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2024

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Articles 13051 - 13080 of 13238

Full-Text Articles in Life Sciences

Comparing Efficiencies Of Population Control Methods For Responding To Introductions Of Transboundary Animal Diseases In Wild Pigs, Nathan P. Snow, Benjamin Smith, Michael J. Lavelle, Michael P. Glow, Kayleigh Chalkowski, Bruce R. Leland, Sarah Sherburne, Justin W. Fischer, Keely J. Kohen, Seth M. Cook, Hatton Smith, Kurt C. Vercauteren, Ryan S. Miller, Kim M. Pepin Jan 2024

Comparing Efficiencies Of Population Control Methods For Responding To Introductions Of Transboundary Animal Diseases In Wild Pigs, Nathan P. Snow, Benjamin Smith, Michael J. Lavelle, Michael P. Glow, Kayleigh Chalkowski, Bruce R. Leland, Sarah Sherburne, Justin W. Fischer, Keely J. Kohen, Seth M. Cook, Hatton Smith, Kurt C. Vercauteren, Ryan S. Miller, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Introductions of transboundary animal diseases (TADs) into free-ranging wildlife can be difficult to control and devastating for domestic livestock trade. Combating a new TAD introduction in wildlife with an emergency response requires quickly limiting spread of the disease by intensely removing wild animals within a contiguous area. In the case of African swine fever virus (ASFv) in wild pigs (Sus scrofa), which has been spreading in many regions of the world, there is little information on the time- and cost-efficiency of methods for intensively and consistently culling wild pigs and recovering carcasses in an emergency response scenario. We compared the …


Temporal And Spatial Influences On Fawn Summer Survival In Pronghorn Populations: Management Implications From Noninvasive Monitoring, Cole A. Bleke, Eric M. Gese, Juan J. Villalba, Shane B. Roberts, Susannah S. French Jan 2024

Temporal And Spatial Influences On Fawn Summer Survival In Pronghorn Populations: Management Implications From Noninvasive Monitoring, Cole A. Bleke, Eric M. Gese, Juan J. Villalba, Shane B. Roberts, Susannah S. French

United States Department of Agriculture Wildlife Services: Staff Publications

Monitoring vital rates allowsmanagers to estimate trends in growth rates of ungulate populations. However, connecting the influence of nutrition on ungulate demography is challenging. Noninvasive sampling offers a low-cost, low-effort alternative for measuring nutritional indices, allowing for an increased understanding of the mechanistic relationships between environmental factors, nutrition, and specific population vital rates. We examined the temporal influence of intrinsic and extrinsic factors on pronghorn (Antilocapra americana) fawn recruitment. We collected fresh fecal samples from adult female pronghorn in five subpopulations spanning three sampling periods associated with critical maternal life-history stages (late gestation, early lactation, breeding season) for …


Susceptibilities And Viral Shedding Of Peridomestic Wildlife Infected With Clade 2.3.4.4b Highly Pathogenic Avian Influenza Virus (H5n1), J. Jeffrey Root, Stephanie M. Porter, Julianna B. Lenoch, Jeremy W. Ellis, Angela M. Bosco-Lauth Jan 2024

Susceptibilities And Viral Shedding Of Peridomestic Wildlife Infected With Clade 2.3.4.4b Highly Pathogenic Avian Influenza Virus (H5n1), J. Jeffrey Root, Stephanie M. Porter, Julianna B. Lenoch, Jeremy W. Ellis, Angela M. Bosco-Lauth

United States Department of Agriculture Wildlife Services: Staff Publications

We tested the ability of six peridomestic wildlife species to replicate a highly pathogenic (HP) clade 2.3.4.4b AIV (H5N1) isolated in the United States during 2022. All tested species replicated and shed virus, at least to some degree. Of the six species evaluated (house sparrows (Passer domesticus), European starlings (Sturnus vulgaris), feral pigeons (Columba livia), striped skunks (Mephitis mephitis), Virginia opossums (Didelphis virginiana), and cottontails (Sylvilagus sp.)), striped skunks and Virginia opossums shed the highest viral titers of 106.3 PFU/mL and 105.0 PFU/mL, respectively. Overall, the results of this …


Chronic Wasting Disease Effects On A Breeding Season Behavior In White-Tailed Deer (Odocoileus Virginianus), Miranda Hsiang-Ning Jacobson Huang, Stephen Demarais, Bronson K. Strickland, Allan Houston, Alejandro Banda, Kurt C. Vercauteren Jan 2024

Chronic Wasting Disease Effects On A Breeding Season Behavior In White-Tailed Deer (Odocoileus Virginianus), Miranda Hsiang-Ning Jacobson Huang, Stephen Demarais, Bronson K. Strickland, Allan Houston, Alejandro Banda, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife disease outbreaks can lead to population declines, which are usually attributed to increased direct or indirect mortality. Alternatively, behavior associated with sickness can lead to social isolation, potentially decreasing fitness of affected individuals. A useful case study to examine this dynamic is chronic wasting disease (CWD), a neurological disease of cervids, known to affect behavior and movement. In this study, we monitored scraping, a White-tailed Deer (Odocoileus virginianus; WTD) breeding season behavior, in an area of high CWD prevalence to determine if this reproductive behavior is affected by CWD. At 107 scrape sites, we detected 3,063 scrape interactions and …


Torque Teno Sus Virus 1: A Potential Surrogate Pathogen To Study Pig-Transmitted Transboundary Animal Diseases, Xiaolong Li, Brandon M. Parker, Raoul K. Boughton, James C. Beasley, Timothy J. Smyser, James D. Austin, Kim M. Pepin, Ryan S. Miller, Kurt C. Vercauteren, Samantha M. Wisely Jan 2024

Torque Teno Sus Virus 1: A Potential Surrogate Pathogen To Study Pig-Transmitted Transboundary Animal Diseases, Xiaolong Li, Brandon M. Parker, Raoul K. Boughton, James C. Beasley, Timothy J. Smyser, James D. Austin, Kim M. Pepin, Ryan S. Miller, Kurt C. Vercauteren, Samantha M. Wisely

United States Department of Agriculture Wildlife Services: Staff Publications

Understanding the epidemiology and transmission dynamics of transboundary animal diseases (TADs) among wild pigs (Sus scrofa) will aid in preventing the introduction or containment of TADs among wild populations. Given the challenges associated with studying TADs in free-ranging populations, a surrogate pathogen system may predict how pathogens may circulate and be maintained within wild free-ranging swine populations, how they may spill over into domestic populations, and how management actions may impact transmission. We assessed the suitability of Torque teno sus virus 1 (TTSuV1) to serve as a surrogate pathogen for molecular epidemiological studies in wild pigs by investigating …


Common Grackle (Quiscalus Quiscula) Predation Of A Great Lakes Piping Plover (Charadrius Melodus) Nest And Its Conservation Implications, Jade R. Arneson, Dennis A. Peloquin, Thomas G. Prestby, Sarah P. Saunders Jan 2024

Common Grackle (Quiscalus Quiscula) Predation Of A Great Lakes Piping Plover (Charadrius Melodus) Nest And Its Conservation Implications, Jade R. Arneson, Dennis A. Peloquin, Thomas G. Prestby, Sarah P. Saunders

United States Department of Agriculture Wildlife Services: Staff Publications

Common grackle (Quiscalus quiscula) was observed consuming eggs from an exclosed (protected) Great Lakes piping plover (Charadrius melodus) nest in the lower bay of Green Bay, Lake Michigan in Wisconsin, USA during June 2023. The observation, captured by a trail camera, is the first photographic documentation of grackle predation in any of the three piping plover breeding populations. This behavior adds common grackle to the suite of egg predators and has critical implications for this shorebird species, particularly in the Great Lakes region where piping plover is listed as federally endangered and common grackles are relatively …


Tracking Sero-Molecular Trends Of Swine Brucellosis In Hawai'i And The Central Pacific, Thi Hai Au La, Ian A. Mcmillan, Prashant Dahal, Andrew H. Burger, Mahdi Belcaid, Darrin M. Phelps, Samuel M. Goldstein, Vienna R. Brown, Michael H. Norris Jan 2024

Tracking Sero-Molecular Trends Of Swine Brucellosis In Hawai'i And The Central Pacific, Thi Hai Au La, Ian A. Mcmillan, Prashant Dahal, Andrew H. Burger, Mahdi Belcaid, Darrin M. Phelps, Samuel M. Goldstein, Vienna R. Brown, Michael H. Norris

United States Department of Agriculture Wildlife Services: Staff Publications

Introduction

Brucellosis is a zoonotic disease of mammals caused by bacterial species of the Brucella genus. The reservoir for disease is typically mammals, with species of Brucella found infecting amphibians, bats, and marine mammals. Brucella spp. can pass directly to humans through contact with infected animals or their products. Brucella spp. can cause chronic debilitating infections in mammals, including humans, and is associated with spontaneous abortions in infected animals, causing reduced fecundity. In Hawai‘i, terrestrial species that could harbor Brucella spp. include swine, cattle, horses, and axis deer among others. The numerous feral swine in Hawai‘i are known to carry …


Discovery Of A Novel Invasive Rodent Species On Wake Atoll With A Desert Southwest Usa Origin, Antoinette J. Piaggio, Eric Lanners, Daniel R. Taylor, Aaron B. Shiels, Marjorie Matocq, John Eisemann Jan 2024

Discovery Of A Novel Invasive Rodent Species On Wake Atoll With A Desert Southwest Usa Origin, Antoinette J. Piaggio, Eric Lanners, Daniel R. Taylor, Aaron B. Shiels, Marjorie Matocq, John Eisemann

United States Department of Agriculture Wildlife Services: Staff Publications

Invasive species, particularly omnivorous rodents, have damaged island ecosystems around the world. The unique flora and fauna of island systems have typically not evolved with omnivorous rodents and are heavily impacted by their introduction. Wake Atoll of the southern Pacific Ocean is a 707-hectare coral island complex of three islands managed by the United States Department of Defense (DoD). DoD restricts civilian access to the atoll but aircraft and seacraft regularly visit the island to transport military equipment and to sustain the year-round military and contractor personnel stationed on the atoll. Wake Atoll had been invaded by Rattus rattus complex …


Trichinella Murrelli Identified In Red Foxes (Vulpes Vulpes) In Pennsylvania, Usa, Jitender Dubey, Peter C. Thompson, Larissa S. De Araujo, Aditya Gupta, Sasha Kay, Oliver C. H. Kwok, Jaquin Battle, Kyle R. Van Why, Justin D. Brown, Benjamin Rosenthal Jan 2024

Trichinella Murrelli Identified In Red Foxes (Vulpes Vulpes) In Pennsylvania, Usa, Jitender Dubey, Peter C. Thompson, Larissa S. De Araujo, Aditya Gupta, Sasha Kay, Oliver C. H. Kwok, Jaquin Battle, Kyle R. Van Why, Justin D. Brown, Benjamin Rosenthal

United States Department of Agriculture Wildlife Services: Staff Publications

Trichinella infections have been eliminated from pork where pigs are raised in biosecure facilities, but wildlife infections persist. Trichinella murrelli is the primary zoonotic species in wild carnivores in the United States, having been identified in several species of omnivores and carnivores. Here, we document its occurrence in seven of 21 (33.3%) red foxes (Vulpes vulpes) from six counties in Pennsylvania. Encysted Trichinella juveniles were detected in muscle squashes (< 5 g samples) of all seven foxes, and in histological sections of the tongue and limb muscle of three. Juveniles from muscle squashes were pooled and tested in a multiplex PCR capable of differentiating all Trichinella species native to the USA; all samples contained only T. murrelli. This is the first identification of T. murrelli in red foxes from Pennsylvania, …


The Influence Of Social And Spatial Processes On The Epidemiology Of Environmentally Transmitted Pathogens In Wildlife: Implications For Management, Aakash Pandey, Chris Wojan, Abigail Feuka, Meggan E. Craft, Kezia Manlove, Kim M. Pepin Jan 2024

The Influence Of Social And Spatial Processes On The Epidemiology Of Environmentally Transmitted Pathogens In Wildlife: Implications For Management, Aakash Pandey, Chris Wojan, Abigail Feuka, Meggan E. Craft, Kezia Manlove, Kim M. Pepin

United States Department of Agriculture Wildlife Services: Staff Publications

Social and spatial structures of host populations play important roles in pathogen transmission. For environmentally transmitted pathogens, the host space use interacts with both the host social structure and the pathogen’s environmental persistence (which determines the timelag across which two hosts can transmit). Together, these factors shape the epidemiological dynamics of environmentally transmitted pathogens. While the importance of both social and spatial structures and environmental pathogen persistence has long been recognized in epidemiology, they are often considered separately. A better understanding of how these factors interact to determine disease dynamics is required for developing robust surveillance and management strategies. Here, …


Bayesian Integrated Species Distribution Models For Hierarchical Resource Selection By A Soaring Bird, Ryo Ogawa, Guiming Wang, L. Wes Burger, Bronson Strickland, J. Brian Davis, Fred L. Cunningham Jan 2024

Bayesian Integrated Species Distribution Models For Hierarchical Resource Selection By A Soaring Bird, Ryo Ogawa, Guiming Wang, L. Wes Burger, Bronson Strickland, J. Brian Davis, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Migratory birds exhibit seasonal geographic range (hereafter, range) dynamics during the annual cycle. Few studies have examined how migratory birds select their habitats for range occupancy at the species level and space use at the individual level simultaneously. We hypothesized that environmental variables directly related to fitness components would affect the range occupancy probabilities of migrants, whereas environment variables related to movements and flights would affect the space use intensities of migrants. We built Bayesian integrated species distribution models (ISDMs) to evaluate the effects of climate conditions, wind conditions, and landcover compositions on the seasonal range dynamics of American white …


Agricultural And Ecological Resources Safeguarded By The Prevention Of Wild Pig Population Expansion, Colin Jareb, Kim M. Pepin, Ryan S. Miller, Stephanie A. Shwiff, Sophie C. Mckee Jan 2024

Agricultural And Ecological Resources Safeguarded By The Prevention Of Wild Pig Population Expansion, Colin Jareb, Kim M. Pepin, Ryan S. Miller, Stephanie A. Shwiff, Sophie C. Mckee

United States Department of Agriculture Wildlife Services: Staff Publications

Wild pigs (Sus scrofa) are one of the most destructive invasive species in the United States, known for causing extensive damage to agricultural commodities, natural resources, and property, and for transmitting diseases to livestock. Following the establishment of the National Feral Swine Damage Management Program (NFSDMP) in 2014, the expansion of wild pig populations has been successfully slowed. This paper combines two modeling approaches across eight separate models to characterize the expansion of wild pig populations in the absence of intervention by the NFSDMP and forecasts the value of a subset of resources safeguarded from the threat of …


Raccoon Density Estimation From Camera Traps For Raccoon Rabies Management, Amy J. Davis, Wesley C. Dixon, Richard B. Chipman, Amy T. Gilbert, Jacob E. Hill, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan Jan 2024

Raccoon Density Estimation From Camera Traps For Raccoon Rabies Management, Amy J. Davis, Wesley C. Dixon, Richard B. Chipman, Amy T. Gilbert, Jacob E. Hill, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

Density estimation for unmarked animals is particularly challenging, yet density estimates are often necessary for effective wildlife management. Raccoons (Procyon lotor) are the primary terrestrial wildlife reservoir for Lyssavirus rabies within the United States. The raccoon rabies variant (RRVV) is actively managed at landscape scales using oral rabies vaccination (ORV) within the eastern United States. To effectively manage RRVV, it is important to know the density of raccoons to appropriately scale the density of ORV baits distributed on the landscape. We compared methods to estimate raccoon densities from camera‐trap data versus more intensive capture‐mark‐recapture (CMR) estimates across 2 …


Surveillance Of Highly Pathogenic Avian Influenza Virus In Wild Canids From Pennsylvania, Usa, Kevin D. Niedringhaus, Taylor C. Chan, Ashley Mcdowell, Lauren Mxwell, Madison Stevens, Lane Potts, Erica Miller, Eman Anis, Kyle Van Why, Thomas Keller, David Stallknecht, Rebecca L. Poulson, Kaitlyn Bahrs, Justin D. Brown Jan 2024

Surveillance Of Highly Pathogenic Avian Influenza Virus In Wild Canids From Pennsylvania, Usa, Kevin D. Niedringhaus, Taylor C. Chan, Ashley Mcdowell, Lauren Mxwell, Madison Stevens, Lane Potts, Erica Miller, Eman Anis, Kyle Van Why, Thomas Keller, David Stallknecht, Rebecca L. Poulson, Kaitlyn Bahrs, Justin D. Brown

United States Department of Agriculture Wildlife Services: Staff Publications

The avian influenza virus is a global pathogen with significant health and economic implications. While primarily a pathogen of wild and domestic birds, recent outbreaks of the H5N1 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b have caused mortality in a wide variety of mammals, including members of the Canidae family, on multiple continents. Despite sporadic mortality events globally, the epidemiology and pathobiology of H5N1 HPAIV in wild canids remains poorly defined. During 2022–2024, 41 wild canid carcasses (diagnostic cases), including 23 red foxes and 18 gray foxes, were tested for the influenza A virus (IAV) via PCR, with five …


Rabies, Amy T. Gilbert, Christine Ellis Jan 2024

Rabies, Amy T. Gilbert, Christine Ellis

United States Department of Agriculture Wildlife Services: Staff Publications

Illustrated fact sheet on rabies.


Modulation Of Persistent Inward Currents With Changes In Posture And Cutaneous Sensory Input, Ryan William Weller Jan 2024

Modulation Of Persistent Inward Currents With Changes In Posture And Cutaneous Sensory Input, Ryan William Weller

Theses and Dissertations (Comprehensive)

Spinal motor neuron (MN) persistent inward currents (PIC) increase and sustain the MN output. PIC is amplified by descending monoamines and reduced by afferent inhibition. There is strong coupling between plantar cutaneous sensory input and lower limb MNs. Given that monoaminergic drive is altered with postures and motor tasks, our purpose was to assess posture-dependent plantar cutaneous sensory modulation of tibialis anterior (TA) MNs. We hypothesize that: 1) a supine position will suppress PIC, 2) removing the load from the bottom of the heel will inflate PIC, and 3) cutaneous stimulation of the plantar aspect of the heel will reduce …


Synthesis And Biophysical Analysis Of Modified Cell-Penetrating Peptides, Joel Mitchell Jan 2024

Synthesis And Biophysical Analysis Of Modified Cell-Penetrating Peptides, Joel Mitchell

Theses and Dissertations (Comprehensive)

Cell-penetrating peptides (CPPs) are a family of peptides that have the ability to penetrate biological membranes. They were discovered in the late 1980s and have been the topic of many studies. Much of the interest in CPPs has been due to their ability to translocate biological membranes, and the possibility that they could offer a novel drug delivery method by conjugation to biologically active molecules. Linear CPPs can be modified to form cyclic structures. This change in structure has been observed to enhance the stability and penetrative ability of the CPPs which have been studied. The current thesis focuses on …


Returning To Physical Activity Following Injury: Exploring Psychological Readiness In Middle-Aged Adults, Hunter Martin Jan 2024

Returning To Physical Activity Following Injury: Exploring Psychological Readiness In Middle-Aged Adults, Hunter Martin

Theses and Dissertations (Comprehensive)

Previous researchers have focused on a variety of psychological aspects of injury rehabilitation in the context of returning to competitive sport (Ardern et al., 2016; Donald, 2019; Podlog et al., 2022; Webster et al., 2018). Return to sport decisions have been largely based on physical assessment and functional ability tests with little focus on psychological elements of recovery (Podlog et al., 2015). The existing literature on psychological readiness (PR) to return to sport has grown in recent years, primarily exploring the experiences of young adult athletes aged 18-30 (Podlog et al., 2022). There has been no previous research exploring the …


Structural And Functional Analysis Of The Putatively Virulent Gene Products Tde1414, Tde1511, And Tde2714 From The Oral Pathogen Treponema Denticola, Brock W. Corbett Jan 2024

Structural And Functional Analysis Of The Putatively Virulent Gene Products Tde1414, Tde1511, And Tde2714 From The Oral Pathogen Treponema Denticola, Brock W. Corbett

Theses and Dissertations (Comprehensive)

Periodontitis is a destructive polymicrobial disease of the teeth and gums characterized by dental plaque biofilms on the tooth surface, severe inflammation of surrounding gum tissues, and the resorption of alveolar bone. Discussed as one of the most prevalent conditions plaguing humankind, increased clinical parameters of periodontitis is associated with the increased presence of three bacteria known as the “red complex”: Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Various transcriptomic and proteomic studies of T. denticola when incorporated into mature biofilms have illuminated key gene targets the bacterium may use as virulence factors to aid in pathogenesis. …


Variation In Mainland Northwest Territories Late-Winter Muskox (Ovibos Moschatus) Density Estimations And Habitat Associations Above And Below Treeline., Charlotte Rentmeister Jan 2024

Variation In Mainland Northwest Territories Late-Winter Muskox (Ovibos Moschatus) Density Estimations And Habitat Associations Above And Below Treeline., Charlotte Rentmeister

Theses and Dissertations (Comprehensive)

The Arctic and Sub-Arctic ecosystems are seeing accelerated changes in temperature, landcover, and consequently species abundance and distributions. Reliable distributions, and associated population density estimates, are essential for effective conservation and management efforts. Growing concerns from northern communities regarding the relationship between muskox and declining caribou populations strengthens the need for updated information on muskox populations within mainland Northwest Territories (NWT). The first objective for my research was to quantify and map updated winter estimates of abundance, density, and distribution of muskoxen within three recent survey regions located in mainland NWT, using a multiple covariate distance sampling method (MCDS), paired …


Effect Of Rare Earth Element Mixtures On Daphnia Magna, Celine Do Jan 2024

Effect Of Rare Earth Element Mixtures On Daphnia Magna, Celine Do

Theses and Dissertations (Comprehensive)

Rare earth elements (REEs) are increasingly being used in modern technologies and as such, there is an increasing concern for the potential environmental risk associated with anthropogenic contamination. In addition to there being very little data available for individual REEs, there is also a lack of knowledge concerning mixtures. The objective of my study was to investigate the chronic effects of lanthanum (La) and yttrium (Y) as well as the acute effects of neodymium (Nd), praseodymium (Pr) and Y as a single metal and as a mixture to Daphnia magna. Standard 21-d chronic tests and 48-h single metal acute …


Geochemistry Of Rare Earth Elements In Simulated Natural Waters: Experiments And Modelling Of Precipitation, Complexation, And Bioavailability., Samantha Zulian Jan 2024

Geochemistry Of Rare Earth Elements In Simulated Natural Waters: Experiments And Modelling Of Precipitation, Complexation, And Bioavailability., Samantha Zulian

Theses and Dissertations (Comprehensive)

Rare earth elements (REEs) are an important part of modern technology and used for many applications. Mining, agriculture, improper recycling and medical applications can increase the concentration of these elements in surface waters. Metals in the environment including REEs can be found naturally but understanding the implications increase concentrations from anthropogenic inputs is important. REE mobility, persistence and toxicity is imperative to risk assessment as Canada begins to mine REE. Ultimately, as with other metals, the impacts of REEs in the environment should be dependent on the specific physical and chemical forms of the elements. Fractionation provides a practical method …


Examining Modulating Factors Of Dynamic Visual Acuity In Young Adults And Athletes With And Without Recent Concussion History., Katelyn Mitchell Jan 2024

Examining Modulating Factors Of Dynamic Visual Acuity In Young Adults And Athletes With And Without Recent Concussion History., Katelyn Mitchell

Theses and Dissertations (Comprehensive)

Visual attention is challenged in everyday environments with exposure to busy urban scenes and access to advancing technology. In addition, high performance sport consists of unique neurocognitive and visual demands that may distinguish cognitive functioning of an experienced athlete from the general population (Faubert, 2013; Hüttermann & Memmert, 2014; van Paridon et al., 2022). In strategic team sports, such as rugby and ice hockey, athletes must quickly process constantly-evolving visual scenes and make accurate decisions to perform successful motor actions while under high levels of physical stress (Dubois et al., 2017; van Paridon et al., 2022). The ability to attend …


Evaluating The Risk Posed By Gadolinium In The Grand River Watershed, Johann Memmel Jan 2024

Evaluating The Risk Posed By Gadolinium In The Grand River Watershed, Johann Memmel

Theses and Dissertations (Comprehensive)

Gadolinium (Gd) is a rare earth element (REE), primarily used in contrast agents for magnetic resonance imaging (MRI), with additional applications in metallurgy, phosphors, neutron shielding, and other niche applications. Both Gd and Gd-based contrast agents (GBCAs, the form used for MRIs) have been detected downstream of wastewater effluent discharges and there is currently little research into the risk this poses to aquatic ecosystems. This study investigated the potential environmental risks of Gd and GBCAs using the Grand River watershed (GRW) in southwestern Ontario as a model ecosystem due to it containing a variety of land uses (urban, industrial, agricultural) …


The Characterization Of Vig-1’S Expression Patterns In Ipnv-Infected, Or Dsrna-Treated, Rainbow Trout Cells, Samantha Lum Jan 2024

The Characterization Of Vig-1’S Expression Patterns In Ipnv-Infected, Or Dsrna-Treated, Rainbow Trout Cells, Samantha Lum

Theses and Dissertations (Comprehensive)

In Canada, annual trout production is valued at over $60M with approximately 10,000 tonnes of trout produced per year. Rainbow trout (Oncorhynchus mykiss) are one of the most commonly farmed fresh-water fish in Canada. The high-density farming practices involved in aquaculture increase rainbow trout susceptibility to aquatic viruses such as infectious pancreatic necrosis virus (IPNV). The innate antiviral immune response in rainbow trout is poorly characterized, and the functions of numerous interferon stimulated genes (ISG) in rainbow trout remain unclear. One such gene, virus-induced gene 1 (vig-1) has been poorly studied; however, the human orthologue for vig-1 …


The Effects Of Warmer Temperatures On The Physiology Of Invasive Sea Lamprey And Imperiled Populations Of Lake Sturgeon In The Laurentian Great Lakes, Milica Koledin Jan 2024

The Effects Of Warmer Temperatures On The Physiology Of Invasive Sea Lamprey And Imperiled Populations Of Lake Sturgeon In The Laurentian Great Lakes, Milica Koledin

Theses and Dissertations (Comprehensive)

Invasive sea lamprey (Petromyzon marinus) contributed to massive declines in fisheries in the Laurentian Great Lakes due to their parasitism of large-bodied salmonid fishes in the 20th century. Chemical control measures, which involve the application of 3-trifluoromethyl-4-nitrophenol (TFM) into rivers containing larval sea lamprey, were successfully implemented approximately 60 years ago to control populations. Recently, however, it was discovered that TFM tolerance increases in sea lamprey with a rise in temperature for reasons which are incompletely understood. Nor is it understood how sea lamprey will respond to warmer temperatures due to climate change, which could affect their …


Erwinia Amylovora Phage Therapy: Biocontrol Formulation, Receptor Identification, Resistance Mechanisms, Nassereldin Ibrahim Jan 2024

Erwinia Amylovora Phage Therapy: Biocontrol Formulation, Receptor Identification, Resistance Mechanisms, Nassereldin Ibrahim

Theses and Dissertations (Comprehensive)

Fire blight is known as a disease of Rosaceae and it displays infection symptoms in about 200 species in 40 rosaceous genera. The most economically important crops that are affected by fire blight are apples and pears. Fire blight can cause severe outbreaks and a single fire blight outbreak can disrupt orchard production for years. The bacterium that causes this disease is indigenous in North America, and according to Statistics Canada, economic losses in apples and pears were valued at an estimated $4 million in 2005, which is approximately 5% of the total production. In addition, production costs can increase …


Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson Jan 2024

Comparing Ionoregulation And Modes Of Nitrogen Excretion Across The Life Cycle Of Parasitic And Non-Parasitic Lamprey Species, Shannon Davidson

Theses and Dissertations (Comprehensive)

Abstract

Ionoregulation and nitrogenous waste (N-waste) metabolism in fishes has been extensively documented in teleosts and elasmobranchs, but less so in lampreys (Petromizontiformes). All lamprey species undergo metamorphosis which drastically changes their physiology and modes of feeding. However, differences in ionoregulatory mechanisms due to anadromous versus non anadromous life history strategies emerge following metamorphosis in different lamprey species. Furthermore, some species, such as anadromous juvenile sea lamprey (Petromyzon marinus), are parasitic and migrate to seawater (SW) to ingest blood protein from host fishes, while juveniles of freshwater (FW), non-parasitic species, such as the American brook lamprey …


Understanding The Significance Of Object Recognition In Cowbirds: Exploring The Interplay Of Cognition, Social Behaviour And Reproductive Success, Eric Rushton Jan 2024

Understanding The Significance Of Object Recognition In Cowbirds: Exploring The Interplay Of Cognition, Social Behaviour And Reproductive Success, Eric Rushton

Theses and Dissertations (Comprehensive)

Every day, animals use cognitive processes to make decisions in their environment such as those regarding food sources, threats and mates. One such important process provides the ability to recognize objects and individuals in order to guide future actions. Since object recognition and individual recognition are related processes, they may be linked to social cognition and to fitness; links not commonly explored in the literature. In this thesis I seek to examine (1) how brown-headed cowbirds (Molothrus ater) attend to and react to novel objects in their environment and (2) how this ability to recognize objects is related …


Impacts Of Environmental Stressors On Mummichog (Fundulus Heteroclitus) Growth And The Gh-Igf1 Pathway Using A Laboratory Bioassay, Olena Kuntyj Jan 2024

Impacts Of Environmental Stressors On Mummichog (Fundulus Heteroclitus) Growth And The Gh-Igf1 Pathway Using A Laboratory Bioassay, Olena Kuntyj

Theses and Dissertations (Comprehensive)

Using a flow-through laboratory bioassay, experiments investigated the effects of limited feeding, increased temperature, ammonium chloride (NH4Cl), and 17α-ethinylestradiol (EE2) on juvenile mummichog (Fundulus heteroclitus) growth. Weight measurements were taken every three days as the apical growth endpoint. Gene expression was examined by qPCR for genes in the GH (growth hormone)-IGF1 (insulin-like growth factor 1) pathway, including gh, igf1, and their receptors (ghra, ghrb, igf1ra, igf1rb). In Experiment 1, juvenile mummichog were exposed to excess or limited feed for 21 days. The limited-fed mummichog weighed less, were …