Neutrophils are known to be key innate defenders through performing vital and diverse functions such as degranulation, oxidative burst, and generation of extracellular trap (NET). Recent data suggest that neutrophils may also play key roles in modulating tissue inflammatory/immune environment by secreting soluble mediators as well as surface-attached co-activators. Furthermore, neutrophils may adopt distinct functional states either conducive or detrimental for tumor-growth through cellular contact with cancer cells and/or other immune cells such as T helper cells. However, molecular mechanisms that modulate functional adaptations of neutrophils are not well understood. The objective of my thesis is to identify the role of Tollip, a novel TLR signaling adaptor molecule, in modulating neutrophil functions by suppressing the inflammatory signaling pathway. Preliminary data from our lab suggest Tollip deficient neutrophils may be programed to exhibit enhanced anti-tumor activities. Based on these novel findings, I tested the hypothesis that neutrophils also have subsets with different functions similar to monocyte/macrophages, and Tollip deficient neutrophils may be programmed into an enhanced anti-tumor state through upregulating inflammatory signaling processes and mediators. / Ph. D. / Cancer immunotherapy gained instant popularity overnight after former president of the United States, Jimmy Carter, announced successful treatment of his metastatic melanoma. Since then, FDA has approved the first immunotherapy in the summer of 2017. Current cancer immunotherapy focuses heavily on the potential of T cells to target unregulated cells in the host. However, time and specificity have proven a difficult challenge to overcome. Innate immune cells may circumvent these challenges and present equal potential as therapy in the fight against cancer. Neutrophils are one of the innate immune cells that provide first line of defense against pathogens. Neutrophils can clear danger or maintain the situation until more cells arrive to help clear the danger. They were originally thought to confer simple and transient effects, but emerging data suggest they may have more diverse role in host defense. We propose programming neutrophils will make the cells less susceptible to cancer manipulation and provide enhanced protection against cancer establishment and maintenance.

21st century political science has seen a growing field of research focused around the idea of political polarization. While authors like Fiorina and Abramowitz have been debating the existence of such polarization, the literature has come to understand that perhaps the root of the issue lies in differing definitions. The never-ending quest for clarity has produced a variety of measures of polarization and, subsequently, theories on why 21st century Americans may be experiencing such polarization. Unsurprisingly, as political science questions what may be causing various trends in 21st century voter behaviors and attitudes, the Internet is often mentioned. With the Internet being a clearly powerful tool for political mobilization, whether or not it is divisive among the public could have politically consequential implications. Because of its interactive nature, it is difficult to evaluate a person's social media use. This study uses a unique survey to evaluate a respondent's general social media and internet use, as well as measures of political polarization. Using this information, along with analysis of the 2016 ANES, I am able to make associations of various levels of social media activity and political polarization. Using means comparison and multivariate regression, I am able to evaluate social media use controlling for effects of age and other confounding variables and how it relates to measures of political polarization. The survey results ultimately provide some evidence for the claim that increasing social media use is associated with higher levels of political polarization. Additionally, in an OLS regression model testing the effects of different sources of political news, increases in internet use are highly correlated with an increase in political polarization. / Master of Arts / Since the 2016 US Presidential election, there have been increasing concerns over how divided the country is getting. Part of the reason why people feel so polarized is likely being exaggerated by social media and breaking news headlines. While Americans may be closer on the issues than they care to believe, the perception of a divided country may be just as consequential. It is difficult to say to what degree our country is truly polarized, if at all. What we can be sure of is that political activists are able to be heard much louder given the platform of the internet. What motivates people to spend hours of their day scrolling through platforms like Facebook is an individual preference, but it is clear that these companies can directly profit from click-bait news headlines. In order to explore the degree to which different groups are polarized in America, I used an online survey asking respondents about their internet use and political leanings. Using this information, I am able to see what associations might exist between things such as amount of time spent on social media per day and how committed one is to their ideology. These measures themselves are widely debated in political science, so the study also aims to examine in what ways different measures of polarization may be used effectively. The results of the study do find some evidence that increased social media use is correlated with an increase in political polarization. However, other measures of political activity on the internet are seen to be highly correlated with an increase in political polarization.

Este estudo abordou os aspectos teóricos e experimentais relacionados ao desenvolvimento de um sistema de tomografia por coerência óptica (OCT) no domínio de Fourier sensível à polarização (PS-FD-OCT) e a sua utilização na determinação da Matriz de Mueller (MM-OCT). O estudo iniciou-se com uma revisão bibliográfica que abordou desde os primeiros estudos relacionados à técnica até o estado da arte, bem como o formalismo matemático da interferometria de baixa coerência no domínio espectral e polarização da luz. Realizaram-se estudos baseados em simulação numérica sobre três tipos diferentes de algoritmos, responsáveis pela recuperação do sinal de espalhamento, sendo eles: a Transformada de Fourier Direta; Interpolação e Zero-Filling. Ao fim dessa etapa concluiu-se que o algoritmo Zero-Filling 2N apresentou melhores características quando comparado aos outros algoritmos. Na parte experimental, primeiramente, diferentes arranjos OCT foram montados e medidas realizadas para verificação aspectos relacionados à teoria. Consecutivamente, utilizando uma amostra polimérica, realizaram-se imagens de birrefringência, que permitiram a determinação da birrefringência da amostra quantitativamente. Finalmente, imagens em diferentes estados de polarização foram realizadas, através delas determinou-se as imagens referentes aos elementos das Matrizes de Mueller, que foram analisadas individualmente. / This study approached theoretical and experimental aspects related with the development of a polarization sensitive, Fourier domain, optical coherence tomography system (PS-FD-OCT) and its utilization on the Mueller Matrix determination. This work began with a bibliographic revision, which describes since the early studies to the actual state of the art of the technique. The mathematical formalism of Fourier domain low coherence interferometry and light polarization was performed as well. Studies based on numerical simulations, of three different algorithm types, responsible to recover the scattering profile, were done. The implemented algorithms were: Direct Fourier Transform, Interpolation and Zero-Filling. By the end of the simulation study, was possible to conclude that the algorithm Zero-Filling 2N presented better characteristics when compared with the others. In the experimental part, firstly different OCT setups were assembled and measurements were done in order to verify aspects related with the theory. Then, using a polymeric sample, birefringence images were performed, which allowed determining the sample birefringence quantitatively. Finally, images taken of different polarization states were collected, and through then images related with the Mueller Matrix elements were calculated, which were analyzed individually.

Since the mid-1970s, partisan polarization has been increasing in Congress and the Presidency, and, although most voters lack a stable, consistent ideology, non-ideological forms of partisan polarization have emerged in the mass public in recent decades. Moreover, ideological polarization among elites is highly asymmetrical, with increased Republican conservatism accounting for most of the increased ideological distance between the parties. Here, I develop a racial-threat backlash theory and argue that increased rates of immigration are associated with increased asymmetrical ideological polarization among elites and in the mass public. Tests of this theory on voters, the mass public in the states, state legislators, and Senators provide support for my theory. In addition, when accounting for the effects of immigration, I do not find support for the alternative explanation that increased income inequality leads to increased asymmetrical partisan polarization.

In this thesis, I will describe the polarization properties of two separate but similar optical systems. I will begin by showing anisotropy in a dielectric photonic crystal slab patterned with a periodic circular hole array. This anisotropy can be utilized in manipulating the gain properties of surface emitting photonic crystal lasers. I will then describe a metallic, planar metamaterial patterned similarly with a 2d periodic array of holes. The enhanced optical transmission of this system is demonstrated computationally and experimentally, with a good agreement between the two. I will also demonstrate polarization rotation in this array. The effect is shown to minimize the background contribution to the transmission resulting in the narrowing of the line width and improvement between on and off resonance contrast. I then provide a theory behind the polarization rotation in transmission through a metamaterial based upon a Jones matrix formulation, which is dependent only upon the existence of separate s and p resonances in a photonic system. / text

Sensing in scattering environments, such as fog and dust, poses a serious challenge for all optical systems and is important for many critical surveillance applications. The use of polarized light, specifically circularly polarized light, has shown great promise for improving detection range and sensing in highly scattering, real-world environments. While the potential impact to application is significant, the optical science and sensing community lacks data on broad wavelength and environmental parameters where circularly polarized light outperforms linearly polarized light, increasing detection range and signal persistence. In this dissertation I quantify, through simulation and experimental results, the advantage of circularly polarized light in laboratory and real-world scattering environments - focusing on circularly polarized light's superior persistence in these environments. I present new and unique contributions to the study of polarized light in both isotropic (Rayleigh regime) and forward-scattering environments, showing circular polarization's superior persistence increases detection range for real-world environments over broad wavelength and particle size regimes. Utilizing polarization-tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, I quantify when circular polarization outperforms linear polarization in maintaining the illuminating polarization state for large optical thicknesses, persisting to longer ranges. I identify many real-world environments with particle sizes of radiation fog, advection fog, and Sahara dust where circular polarization outperforms linear polarization over broad wavelength ranges in the infrared spectrum. This enhancement with circular polarization can be exploited to improve sensing range and target detection in obscurant environments that are important in many critical surveillance applications. Conversely, I also identify a few environmental configurations where linear polarization outperforms circular polarization. However, circular polarization's response is generally larger and over broader wavelength ranges in the infrared regime for real-world scattering environments. Experiments were conducted for both 1) isotopically-scattering (Rayleigh regime) environments and 2) forward-scattering environments using polystyrene microspheres with well-defined diameters. These measurements demonstrated that in the forward-scattering environments, circular polarization persists through increasing optical thickness better than linear polarization. Variations in persistence were investigated as a function of collection geometry, angular field of view, and collection area. Persistence for both linear and circular polarization was found to be more susceptible to collection geometry, specifically increased collection area, in the isotropically-scattering (Rayleigh regime) environment. Similarly, linear polarization in the forward-scattering environments is dependent upon changes in collection geometry. Significantly, circular polarization's response is nearly unaffected by variations of both field of view and collection area for the forward-scattering environments. Circular polarization proves to be not only generally better in persistence but also more tolerant of variations in angular collection and collection area compared to linear polarization, making it ideal and flexible for use in optical sensing systems in scattering environments. Finally, I present simulation results that show the evolution of linear and circularly polarized light as it scatters throughout both isotropic (Rayleigh regime) and forward-scattering environments as a function of scattering event. Circularly polarized light persists through a larger number of scattering events longer than linearly polarized light for all forward-scattering environments; but not for scattering in the Rayleigh regime. Circular polarization's increased persistence occurs for both forward and backscattered light. The evolution of the polarization states as they propagate through the various environments are illustrated on the Poincaré sphere after successive scattering events. This work displays individual scattering events as well as a cumulative, measureable result, in an intuitive manner. Throughout this dissertation I quantify the polarization persistence and memory of circularly polarized light in real-world scattering environments over broad wavelength, particle size, and collection-geometry parameter spaces; and for the first time, detail the evolution and modification of both circularly and linearly polarized states through isotropic and forward-scattering environments. These results show how circular polarization can extend range and sensing capability in surveillance sensing applications in real-world scattering environments.

Thesis (Master of Science)--Miami University, Dept. of Physics, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], ???, ??? p. : ill. Includes bibliographical references (p. Xx-Xx).

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Este estudo abordou os aspectos teóricos e experimentais relacionados ao desenvolvimento de um sistema de tomografia por coerência óptica (OCT) no domínio de Fourier sensível à polarização (PS-FD-OCT) e a sua utilização na determinação da Matriz de Mueller (MM-OCT). O estudo iniciou-se com uma revisão bibliográfica que abordou desde os primeiros estudos relacionados à técnica até o estado da arte, bem como o formalismo matemático da interferometria de baixa coerência no domínio espectral e polarização da luz. Realizaram-se estudos baseados em simulação numérica sobre três tipos diferentes de algoritmos, responsáveis pela recuperação do sinal de espalhamento, sendo eles: a Transformada de Fourier Direta; Interpolação e Zero-Filling. Ao fim dessa etapa concluiu-se que o algoritmo Zero-Filling 2N apresentou melhores características quando comparado aos outros algoritmos. Na parte experimental, primeiramente, diferentes arranjos OCT foram montados e medidas realizadas para verificação aspectos relacionados à teoria. Consecutivamente, utilizando uma amostra polimérica, realizaram-se imagens de birrefringência, que permitiram a determinação da birrefringência da amostra quantitativamente. Finalmente, imagens em diferentes estados de polarização foram realizadas, através delas determinou-se as imagens referentes aos elementos das Matrizes de Mueller, que foram analisadas individualmente. / This study approached theoretical and experimental aspects related with the development of a polarization sensitive, Fourier domain, optical coherence tomography system (PS-FD-OCT) and its utilization on the Mueller Matrix determination. This work began with a bibliographic revision, which describes since the early studies to the actual state of the art of the technique. The mathematical formalism of Fourier domain low coherence interferometry and light polarization was performed as well. Studies based on numerical simulations, of three different algorithm types, responsible to recover the scattering profile, were done. The implemented algorithms were: Direct Fourier Transform, Interpolation and Zero-Filling. By the end of the simulation study, was possible to conclude that the algorithm Zero-Filling 2N presented better characteristics when compared with the others. In the experimental part, firstly different OCT setups were assembled and measurements were done in order to verify aspects related with the theory. Then, using a polymeric sample, birefringence images were performed, which allowed determining the sample birefringence quantitatively. Finally, images taken of different polarization states were collected, and through then images related with the Mueller Matrix elements were calculated, which were analyzed individually.