Five year prognosis in patients with angina identified in primary care : incident cohort study

Peer reviewedPublisher PD

Identifying overlooked mechanisms for organic phosphorus and nitrogen acquisition in environmental bacteria

All living organisms require phosphorus (P) and nitrogen (N), which exist in many forms, from inorganic phosphate (Pi) or ammonium, to multiple and diverse organic P (Po) and N molecules. As essential elements, bacteria possess multiple mechanisms that allow them to acquire P and N from their surrounding environment. Many environmental niches, including regions of the global ocean and the rhizosphere of crop plants, exhibit N and P limitation, and thus bacteria must possess mechanisms to overcome this nutrient limitation. Over the past seven years, I have contributed to, and led, research uncovering hitherto overlooked mechanisms for N and P acquisition and characterising others. This research has resulted in several published papers, including two first author papers within this field as outputs. In particular, I have contributed to research into the mechanisms displayed by rhizobacteria associated with oilseed rape (Brassica napus), including Pseudomonas and Flavobacteria spp., using analysis of proteomics data. The biological insights provided from this work were used to develop further foci of study, including the activity, functional role and distribution of a newly identified phosphatase, and the extracellular activity of Po-mineralising enzymes and its consequences for Pi availability. I have also led research into the identification, characterisation, and environmental distribution of 2-aminoethylphosphonate (2AEP) transporters, showing a novel 2AEP transporter to be the most transcribed phosphonate transporter in the global ocean. I followed this research with further investigation into the molecular mechanisms underpinning the regulation of 2AEP transport and degradation in Pseudomonas putida BIRD-1. By utilising my developed skill sets in both wet lab and bioinformatics techniques, I also contributed to papers investigating lipid remodelling, a mechanism by which bacteria reduce the quantity of phospholipids in their lipid membranes, in both environmental and pathogenic bacteria. Additionally, I have contributed to, and written, other papers within the field of environmental microbiology, which go beyond the scope of this thesis. As such, the works presented in this thesis represent a coherent body of work demonstrating my contribution to the research field

Relationships of Biomass-Burning Aerosols to Ice in Orographic Wave Clouds

Ice concentrations in orographic wave clouds at temperatures between −24° and −29°C were shown to be related to aerosol characteristics in nearby clear air during five research flights over the Rocky Mountains. When clouds with influence from colder temperatures were excluded from the dataset, mean ice nuclei and cloud ice number concentrations were very low, on the order of 1–5 L^(−1). In this environment, ice number concentrations were found to be significantly correlated with the number concentration of larger particles, those larger than both 0.1- and 0.5-μm diameter. A variety of complementary techniques was used to measure aerosol size distributions and chemical composition. Strong correlations were also observed between ice concentrations and the number concentrations of soot and biomass-burning aerosols. Ice nuclei concentrations directly measured in biomass-burning plumes were the highest detected during the project. Taken together, this evidence indicates a potential role for biomass-burning aerosols in ice formation, particularly in regions with relatively low concentrations of other ice nucleating aerosols

Observation of playa salts as nuclei in orographic wave clouds

During the Ice in Clouds Experiment-Layer Clouds (ICE-L), dry lakebed, or playa, salts from the Great Basin region of the United States were observed as cloud nuclei in orographic wave clouds over Wyoming. Using a counterflow virtual impactor in series with a single-particle mass spectrometer, sodium-potassium-magnesium-calcium-chloride salts were identified as residues of cloud droplets. Importantly, these salts produced similar mass spectral signatures to playa salts with elevated cloud condensation nuclei (CCN) efficiencies close to sea salt. Using a suite of chemical characterization instrumentation, the playa salts were observed to be internally mixed with oxidized organics, presumably produced by cloud processing, as well as carbonate. These salt particles were enriched as residues of large droplets (>19 μm) compared to smaller droplets (>7 μm). In addition, a small fraction of silicate-containing playa salts were hypothesized to be important in the observed heterogeneous ice nucleation processes. While the high CCN activity of sea salt has been demonstrated to play an important role in cloud formation in marine environments, this study provides direct evidence of the importance of playa salts in cloud formation in continental North America has not been shown previously. Studies are needed to model and quantify the impact of playas on climate globally, particularly because of the abundance of playas and expected increases in the frequency and intensity of dust storms in the future due to climate and land use changes

Clinical effectiveness and cost-effectiveness of open and arthroscopic rotator cuff repair [the UK Rotator Cuff Surgery (UKUFF) randomised trial]

Peer reviewedPublisher PD

Five-Year Prognosis in an Incident Cohort of People Presenting with Acute Myocardial Infarction

Peer reviewedPublisher PD

SGAS 143845.1+145407: A Big, Cool Starburst at Redshift 0.816

We present the discovery and a detailed multi-wavelength study of a strongly-lensed luminous infrared galaxy at z=0.816. Unlike most known lensed galaxies discovered at optical or near-infrared wavelengths this lensed source is red, r-Ks = 3.9 [AB], which the data presented here demonstrate is due to ongoing dusty star formation. The overall lensing magnification (a factor of 17) facilitates observations from the blue optical through to 500micron, fully capturing both the stellar photospheric emission as well as the re-processed thermal dust emission. We also present optical and near-IR spectroscopy. These extensive data show that this lensed galaxy is in many ways typical of IR-detected sources at z~1, with both a total luminosity and size in accordance with other (albeit much less detailed) measurements in samples of galaxies observed in deep fields with the Spitzer telescope. Its far-infrared spectral energy distribution is well-fit by local templates that are an order of magnitude less luminous than the lensed galaxy; local templates of comparable luminosity are too hot to fit. Its size (D~7kpc) is much larger than local luminous infrared galaxies, but in line with sizes observed for such galaxies at z~1. The star formation appears uniform across this spatial scale. In this source, the luminosity of which is typical of sources that dominate the cosmic infrared background, we find that star formation is spatially extended and well organised, quite unlike the compact merger-driven starbursts which are typical for sources of this luminosity at z~0.Comment: 18 pages, 10 figure