The osteological paradox addresses how well interpretations of past population health generated from human skeletal remains reflect the health of the living population from which they were drawn. Selective mortality and hidden heterogeneity in frailty are particularly relevant when assessing childhood health in the past, as subadults are the most vulnerable group in a population and are therefore less likely to fully represent the health of those who survived. The ability of subadults to represent the health of those who survived is tested here by directly comparing interpretations of childhood stress based on non-survivors (subadults aged 6-20,14 females and 9 males) to those based on retrospective analyses of survivors (adults aged 21-46, 26 females and 27 males). Non-survivors and survivors were directly matched by birth year, using the Coimbra Identified Skeletal Collection; therefore interpretations of childhood stress reflect a shared childhood. Long bone and vertebral canal growth, linear enamel hypoplasia, cribra orbitalia, porotic hyperostosis, scurvy indicators and periosteal bone reactions were assessed for both groups. Overall, long bone growth generates the same interpretation of health for both non-survivors and survivors, and both groups exhibit the same range of stress (mild to severe), but the pattern of stress experienced in childhood differs between the two groups. Female survivors reveal different timing of stress episodes and a higher degree of stress than female non-survivors. Male survivors exhibit less stress than male non-survivors. These different patterns suggest that interpretations based solely on non-survivors would under-represent the stress experienced by female survivors and over-represent the stress experienced by male survivors, further demonstrating the importance of addressing issues of selective mortality. In addition, these different patterns suggest that hidden heterogeneity of frailty may be sex specific where males are more vulnerable to stress and females more able to develop resistance to stress and survive.

In this thesis we investigate two different aspects of the AdS/CFT correspondence. We first investigate the holographic AdS/CMT correspondence. Gravitational backgrounds in d+2 dimensions have been proposed as holographic duals to Lifshitz-like theories describing critical phenomena in d+1 dimensions with critical exponent z>1. We numerically explore a dilaton-Einstein-Maxwell model admitting such backgrounds as solutions. We show how to embed these solutions into AdS space for a range of values of z and d. We next investigate the AdS3/CFT2 correspondence and focus on the microscopic CFT description of the D1-D5 system on T^4*S_1. In the context of the fuzzball programme, we investigate deforming the CFT away from the orbifold point and study lifting of the low-lying string states. We start by considering general 2D orbifold CFTs of the form M^N/S_N, with M a target space manifold and S_N the symmetric group. The Lunin-Mathur covering space technique provides a way to compute correlators in these orbifold theories, and we generalize this technique in two ways. First, we consider excitations of twist operators by modes of fields that are not twisted by that operator, and show how to account for these excitations when computing correlation functions in the covering space. Second, we consider non-twist sector operators and show how to include the effects of these insertions in the covering space. Using the generalization of the Lunin-Mathur symmetric orbifold technology and conformal perturbation theory, we initiate a program to compute the anomalous dimensions of low-lying string states in the D1-D5 superconformal field theory. Our method entails finding four-point functions involving a string operator O of interest and the deformation operator, taking coincidence limits to identify which other operators mix with O, subtracting conformal families of these operators, and computing their mixing coefficients. We find evidence of operator mixing at first order in the deformation parameter, which means that the string state acquires an anomalous dimension. After diagonalization this will mean that anomalous dimensions of some string states in the D1-D5 SCFT must decrease away from the orbifold point while others increase. Finally, we summarize our results and discuss some future directions of research.

The osteological paradox addresses how well interpretations of past population health generated from human skeletal remains reflect the health of the living population from which they were drawn. Selective mortality and hidden heterogeneity in frailty are particularly relevant when assessing childhood health in the past, as subadults are the most vulnerable group in a population and are therefore less likely to fully represent the health of those who survived. The ability of subadults to represent the health of those who survived is tested here by directly comparing interpretations of childhood stress based on non-survivors (subadults aged 6-20,14 females and 9 males) to those based on retrospective analyses of survivors (adults aged 21-46, 26 females and 27 males). Non-survivors and survivors were directly matched by birth year, using the Coimbra Identified Skeletal Collection; therefore interpretations of childhood stress reflect a shared childhood. Long bone and vertebral canal growth, linear enamel hypoplasia, cribra orbitalia, porotic hyperostosis, scurvy indicators and periosteal bone reactions were assessed for both groups. Overall, long bone growth generates the same interpretation of health for both non-survivors and survivors, and both groups exhibit the same range of stress (mild to severe), but the pattern of stress experienced in childhood differs between the two groups. Female survivors reveal different timing of stress episodes and a higher degree of stress than female non-survivors. Male survivors exhibit less stress than male non-survivors. These different patterns suggest that interpretations based solely on non-survivors would under-represent the stress experienced by female survivors and over-represent the stress experienced by male survivors, further demonstrating the importance of addressing issues of selective mortality. In addition, these different patterns suggest that hidden heterogeneity of frailty may be sex specific where males are more vulnerable to stress and females more able to develop resistance to stress and survive.

Life history theory assumes that correlations among fitness-related life history traits should be negative among individuals, reflecting resource allocation constraints among traits such as growth and reproduction. These traits trade off because they cannot be simultaneously maximized in individuals facing finite resource acquisition. Positive correlations among traits that are expected to be negative (e.g. between energetically costly traits) have been regularly observed, however, and have usually been ascribed to genetic or resource acquisition differences. In the freshwater zooplankton Cladoceran Daphnia, positive correlations have been particularly well documented even when genetic and environmental variation have been controlled. The sign of these correlations represent a problem for life history theory, which is underpinned by the notion of universal and unavoidable costs associated with investing in a given trait. It has been suggested, however, that costs vary with environment and thus can change the sign of a correlation. A change in correlation sign over an environmental gradient may indicate that the assumed universality of costs and constraints are not as universal as expected by life history theory. Few life history experiments have examined traits in multiple environments, and fewer have done so while controlling resource acquisition and genetic variation. Here I ask whether the positive genetic correlations among somatic growth rate, egg production rate, and longevity are present in the face of equal ingestion, clonal individuals, and a finely resolved gradient of food quality, an environmental factor that frequently affects Daphnia. I partition trait covariation into genetic and residual, or environmental, sources. All resulting genetic correlations were non-significant. Residual correlations trended from significantly positive to negative between longevity and growth rate and remained near zero between longevity and egg rate. The residual correlation between growth and reproduction, two expensive traits, displayed significantly positive residual correlations across the food quality gradient remained significantly positive. Given the experimental controls in place, I suggest that differences in individual ontogeny may give rise to differential resource utilization or assimilation efficiency. This may be a mechanism for differential resource acquisition in the absence of ingestion variation. Additionally, the different ways genetic and residual correlations change over an environmental gradient may provide insight on one manner by which genotypes might coexist and provide a candidate explanation for the second paradox of the plankton. / Thesis (Master, Biology) -- Queen's University, 2014-03-31 07:01:21.774

Purpose: To explore new methodologies to quantify binocular interactions and shed light on their possible neural generators. Methods: Binocular inhibition (BI) was experimentally produced in 40 visually healthy subjects by inserting a series of neutral density (ND) filters in front of one eye. Visual evoked potentials were recorded with stimuli tuned for check size, location and contrast. The Pulfrich effect was investigated using computerized pendulums. Results: Stimulus parameters required to generate maximal BI differ from those for maximal binocular summation (BS). The phase shift required to reverse the Pulfrich effect was proportional to the strength of the ND filter used, and the implicit time measured with VEPs and calculated with the PE correlate. Conclusion: It appears separate neural generators are responsible for BI and BS.

The content of this thesis is two-fold. The first part takes the form of an essay while the second part presents a theoretical project for an architectural installation. Using these two modes as different ways to address similar issues, the present work proposes to question the instrumentalisation of geometry in today's architectural practice. The work of Lewis Carroll (Charles L. Dodgson) and, more specifically, his masterpiece, Alice's Adventures in Wonderland, will be approached and interpreted in order to observe the participation of geometry---of Euclidean geometry---in our understanding of the notions of space and time, and to reveal their paradoxical aspect. The aim is to explore how geometry, language and nonsense bear intimate connections to our perception of space and time. Once revealed, these connections will enable us to address the following question: can architecture be comprehended and experienced as an event?

In the last four decades, one of the fastest-growing fields of research in economics has been the contractual theory of the firm developed in Coase’s (1937) footsteps. Yet despite what otherwise seems to be a genuine success story the question of the nature of the firm remains an empirical and theoretical challenge, painfully illustrated by the lack of consensus regarding the definition and boundaries of the firm. The argument of this thesis is that many thorny questions that plague the literature, including issues related to ownership, boundaries, and intra-firm authority, are due to the fact that contractual theorists of the firm have generally overlooked a key legal feature of the economic system, without which theories of the firm are like Hamlet without the Prince. An elementary institutional fact about firms and markets is that in order to become a fully operational firm in a modern market economy, an entrepreneur or an association of resource owners need to go through a registration or incorporation procedure by which the legal system creates a separate legal person or legal entity in which ownership rights over assets used in production are vested, in whose name contracts are made, and thanks to which the firm has standing in court. With this assignment of legal personality, the legal system creates the efficiency-enhancing nexus for contracts that literally carries the organizational framework of the firm, and secures its continuity by locking-in the founders’ committed capital, thereby allowing them to pledge assets, raise finance and do business in the firm’s own name. Given the basic principle that only legal persons may own property and have the capacity to contract, and the implication that legally enforceable contracts can only exist between legal persons, it is something of a paradox that the notion of legal personality is absent from the prevailing narrative in the contractual theory of the firm. The thesis examines the reasons behind this state of affairs, and identifies alongside the widespread view among economists that firms can be defined with little or no reference to law, particularly statutory law, the lasting influence of Jensen and Meckling’s (1976) ambiguous dismissal of legal personality as a legal fiction that unavoidably leads to misleading reification. In order to disentangle the issues involved, the thesis puts this argument into historical perspective, and suggests that much can be learned from the corporate personality controversy that in the past has addressed the same questions. As the overview of the history of this debate reveals, the category mistakes that Jensen and Meckling presented as inevitable can be easily avoided once the meaning and functions of legal personality are properly understood. The thesis dispels enduring misunderstandings surrounding the notion of personhood, and proposes a legally-grounded view of the nature and boundaries of the firm that recognizes in law’s provision of legal entity status a fundamental institutional support for the firm while fitting the overall Coasean narrative.

Beams of light can carry spin and orbital angular momentum. Spin angular momentum describes how the direction of the electric field rotates about the propagation axis, while orbital angular momentum describes the rotation of the field amplitude pattern. These concepts are well understood for monochromatic beams, but previous theoretical studies have constructed polychromatic superpositions where the connection between angular momentum and rotation of the electric field becomes much less clear. These states are superpositions of two states of light carrying opposite signs of angular momentum and slightly detuned frequencies. They rotate at the typically small detuning frequency and thus we call them slowly rotating modes of light. Strangely, some of these modes appear to rotate in the direction opposing the sign of their angular momentum, while others exhibit overall rotation with no angular momentum at all! These findings have been the subject of some controversy, and in 2012, Susanna Todaro (HMC ’12) and I began work on trying to shed light on this “angular momentum paradox." In this thesis, I extend previous work in theory, simulation, and experiment. Via theory and modeling in Mathematica, I present a possible intuitive explanation for the angular momentum paradox. I also present experimental realization of slowly rotating spin superpositions, and outline the steps necessary to generate slowly rotating orbital angular momentum superpositions.

Studies have shown that computers have a positive impact on productivity, but the reality remains that the productivity figures have not yet changed. This aforementioned irregularity is referred to as the “productivity paradox”. The question of how productivity is measured is complicated when, for example, a company connects all their computers onto a network or installs an information system to keep record of customer information or even supplier information, for there are no input and output ratios that can be measured. In these cases, productivity is not so evident, and some might argue that it does not exist. Companies always look for the competitive advantage and it is therefore important to show whether investing in information technology does in effect give them a greater return on investment. The question of why it is important for information technology to increase productivity is answered by looking at what all companies seek, which is sustainable growth. This can be measured by the accounting return on investment, economic value added (EVA), and growth in sales or assets. The goal of this study is to determine the impact the information technology productivity paradox has on the heavy metal engineering industries, whether it be good or bad. Information technology has expanded to such an extent that more people are starting to rely on information technology in order to do their work and communicate with one another. This is what makes this study so important, especially from an organisation's perspective, as the organisation is spending more money on expanding its information systems. One of the aspects to be covered in this study is the evolution pertaining to the history of information technology and how it has improved over the years. It also looks at the laws of information technology like Moore's Law which explains that the transistors on a chip would roughly double every two years, and Gilder's Law that explains in total communication a system triples every twelve months. Within this study the knowledge expansion and how human knowledge had to expand in order to keep up with the ever escalating information technology is covered. When looking at the future and the rate at which knowledge increases people tend to assume that the current rate of progress will continue in future periods. This, however, when looking at the rate at which technology progresses, is evident that the progress is not constant. The research topic for this study is the information technology productivity paradox. This term suggests that there is no correlation between a company’s investment in information systems and its business performance measured in terms of productivity. This phenomenon was shown to exist within this study. Open source systems are covered, which is a method of developing software that harnesses the power of distributed peer review and transparency of process. Open source systems have the following advantages like easing of licensing restrictions; cross–platform simplicity; possibility to run modules on any operating system; low cost due to no licensing fees; modification of system is possible; and disadvantages like lack of necessary expertise to do modifications; less user–friendly, support is not always available; security might be a problem. In this way open source systems will affect productivity in information technology due to the less user–friendly interface. Some of these open source systems might take longer to do the task than it would on the commercial software. Implementation of the open source system might take longer than that of a commercial system as there might be a lack of support for the system. Another topic covered within this study is the development of human capital, which is a necessity for employees in an organisation in order to enhance both knowledge and skills within an organisation. This is, however, a double bladed sword as even though the combined knowledge and skills of an organisation are expanded, it takes time which inevitably leads to productivity loss. Finally this study investigates social networking, which is defined as the application of websites that support the maintenance of personal relationships, the discovery of potential relationships and should aim in the conversion of potential ties into weak and strong ties. List of key terms: Information technology, productivity paradox, social networking, competitive advantage, knowledge expansion, development of human capital. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.

Studies have shown that computers have a positive impact on productivity, but the reality remains that the productivity figures have not yet changed. This aforementioned irregularity is referred to as the “productivity paradox”. The question of how productivity is measured is complicated when, for example, a company connects all their computers onto a network or installs an information system to keep record of customer information or even supplier information, for there are no input and output ratios that can be measured. In these cases, productivity is not so evident, and some might argue that it does not exist. Companies always look for the competitive advantage and it is therefore important to show whether investing in information technology does in effect give them a greater return on investment. The question of why it is important for information technology to increase productivity is answered by looking at what all companies seek, which is sustainable growth. This can be measured by the accounting return on investment, economic value added (EVA), and growth in sales or assets. The goal of this study is to determine the impact the information technology productivity paradox has on the heavy metal engineering industries, whether it be good or bad. Information technology has expanded to such an extent that more people are starting to rely on information technology in order to do their work and communicate with one another. This is what makes this study so important, especially from an organisation's perspective, as the organisation is spending more money on expanding its information systems. One of the aspects to be covered in this study is the evolution pertaining to the history of information technology and how it has improved over the years. It also looks at the laws of information technology like Moore's Law which explains that the transistors on a chip would roughly double every two years, and Gilder's Law that explains in total communication a system triples every twelve months. Within this study the knowledge expansion and how human knowledge had to expand in order to keep up with the ever escalating information technology is covered. When looking at the future and the rate at which knowledge increases people tend to assume that the current rate of progress will continue in future periods. This, however, when looking at the rate at which technology progresses, is evident that the progress is not constant. The research topic for this study is the information technology productivity paradox. This term suggests that there is no correlation between a company’s investment in information systems and its business performance measured in terms of productivity. This phenomenon was shown to exist within this study. Open source systems are covered, which is a method of developing software that harnesses the power of distributed peer review and transparency of process. Open source systems have the following advantages like easing of licensing restrictions; cross–platform simplicity; possibility to run modules on any operating system; low cost due to no licensing fees; modification of system is possible; and disadvantages like lack of necessary expertise to do modifications; less user–friendly, support is not always available; security might be a problem. In this way open source systems will affect productivity in information technology due to the less user–friendly interface. Some of these open source systems might take longer to do the task than it would on the commercial software. Implementation of the open source system might take longer than that of a commercial system as there might be a lack of support for the system. Another topic covered within this study is the development of human capital, which is a necessity for employees in an organisation in order to enhance both knowledge and skills within an organisation. This is, however, a double bladed sword as even though the combined knowledge and skills of an organisation are expanded, it takes time which inevitably leads to productivity loss. Finally this study investigates social networking, which is defined as the application of websites that support the maintenance of personal relationships, the discovery of potential relationships and should aim in the conversion of potential ties into weak and strong ties. List of key terms: Information technology, productivity paradox, social networking, competitive advantage, knowledge expansion, development of human capital. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2012.