Substrate-mediated delivery involves the immobilization of DNA, complexed with nonviral vectors, to a biomaterial or surface that supports cell adhesion. Cells cultured on the substrate are exposed to elevated DNA concentrations within the local microenvironment, which enhances transfection. As surface properties are critical to this delivery approach, self-assembled monolayers (SAMs)...
Wave propagation at the bottom of the electromagnetic spectrum (below 300 kHz) in the Earth-ionosphere system is a problem having a rich history of theoretical investigation extending over many decades. Propagation within this system involves complex interactions of electromagnetic waves with the lithosphere, oceans, and ionosphere, leading to resonances that...
Should the government subsidize entry to promote competition? In theory, free entry does not guarantee the socially optimum number of entrants. In differentiated product markets, free entry can result either in excessive or insufficient entry. Quantifying this inefficiency and identifying the optimal subsidy level require an empirical framework that combines...
This dissertation studies the organizing local approach to labor renewal, a union model centered on organizing new workers. I examine the role of activists and what motivates them to participate beyond a rational evaluation of gains. Additionally, I establish the conditions for successful union reform, specifically, how to overcome inertial...
The motion of thin drops under the effects of surfactants and gravity is studied. First, the effects of surfactant and temperature on the spreading of a viscous droplet are considered. Lubrication theory is used to develop a two-dimensional model for the evolution of the droplet. The surfactant is assumed to...
The goal of this dissertation was to examine the influence of motivational incentives on visual spatial attention in patients with probable Alzheimer's Disease (PRAD), patients with mild cognitive impairment (MCI) and healthy age-matched control subjects (EC). Specifically, I compared the ability of monetary incentives to influence behavioral and neural performance...
I examine horizontally differentiated firms in three different contexts. First, I look at an industry where firms can develop self-customizable products -- products which appeal to different consumers for different reasons. This addition results in an unexpected conclusion that sometimes more differentiated firms can end up with lower profits than...
Ceramic matrix composites are known for their low density, high strength and high stiffness, but lower fracture toughness compared to metal matrix composites. The addition of a reinforcing agent within the matrix can increase the toughness of the composite via many strain energy absorption mechanisms such as plastic deformation. This...
The goal of this study was to investigate the properties of the retinal ganglion cell receptive field at low light levels. There has been considerable interest in whether the surround of a ganglion cell receptive field disappears and the center expands in size under scotopic conditions. The previous data from...
Modeling and simulation at different scales were used to study mass transport, residence times and selective oxidation in nanostructured membranes. First, analytical equations of the possible mass transport mechanisms inside the pores were used to determine that diffusion dominates over convection under the conditions of interest for selective oxidation: 700...
The purpose of this dissertation study was to build on scholarly work in the area of critical mathematics by such scholars as Gutstein (2003) and Gutierrez (2002). Critical pedagogy is designed to foster political agency and critical consciousness in students (Freire, 1971). That is the aim of critical mathematics in...
The abundance and breadth of condition data generated by advanced inspection technologies have increased the frequency and accuracy of data collection, which is not exploited by the existing performance models. Moreover, simultaneity of deterioration and maintenance causes difficulty of estimating effectiveness of maintenance activities for existing performance models. To address...
The optical and magneto-optical properties of the ferromagnetic semiconductors, InMnAs and its alloy InMnAsP were investigated to determine the band structure and nature of the ferromagnetism in these materials. Alloys were grown by metal-organic vapor phase epitaxy. Infrared absorption of InMnAs was investigated to determine the presence and properties of...
Experimental and numerical studies of lasing in multiple light scattering media with gain are presented in this thesis. Depending on the dielectric constant spatial distribution is random or periodic, two different kinds of lasers are discussed: the random laser and the photonic crystal laser. This thesis, therefore, is divided into...
Spectral elements are p-type element which can provide better accuracy
and faster convergence. However, applications of these elements make
conformation to discontinuities in the function or its derivative
difficult. The eXtended Finite Element Method (XFEM) recently
developed at Northwestern University can easily treat the arbitrarily
aligned discontinuities, i.e. independent of...
Two-year colleges are a critical site for the expansion of educational opportunity in the United States. They enroll nearly half of all postsecondary students and are a gateway to higher education for low-income, non-traditional, racial and ethnic minority, and first-generation college students. Degree completion rates in the two-year sector are...
Most women diagnosed with epithelial ovarian carcinoma (EOC) initially present with metastases, but little is known about the regulation of ovarian tumor cell dissemination by the tumor microenvironment. Because ovarian cancer cell dissemination is mostly limited to the peritoneal cavity and often results in the accumulation of malignant ascites, the...
Arsenic trioxide (As<sub>2</sub>0<sub>3</sub>) is an arsenic-derivative that exhibits potent growth inhibitory effects against malignant cells. The remarkable antitumor effects of As<sub>2</sub>0<sub>3</sub> in vitro and in vivo have prompted the development of various clinical trials that established its activity in acute promyelocytic leukemia (APL). As<sub>2</sub>0<sub>3</sub> is part of the standard treatment...
The work presented here represents a series of research projects that are unified in their goal: to use volume holographic gratings to enhance traditional signal processing applications in ways that would otherwise not be possible. To this end, we have completed work that can be classified into four different projects....