On the irreversibility of entanglement distillation

We investigate the irreversibility of entanglement distillation for a symmetric d-1 parameter family of mixed bipartite quantum states acting on Hilbert spaces of arbitrary dimension d x d. We prove that in this family the entanglement cost is generically strictly larger than the distillable entanglement, such that the set of states for which the distillation process is asymptotically reversible is of measure zero. This remains true even if the distillation process is catalytically assisted by pure state entanglement and every operation is allowed, which preserves the positivity of the partial transpose. It is shown, that reversibility occurs only in cases where the state is quasi-pure in the sense that all its pure state entanglement can be revealed by a simple operation on a single copy. The reversible cases are shown to be completely characterized by minimal uncertainty vectors for entropic uncertainty relations.Comment: 5 pages, revtex

Role of mitochondria in Parkinson disease

The cause of the selective degeneration of nigrostriatal neurons in Parkinson disease (PD) has remained largely unknown. Exceptions include rare missense mutations in the alpha-synuclein gene on chromosome 4, a potentially pathogenic mutation affecting the ubiquitin pathway, and mutations in the parkin gene on chromosome 6. However, unlike classical PD, the latter syndrome is not associated with the formation of typical Lewy bodies. In contrast, a biochemical defect of complex I of the mitochondrial respiratory chain has been described in a relatively large group of confirmed PD cases. Recent cybrid studies indicate that the complex I defect in PD has a genetic cause and that it may arise from mutations in the mitochondrial DNA, Sequence analysis of the mitochondrial genome supports the view that mitochondrial point mutations are involved in PD pathogenesis. However, although mitochondria function as regulators in several known forms of cell death, their exact involvement in PD has remained unresolved. This is of relevance because classical apoptosis does not appear to play a major role in the degeneration of the parkinsonian nigra

Entropic uncertainty relations and entanglement

We discuss the relationship between entropic uncertainty relations and entanglement. We present two methods for deriving separability criteria in terms of entropic uncertainty relations. Especially we show how any entropic uncertainty relation on one part of the system results in a separability condition on the composite system. We investigate the resulting criteria using the Tsallis entropy for two and three qubits.Comment: 8 pages, 3 figures, v2: small change

A Public Good Version of the Collective Household Model: An Empirical Approach with an Application to British Household Data

In this paper we consider an empirical collective household model of time allocation for two-earner households. The novelty of this paper is that we estimate a version of the collective household model, where the internally produced goods and the externally purchased goods are assumed to be public. The empirical results suggest that: (1) Preferences of men and women differ; (2) Although there are significant individual variations, on average the utility functions of men and women are equally weighted in the household utility function; (3) Differences in the ratio of the partners' hourly wages are explanatory for how individual utilities are weighted in the household utility function. (4) The female's preference for household production is influenced by family size, but this does not hold for the male; (5) Both the male and the female have a backward-bending labor supply curve; (6) Labor-supply curves are forward-bending with respect to the partner's wage rate; (7) Our model rejects the unitary Slutsky symmetry condition.labor supply, collective household models, household behavior,