Background: After a transient ischemic attack (TIA) or minor stroke, the long-term risk of subsequent stroke is uncertain. Methods: Electronic databases were searched for observational studies reporting subsequent stroke during a minimum follow-up of 1 year in patients with TIA or minor stroke. Unpublished data on number of stroke events and exact person-time at risk contributed by all patients during discrete time intervals of follow-up were requested from the authors of included studies. This information was used to calculate the incidence of stroke in individual studies, and results across studies were pooled using random-effects meta-analysis. Results: Fifteen independent cohorts involving 129794 patients were included in the analysis. The pooled incidence rate of subsequent stroke per 100 person-years was 6.4 events in the first year and 2.0 events in the second through tenth years, with cumulative incidences of 14% at 5 years and 21% at 10 years. Based on 10 studies with information available on fatal stroke, the pooled case fatality rate of subsequent stroke was 9.5% (95% CI, 5.9 – 13.8). Conclusions: One in five patients is expected to experience a subsequent stroke within 10 years after a TIA or minor stroke, with every tenth patient expected to die from their subsequent stroke.

With many non-human primates (NHPs) showing continued population decline, there is an ongoing need to better understand their ecology and conservation threats. One such threat is the risk of disease, with various bacterial, viral and parasitic infections previously reported to have damaging consequences for NHP hosts. Strongylid nematodes are one of the most commonly reported parasitic infections in NHPs. Current knowledge of NHP strongylid infections is restricted by their typical occurrence as mixed infections of multiple genera, which are indistinguishable through traditional microscopic approaches. Here, modern metagenomics approaches were applied for insight into the genetic diversity of strongylid infections in South-East and East Asian NHPs. We hypothesized that strongylid nematodes occur in mixed communities of multiple taxa, dominated by Oesophagostomum, matching previous findings using single-specimen genetics. Utilizing the Illumina MiSeq platform, ITS-2 strongylid metabarcoding was applied to 90 samples from various wild NHPs occurring in Malaysian Borneo and Japan. A clear dominance of Oesophagostomum aculeatum was found, with almost all sequences assigned to this species. This study suggests that strongylid communities of Asian NHPs may be less species-rich than those in African NHPs, where multi-genera communities are reported. Such knowledge contributes baseline data, assisting with ongoing monitoring of health threats to NHPs.

Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array’s (MWA) Phase II compact configuration offers us opportunities for both redundant calibration and sky-based calibration algorithms; using the two in tandem is a potential approach to mitigate calibration errors caused by inaccurate sky models. The MWA Epoch of Reionization (EoR) experiment targets three patches of the sky (dubbed EoR0, EoR1, and EoR2) with deep observations. Previous work in Li et al. (2018) and (2019) studied the effect of tandem calibration on the EoR0 field and found that it yielded no significant improvement in the power spectrum (PS) over sky-based calibration alone. In this work, we apply similar techniques to the EoR1 field and find a distinct result: the improvements in the PS from tandem calibration are significant. To understand this result, we analyse both the calibration solutions themselves and the effects on the PS over three nights of EoR1 observations. We conclude that the presence of the bright radio galaxy Fornax A in EoR1 degrades the performance of sky-based calibration, which in turn enables redundant calibration to have a larger impact. These results suggest that redundant calibration can indeed mitigate some level of model incompleteness error.

A series of direct numerical simulations of a fully developed turbulent channel flow is conducted in order to clarify the effects of travelling wave-like wall blowing and suction on dissimilar heat transfer enhancement. While the wave form is kept sinusoidal and its amplitude is set to be 5 % of the bulk mean velocity, the wavelength and phase speed of the travelling wave are systematically changed in a wide parameter space. As a result, the global optimum of the parameter set for maximizing the analogy factor, which is defined as the ratio between the Stanton number and the skin-friction coefficient, is identified. Interestingly, the obtained globally optimal mode agrees well with that predicted from the optimal control theory taking into account the future dynamics within a limited time horizon by Yamamoto et al. (J. Fluid Mech., vol. 733, 2013, pp. 189–220). The instantaneous velocity and thermal fields are decomposed into coherent and random components in order to evaluate the contribution from each component to dissimilar heat transfer enhancement. The detailed mechanisms of dissimilarity are explained by the budget analyses of the coherent and random contributions. Also, their relationships with the near-wall turbulent structures modified by the applied control are discussed through flow visualization. It is found that the random component makes a dominant contribution to dissimilarity, and this can be explained by an indirect effect through the modification of the coherent field by the applied control. Based on the above mechanisms, we propose a simple unsteady Reynolds-averaged Navier–Stokes (URANS) approach, where the phase-averaged velocity and thermal fields are solved directly whereas the effects of the random component are modelled by the Boussinesq eddy viscosity and diffusivity hypothesis. It is shown that the present URANS can capture the overall trend of dissimilar heat transfer enhancement in a wide parameter range. The present results also explain why the optimal control theory with a limited time horizon succeeds in predicting the globally optimal control mode.

We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.

Recently, an epoch-making printing technology called “SuPR-NaP (Surface Photo-Reactive Nanometal Printing)” that allows easy, high-speed, and large-area manufacturing of ultrafine silver wiring patterns has been developed. Here we demonstrate low-voltage operation of organic thin-film transistors (OTFTs) composed of printed source/drain electrodes that are produced by the SuPR-NaP technique. We utilize an ultrathin layer of perfluoropolymer, Cytop, that functions not only as a base layer for producing patterned reactive surface in the SuPR-NaP technique but also as an ultrathin gate dielectric layer of OTFTs. By the use of 22 nm-thick Cytop gate dielectric layer, we successfully operate polycrystalline pentacene OTFTs below 2 V with negligible hysteresis. We also observe the improvement of carrier injection by the surface modification of printed silver electrodes. We discuss that the SuPR-NaP technique allows the production of high-capacitance gate dielectric layers as well as high-resolution printed silver electrodes, which provides promising bases for producing practical active-matrix OTFT backplanes.

Here we discuss requirements for high performance and solution processable organic semiconductors, by presenting a systematic investigation of 7-alkyl-2-phenyl[1]benzothieno[3,2-b][1]benzothiophenes (Ph-BTBT-Cn ’s). We found that the solubility and thermal properties of Ph-BTBT-Cn ’s depend systematically on the substituted alkyl-chain length n. The observed features are well understood in terms of the change of molecular packing motif with n: The compounds with n ≤ 4 do not form independent alkyl chain layers, whereas those with n ≥ 5 form isolated alkyl chain layers. The latter compounds afford a series of isomorphous bilayer-type crystal structures that form two-dimensional carrier transport layers within the crystals. We also show that the Ph-BTBT-C10 afford high performance single-crystalline field-effect transistors the mobility of which reaches as high as 15.9 cm2/Vs. These results demonstrate a crucial role of the substituted alkyl chain length for obtaining high performance organic semiconductors and field-effect transistors.

Polymeric nanoparticles having redox-active catechol moieties, a common structural motif found in naturally-occurring antioxidants, were developed. We synthesized an amphiphilic catechol-bearing polymer that self-assembled to form nanoparticles with a diameter of 126 nm. The nanoparticles showed enhanced ROS-scavenging activity compared to the small catecholic compound dopamine. Furthermore, the nanoparticles inhibited ROS-mediated angiogenesis as shown by the endothelial cell tube formation assay and the chicken chorioallantoic membrane (CAM) assay.

As a method to evaluate high-temperature equation of state (EOS) data of fissile materials precisely and safely, we numerically examined an experimental setup based on a sub-range fissile target and a high-intensity short-pulsed heavy-ion beam. As an example, we calculated one-dimensional hydrodynamic motion of a uranium target with ρ = 0.03ρsolid (ρsolid ≡ solid density = 19.05 g/cm3) induced by a pulsed 23Na+ beam with a duration of 2 ns and a peak power of 5 GW/mm2. The projectile stopping power was calculated using a density- and temperature-dependent dielectric response function. To heat the target uniformly, we optimized the experimental condition so that the energy deposition could occur almost at the top of the Bragg peak. The energy deposition inhomogeneity could be reduced to ±5% by adjusting the incident energy and the target thickness to be 2.02 MeV/u and 180 μm, respectively. The target could be heated homogeneously up to kT =7 eV well before the arrival of the rarefaction waves at the center of the target. In principle, the EOS data can be evaluated by iteratively adjusting the data embedded in the hydro code until the measured hydrodynamic motion is reproduced by the calculation. This method is consistent with the conditions of nuclear nonproliferation, because a very small amount of fissile material is enough to perform the experiment, and no shock compression occurs in the target.

Recent epidemiological data suggest a link between the consumption of bovine offal products and Shiga toxin-producing Escherichia coli (STEC) infection in Japan. This study thus examined the prevalence of STEC in various types of these foods. PCR screened 229 bovine offal products for the presence of Shiga toxin (stx) gene. Thirty-eight (16·6%) samples were stx positive, of which eight were positive for rfbEO157 and three were positive for wzyO26. Four O157 and one O26 STEC isolates were finally obtained from small-intestine and omasum products. Notably, homogenates of bovine intestinal products significantly reduced the extent of growth of O157 in the enrichment process compared to homogenates of beef carcass. As co-incubation of O157 with background microbiota complex from bovine intestinal products in buffered peptone water, in the absence of meat samples, tended to reduce the extent of growth of O157, we reasoned that certain microbiota present in offal products played a role. In support of this, inoculation of generic E. coli from bovine intestinal products into the homogenates significantly reduced the extent of growth of O157 in the homogenates of bovine intestinal and loin-beef products, and this effect was markedly increased when these homogenates were heat-treated prior to inoculation. Together, this report provides first evidence of the prevalence of STEC in a variety of bovine offal products in Japan. The prevalence data herein may be useful for risk assessment of those products as a potential source of human STEC infection beyond the epidemiological background. The growth characteristic of STEC O157 in offal products also indicates the importance of being aware when to test these food products.

An ion source for generation of low-charged heavy ions has been developed using low-power KrF excimer and frequency-doubled Nd:YAG lasers. The ion source was examined with two experimental modes of low-voltage DC extraction at ∼20 kV and high-voltage pulse extraction at 150 kV. Normalized emittance of extracted beams composed of Cu+ and Cu2+ ions was measured to be about 0.05 and 0.8 πmm-mrad for the DC extraction and the pulse extraction, respectively. Electron temperature was observed by means of a single probe method to be 0.8 to 2.5 eV, depending on the intensity of the KrF laser.

The interaction process between fast heavy ions and dense plasma was experimentally investigated. We injected 4.3-MeV/u or 6.0-MeV/u iron ions into a z-pinch-discharge helium plasma and measured the energy loss of the ions by the time of flight method. The energy loss of 4.3-MeV/u ions fairly agreed with theoretical prediction when the electron density of the target was on the order of 1018 cm−3. With increasing electron density beyond 1019 cm−3, the difference between the experiment and the theory became remarkable; the experimental energy loss was 15% larger than the theoretical value at the peak density. For 6.0-MeV/u ions, the deviation from the theory appeared even at densities below 1019 cm−3. These discrepancies indicated that density effects such as ladderlike ionization caused the enhancement of the projectile mean charge in the target.

Activities of research and development on repetitive induction voltage modulators in the Tokyo Institute of Technology–High Energy Accelerator Research Organization group are presented along with a discussion of the magnetic response of ferro-magnetic materials to fast magnetization and a transient beam loading in the modulators. The modulator is composed of independently driven modules switched by field effect transistors. To make waveform control, the induced voltages are stacked and synthesized in the induction unit. A proof-of-principle experiment shows that the module elements are successfully operated up to megahertz levels with good reproducibility. For the evaluation of magnetic core response, magnetic characteristics are investigated over a wide range of parameters, and an empirical core loss scaling is derived at minor-hysteresis loops. Using the prototype induction module, we have also investigated the effect of beam loading. Results indicate that the effect depends not only on the impedance of the driving circuit but on nonlinearity of the magnetic-core response. This means that the response of the induction modulator depends on the time scale of domain motion and operating point in the B-H plane of magnetic materials. Based on the progress of the component technology in the induction accelerator and database of magnetic materials, a system design has been developed.

The charge-state distribution and the energy loss of oxygen ions in a laser-produced hydrogen plasma have been investigated experimentally. The plasma target had a maximum electron density of 5 × 1018 cm−3 and a maximum electron temperature of 13 eV. The mean charge state of the oxygen ions in the hydrogen plasma was measured to be 5.1, which was considerably higher than that in hydrogen gas. The energy loss of oxygen ions in the plasma of a density less than 1 × 1018 cm−3 in the plasma showed a large enhancement compared with that in hydrogen gas. However, the energy loss in the plasma of a density above 1 × 1018 cm−3 showed no enhancement.

This article reports on the interaction between slow ions and a partially ionized plasma. Temporal evolutions of energy loss and charge distribution of 2.4 MeV oxygen beams in the laser-induced polyethylene plasma were measured. The charge distribution showed strong stripping ability in the early phase of the plasma. Stopping power deduced from the experimental energy loss was 1.9 times larger than that for the solid. The effective charge of the projectile ion was estimated from the yields of 4+ and 6+ states. The peak value of the effective charge was 1.4 times larger than that of the solid. The stopping power equation given by Sigmund was extended for the partially ionized plasma and it could reproduce the measured energy loss.

An energy loss of 240 MeV argon ions in a Z-pinch helium plasma has been for the first time observed throughout the entire pinching process. Standard Stark broadening analysis gives an electron density ranging from 4 to 6 × 1017 cm−3 during the pinch. To deduce stopping power from the energy loss, the target thickness of the helium plasma has been evaluated assuming the mean charge of helium based on thermal equilibrium. The observed electron density and the mean charge of helium give a target thickness of 30 ± 3 μg cm−2 from 1 μs to 1.8 μs after the discharge ignition. The measured stopping power exceeds a tabulated value for cold helium gas by a factor of 2 to 3 around the time of the first pinch. The experimental stopping power is compared with theoretical values calculated using an equation of stopping power for a partially ionized plasma.

Magnetic properties of Co-doped rutile (Ti1-xCoxO2) film in combinatorial composition-spread form have been surveyed by means of a Scanning Superconducting-quantum-interference-device Microscope (SSM). As a consequence, we found magnetic domains in the spatial regions with x>0.05 without external field, giving strong evidence for ferromagnetism with finite spontaneous magnetization. The magnetic moment was monotonously increased with increasing doping level x from 0.05 to ∼ 0.13. On the other hand, it was almost unchanged for x > ∼ 0.13, suggesting that Co does not dissolve into rutile film beyond x ∼ 0.13. The SSM results on the rutile Ti0.95Co0.05O2 thin films with different thickness showed that the magnetic moment is proportional to film thickness, leading to a conclusion that the presently observed ferromagnetism does not result from Co or Co-based oxide particles on the film surface.