22689 research outputs found
Sort by
THE ROLE OF LOCAL ZONING REGULATIONS IN THE SITING AND AVAILABILITY OF SUBSTANCE USE DISORDER TREATMENT FACILITIES
No full textBackground
This study examines how local zoning policies and community dynamics affect the availability and distribution of substance use disorder treatment (SUDT) facilities in urban areas. Despite expanding evidence-based treatment options, access remains limited due to zoning restrictions, regulatory barriers, and community stigma. These challenges limit where SUDT facilities can be established, leading to uneven service distribution and compounding difficulties in treating individuals with SUDs. The study uses a mixed-methods approach to explore how these factors shape SUDT availability, with a focus on U.S. cities, including Baltimore, MD.
Methods
The study was divided into three aims. Aim 1 involved a cross-sectional analysis of zoning ordinances in 20 geographically diverse U.S. cities, focusing on land-use definitions, buffer requirements, and special permit processes that impact SUDT facility siting. Aim 2 used semi-structured interviews with 20 SUDT providers to explore local factors influencing facility siting, including zoning, community opposition, and transportation access. Aim 3 used a spatial analysis of Baltimore’s SUDT facilities from 2010 to 2022, examining how neighborhood characteristics, zoning, and healthcare infrastructure shaped facility availability.
Results
Aim 1 revealed significant variation in how cities regulate SUDT facilities, with many requiring distance buffers or special permits, illustrating barriers to access. Aim 2 found that zoning laws, community stigma, and transportation access were key challenges for providers, with community opposition and restrictive zoning often delaying or preventing new facilities. Aim 3 showed that SUDT facilities in Baltimore expanded from 2010 to 2022, particularly in vulnerable neighborhoods. However, facility clustering raised concerns about overconcentration and limited access in less vulnerable areas. Health system infrastructure was positively associated with facility locations, while zoning had a slight but notable impact on distribution.
Discussion
Zoning regulations and community dynamics play a significant role in shaping access to SUD treatment. Zoning restrictions often limit the establishment of new SUDT facilities, particularly in areas with organized community opposition. While health infrastructure supports access, further research is needed to explore how zoning reforms may ensure a more equitable distribution of services across urban areas. Addressing zoning barriers is essential to expanding access to SUD treatment for those most in need
Using the Zebrafish to Characterize Postprandial Intestinal Lipoprotein Dynamics
No full textDyslipidemia and metabolic disease are umbrella terms for aberrant lipid
metabolism. Dietary modifications are a common practice to manage dyslipidemia, even in the context of disease-causing genetic mutations. In order to provide comprehensive
care for metabolic disease, the regulation and transport of dietary lipid must be more fully understood. Largely overlooked as a passive organ, the intestine is responsible for detecting and triggering biological responses to maintain host homeostasis. The intestine is the first organ to receive exogenous lipid from the environment. In this work, I outline intestinal lipid processing as it encompasses lipid absorption, storage, catabolism, and the secretion of lipoproteins. However, there remain large gaps in understanding the regulation and timing of lipoprotein synthesis and secretion from the intestinal enterocyte, specifically. Chylomicrons are the subclass of lipoproteins that are secreted from enterocytes to transport dietary lipid to the liver and other peripheral organs. The work in these chapters utilizes the zebrafish as a tool to explore open questions in lipoprotein biology and builds on prior studies that established that the zebrafish is a model of human lipoprotein biology. With a complete gastrointestinal tract resembling that of the human, the zebrafish expresses key genes required for lipoprotein production. Throughout this work, I explored poorly understood genes in the context of intestinal lipid metabolism— such as Asgr1 and Creb3l3— to uncover novel physiology with relevance to human metabolic disease. The chapters in this thesis focus on 1) the lipoprotein response to specialized, high-fat diets 2) using zebrafish genetics to investigate lipoprotein processing, and 3) describing the cellular response to a disruption in lipid flux through the intestine. Understanding the molecular response of intestinal cells to dietary lipid in the zebrafish has the potential to highlight avenues for the development of novel therapies for dyslipidemia. The data presented indicate that the regulation of chylomicron secretion must be dependent on many, highly coordinated cellular processes
DESIGN CONSIDERATIONS FOR QUALITY IMPROVEMENT STUDIES WITH NO CONCURRENT CONTROLS
Get PDFOveruse of diagnostic tests in hospital settings can affect the patient's experience, increase costs, and even lead to unnecessary antibiotic use and resistance. Literature suggests that diagnostic stewardship programs can reduce testing, with some studies highlighting no negative impacts to the patient's health. Researchers should inform the design of diagnostic stewardship programs in anticipation of measuring the impact of the intervention on patient outcomes. Different scenarios may require different assumptions and definitions of the treatment effect (estimand). Our goal was to conduct a simulation study to assess different data assumptions and estimand definitions using a previously conducted diagnostic stewardship study that resulted in reductions in blood culture rates and antibiotic use. Percent bias and power calculations were assessed to observe the estimands under various data distributions and to review the power of these estimands under the various distributions and estimands
CHARACTERIZATION OF T CELLS IN A MURINE MODEL OF THE FOREIGN BODY RESPONSE TO SYNTHETIC MATERIAL IMPLANTS
No full textThe foreign body response (FBR) to implanted biomaterials frequently culminates in fibrosis, compromising functionality. Although T cells are traditionally considered minor contributors to the FBR, emerging evidence highlights their pivotal roles in this process. Using a murine model of the FBR based on poly-caprolactone particle implantation in a volumetric muscle loss injury, we employed single cell RNA sequencing, single cell T cell receptor sequencing, and the communication inference tool dominoSignal to elucidate T cell phenotypic and functional dynamics. Our analyses revealed distinct T cell subsets, including expanding regulatory T cell (Treg) populations with specialized functions and effector phenotypes of γδ T cells, alongside temporal shifts in T cell population abundance. T cell receptor repertoire analysis demonstrated increasing clonal expansion within specific T cell populations as fibrosis progressed. DominoSignal communication analysis inferred signaling networks between T cells and stromal populations, implicating T cells in fibrotic and vascular remodeling. Bulk RNA sequencing of fibrotic tissue from Treg and γδ T cell depletion models confirmed their roles in inflammation, extracellular matrix production, and angiogenesis. Our improved cell communication inference algorithm was instrumental in uncovering critical signaling pathways, underscoring the utility of computational frameworks in advancing biological insights. These findings reveal the intricate interplay between adaptive immunity and the FBR, highlighting the potential for targeting T cell activity to improve biomaterial integration and mitigate fibrosis. This work advances our understanding of adaptive immune responses to synthetic materials and the fibrotic microenvironment arising from material implantation
MITOCHONDRIAL BIOGENESIS AND THE PROGRESSION OF PARKINSON’S DISEASE: PINK1, Parkin, PARIS, PGC-1alpha
Get PDFParkinson’s disease (PD) is a widespread, progressive, neurodegenrative disorder. A common symptom in Parkinson’s disease is mitochondrial mass dysregulation in the affected dopaminergic neurons. Neurons require a consistent supply of energy making them particularly vulnerable to mitochondrial dysfunction. Mitochondrial mass in neurons, is regulated by the two constantly occuring processes of mitophagy and mitochondrial biogenesis. While dysfunction in mitophagy was considered to be a key factor in Parkinson’s disease progression, it has been recently discovered, that neurons have built-in redundancies to continue to clear out damaged mitochondria. Instead, growing evidence points to dysfunction in mitochondrial biogenesis as a pivotal factor in PD progression, played out in the interactions of three molecules: PINK1, Parkin, PARIS and the resultant repression of master regulator molecule PGC-1alpha.
Experimental models in Parkinson’s disease show that agents targeting the molecules Parkin and PARIS improve mitochondrial biogenesis in the neuron and protect against neurodegeneration. Thus, this pathway shows promise for new therapeutics to treat patients and as these agents move toward clinical testing there is a need to educate patients, clinicians, students and scientists.
Current material for education about this pathway includes content and visuals that are overly complex, limiting them to an audience with a deep understanding of the science of PD. Currently available materials also limit viewer engagement and any exploration that would enhance comprehension of the complexity of the interactions. Further, the current format for the material, i.e. in static 2D images, is less effective in expressing the progression of interactions across space and time.
This thesis aims to educate a general audience about this pathway using 3D animation and an interactive web module. An engaging 3D animation will serve as an introduction to explain the interaction of the molecules by linearizing the narrative of the complex research and animating the interactions. It aims to be a more effective method to explain the spatial and temporal changes in this novel pathway. Further, an interactive web module will allow more self-directed learning of the molecular interactions in PD pathogenesis and provide a basis to explain interventional strategies for clinicians, scientists and students
THE ‘SAME COIN’ FALLACY: TARGET ENHANCEMENT AND DISTRACTOR SUPPRESSION IN HUMAN VISUAL ATTENTION
No full textI present here eight experiments with the aim of better understanding the processes which underlie selective visual attention. In Chapter 1 I overview the foundational literature on selective attention. I discuss at large the categories of attention and the current debate on whether categories of attention should be revised. I focus this discussion on the traditional dichotomous framework of attention versus the recently proposed trichotomous attention framework. The next three chapters focus on my empirical investigations of selective attention, to which I largely used individual difference approaches. In Chapter 2, I investigated whether the processes underlying the prioritization of relevant target information (i.e. target enhancement) are the same processes underlying the deprioritization of irrelevant distractor information (i.e., distractor suppression), i.e., two sides of the same coin. I found instead that individual difference measures of enhancement are dissociable from measures of suppression, suggesting independent underlying processes. Next in Chapter 3, I focus my investigations on only target enhancement. I examined whether processes underlying target enhancement are generalizable across forms of attentional control (e.g., voluntary attentional control, experience-based attentional control). I found, instead, evidence for dissociable and independent enhancement processes across voluntary and experience-based attentional control. I additionally found that, while measures of voluntary enhancement were reliable across days, measures of experience-based enhancement were not. This contrast suggests that experience-based attentional control may be more sensitive to state factors that change across days. In Chapter 4, I explore whether familiarity with the physical environment affects measures of attention. I found preliminary evidence that familiarization with our testing environment affected enhancement and suppression differently. While enhancement measures were similar between familiarized and not familiarized groups, measures of suppression were only significant after familiarized with the testing space. Furthermore, the magnitude of the suppression effect was four times larger in the group familiarized with the testing space. This suggests that suppression may be particularly sensitive to environmental familiarity and provides additional evidence for independent mechanisms of enhancement and suppression. Lastly, in Chapter 5, I openly discuss implications of my findings in feature-based attention as well as the influence of environmental factors on attention
INVESTIGATING ACCESS AND OPPORTUNITY FOR EMERGING MULTILINGUAL LEARNERS: A 3-STUDY DISSERTATION
Get PDFNational calls to improve educational outcomes for emerging multilingual learners (EMLs) focus on academic outcome disparities between students labeled English learners (EL) and their peers without the label. This narrative ignores the nuances of the EML trajectory. In this dissertation, I investigate how outcomes vary for EMLs over the course of their trajectory rather than simply focusing on whether they are labeled EL. In Study 1, I use multi-level Poisson regression to assess the relationship between being labeled EL and likelihood for suspension. I find that students labeled EL are more than twice as likely to be suspended compared to peers without the label, holding student and school characteristics constant. In Study 2, I used school-cluster robust inverse probability weighted regression to approximate a causal estimate of the relationship between being reclassified as English fluent by 3rd and 5th grade on English Language Arts (ELA) scores. I found a positive and significant relationship between reclassifying as English fluent by 5th grade and ELA scores. In both studies, I used longitudinal student- and school-level administrative data from 2014 to 2019 from one mid-sized urban school district in California. Finally, in Study 3, using interview data from 14 school leaders in California, I examined how knowledge about the school community informed school-level decision-making regarding EMLs. I found that principals who demonstrated a deep understanding of their school community—students, families, staff—were more likely to implement transformative policies that went above and beyond policy requirements and prioritized equity and social justice. Taken together, these studies support strengthening curricular programming over the EML course-taking trajectory so that they can receive the quality of education typically afforded to monolingual peers. Additionally, if programs cannot be immediately improved upon, the findings from this dissertation highlight the importance of supporting students to be reclassified as English fluent before they exit elementary school. Finally, the qualitative findings from this dissertation provide actionable recommendations for school leaders to implement transformative policies and programs and improve how they serve their EML population
BENEATH THE LACQUER: EXAMINING DOMESTIC MOTIVATORS FOR CHINA’S TRADE-RELATED ECONOMIC COERCION
No full textIn recent years, the U.S. and its allies have become increasingly concerned about China’s use of trade-related economic coercion, and are devoting resources to counter it. Existing examinations of the China’s modern use of economic coercion predominantly focus on external factors, and assume that China employs such measures primarily for deterrence and punishment, to coerce targeted countries into restraint in asserting their interests in the face of conflicting political or geopolitical interests from China. I argue that domestic factors play a role in driving whether and how China employs trade-related economic coercion—an aspect largely overlooked in academic and policy literature.
Using a process tracing approach, I examine six case studies from 2010 to 2020, including incidents of Chinese trade-related economic coercion on Japan, the Philippines, Canada, and Australia, and comparable cases where such coercion did not occur. I explore domestic motives through three variables, 1) institutions and the preferences of senior party officials, 2) nationalist sentiments and public opinion, and 3) the state’s domestic economic or environmental policies. I find that external factors alone do not explain China’s trade-related economic coercion. Rather, China is more likely to engage in trade-related economic coercion when nationalist sentiments are present and strong, and when domestic institutions, shaped by the centralization or decentralization of power, and the preferences of senior officials allow it. Additionally, broader domestic environmental or economic goals often align with the targeting of specific goods.
Over the past several years, China has become more assertive and sophisticated in its use of trade-related economic coercion. To develop more effective frameworks or responses to this challenge, policymakers must recognize that domestic factors can play a crucial role in shaping China’s behavior. Understanding how a country’s actions in sensitive political or geopolitical situations may interact with and impact China’s domestic drivers can help policymakers anticipate China’s behavior and manage risks more effectively. While efforts by allied countries to collectively counter China’s coercion may raise external costs for China, these efforts may be less effective or counterproductive if the domestic motives of China’s actions remain strong
NUMERICAL ANALYSIS OF 3D PRINTING INKS AND PARTICLE DISTRIBUTION INSIDE THE NOZZLE
Get PDFThe aim of the project is to create a general simulation framework for
non-Newtonian 3D printing inks using COMSOL Multiphysics. Moreover,
another goal is to determine the particle distribution at the outlet of the
nozzle with respect to different material parameters, processing conditions
and the nozzle geometry. A cylindrical nozzle is used initially, and more
geometry designs are explored and made to find the relations of particle
distribution. Based on those results, several design suggestions are given
for determining the desirable particle distribution people wanted in real life
experiments. For example, an even particle distribution ensures the stress
is evenly distributed so that reduces the risks of fatigue. This numerical
analysis helps people understand the hidden physics more and reduces
time and costs. Moreover, the model can also be a reference for designing
nozzle with respect to particle distribution. The limitation of this numerical
simulation is the particle-particle interaction module was not used. The
results are only workable for the first wave of the particle releasing
THE DIRECT IMPACT OF HIV-ANTIRETROVIRAL THERAPY ON THE GUT MICROBIOME AND VIROME AND HOST METABOLIC AND NEUROCOGNITIVE HEALTH
No full textHIV-antiretroviral therapy (ART) is highly efficacious at suppressing HIV-replication and restoring immunocompetence. Despite these benefits, people living with HIV (PLWH) are at an elevated risk for chronic non-communicable diseases such as obesity, metabolic syndrome, depression, and anxiety. The underlying etiology of this elevated risk remains elusive, but may involve the interactions with the gut microbiome and virome, both of which have been implicated in the pathogenesis of these conditions. Thus, we hypothesize that ART may directly impact the gut microbiome and virome which, in turn, can elicit these elevated risks for metabolic and neurocognitive diseases. While some studies have investigated the impact of ART on the gut microbiome and host health, the results were confounded by the presence of an HIV infection. An HIV-infection is known to alter the microbiome and increase the risk of metabolic and neurocognitive disease, which means ART studies in PLWH have their results confounded by the HIV-infection itself. To circumvent this issue, we use HIV-naïve mice models to decipher the direct impact of ART on host health and the gut microbiome and virome. We reveal that ART can have differential, direct impacts on metabolic health while also having no impact on neurocognitive health in a non-stress-inducing environment independent of an HIV infection. Because we saw that ART can impact host metabolic health independent of an HIV infection, we then explored the impact of the ART on the virome. We show for the first time that ART can directly impact the gut virome. In vitro liquid cultures of Lactiplantibacillus plantarum and B2 phage represent the first exploration of the potential mechanisms by which ART impact the gut virome