5,454 research outputs found
Statistics and quantum maximum entropy principle
By using the reduced Wigner formalism we consider a kinetic theory for a quantum gas. We introduce a set of generalized kinetic fields and obtain a hierarchy of Quantum Hydrodynamic (QHD) equations for the corresponding macroscopic variables. To close the QHD system a maximum entropy principle is asserted, and to explicitly incorporate particles indistinguishability a proper quantum entropy is analyzed in terms of the reduced density matrix. This approach implies a quantum generalization of the corresponding Lagrange multipliers. Quantum contributions
are expressed in powers of ÂŻh2
Variety, Competition, and Population in Economic Growth : Theory and Empirics
We provide aggregate macroeconomic evidence on how, in the long-run, a diverse degree of complexity in production may affect not only the rate of economic growth, but also the correlation between the latter, population growth and the monopolistic (intermediate) markups. For a sample of OECD countries, we find that the impact of population change on economic growth is slightly positive. According to our the- oretical model, this implies that the losses due to more complexity in production are lower than the corresponding specialization gains. Using a Finite Mixture Model, we also classify the countries in the sample and verify for each cluster the impact that the population growth rate and the intermediate sector\u2019s markups exert on the 5-year average real GDP growth rate
Credit rationing and credit view: empirical evidence from an ethical bank in Italy
Attempts have been made in the empirical literature to identify credit rationing
and its determinants using balance sheet data or evidence from
corporate surveys. However, observational equivalence, identification problems,
and interview biases are serious problems in these studies.We analyze
directly the determinants of credit rationing in credit files by examining the
difference between the amounts demanded by and supplied to each borrower,
as shown by official bank records. Our findings provide microeconomic evidence
that supports the credit view hypothesis by showing that the European
Central Bank refinancing rate is significantly and positively related to partial
(but not total) credit rationing. This finding is consistent with the hypothesis
that this variable affects the total volume of bank loans
Variety, Competition, and Population in Economic Growth: Theory and Empirics
We provide aggregate macroeconomic evidence on how, in the long-run, a diverse degree of production-complexity may affect not only the rate of economic growth, but also the correlation between the latter, population growth and the monopolistic (intermediate) markups. For a sample of OECD economies, we find that the losses due to more complexity in production are lower than the corresponding specialization gains. According to our theoretical model, this implies that the impact of population change on economic growth is slightly positive. Using a Finite Mixture Model, we also classify the countries in the sample and verify for each cluster the impact that the population growth rate and the intermediate sector's markups exert on the 5-year average real GDP growth rate
The Role of physical activity and nutrition in the sarcopenia of cirrhosis.
The aim of this review is to understand how physical activity and nutrition are involved in the improvement of sarcopenia in patients affected by liver cirrhosis. The pathogenesis of sarcopenia in cirrhosis involves three major factors: inadequate dietary intake, metabolic disturbances, and malabsorption. Although in the early stages muscles appear to be spared, sarcopenia progressively leads to mobility limitations and its consequences, such as propensity to falls and drastically reducing life quality. Several studies confirm the important role played by physical activity and balanced nutrition in this chronic condition. Exercise and nutritional intervention should be recommended in these patients in order to improve quality of life
Experience with the Platelia Candida ELISA for the diagnosis of invasive candidosis in neonatal patients
ABSTRACTThis preliminary study evaluated the use of the Platelia Candida antigen kit for the diagnosis of invasive candidosis in 70 of 184 pre-term infants admitted to a neonatal intensive care unit between March 2004 and March 2006. The frequency of confirmed candidaemia was 6.5%. The sensitivity and specificity of the assay were 94.4% and 94.2%, respectively, with a positive predictive value of 85% and a negative predictive value of 98%. These results suggest that the inclusion of regular serological surveillance for mannanaemia in some pre-term infants would complement blood cultures for the early detection of candidosis
Cryptococcus neoformans and Cryptococcus gattii Species Complex Isolates on the Slopes of Mount Etna, SICILY, Italy
This study investigated the presence of Cryptococcus neoformans and Cryptococcus gattii species complex isolates on olive trees growing in the Eastern part of Sicily (Italy) characterized by the presence of the volcano Etna and the ability of these fungal pathogens to sexually reproduce on medium containing volcanic soil. Samples from 124 olive trees were collected from 14 different sites around Mount Etna. Eighteen trees (14.5%) resulted colonized by C. neoformans VNI-\u3b1A isolates, one (0.8%) by VNIV-\u3b1D isolates, and two (1.6%) by C. gattii VGI-\u3b1B isolates. The ability of environmental and reference strains belonging to VNI, VNIV, and VGI molecular types to sexually reproduce on a medium containing volcanic soil was also tested. VNI and VNIV strains were able to produce filaments and basiodiospores more vigorously than on the control medium, whereas VGI strains were not fertile. In conclusion, the present study identified which C. neoformans and C. gattii species complex genotypes are circulating in Eastern Sicily and confirmed the ecological role of olive trees as environmental reservoir of these pathogens. It also showed that Cryptococcus is able to colonize and sexually reproduce in inhospitable environments such as the slopes of a volcano
Lattice model for cold and warm swelling of polymers in water
We define a lattice model for the interaction of a polymer with water. We
solve the model in a suitable approximation. In the case of a non-polar
homopolymer, for reasonable values of the parameters, the polymer is found in a
non-compact conformation at low temperature; as the temperature grows, there is
a sharp transition towards a compact state, then, at higher temperatures, the
polymer swells again. This behaviour closely reminds that of proteins, that are
unfolded at both low and high temperatures.Comment: REVTeX, 5 pages, 2 EPS figure
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