22 research outputs found

    Gs-ema:Integrating Gradient Surgery Exponential Moving Average with Boundary-Aware Contrastive Learning for Enhanced Domain Generalization in Aneurysm Segmentation

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    The automated segmentation of cerebral aneurysms is pivotal for accurate diagnosis and treatment planning. Confronted with significant domain shifts and class imbalance in 3D Rotational Angiography (3DRA) data from various medical institutions, the task becomes challenging. These shifts include differences in image appearance, intensity distribution, resolution, and aneurysm size, all of which complicate the segmentation process. To tackle these issues, we propose a novel domain generalization strategy that employs gradient surgery exponential moving average (GS-EMA) optimization technique coupled with boundary-aware contrastive learning (BACL). Our approach is distinct in its ability to adapt to new, unseen domains by learning domain-invariant features, thereby improving the robustness and accuracy of aneurysm segmentation across diverse clinical datasets. The results demonstrate that our proposed approach can extract more domain-invariant features, minimizing over-segmentation and capturing more complete aneurysm structures

    Unsupervised Domain Adaptation for Brain Vessel Segmentation through Transwarp Contrastive Learning

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    Unsupervised domain adaptation (UDA) aims to align the labelled source distribution with the unlabelled target distribution to obtain domain-invariant predictive models. Since cross-modality medical data exhibit significant intra and inter-domain shifts and most are unlabelled, UDA is more important while challenging in medical image analysis. This paper proposes a simple yet potent contrastive learning framework for UDA to narrow the inter-domain gap between labelled source and unlabelled target distribution. Our method is validated on cerebral vessel datasets. Experimental results show that our approach can learn latent features from labelled 3DRA modality data and improve vessel segmentation performance in unlabelled MRA modality data

    Private placements of equity and accessibility of bank loans

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    This study investigates the changes in quantity and cost of bank loans after a private placement of common stocks by A-share listed companies in China from 2011 to 2021. This research is derived from the signaling theory and is based on a difference-in-difference design. Through propensity score matching, the sample comprises companies that placed equity privately in the experiment group and companies that did not place equity privately in the control group. We find evidence that the increase in bank loans slowed down, and the cost of bank loans increased after the private placement. The signaling effect of private placements is robust to various additional tests. Further analysis indicates that when state-owned enterprises place equity privately, their access to bank loans is not affected. When institutional investors participate in the private placement, the company’s access to bank credit does not go through significant changes. In addition, private placements by companies located in regions with higher levels of marketization of the financial market do not reduce the cost of bank loans

    Appendix S2 Fossil records of Annonaceae

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    Appendix S2 Fossil records of Annonacea

    Data from: The early history of Annonaceae (Magnoliales) in Southeast Asia suggests floristic exchange between India and Pan-Indochina by the late Oligocene

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    The collision between India and Eurasia in the mid‐Palaeogene facilitated terrestrial floristic exchange. However, due to the complexity of this geological event and scarcity of fossil record, the plant migration patterns between the two plates are still highly debated. In this study, we focus on the Oligocene floristic exchange between India and Pan‐Indochina mainly based on a carpological study of Annonaceae, an emblematic family unique in its pantropical distribution and frugivore‐based dispersal strategy. A new seed species, Anonaspermum orientalis sp. nov., is described from the upper Oligocene Yongning Formation of Guangxi, southern China. The species represents the earliest known occurrence of this family in Pan‐Indochina. The specimens are characterized by ovate–elliptic seed shape, thicker seed testa, two‐lobed organization, lamelliform rumination and an obvious cone‐like plug. The palaeobiogeographical reconstruction of Annonaceae indicates that the most parsimonious dispersal scenario for the annonaceous taxon from the late Oligocene of China is the Out‐of‐India route, in parallel with other plant genera inferred to have migrated between India and Pan‐Indochina during that period

    Adaptive Semi-supervised Segmentation of Brain Vessels with Ambiguous Labels

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    Accurate segmentation of brain vessels is crucial for cerebrovascular disease diagnosis and treatment. However, existing methods face challenges in capturing small vessels and handling datasets that are partially or ambiguously annotated. In this paper, we propose an adaptive semi-supervised approach to address these challenges. Our approach incorporates innovative techniques including progressive semi-supervised learning, adaptative training strategy, and boundary enhancement. Experimental results on 3DRA datasets demonstrate the superiority of our method in terms of mesh-based segmentation metrics. By leveraging the partially and ambiguously labeled data, which only annotates the main vessels, our method achieves impressive segmentation performance on mislabeled fine vessels, showcasing its potential for clinical applications.</p

    Strategies and New Technologies for Improving the Tolerance of Lactic Acid Bacteria to Processing and Gastrointestinal Environments

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    The market and demanding of lactic acid bacteria and their products keep increasingly in recent years. However, it is difficult to maintain the activity of lactic acid bacteria during the processing and storage periods due to the stress caused by heating and oxygen exposure conditions for these anaerobic and heat-sensitive bacteria. This also causes a significant reduction in the quantity of live lactic acid bacteria in the end products. The activity of lactic acid bacteria will further decrease under the high acid condition in stomach and the high bile content in gut tract, which greatly reduce the end probiotic efficacy of this kind of probiotic products. Until now, numerous efforts have been made to enhance the tolerance of lactic and bacteria against heat, oxygen and gastrointestinal conditions, resulting in the emergence of several novel technologies. However, it is still challenging to select the most suitable technologies for practical application, as the results from various studies have not been thoroughly summarized and compared. In this study, the currently developed techniques for improving the activity of lactic acid bacteria during processing, under gastrointestinal condition, and in intestinal delivery are comprehensively summarized. The results from different studies are well compared. The application of electrostatic spinning, electrostatic spray, emulsion droplet technology, polyphenol nano armor, and heat induction pretreatment in the process of live lactic acid bacteria is also introduced. The information presented in this study can provide useful guidance for further research and the application of the currently developed techniques
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