93 research outputs found

    TransVOD: End-to-End Video Object Detection with Spatial-Temporal Transformers

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    Detection Transformer (DETR) and Deformable DETR have been proposed to eliminate the need for many hand-designed components in object detection while demonstrating good performance as previous complex hand-crafted detectors. However, their performance on Video Object Detection (VOD) has not been well explored. In this paper, we present TransVOD, the first end-to-end video object detection system based on spatial-temporal Transformer architectures. The first goal of this paper is to streamline the pipeline of VOD, effectively removing the need for many hand-crafted components for feature aggregation, e.g., optical flow model, relation networks. Besides, benefited from the object query design in DETR, our method does not need complicated post-processing methods such as Seq-NMS. In particular, we present a temporal Transformer to aggregate both the spatial object queries and the feature memories of each frame. Our temporal transformer consists of two components: Temporal Query Encoder (TQE) to fuse object queries, and Temporal Deformable Transformer Decoder (TDTD) to obtain current frame detection results. These designs boost the strong baseline deformable DETR by a significant margin (3%-4% mAP) on the ImageNet VID dataset. Then, we present two improved versions of TransVOD including TransVOD++ and TransVOD Lite. The former fuses object-level information into object query via dynamic convolution while the latter models the entire video clips as the output to speed up the inference time. We give detailed analysis of all three models in the experiment part. In particular, our proposed TransVOD++ sets a new state-of-the-art record in terms of accuracy on ImageNet VID with 90.0% mAP. Our proposed TransVOD Lite also achieves the best speed and accuracy trade-off with 83.7% mAP while running at around 30 FPS on a single V100 GPU device.Comment: Accepted to IEEE Transactions on Pattern Analysis and Machine Intelligence (IEEE TPAMI), extended version of arXiv:2105.1092

    Enhanced Boundary Learning for Glass-like Object Segmentation

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    Glass-like objects such as windows, bottles, and mirrors exist widely in the real world. Sensing these objects has many applications, including robot navigation and grasping. However, this task is very challenging due to the arbitrary scenes behind glass-like objects. This paper aims to solve the glass-like object segmentation problem via enhanced boundary learning. In particular, we first propose a novel refined differential module that outputs finer boundary cues. We then introduce an edge-aware point-based graph convolution network module to model the global shape along the boundary. We use these two modules to design a decoder that generates accurate and clean segmentation results, especially on the object contours. Both modules are lightweight and effective: they can be embedded into various segmentation models. In extensive experiments on three recent glass-like object segmentation datasets, including Trans10k, MSD, and GDD, our approach establishes new state-of-the-art results. We also illustrate the strong generalization properties of our method on three generic segmentation datasets, including Cityscapes, BDD, and COCO Stuff. Code and models is available at \url{https://github.com/hehao13/EBLNet}.Comment: ICCV-2021 Code is availabe at https://github.com/hehao13/EBLNe

    A Case of Paradoxical Embolism Causing Anterior Spinal Cord Syndrome and Acute Myocardial Infarction Following the Intradiscal Oxygen-Ozone Therapy

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    We report a case of a 66-year-old female who burst into flaccid paralysis of the lower extremities, accompanied by loss of pain and temperature sensation below T4 level, during an oxygen–ozone injection for disc herniation. Half an hour later, she suffered from chest pain. Magnetic resonance imaging (MRI) showed long segment hyperintensity in the thoracic spinal cord from T2 to 10 level on sagittal T2-weighted images (T2WI). The electrocardiogram (ECG) showed ST-segment elevation in V1–V6 leads. She was diagnosed with spinal cord infarction and ST-elevation myocardial infarction (STEMI). Transthoracic echocardiography with saline contrast showed existence of a large patent foramen ovale (PFO) correlating with the detection of massive microbubbles in the left atrium. We discuss the potential role of paradoxical embolism in spinal cord infarction and myocardial infarction

    Recent Advances on Cellulosic Emulsions for Encapsulation of Bioactive Substances

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    Protection, dispersion and delivery of the functional components can implement in the emulsion-encapsulating systems. Among the stabilizers of the emulsion, specific structure of the cellulose may improve the stability of the system, and supplying the utilization of the bioactive substances on encapsulation and release. Therefore, the recent advances on stabilizing mechanism, cellulosic materials, properties of bioactive substances and factors affecting on the release of cellulosic emulsion-encapsulating systems are summarized in this review. In addition, the paper focuses on the release process and regulated mechanism of cellulose, which shows high length-diameter ratio and mechanical strength in the emulsion-delivery system of bioactive substances, and providing reference for the development of the food-grade delivery system. Studies indicates that cellulose-stabilized emulsion can improve the dispersion and oxidation stability of the bioactive substances, while controlling the release and improving the bioavailability of the functional factors. However, there is still vast research space for its safety evaluation in the food system, and related toxicological experiments urgently need to be carried out

    The Epidemiological Characteristics of Stroke in Hunan Province, China

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    Previous studies have shown that Hunan Province has a high incidence of stroke and a high proportion of intracerebral hemorrhage (ICH). Considering the changes over the past three decades, little is known about the current epidemiological characteristics of stroke in Hunan Province. In 2013, a cross-sectional study was conducted at seven national disease surveillance points (DSPs) in Hunan Province. A multistage cluster sampling method was used to select a representative sample. A total of 21,156 participants aged 20 years and older were examined. Among the 21,156 participants, the number of prevalent strokes, incident strokes and deaths was 307, 87, and 36, respectively. The 2010 China census-standardized prevalence, incidence and mortality were 1191.0 per 100,000 people [95% confidence interval (CI) 1044.8–1337.2], 333.6 per 100,000 person-years (95% CI 255.7–411.5) and 129.7 per 100,000 person-years (95% CI 81.1–178.3), respectively. Ischemic stroke (IS), ICH, subarachnoid hemorrhage (SAH), and stroke of undetermined type (UND) constituted 50.6, 41.4, 5.7, and 2.3% of all incident stroke cases, respectively. Tianxin, Liuyang, Wuling, and Hongjiang have high proportions of ICH (61.5, 58.3, 60, and 50%, respectively). Hypertension is the most common risk factor for prevalent stroke (71.34%), followed by smoking (30.62%) and alcohol use (25.73%). In conclusion, Hunan Province has an extremely heavy stroke burden. The high proportion of ICH is not limited to the Changsha community; it represents an important issue for all of Hunan Province

    Mowing exacerbates the loss of ecosystem stability under nitrogen enrichment in a temperate grassland

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    1. Global reactive nitrogen (N) is projected to further increase in the coming years. Previous studies have demonstrated that N enrichment weakens the temporal stability of the ecosystem and the primary productivity through decreased biodiversity and species asynchrony. Mowing is a globally common practise in grasslands; and infrequent mowing can maintain or increase plant diversity under N enrichment conditions. However, it is unclear how infrequent mowing affects ecosystem stability in the face of N enrichment. 2. By independently manipulating the frequency (twice vs. monthly additions per year) and rate (i.e. 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m(-2) year(-1)) of NH4NO3 inputs and mowing (unmown vs. mown) over 3 years (2011-2013) in a temperate grassland of northern China, we aimed to examine the interactive effects of N enrichment and mowing on ecosystem stability. 3. The results show that mowing maintained a positive relationship between species richness and ecosystem stability despite N addition, but that it exacerbated the negative effects of N addition on ecosystem stability. Mowing increased mean primary productivity and plant species richness, but it also increased the synchrony of population fluctuations and the variability of primary productivity under N enrichment, thereby contributing to a decline in the ecosystem stability. 4. Thus, our study reveals that infrequent mowing can buffer the negative effects of N enrichment on biodiversity to some extent and further increase the primary productivity, but it exacerbates the loss of ecosystem stability with N enrichment, thereby threatening local and/or semiarid regional food security

    Nitrogen enrichment and grazing accelerate vegetation restoration in degraded grassland patches

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    A rapid increase in grazing intensity since the 1980s has caused large areas of the Inner Mongolian grasslands to become degraded. Increasing atmospheric nitrogen (N) deposition might exert an important influence on vegetation restoration in these degraded grasslands by increasing available N and relieving N limitations on productivity. However, no previous studies have tested the assumption that increasing N deposition promotes vegetation restoration in degraded grasslands. By conducting a 4-year field restoration experiment with four N addition treatments (0, 5, 10, and 20 g Nm (2) year (1)) and two grazing treatments (grazed and ungrazed), we investigated the effects of N enrichment and grazing on the restoration of patches in which vegetation had been degraded. N addition significantly accelerated the restoration of vegetation-degraded grassland patches regarding both plant cover and diversity. Moderate grazing also promoted the restoration of degraded-vegetation patches in term of both plant diversity and species similarity. Importantly, the positive effects of N addition on the restoration of degraded patches may be augmented by grazing. This study demonstrate that low levels of N enrichment (or increasing atmospheric N deposition) positively impact vegetation restoration in degraded grassland patches, particularly under moderate grazing practices. Our findings provide new insights into the management of severely degraded grasslands through the regulation of N inputs and grazing practices. (C) 2014 Elsevier B.V. All rights reserved
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