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Valuing Coastal Nature-Based Solutions: Investigating Preferences, Perceptions, and Policies for Coastal Adaptation in Florida
No full textCoastal communities are increasingly threatened by the impacts of climate change and environmental degradation. The use of coastal nature-based solutions (NbS) is being explored to address these threats and to provide additional societal benefits. However, coastal NbS is met with concerns of coastline users regarding trade-offs between coastline uses thereby challenging their implementation. Despite these challenges, there are considerable efforts to engage in the inclusive planning and design of coastal NbS. This thesis applies an interdisciplinary lens of Environmental Economics and Policy Analysis to evaluate the social, economic, and institutional factors that shape the planning and implementation of coastal NBS in Florida. This thesis is divided into four chapters: Chapter 1 provides an overview of nature-based solutions, its origins, definitions, and the theoretical framework (transformative adaptation) guiding this thesis. Chapter 2 investigates residential preferences toward hard vs. nature-based solutions (i.e., seawalls vs. mangroves) using a quantitative survey (a choice experiment) and logit models. This chapter provides dollar estimates of how much residents in Miami-Dade County are willing-to-pay for project options that support coastal protection as well as distinguishes socio-economic profiles of residents who prefer to ‘take action’ versus ‘no action’ to reduce coastal risk. Chapter 3 draws from expert perceptions and coastal management policies toward coastal nature-based solutions in Florida (i.e., living shorelines) using an integrated methodology of semi-structured interviews and policy documentary analysis. This chapter is discussed in two parts: the first part reveals perceived barriers and enablers of Florida living shorelines and the second part contextualizes priority patterns of coastal management policies in select Southeast Florida counties. Finally, Chapter 4 provides key messages for Florida decision-makers drawn from major findings of this dissertation as well as recommendations for future research.</p
The Impact of Recent Incarceration and Structural Barriers on the HIV Treatment Cascade
No full textIntroduction: Although incarceration may provide a chance for people living with HIV (PLWH) to receive HIV treatment, there is a notable drop-off in care that happens after release. The current study sought to examine how recent incarceration is associated with structural barriers and the HIV care cascade in a sample of recently incarcerated and never incarcerated PLWH in Miami. Methods: A sample of 725 participants (97 recently incarcerated, 628 never incarcerated) receiving HIV care at a large public HIV clinic in Miami completed an interviewer-administered survey. HIV viral load and dates of HIV care visits over time since completing the survey were extracted from medical charts. Linear regressions were used to examine the relationship between recent incarceration and experiencing structural barriers (unstable housing, lower education level, and lower health literacy). Then, survival analyses were used to determine whether the time to falling off the HIV care cascade differed based on incarceration history. Lastly, structural barriers and substance use were added to the survival analysis model. Results: Recent incarceration was associated with a higher likelihood of experiencing unstable housing and having a lower education level, but was not associated with health literacy. Using survival analysis, participants who were recently incarcerated fell out of HIV care over one year (398.05 days) sooner than those without a history of incarceration. Lastly, after the structural barriers and substance use were added to the model, the model remained significant. The structural barrier variables did not significantly contribute to the model; however, substance use was significantly related. Conclusions: The findings highlight the unique contribution that past-year incarceration contributes to likelihood of falling out of HIV care. The specific reasons for this relationship need further exploration to inform and develop interventions specific for PLWH being released from incarceration to ensure they are able to maintain proper HIV health after release.</p
Spinal Spheroids as Screening Platform for Peripheral Neuropathies
No full textThe lack of effective disease-modifying therapies for axonopathies highlights the need for novel preclinical models suitable for treatment development. Two-dimensional neuronal cultures lack the directional axonal distribution required to investigate length-dependent processes such as peripheral neuropathies. To optimize this well-established model system, we developed a robust human platform to study axonal morphology and physiology based on three-dimensional motor neuron cultures (i.e., spinal spheroids). We differentiate motor neurons from human induced pluripotent stem cells, purify them by magnetic sorting, and culture them in suspension until they form spheroids. Axons are allowed to grow out of plated spinal spheroids in a radial fashion at an average rate of 200 micrometers/day and reach up to 1 cm in length. This system is optimized for morphological analysis, including high content imaging, investigation of axonal protein expression, and time-lapse imaging of axonal transport
Nitric Oxide Reduction at a Single Iron Site Facilitated by Second Coordination Sphere Hydrogen Bonding via a Putative Fe(IV)-Oxo Intermediate
No full textMetalloenzymes use second coordination sphere (SCS) hydrogen bond (H-bond) donors and acceptors to facilitate small molecule activation by lowering the activation energies for chemical transformations or by stabilizing reactive intermediates. Borovik and co-workers studied the role of SCS groups in dioxygen and chalcogen activation in well-defined mononuclear model complexes. Here, we use the same complex, K[Fe
(H
L)], to study the role of H-bonding for nitric oxide (NO) activation. Remarkably, in solution, K[Fe
(H
L)] is capable of direct NO reduction to nitrous oxide (N
O) at a single Fe center. Initial formation of a hs-{FeNO}
intermediate is followed by fast attack by a second NO molecule to form N
O and a putative Fe
═O intermediate, which then undergoes multiple decomposition pathways, forming an antiferromagnetically coupled
= 1/2 Fe
/Fe
dimer and a diamagnetic diferric species as confirmed by Mössbauer and EPR spectroscopy. Notably, in the absence of the SCS H-bond donors, only the formation of a stable hs-{FeNO}
species is observed. Intermediates of NO reduction were observed by reacting K[Fe
(H
L)] in the solid state with NO, which leads to the formation of hs-{FeNO}
species, N
O, and the Fe
═O intermediate, as confirmed by IR spectroscopy. To the best of our knowledge, direct reduction of NO at a single Fe center has not been reported. Furthermore, the ability to form a high-valent metal-oxo species directly from NO is unprecedented for nonheme iron chemistry. This novel reactivity has significant implications in biology and for catalytic systems for NO
reduction
Treatment-related Outcomes and Patterns of Relapse in Secondary CNS Involvement by Large B-cell Lymphoma
No full textSecondary central nervous system (CNS) large B-cell lymphoma (SCNSL) occurs in the de novo setting, as a CNS-isolated relapse, or synchronous (concomitant CNS and systemic) relapse. SCNSL is a devastating event without therapeutic consensus. Thus, we aimed to evaluate treatment outcomes in an international cohort. Progression-free survival (PFS), overall survival (OS) and cumulative incidence of relapse (CIR, estimated using competing-risk models) were reported. Prognostic factors were identified in a 6-month landmark multivariate analysis. Outcomes following thiotepa autologous stem cell transplant (ASCT) and chimeric antigen receptor T-cell therapy (CAR-T) delivered at relapse were compared following propensity score matching (PSM). A total of 1139 patients were included in the analysis (de novo: 537; relapsed SCNSL: 602). 2-year PFS estimates were 40.4%, 43.9% and 16.2% for de novo SCNSL, CNS-isolated relapse, and synchronous relapse respectively. Patients with CNS-isolated relapse demonstrated low rates of systemic recurrence (24-month CIR 6%). Thiotepa-ASCT correlated with longer survival in de novo SCNSL (PFS: HR=0.57; P=0.005; and OS: HR=0.62; P=0.023) and CNS-isolated relapses (PFS: HR=0.55; P=0.002; and OS: HR=0.39; P<.0001) in 6-month multivariable landmark analysis. ASCT (thiotepa or non-thiotepa) also associated with improved survival in synchronous relapses (PFS: HR=0.57; P=0.023; and OS: HR=0.48; P=0.019). Higher survival with thiotepa-ASCT compared to CAR-T was observed in survival analyses following PSM (PFS: HR=0.45; P=0.005 and OS: HR=0.41; P=0.014). These data support thiotepa-ASCT in eligible patients, particularly de novo disease and CNS-isolated relapses. CNS-isolated relapse was infrequently associated with systemic recurrence, supporting treatment regimens adopted from primary CNS lymphoma
Race, Ethnicity, and Social Determinants of Health in PICU Mode of Death: Single-Center Retrospective Cohort Study
No full textIMPORTANCE:
Black and Hispanic/Latino patients are underrepresented in pediatric mode of death (MOD) studies. Although significant disparities have been reported, the associations of MOD with patient-level social determinants of health (SDOH) and the Child Opportunity Index (COI) are unknown.
OBJECTIVES:
To investigate associations between PICU MOD, race and ethnicity, SDOH, and COI.
DESIGN, SETTING, AND PARTICIPANTS:
Retrospective, single-center cohort study at a twenty-four-bed PICU within a large safety-net, public hospital, including all PICU deaths between January 2010 and December 2019.
MAIN OUTCOMES AND MEASURES:
We examined MOD by race and ethnicity, COI, and SDOH, including preferred language, health insurance, single-parent household status, parental occupation, and healthcare barriers abstracted from medical records. MOD was categorized as limitation of artificial life-sustaining therapies/technology (LOT) or withdrawal of artificial life-sustaining therapies/technology (WOT), failed resuscitation (FR), and death by neurologic criteria (DNC).
RESULTS:
Of 238 deaths, Black non-Hispanic/Latino patients comprised 42% (n = 100), Hispanic/Latino patients of all races 35% (n = 83), and White non-Hispanic/Latino patients 19% (n = 46). LOT/WOT was the predominant MOD (75%, n = 174; LOT = 109, WOT = 65). Racial and ethnic groups showed significant differences in COI, SDOH, and healthcare barriers. Despite this, there were no significant differences in MOD by Race and Ethnicity, SDOH, or healthcare barriers. Median COI was lower for DNC compared to LOT and WOT, and for FR compared with WOT. However, when examined within individual racial and ethnic groups, there was no difference in median COI between FR, LOT, and WOT.
CONCLUSION AND RELEVANCE:
We found no differences in MOD by Race and Ethnicity, SDOH, or barriers. Median COI was lower for FR compared with WOT. This suggests that COI, as opposed to race and ethnicity, may play a role in pursuing or forgoing resuscitation at end-of-life. This study adds to the examination of pediatric healthcare disparities at end-of-life by including SDOH and COI data in MOD analysis
Chronic Urticaria Part II: Clinical management and therapeutics
No full textChronic urticaria (CU) is a mast-cell driven disease characterized by recurrent wheals, angioedema, or both, lasting more than six weeks. Timely, appropriate treatment is essential to achieve complete disease control, minimize burden, and improve quality of life. The goal of management is elimination of symptoms with safe, effective therapies at the lowest necessary dose. This two-part continuing medical education series provides a comprehensive review of CU. Part II focuses on the complex management of CU including the role of antihistamines, immunosuppressants, and biologics, as well as novel approaches. The CU therapeutic landscape is evolving, with investigations ongoing for biologics, small molecules, and specific mast cell-directed agents
Douching Is Associated With Dysregulated Rectal Mucosal Immunity in Sexual Minority Men
No full textReceptive condomless anal sex (CAS) associates with elevated rectal inflammation and mucosal injury, increasing HIV acquisition risk. Although douching may amplify rectal inflammation and alter microbial communities, this has not been well characterized in sexual minority men (SMM).Ninety-two SMM (median age, 34.6 years) who were HIV negative and reported receptive CAS provided rectal swabs during sexually transmitted infection (STI) clinic visits. Associations among rectal douching, rectal cytokine/chemokine levels, and microbial communities, evaluated via immunoassay and 16S rRNA gene sequencing, respectively, were assessed.When compared with nondouching SMM (n = 27), SMM who douched (n = 64) reported more receptive CAS partners and displayed elevations in rectal cytokine/chemokines linked to immune activation and inflammation. Lower microbial richness, evenness, and Shannon diversity in SMM who reported douching were observed. Significant associations were identified between microbial alpha diversity metrics and rectal chemokine/cytokine levels. Finally, significant correlations were observed between rectal cytokine/chemokine levels and individual microbial genera.Among SMM engaging in receptive CAS, douching may identify those with amplified biobehavioral HIV and STI risk. Elucidating the mechanisms whereby douching dysregulates rectal immune function and alters rectal microbial communities could yield targets for biomedical approaches to optimize HIV/STI prevention in SMM during receptive CAS
Effect of methylprednisolone in cervical spinal cord injury stratified by injury severity: analysis in 908 patients
No full textCohort study.
Although the effectiveness of methylprednisolone sodium succinate (MPSS) in spinal cord injury (SCI) is controversial, it is hypothesized that the effectiveness and safety profile of MPSS may vary in select cervical SCI sub-populations. The objective of this study is to clarify the effect of MPSS and its impact on adverse events in patients with cervical SCI, stratified by baseline neurological status.
Three large prospective, multicenter data sets of patients with acute SCI.
Patients with acute cervical SCI were enrolled. The primary outcomes were upper extremity motor scores (UEMS) and lower extremity motor scores (LEMS) at 1 year. Patients were grouped by baseline American Spinal Injury Association Impairment Scale (AIS) grade.
908 patients meeting inclusion criteria were analyzed. In AIS grade A patients, the use of MPSS resulted in significantly improved LEMS (mean difference [MD], 3.0; 95% CI, 0.3-5.6; p = 0.02), but not UEMS (MD, 0.5; 95% CI, -2.5-3.5; p = 0.74), at 1 year. In contrast, no significant benefit was observed in patients with AIS grades B, C, or D. In AIS grade A patients, the MPSS group had a lower incidence of cardiopulmonary adverse events (42.5 vs. 62.8%; p < 0.001) and gastrointestinal/genitourinary adverse events (13.7 vs. 22.4%; p = 0.04).
MPSS was associated with improved lower extremity motor recovery in AIS grade A cervical SCI patients. No significant effect was seen in patients with incomplete injuries. MPSS was not associated with an overall increase in adverse events, suggesting it may be selectively beneficial in severe cervical SCI
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