A polarizable interatomic force field for TiO2_2 parameterized using density functional theory

We report a classical interatomic force field for TiO$_2$, which has been parameterized using density functional theory forces, energies, and stresses in the rutile crystal structure. The reliability of this new classical potential is tested by evaluating the structural properties, equation of state, phonon properties, thermal expansion, and some thermodynamic quantities such as entropy, free energy, and specific heat under constant volume. The good agreement of our results with {\em ab initio} calculations and with experimental data, indicates that our force-field describes the atomic interactions of TiO$_2$ in the rutile structure very well. The force field can also describe the structures of the brookite and anatase crystals with good accuracy.Comment: Accepted for publication in Phys. Rev. B; Changes from v1 include multiple minor revisions and a re-write of the description of the force field in Section II

Linking transport, health and sustainability: Better data sets for better policy-making

The impact transport has on our physical and mental health and on the environment is increasingly recognised by academics, practitioners and decision-makers. To inform policy-making and research, it is crucial to have access to sufficient comprehensive datasets linking these topics. Large scale surveys rarely combine questions on transport, health and sustainability, limiting their usefulness in research and policy-making. This project set out to identify the gaps in administrative and survey datasets to link health outcomes to travel behaviour and the quality of the environment; investigate the impact this has on research and policy-making; assess how these gaps might be addressed; and identify what the needs are for joined datasets. To achieve this, the project interviewed key decision-makers and stakeholders across England, including civil servants within national or local government and third sector organisations. The results highlight gaps within national datasets; the insufficient links between health, transport, and sustainability datasets; and the need for further joined data in various fields, in particular active travel, health and wellbeing. Participants suggested several solutions, including better harmonisation of surveys and data fusion

Classification and unscrambling a class-inside-class situation by object target rotation : Hungarian silver coins of the Árpád Dynasty, 997 – 1301 AD

Classification is an important part of chemometrics and mostly based on optimization by vector rotations. The present study is a continuation of the classification of medieval Hungarian silver coins including the 16 kings of the Hungarian Árpád Dynasty (997AD – 1301AD) (Rácz et al.: Heritage Science 2013 1:2) The Rácz et al. paper identified three historical periods of the Árpád Dynasty from chemical data. The aim of the present study is to test whether the classification could be further refined by marker object projection aided classification. It offers an example of the efficiency of this method in unscrambling a classinside- class situation. The frequency distribution of concentrations of the coins are skewed and to a certain extent bi- modal, and the arithmetic mean value and standard deviation around the mean frequently used in parametric methods may be poor descriptors of the information carried by the data. We test a combination of principal components decomposition and the nonparametric, non-iterative object target rotation method to overcome some of the theoretical limitations of parametric methods. This test includes identification of archetypical class ―Ambassadors‖ of each of the three historical periods of the Árpád Dynasty and shows a class-inside-class situation

Exploring views on satisfaction with life in young children with chronic illness: an innovative approach to the collection of self-report data from children under 11

The objective of this study was to explore young children’s views on the impact of chronic illness on their life in order to inform future development of a patient-based self-report health outcome measure. We describe an approach to facilitating self-report views from young children with chronic illness. A board game was designed in order to obtain qualitative data from 39 children with a range of chronic illness conditions and 38 healthy controls ranging in age from 3 to 11 years. The format was effective in engaging young children in a self-report process of determining satisfaction with life and identified nine domains. The board game enabled children aged 5–11 years with chronic illness to describe the effects of living with illness on home, family, friends, school and life in general. It generated direct, non-interpreted material from children who, because of their age, may have been considered unable or limited their ability to discuss and describe how they feel. Obtaining this information for children aged 4 and under continues to be a challenge

Occurrence of Aspergillus species and aflatoxin contamination in raw and roasted peanuts from formal and informal markets in Eldoret and Kericho towns, Kenya

Published Online: August 2013.The population and diversity of fungal species and levels of aflatoxin contamination were investigated in 228 marketed peanut samples; 140 from formal and 88 from informal markets, in Kericho and Eldoret towns of Kenya. Ground pea- nut samples were cultured on Modified Dichloran Rose Bengal (MDRB) agar while aflatoxin level was quantified based on indirect competitive ELISA. Correlation between the incidence of major aflatoxin-producing fungal species and aflatoxin levels was also established. Fungal species commonly isolated from the peanut samples included Asper-gillus flavus L strain, A. flavus S strain, A. parasiticus, A. tamarii, A. caelatus, A. alliaceus (all of Aspergillus section Flavi) and A. niger. Fungi isolated in low frequency included Fusarium spp., Penicillium spp., Mucor spp. and Rhi- zopus spp. Aflatoxin levels in peanut products ranged from 0 to 2345 μg/kg in raw peanuts, 0 to 382 μg/kg in roasted coated peanuts, and 0 to 201 μg/kg in roasted de-coated peanuts. Overall, levels of total aflatoxin were higher in sam- ples from informal (mean = 97.1 μg/kg) than formal (mean = 55.5 μg/kg) market outlets. There was a positive and sig- nificant correlation (R2 = 0.63; p ≤ 0.05) between aflatoxin levels and the major aflatoxin producing fungi in raw pea- nuts from formal markets in Eldoret town. Additionally, total aflatoxin in raw peanut samples from informal markets in Kericho was positively and significantly correlated (R2 = 0.81; p ≤ 0.05) to the population of A. flavus (L and S strains). In roasted coated peanuts sampled from formal market outlets in Eldoret, aflatoxin levels correlated positively and sig- nificantly (R2 = 0.37; p ≤ 0.05) with A. flavus S strain. There is need to create awareness among peanut traders and con- sumers on proper handling of peanuts and health risks associated with consumption of unsafe peanut products

Chemistry of dense clumps near moving Herbig-Haro objects

Localised regions of enhanced emission from HCO+, NH3 and other species near Herbig-Haro objects (HHOs) have been interpreted as arising in a photochemistry stimulated by the HHO radiation on high density quiescent clumps in molecular clouds. Static models of this process have been successful in accounting for the variety of molecular species arising ahead of the jet; however recent observations show that the enhanced molecular emission is widespread along the jet as well as ahead. Hence, a realistic model must take into account the movement of the radiation field past the clump. It was previously unclear as to whether the short interaction time between the clump and the HHO in a moving source model would allow molecules such as HCO+ to reach high enough levels, and to survive for long enough to be observed. In this work we model a moving radiation source that approaches and passes a clump. The chemical picture is qualitatively unchanged by the addition of the moving source, strengthening the idea that enhancements are due to evaporation of molecules from dust grains. In addition, in the case of several molecules, the enhanced emission regions are longer-lived. Some photochemically-induced species, including methanol, are expected to maintain high abundances for ~10,000 years.Comment: 7 pages, 3 figure

Transverse phase space characterization in an accelerator test facility

We compare three techniques for characterising the transverse phase space distribution of the beam in CLARA FE (the Compact Linear Accelerator for Research and Applications Front End, at Daresbury Laboratory, UK): emittance and optics measurements using screens at three separate beamline locations; quadrupole scans; and phase space tomography. We find that where the beam distribution has significant structure (as in the case of CLARA FE at the time the measurements presented here were made) tomography analysis is the most reliable way to obtain a meaningful characterisation of the transverse beam properties. We present the first experimental results from four-dimensional phase space tomography: our results show that this technique can provide an insight into beam properties that are of importance for optimising machine performance