This dissertation is a multi-method study of the relocation process under the Chicago Housing Authority's implementation of federal redevelopment policies intended to decrease the racial and economic isolation of public housing tenants. It combines quantitative and spatial analysis of program administrative data, interviews with 'expert respondents,' and qualitative semi-structured interviews...
The role that spinal motion plays during ambulation is not clearly understood. Little in vivo regional spinal motion data exists in the literature with regard to walking and most gait models disregard the upper body altogether, or regard it as a single rigid structure. This study aims to increase understanding...
Fundamental investigations on the origins of friction at the nanoscale were carried out using both theoretical and experimental approaches. A model was developed that analytically solves for friction by the motion of dislocations at atomically flat crystalline interfaces. It combines known concepts from dislocation drag, grain boundary theory, and contact...
Solid oxide fuel cells (SOFCs), renowned for their high electrical generation efficiency with low pollutant production, are promising for reducing global energy and environmental concerns. However, there are major barriers for SOFC commercialization. A primary challenge is reducing the capital cost of SOFC power plants to levels that can compete...
Stem cells show great promise as cellular replacement and drug delivery therapies for a number of neurological disorders. This dissertation examines embryonic and adult types of stem cells, their plasticity, and mechanisms governing their development (Chapters 1-5). Our studies illustrate that leukemia inhibitory factor (LIF) signaling and bone morphogenetic protein...
Biomorphic silicon carbide (bioSiC) is a novel porous ceramic material derived directly from wood precursors. This material is fabricated by pyrolysis of a natural wood precursor in an inert atmosphere leaving an amorphous carbon scaffold. The amorphous carbon is infiltrated with molten Si in vacuum at elevated temperature, which reacts...
Neurofibrillary tangle (NFT) formation in Alzheimer's disease (AD) and tauopathies occurs when tau protein adopts secondary structure and self-aggregates within neurons. Accompanying NFT maturation are post-translational modifications to tau; hyperphosphorylation, truncation and conformational changes occur in a highly sequential manner. In contrast, granulovacuolar degeneration bodies (GVDs) are a second type...
The electronic transport and magnetoresistive properties of the ferromagnetic semiconductor In1-xMnxAs were investigated in order to determine the nature of the transport and ferromagnetism in the films. p-InMnAs/n-InAs and metal/oxide/InMnAs heterojunctions were fabricated and characterized to elucidate the transport and magnetoresistance mechanisms at these technologically important interfaces.
The electronic transport...
The Galactic center (GC) is a dense and chaotic region filled with unusual sources, such as intense star forming regions, dense star clusters, nonthermal radio filaments, and a massive black hole. The proximity of the GC region makes it an ideal place to study the unusual processes that tend to...
Flexibility can be created in manufacturing and service operations by using multipurpose production sources such as cross-trained labor and flexible machines/factories. We focus on control and design issues in systems with flexible resources. In Chapter 2, we consider optimal scheduling of a fully cross-trained server in a finite-population queueing system...
Two new strategies have been developed to accomplish direct nucleophilic acylation reactions. In the first approach, acylsilanes are added to various electrophiles using N-heterocyclic carbenes as catalysts. The second method utilizes O-silyl thiazolium carbinols as stoichiometric acyl anion precursors to afford acylated products under mild reaction conditions.
N-heterocyclic carbenes generated...
The rapid growth of digital imaging technology and the accumulation of large collections of digital images has created the need for efficient and intelligent schemes for content-based image retrieval. Our goal is to organize the contents semantically, according to meaningful categories. We present a new approach for semantic classification that...
><p><em>Vibrio cholerae</em>, the causative agent of the severe diarrheal disease cholera, secretes several "accessory" toxins including RTX toxin, which causes cross-linking of the actin cytoskeleton. The rtx locus of <em>V. cholerae</em> is located adjacent to the integrated CTX? prophage. The RTX toxin itself is encoded by the <em>rtxA</em> gene found...
In response to construction activities and loads from permanent structures, soil generally is subjected to a variety of loading modes varying both in time and location. It also has been increasingly appreciated that the strains around well-designed foundations, excavations and tunnels are mostly small, with soil responses at this strain...