The influence of cis/trans isomerism on the physical properties of a cyano-bridged dinuclear mixed valence complex

The cyano-bridged complexes cis-[L14CoIIINCFeII(CN)5]– and cis-[L14CoIIINCFeIII(CN)5] (L14= 6-methyl-1,4,8,11-tetraazacyclotetradecan-6-amine) are prepared and characterised spectroscopically, electrochemically and structurally: Na{cis-[L14CoIIINCFeII(CN)5]}·9H2O, monoclinic space group P21/c, a= 14.758(3), b= 10.496(1), c= 19.359(3) , = 92.00(2)°, Z= 4; cis-[L14CoIIINCFeIII(CN)5]·4H2O, orthorhombic space group P212121, a= 9.492(1), b= 14.709(2), c= 18.760(3) , Z= 4. In both complexes, the pendant amine is cis to the bridging cyanide ligand. An analysis of the metal-to-metal charge transfer (MMCT) transition in these systems with Hush theory has been carried out. This has revealed that the change in the configuration of the macrocycle both decreases the redox isomer energy difference (E1/2) and increases the reorganisational energy () of the cis-[L14CoIIINCFeII(CN)5]– complex with respect to the trans-[L14CoIIINCFeII(CN)5]– complex, the result being that both isomers display an MMCT transition of similar energy. The variation in redox isomer energy differences of the configurational isomers has been related to strain energy differences by molecular mechanics analysis of the [CoL14Cl]2+/+ precursor complexes.

Child welfare workers' use of theory in working with physical child abuse: Implications for professional supervision

This article examines child welfare workers' understanding of physical child abuse and the Implications for those supervising these workers. The article Is based on the results of a study that involved In-depth Interviews and focus groups with statutory child welfare workers. Analysis revealed that workers' understanding of physical child abuse embodied a wide range of ideas that were generally consistent with existing literature. The study highlights the value and utility of a reflective approach In stimulating and making explicit the theoretical underpinnings of child welfare workers practice. Specific Implications for professional supervision are addressed.

Preliminary characterisation and extraction of anterior adhesive secretion in monogenean (platyhelminth) parasites

Secreted anterior adhesives, used for temporary attachment to epithelial surfaces of fishes (skin and gills) by some monogenean (platyhelminth) parasites have been partially characterised. Adhesive is composed of protein. Amino acid composition has been determined for seven monopisthocotylean monogeneans. Six of these belong to the Monocotylidae and one species, Entobdella soleae (van Beneden et Hesse, 1864) Johnston, 1929, is a member of the Capsalidae. Histochemistry shows that the adhesive does not contain polysaccharides, including acid mucins, or lipids. The adhesive before secretion and in its secreted form contains no dihydroxyphenylalanine (dopa). Secreted adhesive is highly insoluble, but has a soft consistency and is mechanically removable from glass surfaces. Generally there are high levels of glycine and alanine, low levels of tyrosine and methionine, and histidine is often absent. However, amino acid content varies between species, the biggest differences evident when the monocotylid monogeneans were compared with E. soleae. Monogenean adhesive shows similarity in amino acid profile with adhesives from starfish, limpets and barnacles. However, there are some differences in individual amino acids in the temporary adhesive secretions of, on the one hand, the monogeneans and, on the other hand, the starfish and limpets. These differences may reflect the fact that monogeneans, unlike starfish and barnacles, attach to living tissue (tissue adhesion). A method of extracting unsecreted adhesive was investigated for use in further characterisation studies on monogenean glues.

Physical aging of amorphous fructose

Physical aging of amorphous anhydrous fructose at temperature 5 degreesC and at 22 degreesC was studied using differential scanning calorimetry (DSC). The dynamic glass transitions temperature, T-g0 for unaged samples was 16 degreesC and 13.3 degreesC for heating rate of 10 degreesC/min and 1 degreesC/min, respectively. The fictive temperature, T-f0 for unaged samples calculated by Richardson and Savill method was 12 degreesC, which is close to the dynamic value obtained from the lower DSC heating rate. The fictive temperature T-f of the aged fructose glasses at temperatures both below and above the transition region was fitted well by a non-exponential decay function (Williams-Watts form). Aging above the transition region (22 degreesC) for 18 d increased both the dynamic glass transition temperature T and the fictive temperature T-f. However, aging below the transition region (5 degreesC) for I d increased the dynamic glass transition temperature T-g but decreased the fictive temperature T-f.

A system for the heterologous expression of complex redox proteins in Rhodobacter capsulatus: characterisation of recombinant sulphite : cytochrome c oxidoreductase from Starkeya novella

The phototrophic purple non-sulfur bacterium Rhodobacter capsulatus expresses a wide variety of complex redox proteins in response to changing environmental conditions. Here we report the construction and evaluation of an expression system for recombinant proteins in that organism which makes use of the dor promoter from the same organism. A generic expression vector, pDorEX, was constructed and used to express sulphite:cytochrome c oxidoreductase from Starkeya novella, a heterodimeric protein containing both molybdenum and haem c. The recombinant protein was secreted to the periplasm and its biochemical properties were very similar to those of the native enzyme. The pDorEX system therefore seems to be potentially useful for heterologous expression of multi-subunit proteins containing complex redox cofactors. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

Up close and personal on physical education teachers' identity: Is conflict an issue?

Much of the research on teachers' work is informed by role theory, that assumes teachers' identity is largely ascribed. When there are inconsistencies in teachers' and others' expectations for different occupational roles such as physical education teacher and sports coach, 'role conflict' is said to occur. This stud), sought to investigate if role conflict was a major concern for Australian physical education teacher/coaches. Findings, informed by case studies with five teacher/coaches, challenge the assumption that moving between professional responsibilities causes role conflict. Rather, in moving across contexts, the physical education teachers managed inconsistencies in ways that resulted in positive and rawarding work experiences.

Correlates of adults' participation in physical activity: review and update

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Behaviour of the black flying fox Pteropus alecto: 1. An ethogram of behaviour, and preliminary characterisation of mother-infant interactions

The black flying fox Pteropus alecto is one of four species of flying fox found on the Australian mainland. Little information exists about the specific behaviour of this species, and no framework for the study of its behaviour has yet been constructed. In the study reported here, two P alecto colonies were observed at two day roosts in South East Queensland, Australia, between 1998-2000. Observations focused on solitary and social actions in general and on mother-infant interactions in some detail and led to the construction of an ethogram that defines each action structurally and functionally, describing accompanying vocalisations where appropriate. Diurnal activity patterns of P. alecto throughout the year consisted predominantly of roosting, grooming and sleeping, and involved little social activity. Social interactions were largely restricted to the seasonal contexts of the birthing/rearing period of October to March and the subsequent courtship/mating season of February to April. In all, 74 behavioural units were defined with the aim of facilitating further research and the implementation of effective conservation strategies for the species.

Differences in physical activity between black and white girls living in rural and urban areas

This study examined the relationship of race and rural/urban setting to physical, behavioral, psychosocial, and environmental factors associated with physical activity. Subjects included 1,668 eighth-grade girls from 31 middle schools: 933 from urban settings, and 735 from rural settings. Forty-six percent of urban girls and 59% of rural girls were Black. One-way and two-way ANOVAs with school as a covariate were used to analyze the data. Results indicated that most differences were associated with race rather than setting. Black girls were less active than White girls, reporting significantly fewer 30-minute blocks of both vigorous and moderate-to-vigorous physical activity. Black girls also spent more time watching television, and had higher BMIs and greater prevalence of overweight than White girls. However, enjoyment of physical education and family involvement in physical activity were greater among Black girls titan White girls. Rural White girls and urban Black girls had more favorable attitudes toward physical activity. Access to sports equipment, perceived safety of neighborhood, and physical activity self-efficacy were higher in White girls than Black girls.