STEM Materials Derived from the Cycloid

A cycloid is a plane curve obtained as the locus of a point fixed on a circle, when the circle rolls on a straight line without slipping. Similar plane curves can be considered if we replace a base line with other curves such as parabola, hyperbola, circles. Conversely, we examine the inverse problem. That is, for a given curve, what is the base for which a fixed point on a rolling circle yields the curve as the locus? In general, this is hard to solve, but we discuss two approaches from viewpoints of differential equation and geometry. For the latter, we propose an implementation for the computational software Mathematica.本研究はJSPS科研費JP17H00820の助成を受けたものである

Production of viral vectors using recombinase-mediated cassette exchange

DNA viruses are often used as vectors for foreign gene expression, but large DNA region from cloned or authentic viral genomes must usually be handled to generate viral vectors. Here, we present a unique system for generating adenoviral vectors by directly substituting a gene of interest in a small transfected plasmid with a replaced gene in a replicating viral genome in Cre-expressing 293 cells using the recombinase-mediated cassette exchange (RMCE) reaction. In combination with a positive selection of the viral cis-acting packaging signal connected with the gene of interest, the purpose vector was enriched to 97.5 and 99.8% after three and four cycles of infection, respectively. Our results also showed that the mutant loxP V (previously called loxP 2272), a variant target of Cre used in the RMCE reaction, was useful as a non-compatible mutant to wild-type loxP. This method could be useful for generating not only a large number of adenovirus vectors simultaneously, but also other DNA virus vectors including helper-dependent adenovirus vector

The Mathematics of Mercator Map: As a STEM topic for undergraduates

The Mercator map or projection is one of the map projections treated in Social Studies of junior high and high school courses. The most important feature is that the projection is conformal meaning that it preserves angles. In this article, we first explain this conformal property elementarily but rigorously in order to propose that the topic is suitable for undergraduates as a STEM topic. Also, we give a parametrization of the plane curve obtained by projecting a great circle on the earth onto the Mercator map. Finally, we examine a rhumb line and calculate the distance along it.本研究は，JSPS科研費JP17H00820の助成を受けたものである

Three-dimensional visualization of thoracodorsal artery perforators using photoacoustic imaging

Introduction: Diagnostic imaging modalities to evaluate the three-dimensional distribution of thoracodorsal artery perforators (TDAPs) are lacking. In this study, TDAPs were visualized and characterized using photoacoustic imaging. Material and methods: In this study, 34 sites in the lateral chest wall of 18 individuals were analyzed. The region extending 5 cm ventral and 5 cm dorsal to the lateral edge of the latissimus dorsi (LD) and 5–15 cm from the posterior axillary fold was scanned using photoacoustic imaging. The largest perforator closest to the edge of the LD was characterized. The location of the stem portion and the orientation of the longest cutaneous branch of the perforator were described. The relationship between the maximal depth of delineation on photoacoustic images and the depth of the deep fascia was assessed. Results: On average, 2.6 perforators (range, 1–5 perforators) were visualized in the region of interest. The distribution of the TDAP stem portion was similar to that in previous studies. Cutaneous branches were preferentially oriented in a medial-caudal direction. The length of delineated cutaneous branches varied (range, 7–78 mm) depending on the thickness of the subcutaneous layer. Vessels under the LD were observed when the subcutaneous layer was thin. Conclusion: Photoacoustic imaging can successfully visualize TDAPs in three dimensions. Visualization of TDAPs varied by the thickness of the subcutaneous layer. A thin deep fascia of the LD might be a cause of deep laser penetration

Developing a Learning Material to Understand and Explore Solar Eclipses as a STEM Topic

We propose a learning material for high-school students to understand the mechanism of solar eclipses and explore them from various viewpoints as a STEM topic. The purpose of this material is not to predict solar eclipses accurately, but the prediction error is small, which may provide the students the value of our material. In the next Course of Study, a new subject called the explorations in Math and Science will be launched. We expect that our material can be used there.本研究は，JSPS科研費JP17H00820の助成を受けたものである

Depth profiles of radioactive cesium in soil using a scraper plate over a wide area surrounding the Fukushima Dai-ichi Nuclear Power Plant, Japan

AbstractDuring the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident, radioactive cesium was released in the environment and deposited on the soils. Depth profiles of radioactive cesium in contaminated soils provide useful information not only for radiation protection and decontamination operations but also for geoscience and radioecology studies. Soil samples were collected using a scraper plate three times between December 2011 and December 2012 at 84 or 85 locations within a 100-km radius of the Fukushima Dai-ichi NPP. In most of the obtained radioactive cesium depth profiles, it was possible to fit the concentration to a function of mass depth as either an exponential or hyperbolic secant function. By using those functions, following three parameters were estimated: (i) relaxation mass depth β (g cm−2), (ii) effective relaxation mass depth βeff (g cm−2), which is defined for a hyperbolic secant function as the relaxation mass depth of an equivalent exponential function giving the same air kerma rate at 1 m above the ground as the inventory, and (iii) 1/10 depth L1/10 (cm), at which the soil contains 90% of the inventory. The average β value (wet weight) including ones by hyperbolic secant function in December 2012, was 1.29 times higher than that in December 2011. In fact, it was observed that depth profiles at some study sites deviated from the typical exponential distributions over time. These results indicate the gradual downward migration of radioactive cesium in the soils. The L1/10 values in December 2012 were summarized and presented on a map surrounding the Fukushima Dai-ichi NPP, and the average value of L1/10 was 3.01 cm (n = 82) at this time. It was found that radioactive cesium remained within 5 cm of the ground surface at most study sites (71 sites). The sech function can also be used to estimate the downward migration rate V (kg m−2 y−1). The V values in December 2012 (n = 25) were in good agreement with those found by a realistic approach using a diffusion and migration model. Almost all values ranged between 1.7 and 9.6 kg m−2 y−1 in this study

High HbA1c levels correlate with reduced plaque regression during statin treatment in patients with stable coronary artery disease: Results of the coronary atherosclerosis study measuring effects of rosuvastatin using intravascular ultrasound in Japanese subjects (COSMOS)

Abstract Background The incidence of cardiac events is higher in patients with diabetes than in people without diabetes. The Coronary Atherosclerosis Study Measuring Effects of Rosuvastatin Using Intravascular Ultrasound in Japanese Subjects (COSMOS) demonstrated significant plaque regression in Japanese patients with chronic coronary disease after 76 weeks of rosuvastatin (2.5 mg once daily, up-titrated to a maximum of 20 mg/day to achieve LDL cholesterol Methods In this subanalysis of COSMOS, we examined the association between HbA1c and plaque regression in 40 patients with HbA1c ≥6.5% (high group) and 86 patients with HbA1c Results In multivariate analyses, HbA1c and plaque volume at baseline were major determinants of plaque regression. LDL cholesterol decreased by 37% and 39% in the high and low groups, respectively, while HDL cholesterol increased by 16% and 22%, respectively. The reduction in plaque volume was significantly (p = 0.04) greater in the low group (from 71.0 ± 39.9 to 64.7 ± 34.7 mm3) than in the high group (from 74.3 ± 34.2 to 71.4 ± 32.3 mm3). Vessel volume increased in the high group but not in the low group (change from baseline: +4.2% vs −0.8%, p = 0.02). Change in plaque volume was significantly correlated with baseline HbA1c. Conclusions Despite similar improvements in lipid levels, plaque regression was less pronounced in patients with high HbA1c levels compared with those with low levels. Tight glucose control during statin therapy may enhance plaque regression in patients with stable coronary disease. Trial registration ClinicalTrials.gov, Identifier NCT00329160</p

Successful management of tracheo-innominate artery fistula with endovascular stent graft repair

AbstractTracheo-innominate artery fistula is a highly lethal complication after tracheostomy. A 37-year-old man who had undergone a tracheostomy 14 years earlier because of dysphagia after brain surgery had a tracheo-innominate artery fistula with exsanguinating hemorrhage from his tracheostomy site. After temporary control of the bleeding, a stent graft was implanted in the innominate artery through the brachial artery. The patient recovered uneventfully and remained well 14 months after the procedure, with no sign of infection. Endovascular stent grafting may be the treatment of choice for patients with tracheo-innominate artery fistula. (J Vasc Surg 2001;33:1280-2.

Comparisons in temperature and photoperiodic-dependent diapause induction between domestic and wild mulberry silkworms

The bivoltine strain of the domestic silkworm, Bombyx mori, has two generations per year. It shows a facultative diapause phenotype determined by environmental conditions, including photoperiod and temperature, and nutrient conditions during embryonic and larval development of the mother. However, it remains unclear how the environmental signals received during development are selectively utilized as cues to determine alternative diapause phenotypes. We performed a comparative analysis between the Kosetsu strain of B. mori and a Japanese population of the wild mulberry silkworm B. mandarina concerning the hierarchical molecular mechanisms in diapause induction. Our results showed that for the Kosetsu, temperature signals during the mother's embryonic development predominantly affected diapause determination through the thermosensitive transient receptor potential ankyrin 1 (TRPA1) and diapause hormone (DH) signaling pathways. However, embryonic diapause in B. mandarina was photoperiod-dependent, although the DH signaling pathway and thermal sensitivity of TRPA1 were conserved within both species. Based on these findings, we hypothesize that TRPA1-activated signals are strongly linked to the signaling pathway participating in diapause induction in Kosetsu to selectively utilize the temperature information as the cue because temperature-dependent induction was replaced by photoperiodic induction in the TRPA1 knockout mutant.ArticleScientific Report 11(1) : 8052-(2021)journal articl