3,007 research outputs found
LETS get real: constraints on the development of Local Exchange Trading Schemes
Local Exchange Trading Schemes (LETS) are widely promoted as a new tool for local economic development, but until recently the focus has been on their alleged ‘potential’ rather than the realities of their operation. This paper assesses the practical economic role of LETS by examining the amount of trading conducted, and demonstrates that both the volume of trading and the value of the trades are very low. Drawing on an intensive case study of the first UK LETS created explicitly as part of a local authority’s anti-poverty strategy, explanations for the low levels of participation are suggested, and significant structural constraints on the development of LETS are identified
Development of an empirically based dynamic biomechanical strength model
The focus here is on the development of a dynamic strength model for humans. Our model is based on empirical data. The shoulder, elbow, and wrist joints are characterized in terms of maximum isolated torque, position, and velocity in all rotational planes. This information is reduced by a least squares regression technique into a table of single variable second degree polynomial equations determining the torque as a function of position and velocity. The isolated joint torque equations are then used to compute forces resulting from a composite motion, which in this case is a ratchet wrench push and pull operation. What is presented here is a comparison of the computed or predicted results of the model with the actual measured values for the composite motion
Mixing with the radiofrequency single-electron transistor
By configuring a radio-frequency single-electron transistor as a mixer, we
demonstrate a unique implementation of this device, that achieves good charge
sensitivity with large bandwidth about a tunable center frequency. In our
implementation we achieve a measurement bandwidth of 16 MHz, with a tunable
center frequency from 0 to 1.2 GHz, demonstrated with the transistor operating
at 300 mK. Ultimately this device is limited in center frequency by the RC time
of the transistor's center island, which for our device is ~ 1.6 GHz, close to
the measured value. The measurement bandwidth is determined by the quality
factor of the readout tank circuit.Comment: Submitted to APL september 200
Noise-enabled precision measurements of a Duffing nanomechanical resonator
We report quantitative experimental measurements of the nonlinear response of
a radiofrequency mechanical resonator, with very high quality factor, driven by
a large swept-frequency force. We directly measure the noise-free transition
dynamics between the two basins of attraction that appear in the nonlinear
regime, and find good agreement with those predicted by the one-dimensional
Duffing equation of motion. We then measure the response of the transition
rates to controlled levels of white noise, and extract the activation energy
from each basin. The measurements of the noise-induced transitions allow us to
obtain precise values for the critical frequencies, the natural resonance
frequency, and the cubic nonlinear parameter in the Duffing oscillator, with
direct applications to high sensitivity parametric sensors based on these
resonators.Comment: 5 pages, 5 figure
Medical student fitness to practise committees at UK medical schools
Abstract Background The aim was to explore the structures for managing student fitness to practise hearings in medical schools in the UK. We surveyed by email the named fitness to practise leads of all full members of the UK Medical Schools Council with a medical undergraduate programme. We asked whether student fitness to practise cases were considered by a committee/panel dedicated to medicine, or by one which also considered other undergraduate health and social care students. Findings All 31 medical schools responded. 19 medical schools had a fitness to practise committee dealing with medical students only. Three had a committee that dealt with students of medicine and dentistry. One had a committee that dealt with students of medicine and veterinary medicine. Eight had a committee that dealt with students of medicine and two or more other programmes, such as dentistry, nursing, midwifery, physiotherapy, dietetics, social work, pharmacy, psychology, audiology, speech therapy, operating department practice, veterinary medicine and education. Conclusion All 31 UK medical schools with undergraduate programmes have a fitness to practise committee to deal with students whose behaviour has given rise to concern about their fitness to practise. The variation in governance structures for student fitness to practise committees/panels can in part be explained by variations in University structures and the extent to which Universities co-manage undergraduate medicine with other courses.</p
Patient attitudes towards analgesia and their openness to non-pharmacological methods such as acupuncture in the emergency department
Aims: To investigate patient attitudes to analgesia, opioids and non-pharmacological analgesia including acupuncture, in the ED.
Methods: ED patients with pain were surveyed regarding: pain scores, satisfaction, addiction concern, non-pharmacological methods of pain relief, and acupuncture. Data were analysed using logistic regression.
Results: Of 196 adult patients, 52.8% were ‘very satisfied’ with analgesia. Most patients (84.7%) would accept non-pharmacological methods including acupuncture (68.9%) and 78.6% were not concerned about addiction. Satisfaction was associated with male gender, and ‘adequate analgesia’ but not with opioids.
Conclusion: Most patients were generally satisfied with ED analgesia and were open to non-pharmacologic analgesia including acupuncture
“Coming Out”:Stigma, reflexivity and the drug researcher’s drug use
Some personal experience of illicit drug use undoubtedly exists within the population of academic drug researchers. But it is rarely acknowledged, and even more rarely reflected upon, in their published work. This is understandable: criminal, professional and social sanctions may follow public admission of illicit activities. However, to not “come out” seems contrary to some core academic principles, such as transparency in data collection and reflexivity in the research process. Coming out may present researchers with an opportunity for improving knowledge of, and policies toward, drug use. In this article, we identify reasons for and against the public disclosure of drug use and the impact of such disclosure across a range of spheres, including research, teaching, policy influence and private lives. Reasons against coming out include the risks of undermining professional reputations and hence the ability to contribute to academic and policy debates, the threat of criminal justice sanctions, and impacts on loved ones. However, coming out can have academic benefit (i.e., improving our understanding of drugs, of people who use drugs, and of drug research) and contribute to activist goals (e.g., de-stigmatization of drug use and demarginalization of people who use drugs). Both the risks and benefits of public drug use disclosure have implications for how research and researchers may influence drug policy. Two key themes, stigma and reflexivity, underpin the discussion. We do not conclude with clear recommendations for drug-using drug researchers; to come out or to not come out is a personal decision. However, we argue that there is clear merit to further open discussion on the role of disclosure and reflection on personal drug use experience among those working in drug research and drug policy—where such reflection is relevant and where such researchers feel able to do so
Pattern Reduction in Paper Cutting
A large part of the paper industry involves supplying customers with reels of specified width in specifed quantities. These 'customer reels' must be cut from a set of wider 'jumbo reels', in as economical a way as possible. The first priority is to minimize the waste, i.e. to satisfy the customer demands using as few jumbo reels as possible. This is an example of the one-dimensional cutting stock problem, which has an extensive literature. Greycon have developed cutting stock algorithms which they include in their software packages.
Greycon's initial presentation to the Study Group posed several questions, which are listed below, along with (partial) answers arising from the work described in this report.
(1) Given a minimum-waste solution, what is the minimum number of patterns required?
It is shown in Section 2 that even when all the patterns appearing in minimum-waste solutions are known, determining the minimum number of patterns may be hard. It seems unlikely that one can guarantee to find the minimum number of patterns for large classes of realistic problems with only a few seconds on a PC available.
(2) Given an n → n-1 algorithm, will it find an optimal solution to the minimum- pattern problem?
There are problems for which n → n - 1 reductions are not possible although a more dramatic reduction is.
(3) Is there an efficient n → n-1 algorithm?
In light of Question 2, Question 3 should perhaps be rephrased as 'Is there an efficient algorithm to reduce n patterns?' However, if an algorithm guaranteed to find some reduction whenever one existed then it could be applied iteratively to minimize the number of patterns, and we have seen this cannot be done easily.
(4) Are there efficient 5 → 4 and 4 → 3 algorithms?
(5) Is it worthwhile seeking alternatives to greedy heuristics?
In response to Questions 4 and 5, we point to the algorithm described in the report, or variants of it. Such approaches seem capable of catching many higher reductions.
(6) Is there a way to find solutions with the smallest possible number of single patterns?
The Study Group did not investigate methods tailored specifically to this task, but the algorithm proposed here seems to do reasonably well. It will not increase the number of singleton patterns under any circumstances, and when the number of singletons is high there will be many possible moves that tend to eliminate them.
(7) Can a solution be found which reduces the number of knife changes?
The algorithm will help to reduce the number of necessary knife changes because it works by bringing patterns closer together, even if this does not proceed fully to a pattern reduction. If two patterns are equal across some of the customer widths, the knives for these reels need not be changed when moving from one to the other
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