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FAculty of SCience School of Cheistry 9910913j messai@auvum.chem.wits.ac.za / The monodentate phosphine complexes bui3PMX (2a: M = Cu, X = Cl, 2b: M = Cu, X = I, 2c: M = Ag, X = Cl, 2d: M = Au, X = Cl) were synthesised in high yields from bui3P and MX. Their reaction with [Li{μ-N(R)C(but)C(H)R}]2 (R = SiMe3) gave the monomeric complexes bui3PCuN(R)C(but)=C(H)R (3a) and bui3PMC(H)RC(but)=NR (3b: M = Ag, 3c: M = Au) in moderate to high yields. The bonding mode in the 1-aza-allyl complexes 3a-c was found to depend strongly on the metal ion, with 3a being an enamide complex and 3b and 3c iminoalkyl complexes. The reaction of bidentate ligand dpmaaH2 (2,3-bis(diphenylphosphino)maleic acid) with R2Sn-precursors led to novel dialkyl tin dpmaa complexes (R2Sn)(O,O dpmaa) (6) (where 6a, R = Me; 6b, R = Bu) were synthesized. Complexation of the tin/phosphine complexes led to the heterobimetallic complexes {Au[(dpmaaO,O)(SnR2)]2}Cl (7a and 8a) {Au[(dpmaaO,O)(SnR2)][dpmaaH2]}Cl (7b and 8b) (where 7a and 8a, R = Me; 7b and 8b, R = Bu) and the mixed metal complexes {Au[(dpmaaO,O)(RuCl)]2}Cl (9a) {Au[(dpmaaO,O)(SnBu2)(dpmaaO,O)RuCl)]}Cl (9b) and {Au[(dpmaaO,O)(RuCl)][dpmaa]}Cl (9c). All compounds were fully characterised by multinuclear NMR spectroscopy and microanalysis (not 3a, 3b, 4 and 5) solid state IR spectroscopy (KBr-pellets) (4-9) and mass spectrometry (6-8). The solid state structures of complexes 2c, 2d, 3c, 6a and 6b (two polymorphs) have been determined by X-ray crystallography revealing the presence of rare trimeric macrocycles in the case of 6a and 6b. The anti-tumour activity of the metal complexes (6b and 7-9) was tested on a single cell-line (except 7a and 8a which were on eight cell-lines) and their activity was compared to cisplatin.

This thesis comprises four articles and a summarizing text. The articles build on three sets of data regarding various aspects of the teaching profession. One objective is to illustrate and discuss what may make teaching appear to be a complex and intensive profession, as well as what conditions are necessary to make the relationship between teachers and pupils appear to be characterized by asymmetry. A second objective is to discuss which changes to working conditions could in turn lead to changes to the apparent complications in teachers’ working conditions. Using a systemic approach as the point of departure, different mechanisms that may contribute to the constitution of teachers’ identity and role are discussed. On the one hand the systemic analysis moves from a biological point of view, via a cultural, a psychological and a societal point of view, to explain and comprehend how groups can develop asymmetrical relationships. On the other hand, curriculum changes, as well as changes in the school system over the last twenty years and the synchronous nature of teacher work, are used in discussing the complex and intensive character of teaching. Abduction makes it possible to explain the complex and intensive character of the teaching profession, as well as the asymmetric relationship between teachers and pupils, using these mechanisms. It is also proposed that interplay exists between these two aspects. A third result is the proposal that many of these problems may be explained by the extensive reforms that have burdened teachers and schools since the end of the last century. In conclusion, changes in teachers’ attitudes towards innovation, their approach to knowledge, the relationship with the pupils, and the teachers’ mission, are suggested as possible means of modifying the situation.

This study examines changes in a company’s audit committee accounting expertise following an M&A transaction. M&A accounting (ASC 805) is complex, nuanced, and error-prone. An M&A also involves significant operational and financial changes for the acquirer, including changes in internal control over financial reporting. Thus, an acquirer’s demand for accounting expertise is likely heightened at the time of an M&A. This study provides the first insights (to my knowledge) regarding the role of accounting experts in the dynamic M&A setting. In a sample of relatively large (on average) M&As, I document that there are financial reporting benefits (reduced likelihood of restatements, higher likelihood of timely goodwill impairments, and smaller allocations of purchase price to in-process research and development) associated with changes/increases in audit committee accounting expertise. Further, my results suggest that changes/increases in audit committee accounting expertise matter more than changes/increases in other types of audit committee expertise (supervisory, industry, and M&A contextual). I document that changes/increases in audit committee accounting expertise are positively associated with accounting and business complexities. Collectively, the evidence suggests that accounting expertise is valuable in the M&A setting. This provides support for the SEC’s definition (in its 2002 proposal, although not in its final 2003 rule) of audit committee financial experts as those with accounting-specific backgrounds (SEC 2002, 2003). / Business Administration/Accounting

Construction waste generation is a global issue in the sustainable construction context and several studies have been performed in different parts of the world to develop methods and tools for waste prevention, reduction, reuse and recycling. Most of these studies adopted a linear approach by focussing on a specific project phase, such as design, procurement or construction. However, there is a consensus in the literature that factors causing construction waste span across the project life cycle and recent researchers emphasised the need for a more integrated lifecycle approach to holistically assess and evaluate causes of waste to suggest recommendations to reduce lifecycle construction waste generation. Over recent years, the UK government has been investing billions of pounds in new and refurbished healthcare projects, where the healthcare buildings are often referred to, in literature, as complex buildings. This large investment has created a number of sustainability issues including water consumption, CO2 emissions, energy consumption, and more significantly construction waste generation. However, no significant research has been undertaken to propose a systematic construction waste minimisation mechanism for healthcare construction projects. Therefore, this research aims to develop a lifecycle construction waste minimisation framework for healthcare projects (HC-WMF). In order to identify the research problem and construction waste generation issues peculiar to healthcare projects, nine preliminary interviews were conducted with healthcare clients (N=3), architects (N=3), and contractors (N=3). The findings revealed that healthcare projects generate high rates of waste compared to other building projects throughout the project lifecycle, identified complex features that have an effect on waste generation, and identified particular causes of construction waste in healthcare projects. A further in-depth study based on four case studies was undertaken to understand the impact of waste generation due to the causes of waste, the relationship between complex features in healthcare projects and the causes of waste, and best waste minimisation practices to be implemented throughout a healthcare project lifecycle to address construction waste causes. Three interviews (client, architect, and contractor) from each case study were undertaken during the data collection stage. A Healthcare Construction Waste Minimisation Framework (HC-WMF) and Self-Assessment Tool (SAT) were then developed based on the findings of the literature review, preliminary data collection study and case studies, and adoption of the key concepts of problem solving methodology. This HC-WMF comprised six waste minimisation strategies (project documents management, stakeholders waste awareness, communication and coordination, buildability, materials selection and procurement, and change management) to be followed throughout the lifecycle stages of a healthcare project. SAT provides a means to assess the effectiveness in implementing HC-WMF and to obtain feedback and learning outcomes for continuous further improvements. In order to validate the developed HC-WMF and SAT a validation questionnaire (N=26) and validation interviews (N=4) were conducted. The validation results showed that the HC-WMF and SAT would be very useful in reducing construction waste generation from healthcare projects. The research contributes to construction waste minimisation research introducing a novel approach to lifecycle waste reduction. Also, the research revealed the complex features in healthcare projects that affect construction waste generation, causes and origins of waste peculiar to healthcare projects, and best waste minimisation strategies to implement to reduce construction waste generation from healthcare projects. Most importantly, through HC-WMF, this research produced a set of guidelines to be followed throughout the healthcare project lifecycle to reduce construction waste generation. The study has made recommendations which, if adopted, will lead to significant improvements in sustainable healthcare construction due to construction waste minimisation. The content should be of interest to clients, designers, and contractors dealing with construction waste minimisation and sustainable construction in healthcare projects. Key words: Construction waste, Healthcare, Causes of waste, Healthcare complexities, Waste minimisation, UK.

With the increased demand for the utilization of computerized information systems by business users, the need for investigating the impact of various user interfaces has been well recognized. It is usually assumed that providing the user with assistance in the usage o-f a system would significantly increase the user's productivity. There is, however, a dearth of systematic inquiry into this commonly held notion to verify its validity in a scientific fashion. The purpose of this study is to investigate the impact of system-provided user assistance and complexity level of the problem on novice users' productivity in specifying database queries. The study is theoretical in the sense that it presents an approach adopted from research in deductive database systems to attack problems concerning user interface design. It is empirical in that it conducts an experiment in a controlled laboratory setting to collect primary data for the testing of a series of hypotheses. The two independent variables are system-provided user assistance and problem complexity, while the dependent variable is the user's query specification productivity. Three measures are used as separate indicators of query specification productivity: number of syntactic errors, number of semantic errors, and time required for completing a query task. Due to the lack of a well-defined metric for user assistance, the study first presents a generic classification scheme for relational query specification. Based on this classification scheme, two quantitative metrics for measuring the amount of user assistance in terms of prompts and defaults were developed. The user assistance is operationally defined with these two metrics. Four findings emerge as significant results of the study. First, user assistance has a significant main effect on all of the three dependent measures at the 1 percent significance level. Second, problem complexity also has a significant impact on the three productivity measures at the 1 percent significance level. Third, the interaction effect of user assistance and problem complexity on the number of semantic errors and the amount of time for completion is significant at the 1 percent level. Fourth, Although this interaction effect on the number of syntactic errors is not significant at the 5 percent level, it is at the 10 percent level. More research is needed to permit a thorough understanding of the issue of user interface design. A list of topics is suggested for future research to confirm or to modify the findings of this study.

The problem of cross-cultural complexities is a hindrance to effective multicultural team leadership across many industries. Cultural differences among project team members cause conflict, misunderstanding, and poor project performance. The absence of competent leaders is a problem because business in the future will rely increasingly on the use of multicultural project teams. The purpose of this qualitative exploratory case study was to explore the challenges faced and the cultural competencies needed by project managers leading multicultural software development project teams to successfully manage and resolve cross-cultural interpersonal conflict amongst project team members. The researcher collected data using semi-structured interviews with the population of 12 project managers recruited from the Project Management Institute’s credentialed project management professionals LinkedIn group. Through a cross-case synthesis, the researcher identified common themes and aligned them with the two study constructs: cross-cultural interpersonal conflict resolution and multicultural skills. The findings of the research revealed that the project managers perceived challenges including language barriers, cycles of mistrust, and competitive attitudes when managing multicultural teams. In order to mitigate these difficulties, the participants reported that project managers require excellent communication, negotiation, and emotional intelligence skills. The contributions of this study to the field of conflict analysis and resolution include highlighting common cross-cultural complexities encountered in multicultural teams, as well as effective methods of minimizing, eliminating, or mitigating these issues and the resulting interpersonal conflict.

This thesis studies the generalization ability of machine learning algorithms in a statistical setting. It focuses on the data-dependent analysis of the generalization performance of learning algorithms in order to make full use of the potential of the actual training sample from which these algorithms learn.¶ First, we propose an extension of the standard framework for the derivation of generalization bounds for algorithms taking their hypotheses from random classes of functions. This approach is motivated by the fact that the function produced by a learning algorithm based on a random sample of data depends on this sample and is therefore a random function. Such an approach avoids the detour of the worst-case uniform bounds as done in the standard approach. We show that the mechanism which allows one to obtain generalization bounds for random classes in our framework is based on a “small complexity” of certain random coordinate projections. We demonstrate how this notion of complexity relates to learnability and how one can explore geometric properties of these projections in order to derive estimates of rates of convergence and good confidence interval estimates for the expected risk. We then demonstrate the generality of our new approach by presenting a range of examples, among them the algorithm-dependent compression schemes and the data-dependent luckiness frameworks, which fall into our random subclass framework.¶ Second, we study in more detail generalization bounds for a specific algorithm which is of central importance in learning theory, namely the Empirical Risk Minimization algorithm (ERM). Recent results show that one can significantly improve the high-probability estimates for the convergence rates for empirical minimizers by a direct analysis of the ERM algorithm. These results are based on a new localized notion of complexity of subsets of hypothesis functions with identical expected errors and are therefore dependent on the underlying unknown distribution. We investigate the extent to which one can estimate these high-probability convergence rates in a data-dependent manner. We provide an algorithm which computes a data-dependent upper bound for the expected error of empirical minimizers in terms of the “complexity” of data-dependent local subsets. These subsets are sets of functions of empirical errors of a given range and can be determined based solely on empirical data. We then show that recent direct estimates, which are essentially sharp estimates on the high-probability convergence rate for the ERM algorithm, can not be recovered universally from empirical data.

This study examines the slave narratives The Interesting Narrative of the Life of Olaudah Equiano, The History of Mary Prince, A West Indian Slave, Related by Herself and The Bondwoman’s Narrative to determine the way in which these texts depict the economics of labor in slave society. Taking into account the specific socio-historical contexts in which these narratives were written, this study analyzes the way in which the representations of labor in these narratives interrogate slavery and address issues relating to the social relations and power dynamics of their respective societies. Emphasis is given to the way in which the gender complexities of slavery merge with the dynamics of labor thereby underscoring some of the peculiarities of the female slave experience.

Dans cette thèse, nous nous intéressons au problème de recherche incrémentale de motifs dans des séquences fortement similaires (On-line Pattern Matching on Highly Similar Sequences), issues de technologies de séquençage à haut débit (SHD). Ces séquences ne diffèrent que par de très petites quantités de variations et présentent un niveau de similarité très élevé. Il y a donc un fort besoin d'algorithmes efficaces pour effectuer la recherche rapide de motifs dans de tels ensembles de séquences spécifiques. Nous développons de nouveaux algorithmes pour traiter ce problème. Cette thèse est répartie en cinq parties. Dans la première partie, nous présentons un état de l'art sur les algorithmes les plus connus du problème de recherche de motifs et les index associés. Puis, dans les trois parties suivantes, nous développons trois algorithmes directement dédiés à la recherche incrémentale de motifs dans un ensemble de séquences fortement similaires. Enfin, dans la cinquième partie, nous effectuons une étude expérimentale sur ces algorithmes. Cette étude a montré que nos algorithmes sont efficaces en pratique en terme de temps de calcul / In this thesis, we are interested in the problem of on-line pattern matching in highly similar sequences, On-line Pattern Matching on Highly Similar Sequences, outcoming from Next Generation Sequencing technologies (NGS). These sequences only differ by a very small amount. There is thus a strong need for efficient algorithms for performing fast pattern matching in such specific sets of sequences. We develop new algorithms to process this problem. This thesis is partitioned into five parts. In the first part, we present a state of the art on the most popular algorithms of finding problem and the related indexes. Then, in the three following parts, we develop three algorithms directly dedicated to the on-line search for patterns in a set of highly similar sequences. Finally, in the fifth part, we conduct an experimental study on these algorithms. This study shows that our algorithms are efficient in practice in terms of computation time.