Simulation and measurement of hts josephson heterodyne oscillator

We report continuing investigations into practical applications of the ac Josephson effect as the basis for a voltage-tunable radio-frequency oscillator. We have previously demonstrated experimentally that useful power levels (10 s of nW) and linewidths of a few kHz can be achieved in the heterodyne output from a High-Temperature-Superconducting Resistive SQUID (HTS-RSQUID) operating in the frequency range 1-50 MHz. Those results were achieved with 2-junction R-SQUIDs incorporating current-biased shunt resistors of a few micro-ohms. We have now modified the fabrication procedures, and adjusted the shunt resistors and bias current values so that higher frequencies can be achieved. The Josephson junctions are of step-edge type, rather than the bi-crystal type used in our earlier work. The step-edge technique permits much more flexibility in the geometrical lay-out and utilizes the more cost-effective single-crystal MgO substrates. In the present paper, we report numerical simulations and experimental measurements on these devices in the frequency range up to 2 GHz

Systematic review of trends in emergency department attendances : an Australian perspective

Emergency departments (EDs) in many developed countries are experiencing increasing pressure due to rising numbers of patient presentations and emergency admissions. Reported increases range up to 7% annually. Together with limited inpatient bed capacity, this contributes to prolonged lengths of stay in the ED; disrupting timely access to urgent care, posing a threat to patient safety. The aim of this review is to summarise the findings of studies that have investigated the extent of and the reasons for increasing emergency presentations. To do this, a systematic review and synthesis of published and unpublished reports describing trends and underlying drivers associated with the increase in ED presentations in developed countries was conducted. Most published studies provided evidence of increasing ED attendances within developed countries. A series of inter-related factors have been proposed to explain the increase in emergency demand. These include changes in demography and in the organisation and delivery of healthcare services, as well as improved health awareness and community expectations arising from health promotion campaigns. The factors associated with increasing ED presentations are complex and inter-related and include rising community expectations regarding access to emergency care in acute hospitals. A systematic investigation of the demographic, socioeconomic and health-related factors highlighted by this review is recommended. This would facilitate untangling the dynamics of the increase in emergency demand

Why did mainstream economics miss the crisis? The role of epistemological and methodological blinkers

Purpose - In this paper, we show how the translation of a logical positivist epistemology into neoclassical economics has had profound methodological consequences which over-determine an inability to predict cusps and their associated crises. Design/methodology/approach - Based on a review of epistemological and methodological literature, we argue that the financial crises of the past 20 years ought to initiate a questioning of the epistemological foundations of the discipline. Findings - As an alternative, we suggest that an economics methodology informed by critical realism would increase the probability of a timely prediction of crises. Originality/value - It de-emphasises falsification as a key criterion for assessing the quality of knowledge, provides more space for non-quantified reflections on relationships, a thicker model of human agency, a well-specified model of collective human economic behaviour as well as an endogenous possibility of dramatic change within the economic domain

Granger inspired testing the ISDs for possible causal relationships

Arjan de Haan and his co-authors are keen to use the ISS Indicators of Social Development (hereafter the ISDs) to show how institutional structuration processes can cause improvements in human well-being, including economic growth (de Haan et al, 2011). Developing this aspiration, though not uncritically, this paper explores how the ISS ISDs might be used to stimulate thinking about causal relationships by linking the ISDs to each other and conventional measures of country-level development status. But before undertaking the task of attributing causality, it is necessary to reflect on the nature of the data being used. The challenges in using the ISDs’ data can be summarised into six problems which need diagnostic reflection before interpretation of causal relationships can be convincingly undertaken ....

Livelihood decisions under the shadow of conflict in the Chittagong Hill Tracts of Bangladesh

We analyse rural household livelihood and children’s school enrolment decisions in a postconflict setting in the Chittagong Hill Tracts region of Bangladesh. The innovation of the paper lies in the fact that we employ information about current subjective perceptions regarding the possibility of violence in the future and past actual experiences of violence to explain household economic decision-making. Preferences are endogenous in line with behavioural economics. Regression results show that heightened subjective perceptions of future violence and past actual experiences of conflict influences current consumption increases child enrolment, and encourages risky mixed crop cultivation. The trauma emanating from past experiences combined with current high perceptions of risk of violence may induce bolder and riskier behaviour in line with prospect theories of risk. Furthermore, a, post-conflict household-level Phoenix or economic revival factor may be in operation, based in part on greater within group trust

Durability of saphenous vein grafts: 44-year follow-up of a saphenous vein interposition graft in a pediatric patient

We report the 44-year follow-up of a 9-year-old girl who underwent a saphenous vein interposition graft in 1964 after suffering extensive pelvic trauma with complete disruption of the right common femoral artery. The patient recovered from this injury and experienced no disability or pain until 2008, when she suddenly developed numbness in the right leg. Evaluation at that time showed a new occlusion of the saphenous vein graft, and she underwent uneventful repeat revascularization with autogenous vein. To our knowledge, this 44-year patency is the longest reported for a saphenous vein graft