Solar and geomagnetic activity dependence of 150-km echoes observed by the Equatorial Atmosphere Radar in Indonesia

The occurrence characteristics of 150-km echoes in low-latitude regions are studied using the Equatorial Atmosphere Radar (EAR) in Indonesia. The long-term observation of the 150-km echoes by the EAR enables us to study the occurrence characteristics of 150-km echoes statistically. It is shown that the occurrence rate of the 150-km echoes observed by the EAR shows a semiannual variation with two peaks in solstices and a negative correlation with both the EUV flux and ΣKp index, that is, the solar and the geomagnetic activity. Geomagnetic activity correlates with the occurrence rate of 150-km echoes observed one day after when the ΣKp was measured. However, the occurrence rate is always low during the high solar activity period regardless of the geomagnetic activity. While the seasonal variation and the solar activity dependence of the occurrence of 150-km echoes are consistent with previous studies, this is the first time a negative correlation with geomagnetic activity is reported

Grouping synergy generates the kin-selected benefit of bee workers

Endogenous P300 and exogenous slow vertex potentials were obtained with tone and speech stimuli in a group of five children using a cochlear implant (CI) with poor speech recognition (group A) and compared with those from another group of five children using a CI with good speech recognition (group B). The responses were also compared to those of children with normal hearing (n= 14) and a group of adult CI users (n=9). N1 and P2 latencies of CI group A and group B were prolonged compared to those of normally-hearing children. In group A, P300 was present when contrasts with tone stimuli were used. When speech stimuli were used, P300 potentials were absent or delayed. P300 potentials obtained in group B were no different from those obtained in normally-hearing children. It is suggested that the poor results evoked with speech stimuli in contrast to those evoked with pure-tone stimuli in group A are due to the immaturity of (sub) cortical generators associated with acoustical and phonetic processing. In contrast to the children in group B, all children in group A suffered from congenital deafness

Statistical Analysis of Medium-Scale Traveling Ionospheric Disturbances Over Japan Based on Deep Learning Instance Segmentation

Medium-scale traveling ionospheric disturbances (MSTIDs) are observed as parallelly arrayed wavelike perturbations of Total Electron Content (TEC) in ionospheric F region leading to satellite navigation error and communication signal scintillation. The observation method for MSTIDs, detrended TEC (dTEC) map, summarizes the perturbation component of TEC having the merits of full-time and two-dimensional. However, previous automatic processing methods for dTEC map cannot discriminate MSTIDs from other irregular ionospheric perturbations intelligently. With the development of artificial intelligence in recent years, deep learning approach is expecting to clarify the controversy of MSTID external dependence (season and solar/geomagnetic activity) under debating for decades. Therefore, this research proposes a real-time processing algorithm for dTEC maps based on Mask Region-Convolutional Neural Network (R-CNN) model of deep learning instance segmentation to detect wavelike perturbations intelligently with an accuracy of about 80% and a processing speed of about 8 fps. Then isolated perturbations are eliminated and only MSTID waveforms are chosen to obtain statistical characteristics of MSTIDs. With this algorithm, we analyzed up to 1, 209, 600 dTEC maps from 1997 to 2019 over Japan automatically and established a database of hourly averaged MSTID characteristics. This research introduces the partial correlation coefficient for the first time to clarify the solar/geomagnetic activity dependence of MSTID characteristics which is independent with each other

Nighttime Midlatitude E-F Coupling in Geomagnetic Conjugate Ionospheres: A Double Thin Shell Model and a Multi-Source Data Investigation

Geomagnetic conjugate mid-latitude nighttime ionospheres are frequently simultaneously populated with electrified nighttime medium-scale traveling ionospheric disturbances (MSTIDs). Earlier observations and theoretical analysis have underscored the ionosphere E-F coupling and the postulation of coupled conjugate hemispheres, playing a pivotal role in the formation of electrified MSTIDs. In this paper, the conjugate MSTIDs are studied to elucidate the causes and effects of E-F coupling in the interhemispheric coupled ionosphere. The hemisphere-coupled ionospheres over Japan and Australia are observed and analyzed using total electron content (TEC) measurements, supplemented with multi-source observations from ionosondes, Ionospheric Connection Explorer (neutral wind), Constellation Observing System for Meteorology, Ionosphere, and Climate (electron density), and Swarm (magnetic field). A double-thin-shell model is introduced to analyze the ionospheric responses in E and F regions during the coupling process. For the first time, observation results provide the evidence that F-region geomagnetic conjugate irregularities in both hemispheres are mainly driven by the Es layers in the summer hemisphere. The Es layer in the summer hemisphere subsequently triggers local E-F coupling and inter-hemispheric coupling. In the winter hemisphere, Es layers show amplitude reduction or even dissipation during the interhemispheric coupling process. Furthermore, thermospheric winds, non-equipotential magnetic field lines, and background TEC are presumed candidates for the inter-hemispheric asymmetry in MSTIDs amplitudes and growth rates

A Quantitative and Qualitative Evaluation for an Introduction of New Language Education Program: Based on a Questionnaire Survey to Students

This article is an empirical study based on a questionnaire survey for undergraduates and faculty members on educational materials for a new English program. Materials used in class may seem too technical for sophomore level undergraduates. Our quantitative and qualitative analyses find following points: requests about lectures themselves, which are also seen in existing subjects, gap between the language ability of students and that assumed by teachers, demand for new language course using technical materials, and (un)clear relation between this program and English tests given by third parties. These findings suggest that the satisfaction level depends on the lack of communication between concept originator and undergraduates about the “P (Plan) phase” of new program introduction

Effect of the GSTM1 Null Genotype on Glutathione S-Transferase (GST) Activity in Patients with Non-Viral Liver Tumors

Glutathione S-transferase (GST) is a major phase II drug-metabolizing enzyme. Several isoforms of human GST as well as different GST genetic polymorphisms are known, but limited data exists concerning the relationship between GST polymorphisms and GST activity using 1-chloro-2,4-dinitrobenzene in human liver. To resolve this query, we analyzed the genetic polymorphisms of four main GST isoforms [GST mu 1 (GSTM1), GST theta 1 (GSTT1), GST alpha 1 (GSTA1), GST pi 1 (GSTP1)] and measured hepatic GST activity isolated from the same patients. We found that GSTM1 null individuals have significantly lower (P=0.0082) GST activity compared with GSTM1 positive individuals. No significant changes in GST activity were observed in individuals with GSTT1, GSTA1, and GSTP1 genotypes. Interestingly, the levels of GST activity exhibited were similar when compared with GSTA1*A/*A and GSTA1*A/*B, and GSTP1*A/*A and GSTP1*A/*B, respectively, if the genotype was GSTM1 null. Therefore, the genotypes of GSTA1*A/*B and GSTP1*A/*B individuals do not significantly affect the level of hepatic GST activity. An examination of the correlation between GST mRNA expression and GST activity subsequently revealed a significant correlation between GSTM1 mRNA levels and GST activity (r=0.626, P=0.007). These data are expected to facilitate research on the prediction of efficacy and safety of GSTM1 null-mediated drug metabolism and may establish whether genetic polymorphisms of the GST gene, specifically GSTM1, can act as a biomarker