This paper examines the evolution of government policy through Congressional debate and citizen involvement on the topic of Agent Orange. Use of primary sources from newspaper and journal articles, Congressional records, scientific studies, and press releases and some secondary literature by scholars from multiple disciplines builds a picture of the ongoing debate of Agent Orange and its two component herbicides from circa 1940 to 1991. Within this paper are four primary focuses, divided into three parts. First, the Congressional discussions prior to 1970 of 2,4-D and 2,4,5-T, the two herbicides that comprise Agent Orange. Second and third, discussed in the same section, the involvement of the scientific community and the ratification of the Geneva Protocol. Lastly, the movement after the Vietnam War for veteran benefits due to Agent Orange exposure.

Optimal Foraging Theory is a set of mathematical models used in the field of behavioral ecology to predict how animals should weigh foraging costs and benefits in order to maximize their food intake. One popular model, referred to as the Optimal Diet Model (ODM), focuses on how individuals should respond to variation in food quality in order to optimize food selection. The main prediction of the ODM is that low quality food items should only be accepted when higher quality items are encountered below a predicted threshold. Yet, many empirical studies have found that animals still include low quality items in their diet above such thresholds, indicating a sub-optimal foraging strategy. Here, we test the hypothesis that such ‘partial preferences’ are produced as a consequence of incomplete information on prey distributions resulting from memory limitations. To test this hypothesis, we used agent-based modeling in NetLogo to create a model of flower choice behavior in a virtual bumblebee forager (SimBee). We program virtual bee foragers with an adaptive decision-making algorithm based on the classic ODM, which we have modified to include memory. Our results show that the probability of correctly rejecting a low quality food item increases with memory size, suggesting that memory limitations play a significant role in driving partial preferences. We discuss the implications of this finding and further applications of our SimBee model in research and educational contexts.

Optimal Foraging Theory is a set of mathematical models used in the field of behavioral ecology to predict how animals should weigh foraging costs and benefits in order to maximize their food intake. One popular model, referred to as the Optimal Diet Model (ODM), focuses on how individuals should respond to variation in food quality in order to optimize food selection. The main prediction of the ODM is that low quality food items should only be accepted when higher quality items are encountered below a predicted threshold. Yet, many empirical studies have found that animals still include low quality items in their diet above such thresholds, indicating a sub-optimal foraging strategy. Here, we test the hypothesis that such ‘partial preferences’ are produced as a consequence of incomplete information on prey distributions resulting from memory limitations. To test this hypothesis, we used agent-based modeling in NetLogo to create a model of flower choice behavior in a virtual bumblebee forager (SimBee). We program virtual bee foragers with an adaptive decision-making algorithm based on the classic ODM, which we have modified to include memory. Our results show that the probability of correctly rejecting a low quality food item increases with memory size, suggesting that memory limitations play a significant role in driving partial preferences. We discuss the implications of this finding and further applications of our SimBee model in research and educational contexts.

Objective: This study aimed to assess the impact of in vitro erosion provoked by different cola-based drinks (Coke types), associated or not with toothbrushing, to bonding to enamel. Material and methods: Forty-six bovine enamel specimens were prepared and randomly assigned into seven groups (N=8): C- Control (neither eroded nor abraded), ERO-RC: 3x/1-minute immersion in Regular Coke (RC), ERO-LC: 3x/1-minute immersion in Light Coke (LC), ERO-ZC: 3x/1-minute immersion in Zero Coke (ZC) and three other eroded groups, subsequently abraded for 1-minute toothbrushing (EROAB-RC, EROAB-LC and EROAB-ZC, respectively). After challenges, they were stored overnight in artificial saliva for a total of 24 hours and restored with Adper Single Bond 2/Filtek Z350. Buildup coronal surfaces were cut in 1 mm2-specimens and subjected to a microtensile test. Data were statistically analyzed by two-way ANOVA/Bonferroni tests (a=0.05). Failure modes were assessed by optical microscopy (X40). The Interface of the restorations were observed using Confocal Laser Scanning Microscopy (CLSM). Results: All tested cola-based drinks significantly reduced the bond strength, which was also observed in the analyses of interfaces. Toothbrushing did not have any impact on the bond strength. CLSM showed that except for Zero Coke, all eroded specimens resulted in irregular hybrid layer formation. Conclusions: All cola-based drinks reduced the bond strength. Different patterns of hybrid layers were obtained revealing their impact, except for ZC. / This study was supported in part by grants given by the São Paulo Research Foundation (FAPESP), Process no. 2009/14986-0, and the National Council for Scientific and Technological Development (CNPq), Process no. 480038/2007-4. In Addition, this study was performed by V.D.M. and A.C.H. as fulfillment of their graduation research, which was supported by FAPESP (Processes no. 2009/01376-9 and 2009/01377-5, respectively). The authors are also grateful to Oral B and SDI, which donated the materials used in the study. / Revisión por pares

Thesis advisor: Hideo Konishi / This dissertation covers three essays in modelling the market competitions with the presence of consumer search. The first two essays add on Wolinsky's (1986) model to investigate firms' optimal choice of their way of doing business in response to the changing consumer search behaviors during the information age. The third essay modifies the Varian's (1980) model to provide a new mechanism to rationalize the countercyclical markups in supermarkets. The first essay concerns the formation of referral alliance. It extends the Wolinsky's (1986) model to a three-stage game with two types of products produced by a continuum of firms with each one having strength in a single type only. In the first stage, firms simultaneously decide on the formation of referral alliances, in which each alliance consists of a pair of firms producing different types of products. In the second stage, they set price simultaneously. In the third stage, each consumer who only values one type of product searches sequentially for the right product. We show that firms with low ability to deal with the unmatched consumers are positively assorted together in the formation of referral alliance with multiple equilibrium possible. The proliferation of referral alliance always benefits consumers but not necessarily firms. One the one hand, it intensifies competition and drives down the market price. On the other hand, it increases the mass of consumers participating in the search market. The price elasticity of demand together with our stability condition govern the changes in consumer and social welfare as the search cost varies. The reduction in search cost always increases consumer and social welfare only if the equilibrium is stable with elastic demand. The policy implication from our results is that it might be more effective to improve consumer and social welfare by inducing more firms to participate in the referral alliances rather than reducing the consumers' search cost. The second essay studies the incentives for stores to invest effort in serving customers if effort is costly and might be merely persuasive that reduces consumption utility. We incorporate a sales agent to each store in Wolinsky's (1986) model, in which the sales agent is paid either by fixed wage or by commissions. The commissions motivate sales agents to provide more advice, which could be indeed useful to increase clients' willingness to pay or merely persuasive without affecting it. Consumers are sophisticated that understand the dual roles of effort before visiting firms, but they might be impressionable and therefore could not stay away from the effect of persuasion when they are making the purchasing decision. When consumers are heterogeneous in terms of their impressionability, they are sorted into stores with fixed wage and commissions in the equilibrium. The composition of stores varies with the search cost and the ability of sales agents to increase consumers' willingness to pay (effectiveness of advice). When the advice is relatively ineffective, there will be an increase in mass of fixed wage stores in response to a reduction in search cost. The reverse is true when the advice is sufficiently effective. Additionally, the mass of fixed wage stores always increases as the advice becomes less effective. The competitive equilibrium outcome might imply that there are too little commission-based stores, so it could be social welfare enhancing by encouraging more consumers to visit the stores with commissions. The third essay provides a simple mechanism that rationalizes the countercyclical markups in supermarkets with the presence of a warehouse club. We first provide a mechanism on the higher supermarket prices upon the entry of the warehouse club. The new warehouse club attracts price-sensitive consumers away from supermarkets, which reduces the price elasticity of the consumers in the supermarket regime. This relaxes price competition resulting in higher supermarket prices. After that we apply the same mechanism to explain the countercyclical markups in supermarkets. During economic booms, the time value of consumers increases making them less willing to visit the warehouse club. Thus, economic booms increase the amount of price-sensitive consumers in supermarkets, intensifying price competition and inducing a lower price relative to cost in booming times. / Thesis (PhD) — Boston College, 2015. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Thesis advisor: Jean-Luc Solère / This dissertation examines the noetics of several early thirteenth-century Latin Augustinian thinkers, who first received Aristotle's noetic from the Arabs, examining in detail the early Latin reception of Aristotelian proposal that human thought is caused by the `agent intellect'. I argue that the early Latin-Augustinian reactions to the Arab noetics reveal an abiding Latin commitment to a concept of selfhood in natural thought. For different reasons, these early 13th century Latin thinkers explicitly locate the principle of natural thought within the individual's soul, thus conceiving the individual as the spontaneous origin of the activity of his or her thinking. I propose that there is a progressively more refined development of this concept within the interpretation of the Peripatetic noetic proposed within the early 13th century Franciscan school. I trace this development through John of La Rochelle to the anonymous author of the Summa Fratris Alexandri Book 2 to Bonaventure's early thought. At the same time, I analyze this Franciscan development relative to William of Auvergne's well-conceived opposition to all interpretations of the Aristotelian noetic. I make the case that William's critique sets the standard for the noetic of the individual to which these Franciscans adhere, even in their adoption of the Aristotelian noetic. I then argue that to adhere to William's standard, these Franciscans drew on Averroes' account of the agent intellect as found in Averroes' Commentarium Magnum in Aristotelis De Anima Libros. Finally, I argue that within the early 13th century's development of the noetic of the individual, there is an important, self-conscious development of the historico-philosophical concept of the Western self. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Philosophy.

Nanomateriais têm sido amplamente estudados, como resultado de suas propriedades físicas e químicas diferenciadas, que oferecem um grande número de possibilidades para aplicações em biomedicina, principalmente na terapia de câncer e no desenvolvimento de estratégias de diagnóstico não invasivo. O óxido de ferro superparamagnético (SPION) é o principal material estudado como agente de contraste para imagem por ressonância magnética, devido à sua capacidade de reduzir o tempo de relaxação transversal (T2) em diferentes tecidos e sua menor toxicidade que os complexos de Gd3+ e Mn2+ usados atualmente. Entretanto, o acumulo de SPIONs pode ser facilmente confundido com sinais referentes à calcificação, depósito de metais pesados e sangramentos, e a alta susceptibilidade magnética do material promove distorções na imagem. Assim, alguns aspectos são desejáveis em material para que este tenha potencial para substituir o SPION, tais como forma nanoparticulada, para fácil modificação de superfície e possibilidade de funcionalização com agentes biosseletivos, e contraste positivo em T1. As nanopartículas (NPs) antiferromagnéticas de MnO atendem a todos os requisitos necessários para substituir o óxido de ferro. As NPs de MnO foram sintetizadas a partir da decomposição térmica do acetilacetonato de manganês(II) em uma variação do método poliol modificado, resultando na formação de NPs com tamanho médio de 21 ± 3,9 nm. Foi realizada a substituição de ligantes de superfície para que se substituísse o ácido oleico adsorvido sobre o material por 3-aminopropiltrimetoxisilano (APTMS) e foi determinada a concentração de grupamentos amino sobre a superfície das NPs. Posteriormente, obteve-se uma estrutura do tipo \"core/shell\" dispersível em meio aquoso e biocompatível pela reação dos grupos amino livres com o carboxilato da carboximetil dextrana (CMDex). O potencial de superfície e a estabilidade coloidal das NPs funcionalizadas foram caracterizados por mobilidade eletroforética e por espalhamento de luz dinâmico em água deionizada e em condições que mimetizavam o sangue. As NPs apresentaram toxicidade em células cancerosas de carcinoma cervical humano (HeLa). Entretanto, não foi observada toxicidade significativa na linhagem de células não cancerosas NCTC clone L929. Tanto as NPs como sintetizadas quanto as recobertas com CMDex apresentaram controle de tamanho e forma, apresentando distribuição de tamanho compatível com o esperado para as aplicações em biomedicina. / Nanomaterials have been widely studied as a result of their interesting physical and chemical properties, which offer a large number of possibilities for applications in biomedicine mainly in cancer therapy and the development of strategies for non-invasive diagnosis. The superparamagnetic iron oxide nanoparticles (SPION) is the main studied material as contrast agent for magnetic resonance imaging (MRI) due to its ability to reduce the transverse relaxation time (T2) in different tissues and lower toxicity than Gd3+ and Mn2+ complexes currently used. However, this SPIONs accumulation can be confused with signals from calcification, bleeding or metal deposits, and the high magnetic susceptibility distorts the background image because its ferromagnetic behavior. Some aspects are desirable to replace SPIONs, such as nanoparticulate form for simple surface modification and labeling with targeting agents, and positive longitudinal T1 relaxation time contrast ability. The antiferromagnetic MnO NPs attend all these requirements and overcome the drawback of using SPION. In our study, MnO NPs were synthesized by the thermal decomposition of Mn(II) acetylacetonate by a variation of the modified polyol process resulting in spherical nanoparticles with average size of 21 ± 3,9 nm. The ligand-exchange step was used to replace the oleic acid adsorbed on the as-synthesized NPs surface by 3-aminopropyltriethoxysilane (APTMS) and the total free amine groups on the NPs surface was determined. After that, a biocompatible and water-dispersible core/shell structure was obtained by coating with carboxymethyl dextran (CMDex) using the free amine-terminal group from APTMS and the carboxylate groups present in the CMDex molecules conjungation. Surface potential and colloidal stability of these functionalized NPs were evaluated by electrophoretic mobility and dynamic light scattering techniques in both water and artificial blood by using the Simulated Body Fluid (SBF) medium. While the water-dispersible NPs have shown toxicity in the human cell line derived from cervical cancer (HeLa), they have not shown significantly cytotoxicity in the healthy fibroblast cells (cell line L929). Both the as-synthesized and coated NPs present controlled size and shape and the final NPs size distribution and magnetic properties are compatible with the expected for biomedical applications.

The paper studies the impact of a diversification vs. a core-competence oriented strategy using an agent-based simulation model. The aim of the paper is twofold: first, we analyze whether agent-based models are a viable tool for analyzing questions related to corporate strategy. We show that standard results from the strategy literature can indeed be reproduced and refined by using this type of models. Second, the agent-based model allows us to formulate more precise hypotheses and more precisely delineate the scope of situations in which standard results from the strategy literature apply. For the problem of diversification analyzed in this paper, the results from the agent-based simulation lead to the conclusion that in addition to environmental dynamics, overall market size is also an important factor, which was not considered in the previous literature. / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"

This dissertation studies an economy where efficiency depends on the correct match between projects and two experts. A low-skill expert has low fixed cost and low productivity, so he is more efficient in handling low-potential or low-difficulty projects. And the opposite is true for a high-skill expert. The dissertation studies the effectiveness of markets and organizations in overcoming asymmetric information issues, experts' incentives to acquire project information at a cost, and how experts use the information to facilitate the correct match. The first chapter studies a market where a referring expert privately knows a project's potential and may refer it at any price. Inspection benefits the referred expert. First, it allows him to find out the project's potential before accepting the referral offer. Second, it allows him to tailor production effort to the project's potential for maximum efficiency. In equilibrium, the referring expert pools projects into subsets and refers each subset at a different price. A higher price signals a subset of projects with higher potentials. The referred expert almost always inspects and then uses the information to make the acceptance decision. Each subset must be small enough to incentivize the referral at a price, but also large enough to incentivize inspection by the referred expert. The second chapter studies contract design within an organization. A principal has to rely on the two experts to learn about projects' difficulties. If information cost is small, the principal can implement the first best by an optimal mechanism with the low-skill expert acting as a gatekeeper. The low-skill gatekeeper expert is incentivized to acquire information and report it truthfully. Subsequently, the principal efficiently assigns the project based on the report. The third chapter studies a market where each of the two experts can exert a variable effort to acquire project information imperfectly. In the first best, experts coordinate their information acquisition efforts. In the market, either one or both experts acquire information. The two experts may fail to coordinate because one acquires information for efficient match but the other acquires information again to protect himself.

This research complements and combines market microstructure theory and mechanism design to optimize the market structure of financial markets systematically. We develop an agent-based model featuring near-zero-intelligence traders operating in a call market with a wide range of trading rules governing the determination of prices, which orders are executed as well as a range of parameters regarding market intervention by market makers and the presence of informed traders. The market structure which generates the best market performance is determined by applying the search technique Population-based Incremental Learning, guided by a number of performance measures, including maximizing trading volume or price, minimizing bid-ask spread or return volatility. We investigate the credibility of our model by observing the trading behavior of near-zero-intelligence traders with stylized facts in real markets. Based on computer simulations, we conform that the model is capable to reproduce some of the most important stylized facts found in financial markets. Thereafter, we investigate the best found market structure using both single-objective optimization and multi-objective optimization techniques. Our results suggest that the best-found combination of trading rules used to enhance trading volume may not be applied to achieve other objectives, such as reducing bid-ask spread. The results of single-objective optimization experiments show that significantly large tick sizes appear in the best market structures in most cases, except for the case of maximizing trading volume. The tick size is always correlated with the selection of multi-price rules. Though there is no particular combination of priority rule and multiprice rule achieving the best market performance, the time priority rule and the closest multi-price rule are the most frequently obtained rules. The level of market transparency and the extend of market maker intervention show ambiguous results as their representative parameter values change in a wide range. We also nd that the results of multi-objective optimization experiments are much similar to those obtained in the single-objective optimization experiments, except for the market transparency represented by the fraction of informed trader, which shows a clear trend in the multi-objective optimization. Using the results obtained from this research we can derive recommendations for exchanges and regulators on establishing the optimal market structure; for securities issuers on choosing the best exchange for their listing; and for investors on choosing the most suitable exchange for trading.