We report fourteen and twenty-eight protocluster candidates at z = 5.7 and 6.6 over 14 and 19 deg2 areas, respectively, selected from 2,230 Lyα emitters (LAEs) photometrically identified with Subaru/Hyper Suprime-Cam (HSC) deep images. Six out of the 42 protocluster candidates include at least 1 spectroscopically confirmed LAEs at redshifts up to z = 6.574. By the comparisons with the cosmological Lyα radiative transfer (RT) model reproducing LAEs with the reionization effects, we find that more than a half of these protocluster candidates might be progenitors of the present-day clusters with a mass of ≳ 1014M⊙. We also investigate the correlation between LAE overdensity and Lya rest-frame equivalent width (EW), because the cosmological Lyα RT model suggests that a slope of EW-overdensity relation is steepened towards the epoch of cosmic reionization (EoR), due to the existence of the ionized bubbles around galaxy overdensities easing the escape of Lyα emission from the partly neutral intergalactic medium. The available HSC data suggest that the slope of the EW-overdensity correlation does not evolve from the post-reionization epoch z = 5.7 to the EoR z = 6.6 beyond the moderately large statistical errors.

In recent years, the discovery of massive quasars at $z\sim7$ has provided a striking challenge to our understanding of the origin and growth of supermassive black holes in the early Universe. Mounting observational and theoretical evidence indicates the viability of massive seeds, formed by the collapse of supermassive stars, as a progenitor model for such early, massive accreting black holes. Although considerable progress has been made in our theoretical understanding, many questions remain regarding how (and how often) such objects may form, how they live and die, and how next generation observatories may yield new insight into the origin of these primordial titans. This review focusses on our present understanding of this remarkable formation scenario, based on the discussions held at the Monash Prato Centre from November 20 to 24, 2017, during the workshop ‘Titans of the Early Universe: The Origin of the First Supermassive Black Holes’.

We theoretically investigate the impact of feedback and its metallicity dependence in massive star formation from prestellar cores at all metallicity range. We include the feedback by MHD disk winds, radiation pressure, and photoevaporation solving the evolution of protostars and accretion flows self-consistently. Interestingly, we find that the feedback does not set the upper mass limit of stellar birth mass at any metallicity. At the solar metallicity, the MHD disk wind is the dominant feedback to set the star formation efficiencies (SFEs) from the prestellar cores similar to low-mass star formation. The SFE is found to be lower at lower surface density environment. The photoevaporation becomes significant at the low metallicity of Z < 10−2 Z⊙. Considering this efficient photoevaporation, we conclude that the IMF slope is steeper, i.e., massive stars are rarer at the extremely metal-poor environment of 10−5 − 10−3Z⊙. Our study raises a question on the common assumption of the universal IMF with a truncated at 100M⊙. Since the total feedback strength in the cluster/galaxy scale is sensitive to the number fraction of massive stars, the re-evaluations of IMF at various environments are necessary.

Emanating from coronals holes (CHs), high speed streams (HSSs) cause recurrent geomagnetic disturbances in the Earth’s magnetosphere. For this reason being able to predict the occurrence and timing of the high speed solar wind is one of the more important issues in space weather forecasting. Currently, it is still difficult to estimate the effect of a CH in case that it extends from high latitudes to lower ones. To monitor the global solar wind condition we have therefore developed a three-dimensional MHD simulation code, the REProduce Plasma Universe (REPPU) code, that is driven by the solar magnetic field from the solar surface to 1AU. The connectivity of magnetic field lines from CHs to Earth’s orbit via HSSs has been investigated. Simulation results are presented and the usefulness of our model is discussed.

We present the development of physics-based models of solar-terrestrial regions from the solar surface to the Earth’s atmosphere at NICT. Our models consist of three regions: (1) the solar surface and solar wind, (2) the Earth’s magnetosphere-ionosphere, and (3) a model of the whole atmosphere from the troposphere to the ionosphere, called the Ground to Topside Model of Atmosphere and Ionosphere for Aeronomy (GAIA). We also have a solar wind and CME model, Space-weather-forecast-Usable System Anchored by Numerical Operations and Observations (SUSANOO). Furthermore, we have developed a high-resolution plasma bubble model. The coupling of these models is a future work.

We perform simulations of the interplanetary coronal mass ejections relating to the magnetic storm on 17 March 2015. A hierarchical mesh structure is used, which is controlled by an adaptive mesh refinement technique, with fine-scale cells where it matters, the structure of the running shock waves of the coronal mass ejections and co-rotating interactive regions. The initial and the inner-boundary conditions are derived from another simulation, which uses a split dodecahedron grid. The resulting shock-wave with the models adjusted to the observed ejection speed on the sky plane show delays by 20% in the arrival time at the Earth from the observed data. By contrast, the model adjusted to the observed arrival time at the Earth needs the ejection speed 30% higher than that in the above models.

Objectives: Excessive adipose tissue, especially in the abdominal area, is associated with increased risk of dementia in older adults. However, the mechanisms underlying this relationship are poorly understood. As increased adiposity is also associated with lower circulating levels of brain-derived neurotrophic factor (BDNF), a key molecule modulating brain plasticity and neuronal regeneration, we hypothesized that the changes in cognition that occur as a result of excessive abdominal adiposity would be driven by lower levels of circulating BDNF. Methods: Fasting blood samples were obtained from 60 participants aged 40–60 years (mean±SD=52.3±5.6) and BDNF levels were assessed with an enzyme linked immunosorbent assay. Abdominal adiposity was measured using a ratio of waist circumference to hip circumference (WHR). Participants also completed a neuropsychological assessment battery to assess executive function. Statistical mediation was assessed using traditional causal steps and nonparametric bootstrapping. Results: Higher WHR was significantly associated with poorer performance on the Controlled Oral Word Association (COWA) letter fluency test (β=−0.489; p=.003) and lower levels of circulating BDNF (β=−0.345; p=.006). Linear regression and bootstrapping methods indicated that BDNF fully mediated the relationship between WHR and performance on the COWA (β=0.60; 95% confidence interval [−3.79, −0.26]). Conclusions: The relationship between higher WHR and verbal fluency was fully statistically mediated by circulating BDNF levels. The BDNF pathway is thus a useful probable mechanism through which executive function decline occurs in individuals with high abdominal adiposity. BDNF enhancing interventions (physical exercise and dietary restriction) could thus be used to improve executive function in these individuals. (JINS, 2016, 22, 1–8)

We report on the first results from our pilot observation of nearby galaxies with Hyper Suprime-Cam. We have observed two galaxies with mass similar to that of the Milky Way Galaxy and measured the abundance of their satellite galaxies in order to address the missing satellite problem outside of the Local Group. We find that (1) the abundance of dwarf galaxies is smaller by a factor of two than the prediction from one of the current hydro-dynamical simulations and (2) there is a large halo to halo scatter. Our results highlight the importance of a statistical sample of nearby galaxies to address the missing satellite problem.

We propose a low-contrast pre-coronagraph that can provide additional dark-hole contrast to a main coronagraph.

Origins of superluminous supernovae (SLSNe) discovered by recent SN surveys are still not known well. One idea to explain the huge luminosity is the collision of dense CSM and SN ejecta. If SN ejecta is surrounded by dense CSM, the kinetic energy of SN ejecta is efficiently converted to radiation energy, making them very bright. To see how well this idea works quantitatively, we performed numerical simulations of collisions of SN ejecta and dense CSM by using one-dimensional radiation hydrodynamics code STELLA and obtained light curves (LCs) resulting from the collision. First, we show the results of our LC modeling of SLSN 2006gy. We find that physical parameters of dense CSM estimated by using the idea of shock breakout in dense CSM (e.g., Chevalier & Irwin 2011, Moriya & Tominaga 2012) can explain the LC properties of SN 2006gy well. The dense CSM's radius is about 1016 cm and its mass about 15 M⊙. It should be ejected within a few decades before the explosion of the progenitor. We also discuss how LCs change with different CSM and SN ejecta properties and origins of the diversity of H-rich SLSNe. This can potentially be a probe to see diversities in mass-loss properties of the progenitors. Finally, we also discuss a possible signature of SN ejecta-CSM interaction which can be found in H-poor SLSN.

We review the position-controlled growth of III-V nanowires (NWs) by selective-area metal-organic vapor-phase epitaxy (SA-MOVPE). This epitaxial technique enables the positioning of the vertical NWs on (111) oriented surfaces with lithographic techniques. Core-shell structures have also been achieved by controlling the growth mode during SA-MOVPE. The core-shell III-V NW-based devices such as light-emitting diodes, photovoltaic cells, and vertical surrounding-gate transistors are discussed in this article. Nanometer-scale growth also enabled the integration of III-V NWs on Si regardless of lattice mismatches. These demonstrated achievements should have broad applications in laser diodes, photodiodes, and high-electron mobility transistors with functionality on Si not made possible with conventional Si-CMOS techniques.

Studying a multi-dimensional structure of supernovae (SNe) gives important constraints on the mechanism of the SN explosion. Polarization measurement is one of the most powerful methods to study the explosion geometry of extragalactic SNe. Especially, Type Ib/c SNe are the ideal targets because the core of the explosion is bare. We have performed spectropolarimetric observations of Type Ib/c SNe with the Subaru telescope. We detect a rotation of the polarization angle across the line, which is seen as a loop in the Q - U plane. This indicates that axisymmetry is broken in the SN ejecta. Adding our new data to the sample of stripped-envelope SNe with high-quality spectropolarimetric data, five SNe out of six show a loop in the Q - U plane. This implies that the SN explosion commonly has a non-axisymmetric, three-dimensional geometry.

We developed ultra-violet field-emission devices using rare-earth nitrides of Al1-x Gd x N grown by a reactive radio-frequency magnetron sputtering technique. The Al1-x Gd x N phosphor film excited by high-energy electrons shows a resolution limited, narrow intra-orbital luminescence from Gd3+ ions at 318 nm. The devise characteristics depend on injected current and acceleration voltage, which were analyzed by considering multiple excitation process of injected high-energy electrons.

We have mapped the nearby face-on spiral galaxy M 33 in the 1.1 mm dust continuum using AzTEC on Atacama Submillimeter Telescope Experiment (ASTE). The preliminary results are presented here. The observed dust has a characteristic temperature of ~ 21 K in the central kpc, radially declining down to ~ 13 K at the edge of the star forming disk. We compare the dust temperatures with KS band flux and star formation tracers. Our results imply that cold dust heating may be driven by long-lived stars even nearby star forming regions.

Spherical particles of ferrite (intermediate between Fe3O4 and γ-Fe2O3) were grown on seed crystals (∼9 nm) via the green rust route in an aqueous solution added with sucrose, which promotes spherical growth. By highly dispersing the seed crystals in an HNO3 solution, we could control the diameter of the particles over a wide range of 20–200 nm (geometric standard deviation: 1.1–1.4) by changing the amount of the seed crystals. At the beginning of the seed growth, clusters of the seed crystals were resolved into smaller clusters, each composed of a few seed crystals.

The effectiveness and safety of yokukansan (TJ-54), a traditional Japanese medicine (kampo) for the treatment of the behavioural and psychological symptoms of dementia (BPSD), were evaluated in 106 patients diagnosed as having Alzheimer's disease (AD) (including mixed-type dementia) or dementia with Lewy bodies. Patients were randomly assigned to group A (TJ-54 treatment in period I and no treatment in period II; each period lasting 4 wk) or group B (no treatment in period I and TJ-54 treatment in period II). BPSD and cognitive functions were evaluated using the Neuropsychiatric Inventory (NPI) and the Mini-Mental State Examination (MMSE), respectively. Activities of daily living (ADL) were evaluated using Instrumental Activities of Daily Living (IADL) in outpatients and the Barthel Index in in-patients. For the safety evaluation, adverse events were investigated. Significant improvements in mean total NPI score associated with TJ-54 treatment were observed in both periods (Wilcoxon test, p=0.040 in period I and p=0.048 in period II). The mean NPI scores significantly improved during TJ-54 treatment in groups A and B (p=0.002 and p=0.007, respectively) but not during periods of no treatment. Among the NPI subscales, significant improvements were observed in delusions, hallucinations, agitation/aggression, depression, anxiety, and irritability/lability. The effects of TJ-54 persisted for 1 month without any psychological withdrawal symptoms in group A. TJ-54 did not show any effect on either cognitive function or ADL. No serious adverse reactions were observed. The present study suggests that TJ-54 is an effective and well-tolerated treatment for patients with BPSD.

Since the ternary intermetallic compound Co3(Al,W) with the L12 structure was discovered, two-phase Co-base alloys composed of the γ-Co solid-solution phase and the γ'-Co3(Al,W) phase as a strengthening phase have been investigated as promising high-temperature materials. Some Co-base alloys have been reported to exhibit high-temperature strength greater than those of conventional Ni-base superalloys. Although the excellent high-temperature physical properties of the Co-based alloys are considered to result from the phase stability and strength of Co3(Al,W), the pristine physical properties of Co3(Al,W) have not been fully understood, supposedly due to the difficulties in obtaining single-phase Co3(Al,W). In the present study, we examine the effect of heat treatment on the microstructure of alloys with compositions close to single-phase Co3(Al,W) as well as their mechanical properties, e.g. elastic modulus, thermal expansion, etc., in hope of deriving the pristine properties of the Co3(Al,W) phase. A single crystal with the composition of Co-10Al-11W grown by floating-zone melting exhibits a thermal expansion coefficient of 10×10-6 K-1 at room temperature, which is virtually identical to those of the commercial Ni-base superalloys. However, it increases with increasing temperature followed by a discontinuity at around 1000°C, inferring the phase transformation from γ' to γ. The investigated thermal expansion behavior indicates that the lattice mismatch between the γ' and γ phases is reversed from positive at room temperature to negative at high temperatures above around 500°C. The results of elastic property measurement and environmental embrittlement investigation of polycrystalline Co3(Al,W) will also be presented.

Single-crystal elastic constants of Co3(Al,W) with the cubic L12 structure have been experimentally measured by resonance ultrasound spectroscopy at liquid helium temperature. The values of all the three independent single-crystal elastic constants and polycrystalline elastic constants of Co3(Al,W) experimentally determined are 15~25% larger than those of Ni3(Al,Ta) but are considerably smaller than those previously reported. Two-phase microstructures with cuboidal L12 precipitates being well aligned parallel to <100> and well faceted parallel to {100} are expected to form very easily in Co-base superalloys because of the large value of E 111/E 100 and cij of Co3(Al,W). This is indeed confirmed by experiment. Values of yield stress obtained for both [001] and [¯123] orientations of L12/fcc two-phase single crystals moderately decrease with the increase in temperature up to 800°C and then decrease rapidly with temperature above 800°C without any anomaly in yield stress. Slip on {111} is observed to occur for both orientations in the whole temperature range investigated.

Because the biological pathological process is observed decades years before the clinical onset of Alzheimer's disease (AD), there is a theoretical ad-vantage in using biological markers for the early diagnosis of AD. Neuro-psychological test batteries, brain imaging and biological markers are expected to be used for screening and differential diagnosis of dementia and also for evaluation of the efficacy of early intervention.

No single biological marker can serve all the purposes of screening, differential diagnosis and measurement of severity. Biological markers that reflect molecular stress, such as oxidative, ribotoxic, and nitroso stress, need to be developed, particularly for measuring the clinical outcomes of interventions. As well as providing a better understanding of the molecular pathogenesis of AD, there is a possibility of finding a surrogate marker of AD, which might fulfill the requirement of sufficient sensitivity and specificity for AD diagnosis, as well as indicating the disease-modifying activity of interventions. In this study we examine whether the mechanism of secretase activity will offer a new surrogate marker of AD.