1,265 research outputs found
MACRIB High efficiency - high purity hadron identification for DELPHI
Analysis of the data shows that hadron tags of the two standard DELPHI particle identification packages RIBMEAN and HADSIGN are weakly correlated. This led to the idea of constructing a neural network for both kaon and proton identification using as input the existing tags from RIBMEAN and HADSIGN, as well as preproccessed TPC and RICH detector measurements together with additional dE/dx information from the DELPHI vertex detector. It will be shown in this note that the net output is much more efficient at the same purity than the HADSIGN or RIBMEAN tags alone. We present an easy-to-use routine performing the necessary calculations
A neural network z-vertex trigger for Belle II
We present the concept of a track trigger for the Belle II experiment, based
on a neural network approach, that is able to reconstruct the z (longitudinal)
position of the event vertex within the latency of the first level trigger. The
trigger will thus be able to suppress a large fraction of the dominating
background from events outside of the interaction region. The trigger uses the
drift time information of the hits from the Central Drift Chamber (CDC) of
Belle II within narrow cones in polar and azimuthal angle as well as in
transverse momentum (sectors), and estimates the z-vertex without explicit
track reconstruction. The preprocessing for the track trigger is based on the
track information provided by the standard CDC trigger. It takes input from the
2D () track finder, adds information from the stereo wires of the
CDC, and finds the appropriate sectors in the CDC for each track in a given
event. Within each sector, the z-vertex of the associated track is estimated by
a specialized neural network, with a continuous output corresponding to the
scaled z-vertex. The input values for the neural network are calculated from
the wire hits of the CDC.Comment: Proceedings of the 16th International workshop on Advanced Computing
and Analysis Techniques in physics research (ACAT), Preprint, reviewed
version (only minor corrections
Cerebellar Degeneration as Presenting Symptom of Recurrent Endometrial Stromal Sarcoma with Sex-Cord Elements
We report a 66-year-old woman with slowly progressive ataxia due to cerebellar atrophy. Imaging studies revealed multiple lesions in both the lungs and dorsal subpleural space. A biopsy identified the lesions as metastases of a low-grade endometrial stromal sarcoma containing sex-cord elements. The histological appearance was identical to a uterine tumor the patient was treated for with hysterectomy 16 years before. The metastases were removed surgically, and after 3 months ataxia had regressed. We conclude that the presenting cerebellar degeneration in this patient resulted from the metastatic recurrence of the endometrial tumor
Two Photon Couplings of Hybrid Mesons
A new formalism is developed for the two photon production of hybrid mesons
via intermediate hadronic decays. In an adiabatic and non-relativistic context
with spin 1 pair creation we obtain the first absolute estimates of unmixed
hybrid production strengths to be small (0.03 - 3 eV) in relation to
experimental meson widths (0.1 - 5 keV). Within this context, two photon
experiments at Babar, Cleo II, LEP2 and LHC therefore strongly discriminate
between hybrid and conventional meson wave function components, filtering out
conventional meson components. Decay widths of unmixed hybrids vanish.
Conventional meson two photon widths are roughly in agreement with experiment.Comment: 15 pages, LaTeX, 2 postscript figures, uses epsf. Rewritten for
clarificatio
Evaluation of a Brown Seaweed Extract from Dictyosiphon foeniculaceus as a Potential Therapeutic Agent for the Treatment of Glioblastoma and Uveal Melanoma
Ingredients of brown seaweed like fucoidans are often described for their beneficial biological effects, that might be interesting for a medical application. In this study, we tested an extract from Dictyosiphon foeniculaceus (DF) to evaluate the effects in glioblastoma and uveal melanoma, looking for a possible anti-cancer treatment. We investigated toxicity, VEGF (vascular endothelial growth factor) secretion and gene expression of tumor and non-tumor cells. SVGA (human fetal astrocytes), the human RPE (retinal pigment epithelium) cell line ARPE-19, the tumor cell line OMM-1 (human uveal melanoma), and two different human primary glioblastoma cultures (116-14 and 118-14) were used. Tests for cell viability were conducted with MTS-Assay (3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium), and the proliferation rate was determined with cell counting. VEGF secretion was assessed with ELISA (enzyme-linked immunosorbent assay). The gene expression of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2) and VEGF-A was determined with real-time qPCR (quantitative polymerase chain reaction). DF lowered the cell viability of OMM-1. Proliferation rates of ARPE-19 and OMM-1 were decreased. The VEGF secretion was inhibited in ARPE-19 and OMM-1, whereas it was increased in SVGA and 116-14. The expression of VEGFR1 was absent and not influenced in OMM-1 and ARPE-19. VEGFR2 expression was lowered in 116-14 after 24 h, whereas VEGF-A was increased in 118-14 after 72 h. The extract lowered cell viability slightly and was anti-proliferative depending on the cell type investigated. VEGF was heterogeneously affected. The results in glioblastoma were not promising, but the anti-tumor properties in OMM-1 could make them interesting for further research concerning cancer diseases in the human eye
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