Domain Nucleation and Annihilation in Uniformly Magnetized State under Current Pulses in Narrow Ferromagnetic Wires

We investigate the current-driven magnetization dynamics in narrow Permalloy wires by means of Lorentz microscopy and electron holography. Current pulses are found to transform the magnetic structure in the uniformly magnetized state below the Curie temperature. A variety of magnetic states including reversed magnetic domains are randomly obtained in low probability. The dynamics of vortices found in most of observed magnetic states seems to play a key role in triggering the magnetization reversal.Comment: 11 pages, 3 figures, 1 video, to appear in Japanese Journal of Applied Physics (Express Letter

Lyso-GM2 Ganglioside: A Possible Biomarker of Tay-Sachs Disease and Sandhoff Disease

To find a new biomarker of Tay-Sachs disease and Sandhoff disease. The lyso-GM2 ganglioside (lyso-GM2) levels in the brain and plasma in Sandhoff mice were measured by means of high performance liquid chromatography and the effect of a modified hexosaminidase (Hex) B exhibiting Hex A-like activity was examined. Then, the lyso-GM2 concentrations in human plasma samples were determined. The lyso-GM2 levels in the brain and plasma in Sandhoff mice were apparently increased compared with those in wild-type mice, and they decreased on intracerebroventricular administration of the modified Hex B. The lyso-GM2 levels in plasma of patients with Tay-Sachs disease and Sandhoff disease were increased, and the increase in lyso-GM2 was associated with a decrease in Hex A activity. Lyso-GM2 is expected to be a potential biomarker of Tay-Sachs disease and Sandhoff disease

FcRγ-dependent immune activation initiates astrogliosis during the asymptomatic phase of Sandhoff disease model mice

Sandhoff disease (SD) is caused by the loss of β-hexosaminidase (Hex) enzymatic activity in lysosomes resulting from Hexb mutations. In SD patients, the Hex substrate GM2 ganglioside accumulates abnormally in neuronal cells, resulting in neuronal loss, microglial activation, and astrogliosis. Hexb−/− mice, which manifest a phenotype similar to SD, serve as animal models for examining the pathophysiology of SD. Hexb−/− mice reach ~8 weeks without obvious neurological defects; however, trembling begins at 12 weeks and is accompanied by startle reactions and increased limb tone. These symptoms gradually become severe by 16–18 weeks. Immune reactions caused by autoantibodies have been recently associated with the pathology of SD. The inhibition of immune activation may represent a novel therapeutic target for SD. Herein, SD mice (Hexb−/−) were crossed to mice lacking an activating immune receptor (FcRγ−/−) to elucidate the potential relationship between immune responses activated through SD autoantibodies and astrogliosis. Microglial activation and astrogliosis were observed in cortices of Hexb−/− mice during the asymptomatic phase, and were inhibited in Hexb−/− FcRγ−/− mice. Moreover, early astrogliosis and impaired motor coordination in Hexb−/− mice could be ameliorated by immunosuppressants, such as FTY720. Our findings demonstrate the importance of early treatment and the therapeutic effectiveness of immunosuppression in SD

Applying the functional resonance analysis method (FRAM) to flood risk management at a community level: Koriyama city's emergency-response process during Typhoon Hagibis

This study used the functional resonance analysis method (FRAM) to analyze a real-world example of an emergency-response process, one that occurred in Koriyama city, Japan, during Typhoon Hagibis (known in Japan as Typhoon No. 19, or Reiwa 1 East Japan Typhoon). The analysis revealed nine functions that constitute the municipality's emergency-response process (including Public Communication, Provision/Management of Evacuation Shelters, Evacuation, and Rescue Operations) as well as the interactive relationships between these functions. It also revealed how variabilities in the timeliness and accuracy of the functions resonated with (reinforced) each other, culminating in an incident involving a backlog of emergency calls. From these results, two recommendations were derived: reviewing the public communication system and building a framework for minimizing variability in evacuation behavior. And also, based on the FRAM analysis we could contextualize the interview data and the individual phenomena described fragmentally in the retrospective report (used for evaluating the disaster response), thereby gaining an understanding of the incident generation mechanism. In conclusion, the study demonstrated FRAM can be an effective tool for retrospective evaluation of disaster response or revising a disaster plan

Dermoscopy of keratosis follicularis squamosa

Although the characteristic clinical appearance and the differences in distribution, it is often difficult to differentiate keratosis follicularis squamosa (Dohi) from other keratotic disorders. Here, we describe the case of a 5-year-old boy with Dohi in the first time that by using dermoscopy. Dermoscpoy of the lesion showed typical lotus leaves on the water appearance and follicular plug in the center. We reported the usefulness of dermosocopy in Dohi