Evaluating the stability of disulfide bridges in proteins: a torsional potential energy surface for diethyl disulfide

Disulfide bonds formed by the oxidation of cysteine residues in proteins are the major form of intra- and inter-molecular covalent linkages in the polypeptide chain. To better understand the conformational energetics of this linkage, we have used the MP2(full)/6-31G(d) method to generate a full potential energy surface (PES) for the torsion of the model compound diethyl disulfide (DEDS) around its three critical dihedral angles (χ2, χ3, χ2′). The use of ten degree increments for each of the parameters resulted in a continuous, fine-grained surface. This allowed us to accurately predict the relative stabilities of disulfide bonds in high resolution structures from the Protein Data Bank. The MP2(full) surface showed significant qualitative differences from the PES calculated using the Amber force field. In particular, a different ordering was seen for the relative energies of the local minima. Thus, Amber energies are not reliable for comparison of the relative stabilities of disulfide bonds. Surprisingly, the surface did not show a minimum associated with χ2 − 60°, χ390, χ2′ − 60°. This is due to steric interference between Hα atoms. Despite this, significant populations of disulfides were found to adopt this conformation. In most cases this conformation is associated with an unusual secondary structure motif, the cross-strand disulfide. The relative instability of cross-strand disulfides is of great interest, as they have the potential to act as functional switches in redox processes.

William Wardell's 1859 St John's College - a rare realisation of Pugin's ideal Catholic College?

William Wardell’s St John’s College, Sydney, considered the grandest and architecturally most distinguished university college in New South Wales, is an exceptional example of 19th century Gothic Revival architecture.  The information board outside the college states that St John’s is ‘a rare realisation of Pugin’s ideal Catholic College’ and further that ‘it demonstrates [Pugin]’s profound influence on the work of Wardell’. This is but a small part of the story. The commission for St John’s College was far more complex.  The correspondence between the architects, William Wardell, Edmund Blacket and others, and St John’s Council indicates that right from the beginning there was a general lack of understanding of Wardell’s original design concept for the building. This has continued to the present day, as evidenced by the information on the board outside St John’s College, in which it is incorrectly assumed that Wardell’s proposal included a quadrangle as featured in Pugin’s ‘ideal College’. This paper, based largely on primary sources, investigates such claims about St John’s, considers William Wardell and the Gothic Revival, examines St John’s College within the University of Sydney – its design and its translation and posits a few conclusions leading to new understandings.

Technical factors for implementing SOA-Based business intelligence architecture : an exploratory study

Business intelligence (BI) architecture based on service-oriented architecture (SOA) concept enables enterprises to deploy agile and reliable BI applications. However, the key factors for implementing a SOA-based BI architecture from technical perspectives have not yet been systematically investigated. Most of the prior studies focus on organisational and managerial perspectives rather than technical factors. Therefore, this study explores the key technical factors that are most likely to have an impact on the implementation of a SOA-based BI architecture. This paper presents a conceptual model of BI architecture built on SOA concept. Drawing on academic and practitioner literature related to SOA and software architectural design, we propose fourteen key factors that may influence the implementation of a SOA-based BI architecture. This study bridges the gap between academic and practitioners.

Bridges

Bridges is a hand-drawn film. Some elements have been printed onto clear acatate that has then been glued onto a clear film surface, which itself has been prepared by bleaching away parts of the sound and image of the original film, a documentary about bridges.The sound develops a chant like quality using the rhythm of a race call and a the commentary of a football match. A celebration of the Australian voice.

The silent witness: art as a mode of representation of voices and visions of how,as a woman, I build borders and bridges in enacting my identit(ies)

Feminist theorists unveil how women negotiate their identities within complex entanglements of social constructs such as race, ethnicity, religious belief and practices, cultural tradition, and values. Feminist artists use subjective experiences that shape representation and performativity in empowering women to have a ‘voice’. In this paper, I focus on ‘breaking silences’ through series of my artworks (as part of my PhD research) that represent self-narratives as subjectivities of life experiences, contingencies, and cultural shifts through migration transitions as new ways of figuration and reflection on such issues. I look through discourses of gender differences, nomadic subjectivity, and new ways of figurations (Braidotti 2011, 10) and the affect theory (Gregg and Seigworth 2010), and the concept of giving ‘voice’ (Berlant 2011). Such discourses frame how I interrogate and represent my gendered identities.

China in a book: Victorian representations of the 'celestial kingdom' in William Dalton’s 'The wolf boy of China'

Despite the wealth of material related to China in Victorian and Edwardian children’s literature, relatively few scholarly works have been published on the subject. Critics who have discussed the topic have tended to emphasize the negative discourse and stereotypical images of the Chinese in late nineteenth-century children’s literature. I use the case of William Dalton’s The Wolf Boy of China (1857), one of the earliest full-length Victorian children’s novels set in China, to complicate previous generalizations about negative representations of China and the Chinese and to highlight the unpredictable nature of child readers’ reactions to a text. First, in order to trace the complicated process of how information about the country was disseminated, edited, framed, and translated before reaching Victorian and Edwardian readers, I analyse how Dalton wove fragments from his reading of a large archive of texts on China into his novel.
Although Dalton may have preserved and transmitted some ‘factual’ information about China from his sources, he also transformed material that he read in innovative ways. These are reflected in the more subversive and radical parts of the novel, which are discussed in the second part of the essay. In the final section, I provide examples of historical readers of The Wolf Boy of China to challenge the notion that children passively accept the imperialist messages in books of empire.