Fabrication of mesoscale topographical gradients in bulk titanium and their use in injection moulding

Fabrication methods for titanium substrates exhibiting continuous micro and nano scale arrays, with increasing feature heights over the length of the array are reported. The resultant feature heights spanned 0–2 μm. Patterned gradient arrays of circular features with diameters of: 500 nm, 1 μm and 2 μm, spaced by twice the diameter were manufactured by the process using specially prepared titanium substrates. Patterns were exposed by electron beam lithography and the length of the patterned arrays was 15 mm or 20 mm. This work presents two selectivity amplification processes to achieve a gradient of feature heights ranging over the titanium array after consecutive reactive ion etching processes. The first, route A: a HSQ on Ti, gradient amplification process. The second, route B, a SiO2 layer amplification transfer into Ti. The crucial initial gradient component deposited for the amplification process for both routes was a diffusion limited plasma polymerised hexane gradient. Etching using respective reactive ion etch chemistries for each gradient transfer through the various selectivity amplification layers (employing consecutive etch steps, in this way) enables a dual amplification for each route to manufacture. The original gradient is transferred into titanium as a function of the sum of the respective selectivities between the materials, using the appropriate dry etch plasma conditions. The substrates henceforth are referred to as inlays, and were tested for use as a high throughput platform for polymer replication by injection moulding. It is envisaged that the fabrication methodology and resultant topographies have use in a range of engineering applications. The overall selectivity to Ti for polymerised hexane is increased by more than 20 times using each dual amplification process

The evolution and performance of river basin management in the Murray-Darling Basin

We explore bioregional management in the Murray-Darling Basin (MDB) in Australia through the institutional design characteristics of the MDB River Basin Organization (RBO), the actors and organizations who supported and resisted the establishment of the RBO, and the effectiveness of the RBO. During the last 25 years, there has been a major structural reform in the MDB RBO, which has changed from an interstate coordinating body to an Australian government agency. Responsibility for basin management has been centralized under the leadership of the Australian government, and a comprehensive integrated Basin plan has been adopted. The driving forces for this centralization include national policy to restore river basins to sustainable levels of extraction, state government difficulties in reversing overallocation of water entitlements, the millennium drought and its effects, political expediency on the part of the Australian government and state governments, and a major injection of Australian government funding. The increasing hierarchy and centralization of the MDB RBO does not follow a general trend toward multilevel participative governance of RBOs, but decentralization should not be overstated because of the special circumstances at the time of the centralization and the continuing existence of some decentralized elements, such as catchment water plans, land use planning, and water quality. Further swings in the centralization–decentralization pendulum could occur. The MDB reform has succeeded in rebalancing Basin water allocations, including an allocation for the environment and reduced diversion limits. There are some longer term risks to the implementation of reform, including lack of cooperation by state governments, vertical coordination difficulties, and perceived reductions in the accountability and legitimacy of reform at the local level. If implementation of the Basin plan is diverted or delayed, a new institution, the Commonwealth Environmental Water Holder, can play a major role in securing and coordinating environmental water supplies

How can subnational governments deliver their policy objectives in the age of austerity? Reshaping homelessness policy in Wales

This article explores how a devolved government in a small country, faced with external constraints beyond its immediate control, can deploy policy resources to shape a distinctive approach to public services. We analyse recent homelessness policy in Wales using the NATO (Nodality, Authority, Treasure, Organisation) typology of tools of government proposed by Hood and Margetts, and show how this can be applied usefully to understand the choices that governments must make in conducting relationships with other institutions. We conclude that a combination of Nodality and Authority provide powerful resources for a subnational government which has only limited formal powers and fiscal autonomy

Prelates as part-time Parliamentarians: The attendance and participation of the Lords Spiritual in the contemporary House of Lords

As full-time Church of England diocesan bishops, the Lords Spiritual are necessarily very much part-time Parliamentarians. This presents them with challenges in terms of maintaining a presence, and demonstrating its legitimacy, in an increasingly ‘professionalised’ House of Lords. This article draws on original interviews to explore the factors which shape the Bishops’ attendance and participation in the House of Lords. It suggests that although long-standing constraints on their attendance have persisted and indeed increased in recent decades, they have nonetheless found ways to maintain and increase their Parliamentary activity in the light of changes in the Church, Parliament and society

Why did Frank Field fail? New Labour and welfare reform, 1997-8.

This thesis considers the development of welfare reform policy by the British Labour government in the period 1997-8, with a particular emphasis on the role and ideas of Frank Field, Minister of State for welfare reform from May 1997 to July 1998. It examines the significance of welfare reform to the New Labour project and the competing positions associated with Field and with (Chancellor of the Exchequer) Gordon Brown in the 1990s, with an in-depth discussion of Field's broader political philosophy and of his ministerial career, and of Brown's political philosophy with particular reference to welfare policy. We broadly adopt a model of structure and agency to explain the direction which welfare reform took under the first Blair government, and conclude that there are two reasons why Field's ideas did not prove to be the model for the government's welfare reform programme. The first, and lesser, reason relates to Field's performance as an actor in core executive politics. Field, we argue, misunderstood the contingent and negotiated nature of power in the core executive, and the structures which constrain capacity to act within it. The second, and ultimately more significant reason, is that Field's philosophy- in particular, his beliefs about the role of the state- was fundamentally incompatible with the discourse of New Labour, which emphasised an active state as an engine of national economic and social well-being. Brown's views, by contrast, were well-integrated with this discourse. The need for consistency with this discourse thus constrained New Labour's freedom of action in respect of welfare reform

Avian Resistance to Campylobacter jejuni Colonization Is Associated with an Intestinal Immunogene Expression Signature Identified by mRNA Sequencing

peer-reviewedThis research was funded by the The Irish Department of Agriculture and Food’s Food Institutional Research Measure (http://www.agriculture.gov.ie/ research/foodinstitutionalresearchmeasurefirm) – Grant No: 06_RDD_486.Campylobacter jejuni is the most common cause of human bacterial gastroenteritis and is associated with several post-infectious manifestations, including onset of the autoimmune neuropathy Guillain-Barré syndrome, causing significant morbidity and mortality. Poorly-cooked chicken meat is the most frequent source of infection as C. jejuni colonizes the avian intestine in a commensal relationship. However, not all chickens are equally colonized and resistance seems to be genetically determined. We hypothesize that differences in immune response may contribute to variation in colonization levels between susceptible and resistant birds. Using high-throughput sequencing in an avian infection model, we investigate gene expression associated with resistance or susceptibility to colonization of the gastrointestinal tract with C. jejuni and find that gut related immune mechanisms are critical for regulating colonization. Amongst a single population of 300 4-week old chickens, there was clear segregation in levels of C. jejuni colonization 48 hours post-exposure. RNAseq analysis of caecal tissue from 14 C. jejuni-susceptible and 14 C. jejuni-resistant birds generated over 363 million short mRNA sequences which were investigated to identify 219 differentially expressed genes. Significantly higher expression of genes involved in the innate immune response, cytokine signaling, B cell and T cell activation and immunoglobulin production, as well as the renin-angiotensin system was observed in resistant birds, suggesting an early active immune response to C. jejuni. Lower expression of these genes in colonized birds suggests suppression or inhibition of a clearing immune response thus facilitating commensal colonization and generating vectors for zoonotic transmission. This study describes biological processes regulating C. jejuni colonization of the avian intestine and gives insight into the differential immune mechanisms incited in response to commensal bacteria in general within vertebrate populations. The results reported here illustrate how an exaggerated immune response may be elicited in a subset of the population, which alters host-microbe interactions and inhibits the commensal state, therefore having wider relevance with regard to inflammatory and autoimmune disease

Investigating the influence of the core material on the mechanical performance of a nitinol wire wrapped helical auxetic yarn.

Helical Auxetic Yarns (HAYs) can be used in a variety of applications, from healthcare to blast and impact resistance. This work focuses on the effect of the use of different core materials (e.g. rubber, polyurethane, polytetrafluoroethylene/teflon, polypropylene, polyetheretherketone, polycarbonate, acetal) with a nitinol wire wrap component on the maximum Negative Poisson Ratio (NPR) produced, and therefore the auxetic performance of Helical Auxetic Yarns (HAYs). From the analytical model, it was found that an acetal core produced the largest NPR when compared to the other six materials. The trend obtained from the experimental tensile tests (validation) correlated closely with the theoretical predictions of the NPR as axial strain was increased. The experimental method presented a maximum NPR at an average axial strain of 0.148, which was close to the strain of 0.155 predicted by theory. However, the maximum experimental NPR was significantly lower than that predicted by the analytical model

The Use of Molecular Dynamics to Predict the Stability of Squaraine Rotaxanes

Squaraine rotaxanes are fluorescent molecules comprised of two parts—a dumbbell-shaped squaraine dye threaded through a ring-shaped macrocycle—that are held together by hydrogen bonding, hydrophobic effects, and the size of the opening in the macrocycle1. Since the squaraine is an extremely electrophilic species3, nucleophilic attack by water is possible when it slips out of the macrocycle. This results in a loss of fluorescence. These near-IR dyes have many applications, including effective labeling of bacterial cells4. Previous studies have shown that the unprotected squaraine dye is unstable, and the adamantyl rotaxane degrades over time while the isophthalamidyl and pyridinyl rotaxanes remain stable2(Fig. 2). In this study, we aim to determine if molecular dynamics (MD) is an effective method of ascertaining the relative stabilities of squaraine rotaxanes in solution

Can meso-governments use metagovernance tools to tackle complex policy problems?

In recent years, a range of countries have devolved significant powers, responsibilities and funding to the regional level. This paper explores how and why the resulting meso-governments may use the tools of metagovernance. A detailed empirical analysis of homelessness policy in Wales found that skilful deployment of metagovernance tools enabled its meso-government to exploit the advantages of geographical and relational proximity to policy communities, while mitigating some of the constraints of its intermediate constitutional status, including limited formal powers and policy capacity. Junior government officials played multiple roles in homelessness networks, shaping and steering them through active network management while also participating in them. This ‘governor-participant’ role blurs the distinction made in the existing literature between ‘hands-on’ and ‘hands-off’ metagovernance tools. It also shows that, in the case of meso-governments at least, it is possible for low-ranking officials to exercise greater agency in policy development than has previously been assumed