The influence of interpolation and station network density on the distributions and trends of climate variables in gridded daily data

We study the influence of station network density on the distributions and trends in indices of area-average daily precipitation and temperature in the E-OBS high resolution gridded dataset of daily climate over Europe, which was produced with the primary purpose of Regional Climate Model evaluation. Area averages can only be determined with reasonable accuracy from a sufficiently large number of stations within a grid-box. However, the station network on which E-OBS is based comprises only 2,316 stations, spread unevenly across approximately 18,000 0.22A degrees grid-boxes. Consequently, grid-box data in E-OBS are derived through interpolation of stations up to 500 km distant, with the distance of stations that contribute significantly to any grid-box value increasing in areas with lower station density. Since more dispersed stations have less shared variance, the resultant interpolated values are likely to be over-smoothed, and extreme daily values even more so. We perform an experiment over five E-OBS grid boxes for precipitation and temperature that have a sufficiently dense local station network to enable a reasonable estimate of the area-average. We then create a series of randomly selected station sub-networks ranging in size from four to all stations within the E-OBS interpolation search radii. For each sub-network realisation, we estimate the grid-box average applying the same interpolation methodology as used for E-OBS, and then evaluate the effect of network density on the distribution of daily values, as well as trends in extremes indices. The results show that when fewer stations have been used for the interpolation, both precipitation and temperature are over-smoothed, leading to a strong tendency for interpolated daily values to be reduced relative to the "true" area-average. The smoothing is greatest for higher percentiles, and therefore has a disproportionate effect on extremes and any derived extremes indices. For many regions of the E-OBS dataset, the station density is sufficiently low to expect this smoothing effect to be significant and this should be borne in mind by any users of the E-OBS dataset

4',5',6',7'-Tetrachlorospiro[cyclohex-2-ene-1,2'-indan]-1',3'-dione

The title compound, C₁₄H₈Cl₄O₂, has been isolated following irradiation of a dichloromethane solution of N-acetyltetrachlorophthalimide and cyclohexene. The structure refinement is slightly compromised by the disorder over two positions of equal occupancy of a methylene groupβ to the spiro C atom

(1RS,2SR,7RS,8RS)-N-Benzoyltricyclo[6.2.2.0²,⁷]dodeca-9,11-diene-1,10-dicarboximide

The title 1,4-photoadduct, C₂₁H₁₉NO₃, was formed on irradiation of N-benzoylphthalimide in dichloromethane containing cyclohexene. The bond lengths and angles are generally within the normal ranges. A notable feature of the molecule is the presence within it of four contiguous chiral centres

A freshwater diet-derived C-14 reservoir effect at the Stone Age sites in the Iron Gates gorge

Human bones from single inhumation burials and artifacts made from terrestrial mammal (ungulate) bone found in direct association with the skeletons were obtained from the Stone Age site of Schela Cladovei situated just below the iron Gates Gorge of the River Danube. The results of stable isotope analyses of the human bone collagen are consistent with a heavy dependence on aquatic protein while radiocarbon dating of the samples reveals an offset of 300-500 years between the two sample types, indicating a freshwater reservoir effect in the human bone samples, Since protein consumption is by far the major source of nitrogen in the human diet we have assumed a linear relationship between delta(15)N and the level of aquatic protein in each individual's diet and derived a calibration for C-14 age offset versus delta(15)N which has been applied to a series of results from the site at Lepenski Vir within the gorge, The corrected C-14 ages (7310-6720 BP) are now consistent with the previous C-14 age measurements made on charcoal from related contexts (7360-6560 BP). In addition, the data indicate a change from a primarily aquatic to a mixed terrestrial/aquatic diet around 7100 BP and this may be argued as supporting a shift from Mesolithic to Neolithic. This study also has wider implications for the accurate dating of human bone samples when the possibility exists of an aquatic component in the dietary protein and strongly implies that delta(15)N analysis should be undertaken routinely when dating human bones

Tarsal Tunnel Syndrome – a narrative review of the literature

International audienceThe effect of the mean effective stress on the elastic properties of unbound granular materials is a well-known experimental result. Power laws between the mean effective stress and the shear modulus G vhmax of three natural sands are established for isotropic stress paths using bender elements. Triaxial test results reveal that such power laws are also suitable for contracting deviatoric stress paths whereas it is no longer the case for dilating deviatoric stress paths. Fabric changes during shearing are therefore highlighted. These observations seem to be a typical feature of the behavior of granular materials

Towards an institutional PLE

PLEs in their broader sense (the ad-hoc, serendipitous and potentially chaotic set of tools that learners bring to their learning) are increasingly important for learners in the context of formal study. In this paper we outline the approach that we are taking at the University of Southampton in redesigning our teaching and learning infrastructure into an Institutional PLE. We do not see this term as an oxymoron. We define an Institutional PLE as an environment that provides a personalised interface to University data and services and at the same time exposes that data and services to a student’s personal tools. Our goal is to provide a digital platform that can cope with an evolving learning and teaching environment, as well as support the social and community aspects of the institution

2-Benzoylspiro[1H-isoindole-1,3'-isochromene]-1',3,4'(2H,3'H)-trione

The title compound, C₂₃H₁₃NO₅, was isolated following irradiation of N-benzoylphthalimide in toluene. The bond lengths and angles are typical of a molecule of this kind, but the molecule itself is of some interest. The most challenging aspect of the refinement was to devise a model to cater for disorder in one part of the molecule