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Full-Text Articles in Physical Sciences and Mathematics
Harmful Algal Blooms In Caesar Creek Lake And Their Relationship To Riparian Cover, Morgan C. Grunden
Harmful Algal Blooms In Caesar Creek Lake And Their Relationship To Riparian Cover, Morgan C. Grunden
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Caesar Creek Lake (CCL) in Warren County, OH has recently been experiencing harmful algal blooms (HABs) which are most likely attributed to an excess of phosphorus (P) from fertilizers and manures applied to surrounding fields. Sediments act as a sink for P later supplying a source of P in lakes for HABs when waters become thermally stratified and anoxic. This study seeks to determine the relationship between HABs in CCL and riparian cover at the main tributaries, Anderson Fork and Caesar Creek. In order to do this, sediment samples were collected from four sample sites along Anderson Fork and three …
Mercury Methylation In Oxic Sub-Polar Marine Regions Linked With Nitrification, Marissa Collins Despins
Mercury Methylation In Oxic Sub-Polar Marine Regions Linked With Nitrification, Marissa Collins Despins
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Methylmercury (MeHg) is a neurotoxin that bioaccumulates to potentially harmful concentrations in Arctic marine wildlife and in those that consume them. Monitoring and modeling MeHg bioaccumulation and biogeochemical cycling in the ocean requires understanding of the mechanisms behind net mercury (Hg) methylation. The key functional gene for Hg methylation, hgcAB, is widely distributed throughout ocean basins and spans multiple microbial phyla. While multiple microbially-mediated anaerobic pathways for Hg methylation are known, in the ocean, the majority of hgcA homologs have been found in oxic subsurface waters, in contrast to other ecosystems. In particular, microaerophilic Nitrospina, a genera of nitrite-oxidizing bacteria …
Has Winter Weather In Southwest Ohio Been Affected By The El Niño Southern Oscillation, The North Atlantic Oscillation, The Pacific Decadal Oscillation, And The Atlantic Multidecadal Oscillation?, John A. Blue
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Winter temperature and precipitation in Southwest Ohio over the last century were examined for anomalies attributable to teleconnections with large-scale atmospheric perturbations caused by the El Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), and the Atlantic Multidecadal Oscillation (AMO). The record of temperature gives evidence of a teleconnection with the NAO, ENSO, and PDO, with the strongest link being for phases of the NAO. Most winters during positive NAO phases had mean monthly temperature warmer than the century long mean, and the majority of negative NAO phase winters had colder temperatures. The difference …
Detection Of Benzotriazole And Related Analogues In Surface Samples Collected Near An Ohio Airpark, Clara Leedy
Detection Of Benzotriazole And Related Analogues In Surface Samples Collected Near An Ohio Airpark, Clara Leedy
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Benzotriazoles are a class of contaminant of emerging concern which are commonly used as anticorrosive agents in aircraft deicer and anti-icing fluids (ADAFs). The analogues 1H-benzotriazole (BTZ), 4-methyl-1H-benzotrizole (4m-BTZ), and 5-methyl-1H-benzotriazole (5m-BTZ) are commonly found in environmental occurrence together. The two methylated isomers, collectively known as tolytriazole (TTZ), have different toxicity and stability. These contaminants are highly water soluble and resistant to biodegradation, making them persistent through water treatment. Benzotriazoles have been detected worldwide; this investigation focuses on monitoring three sites near a small airpark in Wilmington, Ohio. Two sites that receive runoff from the airpark, Lytle Creek and Indian …
Evaluating Energy-Based Trait Shifts And Population Level Impacts Of Big Brown Bats (Eptesicus Fuscus) With Long-Term Exposure To Pseudogymnoascus Destructans, Molly C. Simonis
Evaluating Energy-Based Trait Shifts And Population Level Impacts Of Big Brown Bats (Eptesicus Fuscus) With Long-Term Exposure To Pseudogymnoascus Destructans, Molly C. Simonis
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Disturbances in environment can lead to a wide range of host physiological responses. These responses can either allow hosts to adjust to new conditions in their environment or can reduce their survival, and can subsequently cause host traits to shift. Small mammals are particularly vulnerable to stochastic disturbances, like a pathogen introduction, because of their high energy demands. Studies examining host responses to pathogens often focus on species highly susceptible to infection that typically have high mortality rates, leading to a gap in understanding the responses of less susceptible species. My dissertation evaluates the energy balance of Eptesicus fuscus (big …
Mercury Concentrations And Mercury Methylation Along The Freshwater To Marine Continuum, Lindsay D. Starr
Mercury Concentrations And Mercury Methylation Along The Freshwater To Marine Continuum, Lindsay D. Starr
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Mercury (Hg) is a neurotoxin that can have detrimental impacts on the human nervous system and on brain development in infants. Methylmercury (MeHg) is the most toxic form of Hg and can concentrate to potentially harmful levels in higher levels of marine food webs. Production of MeHg in oxic water columns is poorly understood due to lack of knowledge of the mechanisms of formation and distribution. Recent work has reported widespread, putative Hg methylation genes in nitrite oxidizers, but any relationship with nitrifiers is unknown. This work focuses on Hg water column distribution, speciation, and methylation. The aims of this …