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This multicentre, phase 2, randomized, controlled study of allogeneic haematopoietic stem cell transplantation (allo-HSCT) recipients compared the immunogenicity of two anti-pneumococcal vaccine regimens: four doses of 13-valent pneumococcal conjugate vaccine (PCV13) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) (3+1+1 experimental group), and three doses of PCV13 followed by PPSV23 (3+0+1 group).Allo-HSCT recipients without active graft-versus-host disease at enrolment were eligible. The primary endpoint was the IgG response rate (≥0.20 mg/mL) for all eight measured serotypes at 5 months after the PPSV23 booster.Seventy-two recipients were randomized, and seventy recipients who received over one PCV13 dose were analysed. The mean ages were 47.2 years (standard deviation, 14.4) in the 3+1+1 group (n = 35) and 49.0 years (standard deviation, 14.3) in the 3+0+1 group (n = 35). There was no significant difference in the overall IgG response rate at 5 months after the PPSV23 booster between the 3+1+1 and 3+0+1 groups (100% (26/26) vs. 93% (27/29), respectively, relative risk (RR): 1.07; 95% confidence interval (CI): 0.97-1.19). This rate was high immediately before the PPSV23 booster in the 3+1+1 group (100% (26/26) compared with 81% (21/26), respectively, RR: 1.24; 95% CI: 1.03-1.49), but this difference disappeared 1 month after the PPSV23 booster (100% (26/26) vs. 97% (28/29), respectively, RR: 1.04; 95% CI; 0.97-1.11). No serious adverse events leading to study dropout occurred.We were not able to determine the efficacy of the experimental arm based on the IgG response rate at 5 months after the PPSV23 booster in allo-HSCT recipients.

The purpose of this study was to investigate Karnofsky performance status (KPS) scores and visual analogue scale (VAS) scores to explain which domains in the standardized self-reported quality of life (QOL) are instrumental for long-term hematopoietic stem cell transplantation (HSCT) survivors. We conducted a nationwide cross-sectional questionnaire study on 221 survivors with allogeneic-HSCT in 28 pediatric centers. Patient-reported QOL was assessed at a single time point using the 36-item Short-Form Survey (SF-36), the Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT), and VAS scores. KPS scores were significantly correlated with both physical and role component summary scores of the SF-36, while the VAS provided by the patient (VASpt) was significantly correlated with the mental component summary score of the SF-36 and many subscales of the FACT-BMT. The VAS provided by the participants' attending physician (VASdoc) was correlated well with KPS scores. A VASpt score more than 40% lower than KPS scores suggested mental health problems. In conclusion, KPS scores might be considered as an indicator for physical and role/social components and VASpt score as an indicator for mental components and HSCT-specific QOL.

The theory of special relativity has reexamined and reconstructed the concepts of space and time, which are indispensable for describing physical laws, consequently instigating a major revolution in physics in general. Although the correctness of the special theory of relativity has been con-firmed by many observations and experiments, it is unclear why the "principle of relativity" and the "principle of the constant speed of light," which form the basis of the idea, are valid. Moreo-ver, although special relativity has advanced our understanding of time, our understanding of the fundamental question, "What is time?" is still limited. The theory of special relativity regards space as a four-dimensional construct consisting of one-dimensional time and three-dimensional space. This paper proposes an alternative framework, wherein real space is uniform and isotropic four-dimensional space, and elementary particles are waves that propagate through this four-dimensional space at a constant speed. This new perspective provides evidence to support two of Einstein’s key principles—the "principle of relativity" and the "principle of the constant speed of light." Furthermore, this model clarifies what time is and why time flows at a constant rate from the past to the future.

The formation of massive stars in dense and cold molecular clouds is a fundamental problem in star formation. In this work, we studied three compact massive star-forming regions, M8E, RAFGL 6366S, and IRAS 18317−0513, to investigate the environment of massive star formation, specifically the possibility of a local feedback process. Our new mid-infrared observations using miniTAO/MAX38 at 31 and 37 μm resolved individual objects in each region and allowed us to obtain their individual luminosities and masses. Together with existence/absence of ultra-compact H ii regions, it is suggested that less-massive objects are more evolved than the more-massive objects in two out of the three regions. Because the objects that are more massive evolve faster, those that are less massive form earlier. This formation trend of local mass-sequential star was first suggested in 0.1 pc-scale massive star-forming regions. Therefore, feedback, such as outflows, jets, or radiative heating, from previously formed lower-mass young stellar objects might affect the environment of parental clouds and lead to next-generation massive young stellar objects.

We conducted a cross-sectional observational study investigating socioeconomic status among Japanese survivors of pediatric hematopoietic stem cell transplantation (HCT) and the impact of chronic graft-versus-host disease (cGVHD) on socioeconomic outcomes, which are topics not well explored in the previous research. We collected data on socioeconomic outcomes from 442 HCT survivors through a questionnaire and obtained demographic and clinical information from their attending physicians and a national database between February 2013 and November 2014. We used logistic regression analysis to examine the relationship between cGVHD and socioeconomic outcomes in allogeneic HCT (allo-HCT) survivors. Most survivors did not experience socioeconomic problems. Nevertheless, allo-HCT survivors with cGVHD aged 8–15 years had poorer economic status (p = 0.013), and allo-HCT survivors with cGVHD aged ≥ 16 years were more likely to have never married (p = 0.034) and less likely to have more than a high school education (p = 0.023), compared with allo-HCT survivors without cGVHD. Thus, cGVHD in Japanese allo-HCT survivors was a risk factor for economic difficulties for those aged 8–15 years, and for never marrying and low educational achievement in those aged ≥ 16 years.

We investigated the efficacy and safety profiles of 4-weekly docetaxel for castration-resistant prostate cancer. Patients treated with ≥2 courses of docetaxel chemotherapy (median, 70 mg/m2) betwee...

We conducted a cross-sectional observational study investigating socioeconomic status among Japanese survivors of pediatric hematopoietic stem cell transplantation (HCT) and the impact of chronic graft-versus-host disease (cGVHD) on socioeconomic outcomes, which are topics not well explored in the previous research. We collected data on socioeconomic outcomes from 442 HCT survivors through a questionnaire and obtained demographic and clinical information from their attending physicians and a national database between February 2013 and November 2014. We used logistic regression analysis to examine the relationship between cGVHD and socioeconomic outcomes in allogeneic HCT (allo-HCT) survivors. Most survivors did not experience socioeconomic problems. Nevertheless, allo-HCT survivors with cGVHD aged 8-15 years had poorer economic status (p = 0.013), and allo-HCT survivors with cGVHD aged ≥ 16 years were more likely to have never married (p = 0.034) and less likely to have more than a high school education (p = 0.023), compared with allo-HCT survivors without cGVHD. Thus, cGVHD in Japanese allo-HCT survivors was a risk factor for economic difficulties for those aged 8-15 years, and for never marrying and low educational achievement in those aged ≥ 16 years.

Understanding of the impact of stem cell donation on donors’ health-related quality of life (HRQOL) remains limited. A prospective observational study of eligible unrelated donors enrolled in the Japan Marrow Donor Program was conducted to compare HRQOL and adverse events (AEs) between peripheral blood stem cell (PBSC) and bone marrow (BM) donors. In total, 107 PBSC donors and 108 BM donors were enrolled. HRQOL scores for physical status were significantly lower in BM donors 1 week post-harvest (P

Reduced-intensity conditioning (RIC) has been facilitating allogeneic hematopoietic cell transplantation (allo-HCT) for patients originally considered ineligible for HCT with myeloablative conditioning. Fludarabine (Flu) with reduced doses of busulfan (Bu) (Flu + Bu) and Flu with reduced doses of melphalan (Mel) (Flu + Mel) are widely used RIC regimens for acute myeloid leukemia (AML). A nationwide retrospective study comparing clinical outcomes of adult patients with AML receiving first allo-HCT after RIC between 2001 and 2010 was performed. Cumulative incidences of relapse were not significantly different among the Flu + ivBu-based (FBiv), Flu + poBu-based (FBpo), and Flu + Mel-based (FM) groups (p = 0.29). Non-relapse mortality (NRM) was significantly lower in patients receiving FBiv compared with FBpo (p = 0.003) and FM (p

Estimation and understanding of the state of the fuel debris and fission products inside the plant comprise an essential step in the decommissioning of Tokyo Electric Power Company Holdings’ Fukush...

The synergistic extraction of trivalent lanthanoid (Ln(III)) ions with 4-isopropyltropolone (Hipt) and 1,10-phenanthroline (phen) in o-dichrolobenzene (DCB) was investigated. The synergistic effect in DCB is more significant than that in toluene, and the polynuclear complexes found in toluene are not formed in DCB. Based on the 3-dimensional equilibrium analysis, the extracted species for La(III), Eu(III), and Lu(III) are found to be ion-pairs, such as Ln(ipt)2phen·ClO4 and Ln(ipt)2(phen)·ClO4 in the presence of NaClO4 as a salt, and the extraction constants of the respective species were determined. The simultaneous extraction of different lanthanoids in the present extraction system was demonstrated. The separation factors between lighter lanthanoids were larger than those with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester, an excellent extractant for the separation of lanthanoid ions, in decane.

Understanding the final distribution of core materials and their characteristics is important for decommissioning the Fukushima Daiichi Nuclear Power Station (1F). Such characteristics depend on the accident progression in each unit. However, boiling water reactor (BWR) accident progression involves great uncertainty. This uncertainty, which was clarified by MAAP-MELCOR crosswalk, cannot be resolved with existing knowledge and was thus addressed in this work through core material melting and relocation (CMMR) tests. For the test bundle, ZrO2 pellets were installed instead of UO2 pellets. A plasma heating system was used for the tests. In the CMMR-4 test, useful information was obtained on the core state just before slumping. The presence of macroscopic gas permeability of the core approaching ceramic fuel melting was confirmed, and the fuel columns remained standing, suggesting that the collapse of fuel columns, which is likely in the reactor condition, would not allow effective relocation of the hottest fuel away from the bottom of the core. This information will help us comprehend core degradation in boiling water reactors, similar to those in 1F. In addition, useful information on abrasive water suspension jet (AWSJ) cutting for debris-containing boride was obtained in the process of dismantling the test bundle. When the mixing debris that contains oxide, metal, and boride material is cut, AWSJ may be repelled by the boride in the debris, which may cut unexpected parts, thus generating a large amount of waste in cutting the boride part in the targeted debris. This information will help the decommissioning of 1F.

Background Campylobacter fetus is an uncommon Campylobacter species, and its infections mainly cause infective endocarditis, aortic aneurysm, and meningitis rather than enteritis. It is more likely to be detected in blood than Campylobacter jejuni or Campylobacter coli, specifically reported in 53% of patients. In our case, C. fetus was detected in both blood and cerebrospinal fluid (CSF) cultures. Case presentation A 33-year-old woman, who was on maintenance chemotherapy for acute lymphoblastic leukemia (ALL), presented to our clinic with chief complaints of severe headache and nausea. Blood and CSF cultures revealed C. fetus. We administrated meropenem 2 g intravenously (IV) every 8 h for 3 weeks, and she was discharged without neurological sequelae. Conclusion We encountered a case of C. fetus meningitis without gastrointestinal symptoms, neck stiffness or jolt accentuation in a patient with ALL. Undercooked beef was considered the source of C. fetus infection in this case, suggesting that the need for a neutropenic diet and safe food handling be considered.

Halorhodospira (Hlr.) halochloris is a unique phototrophic purple bacterium because it is a triple extremophile-the organism is thermophilic, alkalophilic, and halophilic. The most striking photosynthetic feature of Hlr. halochloris is that the bacteriochlorophyll (BChl) b-containing core light-harvesting (LH1) complex surrounding its reaction center (RC) exhibits its LH1 Q

A nationwide cross-sectional survey was conducted in long-term survivors of allogeneic hematopoietic stem cell transplantation (HSCT) in childhood to investigate the effect of chronic graft-versus-host disease (cGVHD) on quality of life (QOL) and differences in QOL assessments between raters. QOL was evaluated by a visual analogue scale (VAS). Assessments were compared between the survivor, guardian, and attending pediatrician for those aged 15 years or younger, and between the survivor and attending pediatrician for those aged 16 years or older. For cGVHD, severity scores were obtained by organ and their association with the VAS score was analyzed. The average pediatrician-rated VAS score was higher than that of other raters for both patient age groups ( 15 years and 16 years). By organ, involvement of the skin, digestive organs, and joints in GVHD affected the VAS scores. A high joint score was associated with a low VAS score, and conversely, a high lung score was associated with a low pediatrician-rated VAS score. Our results indicate that differences between raters must be considered when evaluating QOL of HSCT survivors, because patients appeared to experience grater inconvenience and difficulties due to joint GVHD than their pediatricians perceived.

The need for long-term follow-up (LTFU) after allogeneic hematopoietic cell transplantation (HCT) has been increasingly recognized for managing late effects such as subsequent cancers and cardiovascular events. A substantial population, however, has already terminated LTFU at HCT centers. To better characterize follow-up termination, we analyzed the Japanese transplant registry database. The study cohort included 17 980 survivors beyond 2 years who underwent their first allogeneic HCT between 1974 and 2013. The median patient age at HCT was 34 years (range, 0-76 years). Follow-up at their HCT center was terminated in 4987 patients. The cumulative incidence of follow-up termination was 28% (95% confidence interval [CI], 27%-29%) at 10 years, increasing to 67% (95% CI, 65%-69%) at 25 years after HCT. Pediatric patients showed the lowest probability of follow-up termination for up to 16 years after HCT, whereas adolescent and young adult (AYA) patients showed the highest probability of follow-up termination throughout the period. Follow-up termination was most often made by physicians based on the patient’s good physical condition. Multivariate analysis identified 6 factors associated with follow-up termination: AYA patients, female patients, standard-risk malignancy or nonmalignant disease, unrelated bone marrow transplantation, HCT between 2000 and 2005, and absence of chronic graft-versus-host disease. These results suggest the need for education of both physicians and patients about the importance of LTFU, even in survivors with good physical condition. The decreased risk for follow-up termination after 2005 may suggest the increasing focus on LTFU in recent years.

To characterize the incidences and outcomes of late acute (LA) and chronic graft-versus-host disease (GVHD) in East Asians according to the 2014 National Institutes of Health criteria, we retrospectively analyzed 506 consecutive Japanese patients who had a first allogeneic hematopoietic cell transplantation (HCT) at our center between 2006 and 2013. According to manifestations at onset 91 patients (60%) had LA GVHD and 60 (40%) had chronic GVHD. The cumulative incidences of LA and chronic GVHD were 20% and 17%, respectively, at 48 months after HCT. The involved sites at the onset of LA GVHD included the skin (71%), gut (13%), and liver (8%). The cumulative incidences of relapse, nonrelapse mortality (NRM), transition to chronic GVHD, and discontinued systemic treatment were 11%, 6%, 22%, and 46%, respectively, at 48 months after onset of LA GVHD. Cox models showed that prior acute GVHD was associated with NRM, and HCT from a female donor to a male patient, myeloablative conditioning, and low Karnofsky performance status were associated with a longer duration of systemic treatment after LA GVHD. The most frequently involved sites at the onset of chronic GVHD included the mouth (83%), liver (75%), skin (69%), and eyes (62%). Cox models showed that use of antithymocyte globulin in conditioning regimens was associated with a higher risk of discontinued systemic treatment after the onset of chronic GVHD. The cumulative incidences of relapse, NRM, and discontinued systemic treatment were 16%, 11%, and 41%, respectively, at 48 months after the onset of chronic GVHD. Our results suggested several potential differences between Japanese patients and those of other ethnicities. A direct comparison is needed to formally investigate ethnic differences.

Fe-based superconductors: Characterizing the nematic phase transition New measurements of quantum oscillations in FeSe1-xSx help understanding the nature of the nematic phase transition in Fe-based superconductors. Nematic order — an electronic order that breaks the rotational symmetry of the underlying substrate — is thought to play an important role in the appearance of superconductivity in Fe-based superconductors. A way to investigate the interplay between nematicity and superconductivity is to apply chemical pressure, in this case by substituting Se with S in FeSe samples. Amalia Coldea from the University of Oxford, UK, and colleagues used Shubnikov-de Haas oscillations to characterize the evolution of the Fermi surfaces across the nematic phase transition. They found a strongly correlated state inside the nematic phase and weakening electronic correlations outside it, and evidence for a Lifshitz transition that had not been detected before.

PURPOSE Advances in allogeneic hematopoietic cell transplantation (allo-HCT) have resulted in a growing number of transplant survivors; however, long-term survivors are at risk of developing late complications, and published guidelines recommend screening of this population. We conducted a single-center prospective study to evaluate the adherence to and usefulness of recommended screenings at a long-term follow-up (LTFU) clinic. METHODS We included consecutive patients who received allo-HCT at our center from 2014, as well as post-HCT patients visiting our outpatient clinic. Visits and screenings were planned at 3 months, 6 months, and 1 year after allo-HCT, and annually thereafter. Outcomes were reported by physicians including the incidence of findings at each screening that led to interventions. RESULTS Among the 216 participants, 95% visited the LTFU clinic, and 94% completed planned screenings. However, the rate of secondary cancer screenings targeting high-risk subjects was lower (38% to 68%). The overall percentage of screening results leading to interventions was 4.5%, with higher percentages (> 10%) for bone density testing, ophthalmological examinations, dental assessment, upper gastrointestinal endoscopy, and colonoscopy, with two patients diagnosed with secondary cancers. CONCLUSIONS Although the overall screening rate was high, it should be possible to improve the detection rate of late complications by decreasing screening failures, especially the screening for secondary cancers limited for high-risk survivors. A nationwide effort to educate HCT survivors and health practitioners using standardized nationwide LTFU tools may be effective, along with the development of institutional, local, and nationwide networks to maintain effective follow-up systems.

We have developed an integral field unit (IFU) for the existing optical imaging spectrograph, Faint Object Camera And Spectrograph (FOCAS), on the Subaru telescope. FOCAS IFU finally saw a first light on March 2nd, 2018, and started the common use from 2019. In order to observe faint targets like distant galaxies, our IFU has a coarse sampling comparable to the best seeing size and high throughput. The field of view is 13.4 10.0 arcsec2 which is divided into 23 slices with the width of 0.435 arcsec. Our IFU has a slit separated by about 5.2 arcmin from an object field in order to simultaneously obtain a sky spectrum. We confirmed that the image quality is good enough for the 0.435-arcsec slice width and the best seeing size of 0.4 arcsec. Mean and median throughput of the IFU are respectively 85.0% and 87.3%. However some fields show lower throughput due to misalignment of the IFU optics and the worst throughput is 61.9% at one field corner. Flat fielding error is almost within ±3%, but worse errors are found at the low-throughput region. The worst error is 9% at the lowest throughput region.

How much light from the astronomical object actually reaches the focal plane of a telescope? To what extent the sensitivity can be extended to both ends of the visible wavelengths – ultraviolet (UV) and infrared (IR) – as much as possible from the ground? And how to maintain good throughput of the telescope optics? In this report, we make a simplified model to show effect in the reflectivity change of the telescope mirror from the recoating and cleaning versus degradation focusing on a segmented primary mirror of a telescope. The better understandings and monitoring of these competing factors will help fine tune the scheduling of the in-situ cleaning such as CO2 cleaning. By maintaining the high throughput of the optics, it becomes more feasible to catch rare atmospheric condition whenever it becomes available for very sensitive UV or IR observations during Moon’s dark and bright phases, respectively. The degradation not recoverable by the cleaning is reset by replacing dirty segments with freshly coated ones. The importance of regular in-situ cleaning is evident when it takes long time to replace the large number of freshly coated segments. It is important to clean the entire aperture as much as possible when a wet condition is forecast; for once the contamination settles on the surface, CO2 cleaning alone won’t be able to recover good surface characteristics of reflectivity, scattering, and emissivity.

The Faint Object Camera and Spectrograph (FOCAS) is an optical imaging and spectroscopy instrument for the Subaru Telescope. It has been a workhorse instrument since the first-light phase of the telescope. We describe an integral field unit (IFU) that has recently been installed in FOCAS. The IFU utilizes an image slicer that divides a ${13{^{\prime \prime }_{.}}5}$ × ${10{^{\prime \prime }_{.}}0}$ field of view into 23 stripes, with a width of ${0{^{\prime \prime }_{.}}435}$. A sky spectrum separated from an object by approximately ${5{^{\prime }_{.}}2}$ can be obtained at the same time as an object spectrum. Test observations confirmed that the image quality of the IFU does not degrade the ${0{^{\prime \prime }_{.}}435}$ sampling, and that slice width and length are consistent with the design. Highly reflective multilayer dielectric coatings were coated on all the mirrors in the IFU, thereby offering a high mean IFU throughput of ∼85% over the field. However, the outer part of the field showed throughput degradation, which was mainly caused by vignetting as a result of misalignment. The flat-fielding accuracy was degraded by the vignetting, with the variation depending on the direction of the telescope.

An optimal pretransplant conditioning regimen for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in older adults has not been established. Three prospective multicenter phase II studies were conducted, in which 142 patients older than 54 years (median age, 61 years; range 55–70 years) with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) received a myeloablative dose of intravenous busulfan (ivBu, 12.8 mg/kg) along with fludarabine (180 mg/m2) ± low dose total body irradiation for allo-HSCT between September 2009 and February 2013. A total of 103 AML and 39 MDS patients including 21 related bone marrow (BM) or peripheral blood (PB), 50 unrelated BM, and 71 unrelated cord blood (UCB) transplantation were enrolled. Grade 3 or greater toxicities were observed in 105 patients. Neutrophil engraftment was achieved in 70 out of the 71 related PB/BM or unrelated BM recipients, and 61 out of the 71 UCB recipients. The cumulative incidence rates of relapse and non-relapse mortality after 2 years were 24.0 and 24.1%, respectively. The overall and event-free survival rates at 2 years were 53.3 and 47.4%, respectively. The myeloablative dose of ivBu was well tolerated without increased toxicity-related mortality in older adults who underwent allo-HSCT with any donor source.

The authors are developing an experimental technology for simulating severe accident (SA) conditions using simulant fuel material (ZrO2) that would contribute, not only to Fukushima Daiichi (1 F) decommissioning, but also to enhance the safety of worldwide existing and future nuclear power plants through clarification of accident progression behavior. Nontransfer (NTR) type plasma, which has been in practical use with a large torch capacity as high as 2 MW, has the potential to heat subject materials to very high-temperatures without selecting the target to be heated. When simulating 1 F with SA code (Severe Core Damage Analysis Package (SCDAP), Methods for Estimation of Leakages and Consequences of Releases (MELCOR) and Modular Accident Analysis Program (MAAP)), the target of this core-material-melting and relocation (CMMR) experiment was to confirm that NTR plasma has a sufficient heating performance realizing large temperature gradients (>2000 K/m) expected under 1 F conditions. The authors selected NTR-type plasma-heating technology that has the advantage of continuous heating in addition to its high-temperature level. A prototype large-scale experiment (1 m × 0.3 m dia.), called CMMR-0, was conducted in 2016, in which a large temperature gradient was realized and basic characteristics of a heated test assembly were studied. However, the maximum temperature was limited in this test by the instability of the plasma torch under low-oxygen concentrations. It was clarified through this test that an improvement in plasma-heating technology was necessary to heat the large-scale test assembly. The CMMR-1/-2 experiments were carried out in 2017 with a test assembly similar to CMMR-0, applying the improved technology (higher heating power and controlled oxygen concentration). In these two tests, heating history was different, resulting in similar physical responses with more pronounced material melting and relocation in the CMMR-2 experiment. The CMMR-2 experiment was selected from the perspective of establishing an experimental technology. The CMMR-2 experiment adopted a 30-min heating period, wherein the power was increased to a level where a large temperature gradient was expected at the lower part of the core under actual 1 F accident conditions. Most of the control blade and channel box migrated from the original position. After heating, the simulated fuel assembly was measured by X-ray-computed tomography (CT) technology and by electron probe micro-analyzer (EPMA). CT pictures and elemental mapping demonstrated its excellent performance with rather good precision. Based on these results, an excellent perspective, in terms of applicability of the NTR-type plasma-heating technology to the SA experimental study, was obtained.

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

We followed up the massive young stellar object S255-NIRS3 (= S255-IRS1b) during its recent accretion outburst event in the $K_{\rm s}$ band with Kanata/HONIR for four years after its burst and obtained a long-term light curve. This is the most complete near-infrared light curve of the S255-NIRS3 burst event that has ever been presented. The light curve showed a steep increase reaching a peak flux that was 3.4 mag brighter than the quiescent phase and then a relatively moderate year-scale fading until the last observation, similar to that of the accretion burst events such as EXors found in lower-mass young stellar objects. The behavior of the $K_{\rm s}$-band light curve is similar to that observed in 6.7 GHz class II methanol maser emission, with a sudden increase followed by moderate year-scale fading. However, the maser emission peaks appear 30–50 d earlier than that of the $K_{\rm s}$ band emission. The similarities confirmed that the origins of the maser emission and the $K_{\rm s}$-band continuum emission are common, as previously shown from other infrared and radio observations by Stecklum et al. (2016, Astronomer’s Telegram, 8732), Caratti o Garatti et al. (2017b, Nature Phys., 13, 276), and Moscadelli et al. (2017, A&A, 600, L8). However, the differences in energy transfer paths, such as the exciting/emitting/scattering structures, may cause the delay in the flux-peak dates.