Open Access. Powered by Scholars. Published by Universities.®

Environmental Health Commons

Open Access. Powered by Scholars. Published by Universities.®

University of South Carolina

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 61 - 90 of 114

Full-Text Articles in Environmental Health

Development, Validation, And Application Of A Novel Method To Separate And Quantify Silver Intracellular Uptake In Pseudomonas Aeruginosa, Mohammed A. Othman Apr 2020

Development, Validation, And Application Of A Novel Method To Separate And Quantify Silver Intracellular Uptake In Pseudomonas Aeruginosa, Mohammed A. Othman

Theses and Dissertations

Silver nanoparticles (AgNPs) have attracted tremendous attention as a potential broadspectrum antimicrobial agent to overcome multidrug resistant (MDR) infections. However, a comprehensive understanding to AgNPs bactericidal mechanism of action and the relative role of particulate versus ionic Ag in AgNPs antibacterial activity is lacking but essential for their optimization for potential medical applications. Therefore, a novel method to separate and quantify Ag internalization in P. aeruginosa was developed and validated through multimethod approach. The methods used were optical density at 600 nm (OD600), LIVE/DEAD staining, transmission electron microscopy (TEM), and sorbed Ag liberation assays. After optimizing the method, it was …


Host Abundance Correlates With Gulf War Illness Symptom Persistence Via Nlrp3-Mediated Neuroinflammation And Decreased Brain-Derived Neurotrophic Factor, Diana Kimono, Dipro Bose, Ratanesh K. Seth, Ayan Mondal, Punnag Saha, Patricia Janulewicz, Kimberly Sullivan, Stephen Lasley, Ronnie Horner, Nancy Klimas, Saurabh Chatterjee Jan 2020

Host Abundance Correlates With Gulf War Illness Symptom Persistence Via Nlrp3-Mediated Neuroinflammation And Decreased Brain-Derived Neurotrophic Factor, Diana Kimono, Dipro Bose, Ratanesh K. Seth, Ayan Mondal, Punnag Saha, Patricia Janulewicz, Kimberly Sullivan, Stephen Lasley, Ronnie Horner, Nancy Klimas, Saurabh Chatterjee

Faculty Publications

Neurological disorders are commonly reported among veterans who returned from the Gulf war. Veterans who suffer from Gulf War illness (GWI) complain of continued symptom persistence that includes neurological disorders, muscle weakness, headaches, and memory loss, that developed during or shortly after the war. Our recent research showed that chemical exposure associated microbial dysbiosis accompanied by a leaky gut connected the pathologies in the intestine, liver, and brain. However, the mechanisms that caused the symptoms to persist even 30 years after the war remained elusive to investigators. In this study, we used a rodent model of GWI to investigate the …


Gut Dna Virome Diversity And Its Association With Host Bacteria Regulate Inflammatory Phenotype And Neuronal Immunotoxicity In Experimental Gulf War Illness, Ratanesh K. Seth, Rabia Maqsood, Ayan Mondal, Dipro Bose, Diana Kimono, Larinda A. Holland, Patricia Janulewicz Lloyd, Nancy Klimas, Ronnie Horner, Kimberly Sullivan, Efrem S. Lim, Saurabh Chatterjee Oct 2019

Gut Dna Virome Diversity And Its Association With Host Bacteria Regulate Inflammatory Phenotype And Neuronal Immunotoxicity In Experimental Gulf War Illness, Ratanesh K. Seth, Rabia Maqsood, Ayan Mondal, Dipro Bose, Diana Kimono, Larinda A. Holland, Patricia Janulewicz Lloyd, Nancy Klimas, Ronnie Horner, Kimberly Sullivan, Efrem S. Lim, Saurabh Chatterjee

Faculty Publications

Gulf War illness (GWI) is characterized by the persistence of inflammatory bowel disease, chronic fatigue, neuroinflammation, headache, cognitive impairment, and other medically unexplained conditions. Results using a murine model show that enteric viral populations especially bacteriophages were altered in GWI. The increased viral richness and alpha diversity correlated positively with gut bacterial dysbiosis and proinflammatory cytokines. Altered virome signature in GWI mice also had a concomitant weakening of intestinal epithelial tight junctions with a significant increase in Claudin-2 protein expression and decrease in ZO1 and Occludin mRNA expression. The altered virome signature in GWI, decreased tight junction protein level was …


Dysbiosis-Associated Enteric Glial Cell Immune-Activation And Redox Imbalance Modulate Tight Junction Protein Expression In Gulf War Illness Pathology, Diana Kimono, Sutapa Sarkar, Muayad Albadrani, Ratanesh K. Seth, Dipro Bose, Ayan Mondal, Yuxi Li, Amar N. Kar, Mitzi Nagarkatti, Prakash Nagarkatti, Kimberly Sullivan, Patricia Janulewicz, Stephen Lasley, Ronnie Horner, Nancy Klimas, Saurabh Chatterjee Oct 2019

Dysbiosis-Associated Enteric Glial Cell Immune-Activation And Redox Imbalance Modulate Tight Junction Protein Expression In Gulf War Illness Pathology, Diana Kimono, Sutapa Sarkar, Muayad Albadrani, Ratanesh K. Seth, Dipro Bose, Ayan Mondal, Yuxi Li, Amar N. Kar, Mitzi Nagarkatti, Prakash Nagarkatti, Kimberly Sullivan, Patricia Janulewicz, Stephen Lasley, Ronnie Horner, Nancy Klimas, Saurabh Chatterjee

Faculty Publications

About 14% of veterans who suffer from Gulf war illness (GWI) complain of some form of gastrointestinal disorder but with no significant markers of clinical pathology. Our previous studies have shown that exposure to GW chemicals resulted in altered microbiome which was associated with damage associated molecular pattern (DAMP) release followed by neuro and gastrointestinal inflammation with loss of gut barrier integrity. Enteric glial cells (EGC) are emerging as important regulators of the gastrointestinal tract and have been observed to change to a reactive phenotype in several functional gastrointestinal disorders such as IBS and IBD. This study is aimed at …


The Gut-Microbiome In Gulf War Veterans: A Preliminary Report, Patricia A. Janulewicz, Ratanesh K. Seth, Jeffrey M. Carlson, Joy Ajama, Emily Quinn, Timothy Heeren, Nancy Klimas, Steven M. Lasley, Ronnie Horner, Kimberly Sullivan, Saurabh Chatterjee Oct 2019

The Gut-Microbiome In Gulf War Veterans: A Preliminary Report, Patricia A. Janulewicz, Ratanesh K. Seth, Jeffrey M. Carlson, Joy Ajama, Emily Quinn, Timothy Heeren, Nancy Klimas, Steven M. Lasley, Ronnie Horner, Kimberly Sullivan, Saurabh Chatterjee

Faculty Publications

Gulf War Illness (GWI) is a chronic multi-symptom disorder affecting the central nervous system (CNS), immune and gastrointestinal (GI) systems of Gulf War veterans (GWV). We assessed the relationships between GWI, GI symptoms, gut microbiome and inflammatory markers in GWV from the Boston Gulf War Illness Consortium (GWIC). Three groups of GWIC veterans were recruited in this pilot study; GWV without GWI and no gastrointestinal symptoms (controls), GWV with GWI and no gastrointestinal symptoms (GWI-GI), GWV with GWI who reported gastrointestinal symptoms (GW+GI). Here we report on a subset of the first thirteen stool samples analyzed. Results showed significantly different …


Study Of The Inflammatory And Fibrotic Pathology In The Gut Following Microcystin Exposure Under Conditions Of Non-Alcoholic Fatty Liver Disease., Sutapa Sarkar Oct 2019

Study Of The Inflammatory And Fibrotic Pathology In The Gut Following Microcystin Exposure Under Conditions Of Non-Alcoholic Fatty Liver Disease., Sutapa Sarkar

Theses and Dissertations

Non-alcoholic fatty liver disease (NAFLD) has become a global pandemic with increased risks of chronic inflammation in obese and elderly population. It has become a major public health concern due to the unavailability of proper therapeutic approaches. NAFLD is a condition of the liver involving wide spectrum of events including accumulation of fat in the liver and inflammation, which can progress to a fibrotic and cirrhotic phenotype, often termed as non-alcoholic steatohepatitis (NASH). In this backdrop, exposure to environmental toxins from harmful algal blooms could prove detrimental to the overweight, obese or elderly population. NAFLD not only affects the liver …


Revisiting The Standard Soil Test: The Potential Of Macro- And Microbiological Measures To Improve Agricultural Health And Productivity, Gabriel Jacob Kenne Oct 2019

Revisiting The Standard Soil Test: The Potential Of Macro- And Microbiological Measures To Improve Agricultural Health And Productivity, Gabriel Jacob Kenne

Theses and Dissertations

The agricultural ecosystem has become the largest non-ice-covered terrestrial ecosystem on the planet and has significant direct and indirect impacts on the global health of both the environment and humanity. Recent shifts in modern agriculture are beginning to focus on the health of soil versus a focus traditionally on crop health and yield at any cost. By managing farmland regeneratively, systems are able to reverse many of the problems created by conventional land management such as erosion and unwanted nutrient runoff, and simultaneously create opportunities to move C from the atmosphere back into the soil. While the ways in which …


Microcystin Exposure And Liver Injury Outcomes In Nafld, Muayad Albadrani Oct 2019

Microcystin Exposure And Liver Injury Outcomes In Nafld, Muayad Albadrani

Theses and Dissertations

Non-alcoholic fatty liver disease (NAFLD) is an emerging worldwide pandemic which is highly prevalent among obese individuals including children and adults. In a NAFLD condition, exposure to environmental contaminants or toxins can act as a second/ multiple hit, which leads to the progression of simple steatosis to NASH and ultimately may result in liver cirrhosis. With climate change today, elevated levels of microcystins are an emerging problem in fresh water bodies, which are a source of drinking water. Individuals are therefore at risk of exposure to microcystin through consuming contaminated water. In the progression of NAFLD from one clinical stage …


Investigating The Relationship Of Copd, Lung Cancer, And Polycyclic Aromatic Hydrocarbons From Ambient Air Pollution, Daniel John Kilpatrick Oct 2019

Investigating The Relationship Of Copd, Lung Cancer, And Polycyclic Aromatic Hydrocarbons From Ambient Air Pollution, Daniel John Kilpatrick

Theses and Dissertations

Polycylic aromatic hydrocarbons (PAHs) are a group of chemically-related compounds with a well-established body of evidence of adverse human health impacts. Additionally, there is a growing area of research on the health outcomes following PAH exposure via air pollution, specifically with chronic obstructive pulmonary disorder (COPD) and lung cancer. The purpose of this dissertation was to investigate the strength of associations among PAHs, COPD, and lung cancer from ambient (outdoor) air pollution. The first objective was to determine if there is a potential environmental link among PAHs, COPD, and lung cancer occurrence among nonsmokers using data from the National Health …


The Effects Of Climate Change On The Ecotoxicology Of Contaminants Of Emerging Concern: Flame Retardants, Contemporary Use Pesticides And Pharmaceuticals Personal Care Products On The Estuarine Grass Shrimp, Palaemontes Pugio, Rajaa Nouri Al-Yassein Jul 2019

The Effects Of Climate Change On The Ecotoxicology Of Contaminants Of Emerging Concern: Flame Retardants, Contemporary Use Pesticides And Pharmaceuticals Personal Care Products On The Estuarine Grass Shrimp, Palaemontes Pugio, Rajaa Nouri Al-Yassein

Theses and Dissertations

Global Climate Change may adversely affect the environment, increasing water temperature and altered salinity which may affect the toxicity of both legacy pollutants and Contaminants of Emerging Concern (CECs). Acute, 96 hour toxicity tests with adult grass shrimp (Palaemonetes pugio) assessed the effects of CECs (Polybrominated Diphenyl Esther (PBDE) – 47, ibuprofen, bifenthrin, triclosan, and bifenthrin/triclosan mixtures) under Standard Conditions (20°C, 20psu) and different Climate Change Conditions (30°C, and/or35psu) In addition, the grass shrimp microbiome (e.g. Vibrio bacteria) were assessed following acute triclosan exposures at the Maximum Exposure Concentration (MECs) and Minimum Inhibitory Concentration (MICs) under standard conditions. …


The Health Implication And Application Of Silver And Iron Oxide Nanoparticles, Sahar Pourhoseini Jul 2019

The Health Implication And Application Of Silver And Iron Oxide Nanoparticles, Sahar Pourhoseini

Theses and Dissertations

Nanoscience and nanotechnology have successfully created different nanomaterials, which are defined as materials with at least one dimension between 1-100 nm. This small size gives nanomaterials unique and novel properties compared with bulk material, such as a high surface area, specific mechanical, optical and magnetic properties. These novel properties have stimulated the interest of using nanoparticles in a wide range of consumer products and applications including biomedical, pharmaceutical and drug delivery. Silver and iron oxide nanoparticles attracted more attention commercially due to their antibacterial and magnetic properties, respectively. So, the overall objective of this dissertation was: 1) to examine the …


Environmental Microcystin Targets The Microbiome And Increases The Risk Of Intestinal Inflammatory Pathology Via Nox2 In Underlying Murine Model Of Nonalcoholic Fatty Liver Disease, Sutapa Sarkar, Diana Kimono, Muayad Albadrani, Ratanesh K. Seth, Philip Busbee, Hasan Alghetaa, Dwayne E. Porter, Geoff I. Scott, Bryan Brooks, Mitzi Nagarkatti, Prakash Nagarkatti, Saurabh Chatterjee Jun 2019

Environmental Microcystin Targets The Microbiome And Increases The Risk Of Intestinal Inflammatory Pathology Via Nox2 In Underlying Murine Model Of Nonalcoholic Fatty Liver Disease, Sutapa Sarkar, Diana Kimono, Muayad Albadrani, Ratanesh K. Seth, Philip Busbee, Hasan Alghetaa, Dwayne E. Porter, Geoff I. Scott, Bryan Brooks, Mitzi Nagarkatti, Prakash Nagarkatti, Saurabh Chatterjee

Faculty Publications

With increased climate change pressures likely to influence harmful algal blooms, exposure to microcystin, a known hepatotoxin and a byproduct of cyanobacterial blooms can be a risk factor for NAFLD associated comorbidities. Using both in vivo and in vitro experiments we show that microcystin exposure in NAFLD mice cause rapid alteration of gut microbiome, rise in bacterial genus known for mediating gut inflammation and lactate production. Changes in the microbiome were strongly associated with inflammatory pathology in the intestine, gut leaching, tight junction protein alterations and increased oxidative tyrosyl radicals. Increased lactate producing bacteria from the altered microbiome was associated …


A Site Characterization And Assessment Of The Bushy Park Reservoir, A Charleston-Area Drinking Water Source, And Its Surrounding Watersheds In Response To Community Concerns, Bradley Joseph Chandler Apr 2019

A Site Characterization And Assessment Of The Bushy Park Reservoir, A Charleston-Area Drinking Water Source, And Its Surrounding Watersheds In Response To Community Concerns, Bradley Joseph Chandler

Theses and Dissertations

Access to clean, safe drinking water is considered a basic human right (WHO 2004). It is vital to maintain adequate monitoring of source waters as well as to investigate claims of degraded source waters. In June of 2017, inaccurate reporting led many community members in Mt. Pleasant, SC to believe that their drinking water might be tainted, leading to elevated cases of brain cancer in children. Though steps were taken to test and ensure the drinking water was safe, fear over the health of the city’s drinking water still persists. This is largely due to the involvement of famed water …


Nutrient Limitation Of Phytoplankton In Lake Wateree, South Carolina: Implications For Future Water Quality Management, Kara M. Clyburn Apr 2019

Nutrient Limitation Of Phytoplankton In Lake Wateree, South Carolina: Implications For Future Water Quality Management, Kara M. Clyburn

Theses and Dissertations

Cultural eutrophication is a primary contributor to phytoplankton production in freshwater lakes from excess anthropogenic nutrient inputs, and resulting impacts on water quality, aquatic ecosystems, human and animal health are increasing worldwide. Understanding the factors that limit phytoplankton growth is an important strategy for identifying and managing nutrient sources and successfully controlling the over- enrichment of nitrogen (N) and/or phosphorus (P) in freshwater lakes. The Redfield molecular ratio of carbon (C), N and P maintains that the C:N:P molar ratio is 106:16:1 when nutrients are not limiting, and the ecosystem is balanced. A N:P molar ratio > 20:1 tends to be …


Relative Importance Of Ions And Particles In Silver Nanoparticle Uptake And Accumulation In Keystone Estuarine Organisms; Prorocentrum Minimum And Crassostrea Virginica, Shelby Victoria Butz Apr 2019

Relative Importance Of Ions And Particles In Silver Nanoparticle Uptake And Accumulation In Keystone Estuarine Organisms; Prorocentrum Minimum And Crassostrea Virginica, Shelby Victoria Butz

Theses and Dissertations

In marine systems, silver is regarded as being one of the most toxic and readily accumulated metals, and is known to be taken up and accumulate within marine invertebrates, fish, phytoplankton and seaweeds. Reported open ocean concentrations of silver range from 0.1 – 2 ng L-1 while silver concentrations in coastal waters are typically 5 to 10 times higher than open ocean values (0.1 - 50 ng L-1). The determination of silver in marine and coastal waters presents several challenges including low concentrations and matrix complexity of seawater, which creates interferences and other challenges for many instrumental techniques creating a …


Resveratrol Attenuates Allergic Asthma And Associated Inflammation In The Lungs Through Regulation Of Mirna-34a That Targets Foxp3 In Mice, Esraah Alharris, Hasan Alghetaa, Ratanesh K. Seth, Saurabh Chatterjee, Narendra P. Singh, Mitzi Nagarkatti, Prakash Nagarkatti Dec 2018

Resveratrol Attenuates Allergic Asthma And Associated Inflammation In The Lungs Through Regulation Of Mirna-34a That Targets Foxp3 In Mice, Esraah Alharris, Hasan Alghetaa, Ratanesh K. Seth, Saurabh Chatterjee, Narendra P. Singh, Mitzi Nagarkatti, Prakash Nagarkatti

Faculty Publications

Asthma is a chronic inflammatory disease of airways mediated by T-helper 2 (Th2) cells involving complex signaling pathways. Although resveratrol has previously been shown to attenuate allergic asthma, the role of miRNA in this process has not been studied. We investigated the effect of resveratrol on ovalbumin-induced experimental allergic asthma in mice. To that end, BALB/c mice were immunized with ovalbumin (OVA) intraperitoneally followed by oral gavage of vehicle (OVA-veh) or resveratrol (100 mg/kg body) (OVA-res). On day 7, the experimental groups received intranasal challenge of OVA followed by 7 days of additional oral gavage of vehicle or resveratrol. At …


Macromolecular-Clustered Facial Amphiphilic Antimicrobials, Md Anisur Rahman, Marpe Bam, Edgar Luat, Moumita Sharmin Jui, Mitra S. Ganewatta, Tinom Shokfai, Mitzi Nagarkatti, Alan W. Decho Dec 2018

Macromolecular-Clustered Facial Amphiphilic Antimicrobials, Md Anisur Rahman, Marpe Bam, Edgar Luat, Moumita Sharmin Jui, Mitra S. Ganewatta, Tinom Shokfai, Mitzi Nagarkatti, Alan W. Decho

Faculty Publications

Bacterial infections and antibiotic resistance, particularly by Gram-negative pathogens, have become a global healthcare crisis. We report the design of a class of cationic antimicrobial polymers that cluster local facial amphiphilicity from repeating units to enhance interactions with bacterial membranes without requiring a globally conformational arrangement associated with highly unfavorable entropic loss. This concept of macromolecular architectures is demonstrated with a series of multicyclic natural product-based cationic polymers. We have shown that cholic acid derivatives with three charged head groups are more potent and selective than lithocholic and deoxycholic counterparts, particularly against Gram-negative bacteria. This is ascribed to the formation …


Influenza Virus Infectivity Is Retained In Aerosols And Droplets Independent Of Relative Humidity, Karen A. Kormuth, Kaisen Lin, Aaron J. Prussin, Eric P. Vejerano, Andrea J. Tiwari, Steve S. Cox, Micheal M. Myerburg, Seema S. Lakdawala, Linsey C. Marr Sep 2018

Influenza Virus Infectivity Is Retained In Aerosols And Droplets Independent Of Relative Humidity, Karen A. Kormuth, Kaisen Lin, Aaron J. Prussin, Eric P. Vejerano, Andrea J. Tiwari, Steve S. Cox, Micheal M. Myerburg, Seema S. Lakdawala, Linsey C. Marr

Faculty Publications

Pandemic and seasonal influenza viruses can be transmitted through aerosols and droplets, in which viruses must remain stable and infectious across a wide range of environmental conditions. Using humidity-controlled chambers, we studied the impact of relative humidity on the stability of 2009 pandemic influenza A(H1N1) virus in suspended aerosols and stationary droplets. Contrary to the prevailing paradigm that humidity modulates the stability of respiratory viruses in aerosols, we found that viruses supplemented with material from the apical surface of differentiated primary human airway epithelial cells remained equally infectious for 1 hour at all relative humidities tested. This sustained infectivity was …


Aerosol Microdroplets Exhibit A Stable Ph Gradient, Haoran Wei, Eric P. Vejerano, Weinan Leng, Qishen Haung, Marjorie R. Willner, Linsey C. Marr, Peter J. Vikesland Jul 2018

Aerosol Microdroplets Exhibit A Stable Ph Gradient, Haoran Wei, Eric P. Vejerano, Weinan Leng, Qishen Haung, Marjorie R. Willner, Linsey C. Marr, Peter J. Vikesland

Faculty Publications

Suspended aqueous aerosol droplets (<50 μm) are microreactors for many important atmospheric reactions. In droplets and other aquatic environments, pH is arguably the key parameter dictating chemical and biological processes. The nature of the droplet air/ water interface has the potential to significantly alter droplet pH relative to bulk water. Historically, it has been challenging to measure the pH of individual droplets because of their inaccessibility to conventional pH probes. In this study, we scanned droplets containing 4-mercaptobenzoic acid–functionalized gold nanoparticle pH nanoprobes by 2D and 3D laser confocal Raman microscopy. Using surface-enhanced Raman scattering, we acquired the pH distribution inside approximately 20-μm-diameter phosphate-buffered aerosol droplets and found that the pH in the core of a droplet is higher than that of bulk solution by up to 3.6 pH units. This finding suggests the accumulation of protons at the air/water interface and is consistent with recent thermodynamic model results. The existence of this pH shift was corroborated by the observation that a catalytic reaction that occurs only under basic conditions (i.e., dimerization of 4-aminothiophenol to produce dimercaptoazobenzene) occurs within the high pH core of a droplet, but not in bulk solution. Our nanoparticle probe enables pH quantification through the cross-section of an aerosol droplet, revealing a spatial gradient that has implications for acid-base–catalyzed atmospheric chemistry.


High Circulatory Leptin Mediated Nox-2-Peroxynitrite-Mir21 Axis Activate Mesangial Cells And Promotes Renal Inflammatory Pathology In Nonalcoholic Fatty Liver Disease, Firas Alhasson, Ratanesh K. Seth, Sutapa Sarkar, Diana A. Kimono, Muayad S. Albadrani, Diptadip Dattaroy, Varun Chandrashekaran, Geoffry Scott, Samir Raychoudhury, Mitzi Nagarkatti, Prakash Nagarkatti, Anna Mae Diehl, Saurabh Chatterjee Jul 2018

High Circulatory Leptin Mediated Nox-2-Peroxynitrite-Mir21 Axis Activate Mesangial Cells And Promotes Renal Inflammatory Pathology In Nonalcoholic Fatty Liver Disease, Firas Alhasson, Ratanesh K. Seth, Sutapa Sarkar, Diana A. Kimono, Muayad S. Albadrani, Diptadip Dattaroy, Varun Chandrashekaran, Geoffry Scott, Samir Raychoudhury, Mitzi Nagarkatti, Prakash Nagarkatti, Anna Mae Diehl, Saurabh Chatterjee

Faculty Publications

High circulatory insulin and leptin followed by underlying inflammation are often ascribed to the ectopic manifestations in non-alcoholic fatty liver disease (NAFLD) but the exact molecular pathways remain unclear. We have shown previously that CYP2E1-mediated oxidative stress and circulating leptin in NAFLD is associated with renal disease severity. Extending the studies, we hypothesized that high circulatory leptin in NAFLD causes renal mesangial cell activation and tubular inflammation via a NOX2 dependent pathway that upregulates proinflammatory miR21. High-fat diet (60% kcal) was used to induce fatty liver phenotype with parallel insulin and leptin resistance. The kidneys were probed for mesangial cell …


Physico-Chemical Characteristics Of Evaporating Respiratory Fluid Droplets, Eric P. Vejerano, Linsey C. Marr Feb 2018

Physico-Chemical Characteristics Of Evaporating Respiratory Fluid Droplets, Eric P. Vejerano, Linsey C. Marr

Faculty Publications

The detailed physico-chemical characteristics of respiratory droplets in ambient air, where they are subject to evaporation, are poorly understood. Changes in the concentration and phase of major components in a droplet—salt (NaCl), protein (mucin) and surfactant (dipalmitoylphosphatidylcholine)—may affect the viability of any pathogens contained within it and thus may affect the efficiency of transmission of infectious disease by droplets and aerosols. The objective of this study is to investigate the effect of relative humidity (RH) on the physico-chemical characteristics of evaporating droplets of model respiratory fluids. We labelled these components in model respiratory fluids and observed evaporating droplets suspended on …


Linking Microbial Phylogenetic And Functional Gene Diversity To Microbial Mat Ecosystem Function Following Environmental Disturbance, Eva Christine Preisner Jan 2018

Linking Microbial Phylogenetic And Functional Gene Diversity To Microbial Mat Ecosystem Function Following Environmental Disturbance, Eva Christine Preisner

Theses and Dissertations

The ability of ecosystems to adapt to environmental perturbations depends on the duration and intensity of change and the overall biological diversity of the system. In this study, a microbial mat ecosystem located on San Salvador Island, the Bahamas was used as a model to examine how environmental disturbance affects microbial community resistance, their protein synthesis potential (PSP), ecosystem function as measured by biogeochemical cycling, community stability, and resilience. This ecosystem experienced a large shift in salinity (230 to 65 g kg-1) during 2011–2012 following the landfall of Hurricane Irene on San Salvador Island. High throughput sequencing and analysis of …


Effect Of Environmental Factors On The Aggregation Behavior Of Silver Nanoparticles In The Aquatic Environment, Kamelia Afshinnia Jan 2018

Effect Of Environmental Factors On The Aggregation Behavior Of Silver Nanoparticles In The Aquatic Environment, Kamelia Afshinnia

Theses and Dissertations

Understanding the environmental factors that affect the fate and effects of engineered nanoparticles (ENPs) in the environment is crucial for NP risk assessment. Silver nanoparticles (Ag NPs) readily transform in the environment, which alters their properties and subsequently their transport, fate, and toxicity. The overall aim of this dissertation was to evaluate the effects of Ag NPs physicochemical properties (e.g., size, surface charge, surface coating) and water chemistry (e.g., buffer concentration, organic ligands, natural organic matter) in controlling Ag NPs colloidal stability. This aim was achieved by systematically 1) review and rationalize many studies that investigated the aggregation kinetics of …


Application Of Polymer-Coated Magnetic Nanoparticles For Oil Separation, Seyyedali Mirshahghassemi Jan 2018

Application Of Polymer-Coated Magnetic Nanoparticles For Oil Separation, Seyyedali Mirshahghassemi

Theses and Dissertations

Oil spills and storm water runoffs can have serious impact on the environment with potentially major economic impacts. Given the limitation of current oil clean-up technique, the application of nanotechnology for oil remediation has been widely studied showing a promising avenue of research. This dissertation reports a cheap, facile and cost-effective nanotechnology-based oil clean-up technique that has been optimized for effectiveness and feasibility and reduced adverse environmental impacts. The synthesized polyvinylpyrrolidone (PVP)-coated magnetic nanoparticles (NPs) have been characterized using different techniques and the oil removal efficiency investigated under a wide range of environmentally relevant conditions. Based on the characterization data, …


Inhibition Of Aflatoxin Biosynthesis With Vibrio Gazogenes, Phani Madhuri Gummadidala Jan 2018

Inhibition Of Aflatoxin Biosynthesis With Vibrio Gazogenes, Phani Madhuri Gummadidala

Theses and Dissertations

Aflatoxin, a mycotoxin, is one of the world’s most potent carcinogen. It contaminates major food products such as milk, grains, nuts, corn, etc., leading to greater than $ 1 billion in economic losses and when ingested causes hepatocellular carcinoma (HCC). It is the primary risk factor for 75% HCC cases in the developing world and 3% HCC cases in developed world. Most common methods used in agriculture to reduce aflatoxin contamination are expensive, time consuming and have low efficiency with limited success rates where as biological controls were proven to be most effective in inhibiting aflatoxins and aflatoxin producing fungi. …


Understanding The Impact Of Land Use On Microbial Water Quality To Support Decisions For A Future Land Use Plan, Mohammed Tawfiq Aljassim Jan 2018

Understanding The Impact Of Land Use On Microbial Water Quality To Support Decisions For A Future Land Use Plan, Mohammed Tawfiq Aljassim

Theses and Dissertations

May River meandering through the Town of Bluffton, South Carolina has been known for its high level of water quality. The May River is one of the major sources of shellfish harvesting in South Carolina. Due to the non-point source pollution of fecal coliform, the water quality of the May River became degraded. As a result, shellfish harvesting classification in the May River was downgraded for the first time in its history. The rapid growth of the Town has led to a change in land use, which might be related to the increased levels of fecal coliform in the stream …


Environmental Impacts On Enterococcus In Shem Creek, South Carolina, And Characterization Of Changing Land Use, Maria Elizabeth Zubizarreta Jan 2018

Environmental Impacts On Enterococcus In Shem Creek, South Carolina, And Characterization Of Changing Land Use, Maria Elizabeth Zubizarreta

Theses and Dissertations

Zoning and land-use practices have a direct influence on hydrologic systems and can impact water resources. Linkages between change in land uses and degradation of water quality in stream and watershed environments have been well established. Shem Creek, located in Mount Pleasant, SC, has a history of fecal indicator bacteria levels that exceed the Environmental Protection Agency’s recreational water quality standards. With recent coastal population and development trends, proper management and the sustainability of beach and estuary environments are a rising public health concern. The objective of this study is to determine what climatic and water quality parameters are associated …


Investigating The Toxicity And Accumulation Of 2,4-Dichlorophenoxyacetic Acid (2,4-D) And Glyphosate In Eisenia Fetida, Caitlin Lazurick, Nicole Lidzbarski, Rachel Owings, Jeff Brotherton, Edna Steele Nov 2017

Investigating The Toxicity And Accumulation Of 2,4-Dichlorophenoxyacetic Acid (2,4-D) And Glyphosate In Eisenia Fetida, Caitlin Lazurick, Nicole Lidzbarski, Rachel Owings, Jeff Brotherton, Edna Steele

Journal of the South Carolina Academy of Science

Glyphosate, the main ingredient in Roundup®, is the most widely used herbicide in the world. It is also used in combination with another effective herbicide, 2,4-D, in the formulation called Enlist Duo®. The EPA approved the use of Enlist Duo® on certain crops including those genetically modified to be resistant to both herbicides. The predicted significant increase in the use of these herbicides raised concerns from the general public because both compounds have been classified as possibly or probably carcinogenic. Since herbicides are applied directly to vegetation, the safety of organisms that come in contact …


Exopolysaccharides Regulate Calcium Flow In Cariogenic Biofilms, Monika Astasov-Frauenhoffer, Muth M. Varenganayil, Alan W. Decho, Tuomas Waltimo, Olivier Braissant Oct 2017

Exopolysaccharides Regulate Calcium Flow In Cariogenic Biofilms, Monika Astasov-Frauenhoffer, Muth M. Varenganayil, Alan W. Decho, Tuomas Waltimo, Olivier Braissant

Faculty Publications

Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS) provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya’s agar. Calcium tolerance was assessed …


Hmgb1-Rage Pathway Drives Peroxynitrite Signaling-Induced Ibd-Like Inflammation In Murine Nonalcoholic Fatty Liver Disease, Varun Chandrashekaran, Ratanesh K. Seth, Diptadip Dattaroy, Firas Alhasson, Jacek Ziolenka, James Carson, Franklin G. Berger, Balaraman Kalyanaraman, Anna Mae Diehl, Saurabh Chatterjee Oct 2017

Hmgb1-Rage Pathway Drives Peroxynitrite Signaling-Induced Ibd-Like Inflammation In Murine Nonalcoholic Fatty Liver Disease, Varun Chandrashekaran, Ratanesh K. Seth, Diptadip Dattaroy, Firas Alhasson, Jacek Ziolenka, James Carson, Franklin G. Berger, Balaraman Kalyanaraman, Anna Mae Diehl, Saurabh Chatterjee

Faculty Publications

Recent clinical studies found a strong association of colonic inflammation and Inflammatory bowel disease (IBD)-like phenotype with NonAlcoholic Fatty liver Disease (NAFLD) yet the mechanisms remain unknown. The present study identifies high mobility group box 1 (HMGB1) as a key mediator of intestinal inflammation in NAFLD and outlines a detailed redox signaling mechanism for such a pathway. NAFLD mice showed liver damage and release of elevated HMGB1 in systemic circulation and increased intestinal tyrosine nitration that was dependent on NADPH oxidase. Intestines from NAFLD mice showed higher Toll like receptor 4 (TLR4) activation and proinflammatory cytokine release, an outcome strongly …