1,105 research outputs found

    The Impacat of Personality Type on Blog Participation

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    The objective of this study is to explore the impact of individual personality type on blog participation. Results indicate that blog participants are more likely to be introverts and perceptives

    Geometric Path Integrals. A Language for Multiscale Biology and Systems Robustness

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    In this paper we suggest that, under suitable conditions, supervised learning can provide the basis to formulate at the microscopic level quantitative questions on the phenotype structure of multicellular organisms. The problem of explaining the robustness of the phenotype structure is rephrased as a real geometrical problem on a fixed domain. We further suggest a generalization of path integrals that reduces the problem of deciding whether a given molecular network can generate specific phenotypes to a numerical property of a robustness function with complex output, for which we give heuristic justification. Finally, we use our formalism to interpret a pointedly quantitative developmental biology problem on the allowed number of pairs of legs in centipedes

    Semiclassical mechanics of a non-integrable spin cluster

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    We study detailed classical-quantum correspondence for a cluster system of three spins with single-axis anisotropic exchange coupling. With autoregressive spectral estimation, we find oscillating terms in the quantum density of states caused by classical periodic orbits: in the slowly varying part of the density of states we see signs of nontrivial topology changes happening to the energy surface as the energy is varied. Also, we can explain the hierarchy of quantum energy levels near the ferromagnetic and antiferromagnetic states with EKB quantization to explain large structures and tunneling to explain small structures.Comment: 9 pages. For related works see "http://www.msc.cornell.edu/~clh/clh.html

    Patterns of environmental variance across environments and traits in domestic cattle

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    The variance in phenotypic trait values is a product of environmental and genetic variation. The sensitivity of traits to environmental variation has a genetic component and is likely to be under selection. However, there are few studies investigating the evolution of this sensitivity, in part due to the challenges of estimating the environmental variance. The livestock literature provides a wealth of studies that accurately partition components of phenotypic variance, including the environmental variance, in well-defined environments. These studies involve breeds that have been under strong selection on mean phenotype in optimal environments for many generations, and therefore represent an opportunity to study the potential evolution of trait sensitivity to environmental conditions. Here, we use literature on domestic cattle to examine the evolution of micro-environmental variance (CVR-the coefficient of residual variance) by testing for differences in expression of CVR in animals from the same breed reared in different environments. Traits that have been under strong selection did not follow a null expectation of an increase in CVR in heterogenous environments (e.g., grazing), a pattern that may reflect evolution of increased uniformity in heterogeneous environments. When comparing CVR across environments of different levels of optimality, here measured by trait mean, we found a reduction in CVR in the more optimal environments for both life history and growth traits. Selection aimed at increasing trait means in livestock breeds typically occurs in the more optimal environments, and we therefore suspect that the decreased CVR is a consequence of evolution of the expression of micro-environmental variance in this environment. Our results highlight the heterogeneity in micro-environmental variance across environments and point to possible connections to the intensity of selection on trait means

    Acoustic Emission from crumpling paper

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    From magnetic systems to the crust of the earth, many physical systems that exibit a multiplicty of metastable states emit pulses with a broad power law distribution in energy. Digital audio recordings reveal that paper being crumpled, a system that can be easily held in hand, is such a system. Crumpling paper both using the traditional hand method and a novel cylindrical geometry uncovered a power law distribution of pulse energies spanning at least two decades: (exponent 1.3 - 1.6) Crumpling initally flat sheets into a compact ball (strong crumpling), we found little or no evidence that the energy distribution varied systematically over time or the size of the sheet. When we applied repetitive small deformations (weak crumpling) to sheets which had been previously folded along a regular grid, we found no systematic dependence on the grid spacing. Our results suggest that the pulse energy depends only weakly on the size of the paper regions responsible for sound production.Comment: 12 pages of text, 9 figures, submitted to Phys. Rev. E, additional information availible at http://www.msc.cornell.edu/~houle/crumpling

    Acoustic Emission from Paper Fracture

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    We report tensile failure experiments on paper sheets. The acoustic emission energy and the waiting times between acoustic events follow power-law distributions. This remains true while the strain rate is varied by more than two orders of magnitude. The energy statistics has the exponent β∼1.25±0.10\beta \sim 1.25 \pm 0.10 and the waiting times the exponent τ∼1.0±0.1\tau \sim 1.0 \pm 0.1, in particular for the energy roughly independent of the strain rate. These results do not compare well with fracture models, for (brittle) disordered media, which as such exhibit criticality. One reason may be residual stresses, neglected in most theories.Comment: 4 pages, 5 figure

    Clinical and organizational quality indicators for the optimal management of stroke in adults: Scoping review protocol

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    ABSTRACT Introduction Clinical and organizational indicators have been developed to measure current stroke practices in different organizations. Although there is a broad range of indicators regarding the acute stroke phase, there is no synthesis of these indicators during this phase, and information is missing on how they have been tested, validated and integrated within organizations and clinical practice. The present article describes a scoping review protocol to identify clinical and organizational indicators conducive to the optimal management of acute ischemic stroke in adults. Method and analysis Our scoping review will be based on the methodological framework developed by Arskey and O’Malley (2005). Medline, CINHAL, Academic search complete and Cochrane Library databases will be used along with Google Scholar and Google to identify writings that meet the inclusion criteria. All scientific studies and grey litterature conducted and published since 2015, in French and English, dealing with clinical and organizational indicators for the management and optimal care of adults with acute ischemic stroke will be retained. Indicators will be classified based on the dimensions of care performance. Next, an advisory committee composed of clinical and scientific experts together with the partner patient will draw up a final list of indicators using the Delphi process. We expect this scoping review to identify the best clinical and organizational indicators for optimal acute stroke management, thus allowing for improved supervision of quality of care. Ethics and dissemination No ethical approval is required. Dissemination of the results will be made through scientific publications, poster and oral presentations
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