791 research outputs found

    Inequalities for quantum skew information

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    We study quantum information inequalities and show that the basic inequality between the quantum variance and the metric adjusted skew information generates all the multi-operator matrix inequalities or Robertson type determinant inequalities studied by a number of authors. We introduce an order relation on the set of functions representing quantum Fisher information that renders the set into a lattice with an involution. This order structure generates new inequalities for the metric adjusted skew informations. In particular, the Wigner-Yanase skew information is the maximal skew information with respect to this order structure in the set of Wigner-Yanase-Dyson skew informations. Key words and phrases: Quantum covariance, metric adjusted skew information, Robertson-type uncertainty principle, operator monotone function, Wigner-Yanase-Dyson skew information

    The Protomedicato Tribunal and minorities in Castile at the end of the 17th century: the case of surgeon Roldán Solimán

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    [EN] This note aims to provide a small set of documents which report the vicissitudes of a North-African Muslim surgeon who tried to settle professionally during the late seventeenth century in the Kingdom of Castile. The four letters exchanged between the Royal Palace and the Castilian tribunal of the Protomedicato reveal that the Spanish king Charles II (1661-1700) resoluted supported the surgeon's aspirations, and the Protomedicato's concerted resistence to the royal will. These eloquent documents shed light on the history of the Castilian Protomedicato during the final years of the reign of the last Habsburg king in Spain by providing evidence about the role of this institution in the process of segregation/exclusion of ethnic minorities from the practice of health professions.[ES] El objeto de esta nota es presentar y editar una colección documental muy breve cuyo contenido nos informa sobre las vicisitudes de un cirujano musulmán norteafricano que a finales del siglo XVII busca su asentamiento profesional en la Corona de Castilla. Las cuatro cartas entre el Palacio Real y el Tribunal del Protomedicato, que se conservan en relación a este asunto, revelan tanto el decidido apoyo del Rey Carlos 11 (1665-1700) a las pretensiones del cirujano, como la fuerte resistencia ofrecida por el Protomedicato a la voluntad real. Esta expresiva documentación arroja luz en torno a la historia del Protomedicato en la Corona de Castilla durante los años finales del reinado del último Habsburgo en España, ilustrándonos sobre el papel entonces jugado por esta institución en el proceso de segregación/exclusión de las minorías étnicas, de la práctica de las ocupaciones sanitarias.Peer reviewe

    A volume inequality for quantum Fisher information and the uncertainty principle

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    Let A1,...,ANA_1,...,A_N be complex self-adjoint matrices and let ρ\rho be a density matrix. The Robertson uncertainty principle det(Covρ(Ah,Aj))det(i2Tr(ρ[Ah,Aj])) det(Cov_\rho(A_h,A_j)) \geq det(- \frac{i}{2} Tr(\rho [A_h,A_j])) gives a bound for the quantum generalized covariance in terms of the commutators [Ah,Aj][A_h,A_j]. The right side matrix is antisymmetric and therefore the bound is trivial (equal to zero) in the odd case N=2m+1N=2m+1. Let ff be an arbitrary normalized symmetric operator monotone function and let ρ,f_{\rho,f} be the associated quantum Fisher information. In this paper we conjecture the inequality det(Covρ(Ah,Aj))det(f(0)2ρ,f) det (Cov_\rho(A_h,A_j)) \geq det (\frac{f(0)}{2} _{\rho,f}) that gives a non-trivial bound for any natural number NN using the commutators i[ρ,Ah]i[\rho, A_h]. The inequality has been proved in the cases N=1,2N=1,2 by the joint efforts of many authors. In this paper we prove the case N=3 for real matrices

    Parametric improvement for the ingestion dose module of the European ARGOS and RODOS decision support systems

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    The European decision support systems ARGOS and RODOS rely on the ECOSYS model for prognoses of ingestion doses. ECOSYS needs an update of various parameter values to provide reliable estimates. This paper reports on some results of a Nordic initiative to derive parameter values that are specific to Nordic conditions, as well as to improve generic parameter values in ECOSYS, taking into account the host of useful measurement data accumulated since ECOSYS was created

    A spatial judgement task to determine background emotional state in laboratory rats (Rattus norvegicus)

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    Humans experiencing different background emotional states display contrasting cognitive (e.g. judgement) biases when responding to ambiguous stimuli. We have proposed that such biases may be used as indicators of animal emotional state. Here, we use a spatial judgement task, in which animals are trained to expect food in one location and not another, to determine whether rats in relatively positive or negative emotional states respond differently to ambiguous stimuli of intermediate spatial location. We housed 24 rats with environmental enrichment for seven weeks. Enrichment was removed for half the animals prior to the start of training (‘U’: unenriched) to induce a relatively negative emotional state, whilst being left in place for the remaining rats (‘E’: enriched). After six training days, the rats successfully discriminated between the rewarded and unrewarded locations in terms of an increased latency to arrive at the unrewarded location, with no housing treatment difference. The subjects then received three days of testing in which three ambiguous ‘probe’ locations, intermediate between the rewarded and unrewarded locations, were introduced. There was no difference between the treatments in the rats’ judgement of two out of the three probe locations, the exception being when the ambiguous probe was positioned closest to the unrewarded location. This result suggests that rats housed without enrichment, and in an assumed relatively negative emotional state, respond differently to an ambiguous stimulus compared to rats housed with enrichment, providing evidence that cognitive biases may be used to assess animal emotional state in a spatial judgement task

    Relic Neutralino Densities and Detection Rates with Nonuniversal Gaugino Masses

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    We extend previous analyses on the interplay between nonuniversalities in the gaugino mass sector and the thermal relic densities of LSP neutralinos, in particular to the case of moderate to large tan beta. We introduce a set of parameters that generalizes the standard unified scenario to cover the complete allowed parameter space in the gaugino mass sector. We discuss the physical significance of the cosmologically preferred degree of degeneracy between charginos and the LSP and study the effect this degree of degeneracy has on the prospects for direct detection of relic neutralinos in the next round of dark matter detection experiments. Lastly, we compare the fine tuning required to achieve a satisfactory relic density with the case of universal gaugino masses, as in minimal supergravity, and find it to be of a similar magnitude. The sensitivity of quantifiable measures of fine-tuning on such factors as the gluino mass and top and bottom masses is also examined.Comment: Uses RevTeX; 14 pages, 16 figure

    Ground-state properties of tubelike flexible polymers

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    In this work we investigate structural properties of native states of a simple model for short flexible homopolymers, where the steric influence of monomeric side chains is effectively introduced by a thickness constraint. This geometric constraint is implemented through the concept of the global radius of curvature and affects the conformational topology of ground-state structures. A systematic analysis allows for a thickness-dependent classification of the dominant ground-state topologies. It turns out that helical structures, strands, rings, and coils are natural, intrinsic geometries of such tubelike objects
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