386 research outputs found
Decoupled Contrastive Learning
Contrastive learning (CL) is one of the most successful paradigms for
self-supervised learning (SSL). In a principled way, it considers two augmented
"views" of the same image as positive to be pulled closer, and all other images
as negative to be pushed further apart. However, behind the impressive success
of CL-based techniques, their formulation often relies on heavy-computation
settings, including large sample batches, extensive training epochs, etc. We
are thus motivated to tackle these issues and establish a simple, efficient,
yet competitive baseline of contrastive learning. Specifically, we identify,
from theoretical and empirical studies, a noticeable negative-positive-coupling
(NPC) effect in the widely used InfoNCE loss, leading to unsuitable learning
efficiency concerning the batch size. By removing the NPC effect, we propose
decoupled contrastive learning (DCL) loss, which removes the positive term from
the denominator and significantly improves the learning efficiency. DCL
achieves competitive performance with less sensitivity to sub-optimal
hyperparameters, requiring neither large batches in SimCLR, momentum encoding
in MoCo, or large epochs. We demonstrate with various benchmarks while
manifesting robustness as much less sensitive to suboptimal hyperparameters.
Notably, SimCLR with DCL achieves 68.2% ImageNet-1K top-1 accuracy using batch
size 256 within 200 epochs pre-training, outperforming its SimCLR baseline by
6.4%. Further, DCL can be combined with the SOTA contrastive learning method,
NNCLR, to achieve 72.3% ImageNet-1K top-1 accuracy with 512 batch size in 400
epochs, which represents a new SOTA in contrastive learning. We believe DCL
provides a valuable baseline for future contrastive SSL studies.Comment: Accepted by ECCV202
Effects of Lower Limb Cycling Training on Different Components of Force and Fatigue in Individuals With Parkinson’s Disease
The strength of lower extremity is important for individuals to maintain balance and ambulation functions. The previous studies showed that individuals with Parkinson’s disease suffered from fatigue and strength loss of central origin. The purpose of this study was to investigate the effect of lower extremities’ cycling training on different components of force and fatigue in individuals with Parkinson’s disease. Twenty-four individuals (13 males, 11 females, mean age: 60.58 ± 8.21 years) diagnosed with idiopathic Parkinson’s disease were randomized into training and control groups. The maximum voluntary contraction (MVC) force, voluntary activation level (VA), and twitch force of knee extensors were measured using a custom-made system with surface electrical stimulation. The general, central, and peripheral fatigue indexes (GFI, CFI, and PFI) were calculated after a fatiguing cycling protocol. Subjects received 8 weeks of low resistance cycling training (training group) or self-stretching (control group) programs. Results showed that MVC, VA, and twitch force improved (p \u3c 0.05) only in the training group. Compared to the baseline, central fatigue significantly improved in the training group, whereas peripheral fatigue showed no significant difference in two groups. The cycling training was beneficial for individuals with Parkinson’s disease not only in muscle strengthening but also in central fatigue alleviation. Further in-depth investigation is required to confirm the effect of training and its mechanism on central fatigue
Reciprocal regulation of MicroRNA-99a and insulin-like growth factor I receptor signaling in oral squamous cell carcinoma cells
BACKGROUND: MicroRNAs (miRNAs), small noncoding RNA molecules can function as oncogenes or tumor suppressors in tumorigenesis. Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide with a 5-year survival rate of approximately 50%. METHODS: The expression of microRNA-99a (miR-99a) in OSCC tissues and cell lines was investigated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. The functions of miR-99a in migration/invasion and lung colonization were determined by transwell and tail vein injection assays, respectively. Specific targets of miR-99a were determined by software prediction, correlation with target protein expression, and luciferase reporter assay. The signaling pathways involved in regulation of miR-99a were investigated using the kinase inhibitors. RESULTS: We observed reduced levels of miR-99a, identified as one of the most downregulated miRNA in OSCC and all tested OSCC cell lines compared to normal oral keratinocytes. Ectopic miR-99a expression in OSCC cells markedly reduced migration and invasion in vitro as well as lung colonization in vivo. When evaluating the specific targets of miR-99a, we found that ectopic miR-99a expression downregulates insulin-like growth factor 1 receptor (IGF1R) protein and that the expression of miR-99a correlates negatively with IGF1R protein in OSCC cells. Insertion of the 3′UTR of IGF1R mRNA into the 3′UTR of a reporter gene markedly reduced luciferase activity in OSCC cells expressing miR-99a, suggesting that miR-99a reduces luciferase activity by targeting the 3′UTR of IGF1R mRNA. When evaluating the mechanisms of miR-99a downregulation, we observed the upregulation of miR-99a expression in serum-starved conditions and its suppression in response to insulin-like growth factor (IGF1) stimulation. Inhibitors of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) kinase inhibited IGF1-induced suppression of miR-99a, suggesting the negative regulation of miR-99a expression by IGF1R signaling. CONCLUSION: Overall, results indicate that miR-99a functions as a tumor metastasis suppressor in OSCC cells and mutually regulates IGF1R expression in a reciprocal regulation
Gen4Gen: Generative Data Pipeline for Generative Multi-Concept Composition
Recent text-to-image diffusion models are able to learn and synthesize images
containing novel, personalized concepts (e.g., their own pets or specific
items) with just a few examples for training. This paper tackles two
interconnected issues within this realm of personalizing text-to-image
diffusion models. First, current personalization techniques fail to reliably
extend to multiple concepts -- we hypothesize this to be due to the mismatch
between complex scenes and simple text descriptions in the pre-training dataset
(e.g., LAION). Second, given an image containing multiple personalized
concepts, there lacks a holistic metric that evaluates performance on not just
the degree of resemblance of personalized concepts, but also whether all
concepts are present in the image and whether the image accurately reflects the
overall text description. To address these issues, we introduce Gen4Gen, a
semi-automated dataset creation pipeline utilizing generative models to combine
personalized concepts into complex compositions along with text-descriptions.
Using this, we create a dataset called MyCanvas, that can be used to benchmark
the task of multi-concept personalization. In addition, we design a
comprehensive metric comprising two scores (CP-CLIP and TI-CLIP) for better
quantifying the performance of multi-concept, personalized text-to-image
diffusion methods. We provide a simple baseline built on top of Custom
Diffusion with empirical prompting strategies for future researchers to
evaluate on MyCanvas. We show that by improving data quality and prompting
strategies, we can significantly increase multi-concept personalized image
generation quality, without requiring any modifications to model architecture
or training algorithms.Comment: Preprint; Project Page: https://danielchyeh.github.io/Gen4Gen
Improving Success Rates of Percutaneous Coronary Intervention for Chronic Total Occlusion at a Rural Hospital in East Taiwan
SummaryBackgroundWe aimed to report the results of percutaneous coronary intervention for chronic total occlusion (CTO) in a remote hospital of southeast Taiwan that does not have on-site coronary artery bypass graft support and has insufficient medical resources.MethodsFrom 2006 to 2009, we identified 96 patients who underwent percutaneous coronary intervention and whose coronary angiogram showed CTO lesions. On-site cardiovascular surgeons were unavailable from 2006 to 2009.ResultsThe success rate (test for trend, p = 0.02) and numbers of guidewires used (test for trend, p = 0.59) significantly increased from 2006 to 2009, and the procedural time reduced significantly (test for trend, p = 0.001). The volume of contrast media injected decreased, although this result was not statistically significant (p = 0.70).ConclusionOur experience in managing CTO lesions substantially improved and the procedural time reduced over 4 years, even when constrained by a relative shortage of medical resources
Intensity modulated radiotherapy for elderly bladder cancer patients
<p>Abstract</p> <p>Background</p> <p>To review our experience and evaluate treatment planning using intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) for the treatment of elderly patients with bladder cancer.</p> <p>Methods</p> <p>From November 2006 through November 2009, we enrolled 19 elderly patients with histologically confirmed bladder cancer, 9 in the IMRT and 10 in the HT group. The patients received 64.8 Gy to the bladder with or without concurrent chemotherapy. Conventional 4-field "box" pelvic radiation therapy (2DRT) plans were generated for comparison.</p> <p>Results</p> <p>The median patient age was 80 years old (range, 65-90 years old). The median survival was 21 months (5 to 26 months). The actuarial 2-year overall survival (OS) for the IMRT vs. the HT group was 26.3% <it>vs </it>.37.5%, respectively; the corresponding values for disease-free survival were 58.3% <it>vs</it>. 83.3%, respectively; for locoregional progression-free survival (LRPFS), the values were 87.5% <it>vs</it>. 83.3%, respectively; and for metastases-free survival, the values were 66.7% <it>vs</it>. 60.0%, respectively. The 2-year OS rates for T1, 2 <it>vs</it>. T3, 4 were 66.7% <it>vs</it>. 35.4%, respectively (<it>p </it>= 0.046). The 2-year OS rate was poor for those whose RT completion time greater than 8 weeks when compared with the RT completed within 8 wks (37.9% vs. 0%, <it>p </it>= 0.004).</p> <p>Conclusion</p> <p>IMRT and HT provide good LRPFS with tolerable toxicity for elderly patients with invasive bladder cancer. IMRT and HT dosimetry and organ sparing capability were superior to that of 2DRT, and HT provides better sparing ability than IMRT. The T category and the RT completion time influence OS rate.</p
TRPV1 is a Responding Channel for Acupuncture Manipulation in Mice Peripheral and Central Nerve System
Background/Aims: Acupuncture involves inserting a fine needle into a specific point, often called an acupoint, thereby initiating a therapeutic effect accompanied by phenomena such as soreness, heaviness, fullness, and numbness. Acupoints are characterized as points located in deep tissues with abundant sensory nerve terminals, which suggests that there is a strong relationship between acupoints and peripheral sensory afferents. In this study, we determined whether manual acupuncture (MA) or different frequencies of electroacupuncture (EA) share similar mechanisms for activating excitatory neurotransmission. Methods: We performed MA or EA at acupoint ST36 and we also used western blot and immunostaining techniques to determine neural changes at the peripheral dorsal root ganglion (DRG), spinal cord (SC), and somatosensory cortex (SSC) levels. Results: Our results show that either MA or EA at the ST36 acupoint significantly increased components of the TRPV1-related signaling pathway, such as pPKA, pPI3K, pPKC-pERK, and pAKT (but not pp38 or pJNK) at the peripheral DRG and central SC-SSC levels. Furthermore, excitatory phosphorylated N-methyl-D-aspartate receptor (pNMDA) and pCaMKIIα (but not pNR2B, pCaMKIIδ, or pCaMKIIγ) also increased. These molecules could not increase in the DRG and SC-SSC of TRPV1–/–mice. Conclusion: Our data demonstrates that both MA and EA can activate excitatory signals in either peripheral or central levels. We also define that TRPV1 is crucial for an acupuncture effect and then initiate excitatory pNR1-pCaMKII pathway, at peripheral DRG and central SC-SSC level. We suggest that the TRPV1 signaling pathway is highly correlated to Acupuncture effect that implies the real clinical significance
Transcriptome analysis of Dnmt3l knock-out mice derived multipotent mesenchymal stem/stromal cells during osteogenic differentiation
Multipotent mesenchymal stem/stromal cells (MSCs) exhibit great potential for cell-based therapy. Proper epigenomic signatures in MSCs are important for the maintenance and the subsequent differentiation potential. The DNA methyltransferase 3-like (DNMT3L) that was mainly expressed in the embryonic stem (ES) cells and the developing germ cells plays an important role in shaping the epigenetic landscape. Here, we report the reduced colony forming ability and impaire
Identifying early decline of daily function and its association with physical function in chronic kidney disease: performance-based and self-reported measures
Objective To verify self-reported basic and instrumental activities of daily living (IADL) with a disability and the results of performance-based tests (namely the Taiwan performance-based IADL (TPIADL), the 2-minute step test (2MST), the 30-second chair-stand test (30-s CST), and handgrip dynamometer measurement) to identify disability early and assess the associations with functional fitness in patients with advanced chronic kidney disease (CKD). Methods A cross-sectional study of 99 patients with stage 4–5 CKD and 57 healthy elderly adults were recruited. Self-reported measures were used to collect information on basic (Barthel Index) and IADL (Lawton–Brody scale). Objective measures of the TPIADL and functional fitness (2MST, 30-s CST, handgrip dynamometer) were also assessed. Results Only IADL, as detected by the TPIADL, were impaired to a greater extent in the CKD patients than those of healthy elderly adults. Among all the patients with CKD, a greater impairment in the TPIADL remained statistically associated with a lower ability in the 2MST. A one step increase in the 2MST score was significantly associated with an improvement of 0.2 s in the total performance time of the TPIADL. Conclusion Performance-based measures, such as the TPIADL, may detect a functional limitation before it becomes measurable by traditional self-reported basic and IADL scales; functional limitation is mainly associated with cardiac endurance for advanced CKD
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