The studies in this thesis are directed towards defining the signaling mechanisms that regulate astrogliosis after SCI and towards developing potential therapeutic techniques for modifying this process. The central hypothesis is that alteration of the extracellular milieu after SCI can limit the deleterious effects of glial scar formation and enhance...
All-optical switches have far reaching applications in both quantum and classical information processing. Most current all-optical switches depend on intense interactions between light and nonlinear media which may be extremely inefficient. The need for high switching beam powers have prevented all-optical switching from being very useful in most applications. Our...
Interfacial phenomena play a considerable role in many physical, chemical and biological systems. Some of these systems exhibit interaction of several interfaces. This thesis contains a study of two types of systems characterized by interacting interfaces. First, a theory of the formation of nanoscale porous structures in oxides of metals...
Problems involving irregularly shaped domains or embedded interfaces occur in a wide range of mathematical models. These include models in computational biology, fluid mechanics, and solidification. Numerical solutions for this type of problem can be difficult to obtain, and therefore a variety of methods have been devised to solve them....
My dissertation, entitled "Mobile Islands: Home, Migrancy and Identity in French Caribbean Narratives", examines the representation of home, space and migration in French-Caribbean literature and film. Using original narratives of Guadeloupean and Martinican writers and filmmakers, I demonstrate that the sociological phenomenon of mobility between the Caribbean and France has...
Recent assessment of material property requirements for blast resistant applications, especially for the naval ship hulls, has defined the need to design steels with high stretch ductility and fragment penetration resistance, along with high strength and adequate toughness. Using a system based computational materials design approach, two series of austenitic...
The majority of research on voluntary visual attention has focused primarily on specific attentional processes. While we know much about individual attentional abilities such as shifting attention among spatial locations, tracking multiple objects and maintaining attention for specific targets, we know little about how these attentional processes relate to one...
Microbiological dating of a crack's age depends upon establishing a viable method of sampling biomass from surfaces. Age is based upon the hypothesis that the amount of biomass on a given crack surface is proportional to the time that has passed since the surface was exposed. Presented herein is the...
The main theme of this dissertation are departures from standard assumptions in economic theory, specifically, departures from the model of subjective expected utility in decision theory.
Part 1 axiomatizes the robust control criterion of multiplier preferences introduced by Hansen and Sargent (2001). The axiomatization shows that the class of multiplier...
Several semiparametric estimators recently developed in the econometrics literature are based on the rank correlation between the dependent and explanatory variables. Examples include the maximum rank correlation estimator (MRC) of Han (1987), the monotone rank estimator (MR) of Cavanagh and Sherman (1998), the pairwise-difference rank estimators (PDR) of Abrevaya (2003),...
The new binuclear organo-zirconium and -titanium metal complexes {2,7-di-[(2,6diisopropylphenyl)imino]-1,8-naphthalenediolato group 4 metal complexes {1,8-(O)2C10H4-2,7[CH=N(2,6-iPr2C6H3)]2}Zr2Cl6(THF)2 (FI2-Zr2) and {1,8-(O)2C10H4-2,7-[CH=N(2,6-
i 2 t
Pr2C6H3)]2}Ti2Cl6(THF)2 (FI -Ti2) are compared to the mononuclear analogues {3- Bu-2(O)C6H3CH=N(2,6-iPr2C6H3)}ZrCl3(THF) (FI-Zr1) and {3-tBu-2-(O)C6H3CH=N(2,6-
i
Pr2C6H3)}TiCl3(THF) (FI-Ti1), respectively, in ethylene polymerization and ethylene + olefin copolymerization processes. The comonomers studied...
Assembly of the large and small subunits of the <em>E. coli</em> ribosome is a complicated process that involves transcription, processing, and modifying of the ribosomal RNA, the binding of ribosomal proteins, and the folding of the particles into complex structures. A number of ribosome assembly factors, including maturation factors, GTPases,...
My dissertation argues that certain continuities among U.S. theatre collectives in the 20th and 21st centuries have gone unnoticed largely because the aesthetics and politics of these companies are seemingly so unrelated. These continuities, which connect the 1960s' anarcho-pacifist spectacles of the Living Theatre to the contemporary "community" theatre of...
Saccades are rapid eye movements that bring visual images into focus by placing them on the fovea. The control of accurate and precise saccades is essential for normal visual perception of the world around us. Disruptions in saccade production are the hallmark of several neurological disorders such as schizophrenia and...
Latent membrane protein 2A (LMP2A) and LMP2B are viral proteins expressed during Epstein-Barr virus (EBV) latency in EBV-infected B cells both in cell culture and in vivo. Although Lyn has been shown to be important in mediating LMP2A signaling, it is still unclear if Lyn is used preferentially or if...
A critical challenge in improving the quality of life for spinal cord injury survivors is to restore the capacity to grasp and manipulate objects. While progress has been made to restore hand function by using functional electrical stimulation (FES) to activate muscles, providing the means to control the multiple degrees...
This thesis is organized into three essays, each with particular insights involving public policy and family formation:
In the first essay, I address the well-documented correlation between the prestige of the university and the labor market income of its graduates by investigating whether a possible medium for this effect is...
The expansion of public education at the beginning of the twentieth century had a profound effect on the American economy. This dissertation explores the impact of changing educational institutions on both individuals and communities with a study of Iowa during its introduction of modern grammar schools and high schools during...
I show that the speed of price adjustment to aggregate technology shocks is substantially larger than to monetary policy shocks. In the context of large Bayesian Vector Autoregression models, I establish that aggregate and disaggregate prices adjust very quickly to technology shocks, while they only respond sluggishly to monetary policy...
Most cognitive research on conceptual structure has studied undergraduate populations and either natural (biological) or artificial (experiment-specific) categories. This project investigates how people with extensive, rich knowledge about a complex real-world domain organize and use that knowledge. The research extends prior work on differences among types of experts within biological...
Tissue engineering offers a promising approach for the replacement of diseased or injured tissues, and is based upon the premise that cells can be induced to form new tissues when presented with the appropriate set of environmental cues. Polymer scaffolds play a central role in most tissue engineering strategies by...
A multicomponent bimodal poly(vinyl acetate) (PVAc) polymer composite has been scientifically designed to increase biaxial plastic flow stabilization for the achievement of large biaxial deformations. For this, a systems-based approach was used for the computational materials design of a high performance bubblegum whose mean in-vivo bubble diameter exceeds that of...
The light field is a 4D function that describes the flow of light in all directions through every point in free space. Digital cameras only capture a 2D projection of the 4D light field entering the camera lens. In this dissertation I modify the light field as it enters a...
The safe and efficient storage of hydrogen is possibly the chief obstacle to its use as a fuel on a large scale. Metal-organic frameworks (MOFs) are well poised to provide unique solutions to hydrogen storage, and gas storage in general, a result of their crystalline, porous networks that present the...
Au nanoprisms are a new type of inorganic nanoparticle that is particularly interesting because these particles can be made in high yield, are composed of a metal with well known surface chemistry, exhibit strong, architecture and environment-sensitive optical features, and have well-defined crystallographic facets. All of these features make Au...
With the interference of several coherent beams, a periodical potential is produced for the particles trapped inside. The theoretical calculations show that the optical force applied on the particle in such optical lattice is in sinusoidal form. The force amplitudes vary greatly depending on the ratio of the particle size...
Forest Politics in Colonial and Postcolonial Kenya, 1940-1990s Alphonse Omondi Otieno In the period 1940-1990s, the Kenyan forestry policy evolved from an emphasis on preservation to a combination of programs which embodied both rural Africans' interests and practices and state interests in environmental issues. Using four cases from the western...
For all its significance in world affairs, the United Nations is full of paradoxes. As a system - i.e. as a collection of independent yet interrelated entities - its contradictions derive from the juxtaposition of forces encouraging fragmentation and calls for improved harmonization. On its part, the reality of inter-organizational...
The vertebrate brain, which is made up of a vast array of individual neurons, is responsible for controlling numerous functions and behaviors, including distinguishing between visual cues, learning to navigate in a new environment, or making complex decisions. These neurons form specific networks that receive, process, and integrate chemical and...
I examine how consumers' purchase' decisions and intentions of purchases are affected by uncertainty about future deals (temporary price cuts or sales) for a product and how these results affect retailers' optimal pricing and marketing strategies. First I look at the effects of uncertainty about the timing of deals (i.e....
Magnetic resonance imaging (MRI) is an advanced imaging modality that is experiencing increasing popularity in clinical and experimental settings. MRI enjoys the benefit of high-resolution, the use of non-ionizing radiation, and the ability to distinguish between soft tissues. MR imaging is enhanced with the use of Gd3+ chelated contrast agents;...
As device sizes decrease, more functionality can be placed in an integrated circuit. Therefore, the design complexity of these circuits increases. To deal with complexity, designers move to higher abstraction levels. Currently, the highest abstraction level is the system-level. In our work we investigate the synthesis and verification problem at...
This dissertation studies whether stock mergers creates value for acquirers. The first chapter of this dissertation conducts a comprehensive review of the existing merger literature relevant to this topic. It includes existing merger theories, empirical studies on whether mergers are value destroying or value creating, and methodological issues on empirical...
Resource recovery is a promising category of polymer recycling where polymeric waste is converted via thermal or chemical means to monomer and chemical feedstocks. Specifically, pyrolysis is an attractive method because of its simplicity and ability to handle a heterogeneous feedstock. Polymer pyrolysis is characterized by a complex free radical...
End-Labeled Free-Solution Electrophoresis, or ELFSE, is an alternative strategy for DNA sequencing that proposes to eliminate the need for a viscous sieving matrix for size-based DNA separation. In this bioconjugate method, a perturbing entity or "drag-tag" is attached to differently sized DNA fragments produced by the Sanger reaction. This drag-tag...
This work explores the development and implementation of a biofilm model for multiple solid species and multiple dissolved components. The model makes use of several different advanced numerical methods in order to achieve the goal of describing the behavior of biofilms growing in wastewater treatment reactors. Using the model we...
Cardiovascular disease is a leading cause of morbidity and mortality worldwide. While many therapies have been used to treat vascular disease symptomatically, gene therapy offers a means of treating the molecular dysfunctions driving disease pathogenesis. Unfortunately, gene therapy has achieved only modest therapeutic success in clinical trials due to a...
Herpes simplex virus (HSV) infection of host cells requires virus attachment to the cell surface and subsequent membrane fusion between the virus envelope and host cell membrane to deliver the nucleocapsid containing the viral genome into the host cell. A proposed mechanism for HSV glycoprotein-induced membrane fusion is gD binding...
The promise of a clean, renewable, and abundant energy supply make the efficient conversion of solar energy to electricity a compelling scientific and societal goal. In the following chapters, I will describe my efforts to advance one class of photovoltaic technology, dye-sensitized solar cells, by demonstration and characterization of unexplored...
The mechanisms governing selective CaCO3 crystal nucleation in living organisms remain unclear. For example, nacreous layers from the inner surfaces of shells are built as brick-and-mortar complexes of plate-like aragonite single crystals and organic layers. Unstable [001] surfaces of calcite columns in prismatic layers are also stabilized by organic molecules....
In the first chapter we analyze profits and efficiency implications of a relation between an upstream duopoly and downstream monopoly in Hotelling linear city model. While exclusive contracts maximize the monopolist's profit, at the same time socially they are inefficient. Linear prices, while more efficient, usually also do not achieve...
Polarized epithelial cells are divided by tight junctions into an apical membrane domain, which faces the lumen of an organ, and a basolateral domain, which is in contact with underlying connective tissues. To establish and maintain polarity, newly synthesized and recycling transmembrane proteins are sorted to either the apical or...
We present initial results from Hertz/VPM, the first submillimeter polarimeter employing the dual Variable-delay Polarization Modulator (dual-VPM). This device differs from previously used polarization modulators in that it operates in translation rather than mechanical rotation. We discuss the basic theory behind this device, and its potential advantages over the commonly...
This dissertation consists of three essays on the identification analysis of econometric models.
The first essay explores the identification question in semiparametric binary response models when all regressors have discrete support. I suggest a recursive procedure that finds sharp bounds on the parameter of interest and can be applied to...
The idea of the unity of audition and vision has been a topic of interest since the time of ancient Greece. Investigation of this idea has continued to grow in many areas, especially in psychology, music, visual art, and computer science, most notably since the invention of the world's earliest...
Breakout reactions from the CNO cycles leading into the rp-process in explosive stellar hydrogen burning environments have been studied using the Argonne Tandem Linac Accelerator System (ATLAS). Earlier work is reported and summarized with an introduction to the beam, target and detector development in the nuclear astrophysics group at Argonne...
Traditional classroom practices communicate epistemic commitments and goals that might be contrary to those needed for meaningful participation in scientific inquiry practices. In this dissertation, I explore how traditional classroom practices influence students' participation in the practice of scientific argumentation. I address this through a two-pronged approach. First, given that...
A pyramidal neuron receives thousands of inputs spread throughout its dendritic tree, which it must integrate into a decision about whether or not to fire action-potential output. Since action potentials are the primary means by which these neurons communicate with their network partners, understanding this input-output relationship is critical for...
This dissertation consists of three self-standing essays, each of which focuses on a dialogue from Plato's later period. Together, they touch on some of his well-known views in metaphysics and moral psychology, from his theory of forms to his theory of the tripartite soul. But the topic that unifies these...
In the first part of the dissertation I study mechanism design under limited communication. Chapter 1 offers a detailed analysis of auctions with simultaneous limited communication. I solve for both welfare and revenue maximizing equilibria. The striking feature of optimal equilibria is that they are asymmetric even when the setup...