Opioid medications are medicine's best weapon against severe intractable pain, but prolonged use of these medications can be complicated by side effects like tolerance and mental clouding which, themselves, can be disabling. The present study examined the independent and combined effects of inflammatory pain and opioid medication on spatial memory for a well learned task in Sprague-Dawley rats. The Hargreaves method was used to verify the pain state of the animals after complete Freund's adjuvant injection and morphine treatment. Whereas pain had little effect on spatial memory, morphine had profound detrimental effects that persisted beyond the analgesic effectiveness of the drug. However, morphine-induced cognitive deficits were absent when morphine was provided to animals in chronic pain. Also, analgesic tolerance was significantly attenuated in these animals. Taken together, these results suggest that chronic pain activates a neural mechanism that antagonizes the unwanted effects of opioids.

Accurate rainfall forecasting using weather radar imagery has always been a crucial and predominant task in the field of meteorology [1], [2], [3] and [4]. Competitive Radial Basis Function Neural Networks (CRBFNN) [5] is one of the methods used for weather radar image based forecasting. Recently, an alternative CRBFNN based approach [6] was introduced to model the precipitation events. The difference between the techniques presented in [5] and [6] is in the approach used to model the rainfall image. Overall, it was shown that the modified CRBFNN approach [6] is more computationally efficient compared to the CRBFNN approach [5]. However, both techniques [5] and [6] share the same prediction stage. In this thesis, a different GRBFNN approach is presented for forecasting Gaussian envelope parameters. The proposed method investigates the concept of parameter dependency among Gaussian envelopes. Experimental results are also presented to illustrate the advantage of parameters prediction over the independent series prediction.

We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 mu m), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R similar to 150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of low-mass planets using the Doppler technique, iLocater will also advance areas of research that involve crowded fields, line-blanketing, and weak absorption lines.

Specific power output from a Low Pressure (LP) steam turbine can be enhanced by increasing the stage efficiency or raising its pressure ratio; both methods are interlinked and must be dealt with together. The latter is achieved by connecting to the exhaust diffuser; space and cost constraints often insist the use of an axial-radial diffuser with high levels of diffusion. The present study aims to investigate the interaction between the last-stage blade and the axial-radial diffuser, which can influence the diffuser performance and thus the total work output from the stage. This work is carried out using CFD simulations of a generic last stage low pressure (LP) turbine and axial-radial exhaust diffuser attached to it. In order to determine the validity of the computational method, the CFD predictions are first compared with data obtained from an experimental test facility. A computational study is then performed for different design configurations of the diffuser and rotor casing shapes. The study focuses on typical flow features such as effects of rotor tip leakage flows and subsequent changes in the rotor-diffuser interactions. The results suggest that the rotor casing shape and diffuser configurations influences the rotor work extraction capability and yields significant improvements in the static pressure recovery.

There are two main features in this thesis. The first is a study of the role of "tracts" of finite determination on the growth of integral functions. Such a study is of importance, since most of the known results in this field are based on the extreme case where the tracts of finite determination reduce to single lines. The second is the construction of functions, meromorphic and integral, bounded in tracts of positive angular measure, where the tracts are not confined to radial sectors.

Proximal forearm fractures account for over 10% of all upper limb fractures. There is limited epidemiological data available and much of the literature focuses on the more complex fracture patterns, with the role of non-operative management for the isolated proximal forearm fracture still to be defined. Prospective short and long-term patient reported outcome data for simple isolated fractures of the radial head and olecranon would help define the indications for the non-operative management of these injuries. This thesis aims to test the hypothesis that non-operative management provides a comparable outcome to operative intervention for defined fractures of the proximal forearm. A large prospective database of 6872 fractures collected over a one-year period was used to define the epidemiology of proximal forearm fractures. A separate large prospective study carried out over an eighteen-month period using a pre-defined management protocol for all isolated radial head and neck fractures was analysed to determine the short and long-term outcome. Additional retrospective databases were collected and analysed to determine the short and long-term outcome for the non-operative and operative management of olecranon fractures, as well as the operative management of complex radial head fractures. Finally, two prospective randomised controlled trials (PRCTs) of isolated displaced fractures of the olecranon were carried out to compare 1) tension band wire (TBW) versus plate fixation in younger patients (< 75 years) and 2) operative versus non-operative management in elderly patients (≥75 years). The primary outcome measure for these studies was the upper limb specific patient reported Disabilities of the Arm, Shoulder and Hand (DASH) score. Secondary outcome measures included surgeon reported outcome scores, complication rates and cost. The incidence of proximal forearm fractures was 68 per 100,000. Radial head fractures fit a type D distribution curve (unimodal young man, bimodal woman) and radial neck type A (unimodal young man, unimodal older woman). Proximal ulna and olecranon fractures were both a type F (unimodal older man, unimodal older woman), with an increasing incidence after the 6th decade. Over 90% of proximal radial fractures were isolated stable fractures. Prospective analysis of 201 isolated proximal radius fractures found that the patient and surgeon reported outcome following primary non-operative management for Mason type 1 and type 2 (n=185) fractures was excellent in the short and long-term, with < 2% of patients undergoing secondary surgical intervention. At a mean of 10 years post injury (n=100), the mean DASH score was 5.8 and 92% of patients were satisfied. Factors associated with a poorer short and long-term patient reported outcome included increasing fracture displacement (≥5mm) and socio-economic deprivation. Retrospective analysis of 105 acute unstable complex radial head fractures found that the mean short-term functional outcome was good (mean Broberg and Morrey Score 80) following radial head replacement. In the long-term (mean 7 years), 28% of patients required removal or revision of the prosthesis, with younger patients and silastic implants independent risk factors (both p < 0.05). Retrospective analysis of 36 operatively managed isolated displaced olecranon fractures found satisfactory short and long-term outcomes, with the symptomatic metalwork removal rate 47% and the mean DASH 2.5 at a mean of seven years post injury. In the PRCT of plate (n=34) versus TBW (n=33) fixation, comparable functional and patient reported outcomes (DASH 8.5 vs 13.5; p=0.252) were found at one year following injury. Complication rates were significantly higher in the TBW group (63.3% vs 37.5%; p=0.042), predominantly due to a significantly higher rate of symptomatic metalwork removal (50.0% vs 21.9%; p=0.021), resulting in equivocal costs for both techniques (p=0.131). In older lower-demand patients, short and long-term retrospective analysis found very satisfactory outcomes following non-operative management of isolated displaced fractures of the olecranon, with patient satisfaction 91% and no patients requiring surgery for a symptomatic non-union. The preliminary results of the PRCT of non-operative (n=8) versus operative (n=11) management demonstrated comparable functional and patient reported outcomes at all points over the one-year following injury (all p≥0.05), with a higher rate of complications (81.8% vs 14.3%; p=0.013) and cost (p=0.01) following surgical intervention. The association found between fragility and the epidemiology of proximal forearm fractures highlighted the importance of considering non-operative management for these injuries. These findings support non-operative management for isolated stable radial head and neck fractures. For more complex injuries when radial head replacement is indicated, there is a high rate of removal or revision, with younger patients most at risk. In younger active patients with an isolated displaced fracture of the olecranon, TBW and plate fixation provide comparable short-term results, with TBW fixation as cost effective despite an increased rate of metalwork removal. In older lower demand patients, this data provides strong evidence for the non-operative management of isolated displaced olecranon fractures.

Lui, Fung Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 83-92). / Abstracts in English and Chinese. / Acknowledgement --- p.iii / Abbreviation --- p.xii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Related Work --- p.6 / Chapter 1.2.1 --- Parametric Optimization Method and Radial Basis Functions --- p.6 / Chapter 1.3 --- Contribution and Organization of the Dissertation --- p.7 / Chapter 2 --- Level Set Method for Structure Shape and Topology Optimization --- p.8 / Chapter 2.1 --- Primary Ideas of Shape and Topology Optimization --- p.8 / Chapter 2.2 --- Level Set models of implicit moving boundaries --- p.11 / Chapter 2.2.1 --- Representation of the Boundary via Level Set Method --- p.11 / Chapter 2.2.2 --- Hamilton-Jacobin Equations --- p.13 / Chapter 2.3 --- Numerical Techniques --- p.13 / Chapter 2.3.1 --- Sign-distance function --- p.14 / Chapter 2.3.2 --- Discrete Computational Scheme --- p.14 / Chapter 2.3.3 --- Level Set Surface Re-initialization --- p.16 / Chapter 2.3.4 --- Velocity Extension --- p.16 / Chapter 3 --- Structure Topology Optimization with Discrete Level Sets --- p.18 / Chapter 3.1 --- A Level Set Method for Structural Shape and Topology Optimization --- p.18 / Chapter 3.1.1 --- Problem Definition --- p.18 / Chapter 3.2 --- Shape Derivative: an Engineering-oriented Deduction --- p.21 / Chapter 3.2.1 --- Sensitivity Analysis --- p.23 / Chapter 3.2.2 --- Optimization Algorithm --- p.28 / Chapter 3.3 --- Limitations of Discrete Level Set Method --- p.30 / Chapter 4 --- RBF based Parametric Level Set Method --- p.32 / Chapter 4.1 --- Introduction --- p.32 / Chapter 4.2 --- Radial Basis Functions Modeling --- p.33 / Chapter 4.2.1 --- Inverse Multiquadric (IMQ) Radial Basis Functions --- p.38 / Chapter 4.3 --- Parameterized Level Set Method in Structure Topology Optimization --- p.39 / Chapter 4.4 --- Parametric Shape and Topology Structure Optimization Method with Radial Basis Functions --- p.42 / Chapter 4.4.1 --- Changing Coefficient Method --- p.43 / Chapter 4.4.2 --- Moving Knot Method --- p.45 / Chapter 4.4.3 --- Combination of Changing Coefficient and Moving Knot method --- p.46 / Chapter 4.5 --- Numerical Implementation --- p.48 / Chapter 4.5.1 --- Sensitivity Calculation --- p.48 / Chapter 4.5.2 --- Optimization Algorithms --- p.49 / Chapter 4.5.3 --- Numerical Examples --- p.52 / Chapter 4.6 --- Summary --- p.65 / Chapter 5 --- Conclusion and Future Work --- p.80 / Chapter 5.1 --- Conclusion --- p.80 / Chapter 5.2 --- Future Work --- p.81 / Bibliography --- p.83

Tese de doutoramento. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2010

Abdominal aortic aneurysms are a focal dilation of the aorta which can be potentially life threatening if left untreated. Endovascular aneurysm repair (EVAR) is a noninvasive treatment that can reduce the mortality rate when compared to the standard open repair. Yet, EVAR is associated with other complications that can arise such as migration, endoleaks, or device related failures. These complications drive the need for reinterventions which have been shown to occur more frequently with EVAR than with open repair. The long term fixation and sealing characteristics of these devices is likely related to the nature of its apposition to the aortic wall. Currently there is little understanding of these mechanics and factors in how the device performs at the time of deployment. A computational model that reflects the compressive nature of an endovascular graft is beneficial in investigating these mechanics. The aims of the study are; 1) formulate an experimental methodology that captures the radial compressive nature of the stent graft, 2) develop a parameterized finite element model of the stent structure, and 3) compare the compressive behavior this model against the acquired experimental data. A 2 mil polyethylene sleeve was used to transfer a compressive vacuum pressure from the sleeve onto 10 independent stent grafts. The loading-unloading pressure was cycled from 0 to -50 mmHg (complete collapse) over 5 minutes. A pressure transducer and optical micrometer were used to capture the vacuum pressure and diameter relationship. All ten grafts compressed in a similar elliptical shape configuration. Commercial software was leveraged to construct a parameterized model of the stent geometry. All crest and trough vertex locations of the sinusoidal stent structure were validated within 1 mm of a measured value. A dynamic quasi-static computational simulation was completed that included large deformations and contact between the sleeve and stent as well as self-contact in the sleeve. Our results show that the model is representative of the experiments and can be used to interrogate how a stent graft will perform during certain stages of deployment and immediately after deployment with some caution in regard to the stated limitations.

The desmosome is one of the major cell adhesion junctions found in the epithelia, heart, and hair follicle. Described as a “rivet” that hold cells together, it provides these tissues with the integrity to withstand the tremendous forces they face in everyday life. Defects in this junction can lead to devastating diseases where patients are susceptible to skin infections and cardiovascular defects. Limited treatments exist for diseases of the desmosome, and strategies do not target all symptoms. Therefore, delineating the function and regulation of desmosomes is of paramount importance for the development of prevention and treatment strategies. The Xenopus laevis has been utilized for the study of embryonic development and tissue movements. This study takes advantage of the frog model to study a key desmosomal protein, desmoplakin (Dsp), in the epidermal development of the embryo. First, Xenopus embryonic epidermis has junctional desmosomes as early as the blastula stages. Desmosomes numbers per junction increase as the embryo develops. Dsp is present in many epidermally-derived structures in the embryo at varying levels. Xenopus embryos deficient in desmoplakin have phenotypic defects in epidermal structures and the heart, mimicking mammalian models. Embryos with reduced Dsp exhibit an increased susceptibility to epidermal damage under applied mechanical forces. Assays also reveal a potential role for desmosomes in radial intercalation, a process through which cells move from the inner to the outer epidermal layers. Embryos with reduced Dsp exhibit a slight reduction in intercalation and defects in intercalating cell types, including multiciliated cells and small secretory cells. Finally, c-Jun N-terminal kinase (JNK) may have a potential role in the regulation of desmosome assembly and adhesion. Embryos with deficient Dsp display a partial recovery of mechanical integrity when treated with a JNK inhibitor.