174 research outputs found

    Minority-Oriented Vicinity Expansion with Attentive Aggregation for Video Long-Tailed Recognition

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    A dramatic increase in real-world video volume with extremely diverse and emerging topics naturally forms a long-tailed video distribution in terms of their categories, and it spotlights the need for Video Long-Tailed Recognition (VLTR). In this work, we summarize the challenges in VLTR and explore how to overcome them. The challenges are: (1) it is impractical to re-train the whole model for high-quality features, (2) acquiring frame-wise labels requires extensive cost, and (3) long-tailed data triggers biased training. Yet, most existing works for VLTR unavoidably utilize image-level features extracted from pretrained models which are task-irrelevant, and learn by video-level labels. Therefore, to deal with such (1) task-irrelevant features and (2) video-level labels, we introduce two complementary learnable feature aggregators. Learnable layers in each aggregator are to produce task-relevant representations, and each aggregator is to assemble the snippet-wise knowledge into a video representative. Then, we propose Minority-Oriented Vicinity Expansion (MOVE) that explicitly leverages the class frequency into approximating the vicinity distributions to alleviate (3) biased training. By combining these solutions, our approach achieves state-of-the-art results on large-scale VideoLT and synthetically induced Imbalanced-MiniKinetics200. With VideoLT features from ResNet-50, it attains 18% and 58% relative improvements on head and tail classes over the previous state-of-the-art method, respectively.Comment: Accepted to AAAI 2023. Code is available at https://github.com/wjun0830/MOV

    Leveraging Hidden Positives for Unsupervised Semantic Segmentation

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    Dramatic demand for manpower to label pixel-level annotations triggered the advent of unsupervised semantic segmentation. Although the recent work employing the vision transformer (ViT) backbone shows exceptional performance, there is still a lack of consideration for task-specific training guidance and local semantic consistency. To tackle these issues, we leverage contrastive learning by excavating hidden positives to learn rich semantic relationships and ensure semantic consistency in local regions. Specifically, we first discover two types of global hidden positives, task-agnostic and task-specific ones for each anchor based on the feature similarities defined by a fixed pre-trained backbone and a segmentation head-in-training, respectively. A gradual increase in the contribution of the latter induces the model to capture task-specific semantic features. In addition, we introduce a gradient propagation strategy to learn semantic consistency between adjacent patches, under the inherent premise that nearby patches are highly likely to possess the same semantics. Specifically, we add the loss propagating to local hidden positives, semantically similar nearby patches, in proportion to the predefined similarity scores. With these training schemes, our proposed method achieves new state-of-the-art (SOTA) results in COCO-stuff, Cityscapes, and Potsdam-3 datasets. Our code is available at: https://github.com/hynnsk/HP.Comment: Accepted to CVPR 202

    Numb Chin Syndrome with Concomitant Painful Ophthalmoplegia Leading to a Diagnosis of Diffuse Large B Cell Lymphoma

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    Painful ophthalmoplegia (PO) and concomitant numb chin syndrome (NCS) is a very rare event. There are a few reports in the literature about PO and concomitant NCS that have preceded the diagnosis of a malignancy. In this report, we describe a patient with diffuse large B cell lymphoma who presented with PO and concomitant NCS as the initial symptom of the disease

    Knockdown of Y-box binding protein 1 induces autophagy in early porcine embryos

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    Y-box binding protein 1 (YBX1) plays important roles in RNA stabilization, translation, transcriptional regulation, and mitophagy. However, its effects on porcine preimplantation embryos remain unclear. In this study, we knocked down YBX1 in the one-cell (1C) stage embryo via small interfering RNA microinjection to determine its function in porcine embryo development. The mRNA level of YBX1 was found to be highly expressed at the four-cell (4C) stage in porcine embryos compared with one-cell (1C) and two-cell (2C) stages. The number of blastocysts was reduced following YBX1 knockdown. Notably, YBX1 knockdown decreased the phosphatase and tensin homolog-induced kinase 1 (PINK1) and parkin RBR E3 ubiquitin protein ligase (PRKN) mRNA levels. YBX1 knockdown also decreased PINK1, active mitochondria, and sirtuin 1 levels, indicating reduced mitophagy and mitochondrial biogenesis. Furthermore, YBX1 knockdown increased the levels of glucose-regulated protein 78 (GRP78) and calnexin, leading to endoplasmic reticulum (ER) stress. Additionally, YBX1 knockdown increased autophagy and apoptosis. In conclusion, knockdown of YBX1 decreases mitochondrial function, while increasing ER stress and autophagy during embryonic development

    Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43

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    Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43

    The Efficacy of the Prophylactic Use of Octreotide after a Pancreaticoduodenectomy

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    This study was performed to analyze the efficacy of the prophylactic use of octreotide (Novartis, Stein, Switzerland) for pancreatic fistula following a pancreaticoduodenectomy. The medical records of 190 patients who underwent a pancreaticoduodenectomy at the Samsung Medical Center in Seoul, Korea between January 2000 and December 2002 were reviewed. Patients were divided into either the octreotide (n = 81) or control group (n = 109). The octreotide group received subcutaneous injections of 100 Āµg of octreotide every 12 hours for more than five days after surgery. The control group was not treated with octreotide. The criterion of pancreatic fistula was the drainage of the amylase rich fluid, over 500 U/mL in the three days after surgery. The morbidity and mortality rates were 32.1% and 1.2% in the octreotide group and 31.2% and 0% in the control group, respectively. Pancreatic fistula was the second most common complication (8.4%). In the univariate analysis, octreotide was ineffective in reducing pancreatic fistula (p = 0.26). However, in the multivariate regression analysis, combined gastrectomy (p = 0.018), cellular origin of the disease (p = 0.049), and use of octreotide (p = 0.044) were the risk factors that increased the frequency of pancreatic fistula. Therefore, the routine use of octreotide after a pancreaticoduodenectomy should be avoided until a worldwide consensus is established

    Humanized Anti-hepatocyte Growth Factor Monoclonal Antibody (YYB-101) Inhibits Ovarian Cancer Progression

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    Current chemotherapy regimens have certain limitations in improving the survival rates of patients with advanced ovarian cancer. Hepatocyte growth factor (HGF) is important in ovarian cancer cell migration and invasion. This study assessed the effects of YYB-101, a humanized monoclonal anti-HGF antibody, on the growth and metastasis of ovarian cancer cells. YYB-101 suppressed the phosphorylation of the HGF receptor c-MET and inhibited the migration and invasion of SKOV3 and A2780 ovarian cancer cells. Moreover, the combination of YYB-101 and paclitaxel synergistically inhibited tumor growth in an in vivo ovarian cancer mouse xenograft model and significantly increased the overall survival (OS) rate compared with either paclitaxel or YYB-101 alone. Taken together, these findings suggest that YYB-101 has therapeutic potential in ovarian cancer when combined with conventional chemotherapy agents.1
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