Reproducibility and relative validity of dietary glycaemic index and glycaemic load assessed by the food-frequency questionnaire used in the Dutch cohorts of the European prospective investigation into Cancer and Nutrition

Limited information is available on the reproducibility and validity of dietary glycaemic index (GI) and glycaemic load (GL) estimated by habitual diet assessment methods such as FFQ, including the FFQ used in the Dutch cohorts of the European Prospective Investigation into Cancer and Nutrition study. To examine the reproducibility and relative validity of GI and GL, we used data from 121 Dutch men and women aged 23–72 years. They completed the FFQ three times at intervals of 6 months and twelve 24-h dietary recalls (24HDR) monthly during 1991–2. GI and GL were calculated using published values. Intra-class correlation coefficients of the three repeated FFQ were 0·78 for GI and 0·74 for GL. Pearson correlation coefficients between the first FFQ and the weighted average of the 24HDR were 0·63 for both GI and GL. Weighted ¿ values between the first FFQ and the average of the 24HDR (in quintiles) were 0·40 for GI and 0·41 for GL. Bland–Altman plots showed a proportional bias in GI (ß = 0·46), but not in GL (ß = 0·06). In conclusion, this FFQ can be used in epidemiological studies to investigate the relationship of GI and GL with disease risks, but the proportional bias should be taken into account when using this FFQ to assess the absolute GI values

A New GISc Framework and Competency Set for Curricula Development at South African Universities

In this study the commonalities and inconsistencies between three Geographical Information Science (GISc) competency sets are used to develop a new framework of essential competencies that can be used for curricula development at South African universities that meet local and international requirements. A prototype GISc framework of 16 knowledge areas (KAs), consisting of 20 fundamental and 89 core competencies, was introduced to a group of GISc experts to gauge its usefulness and to determine the relative importance of specific KAs. The responses showed that some KAs, in particular Physics and Organisational and Institutional Aspects are considered less important than Data Modelling and Geospatial Data. However, all the KAs were considered essential by the workshop participants for inclusion in the GISc framework. A simple algorithm was developed and implemented to determine whether a particular competency should be included in the GISc framework. The new framework is an extension of the Geographical Information Science and Technology (GI S&T) Body of Knowledge (BoK) and consists of 14 KAs and can be used to develop curricula that meet the requirements of the South African and international GISc industries

A Comparison of Geographical Information Science Competency Requirements

Because universities often provide training in geographical information science (GISc) as part of geography, surveying as well as environmental and computer science programmes, the content, outcomes, extent and quality of training can vary significantly. Very little research has been done on how the existing sets of competency requirements for GISc overlap or differ. No literature exists that identifies commonalities and inconsistencies (gaps) at detail level that could assist with developing a framework that incorporates both South African and international GISc curricula guidelines.Three sets of competency guidelines, namely the U.S.-developed Geographic Information Science and Technology (GI S&T) Body of Knowledge (BoK) developed by the University Consortium for Geographic Information Science (UCGIS), the South African Unit Standards-Based Qualifications (USBQ) and the South African Council for Professional and Technical Surveyors (PLATO) model, are compared qualitatively and quantitatively to identify commonalities and inconsistencies. The exercise identified duplication among the three models and highlighted themes that the South African GISc community deems to be important. The study further identifies topics in the GI S&T BoK that the GISc community in the U.S. considers to be essential knowledge for anyone wishing to practice in the GISc field. The BoK offers the most comprehensive and detailed set of GI competencies, but lacks generic competencies such as physics. Some competencies are unique to a specific set, for example physics and geographical science in the PLATO model, while training is unique to the USBQ. The authors conclude that a new competency set based on the findings of the research is needed to best serve the GISc industry and academia. Recommendations for further research are made.Keywords: Curriculum design, data acquisition, geographical information science (GISc), knowledge and skills requirements, mathematics,  photogrammetry, physics, professional body, unit standards-based  qualification (USBQ), remote sensing, statistics

Wall effects on granular heap stability

We investigate the effects of lateral walls on the angle of movement and on the angle of repose of a granular pile. Our experimental results for beads immersed in water are similar to previous results obtained in air and to recent numerical simulations. All of these results, showing an increase of pile angles with a decreasing gap width, are explained by a model based on the redirection of stresses through the granular media. Two regimes are observed depending on the bead diameter. For large beads, the range of wall effects corresponds to a constant number of beads whereas it corresponds to a constant characteristic length for small beads as they aggregate via van der Waals forces

Bifurcation Diagram for Compartmentalized Granular Gases

The bifurcation diagram for a vibro-fluidized granular gas in N connected compartments is constructed and discussed. At vigorous driving, the uniform distribution (in which the gas is equi-partitioned over the compartments) is stable. But when the driving intensity is decreased this uniform distribution becomes unstable and gives way to a clustered state. For the simplest case, N=2, this transition takes place via a pitchfork bifurcation but for all N>2 the transition involves saddle-node bifurcations. The associated hysteresis becomes more and more pronounced for growing N. In the bifurcation diagram, apart from the uniform and the one-peaked distributions, also a number of multi-peaked solutions occur. These are transient states. Their physical relevance is discussed in the context of a stability analysis.Comment: Phys. Rev. E, in press. Figure quality has been reduced in order to decrease file-siz

‘Goldilocks anatomy’ – data-conserving anatomy video tutorials during emergency remote teaching

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