483 research outputs found
二次元アンチドット光格子中におけるボース気体の位相コヒーレンスに関する実験的研究
京都大学0048新制・課程博士博士(人間・環境学)甲第22546号人博第949号新制||人||226(附属図書館)2019||人博||949(吉田南総合図書館)京都大学大学院人間・環境学研究科相関環境学専攻(主査)准教授 木下 俊哉, 教授 吉田 鉄平, 教授 森成 隆夫学位規則第4条第1項該当Doctor of Human and Environmental StudiesKyoto UniversityDGA
Remarks on mod-2 elliptic genus
For physicists: For supersymmetric quantum mechanics, there are cases when a
mod-2 Witten index can be defined, even when a more ordinary
-valued Witten index vanishes. Similarly, for 2d supersymmetric
quantum field theories, there are cases when a mod-2 elliptic genus can be
defined, even when a more ordinary elliptic genus vanishes. We study such mod-2
elliptic genera in the context of supersymmetry, and show
that they are characterized by mod-2 reductions of integral modular forms,
under some assumptions.
For mathematicians: We study the image of the standard homomorphism for or
, by relating them to the mod-2 reductions of integral modular forms.Comment: 31 page
The Firing Squad Synchronization Problems for Number Patterns on a Seven-Segment Display and Segment Arrays
The Firing Squad Synchronization Problem (FSSP), one of the most well-known problems related to cellular automata, was originally proposed by Myhill in 1957 and became famous through the work of Moore [1]. The first solution to this problem was given by Minsky and McCarthy [2] and a minimal time solution was given by Goto [3]. A significant amount of research has also dealt with variants of this problem. In this paper, from a theoretical interest, we will extend this problem to number patterns on a seven-segment display. Some of these problems can be generalized as the FSSP for some special trees called segment trees. The FSSP for segment trees can be reduced to a FSSP for a one-dimensional array divided evenly by joint cells that we call segment array. We will give algorithms to solve the FSSPs for this segment array and other number patterns, respectively. Moreover, we will clarify the minimal time to solve these problems and show that there exists no such solution
Flow Cytometric Nuclear DNA Analysis in Ulcerative Colitis
The purpose of this study was to assess the usefulness of nuclear DNA analysis in early cancer detection in patients with ulcerative colitis. The results of flow cytometric nuclear DNA anaiysis of tissue specimens from patients with ulcerative colitis, colonic adenoma, and colorectal carcinoma were compared. DNA aneuploidy was observed in 53.1 % of patients with ulcerative colitis and 16.7 % of patients with colonic adenoma. The degree of atypism of the tumor cells was related to the incidence of DNA aneuploidy. DNA aneuploidy was noted in 48.6 % of the patient with ulcerative colitis and coexistent colorectal carcinoma. The degree of dysplasia of the tumor cells was also correlated with the incidence of DNA aneuploidy. DNA aneuploidy was found in 14.3 % of specimens of mucosal tissue that were without cancerous or dysplastic cells. DNA aneuploidy was found in 8.5 % of specimens of mucosal tissue collected from patients with ulcerative colitis alone. Our findings showed that abnormalities in DNA content was closely correlated with histological atypism. In addition, our findings suggested that DNA aneuploidy may precede dysplastic changes in some cases of ulcerative colitis. We concluded that DNA analysis using flow cytometry is a useful method for identification of patients with ulcerative colitis at high risk for the development of cancer
Equilibrium-point control of human elbow-joint movement under isometric environment by using multichannel functional electrical stimulation
Functional electrical stimulation (FES) is considered an effective technique for aiding quadriplegic persons. However, the human musculoskeletal system has highly nonlinearity and redundancy. It is thus difficult to stably and accurately control limbs using FES. In this paper, we propose a simple FES method that is consistent with the motion-control mechanism observed in humans. We focus on joint motion by a pair of agonist-antagonist muscles of the musculoskeletal system, and define theelectrical agonist-antagonist muscle ratio (EAA ratio) and electrical agonist-antagonist muscle activity (EAA activity) in light of the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, respectively, to extract the equilibrium point and joint stiffness from electromyography (EMG) signals. These notions, the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, are based on the hypothesis that the equilibrium point and stiffness of the agonist-antagonist motion system are controlled by the central nervous system. We derived the transfer function between the input EAA ratio and force output of the end-point. We performed some experiments in an isometric environment using six subjects. This transfer-function model is expressed as a cascade-coupled dead time element and a second-order system. High-speed, high-precision, smooth control of the hand force were achieved through the agonist-antagonist muscle stimulation pattern determined by this transfer function model
Predicting Therapeutic Effects using PET/CT
This study investigated the usefulness of [18F]-3’-deoxy-3’-fluorothymidine (18F-FLT) and [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging for predicting the therapeutic efficacy of non-small cell lung cancer (NSCLC) irradiation at an early stage after radiation treatment. Mice were xenografted with the human lung adenocarcinoma line A549 or large cell lung cancer line FT821. Tumour uptake of 18F-FLT and 18F-FDG was imaged using PET/CT before and 1 week after irradiation. In A549 tumours, 18F-FLT uptake was significantly decreased, and 18F-FDG uptake was unchanged post-irradiation compared with pre-irradiation. In FT821 tumours, uptake of both 18F-FLT and 18F-FDG uptake was substantially decreased post-irradiation compared with pre-irradiation. In both xenografts, tumour volumes in the irradiated groups were significantly decreased compared with those in the control group. 18F-FLT is expected to contribute to individual NSCLC therapy because it accurately evaluates the decrease in tumour activity that cannot be captured by 18F-FDG. 18F-FDG may be useful for evaluating surviving cells without being affected by the inflammatory reaction at an extremely early stage, approximately 1 week after irradiation. Combined use of 18F-FLT and 18F-FDG PET/CT imaging may increase the accurate prediction of radiotherapy efficacy, which may lead to improved patient outcomes and minimally invasive personalised therapy
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