Digital Commons Network^™

Taphonomic Signatures Of Early Scavenging By Black And Turkey Vultures, Marian L. Wahl, Grant N. Burcham, Amanda M. Herbert, Lee A. Humberg, Patrick A. Zollner, Landon R. Jones, Brandon M. Quinby, Bryan M. Kluever

United States Department of Agriculture Wildlife Services: Staff Publications

Scavenging is critical for nutrient cycling and maintenance of healthy ecosystems. While there is substantial research into the identification of taphonomic signatures from facultative mammalian scavengers, early stage scavenging signatures by vultures remain unknown. Further, some vulture species are opportunistic predators, highlighting the need to define signatures observed in the course of normal scavenging behavior. We placed stillborn neonatal calves in an unoccupied pasture and used motion-trigger camera traps to quantify scavenging effort, then conducted necropsies to evaluate the effect of black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) scavenging effort on carcass consumption. We …

Relief Displacement Of Airborne Objects, Esteban Fernández-Juricic, Joe Crumpton, Morgan B. Pfeiffer, Sathishkummar Saiappan, Jared A. Elmore, Landon R. Jones, B. Santhana Krishnan, Raymond B. Iglay, Bradley F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

The increasing availability of unoccupied aircraft systems (UAS, also referred to as drones) has led to their use in taking vertical aerial photographs at relatively small spatial scales. These photographs can be used to measure the distances between objects appearing in the photographs. However, relief displacement can cause an object above or below ground level to appear at a point in a vertical aerial photograph that is not directly in-line with the object’s actual location, causing a measurement error. A UAS was used in this study as a photographed airborne object because its location and altitude could be controlled. We …

Reemergence Of A Big Brown Bat Lyssavirus Rabies Variant In Striped Skunks In Flagstaff, Arizona, Usa, 2021–2023, Amy T. Gilbert, Lolita I. Van Pelt, Lias A. Hastings, Crystal M. Gigante, Lillian A. Orciari, Sabrina Kelley, Kathryn Fitzpatrick, René Edgar Condori, Yu Li, Scott Brunt, April Davis, Matthew W. Hopken, Clara C. P. Mankowski, Ryan M. Wallace, Charles E. Rupprecht, Richard B. Chipman, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Background

Throughout the Americas, Lyssavirus rabies (RV) perpetuates as multiple variants among bat and mesocarnivore species. Interspecific RV spillover occurs on occasion, but clusters and viral host shifts are rare. The spillover and host shift of a big brown bat (Eptesicus fuscus) RV variant Ef-W1 into mesocarnivores was reported previously on several occasions during 2001–2009 in Flagstaff, Arizona, USA, and controlled through rabies vaccination of target wildlife. During autumn 2021, a new cluster of Ef-W1 RV cases infecting striped skunks (Mephitis mephitis) was detected from United States Department of Agriculture enhanced rabies surveillance in Flagstaff. The …

Population Response Of Eastern Wild Turkey To Removal Of Wild Pigs, Matthew T. Mcdonough, Stephen J. Zenas, Robert A. Gitzen, Mark D. Smith, Kurt C. Vercauteren, Stephen S. Ditchkoff

United States Department of Agriculture Wildlife Services: Staff Publications

There is insufficient understanding of interspecific interactions with the eastern wild turkey (Meleagris gallopavo silvestris) and wild pigs (Sus scrofa). Wild pigs compete with wild turkeys and predate nests and adults; however, population‐level effects on wild turkeys are not clear. Using cameras, we assessed responses of wild turkey populations to wild pig removal in central Alabama, USA, from 2018–2021. We compared wild turkey relative abundance and occupancy on 3 large‐scale pigremoval treatment sites (3,407–5,531 ha) relative to a control site (2,510 ha) during 1 pre‐treatment year and 2 posttreatment years, with analyses including a covariate expressing the cumulative …

Genomic Characterization Of Highly Pathogenic H5 Avian Influenza Viruses From Alaska During 2022 Provides Evidence For Genotype-Specific Trends Of Spatiotemporal And Interspecies Dissemination, Christina A. Ahlstrom, Mia Kim Torchetti, Julianna Lenoch, Kimberlee Beckmen, Megan Boldenow, Evan J. Buck, Bryan Daniels, Krista Dilione, Robert Gerlach, Kristina Lantz, Angela Matz, Rebecca L. Poulson, Laura C. Scott, Gay Sheffield, David Sinnett, David E. Stallknecht, Raphaela Stimmelmayr, Eric Taylor, Alison R. Williams, Andrew M. Ramey

United States Department of Agriculture Wildlife Services: Staff Publications

The ongoing panzootic of highly pathogenic H5 clade 2.3.4.4b avian influenza (HPAI) spread to North America in late 2021, with detections of HPAI viruses in Alaska beginning in April 2022. HPAI viruses have since spread across the state, affecting many species of wild birds as well as domestic poultry and wild mammals. To better understand the dissemination of HPAI viruses spatiotemporally and among hosts in Alaska and adjacent regions, we compared the genomes of 177 confirmed HPAI viruses detected in Alaska during April–December 2022. Results suggest multiple viral introductions into Alaska between November 2021 and August or September 2022, as …

Wildlife Monitoring With Drones: A Survey Of End Users, Raymond B. Iglay, Landon R. Jones, Jared E. Elmore, Kristine O. Evans, Sathish Samiappan, Morgan B. Pfeiffer, Brad F. Blackwell

United States Department of Agriculture Wildlife Services: Staff Publications

Rapid advancements in technology often yield research inquiry into novel applications and drone (i.e., unoccupied aircraft systems or UAS) applications in wildlife management are no exception. We questioned the time lag between drone‐related research and end‐user assessments. We implemented an online, cross‐sectional survey of wildlife professionals to better understand current drone use and benefits or concerns, complemented by a review of contemporary peer‐reviewed and gray literature. We found little disparity between scientific inquiry and end‐user experiences (i.e., similar trends among concerns in published literature and survey results). Exploring new (i.e., advancements in computer vision) and refining original drone applications (i.e., …

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

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

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

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 …

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, …

Heating Decoys To Mimic Thermal Signatures Of Live Animals For Drones, Landon R. Jones, Cerise Mensah, Jared S. Elmore, Kristine O. Evans, Morgan B. Pfeiffer, Brad F. Blackwell, Raymond B. Iglay

United States Department of Agriculture Wildlife Services: Staff Publications

Method name

Heating animal decoys to mimic thermal signatures for drones

Abstract

Thermal sensors mounted on drones (unoccupied aircraft systems) are popular and effective tools for monitoring cryptic animal species, although few studies have quantified sampling error of ani- mal counts from thermal images. Using decoys is one effective strategy to quantify bias and count accuracy; however, plastic decoys do not mimic thermal signatures of representative species. Our objective was to produce heat signatures in animal decoys to realistically match thermal images of live animals obtained from a drone-based sensor. We tested commercially available methods to heat plastic decoys of …

Competitive Behaviors Between Black Vultures (Coragyps Atratus) And Turkey Vultures (Cathartes Aura) During Scavenging / Comportamientos Competitivos Entre Coragyps Atratus Y Cathartes Aura Durante El Carroñeo, Amanda M. Herbert, Patrick A. Zollner, Landon R. Jones, Marian L. Wahl, Grant N. Burcham, Bryan M. Kluever, Lee A. Humberg, Brandon M. Quinby

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract

Interference competition occurs when an individual prohibits another’s access to a resource through antagonistic interactions. Despite considerable research on scavenger interactions at carrion, the limited evidence for competitive interactions between black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) relies upon the frequency of antagonistic interactions without considering other forms of competition. Using remote cameras, we recorded the duration of aggression, scavenging, and vigilance behaviors exhibited by individual black vultures and turkey vultures scavenging stillborn domestic cattle carcasses within flocks composed of one or both vulture species. We tested for differences of durations of each …

The Texas Feral Swine Eradication And Control Pilot Program, David R. Pipkin, Bruce R. Leland, Katherine Garwood, Linda Tschirhart-Hejl, Michael J. Bodenchuk, John M. Tomecek

United States Department of Agriculture Wildlife Services: Staff Publications

The United States Agriculture Improvement Act of 2018 (the 2018 Farm Bill) established the Feral Swine Eradication and Control Pilot Program. The program funded US$75M for 5 years, split evenly between the Natural Resources Conservation Service (NRCS) and the Animal and Plant Health Inspection Service (APHIS), both programs within the United States Department of Agriculture. The agencies solicited joint programs from states with high densities of feral swine in two phases. In Texas, NRCS and APHIS submitted three multi-county project areas along watersheds for Phase I funding and one eradication effort along with two crop protection projects in Phase II. …

Spatiotemporal Partitioning Of Two Invasive Ungulates In Guam [Abstract], Kelly J. Koriakin, Kurt C. Vercauteren, Nathan P. Snow, D. Buck Jolley

United States Department of Agriculture Wildlife Services: Staff Publications

Interspecific interactions are crucial in shaping ecosystem dynamics (Connell 1983, Tilman 1987, Barbosa and Castellanos 2005). Non-native ungulates have been introduced across the globe (Ferretti and Lovari 2014, Volery et al. 2021) and in environments where multiple invasives thrive, these co-occurring sympatric species may shift spatiotemporal patterns to minimize interspecific competition (Schoener 1974, Chesson 2000). Spatiotemporal shifts can lead to cascading effects to the native flora and fauna (Simberloff and Von Holle 1999). Given the potential negative impacts, understanding these interactions is vital for effective management of these ecosystems.

Two invasive ungulates, the wild pig (Sus scrofa) and …

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, …

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

United States Department of Agriculture Wildlife Services: Staff Publications

Illustrated fact sheet on rabies.

Valuing Social Data, Amanda Parsons, Salome Viljoen

Articles

Social data production—accumulating, processing, and using large volumes of data about people—is a unique form of value creation that characterizes the digital economy. Social data production also presents critical challenges for the legal regimes that encounter it. This Article provides scholars and policymakers with the tools to comprehend this new form of value creation through two descriptive contributions. First, it presents a theoretical account of social data, a mode of production that is cultivated and exploited for two distinct (albeit related) forms of value: prediction value and exchange value. Second, it creates and defends a taxonomy of three “scripts” that …

Tying Law For The Digital Age, Daniel A. Crane

Articles

Tying arrangements, a central concern of antitrust policy since the early days of the Sherman and Clayton Acts, have come into renewed focus with re-spect to the practices of dominant technology companies. Unfortunately, tying law’s doctrinal structure is a self-contradictory and incoherent wreck. A con-ventional view holds that this mess is due to errant Supreme Court precedents, never fully corrected, that expressed hostility to tying based on faulty economic understanding. That is only part of the story. Examination of tying law’s origins and development shows that tying doctrine was built on a now-dated paradigm of what constitutes a tying arrangement. …

Immigration Detention Abolition And The Violence Of Digital Cages, Sarah R. Sherman-Stokes

Faculty Scholarship

The United States has a long history of devastating immigration enforcement and surveillance. Today, in addition to more than 34,000 people held in immigration detention, Immigration and Customs Enforcement (“ICE”) surveils an astounding 296,000 people under its “Alternatives to Detention” program. The number of people subjected to this surveillance has grown dramatically in the last two decades, from just 1,339 in 2005. ICE’s rapidly expanding Alternatives to Detention program is marked by “digital cages,” consisting of GPS-outfitted ankle shackles and invasive phone and location tracking. Government officials and some immigrant advocates have categorized these digital cages as a humane “reform”; …

Reinstatement Of The Poly Canyon Caretaker Program Through The Development Of A Tiny Home Community, Leily Martin

Construction Management

The Poly Canyon Experimental Structures Laboratory, through its Design/Build program, is unique in the educational opportunity it provides Cal Poly College of Architecture and Environmental Design (CAED) students. However, since the conclusion of the Caretaker Program in 2011, the facility’s structures have deteriorated due to vandalism, purposeful destruction, and weathering. This study examines the perspectives of CAED students, the interim CAED Dean, Kevin Dong, and Cal Poly Risk Manager, Mike Morgan, on the effectiveness in reinstating the Caretaker Program through the development of a tiny home community. Results indicated educational value in this facility, so addressing these issues must occur …

The California Bridge Model For Emergency Department-Initiated Medication-Assisted Treatment For Opioid Use Disorder: Adaptations For Perinatal Hospital Services, Devin C. Thomas

Yale School of Nursing Digital Theses

Background: Poor access to gender-specific, pregnancy-focused medication-assisted treatment for perinatal opioid use disorder greatly contributes to adverse outcomes for pregnant patients, infants, and society, at large. It is well established that Emergency Department-initiated pharmacotherapy for opioid use disorder is safe, effective, and can be rapidly adopted by hospital systems to improve access to care for people who misuse opioids. Like the Emergency Department, perinatal hospital services are well positioned to serve as critical access points in the treatment of perinatal opioid use disorder. However, concerns such as lack of training, workflow inefficiencies, and bias act as barriers to co-located, integrated …

Co-Expression Of Prepulse Inhibition And Schizophrenia Genes In The Mouse And Human Brain, Lillian Garrett, Dietrich Trümbach, Donghyung Lee, Silvia Mandillo, Rodney Samaco, Ann M Flenniken, Michelle Stewart, Impc Consortium, Jacqueline K White, Colin Mckerlie, Lauryl M J Nutter, Igor Vukobradovic, Surabi Veeraragavan, Lisa Yuva, Jason D Heaney, Mary E Dickinson, Hamid Meziane, Yann Hérault, Sara Wells, K C Kent Lloyd, Lynette Bower, Louise Lanoue, Dave Clary, Annemarie Zimprich, Valerie Gailus-Durner, Helmut Fuchs, Steve D M Brown, Elissa J Chesler, Wolfgang Wurst, Martin Hrabě De Angelis, Sabine M Hölter

Faculty, Staff and Students Publications

Schizophrenia is a complex psychiatric disorder with genetic and phenotypic heterogeneity. Accumulating rare and genome-wide association study (GWAS) common risk variant information has yet to yield robust mechanistic insight. Leveraging large-scale gene deletion mouse phenomic data thus has potential to functionally interrogate and prioritize human disease genes. To this end, we applied a cross-species network-based approach to parse an extensive mouse gene set (188 genes) associated with disrupted prepulse inhibition (PPI), a Schizophrenia endophenotype. Integrating PPI genes with high-resolution mouse and human brain transcriptomic data, we identified functional and disease coherent co-expression modules through hierarchical clustering and weighted gene co-expression …

Understanding The Dynamics Of Food And Economic Development In The Community Of Kakisa, Northwest Territories, Canada, Laura Rodriguez Reyes

Theses and Dissertations (Comprehensive)

For Indigenous Peoples, the land embodies a source of cultural and spiritual well-being that is linked to their way of life and identities through divine and traditional connections. Unfortunately, colonial powers, the global food system, socioeconomic inequalities and environmental degradation are impacting northern Indigenous lands and food systems, leading to food insecurity. Nevertheless, communities are still thriving in the face of adversity. In the Northwest Territories, on the lands of Ka’a’gee Tu First Nations (KTFN) in the community settlement of Kakisa, people are growing food through vegetable gardens and greenhouses to support their vision of a resilient food system.

Through …

Fishes In Murky Waters: Effects Of Total Suspended Solids On Fish Gills And Performance, Xena Montoya

Theses and Dissertations (Comprehensive)

Total suspended solids (TSS) naturally occur in aquatic habitats, but climate change and other anthropogenic disturbances can lead to increased levels. Exposure to high levels of TSS has the potential to damage fish gills through abrasion, leading to impairment of gill function and fish physiology. However, little work has been done exploring the linkages between TSS-induced gill damage and animal performance. Therefore, we tested the hypothesis that TSS damages gill structure, causing gill dysfunction and reducing swimming performance. We exposed salmonids (rainbow trout, brook trout and cutthroat trout) and non-salmonids (fathead minnow and longnose dace) to different TSS concentrations (0-1000 …

Advancing Machine Learning Interpretability: Lime Applications To Temporal Data And A Novel Method Of Counterfactual Generation, Shou Nakano, Yang Liu

Theses and Dissertations (Comprehensive)

As machine learning has advanced significantly over the past decade, predictive models have achieved substantial success across various domains. However, they often lack transparency in their decision-making processes. This opacity presents risks, particularly in sectors like healthcare and finance, where transparency is crucial. To address these challenges, explainable artificial intelligence (XAI) has risen in importance. Techniques such as LIME (Local Interpretable Model-agnostic Explanations) have been developed, utilizing simpler alternative models like linear regression or tree-based models to explain decisions for specific instances.

This thesis initially concentrates on the application of LIME to three global annual datasets, specifically within the relatively …

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 …

Genome-Based Pathogenicity Potential Of Salmonella Isolated From Diverse Sources, Jared Mr Crocco

Theses and Dissertations (Comprehensive)

Bacterial human pathogens are among the leading causes of death around the world, especially in low income and developing countries. One important element in a bacterium’s ability to cause disease are genes that directly contribute to pathogenicity called virulence factors. A second significant aspect are antimicrobial resistance genes which allow microorganisms to persist in the presence of antimicrobial agents. In this project I aimed to determine if Salmonella isolated from different sources differed in pathogenicity profiles based on the complement of genes identified through genomic analysis. Accordingly, Salmonella genomes were organized into 8 groups: animal, clinical, human, environmental, food, water …

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) …