Validation of CFD Codes for the Helicopter Wake in Ground Effect

When a helicopter takes off, lands, or makes hovering or taxiing flights in ground effect, its downwash interferes with the ground. Encounters with such highly turbulent helicopter wakes have been blamed for two fixed-wing aircraft crashes in the United Kingdom. Additional incidents including tents blown away are reported in Japan. Due to these accidents, the Japan Aerospace Exploration Agency (JAXA) and the University of Glasgow (UoG) are investigating the helicopter wake structure in ground effect, especially during taxiing, by means of computational fluid dynamics (CFD). In this study, CFD codes of UoG and JAXA are validated through comparing numerical results of each party and flight experiment data. As a result, it is found that the CFD codes show qualitatively the same results each other and they are also close to the experiment

Difference in Serum Levels of Vitamin D Between Canalolithiasis and Cupulolithiasis of the Horizontal Semicircular Canal in Benign Paroxysmal Positional Vertigo

Background and Purpose: In the horizontal canal benign paroxysmal positional vertigo (BPPV), cupulolithiasis shows apogeotropic direction changing nystagmus lasting more than 1 min, while canalolithiasis leads to geotropic direction changing nystagmus lasting < 1 min. The difference between cupulolithiasis and canalolithiasis is widely accepted to be the attachment of the displaced otoconia to the cupula of a semicircular canal. Several studies have shown a relationship between BPPV and vitamin D deficiency, but no studies have compared serum levels of vitamin D between canalolithiasis and cupulolithiasis patients. The purpose of this study was to clarify the difference in vitamin D serum level between canalolithiasis and cupulolithiasis of the horizontal canal.Methods: This retrospective study included 20 and 15 patients with canalolithiasis and cupulolithiasis of the horizontal canal, respectively. Serum levels of 25-hydroxyvitamin D [25(OH)D] during the acute phase of BPPV were measured.Results: The mean 25(OH)D serum level in patients with canalolithiasis and cupulolithiasis was 13.2 ± 1.4 and 20.4 ± 1.6 ng/mL, respectively, and the difference was statistically significant (p = 0.0014), also after adjusting for age and sex (p = 0.0351). Eighteen out of 20 (90%) and 5 of 15 (33%) patients were diagnosed with vitamin D deficiency in the canalolithiasis and cupulolithiasis groups, respectively, and this difference was also statistically significant (p = 0.0005).Conclusion: We found that serum vitamin D level in patients with canalolithiasis was significantly lower than that in patients with cupulolithiasis of the horizontal canal

Smaller Hippocampal Volume and Degraded Peripheral Hearing Among Japanese Community Dwellers

A growing body of literature has demonstrated that dementia and hearing loss are interrelated. Recent interest in dementia research has expanded to brain imaging analyses with auditory function. The aim of this study was to investigate the link between hearing ability, which was assessed using pure-tone audiometry, and the volume of brain regions, specifically the hippocampus, entorhinal cortex, Heschl’s gyrus, and total gray matter, using Freesurfer software and T1-weighted brain magnetic resonance imaging. The data for 2082 samples (age range = 40–89 years) were extracted from a population-based cohort of community dwellers. Hearing-impaired individuals showed significantly smaller hippocampal volumes compared with their non-hearing-impaired counterparts for all auditory frequency ranges. In addition, a correlational analysis showed a significant dose-response relationship for hearing ability and hippocampal volume after adjusting for potential confounding factors so that the more degraded the peripheral hearing was, the smaller the hippocampal volume was. This association was consistent through the auditory frequency range. The volume of the entorhinal cortex, right Heschl’s gyrus and total gray matter did not correlate with hearing level at any frequency. The volume of the left Heschl’s gyrus showed a significant relationship with the hearing levels for some auditory frequencies. The current results suggested that the presence of hearing loss after middle age could be a modifier of hippocampal atrophy

A phase II study of amrubicin and carboplatin for previously untreated patients with extensive-disease small cell lung cancer

Background: Amrubicin is active in the treatment of extensive-disease small cell lung cancer (ED-SCLC), and carboplatin is an analogue of cisplatin with less non-hematological toxicity. Purpose: The purpose of this study was to determine the efficacy and toxicity of amrubicin and carboplatin combination chemotherapy for previously untreated patients with ED-SCLC. Patients and methods: Eligibility criteria were chemotherapy-naive ED-SCLC patients, performance status 0-1, age ?75, and adequate hematological, hepatic and renal function. Based on the phase I study, the patients received amrubicin 35 mg/m2 i.v. infusion on days 1, 2, and 3, and carboplatin AUC 5 i.v. infusion on day 1. Four cycles of chemotherapy were repeated every 3 weeks. Results: Thirty-five patients were enrolled, and 34 patients were eligible and assessable for response, toxicity, and survival. Patients\u27 characteristics were as follows: male/female = 26/8; performance status 0/1 = 4/30; median age (range) = 64 (41-75); stage IV = 34. Evaluation of responses was 6 complete response, 21 partial response, and 7 stable disease (response rate 79.4 %, 95 % CI 63.6-88.5 %). Grade 3 and 4 leukopenia, neutropenia, and thrombocytopenia occurred in 59, 82, and 26 %, respectively. There were no treatment-related deaths or pneumonitis. Three patients experienced hypotension as an amrubicin infusion reaction. The median progression-free survival time was 6.5 months. The median overall survival time and 1-, 2-, and 3-year survival rates were 15.6 months, and 63, 28, and 7 %, respectively. Conclusions: Amrubicin and carboplatin were effective and tolerable as chemotherapy for previously untreated patients with ED-SCLC. Further investigation of amrubicin and carboplatin is warranted

Imaging radio-frequency power distributions by an EBG absorber

A thin electromagnetic band-gap (EBG) absorber is employed to capture the 2-d image of radio-frequency (RF) power distribution. The EBG absorber consists of an array of mushroom unit cells formed on a thin dielectric substrate with a metal backplane, and lumped resistors interconnecting the surface patches of the mushrooms. Around the resonance frequency at which the EBG structure acts as a high-impedance surface, the RF power incident on the surface is absorbed by the lumped resistors which are matched with the incident wave impedance. By detecting directly the amounts of power consumed by the individual resistors, an "RF power imager" can be constructed which captures the 2-d distribution of the RF power illuminating the EBG surface, where polarization discrimination is possible. The resonance (i.e., absorption) frequency is made tunable by adding varactor diodes in parallel with the lumped resistors. The EBG absorber tunable in the frequency range of 700 MHz-2.7 GHz is designed and fabricated, and its performance is evaluated by an equivalent-circuit analysis, simulation and measurement. It is shown that the small resistance of the varactors have a considerable effect on the absorption performance. RF power distributions radiated from a dipole antenna are successfully measured by a matrix of sensitive power detectors installed on the backside of the absorber. Using such an RF power imager, the power distributions of even impulsive RF signals and/or noises can be captured and visualized in situ and in real-time, while the electromagnetic environment is almost undisturbed by the EBG absorber. © 2011 The Institute of Electronics, Information and Communication Engineers

High-Quality Draft Genome Sequence of Burkholderia contaminans CH-1, a Gram-Negative Bacterium That Metabolizes 2-Azahypoxanthine, a Plant Growth-Regulating Compound

publishe