Histone modifications influence the action of Snf2 family remodelling enzymes by different mechanisms

AbstractAlteration of chromatin structure by chromatin modifying and remodelling activities is a key stage in the regulation of many nuclear processes. These activities are frequently interlinked, and many chromatin remodelling enzymes contain motifs that recognise modified histones. Here we adopt a peptide ligation strategy to generate specifically modified chromatin templates and used these to study the interaction of the Chd1, Isw2 and RSC remodelling complexes with differentially acetylated nucleosomes. Specific patterns of histone acetylation are found to alter the rate of chromatin remodelling in different ways. For example, histone H3 lysine 14 acetylation acts to increase recruitment of the RSC complex to nucleosomes. However, histone H4 tetra-acetylation alters the spectrum of remodelled products generated by increasing octamer transfer in trans. In contrast, histone H4 tetra-acetylation was also found to reduce the activity of the Chd1 and Isw2 remodelling enzymes by reducing catalytic turnover without affecting recruitment. These observations illustrate a range of different means by which modifications to histones can influence the action of remodelling enzymes

Leading with political astuteness: A study of public managers in Australia, New Zealand and the United Kingdom

Combining quantitative survey data from over 1000 middle and senior public managers, as well as qualitative data from 42 in-depth interviews, the study sheds light on how managers understand politics in their work; how they rate their own and their colleagues’ political skills; how they use their political skills; and how these skills were developed. The report also sets forth recommendations to improve the development of managers’ political astuteness at the level of the individual, the organisation, and the professional body/training provider

Discourses of Neo-Liberalisation in New Zealand: From the ‘Managed Economy’ to the ‘Mum and Dad Investor’, Prime Ministers’ Speeches of 1987-2011 (a Critical Discourse Analysis)

In this project I aim to challenge the conception of neo-liberalism as a monolithic ideology and theory of state practice. To achieve this, I use Norman Fairclough’s ‘order of discourse’ model of critical discourse analysis to examine seven speeches delivered by New Zealand Prime Ministers of 1987 to 2011. Using these speeches I chart a number of breaks, shifts, contradictions, and instabilities between both Prime Ministers and Governments, which are often specific to New Zealand. The analyses of the seven speeches highlight the contradictions and tensions inherent in on-going processes of neo-liberalisation in New Zealand. Among other instabilities and contradictions, I examine David Lange’s conflicting articulations of economic management in market-led governing. I note the role of technocracy under Geoffrey Palmer, and the inconsistencies in his push to institutionalise the Treaty of Waitangi while decentralising the role of the state in governing. I outline the specificities of New Zealand as a colonial settler society through the signifier “battler” deployed by Mike Moore. I also sketch the functions of Jim Bolger’s communitarianism, and the way it flanks the market logics deployed by Minister of Finance Ruth Richardson, between 1990 and 1993. The effect and significance of Jenny Shipley’s ‘Code of Social and Family Responsibility’ is examined, noting the way it crystallises the role of social capital in practices of governing. The impact of Helen Clark’s Third Way and ‘inclusive’ neo-liberalism are then charted. Clark’s use of diverse ideological forms suggests a mobile and mediating moment in neo-liberalism, which attempts to overcome some of the problems generated by earlier speakers. I finally cover the way that John Key’s anti-ideological position results in what is labelled the ‘market ideology’, crystallising market logic as a rubric for governing through terms like the “mum and dad investor”, and the “kiwi”. I then offer some concluding comments and note the project’s limitations, before offering some tentative prospects of neo-liberalism’s fortune in a post-2008 crisis world

Subjective Reality: The Hard Question

The manner in which the 100 billion or so neurons in the human brain work together to give us the rich subjective of conscious experience has been referred to as the hard question . This paper seeks to explore this question: exposing some of its difficult dimensions as well as noting and critiquing various attempts to probe and explain its mysteries. The views of some prominent Christian scholars, such as Donald McKay and Charles Taliaferro, conclude this analysis

An analysis of baseflow recession in the Republic of South Africa.

Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.Demands on the water resources of South Africa are ever increasing owing to population growth and increased development of urban, peri-urban and rural communities. Problems in terms of water quantity and quality are likely to be experienced during baseflow recessions. It is therefore imperative that water resources managers not only understand these baseflow periods of streamflow, but are able to model them with confidence. Research for this study thus included a comprehensive literature survey of the factors which affect baseflow as well as the approaches that previous studies have utilised to analyse and model baseflow recession. The primary aims of this study were to establish a streamflow database, to construct master recession curves (MRCs) for each catchment under consideration, evaluate the assumption that South African rivers recede exponentially, to determine a representative set of catchment characteristics for use in the baseflow recession analysis, to attempt to explain the MRC trends using these catchment characteristics and to investigate the feasibility of establishing a rule based model for baseflow recession. A streamflow database for South Africa was therefore established. This consisted initially of 202 catchments which were deemed to be recording natural streamflow. MRCs were established for 134 of these catchments. Those MRCs which were established indicate that the majority of South African rivers do not conform to an exponential model of recession. In order to account for the trends defined by the MRCs, catchment area, average catchment slope, drainage density, mean annual precipitation, rainfall concentration, rainfall seasonality, two independent estimates of groundwater recharge and a geological index were calculated for each catchment. Limited success was achieved when the data set was divided into subsets in order to group catchments with similar baseflow recession responses. The geological composition of the catchments appeared to provide the best results in that those trends exhibited by the MRCs could be explained by the types and proportions of the lithologies present. Owing to the lack of readily useable results it was concluded that until further results were forthcoming the development of a rule based model for baseflow recession analysis in South Africa would be premature. The establishment of a readily accessible database containing streamflows and associated catchment characteristics lends itself to future research

Created in the Image of God: A Christian View of Human Personality

It is not the purpose of this paper to provide a theological exposition of the term, image of God. This has been done elsewhere (Barth 1958 p. 192 ff; Berkouwer 1962; Clines 1967; Jewett 1975). It is the purpose of this paper, rather, to explore some of the areas of contact between human personality theory and the Christian understanding of the image of God. The literature that presents human personality within the context of the image of God (Genesis 1:26; 5:2 and 9:6) will be briefly reviewed. This will be followed by an attempt to synthesize the common elements of the literature surveyed. A model will then be advanced that presents the concept of the image of God in a structured form. The paper concludes with a summary statement of the significance of the issues addressed for Christian teachers

Manufacture of DPFC-DMS polymer in the SKG range

BPFC-DMS block copolymers were synthesized on a pre-pilot scale (i.e., to 5 Kg lots) and subsequently fabricated into clear, colorless films. Details of the synthesis procedures, property determinations, and film casting techniques are presented. Solubility, viscosity and molecular weight characteristics of the resulting product are reported

Micrococcal Nuclease Does Not Substantially Bias Nucleosome Mapping

We have mapped sequence-directed nucleosome positioning on genomic DNA molecules using high-throughput sequencing. Chromatins, prepared by reconstitution with either chicken or frog histones, were separately digested to mononucleosomes using either micrococcal nuclease (MNase) or caspase-activated DNase (CAD). Both enzymes preferentially cleave internucleosomal (linker) DNA, although they do so by markedly different mechanisms. MNase has hitherto been very widely used to map nucleosomes, although concerns have been raised over its potential to introduce bias. Having identified the locations and quantified the strength of both the chicken or frog histone octamer binding sites on each DNA, the results obtained with the two enzymes were compared using a variety of criteria. Both enzymes displayed sequence specificity in their preferred cleavage sites, although the nature of this selectivity was distinct for the two enzymes. In addition, nucleosomes produced by CAD nuclease are 8–10 bp longer than those produced with MNase, with the CAD cleavage sites tending to be 4–5 bp further out from the nucleosomal dyad than the corresponding MNase cleavage sites. Despite these notable differences in cleavage behaviour, the two nucleases identified essentially equivalent patterns of nucleosome positioning sites on each of the DNAs tested, an observation that was independent of the histone type. These results indicate that biases in nucleosome positioning data collected using MNase are, under our conditions, not significant