27 research outputs found
Semi-classical limit and minimum decoherence in the Conditional Probability Interpretation of Quantum Mechanics
The Conditional Probability Interpretation of Quantum Mechanics replaces the
abstract notion of time used in standard Quantum Mechanics by the time that can
be read off from a physical clock. The use of physical clocks leads to apparent
non-unitary and decoherence. Here we show that a close approximation to
standard Quantum Mechanics can be recovered from conditional Quantum Mechanics
for semi-classical clocks, and we use these clocks to compute the minimum
decoherence predicted by the Conditional Probability Interpretation.Comment: 8 pages, references adde
Searching the Higgs with the Neurochip TOTEM
We show that neural network classifiers can be helpful in discriminating
Higgs production events from the huge background at LHC, assuming the case of a
mass value GeV. We use the high performance neurochip TOTEM,
trained by the Reactive Tabu Search algorithm (RTS), which could be used for
on-line purposes. Two different sets of input variables are compared.Comment: 4 pages,1 figure, requres espcrc2.sty and epsfig.sty. Work prsented
in The 5th Topical Seminar on ``The irresistible rise of the Standard
Model'', San Miniato, Tuscany, Italy, April 21-25 199
Carcinogenic Effects in a Phenylketonuria Mouse Model
Phenylketonuria (PKU) is a metabolic disorder caused by impaired phenylalanine hydroxylase (PAH). This condition results in hyperphenylalaninemia and elevated levels of abnormal phenylalanine metabolites, among which is phenylacetic acid/phenylacetate (PA). In recent years, PA and its analogs were found to have anticancer activity against a variety of malignancies suggesting the possibility that PKU may offer protection against cancer through chronically elevated levels of PA. We tested this hypothesis in a genetic mouse model of PKU (PAHenu2) which has a biochemical profile that closely resembles that of human PKU. Plasma levels of phenylalanine in homozygous (HMZ) PAHenu2 mice were >12-fold those of heterozygous (HTZ) littermates while tyrosine levels were reduced. Phenylketones, including PA, were also markedly elevated to the range seen in the human disease. Mice were subjected to 7,12 dimethylbenz[a]anthracene (DMBA) carcinogenesis, a model which is sensitive to the anticancer effects of the PA derivative 4-chlorophenylacetate (4-CPA). Tumor induction by DMBA was not significantly different between the HTZ and HMZ mice, either in total tumor development or in the type of cancers that arose. HMZ mice were then treated with 4-CPA as positive controls for the anticancer effects of PA and to evaluate its possible effects on phenylalanine metabolism in PKU mice. 4-CPA had no effect on the plasma concentrations of phenylalanine, phenylketones, or tyrosine. Surprisingly, the HMZ mice treated with 4-CPA developed an unexplained neuromuscular syndrome which precluded its use in these animals as an anticancer agent. Together, these studies support the use of PAHenu2 mice as a model for studying human PKU. Chronically elevated levels of PA in the PAHenu2 mice were not protective against cancer
Gaussian quantum operator representation for bosons
We introduce a Gaussian quantum operator representation, using the most general possible multimode Gaussian operator basis. The representation unifies and substantially extends existing phase-space representations of density matrices for Bose systems and also includes generalized squeezed-state and thermal bases. It enables first-principles dynamical or equilibrium calculations in quantum many-body systems, with quantum uncertainties appearing as dynamical objects. Any quadratic Liouville equation for the density operator results in a purely deterministic time evolution. Any cubic or quartic master equation can be treated using stochastic methods