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Background: The End of Life Care Strategy stated that there should be a reduction of expected deaths in the acute setting. In order to achieve this goal, when it has been identified that where the patient's preferred place of care is home, clinicians need to be able to recognise when a patient is dying in order to achieve their preferred place of death. The aims of this study were to identify any factors that help or hinder a clinician when they are determining when irreversible dying begins and to seek consensus on which of these topics would be useful to include in an education programme. Method: A 3 stage mixed methods study was developed. Phase 1was a Systematic Review of current primary research in order to provide an evidence base for the study. Phase 2 involved unstructured interviews with clinicians in the acute setting utilising the Grounded Theory approach to the analysis identify potential factors. Phase 3 was a Delphi study used to identify which of these factors would be useful in an education programme. Conclusions: The Systematic Review identified four themes "Patient Observation", "Knowledge of the Patient", "Communication" and "Attitudes of the Clinician". These were confirmed by the interviews and a further theme "Experience" identified. The over-arching theme emerging from the findings of the interviews was that clinicians have a fear of getting the timing of the recognition of irreversible dying wrong because the decision making process is so complex and this is exacerbated by fear of missing the treatable. Many factors identified in the interviews were acknowledged as factors that could be included in an education package. It was also identified that there is the need for a culture shift in society regarding death and dying and a change in the philosophy of care for health care professionals.

Although previous literature has examined family caregiving in a number of environments, there has been a lack of information and understanding of the nature of family caregiving within palliative care. Two studies were undertaken to establish the expected and actual role and position of family caregivers in palliative care, from a health professional and a lay person perspective. In the first study health professionals from a range of backgrounds in both primary care and specialist palliative care were approached to discover their perception of family caregiving and their role in palliative care. Secondly the family caregiver's perspective of their role and potion in palliative care was examined using a case study methodology. In addition, this second study also sought to understand the nature of the relationship of family caregivers with visiting health professionals and other sources of social support. The findings revealed that family caregivers in palliative care settings are frequently in an ambiguous position. Whilst they are considered essential to the well being of a palliative care patient, there are little or no guidelines for health professionals as to the role of these individuals within a total package of care. Family caregivers themselves are often equivocal about their role, and many do not identify with the term 'carer' at all. Because of the ambiguity, family caregivers often assume a subservient role to that of the patient and ignore or deny their own needs for emotional support. Their relationship with health professionals is often limited to discussions of care and management of the ill person, rather than their own needs. In addition they often act as co-ordinators of information between health professionals. Family caregivers seek emotional and practical help from other family members first and foremost, and friends and neighbours generally in the absence of close family support.

Fewer patients are able to die at home than would wish to do so. A literature review showed that palliative home care patients are more likely to die at home than others. However, findings may be due to case mix differences, as variables which are positively associated with home death, are also positively associated with access to palliative home care. The thesis investigated the impact of a hospice at home (HAH) service on place of death. An observational, case control study compared 121 patients referred to HAH with 206 patients not referred. Multivariate logistic regression analysis showed that HAH care was strongly positively associated with home death. However, case mix effects could not be discounted. A randomised controlled trial (RCT) compared 186 patients allocated to HAH care with 43 controls. Analysis was intention to treat. Intervention patients were not significantly more likely to die at home than control patients (67% versus 58%). The RCT suffered loss of power and dilution of the treatment effect. Post hoc multivariate logistic regression analysis showed a positive association between actual HAH input and home death. However, this association was no stronger than that between less intensive home care services and home death. Concerns about case mix effects remained. Content analysis of professional and family carers' explanations of endstage inpatient admissions for RCT patients suggested such admissions were mainly perceived to result from factors unrelated to insufficient home care. While some patients may have benefited from added home support, this may not have affected place of death. Additional home care introduced on top of good existing provision, among patients who are already likely to die at home, may have little impact on home deaths. Careful consideration of service aims, target group, other health service context is required before introduction of further hospice at home services.

Terminal Body Outreach is a collection of poems that navigates the different maps of personhood, family, grief, intimacy, landscape, and the essence of who the speaker is and who the speaker is actively becoming, all with a focus on the "Body." "Terminal" signifies not only an end, but also a place of departure, a constant reaching or "Outreach" for something, somewhere, or someone. Readers are asked to develop associations between jumping language and image narratives that these poems invite. Self-portraits serve as touchstones in the manuscript, embodying the core movement of departure and return. The speaker searches through the Natural world and their interpersonal environment, particularly what seems to flower and perish, looking for answers to what makes this life necessary, sometimes without success. The desire for these answers slowly dissolves as the speaker is pulled by what and who they carry all the way to the end, where the speaker inhabits ideas of who we are once we're dead, whether or not dead really means gone, and the need to leave something plentiful behind.

This systematic review is an update and expansion to the population and methods of a previous systematic review concerning spiritual and religious interventions for the well-being of terminally ill adults. After expanding the criteria to incorporate a more diverse population and including non-randomized experimental studies that contained relatively few concerns of bias, the results of the review are inconclusive due to insufficient data. The lack of usable data in the field highlights the ethical and theoretical issues with the use of experimental trials in analyzing the efficacy of spiritual and religious interventions. The development of spirituality in healthcare will remain stagnant until large volumes of high-fidelity data can be generated. The implementation of a spiritual history in a patient history will aid in achieving this goal by making retrospective cohort studies feasible. Spiritual histories not only enable further research endeavors but streamline comprehensive holistic care. Initiatives by healthcare administrators should implement spiritual histories for the benefits of both research and patient care.

A route-level transit origin-destination (OD) flow matrix represents passenger flows from each boarding stop to each alighting stop along a transit route. Route-level passenger OD flow matrices provide important information for planning, designing, and managing transit systems. However, manually collecting transit passenger OD flows is time consuming and labor intensive. With the increasing availability of automatic passenger count (APC) technologies, which collect boarding and alighting passenger volumes at all bus stops, algorithms have been developed to estimate route-level OD flow matrices using APC boarding and alighting data. The Iterative Proportional Fitting (IPF) method is commonly used to estimate OD flow matrices from the boarding and alighting counts. Typically, the IPF method is applied to boarding and alighting counts for a single bus trip defined by the time between the departure of a bus from a specified start terminal and its arrival at a specified end terminal. It is assumed that passengers who board at a stop on a given bus trip alight at a downstream stop on the same bus trip. Therefore, this typical use of the IPF method cannot capture “carry-over” OD movements, where passengers board at stops on one bus trip and alight at downstream stops on the next bus trip.In this thesis, a modification to this typical, or “original” IPF-based estimation method is proposed to capture carry-over passenger movements. The “modified” method, which consists of extending the OD matrix to be estimated to consider alighting stops on the next bus trip, is illustrated on a simple hypothetical bus route. A Monte Carlo simulation approach based on two of The Ohio State University’s Campus Area Bus Service routes during two different time-of-day periods is implemented to evaluate the estimation accuracy of the modified method with respect to the accuracy of the original method. The simulation results show that the OD matrices estimated using the modified method are consistently more accurate than the OD matrices estimated using the original method. The results also indicate that the accuracy of the estimated flows strongly depend on the route and time-of-day period forming the basis of the simulation inputs. Regression analyses are conducted to investigate the influence of characteristics associated with the route and time-of-day period OD flow matrices on the accuracy of the estimated flows and the improvement in accuracy the modified method offers over the original method. Specifically, the effects of average trip volume, uniformity of the OD flow matrix, and the proportion of the carry-over passenger movements are investigated. It is found that higher trip volumes result in better estimates when using either method, but that the improvement offered by the modified method over the original method decreases with increased trip volume. In addition, less uniform OD flows result in better estimates for both methods, but again, the improvement offered by the modified method decreases as the flows become less uniform. It is also seen that poorer estimates are obtained for both methods as the proportion of carry-over flows in the simulated true monthly OD matrix increases, but as expected, the improvement offered by the modified method over the original method increases as the proportion of carry-over flows increases.Since the modified method only requires an extension of the OD flow matrix to be estimated, with no methodological changes to the IPF algorithm, the results of this study motivate the use of the modified OD estimation method to capture carry-over passenger movements where the IPF algorithm is presently used to estimate transit OD flow matrices.

The study presented here focuses on the total energy absorption of fluid-filled structures during impact. The potential for an increase in energy absorption efficiency can be applied to larger structures for guardrail end terminal replacement or similar applications. For this study, an impact apparatus was designed and fabricated to facilitate testing of samples under low speed impact conditions. Samples were made consisting of plastic containers filled with fluid at varying levels. Samples were also made having an interior bottle with orifices allowing fluid to transfer between the bottles. Addition of orifices allows the flow of water to be controlled in a desired direction. This allows for energy transfer away from the impact direction reducing peak forces and increasing energy absorption efficiency. The preliminary results of this study show that the addition of fluid and an interior structure can potentially reduce the peak forces imparted on the impact ram as well as the energy absorption efficiency. The sample with the best performance was the sample with 2 orifices in the interior bottle and 25% filled with fluid. This sample recorded a peak force of 861.1988 N and an energy absorption efficiency of 14.2191 J/kN. This results in a 46.4% decrease in peak force and a 102.2% increase in energy absorption efficiency with respect to the filled sample without an interior bottle.

Background: Dignity therapy is psychotherapy to relieve psychological and existential distress in patients at the end of life. Little is known about its effect. Aim: To analyse the outcomes of dignity therapy in patients with advanced life-threatening diseases. Design: Systematic review was conducted. Three authors extracted data of the articles and evaluated quality using Critical Appraisal Skills Programme. Data were synthesized, considering study objectives. Data sources: PubMed, CINAHL, Cochrane Library and PsycINFO. The years searched were 2002 (year of dignity therapy development) to January 2016. `Dignity therapy¿ was used as search term. Studies with patients with advanced life-threatening diseases were included. Results: Of 121 studies, 28 were included. Quality of studies is high. Results were grouped into effectiveness, satisfaction, suitability and feasibility, and adaptability to different diseases and cultures. Two of five randomized control trials applied dignity therapy to patients with high levels of baseline psychological distress. One showed statistically significant decrease on patients¿ anxiety and depression scores over time. The other showed statistical decrease on anxiety scores pre¿post dignity therapy, not on depression. Nonrandomized studies suggested statistically significant improvements in existential and psychosocial measurements. Patients, relatives and professionals perceived it improved end-of-life experience. Conclusion: Evidence suggests that dignity therapy is beneficial. One randomized controlled trial with patients with high levels of psychological distress shows DT efficacy in anxiety and depression scores. Other design studies report beneficial outcomes in terms of end-of-life experience. Further research should understand how dignity therapy functions to establish a means for measuring its impact and assessing whether high level of distress patients can benefit most from this therapy.

This dissertation conducts a systematic study of terminal area traffic management using optimization methods. The critical role that the airport plays in national airspace system is introduced. The challenges in managing complex terminal traffic are explained. The necessity and importance of the study is addressed. To assist human air traffic controllers in managing complex terminal traffic, our solution strategy is to calculate each flight's optimal arrival/departure schedule, to minimize the overall flight delay and runway congestion in the entire airport. Three solutions are developed in the thesis, including the static solution, the dynamic solution, and the stochastic solution. The static solution uses one computation and attempts to optimize the schedules of many flights arriving/departing the airport within a wide time window. The accuracy of its solution heavily relies on the quality of the predicted traffic situation acquired right before the computation. On the contrary, the dynamic solution attempts to divide the entire traffic flow into a series of small pieces, and optimize flight schedules piece by piece. It collects the latest traffic information before each computation and experiences far less computational load. Both static and dynamic solutions assume the traffic information to be explicitly known. They are inherently deterministic solutions. The third solution proposed in this thesis is a stochastic solution. It assumes that traffic information is not known with certain due to a variety of random factors in actual flight operations. This stochastic solution is mathematically and structurally designed to handle multiple sources of uncertainties in managing terminal traffic. In the last, the conclusion is given based upon the simulation tests of the three proposed runway scheduling solutions. Future work is also suggested.

Miscible blend dynamics have been long been a subject of interest and are not as well understood as dynamics of homopolymer melts. Their anomalous behavior, such as time-temperature superposition failure, broadening of calorimetric glass transition, etc., makes these systems very intriguing and challenges our understanding of miscible blend dynamics. In this work we investigated temperature and composition dependence of two different, dynamically heterogeneous blend systems using rheology and forced Rayleigh scattering (FRS). The first blend investigated was a weakly interacting one comprising poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA). Monomeric friction factors of PEO and PMMA were reported for a wide range of temperature and composition. PEO terminal dynamics were found to have strong composition dependence unlike that of PEO segmental dynamics previously reported. Also, PEO maintained its rapid relaxation mechanisms even in stiffer surroundings. The PEO hydroxyl end groups were found to have no significant impact on component chain dynamics. The FRS and rheology results agreed remarkably well for this system. The Lodge-McLeish model failed to describe the experimental results. In order to understand the role of hydrogen bonding on chain dynamics, a strongly interacting system of PEO/poly(vinyl phenol) (PVPh) was investigated using rheology. The blends consisted of a high molecular polymer tracer dispersed in low molecular weight matrix to extract relevant dynamic information from tracer contribution to material properties. Monomeric friction factors were reported for a wide temperature and composition range. Time-temperature superposition failure was observed in PEO tracer blends at high PVPh concentration. The shape of tracer relaxation spectra for PVPh tracer blends had a strong composition dependence while those for PEO tracer blends were independent of composition. The tracer contribution to blend viscosity had a strong temperature dependence at high PVPh composition. Across the composition range, single and narrow glass transitions were observed for these blends. PVPh chain conformations were investigated using SANS and contradictory conclusions were reached. Therefore, no conclusive remarks can be made regarding PVPh chain conformations in dilute solution.

This research will show that with a design of a new landside airport terminal facility, stress can influence, develop and shape areas contained within the facility; implemented without diminishing the high level of security needed in a post 9/11 era. Airport security is essential for the safety and protection of the traveling public, a critical component, often designed with little attention because security is not considered a significant characteristic of the design experience. As architects, our number one responsibility is to protect the health, safety and welfare of the public; we fail our duty when we do not design for security as much as we design the facade of the terminal. Following 9/11, the United States is aware another terrorist attack could occur, but difficult to anticipate. However at airports, potential attacks must be planned for because anyone can develop a plan to damage public areas. The duty of the architect is to design a program, protecting the occupants of the building and limit the loss of life. Recent security measures have put an increased amount of stress on the traveling public, generating a need to lower the stress and anxiety of the passenger. Reduction of stress is critical to the success of any new security measure; passengers should be able to experience security measures with transparency, because awareness of security will trigger anxiety and stress.

Rhetorical agency has surfaced recently as an important source of discussion and debate in contemporary rhetorical theory. In some recent scholarship, including Karlyn Kohrs Campbell's and Carl G. Herndl and Adela C. Licona's, rhetoricians have worked to rearticulate a role for agency after and within the de-centering of the modernist self suggested in much poststructuralist and postmodernist thinking, establishing in the process a conception of agency as "a field of relations" operating outside of the human subject but nevertheless constraining and enabling potential actions. In what I term both/and conceptions of agency, external determinants, such as ideology, historicality, and sociality, serve to enable and constrain agentive capacity by limiting, as Herndl and Licona suggest, the agent functions available to human subjects. Missing from these accounts, however, is how spatiality—in collaboration with historicality and sociality—constitutes a similar external determinant constraining and enabling agent functions in social systems and, more specifically, in rhetorical situations. In this thesis, I address this gap by situating rhetorical agency as a field of relations involving various determinants, including spatiality, historicality, and sociality, that together serve to produce relations within the conditions of late capitalism. Focusing specifically on spatiality in the production of relations, I argue that rhetorical theory tends to privilege symbolic or imagined spaces over real or material spaces, a preference that, as Roxanne Mountford suggests, often ignores how material arrangements serve as constraints within communicative events. Furthermore, and as I argue in this thesis, recognizing how real and imagined spaces produce relations in lived spaces may in turn suggest additional agent functions already available within rhetorical spaces. To illustrate how agency functions as a field of relations in rhetorical spaces, I focus on non-places—ubiquitous utilitarian spaces such as airport terminals, malls, supermarkets, etc.—that, as Marc Augé argues, are designed to facilitate specific roles or agent functions. As such, non-places, as described by Augé, offer a unique social space in which to examine the limits of agency as a social location producing relations insofar they constrain agency by limiting occupants' shared identities, relations, and histories. In particular, I examine two specific non-places—the international airport terminal and the first-year composition classroom—in terms of the agentive potentials constituting relations within these spaces. As an introduction to non-places and their importance within the conditions of late capitalism, and in particular their capacities to constrain relations, identities, and histories expressive of anthropological places, I offer an analysis of terminal space in which I argue that, by virtue of their role as utilitarian transit spaces, terminals serve to limit the agent functions available to travelers. In this respect, I argue, travelers are interpellated, in the Althusserian sense, into de-historicized agent functions always already constituted within the terminal's field of relations. In Chapter 3, I extend these arguments, suggesting that the first-year composition classroom may be understood as a similar form of non-place, constraining student's shared relations, identities, and histories through pedagogies designed exclusively around the inhabitation of imagined geographies. Building on Edward W. Soja's concept of the trialectics of spatiality, I argue that composition studies' emphases on imagined geographies, such as the discourse community, serve to mask the material conditions informing the teaching and practice of writing in composition courses. To reveal additional agent functions available to student writers in classroom non-place, I conclude, compositionists should develop pedagogies that work to balance emphases on real, imagined, and lived spaces and their complex interrelationships within the production of relations.

This dissertation concentrates on the development of a frame of reference grounded on evolutionary ecology theory and based on ecological, paleoecological, and ethnographic data in order to examine the archaeological record from eastern Central Brazil for the Terminal Pleistocene and Early/Middle Holocene epochs. Particular emphasis is given to the diet breadth model, which is used to generate expected values for comparison with empirical data from three sites (Santana do Riacho, Lapa do Boquete, and Lapa dos Bichos) in order to understand and explain the postglacial foraging economies in this part of Brazil. In this study I examine the hypothesis that when the first Terminal Pleistocene hunter-gatherers settled in eastern Central Brazil some of the highest-ranked resource types (e.g., megafauna) were already scarce or absent, and based on optimal diet breadth models it is predicted that those foraging societies would have employed a generalized gathering and opportunistic hunting strategy that included several low-ranked resource types. Analyses of faunal remains show that small- and medium-size animals predominate in the assemblages. The absence of high-ranked items like giant anteater, giant armadillo, capybara, and very low frequencies of other high-ranked species such as tapir, peccaries, and even deer, together with the presence and high frequency of several low-ranked resource types including cavies, opossum, and reptiles, indicate subsistence stress. Diet diversification and more labor-intensive processing strategies, predicted to be the first risk-buffering mechanisms against environmental stresses, were already being employed, and could not be substantially increased. Thus, higher level risk-management strategies, notably the development of social networks, the most inclusive risk-management strategy, is expected to have been employed by hunter-gatherer societies in eastern Central Brazil during Terminal Pleistocene and Early Holocene time. Some indirect evidence such as lithic technology, exotic raw materials, and notably rock art, supports the prediction of the development of social networks on which interlocking, widespread foraging groups could rely during periods of extreme stress.

Bacterial pathogens employ unique ways to interact with their animal and plant hosts. A common strategy is to directly modulate the signal transduction pathways of the host. Yersiniae do this by translocating six effector proteins directly into the host cytoplasm by a type III secretion system. One of these effectors is YopH, a 51-kDa modular protein composed of at least two distinct domains. The carboxy-terminal domain (residues 204--468) is a potent protein tyrosine phosphatase essential for the antiphagocytic function of YopH and for virulence. The amino-terminal domain (residues 1--129) has at least two functions. It contains regions essential for secretion (1--17) and translocation (18--71) of YopH into the host cell. It also binds its specific chaperone, SycH, also essential for successful translocation into the host cell. Secondly, experimental evidence suggests the YopH amino-terminal domain after entering the eukaryotic cell targets the catalytic domain to specific substrates by binding to tyrosine-phosphorylated proteins. This behavior is similar to eukaryotic proteins that contain adaptor modules such as SH2 and PTB domains. To understand the structural requirements for chaperone and substrate binding, the crystal structure of the amino-terminal domain of YopH (residues 1--129) has been determined. The polypeptide, expressed with a carboxy-terminal hexahistidine tag, crystallizes in the space group C222 1 with unit cell dimensions a = 47.9 A, b = 120.7 A, and c = 48.8 A. Diffraction data were phased by multiple isomorphous replacement using three heavy atom derivatives. The final structure was refined with all data between 22.0 and 2.2 A resolution to an Rwork of 0.224 and Rfree = 0.257. In the crystal structure, the amino-terminal domain forms a domain-swapped dimer of two crystallographically related molecules. The dimer has dimensions of approximately 54 A x 37 A x 40 A and is butterfly-shaped. Each subunit adopts an alpha+beta fold containing four alpha-helices and four beta-strands. The swapped polypeptide (residues 2--29) of each subunit forms an alpha-helix and beta-strand that extends away from the core domain (30--129) and interacts primarily with the other monomer. Dynamic light scattering and gel filtration confirm that the YopH domain is a dimer in solution. But similar studies at low pH and NMR relaxation experiments show that the protein can also exist as a monomer. Since the protein readily aggregates and forms a dimer, it suggests that the polypeptide involved in the domain swap may be unfolded. Such a partially unfolded structure would allow chaperone binding and expose the initial 17 residues for recognition by the secretion machinery. Once in the host cell, the amino-terminal YopH can adopt a conformation and form suitable binding site(s) for tyrosine-phosphorylated proteins.

MWTerm is a terminal emulator that runs on an Apple Macintosh computer. It provides a multiple window interface in which each window maps to a independent process on the host computer. It is designed to run in conjunction with a cooperating program on the host computer, under the Unix operating system. This paper describes the ideas behind the user interface presented by MWTerm. The implementation of both the Macintosh and the Unix ends is described. A discussion of the lessons learned and future enhancements is provided.

It has been shown that 12-O-Tetradecanoylphorbol-13-Acetate (TPA) affects the programmed process of terminal differentiation in the renewing epidermis. One of the well documented effects of TPA in adult mouse epidermis is the increase in thickness of the granular layer accompanied with the increase in synthesis of the granular cell specific protein, histidine-rich protein (HRP). However, the significance of the role of this effect, as a part of the tumor promoting process, is still conjectural. This dissertation reports the results of a study of the induction of HRP synthesis by TPA in cultured rat keratinocytes. A kinetic study of HRP induction in the basal cell population exposed to TPA was performed in either monolayer cultures maintained in low calcium (0.1 mM) medium or stratifying cultures after being transferred to normal (2.0 mM) medium. HRP was assayed immunocytochemically with a monoclonal antibody, 3F6-6, raised against HRPII isolated from newborn rat epidermis. Exposure of stratifying cultures to TPA, resulted in the appearance of positive immunostaining for HRP much earlier and much more intensively than in the absence of TPA. TPA also enhanced stratification of these cultures but the positive expression of HRP preceded the stratification. These observations suggest that the TPA-induced process of terminal differentiation triggered the stratification. The observation of the induction of HRP synthesis in monolayer cultures containing mainly basal cells confirmed that the enhancement of HRP synthesis by TPA exposure is the result of TPA-induced acceleration of terminal differentiation and that the induction of terminal differentiation occurs independently of stratification. At the time most of the cells in monolayer cultures were becoming HRP positive, DNA and protein synthesis had decreased to 5% and 40%, respectively. Although a transient mitogenic response was obvious during the early period of TPA exposure, there was no concomitant increase in DNA synthesis, suggesting that cultured rat keratinocytes are not the target of the hyperplastic capacity of TPA. In conclusion, the potent tumor promoter, TPA, has been shown to cause the basal cell population to commit to terminal differentiation and accelerate the rate of the terminal differentiation process in cultures of rat keratinocyte.

Regulation of growth and differentiation is of paramount importance to the cell, and disruption of signal transduction pathways that control these functions can result in oncogenesis. Considerable evidence indicates that the low-molecular-weight GTPase, Ras, is central to multiple signaling pathways involved in maintaining controlled cell growth within eukaryotic organisms. Understanding the regulation of Ras will give us insight into these signaling pathways, and aid us in resolving the complexities of Ras-mediated oncogenesis. One critical regulator of Ras is the p120 GTPase-activating protein (GAP). At the cell membrane, p120 GAP accelerates the inactivation of Ras, thereby inhibiting its mitogenic signal. I have characterized some of the parameters that influence the interaction of p120 with another GAP, p190, which regulates the Rho family of GTPases. Both tyrosine phosphorylation of p190 and the presence of two SH2 domains in p120 GAP are necessary for maximal p120/p190 complex formation in vitro. Consistent with these findings, tyrosine phosphorylation of p190 in Src transformed cells correlates with increased p120/p190 complex formation. These results suggest a model in which formation of p120/p190 complexes in the cytosol prolongs the Ras mitogenic signal by preventing p120 GAP from accessing Ras at the cell membrane. In addition, p120/p190 complex formation may couple Ras and Rho signaling pathways, thus coordinating DNA replication with changes in cell morphology. To determine whether p120 GAP N-terminal sequences directly contribute to regulation of its catalytic activity towards Ras, I constructed and characterized a collection of p120 GAP deletion mutants. Analysis of p120 mutants containing deletions within the SH2 and SH3 regions demonstrated that the presence of these sequences is essential for full p120 catalytic activity. Consistent with these results, the N-terminal portion of p120 GAP containing SH2 and SH3 domains enhanced catalytic activity of neurofibromin, another GAP that regulates Ras in the cell. Together, my results suggest multiple roles for p120 GAP N-terminal sequences in regulation of both protein-protein interactions as well as catalytic activity. These findings have important implications for understanding regulation of Ras in normal mitogenic signaling and oncogenesis.

This thesis describes (1) the purification and initial characterization of cytochromes $ba\sb3$ and $b\sb{562}$, two new respiratory proteins from plasma membranes of the thermophilic, aerobic bacterium, Thermus thermophilus, and (2) studies of the reaction of cytochrome $c\sb{1}aa\sb3$, a Thermus terminal oxidase with peroxides. Cytochromes $ba\sb3$ catalyzes the consumption of O$\sb2$ in the presence of the substrates, horse heart cytochrome c, and the artificial dye TMPD. Metal analysis and pyridine hemochrome spectra revealed the presence of heme A, heme B, and Cu in a ratio of $\sim$1:1:2. Amino acid analysis yielded a minimum molecular weight of 34,500, including $\sim$1 cysteine and $\sim$9 hisitidines, per heme A. EPR spectra showed (1) resonances attributed to low-spin heme, and (2) features similar to those exhibited by Cu$\sb{\rm A}$ of $aa\sb3$-type oxidases; only 50% of the total Cu and 50% of the total Fe were detectable. Mossbauer spectra of the oxidized protein showed a component due to a paramagnetic, low-spin cytochrome, and components due to a coupled cytochrome. Our preliminary interpretation is that this protein contains heme A and one Cu ion coupled in a manner similar to cytochrome $a\sb3$ and Cu$\sb{\rm B}$ of $aa\sb3$-type oxidases, and two magnetically isolated chromophores: heme B and a second Cu ion. Metal, protein, and amino acid analyses, pyridine hemochrome spectra, and denaturing gel electrophoresis of cytochrome $b\sb{562}$ were consistent with $\sim$2 hemes B per $\sim$31,000 kDa. Reduced cytochrome $b\sb{562}$ readily transferred electrons to cytochrome c, and thus appeared to have a relatively low reduction potential ($