Translational Symmetry Breaking in Higgs & Gauge Theory, and the Cosmological Constant

We argue, at a very basic effective field theory level, that higher dimension operators in scalar theories that break symmetries at scales close to their ultraviolet completion cutoff, include terms that favour the breaking of translation (Lorentz) invariance, potentially resulting in striped, chequered board or general crystal-like phases. Such descriptions can be thought of as the effective low energy description of QCD-like gauge theories near their strong coupling scale where terms involving higher dimension operators are generated. Our low energy theory consists of scalar fields describing operators such as $\bar{q} q$ and $\bar{q} F^{(2n)} q$. Such scalars can have kinetic mixing terms that generate effective momentum dependent contributions to the mass matrix. We show that these can destabilize the translationally invariant vacuum. It is possible that in some real gauge theory such operators could become sufficiently dominant to realize such phases and it would be interesting to look for them in lattice simulations. We present a holographic model of the same phenomena which includes RG running. A key phenomenological motive to look at such states is recent work that shows that the non-linear response in $R^2$ gravity to such short range fluctuations can mimic a cosmological constant. Intriguingly in a cosmology with such a Starobinsky inflation term, to generate the observed value of the present day acceleration would require stripes at the electroweak scale. Unfortunately, low energy phenomenological constraints on Lorentz violation in the electron-photon system appear to strongly rule out any such possibility outside of a disconnected dark sector.Comment: 9 pages, 1 figure; minor changes. Version to be published in PR

Investigating the use of Ionic Liquids as a novel magnetic lubricant

The main body of this work explores ionic liquids (ILs) to be used as a magnetic lubricant and sealant in a vacuum pump. The problem has arisen due to upcoming legislation governed by the Stockholm Convention with respect to persistent organic pollutants; where the current lubricant falls into this category due to it’s fluorinated composition and it’s inability to decompose naturally. Other factors include the current lubricant’s high viscosity and difficulty in removing and cleaning the parts of the pump where the lubricant has come into contact. Further to this, due to a gap in the current market it was hypothesized that a magnetic lubricant could enhance performance by using a magnetic field to hold the lubricant in the relevant parts of the pump, enabling less lubricant to be used, whilst also being used to create a seal and in turn enhance performance of the vacuum pump. In addition to this, a contribution to the IL modelling field with respect to XPS is completed, where novel dicationic ILs are modelled with respect to the C1s region using models derived and developed from existing methods. 12 core samples based on ionic liquids with paramagnetic anions derived from Fe3+ and Dy3+ and imidazolium or pyridinium-based cations are explored as lubricants. Key tests were performed to begin collecting data to allow for informed decisions on what samples may be more suitable for purpose. Viscosity measurements were performed using a Brookfield DV-III digital rheometer equipped with a small sample adapter at room temperature initially, followed by ramped measurements up to 80 °C and then followed by viscosity index (VI) calculations. VI calculations require a known density of the sample, this was completed by weighing 1 mL of the sample at room temperature, this was a fixed density where it is known density will decrease with a temperature increase. Thermal stability was measured using thermogravimetric analysis on a ramped rate moving from room temperature up to 450 °C at a rate of 10 °C per minute. Contact angles were measured on three different substrates namely steel aluminium and a fluoroelastomer comprised of hexafluoropropylene and vinylidene fluoride. The method used a Krüss DSA 25E contact angle goniometer with a standard automated syringe dosing unit, applying the touch on method where an average timed dynamic measurement was recorded. Paramagnetism was measured using an Evans balance and friction behaviour. Specifically, the coefficient of friction was measured using a Bruker UMT Tribolab. This test made used of a ball of specified material applied at a specified force onto a steel plate which reciprocated at a specified Hz with a small amount of sample applied between the surfaces. Further to this, a surface profilometer was employed to analyse the wear scar left on the steel plate after the test had been completed using a Bruker DektakXT stylus profilometer. Friction behaviour also entails analysis of the sample after being subjected to friction testing to determine any chemical composition changes utilising X-Ray Photoelectron Spectroscopy (XPS) and infrared (IR) spectroscopy. At this point, trends relating chemical composition to physical properties have began to be deduced; whereby in it’s simplest form extending the alkyl chain component of the cation within the ionic liquid generally results in an increase in viscosity as well as a decrease in density. With regards to VI, increasing the alkyl chain length results in a decrease in VI. The same effect of alkyl chain length on contact angle can be seen whereby a longer alkyl component results in a decrease in contact angle for all surfaces investigated. The 12 core samples all displayed a paramagnetic response to the Evans balance with the Dysprosium samples showing a higher magnetic moment than the Iron-based samples, an expected result. Work involving coefficient of friction experiments also found that the core samples gave lower COF values than the control lubricants, but XPS discovered the short chain ionic liquid samples were potentially less stable than their longer chain counterparts when compared to their original state based on changes to their spectra for before and after COF studies, IR spectroscopy also deduced subtle changes in composition. The work finishes with one sample being scaled up, based on performances in previous tests and tested in a live pump with mixed results. Despite performing well as a lubricant relative to two control lubricants, compatibility issues arise resulting in problematic changes in chemical and physical composition of the scaled-up sample. The remainder of the work covered troubleshooting the scaled-up sample by utilising the same previous analytical tools such as XPS and IR but also covered Mass Spectrometry (MS). This was used to determine potential impurities present in the used sample and inform on potential degradation pathways. This troubleshooting phase concluded that residual Fomblin (the control lubricant used previously) was causing contamination when analysing with XPS, further to this MS found peaks relating to a brand of antioxidants, known as Irganox which is likely to be from its use as an additive in Fomblin. Furthermore, an unexpected result in this work was the magnetic properties of the samples were deemed not strong enough to fulfil their original objective; this resulted in further work being completed to remedy the issue. Initially, inspired by ferrofluids it was hypothesised that perhaps an ionic liquid could be used as the carrier solvent for magnetic nanoparticles as an option to boost magnetism based on magnetite, Fe3O4 following a co-precipitation method. Confirmation of nanoparticle synthesis was completed using XRD with peaks matching a reference sample taken from ICSD. However, difficulties were experienced with relation to nanoparticle stability within the ionic liquid. Surfactants were briefly explored based on oleic acid and decyl, methylimidazolium bromide with no positive results. Novel in-situ methods using an ionic liquid as reaction media for the preparation of magnetite were explored with preliminary dynamic light scattering (DLS) measurements suggesting differences in size of nanoparticle relating to ionic liquid being used as the medium. Further novelty was beginning to be explored with respect to a new type of poly(Ionic Liquid) based on a dysprosium anion. There were difficulties in characterizing the new material which leaves room for future work, however again the paramagnetic response despite being larger than the core samples explored was still not deemed strong enough for manipulation with a typical magnet. In summary, this work has demonstrated that ionic liquids can be used as a lubricant in a vacuum pump, purely as a lubricant as opposed to a lubricant and sealant which was the aim of this project. The scaled up sample performed well on performance of the pump however clearly it had degraded over the 2000 hours that it had run for. The inability to be manipulated with a standard magnet raised issues quickly with respect to utilising as a sealant within the pump. However, these issues enabled further work to be explored including nanoparticles and polymers and despite only being in the preliminary stages offers optimism that both objectives could perhaps be achieved. This work offers further insight into how ionic liquids may perform in large scale experiments as opposed to bench top experiments in the laboratory. It has been seen that COF measurements may not give the full picture of how ionic liquids perform as lubricants as demonstrated by the unanticipated degradation when in the live test pump. But with respect to the test pump, this is a great contribution to the field where it is believed this type of experiment has not been reported in the literature to date

Evaluation of patient perception towards dynamic health data sharing using blockchain based digital consent with the Dovetail digital consent application : a cross sectional exploratory study

Background New patient-centric integrated care models are enabled by the capability to exchange the patient’s data amongst stakeholders, who each specialise in different aspects of the patient’s care. This requires a robust, trusted and flexible mechanism for patients to offer consent to share their data. Furthermore, new IT technologies make it easier to give patients more control over their data, including the right to revoke consent. These characteristics challenge the traditional paper-based, single-organisation-led consent process. The Dovetail digital consent application uses a mobile application and blockchain based infrastructure to offer this capability, as part of a pilot allowing patients to have their data shared amongst digital tools, empowering patients to manage their condition within an integrated care setting. Objective To evaluate patient perceptions towards existing consent processes, and the Dovetail blockchain based digital consent application as a means to manage data sharing in the context of diabetes care. Method Patients with diabetes at a General Practitioner practice were recruited. Data were collected using focus groups and questionnaires. Thematic analysis of the focus group transcripts and descriptive statistics of the questionnaires was performed. Results There was a lack of understanding of existing consent processes in place, and many patients did not have any recollection of having previously given consent. The digital consent application received favourable feedback, with patients recognising the value of the capability offered by the application. Patients overwhelmingly favoured the digital consent application over existing practice. Conclusions Digital consent was received favourably, with patients recognising that it addresses the main limitations of the current process. Feedback on potential improvements was received. Future work includes confirmation of results in a broader demographic sample and across multiple conditions

IL-17 can be protective or deleterious in murine pneumococcal pneumonia

Streptococcus pneumoniae is the major bacterial cause of community-acquired pneumonia, and the leading agent of childhood pneumonia deaths worldwide. Nasal colonization is an essential step prior to infection. The cytokine IL-17 protects against such colonization and vaccines that enhance IL-17 responses to pneumococcal colonization are being developed. The role of IL-17 in host defence against pneumonia is not known. To address this issue, we have utilized a murine model of pneumococcal pneumonia in which the gene for the IL-17 cytokine family receptor, Il17ra, has been inactivated. Using this model, we show that IL-17 produced predominantly from γδ T cells protects mice against death from the invasive TIGR4 strain (serotype 4) which expresses a relatively thin capsule. However, in pneumonia produced by two heavily encapsulated strains with low invasive potential (serotypes 3 and 6B), IL-17 significantly enhanced mortality. Neutrophil uptake and killing of the serotype 3 strain was significantly impaired compared to the serotype 4 strain and depletion of neutrophils with antibody enhanced survival of mice infected with the highly encapsulated SRL1 strain. These data strongly suggest that IL-17 mediated neutrophil recruitment to the lungs clears infection from the invasive TIGR4 strain but that lung neutrophils exacerbate disease caused by the highly encapsulated pneumococcal strains. Thus, whilst augmenting IL-17 immune responses against pneumococci may decrease nasal colonization, this may worsen outcome during pneumonia caused by some strains

A manifesto for cyborg pedagogy?

This paper was published in International Research in Geographical and Environmental Education, 10 (2), pp. 195 - 201, 2001. © 2001 T. Angus et al.This paper seeks to give an impression of what can happen if teachers encourage their students to take personally the issues they study, and to think and to write about how their identities and everyday lives are inseparable from the kinds of issues studied in the geography classroom. It discusses three principles – situated knowledge, cyborg ontologies and border pedagogy – which have guided the organisation of an undergraduate course on the geographies of material culture. This attempts to get students to think through their connections with the lives of distant others through simple acts of consumption, and the responsibilities which they might therefore have. This paper illustrates the kinds of student writing that can come out of such a course and the ways in which this issue of responsibility should be, and is, talked about

Using Part-time Working to Support Graduate Employment: Needs and Perceptions of Employers

An exploration of the value attached to the work experience of graduates, and particularly the value of part-time working whilst studying for a degree, from an employer’s perspective, is reported. A documentary analysis of graduate recruiters was conducted to assess the extent to which work experience was specified for graduate employment programmes. Further interviews were then carried out with a sample of small and medium-sized enterprises (SMEs) to explore how the part-time working of graduates is perceived by employers. Work experience is deemed to be important to employers, not only as a differentiator but also as a measure of how graduates will perform in-post. Employers generally signalled the value of work experience, but indicated that graduates did not make best use of it in their job applications. It is argued that the findings will provide information to universities and educators about the contribution and importance of students’ part-time working in terms of graduate employment prospects and with respect to the employability agenda in the HE curriculum in the UK

How the network properties of shareholders vary with investor type and country

We construct two examples of shareholder networks in which shareholders are connected if they have shares in the same company. We do this for the shareholders in Turkish companies and we compare this against the network formed from the shareholdings in Dutch companies. We analyse the properties of these two networks in terms of the different types of shareholder. We create a suitable randomised version of these networks to enable us to find significant features in our networks. For that we find the roles played by different types of shareholder in these networks, and also show how these roles differ in the two countries we study