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Real-Time Occupational and Environmental Health Monitoring using Solid-State Sensor Arrays: A Focus on Drowsiness Detection and Firefighter Safety
No full textThis dissertation presents the development, deployment, and evaluation of advanced solid-state sensor arrays for real-time health monitoring, with a primary focus on drowsiness detection in drivers and firefighter safety. These sensor arrays were designed using commercial sensors specifically tailored to detect volatile organic compounds (VOCs) present in the breath of drowsy individuals and were calibrated for precision detection both in laboratory settings and real-world scenarios. Comprehensive breath analysis of resident surgeons before and after prolonged shifts revealed notable elevations in VOC biomarkers correlated with fatigue, emphasizing the array's efficacy in capturing physiological markers indicative of drowsiness. These sensor arrays were integrated into vehicular systems to enable real-time monitoring of driver alertness levels. Rigorous spike testing conducted within vehicular environments demonstrated the arrays' ability to detect target compounds' minute concentrations, affirming their viability to be integrated in a vehicle.Additionally, custom-designed sensor arrays were engineered to identify and monitor exposure to polycyclic aromatic hydrocarbons (PAHs) in firefighting environments, facilitated by dedicated testing chambers for sensor calibration to specific PAHs like naphthalene. Deployment of these sensors during controlled training fires exhibited discernible deviations in sensor responses, highlighting an increased presence of PAHs, while their integration onto remotely operated vehicles enhanced situational awareness by scouting potential exposure risks ahead of firefighters. With ongoing refinements, this prototype holds considerable promise in furnishing invaluable real-time insights crucial for bolstering occupational safety measures and environmental health monitoring, thereby ushering in transformative advancements in other fields beyond simply firefighting and drowsy driving prevention
Mesoscale Eddy Effects on Oceanic Tracers
No full textOcean mesoscale eddies play a key role in the large-scale transport and redistribution of important oceanic tracers such as nutrients and anthropogenic carbon. This thesis investigates the properties, mechanisms, and parameterizations of important mesoscale eddy-induced effects on these tracers, including stirring, dispersion, frontogenesis and mixing. The first chapter describes how mesoscale eddies affect the stirring and dispersion of idealized tracers in a realistic model of the Gulf Stream region, by using a novel advection-based framework. The proposed framework models the eddy tracer forcing, which represents the net effect of eddies on tracer distribution, and involves anisotropic stirring and dispersion. The second chapter examines the relative importance of mesoscale eddies and large-scale currents in the formation and evolution of a large-scale tracer front, associated with the eastward extension of a western boundary current. The study demonstrates that the eddies act to sharpen the front, whereas the large-scale advection counteracts this effect. The eddy-driven frontogenesis is then described in terms of the novel advective framework. The third chapter compares the Lagrangian and Eulerian diagnostics of eddy mixing rate (diffusivity) and uses Lagrangian particles to estimate the Eulerian eddy diffusivity in an idealized eddy-resolving double-gyre model. The Lagrangian diffusivity estimated from particle trajectories is shown to differ from the Eulerian diffusivity estimated from the flux-gradient relation. A novel approach to calculating the Eulerian diffusivity from Lagrangian particles is then proposed. The thesis advances the understanding of the effects of mesoscale eddies on oceanic tracers with an emphasis on eddy-induced tracer advection, potentially improving the tracer simulations in ocean climate models, and provides a new way to utilize Lagrangian measurements to generate Eulerian eddy diffusivity maps
The Interplay Between HIV Infection and the Development of the Early Life Immune System
No full textDespite the introduction of antiretroviral therapy (ART) in the prevention of mother to child transmission (PMTCT) of HIV, there is still vertical transmission of HIV with 1.5 million children living with HIV worldwide and approximately 130,000 new infections in 2022. HIV targets CD4 T cells and causes immune dysregulation which could be detrimental for the development of the immune system during early life. Early ART initiation has been shown to limit the viral reservoir size, disease progression and partially reduce immune activation, but there is still persistent immune activation, microbial translocation, and elevated exhausted immune cells during suppressive ART therapy. Understanding the interplay between HIV and the early life immune system could provide insight into the long-term effects of infection on these children and provide information on immune-based intervention strategies for early life.To investigate the effect of HIV infection of early life immune development and the infant anti-HIV response, a group of perinatally HIV exposed infected infants (HEI) enrolled at 1 to 2 months of age that initiated ART at enrollment and a group of age-matched perinatally HIV exposed uninfected infants (HEU) were enrolled and followed prospectively during the first 2 years of life. Utilizing multiparameter flow cytometry and single cell-RNA sequencing (scRNA-seq) approaches we investigated the development of both the innate and adaptive immune system and the effect of HIV infection. We observed altered distribution of major subsets in the T and NK cell compartment and elevated immune activation in T cells, NK cells, monocytes, and Dendritic cells (DC) at Pre-ART initiation in HEI compared to age-matched uninfected infants that was observed until 18 months in T cells. In addition, we identified by scRNA-seq a cluster of CD8 T cells with a gene profile consistent with CTLs in only HEI. This thesis provides insight into potential immune populations that are associated with viral replication, or control, that can be used as target for immune-based HIV cure strategies during early life.</p
Hydrogel Platform for Localized and Sustained Delivery of Human IgG-Based Immunomodulatory Biologics
No full textBeta cell replacement therapy for type 1 diabetes (T1D) requires chronic systemic immunosuppression for long-term allograft survival. This causes general immunodeficiency and adverse events, which limits the applicability of these therapies. Therefore, I aimed to develop implantable IgG-capturing enzymatically degradable polyethylene glycol (PEG) hydrogels to deliver IgG-based immunomodulatory biologics locally in the cell transplant site in a sustained and prolonged manner (>1 month) to prevent allograft rejection with negligible systemic adverse effects. Here, I tested the effects of in vitro PEGMAL concentration, hydrogel degradability, crosslinking density, and drug-gel binding on drug release kinetics. Additionally, I investigated in vivo hydrogel degradation by implanting fluorescently labelled hydrogels and insulinoma cell cluster allografts in C57BL/6 mice and quantifying graft site fluorescence over time. I found faster FITC-IgG drug release from 5% PEGMAL hydrogels compared to 10% PEGMAL hydrogels, as well as from fully degradable versus half degradable hydrogels. Additionally, I found that hydrogels with passively loaded FITC-IgG follow a first-order burst drug release kinetics, while drug-gel binding hydrogels achieve a zero-order constant release kinetics with reduced burst release. Moreover, the gel binding of FITC-IgG via the MAL Fc-III peptide was also shown to reduce the burst release of FITC-IgG compared to passively loaded hydrogels with no Fc-III. Lastly, I found that in vivo hydrogel degradation occurs 3.2 months after implantation. These experiments suggest that PEG hydrogel degradation can be tuned by varying the polymer concentration, crosslinking density, and using drug-gel conjugation to achieve desired drug release kinetics. This enzymatically degradable drug-binding PEG hydrogel biomaterial platform could enable the sustained delivery of clinically effective IgG-based biologics locally within the transplant site to increase safety and efficacy of allogeneic cell transplant-based regenerative medicine therapies
Standardization of Shark Blood and Collection Methodology and Validation of the Arkray Lactate Pro 2LT-1730 in Nurse (Ginglymostoma cirratum), Blacknose (Carcharhinus acronotus), and Bonnethead (Sphyrna tiburo) Sharks
No full textStress physiology in elasmobranchs remains a relatively understudied field, especially in comparison to teleosts and other vertebrates. Understanding the physiological response of elasmobranchs to challenging external stimuli, whether natural or anthropogenic, helps inform fisheries policies and regulations. In elasmobranchs, phlebotomy provides a consistent method of quantifying the physiological stress response by analyzing relative changes in hematological indicators (i.e., lactate). Lactate is a metabolite associated with anaerobic glycolysis in response to capture stress (anthropogenic) or exhaustive exercise (e.g., burst swimming). Increases in lactate concentration are often correlated with increased physiological stress, with intensity of the response varying across species. This study focused on three species commonly found in South Florida: nurse sharks (Ginglymostoma cirratum), blacknose sharks (Carcharhinus acronotus), and bonnethead sharks (Sphyrna tiburo). Phlebotomy techniques and how samples are handled will vary between researchers due to differences in access to equipment, funding, or physical constraints. One goal of this study was to analyze the effects of sample handling practices and to consider the need for greater standardization of sample collection and handling processes. This study evaluated the extent to which variations in sample handling methodology may affect measurable physiological parameters, specifically, lactate. Additionally, this study validated the use of the Arkray Lactate Pro 2LT-1730 for field physiology applications with blacknose sharks and bonnethead sharks. The Lactate Pro predictably underestimated lactate concentrations compared to laboratory assay values, however, these differences can be accounted for using a correction curve. While more research is needed on the effects of varying storage and handling practices on lactate concentration, the results from this study can inform future stress physiology studies and help develop best practices to ensure sample and scientific integrity.</p
Applying Comparative Multiomics to Study the Holobiont of the Reef-Forming Coral Pseudodiploria strigosa Through Health and Disease
No full textCorals are sessile invertebrates that rely on relatively stable environmental parameters for longevity and survivorship. There is a myriad of microbial associations that provide beneficial functions to the coral host and its associated microbiome. Although not all coral-microbial associations are beneficial and during periods of environmental perturbations, the microbiome shifts through host stress and pathogenic microbes can proliferate. The majority of microbe-host associations in corals remain unknown, such as the function of the highly abundant apicomplexans, the corallicolids within the holobiont. By first understanding what microbes the coral host, Pseudodiploria strigosa, associates with during a healthy state we can establish a baseline. Additionally, by analyzing what protein-level machinery the host is producing can provide insight to better understanding the functional contribution from the microbiome. Previous literature has shown environmental parameters such as light and oxygen availability play a large role in what proteins and enzymatic reactions are required for homeostasis. Therefore, analyzing the host and its associated microbiome over six-hour intervals through replicated days can provide a higher resolution with respect to what is occurring mechanistically at a cellular-level through day and night cycles. Using this baseline, microbial assemblages and host transcriptional responses can be compared to provide context into how the coral and its associated microbiome undergoes disease progression. Using several coral diseases collected from Curaçao, such as black band disease, red band disease, Caribbean ciliate infection, and stony coral tissue loss disease, we can use comparative multiomics to study the holobiont of the reef-forming coral, Pseudodiploria strigosa through health and disease.</p
Gossip, Internalized Sexual Stigma, and Suicidal Ideation in BIPOC Individuals Who are Lesbian, Gay, or Bisexaul
No full textIn contrast to heterosexual individuals, sexual minority individuals (e.g., lesbian, gay, bisexual, LGB) face a heightened risk of suicide (Hottes et al., 2016). This increased risk is often due to high levels of family rejection and other forms of sexual minority discrimination (Carnelly et al., 2011; Willoughby et al., 2006). Although sexual stigma is pervasive within most cultures, research highlights especially prevalent homophobic attitudes within many Black, Indigenous, and other People of Color (BIPOC) communities. This may lead to heightened experiences of discrimination and distress for BIPOC sexual minorities. A significant way to transmit discrimination towards sexual minorities is through gossip, or the act of relaying either positive or negative information about in-group and out-group members. Gossip affirms social conventions that informally police group members to reinforce further social norms and values (Baumeister et al., 2004; Gluckman, 1963). Using a sample of 303 BIPOC (153 heterosexual and 150 sexual minority individuals), the current study assessed the relationship between perceived family gossip and suicidal ideation (SI), along with factors that may further help explain this relationship. Greater perceived family gossip was associated with greater SI. However, in line with study hypotheses, this finding was moderated by sexual orientation, such that the relationship was positive and significant for sexual minorities, but not for heterosexuals. Other potential mediators and moderators of the relationship between gossip and SI were also examined and will be discussed. Our findings suggest that targeting communication patterns in therapy, such as how families share information (e.g., gossip), may be one important avenue to help reduce the risk of SI in BIPOC populations.</p
Books Aren't Magic: Amazon, Indie Bookstores, and the Utility of Literature
No full textThis dissertation analyzes the competing discourses and media representations that attend independent bookstores, the Amazon corporation, and public libraries as a means to interrogate the concept that “books are magic” in the digital age. By comparing and contrasting different approaches to book production, distribution, acquisition, consumption, and evaluation in the 21st century, I substantiate my claim that the book-bound, spatialized, past-oriented “magic” of indie bookstores and the digital, placeless, future-oriented “magic” of Amazon operate synergistically, rerouting material and imaginative resources away from the present of our increasingly underfunded public library systems and the “un-magical” books that they contain. Ultimately, I demonstrate that one of the primary utilities that literature can provide in the era of the internet derives from its ability to metaphorize, and in some cases logistically disrupt, the imaginaries and distribution systems that sustain literary production and consumption under capitalism. Taking its title from the beloved Brooklyn-based indie bookstore Books Are Magic, this dissertation contends that engaging with the claim that “books are magic” can help readers to recognize and reappropriate the aesthetic, social, affective, and political potentialities often coopted and commodified by the discourses of magic that animate our ever-evolving relationship with books, bookstores, and libraries. Though I criticize indie bookstores and Amazon, I intend for those critiques to highlight how these private enterprises can supply us with what Ernst Bloch calls “wishful images,” the glimpses of a future in which a more complicated perception of how we produce, acquire, and use books can allow libraries of all kinds to feel magical again
Reasoned Change in Logic
No full textBy a reasoned change in logic I mean a change in the logic with which you make inferences that is based on your evidence. An argument sourced in recently published material Kripke lectured on in the 1970s, and dubbed the Adoption Problem by Birman (then Padró) in her 2015 dissertation challenges the possibility of reasoned changes in logic. I explain why evidentialists should be alarmed by this challenge, and then I go on to dispel it. The Adoption Problem rests on a failure to distinguish between logical principles such as Universal Instantiation and Modus Ponens which might or might not govern your inferences with superficially similar laws which must govern your cognitive architecture
Analysis of separation control mechanism of turbulent co-flow wall jet
No full textUtilizing an upstream tangential injection and downstream streamwise suction, co-flow wall jet (CFWJ) is demonstrated to be an effective and efficient zero-net-mass-flux active flow control method. However, the underlying separation control mechanism is not fully understood. This paper conducts a theoretical analysis using two-dimensional (2D) differential and integral wall jet momentum equations, which are supported by quantitative solutions of 2D unsteady Reynolds averaged Navier-Stokes equations for the NASA hump flows. This study reveals the CFWJ working mechanism with three factors: 1) A CFWJ establishes the required large clockwise spanwise vorticity and transverse gradient of vorticity magnitude near the wall by tangential injection and streamwise suction. This is essential to offset the adverse pressure gradient (APG) by enhancing the turbulent diffusion and the wall vorticity flux. 2) The wall jet provides the required streamwise mass flux to enhance the streamwise inertia force that offsets the APG. 3) The turbulent diffusion is enhanced by the severe APG, which in turn counteracts the effect of APG. The validated numerical simulation demonstrates that turbulent diffusion plays a dominant role in offsetting APG. It is observed that immersing the entire CFWJ in the APG region is most effective and efficient for flow separation control.</p