Browsing by Author "Luo, Xi"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Detection of diffusely abnormal white matter in multiple sclerosis on multiparametric brain MRI using semi-supervised deep learning
    (Springer Nature, 2024) Musall, Benjamin C.; Gabr, Refaat E.; Yang, Yanyu; Kamali, Arash; Lincoln, John A.; Jacobs, Michael A.; Ly, Vi; Luo, Xi; Wolinsky, Jerry S.; Narayana, Ponnada A.; Hasan, Khader M.
    In addition to focal lesions, diffusely abnormal white matter (DAWM) is seen on brain MRI of multiple sclerosis (MS) patients and may represent early or distinct disease processes. The role of MRI-observed DAWM is understudied due to a lack of automated assessment methods. Supervised deep learning (DL) methods are highly capable in this domain, but require large sets of labeled data. To overcome this challenge, a DL-based network (DAWM-Net) was trained using semi-supervised learning on a limited set of labeled data for segmentation of DAWM, focal lesions, and normal-appearing brain tissues on multiparametric MRI. DAWM-Net segmentation performance was compared to a previous intensity thresholding-based method on an independent test set from expert consensus (N = 25). Segmentation overlap by Dice Similarity Coefficient (DSC) and Spearman correlation of DAWM volumes were assessed. DAWM-Net showed DSC > 0.93 for normal-appearing brain tissues and DSC > 0.81 for focal lesions. For DAWM-Net, the DAWM DSC was 0.49 ± 0.12 with a moderate volume correlation (ρ = 0.52, p < 0.01). The previous method showed lower DAWM DSC of 0.26 ± 0.08 and lacked a significant volume correlation (ρ = 0.23, p = 0.27). These results demonstrate the feasibility of DL-based DAWM auto-segmentation with semi-supervised learning. This tool may facilitate future investigation of the role of DAWM in MS.
  • Thumbnail Image
    Item
    Dinosaur of the Anthropocene
    (2020-04-15) Luo, Xi; Finley, Dawn; Colman, Scott W; Casbarian, John
    In its descent from cabinets of curiosities to museums, the exhibition of knowledge is shifted from inclusiveness to specialization. This evolution from the general to the specific is well-preserved in London’s Albertopolis. Where the ultimate cabinet - the Crystal Palace - once thrived, later museums diversified along three major branches: natural history, science, and applied art. Embodying expansion by categorization, these London museums became fossilized remains of an obsolete division of the world. In the age of the Anthropocene, this thesis proposes an inclusive museum that eliminates the redundant divisions of knowledge established in the Victorian era. Through archeological excavation and geological sampling, the individual museums of the Albertopolis are understood as distinctive artefacts in a single collection. The scattered bones of the Albertopolis are assembled into an integrated whole - a dinosaur of the Anthropocene. Swallowed into one cabinet, the world can no longer be separated into the organic, the inorganic and the synthetic.
  • Thumbnail Image
    Item
    Topology stabilized fluctuations in a magnetic nodal semimetal
    (Springer Nature, 2023) Drucker, Nathan C.; Nguyen, Thanh; Han, Fei; Siriviboon, Phum; Luo, Xi; Andrejevic, Nina; Zhu, Ziming; Bednik, Grigory; Nguyen, Quynh T.; Chen, Zhantao; Nguyen, Linh K.; Liu, Tongtong; Williams, Travis J.; Stone, Matthew B.; Kolesnikov, Alexander I.; Chi, Songxue; Fernandez-Baca, Jaime; Nelson, Christie S.; Alatas, Ahmet; Hogan, Tom; Puretzky, Alexander A.; Huang, Shengxi; Yu, Yue; Li, Mingda
    The interplay between magnetism and electronic band topology enriches topological phases and has promising applications. However, the role of topology in magnetic fluctuations has been elusive. Here, we report evidence for topology stabilized magnetism above the magnetic transition temperature in magnetic Weyl semimetal candidate CeAlGe. Electrical transport, thermal transport, resonant elastic X-ray scattering, and dilatometry consistently indicate the presence of locally correlated magnetism within a narrow temperature window well above the thermodynamic magnetic transition temperature. The wavevector of this short-range order is consistent with the nesting condition of topological Weyl nodes, suggesting that it arises from the interaction between magnetic fluctuations and the emergent Weyl fermions. Effective field theory shows that this topology stabilized order is wavevector dependent and can be stabilized when the interband Weyl fermion scattering is dominant. Our work highlights the role of electronic band topology in stabilizing magnetic order even in the classically disordered regime.