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Full-Text Articles in Life Sciences

1,4-Dioxane Biodegradation In Propanotrophs: Molecular Foundations And Implications For Environmental Remediation, Li Fei Aug 2020

1,4-Dioxane Biodegradation In Propanotrophs: Molecular Foundations And Implications For Environmental Remediation, Li Fei

Dissertations

1,4-Dioxane (dioxane) has emerged with an escalating concern given its human carcinogenicity and widespread occurrence in groundwater. Bioremediation is promising as an effective and cost-efficient treatment alternative for in situ or ex situ cleanup of dioxane and co-existing pollutants in the field. Soluble di-iron monooxygenases (SDIMOs) are reputed for their essential roles in initiating the cleavage of dioxane and other pollutants. In this doctoral dissertation, molecular foundations for SDIMOs-mediated dioxane biodegradation are untangled to promote the development and implication of site-specific bioremediation and natural attenuation strategies. This dissertation focused on propanotrophic bacteria given their pivotal roles in dioxane metabolism and …


Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen May 2020

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …


Investigating The Mechanism Of The Coronavirus Endoribonuclease In Antagonizing Innate Immune Signaling, Matthew Hackbart Jan 2020

Investigating The Mechanism Of The Coronavirus Endoribonuclease In Antagonizing Innate Immune Signaling, Matthew Hackbart

Dissertations

Coronaviruses (CoVs) are positive-sense RNa viruses that can emerge from endemic reservoirs and infect zoonotically, causing significant morbidity and mortality. CoVs encode an endoribonuclease (EndoU) that cleaves RNa in biochemical assays, but the target and function of EndoU activity during viral replication was not known. My work focused on characterizing the functions of EndoU during infection. I report that EndoU is an innate immune antagonist. to function as an immune antagonist, EndoU cleaves the 5'-Poly-Uridines from Negative-sense viral RNA, termed PUN RNA, which is the product of polyA-templated RNa synthesis. Using a virus containing an EndoU catalytic-inactive mutation, I detected …


Elucidating The Impact And Mechanism Of Hepatitis C Virus Cell-To-Cell Spread, Karina Durso-Cain Jan 2020

Elucidating The Impact And Mechanism Of Hepatitis C Virus Cell-To-Cell Spread, Karina Durso-Cain

Dissertations

Virus cell-to-cell spread has been implicated in the establishment of persistent infection and has been shown to be involved in the transmission of antiviral resistant mutants. However, relatively little is known about how virus cell-to-cell spread impacts infection or the specific mechanisms by which cell-to-cell spread occurs. as such, this dissertation focused on investigating HCV cell-to-cell spread not only to learn more about this medically important virus, but also to determine the broader impact cell-to-cell spread has on viral infection dynamics, identify the cellular factors involved, and perhaps ultimately provide insight into antiviral strategies that might enhance the barrier to …


Distinct Roles For Carbohydrate And Protein Receptors In Coronavirus Infection, Enya Qing Jan 2020

Distinct Roles For Carbohydrate And Protein Receptors In Coronavirus Infection, Enya Qing

Dissertations

Coronaviruses (CoVs) are common human and animal pathogens. in humans, four endemic CoV species together account for one third of mild respiratory infections worldwide. More severe and frequently fatal respiratory pathologies are caused by recent CoV outbreaks that resulted from occasional zoonotic spillover from animal CoV reservoirs, namely, SARS-CoV in 2002, MERS-CoV in 2012, and SARS-CoV-2 in 2019. Because CoVs threaten global health, any chance of relieving CoV's threat on human populations would rely heavily on our understanding of the mechanistic requirements for CoV tropism, whose major determinant is at the level of viral entry. CoVs have evolved to use …


Elucidating The Targets And Function Of The Mlr Compass-Like Complex During Development, David Joseph Ford Jan 2020

Elucidating The Targets And Function Of The Mlr Compass-Like Complex During Development, David Joseph Ford

Dissertations

MLR COMPASS-like complexes are highly-conserved epigenetic regulators required for enhancer establishment and subsequent reprogramming during differentiation and development. Mutation of MLR complex subunits in humans is associated with cancer and developmental disorder, yet much remains to be determined concerning both the healthy and disease-altered functions of these complexes. Using the developmental model Drosophila melanogaster, I further elucidate the functions of the MLR complex during in vivo organ development as well as stress response. I characterize the miRNa bantam as a regulatory target of the complex, required for proper tissue patterning during wing and compound eye formation. in the same systems …