Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission

General ion recombination effect in a liquid ionization chamber in high-dose-rate pulsed photon and electron beams

Liquid ionization chambers (LICs) are highly sensitive to dose irradiation and have small perturbations because of their liquid-filled sensitive volume. They require a sensitive volume much smaller than conventional air-filled chambers. However, it has been reported that the collection efficiency has dependencies on the dose per pulse and the pulse repetition frequency of a pulsed beam. The purpose of this study was to evaluate in detail the dependency of the ion collection efficiency on the pulse repetition frequency. A microLion (PTW, Freiburg, Germany) LIC was exposed to photon and electron beams from a TrueBeam (Varian Medical Systems, Palo Alto, USA) linear accelerator. The pulse repetition frequency was varied, but the dose per pulse was fixed. A theoretical evaluation of the collection efficiency was performed based on Boag’s theory. Linear correlations were observed between the frequency and the relative collection for all energies of the photon and electron beams. The decrease in the collected charge was within 1% for all the flattened photon and electron beams, and they were 1.1 and 1.8% for the 6 and 10 MV flattening filter-free photon beams, respectively. The theoretical ion collection efficiency was 0.990 for a 10 MV flattened photon beam with a dose rate of 3 Gy·min−1. It is suggested that the collected charge decreased because of the short time intervals of the beam pulse compared with the ion collection time. Thus, it is important to correctly choose the pulse repetition frequency, particularly when flattening filter-free mode is used for absolute dose measurements

Involvement of Adrenomedullin Expression in Tumor Cells and Stroma in the Development of Diabetes in Pancreatic Cancer Patients

Some studies have reported that adrenomedullin （AM） is involved in diabetes mellitus （DM） associated with pancreatic cancer. Therefore, in this study we investigated the relationship between diabetes and AM expression in patients with pancreatic cancer. We examined 48 biopsies and 26 surgical resections from 74 patients with histologically diagnosed pancreatic cancer. Patients were classified into either DM or non-DM groups. The immunohistochemical expression of AM and various clinicopathological factors were compared between the two groups. Among the biopsy cases, 21 were classified as DM and 27 as non-DM. AM expression in pancreatic cancer cells was significantly lower in the DM group （p＝0.03）. No significant differences were noted in age, body mass index, tumor diameter or location, serum CA19-9, amylase, or C-reactive protein levels, pancreatic ductal dilatation, portal vein invasion, clinical stage, or histological differentiation between the DM and non-DM groups. The proportion of men was significantly lower in the DM group （p＝0.04）, as was the frequency of liver metastasis at diagnosis （p＝0.03）. Among the resection cases, 13 were classified as DM and 13 as non-DM. There were no significant differences in AM expression in pancreatic cancer cells between the two groups. However, marked AM expression was observed in the inflammatory cells and fibroblasts of the tumor stroma in all cases. In addition, the inflammatory response in the tumor stroma tended to be stronger in the DM group. Although the present study failed to find a positive correlation between diabetes and AM expression in pancreatic cancer cells, the results indicate that AM expression in stromal cells may be more closely related to the development of DM in pancreatic cancer patients

Influence of secondary neutrons induced by proton radiotherapy for cancer patients with implantable cardioverter defibrillators

<p>Abstract</p> <p>Background</p> <p>Although proton radiotherapy is a promising new approach for cancer patients, functional interference is a concern for patients with implantable cardioverter defibrillators (ICDs). The purpose of this study was to clarify the influence of secondary neutrons induced by proton radiotherapy on ICDs.</p> <p>Methods</p> <p>The experimental set-up simulated proton radiotherapy for a patient with an ICD. Four new ICDs were placed 0.3 cm laterally and 3 cm distally outside the radiation field in order to evaluate the influence of secondary neutrons. The cumulative in-field radiation dose was 107 Gy over 10 sessions of irradiation with a dose rate of 2 Gy/min and a field size of 10 × 10 cm². After each radiation fraction, interference with the ICD by the therapy was analyzed by an ICD programmer. The dose distributions of secondary neutrons were estimated by Monte-Carlo simulation.</p> <p>Results</p> <p>The frequency of the power-on reset, the most serious soft error where the programmed pacing mode changes temporarily to a safety back-up mode, was 1 per approximately 50 Gy. The total number of soft errors logged in all devices was 29, which was a rate of 1 soft error per approximately 15 Gy. No permanent device malfunctions were detected. The calculated dose of secondary neutrons per 1 Gy proton dose in the phantom was approximately 1.3-8.9 mSv/Gy.</p> <p>Conclusions</p> <p>With the present experimental settings, the probability was approximately 1 power-on reset per 50 Gy, which was below the dose level (60-80 Gy) generally used in proton radiotherapy. Further quantitative analysis in various settings is needed to establish guidelines regarding proton radiotherapy for cancer patients with ICDs.</p

Acute urinary retention in a 23-year-old woman with mild encephalopathy with a reversible splenial lesion: a case report

<p>Abstract</p> <p>Introduction</p> <p>Patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion present with relatively mild central nervous system disturbances. Although the exact etiology of the condition remains poorly understood, it is thought to be associated with infective agents. We present a case of a patient with mild encephalitis/encephalopathy with a reversible splenial lesion, who had the unusual feature of acute urinary retention.</p> <p>Case presentation</p> <p>A 23-year-old Japanese woman developed mild confusion, gait ataxia, and urinary retention seven days after onset of fever and headache. Magnetic resonance imaging demonstrated T2 prolongation in the splenium of the corpus callosum and bilateral cerebral white matter. These magnetic resonance imaging abnormalities disappeared two weeks later, and all of the symptoms resolved completely within four weeks. Except for the presence of acute urinary retention (due to underactive detrusor without hyper-reflexia), the clinical and radiologic features of our patient were consistent with those of previously reported patients with mild encephalitis/encephalopathy with a reversible splenial lesion. To the best of our knowledge, this is the first report of acute urinary retention recognized in a patient with mild encephalitis/encephalopathy with a reversible splenial lesion.</p> <p>Conclusion</p> <p>Our findings suggest that mild encephalitis/encephalopathy with a reversible splenial lesion can be associated with impaired bladder function and indicate that acute urinary retention in this benign disorder should be treated immediately to avoid bladder injury.</p

JASMINE: Near-infrared astrometry and time-series photometry science

The Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is Galactic archaeology with a Galactic Center survey, which aims to reveal the Milky Way’s central core structure and formation history from Gaia-level (∼25 ${\mu}$as) astrometry in the near-infrared (NIR) Hw band (1.0–1.6 ${\mu}$m). The other is an exoplanet survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic Center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information on the stars in the Galactic Center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic Center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars, and microlensing studies, including discovery of (intermediate-mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions

Data from: Distribution and drift dispersal dynamics of a caddisfly grazer in response to resource abundance and its ontogeny

Stream grazers have a major impact on food web structure and the productivity of stream ecosystems; however, studies on the longitudinal (upstream versus downstream) and temporal changes in their drift dynamics and resulting distributions remain limited. Here, we investigated the longitudinal and temporal distributions and drift propensity of a trichopteran grazer, the caddisfly, Micrasema quadriloba, during its life cycle in a Japanese stream. The distribution of larvae significantly shifted downstream during the fifth instar larval stage during late winter; with periphyton abundance (i.e. their food source) showing similar shifts downstream. Therefore, our results show that the drift dispersal the caddisfly occurs in response to decline in available food resources (i.e. food-resource scarcity) and an increase in food requirements by growing individuals. Furthermore, our results show that this observed longitudinal shift in larval distribution varies through their life cycle, because the drift dispersal of fifth instar larvae was greater than that of immature larvae. The correlation between periphyton abundance and drift propensity of fourth instar larvae was not statistically significant, whereas that of fifth instar larvae was significantly negative. In conclusion, we detected an ontogenetic shift in drift propensity, which might explain the longitudinal and temporal distributions of this species

A diamond 14 MeV neutron energy spectrometer with high energy resolution

A self-standing single-crystal chemical vapor deposited diamond was obtained using lift-off method. It was fabricated into a radiation detector and response function measurements for 14 MeV neutrons were taken at the fusion neutronics source. 1.5% of high energy resolution was obtained by using the C-12(n, alpha)Be-9 reaction at an angle of 100 degrees with the deuteron beam line. The intrinsic energy resolution, excluding energy spreading caused by neutron scattering, slowing in the target and circuit noises was 0.79%, which was also the best resolution of the diamond detector ever reported

Dataset-Katano_et_al_RSOS

The all data used in the paper, grazer (M. quadriloba larvae) density and chlorophyll (chl) a of periphyton in the stream