Structure and kinetics of phosphonopyruvate hydrolase from Variovorax sp. Pal2: New insight into the divergence of catalysis within the PEP mutase/isocitrate lyase superfamily .

Phosphonopyruvate (P-pyr) hydrolase (PPH), a member of the phosphoenolpyruvate (PEP) mutase/isocitrate lyase (PEPM/ICL) superfamily, hydrolyzes P-pyr and shares the highest sequence identity and functional similarity with PEPM. Recombinant PPH from Variovorax sp. Pal2 was expressed in Escherichia coli and purified to homogeneity. Analytical gel filtration indicated that the protein exists in solution predominantly as a tetramer. The PPH pH rate profile indicates maximal activity over a broad pH range.The steady-state kinetic constants determined for a rapid equilibrium ordered kinetic mechanism with Mg+2 binding first (Kd =140 ± 40 M), are kcat = 105 ± 2 s-1 and P-pyr Km = 5 ± 1 M. PEP (slow substrate kcat = 2 × 10-4 s-1), oxalate, and sulfopyruvate are competitive inhibitors with Ki values of 2.0 ± 0.1 mM, 17 ± 1 M, and 210 ± 10 M, respectively. Three PPH crystal structures have been determined, that of a ligand-free enzyme, the enzyme bound to Mg2+ and oxalate (inhibitor), and the enzyme bound to Mg2+ and P-pyr (substrate). The complex with the inhibitor was obtained by cocrystallization, whereas that with the substrate was obtained by briefly soaking crystals of the ligand-free enzyme with P-pyr prior to flash cooling. The PPH structure resembles that of the other members of the PEPM/ICL superfamily and is most similar to the functionally related enzyme, PEPM. Each monomer of the dimer of dimers exhibits an (/)8 barrel fold with the eighth helix swapped between two molecules of the dimer. Both P-pyr and oxalate are anchored to the active site by Mg2+. The loop capping the active site is disordered in all three structures, in contrast to PEPM, where the equivalent loop adopts an open or disordered conformation in the unbound state but sequesters the inhibitor from solvent in the bound state. Crystal packing may have favored the open conformation of PPH even when the enzyme was cocrystallized with the oxalate inhibitor. Structure alignment of PPH with other superfamily members revealed two pairs of invariant or conservatively replaced residues that anchor the flexible gating loop. The proposed PPH catalytic mechanism is analogous to that of PEPM but includes activation of a water nucleophile with the loop Thr118 residue.

Between the devil and the deep blue sea: Nationality, power and symbolic trade-offs among evangelical Protestants in contemporary Northern Ireland

National identity is symbolically complex configuration, with shifts of emphasis and reprioritisations of content negotiated in contexts of power. This paper shows how they occur in one post-conflict situation - Northern Ireland - among some of the most extreme of national actors - evangelical Protestants. In-depth interviews reveal quite radical shifts in the content of their British identity and in their understanding of and relation to the Irish state, with implications for their future politics. The implications for understanding ethno-religious nationalism, nationality shifts and the future of Northern Ireland are drawn out.

Muldoon's Betweenness

Muldoon’s poetry frequently explores states of being ‘in-between’ and this can plausibly be related to his Catholic Northern Irish identity. He seems to be aware of the effects comprised in Derrida’s concept of différance, one version of which is the entre (‘between’). Nevertheless, Muldoon is more interested in exploring the experience of postmodernity than in offering a theory, or relating it to one culture. But this exploration has as many similarities with the concerns of existentialism and phenomenology as with deconstruction. Poems from Why Brownlee Left to Moy Sand and Gravel are discussed, and topics addressed include the South American exotic (new sources are suggested) and the troping on yarrow (compare Derrida’s pharmakon) in The Annals of Chile. Formal effects of repetition and difference reflect the themes. The redemption of repetition is studied with the help both of Kierkegaard and of Muldoon’s thoughts on the ‘magic mist’ of Irish romance.

Understandings of citizenship education in Northern Ireland and the Republic of Ireland: Public discourses among stakeholders in the public and private sectors

Internationally, citizenship education has come to the fore in the past decade. It may be particularly importantwithin the context of societies with a legacy of political conflict, such as Northern Ireland and the Republic of Ireland, where it is being implemented as part of the statutory curriculum. This article explores understandingsof citizenship education among stakeholders in the private and public sectors in Northern Ireland and the Republic of Ireland with the aim to compare these with curricular conceptualizations of citizenship inboth contexts. Semi-structured interviews were conducted in both societies involving non-governmentalorganizations, political parties, trade unions and the police. Results indicated that levels of awareness aboutcitizenship education varied substantially and understandings mainly reflected current theory and curriculumpractice in citizenship. Commonalities emerged as in both societies similar key concepts were identified whiledifferences transpired over issues relating to national identity and political conflict, which may raise questionsfor history and citizenship education in both societies.

Transmission line matching effects on the performance of shunt-C/series-tuned and series-L/parallel-tuned Class-E amplifiers

The impact that the transmission-line load-network has on the performance of the recently introduced series-L/parallel-tuned Class-E amplifier and the classic shunt-C/series-tuned configuration when compared to optimally derived lumped load networks is discussed. In addition an improved load topology which facilitates harmonic suppression of up to 5 order as required for maximum Class-E efficiency as well as load resistance transformation and a design procedure involving the use of Kuroda's identity and Richard's transformation enable a distributed synthesis process which dispenses with the need for iterative tuning as previously required in order to achieve optimum Class-E operation. © 2005 IEEE.

Troubled Geographies: A Spatial History of Religion and Society in Ireland

Ireland’s landscape is marked by fault lines of religious, ethnic, and political identity that have shaped its troubled history. Troubled Geographies maps this history by detailing the patterns of change in Ireland from 16th century attempts to “plant” areas of Ireland with loyal English Protestants to defend against threats posed by indigenous Catholics, through the violence of the latter part of the 20th century and the rise of the “Celtic Tiger.” The book is concerned with how a geography laid down in the 16th and 17th centuries led to an amalgam based on religious belief, ethnic/national identity, and political conviction that continues to shape the geographies of modern Ireland. Troubled Geographies shows how changes in religious affiliation, identity, and territoriality have impacted Irish society during this period. It explores the response of society in general and religion in particular to major cultural shocks such as the Famine and to long term processes such as urbanization.

The Macroeconomic Factors Conditioning the Impact of Identity on Attitudes towards the EU

Factors relating to identity and to economics have been shown to be important predictors of attitudes towards the European Union (EU). In this article, we show that the impact of identity is conditional on economic context. First, living in a member state that receives relatively high levels of EU funding acts as a 'buffer', diluting the impact of an exclusive national identity on Euroscepticism. Second, living in a relatively wealthy member state, with its associated attractiveness for economic migrants, increases the salience of economic xenophobia as a driver of sceptical attitudes. These results highlight the importance of seeing theories of attitude formation (such as economic and identity theories) not as competitors but rather as complementary, with the predictive strength of one theoretical approach (identity) being a function of system-level variation in factors relating to the other theoretical approach (macro-level economic conditions).

'Ideological content and institutional frameworks: Unionist identities in Northern Ireland and Scotland'

This article examines the complex interactions between British national identity and the territorial identities of Northern Ireland and Scotland. We argue that the current literature on national identities in Britain misunderstands the nature of British identities in Northern Ireland and Scotland. Indeed, much of this literature wrongly defines Unionists in both of these areas. By examining the content of British national identity, a comparison of Scotland and Northern Ireland reveals that Unionism finds political significance through an ideological project committed to the Union. However, we also have to account for the differences in the Unionist ideology of Scotland and Northern Ireland. We argue that the institutional framework in which these identities and ideologies are exercised explains this variation. Overall, we argue that the debate on nationalism in the United Kingdom has not adequately shown how the integrative functions of British national identity can co-exist with the separatist nature of territorial national identity.

Predatory fish loss affects the structure and functioning of a model marine food web

The rate of species loss is increasing on a global scale and predators are most at risk from human-induced extinction. The effects of losing predators are difficult to predict, even with experimental single species removals, because different combinations of species interact in unpredictable ways. We tested the effects of the loss of groups of common predators on herbivore and algal assemblages in a model benthic marine system. The predator groups were fish, shrimp and crabs. Each group was represented by at least two characteristic species based on data collected at local field sites. We examined the effects of the loss of predators while controlling for the loss of predator biomass. The identity, not the number of predator groups, affected herbivore abundance and assemblage structure. Removing fish led to a large increase in the abundance of dominant herbivores, such as Ampithoids and Caprellids. Predator identity also affected algal assemblage structure. It did not, however, affect total algal mass. Removing fish led to an increase in the final biomass of the least common taxa (red algae) and reduced the mass of the dominant taxa (brown algae). This compensatory shift in the algal assemblage appeared to facilitate the maintenance of a constant total algal biomass. In the absence of fish, shrimp at higher than ambient densities had a similar effect on herbivore abundance, showing that other groups could partially compensate for the loss of dominant predators. Crabs had no effect on herbivore or algal populations, possibly because they were not at carrying capacity in our experimental system. These findings show that contrary to the assumptions of many food web models, predators cannot be classified into a single functional group and their role in food webs depends on their identity and density in 'real' systems and carrying capacities.

Resolving genetic functions within microbial populations: In situ analyses using rRNA and mRNA stable isotope probing coupled with single-cell raman-fluorescence in situ hybridization

Prokaryotes represent one-half of the living biomass on Earth, with the vast majority remaining elusive to culture and study within the laboratory. As a result, we lack a basic understanding of the functions that many species perform in the natural world. To address this issue, we developed complementary population and single-cell stable isotope (C-13)-linked analyses to determine microbial identity and function in situ. We demonstrated that the use of rRNA/mRNA stable isotope probing (SIP) recovered the key phylogenetic and functional RNAs. This was followed by single-cell physiological analyses of these populations to determine and quantify in situ functions within an aerobic naphthalene-degrading groundwater microbial community. Using these culture-independent approaches, we identified three prokaryote species capable of naphthalene biodegradation within the groundwater system: two taxa were isolated in the laboratory (Pseudomonas fluorescens and Pseudomonas putida), whereas the third eluded culture (an Acidovorax sp.). Using parallel population and single-cell stable isotope technologies, we were able to identify an unculturable Acidovorax sp. which played the key role in naphthalene biodegradation in situ, rather than the culturable naphthalene-biodegrading Pseudomonas sp. isolated from the same groundwater. The Pseudomonas isolates actively degraded naphthalene only at naphthalene concentrations higher than 30 mu M. This study demonstrated that unculturable microorganisms could play important roles in biodegradation in the ecosystem. It also showed that the combined RNA SIP-Raman-fluorescence in situ hybridization approach may be a significant tool in resolving ecology, functionality, and niche specialization within the unculturable fraction of organisms residing in the natural environment.

Legitimacy Through Neutrality: Probation and Conflict in Northern Ireland

The conflict in Northern Ireland known as the Troubles presented numerous challenges for the administration of traditional forms of criminal justice and has led to a variety of adaptations that have been widely discussed in the literature in criminology and transitional justice. The role of Northern Ireland's probation service is often forgotten or ignored in such analyses. This brief article is intended to begin to fill this gap by exploring how the Troubles impacted on probation practice during the Conflict and beyond. In particular, we argue that the 'neutrality stance' taken by probation in the mid-1970s, when officers decided to cease mandated work with individuals charged with 'politically-motivated' offences, has had a lasting impact on the identity and role of probation in the region. The deep immersion into, and engagement with, marginalised communities during this time, facilitated by this neutrality stance, has overlooked implications for probation practice more widely in the United Kingdom and abroad.

Autopoiesis and the Home Confined Consumer: The Role of Personal Communities

Purpose – The purpose of this paper is to explore the consumption of a personal community and its role in the everyday life of the home-confined consumer. Design/methodology/approach – Using a Radical Constructivist approach, three cases of home confinement were explored in depth over a period of two years. Ongoing “conversations” captured the consumption experiences with personal communities. Findings – In relation to the home-confined context, the ability to attain individuality, empowerment and creativity are all heightened as a result of personal community construction. An underlying concern for home-confined consumers is their removal from independent living to institutionalized living, and, as a result the need to construct, manage and maintain a personal community is of major concern. Research limitations/implications – Although the study addresses a home-confined context, it is nevertheless reflective of concerns that are significant to all consumers, namely the attainment of individuality and independence irrespective of marginalization or not. Practical implications – The importance of a personal community in terms of both self-empowerment and self-identity with respect to marginalized groups and vulnerable individuals should not be underestimated. The supporting role of a personal community provides, in times of uncertainty, a framework to maintain self-identity and independence. Originality/value – This paper provides a better understanding of the role of a personal community in the consumption experiences of those consumers marginalized and vulnerable as a consequence of context. Home-confined consumers are “invisible” in the marketplace and the personal community is a means of redressing this imbalance by empowering such individuals.

Contemporary Radio Art and Spatial Politics: The Critical Radio Utopias of Anna Friz

The article explores the work of the Canadian sound artist Anna Friz over the last decade. Her work deals explicitly with issues of technology and the relative absence of women's voices on radio. Exploring her work as a composer, installation artist, instrumentalist, performance artist and storyteller, and contextualising these practices within feminist critiques and radio conventions, the article explores Friz's ‘self-reflexive radio’. Ideas of ‘supermodernity’, ‘displacement’ and ‘critical utopia’ are deployed to discuss specific pieces of Friz's work in relation to identity and space. The article argues that Friz reconfigures the radio as a site of resistance to dominant constructions of contemporary globalised space and cultures, the politics of informational capitalism and the uneven flows that these cultures and politics engender.

Nostalgically Man dwells on this Earth: Objects and domestic space in The Royal Tenenbaums and The Darjeeling Ltd

The films of Wes Anderson feature a peculiar attention to the representation of dwellings in relation to narrative development, filmic style and characters' identities. As is true of clothing, in Anderson's cinema homes with their architecture, furniture and objects strongly contribute to a nostalgic dislocation of the characters from contemporary time. Considering the house as the prime locus of identity and the core of the patriarchal family, the family home is often depicted by Anderson as the last physical trace left by the absent father; a utopian place that the characters aim to rebuild or to recall through its objectification. This paper aims to analyse the (re)construction of the family home in The Royal Tenenbaums, and will investigate its absence and surrogates in The Darjeeling Ltd.