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Full-Text Articles in Toxicology

Growth And Survival Of Amphibians Exposed To Road Salt And Glyphosate-Based Herbicide, Jerica Eaton Jan 2023

Growth And Survival Of Amphibians Exposed To Road Salt And Glyphosate-Based Herbicide, Jerica Eaton

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations are threatened by increasing levels of environmental pollution resulting from human activities. Areas with mixed land use that include agriculture and urban development experience increased contamination from surface herbicide and road deicer application. Upon entering water sources, these chemicals have the capacity to disrupt the natural dynamics of aquatic ecosystems. This study aimed to evaluate the effects of these contaminants on amphibian populations. I used the spotted salamander (Ambystoma maculatum) as a model, rearing larvae from hatching to metamorphosis. I subjected larvae in each of the treatment groups to varying levels of herbicide and salt concentrations. …


Neonicotinoids Can Cause Arrested Pupal Ecdysis In Lepidoptera, Niranjana Krishnan, Russell A. Jurenka, Steven P. Bradbury Aug 2021

Neonicotinoids Can Cause Arrested Pupal Ecdysis In Lepidoptera, Niranjana Krishnan, Russell A. Jurenka, Steven P. Bradbury

Biological Sciences Faculty Research & Creative Works

Recently, we reported a novel mode of action in monarch butterfly (Danaus plexippus) larvae exposed to neonicotinoid insecticides: arrest in pupal ecdysis following successful larval ecdysis. In this paper, we explore arrested pupal ecdysis in greater detail and propose adverse outcome pathways to explain how neonicotinoids cause this effect. Using imidacloprid as a model compound, we determined that final-instar monarchs, corn earworms (Helicoverpa zea), and wax moths (Galleria mellonella) showed high susceptibility to arrested pupal ecdysis while painted ladies (Vanessa cardui) and red admirals (Vanessa atalanta) showed low susceptibility. Fall …


The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek Apr 2020

The Impact Of Nicotine Accumulation Exposure On Lithobates Catebeianus Larvae Mortality, Luke Micek

UCARE Research Products

Cigarette butts are the most littered item in the world and contain over 4,000 chemicals, including the organic compound nicotine (Slaughter et al. 2011). Billions of cigarette butts are littered each year which may wash into bodies of water, impacting the local wildlife. To determine how introduced chemicals impact the environment, it is important to study its effects on indicator species. Amphibians, such as Lithobates catebeianus, act as indicator species due to their extreme sensitivity to chemical changes in its environment. The purpose of this research project was to obtain data to help determine the impact nicotine accumulation has …


The Value Of Chemical Defense: The Effects Of Toxin Milking On The Physical, Physiological, And Behavioral Performance Of Cane Toads (Rhinella Marina), Ryann Blennerhassett Oct 2018

The Value Of Chemical Defense: The Effects Of Toxin Milking On The Physical, Physiological, And Behavioral Performance Of Cane Toads (Rhinella Marina), Ryann Blennerhassett

Independent Study Project (ISP) Collection

Amphibians have cutaneous glands on their skin which produce a number of toxic compounds that serve as protection against predators and microorganisms. Cane toads (Rhinella marina) have large parotoid glands located on their shoulders to store toxins, many of which are derived from lipids and are thus energetically expensive to produce. I used a combination of field and laboratory studies to investigate behavioral and physiological consequences of toxin loss and replenishment in cane toads. In a cross-sectional study, free-ranging toads were euthanized and dissected to identify correlations between toxin content and morphology /physiology. Experimental manipulations (manually expressing toxin from glands) …


Importance Of Growth Rate On Hg And Pcb Bioaccumulation In Fish, Jiajia Li, G. Douglas Haffner, Gordon Paterson, David M. Walters, Michael D. Burtnyk, Ken G. Drouillard Jan 2018

Importance Of Growth Rate On Hg And Pcb Bioaccumulation In Fish, Jiajia Li, G. Douglas Haffner, Gordon Paterson, David M. Walters, Michael D. Burtnyk, Ken G. Drouillard

Great Lakes Institute for Environmental Research Publications

To evaluate the effect of fish growth on mercury (Hg) and polychlorinated biphenyls (PCBs) bioaccumulation, a non-steady state toxicokinetic model, combined with a Wisconsin bioenergetics model, was developed to simulate Hg and PCB bioaccumulation in Bluegill (Lepomis macrochirus). The model was validated by comparing observed versus predicted Hg and PCB 180 concentrations across 5 age classes from five different waterbodies across North America. The non-steady state model generated accurate predictions for Hg and PCB bioaccumulation in three of five waterbodies: Apsey, Sharbot and Stonelick Lake. The poor performance of the model for the Detroit River and Lake Hartwell, …


The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub Jun 2017

The Effect Of Target-Specific Biomolecules In Breast Cancer, Mohannad Garoub

FIU Electronic Theses and Dissertations

Cancer is the second leading cause of mortality in the United States and the World, therefore, early effective prevention, diagnosis, and therapy is needed. Estrogens play a major role in the initiation and progression of breast cancer. Elevated lifetime exposure to estrogens is associated with an increased risk of developing breast cancer. Estrogens through influencing mitochondria contribute to estrogen induced breast carcinogenesis; however, the exact mitochondrial mechanisms underlying the estrogen carcinogenic effect in breast tissue are not clearly understood. For this dissertation, the mitotoxic and cytotoxic effects of triphenylphosphonium cation (TPP) and Origanum majorana organic extract (OME) as well as …


Growth And Survival Of Salamanders Exposed To Different Formulations Of Glyphosate-Based Herbicide, Jessica Johnson Jun 2017

Growth And Survival Of Salamanders Exposed To Different Formulations Of Glyphosate-Based Herbicide, Jessica Johnson

Mahurin Honors College Capstone Experience/Thesis Projects

Amphibian populations have been experiencing rapid declines worldwide in the past few decades. There are many proposed causations, including the use of agricultural chemicals such as herbicides. Glyphosate based herbicides are one of the most widely used herbicides. This study looks at the effects of different brands of glyphosate-based herbicides, including those intended for aquatic use, on the survival and growth of axolotl salamander larvae. Out of four brands of glyphosate herbicide (Aquamaster, Aquaneat, Helosate plus, and Roundup Pro), the survival rates of Roundup Pro were the lowest. Most mortality occurred between the 3 mg/L and 6 mg/L concentrations, during …


Effect Of Bisphenol-A On Neurodevelopment In Drosophila Melanogaster Larvae, Alexandra M. Streifel May 2016

Effect Of Bisphenol-A On Neurodevelopment In Drosophila Melanogaster Larvae, Alexandra M. Streifel

All College Thesis Program, 2016-2019

This paper examines the effects of the chemical preservative bisphenol-A on the developing nervous systems of Drosophila melanogaster, or fruit fly, larvae. This study examines the effects of bisphenol-A using both behavioral as well as morphological paradigms. It was determined that bisphenol-A significantly increased the amount of time larvae spent in seeking behavior, the number of peristaltic contractions, and the distance traveled in a linear fashion. In the morphological analysis, indications of increased dendritic area in experimental larvae existed, but there was not enough data to determine significance. For future research, it is recommended that more data be gathered to …


Northern Fulmars (Fulmarus Glacialis) As Bio-Indicators Of Endocrine Disrupting Plasticizers In The Marine Surface Environment., Olivia Feinstein Jan 2012

Northern Fulmars (Fulmarus Glacialis) As Bio-Indicators Of Endocrine Disrupting Plasticizers In The Marine Surface Environment., Olivia Feinstein

Summer Research

The plastics that make up over 10% of human waste are synthesized with phthalate plasticizers which are utilized in plastics as an additive to improve durability and flexibility. Many phthalates have been identified as endocrine disrupting chemicals (EDCs) and studies have shown dramatic deleterious effects as a result of species exposure to growing numbers of EDCs in the environment. Northern Fulmars (Fulmarus glacialis) are a northern hemisphere seabird species that forages opportunistically, meaning that they take advantage of a wide variety of different food sources, including inadvertent consumption of plastic. In addition to occupying space in the individuals’ …


Interaction Of Fish Aryl Hydrocarbon Receptor Paralogs (Ahr1 And Ahr2) With The Retinoblastoma Protein, Rebeka R. Merson, Sibel I. Karchner, Mark E. Hahn Aug 2009

Interaction Of Fish Aryl Hydrocarbon Receptor Paralogs (Ahr1 And Ahr2) With The Retinoblastoma Protein, Rebeka R. Merson, Sibel I. Karchner, Mark E. Hahn

Faculty Publications

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) and related compounds. In some mammalian cell lines, TCDD induces G1 cell cycle arrest, which depends on an interaction between the AHR and the retinoblastoma tumor suppressor (RB). Mammals possess one AHR, whereas fishes possess two or more AHR paralogs that differ in the domains important for AHR-RB interactions in mammals. To test the hypothesis that fish AHR paralogs differ in their ability to interact with RB, we cloned RB cDNA from Atlantic killifish, Fundulus heteroclitus, and studied the interactions of killifish RB protein with killifish AHR1 and …


Occurrence And Biological Effect Of Exogenous Steroids In The Elkhorn River, Nebraska, Usa, Alan S. Kolok, Daniel D. Snow, Satomi Kohno, Marlo K. Sellin, Louis J. Guillette Jr. Dec 2007

Occurrence And Biological Effect Of Exogenous Steroids In The Elkhorn River, Nebraska, Usa, Alan S. Kolok, Daniel D. Snow, Satomi Kohno, Marlo K. Sellin, Louis J. Guillette Jr.

Biology Faculty Publications

Recent studies of surface waters in North America, Japan, and Europe have reported the presence of steroidogenic agents as contaminants. The current study has three objectives: 1) to determine if steroidogenic compounds are present in the Elkhorn River, 2) to determine if sediments collected from the Elkhorn River can act as a source of steroidogenic compounds to aquatic organisms, and 3) to determine if site-specific biological effects are apparent in the hepatic gene expression of fathead minnows. Evidence was obtained using three approaches: 1) deployment of polar organic chemical integrative samplers (POCIS), 2) deployment of caged fathead minnows, and 3) …


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 Feb 2000

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.


Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall Jan 1999

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Biological Sciences Faculty Publications

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasglow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al, 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …


Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny Jan 1999

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Biological Sciences Faculty Publications

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …