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

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

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

A Rare Case of a Signet Ring Cell Carcinoma of the Colon Mimicking a Juvenile Polyp

Primary signet ring cell carcinoma (SRC) of colon at early stage is quite rare. Only 26 cases were reported until now. We report an early stage of primary SRC which was misdiagnosed as a juvenile polyp and treated with polypectomy followed by surgical resection. A 21-year-old male was administered for hematochezia. Abdominopelvic enhanced computed tomography revealed a polyp with active bleeding at the proximal rectum just below the rectosigmoid junction. Colonoscopy examination revealed a colon polyp with 0.5 cm sized head. Polypectomy was performed with snare and the polyp was completely removed. Biopsy revealed SRC. Surgical resection was also performed and there were no residual tumor or lymph node metastasis in the surgical specimen

Elevation of serum lactate dehydrogenase in patients with pectus excavatum

INTRODUCTION: Pectus excavatum is the most common congenital chest wall deformity and the depression of the anterior chest wall, which compresses the internal organs. The aim of the present study is to investigate the effects of pectus excavatum on blood laboratory findings. MATERIAL AND METHODS: From March 2011 to December 2011, 71 patients with pectus excavatum who visited Seoul Saint Mary Hospital for Nuss procedure were reviewed and analyzed. The blood samples were routinely taken at the day before surgery and pectus bar removal was usually performed in 2 to 3 years after Nuss procedure. To investigate the effects on blood laboratory findings, preoperative routine blood laboratory data and postoperative changes of abnormal laboratory data were analyzed. RESULTS: Only lactate dehydrogenase (LDH), one of 26 separate routine laboratory tests, was abnormal and significantly elevated than normal value (age <10, p = 0.008; age ≥10, p < 0.001). However, there was no significant correlation between LDH levels and severities of pectus excavatum. The symmetric subgroup had significantly higher LDH level than the asymmetric subgroup (p <0.001) and there was a significant decrease of LDH level after correction of deformity (p = 0.017). CONCLUSION: In conclusion, only LDH, one of the routine laboratory tests, was significantly elevated than normal value, which was thought to be caused by etiologies of pectus excavatum and the compression of the internal organs. Further studies on LDH including isoenzyme studies in patients with pectus excavatum will be needed, and these studies will provide a deeper and wider comprehension of pectus excavatum

Enhanced Electrokinetic Transport of Sulfate in Saline Soil

The electrokinetic transport of sulfate was investigated as a means of treating and restoring a sulfate-accumulating saline soil. The electrokinetic treatment decreased the electrical conductivity of the soil, an indicator of soil salinity, to 58.6%, 73.1%, and 83.5% for 7, 14 and 21 days, respectively. More than 96% of the chloride and nitrate were removed within 7 days. However, the removal of sulfate was highly influenced by the anode material. An iron anode removed sulfate effectively, whereas, sulfate was hyper-accumulated in the anodic region when an inert anode was used. The iron anode was oxidized in a sacrificial anodic reaction, which competed with the electrolysis reaction of water at the anode, and finally the reaction prevented the severe acidification of the soil in the anodic region. However, the competing reactions produced hydrogen ions at the anode, and the ions were transported toward the cathode, which, in turn, acidified the soil, especially, in the anodic region. The acidification switched the surface charge of the soil from negative to positive, increasing the interaction between the soil surface and sulfate, and thus inhibiting the transport of sulfate under the electric field. The zeta potential analysis of the soil provided an explanation. The results indicate that preventing severe acidification is an important factor which influences the transport of anions and iron anode for the enhanced removal of anionic pollutants by electrokinetic remediation

Prevalence and Risk Factors of Gastric Adenoma and Gastric Cancer in Colorectal Cancer Patients

Background/Aims. To evaluate the incidence of gastric adenoma and gastric cancer in colorectal cancer patients, as well as the clinicopathological features that affect their incidence. Methods. Among patients who underwent surgery after being diagnosed with colorectal cancer between January 2004 and December 2013 at Chungnam National University Hospital, 142 patients who underwent follow-up upper gastrointestinal endoscopy were assigned to the patient group. The control group included 426 subjects randomly selected. The patient group was subdivided into two: one that developed gastric adenoma or cancer and one that did not. Clinicopathological characteristics were compared between these groups. Results. In total, 35 (24.6%) colorectal cancer patients developed a gastric adenoma or gastric cancer, which was higher than the number in the control group (20 [4.7%] patients; p<0.001). Age, alcohol history, and differentiation of colorectal cancer were associated with higher risks of gastric adenoma or gastric cancer, with odds ratios of 1.062, 6.506, and 5.901, respectively. Conclusions. In colorectal cancer patients, screening with upper gastrointestinal endoscopy is important, even if no lesions are noted in the upper gastrointestinal tract at colorectal cancer diagnosis. Endoscopic screening is particularly important with increasing age, history of alcohol consumption, and poor cancer differentiation

Mesenteric Pseudocyst of the Small Bowel in Gastric Cancer Patient: A Case Report

Mesenteric pseudocyst is rare. This term is used to describe the abdominal cystic mass, without the origin of abdominal organ. We presented a case of mesenteric pseudocyst of the small bowel in a 70-year-old man. Esophago-gastro-duodenoscopy showed a 3.5 cm sized excavated lesion on the posterior wall of angle. Endocopic biopsy confirmed a histologic diagnosis of the poorly differentiated adenocarcinoma, which includes the signet ring cell component. Abdominal computed tomography scan showed a focal mucosal enhancement in the posterior wall of angle of the stomach, a 2.4 cm sized enhancing mass on the distal small bowel loop, without distant metastases or ascites in rectal shelf, and multiple gallbladder stones. The patient underwent subtotal gastrectomy with gastroduodenostomy, segmental resection of the small bowel, and cholecystectomy. The final pathological diagnosis was mesenteric pseudocyst. This is the first case report describing incidentally detected mesenteric pseudocyst of the small bowel in gastric cancer patients

Recurrent Renal Leiomyosarcoma Mimicking a Colonic Submucosal Tumor: A Case Report

A primary leiomyosarcoma of the kidney is a rare, but highly aggressive, neoplasm, accounting for only 0.1% of all invasive renal tumors. Local or systemic recurrence is common, but a leiomyosarcoma is difficult to diagnose preoperatively. We recently encountered an interesting case of an unusual recurrence of a renal leiomyosarcoma. A 57-year-old woman visited our hospital complaining of lower abdominal pain. Four years previously, she had undergone a left nephrectomy. She had a primary leiomyosarcoma of the kidney that had been misdiagnosed as a renal cell carcinoma. Colonoscopy revealed the presence of a lesion similar to a submucosal tumor in the descending colon. Postoperative pathologic examination confirmed that the mass was a recurrent leiomyosarcoma. We report this unusual case and present a review of the literature