401 research outputs found

    Boiling the Frog Slowly:The Immersion of C-Suite Financial Executives into Fraud

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    This study explores how financial executives retrospectively account for their crossing the line into financial statement fraud while acting within or reacting to a financialized corporate environment. We conduct our investigation through face-to-face interviews with 13 former C-suite financial executives who were involved in and indicted for major cases of accounting fraud. Five different themes of accounts emerged from the narratives, characterizing executives' fraud immersion as a meaning-making process by which the particulars of the proximal social context (the influence of social actors and contextual characteristics) and individual motivations collectively molded executives' vocabularies of fraud immersion. Our executives' narratives portray their fraud entanglement as typically occurring in small, incremental steps. Their accounts expand our understanding of the influence of socialization on executive-level financial fraud beyond the individualized focus of the fraud triangle model

    Folic acid fortification and public health: Report on threshold doses above which unmetabolised folic acid appear in serum

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    BACKGROUND: All flour in the USA is fortified with folic acid at a level of 140 μg/100 g which is estimated to supply an extra 100 μg daily to the average diet. Some researchers have advocated that this be increased to double and even four times this amount. Based on previous research these higher levels are likely to lead to the appearance of unmetabolised vitamin in the circulation, which may have safety implications for sub-groups of the population. The UK and the Republic of Ireland will likely introduce mandatory fortification also in the next year or so. The aim of this study was to capture the short-term effect of folic acid fortification on unmetabolised folic acid in serum after chronic consumption of folic acid. METHODS: After pre-saturation with 400 μg folic acid supplements daily for 14-weeks, healthy folate replete adults (n = 20) consumed folic acid fortified bread, at three different levels (400 μg, 200 μg, 100 μg) over a period of one week each. The dose was administered in two-equal sized slices consumed at 09.00 hrs and 13.00 hrs. Serum samples for total folate and folic acid were collected at baseline, after 14-weeks of supplementation, and pre and post (at 1, 2, 3 and 4 hours) each dose tested. RESULTS: Unmetabolised folic acid was detected after the 14-week supplementation period. Folic acid was not detected in either the 200 μg or 100 μg (current US regime) doses tested but was present at the highest level (400 μg) tested. CONCLUSION: Our findings suggest that persons exposed to the current US fortification programme supplying an average of 100 μg per day or less are unlikely to have unmetabolised folic acid in serum. It also seems that daily consumption of the higher level of 200 μg or less is unlikely to be problematic. Increasing the level however to 400 μg on the other hand is likely to lead to unmetabolised folic acid appearance

    Multi-device study of temporal characteristics of magnetohydrodynamic modes initiating disruptions

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    Disruptions in tokamaks are often preceded by magnetohydrodynamic (MHD) instabilities that can rotate or become locked to the wall. Measurements from magnetic diagnostics in the presence of MHD mode precursors to disruptions can yield potentially valuable input to the plasma control system, with a view to disruption avoidance, prediction and mitigation. This paper presents an exploratory analysis of the growth of MHD modes and corresponding time scales on the basis of magnetic measurements in multiple tokamaks. To this end, a database was compiled using disruptive discharges from COMPASS, ASDEX Upgrade, DIII-D and JET, manually classified according to disruption root cause, and characterized by a great diversity of operational conditions and mode dynamics. The typical time during which a mode can be detected using saddle coils and the duration of the locked mode phase in the database both extend over several orders of magnitude, but generally the time scales increase with plasma size. Several additional factors are discussed that can influence these durations, including the disruption root cause. A scaling law for the locked phase duration was estimated, yielding predictions toward ITER of the order of hundreds of milliseconds or even seconds. In addition, a scaling law for the mode amplitude at the disruption onset, proposed earlier by de Vries et al. (2016), is applied to the database, and its predictive capabilities are assessed. Despite significant uncertainty on the predictions from both scaling laws, encouraging trends are observed of the fraction of disruptions that may be detected with sufficient warning time to allow mitigation or even avoidance, based solely on observations of MHD mode dynamics. When combined with similar analysis of measurements from diagnostics that are sensitive to other disruption precursors, our analysis methods and results may contribute to the reliability, robustness and generalization of disruption warning schemes for ITER

    Giant bowing of the band gap and spin-orbit splitting energy in GaP <sub>1−x</sub> Bi <sub>x</sub> dilute bismide alloys

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    Using spectroscopic ellipsometry measurements on GaP1−xBix/GaP epitaxial layers up to x = 3.7% we observe a giant bowing of the direct band gap (EgΓ{E}_{g}^{{\rm{\Gamma }}}EgΓ) and valence band spin-orbit splitting energy (ΔSO). EgΓ{E}_{g}^{{\rm{\Gamma }}}EgΓ(ΔSO) is measured to decrease (increase) by approximately 200 meV (240 meV) with the incorporation of 1% Bi, corresponding to a greater than fourfold increase in ΔSO in going from GaP to GaP0.99Bi0.01. The evolution of EgΓ{E}_{g}^{{\rm{\Gamma }}}EgΓand ΔSO with x is characterised by strong, composition-dependent bowing. We demonstrate that a simple valence band-anticrossing model, parametrised directly from atomistic supercell calculations, quantitatively describes the measured evolution of EgΓ{E}_{g}^{{\rm{\Gamma }}}EgΓand ΔSO with x. In contrast to the well-studied GaAs1−xBix alloy, in GaP1−xBix substitutional Bi creates localised impurity states lying energetically within the GaP host matrix band gap. This leads to the emergence of an optically active band of Bi-hybridised states, accounting for the overall large bowing of EgΓ{E}_{g}^{{\rm{\Gamma }}}EgΓand ΔSO and in particular for the giant bowing observed for x ≲ 1%. Our analysis provides insight into the action of Bi as an isovalent impurity, and constitutes the first detailed experimental and theoretical analysis of the GaP1−xBix alloy band structure
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