6,399 research outputs found
Quantum systems as classical systems
A characteristical property of a classical physical theory is that the
observables are real functions taking an exact outcome on every (pure) state;
in a quantum theory, at the contrary, a given observable on a given state can
take several values with only a predictable probability. However, even in the
classical case, when an observer is intrinsically unable to distinguish between
some distinct states he can convince himself that the measure of its
''observables'' can have several values in a random way with a statistical
character. What kind of statistical theory is obtainable in this way? It is
possible, for example, to obtain exactly the statistical previsions of quantum
mechanics? Or, in other words, can a physical system showing a classical
behaviour appear to be a quantum system to a confusing observer? We show that
from a mathematical viewpoint it is not difficult to produce a theory with
hidden variables having this property. We don't even try to justify in physical
terms the artificial construction we propose; what we do is to give a general
and rigorous argument showing how the interplay between the classical and
quantum mechanics we offer is interpretable as the difference between an
imaginary very expert observer and another nonexpert observer. This proves also
that besides the well known theorems concerning the impossibility of hidden
variables (cfr. Von Neumann [Neu] and Jauch-Piron [J-P]) there is also room for
a result in favor of the possibility.Comment: late
Financial Development and Income Inequality: A Panel Data Approach
We analyze the link between financial development and income inequality for a broad unbalanced dataset of up to 138 developed and developing countries over the years 1960 to 2008. Using credit-to-GDP as a measure of financial development, our results reject theoretical models predicting a negative impact of financial development on income inequality measured by the Gini coefficient. Controlling for country fixed effects and GDP per capita, we find that financial development has a positive effect on income inequality. These results are robust to different measures of financial development, econometric specifications, and control variables.financial development, income inequality, global, panel analysis
Influence of different fat emulsions with 10 or 20% MCT/LCT or LCT on lipoproteins in plasma of patients after abdominal surgery
In patients after elective abdominal surgery, different fat emulsions were used to compare their efficacy in total parenteral nutrition and in normalizing plasma lipoprotein levels. In five different groups with 5 patients each, half of the nonprotein calories were given as medium-chain triglycerides/ long-chain triglycerides (1:1) or as long-chain triglycerides alone in 10 or 20% fat emulsions or as glucose alone in a control group for 7 days. After surgery, an initial decrease of all plasma lipoprotein components was followed by a different behavior of glyceride-glycerol, cholesterol, phospholipids, and apolipoproteins. Glyceride-glycerol in very-low-density lipoproteins and high-density lipoproteins is increasing during infusion of fat emulsions and decreasing during overnight interruption of infusions. After the 7-day infusion period, there was no significant difference in very-low-density lipoprotein glyceride-glycerol as compared with the values before different infusions, Low-density lipoprotein cholesterol is reaching and exceeding preoperative concentrations between the 4th and the 7th day, most during infusion of 10% fat emulsion and especially due to an increase of free cholesterol, High-density lipoprotein cholesterol and apolipoprotein A-I reach preoperative levels during infusion of fat emulsions but not with glucose alone, Higher than preoperative values are reached in phospholipids with all fat infusions already on day 4, Abnormal lipoprotein X occurred least with the medium-chain/long-chain triglyceride 20% fat-infusion. This fat emulsion is suggested as having the best normalizing effect on plasma lipoproteins and best tolerance in patients after surgery
Homologies in human and Macasa fuscata chromosomes revealed by in situ suppression hybridization with human chromosome specific DNA libraries
We established chromosomal homologies between all chromosomes of the human karyotype and that of an old world monkey (Macaca fuscata) by chromosomal in situ suppression (CISS) hybridization with human chromosome specific DNA libraries. Except for the human chromosome 2 library and limited cross-hybridization of X and Y chromosome libraries all human DNA libraries hybridized to single GTG-banded macaque chromosomes. Only three macaque chromosomes (2, 7, 13) were each hybridized by two separate human libraries (7 and 21, 14 and 15, 20 and 22 respectively). Thus, an unequivocally high degree of synteny between human and macaque chromosomes has been maintained for more than 20 million years. As previously suggested, both Papionini (macaques, baboons, mandrills and cercocebus monkeys, all of which have nearly identical karyotypes) and humans are chromosomally conservative. The results suggest, that CISS hybridization can be expected to become an indispensable tool in comparative chromosome and gene mapping and will help clarify chromosomal phylogenies with speed and accuracy
Structure of the Algebra of Effective Observables in Quantum Mechanics
A subclass of dynamical semigroups induced by the interaction of a quantum
system with an environment is introduced. Such semigroups lead to the selection
of a stable subalgebra of effective observables. The structure of this
subalgebra is completely determined
Orbital moment in CoO and in NiO
The total, orbital and spin moment of the Co2+ ion in CoO has been calculated
within the quasi-atomic approach with taking into account strong correlations,
crystal-field interactions and the intra-atomic spin-orbit coupling. The
orbital moment of 1.39 \mu B amounts at 0 K, in the magnetically-ordered state,
to more than 34% of the total moment (4.01 \mu B). The same calculations yield
for NiO the orbital and total moment of 0.46 \mu B and 2.45 \mu B,
respectively.
PACS No: 71.70.E; 75.10.D
Keywords: 3d magnetism, crystal field, spin-orbit coupling, orbital moment,
CoO, NiOComment: 6 pages in tex+3 figs, submitted for PNSXM-03, Venic
Construction of a Complete Set of States in Relativistic Scattering Theory
The space of physical states in relativistic scattering theory is
constructed, using a rigorous version of the Dirac formalism, where the Hilbert
space structure is extended to a Gel'fand triple. This extension enables the
construction of ``a complete set of states'', the basic concept of the original
Dirac formalism, also in the cases of unbounded operators and continuous
spectra. We construct explicitly the Gel'fand triple and a complete set of
``plane waves'' -- momentum eigenstates -- using the group of space-time
symmetries. This construction is used (in a separate article) to prove a
generalization of the Coleman-Mandula theorem to higher dimension.Comment: 30 pages, Late
Molecular and classical cytogenetic analyses demonstrate an apomorphic reciprocal chromosomal translocation in Gorilla gorilla
The existence of an apomorphic reciprocal chromosomal translocation in the gorilla lineage has been asserted or denied by various cytogeneticists. We employed a new molecular cytogenetic strategy (chromosomal in situ suppression hybridization) combined with high-resolution banding, replication sequence analysis, and fluorochrome staining to demonstrate that a reciprocal translocation between ancestral chromosomes homologous to human chromosome 5 and 17 has indeed occurred
- …