2,210 research outputs found

    Nilpotent normal form for divergence-free vector fields and volume-preserving maps

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    We study the normal forms for incompressible flows and maps in the neighborhood of an equilibrium or fixed point with a triple eigenvalue. We prove that when a divergence free vector field in R3\mathbb{R}^3 has nilpotent linearization with maximal Jordan block then, to arbitrary degree, coordinates can be chosen so that the nonlinear terms occur as a single function of two variables in the third component. The analogue for volume-preserving diffeomorphisms gives an optimal normal form in which the truncation of the normal form at any degree gives an exactly volume-preserving map whose inverse is also polynomial inverse with the same degree.Comment: laTeX, 20 pages, 1 figur

    Share capitalism and worker wellbeing

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    We show that worker wellbeing is determined not only by the amount of compensation workers receive but also by how compensation is determined. While previous theoretical and empirical work has often been preoccupied with individual performance-related pay, we find that the receipt of a range of group-performance schemes (profit shares, group bonuses and share ownership) is associated with higher job satisfaction. This holds conditional on wage levels, so that pay methods are associated with greater job satisfaction in addition to that coming from higher wages. We use a variety of methods to control for unobserved individual and job-specific characteristics. We suggest that half of the share-capitalism effect is accounted for by employees reciprocating for the “gift”; we also show that share capitalism helps dampen the negative wellbeing effects of what we typically think of as “bad” aspects of job quality

    Wage effects of works councils and opening clauses: the German case

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    "German employment relations are characterized by a distinct dual system. First, working conditions and wages are determined by industry-level collective bargaining agreements. Second, on the establishment-level, the works council is responsible for employer - employee negotiations. However, since the mid-1980s, an increasing number of areas of regulation have been transferred from the industry- to the establishment-level using so-called opening clauses. The analysis in this article relies on rich German establishment data and reveals new insights into the institutional machinery of wage bargaining. While the existence of such clauses is related to higher wages, their application results in wage cuts of roughly the same size. The results also suggest that works councils, on average, are able to prevent the negative wage effects of opening clauses." (Author's abstract, IAB-Doku) ((en)

    Telerehabilitation for people with physical disabilities and movement impairment: development and evaluation of an online toolkit for practitioners and patients.

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    PURPOSE: Telerehabilitation has increasingly been used since the COVID-19 pandemic but with limited guidance available on undertaking physical assessments using remote methods. We aimed to provide such guidance by developing a Telerehab Toolkit, an online information and training resource for practitioners, patients, and carers on telerehabilitation for people with physical disabilities and movement impairment. MATERIALS AND METHODS: Development and evaluation of the toolkit were informed by the Knowledge to Action framework and took place iteratively in two phases-knowledge creation and action. Information was collated from various sources including literature review, online survey, service evaluation, and focus group discussions. The toolkit has been evaluated using think-aloud interviews, e-mail and social media feedback from users, and analytics data on user engagement with the website. RESULTS: The Telerehab Toolkit focuses on remote physical assessments, and contains information on technology, digital skills, remote assessment tools, information governance, and safety for telerehabilitation. Resources include top tips from practitioners and patients, how-to guides, checklists, videos, and links to evidence. CONCLUSIONS: The Telerehab Toolkit has been well-received by practitioners, healthcare students, patients, and carers, is being disseminated widely, and is freely available (www.plymouth.ac.uk/research/telerehab). IMPLICATIONS FOR REHABILITATIONTelerehabilitation has been increasingly used since the COVID-19 pandemic, but with limited guidance and training for practitioners on undertaking safe and effective remote physical assessments.The Telerehab Toolkit has been developed iteratively using the Knowledge to Action framework; it is a free online resource for practitioners and patients with specific guidance on telerehabilitation for physical disabilities and movement impairment.It is anticipated that the resource will help to improve the knowledge, skills, and confidence of the current and future rehabilitation workforce

    Advancing understanding on industrial relations in multinational companies: key research challenges and the INTREPID contribution

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    peer-reviewedThis paper has three principal aims. It firstly provides some theoretical background on the key current research issues and challenges in regard to industrial relations in multinational companies. It then presents a concise review of scholarship to date on industrial relations in multinational companies using INTREPID (Investigation of Transnationals Employment Practices: an International Database) data. Finally, the paper identifies some of the main industrial relations issues that remain to be addressed, in effect charting a form of research agenda for future work using the INTREPID data, with particular focus on the potential contribution from ‘late joiners’ to the INTREPID project.ACCEPTEDpeer-reviewe

    From presence to consciousness through virtual reality

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    Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness

    The Effectiveness of Co-Determination Laws in Cooperative and Adversarial Employment Relations: When Does Regulation Have Bite?

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    The German Codetermination Law grants workers of establishments with 200 or more employees the right to have a works councillor who is fully exempted from his or her regular job duties while still paid a regular salary. This article analyses theoretically and empirically how this de jure right to exemption translates into de facto practice, and explicitly takes into account the nature of the employment relations participation regime. It is found that the right of exemption has no effect in cooperative employment relations because exemptions are granted even in the absence of legal rights, but does make a difference in adversarial relations when exemptions are only granted above the threshold where legal rights force employers to do so, i.e. legal rights do make a decisive difference in exactly those situations where the legislators’ intent would not be realized without the right to legal enforcemen

    Interaction of perceptual grouping and crossmodal temporal capture in tactile apparent-motion

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    Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture'' visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left-or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs-one short (75 ms), one long (325 ms)-were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects

    Polarization of coalitions in an agent-based model of political discourse

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    Political discourse is the verbal interaction between political actors in a policy domain. This article explains the formation of polarized advocacy or discourse coalitions in this complex phenomenon by presenting a dynamic, stochastic, and discrete agent-based model based on graph theory and local optimization. In a series of thought experiments, actors compute their utility of contributing a specific statement to the discourse by following ideological criteria, preferential attachment, agenda-setting strategies, governmental coherence, or other mechanisms. The evolving macro-level discourse is represented as a dynamic network and evaluated against arguments from the literature on the policy process. A simple combination of four theoretical mechanisms is already able to produce artificial policy debates with theoretically plausible properties. Any sufficiently realistic configuration must entail innovative and path-dependent elements as well as a blend of exogenous preferences and endogenous opinion formation mechanisms

    UK experience of liver transplantation for erythropoietic protoporphyria

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    Erythropoietic protoporphyria (EPP) is characterised by excess production of free protoporphyrin from the bone marrow, most commonly due to deficiency of the enzyme ferrochelatase. Excess protoporphyrin gives rise to the cutaneous photosensitivity characteristic of the disease, and in a minority of patients leads to end-stage liver disease necessitating liver transplantation (LT). There is limited information regarding the timing, impact and long-term outcome of LT in such patients, thus we aimed to identify the indications and outcomes of all transplants performed for EPP in the UK using data from the UK Transplant Registry. Between 1987 and 2009, five patients underwent LT for EPP liver disease. Median follow-up was 60 months, and there were two deaths at 44 and 95 months from causes unrelated to liver disease. The remaining recipients are alive at 22.4 years, 61 months and 55 months after transplant. A high rate of postoperative biliary stricturing requiring multiple biliary interventions was observed. Recurrent EPP-liver disease occurred in 4/5 (80%) of patients but graft failure has not been observed. Given the role of biliary obstruction in inducing EPP-mediated liver damage, we suggest that consideration should be given for construction of a Roux loop at the time of transplant. Thus we demonstrate that although EPP liver transplant recipients have a good long-term survival, comparable to patients undergoing LT for other indications, biliary complications and disease recurrence are almost universal, and bone marrow transplantation should be considered where possible
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