The phytosociology of calcareous grasslands in the British Isles.

The thesis attempts a broad overall survey and classification according to the Zurich-Montpellier system ofplant sociology, of limestone grassland vegetation in the British Isles The classification is based on some 535 grassland Aufnahmen and 75 Aufnahmen of contact communities. In all, some 13 grassland Associations are recognised, whilst the zonal and successional communities are classified in 16 Associations. The Associations are classified in the system of classification advocated by Lohmeyer et al. (1962), and the phytogeographical relationships of the related Association-groups or Alliances are considered in detail. The limestone grassland communities of the British Isles have been found to be representative of four Classes: - (a) Festuco-Brometea - thermophilous dry grassland communities of the sub-mediterranean and sub - atlantic regions of Europe; (b) Elyno-Seslerietea - dry sub-montane, sub-alpine grass heaths of the low alpine region of central Europe and Scandinavia; ( c ) Molinio-Arrhenatheretea - mesophilous, grazed or mown hay meadows and pastures of the lowland zone of western Europe; (d) Violetea calaminariae - open grassland communities IV of heavy metal - rich strata and spoil banks. The thesis is divided into 5 parts : - Part 1 reviews the methods available for a vegetation survey and phytosociological technique in general; outlines the history and status of limestone grasslands; and summarises the methods used for previous description of British vegetation; Part 2 presents the results of the grassland survey and relates the change in overall floristic composition and grassland type to climatic factors using the climate diagrams of Walter & Lieth (1967); Part 3 considers the successional and zonal relationships of these grassland communities, whilst Part 4 discusses the validity of the methods used for the survey and suggests some of the logical extensions of t h is work with reference to the conservation and management of an area limestone grassland on the Magnesian Limestone of Co. Durham. Part 5 comprises 36 Association Tables and an Aufnahmen locality Appendix, and is to be found in the folio volume. References LOHMEYER, W. et a l . (1962). Contribution a 1 ' unification du systeme phytosociologique pour 1'Europe moyenne et nord-occidentale. Melhoramento, 15, 137-151. Walter, H. & Leith, H. (1967). Klimadiagramm Weltatlas. Jena

Personalized Meal Plans as An Intervention to Enhance Dash Diet Adherence in Hypertensive Adults

The Dietary Approach to Stop Hypertension (DASH) diet is more effective as a standalone treatment at lowering blood pressure than any pharmaceutical intervention alone, but adherence is poor and current interventions to improve adherence only show marginal improvements. Personalized meal plans are effective at improving diet adherence in other chronic conditions and may serve as an effective intervention for DASH diet adherence. In a randomized controlled trial, we will determine whether nutritional counseling plus personalized meal planning (intervention) improves DASH adherence more than nutritional counseling alone (control). We will randomize n=178 adults with primary hypertension to either the intervention or control condition and compare DASH adherence scores after 3- and 12-months. Adherence scores will be compared using Student’s t-tests and a 1.56-point change will be considered clinically significant. Improving DASH diet adherence has the potential to improve medical management of hypertension and lessen its massive social and economic burden

Using action research to design and evaluate sustained and inclusive engagement to improve children’s knowledge and perception of STEM careers

Previous research suggests that early experience of and exposure to the world of work is an important predictor of a child’s future involvement in a STEM career. Many interventions have focused on those in secondary education age 11 years and above. Far fewer interventions have explored the impact of STEM outreach engagements among younger age groups. This study investigates the impact of a project that delivered career-driven STEM interventions on young children’s (7–10 years old) career knowledge and perceptions over time. Using an action research approach, this study outlines 10 distinct features for designing child-centred STEM interventions. These were delivered in 6 primary schools across North-East England over a 2-year period. A STEM Career Knowledge and Aspirations Tool was used to collect data to evaluate the impact of these interventions. Children sorted 30 job cards (mix of STEM and non-STEM) into jobs they knew, and also into jobs they would like to do. Baseline data and follow up data were collected in 2015 (n = 352) and 2017 (n = 356). Data analysis suggests the sustained interventions had a particularly positive effect on girls. In 2015 prior to the interventions, girls were significantly less likely than boys to know the following STEM jobs: surveyor, technician and game tester. In 2017, following the sustained intervention, there was no significant difference between boys and girls. Furthermore, one of the STEM jobs, Engineer, showed the greatest increase in the percentage of boys and girls that wanted to do it in 2017 compared to 2015

Blind and pointed Sunyaev-Zel'dovich observations with the Arcminute Microkelvin Imager

In this thesis I introduce the Arcminute Microkelvin Imager. I analyse observations towards known galaxy clusters and I present the initial results from a blind survey for galaxy clusters.In this thesis I discuss my work on the Arcminute Microkelvin Imager (AMI). I focus on the detection of Sunyaev-Zel’dovich (SZ) signatures at 14-18GHz. Once the background science and operation of the instrument are described I proceed to present my contribution to the calibration of AMI, including: primary beam measurements; refinements to the known antenna geometry and flagging geostationary satellite interference. This is followed by an outline of the software that I have developed to subtract sources from visibilities, concatenate data from multiple observations, simulate data, and perform jack-knife tests to evaluate the magnitude of systematic errors. The Bayesian analysis that I use to obtain parameter estimates and to quantify the significance of putative SZ detections is described. I perform realistic simulations of clusters and use these to characterise the analysis. I then, for the first time, apply the analysis to data from the AMI blind cluster survey. I identify several previously unknown SZ decrements. Finally, I conduct pointed observations towards a high luminosity subsample of eight clusters from the Local Cluster Substructure Survey (LoCuSS). For each of these I provide probability distributions of parameters such as mass, radius, and temperature. I compare my results to those in the literature and find an overall agreement

Deep radio observations of the radio halo of the bullet cluster 1E 0657-55.8

We present deep 1.1-3.1 GHz Australia Telescope Compact Array observations of the radio halo of the bullet cluster, 1E 0657-55.8. In comparison to existing images of this radio halo the detection in our images is at higher significance. The radio halo is as extended as the X-ray emission in the direction of cluster merger but is significantly less extended than the X-ray emission in the perpendicular direction. At low significance we detect a faint second peak in the radio halo close to the X-ray centroid of the smaller sub-cluster (the bullet) suggesting that, similarly to the X-ray emission, the radio halo may consist of two components. Finally, we find that the distinctive shape of the western edge of the radio halo traces out the X-ray detected bow shock. The radio halo morphology and the lack of strong point-to-point correlations between radio, X-ray and weak-lensing properties suggests that the radio halo is still being formed. The colocation of the X-ray shock with a distinctive radio brightness edge illustrates that the shock is influencing the structure of the radio halo. These observations support the theory that shocks and turbulence influence the formation and evolution of radio halo synchrotron emission.Comment: 15 pages, 16 figures, 3 tables. Accepted by MNRA

An enquiry into the appropriation of the Byronic hero in Brontë fiction.

Criticism upon the Byronic hero has previously focussed upon Romantic male authors that aimed to tantalise female audiences with their Byronic creations. However, the most enduring examples of Byronic heroes were arguably created by female authors of the Victorian period, in protofeminist texts. The most famous examples of these Byronic appropriations can undoubtedly be found in the works of the Bronte sisters. This thesis aims to examine why the Brontes adopted and modified the Romantic figure of the Byronic Hero, in the Victorian period, and utilised it for their purpose of reassessing female roles.In order to do this, focus will be placed upon the metamorphosis of the Byronic prototype in the Bronte sisters' fiction. My study will commence by examining how the Brontes imitated the Byronic hero of the masculine Romantic tradition in their juvenilia, attempting to assess to what extent this proves problematic for a collection of female authors. My second chapter will consider the transmutation of the Byronic hero into a female form in their most popular works. In doing so it will outline how the Brontes used the form of the female Bildungsroman, regenerating the Byronic heroine for this genre, in order to sustain the difficult balancing act between individualism and socialisation. The final chapter concludes with a discussion of the possible limitations of the Byronic hero (within in the novel form) in Shirley, but examines how Villette attempts to resolve these constraints.This research attempts to differentiate itself from other research within the field, with regard to the Byronic hero, as it aims to contextualise the character-type within both a Victorian setting and women's fiction. In doing so, this work situates itself within the newly emerging body of research which aims to consider female appropriations of Byronism, in connection with questioning the roles of women in nineteenth-century society. This study will interact with critical works from scholars such as Franklin, Lansdown and Wootton. The objective of this research is to explore two under researched areas of criticism: firstly, female appropriations of the Byronic hero (which have often been dismissed as a cliches), and secondly the possibility that the Byronic hero can exist in a female form

CARMA observations of massive Planck-discovered cluster candidates at z>0.5 associated with WISE overdensities: Breaking the size-flux degeneracy

We use a Bayesian software package to analyze CARMA-8 data towards 19 unconfirmed Planck SZ-cluster candidates from Rodriguez-Gonzalvez et al. (2015), that are associated with significant overdensities in WISE. We used two cluster parameterizations, one based on a (fixed shape) generalized-NFW pressure profile and another based on a beta-gas-density profile (with varying shape parameters) to obtain parameter estimates for the nine CARMA-8 SZ-detected clusters. We find our sample is comprised of massive, Y_{500}=0.0010 \pm 0.0015 arcmin^2, relatively compact, theta_{500}= 3.9 \pm 2.0 arcmin systems. Results from the beta model show that our cluster candidates exhibit a heterogeneous set of brightness-temperature profiles. Comparison of Planck and CARMA-8 measurements showed good agreement in Y_{500} and an absence of obvious biases. We estimated the total cluster mass M_{500} as a function of z for one of the systems; at the preferred photometric redshift of 0.5, the derived mass, M_{500} \approx 0.8 \pm 0.2 \times 10^{15} Msun. Spectroscopic Keck/MOSFIRE data confirmed a galaxy member of one of our cluster candidates to be at z=0.565. Applying a Planck prior in Y_{500} to the CARMA-8 results reduces uncertainties for both parameters by a factor >4, relative to the independent Planck or CARMA-8 measurements. We here demonstrate a powerful technique to find massive clusters at intermediate z \gtrsim 0.5 redshifts using a cross-correlation between Planck and WISE data, with high-resolution follow-up with CARMA-8. We also use the combined capabilities of Planck and CARMA-8 to obtain a dramatic reduction by a factor of several, in parameter uncertainties.Comment: 26 pages, 8 figures, appearing in MNRAS (responded to referee report

Another shock for the Bullet cluster, and the source of seed electrons for radio relics

With Australia Telescope Compact Array observations, we detect a highly elongated Mpc-scale diffuse radio source on the eastern periphery of the Bullet cluster 1E0657-55.8, which we argue has the positional, spectral and polarimetric characteristics of a radio relic. This powerful relic (2.3+/-0.1 x 10^25 W Hz^-1) consists of a bright northern bulb and a faint linear tail. The bulb emits 94% of the observed radio flux and has the highest surface brightness of any known relic. Exactly coincident with the linear tail we find a sharp X-ray surface brightness edge in the deep Chandra image of the cluster -- a signature of a shock front in the hot intracluster medium (ICM), located on the opposite side of the cluster to the famous bow shock. This new example of an X-ray shock coincident with a relic further supports the hypothesis that shocks in the outer regions of clusters can form relics via diffusive shock (re-)acceleration. Intriguingly, our new relic suggests that seed electrons for reacceleration are coming from a local remnant of a radio galaxy, which we are lucky to catch before its complete disruption. If this scenario, in which a relic forms when a shock crosses a well-defined region of the ICM polluted with aged relativistic plasma -- as opposed to the usual assumption that seeds are uniformly mixed in the ICM -- is also the case for other relics, this may explain a number of peculiar properties of peripheral relics.Comment: 10 pages, 9 figures, 1 table, accepted for publication in MNRA

Deep LOFAR 150 MHz imaging of the Bo\"otes field: Unveiling the faint low-frequency sky

We have conducted a deep survey (with a central rms of $55\mu\textrm{Jy}$) with the LOw Frequency ARray (LOFAR) at 120-168 MHz of the Bo\"otes field, with an angular resolution of $3.98^{''}\times6.45^{''}$, and obtained a sample of 10091 radio sources ($5\sigma$ limit) over an area of $20\:\textrm{deg}^{2}$. The astrometry and flux scale accuracy of our source catalog is investigated. The resolution bias, incompleteness and other systematic effects that could affect our source counts are discussed and accounted for. The derived 150 MHz source counts present a flattening below sub-mJy flux densities, that is in agreement with previous results from high- and low- frequency surveys. This flattening has been argued to be due to an increasing contribution of star-forming galaxies and faint active galactic nuclei. Additionally, we use our observations to evaluate the contribution of cosmic variance to the scatter in source counts measurements. The latter is achieved by dividing our Bo\"otes mosaic into 10 non-overlapping circular sectors, each one with an approximate area of $2\:\textrm{deg}^{2}.$ The counts in each sector are computed in the same way as done for the entire mosaic. By comparing the induced scatter with that of counts obtained from depth observations scaled to 150MHz, we find that the $1\sigma$ scatter due to cosmic variance is larger than the Poissonian errors of the source counts, and it may explain the dispersion from previously reported depth source counts at flux densities $S<1\,\textrm{mJy}$. This work demonstrates the feasibility of achieving deep radio imaging at low-frequencies with LOFAR.Comment: A\&A in press. 15 pages, 16 figure