Electromagnetic ion cyclotron (EMIC) waves are believed to cause the loss of relativistic electrons from the outer radiation belt into the atmosphere due to pitch angle scattering. However, it is still unclear whether all EMIC waves can scatter relativistic electrons or which conditions are favorable for pitch angle scattering by EMIC waves. In this study, we performed a 2‐year data analysis of EMIC waves and EMIC wave‐driven electron precipitation (EP), from 1 November 2016–31 October 2018. Electromagnetic ion cyclotron waves were observed using a ground‐based magnetometer installed at Athabasca (ATH, 4.3), Canada. Electron precipitation events were identified from very low‐frequency radio waves propagated from the transmitters at North Dakota (NDK, 3.0) and Seattle (NLK, 2.9) stations in USA to the receiver installed at ATH. The magnetic local time dependence of EMIC waves showed higher occurrence rates in the dawn sector. In contrast, EMIC waves accompanied by EP were localized in the dusk sector and were likely to occur during geomagnetic substorms. We found that EMIC waves accompanied by EP were associated with the main phase of geomagnetic storms and occurred inside the plasmapause. These results suggest that the EMIC waves that cause EP occur in the overlap region between the ring current and dense cold plasma during the main phase of geomagnetic storms. This is consistent with previous studies describing that the electron resonant energy with EMIC waves is lower in regions with high plasma density.

BACKGROUND: To investigate the use of calcineurin inhibitors (CNIs) in pregnant Japanese women and to evaluate their safety in infants. METHODS: Data were extracted from the claims database of the Japan Medical Data Center. The prevalence of CNIs was evaluated 180 days before pregnancy onset, during pregnancy, and within180-days post partum. We investigated the characteristics of the infants, including the presence of major malformations and their diagnoses, for 1 year after birth. RESULTS: A total of 91,865 pregnancies in 80,049 women were included. Fifty-three women were prescribed CNIs between 180-day before pregnancy onset and 180-day postpartum; 35 of the 53 women were prescribed the drugs during pregnancy, and 10 of their infants were born preterm. Three were diagnosed with major congenital malformations, such as patent ductus arteriosus. Six preterm infants presented with infant respiratory distress syndrome. CONCLUSIONS: No congenital anomalies were clearly attributable to the use of CNIs during pregnancy.

To understand the mechanism of the increased frequency of intervals of pulsations of diminishing periods (IPDPs), we analyzed IPDP‐type electromagnetic ion cyclotron (EMIC) waves that occurred on 19 April 2017, using ground and satellite observations. Observations by low‐altitude satellites and ground‐based magnetometers indicate that the increased IPDP frequency is caused by an inward (i.e., Earthward) shift of the EMIC wave source region. The EMIC wave source region moves inward along the mid‐latitude trough, which we used as a proxy for the plasmapause location. A statistical analysis shows that increases in the IPDP frequency showed a positive correlation with polar cap potentials. These results suggest an enhanced convection electric field causes an inward shift of the source region. The inward shift of the source region allows EMIC waves to scatter relativistic electrons over a wide range of radial distances during the IPDP event. This mechanism suggests that IPDP‐type EMIC waves are more likely to scatter relativistic electrons than other EMIC waves. We also show that the decreased phase‐space density of relativistic electrons in the outer radiation belt is consistent with the extent of the source region and the resonant energy of EMIC waves, implying a possible contribution of EMIC waves to outer radiation belt loss during the main phase of geomagnetic storms.

No studies have examined the association of the combination of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs intake with psychological distress during pregnancy. To examine these associations, we divided Japanese pregnant women into 25 groups based on combining quintiles of n-3 PUFAs intake and quintiles of n-6 PUFAs intake. We conducted multivariable logistic regression analyses to assess the risk of psychological distress during pregnancy (Kessler Psychological Distress Scale ≥ 5 or 13). Compared to the third quintile of both n-3 PUFAs and n-6 PUFAs intake, the groups with unbalanced intake, high intake of both, and low intake of both were associated with a higher risk of both Kessler Psychological Distress Scale ≥ 5 and 13 in early and mid-pregnancy. Further research is needed to identify the precise combination of n-3 PUFAs and n-6 PUFAs intake associated with the lowest psychological distress during pregnancy.

In gradual Solar Energetic Particle (SEP) events, shock waves driven by coronal mass ejections (CMEs) play a major role in accelerating particles, and the energetic particle flux enhances substantially when the shock front passes by the observer. Such enhancements are historically referred to as Energetic Storm Particle (ESP) events, but it remains unclear why ESP time profiles vary significantly from event to event. In some cases, energetic protons are not even clearly associated with shocks. Here, we report an unusual, short-duration proton event detected on 5 June 2011 in the compressed sheath region bounded by an interplanetary shock and the leading edge of the interplanetary CME (or ICME) that was driving the shock. While < 10 MeV protons were detected already at the shock front, the higher-energy (> 30 MeV) protons were detected about four hours after the shock arrival, apparently correlated with a turbulent magnetic cavity embedded in the ICME sheath region.

Abstract Background Alcohol use during pregnancy can lead to adverse health consequences for the fetus. Identification of pregnant women who are most likely to drink is essential for targeting interventions. However, evidence on associations of education and income with alcohol use during pregnancy is inconsistent. Methods We analyzed data from 11484 pregnant women who agreed to participate in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study in Japan from 2013 to 2017. Women were dichotomized as current drinker and non-drinker (past drinker, never drinker, constitutionally never drinker) during early pregnancy and during middle pregnancy, respectively. Multivariate logistic regression analyses were conducted to examine whether educational attainment or equivalent household income was associated with alcohol use, after adjusting for women's age, work status, smoking, income/education, and their partners' education. Results Prevalence of alcohol use during early and middle pregnancy was 21.1% and 6.5%, respectively. Higher education and higher income were significantly associated with an increased risk of alcohol use during early pregnancy; the odds ratio (OR) of ≥university education compared with ≤high school education was 1.54 (95% confidence interval [CI], 1.35-1.76), and the OR of ≥ 4 million compared with <2 million Japanese yen was 1.39 (95% CI, 1.20-1.61). Education and income were not associated with alcohol use during middle pregnancy; the corresponding ORs were 1.08 (95% CI, 0.87-1.35) and 1.03 (95% CI, 0.82-1.29), respectively. Conclusions Associations of education and income with alcohol use were observed during early pregnancy, not during middle pregnancy. No amount of alcohol and no time to drink can be considered safe during pregnancy. More public health awareness is needed to prevent alcohol use during early pregnancy. Key messages Different strategies for preventing alcohol use are required during early pregnancy and during middle pregnancy. Interventions for alcohol use during early pregnancy should focus on women with higher education and/or higher income.

Abstract Background Previous studies reported the association between maternal psychological distress (PD) during or after pregnancy and atopic dermatitis in children. However, studies examining the association from both pre- and post-natal aspects are limited. Methods We analysed data from 6,366 mother-child pairs who participated in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study in Japan. Mothers were categorised into four groups of PD (K6 scores ≥5) during early pregnancy and one year after delivery; no PD in both periods, prenatal PD only, postnatal PD only, and PD in both periods. Mothers reported on their children's atopic dermatitis at age two using the International Study of Asthma and Allergies in Childhood (ISAAC). Multivariate logistic regression analysis was conducted to examine the association between maternal PD and atopic dermatitis in children adjusting for maternal age at delivery, maternal education, maternal smoking during early pregnancy, maternal history of atopic diseases, paternal history of atopic diseases, preterm birth, parity, and child's sex. Results The study population included 51.9% without PD in both periods, 14.6% with prenatal PD only, 14.0% with postnatal PD only, and 19.4% with PD in both periods. The prevalence of atopic dermatitis in children at age two was 18.8%. Mothers with postnatal PD only and mothers with PD in both periods had higher risks of children's atopic dermatitis compared with mothers without PD in both periods; the adjusted odds ratios (95% confidence intervals) were 1.37 (1.14-1.65) and 1.38 (1.17-1.63), respectively. The corresponding odds ratio (95% confidence interval) of mothers with prenatal PD only was 1.08 (0.89-1.31). Conclusions Postnatal PD was associated with an increased risk of atopic dermatitis in children. This finding suggests the importance for monitoring mental health among postpartum women. Key messages Postnatal PD has significant effects on atopic dermatitis in children. This study is a first study to examine the association between maternal PD and children’s atopic dermatitis in Japan. Improvements of postnatal care including social support might be effective in preventing atopic dermatitis in children.

Objective: Information on the change in blood pressure (BP) during the life course is essential from both clinical and public health standpoints. Most studies demonstrating age-related trends in BP were based on cross-sectional data. Since an elevated BP at a younger age results in fatal cardiovascular events in later life, the cross-sectional study design contributes to an underestimation of BP in elderly individuals. The present study involved longitudinal analysis to assess age-related trends in BP, using large-scale data. Design and method: We received data of health check-up conducted between 2008–2017 and used a total of 2,235,055 observations from 386,760 individuals aged between 30–74 years in the JMDC database, which contains multiple health checkup data from the Japanese health insurance societies. The age-related trends in BP were estimated using a repeated-measures mixed linear model including age, sex, and an interaction between age and sex. We cross-sectionally summarized the prevalence rate of hypertension and antihypertensive treatment rate among hypertensives in each age group. Results: The number of follow-up examinations without baseline visit was < 2, 3, 4, or > = 5 in 14,453 (3.8%), 33,468 (8.7%), 139,961 (36.2%), and 198,878 (51.4%), respectively. Systolic BP increased consistently from 121.1 mmHg at 36 years to 129.7 mmHg at 66 years in men and from 109.7 mmHg at 33 year to 131.9 mmHg at 74 years in women. The diastolic BP increased from 72.1 mmHg mmHg at 30 years to 80 mmHg at 56 years in men and from 64.7 mmHg at 30 years to 74.6 mmHg at 64 years but decreased after the peak. The prevalence rate of hypertension increased linearly with age; the rates at the age of 60 years were 51.8% for men and 39.5% for women. The antihypertensive treatment rate increased with age but was less than 50% before 50 years.Conclusions: Systolic BP increased linearly with age. There was an inverse-U shaped age-related trend in diastolic BP and the time of the peak in women was approximately ten years later than that in men. The present findings also suggest that the antihypertensive treatment rate in young adults should be enhanced.

Abstract Background The average birth weight in Japan has decreased by 200 g in the last 40 years. Only three studies were reported for the association between maternal dietary patterns and birth weight in East Asia, whose results were inconsistent. We examined what maternal dietary patterns were associated with the birth weight in Japan. Methods Totally 22,493 pregnant women were recruited between July 2013 and September 2016 into the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. We included 17,287 women who had a full-term single healthy baby into the analysis. Consumption of food and beverage items was evaluated based on food frequency questionnaire at the first-trimester. Dietary patterns were analyzed using a machine learning method of k-means clustering algorithm. Birth weight was obtained from the medical record. The association between dietary patterns and birth weight was analyzed using multiple liner regression model adjusted for potential confounders with multiple imputation method for missing values. Results Dietary patterns were classified into seven groups by cluster analysis: “high in rice (reference) (n = 8046)”, “middle in vegetables, beans, mushrooms, seaweeds and miso-soup (n = 4842)”, “high in fruits (n = 1176)”, “high in bread, dairy and alcohol (n = 1091)”, “high in meat and fish (n = 1049)”, “high in coffee, black tea, soft drinks and confections (high in coffee) (n = 585)”, and “high in vegetables, beans, mushrooms, seaweeds and miso-soup (n = 498)” groups. In multiple liner regression models, birth weight was 22.6 g (95%CI: 0.1 to 45.2 g) heavier in “high in fruits” group than in reference group and 39.4 g (95%CI: 8.6 to 70.3 g) lighter in “high in coffee” group than in reference group. The other groups were not statistically significant. Conclusions High consumption of fruits and high consumption of coffee, black tea, soft drinks and confections during early pregnancy were associated with increased and decreased birth weight, respectively. Key messages We found maternal dietary patterns during early pregnancy using a machine learning method of k-means clustering algorithm. We found maternal dietary patterns which associated with the birth weight in Japan.

Convection under the due northward interplanetary magnetic field (IMF) is reproduced by the global simulation. The resulting magnetosphere is closed except in the XZ plane and separated from the solar wind by the separatrix generated from cusp nulls. Inside the separatrix, there exist three plasma regimes of the cusp high-pressure region, the low-latitude boundary layer (LLBL) and the plasma sheet. In the ionosphere, the northward Bz (NBZ) current and the reverse cell occur in higher latitudes than 80 degrees, and the fun-shaped arc-like field-aligned current and the main oval occur in lower latitudes than 80 degrees. Magnetic field lines in the antisunward flow region of the reverse cell are connected to the LLBL that is accelerated to supersonic flow by the cusp pressure. Circulation on the reverse cell in the ionosphere is as a whole constructed to the interchange cycle in the magnetosphere. Convection is looked upon as the process to discharge stress generated by the dayside cusp reconnection. Magnetic stress generated by the reconnection is first converted to thermal energy in the cusp. This thermal energy is drained through three possible routes: release of plasma downtail through the LLBL, dissipation as electromagnetic energy through formation of the dynamo, and evacuation down to the ionosphere through the plasma sheet.

The High Frequency Analyzer (HFA) is a subsystem of the Plasma Wave Experiment onboard the Arase (ERG) space-craft. The main purposes of the HFA include (1) determining the electron number density around the spacecraft from observations of upper hybrid resonance (UHR) waves, (2) measuring the electromagnetic field component of whistler-mode chorus in a frequency range above 20 kHz, and (3) observing radio and plasma waves excited in the storm-time magnetosphere. Two components of AC electric fields detected by Wire Probe Antenna and one component of AC magnetic fields detected by Magnetic Search Coils are fed to the HFA. By applying analog and digital signal processing in the HFA, the spectrograms of two electric fields (EE mode) or one electric field and one magnetic field (EB mode) in a frequency range from 10 kHz to 10 MHz are obtained at an interval of 8 s. For the observation of plasmapause, the HFA can also be operated in PP (plasmapause) mode, in which spectrograms of one electric field component below 1 MHz are obtained at an interval of 1 s. In the initial HFA operations from January to July, 2017, the following results are obtained: (1) UHR waves, auroral kilometric radiation (AKR), whistler-mode chorus, electrostatic electron cyclotron harmonic waves, and nonthermal terrestrial continuum radiation were observed by the HFA in geomagnetically quiet and disturbed conditions. (2) In the test operations of the polarization observations on June 10, 2017, the fundamental R-X and L-O mode AKR and the second-harmonic R-X mode AKR from different sources in the northern polar region were observed. (3) The semiautomatic UHR frequency identification by the computer and a human operator was applied to the HFA spectrograms. In the identification by the computer, we used an algorithm for narrowing down the candidates of UHR frequency by checking intensity and bandwidth. Then, the identified UHR frequency by the computer was checked and corrected if needed by the human operator. Electron number density derived from the determined UHR frequency will be useful for the investigation of the storm-time evolution of the plasmasphere and topside ionosphere.

We report the current status of small-telescope activities and the 1.8-m aperture telescope PLANETS project at Haleakala dedicated to planetary and exoplanetary observations. Continuous monitoring is essential to understand the planetary atmospheric phenomena, and therefore, own facilities with even small-and medium sized telescopes and instruments are important. On the summit of Mt. Haleakala, Hawaii, we are operating a 40 cm (T40) and 60 cm (T60) telescopes for measuring faint atmospheric features such as Io torus, Mercury, and so on. It has uniquely provided long-term Io torus activities for more than ten years. T60 is now observing planetary atmospheres in visible and infrared ranges. The polarization imager DIPOL-2 is also installed to measure the weak polarization of exoplanetary light. In addition, we are carrying out a 1.8-m off-axis telescope project PLANETS at Haleakala. This project is managed by the PLANETS Foundation (www.planets.life) is an international collaboration of several institutes from Japan, USA, Germany, Brazil, and France. This off-axis optical system enables very low-stray light contamination and high-contrast in data, i.e., "high dynamic range". It will achieve unrivaled scientific capabilities on coronagraphy and polarimetry, aimed at detecting exoplanet reflected light and tenuous planetary exo-notsign atmospheres in the Solar system. The main mirror is Clearceram Z-HS with a diameter of 1850 mm, which is now on the final polishing process. We completed the telescope design and wind analysis of the mechanical support and tracking. The "split-ring" mount is so stiff that it has a first vibration mode above 50 Hz.

Abstract Recent studies suggest that electrons with energies up to several hundred keV precipitate into the atmosphere associated with pulsating aurora (PsA). It is debated the highest energy of precipitating electrons associated with PsA. Here we report for the first time that the energy extends to relativistic energies. PsA was observed by THEMIS all‐sky imagers during a substorm that occurred on 27 March 2017. Energetic electron precipitation was detected by very low frequency subionospheric propagation. We found similar time variations between the auroral intensity and perturbation of the received radio signal intensity when the PsA occurred on the radio path. The perturbation showed a short recovery time of ~2 s. The recovery time indicates relaxation from ionospheric modification due to energetic electron precipitation and depends on the stopping altitude of the electrons. The recovery time required a stopping altitude of 50–60 km and indicates that the PsA is accompanied by relativistic electron precipitation.

To understand the magnetosphere‐ionosphere (M‐I) disturbances, it is necessary to know the change in the null‐separator structure along with the development of convection. The present paper explains this proposition by taking the case of the theta aurora that occurs after the switch of interplanetary magnetic field By and reveals auroral development inside the polar cap. The interplanetary magnetic field change is followed by the reformation of the null‐separator structure to cause a convection transient and a successive deformation of separatrices inside the magnetosphere, where separatrices separate the space into different volumes that include different types of magnetic field lines, and intersections of separatrices form separators that connect nulls. By the reconnection on the separator, energy inflow occurs from the solar wind to the magnetosphere. Convection driven by this energy transports nulls. In the case of theta aurora, two new nulls on the dayside coexist with two old nulls carried toward the tail by convection. Each set of nulls generates two open‐closed boundaries (separatrices) bounded by separators. Thus, open‐closed boundaries are divide into four parts. Separatrices generated by different sets partially become side by side near the nightside stem limes. The theta aurora is generated at the area corresponding to the low‐latitude side with respect to both of two boundaries. Thus, the occurrence of the theta aurora is a natural consequence of a transition in the null‐separator structure. The present example indicates that the global structure of the magnetosphere is almost decided from the skeleton of nulls.