Progress Report: Application of the Multiblock Method in Computational Aerodynamics. Aero Report 9621

This report serves as a record of the progress made since October 1995 as a postgraduate research student smdying in the field of computational aerodynamics. The area of interest is the application of the multiblock method to examine real problems in aerodynamics. The experience gained in using various multiblock grid generation packages is discussed, along with an examination of the load balancing problem for parallel execution of aerodynamic flow solvers. Some initial results from the development of a static load balancer based on the method of simulated annealing are presented

Morphological traits and density of foundation species modulate a facilitation cascade in Australian mangroves.

Facilitation cascades are critical to the maintenance of biodiversity in a variety of habitats. Through a series of two experiments, we examined how the morphological traits and density of interacting foundation species influence the establishment and persistence of a facilitation cascade in temperate Australian mangrove forests. In this system, mangrove pneumatophores trap the free-living alga, Hormosira banksii, which, in turn, supports dense and diverse assemblages of epifaunal mollusks. The first experiment, which manipulated pneumatophore height and density, revealed that these two traits each had additive negative effects on the establishment, but additive positive effects on the persistence of the cascade. High densities of tall pneumatophores initially served as a physical barrier to algal colonization of pneumatophore plots, but over the longer-term enhanced the retention of algae. The increased algal biomass, in turn, facilitating epifaunal colonization. The second experiment demonstrated that the retention of algae by pneumatophores was influenced more by algal thallus length than vesicle diameter, and this effect occurred independent of pneumatophore height. Our study has extended facilitation theory by showing that the morphological traits and density of basal and intermediary facilitators influence both the establishment and persistence of facilitation cascades. Hence, attempts to use foundation species as a tool for restoration will require an understanding not only of the interactions among these, but also of the key traits that modify interrelationships

Graft-versus-host disease: a case report of a rare but reversible cause of constrictive pericarditis

BACKGROUND: Constrictive pericarditis (CP), although an uncommon cause of heart failure, requires specialist multidisciplinary input and multi-modality imaging to identify the underlying aetiology and treat potentially reversible causes. CASE SUMMARY: We report the case of a 74-year-old gentleman referred for assessment of progressive exertional dyspnoea and peripheral oedema, 30 months following treatment of acute myeloid leukaemia with high-dose chemotherapy and allogeneic stem cell transplantation. Clinical examination and cardiac imaging revealed a small pericardial effusion and pericardial thickening with constrictive physiology; however, no aetiology was identified despite diagnostic pericardiocentesis. The patient required recurrent hospital admissions for intravenous diuresis, therefore, following multidisciplinary discussions, surgical partial pericardectomy was performed. Histology suggested graft-vs.-host disease (GvHD) and post-operatively, the patient improved clinically. Following immunomodulatory therapy with ruxolitinib for both pericardial and pulmonary GvHD, his functional status improved further with no subsequent hospital admissions. DISCUSSION: Although pericardial disease in cancer patients is common, CP is unusual. Determining the underlying aetiology is important for subsequent management, and here, we describe the use of multi-modality imaging to diagnose a rare cause, GvHD, which responded to surgical treatment and immunomodulatory therapy

Application of the multiblock method in computational aerodynamics

The main challenge in computational aerodynamics is to provide practical, credible, cost and schedule effective methods for routine design application and for full integration of these methods into the design cycle. Although advances in physical modelling and solution algorithms are continuing requirements of the aerospace industry, other more practical difficulties also impede the full realisation of the potential of existing methods. The contribution of this thesis is to examine and tackle several of these issues and to evaluate computational aerodynamics as a tool for engineering design and scientific enquiry. An advanced computational aerodynamics method is evaluated as an engineering tool for axisymmetric forebody and base flow problems. First the adaption of an existing two-dimensional flow solver to axisymmetric flow is described, then specific test cases are considered. The motivation for creating an axisymmetric flow solver is the considerable performance improvements compared to a fully three-dimensional method. The accuracy and robustness of the method are very good for forebody problems. For base flow problems accuracy and robustness are less satisfactory, although the performance of other prediction methods is also poorer for this more demanding problem. For both problem types the speed of the flow solver, the required computing resource and the time and effort necessary for pre- and post-processing are all satisfactory for routine calculation in an engineering environment. Shock reflection hysteresis and plume structure in a low density, axisymmetric highly underexpanded air jet is examined using a Navier-Stokes flow solver. This type of jet is found in a number of applications e.g. rocket exhausts and fuel injectors. The plume structure is complex, involving the interaction of several flow features, making this a demanding problem. Two types of shock reflection appear to occur in the plume, regular and Mach, depending on the jet pressure ratio. The existence of a dual solution domain where either type may occur has been predicted, in agreement with experiment where the same phenomenon has been observed for a nitrogen jet. There is a hysteresis in the shock reflection type; the reflection type observed in the dual solution domain depends on the time history of the plume development. A quasi-steady approach is employed in order to calculate the entire hysteresis loop. The results of the computational study are used to examine the structure of the plume, and are compared with experimental data where possible. Some flow features not initially recognised from experiment have been identified, notably curvature of the Mach disc, recirculation behind the Mach disc and the 'regular' reflection having Mach reflection characteristics. Included in the study is a review of the two dimensional shock reflection hysteresis problem to establish a theoretical background. The value of CFD as a tool for scientific investigation is clearly demonstrated by this study. The need for automation of the multiblock grid generation process is discussed. A new approach to automatically process a multiblock topology in order to prepare it for the grid generation process is described. The method is based on a cost function which attempts to model the objectives of the skilled grid generation software user who at present performs the task of block positioning and shaping in an interactive manner. A number of test cases are examined. It is also suggested that an existing unstructured mesh generation method could be adopted as an initial topology generation tool. Further work towards creating a fully automatic grid generation tool and extension into three dimensions are discussed. The parallel execution of an aerodynamic simulation code on a non-dedicated, heterogeneous cluster of workstations is examined. This type of facility is commonly available to CFD developers and users in academia, industry and government laboratories and is attractive in terms of cost for CFD simulations. However, practical considerations appear at present to discourage widespread adoption of this technology. The main obstacles to achieving an efficient, robust parallel CFD capability in a demanding multi-user environment are investigated. A static load-balancing method is described which takes account of varying processor speeds. A dynamic re-allocation method to account for varying processor loads has been developed. Use of proprietary software has facilitated the implementation of the method

phase i ii first in human trial with m7583 a bruton s tyrosine kinase inhibitor btki in patients with b cell malignancies

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Enhanced activation of an amino-terminally truncated isoform of the voltage-gated proton channel HVCN1 enriched in malignant B cells

The final published version can be found here: http://dx.doi.org/10.1073/pnas.1411390111M.C. is the recipient of a Bennett Fellowship from Leukaemia and Lymphoma Research (ref. 12002). M.A.B. is supported by a GlaxoSmithKline Oncology–Biotechnology and Biological Sciences Research Council Collaborative Awards in Science and Engineering PhD studentship. This work was supported by National Institutes of Health Grants GM087507 and GM102336 (to T.E.D.)