Efficient multi-dimensional assignment algorithms and their application in multi-frame tracking / In this work, we propose a novel convex dual approach to the multidimensional dimensional assignment problem, which is an NP-hard binary programming problem. It is shown that the proposed dual approach is equivalent to the Lagrangian relaxation method in terms of the best value attainable by the two approaches. However, the pure dual representation is not only more elegant, but also makes the theoretical analysis of the algorithm more tractable. In fact, we obtain a su cient and necessary condition for the duality gap to be zero, or equivalently, for the Lagrangian relaxation approach to nd the optimal solution to the assignment problem with a guarantee. Also, we establish a mild and easy-to-check condition, under which the dual problem is equivalent to the original one. In general cases, the optimal value of the dual problem can provide a satisfactory lower bound on the optimal value of the original assignment problem. We then extend the purely dual formulation to handle the more general multidimensional assignment problem. The convex dual representation is derived and its relationship to the Lagrangian relaxation method is investigated once again. Also, we discuss the condition under which the duality gap is zero. It is also pointed out that the process of Lagrangian relaxation is essentially equivalent to one of relaxing the binary constraint condition, thus necessitating the auction search operation to recover the binary constraint. Furthermore, a numerical algorithm based on the dual formulation along with a local search strategy is presented. Finally, the newly proposed algorithm is shown to outperform the Lagrangian relaxation method in a number of multi-target tracking simulations. / Thesis / Doctor of Philosophy (PhD)

The need for a non-invasive, accurate, easy-to-use, and cost-effective colorectal cancer (CRC) detection device is apparent in the low survival rates seen in late-stage diagnoses. Once CRC has progressed past stage I, the 5-year survival rate drops significantly, and treatment options become less favourable. The best way to treat CRC is to catch it early. The development of an RNA-cleaving fluorogenic DNAzyme (RFD) holds the potential to remediate this deficiency. A DNAzyme, called RFD-FN1, was identified from a synthetic random-sequence DNA library to selectively bind to an unknown target associated with Fusobacterium nucleatum, which has been found to be overabundant in pre- and cancerous colorectal tissue and stool. Target recognition by the DNAzyme induces the cleavage of a fluorogenic substrate and generates a fluorescent signal to indicate the presence of the bacterium. This thesis outlines the efforts made towards functionalizing the F. nucleatum-responsive probe in stool samples to create a non-invasive screening test. RFD-FN1 is selective towards a heat-stable F. nucleatum protein, but its limit of detection is only 10^7 CFU/mL. Although able to detect spiked concentrations of F. nucleatum cells in processed stool samples, the use of heat, filtering, centrifugation, antibiotics, culturing or serial dilutions are not sufficient to detect the F. nucleatum that is naturally present in the diseased samples. Experiments designed to enrich the target concentration revealed that the target is not produced consistently in any growing condition tested. Size exclusion chromatography and mass spectrometry analysis identified five potential targets that RFD-FN1 may be responding to. Three candidate targets were cloned and purified, but they failed to induce RFD-FN1’s activity. Due to the COVID-19 pandemic, the purification of the final two proteins was not completed. Purifying the two candidate targets and testing their ability to induce RFD-FN1 represents future research efforts. If the target for the DNAzyme is confirmed, a reselection for a more sensitive DNAzyme, that can function in human stool, can be attempted. / Thesis / Master of Health Sciences (MSc)

Prey-mediated effects of imidacloprid were evaluated for Laricobius nigrinus Fender and Sasajiscymnus tsugae Sasaji and McClure after feeding on hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae). Two methods were evaluated for detecting imidacloprid in hemlock tissues: a commercially available enzyme linked immunoassay (ELISA) kit and a high performance thin-layer chromatography technique for detecting and quantifying imidacloprid residues in hemlock wood and needle tissues. ELISA is advantageous because of its cost, sensitivity, and ease of use. However, matrix effects in the form of false positives and overestimated imidacloprid concentrations were evident in hemlock wood and needle tissue extracts. Matrix effects could be reduced by dilution with water, effectively raising the lower detection range of the kit from 0.2 to 200 ppb. High performance thin-layer chromatography was accurate, quick, easy to use, and matrix effects were not evident. However, the technique is sensitive in the lower ppm range and tissue samples from field-treated hemlocks are often in the ppb range, making this technique less desirable than more sensitive analytical methods. Lethal and sublethal effects on both predators were evident after eastern hemlock branches infested with HWA were spiked with imidacloprid in the laboratory. HWA mortality increased with dosage and time, and its 30 d LC50 was determined to be 242 ppb. Both predator species exhibited reduced survivorship and fitness parameters after feeding on HWA from the treated branches. In a topical application bio-assay, 6 d imidacloprid LD50 values for L. nigrinus and S. tsugae were 2.43 and 1.82 µg/g, respectively. Imidacloprid and its major metabolites in hemlock tissues were analyzed by liquid chromatography-tandem mass spectrometry. Imidacloprid recovery from beetle cadavers was correlated with beetle mortality from feeding on treated hemlock branches. Olefin was the primary imidacloprid metabolite recovered from hemlock wood tissues. When predators fed on HWA from field-treated trees, impacts on survivorship and fitness were variable. In 2005, significantly higher proportions of both species of beetles were affected by feeding on control branches compared with treated branches. In 2006, beetles feeding on HWA from some of the trees treated in the field exhibited longer fliptimes compared with beetles feeding on controls, although beetle mortality was not significant among treatements. In the field, imidacloprid controlled HWA populations 1-3 years post-treatment. Hemlock health improved in the highest dosage group, with significantly greater lengths of new shoots compared with shoots from control trees. Eastern hemlock trees primarily metabolized imidacloprid into the olefin metabolite, which can have increased insecticidal toxicity compared with imidacloprid. Imidacloprid was detected in beetle cadavers after feeding on HWA from treated branches, suggesting that prey-mediated impacts of systemic imidacloprid are possible on nontarget predators. However, because of HWA's sensitivity to imidacloprid, in field situations predators are more likely to be affected by reduced adelgid density and quality. / Ph. D.

The charged pion production reactions d(gamma,pi⁺n), d(gamma,pi^-p), HD(gamma,pi⁺n)X were studied using linearly polarized gamma-rays with energies in the range from 260 MeV to 370 MeV at the Laser Electron Gamma Source (LEGS). A solid HD target was used in this experiment for the first time. The beam asymmetry data for the d(gamma,pi^-p) reaction significantly add to the previously available data. This gives new input to multipole analysis of pion production. A slight deviation from the beam asymmetry predicted for the free neutron is observed. The cross sections in the d(gamma,pi^-p) channel agree with previous measurements. / Ph. D.

In the context of (0, 2) gauged linear sigma models, we explore chains of perturbatively dual heterotic string compactifications. The notion of target space duality (TSD) originates in non-geometric phases and can be used to generate distinct GLSMs with shared geometric phases leading to apparently identical target space theories. To date, this duality has largely been studied at the level of counting states in the effective theories. We extend this analysis in several ways. First, we consider the correspondence including the effective potential and loci of enhanced symmetry in dual theories. By engineering vector bundles with non-trivial constraints arising from slope-stability (i.e. D-terms) and holomorphy (i.e. F-terms) the detailed structure of the vacuum space of the dual theories can be explored. Our results give new evidence that GLSM target space duality may provide important hints towards a more complete understanding of (0,2) string dualities. In addition, we consider TSD theories on elliptically fibered Calabi-Yau manifolds. In this context, each half of the "dual" heterotic theories must in turn have an F-theory dual. Moreover, the apparent relationship between two heterotic compactifications seen in (0,2) heterotic target space dual pairs should, in principle, induce some putative correspondence between the dual F-theory geometries. It has previously been conjectured in the literature that (0,2) target space duality might manifest in F-theory as multiple K3- fibrations of the same elliptically fibered Calabi-Yau manifold. In this work we investigate this conjecture in the context of both six-dimensional and four-dimensional effective theories and demonstrate that in general, (0,2) target space duality cannot be explained by such a simple phenomenon alone. Finally, we consider Landau-Ginzburg (LG) phases of TSD theories and explore their massless spectrum. In particular, we investigate TSD pairs involving geometric singularities. We study resolutions of these singularities and their relationship to the duality. / Doctor of Philosophy / In string theory, the space-time has “hidden” dimensions beyond the three spatial and one time-like dimensions macroscopically seen in our universe. We want to study how the geometries of this “internal space” can affect observable physics, and which geometries are compatible with our universe. Target space duality is a relationship that connects two or more geometries together. In target space duality, gauged linear sigma models (related to string theories) share a common locus (called a Landau-Ginzburg phase) in their parameter space, but are distinct theories. To date, this duality has largely been studied at the level of counting states in the effective theories. In this dissertation, target space duality is studied in more depth. First we extend the analysis to the effective potential and loci of enhanced symmetry. By engineering examples with non-trivial constraints, the detailed structure of the vacuum space of the dual theories can be explored. Our results give new evidence that target space duality may provide important hints towards a more complete understanding of string dualities. We also investigate the conjecture that target space duality might manifest in F-theory, a higher dimensional string theory, as multiple fibrations of the same manifold. We demonstrate that in general, target space duality cannot be explained by such a simple phenomenon alone. In our cases, we provide evidence that non-geometric data in F-theory must play at least some role in the induced F-theory correspondence, while leaving the full determination of the putative new F-theory duality to future work. Finally we explore the complete massless spectrum of the Landau-Ginzburg (LG) phase. Specifically, we calculate the full LG spectra for both sides, and compare the theory with the geometric phases. We find examples in which half of the target space dual geometry is singular. We have probed some approaches to resolving the singularity.

This dissertation takes a three-article approach in which the literature from public administration, political psychology and sociology is synthesized around student veterans as a new phenomenon in higher education and public policy. By examining student veterans through the Social Construction of Target Populations (SCTP) framework, these articles contribute to the theoretical understanding of how social identity at the group and individual levels impact a target population's understanding of and reaction to a policy that does not always align with the policy-makers' intent. Because the current SCTP literature has focused on how policy-makers construct target populations and the practices they use to mitigate any negative effects of policy feedback, these articles offer a new perspective by applying symbolic interactionism as a method for capturing the two-way interaction between the target population and the policy's intent. The articles focus on the policy feedback mechanism in the SCTP framework to explain why and how policies shape the identities of target populations, and how they in turn, engage in the policy process by first presenting student veterans as a new social concept, then presenting a case study of how an organization that represents student veterans achieved policy change, and finally, interviewing veterans, revealing that their individual interpretation of the policy is not always representative of the student veteran identity as constructed by policy-makers and advocates. / Doctor of Philosophy / This dissertation takes a three-article approach to understanding how and why student veterans are different from other veterans based upon the latest policy changes to expand educational benefits available through the G.I. Bill. The first article describes what policy-makers and veterans’ organizations claim a student veterans is – a Post 9/11 veteran pursuing higher education that will lead to a career or fulfill the needs of 21st Century jobs. The second article presents a case-study of how an organization that represents student veterans was able to engage in the policy-making process and succeed in achieving policy changes that resulted in the Harry W. Colmery Veterans Educational Assistance Act of 2017, also known as the Forever G.I. Bill. The third article focuses on the factors influencing veterans’ decision-making process about when and how to use their educational benefits based on how they understand and interpret the policy. All three articles provide a new perspective on the ways in which policy-makers and advocacy groups can create a new social identity group, such as student veterans, and design and implement policies based on the assumptions these policy actors have about the group. However, at the individual level, student veterans might not always behave in the way policy-makers expect them to, causing student veterans to use or not use their educational benefits based on their perceptions of what the Post 9/11 G.I. Bill means to them.

Muscarinic acetylcholine receptors (mAChRs) are G-protein-coupled receptors that are underutilized for controlling insect pests despite their involvement in various physiological functions. To-date, there are no commercialized insecticides targeting insect mAChRs. In this dissertation, effective target-site synergism was demonstrated in susceptible Drosophila melanogaster where mAChR agonism by pilocarpine enhanced the toxicity of insecticides targeting gamma-aminobutyric acid (GABA)-gated chloride channels, indicating the potential of insect mAChRs as a target for developing novel insecticides/synergists to control resistant pests. A point mutation (A301S) in the GABA-gated chloride channel confers resistance to dieldrin (Rdl), lindane, and fipronil, which I have confirmed using different routes of exposure. However, the same synergistic effect was not achieved in the resistant strain with the presence of this target-site mutation. This difference between two strains is perplexing because there is a change in the efficacy of several compound classes that do not directly act upon GABA-gated chloride channels. Specifically, a point mutation appears to influence how the insect central nervous system (CNS) responds to muscarinic compounds, type I pyrethroids, and acetylcholinesterase (AChE) inhibitors. In the case of acetylcholinesterase, the resistant insect increases the expression of Ace gene encoding this enzyme. Fully understanding how the CNS responds to receptor modifications is not well understood and could have a significant impact to pest management strategies. / Doctor of Philosophy / Insects significantly influence the food production, health, and the economy of the human world. Control of insect pest outbreaks relies on the proper use of insecticides. However, extensive application of insecticides has resulted in pests being able to adapt to these compounds, through insecticide resistance. Ultimately, this will affect currently used pest management strategies. To help alleviate this urgent problem, my dissertation provided an alternative strategy to control pests, which is to use a mixture of two molecules that influence different targets in the insect nervous system that could reduce the use of toxic or deleterious compounds that are the active ingredients. It is important to not solely rely on current insecticides on the market and find new insecticides that work differently. I used the fruit fly to help me understand how insecticide mixtures would work, but also understand how the complex nature of insect adaptations at the level of the nervous system continues to threaten pest management. Based on studies that were performed here, we now have a better understanding on how to investigate the failure of insecticides in the field, which will ultimately help us make new molecules.

Unmanned vehicles are increasingly being used for mobile sensing missions. These missions can range from target acquisition to chemical and biological sensing. The reason why these vehicles are increasingly being used is because they can carry many different types of sensors and can function as a cheap platform for carrying these sensors. The sensing that will be explained in this thesis is target acquisition. Target acquisition is the act of locating the exact position of an "area of interest." Currently this task can be completed with different types of complex range sensors. This thesis presents a type of target acquisition scheme for unmanned vehicles that will use a combination of cheap, simple vision sensors and robot inertial navigation data in order to accurately measure the location of a target in real world coordinates. This thesis will first develop an accurate waypoint driving algorithm that will either use dead reckoning or GPS/ compass sensors. We will then develop a robust target extraction algorithm that will be able to pick out a target in an image. After this is completed we will develop an algorithm that will be used to find the distance to the target from the robot. This algorithm will be based on a type of active vision system. Finally we will integrate all of these algorithms together in order to develop a target extraction technique that will be able to accurately find the distance to the target. With the distance we can then find the real world location of the target. / Master of Science

Microarrays containing long oligonucleotides provide sensitive and specific detection of gene expression and are becoming a popular experimental platform. In the process of designing an oligonucleotide microarray for Brucella, we optimized the overall design of the array and created probes to distinguish among the known Brucella species. A 3-way genome comparison identified a set of genes which occur uniquely in only one or two of the sequenced Brucella genomes. Reverse transcriptase PCR assays of over one hundred unique and pairwise-differential regions identified in Brucella revealed several groups of genes that are transcribed in vivo with potential significance for virulence. The structural and thermodynamic properties of a set of 70mer oligonucleotide probes for a combined B. abortus, B. melitensis and B. suis microarray were modeled to help perform quantitative interpretation of the microarray data. Prediction and thermodynamic analysis of secondary structure formation in a genome-wide set of transcripts from Brucella suis 1330 demonstrated that properties of the target molecule have the potential to strongly influence the rate and extent of hybridization between transcript and an oligonucleotide probe in a microarray experiment. Despite relatively high hybridization temperatures used in the modeling process, parts of the target molecules are predicted to be inaccessible to intermolecular hybridization due to the formation of stable intramolecular secondary structure. Features in the Brucella genomes with potential diagnostic use were identified, and the extent to which target secondary structure, a molecular property which is not considered in the array design process, may influence the quality of results was characterized. / Master of Science

El Antiproton Decelerator Target (AD-Target) es un dispositivo único responsable de la generación de Antiprotones en la Organización Europea para la Investigación Nuclear (CERN). En operación, intensos haces de protones con una energía de 26 GeV son impactados en su núcleo, un cilindro de 3 mm de diámetro constituido por un material de alta densidad como el iridio, creando partículas secundarias -entre ellas, antiprotones- como consecuencia de las reacciones nucleares inducidas en el interior de éste. La tesis profundiza en las características del target de producción de antiprotones, y en particular, en la respuesta mecánica de su núcleo, el cual está sometido a un incremento de temperatura de aproximademente 2000 grados centígrados en menos de 0.5 microsegundos cada vez que es impactado por el haz de protones primario. Para ello, una metodología combinando técnicas numéricas y experimentales ha sido llevada a cabo. Se han aplicado herramientas computacionales específicas, llamadas hydrocodes, para simular la respuesta dinámica originada en el núcleo del target y su matriz contenedora, hecha de grafito, indicando su potencial fragmentación como resultado de una onda radial de alta frecuencia de presión compresión-tracción generada después de cada impacto del haz de protones. Asimismo, se ha llevado a cabo un experimento llamado HiRadMat27. En éste, varios cilindros de materiales de alta densidad, candidatos para un futuro diseño del target, tales como Ir, W, W-La, Mo, TZM y Ta, han sido expuestos a condiciones dinámicas equivalentes a las alcanzadas en el AD-Target mediante impactos de haces de protones de 440 GeV en la instalación HiRadMat. Se ha usado instrumentación en línea para medir la onda radial pronosticada, confirmando la precisión de las simulaciones de hydrocodes. Todos los materiales irradiados excepto Ta sufrieron agrietamientos internos desde condiciones 5-7 veces menores a las presentes en el AD-Target, mientras que este último aparentemente sobrevivió. La información obtenida ha sido aplicada para proponer un nuevo diseño optimizado del target, el cual incluye un sistema de refrigeración de aire a presión, una nueva configuración en Ta de su núcleo, y una matriz contenedora hecha de grafito expandido (GE). Se han llevado a cabo cálculos de dinámica de fluidos computacional y elementos finitos para validar el sistema de refrigeración y la vida a fatiga del ensamblaje del target. Además, se ha construido un primer prototipo del núcleo del target y su matrix contenedora. Estas actividades marcan la senda para la fabricación de un nuevo lote de targets que garanticen la física de antiprotones en el CERN durante las siguientes décadas de operación. / The Antiproton Decelerator Target (AD-Target) is a unique device responsible for the production of antiprotons at the European Organization for Nuclear Research (CERN). During operation, intense 26 GeV energy proton beams are impacted into its core, made of a 3 mm diameter rod of a high density material such as iridium, creating secondary particles -including antiprotons- from the nuclear reactions induced in its interior. This thesis delves into the characteristics of antiproton production and in particular in the mechanical response of the target core material, which is exposed to a rise of temperature of approximate 2000 degrees Celsius in less than 0.5 microseconds each time is impacted by the primary proton beam. A coupled numerical-experimental approach has been applied for this purpose. Specific computational tools, called hydrocodes, have been used for simulating the extreme dynamic response taking place in the target core and its containing graphite matrix, indicating their potential damage and fragmentation as a result of a high frequency radial compressive-to-tensile pressure wave generated after each proton beam impact. A challenging first-of-its-kind experiment called HRMT27 was carried out. Several rods of high density materials, candidate for a future optimized target design, such as Ir, W, W-La, Mo, TZM and Ta were brought to equivalent dynamic conditions as reached in the AD-Target core by impacting them with 440 GeV proton beams using the HiRadMat facility. Online instrumentation was used to measure the predicted radial wave, confirming the accuracy of the hydrocode simulations. All of the irradiated target materials except Ta showed internal cracking from conditions 5-7 times below the present in the AD-Target while the latter apparently survived. Lessons learned are applied for proposing a new optimized target design, including a pressurized-air cooling system, Ta core configuration, and a containing matrix made of expanded graphite (EG). Computational Fluid Dynamic and Structural Finite Element analyses have been carried out to validate the new cooling system and fatigue life of the target assembly. A first prototype of the target core and its containing EG matrix has been built. These activities lead the way into manufacturing a new set of antiproton targets to guarantee antiproton physics at CERN during next decades of operation. / L'Antiproton Decelerator Target (AD-Target) és un dispositiu únic responsable de la generació d'Antiprotons a la Organització Europea per la Recerca Nuclear (CERN). En operació, intensos feixos de protons amb una energia de 26 GeV impacten contra el seu nucli, un cilindre de 3 mm de diámetre constituït per un material de densitat alta com l'iridi, creant partícules secundáries - entre elles, antiprotons - com a conseqüència de les reaccions nuclears induïdes a l'interior d'aquest. La tesis profunditza en les característiques del target de producció d'antiprotons i, en particular, a la resposta mecánica del seu nucli, el qual és sotmès a un increment de temperatura de aproximadement 2000 graus centígrads en menys de 0.5 microsegons cada vegada que és impactat pel feix de protons primari. Per aixó, s'ha portat a terme una metodologia que combina tècniques numèriques i experimentals. S'han utilitzat eines computacionals específiques, anomenades hydrocodes, per simular la resposta dinàmica originada al nucli del target i a la seva matriu contenidora, feta de grafit. La dita resposta, indica la seva potencial fragmentació com a resultat d'una ona radial d'alta freqüència de pressió compressió-tracció generada després de cada impact del feix de protons. Així mateix, s'ha portat a terme un experiment anomenat HiRadMat27. En aquest, varis cilindres de materials d'alta densitat, candidats per un futur diseny del target, tals com Ir, W, W-La, Mo, TZM i Ta, han estat exposats a condicions dinàmiques equivalents a les assolides a l'AD-Target mitjanant impactes de feixos de protons de 440 GeV a l'instalació HiRadMat. S'ha utilitzat instrumentació en línia per mesurar l'ona radial pronosticada, confirmant la precisió de les simulacions d'hydrocodes. Tots el materials irradiats excepte Ta van sofrir esquerdaments interns desde condicions de 5-7 vegades menors a les presents a l'AD-Target, mentres que aquest últim aparentment va sobreviure. L'informació obtinguda ha estat aplicada per proposar un nou diseny optimizat del target, el qual inclou un sistema de refrigeració de l'aire a pressió, una nova configuració en Ta del seu nucli, i una matriu contenidora feta de grafit expandit (GE). S'han portat a terme càlculs de dinàmica de fluids computacionals i elements finits per validar el sistema de refrigeració i la vida a fatiga de l'ensambladura del target. S'ha construit un primer prototip del nucli del target i la seva matriu contenidora. Totes aquestes activitats marquen la sendera per a la fabricació del nou lot de targets que garantitzin la física d'antiprotons al CERN durant les següents décades d'operació. / Torregrosa Martín, CL. (2018). Comprehensive Study and Optimized Redesign of the CERN's Antiproton Decelerator Target [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/100489