"March 2003" Bibliography: leaves 206-233. The experimental data presented in this thesis provide evidence that PTP-Pez is an active phosphatase that interacts with and dephosphorylates the adherens junction protein ℓ-catenin. PTP-Pez also associates with proteins that form part of the tight junction complex, the scaffolding protein ZO-1 and the transmembrane protein occludin.

PhD / This thesis is concerned with combining the perceptual abilities of mobile robots and human operators to execute tasks cooperatively. It is generally agreed that a synergy of human and robotic skills offers an opportunity to enhance the capabilities of today’s robotic systems, while also increasing their robustness and reliability. Systems which incorporate both human and robotic information sources have the potential to build complex world models, essential for both automated and human decision making. In this work, humans and robots are regarded as equal team members who interact and communicate on a peer-to-peer basis. Human-robot communication is addressed using probabilistic representations common in robotics. While communication can in general be bidirectional, this work focuses primarily on human-to-robot information flow. More specifically, the approach advocated in this thesis is to let robots fuse their sensor observations with observations obtained from human operators. While robotic perception is well-suited for lower level world descriptions such as geometric properties, humans are able to contribute perceptual information on higher abstraction levels. Human input is translated into the machine representation via Human Sensor Models. A common mathematical framework for humans and robots reinforces the notion of true peer-to-peer interaction. Human-robot information fusion is demonstrated in two application domains: (1) scalable information gathering, and (2) cooperative decision making. Scalable information gathering is experimentally demonstrated on a system comprised of a ground vehicle, an unmanned air vehicle, and two human operators in a natural environment. Information from humans and robots was fused in a fully decentralised manner to build a shared environment representation on multiple abstraction levels. Results are presented in the form of information exchange patterns, qualitatively demonstrating the benefits of human-robot information fusion. The second application domain adds decision making to the human-robot task. Rational decisions are made based on the robots’ current beliefs which are generated by fusing human and robotic observations. Since humans are considered a valuable resource in this context, operators are only queried for input when the expected benefit of an observation exceeds the cost of obtaining it. The system can be seen as adjusting its autonomy at run-time based on the uncertainty in the robots’ beliefs. A navigation task is used to demonstrate the adjustable autonomy system experimentally. Results from two experiments are reported: a quantitative evaluation of human-robot team effectiveness, and a user study to compare the system to classical teleoperation. Results show the superiority of the system with respect to performance, operator workload, and usability.

Fast pushing like forms of knee extension were previously studied (van Ingen Schenau, 1994, Bobbert 1994). From these the role of mono and bi-articular muscles was established for this type of pushing like motion patterns. The way whipping like forms of knee extension are controlled is however less understood. This study investigated the impact of skill level in modulating fast forms of knee extension. The investigation was carried out by using a Taekwondo fast front kicking action, mean peak leg angular velocity 18.65 rads/s, as the subject task. A total of 40 healthy male and female participants volunteered to take part in this study. Of these, 20 were skilled martial arts athletes while the remaining 20 were unskilled. Expert and novice groups were randomly divided into treatment and control groups. A ten week intervention program aimed at increasing the skill level of participants of the expert and novice groups was conducted. The kinematic profile of the execution of a fast front kick performed under various settings of velocity, range of motion and degrees of freedom was obtained by a high speed camera. The myoelectrical activity of selected muscle units was simultaneously obtained while kicks were video recorded. Expert and novice participants were tested pre and post intervention program. Of the available kinematic variables such as segmental angular velocities, joint linear velocities and intersegmental timing and coordination, it was found that only: peak ankle linear and leg angular velocities, intersegmental timing, thigh to leg peak angular velocity ratio and a calculated performance index, have the potential to discriminate differences in skill level in this form of kicking. Pre and post intervention differences between groups were assessed from these variables. It was of interest to this study to identify the sources of these differences. To this end, an inverse dynamics analysis of the interaction between segments during the execution of a front kick was performed. It was found that the interaction between segments evolves with increases in skill level. Expert athletes utilize a i) precursor knee flexion moment to assist hip flexion moment during the initial stages of the kicking action and ii) a late hip flexion moment to assist further increases of kicking speed. These moments were absent in the execution of a front kick by novice athletes. These findings were also obtained form an optimization approach to the analysis of interactive moments during kicking. An important conclusion from these analyses is that the view of a front kick as a proximal to distal motion pattern is inadequate. Evidence from this study suggests that this action is best defined as a distal-proximal-distal motion pattern in an expert population. It then indicates that skill gains rely on the utilization of intrinsic muscle properties to assist the execution of tasks like a front kick.

The results of measurements of the fluxes of momentum, moisture and sensible heat in the marine boundary layer are described. Two techniques for obtaining the fluxes are discussed. The fluxes of these quantities are most directly obtained by the eddy correlation method, that is, by measuring the fluctuating vertical and downstream velocity (w and u), temperature (T) and humidity (q) and computing the covariances wu, wT and wq. The fluxes are also computed by obtaining a measure of the energy dissipation rate from second-order structure functions and relating the dissipation to the production of energy. To use the dissipation methods, values of universal inertial-convective subrange constants (Kolmogoroff constants) are required. Kolmogoroff constants are computed from second and third-order structure functions. Most of the data were collected on R.V. FLIP during BOMEX (Barbados Oceanographic and Meteorological Experiment) and during a pre-BOMEX trial cruise near San Diego. A small amount of additional data was collected from a site at South Beach, Oregon. The value of the Kolmogoroff constant for velocity is consistent with other recent observations. The temperature and humidity constants are found to be equal within the measurement error and have values of about 0.8. The two methods for computing the fluxes agree on average for momentum and moisture flux. The two methods do not agree for sensible heat flux during BOMEX although there is fair agreement for the San Diego data. / Graduation date: 1972

Spectral analysis was used to investigate semidaily mean sea levels and atmospheric pressures at San Francisco, California, Coos Bay, Oregon, and Tofino, British Columbia, in the frequency band 0 to 0.5 cpd. Cross spectral analysis of semidaily mean sea levels and atmospheric pressures at the three stations show that the response of sea level to low-frequency atmospheric pressure fluctuations is nonbarometric in the frequency band studied, and varies with season. Cross spectral analysis of semidaily mean sea levels between adjacent stations shows that there exists significant coherence between the Coos Bay and Tofino sea levels within the frequency band studied and phase difference between the stations is consistent with the hypothesis of continental shelf waves traveling from south to north along the coast. / Graduation date: 1970

The perturbation of a stably-stratified flow by irregular terrain is studied utilizing a seven-layer, hydrostatic, and potential enstrophy and energy conserving primitive equation model. The Island of Oahu, Hawaii, and the surrounding ocean area of 130 km x 100 km is chosen as the model topography. The domain is covered with a 5 km x 5 km mesh of 26 x 20 grid points in the horizontal. A cyclic boundary condition is imposed at the lateral boundaries. In order to give finer resolution to the lower atmosphere, an irregularly spaced sigma-coordinate is used in the vertical. Uniform east-north-easterly large-scale geostrophic winds up to the 400 mb level are imposed in order to represent the typical trade-wind condition. The pressure perturbation related to the mass flux divergence associated with the terrain irregularities, and the land-sea temperature difference associated with the different responses to the insolation during the daytime, are found to play a key role in determining the velocity field in the horizontal as well as in the vertical. Asymmetric surface pressure arises, due to the topographically induced vertical motion, with high pressure at the windward slope and low pressure at the downwind slope of the island. Daytime heating of the island induces low pressure on the island surface. This effect is the most significant at the lee side and inland portion of the island where the effect of cold-air advection from the ocean is minimal. At the lee side of the island the negative pressure perturbation induced by the daytime heating favors the establishment of a reverse flow toward the island, but the mountain range at the lee side of the island and prevailing tradewind prevent this low-level inflow from penetrating further inland. At the upwind side of the island, the flow field is mostly determined by topographic slope rather than by the heating of the island surface. The perturbation to the basic flow decreases rapidly upward. But a vertical cross-section of the horizontal divergence and the vertical velocity fields shows well defined wave motions up to the domain top level. The wave motions also appear downstream and upstream of the island with reduced amplitudes away from the island. These suggest the existence of hydrostatic mountain waves forced by the island contour, as was predicted by previous linear studies. The windward tilt of the wave axis shows upward propagation of wave energy, but the wave momentum flux was negligible. / Graduation date: 1987

Pseudomonas is the most common cause of chronic lung infections leading to death in cystic fibrosis patients. While chronic infection is extremely difficult to eradicate, the initial bacterial-host interactions prior to biofilm formation and establishment of chronic infections represents an attractive therapeutic target. It is clear that interaction between pathogens and the host is a very complex process and successful adaptation requires tight control of virulence factor expression. The aim of this project was to look for early changes in P. aeruginosa global gene expression in response to attachment to epithelial cells. P. aeruginosa PA01 was incubated with polarized HBE cells at a MOI of 100 for 4 hours and bacteria attached to epithelial cells (interacting) were collected separately from those in the supernatant (non-interacting). To minimize media effects observed by others, iron and phosphate were supplemented at appropriate levels to avoid expression changes due to limitation of these nutrients, as confirmed in our microarray experiments. Analysis of 3 independent experiments demonstrated that 766 genes were up or down regulated by more than 1.5 fold during attachment. Among these, 371 genes, including ion, oprC, as well as 3 genes in quorum-sensing systems and 9 genes involved in the pmrAB and phoPQ two-component regulatory systems were found to be induced in the interacting bacteria. On the other hand, 395 genes, including oprG outer membrane porin and pscP involved in type III secretion system were down regulated. To understand the roles of these differentially expressed genes, a cytotoxicity (LDH release) assay was performed and demonstrated that oprG and ion mutants were less capable than the wild type of killing HBE epithelial cells. These findings suggest that, under these interaction assay conditions, regulation of the expression of certain virulence factors provides a potential advantage for successful adaptation. In addition, a mutant lacking a filamentous hemagglutinin like protein was found to be less cytotoxic to HBE cells and also deficient in A549 epithelial cell binding, indicating that this probable non-pilin adhesin has multiple functions in P. aeruginosa.

Desktop-based Windows, Icons, Menus and Pointers (WIMP) interfaces have changed very little in the last 30 years, and are still limited by a lack of powerful and expressive input devices and interactions. In order to make desktop interactions more expressive and controllable, expressive input mechanisms like pressure input must be made available to desktop users. One way to provide pressure input to these users is through a pressure-augmented computer mouse; however, before pressure-augmented mice can be developed, design information must be provided to mouse developers. The problem we address in this thesis is that there is a lack of ergonomics and performance information for the design of pressure-augmented mice. Our solution was to provide empirical performance and ergonomics information for pressure-augmented mice by performing five experiments. With the results of our experiments we were able to identify the optimal design parameters for pressure-augmented mice and provide a set of recommendations for future pressure-augmented mouse designs.

Electrodes implanted into neural systems are known to degrade due to encapsulation by surrounding tissues. The mechanisms of electrode-tissue interactions and prediction of the behavior of electrode are yet to be achieved. This research will aim at establishing the fundamental knowledge of interfacial interactions between the host biological environment and an implanted electrode. We will identify the dynamic mechanisms of such interfacial interactions. Quantitative analysis of the electrical properties of interface will be conducted using Electrochemical Impedance Spectroscopy (EIS). Results will be used to develop a general model to interpret electrical circuitry of the interface. This is expected to expand our understanding in the effects of interfacial interactions to the charge transport. The interfacial interactions of an implanted electrode with neural system will be studied in two types of electrodes: silver and graphene coated. The interfacial impedance of both samples will be studied using EIS. The development of the cellular interaction will be investigated using histological procedure. X-ray photoemission spectroscopy (XPS) will be employed to study the chemical effects on the silver electrodes. Atomic force microscopy and Raman spectroscopy will be used for material characterization of graphene-coated electrodes. In the study of silver electrode, two mechanisms affecting the interfacial impedance are proposed. First is the formation of silver oxide. The other is the immuno-response of tissue encapsulation. Histological results suggest that higher cell density cause higher impedance magnitude at the interface. It is also found that the cellular encapsulation dominates the increase in impedance for longer implanted time. In the study of graphene-coated electrode, it is found that the graphene can strongly prevent the metal substrate from being oxidized. It not only provides good electrical conductivity for signal transport, but also reduces the speed of the accumulation of tissue around the electrode. Such characteristics of graphene have great potential in the application of neural implant. Finally, the dynamic mechanisms of biological interaction are proposed. A model is also developed to represent the general circuitry of the interface between an implanted electrode and the neural system. The model has three major components, which are interfacial double layer, cellular encapsulation, and the substrate. The model presented in this study can compensate for selection and prediction of materials and their behaviors.

This field study examined how elderly and cognitively disabled people used and experienced a social companion robot. The following pages explores the questions: Which are the physical, social and affective qualities during the interaction? The aim was to through observations see how qualities of interaction could activate different forms of behavior. The results show that motion, sound and the eyes together created communicative and emotional changes for users who felt joy and were willing to share the activity with others. The robot stimulated to some extent users to create their own imaginative experiences but often failed to involve user or group for a long time and was also considered too large and heavy to handle. / Denna fältstudie undersökte hur äldre och kognitivt funktionsnedsatta personer använde och upplevde en social robot. Följande sidor utforskar frågorna: Vilka fysiska, sociala och affektiva kvaliteter finns i interaktionen? Målet var att genom observationer se hur kvaliteterna i interaktionen kunde aktivera olika typer av beteenden. Resultatet visar att rörelse, ljud och ögon tillsammans skapade kommunikativa och känslomässiga förändringar hos användarna som visade glädje och som gärna delade upplevelsen med andra. Roboten stimulerade till viss del användarna att skapa egna fantasifulla upplevelser men lyckades inte ofta involvera användare eller grupp under någon längre tid och ansågs även vara för stor och tung att hantera.