657 research outputs found

    Forbidden ordinal patterns in higher dimensional dynamics

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    Forbidden ordinal patterns are ordinal patterns (or `rank blocks') that cannot appear in the orbits generated by a map taking values on a linearly ordered space, in which case we say that the map has forbidden patterns. Once a map has a forbidden pattern of a given length L0L_{0}, it has forbidden patterns of any length LL0L\ge L_{0} and their number grows superexponentially with LL. Using recent results on topological permutation entropy, we study in this paper the existence and some basic properties of forbidden ordinal patterns for self maps on n-dimensional intervals. Our most applicable conclusion is that expansive interval maps with finite topological entropy have necessarily forbidden patterns, although we conjecture that this is also the case under more general conditions. The theoretical results are nicely illustrated for n=2 both using the naive counting estimator for forbidden patterns and Chao's estimator for the number of classes in a population. The robustness of forbidden ordinal patterns against observational white noise is also illustrated.Comment: 19 pages, 6 figure

    On the Stress Tensor Light-ray Operator Algebra

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    We study correlation functions involving generalized ANEC operators of the form dx(x)n+2T(x)\int dx^- \left(x^-\right)^{n+2} T_{--}(\vec{x}) in four dimensions. We compute two, three, and four-point functions involving external scalar states in both free and holographic Conformal Field Theories. From this information, we extract the algebra of these light-ray operators. We find a global subalgebra spanned by n={2,1,0,1,2}n=\{-2, -1, 0, 1, 2\} which annihilate the conformally invariant vacuum and transform among themselves under the action of the collinear conformal group that preserves the light-ray. Operators outside this range give rise to an infinite central term, in agreement with previous suggestions in the literature. In free theories, even some of the operators inside the global subalgebra fail to commute when placed at spacelike separation on the same null-plane. This lack of commutativity is not integrable, presenting an obstruction to the construction of a well defined light-ray algebra at coincident x\vec{x} coordinates. For holographic CFTs the behavior worsens and operators with n2n \neq -2 fail to commute at spacelike separation. We reproduce this result in the bulk of AdS where we present new exact shockwave solutions dual to the insertions of these (exponentiated) operators on the boundary.Comment: 56 pages + appendices, 9 figures; references and minor clarifications adde

    APPARENT SURVIVAL OF BREEDING WESTERN SANDPIPERS ON THE YUKON-KUSKOKWIM RIVER DELTA, ALASKA

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    We used 8 years of live recapture data (1998–2005) to estimate apparent annual survival for male (n = 237) and female (n = 296) Western Sandpipers (Calidris mauri) breeding on a 36-ha plot on the Yukon-Kuskokwim River Delta, western Alaska. Apparent annual survival (Φ) is the product of true survival and site fidelity, and estimates of Φ were corrected for the probability of encounter. Overall return rates (individual returned to the study site in a subsequent season) were lower for females (40%) than males (65%), as was Φ (± SE, females = 0.65 ± 0.05, males = 0.78 ± 0.03), and encounter rate (females = 0.51 ± 0.07, males = 0.74 ± 0.04). Results differed from previous estimates of Φ for this species as our estimates of Φ were higher for both males and females compared to estimates from another breeding site and two nonbreeding locations. Disparity among Φ estimates from breeding and nonbreeding areas highlights the need to delineate site-specific factors throughout the annual cycle that influence population dynamics of the Western Sandpiper

    APPARENT SURVIVAL OF BREEDING WESTERN SANDPIPERS ON THE YUKON-KUSKOKWIM RIVER DELTA, ALASKA

    Get PDF
    We used 8 years of live recapture data (1998–2005) to estimate apparent annual survival for male (n = 237) and female (n = 296) Western Sandpipers (Calidris mauri) breeding on a 36-ha plot on the Yukon-Kuskokwim River Delta, western Alaska. Apparent annual survival (Φ) is the product of true survival and site fidelity, and estimates of Φ were corrected for the probability of encounter. Overall return rates (individual returned to the study site in a subsequent season) were lower for females (40%) than males (65%), as was Φ (± SE, females = 0.65 ± 0.05, males = 0.78 ± 0.03), and encounter rate (females = 0.51 ± 0.07, males = 0.74 ± 0.04). Results differed from previous estimates of Φ for this species as our estimates of Φ were higher for both males and females compared to estimates from another breeding site and two nonbreeding locations. Disparity among Φ estimates from breeding and nonbreeding areas highlights the need to delineate site-specific factors throughout the annual cycle that influence population dynamics of the Western Sandpiper

    House price Keynesianism and the contradictions of the modern investor subject

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    This article conceptualises the marked downturn in UK house prices in the 2007-2009 period in relation to longer-term processes of national economic restructuring centred on a new model of homeownership. The structure of UK house prices has been impacted markedly by the Labour Government‟s efforts to ingrain a particular notion of financial literacy amid the move towards an increasingly asset-based system of welfare. New model welfare recipients and new model homeowners have thereby been co-constituted in a manner consistent with a new UK growth regime of „house price Keynesianism‟. However, the investor subjects who drive such growth are necessarily rendered uncertain as compared with the idealised image of Government policy because of their reliance on the credit-creating decisions of private financial institutions. The recent steep decline in UK house prices is explained here as an epiphenomenon of the disruptive effect on the idealised image caused by the dependence of investor subjects on pricing dynamics not of their making

    Characterising a pH-switch anti-C5 antibody as a tool for human and mouse complement C5 purification and cross-species inhibition of classical and reactive lysis

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    C5 plays a major role in complement activation; C5 convertase cleaves C5 into the pro‐inflammatory C5a, and C5b, the nidus for the formation of the lytic membrane attack complex. C5 is a major target for anti‐complement drugs, necessitating better methods for the study of C5 function. Purification of C5 is complicated; classical methods involve precipitation or pH shifts that result in functional loss and low yield. We here present a method for C5 purification using a novel anti‐C5 monoclonal antibody (mAb); RO7112689 (C5i mAb, SKY59), pH‐switch engineered to induce antibody–antigen dissociation in the acidic endosome (~ pH 5·5). RO7112689 was bound on an affinity column; applied serum was completely depleted of C5. Elution at pH 5 produced fully active C5 at 98% yield. The mAb also bound C5b in the C5b6 complex, preventing C5b6 binding to target membranes and enabling purification of C5b6 from activated serum. RO7112689 inhibited C5 in mouse serum and efficiently purified mouse C5. Used as capture, RO7112689 produced sensitive and specific assays for human and mouse C5. This novel antibody enables efficient production of intact, fully active, pure human and mouse C5, and quantification of C5 in these species. The demonstration that RO7112689 binds C5b6 adds an additional mechanism of membrane attack complex inhibition by this mAb

    Practical guidance on use of TEARS-Q to diagnose post-stroke emotionalism

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    Objective: To evaluate, using a classification tree methodology, the ability of the Testing Emotionalism After Recent Stroke – Questionnaire (TEARS-Q) to determine the need for further assessment of post-stroke emotionalism and to identify those whose emotionalism is sufficiently clear that they need assessment for potential intervention. Setting: Acute stroke units of nine Scottish hospitals in the context of a longitudinal cohort study of post-stroke emotionalism. Subjects: A total of 228 stroke survivors recruited between October 1st 2015 and September 30th 2018, within two weeks of stroke. Measures: The measure was the self-report questionnaire TEARS-Q, constructed based on recognised diagnostic features of post-stroke tearful emotionalism. The reference standard was presence/absence of emotionalism on a diagnostic, semi-structured post-stroke emotionalism interview, administered at the same assessment point. Results: Nine of 159 subjects scoring 0 or 1 on TEARS-Q were diagnosed with post-stroke emotionalism on the reference standard, compared to 11 of 21 subjects scoring 2 to 5 on TEARS-Q and 42 of 48 participants scoring 6 and above. Adding age, sex, deprivation, stroke type, stroke severity, mood, cognition, daily functioning and education did not improve the prediction accuracy sufficiently to change the classification tree. Conclusion: TEARS-Q reliably identifies those who need no further post-stroke emotionalism assessment, those who need further assessment to clarify diagnosis, and those who almost certainly have post-stroke emotionalism and may benefit from intervention
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