Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed.     

Understanding e‐Government portal use in rural India: role of demographic and personality characteristics

Electronic government (e‐Government) is one of the most important ways to bridge the digital divide in developing countries. We develop a model of e‐Government portal use. We use various individual characteristics, namely demographics and personality, as predictors of e‐Government portal use. Specifically, our predictors were (1) gender, age, income and education; (2) the Big Five personality characteristics, i.e. extraversion, neuroticism, conscientiousness, agreeableness and openness to experience; and (3) personal innovativeness with information technology. We conducted a field study in a village in India. We collected data from over 300 heads of household. We found support for our model, with most variables being significant and explaining 40% of the variance in e‐Government portal use.     

What Math Matters? Types of Mathematics Knowledge and Relationships to Methods Course Performance

This study investigated the effect of a departmental focus on enhanced mathematics knowledge for teaching on overall performance in upper elementary mathematics methods courses. The study examined the effect of performance on a new course in mathematics for teaching on performance at the methods course level. In addition, the effect of performance on a high-stakes test of general elementary-level mathematics content knowledge was explored. Mathematics knowledge for teaching was found to be a highly significant predictor of first semester methods course performance, arguably pedagogical content knowledge, whereas knowledge of the general elementary mathematics content appeared less related.     

A multi-criteria decision analysis framework for evaluating point-of-use water treatment alternatives

Despite significant progress on meeting global water targets, the lack of access to safe drinking water remains a significant problem in today’s world. Statistics from health agencies indicate that waterborne diseases are among the leading causes of health-related mortalities, particularly in developing nations. This paper examines the performance and applicability of various point-of-use (POU) water treatment alternatives, namely (i) solar disinfection; (ii) boiling of water; (iii) chlorination; (iv) disinfection–flocculation with a natural coagulant (powdered Moringa seeds); (v) filtration with ceramic pots; and (vi) biosand filtration. We evaluated the efficacy of each alternative using a set of criteria based on environmental sustainability, technological performance, financial viability, and social acceptability. We also integrated several multi-criteria decision analysis (MCDA) approaches to determine the most suitable water treatment method for a given community. The analytic hierarchy process (AHP) was implemented to elicit various preference structures and to generate the weights for the criteria. Subsequent ranking of the POU alternatives was then performed using the technique for order preference by similarity to ideal solutions (TOPSIS) method. Sensitivity analysis and visualization charts were developed to evaluate the impact of changes in preference ratings of each alternative with respect to the criteria. A case study was implemented in a rural area in the Philippines to determine the optimal POU alternatives given variations in AHP and TOPSIS input data. The resulting MCDA framework is flexible and can accommodate the inclusion of other alternatives and criteria, and it can also be generalized for other regions and applications.     

Introduction of sulfhydryl groups and disulfide linkage to mungbean 8Sα globulin and effects on physicochemical and functional properties

Sulfhydryl groups and disulfide bond were introduced in mungbean's major storage protein, 8Sα globulin, by protein engineering to improve structural stability and functional properties. Five modified proteins or mutants (F59C, I99C, A213C, one free sulfhydryl group; I99C/A213, one disulfide bridge; F59C/I99C/A213C, one free sulfhydryl group and one disulfide linkage) were expressed in Escherichia coli at a yield similar to that of the unmodified protein or wild type (WT) in soluble form (38%). The number of introduced groups in the mutants was confirmed by Ellman analysis. Mutant and WT proteins exhibited similar elution patterns on gel filtration indicating their trimeric native conformation. Mutants had 2 to 3.8 °C higher T_m values than WT and were digested by chymotrypsin at 52–58% in 60 min but exhibited different digestion patterns. All mutants showed greater hardness of heat-induced gels than WT, especially I99C/A213C and F59C/I99C/A213C. Results indicate the improved structural stability of the modified 8Sα globulin.     

The Visual Resources Association,its role and its future

The Visual Resources Association is an international organization for those involved in image information management. Membership includes image specialists of all types, librarians, museum curators, gallery representatives, system vendors, historians, artists, and those involved in intellectual property. The Association has a publications program, and has been working on several initiatives over the last ten years in the areas of intellectual property, the development of image cataloguing standards, and professional status standards. As the image information profession changes, the Association is moving in new directions to continually serve its membership.