65 research outputs found
Berry Phase of a Resonant State
We derive closed analytical expressions for the complex Berry phase of an
open quantum system in a state which is a superposition of resonant states and
evolves irreversibly due to the spontaneous decay of the metastable states. The
codimension of an accidental degeneracy of resonances and the geometry of the
energy hypersurfaces close to a crossing of resonances differ significantly
from those of bound states. We discuss some of the consequences of these
differences for the geometric phase factors, such as: Instead of a diabolical
point singularity there is a continuous closed line of singularities formally
equivalent to a continuous distribution of `magnetic' charge on a diabolical
circle; different classes of topologically inequivalent non-trivial closed
paths in parameter space, the topological invariant associated to the sum of
the geometric phases, dilations of the wave function due to the imaginary part
of the Berry phase and others.Comment: 28 pages Latex, three uuencoded postcript figure
I know people who can and who cannot: A measure of the perception of economic inequality in everyday life
Versión preprintThis paper describes the development of the Perceived Economic Inequality in Everyday Life (PEIEL) scale. It is written and validated in Spanish. We first carried out an exploratory study, using a sample of 205 participants (52.2% men and 47.8% women; age: M = 24.69, SD = 8.95). We then conducted a confirmatory study with a sample size of 215 individuals (43.7% men and 56.3% women; age: M = 23.83, SD = 6.46). Results showed that the PEIEL scale is a valid and reliable unidimensional instrument. This scale negatively predicted tolerance of economic inequality over and above perceived inequality measured by wage gap estimates. In addition, perceived economic inequality in everyday life was negatively associated with tolerance of inequality, particularly in individuals with right-wing political ideology.Universidad de Costa Rica/[OAICE-006-2017]/UCR/Costa RicaUCR::Sedes Regionales::Sede de Occident
MOLECULAR-GENETIC AND SERUM DISORDERS MARKERS OF FOLATE METABOLISM IN PATIENTS PROLIFERATIVE DISEASE AND BREAST CANCER
Aim: to study the relationship between homocysteine, cysteine and glutathione in blood serum and various single nucleotide polymorphisms (SNPs) of genes involved in folate metabolism in patients with proliferative breast disease and breast cancer. Material and methods. The study included 112 patients with proliferative breast lesions and breast cancer in Transbaikalia. The control group consisted of 144 women having no breast cancer. Blood levels of homocysteine, cysteine and glutathione were evaluated by HPLC (high performance liquid chromatography). Genotyping was performed by polymerase chain reaction with the detection of amplification product in real-time. Results. Molecular-genetic testing revealed no association between breast disease and genetic polymorphisms of MTHFR(C677T), MTHFR(A1298C), MTR(A2756G), MTRR(A66G) in women with proliferative breast lesions and breast cancer, however, in contrast to the control group, the concentrations of homocysteine and glutathione were increased
Asymmetric synthesis of alpha-arylglycinols viaadditions of lithium methyl p-tolyl sulfoxide to N-(PMP)arylaldimines followed by "non oxidative" Pummererreaction
The results presented in this paper demonstrate that the stereochemical outcome of the reversible additions of lithium (R)-methyl p-tolyl sulfoxide to N-arylidene-p-anisidines (N-PMP imines) is a function of a) the reaction conditions used and b) the electronic properties of the arylidene moiety on the starting imine. High kinetically controlled (2S,RS) diastereoselectivity (−70 °C) was achieved for additions of imines bearing relatively electron-rich N-arylidene groups, while an electron-deficient nature of this group was found to favor the opposite stereochemical outcome. On the other hand, the reactions run under thermodynamically controlled conditions (0 °C) afforded equimolar mixtures of the diastereomeric products regardless of the pattern of substitution on the starting imines. Enantiopure α-arylglycinols were readily synthesized by “non-oxidative” Pummerer rearrangement of diastereomerically pure β-aryl-β-N-(acyl)aminoalkyl sulfoxides, prepared from the corresponding N-PMP derivatives
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