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Viscous fingering occurs when one fluid displaces another fluid of a greater viscosity in a porous medium or a Hele-Shaw cell. Linear stability analysis is used to predict methods of suppressing instability. Then, experiments in which nonlinear growth dominates pattern formation are analysed to explore the nonlinear impact of strategies of suppressing finger growth. Often, chemical treatment fluid is injected into oil reservoirs in order to prevent sand production. This treatment fluid is usually followed by water injection to clean up the well. We explore the potential for viscous instability of the interface between the treatment fluid and the water, and also the treatment fluid and the oil, as a function of the volume of treatment fluid and the injection rate and viscosity ratios of the different fluids. For a given volume of treatment fluid and a given injection rate, we find the optimal viscosity of the treatment fluid to minimise the viscous instability. In the case of axisymmetric injection, the stabilisation associated with the azimuthal stretching of modes leads to a further constraint on the optimisation of the viscosity. In the case of oil production, polymers may be added to the displacing water in order to reduce adverse viscosity gradients. We also explore the case in which these polymers have a time-dependent viscosity, for example through the slow release from encapsulant. We calculate the injection flow rate profile that minimises the final amplitude of instability in both rectilinear and axisymmetric geometries. In a development of the model, we repeat the calculation for a shear-thinning rheology. Finally, experiments are analysed in which the nonlinear growth of viscous fingers develops to test the influence of different injection profiles on the development of instability. Diffusion Limited Aggregation (DLA) simulations are performed for comparison. In all cases, the evolving pattern has a saturation distribution, with an inner zone in which the fingers are static and an outer zone in which the fingers advance and grow. In the very centre of the viscous fingering patterns, there is a small fully-saturated region. In the experiments, the mass distribution in the inner zone varies with radius as a power law which relates to the fractal dimension for the analogue DLA simulations. In the outer region the saturation decreases linearly with radius. The radius of the inner frozen zone is approximately 2/3 of the outer radius in the cases of DLA and -- after a period of evolution -- the viscous fingering experiments. This allows the radial extents of the inner and outer zones to be predicted. The ratio of each radius to the extent of the fully-saturated region is independent of the injection profile and corresponds to values for DLA.

The aetiology of autoimmune disease is a complex interplay between genetics, environment and immunological regulation. Our understanding of the genetic aspects of autoimmunity has increased with recent findings from Genome Wide Association Studies (GWAS). There is now a movement towards meta-analyses of GWA studies in order to increase the number of genetic loci detected. There are also efforts to detect common genetic risk factors amongst groups of diseases that potentially share common aetiopathogenic pathways. Animal models have formed the basis of many genetic discoveries and the domestic dog presents a spontaneous model for many diseases, including autoimmunity. Through man’s efforts to create specific breeds, the dog has acquired a genomic architecture consisting of long haplotype blocks and extensive linkage disequilibrium. This means that a GWAS can be conducted in dog breeds with fewer samples and fewer markers than an equivalent study in humans, reducing costs, cohort collection times, and data handling/storage considerations. Successful canine GWA studies are now starting to be published. Building upon this success, the findings from GWA studies in three canine autoimmune diseases (across six different breeds), with equivalent human pathologies, are presented. Dogs with diabetes mellitus (similar to latent autoimmune diabetes of adulthood in man), lymphocytic thyroiditis (similar to Hashimoto’s thyroiditis), and anal furunculosis (similar to perianal Crohn’s disease) were compared to control dogs to identify genetic susceptibility loci underlying disease. Follow-up genotyping of the top hits from the GWAS analyses were conducted to replicate findings and to better characterise the diseases across a number of dog breeds. Typing of MHC class II genes, important in the immune response, was also undertaken in canine diabetes mellitus and canine lymphocytic thyroiditis. In anal furunculosis, high-throughput, next-generation sequencing was utilised to identify novel mutations and fine-map associations at discovered loci. Several genes were identified in all of these canine autoimmune diseases, many with good candidate function. Some of these genes indicated common genetic susceptibility loci and pathways between canine autoimmune diseases. Breed-specific genetic effects underlying canine diabetes mellitus and canine lymphocytic thyroiditis were identified, which has implications for disease diagnosis and clinical management. Novel loci for investigation in the corresponding human disease studies have been identified and future work will begin to genetically link the conditions in dog and man.

Self-modulated laser wakefield acceleration (SM-LWFA) of electrons, driven by picosecond, kilojoule class laser systems is a promising method to produce versatile x-ray sources. The electron beams, accelerated up to ≈300 MeV, are used to produce broadband (keV to MeV), low divergence (¡ 50 mrad), high photon number (>10¹⁰ photons/keV/sr) x-ray sources utilizing betatron, inverse Compton scattering, and bremsstrahlung generation mechanisms. The x-ray energy spectrum and source size can be tuned by controlling the SM-LWFA directly or the x-ray generation mechanism to provide an optimized source for radiography applications. We will discuss experimental results on electron beam and x-ray source characterization, obtained at the Jupiter Laser Facility (LLNL), and supported by 2D and 3D Particle-In-Cell simulations. Additionally, we will show several static radiography applications relevant to high energy density science and inertial confinement fusion experiments and how this source can be tuned to improve image quality in radiography. X-ray analysis tools have been developed to measure high energy x-ray spectra, source size, and radiography quality, and we have used LLNL’s x-ray ray tracing code HADES to simulate radiographic images of experimental objects and help in planning for future experiments and applications. Finally, MeV x-ray source characterization and radiography applications are explored using laser-solid interactions enhanced by compound parabolic concentrators (CPC). This work was performed under the auspices of the U.s. Department of Energy under Contract No. DE-AC52-07NA27344, DE-SC0019010, DE-SC0010064 (UCLA), DE-SC0021057, NNSA grant DE-NA0003873 (UCLA) and NSF grants 1806046, 1804463, 1734315, and 2003354 (UCLA), LLNL subcontract B634451, FA9550-14-1-0045, and supported by the DOE Office of Science Early Career Research Program (Fusion Energy Sciences) under SCW1575-1.