Proof validation and modification by example generation: A classroom-based intervention in secondary school geometry

ArticleProceedings of the 13th International Congress on Mathematical Education (ICME-13). Hamburg, Germany, 2016-7-24/31, ICME. (2016)journal articl

Correlation Analysis of Features for Fusing in User Verification Using EEG Evoked by Ultrasound

In user verification using electroencephalograms (EEGs) evoked by ultrasound, an error rate of 0% was achieved. However, to achieve this, the classifiers for the number of features multiplied by the number of electrodes must be learned. Therefore, reducing the number of classifiers is crucial and must be achieved. This study confirmed that the random selection of features and electrodes facilitates further reduction in the number of classifiers. Random selection is equivalent to evenly selecting electrodes for each feature and electrode position. Consequently, the effectiveness of even selection was statistically confirmed. Furthermore, even selection resulted in the fusion of uncorrelated features. Thus, four statistical values of an EEG were introduced, and the effectiveness of fusing uncorrelated (independent) features was confirmed

Difference in the Cesium Body Contents of Affected Area Residents Depending on the Evacuation Timepoint Following the 2011 Fukushima Nuclear Disaster

Estimating the internal thyroid dose received by residents involved in the 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been a challenging task because of the shortage of direct human measurements related to the largest contributing radioisotope to the dose, I. In a previous dose estimation, we used the results of whole-body counter (WBC) measurements targeting Cs and Cs, based on the assumption that these radioisotopes were incorporated at the same time as I in the early phase of the accident. The main purpose of this study was to clarify whether the trace of the early intake remained in the WBC measurements that were started several months after the accident. In the present work, WBC data of 1,639 persons from Namie town, one of the heavily contaminated municipalities, were analyzed together with their evacuation behavior data. The results demonstrated that the cesium detection rate in the WBC results was several times higher in the late evacuees [who evacuated outside the 20-km radius of the FDNPP at 3:00 p.m. (Japanese Local Time) on 12 March or later] compared to the prompt evacuees (who evacuated before 3:00 p.m. on 12 March). Among the adults, the cesium detection rates (and the 90th percentile values of the Cs intake) of the prompt and late evacuees were about 20% (5.4 × 10 Bq) and 60% (1.6 × 10 Bq), respectively. Approximately 20% of the individuals analyzed were categorized as late evacuees. These differences in cesium would be caused by exposure to the radioactive plume in the afternoon on 12 March, which was likely to influence the late evacuees. On the other hand, the intake on 15 March, when the largest release event occurred, was expected to be relatively small for Namie town's residents. In conclusion, the trace of the early intake remained in the WBC measurements, although this would not necessarily be true for all subjects. The results obtained from this study would provide useful information for the reconstruction of the early internal thyroid doses from radioiodine in the future

TMC1 and TMC2 Are Components of the Mechanotransduction Channel in Hair Cells of the Mammalian Inner Ear

SummarySensory transduction in auditory and vestibular hair cells requires expression of transmembrane channel-like (Tmc) 1 and 2 genes, but the function of these genes is unknown. To investigate the hypothesis that TMC1 and TMC2 proteins are components of the mechanosensitive ion channels that convert mechanical information into electrical signals, we recorded whole-cell and single-channel currents from mouse hair cells that expressed Tmc1, Tmc2, or mutant Tmc1. Cells that expressed Tmc2 had high calcium permeability and large single-channel currents, while cells with mutant Tmc1 had reduced calcium permeability and reduced single-channel currents. Cells that expressed Tmc1 and Tmc2 had a broad range of single-channel currents, suggesting multiple heteromeric assemblies of TMC subunits. The data demonstrate TMC1 and TMC2 are components of hair cell transduction channels and contribute to permeation properties. Gradients in TMC channel composition may also contribute to variation in sensory transduction along the tonotopic axis of the mammalian cochlea

Retrospective comparison of clinical and angiographic outcomes after primary stenting using sirolimus-eluting and bare-metal stents in nonrandomized consecutive 568 patients with first ST-segment elevated myocardial infarctions

SummaryBackground and purposeThe long-term safety and efficacy of primary stenting using drug-eluting stents (DES) in patients with ST-segment elevation myocardial infarction (STEMI) are not fully understood in Japan. Therefore, we retrospectively examined the midterm clinical and angiographic outcomes in STEMI patients after primary stenting using sirolimus-eluting stents (SES) in a clinical setting through a historical comparison with those of bare-metal stents (BMS).Methods and resultsThe study design was a retrospective, nonrandomized, and single-center study. The clinical outcomes for 568 consecutive patients who presented within 12h of their first STEMI and who were treated with BMS (n=198; 184 STEMIs from June 2003 to August 2004 and 14 STEMIs from September 2004 to May 2007) or SES (n=370; from August 2004 to May 2007) at our medical center in Japan were retrospectively investigated in February 2010. The incidence of post-discharge events (comprising cardiac death and nonfatal recurrent MI) after SES placement (3.9%) was not significantly different from that after BMS placement (6.7%). SES was not related to the risk of post-discharge events (mean follow-up for SES, 1327±415 days; BMS, 1818±681 days) (hazard ratio of 0.369 at 95% CI, 0.119–1.147, p=0.085). The incidence of definite stent thromboses after SES placement (0.54%) was not significantly higher than that after BMS placement (0%). The incidence of binary in-stent restenosis (% diameter stenosis of more than 50% at secondary angiography) after SES placement (8.3%) was significantly lower than that after BMS placement (25.7%; p<0.001).ConclusionsFrom the present historical comparison of SES and BMS, we conclude that primary stenting using SES in a clinical setting has favorable clinical and angiographic outcomes in Japanese STEMI patients

Early Intake of Radiocesium by Residents Living Near the Tepco Fukushima Dai-ichi Nuclear Power Plant After the Accident. Part 2: Relationship Between Internal Dose and Evacuation Behavior in Individuals

The Tokyo Electric Power Company's Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident exposed members of the public to radiation. This study analyses the relation between personal behavior data obtained from 112 out of 174 subjects who underwent whole-body measurements by the National Institute of Radiological Sciences (NIRS) during the period from 27 June to 28 July 2011 and their committed effective doses (CEDs) from Cs and Cs. The whereabouts of the 112 persons living in municipalities near the FDNPP (mainly, Namie town) on several days in March 2011 are graphed on maps. It was confirmed that most subjects started evacuation promptly and had left the 20-km-radius of the FDNPP by the end of 12 March. The individual CEDs were poorly correlated with the person's distances from the FDNPP at any day in March. Meanwhile, the percentage of persons remaining within the 20-km radius of the FDNPP was 100% at 16:00 on 12 March and 42.9% at 0:00 on 15 March for those with CEDs > 0.1 mSv, whereas the corresponding values were much lower for those with CEDs ≤ 0.1 mSv. This suggests that the time of evacuation would be one of the crucial factors for the early intake; however, more personal behavior data are needed to be analyzed to clarify the relevance to the individual internal dose

IL-21 is required for the maintenance and pathogenesis of murine Vγ4+ IL-17-producing γδT cells

Murine IL-17-producing γδT (γδT17) cells are divided into two subsets: natural γδT17 (nγδT17) cells, whose development is restricted to the fetal thymus, and inducible γδT17 cells, which require antigen exposure for their IL-17 production and are presumed to develop from Rorc+Il17a-CCR9+ immature γδT17 cells in the adult thymus and whose T cell receptor (TCR) is biased toward Vγ4. Although IL-23 is known to be involved in developing γδT17 cells, the roles of other cytokines, such as IL-21, which is involved in developing Th17 cells like IL-23, in the development, maintenance, and pathophysiology of γδT17 cells remain unknown. Here, we show that IL-21 is dispensable for the fetal thymic development of nγδT17 cells but is required for the peripheral maintenance of Vγ4+nγδT17 cells. Upon stimulation with γδTCR, IL-1 plus IL-21 induces the proliferation of Vγ4+nγδT17 cells via STAT3 as effectively as IL-1 plus IL-23. Using bone marrow chimeric mice, we demonstrated that immature γδT17 cells are produced de novo in the adult mice from donor adult bone marrow cells and that IL-21 is dispensable for their development. Instead, IL-21 is required to expand newly induced Vγ4+γδT17 cells in the periphery upon immunization. Finally, using adoptive transfer experiments of γδT17 cells, we found that IL-21 receptors on γδT17 cells are involved in maintaining Vγ4+γδT17 cells, subsequent infiltration of Th17 cells into the spinal cord, and exacerbation of experimental autoimmune encephalomyelitis. Collectively, IL-21 plays a vital role in the maintenance and pathogenesis of Vγ4+γδT17 cells