4,940 research outputs found

    A direct proof of Z-stability for AH algebras of bounded topological dimension

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    We prove that a unital simple approximately homogeneous (AH) C*-algebra with no dimension growth absorbs the Jiang-Su algebra tensorially without appealing to the classification theory of these algebras. Our main result continues to hold under the slightly weaker hypothesis of exponentially slow dimension growth.Comment: 15 pages, no figure

    The obsolescing bargain model and oil: the Anglo-Iranian Oil Company 1933–1951

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    We employ archival evidence to investigate events culminating in the nationalisation of the Anglo-Iranian Oil Company (AIOC) in 1951, which followed disagreements over profit allocations arising from a previously negotiated concession. The case study expands the traditional obsolescing bargain model (OBM) by accommodating the use and impact of accounting information in negotiation contexts. The analysis reveals that managerial control and the deployment of accounting information by the AIOC temporarily strengthened its bargaining power vis a vis the Iranian government leading up to the nationalisation crisis, demonstrating the potential importance of these new dimensions in wider contexts

    Quantum gravitational contributions to quantum electrodynamics

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    Quantum electrodynamics describes the interactions of electrons and photons. Electric charge (the gauge coupling constant) is energy dependent, and there is a previous claim that charge is affected by gravity (described by general relativity) with the implication that the charge is reduced at high energies. But that claim has been very controversial with the situation inconclusive. Here I report an analysis (free from earlier controversies) demonstrating that that quantum gravity corrections to quantum electrodynamics have a quadratic energy dependence that result in the reduction of the electric charge at high energies, a result known as asymptotic freedom.Comment: To be published in Nature. 19 pages LaTeX, no figure

    Neck atonia with a focal stimulation-induced seizure arising from the SMA: pathophysiological considerations.

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    A 28-year-old patient with pharmacoresistant non-lesional right frontal epilepsy underwent extra-operative intracranial EEG recordings and electrical cortical stimulation (ECS) to map eloquent cortex. Right supplementary motor area (SMA) ECS induced a brief seizure with habitual symptoms involving neck tingling followed by asymmetric tonic posturing. An additional feature was neck atonia. During atonia and sensory aura, discharges were seen in the mesial frontal electrodes and precentral gyrus. Besides motor signs, atonia, although rare and not described in the neck muscles, and sensations have been reported with SMA stimulation. The mechanisms underlying neck atonia in seizures arising from the SMA can be explained by supplementary negative motor area (SNMA) - though this was not mapped in electrodes overlying the ictal onset zone in our patient - or primary sensorimotor cortex activation through rapid propagation. Given the broad spectrum of signs elicited by SMA stimulation and rapid spread of seizures arising from the SMA, caution should be taken to not diagnose these as non-epileptic, as had previously occurred in this patient

    Going DEEP: an evaluation of a social pedagogy-informed approach to evidence-enriched practice in social care

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    Social care workers benefit from multiple types of evidence to enhance citizen well-being, support their own well-being and improve social care services. Building capacity within social care to find, collect and use different forms of evidence is an international concern. The Developing Evidence Enriched Practice (DEEP) programme in Wales is informed by the values and aims of social pedagogy. It aspires to enhance both the generation and use of evidence in social care. To learn about what works in the programme, we conducted an evaluation based on contribution analysis that explored programme impacts between 2020 and 2023. Based on a co-produced theory of change the evaluation drew on exemplar cases, questionnaire responses, documentary evidence, process data and unsolicited feedback. There was evidence that the DEEP programme contributed to people better valuing and gaining a better understanding of different forms of evidence. Citizen voice could become more central in decision-making, and there were examples of practice, policy and research being informed by diverse evidence. Many people who attended the DEEP learning course enhanced their confidence and skills by using the DEEP approach and said that they would put their learning into practice. It was harder to evidence longer-term impacts and the sustainability of the approach. These findings suggest that there can be merit in developing capacity-building programmes informed by social pedagogy. Such programmes can be characterised as relational, holistic, practice-focused, multifaceted, contextualised and co-produced with intended beneficiaries
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