95038 research outputs found
Sort by
Species-Specific Insights into Mangrove Channel Restoration: An Evaluation of Biodiversity, Growth, and Carbon Sequestration in Chilaw, Sri Lanka
Get PDFThis study examines the long-term ecological impacts of mangrove restoration initiatives conducted in 1996 and 1998 along two channels in Chilaw Lagoon, Sri Lanka. We compared sites originally planted with Rhizophora mucronata (1996) and Rhizophora apiculata (1998) to evaluate species-specific influences on ecosystem development 26 and 28 years after original planting took place. Field survey data collected in 2024 was used for analysis of stem density, biodiversity, canopy height, and above-ground biomass (AGB) estimates. Remote sensing analysis supplemented field data to track mangrove forest growth between 2016-2024. Results reveal distinct ecological trajectories between the two restoration approaches: The R. mucronata site demonstrated greater mangrove biodiversity (Shannon-Wiener H' = 1.099 vs 0.815) and higher stem density (0.297 ± 0.049 mangrove/m²), while the R. apiculata site exhibited stronger species dominance and carbon sequestration potential. Remote sensing confirmed overall ecosystem health with Chilaw mangrove forest extent expanding by 9.8 hectares during an eight-year monitoring period. Significant differences observed in the mangrove inhabiting the regions adjacent to original planting areas along both restored sites highlights how species planting strategy creates tangential impacts on ecosystem structure and function. Findings suggest that restoration practitioners should select Rhizophora mangrove species for planting according to specific management goals. This site-specific research demonstrates that long-term species-specific restoration can be achieved through local management approaches even without formal protections or governance, offering valuable insights for future mangrove conservation and climate mitigation strategies.Bachelor of Art
Spatiotemporal Changes of CHIP and Their Contribution to the Spinocerebellar Ataxias
Get PDFSpinocerebellar ataxia autosomal recessive 16 (SCAR16), caused by mutations in STIP1 homology and U-box containing protein 1 (STUB1), presents with cognitive dysfunction, hyperreflexia, hypogonadism, and neuroinflammatory processes potentially linked to necroptosis, a pro-inflammatory form of programmed cell death. Necroptosis is driven by receptor-interacting protein kinases 1 and 3 (RIPK1 and RIPK3), with carboxyl terminus of HSC70-interacting protein (CHIP) (encoded by STUB1) functioning as an E3 ubiquitin ligase to target these proteins for degradation, thereby inhibiting necrosome formation. However, how CHIP dysfunction contributes to neuroinflammation and cerebellar degeneration in SCAR16 remains unclear. This study characterizes a preclinical mouse model of SCAR16 harboring a CHIP ubiquitin ligase-deficient mutation (T246M) to investigate its role in regulating necroptosis and disease progression. Advanced imaging assessed cerebellar pathology, revealing significant atrophy in the cerebellar lobes of diseased mice, accompanied by elevated RIPK3 levels in affected regions. These findings correlated with higher ataxia scores, suggesting that the loss of CHIP function leads to RIPK3 accumulation, enhancing necroptosis and neuroinflammation. While the role of RIPK1 remains to be explored, the data implicates CHIP dysfunction in driving cerebellar damage via impaired RIPK3 degradation. This study establishes a preclinical framework for investigating SCAR16, highlighting the CHIP-RIPK3 axis as a potential therapeutic target to mitigate neurodegeneration. Further research is necessary to dissect CHIP-dependent regulation of necroptosis and develop interventions for SCAR16 and related disorders.Bachelor of Scienc
The Influence of Early-Life Threat Exposure and Temperamental Negative Emotionality on Psychopathology Outcomes From Preschool to Adolescence: Pathways of Risk, Moderation, and Developmental Specificity
Get PDFThis study adds to the limited yet expanding body of research on temperament × adversity interactions by investigating how early-life threat exposure and temperamental negative emotionality (NE) independently and interactively contribute to the development of psychopathology from preschool through adolescence. Drawing on a longitudinal dataset derived from three linked studies, the present study examined whether early-life threat exposure predicts internalizing and externalizing psychopathology, whether NE functions as a moderator in this relationship, and how these patterns evolve over time across three developmental timepoints. Results indicated that early threat exposure significantly predicted externalizing symptoms across all timepoints, even after controlling for prior psychopathology, suggesting a persistent behavioral impact. NE was strongly associated with both externalizing and internalizing psychopathology in early childhood but showed increasing specificity for internalizing symptoms over time. A significant Threat × NE interaction was observed for externalizing psychopathology at the preschool timepoint, revealing that moderate-to-high NE amplified the effect of threat exposure, while low NE buffered against it. This interaction did not persist into middle childhood or adolescence. These findings underscore the importance of early intervention targeting temperament-based risk in children exposed to threat and suggest that the timing and context of threat may critically shape its psychopathological expression.
Keywords: early threat exposure, negative emotionality, developmental psychopathology, externalizing behavior, longitudinal study, temperament × adversity interactionBachelor of Scienc
Modeling and Simulation of Selective Laser Sintering with COMSOL Multiphysics
Get PDFThis work presents a multiphysics simulation framework developed in COMSOL to model the selective laser sintering (SLS) process for both metallic (Molybdenum) and polymeric (PA12) powders. By incorporating heat transfer, fluid dynamics, phase change, and material-specific rheology, the simulations reproduce key process dynamics observed in experimental studies. The model successfully captures phenomena such as melt pool formation, open and "frozen-in" pores, bubble generation, and spatter events—exhibiting strong qualitative agreement with literature data. In particular, the PA12 simulations, which utilize a non-Newtonian viscoelastic model, reveal spatter behaviors not present in the Newtonian Molybdenum simulations, emphasizing the importance of material properties in defect formation. A comparison between 2D and 3D simulations highlights the limitations of 2D models in estimating melt efficiency, owing to unaccounted thermal losses in out-of-plane directions. These findings underscore the need for full 3D modeling to accurately predict sintering outcomes. Future work will aim to improve model fidelity through enhanced thermal modeling, stochastic powder bed configurations, and experimental validation, as well as explore data-driven optimization using machine learning.Bachelor of Scienc
Investigating the Role Played by Trichomonas vaginalis in Promoting Chlamydial Spread to the Upper Genital Tract
Get PDFIntroduction: Chlamydia trachomatis is the most common bacterial STI in the U.S. and can lead to serious reproductive health issues if it ascends to the upper genital tract. While co-infections with pathogens like Neisseria gonorrhoeae have been linked to more severe disease, a role for Trichomonas vaginalis in C. trachomatis ascension remains unclear. T. vaginalis, a protozoan pathogen, can damage genital tissues and increase susceptibility to other infections. Recent research suggests that T. vaginalis virulence is enhanced by endosymbionts, such as Mycoplasma hominis and Candidatus Mycoplasma girerdii.
Methodology: The TRAC 2 study utilized a longitudinal cohort and cross-sectional evaluation to investigate host immune responses and risk factors associated with C. trachomatis infection. Between November 2019 and June 2023, 120 women aged 15–40 were recruited from an Allegheny County public health clinic. Eligibility was based on clinical presentation or known exposure to sexually transmitted infections. Cervical and vaginal samples were collected and preserved in DNA/RNA Shield, with nucleic acids extracted using Zymo DNA/RNA Miniprep Kits. Quantitative PCR targeting the β-tubulin gene of T. vaginalis was conducted using SYBR Green chemistry and validated with a standard curve using template obtained from a previously characterized clinical specimen. Triplicate reactions, no-template controls, and inter-plate standards were used to ensure reliability and to control for batch effect. Plate maps were designed to distribute clinical profiles evenly and minimize technical variation.
Results: The TRAC 2 cohort, consisting of 120 women, had a mean age of 24.59 years (SD = 5.15), with 65.0% of participants identifying as Black and 93.3% not Hispanic or Latino. A significant portion of the cohort was uninsured (17.5%) or covered by Medicaid (38.3%). Behavioral health data revealed high rates of alcohol consumption (80.8%) and drug use (75.8%). Gynecologic history showed that 48.2% had ever been pregnant, with 56.8% having a history of chlamydia. Pathogen prevalence revealed cervical chlamydial infection in 78.4%, and trichomonas in 11.2% of participants. qPCR analysis indicated significantly higher signal intensities in clinically confirmed T. vaginalis (TV+) cases, with average values of 1.78E+11, compared to 3.35E+10 in TV− cases. Symptoms such as pain or burning and frequent urination were more common among TV+ individuals, while abnormal discharge was more frequently reported in TV− participants. Overall, TV+ individuals reported fewer symptoms when compared to TV− individuals, indicating that the TV+ group had a lower symptom burden. Additionally, individuals with motile Trichomonas exhibited a higher average burden but fewer symptoms than those without motile Trichomonas.
Discussion: Our data provide preliminary evidence that T. vaginalis abundance may be inversely associated with C. trachomatis ascension, echoing previous findings implicating T. vaginalis endosymbionts in modulating genital tract inflammation. While causality cannot be established from this cross-sectional analysis, the results support a potential protective or competitive interaction between T. vaginalis and C. trachomatis that may influence the likelihood of upper genital tract involvement. These findings raise new questions about pathogen-pathogen interactions and highlight the need for mechanistic studies exploring how T. vaginalis and its symbionts may alter epithelial immunity and C. trachomatis pathogenesis.Bachelor of Science in Public Healt
Eschaton
Get PDFA manuscript of original poetry, titled Eschaton. Follows the ideological descent into a black hole. Bachelor of Art
Through the Veil of Tomorrow
Get PDFFinal Honors Thesis exploring the hardships and triumphs of childhood through an adult lens. Bachelor of Arts in Educatio
Biting the Bullet: Dueling and Honor within the Continental Army
Get PDFThis thesis examines the rise of dueling within the Continental Army during the American Revolution, arguing that changing notions of class, masculinity, and honor created a military culture where dueling thrived. Drawing on case studies of duels during the war, it explores how dueling reflected tensions between traditional European ideals and emerging American values. The work contends that dueling not only shaped soldiers’ personal identities but also contributed to the professionalization of the Continental army, and deepened the divide between military and civilian society. Though the practice has long since disappeared, its influence remains embedded in modern American military culture and law.Bachelor of Art
Medical Knowledge Integration Into Reinforcement Learning Algorithms for Dynamic Treatment Regimes
Get PDFThe goal of precision medicine is to provide individualised treatment at each stage of chronic diseases, a concept formalised by dynamic treatment regimes (DTR). These regimes adapt treatment strategies based on decision rules learned from clinical data to enhance therapeutic effectiveness. Reinforcement learning (RL) algorithms allow to determine these decision rules conditioned by individual patient data and their medical history. The integration of medical expertise into these models makes possible to increase confidence in treatment recommendations and facilitate the adoption of this approach by healthcare professionals and patients. In this work, we examine the mathematical foundations of RL, contextualise its application in the field of DTR, and present an overview of methods to improve its effectiveness by integrating medical expertise
AAV-derived Inverted Repeats for Enhanced Gene Editing
Get PDFPrevious studies have shown that a DNA double strand break (DSB) at or near a chromosomal target site enhances homologous recombination (HR) mediated genome editing. As such, designer endonucleases that recognize specific DNA sequences and generate a DSB at a site of interest have risen in popularity, however, concerns exist for in vivo therapeutic applications including the immune response to foreign epitopes and off-target mutagenic activity. A reported alternative to site-specific nucleases are inverted repeats (IRs), structured DNA elements processed to DSBs via endogenous DNA repair. The hypothesis of this work is that adeno-associated virus (AAV) based IR sequences adjacent to a repair template for HR-mediated gene editing will alter editing frequency, towards the objective of generating AAV recombinant genomes enhanced for HR-mediated gene editing. In this work, a truncated AAV IR enhanced for gene editing was randomly mutated in a manner that conserved sequences necessary for vector production thereby generating a mutant IR library of >106 diversity. Compared to the library parent, mutant IRs both decreased and enhanced gene editing frequency, supporting the hypothesis. Sequence analyses highlighted characteristics potentially correlated with altered editing efficiency. Finally, small-scale production experiments demonstrated that the mutant IRs retained the ability to produce recombinant AAV (rAAV), although at lower titer. Together, these results demonstrate that viral IR sequences on the repair molecule stimulate gene editing and offer insights into the generation of AAV vectors that mediate high efficiency genetic engineering in the absence of a site-specific endonuclease.Bachelor of Scienc