Prediction of the equilibrium structures and photomagnetic properties of the Prussian blue analogue RbMn[Fe(CN)6] by density functional theory

A periodic density functional theory method using the B3LYP hybrid exchange-correlation potential is applied to the Prussian blue analogue RbMn[Fe(CN)6] to evaluate the suitability of the method for studying, and predicting, the photomagnetic behavior of Prussian blue analogues and related materials. The method allows correct description of the equilibrium structures of the different electronic configurations with regard to the cell parameters and bond distances. In agreement with the experimental data, the calculations have shown that the low-temperature phase (LT; Fe(2+)(t(6)2g, S = 0)-CN-Mn(3+)(t(3)2g e(1)g, S = 2)) is the stable phase at low temperature instead of the high-temperature phase (HT; Fe(3+)(t(5)2g, S = 1/2)-CN-Mn(2+)(t(3)2g e(2)g, S = 5/2)). Additionally, the method gives an estimation for the enthalpy difference (HT LT) with a value of 143 J mol(-1) K(-1). The comparison of our calculations with experimental data from the literature and from our calorimetric and X-ray photoelectron spectroscopy measurements on the Rb0.97Mn[Fe(CN)6]0.98 x 1.03 H2O compound is analyzed, and in general, a satisfactory agreement is obtained. The method also predicts the metastable nature of the electronic configuration of the high-temperature phase, a necessary condition to photoinduce that phase at low temperatures. It gives a photoactivation energy of 2.36 eV, which is in agreement with photoinduced demagnetization produced by a green laser.

Higher-order factor structures and intercorrelations of the 16PF5 and FIRO-B

This study investigated the intercorrelations and the independent and combined factor structures of the Sixteen Personality Factor Questionnaire Fifth Edition (16PF5) and the Fundamental Interpersonal Orientation-Behaviour Scale (FIRO-B). Four thousand four hundred and fourteen U.S. participants completed these measures as part of executive assessments between 1994 and 2003. Exploratory factor analyses supported the five-factor higher-order structure of the 16PF5; however, the three-component structure for the FIRO-B was not supported. A six-factor structure was found to underlie the variance in the measures in combination. Five of these were close to the 16PF5 higher-order structure, but a sixth factor labelled Social Independence also emerged. This new factor consisted of the 16PF5 primaries of Liveliness and Social Boldness, and the FIRO-B Wanted Control scale.

The microbiology of the eye

Infection of the external structures of the eye is one of the commonest types of eye disease worldwide. In addition, although relatively impermeable to microorganisms, infection within the eye can result from trauma, surgery or systemic disease. This article reviews the general biology of viruses, bacteria, fungi and protozoa and the major ocular infections that they cause. In addition, the effectiveness of the various antimicrobial agents in controlling ocular disease is discussed. Because of changes in the normal ocular flora, continuous monitoring of the microbiology of the eye will continue to be important in predicting future types of eye infection. Basic research is also needed into the interactions of microbes at the ocular surface. There is increasing microbial resistance to the antimicrobial agents used to treat ocular infections and hence, new antimicrobial agents will continue to be needed together with new methods of drug delivery to increase the effectiveness of existing antimicrobial agents.

Mixing the grant cocktail:towards an understanding of the outcomes of financial support to small firms

One of the key policy objectives of government at national and regional level, is to overcome the constraints preventing local industry achieving greater competitiveness in the international market-place. This paper examines the impact of grant assistance to Northern Ireland small firms delivered over the period 1994 ^ 97 by the former Local Enterprise Development Unit through its Growth Business Support Programme (GBSP). Previous work by the authors showed that there was some tentative evidence to suggest a link between employment growth and grant aid provided to very small firms (fewer than 10 employees) assisted under the GBSP. The central objective of the empirical work reported in this paper is to extend the previous analysis by understanding the extent to which the value of financial assistance influences growth (employment, turnover, and productivity measures) and if differential impacts arise depending on the nature and timing (lag structures) of the grant assistance.

Fungal infection of the eye (ocular mycosis)

Although not as important as bacteria or viruses as a cause of eye infection, a large number of fungal species have now been recorded in association with the eye. In addition, several species have been implicated as a cause of eye infection (‘ocular mycosis’) and some may even cause life-threatening conditions. Ocular mycoses are being reported more frequently as a consequence of new medical practice and the increased numbers of immuno-compromised patients in the population, e.g., patients receiving radiation treatment or chemotherapy. This article describes the most common conditions caused by fungi which can affect the different structures of the eye, the importance of fungal contamination of materials as a source of eye infection, and the methods available for treatment.

A study of the regulatory role of retinoic acid receptor gamma in Zebrafish development

Retinoic acid (RA) is thought to signal through retinoic acid receptors (RARs), i.e. RARα, β, and γ to play important roles in embryonic development and tissue regeneration. In this thesis, the zebrafish (Danio rario) was used as a vertebrate model organism to examine the role of RARγ. Treatment of zebrafish embryos with a RARγ specific agonist reduced the axial length of developing embryos, associated with reduced somite number and loss of hoxb13a expression. There were no clear alterations in hoxc11a or myoD expression. Treatment with the RARγ agonist disrupted the formation of anterior structures of the head, the cranial bones and the anterior lateral line ganglia, associated with a loss of sox9 immunopositive cells in the same regions. Pectoral fin outgrowth was blocked by treatment with the RARγ agonist; however, this was not associated with loss of tbx5a immunopositive lateral plate cells and was reversed by wash out of the RARγ agonist or co-treatment with a RARγ antagonist. Regeneration of the transected caudal fin was also blocked by RARγ agonist treatment and restored by agonist washout or antagonist co-treatment; this phenotype was associated with a localised reduction in canonical Wnt signalling. Conversely, elevated canonical Wnt signalling after RARγ treatment was seen in other tissues, including ectopically in the notochord. Furthermore, some phenotypes seen in the RARγ treated embryos were present in mutant zebrafish embryos in which canonical Wnt signalling was constitutively increased. These data suggest that RARγ plays an essential role in maintaining neural crest and mesodermal stem/progenitor cells during normal embryonic development and tissue regeneration when the receptor is in its non-ligated state. In addition, this work has provided evidence that the activation status of RARγ may regulate hoxb13a gene expression and canonical Wnt signalling. Further research is required to confirm such novel regulatory roles.

EPIPOX:immunoinformatic characterization of the shared T-cell epitome between variola virus and related pathogenic orthopoxviruses

Concerns that variola viruses might be used as bioweapons have renewed the interest in developing new and safer smallpox vaccines. Variola virus genomes are now widely available, allowing computational characterization of the entire T-cell epitome and the use of such information to develop safe and yet effective vaccines. To this end, we identified 124 proteins shared between various species of pathogenic orthopoxviruses including variola minor and major, monkeypox, cowpox, and vaccinia viruses, and we targeted them for T-cell epitope prediction. We recognized 8,106, and 8,483 unique class I and class II MHC-restricted T-cell epitopes that are shared by all mentioned orthopoxviruses. Subsequently, we developed an immunological resource, EPIPOX, upon the predicted T-cell epitome. EPIPOX is freely available online and it has been designed to facilitate reverse vaccinology. Thus, EPIPOX includes key epitope-focused protein annotations: time point expression, presence of leader and transmembrane signals, and known location on outer membrane structures of the infective viruses. These features can be used to select specific T-cell epitopes suitable for experimental validation restricted by single MHC alleles, as combinations thereof, or by MHC supertypes.

A hydrogen-bonded polar network in the core of the glucagon-like peptide-1 receptor is a fulcrum for biased agonism:lessons from class B crystal structuress

The glucagon-like peptide 1 (GLP-1) receptor is a class B G protein-coupled receptor (GPCR) that is a key target for treatments for type II diabetes and obesity. This receptor, like other class B GPCRs, displays biased agonism, though the physiologic significance of this is yet to be elucidated. Previous work has implicated R2.60190 , N3.43240 , Q7.49394 , and H6.52363 as key residues involved in peptide-mediated biased agonism, with R2.60190 , N3.43240 , and Q7.49394 predicted to form a polar interaction network. In this study, we used novel insight gained from recent crystal structures of the transmembrane domains of the glucagon and corticotropin releasing factor 1 (CRF1) receptors to develop improved models of the GLP-1 receptor that predict additional key molecular interactions with these amino acids. We have introduced E6.53364 A, N3.43240 Q, Q7.49493N, and N3.43240 Q/Q7.49 Q/Q7.49493N mutations to probe the role of predicted H-bonding and charge-charge interactions in driving cAMP, calcium, or extracellular signal-regulated kinase (ERK) signaling. A polar interaction between E6.53364 and R2.60190 was predicted to be important for GLP-1- and exendin-4-, but not oxyntomodulin-mediated cAMP formation and also ERK1/2 phosphorylation. In contrast, Q7.49394 , but not R2.60190 /E6.53364 was critical for calcium mobilization for all three peptides. Mutation of N3.43240 and Q7.49394 had differential effects on individual peptides, providing evidence for molecular differences in activation transition. Collectively, this work expands our understanding of peptide-mediated signaling from the GLP-1 receptor and the key role that the central polar network plays in these events.

Strategic orientations in practice:Exploring the strategic belief structures of line-managers embedded in practice

Recently researchers have started to investigate the cognitive strategic orientations of individual top managers and have pointed out these may be key in determining the direction and success of their organizations in terms of performance, but they have been unable to effectively operationalize this notion in empirical research and this is holding up knowledge development. To make a contribution that helps overcome this limitation a theoretical framework is developed which specifies the different possible cognitive strategic orientations of top managers as well as those of managers at lower organizational levels involved in the strategy process. This theoretical framework is investigated in the empirical phase of the study into strategic orientations in practice. Additional contributions to knowledge of strategic orientation are made in three main domains. Firstly, current knowledge of strategic orientation is largely limited to analysis at the level of the firm whereas there is a lack of understanding of any relationships with practice at lower organizational levels. The exploratory research undertaken for this thesis contributes to new knowledge of different rational, developmental and interactive strategic orientations of front-line managers and this contributes to a cognitive explanation for emergent strategy linked to strategy processes embedded in practice. In theorising the presence of different strategic orientations in practice the discussion highlights the importance of network and spatial embeddedness within enacted environments. Secondly, a contribution to further knowledge of the links between strategy processes and the content of strategies within a retail context is made. The research highlights different strategy processes used in practice by retail front-line managers in a branch network of stores and these are linked to consequences such as different objectives, performance expectations and the fulfilment of personal goals. Thirdly, a contribution to research methodology is made by addressing problems associated with the comparison of cognitive maps.

An investigation into the network structures of eThylene propylene terpolymer elastomers

A series of ethylene propylene terpolymer vulcanizates, prepared by varying termonomer type, cure system, cure time and cure temperature, are characterized by determining the number and type of cross-links present. The termonomers used represent the types currently available in commercial quantities. Characterization is carried out by measuring the C1 constant of the Mooney Rivlin Saunders equation before and after treatment with the chemical probes propane-2-thiol/piperidine and n-hexane thiol/piperidine, thus making it possible to calculate the relative proportions of mono-sulphidic, di-sulphidic and poly- sulphidic cross-links. The cure systems used included both sulphur and peroxide formulations. Specific physical properties are determined for each network and an attempt is made to correlate observed changes in these with variations in network structure. A survey of the economics of each formulation based on a calculated efficiency parameter for each cure system is included. Values of C1 are calculated from compression modulus data after the reliability of the technique when used with ethylene propylene terpolymers had been established. This is carried out by comparing values from both compression and extension stress strain measurements for natural rubber vulcanizates and by assessing the effects of sample dimensions and the degree of swelling. The technique of compression modulus is much more widely applicable than previously thought. The basic structure of an ethylene propylene terpolymer network appears to be independent of the type of cure system used ( sulphur based systems only), the proportions of constituent cross-links being nearly constant.

The effects of new technology on employment structures in the service sector

This thesis explores the interrelationships between the labour process, the development of technology and patterns of gender differentiation. The introduction of front office terminals into building society branches forms the focus of the research. Case studies were carried out in nine branches, three each from three building societies. Statistical data for the whole movement and a survey of ten of the top thirty societies provided the context for the studies. In the process of the research it became clear that it was not technology itself but the way that it was used, that was the main factor in determining outcomes. The introduction of new technologies is occurring at a rapid pace, facilitated by continuing high growth rates, although front office technology could seldom be cost justified. There was great variety between societies in their operating philosophies and their reasons for and approach to computerisation, but all societies foresaw an ultimate saving in staff. Computerisation has resulted in the deskilling of the cashiering role and increased control over work at all stages. Some branch managers experienced a decrease in autonomy and an increase in control over their work. Subsequent to this deskilling there has been a greatly increased use of part time staff which has enabled costs to be reduced. There has also been a polarisation between career and non-career staff which, like the use of part time staff, has occurred along gender lines. There is considerable evidence that societies' policies, structures and managerial attitudes continue to directly and indirectly discriminate against women. It is these practices which confine women to lower grades and ensure their dependence on the family and which create the pool of cheap skilled labour that societies so willingly exploit by increasing part time work. Gender strategies enter management strategies throughout the operations of the organisation.

Characterizing the hierarchical structures of bioactive sol-gel silicate glass and hybrid scaffolds for bone regeneration

Bone is the second most widely transplanted tissue after blood. Synthetic alternatives are needed that can reduce the need for transplants and regenerate bone by acting as active temporary templates for bone growth. Bioactive glasses are one of the most promising bone replacement/regeneration materials because they bond to existing bone, are degradable and stimulate new bone growth by the action of their dissolution products on cells. Sol-gel-derived bioactive glasses can be foamed to produce interconnected macropores suitable for tissue ingrowth, particularly cell migration and vascularization and cell penetration. The scaffolds fulfil many of the criteria of an ideal synthetic bone graft, but are not suitable for all bone defect sites because they are brittle. One strategy for improving toughness of the scaffolds without losing their other beneficial properties is to synthesize inorganic/organic hybrids. These hybrids have polymers introduced into the sol-gel process so that the organic and inorganic components interact at the molecular level, providing control over mechanical properties and degradation rates. However, a full understanding of how each feature or property of the glass and hybrid scaffolds affects cellular response is needed to optimize the materials and ensure long-term success and clinical products. This review focuses on the techniques that have been developed for characterizing the hierarchical structures of sol-gel glasses and hybrids, from atomicscale amorphous networks, through the covalent bonding between components in hybrids and nanoporosity, to quantifying open macroporous networks of the scaffolds. Methods for non-destructive in situ monitoring of degradation and bioactivity mechanisms of the materials are also included. © 2012 The Royal Society.