Experimental infection (EI) studies, involving the intentional inoculation of animal or human subjects with an infectious agent under controlled conditions, have a long history in infectious disease research. Longitudinal infection response data often arise in EI studies designed to demonstrate vaccine efficacy, explore disease etiology, pathogenesis and transmission, or understand the host immune response to infection. Viral loads, antibody titers, symptom scores and body temperature are a few of the outcome variables commonly studied. Longitudinal EI data are inherently nonlinear, often with single-peaked response trajectories with a common pre- and post-infection baseline. Such data are frequently analyzed with statistical methods that are inefficient and arguably inappropriate, such as repeated measures analysis of variance (RM-ANOVA). Newer statistical approaches may offer substantial gains in accuracy and precision of parameter estimation and power. We propose an alternative approach to modeling single-peaked, longitudinal EI data that incorporates recent developments in nonlinear hierarchical models and Bayesian statistics. We begin by introducing a nonlinear mixed model (NLMM) for a symmetric infection response variable. We employ a standard NLMM assuming normally distributed errors and a Gaussian mean response function. The parameters of the model correspond directly to biologically meaningful properties of the infection response, including baseline, peak intensity, time to peak and spread. Through Monte Carlo simulation studies we demonstrate that the model outperforms RM-ANOVA on most measures of parameter estimation and power. Next we generalize the symmetric NLMM to allow modeling of variables with asymmetric time course. We implement the asymmetric model as a Bayesian nonlinear hierarchical model (NLHM) and discuss advantages of the Bayesian approach. Two illustrative applications are provided. Finally we consider modeling of viral load. For several reasons, a normal-errors model is not appropriate for viral load. We propose and illustrate a Bayesian NLHM with the individual responses at each time point modeled as a Poisson random variable with the means across time points related through a Tricube mean response function. We conclude with discussion of limitations and open questions, and a brief survey of broader applications of these models.

Tertiary institutions in South Africa have experienced radical changes in the past decades, especially due to the change from technikons to universities of technology. These changes created new mental and emotional demands for academic staff and placed them under additional pressure. Problems experienced by tertiary institutions include constantly changing systems, students from underprivileged backgrounds and decreased subsidies from the state. These factors could lead to role overload and role conflict. The objective of this research was to examine the relationships between individual indicators of work climate (job challenge demand, role overload and role conflict, job satisfaction and pay satisfaction and social support) and turnover intention. Further objectives included empirically determining if these indicators of work climate can be used to predict turnover intention and to determine if social support plays a moderating role in the translation of work climate in turnover intention. A cross-sectional survey design was used. A convenience sample was taken from a South African university of technology. Measuring instruments for all the variables of interest were administered. Descriptive statistics were used to analyse the data. Finally, a structural equation model was developed to explain the relations between the variables. The results obtained for the scales proved that four of the seven specific measuring instruments are reliable in terms of their specific use for employees in a South African tertiary institution. Job challenge demand, quantitative role overload and role conflict were less reliable. Results showed that when an employee feels that he/she has too much to do in too little time, or if the task is too difficult to complete, he/she will experience lower levels of job satisfaction which in turn may lead to higher levels of turnover intention. Social support from the supervisor and colleagues increase job satisfaction. A moderating effect for social support between work climate (role characteristics and satisfaction) and turnover intention was demonstrated. By way of conclusion, recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2008.

The South African mining industry is facing rising levels of skills shortage. According to reports, there are a number of reasons for this, one being the low number of graduates who enrol for engineering related qualifications versus the number of graduates who eventually graduate with an engineering qualification. More emphasis needs to be placed on bursaries for university candidates, as well as training in organisations, to groom graduates in this field. The main purpose of this study was to determine the relationship between job characteristics, communication with the manager, organisational commitment, social support and job satisfaction for a sample of employees in South Africa, and specifically to determine whether social support plays a moderating role in this relationship. The participants were a convenience sample of trainees in a mining training academy, in the North–West Province. Participants’ informed consent was sought by explaining what the general purpose of the study is as well as including on the cover page of the questionnaire information around details of the study. Participants had the option of either posting the questionnaires after completing it in their own time (stamped envelope was supplied) or handing the completed questionnaire into their human resource department. This method allowed everyone to complete the questionnaire in their own time. Regarding the relationship between job characteristics (i.e. job autonomy, job challenge, and communication with the manager); all were positively correlated to the outcome variable, namely job satisfaction. None of the interaction terms were significant predictors of the outcome variable (job satisfaction). A conclusion can be drawn from this that social support does not have a moderating effect on the relationship between the measured independent variables (job characteristics and manager communication) and the outcome variable (job satisfaction). However, when only social support from supervisor and colleagues and the job characteristics were considered, it was seen that job autonomy, feedback and social support from colleagues are significant predictors of job satisfaction. This finding indicates that it is not only important for trainees to experience autonomy in the execution of their tasks, but that they also need collegial support and good feedback about such performance in order to experience job satisfaction. In conclusion, recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.

The South African mining industry is facing rising levels of skills shortage. According to reports, there are a number of reasons for this, one being the low number of graduates who enrol for engineering related qualifications versus the number of graduates who eventually graduate with an engineering qualification. More emphasis needs to be placed on bursaries for university candidates, as well as training in organisations, to groom graduates in this field. The main purpose of this study was to determine the relationship between job characteristics, communication with the manager, organisational commitment, social support and job satisfaction for a sample of employees in South Africa, and specifically to determine whether social support plays a moderating role in this relationship. The participants were a convenience sample of trainees in a mining training academy, in the North–West Province. Participants’ informed consent was sought by explaining what the general purpose of the study is as well as including on the cover page of the questionnaire information around details of the study. Participants had the option of either posting the questionnaires after completing it in their own time (stamped envelope was supplied) or handing the completed questionnaire into their human resource department. This method allowed everyone to complete the questionnaire in their own time. Regarding the relationship between job characteristics (i.e. job autonomy, job challenge, and communication with the manager); all were positively correlated to the outcome variable, namely job satisfaction. None of the interaction terms were significant predictors of the outcome variable (job satisfaction). A conclusion can be drawn from this that social support does not have a moderating effect on the relationship between the measured independent variables (job characteristics and manager communication) and the outcome variable (job satisfaction). However, when only social support from supervisor and colleagues and the job characteristics were considered, it was seen that job autonomy, feedback and social support from colleagues are significant predictors of job satisfaction. This finding indicates that it is not only important for trainees to experience autonomy in the execution of their tasks, but that they also need collegial support and good feedback about such performance in order to experience job satisfaction. In conclusion, recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2012.

Project management used to be described as rational and well structured - a notion that builds on a traditional view that project management is about planning, budgeting and controlling. Nevertheless, it has been questioned if this is a full description. Even though project management techniques were developed for large projects, those techniques and models are used today in small projects of short duration - projects that are quite dissimilar to the large ones. The present study takes a practice perspective to investigate what project managers do when they lead such short projects. Its observations and interviews are used to analyze what happens in the everyday life of project managers. Using classical managerial behaviour studies as a foundation, seen through a practice perspective lens, the study finds that the work of project managers in a software development project is fragmented – their time is filled with formal and informal meetings of different kinds and efforts to resist disturbances in the project. Three challenges were found in the project manager’s work. The first was to Understand: to create meaning. The plans were clearly defined at the start of the project but as the goals were later re-defined, it was scarcely possible to finalize them before delivery. Contrary to the traditional view that plans are inflexible, these plans were discussed, negotiated and interpreted throughout the project. This was the continuous work of creating both meaning in the plans and a common understanding of the project. The second challenge was to Order/coordinate: to manage resources. The project manager reacted to emerging issues rather than acting to prevent things from happening. These reactions led to creative ways of managing and finding solutions to problems. One important way of managing new or changed conditions was to reorganize resources to cover the needs of different teams. The meetings played a central role in this work as arenas for negotiating resources, which became especially evident in times of stress or high workload. The third challenge was to Make it in time: to manage time. Time is a central aspect of project management as projects are temporary organizations; they have a beginning and an end. Previous research has found a point in time, in the middle of a project, when the team starts to feel pressured and stressed about meeting their deadlines. For project managers there is always a struggle to manage time, as dates for delivery are one of the things in a project that are not negotiable. In short-duration projects where projects follow each other seriatim, there is an almost constant feeling of urgency; stress and pressure. The project manager used experiential data to determine and plan the amount of time that would be needed to manage changes in the project, intending that the slack created would enable the project to deliver on time. Although changes and deviations were expected, the project manager rarely knew beforehand what they were or when they would come. The three challenges, previously described as separated from each other, were observed to be all managed simultaneously. The site, the practitioner and the practices influence daily work practice.

Resumo: O experimento teve por objetivo avaliar a influência dos aditivos fitogênicos (AF) e ácidos orgânicos (AO), isolados ou associados, sobre a metabolizabilidade dos nutrientes da dieta bem como, avaliar o desempenho e características de carcaça de frangos de corte. Foram realizados dois ensaios em delineamento inteiramente casualizado em esquema fatorial 2 x 2 + 1 com cinco tratamentos sendo constituídos de dieta controle (DC); DC + AF; DC + AO; DC + AF + AO; DC + avilamicina + monensina sódica. No experimento I foram realizados dois ensaios de metabolismo para determinar os coeficientes de metabolizabilidade dos nutrientes da dieta nas fases inicial e crescimento, utilizando 125 frangos de corte machos. No experimento II foram utilizados 2520 pintos de um dia de idade alojados em 40 unidades experimentais e, avaliou-se o desempenho e características de carcaça. Os aditivos fitogênicos e ácidos orgânicos isolados ou associados melhoram a metabolizabilidade dos nutrientes da dieta e substituem os antibióticos melhoradores de desempenho. O uso de ácidos orgânicos isoladamente ou associados aos aditivos fitogênicos em dietas de frangos de corte melhoram o desempenho das aves em relação a dietas isentas de antibióticos melhoradores de crescimento aos 42 dias de idade. Aditivos fitogênicos e ácidos orgânicos isolados e associados proporcionam melhores características de carcaça / Abstract: The experiment evaluated the influence of isolated or associated phytogenics additive (FA) and organic acids (OA) on nutrient metabolization, performance and carcass characteristics of broiler chickens. Two experiments were conducted in a completely randomized design with 2 x 2 + 1 factorial arrangement of treatments. There were five treatments described as follows: control diet (CD), CD+FA, CD+OA, CD+FA+OA and CD + avilamicin + monesin sodium. In the first experiment a total of 125 male broilers were divided in two metabolism trials to determine the coefficients of metabolizability of the nutrients of starter and grower diets. In the second experiment, 2520 one-day-old chicks were housed in 40 experimental units to evaluate the performance and carcass characteristics. The phytogenics additive and organic acids, isolated or combined, improve the nutrient metabolization of the diet and replace the antibiotics for growth promotion. The use of isolated organic acids or combined with phytogenics additive in diets for broilers improve the chicken performance compared with free growth promoter diets at 42 days old. Isolated or associated phytogenics additive (FA) and organic acids (OA) provided better carcass characteristics / Orientador: José Roberto Sartori / Coorientador: Elisabeth Gonzales / Banca: Marcos Barcellos Café / Banca: Alfredo Sampaio Carrijo / Banca: Adriano Sakai Okamoto / Banca: Antonio Carlos Pezzato / Doutor

The goal of this thesis is to advance the use of recurrent neural network language models (RNNLMs) for large vocabulary continuous speech recognition (LVCSR). RNNLMs are currently state-of-the-art and shown to consistently reduce the word error rates (WERs) of LVCSR tasks when compared to other language models. In this thesis we propose various advances to RNNLMs. The advances are: improved learning procedures for RNNLMs, enhancing the context, and adaptation of RNNLMs. We learned better parameters by a novel pre-training approach and enhanced the context using prosody and syntactic features. We present a pre-training method for RNNLMs, in which the output weights of a feed-forward neural network language model (NNLM) are shared with the RNNLM. This is accomplished by first fine-tuning the weights of the NNLM, which are then used to initialise the output weights of an RNNLM with the same number of hidden units. To investigate the effectiveness of the proposed pre-training method, we have carried out text-based experiments on the Penn Treebank Wall Street Journal data, and ASR experiments on the TED lectures data. Across the experiments, we observe small but significant improvements in perplexity (PPL) and ASR WER. Next, we present unsupervised adaptation of RNNLMs. We adapted the RNNLMs to a target domain (topic or genre or television programme (show)) at test time using ASR transcripts from first pass recognition. We investigated two approaches to adapt the RNNLMs. In the first approach the forward propagating hidden activations are scaled - learning hidden unit contributions (LHUC). In the second approach we adapt all parameters of RNNLM.We evaluated the adapted RNNLMs by showing the WERs on multi genre broadcast speech data. We observe small (on an average 0.1% absolute) but significant improvements in WER compared to a strong unadapted RNNLM model. Finally, we present the context-enhancement of RNNLMs using prosody and syntactic features. The prosody features were computed from the acoustics of the context words and the syntactic features were from the surface form of the words in the context. We trained the RNNLMs with word duration, pause duration, final phone duration, syllable duration, syllable F0, part-of-speech tag and Combinatory Categorial Grammar (CCG) supertag features. The proposed context-enhanced RNNLMs were evaluated by reporting PPL and WER on two speech recognition tasks, Switchboard and TED lectures. We observed substantial improvements in PPL (5% to 15% relative) and small but significant improvements in WER (0.1% to 0.5% absolute).

L'étude porte sur l'allocation de ressources aux œufs d’oiseaux selon les caractéristiques du male partenaire ou de l’environnement. les données étudiées sont : taille de la ponte et caractéristiques des œufs (masse, masse des constituants, concentration de testostérone, lysozyme, ovotransferrin). les caractéristiques du male prises en compte sont s'il est choisi ou non par la femelle et son statut social. en plus, l’effet du bruit et d’un vaccination couple avec un surproduction des œufs sont pris en compte. Deux expériences ont été menées sur le canari domestique (Serinus canaria) en laboratoire, au sein du LECC de Paris Ouest Nanterre. Deux expériences ont eu lieu en milieu semi-naturel au DiSIT de l’Università degli Studi del Piemonte Orientale (Italie) sur la perdrix grise (Perdix perdix) et rouge (Alectoris rufa).Chez la perdrix grise, nous observons effets positifs de la préférence et du statut social sur la testostérone et sur le taux d’éclosion. cette hormone peut rendre les oisillons nidifuges plus compétitifs vis-à-vis des couvées voisines. Chez le canari, on observe un effet positif de la préférence sur le poids des œufs et sur le lysozyme, important substance antimicrobienne. en plus, on a trouvé un influence négative du bruit sur la sélection sexuelle et sur le numéro des œufs pondues.Chez la perdrix rouge, nous observons variations significatives des components de l’oeuf en relation a la surproduction des œufs (épuisement des ressources). En conclusion, la femelle n'est pas seule à déterminer les caractéristiques des œufs. le male partenaire et l’environnement ont aussi une influence sur leur composition et donc sur le développement des jeunes. / The study focuses on the allocation of resources to eggs of birds according to the characteristics of the male partner or the environment. The data studied are: clutch size and egg characteristics (mass, mass constituents, testosterone, lysozyme, ovotransferrin). Male characteristics taken into account are if it is selected or not by the female and his social status. In addition, the effect of noise and a vaccination coupled with an overproduction of eggs are taken into account.Two experiments were conducted on the domestic canary (Serinus canaria) in the LECC laboratory of Paris Ouest Nanterre.Two experiments were carried out in semi-natural condition to DiSIT laboratory of the Università degli Studi del Piemonte Orientale (Italy) on grey partridge (Perdix perdix) and red-legged partridge (Alectoris rufa).In the grey partridge, positives effects of preference and social status are observed on testosterone and hatchability. This hormone can make precocial chicks more competitive with neighboring broods.In canaries, there is a positive effect of preference on egg weight and lysozyme, an important antimicrobial substance. In addition, a negative influence of noise is found on sexual selection and number of eggs laid.In the red-legged partridge, significant changes in the egg components are observed in relation to the overproduction of eggs (depletion).In conclusion, the female is not only to determine the characteristics of eggs. The male partner and the environment also have an influence on their composition and therefore on the development of chicks.

With the recent boom in big data and the continuous need for innovation, Artificial Intelligence is carving out a bigger place in our society. Through its computer-based capabilities, it brings new possibilities to tackle many issues within organizations. It also raises new challenges about its use and limits. This thesis aims to provide a better understanding of the role of humans and Artificial Intelligence in the organizational decision making process. The research focuses on knowledge-intensive firms. The main research question that guides our study is the following one:   How can Artificial Intelligence re-design and develop the process of organizational decision making within knowledge-intensive firms?   We formulated three more detailed questions to guide us: (1) What are the roles of humans and Artificial Intelligence in the decision making process? (2) How can organizational design support the decision making process through the use of Artificial Intelligence? (3) How can Artificial Intelligence help to overcome the challenges experienced by decision makers within knowledge-intensive firms and what are the new challenges that arise from the use of Artificial Intelligence in the decision making process?   We adopted an interpretivist paradigm together with a qualitative study, as presented in section 3. We investigated our research topic within two big IT firms and two real estate startups that are using AI. We conducted six semi-structured interviews to enable us to gain better knowledge and in-depth understanding about the roles of humans and Artificial Intelligence in the decision making process within knowledge-intensive firms. Our review led us to the theoretical framework explained in section 2, on which we based our interviews.   The results and findings that emerged from the interviews follow the same structure than the theoretical review and provide insightful information in order to answer the research question. To analyze and discuss our empirical findings that are summarized in the chapter 5 and in a chart in the appendix 4, we used the general analytical procedure for qualitative studies. The structure of chapter 5 follows the same order than the three sub questions.   The thesis highlights how a deep understanding of Artificial Intelligence and its integration in the process of organizational decision making of knowledge-intensive firms enable humans to be augmented and to make smarter decisions. It appears that Artificial Intelligence is used as a decision making support rather than an autonomous decision maker, and that organizations adopt smoother and more collaborative designs in order to make the best of it within their decision making process. Artificial Intelligence is an efficient tool to deal with complex situations, whereas human capabilities seem to be more relevant in situations of uncertainty and ambiguity. Artificial Intelligence also raises new issues for organizations regarding its responsibility and acceptation by society as there is a grey area surrounding machines in front of ethics and laws.

The central theme of this study involves an ethical examination of the issues of justice and poverty in the Democratic Republic of Congo (DRC). Chapter one deals with the methodology of the research. It also provides an overview of the DRC. Chapter two shows that justice occupies a special place in society. It represents a fundamental aspect of human beings that illustrates one’s humanity. In the biblical perspective, justice is considered as a chief attribute of God. Chapter three discusses the phenomenon of poverty in the world, particularly in developing nations where people are unable to meet their basic needs. The chapter explores different causes of poverty on the African continent, as well as the crisis of underdevelopment, which to some extent is attributed to the exploitation of African nations by the Western powers. In chapter four, the researcher deals with the situation of poverty in the DRC. It is argued that regardless of its apparent wealth, the DRC remains one of the poorest countries in the world. The chapter explores the period of economic growth in the DRC, as well as its economic decline. Certain reasons for this economic decline are evoked, of which the most important are the economic policies of Zairianisation and radicalisation In chapter five, research steers toward the role that the Church could play in the areas of justice and poverty in the DRC. The Church is challenged to promote justice and the struggle against poverty in all its forms. It is also challenged to fully play its prophetic role. Chapter six explores poverty in relation to theological reflections. Poverty is considered as being evil. The responsibility of theologians and Christians in general is to promote a fair and just society in which the poor will be empowered in such a manner that they can contribute to the development of their community. In chapter seven, the researcher makes some recommendations to both Church and government and concludes that patriotism, justice, moral values and commitments to African solidarity are pillars on which Congolese citizens should build their nation. / Theological Ethics / D.Th. (Theological Ethics)