High Speed Chaos in Optical Feedback System with Flexible Timescales

We describe a new opto-electronic device with time-delayed feedback that uses a Mach-Zehnder interferometer as passive nonlinearity and a semiconductor laser as a current-to-optical-frequency converter. Bandlimited feedback allows tuning of the characteristic time scales of both the periodic and high dimensional chaotic oscillations that can be generated with the device. Our implementation of the device produces oscillations in the frequency range of tens to hundreds of MHz. We develop a model and use it to explore the experimentally observed Andronov-Hopf bifurcation of the steady state and to estimate the dimension of the chaotic attractor.Comment: 7 pages, 6 figures, to be published in IEEE J. Quantum Electro

Rural water service provision by municipalities and CBOs: Performance milestones and KPIs

The advantages of using Community Based Organisations for the provision of water services in rural areas have been advocated for some time. These benefits have always been intuitively known, however there is little documentation assessing the real experiences of applying this model of service provision on a large scale within the South African context. This paper describes a process of identifying appropriate targets and monitoring standards that have been implemented in a number of areas in the Eastern Cape where a co-operative approach between Municipalities, CBOs and the private sector has been adopted. In the absence of readily available performance and costing benchmarks it has proved difficult to compare the tender proposals and indeed the delivery of services from all role-players. A series of cost estimating tools and responsibility milestones have been developed through an empirical process of critically analysing our experiences and developing an operational model from first principles. These milestones are defined in terms of developing the CBO to take on more and more responsibility, as far as is possible, while ensuring an appropriate and cost effective level of service. The paper will present a number of options that take into account the relative capacity of municipalities and any development process that they may be planning for their own organisation. Critical to the model is that effective delivery of service must be ensured from the start and that any transition as milestones are reached, should be as seamless as possible. Furthermore a series of operational performance indicators and benchmarks are proposed. Water SA Vol.30(5)Special 2004: 549-55

Preregistration house officers in general practice: review of evidence

OBJECTIVES: To examine the strengths and weaknesses of the national and local schemes for preregistration house officers to spend four months in general practice, to identify any added value from such placements, and to examine the impact on career choices. DESIGN: Review of all studies that reported on placements of preregistration house officers in general practice. SETTING: 19 accounts of preregistration house officers’ experience in general practice, ranging from single case reports to a national evaluation study, in a variety of locations in Scotland and England. PARTICIPANTS: Views of 180 preregistration house officers, 45 general practitioner trainers, and 105 consultant trainers. MAIN OUTCOME MEASURES: Main findings or themes weighted according to number of studies reporting them and weighted for sample size. RESULTS: The studies were unanimous about the educational benefits of the placements. The additional learning included communication skills, social and psychological factors in illness, patient centred consultations, broadening of knowledge base, and dealing with uncertainty about diagnosis and referral. CONCLUSIONS: Despite the reported benefits and recommendations of the scheme, it is not expanding. General practitioner trainers reported additional supervision that was unremunerated. The reforms of the senior house officer grade may resolve this problem by offering the placements to senior house officers, who require less supervision

Boosting clinical performance: The impact of enhanced final year placements.

BACKGROUND: This study follows on from a study that investigated how to develop effective final year medical student assistantship placements, using multidisciplinary clinical teams in planning and delivery. AIMS: This study assessed the effects on objective structured clinical examination (OSCE) performance of the in-course enhanced "super-assistantship" placement introduced to a randomly selected sample of 2013-14 final year medical students at Leeds medical school. METHODS: Quantitative data analysis was used to compare the global grades of OSCE stations between students who undertook this placement against those who did not. RESULTS: There was a small overall improvement in the "super-assistantship" student scores across the whole assessment (effect size = 0.085). "Pre-op Capacity", "Admissions Prescribing" and "Hip Pain" stations had small-medium effect sizes (0.226, 0.215, and 0.214) in favor of the intervention group. Other stations had small effect sizes (0.107-0.191), mostly in favor of the intervention group. CONCLUSIONS: The "super-assistantship" experience characterized by increasing student responsibility on placement can help to improve competence and confidence in clinical decision-making "in a simulated environment". The clinical environment and multidisciplinary team must be ready and supported to provide these opportunities effectively. Further in-course opportunities for increasing final year student responsibility should be developed

The Fine-Structure of the Net-Circular Polarization in a Sunspot Penumbra

We present novel evidence for a fine structure observed in the net-circular polarization (NCP) of a sunspot penumbra based on spectropolarimetric measurements utilizing the Zeeman sensitive FeI 630.2 nm line. For the first time we detect a filamentary organized fine structure of the NCP on spatial scales that are similar to the inhomogeneities found in the penumbral flow field. We also observe an additional property of the visible NCP, a zero-crossing of the NCP in the outer parts of the center-side penumbra, which has not been recognized before. In order to interprete the observations we solve the radiative transfer equations for polarized light in a model penumbra with embedded magnetic flux tubes. We demonstrate that the observed zero-crossing of the NCP can be explained by an increased magnetic field strength inside magnetic flux tubes in the outer penumbra combined with a decreased magnetic field strength in the background field. Our results strongly support the concept of the uncombed penumbra

A qualitative study to explore student learning and development of interprofessional collaboration during an online interprofessional education intervention

\ua9 2023, The Author(s).Interprofessional education (IPE) during undergraduate education and training has been found to improve collaboration between health care students. This supports interprofessional working in clinical practice to enhance patient safety and care delivery. Undergraduate students from pharmacy and medical programmes worked online in pairs to review notes of hospital patients due to be discharged. Students were tasked to complete a discharge letter and undertake an online consultation with a simulated patient prior to discharge. Online interactions were recorded and assessed using a validated tool to measure interprofessional professionalism. Students undertook this intervention in different pairings with different patient cases for three iterations after receiving feedback and undertaking a reflective exercise. The aim was to investigate the student learning and development that could be used to inform intervention optimisation and scale-up. Qualitative data were collected from different sources. Method triangulation was employed to develop a comprehensive understanding of the student learning and development. Data was collected from written feedback provided by the assessment team, student reflections on their performance, and from semi-structured interviews conducted with the student pairs and one to one with the assessment team. Content and thematic analysis was used to analyse these data and the Kirkpatrick/Barr evaluation model provided a framework to organise the themes. Eighteen students (nine from each professional programme) completed the study and a total of 27 IPE sessions were conducted. The assessment team completed 54 assessment tools and 31 student reflections were received (from a maximum of 36). Students were interviewed in their interprofessional pairs to yield nine interview transcripts and one interview was conducted with the assessment team. Students reported and were observed to improve in interprofessional collaboration over the three iterations following feedback and rehearsal opportunities. Longitudinal observation and assessment of student interprofessional working in changing teams provided the opportunity to capture the influence of interdependence on student performance and assessment of competence

Cross-sectional study of the provision of interventional oncology services in the UK

Objective: To map out the current provision of interventional oncology (IO) services in the UK. Design: Cross-sectional multicentre study. Setting: All National Health Service (NHS) trusts in England and Scottish, Welsh and Northern Ireland health boards. Participants: Interventional radiology (IR) departments in all NHS trusts/health boards in the UK. Results: A total of 179 NHS trusts/health boards were contacted. We received a 100% response rate. Only 19 (11%) institutions had an IO lead. 144 trusts (80%) provided IO services or had a formal pathway of referral in place for patients to a recipient trust. 21 trusts (12%) had plans to provide an IO service or formal referral pathway in the next 12 months only. 14 trusts (8%) did not have a pathway of referral and no plans to implement one. 70 trusts (39%) offered supportive and disease-modifying procedures. One trust had a formal referral pathway for supportive procedures. 73 trusts (41%) provided only supportive procedures (diagnostic or therapeutic). Of these, 43 (59%) had a referral pathway for disease-modifying IO procedures, either from a regional cancer network or through IR networks and 30 trusts (41%) did not have a referral pathway for disease-modifying procedures. Conclusion: The provision of IO services in the UK is promising; however, collaborative networks are necessary to ensure disease-modifying IO procedures are made accessible to all patients and to facilitate larger registry data for research with commissioning of new services

All-Optical Switching with Transverse Optical Patterns

We demonstrate an all-optical switch that operates at ultra-low-light levels and exhibits several features necessary for use in optical switching networks. An input switching beam, wavelength $\lambda$, with an energy density of $10^{-2}$ photons per optical cross section [$\sigma=\lambda^2/(2\pi)$] changes the orientation of a two-spot pattern generated via parametric instability in warm rubidium vapor. The instability is induced with less than 1 mW of total pump power and generates several $\mu$Ws of output light. The switch is cascadable: the device output is capable of driving multiple inputs, and exhibits transistor-like signal-level restoration with both saturated and intermediate response regimes. Additionally, the system requires an input power proportional to the inverse of the response time, which suggests thermal dissipation does not necessarily limit the practicality of optical logic devices

Controlling Fast Chaos in Delay Dynamical Systems

We introduce a novel approach for controlling fast chaos in time-delay dynamical systems and use it to control a chaotic photonic device with a characteristic time scale of ~12 ns. Our approach is a prescription for how to implement existing chaos control algorithms in a way that exploits the system's inherent time-delay and allows control even in the presence of substantial control-loop latency (the finite time it takes signals to propagate through the components in the controller). This research paves the way for applications exploiting fast control of chaos, such as chaos-based communication schemes and stabilizing the behavior of ultrafast lasers.Comment: 4 pages, 4 figures, to be published in Physical Review Letter

User perceptions of multi-source feedback tools for junior doctors

Context:  The effectiveness of multi-source feedback (MSF) tools, which are increasingly important in medical careers, will be influenced by their users’ attitudes. This study compared perceptions of two tools for giving MSF to UK junior doctors, of which one provides mainly textual feedback and one provides mainly numerical feedback. We then compared the perceptions of three groups, including: trainees; raters giving feedback, and supervisors delivering feedback. Methods:  Postal questionnaires about the usability, usefulness and validity of a feedback system were distributed to trainees, raters and supervisors across the north of England. Results:  Questionnaire responses were analysed to compare opinions of the two tools and among the different user groups. Overall there were few differences. Attitudes towards MSF in principle were positive and the tools were felt to be usable, but there was little agreement that they could effectively identify doctors in difficulty or provide developmental feedback. The text-oriented tool was rated as more useful for giving feedback on communication and attitude, and as more useful for identifying a doctor in difficulty. Raters were more positive than other users about the usefulness of numerical feedback, but, overall, text was felt to be more useful. Some trainees expressed concern that feedback was based on insufficient knowledge of their work. This was not supported by raters’ responses, although many did use indirect information. Trainees selected raters mainly for the perceived value of their feedback, but also based on personal relationships and the simple pragmatics of getting a tool completed. Discussion:  Despite positive attitudes to MSF, the perceived effectiveness of the tools was low. There are small but significant preferences for textual feedback, although raters may prefer numerical scales. Concerns about validity imply that greater awareness of contextual and psychological influences on feedback generation is necessary to allow the formative benefits of MSF to be optimised and to negate the risk of misuse in high-stakes contexts