Majorana meets Coxeter: Non-Abelian Majorana Fermions and Non-Abelian Statistics

We discuss statistics of vortices having zero-energy non-Abelian Majorana fermions inside them. Considering the system of multiple non-Abelian vortices, we derive a non-Abelian statistics that differs from the previously derived non-Abelian statistics. The new non-Abelian statistics presented here is given by a tensor product of two different groups, namely the non-Abelian statistics obeyed by the Abelian Majorana fermions and the Coxeter group. The Coxeter group is a symmetric group related to the symmetry of polytopes in a high-dimensional space. As the simplest example, we consider the case in which a vortex contains three Majorana fermions that are mixed with each other under the SO(3) transformations. We concretely present the representation of the Coxeter group in our case and its geometrical expressions in the high-dimensional Hilbert space constructed from non-Abelian Majorana fermions.Comment: 6 pages, 4 figures, references added, published versio

Non-Abelian statistics of vortices with non-Abelian Dirac fermions

We extend our previous analysis on the exchange statistics of vortices having a single Dirac fermion trapped in each core, to the case where vortices trap two Dirac fermions with U(2) symmetry. Such a system of vortices with non-Abelian Dirac fermions appears in color superconductors at extremely high densities, and in supersymmetric QCD. We show that the exchange of two vortices having doublet Dirac fermions in each core is expressed by non-Abelian representations of a braid group, which is explicitly verified in the matrix representation of the exchange operators when the number of vortices is up to four. We find that the result contains the matrices previously obtained for the vortices with a single Dirac fermion in each core as a special case. The whole braid group does not immediately imply non-Abelian statistics of identical particles because it also contains exchanges between vortices with different numbers of Dirac fermions. However, we find that it does contain, as its subgroup, a genuine non-Abelian statistics for the exchange of the identical particles, that is, vortices with the same number of Dirac fermions. This result is surprising compared with conventional understanding because all Dirac fermions are defined locally at each vortex, unlike the case of Majorana fermions for which Dirac fermions are defined non-locally by Majorana fermions located at two spatially separated vortices.Comment: 32 pages, no figures, v3: published versio

A Case of Rapidly Progressive Diabetic Nephropathy Induced by Osimertinib

The number of patients with diabetic nephropathy is increasing worldwide and it is important to understand the underlying pathological mechanisms of the disease. In early stage diabetic nephropathy, the hyperglycemic environment leads to vascular endothelial cell damage, resulting in overexpression of vascular endothelial growth factor (VEGF) in podocytes and renal pathology of glomerular hypertrophy, glomerular basement membrane thickening, and mesangial hyperplasia. In diabetic nephropathy, renal thrombotic microangiopathy (TMA) develops and the nephropathy progressively worsens in some cases of severe glomerular podocyte damage. Further, receptor tyrosine kinase inhibitors (RTKIs) may suppress VEGF secretion via VEGF receptor-2 tyrosine kinase inhibition in podocytes, which results in renal TMA and rapid deterioration of diabetic nephropathy. Osimertinib, a third-generation irreversible epidermal growth factor receptor (EGFR)-TKI, is approved as a first-line treatment agent for metastatic or locally advanced EGFR mutation-positive non-small cell lung cancer. We encountered a case of a patient with diabetic nephropathy with lung adenocarcinoma treated with osimertinib, whose condition deteriorated from early nephropathy to end-stage renal disease in approximately 4 months. The patient had early diabetic nephropathy, but the use of a RTKI suppressed VEGF expression in podocytes, resulting in the induction of renal TMA and the development of rapidly progressive diabetic nephropathy

Dirac returns: non-Abelian statistics of vortices with Dirac fermions

Topological superconductors classified as type D admit zero-energy Majorana fermions inside vortex cores, and consequently the exchange statistics of vortices becomes non-Abelian, giving a promising example of non-Abelian anyons. On the other hand, types C and DIII admit zero-energy Dirac fermions inside vortex cores. It has been long believed that an essential condition for the realization of non-Abelian statistics is non-locality of Dirac fermions made of two Majorana fermions trapped inside two well-separated vortices as in the case of type D. Contrary to this conventional wisdom, however, we show that vortices with local Dirac fermions also obey non-Abelian statistics.Comment: 5 pages, 1 figure, published versio

The self-esteem and the activities of daily living in inpatients after an ischemic stroke

急性期の脳梗塞患者の自尊感情と日常生活動作の関連を明らかにするために,入院中の脳梗塞患者150人に調査協力を依頼した.調査協力の同意が得られなかった患者25人と調査前に退院された患者17人を除き,108人(72.0%)(男性74人,女性34人,平均年齢64.5(SD 12.5)才)にアンケート調査を実施した.自尊感情(Rosenberg のSelf-Esteem,以下RSE と記載)は平均29.9(SD 6.1)点,日常生活動作(Barthel index,以下BI と記載)は平均89.4(SD 16.0)点であり,RSE とBI の間にはBI が低いとRSE が低いという正の相関がみられた(Spearman のρ= 0.461,p < 0.001).また,BI が低いことと「女性である」「高齢である」「入院時の機能障害が重い」の関連が示唆された.急性期には,脳梗塞患者の日常生活動作の自立に向けた援助と,自尊感情を高める介入が必要であると考えられた.The purpose of this study was to investigate the relationship between self-esteem and the activities of daily living in inpatients after an ischemic stroke. The level of Rosenberg's Self-esteem and the Barthel index were examined. There were 108 respondents (74 males and 34 females). Based on these results, selfesteem was significantly correlated to the Barthel Index (Spearman's ρ=0.461, p<0.001). Findings indicated that low self-esteem related to dependence, and the level of dependence showed a negative association with women, the elderly and severe disability. These results suggested the necessity of rehabilitation for re-acquiring the skills of daily living and enhancement of self-esteem in patients who are dependent.広島保健学学会 特別講

Registration error of the liver CT using deformable image registration of MIM Maestro and Velocity AI

BackgroundUnderstanding the irradiated area and dose correctly is important for the reirradiation of organs that deform after irradiation, such as the liver. We investigated the spatial registration error using the deformable image registration (DIR) software products MIM Maestro (MIM) and Velocity AI (Velocity).MethodsImage registration of pretreatment computed tomography (CT) and posttreatment CT was performed in 24 patients with liver tumors. All the patients received proton beam therapy, and the follow-up period was 4–14 (median: 10) months. We performed DIR of the pretreatment CT and compared it with that of the posttreatment CT by calculating the dislocation of metallic markers (implanted close to the tumors).ResultsThe fiducial registration error was comparable in both products: 0.4–32.9 (9.3 ± 9.9) mm for MIM and 0.5–38.6 (11.0 ± 10.0) mm for Velocity, and correlated with the tumor diameter for MIM (r = 0.69, P = 0.002) and for Velocity (r = 0.68, P = 0.0003). Regarding the enhancement effect, the fiducial registration error was 1.0–24.9 (7.4 ± 7.7) mm for MIM and 0.3–29.6 (8.9 ± 7.2) mm for Velocity, which is shorter than that of plain CT (P = 0.04, for both).ConclusionsThe DIR performance of both MIM and Velocity is comparable with regard to the liver. The fiducial registration error of DIR depends on the tumor diameter. Furthermore, contrast-enhanced CT improves the accuracy of both MIM and Velocity

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Calibration of Patient Positioning System using FPD at HIMAC

Patient positioning is one of important procedures in radiation therapy because it is necessary to position patients properly according to their treatment planning. Flat Panel Detectors (FPDs) was installed for patient position detection system using X-ray in place of image instensifier tubes at National Institute of Radiological Sciences in August, 2009. FPD has many advantages compared with Image Intensifier tube; a) no image distortion, b) higher position resolution, c) wider dinamic range and d) decrease in halation effect due to density differnece. I report the installation of new positoning system including FPD, softwares and networking. I also show QC/QA procedures for FPDs. After installing this system, I measured FPD performance and calibrated FPD position and pixel spacing which means the distance beteween pixels at iso-center. To measure the pixel spacing, I tried three kinds of methods (calculating geometrically, pointing manually two points on a grid board between which distance is known, and analyzing automatically image of grid by computer.) Values of pixel spacing by three methods are all consistent. I summarized checking list for QA. Now new paitient positioning system is normally in operation. Whenever problem about FPD happens, I work to settle it immidiatelly. Now new positioning system is working very well. FPD degradation due to the irradiation beam will be studied.PTCOG4