Maintaining High-Quality Housing for a Predominantly Renter Community: A Housing and Community Engagement Plan for the Jefferson-Chalmers Neighborhood

http://deepblue.lib.umich.edu/bitstream/2027.42/110948/1/wells_housing_strategy_2009.pd

Rheologic Evolution of Carbonates and Shale Along Thrust Faults

Carbonates and shales are an integral component of fold-and-thrust belts. Deformation processes that control the rheology of these faults are influenced by internal and external conditions. To understand how these processes influence fault zone morphology, I examine 1) the evolution of a fault zone with evidence of variable slip rates, 2) the processes that contribute to the formation of a crystallographic fabric in fine-grained dolomite, and 3) the variables that influence the location of, and displacement along, carbonate-shale thrusts. Evidence for variable slip rates is preserved along the Copper Creek thrust, as well as overprinting relationships suggesting episodic instability. Nanograins, vesicular calcite, and coated clasts indicate unstable slip and overprint calcite grains with interpenetrating grain boundaries and four-grain junctions suggesting aseismic creep. Based on cross-cutting relationships, we propose a sequence of deformation events consistent with episodic unstable slip. While a crystallographic fabric in carbonates has been commonly attributed to dislocation creep, a weak fabric is common in fine-grained dolomites that deformed under conditions consistent with diffusion creep. I examine the mechanisms that contribute to the development of a fabric in experimentally and naturally deformed dolomites. Fine-grains that exhibit a weak fabric, four-grain junctions, and subgrains indicate dislocation and diffusion creep. Fine-grains that exhibit a stronger crystallographic fabric and subgrains indicate dislocation creep. Several thrust sheets within the foreland of the Southern Appalachians contain dolomite along the base of the sheet. The locations of the Copper Creek and Town Knobs thrusts correlate with fracturing of the base at the dolomite that allowed infiltration of fluids and precipitation of veins. The Copper Creek thrust contains calcite veins that deformed by a combination of plasticity-induced fracturing and diffusion creep, resulting in a large displacement along a weak shear zone. In contrast, the Town Knobs thrust contains a dolomite, calcite, and silt shear zone that exhibits evidence for diffusion creep, dislocation creep, and cataclasis. These deformation mechanisms in these minerals did not accommodate as large a displacement along this fault, suggesting that increasing stress at a constant strain rate, or increasing strain rate at constant stress conditions, may have resulted in less displacement

Distribution and ecological effects of Azteca Chartifex/Trigona in the Barro Colorado Nature Monument.

This dissertation explores the behavior and ecology of a conspicuous and behaviorally dominant ant species in the tropical rainforest of Panama. Competition with aggressive species is an important factor that shapes local community structure. Eavesdropping on the chemical communication systems of such behaviorally dominant species can help heterospecific species to avoid negative interactions. I review the chemical communication system and known ecological effects of the Neotropical canopy ant, Azteca chartifex/trigona (Chapter 1). There are over 40 known compounds produced by Azteca workers, yet how these compounds impact heterospecific species is unclear in many circumstances. I assessed if heterospecific species respond to A. trigona pheromones by exposing workers of 29 canopy ant species to A. trigona alarm pheromones (Chapter 2). Seven species showed distinct responses to A. trigona pheromones and responses were not associated with phylogeny. The pheromones produced near ant nests may additionally be a reliable source for eavesdropping species and I used open-air sampling techniques to determine whether the air space surrounding A. trigona carton nests has a distinct chemical composition (Chapter 3). The air around disturbed A. trigona nests had higher concentrations of compounds associated with worker alarm pheromones, whereas undisturbed nests were chemically indistinguishable from the surrounding forest air. Azteca trigona workers aggressively outcompete for some resources and I experimentally assessed the effects of A. trigona on the composition of resident and colonizing ants by installing artificial nests in 28 tree crowns (Chapter 4). The presence of A. trigona did not affect the colonization frequency of artificial nests nor species composition of the resident ants in a tree; however, species composition of nest occupants differed between trees and nests located within the foraging territories of A. trigona were colonized less frequently. Finally, I determined if A. trigona was affected by landscape scale factors, including liana presence and canopy height (Chapter 5). A. trigona nests were more frequent in taller trees within older forests and had smaller colony sizes in liana removal plots. Collectively, the results summarized in this dissertation improves our understanding of canopy ant interactions and distributions in a tropical forest

Surface engineering of polymers

Ultra-violet photons and non-equilibrium plasmas have been used as modification methods to treat polymer surfaces. The photoreactivity of polystyrene with oxygen and nitrous oxide was found to be linked to the photochemistry occurring at the polymer/gas interface. In situ mass spectrometry studies of the photolysis and photo- oxidation of polystyrene enabled possible mechanisms of these reactions to be determined, and perhaps proved for the first time the presence of intermediate phenyl radicals. Photo-oxidised and plasma oxidised polystyrene surfaces were compared using valence band and core level XPS, and provided another insight into polystyrene surface oxidation processes. The more reactive experimental conditions during plasma treatment were found to produce a less oxidised surface than during photo-oxidation. These observations were attributed to the sputtering characteristics of a plasma environment. Polyethylene and polystyrene were oxidised by plasma treatment and the aging of the resulting surfaces in air was studied by core level XPS, which showed a gradual loss of surface oxidation after treatment. Valence band XPS of the aged polyethylene surface revealed a uniquely selective surface structure. Oxidised polyethylene rearranged upon aging to give a polypropylene-type structure. The relative importance of substrate/gaseous molecule photo- reactivity was again highlighted by comparing chromophoric (polystyrene)/nonchromophoric (polyethylene) polymers with chromophoric (hexamethyldisilane)/nonchromophoric (tetramethylsilane) species. Greatest reaction occured when both chromophoric alternatives were used. Dehydrochlorination of polyvinylchloride was found to depend upon the surrounding atmosphere, vacuum conditions giving the greatest degree of modification. This reaction was monitored by in situ mass spectrometry, and indicated that the rate of dehydrochlorination depended upon the initiation mechanism of dehydrochlorination

Training Caregivers of Young Children Who Are Deaf / Hard of Hearing To Implement Communication Facilitation Strategies

Caregiver-implemented communication intervention can result in increased communication skills in young children. Parents/caregivers are the first teachers of their children and are in natural positions to provide naturalistic communication intervention throughout their child’s daily life within their home. Professionals who work with young children with communication delays can coach parents in strategies to help facilitate increased communication skills in their children and help incorporate therapeutic techniques into the family’s regular routines. The current study examined the impact of training and coaching on caregivers’ implementation of naturalistic language facilitation strategies with their children who are deaf or hard of hearing using a single case experimental multiple probe design. Two caregivers and their children who are hard of hearing participated in this study. The caregivers each received a training session and one caregiver received a coaching session, all via videoconferencing. Results indicated a potential relationship between training and the caregivers’ use of the naturalistic language facilitation strategies as evidenced by caregivers showing increased ability to use a target skill - reciprocity. In addition, participants stated overall positive perceptions toward their participation in the study, both pre- and post-participation. Discussion of the study’s key findings, limitations, future research, and practical implications is included.KEYWORDS: deaf/hard of hearing, preschool, early childhood, early intervention, communication facilitation, language strategies, language development, vocabulary, speech-language pathology, deaf education, parent coachin

Microstructures and Rheology of a Limestone-Shale Thrust Fault

The Copper Creek thrust fault in the southern Appalachians places Cambrian over Ordovician sedimentary strata. The fault accommodated displacement of 15-20 km at 100-180 °C. Along the hanging wall-footwall contact, microstructures within a ~2 cm thick calcite and shale shear zone suggest that calcite, not shale, controlled the rheology of the shear zone rocks. While shale deformed brittley, plasticity-induced fracturing in calcite resulted in ultrafine-grained (<1.0 μm) fault rocks that deformed by grain boundary sliding (GBS) accommodated primarily by diffusion creep, suggesting low flow stresses. Optical and electron microscopy of samples from a transect across the footwall shale into the shear zone, shows the evolution of rheology within the shear zone. Sedimentary laminations 1 cm below the shear zone are cut by minor faults, stylolites, and fault-parallel and perpendicular calcite veins. At vein intersections, calcite grain size is reduced (to ~0.3 μm), and microstructures include inter-and-intragranular fractures, four-grain junctions, and interpenetrating boundaries. Porosity rises to 6 percent from <1 percent in coarse (25 μm) areas of calcite veins. In coarse-grained calcite, trails of voids follow twin boundaries, and voids occur at twin-twin and twin-grain boundary intersections. At the shear zone-footwall contact, a 350 μm thick calcite band contains coarseand ultrafine-grained layers. Ultrafine-grained (~0.34 μm) layers contain microstructures similar to those at vein intersections in the footwall and display no lattice-preferred orientation (LPO). Coarse-grained layers cross-cut grain-boundary alignments in the ultrafine-grained layers; coarse grains display twins and a strong LPO. Within the shear zone, ultrafine-grained calcite-aggregate clasts and shale clasts (5-350 μm) lie within an ultrafine-grained calcite (<0.31 μm) and shale matrix. Ultrafinegrained calcite (<0.31 μm) forms an interconnected network around the matrix shale. Calcite vein microstructures suggest veins continued to form during deformation. Fractures at twin-twin and twin-grain boundary intersections suggest grain size reduction by plasticity-induced fracturing, resulting in <1 μm grains. Interpenetrating boundaries, four-grain junctions, and no LPO indicate the ultrafine-grained calcite deformed by viscous grain boundary sliding. The evolution of the ultrafine-grain shear zone rocks by a combination of plastic and brittle processes and the deformation of the interconnected network of ultrafine-grained calcite by viscous GBS enabled a large displacement along a narrow fault zone

Improving the evidence base for treatment of Postural Orthostatic Tachycardia Syndrome (POTS)

Postural tachycardia syndrome (POTS) is a chronic debilitating condition characterized by symptoms of light-headedness, fatigue, palpitations, pre-syncope, sleep disturbances, cognitive impairment and brain fog in conjunction with an exaggerated increase in heart rate (HR) when upright, despite maintenance of a normal blood pressure (BP). There is little high-level evidence to inform current guidelines for the investigation and management of POTS, at least in part due to the lack of biological markers to provide clarity on diagnosis and to quantify severity of disease. The objectives of the work described in this thesis was to highlight the gaps in evidence for therapeutic modalities currently available for the treatment of patients with POTS and to study the value of transcranial doppler (TCD) measures of cerebral blood flow velocity (CBFv) during orthostatic and cognitive stress for future therapeutic trials in patients with POTS. The rationale behind use of TCD measurement of CBFv relates to the hypothesis that periodic reduction in cerebral blood flow (CBF) due to inadequate compensation for changes in orthostatic pressure may explain the almost universal symptom of mental clouding described by patients with POTS. Since many patients with POTS describe mental clouding even when recumbent, we hypothesized that regulation of CBF in response to cognitive activation in the absence of orthostatic stress may also be dysfunctional. We therefore studied CBF during both orthostatic and cognitive stress in patients with POTS. An overview of the pathophysiology and co-morbidities associated with POTS is provided in Chapter 1 followed by a systematic review of the efficacy and quality of evidence for therapies currently utilised in the management of patients with POTS (Chapter 2). The results of our pilot study of CBFv in patients with POTS, and controls, is reported in Chapter 3. The contents of these 3 chapters have been published in peer reviewed journals. In our pilot study, the effect of a visual stimulus on CBFv was measured using a handheld duplex TCD. We replicated the methodology previously used to demonstrate a reduction in neurovascular coupling (as demonstrated by a reduced CBFv response to a visual stimulus) in a study of patients with spinal cord injuries. (1) The rationale for replicating this methodology was the authors’ attribution of the reduced neurovascular coupling in patients with spinal cord injury to disruption in the patients’ autonomic feedback loops. As autonomic dysfunction has long been suspected to underlie the pathophysiology of POTS,(2) we considered the robust findings generated through the relatively simple methodology described by Phillips might prove useful in the study of patients with POTS. Unfortunately, this was not the case. Instead, we found similar changes in CBFv in our patient and control groups in response to the brief visual stimulus. As a result of the negative findings from our pilot study (in which a brief visual stimulus was used), in subsequent studies we measured changes in CBFv during a prolonged cognitive stress. Not only was this stimulus a better reflection of the conditions during which patients typically experienced “brain fog” but it also allowed us to measure the effect of fatigue on symptoms scores, CBFv responses, and on cognitive performance. As a result of difficulty in maintaining the angle of insonation in the posterior cerebral artery (PCA) over this prolonged cognitive stress (due to the small diameter of the PCA), we developed a protocol in which CBFv changes were measured in the middle cerebral artery (MCA). As a reduction in CBF may relate to hypocapnia in association with hyperventilation or increased tidal volume,(3),(4),(5) we included the measurement of respiratory rate and end tidal carbon dioxide (ETCO2) in studies with more prolonged stimuli. The results of our study of CBFv responses to orthostatic and prolonged cognitive stress in POTS and control groups are reported in Chapter 4. In this study, we demonstrated that prolonged cognitive stress was associated with a greater reduction in CBFv in the MCA in the patient group when compared with controls. We also studied the effect of midodrine, an alpha adrenergic agonist, on CBFv in the MCA in patients with POTS undergoing orthostatic and prolonged cognitive stress. Participants in this study were selected based on their previous symptomatic improvement in response to midodrine. We set out to determine if this symptomatic response was associated with an improvement in CBFv response to prolonged cognitive stress. The results of this study (reported in Chapter 5) were inconclusive. Whilst patients reported a significant improvement in symptom severity, and we detected an improvement in reaction time during cognitive testing following midodrine, we did not demonstrate an improvement in hemodynamic or CBFv responses to cognitive or orthostatic stress following administration of midodrine. This negative study could reflect a placebo effect in reporting of symptomatic improvement or that the study was underpowered to demonstrate a difference in CBFv response, however it suggests that TCD measurement of CBFv in the MCA in response to orthostatic and prolonged cognitive stress may not be as useful as we had hoped as an objective marker of response for future therapeutic trials in patients with POTS. In Chapter 6 we report on the use of plasma exchange therapy as a novel intervention in treatment resistant POTS. The use of plasma exchange in POTS was based on positive repsonses to plasma exchange in patients with a related condition (autoimmune autonomic ganglionopathy) (6) as well as reports of auto-antibodies in the sera of patients with POTS. (7). The clinical course, cognitive and CBFv reponses to orthostatic and cognitive stress in a patient treated with acute and maintenance plasma exchange therapy are suggestive of some improvement with plasma exchange however the brief duration of response following each treatment and the lack of response in other patients did not support plasma exchange as a viable long term option for POTS. Further studies are needed to evaluate TCD assessment of CBFv in POTS patients to define its utility in clinical practice. It would be of interest to study the CBFv response to prolonged cognitive stress after orthostatic stress in both POTS and control groups. A comparison of CBFv response to cognitive challenge measured by TCD with regional blood flow response using fMRI during an identical cognitive challenge would provide further insight into the utility of TCD as a tool to measure outcomes in clinical trials. As we advance our knowledge on the pathophysiology underlying this condition, a biomarker that correlates well with POTS symptom severity will be immensely valuable for clinicians managing this complex syndrome.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202

Can Your Students Get Jobs? Library Help for Music Students\u27 Career Preparation

Your campus career center may not have the insider knowledge to help music students with their job hunts. Enhance and update your knowledge of industry information, techniques, and resources that support performers, music business professionals, and students pursuing other types of music careers as they enter the job market. Topics covered will include self-promotion for musicians, form contracts, resources for understanding standard contract terms, and locating company profile and industry trend research to identify potential employers and prepare for interviews

Can Your Students Get Jobs? Library Help for Music Students’ Career Prep

Your campus career center may not have the insider knowledge to help music students with their job hunts. Enhance and update your knowledge of industry information, techniques, and resources that support performers, music business professionals, and students pursuing other types of music careers as they enter the job market. Topics covered will include self-promotion for musicians, form contracts, resources for understanding standard contract terms, and locating company profile and industry trend research to identify potential employers and prepare for interviews