Entanglement Distribution and Entangling Power of Quantum Gates

Quantum gates, that play a fundamental role in quantum computation and other quantum information processes, are unitary evolution operators $\hat U$ that act on a composite system changing its entanglement. In the present contribution we study some aspects of these entanglement changes. By recourse of a Monte Carlo procedure, we compute the so called "entangling power" for several paradigmatic quantum gates and discuss results concerning the action of the CNOT gate. We pay special attention to the distribution of entanglement among the several parties involved

The statistics of the entanglement changes generated by the Hadamard-CNOT quantum circuit

We consider the change of entanglement of formation $\Delta E$ produced by the Hadamard-CNOT circuit on a general (pure or mixed) state $\rho$ describing a system of two qubits. We study numerically the probabilities of obtaining different values of $\Delta E$, assuming that the initial state is randomly distributed in the space of all states according to the product measure recently introduced by Zyczkowski {\it et al.} [Phys. Rev. A {\bf 58} (1998) 883].Comment: 12 pages, 2 figure

Estimated generic prices for novel treatments for drug resistant tuberculosis

Background: Estimated annual incidence of MDR-TB is 480,000, representing 5% of TB incidence, but 20% of mortality. Multiple drugs have recently been developed or re-purposed for the treatment of MDR-TB. Currently, treatment for MDR-TB costs thousands of dollars per course. Objectives: To estimate generic prices for novel TB drugs that would be possible given large-scale competitive manufacture. Methods: Prices for linezolid, moxifloxacin, and clofazimine were estimated based on per-kilogram prices of active pharmaceutical ingredient (API). Other costs were added, including formulation, packaging and a profit margin. The costs of projection for sutezolid were estimated to be equivalent to those for linezolid, based on chemical similarit y. Generic prices for bedaquiline, delamanid, and pretomanid were estimated by assessing routes of synthesis, costs/kg of chemical reagents, routes of synthesis, and per-step yields. Costing algorithms reflected variable regulatory requirements, efficiency of scale based on demand, and were validated by testing predictive ability against widely-available TB medicines. Results: Estimated generic prices were USD $8-$17/month for bedaquiline, $5-$16/month for delamanid, $11-$3 /month for pretomanid, $4-$9/month for linezolid, $4-$9/month for sutezolid, $4-$11/month for clofazimine, and $4-$8/month for moxifloxacin. Estimated generic prices were 87%-94% lower than current lowest available prices for bedaquiline, 95%-98% for delamanid, 94%-97% for linezolid. Estimated generic prices were $168-$395 per course for the STREAM trial modified Bangladesh regimens (current cost s $734-$1,799), $53-$276 for pretomanid-based three-drug regimens, and $238-$507 for a delamanid-based four-drug regimen. Conclusions: Competitive large-scale generic manufacture could allow supplies of treatment for 5-10 times more MDR-TB cases within current procurement budgets

The UK register of HIV seroconverters: Methods and analytical issues

A Register of HIV-infected persons who have had a negative antibody test within 3 years of their first antibody positive test (seroconverters) is being set up in the UK to monitor the distribution of times from HIV seroconversion to AIDS (the incubation period) and to death. It will also provide a national resource for use by those designing studies in this group of individuals. Clinicians caring for HIV-positive persons in Genito-Urinary Medicine, Infectious Disease and other departments throughout the UK were asked to participate by providing information on eligible subjects. Most laboratories undertaking HIV antibody testing were also contacted and asked to provide the name of the attending clinician for all seroconverters identified through the HIV laboratory reporting systems of the PHLS Communicable Disease Surveillance Centre (CDSC) and the Scottish Centre for Infection and Environmental Health (SCIEH) and for any other seroconverters known to them but not identified by CDSC or SCIEH. Data items sought for the Register include: sex, ethnic group, probable route of HIV transmission, annual CD4 counts, details of therapy and prophylaxis prescribed, AIDS-defining events and vital status. Follow up information is collected annually. Wherever possible, all seroconverters known to a clinic have been identified, whether currently alive or dead, either from clinic records or laboratory reporting or both. The objective is to establish and update a complete register of seroconverters on a long-term basis to provide reliable estimates of the incubation period on which future projections of AIDS cases in the UK can be made

On the distribution of entanglement changes produced by unitary operations

We consider the change of entanglement of formation $\Delta E$ produced by a unitary transformation acting on a general (pure or mixed) state $\rho$ describing a system of two qubits. We study numerically the probabilities of obtaining different values of $\Delta E$, assuming that the initial state is randomly distributed in the space of all states according to the product measure introduced by Zyczkowski {\it et al.} [Phys. Rev. A {\bf 58} (1998) 883]

Transposable Element Populations Shed Light on the Evolutionary History of Wheat and the Complex Co-Evolution of Autonomous and Non-Autonomous Retrotransposons

Wheat has one of the largest and most repetitive genomes among major crop plants, containing over 85% transposable elements (TEs). TEs populate genomes much in the way that individuals populate ecosystems, diversifying into different lineages, sub-families and sub-populations. The recent availability of high-quality, chromosome-scale genome sequences from ten wheat lines enables a detailed analysis how TEs evolved in allohexaploid wheat, its diploids progenitors, and in various chromosomal haplotype segments. LTR retrotransposon families evolved into distinct sub-populations and sub-families that were active in waves lasting several hundred thousand years. Furthermore, It is shown that different retrotransposon sub-families were active in the three wheat sub-genomes, making them useful markers to study and date polyploidization events and chromosomal rearrangements. Additionally, haplotype-specific TE sub-families are used to characterize chromosomal introgressions in different wheat lines. Additionally, populations of non-autonomous TEs co-evolved over millions of years with their autonomous partners, leading to complex systems with multiple types of autonomous, semi-autonomous and non-autonomous elements. Phylogenetic and TE population analyses revealed the relationships between non-autonomous elements and their mobilizing autonomous partners. TE population analysis provided insights into genome evolution of allohexaploid wheat and genetic diversity of species, and may have implication for future crop breeding

Conditional q-Entropies and Quantum Separability: A Numerical Exploration

We revisit the relationship between quantum separability and the sign of the relative q-entropies of composite quantum systems. The q-entropies depend on the density matrix eigenvalues p_i through the quantity omega_q = sum_i p_i^q. Renyi's and Tsallis' measures constitute particular instances of these entropies. We perform a systematic numerical survey of the space of mixed states of two-qubit systems in order to determine, as a function of the degree of mixture, and for different values of the entropic parameter q, the volume in state space occupied by those states characterized by positive values of the relative entropy. Similar calculations are performed for qubit-qutrit systems and for composite systems described by Hilbert spaces of larger dimensionality. We pay particular attention to the limit case q --> infinity. Our numerical results indicate that, as the dimensionalities of both subsystems increase, composite quantum systems tend, as far as their relative q-entropies are concerned, to behave in a classical way

On the Correlations Between Quantum Entanglement and q-Information Measures

In the present study we revisit the application of the $q$-information measures $R_q$ of R\'enyi's and $S_q$ of Tsallis' to the discussion of special features of two qubits systems. More specifically, we study the correlations between the $q$-information measures and the entanglement of formation of a general (pure or mixed) state $\rho$ describing a system of two qubits. The analysis uses a Monte Carlo procedure involving the 15-dimensional 2-qubits space of pure and mixed states, under the assumption that these states are uniformly distributed according to the product measure recently introduced by Zyczkowski {\it et al} [Phys. Rev. A {\bf 58} (1998) 883].Comment: 7 figures. Submitted for publicatio