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The CANGAROO project incorporates two Čerenkov imaging telescopes at Woomera to obtain stereo images of very high-energy gamma-ray (and cosmic-ray) showers. The first stereo observations, with one imaging system, were made in March 1992, and preliminary stereo imaging observations began in July 1992. This paper describes the stereo imaging technique, the sources under investigation, and the indications from the first data sets.
In this paper the Very High Energy (VHE) gamma-ray astronomy program at the University of Adelaide is described. VHE gamma rays with energies above ~5 × 1011eV are observed using the atmospheric Cerenkov technique. Results from the first three years observations at Woomera and the current upgrading of the telecope are described. The CANGAROO project, a collaboration between the University of Adelaide and a number of Japanese institutions, is also introduced.
Shiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.
The superbubble (SB) 30 Dor C with the strong non-thermal X-ray emission is one of the best targets for study of the cosmic-ray (CR) acceleration. We investigated X-ray spectral properties of the SB with a high spatial resolution of ~10 pc. Consequently, the spectra in the east regions can be described with a combination of absorbed thermal and non-thermal models while the spectra in the west regions can be fitted with an absorbed non-thermal model. We found that the observed photon index and intensity in 2-10 keV show variations of 2.0-3.5 and (0.6-8.0) × 10−7 erg s−1 cm−2 str−1, respectively. The results are possibly caused by the spatial variation of the CR acceleration efficiency and/or the circumstellar environment.
We report the Eu doping induced improvement on the second harmonic generation (SHG) of ZnO nanowires and correlates with the structural modification and corresponding linear absorption. A non-monotonic enhancement in the SHG emission is observed with the increase of Eu concentration. To understand the underlying mechanism, the effective second order non–linear coefficient (deff) is calculated from the theoretical fitting with considering the absorption effect. The highest deff (19.09±0.11 pm/V) is obtained for the 1 at.% Eu doped ZnO nanowires, which is several times larger than the standard SHG material β-BaB2O4 (BBO). Dependence of the deff with the Eu doping, structural modification and absorption magnitude are systematically discussed.
Effect of high-pressure water vapor (HPV) annealing is discussed from density of state (DOS) by capacitance–voltage (C–V) method and ΔVFB by the cyclic C–V measurement. The DOS of HPV samples were smaller than that of conventional atmosphere (AT) annealing around conduction band minimum (Ec). The ΔVFB of HPV samples were also smaller than that of AT. This suggests that HPV annealing is an effective method to decrease electron trap density as compared with AT condition. Especially, HPV 0.5 MPa sample was lower electron trap density and more stable than the other pressure HPV samples. Therefore, it is considered that the HPV in 0.5 MPa is the most promising condition. In addition, we succeeded in demonstrating the analysis of trap density in thin film by C–V method and cyclic C–V measurement.
Maternal food restriction is known to cause developmental hypertension in offspring. We have previously shown that maternal high-protein diet can reverse fetal programming of hypertension and that branched-chain amino acid (BCAA) concentrations in maternal and fetal plasma were increased by maternal high-protein intake. Then, we hypothesized that isocaloric supplementation with BCAA to a maternal food restriction can reverse the adverse outcome. Pregnant rats were divided into four groups at 7.5 days postcoitum: normally nourished (NN) and 70% undernourished (UN) groups with and without BCAA supplementation (NN–standard diet (SD), NN–BCAA, UN–SD and UN–BCAA groups). Compared with pups in the NN groups, those in the UN–SD group had significantly increased systolic blood pressure (SBP) at 8 and 16 weeks of age (P < 0.05). However, the elevation of SBP was not observed in offspring in the UN–BCAA group. Offspring glomeruli number of the UN groups was significantly lower (P < 0.05) than that of the NN groups, independent of BCAA supplementation. Angiotensin II receptor type 2 (ATR2) mRNA and protein expression in the kidney was significantly augmented in the UN–BCAA group at 30 weeks of age. In conclusion, BCAA supplementation during maternal food restriction prevents developmental hypertension together with increased ATR2 expression in adult offspring kidney.
We prepare Nd-Bi codoped zeolites by a method consisting of a simple ion-exchange process and subsequent high-temperature annealing. The emission covers the range of 970∼1450 nm, corresponding to the electronic transitions of Nd3+ ions and Bi-related active centers (BiRAC), respectively. The introduction of Bi distinctly broadens the excitation band of Nd3+ in the visible region, and the lifetime of Nd3+ reaches as long as 354 μs. In the zeolite matrix, Bi ions exist as BiRAC and Bi oxide agglomerates. The former one act as a sensitizer of Nd3+ ions, and the latter one act as a blockage to avoid the quenching effect of coordinated water, which enable Nd3+ ions to show efficient near-infrared (NIR) emission even the zeolites contain large amount of coordinated water. The excellent optical and structural properties make these NIR emitting nanoparticles promising in application as laser materials and biological probes.
An understanding of the dose-effect relationships of ionising radiation for nonhuman biota establishes important baselines for the radiological protection of ecosystems. We used standard laboratory tests to examine the dose-effect relationships of gamma radiation on the survival, growth and reproduction of the earthworm, Eisenia fetida (Oligochaeta). Adult E. fetida were acutely irradiated with increasing doses of gamma radiation, and the subsequent survival, growth in wet weight and number of offspring were examined. The 50% lethal dose (LD50) was 825 Gy, and the 10% and 50% effective doses (ED10 and ED50) for growth were 20.2 and 94.7 Gy, respectively. The ED10 and ED50 for reproduction were 3.3 and 11.1 Gy, respectively.
We examined microorganisms and pollen in a pit (4.5m deep) and a shallow ice core (25.01m long) from Sofiyskiy glacier in the Altai mountains of Russia for potential use in dating ice cores from a mid-latitude glacier. The ice-core and pit samples contained various green algae, cyanobacteria, bacteria, fungi and pollen. In the vertical profiles of the pit, algal biomass peaks corresponded to high δ18O layers and Pinaceae pollen peaks, suggesting that these algae grew during the melt season. In contrast, the layer with the lowest δ18O contained almost no algal cells. Major peaks of the cyanobacteria, bacteria and a fungus roughly corresponded to those of the algae. However, seasonal changes in these microorganisms became indistinct deeper in the core, as did the seasonal variation in δ18O and major ions, most likely due to heavy meltwater percolation and/or post-depositional decomposition. In contrast, clear seasonal cycles were evident in the algal biomass and pollen in snow samples. Assuming that the peaks of the snow algae and Pinaceae pollen marked summer layers and that the layers with almost no snow algae represented the winter layers, we estimated that the ice core contained 16 annual layers (1985–2001). The mean annual mass balance for the period was estimated to be 1.01mw.e. The value agreed well with those estimated from stake measurements, indicating that snow algae and pollen could provide reliable boundary markers of annual layers in the ice cores of this region.