Directional deep brain stimulation contacts provide greater spatial flexibility for therapy than traditional ring-shaped electrodes, but little is known about longitudinal changes of impedance and orientation. We measured monopolar and bipolar impedance of DBS contacts in 31 patients who underwent unilateral subthalamic nucleus deep brain stimulation as part of a randomized study. At different follow-up visits, patients were assigned new stimulation configurations and impedance was measured. Additionally, we measured the orientation of the directional lead during surgery, immediately after surgery, and (...) 1 year later. Here we contrast impedances in directional versus ring contacts with respect to local anatomy, active stimulation contact, and over time. Directional contacts display larger impedances than ring contacts. Impedances generally increase slightly over the first year of therapy, save for a transient decrease immediately post-surgery under general anesthesia during pulse generator placement. Local impedances decrease at active stimulation sites, and contacts in closest proximity to internal capsule display higher impedances than other anatomic sites. DBS leads rotate slightly in the immediate postoperative period but otherwise remain stable over the following year. These data provide useful information for setting clinical stimulation parameters over time. (shrink)

Introduction: Although deep brain stimulation often improves levodopa-responsive gait symptoms, robust therapies for gait dysfunction from Parkinson's disease remain a major unmet need. Walking speed could represent a simple, integrated tool to assess DBS efficacy but is often not examined systematically or quantitatively during DBS programming. Here we investigate the reliability and functional significance of changes in gait by directional DBS in the subthalamic nucleus.Methods: Nineteen patients underwent unilateral subthalamic nucleus DBS surgery with an eight-contact directional lead in the most (...) severely affected hemisphere. They arrived off dopaminergic medications >12 h preoperatively and for device activation 1 month after surgery. We measured a comfortable walking speed using an instrumented walkway with DBS off and at each of 10 stimulation configurations at the midpoint of the therapeutic window. Repeated measures of ANOVA contrasted preoperative vs. maximum and minimum walking speeds across DBS configurations during device activation. Intraclass correlation coefficients examined walking speed reliability across the four trials within each DBS configuration. We also investigated whether changes in walking speed related to modification of step length vs. cadence with a one-sample t-test.Results: Mean comfortable walking speed improved significantly with DBS on vs. both DBS off and minimum speeds with DBS on. Pairwise comparisons showed no significant difference between DBS off and minimum comfortable walking speed with DBS on. Intraclass correlations were ≥0.949 within each condition. Changes in comfortable walk speed were conferred primarily by changes in step length.Conclusion: Acute assessment of walking speed is a reliable, clinically meaningful measure of gait function during DBS activation. Directional and circular unilateral subthalamic DBS in appropriate configurations elicit acute and clinically significant improvements in gait dysfunction related to PD. Next-generation directional DBS technologies have significant potential to enhance gait by individually tailoring stimulation parameters to optimize efficacy. (shrink)

Data platforms represent a new paradigm for carrying out health research. In the platform model, datasets are pooled for remote access and analysis, so novel insights for developing better stratified and/or personalised medicine approaches can be derived from their integration. If the integration of diverse datasets enables development of more accurate risk indicators, prognostic factors, or better treatments and interventions, this obviates the need for the sharing and reuse of data; and a platform-based approach is an appropriate model for facilitating (...) this. Platform-based approaches thus require new thinking about consent. Here we defend an approach to meeting this challenge within the data platform model, grounded in: the notion of ‘reasonable expectations’ for the reuse of data; Waldron’s account of ‘integrity’ as a heuristic for managing disagreement about the ethical permissibility of the approach; and the element of the social contract that emphasises the importance of public engagement in embedding new norms of research consistent with changing technological realities. While a social contract approach may sound appealing, however, it is incoherent in the context at hand. We defend a way forward guided by that part of the social contract which requires public approval for the proposal and argue that we have moral reasons to endorse a wider presumption of data reuse. However, we show that the relationship in question is not recognisably contractual and that the social contract approach is therefore misleading in this context. We conclude stating four requirements on which the legitimacy of our proposal rests. (shrink)

Empirical research is largely supportive of the assertion of instrumental stakeholder theory that a positive relationship exists between “managing for stakeholders” and firm performance. However, despite considerable debate on the subject, the amount of variation across firm investments in stakeholders (stakeholder management performance) has not been adequately investigated. We address this gap using a sample of more than eighteen thousand firm-level observations over ten years. We find evidence to support an inverted U–shaped relationship between variation in stakeholder management performance and (...) Tobin’sq, suggesting that firms that have some imbalance in their stakeholder management, but not too much, perform best. We discuss the implications of our study for instrumental stakeholder theory and managerial practice. (shrink)

C W Evers, J C Walker; Knowledge, Partitioned Sets and Extensionality: a refutation of the forms of knowledge thesis, Journal of Philosophy of Education, Volume.

At Moore’s time, the main-stream ethical theory is the doctrine that pleasure alone is good as an end as held by the hedonistic utilitarianism. Moore, however, asserts that good, not composed of any parts, is a simple notion and indefinable, and naturalistic ethical theories, in particular hedonistic utilitarianism, interpret intrinsic good as a property of a single natural object---pleasure, which is also the sole end of life, thus violates naturalistic fallacy. Moore seems to believe that there exist things other than (...) pleasure that are also intrinsically good and has searched for them. But Moore has not clearly stated what these things are, nor has he given any justification for why they are intrinsically good. This paper discusses Moore’s arguments and difficulties of utilitarianism. With the subjectivistic utilitarian theory of value, Unified Utilitarian Theory (UTT) discards the classification of value into intrinsic and instrumental and proves to be exempt of all theexisting difficulties with utilitarianism related to pleasure, including naturalistic fallacy, vagueness of pleasure and sole end of life, double counting, etc. (shrink)

C W Evers, J C Walker; Pyrotechnics Defended: a reply to Jim Mackenzie, Journal of Philosophy of Education, Volume 21, Issue 1, 30 May 2006, Pages 139–142, http.

Natural science enables us, it is supposed, first to know what science properly is. Other sciences—which purport to exhibit a radically divergent type—are either of doubtful authenticity and highly disputable value, or else humbug, which has long since become transparent. If now the humanists are to be compelled to practise science, they will have perforce, nolentes volentes, to take the natural sciences for their model and adopt their methods. Extra ecclesiam nulla salus. Under no circumstances is recognition extended to a (...) distinctive humanistic type of science side by side with the type of natural science. The distinctions between scientific forms and methods of procedure, which are forthcoming, accordingly all turn out to constitute merely variations within natural science itself. (shrink)

J C Walker; The Philosopher’s Touchstone: towards pragmatic unity in educational studies, Journal of Philosophy of Education, Volume 19, Issue 2, 30 May 2006, P.

This paper argues that the notion of value has been overly simplified and narrowed to focus on economic returns. Stakeholder theory provides an appropriate lens for considering a more complex perspective of the value that stakeholders seek as well as new ways to measure it. We develop a four-factor perspective for defining value that includes, but extends beyond, the economic value stakeholders seek. To highlight its distinctiveness, we compare this perspective to three other popular performance perspectives. Recommendations are made regarding (...) performance measurement for both academic researchers and practitioners. The stakeholder perspective on value offered in this paper draws attention to those factors that are most closely associated with building more value for stakeholders, and in so doing, allows academics to better measure it and enhances managerial ability to create it. (shrink)

Legal battles continue in the UK over the Government’s plans to transport asylum seekers arriving on British shores to Rwanda in East Africa. Originally announced as a system for ‘processing’ asylum seekers, the Government has subsequently made it clear that there would not be an option for asylum seekers to return to the UK. The arrangement forms part of a deal between the UK and Rwanda, with the UK promising to invest £120 m in economic growth and development in Rwanda, (...) along with financing the cost of the ‘offshored’ asylum operation.1 The Government states that the policy is designed to break the business model of people traffickers involved in facilitating hazardous trips across the Channel in small, overcrowded and unseaworthy craft, leading to multiple drownings. Critics argue that the policy will do nothing to stop desperate people from seeking refuge in the UK, that transferring already traumatised people to Rwanda – which has been criticised for its human rights record – is inhumane and potentially outwith international law. Medical bodies, including the BMA, along with refugee organisations have expressed serious concerns about the health impact of such a system of ‘offshoring’. An equivalent system in Australia has been notorious for the devastating health impacts on those ‘offshored’ to the Pacific islands of Manus and Naura. Unusually in the UK the offshoring proposals have been greeted by unanimous condemnation by the Church of England. The lawfulness of the process is also subject to question. On the 14 July, a plane carrying a small number of asylum seekers to Rwanda was halted shortly before take-off following an intervention by the European Court of Human Rights. The ECtHR, part of the Council of Europe, of which the UK is still a member, said an Iraqi man known as KN faced ‘a real …. (shrink)

Stakeholder theory focuses on how more value is created if stakeholder relationships are governed by ethical principles such as integrity, respect, fairness, generosity and inclusiveness. However, it has not adequately addressed strategies that stakeholders perceive as harmful to their interests and how this perception can even lead some stakeholders to view the firm’s strategies as unethical. To fill the void, this paper directly addresses strategies that stakeholders perceive as harmful to their interests, or what we refer to as harmful stakeholder (...) strategies. Specifically, it identifies factors associated with stakeholder perceptions of harm that are likely to cause them to consider a strategy unethical, examines the negative implications for firms that pursue such strategies in terms of likely stakeholder responses and damage to stakeholder relationships, and provides theory to help explain how firms are likely to respond to stakeholder claims that a strategy is unethical, based on factors such as the strategic importance of the claim to the firm, how long the strategy has been in use, the costs of remediation, the risk of stakeholder mobilization or new regulation, and whether firms can reasonably rationalize their actions. Assessing harm allows a firm to make a more accurate estimate of the costs of a strategy and can assist managers in allocating resources intended to reduce or remediate harm. (shrink)

J C Walker; Dusting Off Educational Studies: a methodology for implementing certain proposals of John Wilson’s, Journal of Philosophy of Education, Volume 18, I.