Backbone Can Not be Trained at Once: Rolling Back to Pre-trained Network for Person Re-Identification

In person re-identification (ReID) task, because of its shortage of trainable dataset, it is common to utilize fine-tuning method using a classification network pre-trained on a large dataset. However, it is relatively difficult to sufficiently fine-tune the low-level layers of the network due to the gradient vanishing problem. In this work, we propose a novel fine-tuning strategy that allows low-level layers to be sufficiently trained by rolling back the weights of high-level layers to their initial pre-trained weights. Our strategy alleviates the problem of gradient vanishing in low-level layers and robustly trains the low-level layers to fit the ReID dataset, thereby increasing the performance of ReID tasks. The improved performance of the proposed strategy is validated via several experiments. Furthermore, without any add-ons such as pose estimation or segmentation, our strategy exhibits state-of-the-art performance using only vanilla deep convolutional neural network architecture.Comment: Accepted to AAAI 201

Class-Attentive Diffusion Network for Semi-Supervised Classification

Recently, graph neural networks for semi-supervised classification have been widely studied. However, existing methods only use the information of limited neighbors and do not deal with the inter-class connections in graphs. In this paper, we propose Adaptive aggregation with Class-Attentive Diffusion (AdaCAD), a new aggregation scheme that adaptively aggregates nodes probably of the same class among K-hop neighbors. To this end, we first propose a novel stochastic process, called Class-Attentive Diffusion (CAD), that strengthens attention to intra-class nodes and attenuates attention to inter-class nodes. In contrast to the existing diffusion methods with a transition matrix determined solely by the graph structure, CAD considers both the node features and the graph structure with the design of our class-attentive transition matrix that utilizes a classifier. Then, we further propose an adaptive update scheme that leverages different reflection ratios of the diffusion result for each node depending on the local class-context. As the main advantage, AdaCAD alleviates the problem of undesired mixing of inter-class features caused by discrepancies between node labels and the graph topology. Built on AdaCAD, we construct a simple model called Class-Attentive Diffusion Network (CAD-Net). Extensive experiments on seven benchmark datasets consistently demonstrate the efficacy of the proposed method and our CAD-Net significantly outperforms the state-of-the-art methods. Code is available at https://github.com/ljin0429/CAD-Net.Comment: Accepted to AAAI 202

Bare-metal stents versus drug-eluting stents in large (≥3.5mm) single coronary artery: Angiographic and clinical outcomes at 6 months

SummaryBackgroundAlthough drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival in large randomized trials, the benefit of DES appears to be limited to restenosis. In large arteries, it is not clear which type of stent is more superior in angiographic and clinical outcomes between DES and bare-metal stents (BMS). We compared the angiographic and clinical outcomes of DES versus BMS in large arteries (≥3.5mm).MethodTwo hundred and forty patients from March 2002 to March 2007 received stents; 196 patients were treated with DES (44.9% sirolimus-eluting stents; 43.9% paclitaxel-eluting stents; 11.2% zotarolimus-eluting stents) and 44 with cobalt–chromium BMS for single de novo lesions in a large vessel. All subjects received aspirin, clopidogrel, and/or cilostazol as the standard antiplatelet regimen. The angiographic and clinical outcomes were evaluated at 6 months.ResultsFor the baseline characteristics, there were no significant differences between the DES and BMS groups. In addition, for the initially implanted stent there was no difference in the length, stent diameter, and lesion site between the two groups. After 6 months, the follow-up angiogram showed that in-stent diameter restenosis and late loss was more common with BMS than DES (39±21% vs. 19±17%, p=0.007; 1.44±0.83mm vs. 0.62±0.58mm, p=0.009, respectively). However, the target-lesion revascularization/target-vessel revascularization, and total major adverse cardiac events showed no significant differences between the groups (5.3% vs. 3.6%, p=0.62; 5.3% vs. 4.6%, p=0.86, respectively).ConclusionThe DES and cobalt–chromium BMS placed in large coronary arteries showed equally favorable 6-month clinical outcomes, although the 6-month angiographic results appeared more favorable in the DES group than in the BMS group

Optimization of Antibacterial Activity of Perilla frutescens var. acuta Leaf against Pseudomonas aeruginosa Using the Evolutionary Operation-Factorial Design Technique

This study was undertaken to optimize the conditions for the extraction of antibacterial activity of Perilla frutescens var. acuta leaf against Pseudomonas aeruginosa KCTC 2004 using the evolutionary operation-factorial (EVOP) design technique. Increased antibacterial activity was achieved at higher extraction temperatures and with a longer extraction time. Antibacterial activity was not affected by differing ethanol concentration in the extraction solvent. The maximum antibacterial activity of ethanolic extract of P. frutescens var. acuta leaf against P. aeruginosa, determined by the EVOP factorial technique, was obtained at an extraction temperature of 80 °C (R = −0.800**), 26 h (R = −0.731**) extraction time, and 50% (R = −0.075) ethanol concentration. The population of P. aeruginosa also decreased from 6.660 log CFU/mL in the initial set to 4.060 log CFU/mL in the third set. Also, scanning electron microscopy study of the ethanolic extract of P. frutescens var. acuta revealed potential detrimental effects on the morphology of P. aeruginosa

Propyl Gallate Inhibits Adipogenesis by Stimulating Extracellular Signal-Related Kinases in Human Adipose Tissue-Derived Mesenchymal Stem Cells

Propyl gallate (PG) used as an additive in various foods has antioxidant and anti-inflammatory effects. Although the functional roles of PG in various cell types are well characterized, it is unknown whether PG has effect on stem cell differentiation. In this study, we demonstrated that PG could inhibit adipogenic differentiation in human adipose tissue-derived mesenchymal stem cells (hAMSCs) by decreasing the accumulation of intracellular lipid droplets. In addition, PG significantly reduced the expression of adipocyte-specific markers including peroxisome proliferator-activated receptor-gamma (PPAR-gamma), CCAAT enhancer binding protein-alpha (C/EBP-alpha), lipoprotein lipase (LPL), and adipocyte fatty acid-binding protein 2 (aP2). PG inhibited adipogenesis in hAMSCs through extracellular regulated kinase (ERK) pathway. Decreased adipogenesis following PG treatment was recovered in response to ERK blocking. Taken together, these results suggest a novel effect of PG on adipocyte differentiation in hAMSCs, supporting a negative role of ERK1/2 pathway in adipogenic differentiationclose

A Prospective, Randomized, 6-Month Comparison of the Coronary Vasomotor Response Associated With a Zotarolimus- Versus a Sirolimus-Eluting Stent Differential Recovery of Coronary Endothelial Dysfunction

ObjectivesWe prospectively compared coronary endothelial dysfunction in patients with zotarolimus-eluting stent (ZES) versus sirolimus-eluting stent (SES) implantation at 6-month follow-up.BackgroundA ZES has been associated with uniform and rapid healing of the endothelium.MethodsFifty patients were randomly treated with intravascular ultrasound-guided stenting with a single stent to the mid-segment of the left anterior descending artery (20 ZES, 20 SES, and 10 bare-metal stents), and endothelial function was estimated before and after intervention at 6-month follow-up by incremental acetylcholine (Ach) (10, 20, 50, and 100 μg/min) and nitrate (200 μg/min) infusions into the left coronary ostium. The vascular response was quantitatively measured in the 5-mm segments proximal and distal to the stent.ResultsIn the drug-eluting stent groups, more intense vasoconstriction to incremental doses of Ach was observed at 6-month follow-up compared with the responses before stenting. Endothelial function associated with the ZES was more preserved at 6-month follow-up compared with the SES. Vasoconstriction to Ach was more prominent in the distal segments than the proximal segments in both the ZES and SES groups. Endothelium-independent vasodilation to nitrate did not differ significantly among the study groups.ConclusionsVasoconstriction in response to Ach in the peri-stent region was less pronounced in the ZES group than the SES group at 6-month follow-up, which suggests that endothelial function associated with ZES can be more preserved than the SES