Physical Sciences and Mathematics Commons^™

Low-Emission Beef Production In The Southern Rangelands Of Western Australia: An Analysis Of Herd Structure And Stocking Rate Experiencing Droughts, Christophe D'Abbadie

Animal Production and Livestock Research Articles

Reconciling profitable cattle production with rangeland health and reduced emissions is a key challenge in the southern rangelands of Western Australia (WA). Stocking rate and herd structure selection are crucial decisions to achieve this balance. This study assessed the emission profiles of three contrasting herd structures (weaner production, live export, and slaughter production), and three stocking rates within a herd–carbon accounting modelling framework. The analysis considers the impact of varying drought frequencies on these cattle production systems. Herd models were developed for the semiarid southern WA rangelands. Stocking rates were set at 100%, 80% and 66% of the government recommended …

Density-Dependence Inside A Marine Protected Area Increases Natural Mortality And Stunts The Growth Of A Spiny Lobster, Simon De Lestang, Emma Jade Tuffley

Fisheries Research Articles

Sustainable fisheries management often requires the modelling of stocks under unfished conditions, when the influence of population densities on animal growth and mortality can be substantial. This can be especially true for species such as spiny rock lobster, which are very habitat specific. Using western rock lobster (Panulirus cygnus) tag-recapture data from adjacent and similar fished and unfished areas, the key life history parameters of natural mortality and growth were examined and compared under different population density scenarios. In an area representative of virgin biomass levels, lobsters exhibited reduced growth rates and a substantially higher rate of natural mortality …

Tracing Atlantic Sea Scallops Using Radio Frequency Identification (Rfid) Technology, Will Shoup, David Rudders, Jonathon Peros

The Journal of Extension

Radio Frequency Identification (RFID) represents a technology that has the potential to enhance many aspects of the Atlantic sea scallop fishery. Driven by fishery management and market forces, fishery product traceability benefits fisheries managers, consumers, and fishermen. In order to demonstrate the capabilities of RFID technology in the scallop fishery, a solution is proposed that would help establish clear Chain of Custody (CoC) so that the scallop supply chain can be better documented. Implementation and acceptance of any new technology will hinge on effective communication and extension efforts that can leverage the multi-benefit aspects of adopting RFID into the fishery.

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

School of Natural Resources: Dissertations, Theses, and Student Research

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

Impacts Of Invasive Carp And Their Population Dynamics On Fish Communities In The Missouri River, Joshua F. Kocik

School of Natural Resources: Dissertations, Theses, and Student Research

Invasive Carp species: Silver Carp Hypophthalmichthys molitrix, Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Black Carp Mylopharyngodon piceus have both potential and realized abilities to negatively impact native species. Specifically, Bighead Carp and Silver Carp as filter feeders have been theorized to be detrimental not only to adult filter-feeding species, but to many fish which rely on plankton and algae in their early-life stages. The impact of Invasive Carp on the overall fish community remains underexplored. The fish communities below Gavins Point Dam (Invasive Carp present) and Fort Randall Dam (Invasive Carp absent) afford the …

Phylogenetic And Biogeographic Patterns Of Devonian Proetid Trilobites, Katherine Jane Jordan

Dissertations and Doctoral Documents from University of Nebraska-Lincoln, 2023–

Ecological disruption events such as mass extinctions can result in the permanent alteration in clades and ecosystems. A pivotal time of change during the history of life on Earth can be seen in the Devonian Period. During this time, major transitions in marine and terrestrial system resulted in a different world at the end of the period in comparison to the beginning. One such group most heavily impacted were trilobites. Trilobites were reduced to one order by the end of the Devonian: Proetida. My dissertation focuses on phylogenetic, biogeographic, and paleocommunity patterns of this group, known as the last of …

Road Mitigation Structures Designed For Texas Ocelots: Influence Of Structural Characteristics And Environmental Factors On Non-Target Wildlife Usage, Anna Rivera Roy, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and …

Microplastic Accumulation In The Marsh Periwinkle (Littoraria Irrorata), Sarah Keaton, Hannah Lukhard, Eli Windy, Manar Hasan

DePaul Discoveries

Contamination of oceans by microplastics (mm) currently poses a major threat to aquatic and terrestrial ecosystems worldwide. Recent attention towards this issue has raised questions about the extent to which microplastics have accumulated in the environment, and has led to an increase in studies on the effects of microplastics in various organisms. However, levels of contamination in protected natural areas are still largely unexplored, yet can offer an important empirical perspective on the issue. In addition, little is known about the potential effects of microplastics on behavior in the field. This research was conducted within the protected ACE Basin National …

Postweaning Skull Growth In Living Didelphid Marsupials: The Case Of Gracilinanus Agilis And Cryptonanus Chacoensis, Iveth A. Villalobos Guerrero, Noé U. De La Sancha

DePaul Discoveries

Ontogeny is described as the history of an organism through its lifetime including development, growth, and allometry. The ontogenetic approach in cranial dimensions has proved useful in interpreting evolutionary patterns. Among the largest Didelphidae family of Neotropical marsupials, the species of Gracilinanus agilis and Cryptonanus chacoensis are poorly known. In this study, we address three questions; Is there sexual dimorphism in these species? What is the pattern of allometry? Which allometric patterns best describe the patterns in the skull and mandible? We applied geometric morphometrics to describe and test these differences using MorphoJ. A discriminant function analysis was performed to …

The Fishing Cat: New Insights On Distribution In The Northern Sector Of Chitwan National Park, Nepal, Rupesh Maharjan, Rama Mishra, Jhamak Bahadur Karki

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Fishing cat Prionailurus viverrinus (Bennett, 1833) is an elusive and medium-sized feline species with distinguished marking patterns on their head and body separating them from other feline species. Despite being distributed widely among diverse geographic locations, their abundance has declined due to significant habitat loss and human disturbances. There exists a substantial research gap regarding their abundance and distribution in Nepal. In this article, we presented the updated documentation of the fishing cat distribution in the northern sector of Chitwan National Park through our species-focused camera trapping survey. The study was carried out between April and May 2021 with a …

Biostratigraphic Revision Of Esthonyx (Tillidontia, Mammalia) In The Contect Of Climate Change In The Lower Eocene Of The Bighorn Basin, Wyoming, John Colter Johnson

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Esthonyx is an early Eocene tillodont found in North America, Europe, and India. The genus was named by Edward Drinker (E. D.) Cope in 1874 based on specimens from the San Jose Formation in New Mexico. Since then, several species of Esthonyx have been described from North America alone. The best record of Esthonyx comes from the central Bighorn Basin (BHB) in Wyoming, where it appears in 220 localities in a 640 m-thick stratigraphic succession. Since the last summary of Esthonyx in the BHB, several hundred new specimens have been collected and curated at the Denver Museum of Nature and …

Hybridization Between The Rare Gray-Headed Chickadee And The Abundant Boreal Chickadee In The Midst Of Shifting Climate, Matthew R. Armstrong

School of Natural Resources: Dissertations, Theses, and Student Research

As species respond to changing climate, distributions and abundances may shift and alter species interactions. Hybridization, a relatively widespread phenomenon becoming more common with climate change, can have beneficial and detrimental effects on population growth rates and genetic integrity. Beneficial effects due to the introduction of advantageous alleles and increased genetic diversity may result from hybridization. Species may also accrue fitness costs associated with changing climates if mismatches occur between environmental variables and phenotypes. The gray-headed chickadee, Poecile cinctus lathami, is an extremely rare songbird that has experienced marked declines in recent decades within its restricted distribution in Alaska …

Population Demography, Occupancy, And Connectivity Of Invasive Bigheaded Carp In The Platte River, Nebraska And Its Tributaries, Blake W. Logan

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis, collectively referred to as bigheaded carp, are invasive species in the United States of America that have expanded their range throughout the Missouri River basin in the last three decades. It may be desirable to develop management plans directed at the monitoring, control, or removal of bigheaded carp within the Missouri River basin. However, a knowledge gap exists regarding bigheaded carp ecology in Missouri River tributaries, which may be important for the development of management plans. As such, this study characterized bigheaded carp population demographics, occupancy, and connectivity in …

Virtual Fencing In Livestock Management: Effects On Beef Cattle Stress And Enhancing Wildlife Conservation, Kaitlyn E. Dozler

School of Natural Resources: Dissertations, Theses, and Student Research

I examined the effects of virtual fencing on beef cattle stress and how implementing the technology can aid wildlife habitat conservation at the University of Nebraska Gudmundsen Sandhills laboratory (GSL) near Whitman, NE. First, I examined how virtual fencing influences acute heart rate changes in beef cattle fitted with the virtual fencing collars. No significant difference in the average heart rate of a cow (P > 0.05) was observed between the 30 min control and virtual fenced periods for both trial dates. Second, I examined the influence of topography on wildlife species richness and presence at GSL using wildlife camera …

Spatial Ecology Of Mountain Lions Throughout Their Distribution In California, Kyle D. Dougherty

School of Natural Resources: Dissertations, Theses, and Student Research

Mountain lions (Puma concolor) have been studied extensively throughout their wide geographic distribution in the Western Hemisphere, but most research has been conducted at relatively small spatial scales. We used GPS telemetry data contributed by researchers in 16 study areas throughout California to advance understanding of mountain lion spatial ecology. First, we investigated multi-scale resource selection of mountain lions relative to spatially varying risk of intentional human-caused mortality associated with livestock depredation management. We show that individuals that proactively avoided mortality risk when selecting home ranges were able to relax their avoidance of risk when making resource selection …

Heat Stress Changes The Bovine Methylome And Transcriptome And Investigation Of Two Novel Genetic Defects In Cattle, Rachel Renae Reith

Department of Animal Science: Dissertations, Theses, and Student Research

Heat stress is a major concern for livestock producers due to its negative impact on animal health and productivity. Heat stress does so by altering expression of genes through different regulatory mechanisms such as DNA methylation. Understanding how heat stress alters gene expression will help elucidate the genetic basis of physiological changes as well as identify targets for possible heat stress mitigation. The purpose of the first study was to understand how heat stress alters the adipose and skeletal muscle transcriptomes in zilpaterol-fed Brahman, as zilpaterol improves muscle growth and may mitigate the effects of heat stress. Differential expression and …

Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason

Master's Theses

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury …

Operation Shark: Addressing The Negative Portrayal Of Sharks In Media, Michael R. O'Shea

Masters Theses

Sharks are some of the most well adapted and effective animals in the animal kingdom. Unfortunately, they are also some of the most feared. For many people the word shark evokes images of vicious attacks like those seen in movies such as Jaws. Sharks have also been negatively portrayed in the media. This negative portrayal of sharks has led to misconceptions about sharks that have damaged their populations. Efforts have been made to raise awareness and fight common misconceptions of sharks. However, many people still hold on to the incorrect ideas they have about sharks. This thesis will examine the …

A Potential Of Watercress Nasturtium Officinale Bioactive Compounds In Inhibiting Infectious Myonecrosis Virus (Imnv) By Targeting Rna-Dependent Rna Polymerase (Rdrp) Virus From Several Countries: In Silico Approach, Qurrota A’Yunin, Fatchiyah Fatchiyah, Maftuch Maftuch, Feri Eko Hermanto, Muhammad Hermawan Widyananda, Narendra Santika Hartana, Muhaimin Rifa’I, Yoga Dwi Jatmiko

Karbala International Journal of Modern Science

Infectious myonecrosis virus (IMNV) disease causes mass mortality and decreased shrimp production. The RdRp region projects to the interior, where it may function in transcription. The focus of this study was to determine the effect of amino acid polymorphisms from several countries on the structure of RdRp and identify the potential of watercress in inhibiting IMNV by targeting the RdRp protein of IMNV through an in silico approach. The results showed that the structure of the IMNV RdRp protein from Indonesia was similar to Mexico, and the protein structure from India_QDN was identical to India_QIL. Ligand binding affinity values showed …

A Model Of Oocyte Population Dynamics For Fish Oogenesis, Louis Fostier, Frédérique Clément, Romain Yvinec, Violette Thermes

Biology and Medicine Through Mathematics Conference

No abstract provided.

Impacts Of Hematodinium Infection In A Seasonal Population Model Of The Chesapeake Bay Blue Crab, Gwendolyn R. Sargent, Romuald Lipcius, Leah Shaw, Junping Shi, Jeffrey D. Shields

Biology and Medicine Through Mathematics Conference

No abstract provided.

Heavy Steers And Heifers Run At Low Stocking Rates Enhance Drought Resilience In A Pastoral Region Of Australia, Christophe D'Abbadie, Ross Kingwell, Philip E. Vercoe, Bradley Plunkett, Alan Peggs

Animal Production and Livestock Research Articles

CONTEXT

The semi-arid mulga lands of the Southern Rangelands of Western Australia experience frequent droughts. Maintaining a profitable animal grazing enterprise whilst preserving rangeland condition requires selecting an appropriate stocking rate and herd structure.

OBJECTIVE

We construct and apply bioeconomic models of beef enterprises for the semi-arid Southern Rangelands of Western Australia, to assess the profitability and relative riskiness of three different livestock production systems and three different stocking rates when exposed to different frequencies of drought.

METHODS

We construct bio-economic models of herd structures that separately focus on producing either: (i) 200 kg heifers and 210 kg steers (ii) …

Photobiomodulation Of Bovine Oocytes During Maturation Increases Atp Content And Enhances Subsequent Embryonic Development, Kendall Richey

All Theses

Bovine in-vitro production(IVP) of embryos is a growing field for producing offspring with desirable genetics in the cattle industries. While IVP is effective, oocyte cytoplasmic maturation is compromised, and bovine oocytes matured in-vitro have reduced metabolic activity than those matured in-vivo. Mitochondria are the central unit of oocyte metabolism, producing ATP through OXPHOS. Photobiomodulation is a light treatment reported to improve metabolic activity. In five experiments, we measured the effects of photobiomodulation treatment with red LED at 16-(L-16) and 20 h(L-20) of bovine oocyte in-vitro maturation on subsequent embryonic development, mitochondrial activity and nuclear progression. Bovine COCs were aspirated …

Winter Roost Selection Of Eastern Red Bats And Impacts Of Non-Growing Season Prescribed Fire On Foraging Activity Of Forest Roosting Bats In Tennessee, Ashley D. Epstein

Masters Theses

With an increase in wind energy development and continued deforestation and habitat degradation, eastern red bats (Lasiurus borealis; LABO) and other migratory foliage roosting bats (hoary bat [Lasiurus cinereus; LACI], silver-haired bat [Lasionycteris noctivagans; LANO]) are at risk of severe population declines, potentially leading to the need for protection under the Endangered Species Act. While studies have been done examining the ecology of these species, there is still a lack of research on winter roosting and foraging behaviors. This research aims to fill some of those knowledge gaps by 1) Examining roost use (i.e., trees vs. litter) …

Spatial Ecology Of Mule Deer Migrations From Grand Teton National Park And The Teton Range, Justin K. Schwabedissen

All Graduate Theses and Dissertations, Fall 2023 to Present

The Greater Yellowstone Ecosystem hosts several of the longest, fully intact ungulate migrations remaining in the continental United States. However, expanding development and an increasing human footprint continue to truncate migratory routes. While the endpoints are often a seasonal range on protected lands, these migration corridors frequently cross other jurisdictional boundaries, including large tracts of private or multiple-use lands, with varying levels of protection. Thus, it is critical resource managers understand the dynamics of migratory movements to define population-level corridors and prioritize appropriate conservation strategies. Mule deer in Wyoming have been documented traveling long distances between summer and winter ranges; …

Cradle Explorer: Casfer Interactive Platform For Data And Model Visualization, Olatunde D. Akanbi, Vibha S. Mandayam, Haiping Ai, Arafath Nihar, Erika I. Barcelos, Laura S. Bruckman, Jeffrey Yarus, Yinghui Wu, Huichun (Judy) Zhang, Roger H. French

Student Scholarship

No abstract provided.

Microplastic Quantification On The Effect Of Endoparasite Communities In Florida Seabirds, Sarah N. Prieto

All HCAS Student Capstones, Theses, and Dissertations

Microplastics are being studied in a variety of different projects to better understand their impact and threat to wildlife species. Although there is an understanding that microplastics are affecting our wildlife, there are still questions about how coastal seabirds come to ingest them and how the ingestion is altering critical biological processes, such as that for endoparasite communities. This project aims to determine a better understanding of two main objectives: assessment of the presence of secondary ingestion of microplastics in coastal seabirds due to the fish species they prey on and relationship between microplastics and endoparasite communities' structure and state …

“It’S A No Brainer”: Ensuring Just Transitions In Iceland’S Fishing Industry, Olivia Bowers

Independent Study Project (ISP) Collection

Iceland’s government intends to achieve carbon neutrality by 2040, aiming to target various economic sectors and industries for increased renewable-energy usage. One of its most important plans revolves renewable-energy usage in the fishing industry, which accounts for almost 12% of the country’s GHG emissions. This study aims to understand the perspectives of different stakeholders concerning renewable energy in the fishing industry, using these opinions and existing literature to provide recommendations for a just, equitable, and achievable energy transition. Additionally, this study particularly focuses on the opinions of actors in Vestmannaeyjar, an island community of 4,300 with an especially vibrant, significant, …

A Study Of Anthropogenic Impacts On Echinoderms In The Jambiani Intertidal Area, Zanzibar, Amaury O. Halley

Independent Study Project (ISP) Collection

The coastal region of Jambiani, Unguja, hosts a rich diversity of marine life within its extensive intertidal zones. Despite its ecological significance, this area is increasingly exposed to anthropogenic disturbances due to increased human activities. This study examines the impacts of these disturbances on the biodiversity, zonation, and species abundance of echinoderms in the intertidal habitats of Jambiani. Through a comprehensive field study involving fifteen transects and detailed substrate analysis, the project evaluated the distribution and abundance of echinoderm species and assessed the influence of human activities such as seaweed farming, anchor damage, and beach trampling on these communities. The …

White-Fronted Capuchins (Cebus Albifrons Aequatorialis) In La Hesperia Cloud Forest Reserve: A Study Of Aggressive Behaviors In Response To Human Presence, Marin Lynch

Independent Study Project (ISP) Collection

The Ecuadorian white-fronted capuchin, Cebus albifrons aequatorialis, is a critically endangered primate species native to Ecuador and northern Peru. Their population consists of only a handful of surviving troops spread out across this region. One surviving population exists in La Hesperia Cloud Forest Reserve in Ecuador. This reserve serves as an education and volunteer site for dozens of international travelers every year. I studied the effect of the presence of humans and the lodging they have constructed. Specifically, I investigated the effect on behavior of the proximity of the troops alpha male to manmade structures in the reserve. I …