50,919 research outputs found

    Analysis of free analyte fractions by rapid affinity chromatography

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    The invention is generally directed toward an analytical method to determine the concentration of the free analyte fraction in a sample. More particularly, the method encompasses applying a sample comprising a free and bound analyte fraction to an affinity column capable of selectively extracting the free fraction in the millisecond time domain. The signal generated by the free fraction is then quantified by standard analytical detection techniques. The concentration of the free fraction may then be determined by comparison of its signal with that of a calibration curve depicting the signal of known concentration of the same analyte

    The structural contradictions and constraints on corporate social responsibility: Challenges for corporate social irresponsibility

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    Purpose - This chapter engages critically with the ideas of corporate social responsibility (CSR) and irresponsibility (CSI) in order to examine their utility for the purposes of realizing more socially just and environmentally sustainable social and economic practices. Methodology/approach - The chapter develops Marx's understanding of the twin pressures of class struggle and inter-capitalist competition in setting the limits of agency for corporate actors. It is thus theoretical and discursive in nature. Findings - The findings of the chapter suggest that the scope for corporate agency in relation to responsibility/irresponsibility is severely limited by inter-capitalist competition and capitalist social relations. It therefore argues that those interested in social justice and environmental sustainability should focus on these structural pressures rather than theorizing corporate agency. Social implications - The research suggests that the focus of academic and government attention should be on resolving the contradictions and exploitative social relations inherent in capitalism. Without this emphasis activism, corporate agency and government action will not eradicate the types of problem that advocates of CSR/CSI are concerned about. Originality/value of paper - The value of the paper is that it contests and engages critically with the utility of the notion of CSR and the emergent concept of CSI. It asks proponents of these concepts to think seriously about the structural pressures and constraints within which business and policy makers act. Copyrightr © 2012 by Emerald Group Publishing Limited

    Filamentary fragmentation in a turbulent medium

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    We present the results of smoothed particle hydrodynamic simulations investigating the evolution and fragmentation of filaments that are accreting from a turbulent medium. We show that the presence of turbulence, and the resulting inhomogeneities in the accretion flow, play a significant role in the fragmentation process. Filaments which experience a weakly turbulent accretion flow fragment in a two-tier hierarchical fashion, similar to the fragmentation pattern seen in the Orion Integral Shaped Filament. Increasing the energy in the turbulent velocity field results in more sub-structure within the filaments, and one sees a shift from gravity-dominated fragmentation to turbulence-dominated fragmentation. The sub-structure formed in the filaments is elongated and roughly parallel to the longitudinal axis of the filament, similar to the fibres seen in observations of Taurus, and suggests that the fray and fragment scenario is a possible mechanism for the production of fibres. We show that the formation of these fibre-like structures is linked to the vorticity of the velocity field inside the filament and the filament's accretion from an inhomogeneous medium. Moreover, we find that accretion is able to drive and sustain roughly sonic levels of turbulence inside the filaments, but is not able to prevent radial collapse once the filaments become supercritical. However, the supercritical filaments which contain fibre-like structures do not collapse radially, suggesting that fibrous filaments may not necessarily become radially unstable once they reach the critical line-density.Comment: (Accepted for publication in MNRAS

    The design and evaluation of a sonically enhanced tool palette

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    This paper describes an experiment to investigate the effectiveness of adding sound to tool palettes. Palettes have usability problems because users need to see the information they present, but they are often outside the area of visual focus. We used nonspeech sounds called earcons to indicate the current tool and when tool changes occurred so that users could tell what tool they were in wherever they were looking. Results showed a significant reduction in the number of tasks performed with the wrong tool. Therefore, users knew what the current tool was and did not try to perform tasks with the wrong one. All of this was not at the expense of making the tool palettes any more annoying to use

    Strong (π,0)(\pi,0) spin fluctuations in β\beta-FeSe observed by neutron spectroscopy

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    We have performed powder inelastic neutron scattering measurements on the unconventional superconductor β\beta-FeSe (Tc8KT_{\rm c} \simeq 8\,\mathrm{K}). The spectra reveal highly dispersive paramagnetic fluctuations emerging from the square-lattice wave vector (π,0)(\pi,0) extending beyond 80 meV in energy. Measurements as a function of temperature at an energy of 13meV\sim 13\,\mathrm{meV} did not show any variation from TcT_{\rm c} to 104K104\,\mathrm{K}. The results show that FeSe is close to an instability towards (π,0)(\pi,0) antiferromagnetism characteristic of the parent phases of the high-TcT_{\rm c} iron arsenide superconductors, and that the iron paramagnetic moment is neither affected by the orthorhombic-to-tetragonal structural transition at Ts90KT_{\rm s} \simeq 90\,\mathrm{K} nor does it undergo a change in spin state over the temperature range studied.Comment: Revised version, includes Supplementary Materia

    Integrating testing techniques through process programming

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    Integration of multiple testing techniques is required to demonstrate high quality of software. Technique integration has three basic goals: incremental testing capabilities, extensive error detection, and cost-effective application. We are experimenting with the use of process programming as a mechanism of integrating testing techniques. Having set out to integrate DATA FLOW testing and RELAY, we proposed synergistic use of these techniques to achieve all three goals. We developed a testing process program much as we would develop a software product from requirements through design to implementation and evaluation. We found process programming to be effective for explicitly integrating the techniques and achieving the desired synergism. Used in this way, process programming also mitigates many of the other problems that plague testing in the software development process

    A Bayesian test for the appropriateness of a model in the biomagnetic inverse problem

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    This paper extends the work of Clarke [1] on the Bayesian foundations of the biomagnetic inverse problem. It derives expressions for the expectation and variance of the a posteriori source current probability distribution given a prior source current probability distribution, a source space weight function and a data set. The calculation of the variance enables the construction of a Bayesian test for the appropriateness of any source model that is chosen as the a priori infomation. The test is illustrated using both simulated (multi-dipole) data and the results of a study of early latency processing of images of human faces. [1] C.J.S. Clarke. Error estimates in the biomagnetic inverse problem. Inverse Problems, 10:77--86, 1994.Comment: 13 pages, 16 figures. Submitted to Inverse Problem

    Strengths of singularities in spherical symmetry

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    Covariant equations characterizing the strength of a singularity in spherical symmetry are derived and several models are investigated. The difference between central and non-central singularities is emphasised. A slight modification to the definition of singularity strength is suggested. The gravitational weakness of shell crossing singularities in collapsing spherical dust is proven for timelike geodesics, closing a gap in the proof.Comment: 16 pages, revtex. V2. Classification of irregular singular points completed, Comments and references on singularities with a continuous metric amende
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