A hydro-elastic model of hydrocephalus

We combine elements of poroelasticity and of fluid mechanics to construct a mathematical model of the human brain and ventricular system. The model is used to study hydrocephalus, a pathological condition in which the normal flow of the cerebrospinal fluid is disturbed, causing the brain to become deformed. Our model extends recent work in this area by including flow through the aqueduct, by incorporating boundary conditions which we believe more accurately represent the anatomy of the brain and by including time dependence. This enables us to construct a quantitative model of the onset, development and treatment of this condition. We formulate and solve the governing equations and boundary conditions for this model and give results which are relevant to clinical observations

City extensions : the revitalization of Denver Colorado's Platte River Valley

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Includes bibliographical references (p. 71-73).This thesis examines a process for future city growth in Denver, Colorado. Its objective is to develop a model by which future expansion of the city might build qualities of continuity and identity between adjacent sections of the city and the Platte River through the revitalization and extension of network edges. Present growth trends in Denver have altered traditional city network relationships. The exchange between movement systems, building forms and landscape has deteriorated resulting in the isolation of the pedestrian edges which once made Denver a city of vitality. This thesis begins with observations of a specific problem of discontinuity within Denver's Platte River Valley. It then outlines goals for future growth. The third section defines the task of seaming together valley districts. The fourth section documents a method for analysis and extension. The last section includes strategies and design projections to illustrate how districts of the city might grow, with examples of extensions from a regional size, to examinations in more detail of landscape network and building relationships.by James A. Sobey.M.Arch

An interactive layout exploration and optimisation method for early stage ship design

This paper presents a novel, highly interactive genetic algorithm-based layout exploration and optimisation method for generating spatial configurations of ships in the early stages of the design process. The method draws upon the principles of design-driven architecturally centred ship design processes by enabling the naval architects to make important decisions in a hybrid design process. The method utilises a genetic algorithm-based optimisation tool to rapidly generate and evaluate a diverse set of general arrangement options. It is approached in stages where each stage comprises two steps (manual and automatic). The new genetic algorithm-based layout optimisation tool is demonstrated by being applied to an Offshore Patrol Vessel test case. The advantages and disadvantages of the proposed tool are discussed, as well as the current limitations of the overall approach and future work

A Successful Cool Storage Rate

Houston Lighting & Power (HL&P) initiated design and development of its commercial cool storage program as part of an integrated resource planning process with a targeted 225 MW of demand reduction through DSM. Houston's extensive commercial air conditioning load, which is highly coincident with HL&P's system peak, provided a large market for cool storage technologies. Initial market research made it very clear that a special cool storage rate was required to successfully market the technology. Development of the rate required an integrated, multidepartment effort and extensive use of DSManager, an integrated resource planning model. An experimental version of the rate was initially implemented as part of the initial phase of the cool storage program. A permanent rate, incorporating lessons learned from the experimental rate, was then developed for the long term implementation of the program. The permanent rate went through a lengthy regulatory approval process which included intervention by a local natural gas distribution company. The end result is a very successful cool storage program with 52 projects and 31 megawatts of demand reduction in the first three and one-half years of program implementation

Nox1 oxidase suppresses influenza a virus-induced lung inflammation and oxidative stress

Influenza A virus infection is an ongoing clinical problem and thus, there is an urgent need to understand the mechanisms that regulate the lung inflammation in order to unravel novel generic pharmacological strategies. Evidence indicates that the Nox2-containing NADPH oxidase enzyme promotes influenza A virus-induced lung oxidative stress, inflammation and dysfunction via ROS generation. In addition, lung epithelial and endothelial cells express the Nox1 isoform of NADPH oxidase, placing this enzyme at key sites to regulate influenza A virus-induced lung inflammation. The aim of this study was to investigate whether Nox1 oxidase regulates the inflammatory response and the oxidative stress to influenza infection in vivo in mice. Male WT and Nox1-deficient (Nox1−/y) mice were infected with the moderately pathogenic HkX-31 (H3N2, 1×104 PFU) influenza A virus for analysis of bodyweight, airways inflammation, oxidative stress, viral titre, lung histopathology, and cytokine/chemokine expression at 3 and 7 days post infection. HkX-31 virus infection of Nox1−/y mice resulted in significantly greater: loss of bodyweight (Day 3); BALF neutrophilia, peri-bronchial, peri-vascular and alveolar inflammation; Nox2-dependent inflammatory cell ROS production and peri-bronchial, epithelial and endothelial oxidative stress. The expression of pro-inflammatory cytokines including CCL2, CCL3, CXCL2, IL-1β, IL-6, GM-CSF and TNF-α was higher in Nox1−/y lungs compared to WT mice at Day 3, however, the expression of CCL2, CCL3, CXCL2, IFN-γ and the anti-inflammatory cytokine IL-10 were lower in lungs of Nox1−/y mice vs. WT mice at Day 7. Lung viral titre, and airways infiltration of active CD8+ and CD4+ T lymphocytes, and of Tregs were similar between WT and Nox1−/y mice. In conclusion, Nox1 oxidase suppresses influenza A virus induced lung inflammation and oxidative stress in mice particularly at the early phases of the infection. Nox1 and Nox2 oxidases appear to have opposing roles in the regulation of inflammation caused by influenza A viruses

Stochastic assessment of aerodynamics within offshore wind farms based on machine-learning

Wind turbine flow field prediction is difficult as it requires computationally expensive computational fluid dynamics (CFD) models. The contribution of this paper is to propose and develop a method for stochastic analysis of an offshore wind farm using CFD and a non-intrusive stochastic expansion. The approach is developed through testing a range of machine-learning methods, evaluating dataset requirements and comparing the accuracy against site measurement data. The approach used is detailed and the results are compared with real measurements obtained from the existing wind farm to quantify the accuracy of the predictions. An existing offshore wind farm is modelled using a steady-state CFD solver at several deterministic input ranges and an approximation model is trained on the CFD results. The approximation models compared are Artificial Neural Networks, Gaussian Process, Radial Basis Function, Random Forest and Support Vector Regression. RBF achieves a mean absolute error relative to the CFD model of only 0.54% and the error of the SVR predictions relative to the real data, with scatter, was 12%, compared to 16% from Jensen. This approach has the potential to be used in more complex situations where an existing analytical method is either insufficient or unable to make a good prediction

Nitrite is produced by elicited but not by circulating neutrophils

The generation of nitrite (NO2-) was used as an index of the production of nitric oxide by human and rat polymorphonuclear leukocytes (PMN) and rat peritoneal macrophages. Human peripheral blood PMN did not produce significant levels of NO2-. Attempts to induce NO2- generation in human PMN by incubation with GM–CSF (1 nM), TNFα (0.3 nM), endotoxin (1 μg/ml) or formyl-Met-Leu-Phe (100 nM) for up to 16 h were not successful. Addition of human PMN primed by GM–CSF (1 nM) to rabbit aortic ring preparations precontracted with phenylephrine had no effect on tone. In contrast to these observations, PMN, isolated from the peritoneum of oyster glycogen treated rats, generated NO2- via a pathway sensitive to inhibition by the nitric oxide synthase inhibitor, NG-monomethyl L-arginine. However, peripheral blood rat PMN obtained from the same animals did not produce NO2-, even during prolonged incubation for periods of up to 16 h. It is suggested that detectable NO production by PMN requires NO synthase activity to be induced either by the process of PMN migration or by exposure to certain cytokines produced locally at the site of inflammation