Mise en evidence de plusieurs processus d'échange intramoléculaire dans les iodures de bis(méthyl thio)-1,1 dialkyl iminio-3 propène substitués ou non en 2 et 3

A variable temperature study of iminium salts is carried out. Several hindered rotations are observed around C? N and C? C bonds. Structural information is discussed.     

Stable strontium isotopic ratios from archaeological organic remains from the Thorsberg peat bog

Stable strontium isotope ratios in archaeological finds have frequently been used to determine their place of origin, in order to reconstruct migration and trade. Peat bogs offer favourable burial conditions for the preservation of organic remains such as woollen textiles and leather by a natural tanning process. However, these finds are impregnated by peat substances including contaminant strontium which is likely to mask the original (87)Sr/(86)Sr isotopic ratio of the specimens. In this paper, we present a pilot study analysing stable strontium isotopic ratios from Iron Age textile and leather finds from the Thorsberg peat bog, focusing on a sample processing method which permits the quantitative removal of contaminating strontium from the specimens.     

Selective X-ray generation by heavy ions (Part 1) the use of energetic heavy ions to generate characteristic X-rays from elements in a selective manner

The selective generation of characteristic X-rays during heavy ion bombardment of solids is briefly described. The principles can be understood in terms of the Fano-Lichten model, which postulates that during heavy ion collisions, interactions occur between the electronic systems of the target and projectile atoms, leading to electron promotions and consequent inner shell vacancies. The resultant X-rays have the advantage of being essentially free from the continuous background radiation which accompanies X-rays produced by electron bombardment. It is shown how the characteristic X-rays of certain elements may be generated in a selective manner by bombardment with an appropriate heavy ion of optimum energy. The resultant technique is particularly applicable to the analysis of elements located on or near to surfaces, and may therefore be used for the elucidation of distribution profiles of ion-implanted elements.     

Using simulation to assess cardiac first-responder schemes exhibiting stochastic and spatial complexities

A Monte-Carlo simulation-based model has been constructed to assess a public health scheme involving mobile-volunteer cardiac First-Responders. The scheme being assessed aims to improve survival of Sudden-Cardiac-Arrest (SCA) patients, through reducing the time until administration of life-saving defibrillation treatment, with volunteers being paged to respond to possible SCA incidents alongside the Emergency Medical Services. The need for a model, for example, to assess the impact of the scheme in different geographical regions, was apparent upon collection of observational trial data (given it exhibited stochastic and spatial complexities). The simulation-based model developed has been validated and then used to assess the scheme's benefits in an alternative rural region (not a part of the original trial). These illustrative results conclude that the scheme may not be the most efficient use of National Health Service resources in this geographical region, thus demonstrating the importance and usefulness of simulation modelling in aiding decision making.     

Mortality density forecasts: An analysis of six stochastic mortality models

This paper develops a framework for developing forecasts of future mortality rates. We discuss the suitability of six stochastic mortality models for forecasting future mortality and estimating the density of mortality rates at different ages. In particular, the models are assessed individually with reference to the following qualitative criteria that focus on the plausibility of their forecasts: biological reasonableness; the plausibility of predicted levels of uncertainty in forecasts at different ages; and the robustness of the forecasts relative to the sample period used to fit the model. An important, though unsurprising, conclusion is that a good fit to historical data does not guarantee sensible forecasts. We also discuss the issue of model risk, common to many modelling situations in demography and elsewhere. We find that even for those models satisfying our qualitative criteria, there are significant differences among central forecasts of mortality rates at different ages and among the distributions surrounding those central forecasts.     

Elemental labeling for the identification of proteinaceous-binding media in art works by ICP-MS

In the history of art, artists have used many different organic compounds to dissolve pigments and apply them onto a support to obtain a paint layer. Proteins were used with success from the Middle Ages up to the Renaissance, and the traditional protein sources were animal parts (skins, tendons and bones) or milk and eggs. Moreover, some of these materials are commonly used as adhesive. In this paper, the first application of the metallomic analytical technique to the identification of proteins in artworks is reported. Samples were derivatized with DTPA/Eu and the derivatization procedure was evaluated by matrix‐assisted laser desorption/ionization time‐of‐flight before high performance liquid chromatography inductively coupled plasma MS analysis. This study has been carried out on laboratory models prepared in‐house for method development, resulting in the correct identification of the different classes of proteinaceous binders typically used. In addition, some unknown paint layer samples have been analyzed demonstrating that the method is applicable to very small sample amounts (0.6 mg), which are compatible with the amount normally available for this kind of analysis. The results obtained demonstrate the effectiveness of the method, suggesting the potential future use as novel diagnostic tool in the scientific study of artworks. Copyright © 2011 John Wiley & Sons, Ltd.     

Teaching scenario planning: Lessons from practice in academe and business

In this paper, we engage with O’Brien’s [O’Brien, F.A., 2004. Scenario planning – lessons for practice from teaching and learning. European Journal of Operational Research 152, 709–722] identification of both pitfalls in teaching scenario planning and proposed remedies for these. We consider these remedies in relation to our own experience – based on our practice in both the academic and business arenas – and we highlight further pitfalls and proposed remedies. Finally, we propose the use of “hard” multi-attribute decision analysis as a complement to “soft” scenario planning, in order to allow a more formal method of strategy evaluation against a range of constructed scenarios, This approach is intended to remedy biases that are associated with holistic evaluations – such as lexicographic ranking – where undue attention is paid to particular strategic objectives at the expense of others. From this discussion, we seek to contribute to cumulative refinement of the scenario process.