<p> Early pregnancy in mammals can be disrupted by numerous stimuli. In particular, exposure to males which did not sire the litter disrupts early pregnancy in previously inseminated female mice. This is known as the Bruce effect. Evidence suggests that this effect is mediated by chemical emissions (pheromones) from the males. Castration of the males eliminates the effect whereas testosterone replacement restores it. This has suggested that androgen-dependent male accessory glands might be responsible. In particular, the preputial, vesicular and coagulating glands seem likely candidates for subserving the Bruce effect since they have been implicated in a variety of social behaviors.</p> <p> In these experiments, inseminated females were each housed below either 1) two males which had undergone preputial gland removal or, 2) two males which had undergone vesicular-coagulating gland removal or, 3) two males which had undergone preputial, vesicular and coagulating gland removal or 4) two males which had undergone sham surgery. In each case, males which had undergone gland removal disrupted pregnancy in inseminated females to the same extent as did intact males. Histology showed no regeneration of the glands. These results suggest that none of these major androgen-dependent male accessory glands is responsible for pheromonal emissions involved in the Bruce effect.</p> / Thesis / Master of Science (MSc)

Protection of critical national infrastructure has received significant attention in the past recent years. As a result, researchers have developed methods to preserve and maintain critical infrastructure systems and minimize their vulnerability to disasters and disruptions. However, these models are often customized to meet the characteristics and functionality requirements for a particular system, and are computationally intensive and require simplifying assumptions. In this study, we first develop a tractable and relatively comprehensive model for optimizing maintenance planning of generic network-structured systems. We considered both linear and nonlinear objective functions for our problems. We then reformulate the model in order to enhance its computational effectiveness for large scale complex problems. The proposed modeling framework inherently captures the network topography, the stochastic nature of disruptions, and can be applied to network-structured systems for which performance is assessed based on network flow efficiency and mobility. A hypothetical small-sized network is used to illustrate the developed models, and the pro- posed models are also applied to analyze a larger scale real network in order to assess their relative computational effectiveness and robustness. We selected the Istanbul highway net- work for the latter purpose because of its critical location and also because it has been considered in previous studies, which enables us to compare the effectiveness of our models with an existing model in the literature. We designed several test cases (considering single and multiple treatment types, and linear and nonlinear objectives), and solved them on the NEOS server using different available software. The results demonstrate that our models are capable of attaining optimal solutions within a very short time. Furthermore, the linear model is shown to yield a good approximation to the nonlinear model (it determined solutions within 0.3% of optimality, on average). Moreover, in both cases (our hypothetical illustrative example and the Istanbul highway network), the optimal policies obtained appear to favor the selection of fewer links and to apply a higher quality treatment to them. / Master of Science

This study investigates strategies for improving the operational resilience, i.e. an organisation’s capacity to minimise, manage, and recover from disruptions quickly, ensuring continuity in its primary business processes. The focus has been a national infrastructure company, specifically in energy production, and the large supply chain disruptions it has experienced in the wake of COVID-19 and the Ukraine war. The study primarily compares the investigated strategies with literature and theoretical frameworks from a procurement research perspective. The study is an embedded multiple case study investigating three cases with delayed renewal projects. The identified disruptions and their effect on the projects’ performance have been studied, as well as more direct reasons for delays in the cases, such as organisational issues and procurement processes. A framework for categorising disruptions has been developed and three different portfolio purchasing models were investigated in order to be applied to the findings of the study. Key findings reveal that disruptions have affected the case company’s operations significantly, with more projects being delayed and fewer available suppliers in the wake of these disruptive events. Inefficient decision making processes have also been identified as sources of delays, as well as lack of communication within the organisation. The study concludes in practical recommendations for the case company, which can be applicable for similar companies as well. A significant recommendation was that the case company should form strategic partnerships with suppliers of generators, transformers and control systems in order to ensure ample future availability of key components. Other recommendations include working towards more efficient decision making processes when deviating from the group instructions surrounding competitive tendering as well as improving the communication of procurement strategies within the organisation / Denna studie undersöker strategier för att förbättra den operativa motståndskraften, d.v.s. en organisations förmåga att minimera, hantera och återhämta sig snabbt från störningar, för att säkerställa kontinuitet i sina primära affärsprocesser. Fokus har varit på ett nationellt infrastrukturföretag, specifikt inom energiproduktion, och de stora störningar i leveranskedjorna som de har upplevt i kölvattnet av COVID-19 och kriget i Ukraina. De undersökta strategierna kommer att jämföras med litteratur och teoretiska ramverk främst från ett inköpsperspektiv. Studien är en multipel fallstudie inom en organisation som undersöker tre fall med försenade förnyelseprojekt. De identifierade störningarna och deras effekt på projektens prestanda har studerats, liksom mer direkta orsaker till förseningarna i projekten, såsom organisatoriska problem och inköpsprocesser. Ett ramverk för kategorisering av störningar har utvecklats och tre olika portföljinköpsmodeller undersöktes för att kunna tillämpas på studiens resultat. Studien visar att störningarna har påverkat företagets verksamhet avsevärt, med fler försenade projekt och färre tillgängliga leverantörer som följd av av dessa störande händelser. Ineffektiva beslutsprocesser har också identifierats som källor till förseningar, liksom brist på kommunikation inom organisationen. Studien avslutas med praktiska rekommendationer till företaget, som även kan vara tillämpliga för liknande företag. En betydande rekommendation var att företaget bör bilda strategiska partnerskap med leverantörer av generatorer, transformatorer och kontrollanläggningar för att säkerställa framtida tillgång till kritiska komponenter. Andra rekommendationer inkluderar att arbeta mot mer effektiva beslutsprocesser vid avvikelser från koncerninstruktioner om konkurrensutsättning samt förbättra kommunikationen av inköpsstrategier inom organisationen.

In recent years, a growing number of human pharmaceuticals have been detected in the aquatic environment, generally at low concentrations (sub-ng/L to low μg/L). These compounds are characterised by highly specific mechanisms of action, high potency and prolonged activity in order to minimise dosing requirements and potential toxicity in patients. Among the various classes of pharmaceuticals, steroids and anti-steroids are widely used, as shown by the analysis of their clinical use carried out at the beginning of this Ph.D. project. Although the amounts used are much lower than the amounts of some other pharmaceuticals (e.g. analgesics), their ability to affect important physiological processes in fish (e.g. reproduction) at very low concentrations (ng/L) suggest that this class of compounds should represent a high priority for ecotoxicological research. In particular, this Ph.D. project addressed the question of whether or not dutasteride, a human pharmaceutical mainly used to treat benign prostatic hyperplasia, may cause adverse effects in the teleost fathead minnow (Pimephales promelas) by inhibiting the activity of both isoforms of 5α-reductase (5αR), the enzyme which convert testosterone into dihydrotestosterone (DHT). The theoretical framework used to guide the design of the experimental studies was based on the combination of several conceptual approaches, including the study of the evolutionary degree of conservation and functionality of the drug target in non-target species, and the cross-species extrapolation of pharmacological and toxicological information generated during pre-clinical and clinical studies in mammals during drug development. The results obtained during the first phase of this Ph.D. project strongly suggested that DHT has a physiological role in the fathead minnow. In fact, 5αRs are evolutionary conserved in this species, 5αRs genes are expressed in tissues such as the testis, and DHT circulates in fathead minnow plasma at concentrations similar to those detected in humans. These findings represented the rationale for testing the effects of dutasteride in the fathead minnow. Dutasteride caused significant adverse effects in all the in vivo studies performed in order to evaluate its potential toxicity on fish, including early life stage and short term reproduction studies, and all the tested life stages were sensitive to the inhibition of 5αRs activity; however, none of the observed adverse effects occurred at concentrations of exposure lower than 32 μg/L (measured concentration). The results also showed that female fish are highly sensitive to disruption of the androgenic pathways, highlighting their utility for the evaluation of potential adverse effects caused by anti-androgens on fish. In conclusion, the results presented in this Thesis suggest that, at present, the potential presence of dutasteride in the environment does not represent a risk to wild fish populations, due to the high concentrations required to elict significant adverse effect (LOEC = 32 μg/L) and the low volume of drug prescribed every year (5.07 kg in UK in 2006). However, the high bioaccumulation factor of dutasteride suggest that further studies should be conducted to elucidate the role played by the bioaccumulation process in the toxicity responses observed in fish.

This dissertation studies firms' strategic interactions in anticipation of random service disruption following technology failure. In particular it is aimed at understanding how contracting decisions between a vendor and one or multiple clients affect the firms' subsequent decisions to ensure disruption response and recovery are managed as efficiently as possible. This dissertation consists of three studies that were written as standalone papers seeking to contribute to the literature on contract design and technology management in operations management. Together, the three studies justify the importance of structuring the right incentives to mitigate disruption risks. In the first study we contribute to this literature by means of an analytical model which we use to examine how a client and vendor should balance investments in response capacity when both parties' efforts are critical in resolving disruption and each may have different risk preferences. We study the difference in the client's optimal expected utility between a case in which investment in response capacity is observable and a case in which it is not and refer to the difference in outcomes between the two cases as the cost of complexity. Firstly, we show that the cost of complexity to the client is decreasing in the risk aversion of vendor but increasing in her own risk aversion. Secondly, we find that a larger difference in risk aversion between a client and vendor leads to underinvestment in system uptime in case the client's investment is observable, yet the opposite happens when the client’s investment is not observable. In the second study we further examine the context of the first study through a controlled experiment. We examine how differences in risk aversion and access to information on a contracting partner’s risk preferences interact in affecting contracting and investment decisions between the client and vendor. Comparing subject decisions with the conditionally optimal benchmarks we arrive at two observations that highlight possible heuristic decision biases. Firstly, subjects tend to set and hold on to an inefficiently high investment level even though it is theoretically optimal to adjust decisions under changing differences in risk preferences. Secondly, subjects tend to set and hold on to a penalty that is too high when interacting with more risk averse vendors and too low in case the vendor is equally risk averse. Furthermore, cognitive feedback on the vendor’s risk aversion appears to have counterproductive effects on subject’s performance in the experiment, suggesting cognitive overload can have a reinforcing effect on the heuristic decision biases observed. In the third study we construct a new analytical model to examine the effect of contract design on a provider's response capacity allocation in a setting where multiple clients may be disrupted and available response capacity is limited. The results show that while clients may be incentivized to identify and report network disruptions, competition for scarce emergency resources and the required investment in understanding their own exposure may incentivize clients to deliberately miscommunicate with the vendor.

Redes neurais artificias, tipo \"feedforward\", de duas camadas, foram utilizadas neste trabalho para fazer previsões das instabilidades de disruptura que surgem nas descargas de plasma do tokamak TEXT (E.U.A.), obtendo-se resultados bastante encorajadores. Verificou-se que uma arquitetura de rede, do tipo m:2m:m:1, onde m é dimensão de imersão do atrator do sistema dinâmico em estudo, costuma ser um bom chute inicial para a escolha da arquitetura ideal de trabalho, que costuma ser livre e, não raro, trabalhosa. Utilizando-se, em sinais de raios-X, uma rede neural artificial com arquitetura 15:30:15:1, por exemplo, conseguiu-se fazer previsões com uma antecipação de até 4 ms das instabilidades de disruptura, tempo quatro vezes maior do que o obtido utilizaudo-se sinais magnéticos das bobinas de Mirnov. Tal antecipação é bastante significativa e abre a possibilidade de, no futuro, utilizarem­se mecanismos de defesa da máquina, tais como injeção de partículas neutras (ou\"pellets\"), aplicação de campos magnéticos externos, etc, no sentido de se tentar evitar a ocorrência destas instabilidades, ou, pelo menos, minimizar os seus efeitos nocivos. Isto certamente contribuirá significativamente para a viabilização dos futuros reatores de fusão à plasma. Finalmente, o sistema de diagnóstico de raios-X de baixas energias do tokamak TCABR, que foi projetado e já se encontra em fase de instalação para fornecer sinais que servirão para alimentar a rede neural, também possibilitará a reconstrução tomográfica das regiões de mesma emissividade da coluna de plasma. A análise tomográfica, utilizando-se os sinais de dois conjuntos de detectores de raios-X moles, também será muito útil na investigação dos mecanismos físicos que dão surgimento às instabilidades de disruptura, além de permitir, ainda, a medida da temperatura eletrônica do plasma, através do método dos absorvedores. / Two-layer feedforward neural network has been used in this work to forecast the disruptive instabilities that occur in the TEXT tokamak plasma discharges. For this task, soft X-ray experimental signals were used with very promising results. It was verified that a neural net with an architecture of the type m:2m:m:1, where m is the embedding dimension of the atractor of dynamical system in focus, is usually a good initial guess in the searching process of finding the ideal architecture. A neural network with architecture 15:30:15:1 was capable, for example, to forecast the disruptive instabilities up to 4 ms in advance. This period of time is four time larger than the one obtained when magnetic signals from Mirnov coils were used. This forecasting time is quite significative and opens up the possibility of using defensive mechanisms, such as the injection of neutral particles (or pellets), the application of external magnetic fields, etc, with the objective of avoiding the occurrence of the disruptions or, at least, to minimize their harmful effects. This achievement certainly would be an important contribution to the development of the next generation fusion devices. Finally, the soft X-ray diagnostic system for the TCABR was projected and it is already being installed. This system will provide experimental signals that will be analyzed by neural networks and will be also used to identify, through tomografic image reconstructions, the regions of the plasma that have the same soft X-ray emissivity. The tomography analysis of the plasma, that will be carried out by using the signals of two soft X-ray detectors arrays, will be also very usefull for investigating the triggering mechanism of disruptions and will also allow the determination of the plasma electron temperature through the two foil absorbing method.

Higher education instructors experience many uncivil behavior challenges among students in the classroom that affect learning. The purpose of this qualitative study was to investigate the effect of higher education classroom management behavior strategies on learning. Guided by Bandura's social learning theory and Piaget's cognitive theory, the research questions were designed to explore the perceptions of instructors and students about classroom management behavior strategies used in college settings and how student classroom incivility affects learning. The study included a panel of experts to aid in determining the feasibility of the project study protocol, testing the adequacy of research instruments, and identifying weaknesses in a study. There were 19 prewritten open-ended interview questions used to gather in-depth feelings, attitudes, and perceptions of 5 instructors' and 5 students' experiences toward classroom incivility from a 2-year college in Texas. Participant interviews were transcribed using open, axial, and selective coding to identify common themes. Discipline referral reports and researcher observation notes were gathered to triangulate the data. The findings indicated the instructors needed training on how to better manage uncivil classroom behaviors among students. The findings were used to develop a professional development training called "Classroom Incivility: Address it Now, Later, or Never." This project resulting from the study could have a direct effect on positive social change by equipping instructors with better tools to effectively manage uncivil behavior among students in their classrooms.

The purpose of this thesis is to explore disruptions Swedish wind turbines onshore are exposed to, and to estimate their economic impacts on the operators. We want to investigate whether there is a need for a more developed service and maintenance market within the Swedish wind power market. This study focuses on wind power, a renewable energy source in an emerging market, which experiences exponential growth. Sweden is a minor actor in the wind power market with a production of around 2 TWh yearly. The government aims at a total production of 10TWh in 2015 and 20TWh in 2020, which equals an annual growth of 24%. However, we hypothesize that the Swedish wind power market is negatively affected by a service and maintenance market which is underdeveloped due to a lack of competition. This results in lengthy repair times and disproportionate costs for wind power operators. The study was carried out by conducting semi-structured qualitative interviews and by sending out a survey to approximately 300 wind power operators. Six interviewees were wind power operators and one interviewee was a representative from an independent service supplier. We have also analysed the current cost situation of operators with theories about maintenance costs and we have also carried out an industry analysis on the service and maintenance market, which was based on Porter’s structural industry analysis. After conducting a structural analysis of the service and maintenance market, we can conclude a lack of competition today as there is a dominance of the wind turbine manufacturers as the service supplier. Furthermore we can see that this lack of competition has negative effects on the efficiency of the service and maintenance provided. The results also stress a need for a more developed service and maintenance market. We have found that the profitability for the Swedish wind power operators is challenged if the service and maintenance market is not keeping pace and meeting the demands of the rapidly growing Swedish wind power market as a whole.

This thesis studies inventory control with risk of major supply chain disruptions, specifically border closures and congestion. We first investigate an inventory system in which the probability distributions of order leadtimes are dependent on the state of an exogenous Markov process; we will model border disruptions via this exogenous process. We consider stationary, state-dependent basestock policies, which are known to be optimal for the system under study, and develop an expression for the long-run average cost of an arbitrary policy of this form. Restricting our attention to state-invariant basestock policies, we show how to calculate the optimal basestock (or order-up-to) level and long-run average cost. We provide a sufficient condition for the optimality of a state-invariant basestock policy and monotonicity results for the optimal state-invariant order-up-to level. We finally give the optimal state-invariant order-up-to level for a special class of supply states. Motivated by the possibility of port of entry closures in the event of a security incident, we specialize the previous model to a two-stage international supply chain. A domestic manufacturer orders a single product from a foreign supplier and the orders must cross an international border that is subject to closure. We first assume that border congestion is negligible. The manufacturer's optimal inventory policy and long-run average cost are analyzed. We present structural policy results and the results of a comprehensive numerical study that have important implications for business and for the cooperation between business and government in disruption management and contingency planning. Finally we extend the border closure model to include both border closures and the resulting congestion. We model the border processing system as a discrete-time, single-server queue with constant arrival rate and Markov-modulated service rate. A key task is the development of the leadtime distribution, which is more complex than in the previous model. We present the results of a comprehensive numerical study and provide managerial insights.

<p>The purpose of this thesis is to explore disruptions Swedish wind turbines onshore are exposed to, and to estimate their economic impacts on the operators. We want to investigate whether there is a need for a more developed service and maintenance market within the Swedish wind power market.</p><p>This study focuses on wind power, a renewable energy source in an emerging market, which experiences exponential growth. Sweden is a minor actor in the wind power market with a production of around 2 TWh yearly. The government aims at a total production of 10TWh in 2015 and 20TWh in 2020, which equals an annual growth of 24%. However, we hypothesize that the Swedish wind power market is negatively affected by a service and maintenance market which is underdeveloped due to a lack of competition. This results in lengthy repair times and disproportionate costs for wind power operators.</p><p>The study was carried out by conducting semi-structured qualitative interviews and by sending out a survey to approximately 300 wind power operators. Six interviewees were wind power operators and one interviewee was a representative from an independent service supplier. We have also analysed the current cost situation of operators with theories about maintenance costs and we have also carried out an industry analysis on the service and maintenance market, which was based on Porter’s structural industry analysis.</p><p>After conducting a structural analysis of the service and maintenance market, we can conclude a lack of competition today as there is a dominance of the wind turbine manufacturers as the service supplier. Furthermore we can see that this lack of competition has negative effects on the efficiency of the service and maintenance provided. The results also stress a need for a more developed service and maintenance market. We have found that the profitability for the Swedish wind power operators is challenged if the service and maintenance market is not keeping pace and meeting the demands of the rapidly growing Swedish wind power market as a whole.</p>