Ultrafast Ultrasound Imaging

Among medical imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), ultrasound imaging stands out due to its temporal resolution. Owing to the nature of medical ultrasound imaging, it has been used for not only observation of the morphology of living organs but also functional imaging, such as blood flow imaging and evaluation of the cardiac function. Ultrafast ultrasound imaging, which has recently become widely available, significantly increases the opportunities for medical functional imaging. Ultrafast ultrasound imaging typically enables imaging frame-rates of up to ten thousand frames per second (fps). Due to the extremely high temporal resolution, this enables visualization of rapid dynamic responses of biological tissues, which cannot be observed and analyzed by conventional ultrasound imaging. This Special Issue includes various studies of improvements to the performance of ultrafast ultrasoun

An attempt to quantify Pedagogical Content Knowledge for Japanese high school physics teachers

A CASE STUDY OF HOW TO HANDLE THE ELECTRIC CURRENT CONCEPT For quality science education, it is essential to fully grasp the concept of Pedagogical Content Knowledge (PCK) proposed by Shulman (1987). Therefore, there is a need to develop teachers' PCK in science education. In prior research, CoRes (Content Representations) and PaP-eRs (Pedagogical and Professional-experience Repertoires) (Magnusson et al., 1999) have been used as a framework to elicit from teachers the PCK components: orientations toward science teaching, knowledge of students’ understanding of science, knowledge of science curriculum, knowledge of instructional strategies, and knowledge of assessment in science. The CoRes consist of eight questions designed to elicit the science teacher's understanding of specific aspects of PCK, such as an overview of key ideas, points of confusion. The PaP-eRs is a useful framework for showing the deeper aspects of science teachers' PCK, for example, in this study it consists of CoRes-based interview transcripts. However, these studies represent teachers' PCK qualitatively and remain case studies. Therefore, the  study we are presenting, aims to represent PCK quantitatively based on previous studies. The context of the investigation is how electric current is handled in the first hour of an electricity unit in high school. METHOD Beginning in May 2022, we preliminarily surveyed and analyzed four teachers who teach physics in high schools. Interviews were conducted with teachers based on the CoRes and PaP-eRs frameworks. Interview transcripts are categorized by PCK components. The number of utterances that appeared in each category was then recorded and represented as a radar chart. RESULTS An example of one teacher’s radar chart of the items with the highest number of utterances as 1 is shown in Figure 1 (see Abstract PDF). Each item represents knowledge of students’ understanding of science, knowledge of science curriculum, knowledge of instructional strategies, and knowledge of assessment in science. Since the first hour is assumed, the number of occurrences of knowledge of assessment in science may be low. It should be noted that this figure does not represent teacher qualifications, as the actual context and understanding of the students they teach in their learning varies among the teachers surveyed. In the current analysis, we only consider the number of utterances. Therefore, we would like to consider the need for weighting in future research. Although the number of surveys is limited at this time, we will increase the number of surveys and present a more detailed study. REFERENCES Magnusson, S. J., Borko, H., & Krajcik, J. S. (1999). Nature, sources, and development of pedagogical content knowledge for science teaching. In J. Gess-Newsome & N. Lederman (Eds.), Examining Pedagogical content Knowledge (pp. 95-132), Boston, MA: Kluwer Press. Shulman, L. S. (1987). Knowledge and teaching: Foundations of the new reform. Harvard Educational Review, 57(1), 1–22

Noninvasive evaluation of local myocardial thickening and its color-coded imaging

科研費報告書収録論文(課題番号:08555096・基盤研究(B)(2)・H8～H9/研究代表者:金井, 浩/心筋の早期診断を可能とする心臓壁微小振動の超音波計測及び解析装置の開発

Comparative transcriptional profiling-based identification of raphanusanin-inducible genes

<p>Abstract</p> <p>Background</p> <p>Raphanusanin (Ra) is a light-induced growth inhibitor involved in the inhibition of hypocotyl growth in response to unilateral blue-light illumination in radish seedlings. Knowledge of the roles of Ra still remains elusive. To understand the roles of Ra and its functional coupling to light signalling, we constructed the Ra-induced gene library using the Suppression Subtractive Hybridisation (SSH) technique and present a comparative investigation of gene regulation in radish seedlings in response to short-term Ra and blue-light exposure.</p> <p>Results</p> <p>The predicted gene ontology (GO) term revealed that 55% of the clones in the Ra-induced gene library were associated with genes involved in common defence mechanisms, including thirty four genes homologous to <it>Arabidopsis </it>genes implicated in R-gene-triggered resistance in the programmed cell death (PCD) pathway. Overall, the library was enriched with transporters, hydrolases, protein kinases, and signal transducers. The transcriptome analysis revealed that, among the fifty genes from various functional categories selected from 88 independent genes of the Ra-induced library, 44 genes were up-regulated and 4 were down-regulated. The comparative analysis showed that, among the transcriptional profiles of 33 highly Ra-inducible genes, 25 ESTs were commonly regulated by different intensities and duration of blue-light irradiation. The transcriptional profiles, coupled with the transcriptional regulation of early blue light, have provided the functional roles of many genes expected to be involved in the light-mediated defence mechanism.</p> <p>Conclusions</p> <p>This study is the first comprehensive survey of transcriptional regulation in response to Ra. The results described herein suggest a link between Ra and cellular defence and light signalling, and thereby contribute to further our understanding of how Ra is involved in light-mediated mechanisms of plant defence.</p

Structure-Activity Relationship of Acetylenes from Galls of Hedera rhombea as Plant Growth Inhibitors

The structure-activity relationship of 12 isolated acetylenes from galls of Hedera rhombea (Araliaceae) induced by Asphondylia sp. (Cecidomyiidae) and their derivatives has been studied for the inhibition of the shoot and root growth of rice, perennial ryegrass, cockscomb, lettuce, and cress. Almost all acetylenes generally showed growth inhibitory activity. The diacetylenes exhibited higher activity than the monoacetylenes, suggesting that a conjugated diyne segment is essential for the activity. On the other hand, the acetylenes with a nonoxidated methylene group at C-8 showed stronger activity comparing with those possessing hydroxy and acetoxy groups at C-8. Furthermore, it has been demonstrated that the acetylenes bearing a terminal olefinic group at C-16,C-17 enhanced the activity. It is thus clarified that important sites for the activity of the acetylenes from galls of H. rhombea are a conjugated diyne and a terminal olefinic group connecting to the aliphatic chain and that less oxidated compounds show more activity

Accurate estimation of scattering strength distribution by simultaneous reception of ultrasonic echoes with multichannel transducer array

Recently, there have been several studies on ultrasonic cross-sectional imaging based on simultaneous reception of echo signals with an array transducer without scanning ultrasonic beams during transmission. In those studies, parallel processing was applied to create an image from a data set simultaneously received by the array. However, the lateral resolution of the parallel processing is not high. In this study, in order to improve the spatial resolution of parallel processing, the least-squares estimation and the truncated singular value decomposition (tSVD) are applied to the echo signals from two wire targets simultaneously received with a multichannel transducer array. We introduced a weighting for correcting the effect of the directivity of the elements of the array. The experimental results show a higher lateral resolution of the tSVD method with weighting than that of conventional parallel processing. The axial resolution is also improved by considering the finite duration of the transmitted ultrasonic pulse. A typical application of this method is nondestructive evaluation, that is, the detection of cavities and cracks in welded metal structures

Phylogeographic and Demographic Analysis of the Asian Black Bear (Ursus thibetanus) Based on Mitochondrial DNA.

The Asian black bear Ursus thibetanus is widely distributed in Asia and is adapted to broad-leaved deciduous forests, playing an important ecological role in the natural environment. Several subspecies of U. thibetanus have been recognized, one of which, the Japanese black bear, is distributed in the Japanese archipelago. Recent molecular phylogeographic studies clarified that this subspecies is genetically distantly related to continental subspecies, suggesting an earlier origin. However, the evolutionary relationship between the Japanese and continental subspecies remained unclear. To understand the evolution of the Asian black bear in relation to geological events such as climatic and transgression-regression cycles, a reliable time estimation is also essential. To address these issues, we determined and analyzed the mt-genome of the Japanese subspecies. This indicates that the Japanese subspecies initially diverged from other Asian black bears in around 1.46Ma. The Northern continental population (northeast China, Russia, Korean peninsula) subsequently evolved, relatively recently, from the Southern continental population (southern China and Southeast Asia). While the Japanese black bear has an early origin, the tMRCAs and the dynamics of population sizes suggest that it dispersed relatively recently in the main Japanese islands: during the late Middle and Late Pleistocene, probably during or soon after the extinction of the brown bear in Honshu in the same period. Our estimation that the population size of the Japanese subspecies increased rapidly during the Late Pleistocene is the first evidential signal of a niche exchange between brown bears and black bears in the Japanese main islands. This interpretation seems plausible but was not corroborated by paleontological evidence that fossil record of the Japanese subspecies limited after the Late Pleistocene. We also report here a new fossil record of the oldest Japanese black bear from the Middle Pleistocene, and it supports our new evolutionary hypothesis of the Japanese black bear

Non-uniform distribution of the contraction/extension (C–E) in the left ventricular myocardium related to the myocardial function

AbstractObjectiveWe attempted to disclose the microscopic characteristics of the non-uniform distribution of the contraction and extension (C–E) of the left ventricular (LV) myocardium using a new methodology (echo-dynamography).MethodsThe distributions of the “axial strain rate” (aSR) and the intra-mural velocity in the local areas of the free wall including the posterior wall (PW) and interventricular septum (IVS) were microscopically obtained using echo-dynamography with a high accuracy of 821μm in the spatial resolution. The results were shown by the color M-mode echocardiogram or curvilinear graph. Subjects were 10 presumably normal volunteers.Results(1)Both the C–E in the pulsating LV wall showed non-uniformity spatially and time-sequentially.(2)The C–E property was better evaluated by the aSR distribution method rather than the intra-mural velocity distribution method.(3)Two types of non-uniformity of the aSR distribution were observed: i.e. (i) the difference of its (+)SR (contraction: C) or (−)SR (extension: E) was solely the “magnitude”; (ii) the coexistence of both the (+) SR and (−)SR at the same time.(4)The aSR distribution during systole was either “spotted,” or “multi-layered,” or “toned” distribution, whereas “stratified,” “toned,” or “alternating” distributions were observed during diastole.(5)The aSR distribution in the longitudinal section plane was varied in the individual areas of the wall even during the same timing.(6)To the mechanical function of the LV, there was a different behavior between the IVS and PW.ConclusionsThe aSR and its distribution were the major determinants of the C–E property of the LV myocardium. Spatial as well as time-sequential uniformity of either contraction or extension did not exist. The myocardial function changed depending on the assemblage of the aSR distribution, and by the synergistic effect of (+)SR and (−)SR, the non-uniformity itself potentially served to hold the smooth LV mechanical function

Controlling the concentration gradient in sequentially deposited bilayer organic solar cells via rubbing and annealing

We elucidate the formation mechanism of adequate vertical concentration gradients in sequentially deposited poly(3-hexylthiophene-2, 5-diyl) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) bilayer solar cells. Using advanced analytical techniques, we clarify the origins of the enhanced photovoltaic performances of as-deposited and annealed bilayer P3HT/PCBM organic solar cells upon P3HT layer rubbing prior to PCBM deposition. Energy-dispersive X-ray spectroscopy reveals the individual effects of rubbing and annealing on the formation of adequate concentration gradients in the photoactive layers. Repetitive rubbing of P3HT strongly affects the active layer nanomorphology, forming an intermixed layer in the as-deposited devices which is retained after the annealing process. Infrared p-polarized multiple-angle incidence resolution spectrometry measurements indicate that rubbing induces a minor reorganization of the P3HT molecules in the polymer-only thin films towards face-on orientation. However, the deposition of the upper PCBM layer reverts the P3HT molecules back to their original orientation. These findings suggest that the formation of an adequate concentration gradient upon rubbing corresponds to the dominant contribution to the improved photovoltaic characteristics of rubbed bilayer organic solar cells. Using the reference low bandgap copolymer PCDTBT, we demonstrate that rubbing can be successfully applied to increase the photovoltaic performances of PCDTBT/PCBM organic solar cells. We also demonstrate that rubbing can be an efficient and versatile strategy to improve the power conversion efficiency of non-fullerene solar cells by using the reference materials in the field, PBDB-T and ITIC