35 research outputs found

    Vision Transformer with Cross-attention by Temporal Shift for Efficient Action Recognition

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    We propose Multi-head Self/Cross-Attention (MSCA), which introduces a temporal cross-attention mechanism for action recognition, based on the structure of the Multi-head Self-Attention (MSA) mechanism of the Vision Transformer (ViT). Simply applying ViT to each frame of a video frame can capture frame features, but cannot model temporal features. However, simply modeling temporal information with CNN or Transfomer is computationally expensive. TSM that perform feature shifting assume a CNN and cannot take advantage of the ViT structure. The proposed model captures temporal information by shifting the Query, Key, and Value in the calculation of MSA of ViT. This is efficient without additional coinformationmputational effort and is a suitable structure for extending ViT over temporal. Experiments on Kineitcs400 show the effectiveness of the proposed method and its superiority over previous methods.Comment: 9 page

    On the Performance Evaluation of Action Recognition Models on Transcoded Low Quality Videos

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    In the design of action recognition models, the quality of videos in the dataset is an important issue, however the trade-off between the quality and performance is often ignored. In general, action recognition models are trained and tested on high-quality videos, but in actual situations where action recognition models are deployed, sometimes it might not be assumed that the input videos are of high quality. In this study, we report qualitative evaluations of action recognition models for the quality degradation associated with transcoding by JPEG and H.264/AVC. Experimental results are shown for evaluating the performance of pre-trained models on the transcoded validation videos of Kinetics400. The models are also trained on the transcoded training videos. From these results, we quantitatively show the degree of degradation of the model performance with respect to the degradation of the video quality.Comment: 10 page

    Acute effects of difference in glucose intake on arterial stiffness in healthy subjects

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    Background: Post-prandial hyperglycemia is associated with higher cardiovascular risk, which causes arterial stiffening and impaired function. Although post-prandial increases in blood glucose are proportional to the level of intake, the acute effects of different glucose intakes on arterial stiffness have not been fully characterized. The present study aimed to determine the acute effects of differences in glucose intake on arterial stiffness. Methods: Six healthy middle-aged and elderly individuals (mean age, 60.0 ± 12.1 years) were orally administered 15, 20, and 25 g of glucose on separate days in a randomized, controlled, cross-over fashion. Brachial-ankle pulse wave velocity, heart-brachial pulse wave velocity, cardio-ankle vascular index, brachial and ankle blood pressure, heart rate, and blood glucose and serum insulin concentrations before and 30, 60, and 90 min after glucose ingestion were measured. Results: Compared to baseline, brachial-ankle pulse wave velocity was higher at 30, 60 and 90 min after ingestion of 25 g glucose, and higher at 90 min after ingestion of 20 g glucose, but at no time points after ingestion of 15 g. Cardio-ankle vascular index was higher at 60 min than at baseline after ingestion of 25 g glucose, but not after ingestion of 15 or 20 g. Conclusions: These results suggest that brachial-ankle pulse wave velocity and cardio-ankle vascular index is affected by the quantity of glucose ingested. Proposed presently is that glucose intake should be reduced at each meal to avoid increases in brachial-ankle pulse wave velocity and cardio-ankle vascular index during acute hyperglycemia

    Time Adaptation Shows Duration Selectivity in the Human Parietal Cortex

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    Although psychological and computational models of time estimation have postulated the existence of neural representations tuned for specific durations, empirical evidence of this notion has been lacking. Here, using a functional magnetic resonance imaging (fMRI) adaptation paradigm, we show that the inferior parietal lobule (IPL) (corresponding to the supramarginal gyrus) exhibited reduction in neural activity due to adaptation when a visual stimulus of the same duration was repeatedly presented. Adaptation was strongest when stimuli of identical durations were repeated, and it gradually decreased as the difference between the reference and test durations increased. This tuning property generalized across a broad range of durations, indicating the presence of general time-representation mechanisms in the IPL. Furthermore, adaptation was observed irrespective of the subject's attention to time. Repetition of a nontemporal aspect of the stimulus (i.e., shape) did not produce neural adaptation in the IPL. These results provide neural evidence for duration-tuned representations in the human brain.Peer reviewe

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    多核金属錯体とこれをテンプレートとした低次元混合原子価ハロゲン架橋遷移金属錯体の研究

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    京都大学0048新制・課程博士博士(理学)甲第20201号理博第4286号新制||理||1616(附属図書館)京都大学大学院理学研究科化学専攻(主査)教授 北川 宏, 教授 竹腰 清乃理, 教授 島川 祐一学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

    The Effect of Aerobic Exercise Training Frequency on Arterial Stiffness in a Hyperglycemic State in Middle-Aged and Elderly Females

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    The frequency of aerobic exercise training in reducing the increase in arterial stiffness during acute hyperglycemia, a risk factor for cardiovascular disease, is unknown. The aim of the study was to determine the aerobic exercise training frequency on arterial stiffness in a hyperglycemic state in middle-aged and elderly females. Twenty healthy elderly people were randomly assigned to a two-times-a-week (T2, n = 10) and four-times-a-week (T4, n = 10) exercise group. All participants exercised for 35 min per session, which consisted of jogging exercises with a heart rate intensity of 65%. Brachial-ankle (ba), and heart-brachial (hb) pulse wave velocity (PWV) were measured before, 4 and 8 weeks after intervention; before the oral ingestion of 75-g of glucose; and 30, 60, and 90 min after ingestion. The baPWV before and 4 weeks after the intervention increased in both groups (p < 0.05), but only increased 8 weeks after intervention in the T2 group. hbPWV was unchanged before, 4 and 8 weeks after intervention in both groups. These findings show that frequent aerobic exercise suppresses the increase in arterial stiffness following glucose intake. The results of this study can be used to support the implementation of exercise programs for middle-aged and elderly patients
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