The thesis examines, philosophically and practically, what duties humanity has towards refugees. As the foundation for the thesis, a philosophical background related to human development is provided. Next, a control group of countries in the European Union is used to investigate how refugees impact societies in reality in order to analyze whether countries have an ethical duty to protect their own domestic population, overriding obligations towards refugees. Continuing in this vein, certain political ideologies and religious doctrines are examined in order to determine if there is an underlying theme towards refugees. Stemming from this is an analysis of various international treaties in order to understand what the treaties require and permit countries to do legally. Finally, everything is combined, and the ethical and moral argument related to helping refugees is thoroughly explored. The aim is to uncover the problematization of the current literature and to establish that everyone has ethical duties towards refugees. Refugees are shown not to be a group of people damaging society; not helping refugees in any way damages the human development of a refugee and the inherent moral duties of the person/state/community not providing assistance; all religious doctrines and political ideologies push for...

<p> 1,1-Diarylindenes rearrange when heated or irradiated to give 1,2- and 2,3-diarylindenes. Three 1,1-diarylindenes were synthesized and used in an attempt to probe the transition states for phenyl migration in both the ground and excited state. The three indenes synthesized were: 1-(p-bromophenyl)-1-phenylindene, 1-(p-cyanophenyl)-1-phenylindene and 1-(p-methoxyphenyl)-1-phenylindene.</p> <p> On direct irradiation, the migratory aptitudes were -C6H4CN-p, 98%; -C6H4OCH3-p, 95%; and -C6H4Br-p, 86%. On heating (258°C) the following aptitudes were found: -C6H4CN-p, 82%; -C6H4OCH3-p, 48%; and -C6H4Br-p, 53%. The products were synthesized independently, and the product ratios obtained upon reaction were measured from the n.m.r. of mixtures, and by v.p.c. A charge transfer mechanism was put forward to explain the preference for migration of the substituted group in the excited state. Such charge transfer contributions are known to increase the rates of quenching in donor-acceptor pairs. A radical-type transition state was postulated as being present in the ground state migration. The rate constant for excited state rearrangement was calculated to be 4.9 x 10^9 sec^-1 .</p> / Thesis / Doctor of Philosophy (PhD)

The bacterium Sinorhizobium (Ensifer) meliloti is a member of the Rhizobiaceae family and can enter a mutualistic, diazotrophic relationship with most plants of the genera Medicago, Melilotus, and Trigonella. Medicago sativa (alfalfa) is an agriculturally important legume that hosts S. meliloti and allows the bacterium to invade the plant root and begin fixing nitrogen. Prior to invasion, S. meliloti exists as a free living bacterium and must navigate through the soil to find alfalfa, using chemical signals secreted by the root. Alfalfa is the 4th most cultivated crop in the United States, therefore, identification of plant host signals that lure S. meliloti, and identification of the bacterium's chemoreceptors that perceive the signals can aid in propagating the symbiosis more efficiently, thus leading to greater crop yields. Investigations here focus on discovering alfalfa derived attractant signals and matching them to their respective chemoreceptors in S. meliloti. We have determined the chemotactic potency of alfalfa seed exudate and characterized and quantified two classes of attractant compounds exuded by germinating alfalfa seeds, namely, amino acids and quaternary ammonium compounds (QACs). At all points possible, we have compared alfalfa with the closely related non-host, spotted medic (Medicago arabica). The chemotactic potency of alfalfa seed exudate is the same as spotted medic seed exudate, however, the attractant compositions are chemically different. The amount of each proteinogenic amino acid (AA) exuded by spotted medic is slightly greater than the amounts exuded by alfalfa. In addition, the five QACs studied are exuded in various amounts between the two Medicago species. In comparison, the total amount of proteinogenic AAs exuded be alfalfa and spotted medic are 2.01 μg/seed and 1.94 μg/seed respectively, and the total amount of QACs exuded are 249 ng/seed and 221 ng/seed respectively. By performing a chemotaxis assay with synthetic AA mixtures mimicking the amounts exuded from the medics, it was found that the AA mixtures contribute to 23% and 37% of the responses to alfalfa and spotted medic exudates, respectively. The chemoreceptor McpU was found to be the most important chemoreceptor of the eight for chemotaxis to the whole exudates and the AA mixtures. Furthermore, McpU is shown to mediate chemotaxis to 19 of 20 AAs excluding aspartate. McpU directly interacts with 18 AAs and indirectly mediates chemotaxis to glutamate. Through single amino acid residue substitutions, it is determined that McpU directly binds to amino acids in the annotated region called the Cache_1 domain, likely utilizing residues D155 and D182 to interact with the amino group of AA ligands. In all, McpU is a direct sensor for AAs except for the acidic AAs aspartate and glutamate. Work is presented to show that the QACs betonicine, choline, glycine betaine, stachydrine, and trigonelline are potent attractants for S. meliloti, McpX is the most important chemoreceptor for chemotaxis to these QACs, and we demonstrate the binding strength of McpX to the QACs with dissociation constants ranging from low millimolar to low nanomolar, thus making McpX the first observed bacterial MCP that mediates chemotaxis to QACs. Overall, we match medic derived AAs with McpU and QACs with McpX. These results can aid in optimizing chemotaxis to the host derived attractants in order to propagate the symbiosis more efficiently resulting in greater crop yields. Chapter 2 characterizes the function of the S. meliloti Methyl accepting Chemotaxis Protein U (McpU) as receptor for the attractant, proline. A reduction in chemotaxis to proline is observed in an McpU deletion strain, but the defect is restored in an mcpU complemented strain. Single amino acid substitution mutant strains were created, each harboring a mutant mcpU gene. The behavioral experiments with the mutants display a reduction in chemotaxis to proline when aspartate 155 and aspartate 182 are changed to glutamates. The periplasmic region of wild type McpU was purified and demonstrated to directly bind proline with a dissociation constant (Kd) of 104 μM. The variant McpU proteins show a reduction in binding affinity confirming McpU as a direct proline sensor. Chapter 3, describes the development of a high-throughput technique that is able to observe chemotaxis responses in ten separate chemotaxis chambers all at once. This procedure also allows for real time observations at intervals of two minutes for however long the experiment is scheduled. Using this new method it was found that McpU and the Internal Chemotaxis Protein A (IcpA) are the most involved with chemotaxis to seed exudates followed by McpV, W, X, and Y. The amounts of each proteinogenic amino acid (AA) in host and non-host seed exudates are quantified, which reveals that similar amounts are exuded from each species. It is shown that McpU is the most important receptor for chemotaxis toward synthetic mixtures that mimic the amounts seen in the exudates. Chapter 4 further investigates the role of McpU in sensing amino acids using the high-throughput technique developed in Chapter 3. It is shown that McpU is important for chemotaxis to all individual proteinogenic amino acids except the acidic AA, aspartate. In vitro binding experiments confirm that McpU directly interacts with all AAs except the acidic AAs aspartate and glutamate. Binding parameters are determined for aspartate, glutamate, phenylalanine and proline. In Chapter 5, five quaternary ammonium compounds (QACs) are quantified from the host and non-host seed exudates, which reveals distinctive QAC profiles. S. meliloti is found to display strong chemotaxis to all QACs, which is further shown to be mediated mostly by McpX. McpX is then established as a direct binder to all QACs as well as proline, with dissociation constants ranging from nanomolar to millimolar. These studies have increased our knowledge of how chemoreceptors sense attractants, and they have contributed to the bank of known attractant molecules for bacteria. Our new understandings of chemotaxis and how it relates to the Sinorhizobium-alfalfa model can allow for manipulations of the system to enhance chemotaxis to the host, thus propagating the symbiosis more efficiently, ultimately leading to greater crop yields. / Ph. D.

Sinorhizobium meliloti (Ensifer meliloti) is a bacterium that will exist saprotrophically in the soil and rhizosphere or as a differentiated bacteroid inside root nodules of the legume genera Medicago, Melilotus, and Trigonella. It exists in symbiosis when inside a host plant and will fix gaseous N2 into ammonium for the plant. In return, a population of the bacteria is harbored inside the plant where it can proliferate beyond what would be possible in the rhizosphere or bulk soil. This symbiosis is a defining feature of the Fabaceae (legume) family, a clade that diverged approximately 60 million years ago and is now the 5th largest plant family by species count. Each legume species pairs with one or several strains of bacteria, referred to broadly as rhizobia. The rhizobia identify their proper host plant by a cocktail of secondary metabolites called flavonoids released from specific parts of the roots. Initiation of the symbiosis may only occur at the tips of young root hairs. Therefore, the means rhizobia take to localize themselves to these sites must be the inceptive step in the symbiotic interaction. The studies here examine the mechanisms and priorities rhizobia use to achieve this goal. Movement of bacteria is referred to as motility and is achieved via (in rhizobia, multiple) rotating flagella, proteinaceous extracellular appendages that propel the cell through liquid environments. On their own, flagella may only move but not guide the cell. Navigation is achieved through sensors that detect chemical attractant or repellent cues in the environment and an intracellular signaling system that relays information to appropriately control locomotion. This sensing is called chemotaxis. A research focus is directed on the sensing aspect of chemotaxis to understand which chemical compounds are the preferred attractants for S. meliloti. An emphasis is placed on those compounds released from germinating host seeds. Chapter 2 spearheads our research goals by examining the chemotactic potential of host-derived flavonoids, the compounds that induce the symbiotic signaling in the rhizobial symbiont. While a logical place to start, this study reveals that our strain of rhizobia is not attracted to flavonoids. We determined that the best chemoattractants are hydrophilic in nature and that hydrophobic compounds, such as flavonoids, are not effective chemoattractants. In addition, we discuss the nature of chemotactic agents and symbiosis inducers to fortify our understanding of how classes of compounds contribute to the rhizobia-plant interaction. In chapter 3, we characterize the sensor protein, McpV, and its ligand profile for carboxylates. The protein is first screened using a high-throughput assay to test numerous possible ligands simultaneously. We confirm positive reactions using direct binding studies and quantify dissociation constants. Then, the phenotypic response to these ligands is measured using capillary chemotaxis assays, and the role mcpV plays in this response is confirmed using deletion mutants. Last, the symbiotic context is addressed by quantifying these ligands in exudates of the host alfalfa. These experiments show that McpV is a chemotactic sensor dedicated to detecting 2 – 4 C monocarboxylates. Only one of the compounds found in the ligand profile, glycolate, was detected in seed exudates, so the contribution of McpV to host sensing is yet to be expounded. Chapter 4 follows the model of chapter 2 but is complicated when the ligand screen used previously gives ambiguous results. Using direct binding studies, we were able to confirm the true ligand amidst numerous false positives. Analytical gel filtration suggests that McpT exists as a dimer regardless of ligand binding. Capillary chemotaxis assays quantified the responses mediated by McpT to di- and tri-carboxylates, which were slightly weaker, but still on-par with the responses to McpV ligands. Strains with mcpT deletions showed strongly reduced, but in some cases, not abolished, chemotaxis to carboxylates. Chapter 5 examines McpX – the chemoreceptor already known to be a sensor of quaternary ammonium compounds. This is a structural investigation into the binding of McpX to its ligands. A crystal structure of the ligand binding region of the protein is resolved to understand how ligands fit into the binding pocket of McpX and what determines its structurally diverse ligand profile. The contribution of certain residues to ligand binding are further probed using direct binding studies on single point variants of McpX. The analysis of chemoreceptor functions hint at what kinds of molecules are most important to bacterial survival and reproduction. Knowing what the bacterium is tuned to seek out grants understanding of what niches they prefer, and how they thrive in those niches. For S. meliloti and other rhizobia, the preeminent niche is one in symbiosis with a host plant. The sum of this knowledge we have accrued with S. meliloti lends itself to agricultural goals of soil enrichment, legume inoculation, nutrient cycling, and environmentally safe and efficient crop fertilization. / Doctor of Philosophy / Sinorhizobium meliloti and other soil-dwelling bacteria termed rhizobia are crucial to the cultivation of leguminous crops such as alfalfa, soy, pea, lentil, peanut, and many more. The bacterium can be internalized by the plant host's roots where it will supply the plant with nitrogen. This is a great boon to crops when they need to accumulate more protein in seed stores, or for plants that survive in nutrient depleted soils. The bacterium must begin seeking out the host plant by sensing chemical cues. It can navigate to the proper location by using a process called chemotaxis. This process is centered around chemoreceptors that can be likened to the nose of the bacterium. Using these chemoreceptors, the bacterium will seek out compounds that benefits it – these are usually food sources. Identifying what each individual chemoreceptor senses allows us to understand what the bacterium needs to seek out to survive. We correlate this information with compounds that the plant secretes and find that many chemoreceptors have evolved to sense signals that will lead the bacterium to a plant root. This interaction is a key part of how the symbiosis is propagated and ultimately benefits the agriculture of leguminous plants.

The purpose of the present study is to investigate the relationships among accepting and reminiscing the past, attachment dimensions, and autobiographical memory. University students (N=182) participated to the study (105 women, 77 men). The relationships among attachment anxiety, avoidance, accepting and reminiscing the past, and autobiographical memory were examined within the context of emotionally charged memories and the phenomenological properties of the recalled autobiographical memories, such as the recollection, coherence, and persistence of the reported memories. Results revealed that attachment anxiety significantly predicted the visceral reactions to emotional memories, the vividness and negative valence of the recalled memories, overall the affective aspects of autobiographical memories. Results also indicated that attachment anxiety was a reliable predictor of accepting the past. The interaction between attachment anxiety and avoidance has also a predictive effect on the specifity of memory (specifity of the memory to the person) and vividness, When the patterns of the interaction effect were examined, it was observed that individuals with high attachment anxiety and avoidance (i.e. fearful attachment) reported high scores in specifity, vividness, and cognitive properties of the recalled memories than individuals with low anxiety and high avoidance (i.e., dismissive attachment), suggesting that dismissing individuals repress their memories and fearful hyperactivate them. Attachment avoidance has a significant predictive effect on recollection. Examination of the effect of the accepting the past on the phenomenological properties of autobiographical memory indicated that accepting the past significantly predicted positive and negative valence, perspective, and visceral reactions. Partially supporting the hypotheses, these results suggested that attachment anxiety, but not avoidance has a consistent effect on the affective aspects of autobiographical memory. Findings were discussed on the basis of the literature on both attachment and autobiographical memory.

Aligning two images by point to point correspondence is a hard optimization problem. It can be solved using t-Extremal Optimization or with a modification of this method called Fitness threshold accepting. In this work these two methods are tested and compared to see whether one of the methods should be preferred for image alignment. Since real image data is almost always noisy the performance of the methods under conditions like noisy and outlying data is analyzed too.

Gottman identified the phenomenon accepting influence in couple relationships, defining it as the action of letting one’s partner influence their opinions, as well as the approach of being open-minded towards one’s partner. In this study, we examine accepting influence among a dyadic sample of military couples (N=242 couples). We first replicate Gottman’s findings which link accepting influence to couple satisfaction, and then expand this area of research by examining how accepting influence within the couple relationship relates to family-level outcomes based on theoretical underpinnings from systems theory and the spillover hypothesis. To model relationships within and between partners, we utilize an actor-partner interdependence model. Results demonstrate that accepting influence is related to both couple and family satisfaction in military families, although these were primarily actor effects (i.e., perceptions of accepting influence were primarily associated with personal reports of couple and family satisfaction). Implications for practice and research will be discussed.

In couple relationships, the phenomenon of accepting influence is both an observable action, seen in couples compromising and respecting each other, as well as an approach to the relationship, one’s perception that their partner is someone worthy of sharing power with. This study utilizes a life course perspective to examine the mediated relationship between childhood experiences, partners accepting influence, and relationship satisfaction in a sample of military couples. An actor partner interdependence mediation model was fit in Amos to examine the relationships. Civilian spouses’ childhood experiences were related to their perception their partner accepts influence and service members’ perception their partner accepts influence; this was then related to both partners’ relationship satisfaction. Accepting influence is a potential leverage point for improving relationship satisfaction in military couples who may be at an increased risk due to the nature of military life.

Tracking control algorithms often target the convergence of a tracking error. However, this can be at the expense of other important system characteristics, such as the control effort used to annihilate the tracking error, transient response, or steady-state characteristics, for example. Furthermore, most tracking control methods assume prior knowledge of the system dynamics, which is not always a realistic assumption, especially in the case of highly complex systems. In this thesis, a model-free optimized tracking control architectural heuristic is proposed. The suggested feedback system is composed of two control loops. The first is the tracking loop. It focuses on the convergence of the tracking error. It is implemented using two different model-free control algorithms for comparison purpose: Reinforcement Learning (RL) and the Nonlinear Threshold Accepting (NLTA) technique. The RL scheme reformulates the tracking error combinations into a form of Markov-Decision-Process (MDP) and applies Q-Learning to build the best tracking control policy for the dynamic system under consideration. On the other hand, the NLTA algorithm is applied to tune the gains of a PID controller. The second control loop is in the form of a nonlinear state feedback loop. It is implemented using a feedforward artificial neural network (ANN) to optimize a system-wide cost function which can be flexible enough to encompass a set of desired design requirements pertaining to the targeted system behavior. This may include, for instance, the target overshoot, settling time, rise time, etc. The proposed architectural heuristic provides a model-free framework to tackle such control problems, in the sense that the plant's dynamic model is not required to be known in advance. Yet, at least a subset of the stability region of the optimized gains has to be known in advance so that it can provide a search space for the optimization algorithms. Simulation results on two dynamic systems demonstrate the superiority of the proposed control scheme.

This study explores employees' desire to embrace both a legacy operating system and a new workflow engine utilized in the workplace. The goal is to better understand the partnership and relationship the users build with the technologies and how that impacts usage behavior. The research is centered on a mixed-method case study using survey and episodic interview techniques of data collection. Models and methodologies providing the foundation for this study include Venkatesh and Davis's technology acceptance model 2 (TAM 2) and Venkatesh, Morris, Davis, and Davis' unified theory of acceptance and use of technology (UTAUT) model, coupled loosely with concepts from Brooks and Atkinson's StructurANTion Theory. A new, adapted model is created to capture and understand the anthropomorphic characteristics users apply to the technology. This study yields important information for the future theoretical frameworks as elements such as trust and control, and descriptive variables like age and tenure have not factored into existing theoretical frameworks and models. Users can often anthropomorphize technology, viewing it as part of the social team to help improve their work. Through this lens, users expect information systems to be controllable and trustworthy to respond to their needs both alone and within the function of the team.