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For a closed, connected, and oriented 3-manifold with a non-singular flow, we construct its virtual knot diagram via a “flow-spine” of the manifold. Then, we introduce a coloring invariant of 3-manifolds through their virtual knot diagrams, and classify some 3-manifolds by using the invariant.

Background Recent studies suggest potential roles of immune response in the pathophysiology of epilepsy. Anti-seizure medications (ASMs) are known to have side effects of drug eruption caused by immune responses. A few reports in adults have demonstrated disappearance of seizures after an ASM drug eruption episode. In this paper, we described 2 cases of childhood absence epilepsy (CAE) who showed seizure disappearance after ethosuximide (ESM) drug eruption, suggesting the possibility that the epilepsy disappears due to immune responses to ASM. Case presentation Case 1 was an 8-year-old girl diagnosed with CAE. She was treated with valproate acid (VPA) initially, and then ESM was administered as an additional treatment. Her epileptic seizure disappeared 4 days after initiation of ESM. However, drug eruption appeared 1 week after the administration of ESM. Even after discontinuation of ESM administration, she maintains no seizure after the drug eruption. Case 2 was a 5-year-old boy diagnosed as CAE. He was treated with VPA initially, and ESM was administered additionally. Drug eruption appeared 1 month after the administration of ESM. Even after ESM was terminated, he maintained seizure freedom after the appearance of eruption. Conclusions Epileptic seizures may have been suppressed due to the immune responses caused by ASM eruption. Further studies are needed to elucidate the pathophysiologic effects of drug eruption on epilepsy through immune responses.

Background Transient periictal MRI abnormalities (TPMA) are caused by seizures, and may completely or partially reverse within a few days following seizure. Although TPMA are usually observed in patients with status epilepticus (SE), they have also been rarely reported after isolated/recurrent seizures not fulfilling the criteria for SE. Herein, we present a case of a 1-year-old girl with TPMA. Case A 1-year-old girl with Apert syndrome and epilepsy showed MRI abnormalities in the cortico-subcortical areas of the left temporal, occipital and parietal lobes, as well as the left thalamus. These abnormalities showed as a hyperintense signal on diffusion-weighted imaging and a hypointense signal on apparent-diffusion coefficient maps. On follow-up MRI after 3 days, the abnormal signals were completely reversed. We confirmed TPMA after eliminating other possibilities. When treatment was withdrawn, the patient regained consciousness immediately and did not show any abnormality on subsequent MRI. Conclusion TPMA may occur in young children; recognizing this possibility is important for making the diagnosis and conducting appropriate treatment. As a previous study revealed, the distribution of signal changes in cortico-subcortical areas and the ipsilateral thalamus may be a characteristic feature of TPMA.

Paroxysmal abnormal eye movement in early infancy is one of the initial symptoms of glucose transporter 1 deficiency syndrome (GLUT1DS). We describe four early infants with transient hypoglycorrhachia presenting with abnormal eye movements. Their symptoms disappeared after the introduction of a ketogenic diet (KD), and their development was normal. Since no variants in SLC2A1 were detected, the CSF-to-blood glucose ratios (C/B) were re-examined, and within normal range. None of the four patients displayed recurrent symptoms after withdrawal from the KD. Because long-term KD has potential adverse effects and could affect the quality of life of patients and their families, re-examination of CSF glucose during late infancy should be considered in the case of absence of the SLC2A1 pathogenic variant.

Non-puddling rice cultivation would increase subsequent soybean yield. Soybean (cv. ‘Yukihomare’) was grown in farmers’ fields previously cultivated with puddled transplanted rice (Puddled Rice), non-puddled transplanted rice (Non-puddled Rice), and dry direct-seeded rice (Direct-seeded Rice) in central Hokkaido, Japan. Average soybean yield was significantly (p

Estimating arbuscular mycorrhizal (AM) fungal activity to colonize crop root before cultivation is prerequisite for effective utilization of their functions which enhance growth and yield of the plant especially under low fertilizer input. We have hypothesized that the infection unit (IU) density formed on test plant roots grown for short period (12 days) with soil sampled from soybean production fields would be an effective indicator to predict AM fungal colonization intensity to the plant. In order to test this hypothesis, three-year farmland survey was conducted, in which soil samples before sowing soybean and the plant root samples at third trifoliate (V3) and full bloom (R2) stage were collected from farmers’ fields in two regions in Hokkaido, Iwamizawa and Tokachi. For each sampling spot, IU density was determined by using test plants, and intensity of AM fungal colonization of soybean root was measured. Before pursuing field survey, laboratory experiments were conducted to find out proper soil storage condition that keeps IU density unchanged while handling many soil samples. Our results indicated that IU density was almost comparable to the original value after six-month storage if soil samples were kept in a refrigerator, although storing at ambient temperature significantly decreased the measurement. Air drying also had negative impact on IU density. According to the field survey, IU densities determined using field soil were positively and significantly correlated with AM fungal colonization of soybean roots at both V3 and R2 stages. Differences in climate, soil type, and style of agriculture between Iwamizawa and Tokachi seemed to have little effect on IU density-AM fungal colonization relationship. Other than IU density, soil pH and soil penetration resistance at 10 cm depth were selected as significant explanatory variables for predicting AM fungal colonization by multiple regression analysis. However, IU density was the most influential factor among three. Therefore, IU density is recognized as an effective measure to evaluate AM fungal colonizing activity in field soil.

Accepted: 2019-04-28, 資料番号: SA1190017000

Objective To clarify the incidence and risk factors of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in pediatric patients with febrile status epilepticus (FSE). Methods We retrospectively surveyed patients with FSE (≥20 min and ≥40 min) who were younger than 6 years by mailing a questionnaire to 1123 hospitals in Japan. The survey period was 2 years. We then collected clinical data on patients with prolonged febrile seizures (PFS) ≥40 min and those with AESD, and compared clinical data between the PFS and AESD groups. Results The response rate for the primary survey was 42.3%, and 28.0% of hospitals which had applicable cases responded in the secondary survey. The incidence of AESD was 4.3% in patients with FSE ≥20 min and 7.1% in those with FSE ≥40 min. In the second survey, a total of 548 patients had FSE ≥40 min (AESD group, n = 93; PFS group, n = 455). Univariate analysis revealed significant between-group differences in pH, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase, NH3, procalcitonin (PCT), uric acid, blood urea nitrogen, creatinine (Cr), and lactate. Multivariate analysis using stratified values showed that high PCT was an only risk factor for AESD. A prediction score of ≥3 was indicative of AESD, as determined using the following indexes: HCO3− Conclusion Incidence data and prediction scores for AESD will be useful for future intervention trials for AESD.

We have performed a statistical data analysis on relationship between simultaneous Na density data and cosmic noise absorption (CNA) data, which is an indicator for energetic particle precipitation, obtained at Syowa, Antarctic in 2000–2002. It is found that the Na densities around the topside of Na layers (above $$\sim 95 \,\hbox {km}$$ ∼ 95 km height) tended to be smaller when the CNA was larger. The amounts of Na density responses, i.e., Na density decrease or Na loss, were increasing with magnetic local time (MLT) from dusk hours to dawn hours, and those of CNA responses, i.e., CNA increase, were also increasing with MLT. Thus, there were clear negative correlations between the Na density and CNA variations. These results indicate that the Na loss around the topside of Na layer would be induced by the energetic particle precipitation, and its effect would be more severe in dawn hours.

Aluminum (Al)-tolerant tobacco cell line ALT301 derived from SL (wild-type) hardly exhibits Al-triggered reactive oxygen species (ROS) compared with SL. Molecular mechanism leading to this phenotype was investigated comparatively with SL. Under normal growth condition, metabolome data suggested the activation of glycolysis and lactate fermentation but the repression of the tricarboxylic acid (TCA) cycle in ALT301, namely aerobic fermentation, which seemed to be transcriptionally controlled partly by higher expression of genes encoding lactate dehydrogenase and pyruvate dehydrogenase kinase. Microarray and gene ontology analyses revealed the upregulation of the gene encoding related to APETALA2.3 (RAP2.3)-like protein, one of the group VII ethylene response factors (ERFVIIs), in ALT301. ERFVII transcription factors are known to be key regulators for hypoxia response that promotes substrate-level ATP production by glycolysis and fermentation. ERFVIIs are degraded under normoxia by the N-end rule pathway of proteolysis depending on both oxygen and nitric oxide (NO), and NO is produced mainly by nitrate reductase (NR) in plants. In ALT301, levels of the NR gene expression (NIA2), NR activity and NO production were all lower compared with SL. Consistently, the known effects of NO on respiratory pathways were also repressed in ALT301. Under Al-treatment condition, NO level increased in both lines but was lower in ALT301. These results suggest that the upregulation of the RAP2.3-like gene and the downregulation of the NIA2 gene and resultant NO depletion in ALT301 coordinately enhance aerobic fermentation, which seems to be related to a higher capacity to prevent ROS production in mitochondria under Al stress.

A mountain wave with a significant brightness temperature amplitude and ~500 km horizontal wavelength was observed over the Andes on 24–25 July 2017 in Atmospheric Infrared Sounder (AIRS)/Aqua satellite data. In the Modern‐Era Retrospective Analysis for Research and Applications, version 2 (MERRA‐2), reanalysis data, the intense eastward wind flowed over the Andes. Visible/Infrared Imaging Radiometer Suite (VIIRS)/Suomi‐NPP (National Polar‐orbiting Partnership) did not detect the mountain waves; however, it observed concentric ring‐like waves in the nightglow emissions at ~87 km with ~100 km wavelengths on the same night over and leeward of the Southern Andes. A ray tracing analysis showed that the mountain waves propagated to the east of the Andes, where concentric ring‐like waves appeared above a region of mountain wave breaking. Therefore, the concentric ring‐like waves were likely secondary waves generated by momentum deposition that accompanied mountain wave breaking. These results provide the first direct evidence for secondary gravity waves generated by momentum deposition.

We analyzed OH airglow images observed from an all-sky camera at King Sejong Station, Antarctica for the period of 2012–2016. Using M-transform method, 2D-power spectra of short period waves ...

Subacute combined degeneration of the spinal cord (SACD) is a rare neurologic disorder manifesting progressive symptoms of paresthesia and spastic paralysis. Herein we present an autopsy case of SACD caused by folic acid and copper deficiency. A 16-year-old male presented with gradually worsening unsteady gait, and bladder and rectal dysfunction. He had a medical history of T-cell acute lymphoblastic leukemia (T-ALL), diagnosed 1.5 years previously. The patient had undergone chemotherapy, including methotrexate, as well as allogeneic bone mallow transplantation. Laboratory tests revealed normal vitamin B12 and methylmalonic acid concentration, but reduced serum copper, ceruloplasmin and folic acid concentrations. Magnetic resonance imaging revealed symmetrical T2 signal hyperintensities in the posterior and lateral spinal cord. The patient was treated with oral copper, oral folate, and intravenous vitamin B12. A month after this treatment, the patient’s symptoms were unchanged, and 2 months later he died of acute adrenal insufficiency. The pathological findings of the spinal cord were compatible with SACD. Because SACD is usually reversible with early treatment, it should be suspected in high-risk patients undergoing chemotherapy or those who are malnourished with characteristic symptoms of SACD, even in young patients.

Moyamoya disease (MMD) is characterized by progressive bilateral stenotic changes in the terminal portion of the internal carotid arteries. Although RNF213 was identified as a susceptibility gene for MMD, the exact pathogenesis remains unknown. Immunohistochemical analysis of autopsy specimens from a patient with MMD revealed marked accumulation of hyaluronan and chondroitin sulfate (CS) in the thickened intima of occlusive lesions of MMD. Hyaluronan synthase 2 was strongly expressed in endothelial progenitor cells in the thickened intima. Furthermore, MMD lesions showed minimal staining for CS and hyaluronan in the endothelium, in contrast to control endothelium showing positive staining for both. Glycosaminoglycans of endothelial cells derived from MMD and control induced pluripotent stem cells demonstrated a decreased amount of CS, especially sulfated CS, in MMD. A computational fluid dynamics model showed highest wall shear stress values in the terminal portion of the internal carotid artery, which is the predisposing region in MMD. Because the peri-endothelial extracellular matrix plays an important role in protection, cell adhesion and migration, an altered peri-endothelial matrix in MMD may contribute to endothelial vulnerability to wall shear stress. Invading endothelial progenitor cells repairing endothelial injury would produce excessive hyaluronan and CS in the intima, and cause vascular stenosis.

We have studied atmospheric gravity waves (AGWs) and nighttime medium‐scale traveling ionospheric disturbances (MSTIDs) by applying three‐dimensional spectral analysis technique to 557.7‐ and 630.0‐nm airglow images at Shigaraki (SGK) (35°N, 136°E, 1999–2017) and Rikubetsu (RIK) (44°N, 144°E, 1999–2017), Japan, Athabasca (ATH), Canada, (55°N, 247°E, 2005–2017), and Magadan (MGD), Russia (60°N, 151°E, 2008–2017), focusing on their horizontal wavenumber spectra. For the AGWs in 557.7‐nm images, the power spectra in summer are stronger than in other seasons, probably due to stronger tropospheric convection. The highest energy content of the waves are mostly at wavelengths between 20 and 300 km at MGD, ATH, and RIK, while it is above 200 km at SGK. The largest power spectral density is obtained at RIK at wavelengths of 30–100 km and then ATH. The slopes of the horizontal wavenumber spectra varies from −2.77 to −3.22. From the MSTIDs in 630.0‐nm images, the power spectra in summer at RIK and SGK are stronger than those in other seasons regardless of solar activity. The power spectra in solar quiet time are stronger than those in solar active time at all four stations. These features can be explained by the Perkins instability with coupling between sporadic E and F layers. The spectral slope decreases with increasing latitudes. Weak positive correlations were obtained between the daily wave power of AGWs in 557.7‐nm images and MSTIDs in 630.0‐nm images, suggesting that the MSTIDs in the thermosphere may be partially generated by the AGWs from the mesopause region.

We provide an initial report on polar mesospheric cloud (PMC) observations by the Japanese Geostationary Earth Orbit (GEO) meteorological satellite Himawari-8. Heights of the observed PMCs were estimated to be 80–82 km. Observed PMCs were active only during summertime in both the northern and southern polar regions. These observations are consistent with known PMC behavior. From its almost fixed location relative to the Earth, Himawari-8 is capable of continuously monitoring PMC every 10 min with three visible bands: blue (0.47 µm), green (0.51 µm), and red (0.64 µm). Thus, Himawari-8 can contribute to PMC research in the near future.

It is known that the pass move is not an unknotting operation in classical knot theory. In this paper, we prove that the pass move is an unknotting operation in welded knot theory.

Dust impact detection by electric field instruments is a relatively new method. However, the influence of dust impacts on electric field measurements is not completely understood and explained. A b ...

Simultaneous observation of gravity waves (GWs) in the polar summer mesosphere over Syowa (69°S, 39°E) by a ground-based radar and satellite instrument are presented. On 21 January 2016, at 2.3 UT, the CIPS instrument on the AIM satellite observed Polar Mesospheric Clouds (PMCs) with GW structures over Syowa. The orientation of the wave crests suggests north-west propagation direction. A periodogram analysis indicates GWs with horizontal wavelengths of 105 ± 5 and 60 ± 5 km. Cross-spectral analysis of the PANSY radar horizontal wind components at the same time, location, and altitude indicate two dominant waves with apparent periods of 15 and 9 h, with respective horizontal wavelengths of 100 ± 5 km and 302 ± 130 km. At the PMC altitude of ∼83 km, the mean zonal component of the vertical momentum flux spectra of the observed GWs is westward and the meridional component is northward. The comparable horizontal wavelengths of the 15 h wave observed by PANSY radar and the CIPS instrument, along with the agreement between the direction of vertical flux of horizontal momentum from PANSY, the propagation direction estimated from the cross-spectral analysis, and the orientation of the wave crests from CIPS i.e. north-west propagation direction suggests that the same wave is observed by both instruments. This simultaneous observation of the same wave by CIPS and PANSY radar provide a distinctive view of both the horizontal and vertical extent of a GW in the Antarctic summer mesosphere.

We have obtained horizontal phase velocity distributions of the gravity waves around 90 km from four Antarctic airglow imagers, which belong to an international airglow imager/instrument network known as ANGWIN (Antarctic Gravity Wave Instrument Network). Results from the airglow imagers at Syowa (69°S, 40°E), Halley (76°S, 27°W), Davis (69°S, 78°E), and McMurdo (78°S, 167°E) were compared, using a new statistical analysis method based on 3-D Fourier transform (Matsuda et al., 2014) for the observation period between 7 April and 21 May 2013. Significant day-to-day and site-to-site differences were found. The averaged phase velocity spectrum during the observation period showed preferential westward direction at Syowa, McMurdo, and Halley, but no preferential direction at Davis. Gravity wave energy estimated by I'/I was ~5 times larger at Davis and Syowa than at McMurdo and Halley. We also compared the phase velocity spectrum at Syowa and Davis with the background wind field and found that the directionality only over Syowa could be explained by critical level filtering of the waves. This suggests that the eastward propagating gravity waves over Davis could have been generated above the polar night jet. Comparison of nighttime variations of the phase velocity spectra with background wind measurements suggested that the effect of critical level filtering could not explain the temporal variation of gravity wave directionality well, and other reasons such as variation of wave sources should be taken into account. Directionality was determined to be dependent on the gravity wave periods. ©2017. The Authors.

The potential energy of gravity waves (GWs) per unit mass (Ep), at altitudes of 15–70 km, has been examined from temperature profiles obtained by a Rayleigh/Raman (RR) lidar at Syowa Station (69°S, 40°E) from May 2011 to October 2013, with the exception of the summer months. The GWs with ground-based wave periods longer than 2 h and vertical wavelengths between 1.8 and 16 km were extracted from the temperature profiles. Ep was larger in winter than in spring and fall, although in 2012, at altitudes below 30 km, Ep was larger in spring than in winter and fall. Ep increased with a mean scale height of 11.3 km. Ep profiles showed a local maximum at an altitude of 20 km and a minimum at 25 km in almost every month, which has not been reported by previous studies observed by radiosondes. The values of Ep in October of 2012 were smaller at 35–60 km and larger at 20–35 km than those in October of 2011 and 2013. This difference in the Ep profile is most probably caused by different seasonal variations of zonal winds. The larger and smaller Ep values seem to be observed both below and above the altitude at which the zonal wind speed reached 0 m s-1. This result suggests that wind filtering of gravity waves with small phase speeds is significantly important in early spring.

We analyzed the horizontal phase velocity of gravity waves and medium-scale traveling ionospheric disturbances (MSTIDs) by using the three-dimensional fast Fourier transform method developed by Matsuda et al. [2014] for 557.7-nm (altitude: 90–100 km) and 630.0-nm (altitude: 200–300 km) airglow images obtained at Shigaraki MU Observatory (34.8∘N, 136.1∘E, dip angle: 49∘) over ∼16 years from 16 March 1999 to 20 February 2015. The analysis of 557.7-nm airglow images shows clear seasonal variation of the propagation direction of gravity waves in the mesopause region. In spring, summer, fall, and winter, the peak directions are northeastward, northeastward, northwestward, and southwestward, respectively. The difference in east-west propagation direction between summer and winter is probably caused by the wind filtering effect due to the zonal mesospheric jet. Comparison with tropospheric re-analysis data shows the difference in north-south propagation direction between summer and winter is caused by differences in the latitudinal location of wave sources due to convective activity in the troposphere relative to Shigaraki. The analysis of 630.0-nm airglow images shows that the propagation direction of MSTIDs is mainly southwestward with a minor northeastward component throughout the 16 years. A clear negative correlation is seen between the yearly power spectral density of MSTIDs and F10.7 solar flux. This negative correlation with solar activity may be explained by the linear growth rate of the Perkins instability and secondary wave generation of gravity waves in the thermosphere.

We have performed a statistical investigation of the global response of the Na layer to geomagnetic activity using Na density data from 2004 to 2010 obtained using the Optical Spectrograph and Infrared Imager System (OSIRIS) on board the Odin satellite. In the analysis, we categorized the Na density data according to the auroral electrojet (AE) index, and then compared the resulting datasets. Regarding the results, we found a significant decrease in the Na density above a height of ∼95 km in both the southern and northern polar regions with an increase in the AE index. The cause of the decrease in the Na density is discussed, and we conclude that the decrease in the Na density was mainly due to the effect of energetic particle precipitation.

The global gravity wave (GW) potential energy (PE) per unit mass is derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperatures profiles over the past 14 years (2002-2015). Since the SABER data cover longer than one solar cycle, multivariate linear regression is applied to calculate the trend (means linear trend from 2002 to 2015) of global GW PE and the responses of global GW PE to solar activity, to QBO (quasi-biennial oscillation) and to ENSO (El Nino-Southern Oscillation). We find a significant positive trend of GW PE at around 50°N during July from 2002 to 2015, in agreement with ground-based radar observations at a similar latitude but from 1990 to 2010. Both the monthly and the deseasonalized trends of GW PE are significant near 50°S. Specifically, the deseasonalized trend of GW PE has a positive peak of 12-15% per decade at 40°S-50°S and below 60 km, which suggests that eddy diffusion is increasing in some places. A significant positive trend of GW PE near 50°S could be due to the strengthening of the polar stratospheric jets, as documented from MERRA (Modern Era Retrospective-analysis for Research and Applications) wind data. The response of GW PE to solar activity is negative in the lower and middle latitudes. The response of GW PE to QBO (as indicated by 30 hPa zonal winds over the equator) is negative in the tropical upper stratosphere and extends to higher latitudes at higher altitudes. The response of GW PE to ENSO (as indicated by the MEI index) is positive in the tropical upper stratosphere.

For an effectively n-colorable link L, C n ⁎ ( L ) stands for the minimum number of distinct colors used over all effective n-colorings of L. It is known that C n ⁎ ( L ) ≥ 1 + log 2 ⁡ n for any effectively n-colorable link L with non-zero determinant. The aim of this paper is to prove that C 6 ⁎ ( L ) = 4 and C 8 ⁎ ( L ) = 5 for any effectively 6- and 8-colorable link L, respectively. For ribbon 2-links, we prove the same equalities for n = 6 and 8, and C 13 ⁎ ( L ) = 5 for n = 13 .

A scheme is suggested and tested for forecasting severe space weather (SvSW) using solar wind velocity (V) and the north-south component (Bz) of the interplanetary magnetic field (IMF) measured using the ACE (Advanced Composition Explorer) satellite from 1998 to 2016. SvSW has caused all known electric power outages and telegraph system failures. Earlier SvSW events such as the Carrington event of 1859, Quebec event of 1989 and an event in 1958 are included with information from the literature. Dst storms are used as references to identify 89 major space weather events (DstMin ≤ -100 nT) in 1998-2016. The coincidence of high CME front (or CME shock) velocity ΔV (sudden increase in V over the background by over 275 km/s) and sufficiently large Bz southward at the time of the ΔV increase is associated with SvSW; and their product (ΔV x Bz) is found to exhibit a large negative spike at the speed increase. Such a product (ΔV x Bz) exceeding a threshold seems suitable for forecasting SvSW. However, the coincidence of high V (not containing ΔV) and large Bz southward does not correspond to SvSW, indicating the importance of the impulsive action of large Bz southward and high ΔV coming through when they coincide. The need for the coincidence is verified using the CRCM (Comprehensive Ring Current Model) model, that produces extreme Dst storms (

Small-scale ripple structures observed in OH airglow images are most likely induced by either dynamic instability due to large wind shear or convective instability due to superadiabatic lapse rate. Using the data set taken in the mesopause region with an OH all-sky imager at Yucca Ridge Field Station, Colorado (40.7°N, 104.9°W), from September 2003 to December 2005, we study the characteristics and seasonal variations of ripple structures. By analyzing the simultaneous background wind and temperature observed by the nearby sodium temperature/wind lidar at Fort Collins, Colorado (40.6°N, 105°W), and a nearby medium-frequency radar at Platteville, Colorado (40.2°N, 105.8°W), we are able to statistically study the possible relation between ripples and the background atmosphere conditions. Characteristics and seasonal variations of ripples are presented in detail in this study. The occurrence frequency of ripples exhibits clear seasonal variability, with peak in autumn. The occurrence of ripples shows a local time dependence, which is most likely associated with the solar tides. The lifetime and spatial scale of these ripples are typically 5–20 min and 5–10 km, respectively, and most of the ripples move preferentially either southward or northward. However, more than half of the observed ripples do not advect with background flow; they have higher Richardson numbers than those ripples that advect with background flow. It is possible that they are not instability features but wave structures that are hard to be distinguished from the real instability features.

Great magnetic storms are recorded as aurora sightings in historical documents. The earliest known example of “prolonged” aurora sightings, with aurora persistent for two or more nights within a seven-day interval at low latitudes, in Japan was documented on February 21-23, 1204 in Meigetsuki, when a big sunspot was also recorded in China. We have searched for prolonged events over the 600-year interval since 620 in Japan based on the catalogue of Kanda (1933), and over the 700-year interval since 581 in China based on the catalogues of Tamazawa et al. (2017) and Hayakawa et al. (2015). Before the Meigetsuki event, a significant fraction of the 200 possible aurora sightings in Song dynasty (960-1279) of China was detected at least twice within a seven-day interval and sometimes recurred with approximately the solar rotation period of 27 days. The majority of prolonged aurora activity events occurred around the maximum phase of solar cycles rather than around the minimum, as estimated from the 14C analysis of tree rings. They were not reported during the Oort Minimum (1010-1050). We hypothesize that the prolonged aurora sightings are associated with great magnetic storms resulting from multiple coronal mass ejections from the same active region. The historical documents therefore provide useful information to support estimation of great magnetic storm frequency, which are often associated with power outages and other societal concerns.

Radar and optical simultaneous observations of meteors are important to understand the size distribution of the interplanetary dust. However, faint meteors detected by high power large aperture radar observations, which are typically as faint as 10 mag. in optical, have not been detected until recently in optical observations, mainly due to insufficient sensitivity of the optical observations. In this paper, two radar and optical simultaneous observations were organized. The first observation was carried out in 2009 to 2010 using Middle and Upper Atmosphere Radar (MU radar) and an image-intensified CCD camera. The second observation was carried out in 2018 using the MU radar and a mosaic CMOS camera, Tomo-e Gozen, mounted on the 1.05-m Kiso Schmidt Telescope. In total, 331 simultaneous meteors were detected. The relationship between radar cross sections and optical V-band magnitudes was well approximated by a linear function. A transformation function from the radar cross section to the V-band magnitude was derived for sporadic meteors. The transformation function was applied to about 150,000 meteors detected by the MU radar in 2009--2015, large part of which are sporadic, and a luminosity function was derived in the magnitude range of $-1.5$ to $9.5$ mag. The luminosity function was well approximated by a single power-law function with the population index of $r = 3.52{\pm}0.12$. The present observation indicates that the MU radar has capability to detect interplanetary dust of $10^{-5}$ to $10^{0}$ g in mass as meteors., Comment: Accepted for publication in Planetary & Space Science. 20 pages, 8 figures

Background: IgG4-related disease (IgG4-RD) is characterized by elevated serum IgG4 and tissue infiltration by IgG4-positive plasma cells. The pathogenesis of this disease is not clear. Transcriptom...

A joint special issue explores the potential of collaboration to help understand atmospheric gravity waves in the Polar Regions and their effect on global circulation.

Aluminum (Al)-tolerant tobacco cell line ALT301 derived from SL (wild-type) hardly exhibits Al-triggered reactive oxygen species (ROS) compared with SL. Molecular mechanism leading to this phenotype was investigated comparatively with SL. Under normal growth condition, metabolome data suggested the activation of glycolysis and lactate fermentation but the repression of the tricarboxylic acid (TCA) cycle in ALT301, namely aerobic fermentation, which seemed to be transcriptionally controlled partly by higher expression of genes encoding lactate dehydrogenase and pyruvate dehydrogenase kinase. Microarray and gene ontology analyses revealed the upregulation of the gene encoding related to APETALA2.3 (RAP2.3)-like protein, one of the group VII ethylene response factors (ERFVIIs), in ALT301. ERFVII transcription factors are known to be key regulators for hypoxia response that promotes substrate-level ATP production by glycolysis and fermentation. ERFVIIs are degraded under normoxia by the N-end rule pathway of proteolysis depending on both oxygen and nitric oxide (NO), and NO is produced mainly by nitrate reductase (NR) in plants. In ALT301, levels of the NR gene expression (NIA2), NR activity and NO production were all lower compared with SL. Consistently, the known effects of NO on respiratory pathways were also repressed in ALT301. Under Al-treatment condition, NO level increased in both lines but was lower in ALT301. These results suggest that the upregulation of the RAP2.3-like gene and the downregulation of the NIA2 gene and resultant NO depletion in ALT301 coordinately enhance aerobic fermentation, which seems to be related to a higher capacity to prevent ROS production in mitochondria under Al stress.

We have constructed a scanning Raman lidar to observe the cross-sectional distribution of the water vapor mixing ratio and aerosols near the Earth's surface, which are difficult to observe when a conventional Raman lidar system is used. The Raman lidar is designed for a nighttime operating system by employing a ultra-violet (UV) laser source and can measure the water vapor mixing ratio at an altitude up to 7 km using vertically pointing observations. The scanning mirror system consists of reflective flat mirrors and a rotational stage. By using a program-controlled rotational stage, a vertical scan can be operated with a speed of 1.5°/s. The beam was pointed at 33 angles over range of 0–48° for the elevation angle with a constant step width of 1.5°. The range-height cross sections of the water vapor and aerosol within a 400 m range can be obtained for 25 min. The lidar signals at each direction were individually smoothed with the moving average to spread proportionally with the distance from the laser-emitting point. The averaged range at a distance of 200 m (400 m) from the lidar was 30.0 m (67.5 m) along the lidar signal in a specific direction. The experimental observations using the scanning lidar were conducted at night in the Shigaraki MU radar observatory located on a plateau with undulating topography and surrounded by forests. The root mean square error (RMSE) between the temporal variations of the water vapor mixing ratio by the scanning Raman lidar and by an in-situ weather sensor equipped with a tethered balloon was 0.17 g/kg at an altitude of 100 m. In cross-sectional measurements taken at altitudes and horizontal distances up to 400 m from the observatory, we found that the water vapor mixing ratio above and within the surface layer varied vertically and horizontally. The spatio-temporal variability of water vapor near the surface seemed to be sensitive to topographic variations as well as the wind field and the temperature gradient over the site. From the wide-range cross-sectional observations of the water vapor mixing ratio and the backscatter ratio of aerosols within a 2000 m range, we can detect small-scale water vapor structures on a horizontal scale of several hundred meters in the atmospheric boundary layer.

In this study, we determined the capacity of soybean (Glycine max L. Merr. cv. Hoyoharuka) and sorghum (Sorghum bicolor L. Moench. cv. Hybrid Sorgo) to utilize different forms of nitrogen (N) in a rhizobox system. Seedlings were grown for 35 days without N or with 130 mg N kg–1 soil as ammonium sulfate or farmyard cattle manure. The soil fractions at different distances from the root were sliced millimeter by millimeter in the rhizobox system. We assessed the distribution of different forms of N and microbial metabolism in different soil fractions in the rhizosphere. There are no treatment-dependent changes in biomass production in the roots and shoots of soybeans, however, the ammonium and manure treatment yielded 1.30 and 1.40 times higher shoot biomass of sorghum than the control. Moreover, the depletion of inorganic N and total amino acids (TAA) in the rhizosphere was largely undetectable at various distances from the soybean roots regardless of the treatments employed. The addition of ammonium sulfat...