Life Sciences Commons^™

Developing A Simple Bioassay For Detection Of Alfalfa Autotoxicity In Field Soils, P. Baisley, K. Cassida, S. Gruss, E. Hill

IGC Proceedings (1997-2023)

Alfalfa autotoxicity causes yield reductions in alfalfa production by inhibiting plant establishment and decreasing plant productivity. Accurate predictions regarding autotoxic potential of the soil in a given field at a given time are an essential tool for alfalfa growers to make appropriate planting decisions. To address this issue, we are developing a soil bioassay that can be conducted as a mail-in soil test for alfalfa growers through plant diagnostic service laboratories. We hypothesize that we will detect differences in seed germination, emergence, root length, and root morphology between control and autotoxic soils. A preliminary trial testing alfalfa field soils and …

Density And Germination Characteristics Of Seeds Of Bromus Tectorum In Field Seedbanks, J. A. Young, Charlie D. Clements

IGC Proceedings (1997-2023)

Bromus tectorum is a highly invasive exotic weed that has spread over millions of hectares of grazing land in the semi-arid regions of far western North America. The annual grass is an important grazing resource, but herbage production is highly variable among years, depending on the amount and periodicity of precipitation. When production is abundant, the accumulations of fine-textured, early-maturing herbage increase the chance of ignition and the rate of spread of wildfires. On certain years the area burned in such fires may be several million hectares. Such fires destroy forage resources and degrade watershed quality on extensive areas as …

Ants And Spices: The Potential Of Spices To Repel Pest Ants (Formicidae), Jenny Vu, Hritam Mitra, Joe Steven Hardy, Nirupama Chauhan

2022 REYES Proceedings

We examined the spices nutmeg, cinnamon, Ngo Hiang Spice Mix (anise, galangale, cinnamon and star anise) and turmeric for repellent activity against foraging ants. Control baits consisting of a cracker substrate topped with granulated sugar were presented next to treatment baits (cracker, granulated sugar and spice spread over the sugar) to ants in natural habitats. After an hour, the numbers of ants recruiting to the control and treatment baits were recorded. Jenny Vu first tested nutmeg and then cinnamon; Hritam Mitra tested turmeric; Joe Steven Hardy tested Ngo Hiang Spice Mix and Nirupama Chauhan tested turmeric. Data were analyzed with …

Ants And Spices: Multiple Bioassays Investigating Turmeric (Curcuma Longa) And Chili Powder As Repellents For Ants (Formicidae), Luca Ben Yishay-Sapalio

2022 REYES Proceedings

Spices offer an environmentally friendly method of controlling ants (Formicidae) in homes. In this study, I used three bioassays to examine the effect of Turmeric (Curcuma longa) and one bioassay to examine the effect of Chili Powder as repellents for ants. Tests were conducted near active ants outdoors. All bioassays examined paired control and treatment baits along a transect, and control baits consisted of a small sheet of corrugated cardboard (a sterile yet easy to manipulate substrate) with granulated sugar on top. In the first bioassay, treatment baits were similar to controls but with Turmeric covering the sugar. …

Nutrient Uptake And Water Quality In Great Salt Lake Wetland Impoundments, Rachel L. Buck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Great Salt Lake (GSL) is the largest inland body of water on the Pacific flyway, a major pathway for migratory birds in the Americas that extends from Alaska to Patagonia. The lake is surrounded by approximately 360,000 acres of wetlands, providing critical food, shelter, cover, nesting areas, and protection to between 4–6 million birds that visit each year. Impounded wetlands were created as part of the GSL ecosystem to support waterfowl habitat. These large, shallow, submergent wetlands are diked to control water levels to sustain aquatic plants which are an important food source. Besides providing critical habitat, these impoundments …

A Bioassay To Determine Poa Annua Responses To Indaziflam, Benjamin D. Pritchard

Masters Theses

Herbicide resistance within Poa annua is widespread in managed turfgrass systems. In 2020, a P. annua collection from a golf course in the southeastern United States was reported to be resistant to indaziflam as well as six other mode-of-action groups. Considering P. annua is the most troublesome weed in turfgrass, a bioassay to screen other collections with putative indaziflam resistance is needed. A dose-response experiment was conducted with ten concentrations of indaziflam (0, 250, 500, 750, 1000, 1250, 1500, 2000, 4500, and 9000 pM) in Gelrite® culture during 2021 and 2022. An herbicide-susceptible (S1) collection of P. annua, a …

Ozonized Biochar Filtrate Effects On The Growth Of Pseudomonas Putida And Cyanobacteria Synechococcus Elongatus Pcc 7942, Oumar Sacko, Nancy L. Engle, Timothy J. Tschaplinski, Sandeep Kumar, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

Background

Biochar ozonization was previously shown to dramatically increase its cation exchange capacity, thus improving its nutrient retention capacity. The potential soil application of ozonized biochar warrants the need for a toxicity study that investigates its effects on microorganisms.

Results

In the study presented here, we found that the filtrates collected from ozonized pine 400 biochar and ozonized rogue biochar did not have any inhibitory effects on the soil environmental bacteria Pseudomonas putida, even at high dissolved organic carbon (DOC) concentrations of 300 ppm. However, the growth of Synechococcus elongatus PCC 7942 was inhibited by the ozonized biochar filtrates at …

A Strategy For Detecting Natural Anthelmintic Constituents Of The Grassland Species Plantago Lanceolata, D. L. Gustine, M. A. Sanderson, J. Getzie, S. Donner, R. Gueldner, N. Jennings

IGC Proceedings (1997-2023)

A strategy to detect anthelmintic constituents in plantain (Plantago lanceolata) using a bioassay-driven purification approach was tested. Plantain consumed by cattle may control or reduce internal parasite titers, possibly due to the iridoid glucoside aucubin. Lyophilized, ground leaves of wild P. lanceolata were extracted with 95 % ethanol or boiling water containing calcium carbonate. Partially purified extracts (0 to 250 mg ml^-1), 5 μg ml^-1 of the anthelmintic levamisole, or 5 mg ml^-1 of aucubin were tested with sheathed bovine parasites (Ostertagia ostertagi). The percent moving worms was unchanged for water controls …

Nutrient Hotspots From Patch Burning In A Namibian Rangeland, I. Zimmermann, L. Tjilumbu, G. Diekmann

IGC Proceedings (1997-2023)

No abstract provided.

Helicoverpa Zea (Boddie) (Lepidoptera: Noctuidae) Larval Distribution On Different Bt Technologies And Evaluating Cotton Plant Tissue Assays For Resistance Monitoring, Dawson David Kerns

Masters Theses

Field trials were conducted in 2018 at the West Tennessee Research and Education Center (WTREC) in Jackson, TN and in 2019 at locations in College Station, TX, Tillar, AR, and Jackson, TN. Non-Bt, Cry1Ac + Cry1F, and Cry1Ac + Cry2Ab cotton varieties were either treated with an insecticide or left untreated. After five days, cotton plants were mapped for signs of bollworm, Helicoverpa zea (Lepidoptera: Noctuidae), feeding on floral structures (i.e., bolls, squares, flowers) and the physical presence of larvae. Bt technologies reduced the number of H. zea larvae and the amount of feeding injury, but no major differences in …

Towards More Realistic Estimates Of Dom Decay In Streams: Incubation Methods, Light, And Non-Additive Effects, Julia E. Kelso, Emma J. Rosi, Michelle A. Baker

Ecology Center Publications

Dissolved organic matter (DOM) is the largest pool of organic matter in aquatic ecosystems and is a primary substrate for microbial respiration in streams. However, understanding the controls on DOM processing by microbes remains limited, and DOM decay rates remain largely unconstrained. Many DOM decay rates are quantified with bioassays in dark bottles, which may underestimate DOM decay in streams because these bioassays do not include a benthic zone and do not account for abiotic factors of DOM loss, such as photodegradation and volatilization. We measured decay of labile and semi-labile DOM over 3 d in experimental streams and bottle …

The Discovery Of Metarhizium Anisopliae (Metchnikoff) Sorokin Isolates From Arkansas And Their Pathogenicity To Amblyomma Americanum L., Austin Goldsmith

Graduate Theses and Dissertations

The lone star tick Amblyomma americanum L. is the most abundant tick in Arkansas and has been implicated as a vector of many important disease-causing pathogens. Many species of entomopathogenic fungi have been isolated from several species of ticks, with some of these fungi being utilized for tick biocontrol. However, few studies have assessed the pathogenicity of entomopathogenic fungi to A. americanum. The objectives of this study were to: isolate and identify native Arkansas isolates of entomopathogenic fungi from wild A. americanum ticks exposed to soil and to compare the pathogenicity of one isolate (Metarhizium anisopliae (Metchnikoff) Sorokin isolate Savoy …

Sustainable, Alginate-Based Sensor For Detection Of Escherichia Coli In Human Breast Milk, Nicholas Kikuchi, Margaret May, Matthew Zweber, Jerard Madamba, Craig M. Stephens, Unyoung Kim, Maryam Mobed-Miremadi

Bioengineering

There are no existing affordable diagnostics for sensitive, rapid, and on-site detection of pathogens in milk. To this end, an on-site colorimetric-based sustainable assay has been developed and optimized using an L₁₆ (5⁴) Taguchi design to obtain results in hours without PCR amplification. To determine the level of Escherichia coli (E. coli) contamination, after induction with 150 µL of breast milk, the B-Per bacterial protein extraction kit was added to a solution containing an alginate-based microcapsule assay. Within this 3 mm spherical novel sensor design, X-Gal (5-Bromo-4-Chloro-3-Indolyl β-_D-Galactopyranoside) was entrapped at a concentration of 2 …

Investigating The Effects Of Uv Filters In Sunscreen On Human And Environmental Health, Brittany M. Thompson

Honors Undergraduate Theses

Ultraviolet filters are active ingredients in sunscreen that protect us from harmful UV radiation. However, organic UV filters are thought to have adverse effects on the environment and humans. In recent years, fear of harmful impacts of sunscreen has caused a surge of coral reef safe sunscreens to hit the market. These sunscreens, which contain inorganic metal oxides as UV filters, have been accepted as safe for humans and the environment until recently. Metal oxides in reef safe sunscreens may form intermediates in the water that can harm marine life and can absorb through the skin and into the blood, …

Combinations Of Allelopathic Crop Extracts Reduce Digitaria Spp. And Setaria Faberi Seed Germination, Peter Apicella, Karl Guillard

Honors Scholar Theses

Allelopathic cover crops contain compounds that deter other types of plant seeds from germinating or inhibiting established plants’ growth. Sunflower (Helianthus annuus, SF), buckwheat (Fagopyrum esculentum Moench, BW), sorghum-sudangrass (Sorghum × drummondii [Nees ex. Steud.] Millsp. & Chase, SSG), and winter rye (Secale cereale) are all known allelopathic cover crops. However, there is little information about the use of these allelopathic cover crops used together and their combined impact on weed seed germination. Laboratory bioassays were conducted to determine the effect of the aforementioned cover crops alone and in combinations in reducing the …

Method Development For Monitoring Bean Leaf Beetle, Cerotoma Trifurcata (Forster) (Coleoptera: Chrysomelidae), Susceptibility To Thiamethoxam Seed Treatments On Soybeans, Chelsea L. Tietjen, Thomas Hunt, Daniel D. Snow, David A. Cassada, Blair D. Siegfried

Department of Entomology: Faculty Publications

The increased use of thiamethoxam seed treatments for controlling pests such as the bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), suggests the need for methods to measure and monitor the development of resistance to thiamethoxam. The objectives of this study were to develop a bioassay method that can be used to monitor bean leaf beetle susceptibility to thiamethoxam, and to quantify the relative concentrations of thiamethoxam and clothianidin in early growth stage soybean tissue treated with thiamethoxam as a seed treatment. Overwintered and F1 bean leaf beetles were collected from alfalfa and soybean fields and used in excised soybean …

Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

The 2001 European Commission proposal for the Registration, Evaluation and Authorisation of Chemicals (REACH) aims to improve public and environmental health by assessing the toxicity of, and restricting exposure to, potentially toxic chemicals. The greatest benefits are expected to accrue from decreased cancer incidences. Hence the accurate identification of chemical carcinogens must be a top priority for the REACH system. Due to a paucity of human clinical data, the identification of potential human carcinogens has conventionally relied on animal tests. However, our survey of the US Environmental Protection Agency’s (EPA’s) toxic chemicals database revealed that, for a majority of the …

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …

Animal Carcinogenicity Studies: 1. Poor Human Predictivity, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

The regulation of human exposure to potentially carcinogenic chemicals constitutes society’s most important use of animal carcinogenicity data. Environmental contaminants of greatest concern within the USA are listed in the Environmental Protection Agency’s (EPA’s) Integrated Risk Information System (IRIS) chemicals database. However, of the 160 IRIS chemicals lacking even limited human exposure data but possessing animal data that had received a human carcinogenicity assessment by 1 January 2004, we found that in most cases (58.1%; 93/160), the EPA considered animal carcinogenicity data inadequate to support a classification of probable human carcinogen or non-carcinogen. For the 128 chemicals with human or …

Cancerous Contradictions: The Mis-Regulation Of Human Carcinogens Based On Animal Data, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

The regulation of human exposures to potential carcinogens constitutes society’s most important use of animal carcinogenicity data. However, for environmental contaminants of greatest U.S. concern, we found that in most cases (58.1%; 93/160) the U.S. Environmental Protection Agency (EPA) considered the animal data inadequate to support a classification of probable human carcinogen or noncarcinogen.

The World Health Organisation’s International Agency for Research on Cancer (IARC) is a leading international authority on carcinogenicity assessments. For chemicals lacking human exposure data (the great majority), IARC classifications of identical chemicals were significantly more conservative than EPA classifications (p

Animal Carcinogenicity Studies: 2. Obstacles To Extrapolation Of Data To Humans, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

Due to limited human exposure data, risk classification and the consequent regulation of exposure to potential carcinogens has conventionally relied mainly upon animal tests. However, several investigations have revealed animal carcinogenicity data to be lacking in human predictivity. To investigate the reasons for this, we surveyed 160 chemicals possessing animal but not human exposure data within the US Environmental Protection Agency chemicals database, but which had received human carcinogenicity assessments by 1 January 2004. We discovered the use of a wide variety of species, with rodents predominating, and of a wide variety of routes of administration, and that there were …

Cancerous Contradictions: The Mis-Regulation Of Human Carcinogens Based On Animal Data, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, PhD

The regulation of human exposures to potential carcinogens constitutes society’s most important use of animal carcinogenicity data. However, for environmental contaminants of greatest U.S. concern, we found that in most cases (58.1%; 93/160) the U.S. Environmental Protection Agency (EPA) considered the animal data inadequate to support a classification of probable human carcinogen or noncarcinogen.

The World Health Organisation’s International Agency for Research on Cancer (IARC) is a leading international authority on carcinogenicity assessments. For chemicals lacking human exposure data (the great majority), IARC classifications of identical chemicals were significantly more conservative than EPA classifications (p

Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, PhD

The 2001 European Commission proposal for the Registration, Evaluation and Authorisation of Chemicals (REACH) aims to improve public and environmental health by assessing the toxicity of, and restricting exposure to, potentially toxic chemicals. The greatest benefits are expected to accrue from decreased cancer incidences. Hence the accurate identification of chemical carcinogens must be a top priority for the REACH system. Due to a paucity of human clinical data, the identification of potential human carcinogens has conventionally relied on animal tests. However, our survey of the US Environmental Protection Agency’s (EPA’s) toxic chemicals database revealed that, for a majority of the …

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, Ph.D.

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …

Animal Carcinogenicity Studies: 1. Poor Human Predictivity, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, Ph.D.

The regulation of human exposure to potentially carcinogenic chemicals constitutes society’s most important use of animal carcinogenicity data. Environmental contaminants of greatest concern within the USA are listed in the Environmental Protection Agency’s (EPA’s) Integrated Risk Information System (IRIS) chemicals database. However, of the 160 IRIS chemicals lacking even limited human exposure data but possessing animal data that had received a human carcinogenicity assessment by 1 January 2004, we found that in most cases (58.1%; 93/160), the EPA considered animal carcinogenicity data inadequate to support a classification of probable human carcinogen or non-carcinogen. For the 128 chemicals with human or …

Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jonathan Balcombe, PhD

Conventional animal carcinogenicity tests take around three years to design, conduct and interpret. Consequently, only a tiny fraction of the thousands of industrial chemicals currently in use have been tested for carcinogenicity. Despite the costs of hundreds of millions of dollars and millions of skilled personnel hours, as well as millions of animal lives, several investigations have revealed that animal carcinogenicity data lack human specificity (i.e. the ability to identify human non-carcinogens), which severely limits the human predictivity of the bioassay. This is due to the scientific inadequacies of many carcinogenicity bioassays, and numerous serious biological obstacles, which render profoundly …

Animal Carcinogenicity Studies: 2. Obstacles To Extrapolation Of Data To Humans, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jonathan Balcombe, PhD

Due to limited human exposure data, risk classification and the consequent regulation of exposure to potential carcinogens has conventionally relied mainly upon animal tests. However, several investigations have revealed animal carcinogenicity data to be lacking in human predictivity. To investigate the reasons for this, we surveyed 160 chemicals possessing animal but not human exposure data within the US Environmental Protection Agency chemicals database, but which had received human carcinogenicity assessments by 1 January 2004. We discovered the use of a wide variety of species, with rodents predominating, and of a wide variety of routes of administration, and that there were …

Novel Approaches For Assessment Of Copper Toxicity: Fast Scan Cyclic Voltammetry And Optical Bioassays, Annette R. Tremonti

Wayne State University Dissertations

Anthropogenic activities negatively impact fresh water ecosystems through toxic contaminants that are released into the environment. Copper (Cu) is a water contaminant that is fundamentally persistent once introduced into the environment that has the potential for bioaccumulation. Although Cu toxicity has been studied for decades, there is still a continuing problem with new sources and pathways. New approaches are needed to understand distribution and transport of Cu and its potential for complex biological impacts beyond the simple assessment of lethality. Several novel approaches were used in this research project to advance our understanding of Cu toxicity, including fast scan cyclic …

Assessment Of Variation In Susceptibility Of The Fall Armyworm, Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), To Bacillus Thuringiensis Toxins, Karen Ferreira Da Silva

Department of Entomology: Dissertations, Theses, and Student Research

The fall armyworm, Spodoptera frugiperda, is a polyphagous insect pest affecting multiple crops. Fall armyworm is managed with insecticides and corn hybrids expressing insecticidal proteins derived from Bacillus thuringiensis. The early detection of insect resistance is important for making appropriate management decisions informs IPM and IRM recommendations.

The objective of the first study was to establish baseline susceptibility of fall armyworm populations to the Cry1F Bt insecticidal protein, emphasizing collections from locations where fall armyworm overwinters in the U.S. Fall armyworm neonates were exposed to artificial diet treated with increasing Cry1F concentrations, and mortality and growth inhibition were …

Impact Of Spodoptera Frugiperda Neonate Pretreatment Conditions On Vip3aa19 Insecticidal Protein Activity And Laboratory Bioassay Variation, Karen F. Da Silva, Terence A. Spencer, Carolina Camargo Gil, Blair D. Siegfried, Frederick S. Walters

Department of Entomology: Faculty Publications

BACKGROUND: Variation in response to insecticidal proteins is common upon repetition of insect bioassays. Understanding this variation is a prerequisite to detecting biologically important differences.We tracked neonate Spodoptera frugiperda (J.E. Smith) susceptibility to Vip3Aa19 over 17 generations using standardized bioassay methods. Five larval pretreatment conditions and one bioassay condition were tested to determine whether susceptibility was affected. These included: storage time; prefeeding; storage at reduced temperature; storage at reduced humidity; colony introgression of field-collected individuals. Extremes of photoperiod during the bioassay itself were also examined.

RESULTS: LC₅₀ values for two strains of S. frugiperda varied 6.6-fold or 8.8-fold over …