11 research outputs found

    The Majorization Arrow in Quantum Algorithm Design

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    We apply majorization theory to study the quantum algorithms known so far and find that there is a majorization principle underlying the way they operate. Grover's algorithm is a neat instance of this principle where majorization works step by step until the optimal target state is found. Extensions of this situation are also found in algorithms based in quantum adiabatic evolution and the family of quantum phase-estimation algorithms, including Shor's algorithm. We state that in quantum algorithms the time arrow is a majorization arrow.Comment: REVTEX4.b4 file, 4 color figures (typos corrected.

    Entropy as a Fixed Point

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    Element patterns in albatrosses and petrels: influence of trophic position, foraging range, and prey type

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    We investigated the concentrations of 22 essential and non-essential elements among a community of Procellariiformes (and their prey) to identify the extent to which trophic position and foraging range governed element accumulation. Stable isotope analysis (SIA) was used to characterise trophic (δ15N) and spatial patterns (δ13C) among species. Few consistent patterns were observed in element distributions among species and diet appeared to be highly influential in some instances. Arsenic levels in seabird red blood cells correlated with δ15N and δ13C, demonstrating the importance of trophic position and foraging range for arsenic distribution. Arsenic concentrations in prey varied significantly across taxa, and in the strength of association with δ15N values (trophic level). In most instances, element patterns in Procellariiformes showed the clearest separation among species, indicating that a combination of prey selection and other complex species-specific characteristics (e.g. moult patterns) were generally more important determining factors than trophic level per se

    Diversidade dos noctuĂ­deos (Lepidoptera, Noctuidae) em Salvador do Sul, Rio Grande do Sul, Brasil Diversity of owlet-moth (Lepidoptera, Noctuidae) in Salvador do Sul, Rio Grande do Sul, Brazil

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    <abstract language="eng">Diversity of owlet-moth (Lepidoptera, Noctuidae) in Salvador do Sul, Rio Grande do Sul, Brazil. The purpose of this paper is to describe the Noctuidae community in Salvador do Sul, Rio Grande do Sul. Light traps captured the insects of this research. The quantitative data were collected through weekly sampling, during one year (1994-1995); the qualitative data were collected through non-systematic sampling, during four consecutive years. The community characterization was based on the richness, abundance, specific constancy, diversity indices and abundance distribution; also total richness estimates were calculated, by nonparametric statistical procedures. In the systematized collecting there were captured 4017 noctuids of 108 species, distributed in 14 subfamilies; in the non-systematized, another 189 additional species and two subfamilies. Amphipyrinae, Hadeninae and Ophiderinae had the largest species richness. The more constant species were noctuids of great economic importance; the accessories were related to specific vegetable groups; the accidentals have their host unknown. The accessories and accidental species were captured more in spring and summer; also in these periods were measured the highest values of richness, abundance and diversity. There was no fit between observed/calculated log normal and log series distribution models. The 2nd order Jackknife and Michaelis-Menten equation procedures estimated that the total richness values were close to the total number of the species in the studied area
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