Residential child care in the spotlight: reflections on being involved in the BBC series 'social workers'

Describes how a residential unit offering services for 8 children and young people became involved in the BBC Scotland series 'Social Workers', a fly-on-the-wall documentary about Edinburgh's Social Work Department. Discusses how the unit became involved, the filming process, reactions, and some issues raised. The ethics of filming and broadcasting the lives of young people was contentious. Obviously much was lost when 5 months had to be reduced to 30 minutes, but it was generally agreed the results were positive

Identifying Taste Variation in Choice Models

Among the many attractive features of the mixed logit model is its ability to take account of taste variation among decision-makers by allowing coefficients to follow pre-specified distributions (usually normal or lognormal). Whilst accounting for heterogeneity in the population, simple applications of the technique fail to identify valuable information on differences in behaviour between market segments. This information is likely to be of use to those involved in policy and investment analysis, product design and marketing. The ‘standard’ approach to overcome this problem when working with the mixed logit model is to identify segments prior to modelling and either specify a set of constant coefficients for each market segment together with an additional error term to ‘mop-up’ any residual variation, or by allowing separate distributions for each market segment. An alternative approach is to adapt an exciting new methodology that offers the ability to estimate reliable individual specific parameters (Revelt and Train, 1999). This approach is documented in Section 3 and involves three key stages: • First use maximum simulated likelihood to estimate distributions of tastes across the population. • Next examine individual’s choices to arrive at estimates of their parameters, conditional on know distributions across the population (including accounting for uncertainty in the population estimates). This process again involves the use of maximum simulated likelihood. • Finally, differences in behaviour between market segments are identified by regressing individual ‘part-worths’ against the characteristics of the decision-maker or attributes of the choice alternatives. In the first instance the technique is validated under ‘controlled’ circumstances on a simulated data set with know taste distributions. This simulation involves a binary choice situation in which the alternatives are described in terms of time and cost. The choices of a group of decision-makers are simulated with each with a value of time drawn from a known distribution. The resulting choices are then analysed and individual values recovered with a surprisingly high degree of precision. The findings of this validation are set out in Section 4. Following a successful validation of the technique on simulated data, the methodology is applied to data from two stated preference experiments in which 326 respondents were asked to choose between alternate motor vehicle 1 specifications defined by purchase price, running costs, engine size, emissions and safety features. The results of this analysis are set out in Section 5 and are compared to the findings of previously calibrated models that identified significant differences in tastes across market segments

Modelling the impact of alternative fare structures on train overcrowding

The Strategic Rail Authority (SRA) provides the backbone to rail regulation in Great Britain. As part of its responsibilities, the SRA monitors overcrowding on trains which it measures in terms of the proportion of passengers on trains in excess of the seat capacity for longer distance services, and with an allowance for standing passengers on shorter journeys of less than 20 minutes. Overcrowding on Britain’s railways fell during the early 1990s but has been on the increase since 1996 with particularly acute problems in the morning peak for services travelling to London. In a study conducted on behalf of the SRA we developed the PRAISE rail operations model to include penalties for overcrowding based upon journey purpose, journey time and degree of overcrowding. Using demand, fares and timetable information for an actual case study route, we examine how fares and ticketing restrictions can be set to manage demand throughout the day without significantly reducing the overall demand for rail travel

Safety assessment of biotechnology used in animal production, including genetically modified (GM) feed and GM animals - a review

Since the beginning of the large-scale commercial cultivation of genetically modified (GM) crops in the mid-nineties, it has continuously increased. This has occurred in particular in non-European countries from which these crops may be exported as commodities to Europe and other markets. Before genetically modified organisms (GMO) are allowed onto the market as animal feed and/or food, they have to undergo a regulatory safety assessment as required by the law in many nations, including that of European Union (EU) nations under EU regulations. This safety assessment is based on an internationally harmonized approach of comparative safety assessment, in which the differences identified during the extensive comparison between a GMO and a conventional counterpart serve as basis for a further safety assessment. The GMOs that have been notified for regulatory approval and assessed for their safety as feed and food in the EU have so far been derived from crops and microorganisms. It is expected that in the near future, also several genetically modified (GM) animals may initially reach the market outside the EU. International activities to harmonize the safety assessment of GM animals have already started and have resulted in the issuance of specific guidelines by Codex alimentarius. Moreover, PEGASUS, an EU-funded project, will consider the perceptions, advantages and disadvantages of GM animals, including perspectives from the social-and life-sciences

Faulting in prospective CO2 storage sites in the UK Southern North Sea

Post-depositional folding of Triassic strata, formed largely by the development of salt domes and pillows in the underlying Zechstein Group, led to the formation of numerous large anticlinal structures at the level of the Triassic aged Bunter Sandstone Formation (BSF). These structural closures, some of which have formed effective traps to natural gas, have been mapped across the UK Southern North Sea (SNS), and are currently of interest as potential prospects for the storage of anthropogenic CO2

Estimates of the remainder in Taylor's theorem using the Henstock--Kurzweil integral

When a real-valued function of one variable is approximated by its $n^{th}$ degree Taylor polynomial, the remainder is estimated using the Alexiewicz and Lebesgue $p$-norms in cases where $f^{(n)}$ or $f^{(n+1)}$ are Henstock--Kurzweil integrable. When the only assumption is that $f^{(n)}$ is Henstock--Kurzweil integrable then a modified form of the $n^{th}$ degree Taylor polynomial is used. When the only assumption is that $f^{(n)}\in C^0$ then the remainder is estimated by applying the Alexiewicz norm to Schwartz distributions of order 1.Comment: To appear in Czechoslovak Mathematical Journa