Retention divergence of terpenes with porous graphitized carbon and C18 stationary phases

The significant divergence between the retention of 16 terpene standards on porous graphitized carbon (PGC) and C18 packing materials are illustrated. The PGC surface is shown to provide a selectivity toward shape, polarity, and structure that is not afforded by the C18 surface. This observation is illustrated by plots of the retention factors similar to those typically used to represent 2D-HPLC separations. A geometric approach to factor analysis was used to measure the separation divergence together with the selectivity and the product selectivity factors of closely related species. When a methanol mobile phase was used with the PGC surface, a large fraction of the separation space could be utilized. That is further reflected by a spreading angle of 80.3°. The PGC material was also successful at resolving structural isomers where the C18 phase was not. It was also found that the choice of the mobile phase is important when using this material. A much larger degree of space utilization was seen with methanol than with acetonitrile that displayed a spreading angle of only 40.8°.

Analysing building energy use using sub metering and external weather data

The Intergovernmental Panel on Climate Change and the McKinsey Greenhouse Gas abatement studies have highlighted reduction of building energy consumption as a primary cost-effective element in the abatement of Global Warming. Nevertheless, the energy investigation in most of our existing building stock remains at a novice level at best. Building sub-metering, by which we mean any secondary, hourly, metering (after the main) of various circuits, provides substantial information on when and where energy is used in specific buildings. Furthermore, combining this information with external weather data provides information beyond basic metering results. This paper discusses three case studies and explains how sub-metering, augmented by external solar and temperature data, benefits energy management and identified problems. It explains how different methods of analysing energy usage allowed: justifiable sizing of a solar photovoltaic system, with a calculated Cooling Degree Unit, identified the absence of savings from a proprietary chiller controller, and the energy variation due to user schedules and external conditions indicated anomalies in energy use. The advantages of wireless access are noted. Extracting information in graphical formats suggests better strategies to understand and control energy use.

Sub-lethal UV-C radiation induces callose, hydrogen peroxide and defence-related gene expression in Arabidopsis thaliana

Exposure of plants to UV-C irradiation induces gene expression and cellular responses that are commonly associated with wounding and pathogen defence, and in some cases can lead to increased resistance against pathogen infection. We examined, at a physiological, molecular and biochemical level, the effects of and responses to, sub-lethal UV-C exposure on Arabidopsis plants when irradiated with increasing dosages of UV-C radiation. Following UV-C exposure plants had reduced leaf areas over time, with the severity of reduction increasing with dosage. Severe morphological changes that included leaf glazing, bronzing and curling were found to occur in plants treated with the 1000 J·m(-2) dosage. Extensive damage to the mesophyll was observed, and cell death occurred in both a dosage- and time-dependent manner. Analysis of H2 O2 activity and the pathogen defence marker genes PR1 and PDF1.2 demonstrated induction of these defence-related responses at each UV-C dosage tested. Interestingly, in response to UV-C irradiation the production of callose (β-1,3-glucan) was identified at all dosages examined. Together, these results show plant responses to UV-C irradiation at much lower doses than have previously been reported, and that there is potential for the use of UV-C as an inducer of plant defence.

Response of inflation to shocks: new evidence from Sub-Saharan African countries

In this paper, we investigate whether or not the inflation rate of 17 Sub-Saharan African countries can be modelled as a stationary process. We achieve this goal through using univariate and panel stationarity tests for data over the period 1966 to 2002. We use the Kwiatkowski, Phillips, Schmidt and Shin (KPSS, 1992) univariate test and allow for multiple structural breaks. We find that except for Burkina Faso, Burundi and Gambia, the inflation rate is stationary for the rest of the 14 countries. We then apply the panel version of the KPSS test, developed by Carrion-i-Silvestre et al. (2005), which accounts for multiple structural breaks. We find strong evidence of panel stationarity of the inflation rate. However, for a panel consisting of Burkina Faso, Burundi and Gambia, we could not find evidence that the inflation rate is stationary. © 2013 Elsevier B.V.

Migration-related influences on obesity among sub-Saharan African migrant adolescents in Melbourne, Australia

Aim: The aim of the present study was to examine migration- and socioeconomic-related influences on obesity among African migrant adolescents in Melbourne, Australia. Methods: Anthropometric data were collected from 99 parents and 100 adolescent offspring who also completed questionnaires eliciting demographic, socioeconomic and migration data. Multiple linear regressions were used to assess the relationship between migration- and socioeconomic-related factors and adolescent body mass index (BMI). Results: Only gender and parental BMI were associated with adolescent BMI after adjusting for adolescent age, adolescent gender, religion, parental BMI, parental education level and annual income. Boys (β=-1.45; P < 0.05) had lower BMI than girls. Parental and adolescent BMI were positively associated (β = 0.11; P < 0.05). In examining migration-related factors and adolescent BMI, after adjusting for gender and parental BMI, parental acculturation patterns and pre-migration life environment were associated with adolescent BMI, explaining, respectively, 6.5 and 4.0% of the variance in BMI. An integrated parental acculturation pattern was negatively associated with adolescent BMI (β=-0.17; P < 0.05) while adolescents whose parents came from rural areas had a higher BMI (β = 1.48; P < 0.05) than those whose parents came from urban areas. Adolescent acculturation patterns and length of stay in Australia were non-significantly associated with their BMI. Conclusions: Gender, pre-migration life environment and parental acculturation patterns seem to influence the prevalence of overweight and obesity among African migrant adolescents. Culturally competent obesity prevention programmes targeted towards African adolescents should consider these aspects in their design and delivery; however, further research is required to determine their relative contributions to African adolescent obesity in Australia.