A combined continuous‐wave and pulsed microwave copper chloride discharge

Pulsed and continuous‐wave microwaves at 2.45 GHz combined in an Asmussen resonant cavity are used to vaporize, dissociate, and excite copper chloride discharges. Steady state microwaves from 50 to 150 W sustain a microwave discharge which heats and dissociates the copper chloride to a sufficient vapor pressure. A variable frequency (2.45 to 2.60 GHz) pulsed microwave source with pulse widths ranging from 0.5 to 2 ms, repetition rates of 500 to 5000 Hz and a peak output power of 4,500 W then excites the copper atomic states. The two microwave signals are superimposed using a hybrid junction before input into the resonant cavity. Microwave frequencies of the pulsed portion of the signal around 2.50 GHz provided maximum absorption by the discharge. This device is being examined as a potential pump source for a copper vapor laser.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70269/2/RSINAK-63-2-1792-1.pd

Stereodeficient subjects demonstrate non-linear stereopsis

AbstractThere appear to be two modes of stereoscopic processing: a conventional linear operation that is dependent on correspondence between local luminance components in the two eyes’ views, and a non-linear or second-order processing mode. This second mode may use disparity information provided by particular ‘non-Fourier’ features of the stimulus such as the contrast envelope. Preliminary results suggest that people who fail standard clinical stereotests are able to extract non-linear disparity information from Gabor stimuli [McColl & Mitchell, 1998. Vision Research, 38, 1889–1900]. Here we evaluate the status of the non-linear mechanism in such individuals by using two types of contrast enveloped stimuli, namely random line and Gabor micropatterns, in a task that requires near/far depth judgements [Ziegler & Hess, 1999. Vision Research, 39, 1491–1507]. Although our sample was small, three of our four subjects who had performed poorly on at least one standard clinical test of stereopsis could perform the task, as well as one ‘stereoblind’ subject who had failed all four standard clinical tests. The overall results suggest that individuals with stereoanomalies show a diversity of deficits, but some nevertheless can see depth using ‘non-linear’ mechanisms

Electron density and collision frequency of microwave‐resonant‐cavity‐produced discharges

A review of perturbation diagnostics applied to microwave resonant cavity discharges is presented. The classical microwave perturbation technique examines the shift in the resonant frequency and cavity quality factor of the resonant cavity caused by low‐electron density discharges. However, the modifications presented allow the analysis to be applied to discharges with electron densities beyond the limit predicted by perturbation theory. An ‘‘exact’’ perturbation analysis is presented which models the discharge as a separate dielectric, thereby removing the restrictions on electron density imposed by the classical technique. The ‘‘exact’’ method also uses measurements of the shifts in the resonant conditions of the cavity. Third, an electromagnetic analysis is presented which uses a characteristic equation, based upon Maxwell’s laws, and predicts the discharge conductivity based upon measurements of a complex axial wave number. By allowing the axial wave number of the electromagnetic fields to be complex, the fields are experimentally and theoretically shown to be spatially attenuated. The diagnostics are applied to continuous‐wave microwave (2.45 GHz) discharges produced in an Asmussen resonant cavity. Double Langmuir probes, placed directly in the discharge at the point where the radial electric field is zero, act as a comparison with the analytic diagnostics. Microwave powers ranging from 30 to 100 W produce helium and nitrogen discharges with pressures ranging from 0.5 to 6 Torr. Analysis of the data predicts electron temperatures from 5 to 20 eV, electron densities from 1011 to 3×1012 cm−3, and collision frequencies from 109 to 1011 s−1.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69731/2/JAPIAU-74-6-3724-1.pd

Acceptability of financial incentives for health behaviour change to public health policymakers: a qualitative study

Abstract Background Providing financial incentives contingent on healthy behaviours is one way to encourage healthy behaviours. However, there remains substantial concerns with the acceptability of health promoting financial incentives (HPFI). Previous research has studied acceptability of HPFI to the public, recipients and practitioners. We are not aware of any previous work that has focused particularly on the views of public health policymakers. Our aim was to explore the views of public health policymakers on whether or not HPFI are acceptable; and what, if anything, could be done to maximise acceptability of HPFI. Methods We recruited 21 local, regional and national policymakers working in England via gatekeepers and snowballing. We conducted semi-structured in-depth interviews with participants exploring experiences of, and attitudes towards, HPFI. We analysed data using the Framework approach. Results Public health policymakers working in England acknowledged that HPFI could be a useful behaviour change tool, but were not overwhelmingly supportive of them. In particular, they raised concerns about effectiveness and cost-effectiveness, potential ‘gaming’, and whether or not HPFI address the underlying causes of unhealthy behaviours. Shopping voucher rewards, of smaller value, targeted at deprived groups were particularly acceptable to policymakers. Participants were particularly concerned about the response of other stakeholders to HPFI – including the public, potential recipients, politicians and the media. Overall, the interviews reflected three tensions. Firstly, a tension between wanting to trust individuals and promote responsibility; and distrust around the potential for ‘gaming the system’. Secondly, a tension between participants’ own views about HPFI; and their concerns about the possible views of other stakeholders. Thirdly, a tension between participants’ personal distaste of HPFI; and their professional view that they could be a valuable behaviour change tool. Conclusions There are aspects of design that influence acceptability of financial incentive interventions to public health policymakers. However, it is not clear that even interventions designed to maximise acceptability would be acceptable enough to be recommended for implementation. Further work may be required to help policymakers understand the potential responses of other stakeholder groups to financial incentive interventions

Exploration of the relationship between attitudes and expectations regarding ageing and health behaviours in older adults: a thesis portfolio

Background: With life expectancies continuing to rise and more people living beyond the age of 65, health services are under increasing pressure to provide effective care for an ageing population. Increased life expectancy increases the risk of long-term conditions like Type 2 Diabetes and cardiovascular disease that require self-management – something that poses a challenge for many people, and for older adults there may be additional barriers. Identifying modifiable factors that impede self-management is an ongoing focus in the literature; and in recent years increasing attention has been paid to the impact of individuals’ attitudes to their own ageing. Aims: The first part of this thesis portfolio is a systematic review of the literature that aims to answer the question “Are lower expectations regarding ageing associated with lower levels of physical activity in older adults?” The second is an empirical study that aims to explore the relationships between attitudes to ageing, executive function, glycaemic control and selfmanagement adherence in older adults with Type 2 Diabetes. Method: A systematic literature search was undertaken to identify studies reporting quantitative analyses of the relationship between expectations regarding ageing and physical activity. Methodological quality of the studies was appraised and synthesized, and clinical and research implications discussed. In the empirical study; 77 older adults completed self-report measures of attitudes to ageing and self-management adherence, and two brief measures of executive function. HbA1c; a biological measure of glycaemic control was also recorded for each participant. Correlations and multiple linear regressions tested the relationships between attitudes to ageing, EF, self-management and glycaemic control. Results: 8 studies (derived from 9 papers) were eligible for the systematic review, and were in consensus in their support of lower expectations regarding ageing being associated with lower levels of physical activity. The findings of the empirical study indicated that more negative attitudes to ageing in relation to physical changes predicted poorer self-management; and more negative attitudes to ageing in relation to psychosocial loss predicted poorer glycaemic control. Conclusion: The current findings are in line with an emerging evidence base supporting a relationship between attitudes to ageing, and physical health outcomes and behaviours; with more negative attitudes and perceptions of old age acting as a barrier to health promoting behaviours. Therefore, interventions targeting those cognitions could help to promote better health outcomes for older populations, as well as promoting healthy ageing and valuing older people – a current focus in policy and strategy

The acute hepatic porphyrias

The acute hepatic porphyrias are the result of hereditary partial deficiencies of individual enzymes in the pathway of haem biosynthesis. Seven enzymes are known to be involved in the pathway, converting glycine and succinyl CoA first to porphyrin precursors and then to porphyrins and finally to haem. The rate of the process is regulated by the initial enzyme, delta-aminolaevulinic acid (ALA) synthase,which is under negative feedback control, by haem. The partial block in this pathway, in each of the acute porphyrias,results in compensatory increased activity of ALA synthase and,consequently,overproduction of porphyrins and precursors formed prior to the deficient enzyme. Patients with acute porphyria generally enjoy good health,but exposure to certain recognised factors, namely specific drugs, alcohol, hormones and fasting; may precipitate severe clinical attacks characterized by gastro-intestinal symptoms, psychiatric disturbances and neuropathy. All of the systemic manifestations of the attack are thought to be explained by neurological dys function,but the mechanism by which the abnormal haem biosynthesis causes the neuropathy is not known. Following a general description of haem biosynthesis and the porphyrias, this thesis concentrates on the management of acute hepatic porphyria studying, in turn, the detection of subjects with the genetic trait, the factors which may precipitate attacks in these subjects and the treatment of patients in established attack. Much of the work presented is based upon the ability to measure the activities of the individual enzymes of haem biosynthesis in human peripheral blood cells. The mitochondrial enzymes, ALA synthase, coproporphyrinogen oxidase and ferrochelatase, are measured in leucocytes and the cytosolic enzymes, ALA dehydratase, uroporphyrinogen-1-synthase (URO synthase) and uroporphyrinogen decarboxylase, in erythrocytes. The measurement in peripheral blood cells of the activities of both the rate-controlling enzyme, ALA synthase, and the appropriate genetically deficient intermediate enzyme, is shown to be a sensitive and specific means of detecting latent cases of acute porphyria,the majority of whom have normal excretion of porphyrins and precursors. Enzymatic screening of affected families confirms that the genetic trait is inherited in an autosomal dominant sex-independent manner. The family studies also demonstrate that the vast majority of subjects with the trait remain clinically latent, and the reason why the minority of patients experience clinical manifestations is examined. The activity of the partially deficient enzyme is similar in latent and manifest cases, but ALA synthase activity is higher in patients who have experienced an attack and this may reflect higher circulating levels of endogenous inducing agents. Drugs are an important exogenous precipitating factor for acute porphyria, and an important aspect of the prevention of attacks is the identification of potentially porphyrinogenic drugs. The testing of 26 commonly prescribed drugs, by assessing their effect on hepatic ALA synthase activity in rats, is described. The mechanism by which drugs stimulate ALA synthase activity is examiaed with particular reference to the role of induction of the mixed function oxidase enzyme (MFO) system. A close correlation is noted between induction of the MFO system, as reflected in increased hepatic cytochrome P450 content, and increased activity of ALA synthase, though not the converse. Sequential studies following commencement of phenytoin administration to rats show that the rise in ALA synthase activity is transitory and coincides with the rise in hepatic cytochrome P450 content which is maintained. These observations indicate that induction of the MFO system demands increased ALA synthase activity to provide the additional haem for synthesis of the haemoprotein, cytochrome P450. (Abstract shortened by ProQuest.)

Customer experience challenges: bringing together digital, physical and social realms

This paper discusses important societal issues, such as individual and societal needs for privacy, security, and transparency. It sets out potential avenues for service innovation in these areas

Acceptability of Financial Incentives for Health Behaviours: A Discrete Choice Experiment.

BACKGROUND: Healthy behaviours are important determinants of health and disease, but many people find it difficult to perform these behaviours. Systematic reviews support the use of personal financial incentives to encourage healthy behaviours. There is concern that financial incentives may be unacceptable to the public, those delivering services and policymakers, but this has been poorly studied. Without widespread acceptability, financial incentives are unlikely to be widely implemented. We sought to answer two questions: what are the relative preferences of UK adults for attributes of financial incentives for healthy behaviours? Do preferences vary according to the respondents' socio-demographic characteristics? METHODS: We conducted an online discrete choice experiment. Participants were adult members of a market research panel living in the UK selected using quota sampling. Preferences were examined for financial incentives for: smoking cessation, regular physical activity, attendance for vaccination, and attendance for screening. Attributes of interest (and their levels) were: type of incentive (none, cash, shopping vouchers or lottery tickets); value of incentive (a continuous variable); schedule of incentive (same value each week, or value increases as behaviour change is sustained); other information provided (none, written information, face-to-face discussion, or both); and recipients (all eligible individuals, people living in low-income households, or pregnant women). RESULTS: Cash or shopping voucher incentives were preferred as much as, or more than, no incentive in all cases. Lower value incentives and those offered to all eligible individuals were preferred. Preferences for additional information provided alongside incentives varied between behaviours. Younger participants and men were more likely to prefer incentives. There were no clear differences in preference according to educational attainment. CONCLUSIONS: Cash or shopping voucher-type financial incentives for healthy behaviours are not necessarily less acceptable than no incentives to UK adults.This work is produced under the terms of a Career Development Fellowship research training fellowship issued by the National Institute of Health Research to JA (grant number NIHR-CDF-2011-04-17; http://www.nihr.ac.uk/funding/fellowship-programme.htm). The views expressed are those of the authors and not necessarily those of the NHS, The National Institute for Health Research or the Department of Health. JA is currently funded in full by the Centre for Diet & Activity Research (CEDAR), and the FFS is funded in full by Fuse: the Centre for Translational Research in Public Health. CEDAR and Fuse are UKCRC Public Health Research Centres of Excellence (http://www.ukcrc.org/research-coordination/joint-funding-initiatives/public-health-research/). Funding for CEDAR (grant number MR/K023187/1) and Fuse (grant number MR/K02325X/1) from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.015740

Maximising response to postal questionnaires – A systematic review of randomised trials in health research

Background Postal self-completion questionnaires offer one of the least expensive modes of collecting patient based outcomes in health care research. The purpose of this review is to assess the efficacy of methods of increasing response to postal questionnaires in health care studies on patient populations. Methods The following databases were searched: Medline, Embase, CENTRAL, CDSR, PsycINFO, NRR and ZETOC. Reference lists of relevant reviews and relevant journals were hand searched. Inclusion criteria were randomised trials of strategies to improve questionnaire response in health care research on patient populations. Response rate was defined as the percentage of questionnaires returned after all follow-up efforts. Study quality was assessed by two independent reviewers. The Mantel-Haenszel method was used to calculate the pooled odds ratios. Results Thirteen studies reporting fifteen trials were included. Implementation of reminder letters and telephone contact had the most significant effect on response rates (odds ratio 3.7, 95% confidence interval 2.30 to 5.97 p = <0.00001). Shorter questionnaires also improved response rates to a lesser degree (odds ratio 1.4, 95% confidence interval 1.19 to 1.54). No evidence was found that incentives, re-ordering of questions or including an information brochure with the questionnaire confer any additional advantage. Conclusion Implementing repeat mailing strategies and/or telephone reminders may improve response to postal questionnaires in health care research. Making the questionnaire shorter may also improve response rates. There is a lack of evidence to suggest that incentives are useful. In the context of health care research all strategies to improve response to postal questionnaires require further evaluation