Toxicology Commons^™

Assessment Of Tce And Chiral Pcb Dechlorination Rate, Congener Diversity, And Enantioselectivity In Town Creek, Sc, Usa Sediment Microcosms, Catherine P. Sumner

All Dissertations

Polychlorinated biphenyls (PCBs) and trichloroethene (TCE) are ubiquitous contaminants and are recognized as persistent organic pollutants due to their extreme chemical stability. PCBs were manufactured by chlorinating biphenyls that created 209 congeners with various structures, of which 19 are chiral and can exist as a pair of stable atropisomers. PCBs have been known to cause developmental and neurological toxicity in humans and wildlife; they can act as endocrine disrupters, carcinogens, and teratogens. Sangamo Weston Inc. was an industrial plant located near Town Creek in Pickens Country, South Carolina, that manufactured capacitors and used Aroclors 1016 and 1254 as dialectic fluids …

Degradation Of Chlorpyrifos Residue On Tropical Inceptisol Soil With Indigenous Bacteria Treatment, Asep Kurnia, Hidayatuz Zu`Amah, Baiq Nunung Sulastri, Ria Fauriah Makmur

Makara Journal of Science

The use of soil microbes is one of the most effective methods for degrading pesticide residue in soil. Microbes can accelerate the degradation of persistent pollutants including chlorpyrifos in soil. This research aims to find soil bacteria with the greatest potential to degrade chlorpyrifos residue in tropical inceptisol soil and determine its degradation index (DI). The soil used in this experiment was collected from agricultural fields in the districts of Demak, Central Java Province, Indonesia. The experiment was performed using factorial randomize complete block design composed of two factors and four replications. The first factors were made up of two …

Impact Of Cadmium Stress On Soil Virus Reproduction And The Persistence Of Viruses Under Abiotic Conditions, Zhibo Cheng

Doctoral Dissertations

Soil viruses are ubiquitous and greatly impact the structure and function of soil microbial communities, with their effects modulated by various environmental factors. This study investigates the inactivation of naturally occurring soil viruses in sterilized soil, as well as the effects of cadmium (Cd) exposure and carbon (C) and nitrogen (N) nutrient availability on the population dynamics of virus-host communities in agricultural soil.

Lab-scale slurry and unsaturated experiments were performed to examine virus inactivation in the absence of host bacteria in sterilized soil. In slurry experiments, virus abundance declined by over 90% after 10 days of incubation. The addition of …

The Presence Of Microcystin In The Northwest Indiana Watershed, Breeann Mild

The Journal of Purdue Undergraduate Research

No abstract provided.

The Effects Of Radical Containing Combustion Derived Particulate Matter In Adult Mouse Respiratory System, Jeffrey Harding

LSU Doctoral Dissertations

Epidemiological data associates high levels of combustion-derived particulate matter (PM) with deleterious respiratory outcomes, but the mechanism underlying those outcomes remains elusive. It has been acknowledged by the World Health Organization that PM exposure contributes to more than 4.2 million all-cause mortalities worldwide each year. Current literature demonstrates that PM exacerbates respiratory diseases, impairs lung function, results in chronic respiratory illnesses, and is associated with increased mortality. The proposed mechanisms revolve around oxidative stress and inflammation promoting pulmonary physiological remodeling. Our data demonstrate that environmentally persistent free radicals (EPFRs) stabilized on the surface of PM are capable of inducing oxidative …

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …

Toxicity Of Engineered Nanomaterials To Plant Growth Promoting Rhizobacteria, Ricky W. Lewis

Theses and Dissertations--Plant and Soil Sciences

Engineered nanomaterials (ENMs) have become ubiquitous in consumer products and industrial applications, and consequently the environment. Much of the environmentally released ENMs are expected to enter terrestrial ecosystems via land application of nano-enriched biosolids to agricultural fields. Among the organisms most likely to encounter nano-enriched biosolids are the key soil bacteria known as plant growth promoting rhizobacteria (PGPR). I reviewed what is known concerning the toxicological effects of ENMs to PGPR and observed the need for high-throughput methods to evaluate lethal and sublethal toxic responses of aerobic microbes. I addressed this issue by developing high-throughput microplate assays which allowed me …

Label-Free Surface-Enhanced Raman Spectroscopy-Linked Immunosensor Assay (Slisa) For Environmental Surveillance, Vinay Bhardwaj

FIU Electronic Theses and Dissertations

The contamination of the environment, accidental or intentional, in particular with chemical toxins such as industrial chemicals and chemical warfare agents has increased public fear. There is a critical requirement for the continuous detection of toxins present at very low levels in the environment. Indeed, some ultra-sensitive analytical techniques already exist, for example chromatography and mass spectroscopy, which are approved by the US Environmental Protection Agency for the detection of toxins. However, these techniques are limited to the detection of known toxins. Cellular expression of genomic and proteomic biomarkers in response to toxins allows monitoring of known as well as …

Clinical And Mechanistic Insights Into Novel Probiotic Functions And Formulations, Jordan Bisanz

Electronic Thesis and Dissertation Repository

Using a combination of hypothesis and discovery based approaches, the goal of this thesis was to better describe novel probiotic functions and their mechanisms while striving to better understand the effect of formulation on Bifidobacterium animalis subsp. lactis, Lactobacillus paracasei and L. rhamnosus.

Using RNA-Seq, a bacterial metatranscriptome analysis of a commonly consumed probiotic yogurt showed that the organisms adapted to storage time and flavor additions. This led to the discovery that in addition to the probiotic health benefits, members of the L. casei group (L. rhamnosus and L. paracasei) produce volatile sulfur compounds mediated by a novel …

Response Of Soil Nitrification To The Veterinary Pharmaceuticals Monensin, Ivermectin And Zinc Bacitracin, Magda A. Konopka

Electronic Thesis and Dissertation Repository

Pharmaceutical residues can reach agricultural land through amendment with animal or human waste. Since 2010, a series of replicated plots received annual applications of ivermectin, monensin and zinc bacitracin, either singly or in a mixture, at 0.1 mg/kg and 10 mg/kg concentrations. I collected soil samples before and after the fourth annual application of pharmaceuticals and assayed them for functional changes and amoA gene abundance, a gene needed for ammonia oxidation. In 2013, I exposed the soils to 100 mg/kg in a laboratory experiment which resulted in acceleration of nitrification. Under 10 mg/kg treatments in the field the abundance of …

The Role Of Surface Chemistry In The Toxicity Of Manufactured Cerium Dioxide Nanomaterials To Caenorhabditis Elegans, Emily Kay Oostveen

Theses and Dissertations--Plant and Soil Sciences

Manufactured CeO₂ nanomaterials (CeO₂-MNMs) are used for a wide variety of applications including diesel fuel additives and chemical/mechanical planarization media. To test the effects of CeO₂-MNM surface coating charge on to model organism Caenorhabditis elegans, we synthesized 4 nm CeO₂ with cationic (DEAE-), anionic (CM-), and neutral (DEX) coatings. In L3 nematodes exposed for 24 hours, DEAE-CeO₂ induced lethality at lower concentrations than CM- or DEX-CeO₂. Feeding slightly decreased CeO₂ toxicity, regardless of coating. In L2 nematodes exposed for 48 hours with feeding, DEAE-CeO₂ caused lethality at the …

Integronlike Structures In Campylobacter Spp. Of Human And Animal Origin, Brigid Lucey, D. Crowley, P. Moloney, B. Cryan, M. Daly, F. O'Halloran, E. J. Threlfall, S. Fanning

Department of Biological Sciences Publications

Resistance to antimicrobial agents used to treat severe Campylobacter spp. gastroenteritis is increasing worldwide. We assessed the antimicrobial resistance patterns of Campylobacter spp. isolates of human and animal origin. More than half (n = 32) were resistant to sulphonamide, a feature known to be associated with the presence of integrons. Analysis of these integrons will further our understanding of Campylobacter spp. epidemiology.

Pesticide Effects In A Simulated Soil Ecosystem, Raymond J. Samp

Masters Theses

The screening of pesticides to determine which were most inhibitory to bacteria was accomplished by testing the effects of 10 pesticides on 9 different organisms using the disk assay method. Results showed that Gram positive bacteria were more sensitive to all pesticides tested than were the Gram negative bacteria. In addition, the hormone herbicides were found to be the most inhibitory to these bacteria and 2,4-D (2,4-dichlorophenoxyacetic acid), a hormone herbicide, was chosen for subsequent in vivo studies.

A soil perfusion apparatus was used to determine the effects of 2,4-D in a typical soil ecosystem. Bacterial plate counts and nutrient …