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Schizophrenia is severe, long-term psychiatric disorder, with cognitive deficits emerging in the early, prodromal disease stages and determining the degree of functional recovery. Despite this, there is no licenced medication that sufficiently alleviates the cognitive impairment associated with schizophrenia (CIAS); existing dopamine-targeting antipsychotic drugs improve psychotic symptoms but elicit severe side effects. Amidst the urgent need to develop safe, effective therapeutic interventions for CIAS acting at novel targets beyond dopamine receptors, the glutamatergic system has emerged as a promising candidate. Impaired activity of parvalbumin (PV)-expressing GABAergic interneurons in the prefrontal cortex (PFC) is hypothesised to underpin CIAS neuropathology. The mGlu5 receptor, expressed on postsynaptic PV GABAergic interneurons, thus represents an attractive therapeutic target. Positive allosteric modulators (PAMs) of the mGlu5 receptor have been characterised as a novel, selective strategy to increase receptor sensitivity to glutamate without direct activation. There are, however, numerous questions surrounding the activity of mGlu5 receptor PAMs, including their propensity to stimulate certain intracellular signalling pathways at the expense of others - termed modulation 'bias'. Successful clinical application of these compounds in CIAS requires extensive preclinical evaluation of their effects. The experiments in this thesis aimed to comprehensively investigate the effects of two mGlu5 receptor PAMs, VU0409551 and VU0360172, in the subchronic phencyclidine (scPCP) rat model for schizophrenia. Chapter 2 conducts a full in vivo dose-response assessment of both mGlu5 receptor PAMs in the novel object recognition (NOR) paradigm, followed by a corresponding analysis of PFC intracellular signalling changes. This is followed by Chapter 3, which presents data characterising mGlu5 receptor, parvalbumin (PV), GABAergic (GAD67) and microglial alterations associated with scPCP-induced cognitive deficits. Changes in inflammatory markers (IL-6, IL-10 and phospho-GSK-3β) and microglial activation following scPCP treatment and in vivo administration of mGlu5 receptor PAMs were also measured. Chapter 4 then explores the network-level disruption in the scPCP model and following ex vivo PAM application using PFC slice electrophysiology. This Chapter also evaluates the mechanism of modulation 'bias' in PAM activity. Overall, the scPCP model was associated with impaired NOR performance and reduced PV and GAD67 expression and gamma oscillations in the PFC. Increased PFC microglial activation was also observed, accompanied by elevated IL-6 and reduced IL-10 levels in multiple regions. Both PAMs successfully reversed the scPCP-induced NOR impairment, cytokine changes and the deficit in PFC gamma power. The two PAMs were shown to have divergent effects on p-AKT and p-ERK1/2 expression, and blockade of the PKC pathway inhibited the network-level effects of VU0360172 but not VU0409551. The modulation bias of VU0409551 aligns with existing literature and could be leveraged to maximise therapeutic outcomes and avoid deleterious effects in the treatment of CIAS.

This thesis investigates the sensitivity of phononic metamaterials to the presence of materials and changes in their environment. The behaviour of surface acoustic waves (SAWs) in periodic arrays of holes was investigated with finite element modelling and experimentally. SAW bandstructures and bandgap attenuation were obtained from simulations of arrays of cylindrical and annular holes which were filled with materials with different SAW velocities. Each type of hole array exhibited two distinct scattering regimes (Mie and Bragg scattering). The dependence of the bandgap frequency on the velocity was found to be stronger for annular holes than for cylindrical holes, suggesting that annular holes are potentially a better route to create tuneable phononic metamaterials. Annular holes also displayed a higher bandgap attenuation than cylindrical holes, meaning that annular hole arrays might be exploited for greater sensitivity in applications such as mass loading sensing. SAW attenuation due to mass loading of air was calculated by measuring SAW amplitude on a SAW device using an oscilloscope system and by laser Doppler vibrometry (LDV). An extraordinary increase of 2 to 3 orders of magnitude in mass loading attenuation was observed at the bandgap frequency when a phononic metamaterial was present, with only 4 resonator elements needed to produce this result. The measurements obtained by both experimental systems displayed similar frequency dependencies of mass loading attenuation coefficients. Some mass loading effects were also reproduced using finite element modelling. These approaches show great promise for improving the sensitivity of SAW pressure sensors. Finally, bandstructures were obtained from finite element simulations for an array of annular holes filled with a small sphere comprised of materials with different SAW velocities. The array exhibited similar scattering regimes as before, with an overlapping region. The dependence of the bandgap frequency on the velocity was found to be stronger when the annular holes contained the sphere than when they are fully-filled, suggesting that annular holes are potentially a good candidate for probing biological cells. Higher bandgap attenuation by up to a factor of 2 was exhibited by the single spherical inclusion compared to fully-filled holes. Since annular holes have more degrees of geometrical freedom than conventional phononic crystals, devices with greater sensitivity might be realised for applications such as biological sensing and lab-on-a-chip diagnostics.

Socio-economic status (SES) has a strong influence on language development, including both vocabulary (e.g., Hart & Risley, 1995) and grammar development (e.g. Huttenlocher et al., 2002). SES influences on both language domains have been shown to be partially mediated by spoken and written language exposure (e.g. Fernald et al., 2013; Rowe, 2008). Fewer studies have examined the role of SES in other language domains, and particularly sentence processing. The goal of this research was to examine the influence of SES and cumulative differences in language exposure on skills supporting sentence comprehension and production. Crucially, these differences are explored in a sample of young adults. Two studies tested a newly developed set of measures which assessed written and spoken language exposure using measures adapted from previous studies (e.g., Acheson et al., 2008), including an updated version of the Author Recognition Test (ART; Moore & Gordon, 2015; Stanovich & West, 1989), and newly developed measures (e.g., measures of spoken language exposure, measures of sentence structure familiarity). Measures of objective SES (parental occupation, parental education, and household income) and subjective SES (MacArthur Scale of Subjective Social Status; Adler et al., 2000) were also included. To examine language use, measures were included to assess vocabulary knowledge, and language comprehension and production across domains (e.g., word-level, sentence-level, including standardized tests and real-time processing tasks). Measures of SES significantly predicted vocabulary knowledge but were not found to significantly relate to language exposure or other measures of language use. Language exposure significantly predicted vocabulary knowledge and passage comprehension and showed marginally significant results with online sentence comprehension and online sentence production, with recreational reading and the ART as significant predictors.

The purpose of this study was to explore how former National Collegiate Athletic Association (NCAA) Division I (DI) Black female student-athletes experienced their mid-major athletic departments and to better understand how they navigated these anti-Black spaces. BlackCrit theory (Dumas & Ross, 2019; Johnson, 2019), Black Feminist Thought (BFT) (Collins, 2000), and Intersectionality (Crenshaw, 1989; Collins & Bilge, 2016) comprised the theoretical framework used to examine Black female former NCAA DI student-athletes' lived experiences with athletic departments that lead, cultivate experiences, develop policies, and monitor the safety of student-athletes. Seven Black female former NCAA DI student-athletes who played at mid-major colleges or universities for four consecutive years participated in the study. Data were collected via interviews, and data analysis revealed five emerging themes: Title IX Dynamics, Issues of Race, Lack of Intuitional Support, Perceptions of and Relationships with Athletic Administration, and Anti-blackness. The identification and interpretation of these themes allow for a deeper understanding of what Black female former NCAA DI student-athletes experienced during their collegiate playing careers. Recommendations for practical and leadership levels and directions for future research to continue needed conversations with Black female current and former NCAA DI student-athletes are provided. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]