136 research outputs found
Antineutrino Charm Production and Pentaquark Search in the CHORUS Experiment
During the years between 1994 and 1997, the emulsion target of the CHORUS experiment was exposed to the wide band neutrino beam of the CERN SPS of 27 GeV average energy collecting about 106 neutrino interactions. A measurement of induced charm production and search for anticharmed pentaquark (0 c ) have been performed by using the presence of a 6% component in the beam. By requiring a positive muon charge as determined by the CHORUS muon spectrometer, 46 -induced charm events were observed with an estimated background of 5:20:4 events. By using the data sample, anticharmed pentaquark ( 0 c ) have been searched and no evidence is found. Based on the null observation, the limit on the 0 c production is found as a function of di eren t possible 0 c lifetimes. The tightest bound is 0 c = < 0.039 at 90% C.L by assuming that 0 c lifetime is equal to 0.5 c D 0. (not complete
Does the donor-acceptor concept work for designing synthetic metals? 2. Theoretical investigation of copolymers of 4-(dicyanomethylene)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene and 3,4-(ethylenedioxy)thiophene
Density functional theory (DFT) calculations were performed on oligomers of 3,4-(ethylenedioxy)thiophene (EDOT), 4-(dicyanomethylene)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene (CDM), and co-oligomers (CDM/ EDOT). Oligomer data were extrapolated to polymer values. Theoretical band gaps reproduce λmax from UV spectroscopy for PEDOT and are about 1 eV larger than electrochemical band gaps. λmax of PCDM/EDOT is predicted to be 0.42 eV smaller than that of PEDOT and 0.15 eV smaller than that of PCDM. PCDM/EDOT has a wide valence and an extremely narrow conduction "band". It is probably better not to refer to these localized states as a band at all. This rationalizes the mobility ratio of 500 between p-type and n-type charge carriers and the low n-type conductivity of PCDM/EDOT. The lack of dispersion of the conduction band is due to the very different EAs of EDOT and CDM
Nonrectangular wavelets for multiresolution mesh analysis and compression
We propose a new Set Partitioning In Hierarchical Trees (SPIHT) based mesh compression framework. The 3D mesh is first transformed to 2D images on a regular grid structure. Then, this image-like representation is wavelet transformed and SPIHT is applied on the wavelet domain data. The method is progressive because the resolution of the reconstructed mesh can be changed by varying the length of the ID data stream created by SPIHT algorithm. Nearly perfect reconstruction is possible if full length of 1D data is received
Connectivity-guided adaptive lifting transform for image like compression of meshes
We propose a new connectivity-guided adaptive wavelet transform based mesh compression framework. The 3D mesh is first transformed to 2D images on a regular grid structure by performing orthogonal projections onto the image plane. Then, this image-like representation is wavelet transformed using a lifting structure employing an adaptive predictor that takes advantage of the connectivity information of mesh vertices. Then the wavelet domain data is encoded using "Set Partitioning In Hierarchical Trees" (SPIHT) method or JPEG2000. The SPIHT approach is progressive because the resolution of the reconstructed mesh can be changed by varying the length of the 1D data stream created by the algorithm. In JPEG2000 based approach, quantization of the coefficients determines the quality of the reconstruction. The results of the SPIHT based algorithm is observed to be superior to JPEG200 based mesh coder and MPEG-3DGC in rate-distortion
Rose oil inhalation protects against formaldehyde-induced testicular damage in rats
In this experimental study, harmful effects of formaldehyde (FA) inhalation on
sperm concentration, sperm quality, serum testosterone levels and the rat testes
were investigated. In addition, the possible protective effects of rose oil against
to these harmful effects were evaluated. For this purpose, 21 albino-Wistar rats
were used. The rats in Group I were used as control group. When the rats of
Group II were exposed FA (10 ppm/1 h) for 35 days, the rats of Group III
inhalated rose oil (1 ml/1 h) after FA. The epididymal tissues were taken for
sperm analysing and the testes were removed for histological examination. In
addition, testosterone levels were determined from the blood samples.
Although the testosterone levels, the epididymal sperm concentration, and the
progressive sperm motility significantly decreased, the abnormal sperm rate
significantly increased in the Group II when compared to Group I. In the
Group III, these damages were seen less. When the rats in the Group II
compared with the control group, there were serious histological damages. In
the Group III, it was determined that the histological changes were less than
group II. It can be expressed that serious damages occurred via formaldehyde
exposure in male reproductive system and that the rose oil had protective
effects against these damages
Leading order analysis of neutrino induced dimuon events in the CHORUS experiment
We present a leading order QCD analysis of a sample of neutrino induced
charged-current events with two muons in the final state originating in the
lead-scintillating fibre calorimeter of the CHORUS detector. The results are
based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign
dimuon events collected during the exposure of the detector to the CERN Wide
Band Neutrino Beam between 1995 and 1998. % with GeV
and GeV collected %between 1995 and 1998. The analysis yields a
value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a
value of the ratio of the strange to non-strange sea in the nucleon of , improving the results obtained in similar analyses
by previous experiments.Comment: Submitted to Nuclear Physics
Charged-Particle Multiplicities in Charged-Current Neutrino-- and Anti-Neutrino--Nucleus Interactions
The CHORUS experiment, designed to search for
oscillations, consists of a nuclear emulsion target and electronic detectors.
In this paper, results on the production of charged particles in a small sample
of charged-current neutrino-- and anti-neutrino--nucleus interactions at high
energy are presented. For each event, the emission angle and the ionization
features of the charged particles produced in the interaction are recorded,
while the standard kinematic variables are reconstructed using the electronic
detectors. The average multiplicities for charged tracks, the pseudo-rapidity
distributions, the dispersion in the multiplicity of charged particles and the
KNO scaling are studied in different kinematical regions. A study of
quasi-elastic topologies performed for the first time in nuclear emulsions is
also reported. The results are presented in a form suitable for use in the
validation of Monte Carlo generators of neutrino--nucleus interactions.Comment: 17 pages, 5 figure
Associated Charm Production in Neutrino-Nucleus Interactions
In this paper a search for associated charm production both in neutral and
charged current -nucleus interactions is presented. The improvement of
automatic scanning systems in the {CHORUS} experiment allows an efficient
search to be performed in emulsion for short-lived particles. Hence a search
for rare processes, like the associated charm production, becomes possible
through the observation of the double charm-decay topology with a very low
background. About 130,000 interactions located in the emulsion target
have been analysed. Three events with two charm decays have been observed in
the neutral-current sample with an estimated background of 0.180.05. The
relative rate of the associated charm cross-section in deep inelastic
interactions, has been
measured. One event with two charm decays has been observed in charged-current
interactions with an estimated background of 0.180.06 and the
upper limit on associated charm production in charged-current interactions at
90% C.L. has been found to be .Comment: 10 pages, 4 figure
NOXA expression drives synthetic lethality to RUNX1 inhibition in pancreatic cancer
Evasion from drug-induced apoptosis is a crucial mechanism of cancer treatment resistance. The proapoptotic protein NOXA marks an aggressive pancreatic ductal adenocarcinoma (PDAC) subtype. To identify drugs that unleash the death-inducing potential of NOXA, we performed an unbiased drug screening experiment. In NOXA-deficient isogenic cellular models, we identified an inhibitor of the transcription factor heterodimer CBFβ/RUNX1. By genetic gain and loss of function experiments, we validated that the mode of action depends on RUNX1 and NOXA. Of note is that RUNX1 expression is significantly higher in PDACs compared to normal pancreas. We show that pharmacological RUNX1 inhibition significantly blocks tumor growth in vivo and in primary patient-derived PDAC organoids. Through genome-wide analysis, we detected that RUNX1-loss reshapes the epigenetic landscape, which gains H3K27ac enrichment at the NOXA promoter. Our study demonstrates a previously unknown mechanism of NOXA-dependent cell death, which can be triggered pharmaceutically. Therefore, our data show a way to target a therapy-resistant PDAC, an unmet clinical need
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