19,281 research outputs found
The MONOLITH project
MONOLITH is a proposed massive (34 kt) magnetized tracking calorimeter at the
Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon
neutrinos. The main goal is to establish (or reject) the neutrino oscillation
hypothesis through an explicit observation of the full first oscillation swing.
The Delta m^2 sensitivity range for this measurement comfortably covers the
complete Super-Kamiokande allowed region. Other measurements include studies of
matter effects and the NC/CC and anti-nu/nu ratio, the study of cosmic ray
muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran
Sasso neutrino beam. Depending on approval, data taking with part of the
detector could start in 2004. The detector and its performance are described,
and its potential later use as a neutrino factory detector is addressed.Comment: 6 pages. Contribution to NUFACT'00 neutrino factory workshop,
Monterey, CA, USA, May 22-26, 200
Four species neutrino oscillations at -Factory: sensitivity and CP-violation
The prospects of measuring the leptonic angles and CP-odd phases at a {\em
neutrino factory} are discussed in the scenario of three active plus one
sterile neutrino. We consider the \nu_\mu \raw \nu_e LSND signal. Its
associated large mass difference leads to observable neutrino oscillations at
short ( km) baseline experiments. Sensitivities to the leptonic angles
down to can be easily achieved with a 1 Ton detector. Longer baseline
experiments ( km) with a 1 Kton detector can provide very clean tests
of CP-violation especially through tau lepton detection.Comment: 15 pages, LaTeX2e, 14 eps files, use package epsfi
Mass Determination from Constraint Effective Potential
The Constraint Effective Potential (CEP) allows a determination of the mass
and other quantities directly, without relying upon asymptotic correlator
decays. We report and discuss the results of some mass calculations in
, obtained from CEP and our improved version of CEP (ICEP).Comment: LATTICE99(Higgs, Yukawa, SUSY
Future Atmospheric Neutrino Detectors
Future experiments focusing on atmospheric neutrino detection are reviewed.
One of the main goals of these experiments is the detection of an unambiguous
oscillation pattern (nu_mu reappearance) to prove the oscillation hypothesis.
Further goals include the discrimination of nu_mu - nu_tau and nu_mu -
nu_sterile oscillations, and the detection of a potential small nu_mu - nu_e
contribution. The search for matter effects in three or more flavour
oscillations can be used to constrain hybrid oscillation models and potentially
measure the sign of delta m^2. The detectors and measurement techniques
proposed to achieve these goals are described, and their physics reach is
discussed.Comment: 9 pages, invited talk at the XIX International Conference on Neutrino
Physics and Astrophysics, Sudbury, Canada, June 16-21, 2000, to appear in
Nucl. Phys. B (Proc. Suppl.
Modulation of 5-Aminolevulinic acid mediated photodynamic therapy induced cell death in a human lung adenocarcinoma cell line
Photodynamic therapy (PDT) is a cancer treatment involving the administration of a photosensitising drug which selectively accumulates in tumor tissue, followed by irradiation with appropriate wavelength light. It triggers photochemical reactions inducing reactive oxygen species (ROS) production with the consequent cellular damage, which ultimately leads to cell death. Porphyrins are the only photosensitizers (PSs) endogenously synthesized by means of administration of the biological precursor, 5- aminolevulinic acid (ALA). Several antioxidants and ROS scavenger agents: reduced glutathione (GSH), mannitol (Man), l-tryptophan (Trp), ascorbate (Asc) and trolox (Trx), were assayed to determine their ability to modulate ALA-based PDT (ALA-PDT); it was performed on A549 human lung adenocarcinoma cells, by incubating with 1mM ALA for 3 hr and followed by irradiation with or without 1 hr pre-incubation with the modulators. They were previously tested for possible cytotoxicity/ photoactivity in concentrations ranging from 0.01 to 20 mM. The ratio between cell survival after ALA-PDT in the presence and in the absence of the scavenger agent (protection grade: PG) was determined, and the concentration showing no cytotoxicity/ photoactivity and providing the highest PG was used in the subsequent experiments. ALA-PDT alone induced a high percentage of apoptotic cell death (98.4 ± 3.5%) as revealed by acridine orange/ethidium bromide staining and AnnexinV-FITC/propidium iodide labelling. Pre-incubation with the modulators at their highest PG concentration significantly reduced apoptotic cells to 48.3 ± 2.7% (Asc), 58.8 ± 4.2 (Trx), 78.5 ± 3.1% (GSH), 64.3 ± 1.6% (Man), 74.6 ± 2.3% (Trp). ROS involvement in early cell death induction after ALA-PDT was tested by flow cytometry using the fluorescent probes dihydro-dichlorofluorescein diacetate (H2-DCFDA) and methoxyvinylpyrene (MVP) for detection of peroxides and singlet oxygen, respectively. ROS production increased after ALA-PDT (H2-DCFDA positive cells, control: 1.1 ± 0.1 %; 10 min-PDT: 69.3 ± 5.6%; MVP positive cells, control: 0.65 ± 0.35%; 10 min-PDT: 83.5 ± 1.9%). Asc prevented peroxide formation (H2-DCFDA positive cells: 50.7 ± 2.8%) and mostly prevented singlet oxygen increase (MVP positive cells: 25.4 ± 5.2%) whereas Trx limited peroxides formation (H2-DCFDA positive cells: 20.8 ± 0.5%), but did not significantly affected singlet oxygen production (MVP positive cells: 73.6 ± 3.4%). Selective scavenger mediated protection against PDT-induced cell death, and direct detection of specific pro-oxidative agents, entail the strong involvement of ROS in ALA-PDT-mediated tumor eradication, suggesting that undesired photodamage to normal tissue might be attenuated by administration of antioxidant agents.Fil: Teijo, Maria Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Diez, Berenice Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Battle, A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Fukuda, Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentin
Probing finite size effects in MonteCarlo calculations
The Constrained Effective Potential (CEP) is known to be equivalent to the
usual Effective Potential (EP) in the infinite volume limit. We have carried
out MonteCarlo calculations based on the two different definitions to get
informations on finite size effects. We also compared these calculations with
those based on an Improved CEP (ICEP) which takes into account the finite size
of the lattice. It turns out that ICEP actually reduces the finite size effects
which are more visible near the vanishing of the external source.Comment: LATTICE98(Gauge, Higgs and Yukawa Models
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