3,005 research outputs found
Large-Area Scintillator Hodoscope with 50 ps Timing Resolution Onboard BESS
We describe the design and performance of a large-area scintillator hodoscope
onboard the BESS rigidity spectrometer; an instrument with an acceptance of 0.3
m^{2}sr.
The hodoscope is configured such that 10 and 12 counters are respectively
situated in upper and lower layers.
Each counter is viewed from its ends by 2.5 inch fine-mesh photomultiplier
tubes placed in a stray magnetic field of 0.2 Tesla.
Various beam-test data are presented.
Use of cosmic-ray muons at ground-level confirmed 50 ps timing resolution for
each layer, giving an overall time-of-flight resolution of 70 ps rms using a
pure Gaussian resolution function.
Comparison with previous measurements on a similar scintillator hodoscope
indicates good agreement with the scaling law that timing resolution is
proportional to 1/, where is the effective
number of photoelectrons.Comment: 16 pages, 14 figure
Mars mission solar array Semiannual progress report, period ending 31 Dec. 1969
Design and testing of beryllium-structure solar panel for Mars missio
A new ultra high energy gamma ray telescope at Ohya mine
The search for ultra high energy gamma rays coming from point sources is one of the main experimental aims. A fast air shower timing system was constructed at ICRR for the study of the angular resolution of the system and operated approximately half a year. The characteristics of the surface array of Ohya air shower telescope is described
Bayesian inference with an adaptive proposal density for GARCH models
We perform the Bayesian inference of a GARCH model by the Metropolis-Hastings
algorithm with an adaptive proposal density. The adaptive proposal density is
assumed to be the Student's t-distribution and the distribution parameters are
evaluated by using the data sampled during the simulation. We apply the method
for the QGARCH model which is one of asymmetric GARCH models and make empirical
studies for for Nikkei 225, DAX and Hang indexes. We find that autocorrelation
times from our method are very small, thus the method is very efficient for
generating uncorrelated Monte Carlo data. The results from the QGARCH model
show that all the three indexes show the leverage effect, i.e. the volatility
is high after negative observations
Identification problems of muon and electron events in the Super-Kamiokande detector
In the measurement of atmospheric nu_e and nu_mu fluxes, the calculations of
the Super Kamiokande group for the distinction between muon-like and
electronlike events observed in the water Cerenkov detector have initially
assumed a misidentification probability of less than 1 % and later 2 % for the
sub-GeV range. In the multi-GeV range, they compared only the observed
behaviors of ring patterns of muon and electron events, and claimed a 3 %
mis-identification. However, the expressions and the calculation method do not
include the fluctuation properties due to the stochastic nature of the
processes which determine the expected number of photoelectrons (p.e.) produced
by muons and electrons. Our full Monte Carlo (MC) simulations including the
fluctuations of photoelectron production show that the total mis-identification
rate for electrons and muons should be larger than or equal to 20 % for sub-GeV
region. Even in the multi-GeV region we expect a mis-identification rate of
several % based on our MC simulations taking into account the ring patterns.
The mis-identified events are mostly of muonic origin.Comment: 17 pages, 12 figure
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MicroRNA-383 located in frequently deleted chromosomal locus 8p22 regulates CD44 in prostate cancer.
A major genomic alteration in prostate cancer (PCa) is frequent loss of chromosome (chr) 8p with a common region of loss of heterozygosity (LOH) at chr8p22 locus. Genomic studies implicate this locus in the initiation of clinically significant PCa and with progression to metastatic disease. However, the genes within this region have not been fully characterized to date. Here we demonstrate for the first time that a microRNA component of this region-miR-383-is frequently downregulated in prostate cancer, has a critical role in determining tumor-initiating potential and is involved in prostate cancer metastasis via direct regulation of CD44, a ubiquitous marker of PCa tumor-initiating cells (TICs)/stem cells. Expression analyses of miR-383 in PCa clinical tissues established that low miR-383 expression is associated with poor prognosis. Functional data suggest that miR-383 regulates PCa tumor-initiating/stem-like cells via CD44 regulation. Ectopic expression of miR-383 inhibited tumor-initiating capacity of CD44+ PCa cells. Also, 'anti-metastatic' effects of ectopic miR-383 expression were observed in a PCa experimental metastasis model. In view of our results, we propose that frequent loss of miR-383 at chr8p22 region leads to tumor initiation and prostate cancer metastasis. Thus, we have identified a novel finding that associates a long observed genomic alteration to PCa stemness and metastasis. Our data suggest that restoration of miR-383 expression may be an effective therapeutic modality against PCa. Importantly, we identified miR-383 as a novel PCa tissue diagnostic biomarker with a potential that outperforms that of serum PSA
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