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In the present study, compressible low-Reynolds-number flow past a stationary isolated sphere was investigated by direct numerical simulations of the Navier–Stokes equations using a body-fitted grid with high-order schemes. The Reynolds number based on free-stream quantities and the diameter of the sphere was set to be between 250 and 1000, and the free-stream Mach number was set to be between 0.3 and 2.0. As a result, it was clarified that the wake of the sphere is significantly stabilized as the Mach number increases, particularly at the Mach number greater than or equal to 0.95, but turbulent kinetic energy at the higher Mach numbers conditions is higher than that at the lower Mach numbers conditions of similar flow regimes. A rapid extension of the length of the recirculation region was observed under the transitional condition between the steady and unsteady flows. The drag coefficient increases as the Mach number increases mainly in the transonic regime and its increment is almost due to the increment in the pressure component. In addition, the increment in the drag coefficient is approximately a function of the Mach number and independent of the Reynolds number in the continuum regime. Moreover, the effect of the Mach and Reynolds numbers on the flow properties such as the drag coefficient and flow regime can approximately be characterized by the position of the separation point.
Recent research on Flight-deck Interval Management (FIM), a modern technology for increasing safety and improving airspace and runway utilisation through self-spacing, has led to the development of a new rule-based logic for FIM, namely Interval Management – Speed Planning (IM-SP). In an initial benchmark study, IM-SP showed good spacing performance with a significant reduction in speed commands, a major area of concern with previous FIM logics, resulting in a lower burden on the flight crew during FIM operation. Nevertheless, there remains scope for improvement in other aspects, such as fuel burn. In this study, the internal cost function of IM-SP is further analysed and optimised using speed-constrained multi-objective particle swarm optimisation to improve the performance of IM-SP under the multiple objectives of FIM. The optimisation renders new settings that address the problem areas, improve the speed commands and enhance the overall quality of IM-SP. Two distinctive solutions, viz. a spacing performance optimised setting and a fuel burn optimised setting, are further analysed and discussed, and directions for follow-up research are explored.
The authors evaluated cerebral blood flow response in schizophrenia patients during face perception to test the hypothesis of diminished limbic activation related to emotional relevance of facial stimuli.
Thirteen patients with schizophrenia and 17 comparison subjects viewed facial displays of happiness, sadness, surprise, anger, fear, and disgust as well as neutral faces using the Japanese and Caucasian Facial Expressions of Emotion and Neutral Faces (Matsumoto and Ekman, 1988). Functional magnetic resonance imaging was used to measure blood-oxygen-level-dependent signal changes as the subjects alternated between tasks of discriminating sex with an interleaved reference condition.
The groups did not differ in performance on the task. Healthy participants showed activation in the bilateral fusiform gyrus, medial temporal structures, occipital lobe, and inferior frontal cortex relative to the baseline condition. The increase was greater these regions in the right hemisphere than those in the left hemisphere. In the patients with schizophrenia, minimal focal response in the right fusiform gyrus, medial temporal structures, and occipital lobe was observed for the facial perception task relative to the baseline condition. Contrasting patients and comparison subjects revealed voxels in the left medial temporal structures, occipital lobe in which the healthy comparison subjects had significantly greater activation.
Impaired activation was seen in patients with schizophrenia for detection of facial attributes such as sex. Impairment in the medial temporal structure such as amygdale may lead to misunderstanding of social communication and may underlie difficulties in social adjustment experienced by people with schizophrenia.
Studies on community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP) related to the 13-valent pneumococcal conjugate vaccine (PCV13) introduction in Asia are scarce. This study aimed to investigate the epidemiological and microbiological determinants of hospitalised CAP and PP after PCV13 was introduced in Japan. This observational hospital-based surveillance study included children aged ⩽15 years, admitted to hospitals in and around Chiba City, Japan. Participants had bacterial pneumonia based on a positive blood or sputum culture for bacterial pathogens. Serotype and antibiotic-susceptibility testing of Streptococcus pneumoniae and Haemophilus influenzae isolates from patients with bacterial pneumonia were assessed. The CAP hospitalisation rate per 1000 child-years was 17.7, 14.3 and 9.7 in children aged <5 years and 1.18, 2.64 and 0.69 in children aged 5–15 years in 2008, 2012 and 2018, respectively. There was a 45% and 41% reduction in CAP hospitalisation rates, between the pre-PCV7 and PCV13 periods, respectively. Significant reductions occurred in the proportion of CAP due to PP and PCV13 serotypes. Conversely, no change occurred in the proportion of CAP caused by H. influenzae. The incidence of hospitalised CAP in children aged ⩽15 years was significantly reduced after the introduction of PCV13 in Japan. Continuous surveillance is necessary to detect emerging PP serotypes.
Although longitudinal magnetic resonance imaging (MRI) studies have shown that various brain regions undergo progressive tissue loss during the early phases of schizophrenia, regional pattern of these changes remain unclear.
Longitudinal MRI data were obtained from 18 (12 males and 6 females) patients with first-episode schizophrenia and 20 (11 males and 9 females) healthy controls and at baseline and follow-up with mean scan interval of 2.7 years. To compare gray matter changes over time between patients and controls were evaluated with voxel-based morphometry (VBM) using SPM8 following the longitudinal DARTEL protocol.
In both groups of patient and control longitudinal gray mater reduction was observed in various brain regions including lateral and medial frontal regions and superior temporal region. Excessive decrease in gray matter was found in patients as compared to healthy controls in the left superior temporal region and right inferior frontal region.
Our findings suggest that there are differing longitudinal gray matter changes in patients with schizophrenia during the early phases of the illness as compared to healthy individuals.
Research has shown that ADHD symptoms and functional impairment often persist beyond childhood into adulthood. Thus an effective therapy that can be tolerated over long-term use in adults is needed. This is the first long term safety and tolerability study of an adult ADHD medication in Asia.
Assess long-term safety, tolerability, and efficacy of atomoxetine (ATX) in adult Japanese ADHD patients.
Demonstrate the safety and tolerability of long-term ATX.
ATX (40-120 mg/day) was evaluated based on integrated analyses of a 10 week double-blind (DB) study and a 48 week open-label long term (LT) extension study. Long-term safety and tolerability were assessed by adverse events, discontinuation rate, and vital-signs. Efficacy measures included change from baseline in Conners’ Adult ADHD Rating Scale- Investigator Rated (CAARS-Inv:SV) total symptoms score, behavior Rating Inventory of Executive Function (BRIEF-A), and Adult ADHD/QoL Measure (AAQoL).
233 patients took ATX (LT mean final prescribed dose: 108.3 mg/day). AEs leading to discontinuations were seen in 37 (15.9%) patients, the most common being nausea in 10 (4.3%) patients. Statistically significant baseline-to-endpoint reductions in mean CAARS-Inv:SV total symptoms score during in the DB study continued throughout the LT study. Similar reductions were seen in BRIEF-A Self Report scores. These findings along with AAQoL results indicated that patients perceived improvements in both QoL and Executive Function.
Long-term ATX treatment was shown to be generally safe and tolerable in Japanese adult ADHD patients. Results also suggested ATX improved ADHD core symptoms, QoL and Executive Functions.
Reduced white matter integrity in the corpus callosum (CC) has been reported in treatment-resistant depression (TRD). rTMS is assumed to have remote effect on interconnected area with the stimulation site, and this effect is speculated to be one of the therapeutic mechanisms of rTMS treatment. In this preliminary study, we examined changes of callosal fiber integrity in 5 segments of the CC before and after rTMS treatment for TRD.
The subjects were 2 patients with treatment-resistant unipolar depression and 1 patient with treatment-resistant bipolar depression, and 24 healthy controls (HC group). The patients underwent 4-week high frequency rTMS to their left DLPFC. In diffusion tensor imaging (DTI) tractography, the CC was divided into 5 segments (orbital, frontal, parietal, temporal, and occipital) based on their cortical projection zones, and fractional anisotropy (FA) value of each segment was estimated. We compared FA in the CC between the patients and the HC groups, and examined changes of FA in the CC after rTMS treatment in the patients.
The patients showed reduced FA in the frontal, parietal, temporal, and occipital-callosal segments compared to the HC group. All patients responded to the rTMS treatment, and FA in the orbital, frontal, parietal, temporal-callosal segments increased after the rTMS treatment.
Our results suggest that white matter integrity in the CC is reduced in TRD and that increased white matter integrity in the CC might be related with the therapeutic mechanisms of rTMS treatment.
Impaired self-awareness has been noted as a core feature of schizophrenia. Recent neuroimaging studies examining self-referential process in schizophrenia have yielded inconsistent results. We aimed to examine the self-referential neural network using the self- and other-evaluation tasks in schizophrenia.
Fifteen schizophrenia patients and fifteen age-, sex- and parental education-matched healthy subjects underwent functional magnetic resonance imaging. Subjects were required to make a decision whether the sentence described their own personal trait (self-evaluation) and that of their close friends (other-evaluation).
Both patients and healthy groups showed significant activation in multiple brain regions including the medial- and lateral-prefrontal, temporal and parietal cortices during self- and other-evaluation tasks. The control subjects showed higher activations in left posterior cingulate and parahippocampal gyri during self-evaluation than other-evaluation, whereas there was no difference in activated regions between self- and other-conditions in the patients. As compared with the controls, the patients showed higher activations in the right superior frontal and right supramarginal gyri during self-evaluation.
These findings provide evidence for neural basis for deficits in self-awareness in schizophrenia and may underlie core clinical symptomatology of schizophrenia.
In bipolar disorder (BD), reduced white matter (WM) integrity in the corpus callosum has been reported, but its detailed localization difference has not been clarified. In this study, we examined fiber integrity in 7 segments of the corpus callosum and their relationships with clinical symptoms in BD.
Patients with BD (BD group, n = 17) and age-matched healthy controls (HC group, n = 24) were examined using diffusion tensor imaging tractography. The corpus callosum was divided into 7 segments (orbital frontal, anterior frontal, superior frontal, superior parietal, posterior parietal, temporal, and occipital) based on their cortical projection zones, and fractional anisotropy (FA) value of each segment was estimated. Differences in FA of each segment between the groups were examined using ANOVA with repeated measures. Correlations between FA of each segment and clinical symptoms (HAM-D, YMRS) were assessed using Spearman's rank correlation test in the BD group.
The BD group showed reduced FA in the orbital frontal, superior frontal, and posterior parietal-callosal segments compared to the HC group. In addition, the BD group showed a significant negative correlation between FA in the orbital frontal-callosal segment and HAM-D scores.
Our results suggest that WM integrity in the anterior part of the corpus callosum is reduced in BD and that orbital frontal-callosal disintegrity may be related with severity of bipolar depression.
The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together
programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories.
Flight-deck Interval Management (FIM) is a modern airborne self-spacing technology that improves arrival route throughput and runway utilisation and increases hourly arrival capacity by up to four aircraft per hour and per runway, compared to conventional air traffic controller guided arrivals. The National Aeronautics and Space Administration (NASA) has been the leader in FIM research and formulated a logic that was put to an actual flight test in 2017. Despite the overall success of the project, operational deficiencies concerning the number of speed commands, which led to several recommendations for future research before operational implementation, were discovered. In this study, a new logic that implements a two-stage rule-based selection algorithm was developed to overcome those deficiencies. The proposed logic was compared to NASA’s logic on an arrival in Tokyo International Airport with multiple induced error patterns. The results indicate that the new logic significantly decreases the number of speed commands with only minor aggravations in spacing performance. The results that highlight the strengths and weaknesses of both concepts are discussed, and an outlook on and ideas for future research on FIM and the proposed logic are presented.
We studied a suitable procedure for preparing of water samples used in radiocarbon intercomparisons involving dissolved inorganic carbon (DIC). The water samples must have inter-batch consistency and stable 14C concentrations and no sterilizing agent (e.g., HgCl2) should be added, in order to avoid the production of hazardous material. Six water samples, containing widely different amounts and types of salts, DIC, and 14C concentrations (1–100 pMC), were prepared in order to assess the procedure. Sample consistency was investigated through δ13C and chemical compositions; their low variabilities indicate that our procedure can be applied to radiocarbon intercomparison. A specific sample preparation protocol was developed for this kind of applications.
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.
In this study, direct numerical simulation of the flow around a rotating sphere at high Mach and low Reynolds numbers is conducted to investigate the effects of rotation rate and Mach number upon aerodynamic force coefficients and wake structures. The simulation is carried out by solving the three-dimensional compressible Navier–Stokes equations. A free-stream Reynolds number (based on the free-stream velocity, density and viscosity coefficient and the diameter of the sphere) is set to be between 100 and 300, the free-stream Mach number is set to be between 0.2 and 2.0, and the dimensionless rotation rate defined by the ratio of the free-stream and surface velocities above the equator is set between 0.0 and 1.0. Thus, we have clarified the following points: (1) as free-stream Mach number increased, the increment of the lift coefficient due to rotation was reduced; (2) under subsonic conditions, the drag coefficient increased with increase of the rotation rate, whereas under supersonic conditions, the increment of the drag coefficient was reduced with increasing Mach number; and (3) the mode of the wake structure becomes low-Reynolds-number-like as the Mach number is increased.
For livestock production systems to play a positive role in global food security, the balance between their benefits and disbenefits to society must be appropriately managed. Based on the evidence provided by field-scale randomised controlled trials around the world, this debate has traditionally centred on the concept of economic-environmental trade-offs, of which existence is theoretically assured when resource allocation is perfect on the farm. Recent research conducted on commercial farms indicates, however, that the economic-environmental nexus is not nearly as straightforward in the real world, with environmental performances of enterprises often positively correlated with their economic profitability. Using high-resolution primary data from the North Wyke Farm Platform, an intensively instrumented farm-scale ruminant research facility located in southwest United Kingdom, this paper proposes a novel, information-driven approach to carry out comprehensive assessments of economic-environmental trade-offs inherent within pasture-based cattle and sheep production systems. The results of a data-mining exercise suggest that a potentially systematic interaction exists between ‘soil health’, ecological surroundings and livestock grazing, whereby a higher level of soil organic carbon (SOC) stock is associated with a better animal performance and less nutrient losses into watercourses, and a higher stocking density with greater botanical diversity and elevated SOC. We contend that a combination of farming system-wide trials and environmental instrumentation provides an ideal setting for enrolling scientifically sound and biologically informative metrics for agricultural sustainability, through which agricultural producers could obtain guidance to manage soils, water, pasture and livestock in an economically and environmentally acceptable manner. Priority areas for future farm-scale research to ensure long-term sustainability are also discussed.
The cross power spectrum of the 21 cm signal and Lyman-α emitters (LAEs) is a probe of the Epoch of Reionization. Astrophysical foregrounds do not correlate with the LAE distribution, though the foregrounds contribute to the error. To study the impact of foregrounds on the measurement, we assume realistic observation by the Murchison Widefield Array using a catalogue of radio galaxies, a LAE survey by the Subaru Hyper Supreme-Cam and the redshift of LAEs is determined by the Prime Focus Spectrograph. The HI distribution is estimated from a radiative transfer simulation with models based on results of radiation hydrodynamics simulation. Using these models, we found that the error of cross power spectrum is dominated by foreground terms. Furthermore, we estimate the effects of foreground removal, and find 99% of the foreground removal is required to detect the 21 cm-LAE signal at k ∼ 0.4 h Mpc−1.
In order to investigate the distinguishability about the progenitors of FeCCSNe and ECSNe, we calculate the luminosities and spectra of their pre-SN neutrinos and estimate the number of events at neutrino detectors.