Are we wasting our money on food supplements in elder care wards?

Background. It is reported that undernutrition in older hospitalized patients is commonly found, but estimates of its prevalence vary. It is also not clear which treatment approaches are best because poor methodology prevents comparison of outcomes between different studies. Rationale. The rationale of this observational study was to look at typical elder care wards in order to determine what food supplements were being prescribed. We wished to determine whether serum albumin and/or body mass index (BMI) were appropriately related to the prescription of sip feeds and also to determine the palatability of supplements provided. Method. We monitored the wastage of sip feeds over a 24-hour period and extrapolated an estimated cost. Ninety-six patients were studied, including 23 patients with a BMI of less than 20, of whom 30% were on supplementary feeds. Results. Seventy percentage of prescribed sip feeds were being given to people with a BMI of 20 or more. The mean wastage in this 24-hour period was 63% (pound79.56) in four wards containing 96 older patients. Conclusion. We concluded that there was no relationship between the numbers of patients with a low albumin and BMI and the prescription of sip feeds. We found compliance to be low (37%) because of poor palatability, with a large number of patients who appeared to require sip feeds not being prescribed them and those who received them wasting more than they drank.

Novel actuator design to overcome stiction and backlash for low-velocity applications

This paper presents a novel actuator design that ameliorates or eliminates the effects of non-linearities that are characteristically present in geared actuator systems and which are very problematic for low velocity applications. The design centres on the providing an internal rotational element within a single actuator to ensure operation of actuator away from the stiction region, whilst allowing zero velocity external output of the actuator. The construction has the added advantage of substantially reducing backlash. The prototype comprises two commercially available servo-actuators to test the principle of operation and results presented indicate that the concept is worth exploring further.

Vertical velocity variance and skewness in clear and cloud-topped boundary layers as revealed by Doppler lidar

In this paper, observations by a ground-based vertically pointing Doppler lidar and sonic anemometer are used to investigate the diurnal evolution of boundary-layer turbulence in cloudless, cumulus and stratocumulus conditions. When turbulence is driven primarily by surface heating, such as in cloudless and cumulus-topped boundary layers, both the vertical velocity variance and skewness follow similar profiles, on average, to previous observational studies of turbulence in convective conditions, with a peak skewness of around 0.8 in the upper third of the mixed layer. When the turbulence is driven primarily by cloud-top radiative cooling, such as in the presence of nocturnal stratocumulus, it is found that the skewness is inverted in both sign and height: its minimum value of around −0.9 occurs in the lower third of the mixed layer. The profile of variance is consistent with a cloud-top cooling rate of around 30Wm−2. This is also consistent with the evolution of the thermodynamic profile and the rate of growth of the mixed layer into the stable nocturnal boundary layer from above. In conditions where surface heating occurs simultaneously with cloud-top cooling, the skewness is found to be useful for diagnosing the source of the turbulence, suggesting that long-term Doppler lidar observations would be valuable for evaluating boundary-layer parametrization schemes. Copyright c 2009 Royal Meteorological Society

Velocity-based moving mesh methods for nonlinear partial differential equations

This article describes a number of velocity-based moving mesh numerical methods formultidimensional nonlinear time-dependent partial differential equations (PDEs). It consists of a short historical review followed by a detailed description of a recently developed multidimensional moving mesh finite element method based on conservation. Finite element algorithms are derived for both mass-conserving and non mass-conserving problems, and results shown for a number of multidimensional nonlinear test problems, including the second order porous medium equation and the fourth order thin film equation as well as a two-phase problem. Further applications and extensions are referenced.

Cloud-base vertical velocity statistics: a comparison between an atmospheric mesoscale model and remote sensing observations

The statistics of cloud-base vertical velocity simulated by the non-hydrostatic mesoscale model AROME are compared with Cloudnet remote sensing observations at two locations: the ARM SGP site in Central Oklahoma, and the DWD observatory at Lindenberg, Germany. The results show that, as expected, AROME significantly underestimates the variability of vertical velocity at cloud-base compared to observations at their nominal resolution; the standard deviation of vertical velocity in the model is typically 4-6 times smaller than observed, and even more during the winter at Lindenberg. Averaging the observations to the horizontal scale corresponding to the physical grid spacing of AROME (2.5 km) explains 70-80% of the underestimation by the model. Further averaging of the observations in the horizontal is required to match the model values for the standard deviation in vertical velocity. This indicates an effective horizontal resolution for the AROME model of at least 4 times the physically-defined grid spacing. The results illustrate the need for special treatment of sub-grid scale variability of vertical velocities in kilometer-scale atmospheric models, if processes such as aerosol-cloud interactions are to be included in the future.

Sociality and money

This is a translation of ‘Socialité et argent’, a text by Emmanuel Levinas originally published in 1987. Levinas describes the emergence of money out of interhuman relations of exchange and the social relations – sociality – that result. While elsewhere he has presented sociality as ‘nonindifference to alterity’ it appears here as ‘proximity of the stranger’ and points to the tension between an economic system based on money and the basic human disposition to respond to the face of the other person. Money both encodes and effaces sociality, both designates and disguises social relations. It arises from the way that needs and interests are manifested in exchange relations, in what he calls the ‘interestedness’ of economic life. But interests are always already cut through by the fact that being is always ‘being with others’. Being is always ‘interbeing’. Interestedness is always confronted by disinterestedness, that is, by a sociality marked by the ‘goodness of giving’, attachment to and concern for the poverty of the other person. Levinas concludes with a discussion of sociality and justice, posing questions about the tension between the demand to respond to an Other immediately before me and at the same time to respond to the demands of an other Other (the third person) who also invites a response.

Estimation of the friction velocity in stably stratified boundary-layer flows over hills

A method is suggested for the calculation of the friction velocity for stable turbulent boundary-layer flow over hills. The method is tested using a continuous upstream mean velocity profile compatible with the propagation of gravity waves, and is incorporated into the linear model of Hunt, Leibovich and Richards with the modification proposed by Hunt, Richards and Brighton to include the effects of stability, and the reformulated solution of Weng for the near-surface region. Those theoretical results are compared with results from simulations using a non-hydrostatic microscale-mesoscale two-dimensional numerical model, and with field observations for different values of stability. These comparisons show a considerable improvement in the behaviour of the theoretical model when the friction velocity is calculated using the method proposed here, leading to a consistent variation of the boundary-layer structure with stability, and better agreement with observational and numerical data.

The National Audit Office uses OR to assess the value for money of public services

Supreme audit institutions (SAIs) have an important role in assessing value for money in the delivery of public services. Assessing value for money necessarily involves assessing counterfactuals: good value for money has been achieved if a policy could not reasonably have been delivered more efficiently, effectively, or economically. Operations research modelling has the potential to help in the assessment of these counterfactuals. However, is such modelling too arcane, complex, and technically burdensome for organisations that, like SAIs, operate in a time- and resource-constrained and politically charged environment? We report on three applications of modelling at the UK's SAI, the National Audit Office, in the context of studies on demand management in tax collection, end-of-life care, and health-care associated infections. In all cases, the models have featured in the audit reports and helped study teams come to a value-for-money judgment. We conclude that OR modelling is indeed a valuable addition to the value-for-money auditor's methodological tool box.