Practical guide to sample size calculations: superiority trials

A sample size justification is a vital part of any investigation. However, estimating the number of participants required to give meaningful results is not always straightforward. A number of components are required to facilitate a suitable sample size calculation. In this paper, the steps for conducting sample size calculations for superiority trials are summarised. Practical advice and examples are provided illustrating how to carry out the calculations by hand and using the app SampSize

Baseline geochemical characteristics of urban areas : a record of environmental change in the English Midlands

Systematic baseline sampling of soils in urban and rural areas has been undertaken by the British Geological Survey’s (BGS) Geochemical Baseline Survey of the Environment (G-BASE). Using these urban and rural data in conjunction with each other provides a more powerful, and useful, interpretation of urban soil quality data to be made

Changes in food neophobia and dietary habits of international students

Background International study is becoming more prevalent, yet aspects such as food neophobia often militate against the consumption of a nutritionally balanced diet of visiting students. The purpose of this paper, therefore, was to evaluate the extent to which international postgraduate students experience food neophobia, how this might vary by nationality and other demographic characteristics, and how acculturation might manifest itself in students’ dietary behaviour. Methods International postgraduate students were invited to complete a validated questionnaire during their first week at university. The questionnaire was subsequently re-administered to the same students approximately four and eight months later. Results In total, 226 usable responses were analysed, 124, 58 and 44, respectively, for the first, second and final data collection. Perhaps surprisingly, the overall food neophobia scores increased from an initial value of 27.95 (SD ± 16.95) to 33.67 (SD ± 33.67) after 3 months although when comparing European and Asian students, only the former were significantly different (p<0.05). Both Asian and European students reported small but not significant changes in their eating habits, although after 3 months significantly (p=< 0.05) less changes were reported. No significant changes were reported in students’ perceived healthiness of their diets either by nationality or over time. Conclusions Understanding the complexities of food neophobia, other aspects of dietary change and at what point these changes might take place in the acculturation process when students arrive in the UK needs to be fully understood if a climate for positive learning is to be established

Completion plan for the Geochemical Baseline Survey of the Environment (G-BASE)

In response to NERC national capability (NC) prioritisation which seeks to end systematic regional geochemical mapping, this report contains options and recommendations for the completion of a national geochemical baseline by the G-BASE project by 31st March 2016. The plan delivers samples and analyses from southern England, an area estimated to be 35,500 km2, approximately 7,000 km2 of which is underlain by Chalk (and so would be unsuitable for drainage sampling). A number of options for completing a national geochemical baseline are presented based on the current G-BASE strategy but with an overall reduced sampling density. The Panalytical arrangement for XRFS analysis until January 2016 substantially reduces the analytical budget required, and is therefore a most important criterion of the completion plan. However, the Panalytical deal should not be the sole factor that drives the strategy for finishing off G-BASE. In order to maximise the science and opportunities for collaborative research secondary options are proposed for the collection of a variety of sample media from areas of greatest environmental interest. These secondary options will require additional funding to complete the non-XRFS analyses of samples which could include contributions from external organisations. The proposed work plan is primarily concerned with the “observe and monitor” part of NERC national capability. It excludes any proposal for the data interpretation, modelling and knowledge exchange, and adding value to current geochemical baseline tasks (e.g. London Earth and Clyde Basin) or anything beyond the data gathering phase of completing the geochemical mapping of southern England. It is important that the completion plan does not drive the BGS geochemistry activity into just a sample and data gathering exercise. We must continue to deliver science and information outcomes alongside completing the G-BASE baseline or we will lose the capacity to deliver any science in the future

Practical aspects of modeling aircraft dynamics from flight data

The purpose of parameter estimation, a subset of system identification, is to estimate the coefficients (such as stability and control derivatives) of the aircraft differential equations of motion from sampled measured dynamic responses. In the past, the primary reason for estimating stability and control derivatives from flight tests was to make comparisons with wind tunnel estimates. As aircraft became more complex, and as flight envelopes were expanded to include flight regimes that were not well understood, new requirements for the derivative estimates evolved. For many years, the flight determined derivatives were used in simulations to aid in flight planning and in pilot training. The simulations were particularly important in research flight test programs in which an envelope expansion into new flight regimes was required. Parameter estimation techniques for estimating stability and control derivatives from flight data became more sophisticated to support the flight test programs. As knowledge of these new flight regimes increased, more complex aircraft were flown. Much of this increased complexity was in sophisticated flight control systems. The design and refinement of the control system required higher fidelity simulations than were previously required

Practical guide to sample size calculations: non-inferiority and equivalence trials

A sample size justification is a vital part of any trial design. However, estimating the number of participants required to give a meaningful result is not always straightforward. A number of components are required to facilitate a suitable sample size calculation. In this paper, the steps for conducting sample size calculations for non-inferiority and equivalence trials are summarised. Practical advice and examples are provided that illustrate how to carry out the calculations by hand and using the app SampSize

Changing of flight phenology and ecotype expansion of the European corn borer (Ostrinia nubilalis Hbn.) in Hungary Part

The studies aimed to acquire the widest possible information on the annual flight in Hungary of the European corn borer (ECB), Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae). The investigations used biomathematical (Part 1) and graphical (Part 2) evaluation to document changes in the individual population number.The study was conducted in Hungary using ECB moth capture records from the Plant Protection Information System black light trap system (1991–2004). We have drawn conclusions on the appearance of annual flights and the tendency of alterations in flight direction by means of light trap results in four different areas in Hungary. We calculated the flight peak quotients, the individual population numbers of the second flight peak, the distinctions of individual numbers of two flight peaks in this part.As previously published, alterations in flight direction of ECB flights began at different times in Hungary. In the current study, a gradual disappearance of the univoltine ecotype and gradual appearance of the bivoltine ecotype ECB in Hungary is confirmed by the data obtained between 1991–2004. Flight peak quotients and data concerning the second flight peak have confirmed change this process, too: the appearance of a second flight peak in Northwestern Hungary from 1995–1996 (FP = 1.27), the more significant appearance of flights in August in Western Hungary (FP = 1.05) and Northeastern Hungary (FP = 1.45), and a three and four times more individual number of the second flight peak in Southeastern Hungary (FP = 3.44). Flight peak quotients, individual population numbers of the second flight peak, the tendency towards a difference in population number of the two peaks, and size of increase of these values demonstrates the southeastern-northwestern presence of the bivoltine ecotype in Hungary