Nitration in inert fluids

Nitration in Inert Fluids Traditional methods of nitration have several disadvantages including the environmental problem of disposal of the spent acid. A main aim of this work was to investigate alternative methods for nitration while minimising the amount of acid required. Perfluorocompounds have been used as bulking agents to replace partially the acid solvent. They are chemically inert and may be reused without the need for purification. Mechanistic and synthetic studies of nitration reactions have been made. Toluene was successfully nitrated to trinitrotoluene using less sulfuric acid than in traditional methods. Benzene, styrene and trans-stilbene have been nitrated using nitric acid or dinitrogen pentoxide in perfluorocompounds. Kinetic results have been obtained for the homogeneous nitrations by N(_2)O(_5) in perfluorodecalin of substrates including 4-chloroanisole, 4-bromophenetole, 4- bromophenol and various chlorophenols. The rate constants have been determined and some mechanistic conclusions have been made. The nitration of various amines using dinitrogen pentoxide or nitric acid in perfluorocarbons has been studied. Nitrated derivatives of morpholine, pyrrolidine, piperidine, oxazolidinone and pyrimidine were successfully obtained using N-(^t)butoxycarbonyl, acetyl or silyl amines

Identity dynamics as a barrier to organizational change

This article seeks to explore the construction of group and professional identities in situations of organizational change. It considers empirical material drawn from a health demonstration project funded by the Scottish Executive Health Department, and uses insights from this project to discuss issues that arise from identity construction(s) and organizational change. In the course of the project studied here, a new organizational form was developed which involved a network arrangement with a voluntary sector organization and the employment of “lay-workers” in what had traditionally been a professional setting. Our analysis of the way actors made sense of their identities reveals that characterizations of both self and other became barriers to the change process. These identity dynamics were significant in determining the way people interpreted and responded to change within this project and which may relate to other change-oriented situations

Paradox as invitation to act in problematic change situations

It has been argued that organizational life typically contains paradoxical situations such as efforts to manage change which nonetheless seem to reinforce inertia. Four logical options for coping with paradox have been explicated, three of which seek resolution and one of which ‘keeps the paradox open’. The purpose of this article is to explore the potential for managerial action where the paradox is held open through the use of theory on ‘serious playfulness’. Our argument is that paradoxes, as intrinsic features in organizational life, cannot always be resolved through cognitive processes. What may be possible, however, is that such paradoxes are transformed, or ‘moved on’ through action and as a result the overall change effort need not be stalled by the existence of embedded paradoxes

The invisible plan: how English teachers develop their expertise and the special place of adapting the skills of lesson planning

This paper analyses how English teachers learn to become expert designers of learning and why sharing that expertise is increasingly vital. Its conceptual framework is the widely recognised, empirically tested, five-stage developmental Dreyfus model of skill acquisition, exemplifying the development of teacher expertise, constituted by the “milestone” [m] and “transitory” [t] phases connecting with the five stages of: Novice [m], Advanced Beginner [t], Competent [m], Proficient [t] and Expert [m]. Teacher planning is analysed as one key tacit or non-tangible component of developing expertise. Focusing specifically on English teachers as key participants in this pioneer teacher cognition study, the defining characteristics of milestone stages of expertise development are explored with specific attention to the remarkably under-researched area of planning. We introduce three new categories, defining modes of planning: (i) visible practical planning, (ii) external reflective planning and (iii) internal reflective planning, demonstrating their role in teacher development through the Dreyfus five stages. English is a subject which suffers from frequent disruptive changes to curriculum and assessment: new learning designs are constantly demanded, making planning an ongoing challenge. The implications for practice include the importance of an explicit understanding of how teachers’ planning moves through the three phases from the very “visible” novice phase to the internal relatively “automatic” competent teacher and finally the seemingly “invisible” expert phase. Further research is needed to explore how English teachers can share planning expertise between the three phases to improve teachers’ skills and student learning

Long-term clinical and cost-effectiveness of collaborative care (versus usual care) for people with mental-physical multimorbidity : a cluster-randomised trial.

Background Collaborative care can support the treatment of depression in people with long-term conditions, but long-term benefits and costs are unknown. Aims To explore the long-term (24-month) effectiveness and cost-effectiveness of collaborative care in people with mental-physical multimorbidity. Method A cluster randomised trial compared collaborative care (integrated physical and mental healthcare) with usual care for depression alongside diabetes and/or coronary heart disease. Depression symptoms were measured by the symptom checklist-depression scale (SCL-D13). The economic evaluation was from the perspective of the English National Health Service. Results 191 participants were allocated to collaborative care and 196 to usual care. At 24 months, the mean SCL-D13 score was 0.27 (95% CI, −0.48 to −0.06) lower in the collaborative care group alongside a gain of 0.14 (95% CI, 0.06-0.21) quality-adjusted life-years (QALYs). The cost per QALY gained was £13 069. Conclusions In the long term, collaborative care reduces depression and is potentially cost-effective at internationally accepted willingness-to-pay thresholds

Trends in Depression and Antidepressant Prescribing in Children and Adolescents: A Cohort Study in The Health Improvement Network (THIN)

In 2003, the Committee on Safety of Medicines (CSM) advised against treatment with selective serotonin reuptake inhibitors (SSRIs) other than fluoxetine in children, due to a possible increased risk of suicidal behaviour. This study examined the effects of this safety warning on general practitioners' depression diagnosing and prescription behaviour in children

Economic Impact of Dengue Illness and the Cost-Effectiveness of Future Vaccination Programs in Singapore

Dengue illness is a tropical disease transmitted by mosquitoes that threatens more than one third of the worldwide population. Dengue has important economic consequences because of the burden to hospitals, work absenteeism and risk of death of symptomatic cases. Governments attempt to reduce the disease burden using costly mosquito control strategies such as habitat reduction and spraying insecticide. Despite such efforts, the number of cases remains high. Dengue vaccines are expected to be available in the near future and there is an urgent need to evaluate their cost-effectiveness, i.e. whether their cost will be justified by the reduction in disease burden they bring. For such an evaluation, we estimated the economic impacts of dengue in Singapore and the expected vaccine costs for different prices. In this way we estimated price thresholds for which vaccination is not cost-effective. This research provides useful estimates that will contribute to informed decisions regarding the adoption of dengue vaccination programs