Visual selective attention was examined in a sample of non-referred adolescents with high and low depressive symptomatology. Two standardized depression inventories (CDI, DEQ) were used to classify the adolescents. The two groups were matched on age, sex and intelligence. The adolescents performed a forced-choice reaction time task designed to isolate several sources of interference in visual selective attention. Interference conditions varied with regard to number and type of distractors surrounding the target stimulus. Reaction times of the two groups were compared to identify differences in capacities and strategies utilized in filtering distracting information. Findings were examined with regard to the ability to select relevant information and ignore distracting information from the environment. Data analyses indicated that the reaction times of the adolescents who scored high on the depression scales were slower and more variable. In addition, facilitation occurred only with adolescents with low scores when the number of distractors exceeded visual capacities. The implications for understanding attentional capacities and strategies of adolescents with depressive symptoms are discussed.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 44-53).

Thesis (M.S.)--University of Wisconsin--Madison, 1981. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 42-47).

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Although Pd-Au high-surface area catalysts are used in industry to improve activity and selectivity, a thorough understanding of the nature of these enhancements is lacking. A molecular-level understanding of catalytic reactions under actual reaction conditions is the ultimate goal. This thesis is mainly focused on the application of Pd-Au supported catalysts for vinyl acetate synthesis and CO oxidation reactions using highsurface area catalysts. We have attempted to improve the conventional Pd-Au based catalyst by synthesizing novel acetate-based and polymer-based catalysts. The corresponding catalytic reactivity and selectivity were measured and compared to conventional Pd-Au based catalyst systems. Subsequent characterization was performed using characterization techniques, such as, X-ray diffraction (XRD) and transmission electron microscopy (TEM). From our bimetallic catalytic studies, it was evident that the addition of Au to Pd leads to increased reactivity and selectivity. This surface modification is an important factor in the altered reaction kinetics for vinyl acetate (VA) synthesis and CO oxidation reactions. Promoted and unpromoted Pd-Au/SiO2/K+ catalyst were used for VA synthesis and the effect of pre-adsorbed O2, acetic acid and the role of oxygen were explored. The VA reaction rate of novel acetate-based Pd-Au/SiO2 catalyst was 3.5 times higher than conventional Pd-Au catalysts. Also, 100% selectivity was obtained for acetate-based Pd-Au/SiO2 at 130 oC and the VA formation rate was comparable to that of conventional Pd-Au catalysts. Therefore, the acetate-based Pd-Au/SiO2 catalyst seems very promising and can be explored further. Also, Pd(1):Au(4)/SiO2 catalysts demonstrate 100% CO conversion at much lower temperatures (90 oC) compared with other Pd-Au based catalysts. Furthermore, we were successful in obtaining sufficient CO oxidation activity with increased metal loading (5 wt%) and these catalysts did not deactivate under above-ambient reaction temperature conditions, which make 1:4 Pd- Au/SiO2 catalyst a good candidate for further exploration in CO oxidation reactions.

Thesis (M. Sc. ) -- University of Alberta, 2010. / "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Psychiatry, University of Alberta." Title from pdf file main screen (viewed on January 14, 2010). Includes bibliographical references.

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Selective ligand coordination of zinc over other metals such as copper (II) and iron (III) is desirable and has potential commercial uses in hydrometallurgy. With this in mind ligands have been synthesised that impart a tetrahedral donor array. Binding to zinc which prefers a tetrahedral binding geometry may achieve selectivity over other non-tetrahedrally coordinating metals. Di-N-alkylated bisbenzimidazole-4,4'-dicarboxylic acids have been synthesised and shown by proton NMR, ESMS and IR analysis to bind zinc as an [L(_2)Zn(_2)] species with selectivity over copper, nickel, lead and cadmium. Hence a reversal of the Irving- Williams sequence is observed. Aqueous extraction tests using a lipophilic N-alkylated derivative indicated that the observed selectivity over copper and iron (III) was not reproduced under these experimental conditions. The ligand began to extract in the pH 2.3-3.8 region.2,9-Diphosphinoxymethyl phenanthroline derivatives were synthesised and shown to bind nickel, copper and zinc with similar stability constants, with only marginal enhancement over that of the parent phenanthroline. The 1:1 complexes were produced at acidities below pH 2. Increasing the length of the pendent arm donor groups by using phenylacetic acid moieties did not enhance zinc selectivity. The donor group was not ideal and [ML(_2)] species were generated (i.e. an N(_4) donor set)Two phenol substituted 12N(_3) ligands were synthesised (N-linked and β-C- linked). Complex stability order followed die Irving-Williams sequence Cu > Zn > Ni. The N-linked derivative formed a six membered chelate on binding and had larger metal-ligand stability constants than for the C-linked derivative which formed an eight membered chelate. The N-linked derivative bound the copper (II) cation in a near tetrahedral arrangement and imparted some copper (I) character to the metal