Abundance and Partitioning of OH in a High-pressure Magmatic System: Megacrysts from the Monastery Kimberlite, South Africa

Concentrations of OH, and major and trace elements were determined in a suite of mantle-derived megacrysts that represent the crystallization products of a kimberlite-like magma at ~5 GPa and ~1400–1100°C. OH concentrations, determined by single-crystal Fourier transform infrared spectroscopy, display the following ranges (ppmw H2O): olivine 54–262, orthopyroxene 215–263, garnet 15–74, clinopyroxene 195–620, and zircon 28–34. High OH concentrations in olivine imply mantle conditions of origin, with limited H loss during ascent. OH is consistently correlated with megacryst composition, exhibiting trends with Mg-number that are similar to those of other minor and trace elements and indicating a record of high-pressure magmatic evolution. H substitution is not coupled to minor elements in olivine, but may be in ortho- and clinopyroxene. The OH–Mg-number trends of garnet and clinopyroxene show inflections related to co-precipitation of ilmenite, suggesting minor element (Ti) influence on OH partitioning. During differentiation, relative OH enrichment in clinopyroxene and olivine is consistent with proportional dependence on water activity, whereas that in garnet suggests a higher power-law dependence and/or influence of temperature. Inter-mineral distribution coefficients for OH between cpx, opx, olivine and zircon are thus constant, whereas partitioning between these minerals and garnet shows a factor 4–10 variation, correlated regularly with composition (and temperature). Calculation of solid–melt partition coefficients for H at 5 GPa over a range of magmatic evolution from 1380 to 1250°C yields: ol 0·0053–0·0046, opx 0·0093–0·0059, cpx 0·016–0·013, gt 0·0014–0·0003, bulk (garnet lherzolite–melt) 0·0063–0·0051. These are consistent with experimental studies and similar to values inferred from mid-ocean ridge basalt geochemistry, confirming the moderate incompatibility of H in mantle melting

The Inter-Store Mobility of Supermarket Shoppers

The allegiance of a particular customer, and the distribution across customers of strength of affiliation to a store are important indicators of store health. It is therefore important to understand the extent and determinants of shopper mobility among competing retailers. While shoppers often patronize many stores, they typically have a primary affiliation to a “main store” that captures the majority of their purchases. We examine, in detail, the tendencies of shoppers to transition away from the current main store and adopt another in its place. That is, rather than study all types of store switching behavior, we focus on the decision to change primary allegiance. The model is established in a discrete time hazard framework and estimated as random-effects probit. Data from 548 households taking 88,945 shopping trips among five stores are used to calibrate the model. We find that state dependence is prevalent with nearly three quarters of the shoppers showing progressive attachment to their current main store. Interestingly, this finding is not simply driven by location (i.e., because shoppers are captive to a single store based on geographical distance). More likely, shoppers are unwilling to give up the benefits of store-specific knowledge of assortment, layout and prices. Second, the decision to transition from a current main store is not influenced by temporary price promotions on a common basket of items: Shoppers will cherry-pick, but this alone does not cause them to change primary allegiance. The majority of transitions occur across competing stores of the same price format, which suggests “format loyalty” is an important aspect of shopper behavior. After controlling for unobserved heterogeneity, we find little relationship between observable demographics and the transition probability. We do, however, find that shoppers who spend more per trip are less likely to change main stores, as are less frequent shoppers. Implications for retail management strategy are discussed

Smart Cities and M³: Rapid Research, Meaningful Metrics and Co-Design

The research described in this paper is undertaken under the banner of the smart city, a concept that captures the way urban spaces are re-made by the incursion of new technology. Much of smart is centred on converting everyday activities into data, and using this data to generate knowledge mediated by technology. Ordinary citizens, those that may have their lives impacted by the technology, usually are not properly involved in the ‘smartification’ process. Their perceptions, concerns and expectations should inform the conception and development of smart technologies at the same extent. How to engage general public with smart cities research is the central challenge for the Making Metrics Meaningful (MMM) project. Applying a rapid participatory method, ‘Imagine’ over a five-month period (March – July) the research sought to gain insights from the general public into novel forms of information system innovation. This brief paper describes the nature of the accelerated research undertaken and explores some of the themes which emerged in the analysis. Generic themes, beyond the remit of an explicit transport focus, are developed and pointers towards further research directions are discussed. Participatory methods, including engaging with self- selected transport users actively through both picture creation and programmatically specific musical ‘signatures’ as well as group discussion, were found to be effective in eliciting users’ own concerns, needs and ideas for novel information systems

Trends and Regional Variation in Hip, Knee and Shoulder Replacement

Analyzes patterns in underuse or overuse of joint replacements among Medicare beneficiaries by geographic regions and race/ethnicity. Explores underlying factors and highlights the need for physician and patient education and shared decision making

Statistical Results on the Performance of an Adaptive-Threshold Radar Detector in the Presence of Wireless Communications Interference Revision 1

In an article recently accepted for publication in the IEEE Transactions on Aerospace and Electronic Sys-tems [1], we investigate the problem of specifying interference protection criteria for a radar sharing spectrum with wireless communications. In that paper, we first propose a statistical model for wireless communications interference based on existing interference and clutter models and supported by original simulations. Then we model the statistical effects of such interference on the detection performance of a cell-averaging adaptive-threshold radar detector. While the IEEE paper summarizes the statistical results and plots some representative figures, many additional calculations were computed than could be presented in an IEEE paper. Therefore, this technical report publishes the complete set of statistical results computed, for the interested reader\u27s reference