Health-related quality of life, adiposity, and sedentary behavior in patients with early schizophrenia: Preliminary study

Objective: To examine adiposity and sedentary behavior in relation to health-related quality of life (QoL) in patients with early schizophrenia. Methods: A cross-sectional study was used to assess adiposity by dual-energy X-ray absorptiometry scans, habitual physical activity and idle sitting time by the Short Form International Physical Activity Questionnaire, and health-related QoL by the RAND Medical Outcomes Study SF-36. QoL scores were compared with age-adjusted Canadian normative population data. Results: There were 36 participants with early schizophrenia, average age 25.1 (±3.6). Twenty-nine (72.5%) were males. Mean illness duration was 30 (±18) months, and mean body mass index was 28.3 (±5). Females had higher body fat content than males (30.8±6.9 vs 24.7±10.6; t=-2.6, df=34; P=0.015). Total body fat (F=14; P=0.001), lean body mass (F=10.2; P=0.001), and sedentary behavior (F=5; P=0.013) significantly increased across body mass index categories. Total body fat was correlated with sedentary behavior (r=0.62; P=0.001), and total lean body mass was negatively correlated with sedentary behavior (r=0.39; P=0.03). Based on SF-36scores, participants had significantly lower physical functioning (P=0.0034), role physical (P=0.0003), general health (P,0.0001), vitality (P=0.03), and physical component scores (P=0.003) than Canadian population comparisons. Habitual sedentary behavior, more than activity or adiposity levels, was associated with health-related QoL in early schizophrenia. Conclusion: Health-related QoL is lower in early schizophrenia and is predominantly experienced in the physical domain. QoL in early schizophrenia relates to sedentary behavior more than to activity and adiposity levels. © 2012 Strassnig etal, publisher and licensee Dove Medical Press Ltd

Genotypic diversity in Puccinia striiformis f. sp. tritici, the cause of wheat stripe rust, in western Canada

Non-Peer Reviewe

Wheat stripe rust in Saskatchewan and Alberta: race dynamics and pathogen population

Non-Peer Reviewe

Using synchrotron techniques to understand plant diseases stripe rust and wheat

Non-Peer Reviewe

Three-Omega Thermal-Conductivity Measurements with Curved Heater Geometries

The three-omega method, a powerful technique to measure the thermal conductivity of nanometer-thick films and the interfaces between them, has historically employed straight conductive wires to act as both heaters and thermometers. When investigating stochastically prepared samples such as two-dimensional materials and nanomembranes, residue and excess material can make it difficult to fit the required millimeter-long straight wire on the sample surface. There are currently no available criteria for how diverting three-omega heater wires around obstacles affects the validity of the thermal measurement. In this Letter, we quantify the effect of wire curvature by performing three-omega experiments with a wide range of frequencies using both curved and straight heater geometries on SiO$_2$/Si samples. When the heating wire is curved, we find that the measured Si substrate thermal conductivity changes by only 0.2%. Similarly, we find that wire curvature has no significant effect on the determination of the thermal resistance of a $\sim$65 nm SiO$_2$ layer, even for the sharpest corners considered here, for which the largest measured ratio of the thermal penetration depth of the applied thermal wave to radius of curvature of the heating wire is 4.3. This result provides useful design criteria for three-omega experiments by setting a lower bound for the maximum ratio of thermal penetration depth to wire radius of curvature.Comment: 4 pages, 3 figure

Stripe rust virulence on Yr genes in Saskatchewan

Non-Peer Reviewe

Model breaking points conceptualized

Current curriculum initiatives (e.g. National Governors Association Center for Best Practices & Council of Chief State School Officers, 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot, or arguable should not, be used. In this work, we explore the breaking point of the chip model for integer subtraction and the area model for fraction addition. Breaking is inevitable – either because no one model is robust enough to be applicable in a very large problem space and/or because the modifications required to keep the model functioning weaken or even eliminate its benefits. While models are often intended to serve as visual illustrations or embodiments of a concept, adaptions at the model breaking point can turn model use into nothing more than executing the graphical analogue to a not-well-understood procedure. The act of identifying model breaking points illuminates the affordances and constraints of the model. This provides students a unique opportunity to discriminate across mathematical models to develop a meta-level understanding of the relationship between models and the mathematics those models are intended to support

Density-Functional Theory of Graphene Sheets

We outline a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for graphene sheets that treats slowly-varying inhomogeneous external potentials and electron-electron interactions on an equal footing. The theory is able to account for the the unusual property that the exchange-correlation contribution to chemical potential increases with carrier density in graphene. Consequences of this property, and advantages and disadvantages of using the DFT approach to describe it, are discussed. The approach is illustrated by solving the Kohn-Sham-Dirac equations self-consistently for a model random potential describing charged point-like impurities located close to the graphene plane. The influence of electron-electron interactions on these non-linear screening calculations is discussed at length, in the light of recent experiments reporting evidence for the presence of electron-hole puddles in nearly-neutral graphene sheets.Comment: 11 pages, 9 figures, submitted. High-quality figures can be requested to the author