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Full-Text Articles in Life Sciences

Ants And Spices: The Potential Of Spices To Repel Pest Ants (Formicidae), Jenny Vu, Hritam Mitra, Joe Steven Hardy, Nirupama Chauhan Jul 2022

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 Jul 2022

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. …


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 Jan 2022

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 …


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 Jul 2020

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 …


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 Feb 2020

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 …


Combinations Of Allelopathic Crop Extracts Reduce Digitaria Spp. And Setaria Faberi Seed Germination, Peter Apicella, Karl Guillard May 2018

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 Jan 2017

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 …


Assessment Of Variation In Susceptibility Of The Fall Armyworm, Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), To Bacillus Thuringiensis Toxins, Karen Ferreira Da Silva May 2015

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 Jan 2015

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 …


Jackson Lake Limnology, Wayne A. Wurtsbaugh Oct 2014

Jackson Lake Limnology, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

The limnology of Jackson Lake has been studied very little, despite the fact that it is the uppermost large lake on the headwaters of the Snake River, one of the larger rivers in the country (Hayden 1969). It is also an important fishery, largely for introduced lake trout. In 2014 we took our incoming graduate students to the Jackson Hole and one part of this introductory course focused on the limnology of the lake. Prior to the arrival of the students, a nutrient addition bioassay was initiated to demonstrate an experimental approach to understanding what nutrients might control production processes …


Responses Of Amblyomma Americanum And Dermacentor Variabilis To Odorants That Attract Haematophagous Insects, A. L. Carr, R. M. Roe, C. Arellano, D. E. Sonenshine, C. Schal, C. S. Apperson Jan 2013

Responses Of Amblyomma Americanum And Dermacentor Variabilis To Odorants That Attract Haematophagous Insects, A. L. Carr, R. M. Roe, C. Arellano, D. E. Sonenshine, C. Schal, C. S. Apperson

Biological Sciences Faculty Publications

Carbon dioxide (CO2), 1-octen-3-ol, acetone, ammonium hydroxide, L-lactic-acid, dimethyl trisulphide and isobutyric acid were tested as attractants for two tick species, Amblyomma americanum and Dermacentor variabilis (Acari: Ixodidae), in doseresponse bioassays using Y-tube olfactometers. Only CO2, acetone, 1-octen-3-ol and ammonium hydroxide elicited significant preferences from adult A. americanum, and only CO2 was attractive to adult D. variabilis. Acetone, 1-octen-3-ol and ammonium hydroxide were separately evaluated at three doses against CO2 (from dry ice) at a field site supporting a natural population of A. americanum nymphs and adults. Carbon dioxide consistently attracted the …


Pheromonal Control Of The Invasive Brown Treesnake: Potency Of Female Sexual Attractiveness Pheromone Varies With Ovarian State, Tom Mathies, Breanna Levine, Richard M. Engeman, Julie A. Savidge Jan 2013

Pheromonal Control Of The Invasive Brown Treesnake: Potency Of Female Sexual Attractiveness Pheromone Varies With Ovarian State, Tom Mathies, Breanna Levine, Richard M. Engeman, Julie A. Savidge

USDA Wildlife Services: Staff Publications

The female sex pheromone has potential a s a control tool for the Brown Treesnake, Boiga irregularis Merrem, a pest introduced into Guam. We conducted male-guided bioassays to determine whether potency of the female pheromone varied according to reproductive state and during vitellogenesis. In weekly simultaneous choice tests, we presented males with skin lipid samples from vitellogenic females, non-vitellogenic females, conspecific males, and carrier controls. The total time each sample was tongue-flicked was recorded: mean total tongue-flick time was highest for samples from vitellogenic females followed by samples from non-vitellogenic females. Pair-wise comparisons of male tongue-flick time for samples of …


Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster May 2012

Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster

Department of Entomology: Faculty Publications

A Carlavirus transmitted by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important disease of soybean nurseries in Puerto Rico causing substantial germplasm losses. Insecticide bioassay experiments were conducted at Dow AgroSciences (DAS) Research Station, Santa Isabel, Puerto Rico, either by spraying insecticides on B. tabaci infested soybean leaves or introducing B. tabaci adults onto insecticide-sprayed soybean leaves. Moreover, host plants were surveyed to detect the virus in overwintering hosts that serve as a source of inoculums. The direct spray experiment showed that Nuprid 2F (Imidacloprid), Capture 2 EC (Bifenthrin), Thionex (Endosulfan), Lannate LV (Methomyl), and Dimethoate gave good level ( …


Effects Of Pyriproxyfen And Buprofezin On Immature Development And Reproduction In The Stable Fly, S.S. Liu, A.Y. Li, K. H. Lohmeyer, A.A. Perez De Leon Jan 2012

Effects Of Pyriproxyfen And Buprofezin On Immature Development And Reproduction In The Stable Fly, S.S. Liu, A.Y. Li, K. H. Lohmeyer, A.A. Perez De Leon

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most significant biting flies that affect cattle. The use of traditional insecticides for stable fly control has only a limited success owing to the insect’s unique feeding behaviours and immature development sites. A laboratory study was conducted to evaluate the effects of two insect growth regulator (IGR) products, pyriproxyfen and buprofezin, on the development of the immature stages of the stable fly and the effects of pyriproxyfen on oviposition and egg hatch. Both pyriproxyfen and buprofezin had significant inhibitory effects on immature development. The LC50s of …


Interspecific Variation In Palatability Suggests Cospecialization Of Antipredator Defenses In Sea Hares, Kimberly K. Takagi, Nadia N. Ono, William G. Wright Jan 2010

Interspecific Variation In Palatability Suggests Cospecialization Of Antipredator Defenses In Sea Hares, Kimberly K. Takagi, Nadia N. Ono, William G. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Prey species often deploy different kinds of antipredator defenses, which can interact with each other in ways that are not yet completely understood. Much research into these interactions has utilized gastropod mollusks, usually focusing (in part) on the protective utility of the gastropod shell. This makes the evolutionary reduction of the shell in the opisthobranch gastropods (marine slugs) particularly interesting. This loss of protective function of the shell is associated with the evolution of alternative defenses. Particularly well studied are chemical defenses, especially those using secondary metabolites derived from food resources. As a first step toward understanding interspecific variation in …


Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott J. Meiners Jan 2010

Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott J. Meiners

Faculty Research & Creative Activity

Invasive plant species are often more successful within introduced areas when compared to their natural ranges. Allelopathy has been suggested as a potential mechanism for this success because invasive plants frequently establish monocultures and may produce allelochemicals evolutionarily novel to the recipient community. However, species are typically tested in isolation making the relative strength of allelopathy difficult to assess. We conducted laboratory bioassays for 10 co-occurring non-native species to determine the relative strength of their allelopathic potential. These species represented a suite of successful invaders within a young forest and were from a variety of plant life forms: trees, lianas, …


Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott Meiners Jan 2010

Relative Allelopathic Potential Of Invasive Plant Species In A Young Disturbed Woodland, Nikki Pisula, Scott Meiners

Faculty Research & Creative Activity

Invasive plant species are often more successful within introduced areas when compared to their natural ranges. Allelopathy has been suggested as a potential mechanism for this success because invasive plants frequently establish monocultures and may produce allelochemicals evolutionarily novel to the recipient community. However, species are typically tested in isolation making the relative strength of allelopathy difficult to assess. We conducted laboratory bioassays for 10 co-occurring non-native species to determine the relative strength of their allelopathic potential. These species represented a suite of successful invaders within a young forest and were from a variety of plant life forms: trees, lianas, …


Oxalic Acid: A Prospective Tool For Reducing Varroa Mite Populations In Package Bees, Nicholas P. Aliano, Marion D. Ellis Jan 2009

Oxalic Acid: A Prospective Tool For Reducing Varroa Mite Populations In Package Bees, Nicholas P. Aliano, Marion D. Ellis

Department of Entomology: Faculty Publications

Abstract Numerous studies have investigated using oxalic acid (OA) to control Varroa mites in honey bee colonies. In contrast, techniques for treating package bees with OA have not been investigated. The goal of this study was to develop a protocol for using OA to reduce mite infestation in package bees. We made 97 mini packages of Varroa-infested adult bees. Each package contained 1,613 ± 18 bees and 92 ± 3 mites, and represented an experimental unit. We prepared a 2.8% solution of OA by mixing 35 g OA with 1 l of sugar water (sugar:water = 1:1; w:w). Eight treatments …


Development Of Methods To Evaluate Susceptibility Of Soybean Aphid To Imidacloprid And Thiamethoxam At Lethal And Sublethal Concentrations, Leonardo C. Magalhaes, Thomas E. Hunt, Blair D. Siegfried May 2008

Development Of Methods To Evaluate Susceptibility Of Soybean Aphid To Imidacloprid And Thiamethoxam At Lethal And Sublethal Concentrations, Leonardo C. Magalhaes, Thomas E. Hunt, Blair D. Siegfried

Department of Entomology: Faculty Publications

The soybean aphid, Aphis glycines Matsumura (Homoptera: Aphididae), is a recent introduction (2000) from Asia and has become a serious soybean [Glycine max (L.) Merr. (Fabaceae)] pest in North America. Seed treatments using the neonicotinoid insecticides, imidacloprid and thiamethoxam, have been suggested as a method of control, and the use of these insecticides is becoming widespread. As a consequence, there is increased potential to select for resistance to these compounds. In the case of soybean aphids, baseline susceptibility to neonicotinoid insecticides and standardized methods for bioassay are lacking. A bioassay technique that uses excised soybean leaves immersed in an …


Acute Contact Toxicity Of Oxalic Acid To Varroa Destructor (Acari: Varroidae) And Their Apis Mellifera (Hymenoptera: Apidae) Hosts In Laboratory Bioassays, Nicholas P. Aliano, Marion D. Ellis, Blair D. Siegfried Oct 2006

Acute Contact Toxicity Of Oxalic Acid To Varroa Destructor (Acari: Varroidae) And Their Apis Mellifera (Hymenoptera: Apidae) Hosts In Laboratory Bioassays, Nicholas P. Aliano, Marion D. Ellis, Blair D. Siegfried

Department of Entomology: Faculty Publications

Laboratory bioassays were performed to characterize the acute contact toxicity of oxalic acid (OA) to Varroa destructor (Anderson & Trueman) and their honey bee hosts (Apis mellifera L.). Specifically, glass-vial residual bioassays were conducted to determine the lethal concentration of OA for V. destructor, and topical applications of OA in acetone were conducted to determine the lethal dose for honey bees. The results indicate that OA has a low acute toxicity to honey bees and a high acute toxicity to mites. The toxicity data will help guide scientists in delivering optimum dosages of OA to the parasite and …


Animal Carcinogenicity Studies: Implications For The Reach System, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Mar 2006

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

Experimentation Collection

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: 1. Poor Human Predictivity, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Feb 2006

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

Experimentation Collection

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: 2. Obstacles To Extrapolation Of Data To Humans, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Feb 2006

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

Experimentation Collection

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 …


Animal Carcinogenicity Studies: 3. Alternatives To The Bioassay, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Feb 2006

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

Experimentation Collection

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 …


Cancerous Contradictions: The Mis-Regulation Of Human Carcinogens Based On Animal Data, Andrew Knight, Jarrod Bailey, Jonathan Balcombe Jan 2006

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

Experimentation Collection

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


Baseline Susceptibility Of Western Corn Rootworm (Coleoptera: Crysomelidae) To Cry3bb1 Bacillus Thuringiensis Toxin, Blair D. Siegfried, Ty T. Vaughn, Terrence A. Spencer Aug 2005

Baseline Susceptibility Of Western Corn Rootworm (Coleoptera: Crysomelidae) To Cry3bb1 Bacillus Thuringiensis Toxin, Blair D. Siegfried, Ty T. Vaughn, Terrence A. Spencer

Department of Entomology: Faculty Publications

Susceptibility to Cry3Bb1 toxin from Bacillus thuringiensis (Bt) was determined for western corn rootworm, Diabrotica virgifera virgifera LeConte, neonates from both laboratory and field populations collected from across the Corn Belt. Rootworm larvae were exposed to artificial diet treated with increasing Cry3Bb1 concentrations, and mortality and growth inhibition were evaluated after 4Ð7 d. The range of variation in Bt susceptibility indicated by growth inhibition was similar to that indicated by mortality. Although interpopulation variation in susceptibility was observed, the magnitude of the differences was comparable with the variability observed between generations of the same population. In general, the toxin was …


Resistance Status Of House Flies (Diptera: Muscidae) From Southeastern Nebraska Beef Cattle Feedlots To Selected Insecticides, Paula C.R.G. Marcon, Gustave D. Thomas, Blair D. Siegfried, John B. Campbell, Steven R. Skoda Jun 2003

Resistance Status Of House Flies (Diptera: Muscidae) From Southeastern Nebraska Beef Cattle Feedlots To Selected Insecticides, Paula C.R.G. Marcon, Gustave D. Thomas, Blair D. Siegfried, John B. Campbell, Steven R. Skoda

Department of Entomology: Faculty Publications

The status of resistance to three insecticides (permethrin, stirofos, and methoxychlor), relative to a laboratory-susceptible colony, was evaluated in Þeld populations of house flies, Musca domestica L., collected from two beef cattle feedlots in southeastern Nebraska. Topical application and residual exposure to treated glass surfaces were suitable methods for determining the resistance status of house flies to permethrin, stirofos, or methoxychlor. However, in most cases, residual exposure was more sensitive in resistance detection (i.e., higher resistance ratios). The field populations tested were moderately resistant to permethrin (RR = 4.9-fold and RR = 7.3-fold, for topical application and residual exposure, respectively) …


Repellency Of Ir3535, Kbr3023, Para-Menthane-3,8-Diol, And Deet To Black Salt Marsh Mosquitoes (Diptera: Culicidae) In The Everglades National Park, Donald R. Barnard, Ulrich R. Bernier, Kenneth H. Posey, Rui-De Xue Jan 2002

Repellency Of Ir3535, Kbr3023, Para-Menthane-3,8-Diol, And Deet To Black Salt Marsh Mosquitoes (Diptera: Culicidae) In The Everglades National Park, Donald R. Barnard, Ulrich R. Bernier, Kenneth H. Posey, Rui-De Xue

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

IR3535, KBR3023, para-menthane-3,8-diol (PMD), and deet were evaluated in controlled studies with human subjects (n = 5) for repellency to black salt marsh mosquitoes (Ochlerotatus taeniorhynchus Wiedemann), in the Everglades National Park, FL. In tests of 6-h duration, with an average mosquito biting pressure on exposed forearm skin of 19.5 (±13.7) bites per minute, the mean percent repellencies (SE) for IR3535, KBR3023, PMD, and deet was 88.6 (3.2), 97.5 (1.7), 89.2 (2.9), and 94.8 (2.5), respectively. Mean complete protection times (SE) for IR3535, KBR3023, PMD, and deet were 3.0 (1.0), 5.4 (0.6), 3.8 (1.4), and 5.6 (0.5) h, …


Baseline Susceptibility Of The Corn Earworm (Lepidoptera: Noctuidae) To The Cry1ab Toxin From Bacillus Thuringiensis, Blair D. Siegfried, Terrence A. Spencer, Jessica Nearman Aug 2000

Baseline Susceptibility Of The Corn Earworm (Lepidoptera: Noctuidae) To The Cry1ab Toxin From Bacillus Thuringiensis, Blair D. Siegfried, Terrence A. Spencer, Jessica Nearman

Department of Entomology: Faculty Publications

Susceptibility to Cry1Ab toxin from Bacillus thuringiensis (Bt) was determined for 12 field populations of neonate corn earworm, Helicoverpa zea (Boddie), from the United States. Earworm larvae were exposed to artificial diet treated with increasing Bt concentrations, and mortality and growth inhibition were evaluated after 7 d. The range of variation in Bt susceptibility indicated by growth inhibition was very similar to that indicated by mortality. Although interpopulation variation in susceptibility to both proteins was observed, the magnitude of the differences was small (less than or equal to fivefold). These results suggest that the observed susceptibility differences reflect natural variation …


Baseline Susceptibility Of European Corn Borer (Lepidoptera: Crambidae) To Bacillus Thuringiensis Toxins, Paula C. R. G. Macron, Linda J. Young, Kevin L. Steffey, Blair Siegfried Apr 1999

Baseline Susceptibility Of European Corn Borer (Lepidoptera: Crambidae) To Bacillus Thuringiensis Toxins, Paula C. R. G. Macron, Linda J. Young, Kevin L. Steffey, Blair Siegfried

Department of Entomology: Faculty Publications

Susceptibility to CrylAb and CrylAc toxins from Bacillus thuringiensis was determined for 11 populations of neonate European corn borer, Ostrinia nubilalis (Hiibner), from the United States and 1 from northern Italy. Corn borer larvae were exposed to artificial diet treated with increasing B. thuringiensis concentrations, and mortality and growth inhibition were evaluated after 7 d. The range of variation in B. thuringiensis susceptibility indicated by growth inhibition was very similar to that indicated by mortality. Although interpopulation variation in susceptibility to both proteins was observed, the magnitude of the differences was small (54-fold) and comparable to the variability observed among …