an error bound for the iterative algorithm
A Hybrid Wireless Image Transmission Scheme with Diffusion
We propose a hybrid joint source-channel coding (JSCC) scheme, in which the
conventional digital communication scheme is complemented with a generative
refinement component to improve the perceptual quality of the reconstruction.
The input image is decomposed into two components: the first is a coarse
compressed version, and is transmitted following the conventional separation
based approach. An additional component is obtained through the diffusion
process by adding independent Gaussian noise to the input image, and is
transmitted using DeepJSCC. The decoder combines the two signals to produce a
high quality reconstruction of the source. Experimental results show that the
hybrid design provides bandwidth savings and enables graceful performance
improvement as the channel quality improves
Extending Context Window of Large Language Models via Semantic Compression
Transformer-based Large Language Models (LLMs) often impose limitations on
the length of the text input to ensure the generation of fluent and relevant
responses. This constraint restricts their applicability in scenarios involving
long texts. We propose a novel semantic compression method that enables
generalization to texts that are 6-8 times longer, without incurring
significant computational costs or requiring fine-tuning. Our proposed
framework draws inspiration from source coding in information theory and
employs a pre-trained model to reduce the semantic redundancy of long inputs
before passing them to the LLMs for downstream tasks. Experimental results
demonstrate that our method effectively extends the context window of LLMs
across a range of tasks including question answering, summarization, few-shot
learning, and information retrieval. Furthermore, the proposed semantic
compression method exhibits consistent fluency in text generation while
reducing the associated computational overhead
Application and Curative Effect of Micro-implant Anchorage in Orthodontics
Purpose: To explore and analyze the curative effects of micro - implant anchorages in orthodontics.Methods: A retrospective analysis of 65 patients undergoing orthodontic treatment in Department of Stomatology, Binzhou Medical University Hospital, Shandong, China was carried out. Thirty four cases in the treatment group were treated with a micro-implant as the anchorage, while 31 cases of the control group were treated with a palatal bar and facebow as the anchorage, and the curative results of the two groups were then compared.Results: After a 13-month treatment, both anchorages were clinically effective, but the micro-implant anchorage showed higher efficacy. Measurement indices for the test group, including sella-nasion - A point (SNA) angle (- 1.88 ± 0.71), sella-nasion-B point (SNB) angle (1.39 ± 0.42), A point - nasion - B point (ANB) angle (- 2.40 ± 0.83), upper central incisor - lower central incisor (U1 - L1) angle (25.79 ± 5.90), upper central incisor - sella - nasion (U1 - SN) angle (- 10.13 ± 3.68), lower central incisor â mandibular plane (L1 - MP) angle (- 4.22 ± 0.45), upper central incisor - nasion - A point (U1 - NA) angle (- 1.32 ± 1.35) and lower central incisor - nasion - B point (L1 - NB) angle (- 1.32 ± 1.35) of the test group were significantly different those of the control group Overbite (OB), overjet (OJ), intercanine width and the width of the first molars of treatment and control groups were also remarkably). Moreover, micro-implant was observed to be more stable during treatment.Conclusion: Compared with traditional anchorages, micro-implants possess the advantages of slighter trauma, simpler operation, more reliable curative effect and high stability.Keywords: Micro-implant anchorage, Orthodontics, Facebow anchorage, Oral medicine, Clinical efficac
Transcriptional profiles of different states of cancer stem cells in triple-negative breast cancer
Abstract
Breast cancer stem cells (BCSCs) are thought to be responsible for tumor initiation, metastasis and relapse. Our group and others have described markers useful in isolating BCSCs just as aldehyde dehydrogenase positive (ALDH+) or CD24âCD44+. In fact, cells which simultaneously express both sets of markers have the highest tumor initiating capacity. Although the transcriptomic profile of cells expressing each BCSC marker alone has been reported, the profile of the most tumorigenic population expressing both sets of markers has not. Here we used the biomarker combination of ALDH and CD24/CD44 to sort four populations isolated from triple-negative breast cancer (TNBC) patient-derived xenografts, and performed whole-transcriptome sequencing on each population. We systematically compared the profiles of the three states of BCSCs (ALDH+CD24âCD44+, ALDH+non-CD24âCD44+ and ALDHâCD24âCD44+) to that of the differentiated tumor cells (ALDHânon-CD24âCD44+). For the first time, we compared the ALDH+CD24âCD44+ BCSCs with the other two BCSC populations. In ALDH+CD24âCD44+ BCSCs, we identified P4HA2, PTGR1 and RAB40B as potential prognostic markers, which were virtually related to the status of BCSCs and tumor growth in TNBC cells.https://deepblue.lib.umich.edu/bitstream/2027.42/142395/1/12943_2018_Article_809.pd
MicroRNA100 Inhibits Self-Renewal of Breast Cancer Stemâlike Cells and Breast Tumor Development
miRNAs are essential for self-renewal and differentiation of normal and malignant stem cells by regulating the expression of key stem cell regulatory genes. Here, we report evidence implicating the miR100 in self-renewal of cancer stem-like cells (CSC). We found that miR100 expression levels relate to the cellular differentiation state, with lowest expression in cells displaying stem cell markers. Utilizing a tetracycline-inducible lentivirus to elevate expression of miR100 in human cells, we found that increasing miR100 levels decreased the production of breast CSCs. This effect was correlated with an inhibition of cancer cell proliferation in vitro and in mouse tumor xenografts due to attenuated expression of the CSC regulatory genes SMARCA5, SMARCD1, and BMPR2. Furthermore, miR100 induction in breast CSCs immediately upon their orthotopic implantation or intracardiac injection completely blocked tumor growth and metastasis formation. Clinically, we observed a significant association between miR100 expression in breast cancer specimens and patient survival. Our results suggest that miR100 is required to direct CSC self-renewal and differentiation
Accelerated discovery of molecular nanojunction photocatalysts for hydrogen evolution by using automated screening and flow synthesis
Discovering and optimizing multicomponent organic semiconductors is typically a laborious process. High-throughput experimentation can accelerate this, but the results of small-scale screening trials are not always transferable to bulk materials production. Here we report the accelerated discovery of molecular nanojunction photocatalysts based on a combinatorial donorâacceptor molecular library assisted by high-throughput automated screening. The knowledge gained from this high-throughput batch screening is then transferred to a scaled-up, flow-based synthesis process. The scaled-up molecular nanojunction MTPA-CA:CNP147 (3-(4-(bis(4-methoxyphenyl)amino)phenyl)-2-cyanoacrylic acid:2,6-bis(4-cyanophenyl)-4-(4âČ-fluoro-[1,1âČ-biphenyl]-4-yl)pyridine-3,5-dicarbonitrile) exhibits a sacrificial hydrogen evolution rate of 330.3âmmolâhâ1âgâ1 with an external quantum efficiency of 80.3% at 350ânm, which are among the highest reported for an organic photocatalyst. A one-dimensional nanofibre architecture is identified for this molecular nanojunction, which exhibits efficient charge separation. Electronic structureâproperty correlations across the photocatalyst library show that a moderate binding energy between the donor and the acceptor molecules is a potential factor for efficient molecular nanojunction formation
Xueyan Bai's Quick Files
The Quick Files feature was discontinued and itâs files were migrated into this Project on March 11, 2022. The file URLâs will still resolve properly, and the Quick Files logs are available in the Projectâs Recent Activity
Analysis strategy configurations in risk taking using fuzzy set qualitative comparative analysis model
Risk-taking is a key factor in corporate competitive advantage, and economic development. The type of strategic configuration that can drive high-level risk-taking is a problem worthy of attention. This study takes 2,219 listed firms in China as samples and performs a fuzzy set qualitative comparative analysis (fsQCA) to explore the linkage effect and path choice of strategic change, corporate social responsibility, innovation, diversification, and financialization with corporate risk-taking (CRT). It finds that: (a) a single strategy does not constitute a necessary condition for high-level CRT; (b) three types of adaptive schemes exist for high-level CRT, among which the risk-taking level is the highest under the path of âInnovation, diversification, and financializationâ; and (c) the driving paths of CRT in different regions, industries, and ownership show obvious differences
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