Down Syndrome detection with Swin Transformer architecture

Objective: Down Syndrome, also known as Trisomy 21, is a severe genetic disease caused by an extra chromosome 21. For the detection of Trisomy 21, despite those statistical methods have been widely used for screening, karyotyping remains the gold standard and the first level of testing for diagnosis. Due to karyotyping being a time-consuming and labour-intensive procedure, Computer Vision methodologies have been explored to automate the karyotyping process for decades. However, few studies have focused on Down Syndrome detection with the Transformer technique. This study develops a Down-Syndrome-Detector (DSD) architecture based on the Transformer structure, which includes a segmentation module, an alignment module, a classification module, and a Down Syndrome indicator. Methods: The segmentation and classification modules are designed by homogeneous transfer learning at the model level. Transfer learning techniques enable a network to share weights learned from the source domain (e.g., millions of data in ImageNet) and optimize the weights with limited labeled data in the target domain (e.g., less than 6,000 images in BioImLab). The Align-Module is designed to process the segmentation output to fit the classification dataset, and the Down Syndrome Indicator identifies a Down Syndrome case from the classification output. Results: Experiments are first performed on two public datasets BioImLab (119 cases) and Advanced Digital Imaging Research (ADIR, 180 cases). Our performance metrics indicate the good ability of segmentation and classification modules of DSD. Then, the DS detection performance of DSD is evaluated on a private dataset consisting of 1084 cells (including 20 DS cells from 2 singleton cases): 90.0% and 86.1% for cell-level TPR and TNR; 100% and 96.08% for case-level TPR and TNR, respectively. Conclusion: This study develops a pipeline based on the modern Transformer architecture for the detection of Down Syndrome from original metaphase micrographs. Both segmentation and classification models developed in this study are assessed using public datasets with commonly used metrics, and both achieved good results. The DSDproposed in this study reported satisfactory singleton case-specific DS detection results. Significance: As verified by a medical specialist, the developed method may improve Down Syndrome detection efficiency by saving human labor and improving clinical practice

After the daggers : politics and persuasion after the assassination of Caesar

In this thesis, I examine the nature and role of persuasion in Roman politics in the period immediately following the assassination of Caesar on the Ides of March 44 B.C. until the capture of the city of Rome by his heir Octavianus in August 43 B.C. The purpose of my thesis is to assess the extent to which persuasion played a critical role in political interactions and in the decision-making processes of those involved during this crucial period in Roman history. I do this by means of a careful discussion and analysis of a variety of different types of political interactions, both public and private. As regards the means of persuasion, I concentrate on the role and use of oratory in these political interactions. Consequently, my thesis owes much in terms of approach to the work of Millar (1998) and, more recently, Morstein-Marx (2004) on placing oratory at the centre of our understanding of how politics functioned in practice in the late Roman republic. Their studies, however, focus on the potential extent and significance of mass participation in the late Roman republican political system, and on the contio as the key locus of political interaction. In my thesis, I contribute to improving our new way of understanding late Roman republican politics by taking a broader approach that incorporates other types of political interactions in which oratory played a significant role. I also examine oratory as but one of a variety of means of persuasion in Roman political interactions. Finally, in analyzing politics and persuasion in the period immediately after Caesar’s assassination, I am examining not only a crucial period in Roman history, but one which is perhaps the best documented from the ancient world. The relative richness of contemporary evidence for this period calls out for the sort of close reading of sources and detailed analysis that I provide in my thesis that enables a better understanding of how politics actually played out in the late Roman republic