Evidence For Irruptive Fluctuation In Axis Deer Of Hawai‘I, Steven C. Hess, Jonathan Sprague, Jacob Muise

United States Department of Agriculture Wildlife Services: Staff Publications

Axis deer on the Hawaiian Islands of Maui, Lāna‘i, and Moloka‘i simultaneously experienced one of the most dramatic population crashes on record in 2020-2021, which coincided with extended drought conditions and prompted an emergency declaration for these islands. This phenomenon has been anecdotally documented during previous drought events in 2011-2012, but never formally studied. Newspaper articles document abundant deer becoming a nuisance to agriculture and natural resources, and then experiencing high mortality during droughts. This phenomenon fits Caughley’s (1970) operational definition of eruptive (sic) fluctuation “…as an increase in numbers over at least two generations, followed by a marked decline.” …

Abert’S Squirrel Management In Support Of Endangered Mount Graham Red Squirrel Recovery In Arizona, Aaron R. Morehead, Christopher Carillo, Holly Hicks, Wade Sanders, David L. Bergman

United States Department of Agriculture Wildlife Services: Staff Publications

Recovery of the endangered Mount Graham red squirrel (MGRS) will likely be long and challenging. Its limited habitat, isolation to Pinaleño Mountain range, and demographic characteristics restrict its ability to rebound quickly from threats that impact both the squirrel and its habitat. Currently, threats to the MGRS include habitat degradation and loss through high-severity wildfire, fire suppression activities, insect outbreaks, climate change, and human development, and predation, as well as competition with Abert’s squirrels. The most recent wildfire in 2017 impacted over 48,000 acres of already reduced habitat. A critical first step is to protect and manage the remaining population …

Predation Thresholds For Reintroduction Of Native Avifauna Following Suppression Of Invasive Brown Treesnakes On Guam, Robert M. Mcelderry, Eben H. Paxton, Andre V. Nguyen, Shane R. Siers

United States Department of Agriculture Wildlife Services: Staff Publications

The brown treesnake (BTS) (Boiga irregularis) invasion on Guåhan (in English, Guam) led to the extirpation of nearly all native forest birds. In recent years, methods have been developed to reduce BTS abundance on a landscape scale. To help assess the prospects for the successful reintroduction of native birds to Guåhan following BTS suppression, we modeled bird population persistence based on their life history characteristics and relative sensitivity to BTS predation. We constructed individual-based models and simulated BTS predation in hypothetical founding populations for each of seven candidate bird species. We represented BTS predation risk in two steps: …

Migratory Movements And Home Ranges Of Geographically Distinct Wintering Populations Of A Soaring Bird, Ryo Ogawa, J. Brian Davis, D. Tommy King, L. Wes Burger, Bronson K. Strickland, Marsha A. Sovada, Guiming Wang, Fred L. Cunningham

United States Department of Agriculture Wildlife Services: Staff Publications

Migratory soaring birds exhibit spatiotemporal variation in their circannual movements. Nevertheless, it remains uncertain how different winter environments affect the circannual movement patterns of migratory soaring birds. Here, we investigated annual movement strategies of American white pelicans Pelecanus erythrorhynchos (hereafter, pelican) from two geographically distinct wintering grounds in the Southern and Northern Gulf of Mexico (GOM).We hypothesized that hourly movement distance and home range size of a soaring bird would differ between different geographic regions because of different thermals and wind conditions and resource availability. We calculated average and maximum hourly movement distances and seasonal home ranges of GPS-tracking pelicans. …

Toxicity Of The Technology Critical Elements Germanium And Yttrium To Daphnia Magna And Hyalella Azteca And The Influence Of Toxicity Modifying Factors, Rashid Shah

Theses and Dissertations (Comprehensive)

Technology critical elements (TCEs) are increasingly used in high and green technologies but there is little aquatic toxicity data for TCEs, particularly in fresh water. The objective of this study was to investigate the toxicity of two TCEs, Ge and Y, to Daphnia magna and Hyalella azteca and to understand the role of natural organic matter and cations on toxicity modification. Testing followed standard methods. The 48 h EC50 for D. magna was 11.6 (95% CI of 9.64-13.8) mg Ge/L based on measured dissolved concentrations at test end. The addition of NOM at 10 mg DOC/L resulted in a significant …

Susceptibility Of Wild Canids To Sars-Cov-2, Stephanie M. Porter, Aim E. Hartwig, Helle Bielefeldt-Ohmann, Angela M. Bosco-Lauth, J. Jeffrey Root

United States Department of Agriculture Wildlife Services: Staff Publications

We assessed 2 wild canid species, red foxes (Vulpes vulpes) and coyotes (Canis latrans), for susceptibility to SARS-CoV-2. After experimental inoculation, red foxes became infected and shed infectious virus. Conversely, experimentally challenged coyotes did not become infected; therefore, coyotes are unlikely to be competent hosts for SARS-CoV-2.

Throughout the COVID-19 pandemic, multiple instances of natural infections with SARS-CoV-2 have been reported in pet dogs, likely after exposure to an infected human (1–3). Domestic dogs appear to be minimally susceptible to SARS-CoV-2, as indicated by experimental inoculations resulting in reverse transcription PCR–positive samples and low titer antibody responses but no clinical …

Exploring The Value Of A Global Gene Drive Project Registry, Riley I. Taitingfong, Antoinette J. Piaggio, Cinnamon S. Bloss, Et Al.

United States Department of Agriculture Wildlife Services: Staff Publications

Recent calls to establish a global project registry before releasing any gene-drive-modified organisms (GDOs) have suggested a registry could be valuable to coordinate research, collect data to monitor and evaluate potential ecological impacts, and facilitate transparent communication with community stakeholders and the general public. Here, we report the results of a multidisciplinary expert workshop on GDO registries convened on 8–9 December 2020 involving 70 participants from 14 countries. Participants had expertise in gene drive design, conservation and population modeling, social science, stakeholder engagement, governance and regulation, international policy, and vector control; they represented 45 organizations, spanning national and local governmental …

Discovery Of Inhibitors Of Peptidoglycan O-Acetyltransferase B (Patb) From Neisseria Gonorrhoeae, A New Potential Antibacterial Target, Stefen Stangherlin

Theses and Dissertations (Comprehensive)

Experts project that by 2050, 10 million lives will be lost annually as a result of antimicrobial resistant infections, surpassing all current leading causes of death, and costing the global economy $100 trillion USD on healthcare efforts. To promote research and development of novel antibiotics, the World Health Organization and Centers for Disease Control and Prevention released a list of priority pathogens regarded as serious or urgent threats of antimicrobial resistance. Many pathogenic bacteria, including several priority pathogens, produce O-acetylated peptidoglycan to establish infection and avoid host immune responses. Consequently, the enzymes responsible for producing O-acetylated peptidoglycan in Gram-negative pathogenic …

Changes In Plant Community Composition, Structure, And Function In Response To Permafrost Thaw, Katherine Standen

Theses and Dissertations (Comprehensive)

Air temperature is increasing at three or more times the global average in high latitudes, causing widespread permafrost thaw across the boreal biome. Since the boreal biome stores 30-40% of global terrestrial carbon (C), of which about 30-45% is found in permafrost soils, this temperature increase could cause a large efflux of C to the atmosphere. Climate warming and permafrost thaw are also expected to alter plant community composition and productivity and, given the link between plant functional traits and ecosystem C fluxes, may alter overall ecosystem function. Across the boreal biome of western Canada, we know surprisingly little about …

The Electrophysiological Correlates Of Text Integration And Direct Vs. Indirect Articles: A Centralized And Lateralized Examination, Deanna C. Hall

Theses and Dissertations (Comprehensive)

As we read, we develop mental models of the discourse content called situation models. Situation models are integral to how we keep track of information, and to do so in an ongoing event incoming information needs to be integrated into the model or discarded. The type of information being presented, and its relation to prior data, impacts how that new information is processed. The current research examined discourse passages containing concepts that were either previously mentioned (match), mentioned with a general term (general category), unmentioned in lieu of another concept (mismatch), or completely unmentioned previously (indeterminate), and examined how these …

Arctic Stream Characteristics And Diet Analysis Choice Impact Condition And Diet Estimates Of Ninespine Stickleback (Pungitius Pungitius), Adam Kuhrt

Theses and Dissertations (Comprehensive)

Ninespine stickleback (Pungitius pungitius) are ubiquitous in circumpolar freshwaters, but their ecological role is not well understood. Little research has been conducted on the influence of environmental variables on ninespine stickleback in stream environments, and while they are understood to be generalist feeders, their diet in stream environments is equally understudied. Determining diet is difficult due to biases inherent in all standard diet analysis methods. Morphological gut-content analysis (M-GCA), DNA metabarcoding of gut contents (D-GCA), and stable isotope analysis (SIA) are currently three of the most frequently conducted diet analyses; and while combinations of these methods are commonly …

Impacts Of Changing Permafrost Conditions On Vegetation Productivity In The Northern Boreal Forest, Emily Ogden

Theses and Dissertations (Comprehensive)

Vegetation productivity across the boreal forest has increased over the past several decades. However, at a regional scale there is large variation from increased (greening) to decreased (browning) productivity and large areas with no measured change. Some of this variation can be explained by disturbances, such as wildfire, or by increased climate variability. In northern regions underlain by permafrost, the interactions between climate, disturbance, and vegetation productivity may be more complex. For my thesis, I used a time-series of ground thermal data from permafrost monitoring sites established by the Geological Survey of Canada along a latitudinal transect of the Northwest …

Effects Of 17Α-Ethinylestradiol (Ee2) On Gonadal Development And Gene Expression In Larval Mummichog (Fundulus Heteroclitus), Carly Sing-Judge

Theses and Dissertations (Comprehensive)

The mummichog (Fundulus heteroclitus) is a small-bodied estuarine fish that inhabits the North American east coast and is often used as a model adult saltwater fish in environmental bioassays. This study aimed to describe gonadal development and gene expression levels in five-week-old mummichog under control conditions and following 17α-ethinylestradiol (EE₂) treatment in order to better understand the susceptibility of sex determination (SD) and gonadal differentiation (GD) processes following contaminant exposure. In the first experiment, eggs were fertilized, collected and incubated in the laboratory for three weeks, then yolk-sac larvae were grown out for five weeks and …

Impact Of Orthophosphate As A Corrosion Inhibitor And Chloramine Disinfectant On Drinking Water Biofilm Communities, Mitchell Cooke

Theses and Dissertations (Comprehensive)

A drinking water distribution system (DWDS) must maintain conditions within quality standards which assure the effective and safe transport of finished drinking water from treatment plants to the household tap. Although safe to drink, finished water is not sterile, and may contain hundreds of microorganisms in a single milliliter. These microorganisms are present from the source waters, such as lakes, rivers and aquifers, and have passed through early treatment steps. Final treatment steps, such as the maintenance of disinfectant residuals, are used to further minimize viable cells present and focus on the reduction of harmful organisms. Microbial cells entering the …

Design And Validation Of Artificial Feeders To Study Feeding Preferences And Growth Of Hematophagous Juvenile Sea Lamprey (Petromyzon Marinus), Gracie Li-Ting-Wai

Theses and Dissertations (Comprehensive)

The parasitic and invasive land-locked sea lamprey Petromyzon marinus populations contributed to the collapse of the Great Lakes fisheries in the mid-1900s, while native anadromous populations are currently under threat and require conservation efforts for protection. Despite the increasing concern for both populations of this species, the juvenile stage of the sea lamprey’s life cycle has not been well studied. This is due, in part, to ethical concerns raised around holding live host fish with juveniles and the lack of an alternative feeding method to maintain these juveniles in the laboratory. The feeder should be designed to minimize fouling of …

Young Adult And Adolescent Balance Control Strategies During A Dual-Task Stone-Stepping Paradigm, Emily Ford

Theses and Dissertations (Comprehensive)

Stone-stepping demands greater attention and visuomotor integration, as it requires precise foot placement. The amount of attention required during locomotion is typically assessed with a secondary task, by analyzing the dual-task cost. Adolescents are suggested to have a greater dual-task cost than young adults and demonstrate balance control impairments while dual-tasking walking. The purpose of the current study was to explore the balance control differences between adolescents and young adults during a stone-stepping paradigm. We hypothesized that adolescents would experience greater balance control deficits while performing the secondary task compared to the young adults, especially while on the uneven terrain. …

The Lived Experiences Of Female Informal Caregivers For Individuals With Young-Onset Dementia, Hailey A. O'Neil

Theses and Dissertations (Comprehensive)

Abstract

Objective: Informal CGs for individuals with dementia experience an increased risk of compromised health. However, CGs of individuals with young-onset dementia (CGs-YOD) are more likely to have longer caregiving durations, less social support, and heavier caregiver burdens than those caring for people with LOD (Arai et al., 2007). Further, there are limited resources available to CGs-YOD, increasing their likelihood of negative health outcomes associated with CGs roles. This qualitative study investigated the experiences of female informal CGs-YOD specifically examining the effect of providing informal care on CGs overall health and well-being.

Methods: The theoretical orientation used to guide the …

The Avian Hippocampal Declarative Memory System, Chelsey C. Damphousse

Theses and Dissertations (Comprehensive)

Across Mammalia, memory has long been dissociated into multiple component systems specialized to process specific facets of experience. Among these segregated systems, declarative memory is processed by the hippocampus and surrounding structures, which have collectively been referred to as the hippocampal declarative memory system (HDMS). The HDMS, in turn, can be further divided into parallel streams dedicated to the processing of spatial versus object identity based information, commonly discussed as the ‘what’ and ‘where’ streams. While we know that the organization of the HDMS is conserved in humans, nonhuman primates, and rats, evidence outside Mammalia is lacking. Here HDMS homology …

Psychological Resilience In Student-Athletes During The Covid-19 Pandemic, Henley Lapid

Theses and Dissertations (Comprehensive)

The purpose of this qualitative study was to examine the psychological resilience process in student-athletes during the unique adverse context of the COVID-19 pandemic. The study sought to answer the following research questions guided by Fisher et al.’s (2019) heuristic framework: (1) What resilience mechanisms, (2) promoting factors, and (3) resilience outcomes were experienced by participants in their resilience demonstrations? and (4) How does the resilience process unfold over time across adverse contexts including the COVID-19 pandemic? Nine student-athletes from Wilfrid Laurier University were interviewed on their experiences demonstrating resilience within and outside of the pandemic. A thematic analysis (Braun …

The Role Of Ovarian Hormones In Appetite-Regulation: Examining The Post-Exercise Appetite Response In Pre- Vs Post-Menopausal Females, Jessica A.L. Tucker

Theses and Dissertations (Comprehensive)

INTRODUCTION: Appetite fluctuates across the menstrual cycle, suggesting ovarian hormones are involved in the regulation of appetite hormones and energy intake. Exercise is another regulator of appetite with higher intensity exercise generating a greater and more consistent suppression. Considering there is limited evidence investigating the role of ovarian hormones in appetite regulation, menopause represents a stage of life where ovarian function declines, thus providing an opportunity to further explore the role of ovarian hormones in the appetite-regulatory response to exercise. PURPOSE: To examine the role of ovarian hormones on appetite-regulating hormones in pre- and post-menopausal females following a …

Diversity And Evolution Of Inflorescences In Cuscuta, Morgan Glofcheskie

Theses and Dissertations (Comprehensive)

Cuscuta (dodder) includes ca. 200 species of plant obligate stem parasites with both ecological and economical significance. Inflorescences have been historically used in Cuscuta for species descriptions and identification keys, but no comprehensive study exists to date. The main objective of this study was to survey the diversity of inflorescences, and to understand their evolution and possible form-function relationships. The inflorescence architecture of 132 Cuscuta taxa was analyzed using herbarium specimens, and eight species were grown to study their inflorescence development. Inflorescence traits were mapped into a genus phylogeny obtained from a combined analysis of nuclear ITS and plastid trnL-F …

Endocrine Disruptors: Challenges And Future Directions In Epidemiologic Research, V. Ho, L. Pelland-St-Pierre, S. Gravel, M. F. Bouchard, M.-A. Verner, F. Labrèche

Études primaires

Public concern about the impact of endocrine disrupting chemicals (EDCs) on both humans and the environment is growing steadily. Epidemiologic research provides key information towards our understanding of the relationship between environmental exposures like EDCs and human health outcomes. Intended for researchers in disciplines complementary to epidemiology, this paper highlights the importance and challenges of epidemiologic research in order to present the key elements pertaining to the design and interpretation of an epidemiologic study on EDCs.

The conduct of observational studies on EDCs derives from a thoughtful research question, which will help determine the subsequent methodological choices surrounding the careful …

Evaluating Stability Of Human Spine In Static Tasks: A Combined In Vivo-Computational Study, Farshid Ghezelbash, Ali Shahvarpour, Christian Larivière, Aboulfazl Shirazi-Adl

Études primaires

Various interpretations and parameters have been proposed to assess spinal stability such as antagonist muscle coactivity, trunk stiffness and spinal buckling load; however, the correlation between these parameters remains unknown. We evaluated spinal stability during different tasks while changing the external moment and load height and investigated likely relationships between different EMG- and model-based parameters (e.g., EMG coactivity ratio, trunk stiffness, force coactivity ratio) and stability margins. EMG and kinematics of 40 young healthy subjects were recorded during various quasi-static tasks. Muscle forces, trunk stiffness and stability margins were calculated by a nonlinear subject-specific EMG-assisted-optimization musculoskeletal model of the trunk. …

Microbial Contamination And Metabolite Exposure Assessment During Waste And Recyclable Material Collection, Fabiola Salambaga, Loïc Wingert, Isabelle Valois, Nancy Lacombe, François Gouin, Julien Trépanier, Maximilien Debia, Ewelina Soszczyńska, Magdalena Twarużek, Robert Kosicki, Marta Dias, Susana Viegas, Liliana Caetano, Carla Viegas, Geneviève Marchand

Études primaires

Waste workers are exposed to bioaerosols when handling, lifting and dumping garbage. Bioaerosol exposure has been linked to health problems such as asthma, airway irritant symptoms, infectious, gastrointestinal and skin diseases, and cancer. Our objective was to characterize the exposure of urban collectors and drivers to inhalable bioaerosols and to measured the cytotoxic effect of air samples in order to evaluate their health risk.

Personal and ambient air sampling were conducted during the summer of 2019. Workers from 12 waste trucks collecting recyclables, organic waste or compost were evaluated. Bacteria and fungi were cultured, molecular biology methods were used to …

Occupational Exposure To Wood Dust And The Burden Of Nasopharynx And Sinonasal Cancer In Canada, Amirabbas Mofidi, Emile Tompa, Christina Kalcevich, Christopher Mcleod, Martin Lebeau, Chaojie Song, Joanne Kim, Paul A. Demers

Études primaires

Background: Millions of workers around the world are exposed to wood dust, as a by-product of woodworking. Nasopharynx cancers (NPCs) and sinonasal cancers (SNCs) are two cancers that can be caused by occupational exposure to wood dust, but there is little evidence regarding their burden in Canada. Objective: the aim of this study was to estimate the incidence and economic burden of newly diagnosed cases of NPC and SNC in 2011 in Canada, attributable to occupational exposures to wood dust. Methods: calculating the incidence of cancer attributable to occupational exposure involved three steps of defining relative risk, assessing the prevalence …

Submaximal Electromyography-Driven Musculoskeletal Modeling Of The Human Trunk During Static Tasks: Equilibrium And Stability Analyses, Farshid Ghezelbash, Aboulfazl Shirazi-Adl, Denis Gagnon, Ali Shahvarpour, Navid Arjmand, Amir Hossein Eskandari, Christian Larivière

Études primaires

Conventional electromyography-driven (EMG) musculoskeletal models are calibrated during maximum voluntary contraction (MVC) tasks, but individuals with low back pain cannot perform unbiased MVCs. To address this issue, EMG-driven models can be calibrated in submaximal tasks. However, the effects of maximal (when data points include the maximum contraction) and submaximal calibration techniques on model outputs (e.g., muscle forces, spinal loads) remain yet unknown. We calibrated a subject-specific EMG-driven model, using maximal/submaximal isometric contractions, and simulated different independent tasks. Both approaches satisfactorily predicted external moments (Pearson’s correlation ∼ 0.75; relative error = 44%), and removing calibration tasks under axial torques markedly improved …

Comparative Genomics, Evolutionary Epidemiology, And Rbd-Hace2 Receptor Binding Pattern In B.1.1.7 (Alpha) And B.1.617.2 (Delta) Related To Their Pandemic Response In Uk And India, Chiranjib Chakraborty, Ashish Ranjan Sharma, Manojit Bhattacharya, Bidyut Mallik, Shyam Sundar Nandi, Sang-Soo Lee

Journal Articles: Cellular & Integrative Physiology

BACKGROUND: The massive increase in COVID-19 infection had generated a second wave in India during May-June 2021 with a critical pandemic situation. The Delta variant (B.1.617.2) was a significant factor during the second wave. Conversely, the UK had passed through the crucial phase of the pandemic from November to December 2020 due to B.1.1.7. The study tried to comprehend the pandemic response in the UK and India to the spread of the B.1.1.7 (Alpha, UK) variant and B.1.617.2 (Delta, India) variant.

METHODS: This study was performed in three directions to understand the pandemic response of the two emerging variants. First, …

T-Lymphocyte Tyrosine Hydroxylase Regulates T H 17 T-Lymphocytes During Repeated Social Defeat Stress, Safwan K. Elkhatib, Cassandra M. Moshfegh, Gabrielle F. Watson, Adam J. Case

Journal Articles: Cellular & Integrative Physiology

Posttraumatic stress disorder (PTSD) is a debilitating psychiatric disorder which results in deleterious changes to psychological and physical health. Patients with PTSD are especially susceptible to life-threatening co-morbid inflammation-driven pathologies, such as autoimmunity, while also demonstrating increased T-helper 17 (T_H17) lymphocyte-driven inflammation. While the exact mechanism of this increased inflammation is unknown, overactivity of the sympathetic nervous system is a hallmark of PTSD. Neurotransmitters of the sympathetic nervous system (i.e., catecholamines) can alter T-lymphocyte function, which we have previously demonstrated to be partially mitochondrial redox-mediated. Furthermore, we have previously elucidated that T-lymphocytes generate their own catecholamines, and strong …

Time-Dependent Alteration In The Chemoreflex Post-Acute Lung Injury, Kajal Kamra, Nikolay Karpuk, Ryan Adam, Irving H. Zucker, Harold D. Schultz, Han-Jun Wang

Journal Articles: Cellular & Integrative Physiology

Acute lung injury (ALI) induces inflammation that disrupts the normal alveolar-capillary endothelial barrier which impairs gas exchange to induce hypoxemia that reflexively increases respiration. The neural mechanisms underlying the respiratory dysfunction during ALI are not fully understood. The purpose of this study was to investigate the role of the chemoreflex in mediating abnormal ventilation during acute (early) and recovery (late) stages of ALI. We hypothesized that the increase in respiratory rate (fR) during post-ALI is mediated by a sensitized chemoreflex. ALI was induced in male Sprague-Dawley rats using a single intra-tracheal injection of bleomycin (Bleo: low-dose = 1.25 mg/Kg or …

Discovery Of Pharmaceutical Agents Towards The Inhibition Of P38 Mitogen- Activated Protein Kinase (Mapk): In Silico And In Vitro Studies, Utid Suriya

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, we combined the accelerated in silico screening methods alongside experimental evaluations to search for novel anti-non-small cell lung cancer (NSCLC) drug candidates specifically targeting the up-regulated kinases including epidermal growth factor receptor tyrosine kinase (EGFR TK), p38 mitogen-activated protein kinase (p38 MAPK) and Janus kinase 2 (JAK2). A novel compound scaffold, quinoxalinones including CPD4, CPD15, CPD16, and CPD21 was identified to inhibit the EGFR (L858R/T790M/C797S) TK with an IC50 value down to a nanomolar scale as well as showing a cytotoxic effect against NSCLC cell lines. Apart from that, we employed a drug repositioning platform to elucidate …