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Purpose: The present study aimed to longitudinally clarify differences in physical fitness between Japanese kindergarteners who experienced school closure due to COVID-19 (COVID-19 pandemic group) and those who did not (control group). Methods: For the COVID-19 pandemic group, 51 three-year-old children underwent physical fitness measurements at three years old in November 2019, four years old in November 2020, and five years old in November 2021. In the control group, 52 three-year-old children underwent similar measurements at three years old in November 2017, four years old in November 2018, and five years old in November 2019. For physical fitness measurements, we performed an analysis of variance (ANOVA) of group × time for each gender. Results: Regarding body support duration, the COVID-19 pandemic group performed significantly lower than the control group at four and five years old. Conclusion: The present study longitudinally revealed that muscle endurance among Japanese kindergarteners who experienced school closure due to COVID-19 was impaired.

The purpose of the present study was to clarify comprehensively how and to what extent inhibition, spatial working memory (WM), and auditory WM influence agility, balance, and dexterity of motor co...

This study investigates the effect of spatial receive diversity on specific absorption rate (SAR) reduction based on outage probability analysis for wireless capsule endoscope (WCE). The communication performance of WCE depends much on the transmit power, which is strictly regulated in order to satisfy a safety guideline in terms of SAR, whereas WCE requires high communication performance due to its real-time data transmission. For the purpose of SAR reduction for a WCE scenario, the authors pay attention to the expectation that applying spatial diversity reception to WCE systems can not only improve the wireless communication performance but also reduce SAR. To begin with, based on finite-difference time-domain simulations with a numerical human body model, the outage probability is calculated under this implant propagation channel and the required transmit power is derived to secure a permissible outage probability. Then, the local peak SAR is calculated under the required transmit power when the WCE moves through the digestive organs. Finally, the simulation results demonstrate that applying spatial diversity reception can significantly reduce SAR for WCE.

SUMMARY One of promising application offered by implant body area networks (BANs) is a capsule endoscope localization system. To begin with, this paper performs finite-difference time-domain (FDTD) simulations on implant BAN propagation with a numerical human model, and investigates the propagation characteristics of implant BAN signals at 400 MHz medical implant communication service (MICS) band. Then, the paper presents a capsule endoscope localization system which utilizes only received signal strength indicator (RSSI) and two estimation methods, such as a maximum likelihood (ML) estimation method and a least squares (LS) method. Furthermore, we evaluate the two localization methods by two computer simulation scenarios. Our computer simulation results demonstrate that the ML localization can improve the location estimation accuracy as compared with the LS localization, that is, our performance comparison reveals that a careful consideration the propagation characteristics of implant BANs signals is efficient in terms of estimation performance improvement in capsule endoscope localization.

Sry (sex-determining region on the Y chromosome) is required for testicular differentiation in mammals. In addition to Sry, other genes such as WT1, Fgf9, Dax1, Dmrt1 and Sox9 are widely accepted to be involved in the sex determination in vertebrates. However, the roles of these genes during sex determination still remain unclear in amphibians. This study was undertaken to examine the expression of WT1 and Fgf9 in the developing gonad of amphibians. We first isolated the WT1 cDNA from the frog Rana rugosa. Like WT1 in mice, R. rugosa WT1 showed 2 isoforms; i.e., one had an additional 3 amino acids, KTS, included between the third and fourth zinc fingers. However, 17 amino acids in exon 5 of mammalian WT1 could not be found in R. rugosa WT1, which is also the case in turtle and chicken. The mRNA of both isoforms (+KTS, -KTS) was detected in the lung, kidney and testis, but not in the ovary and muscle of adult frogs. The 2 isoforms were expressed first in the embryos at stage 23. Thereafter, the expressions remained constant in the gonad attached to mesonephros of both sexes during sex determination. We next isolated the R. rugosa Fgf9 cDNA encoding 208 amino acids. The amino acid sequence of Fgf9 had similarity greater than 92% with chicken, mouse and human Fgf9s, suggesting that Fgf9 is highly conserved among vertebrate classes. Fgf9 was expressed in the ovary of an adult frog strongly, but in the lung weakly. In contrast, the Fgf9 mRNA was hardly detected in the kidney, testis and muscle. Moreover, Fgf9 did not show a sexually dimorphic expression pattern during sex determination in R. rugosa. The results, taken together, suggest that both WT1 and Fgf9 are expressed in the indifferent gonad prior to sex determination without any difference in the expression between males and females. Thus, it seems unlikely that they are a key factor to initiate the divergence leading to testicular or ovarian differentiation in R. rugosa.

The (pro)renin receptor [(P)RR] induces the catalytic activation of prorenin, as well as the activation of the mitogen-activated protein kinase (MAPK) signaling pathway; as such, it plays an important regulatory role in the renin-angiotensin system. (P)RR is known to form a homodimer, but the region participating in its dimerization is unknown. Using glutathione S-transferase (GST) as a carrier protein and a GST pull-down assay, we investigated the interaction of several (P)RR constructs with full-length (FL) (P)RR in mammalian cells. GST fusion proteins with FL (P)RR (GST-FL), the C-terminal M8-9 fragment (GST-M8-9), the extracellular domain (ECD) of (P)RR (GST-ECD), and the (P)RR ECD with a deletion of 32 amino acids encoded by exon 4 (GST-ECDd4) were retained intracellularly, whereas GST alone was efficiently secreted into the culture medium when transiently expressed in COS-7 cells. Immunofluorescence microscopy showed prominent localization of GST-ECD to the endoplasmic reticulum. The GST pull-down analysis revealed that GST-FL, GST-ECD, and GST-ECDd4 bound FLAG-tagged FL (P)RR, whereas GST-M8-9 showed little or no binding when transiently co-expressed in HEK293T cells. Furthermore, pull-down analysis using His-tag affinity resin showed co-precipitation of soluble (P)RR with FL (P)RR from a stable CHO cell line expressing FL h(P)RR with a C-terminal decahistidine tag. These results indicate that the (P)RR ECD participates in dimerization.

The (pro)renin receptor [(P)RR] is a single transmembrane protein with a large N-terminal extracellular domain and a short C-terminal cytoplasmic domain. Three molecular forms of (P)RR are known: a full-length form, a C-terminal truncated soluble form [s(P)RR], and an N-terminal truncated transmembrane form (M8-9 fragment). It has been reported that (P)RR forms homodimer, but the region participating in dimerization is unknown. Here we report that the extracellular domain of (P)RR participate in dimerization. Using secretory glutathione S-transferase (GST) as a fusion tag, we developed an in vivo pull-down assay to investigate (P)RR dimerization in the cell. GST-tagged extracellular domain (amino acid residues 17-304) of human (P)RR [GST-ECD], as well as full-length (P)RR [GST-Full] and M8-9 fragment [GST-M8-9], was retained in the cell, while GST alone was efficiently secreted into the culture medium when transiently expressed in COS-7 cells. Consistent with this observation, immunofluorescence microscopy showed prominent localization of GST-ECD to the ER. In vivo GST pull-down experiments revealed that GST-ECD as well as GST-Full bound FLAG-tagged full-length (P)RR, whereas GST-M8-9 bound it little, if any, when transiently coexpressed in HEK293T cells. To investigate whether s(P)RR can form heterodimer with full-length (P)RR, we established a CHO cell line stably expressing human (P)RR with C-terminal 10His-tag. All three forms of (P)RR were detected in the cell lysate and only s(P)RR was detected in the culture medium. Full-length (P)RR and s(P)RR were prominently localized to the ER as observed by immunofluorescence microscopy. Pull down experiment using His-tag affinity resin showed coprecipitation of s(P)RR with full-length (P)RR. These results indicate that the extracellular domain of (P)RR participates in dimerization.

In this paper, we investigate local peak specific absorption rate (SAR) based on required communication performance for a wireless capsule endoscope at 400 MHz medical implant communication service (MICS) band. First, in order to calculate the bit error rate (BER) performance under this implant propagation channel and derive the required transmit power to secure a permissible BER, we perform finite-difference time-domain (FDTD) simulations for implant body area network (BAN) channel modeling with two numerical human body models. Secondly, we calculate the local peak SAR under the required transmit power when the implant transmitter moves along the digestive organs. Based on such an approach, we attempt to determine a threshold transmit power which could be used to ensure the induced SAR not exceeding the safety guideline in the human body.

Implant body area networks (BANs) have so far drawn considerable attention in biomedical applications. Although implant BANs require high throughput performance of wireless communication due to real-time data transmission, the transmit power is strictly regulated in order to satisfy a safety guideline in terms of specific absorption rate (SAR). In this paper, we evaluate the local peak SAR based on required bit error rate (BER) performance for implant BANs at 400 MHz medical implant communication service (MICS) band. To begin with, we first perform finite-difference time-domain (FDTD) simulations for implant BAN propagation with a numerical human body model, and derive the propagation characteristic of implant BAN signals. Then, we calculate the BER performance under this implant propagation channel and derive the required transmit power to secure a permissible BER. Finally, we calculate the local peak SAR under the required transmit power when the implant transmitter moves along the digestive organs. Based on such an approach, we attempt to determine a threshold transmit power which could be used to ensure the induced SAR not exceeding the safety guideline.

One of promising application offered by implant body area networks (BANs) is a capsule endoscope localization system. To begin with, this paper performs finite-difference time-domain (FDTD) simulations on implant BAN propagation with a numerical human model, and investigates the propagation characteristics of implant BAN signals at 400 MHz medical implant communication service (MICS) band. Then, the paper presents a capsule endoscope localization system which utilizes only received signal strength indicator (RSSI) and two localization methods, such as a maximum likelihood (ML) estimation method and a least squares (LS) method. Our simulation results demonstrate that careful consideration of the propagation characteristics of implant BANs signals is efficient in terms of estimation performance improvement in capsule endoscope localization.

This paper evaluates the performance of an equal gain combining (EGC) diversity receiver for implant body area networks (BANs) at 400 MHz medical implant communication service (MICS) band. To begin with, in order to analyze the performance of the EGC diversity receiver, we perform finite-difference time-domain (FDTD) simulations on implant BAN propagation with a numerical human model, and investigate the propagation characteristics of implant BAN signals. Then, this paper presents an EGC diversity system for implant BANs which can improve the communication performance and evaluates the bit error rate (BER) performance by theoretical analysis. In the theoretical analysis, it is difficult to analytically derive the probability density function (pdf) on the combined signal-to-noise power ratio (SNR) at the EGC receiver output. Therefore, we introduce two approximation methods such as the moment generating function (MGF) method and the curve fitting method. The paper demonstrates that the performances by the theoretical analyses with the two approximation methods are almost corresponding to those by the computer simulations.