1,343 research outputs found
DEAP-3600 Dark Matter Search at SNOLAB
The DEAP-3600 detector, currently under construction at SNOLAB, has been
designed to achieve extremely low background rates from all sources, including
39Ar beta decays, neutron scatters (from internal and external sources),
surface alpha contamination and radon. An overview of the detector and its
sensitivity are presented.Comment: Proceedings for the 12th International Conference on Topics in
Astroparticle and Underground Physics (TAUP 2011
The Use of a Computer in the Diagnosis of Intracranial Tumours
Experiments in the use of a computer as an aid to diagnosis of intracranial tumours have been started at St. Bartholomew\u27s Hospital in collaboration with The City University. The computer can estimate the probability that a patient has any given type of tumour by comparing the results of tests with those obtained in previous patients whose diagnoses have been established. The computer also determines which is the best investigation, from a statistical point of view, to perform next on the patient in order to confirm the diagnosis
Inclined plate settling for emergency water treatment: towards optimisation
Previous work revealed the potential of an inclined plate settler (IPS) for water treatment in emergency relief applications. Whilst preliminary data demonstrated the tested IPS prototype’s capacity to achieve stable turbidity reductions, further optimisation was warranted. This paper reports on the optimisation and preliminary field testing of an IPS prototype. Trials revealed that after system modification, treatment objectives with regards to turbidity reductions (i.e. < 5 NTU) could be achieved. Such positive results were largely due to the addition of a hydraulic flocculation (conditioning) stage
The novel mTOR inhibitor RAD001 (Everolimus) induces antiproliferative effects in human pancreatic neuroendocrine tumor cells
Background/Aim: Tumors exhibiting constitutively activated PI(3) K/Akt/mTOR signaling are hypersensitive to mTOR inhibitors such as RAD001 (everolimus) which is presently being investigated in clinical phase II trials in various tumor entities, including neuroendocrine tumors (NETs). However, no preclinical data about the effects of RAD001 on NET cells have been published. In this study, we aimed to evaluate the effects of RAD001 on BON cells, a human pancreatic NET cell line that exhibits constitutively activated PI(3) K/Akt/mTOR signaling. Methods: BON cells were treated with different concentrations of RAD001 to analyze its effect on cell growth using proliferation assays. Apoptosis was examined by Western blot analysis of caspase-3/PARP cleavage and by FACS analysis of DNA fragmentation. Results: RAD001 potently inhibited BON cell growth in a dose-dependent manner which was dependent on the serum concentration in the medium. RAD001-induced growth inhibition involved G0/G1-phase arrest as well as induction of apoptosis. Conclusion: In summary, our data demonstrate antiproliferative and apoptotic effects of RAD001 in NET cells in vitro supporting its clinical use in current phase II trials in NET patients. Copyright (c) 2007 S. Karger AG, Basel
The Serine 814 of TRPC6 Is Phosphorylated under Unstimulated Conditions
TRPC are nonselective cation channels involved in calcium entry. Their regulation by phosphorylation has been shown to modulate their routing and activity. TRPC6 activity increases following phosphorylation by Fyn, and is inhibited by protein kinase G and protein kinase C. A previous study by our group showed that TRPC6 is phosphorylated under unstimulated conditions in a human embryonic kidney cells line (HEK293). To investigate the mechanism responsible for this phosphorylation, we used a MS/MS approach combined with metabolic labeling and showed that the serine at position 814 is phosphorylated in unstimulated cells. The mutation of Ser814 into Ala decreased basal phosphorylation but did not modify TRPC6 activity. Even though Ser814 is within a consensus site for casein kinase II (CK2), we showed that CK2 is not involved in the phosphorylation of TRPC6 and does not modify its activity. In summary, we identified a new basal phosphorylation site (Ser814) on TRPC6 and showed that CK2 is not responsible for the phosphorylation of this site
A methodology for the capture and analysis of hybrid data: a case study of program debugging
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Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping
Liquid-argon scintillation detectors are used in fundamental physics
experiments and are being considered for security applications. Previous
studies have suggested that the addition of small amounts of xenon dopant
improves performance in light or signal yield, energy resolution, and particle
discrimination. In this study, we investigate the detector response for xenon
dopant concentrations from 9 +/- 5 ppm to 1100 +/- 500 ppm xenon (by weight) in
6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength
shifter with dual photomultiplier tubes and is operated in single-phase mode.
Gamma-ray-interaction signal yield of 4.0 +/- 0.1 photoelectrons/keV improved
to 5.0 +/- 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV
improved from (4.4 +/- 0.2)% ({\sigma}) to (3.5 +/- 0.2)% ({\sigma}) with
dopant. Pulse-shape discrimination performance degraded greatly at the first
addition of dopant, slightly improved with additional additions, then rapidly
improved near the end of our dopant range, with performance becoming slightly
better than pure argon at the highest tested dopant concentration. Some
evidence of reduced neutron scintillation efficiency with increasing dopant
concentration was observed. Finally, the waveform shape outside the TPB region
is discussed, suggesting that the contribution to the waveform from
xenon-produced light is primarily in the last portion of the slow component
A Study of the Residual 39Ar Content in Argon from Underground Sources
The discovery of argon from underground sources with significantly less 39Ar
than atmospheric argon was an important step in the development of
direct-detection dark matter experiments using argon as the active target. We
report on the design and operation of a low background detector with a single
phase liquid argon target that was built to study the 39Ar content of the
underground argon. Underground argon from the Kinder Morgan CO2 plant in
Cortez, Colorado was determined to have less than 0.65% of the 39Ar activity in
atmospheric argon.Comment: 21 pages, 10 figure
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