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A Vaisman manifold is a special kind of locally conformally Kähler manifold, which is closely related to a Sasaki manifold. In this paper, we show a basic structure theorem of simply connected homogeneous Sasaki and Vaisman manifolds of unimodular Lie groups, up to holomorphic isometry. For the case of unimodular Lie groups, we obtain a complete classification of simply connected Sasaki and Vaisman unimodular Lie groups, up to modification.
Dog treats might be contaminated with Salmonella. In Canada and the USA, outbreaks of human salmonellosis related to exposure to animal-derived dog treats were reported. Consequently, surveillance data on Salmonella contamination of dog treats have been gathered in many countries, but not in Japan. In the current study, we investigated whether dog treats in Japan were contaminated with Salmonella. Overall, 303 dog treats (of which 255 were domestically produced) were randomly collected and the presence of Salmonella investigated. Seven samples were positive for Salmonella enterica subsp. enterica. Among these isolates, three were identified as serovar 4,5,12:i:–; two were serovar Rissen; and two were serovar Thompson. All serovar 4,5,12:i:– and Thompson isolates were resistant to one or more drugs. Two serovar Rissen isolates were fully susceptible to all tested antimicrobial agents. All Salmonella isolates were susceptible to cefotaxime, ciprofloxacin and nalidixic acid. The gene blaTEM was detected in two serovar 4,5,12:i:– isolates. The blaCTX−M and blaCMY genes were not detected in any isolates. This study demonstrated that dog treats in Japan could constitute a potential source of dog and human Salmonella infections, including multidrug-resistant Salmonella isolates.
A numerical investigation of two locally applied drag-reducing control schemes is carried out in the configuration of a spatially developing turbulent boundary layer (TBL). One control is designed to damp near-wall turbulence and the other induces constant mass flux in the wall-normal direction. Both control schemes yield similar local drag reduction rates within the control region. However, the flow development downstream of the control significantly differs: persistent drag reduction is found for the uniform blowing case, whereas drag increase is found for the turbulence damping case. In order to account for this difference, the formulation of a global drag reduction rate is suggested. It represents the reduction of the streamwise force exerted by the fluid on a plate of finite length. Furthermore, it is shown that the far-downstream development of the TBL after the control region can be described by a single quantity, namely a streamwise shift of the uncontrolled boundary layer, i.e. a changed virtual origin. Based on this result, a simple model is developed that allows the local drag reduction rate to be related to the global one without the need to conduct expensive simulations or measurements far downstream of the control region.
We report Hα imaging observations of nearby galaxies with the Kiso Schmidt telescope. For spiral galaxy NGC 628, we found no clear correlation between Hα and CO intensities, and we discuss the star formation efficiency of this galaxy. No nuclear Hα emission in this galaxy was detected. This is consistent with spectroscopic observations which indicate that the nuclear region is in the post starburst phase. We also describe the Hα image of Hickson's compact group 92 in which diffuse emission is detected extending within the group system.
Although outbreaks of acute respiratory infection (ARI) at shelters are hypothesized to be associated with shelter crowding, no studies have examined this relationship. We conducted a retrospective study by reviewing medical records of evacuees presenting to one of the 37 clinics at the shelters in Ishinomaki city, Japan, during the 3-week period after the Great Eastern Japan Earthquake and tsunami in 2011. On the basis of a locally weighted scatter-plot smoothing technique, we categorized 37 shelters into crowded (mean space <5·5 m2/per person) and non-crowded (⩾5·5 m2) shelters. Outcomes of interest were the cumulative and daily incidence rate of ARI/10 000 evacuees at each shelter. We found that the crowded shelters had a higher median cumulative incidence rate of ARI [5·4/10 000 person-days, interquartile range (IQR) 0–24·6, P = 0·04] compared to the non-crowded shelters (3·5/10 000 person-days, IQR 0–8·7) using Mann–Whitney U test. Similarly, the crowded shelters had an increased daily incidence rate of ARI of 19·1/10 000 person-days (95% confidence interval 5·9–32·4, P < 0·01) compared to the non-crowded shelters using quasi-least squares method. In sum, shelter crowding was associated with an increased incidence rate of ARI after the natural disaster.
The switching speed of a Cu/Ta2O5/Pt atomic switch between a high-resistance (OFF) state and a low-resistance (ON) state was evaluated by transient current measurements under the application of a short voltage pulse. It was found that the SET time from the OFF state to the ON state decreased as low as 1 ns, and the RESET time from the ON state to the OFF state reached a few ns using moderate pulse amplitudes. The switching time depends strongly on the pulse amplitude and the cell resistance before applying a voltage pulse. This observation indicates that oxide-based atomic switches hold potential for fast-switching memory applications. It was also found that Cu nucleation on the Pt electrode is likely to the rate-limiting process determining the SET time and the REST time appears to be preferentially determined by thermochemical reaction.
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.
We investigate the effects of superhydrophobic surfaces (SHS) carrying streamwise grooves on the flow dynamics and the resultant drag reduction in a fully developed turbulent channel flow. The SHS is modelled as a flat boundary with alternating no-slip and free-slip conditions, and a series of direct numerical simulations is performed with systematically changing the spanwise periodicity of the streamwise grooves. In all computations, a constant pressure gradient condition is employed, so that the drag reduction effect is manifested by an increase of the bulk mean velocity. To capture the flow properties that are induced by the non-homogeneous boundary conditions the instantaneous turbulent flow is decomposed into the spatial-mean, coherent and random components. It is observed that the alternating no-slip and free-slip boundary conditions lead to the generation of Prandtl’s second kind of secondary flow characterized by coherent streamwise vortices. A mathematical relationship between the bulk mean velocity and different dynamical contributions, i.e. the effective slip length and additional turbulent losses over slip surfaces, reveals that the increase of the bulk mean velocity is mainly governed by the effective slip length. For a small spanwise periodicity of the streamwise grooves, the effective slip length in a turbulent flow agrees well with the analytical solution for laminar flows. Once the spanwise width of the free-slip area becomes larger than approximately 20 wall units, however, the effective slip length is significantly reduced from the laminar value due to the mixing caused by the underlying turbulence and secondary flow. Based on these results, we develop a simple model that allows estimating the gain due to a SHS in turbulent flows at practically high Reynolds numbers.
We confirmed a specific detection of immunoglobulin E(IgE) by using an aptamer immobilized reduced graphene oxide(rGo) field effect transistor(FET). A detection limit and dynamic range were estimated 8.1 ng/ml and 10000 respectively. These characteristics are comparable with current fluorescent markers. Although a mobility of rGo FET was around 5 cm2/V.sec, and this is two to three orders lower than mechanically exfoliated pristine graphene FET, a sensitivity of it was only one order lower than using pristine graphene.
We investigated electrical and structural properties of Ta-doped SnO2 (TTO) films on anatase TiO2 seed layers with various growth parameters of pulsed laser deposition. We found that anatase TiO2 seed layers induced pseudo-epitaxial (100) growth of TTO films with enhanced mobility (μ) in a wide range of growth parameters. The highest μ of 83 cm2V-1s-1 [resistivity (ρ) of 2.8 × 10-4 Ωcm] and the lowest ρ of 1.8 × 10-4 Ωcm (μ of 60 cm2V-1s-1) were obtained at a substrate temperature of 600 °C. Amorphization and (101)-preferred growth competed with (100) growth on the TiO2 seed layer at low temperatures. Introducing sufficient process oxygen suppressed such unwanted film growth, resulting in improved transport properties.
Sustained friction drag reduction and heat transfer augmentation are simultaneously achieved in a fully developed channel flow where the averaged transport equations and wall boundary conditions for momentum and heat have identical form. Zero-net-mass-flux wall blowing and suction is assumed as a control input and its spatio-temporal distribution is determined based on optimal control theory. When the root-mean-square value of the control input is 5 % of the bulk mean velocity, the friction drag is decreased by 24 % from the uncontrolled value, whereas the heat transfer is more than doubled. Optimizations with different amplitudes of the control input and different Reynolds numbers reveal that the optimal control inputs commonly exhibit the property of a downstream travelling wave, whose wavelength is ∼250 in wall units and phase velocity is ∼30 % of the bulk mean velocity. Detailed analyses of the controlled velocity and thermal fields show that the travelling wave input contributes to dissimilar heat transfer enhancement through two distinct mechanisms, i.e. direct modification of the coherent velocity and thermal fields and an indirect effect on the random fields. The present results show that the divergence-free velocity vector and the conservative scalar are essentially different, and this is a key to achieving dissimilar heat transfer enhancement in turbulent shear flows.
Delirium and dementia are highly interrelated. However, few comprehensive epidemiological studies have examined this altered state of consciousness superimposed on dementia. We investigated the frequency of delirium in patients with dementia, its prevalence in patients with each dementia type, and its association with cerebrovascular disease (CVD) in patients with neurodegenerative dementias.
We studied 261 consecutive outpatients in the memory clinic of a psychiatric hospital between April 2010 and September 2011. All patients underwent routine laboratory tests and computed tomography (CT), and their Mini-Mental State Examination, Neuropsychiatric Inventory (NPI), Physical Self-Maintenance Scale (PSMS), and Delirium Rating Scale – Revised 98 scores were recorded. The diagnosis of delirium was based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision. CVD was detected by CT.
Among the 206 patients with dementia, delirium was present in 40 (19.4%). The proportion of patients who experienced episodes of delirium was 14.7% in the Alzheimer's disease, 34.4% in the vascular dementia, 31.8% in the dementia with Lewy bodies, and none in frontotemporal lobar degeneration. Delirium was frequently observed in patients with dementia and CVD. The NPI total and agitation subscale scores were significantly higher in dementia patients with delirium than in those without delirium. PSMS scores were significantly lower for patients with delirium than for patients without delirium.
The frequency of delirium varies with each dementia type. In addition, delirium decreases activities of daily living, exaggerates behavioral and psychological symptoms dementia, and is associated with CVD in patients with neurodegenerative dementias.
We investigated quantization behavior in conductance of an Ag/Ta2O5/Pt gapless-type atomic switch. Stepwise increases and decreases in the conductance were observed when small positive and negative bias voltages were applied to the Ag electrode, respectively, where each step corresponds to the conductance of a single atomic point contact. The conductance level could also be controlled by applying voltage pulses with varied amplitudes. Furthermore, when the interval time of consecutive input pulses was turned, we also observed long-term potentiation behavior similar to that of biological synapses. These results indicate that the oxide-based, gapless-type atomic switch has potential for use as a building block of neural computing systems.
The gullet worm (Gongylonema pulchrum) has been recorded from a variety of mammals worldwide, including monkeys and humans. Due to its wide host range, it has been suggested that the worm may be transmitted locally to any mammalian host by chance. To investigate this notion, the ribosomal RNA gene (rDNA), mainly regions of the internal transcribed spacers (ITS) 1 and 2, and a cytochrome c oxidase subunit I (COI) region of mitochondrial DNA of G. pulchrum were characterized using parasites from the following hosts located in Japan: cattle, sika deer, wild boars, Japanese macaques, a feral Reeves's muntjac and captive squirrel monkeys. The rDNA nucleotide sequences of G. pulchrum were generally well conserved regardless of their host origin. However, a few insertions/deletions of nucleotides along with a few base substitutions in the ITS1 and ITS2 regions were observed in G. pulchrum from sika deer, wild boars and Japanese macaques, and those differed from G. pulchrum in cattle, the feral Reeves's muntjac and captive squirrel monkeys. The COI sequences of G. pulchrum were further divided into multiple haplotypes and two groups of haplotypes, i.e. those from a majority of sika deer, wild boars and Japanese macaques and those from cattle and zoo animals, were clearly differentiated. Our findings indicate that domestic and sylvatic transmission cycles of the gullet worm are currently present, at least in Japan.
Physical properties of filaments in Cu/HfO2/Pt conducting-bridge memory (CB-RAM) were investigated basing on direct observation by conducting atomic force microscopy (C-AFM) and energy dispersive X-ray spectroscopy (EDS), R-T characteristics until liquid nitrogen temperature, and I-V characteristics both in air and in vacuum. As a result, physical picture of filaments in Cu/HfO2/Pt structures was revealed. Filaments consist of Cu containing large residual resistance and the cross-sectional area of the filament, Sfila, was roughly proportional to set voltage, Vset, even when current compliance was kept constant. Interestingly, resistivities of filaments are same among all the filaments in different samples and are invariant even after repetitive switching that changes resistance of the filaments. Cu/HfO2/Pt obeyed the universal relation that reset current, Ireset, is proportional to the inverse of resistance in a low resistance state, 1/RLRS, which is known to be applicable to oxygen-migration-based resistive switching memories such as Pt/NiO/Pt. Considering the invariance of resistivity of the filament, this suggests the fact that Ireset is decided dominantly by Sfila. In addition, it was suggested that moisture is necessary for dissolution and migration of Cu to form filaments.
Gapless-type atomic switches were fabricated on a flexible plastic substrate by printing ‘solid polymer electrolyte’ (SPE) layers using suitable ink and drop-on-demand ink-jet technique. High surface energy difference between Pt microelectrode patterned on the plastic substrate and the substrate itself, led to the successful printing of electrolytic solution on a bottom Pt electrodes. Bipolar resistive switching behavior was observed in Ag/SPE/Pt cross-point structures under electrical bias. The switching between ON and OFF states is attributed to the formation and dissolution of a metal filament between the electrodes. The cells also exhibited stable switching behavior under mechanical stress as performed by substrate bending. Switching characteristics measured under mechanical stress and without stress are matching well. The results demonstrate that the SPE-printed atomic switch has great potential for flexible switch/memory applications.