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A Dynamic Landscape Of Fear: Human Impacts On Carnivore Communities, Tru Hubbard Jun 2021

A Dynamic Landscape Of Fear: Human Impacts On Carnivore Communities, Tru Hubbard

All NMU Master's Theses

Mammalian carnivores are elusive, enigmatic species that often play keystone roles in ecosystems through direct (i.e., predation) and indirect (i.e., perceived predation risk) effects. Worldwide many carnivore species are experiencing rapid human-mediated population declines due to landscape change and habitat disturbance. For researchers, carnivores present unique challenges due to their large home ranges, low population densities, sensitivity to human disturbance, and direct persecution. Further, growing evidence shows that human activity can impact carnivore behavior and community structure by altering predator-prey interactions, shifting diel activity patterns, and altering wildlife movement leading to increased sightings, nuisance reports, and harvests. To investigate how …


Programming Simulations Of Diel Vertical Migration Behavior Of Zooplankton, Bennett J. Mcafee Jun 2021

Programming Simulations Of Diel Vertical Migration Behavior Of Zooplankton, Bennett J. Mcafee

Lawrence University Honors Projects

Diel vertical migration of zooplankton is the daily cycle of movement towards and away from the surfaceof a lake that results from the need to avoid predation and forage for food.The process of diel vertical migration is one of the main forces creating the spatial and temporal structure of aquatic food webs, often acting as the biological pump that moves carbon around an aquatic environment(Brierley 2014).In Daphnia, a genus of crustacean zooplankton, this behavior is triggered in response to both lightintensity and chemical signaling by predators. As a result, diel vertical migration changes in intensity in response to fish populations …


Longitudinal Study Of Pogonomyrmex Occidentalis (Hymenoptera: Formicideae), Western Harvester Ant, Colony Survival In Western Nebraska, Kathleen H. Keeler Jun 2021

Longitudinal Study Of Pogonomyrmex Occidentalis (Hymenoptera: Formicideae), Western Harvester Ant, Colony Survival In Western Nebraska, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

I observed individual western harvester ant (Pogonomyrmex occidentalis) colonies, marked between 1977 and 1994, to live a mean of 15.65 years (n = 112). The longest-lived colony lived 42 years.


Population Structure And Relative Abundance Of Elasmobranch Species Utilizing Inshore Waters Of Abu Dhabi, Shamsa Mohamed Al Hameli Jun 2021

Population Structure And Relative Abundance Of Elasmobranch Species Utilizing Inshore Waters Of Abu Dhabi, Shamsa Mohamed Al Hameli

Theses

The diversity, abundance, and distribution of elasmobranchs is poorly documented along the Arabian Gulf coast of the United Arab Emirates, with only a handful of publications focusing on elasmobranchs with the majority of data are collected through landing site and market surveys lacking site and species-specific data that are crucial for conservation management plans. The main objectives of this research were to determine the occurrence and utilization; quantify the relative abundance across different seasons; and describe the demographic structure of elasmobranch species that occurs in shallow waters around mangroves in Khor Al Saadiyat and adjacent islands, northeast of Abu Dhabi, …


Anticolon Cancer Activity Of Aristolochia Rotunda Root Extract, Ghufran Ayman Al Salloum Jun 2021

Anticolon Cancer Activity Of Aristolochia Rotunda Root Extract, Ghufran Ayman Al Salloum

Theses

Colon cancer is the third leading cause of cancer death worldwide and the first cause of cancer death in the UAE. While the conventional cancer therapy options like chemotherapy, radiation, and surgery are effective in the treatment of most cancers, they exhibit precarious side effects that can endanger the life of the patient. The present study explores the potential anticancer effect of Aristolochia rotunda root extract against human colorectal cancer cells. The root extract exhibited strong anti-proliferative activity in a concentration- and time-dependent manner against human colorectal cancer cell lines. A. rotunda root extract also inhibited colony growth and induced …


Chemical And Biological Control Of Canker Disease Of Delonix Regia Caused By The Fungus Neoscytalidium Dimidiatum, Seham Mohammed Al Raish Jun 2021

Chemical And Biological Control Of Canker Disease Of Delonix Regia Caused By The Fungus Neoscytalidium Dimidiatum, Seham Mohammed Al Raish

Dissertations

In the United Arab Emirates (UAE), royal poinciana (Delonix regia) trees suffer from stem canker disease. Symptoms of stem canker can be characterized by branch and leaf dryness, bark lesions, discoloration of xylem tissues, longitudinal wood necrosis and extensive gumming. General dieback signs were also observed leading to complete defoliation of leaves and ultimately death of trees in advanced stages. The fungus, Neoscytalidium dimidiatum DSM 109897, was consistently recovered from diseased royal poinciana tissues; this was confirmed by the molecular, structural and morphological studies. Phylogenetic analyses of the translation elongation factor 1-a (TEF1-α) of N. dimidiatum from the …


Inter- And Intracontinental Migration By The Eastern Kingbird (Tyrannus Tyrannus), Daniel H. Kim, Lucas J. Redmond, James R. Fox, Michael T. Murphy Jun 2021

Inter- And Intracontinental Migration By The Eastern Kingbird (Tyrannus Tyrannus), Daniel H. Kim, Lucas J. Redmond, James R. Fox, Michael T. Murphy

Biology Faculty Publications and Presentations

We recovered 12 archival geolocators deployed on Eastern Kingbirds (Tyrannus tyrannus) breeding in New York (NY; n¼3, 2 with 2 years of data), Nebraska (NE; n¼6, 1 with 2 years of data), and Oregon (OR; n¼3) to describe migratory routes, timing and rates of migration, nonbreeding season distributions, and migratory connectedness. NY fall migrants migrated along the Atlantic coast to Florida, flew either nonstop across the Gulf of Mexico (GoM; 2 of 3 birds) or stopped once along the way (Cuba and Cayman Islands in different years) to land in Yucatan/Central America. Fall birds from NE and OR arrived at …


The Importance Of Pre- And Postcopulatory Sexual Selection Promoting Adaptation To Increasing Temperatures, Miguel Gomez-Llano, Eve Scott, Erik I. Svensson Jun 2021

The Importance Of Pre- And Postcopulatory Sexual Selection Promoting Adaptation To Increasing Temperatures, Miguel Gomez-Llano, Eve Scott, Erik I. Svensson

Biological Sciences Faculty Publications and Presentations

Global temperatures are increasing rapidly affecting species globally. Understanding if and how different species can adapt fast enough to keep up with increasing temperatures is of vital importance. One mechanism that can accelerate adaptation and promote evolutionary rescue is sexual selection. Two different mechanisms by which sexual selection can facilitate adaptation are pre- and postcopulatory sexual selection. However, the relative effects of these different forms of sexual selection in promoting adaptation are unknown. Here, we present the results from an experimental study in which we exposed fruit flies Drosophila melanogaster to either no mate choice or 1 of 2 different …


These Fish Were Made For Walking: Morphology And Walking Kinematics In Balitorid Loaches, Callie Hendricks Crawford May 2021

These Fish Were Made For Walking: Morphology And Walking Kinematics In Balitorid Loaches, Callie Hendricks Crawford

Dissertations

Terrestrial excursions have been observed in multiple lineages of marine and freshwater fishes. These ventures into the terrestrial environment may be used when fish are searching out new habitat during drought, escaping predation, laying eggs, or seeking food sources. The physiological demands for life under water and on land are vastly different and require different functional adaptations. Fish with terrestrial excursions must be capable of dealing with the stresses of both aquatic and terrestrial environments for varying periods of time. To deal with these stresses, amphibious fishes exhibit many morphological and behavioral adaptations. These adaptations have led to a range …


Development Of Deep Learning Neural Network For Ecological And Medical Images, Shaobo Liu May 2021

Development Of Deep Learning Neural Network For Ecological And Medical Images, Shaobo Liu

Dissertations

Deep learning in computer vision and image processing has attracted attentions from various fields including ecology and medical image. Ecologists are interested in finding an effective model structure to classify different species. Tradition deep learning model use a convolutional neural network, such as LeNet, AlexNet, VGG models, residual neural network, and inception models, are first used on classifying bee wing and butterfly datasets. However, insufficient data sample and unbalanced samples in each class have caused a poor accuracy. To make improvement the test accuracy, data augmentation and transfer learning are applied. Recently developed deep learning framework based on mathematical morphology …


Into The Neotropics: Perspectives On The Evolution Of Neotropical Myotis, Carlos Alberto Carrión Bonilla Mr May 2021

Into The Neotropics: Perspectives On The Evolution Of Neotropical Myotis, Carlos Alberto Carrión Bonilla Mr

Biology ETDs

In my dissertation, I used morphological, sanger sequencing and next-generation sequencing data sets to explore the evolutionary relationships and study cryptic diversity of a extant Neotropical myotine radiation. Using a integrative approach, I described a new species of Myotis from the montane and premontane forest of Panama, Costa Rica and Eastern Ecuador, refining our undestanding of the taxonomy and systematics of the Myotis pilosatibialis complex of bats. Then, using a single locus barcoding approach I explored genetic diversity partitioning across the Myotis radiation with a focus on Neotropical species, ilustrating the phylogenetic relationships of Neotropical species and exploring their species …


The Role Of Irak-1 Transcripts In Sepsis, Adithya Subramanian Sahasranamam May 2021

The Role Of Irak-1 Transcripts In Sepsis, Adithya Subramanian Sahasranamam

Theses

Sepsis is a complex, life-threatening syndrome that can lead to systemic organ failure and dysfunction. Its high morbidity and mortality rates makes it a critical global health issue. The primary factors at play during sepsis are abnormal inflammation and a lack of oxygen supply to the tissues and muscles. The toll-like receptors play a crucial role in eliciting innate immune in response to infection, primarily through the interleukin-1 receptor-associated kinase (IRAK) pathways. Disturbances in the homeostasis of IRAK signaling cascades can lead to immune dysfunction. n this paper, we review the molecular mechanisms of IRAK-1, an important mediator of TLR-induced …


Determination Of 40k, 226ra And 228ra Concentrations With Dose Rates In Crayfish From Ode Omi River And Radiological Implications To The Consumers, Olusegun Sowole, Qasim Abolanle Adeniji, Muyideen O Olagunju May 2021

Determination Of 40k, 226ra And 228ra Concentrations With Dose Rates In Crayfish From Ode Omi River And Radiological Implications To The Consumers, Olusegun Sowole, Qasim Abolanle Adeniji, Muyideen O Olagunju

Tanzania Journal of Science

Natural radionuclides such as 40K, 226Ra and 228Ra are found naturally in water and sediments of rivers, likewise in soils. They are transferred to aquatic animals through ingestion. Radioactivity concentrations and dose rates of 40K, 226Ra and 228Ra in crayfish species from Ode Omi River in coastal region, Ogun State Southwest of Nigeria were determined by gamma spectrometry using NaI (TI) detector coupled with a pre-amplifier base to a multiple channel analyzer (MCA). 15 samples of crayfish were collected. Cherax tenuimanus had the highest mean concentration and dose rate of values 106.87 ± 9.11 Bq kg–1 and 0.00960 mGy hr–1 …


Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla May 2021

Assessment Of The Quality And Quantity Of Organic Matter In The Rufiji Mangrove Surface Sediments Using Biochemical Composition, Daniel A Shilla

Tanzania Journal of Science

This study was carried out to investigate spatial changes in the quality and quantity of sedimentary organic matter in the Rufiji mangrove system, Tanzania. Sediment samples were collected from three sampling sites. Total organic matter in mangrove sediments ranged from 7.28 ± 2.02% to 10.58 ± 1.34%. Protein concentrations varied from 1,145.33 ± 20.33 μg/g to 2,747.50 ± 25.14 μg/g in the mangrove sediments. Total carbohydrates, lipids and biopolymeric carbon in mangrove sediments ranged between 1,110.50 ± 16.31 μg/g and 1,914.17 ± 27.79 μg/g, 1,436.50 ± 24.13 μg/g and 6,373.50 ± 25.79 μg/g, and 4,496 μg C/g and 10,231.50 μg …


Screening Of Aflatoxin-Producing Fungi In Maize And Groundnuts From Three Regions In Tanzania, Kusiluka Agape, Valence Mk Ndesendo, Sartaz Begum May 2021

Screening Of Aflatoxin-Producing Fungi In Maize And Groundnuts From Three Regions In Tanzania, Kusiluka Agape, Valence Mk Ndesendo, Sartaz Begum

Tanzania Journal of Science

This study screened aflatoxin-producing fungi in maize and groundnuts from Dodoma, Singida and Iringa regions in Tanzania, and assessed the level of peoples’ awareness on aflatoxins health effects. One hundred and twenty samples (20 each crop) were collected and inoculated on Sabouraud dextrose agar and one hundred and eleven samples were observed to have fungal growths that were identified to belong to four genera, namely Aspergillus, Rhizopus, Mucor and Dermatophyte with occurrence frequencies of 75, 2.5, 5 and 10%, respectively. Among the four screened genera of fungi, Aspergillus was observed to be the major aflatoxin-producing fungi. Five species of genus …


Pathological Scanning Of Ochratoxigenic Moulds Impaired Feed In Vivo, Towards Conceptualizing Their Reverberations On Different Organs, Benjamin T Thomas, Omolara D Popoola, Moses O Efuntoye, Mercy O Coker, Ahmed O Tajudeen May 2021

Pathological Scanning Of Ochratoxigenic Moulds Impaired Feed In Vivo, Towards Conceptualizing Their Reverberations On Different Organs, Benjamin T Thomas, Omolara D Popoola, Moses O Efuntoye, Mercy O Coker, Ahmed O Tajudeen

Tanzania Journal of Science

The role of ochratoxigenic moulds in causing several invasive diseases has been documented but little is known about the effects of these ochratoxigenic moulds contaminated feeds in a laboratory control experiment. This study therefore, examined the pathological effects of ochratoxigenic moulds contaminated feed in order to understand their reverberations on different organs. Thirty two albino rats were randomly assigned to four experimental treatments (T) with eight rats per treatment (T1, T2, T3 and T4). T1 and T2 were female and male control rats, respectively that were fed normal feed, while T3 and T4 were male and female experimental rats that …


Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker May 2021

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …


Phantom Rivers Filter Birds And Bats By Acoustic Niche, D. G. E. Gomes, C. A. Toth, H. J. Cole, C. D. Francis, J. R. Barber May 2021

Phantom Rivers Filter Birds And Bats By Acoustic Niche, D. G. E. Gomes, C. A. Toth, H. J. Cole, C. D. Francis, J. R. Barber

Biology Faculty Publications and Presentations

Natural sensory environments, despite strong potential for structuring systems, have been neglected in ecological theory. Here, we test the hypothesis that intense natural acoustic environments shape animal distributions and behavior by broadcasting whitewater river noise in montane riparian zones for two summers. Additionally, we use spectrally-altered river noise to explicitly test the effects of masking as a mechanism driving patterns. Using data from abundance and activity surveys across 60 locations, over two full breeding seasons, we find that both birds and bats avoid areas with high sound levels, while birds avoid frequencies that overlap with birdsong, and bats avoid higher …


Characterizing The Gene Regulatory Network Required To Specify The Excitatory Neurotransmitter Phenotype Of V0v Spinal Interneurons, Amber Kellie Woodard May 2021

Characterizing The Gene Regulatory Network Required To Specify The Excitatory Neurotransmitter Phenotype Of V0v Spinal Interneurons, Amber Kellie Woodard

Theses - ALL

The majority of neurons within the spinal cord are interneurons. Interneurons make important connections with other cells that allow signals to be relayed between the brain and the rest of the body, and aid in functions such as locomotion. One key functional characteristic of interneurons is the neurotransmitter that they use to communicate with other cells. Interneurons that use GABA or glycine neurotransmitters to communicate have an inhibitory phenotype, while interneurons that use glutamate neurotransmitters have an excitatory neurotransmitter phenotype. Without the correct neurotransmitter phenotype, connections within the central nervous system will malfunction. It is therefore important to understand how …


Characterizing The Gene Regulatory Network Required To Specify The Excitatory Neurotransmitter Phenotype Of V0v Spinal Interneurons, Amber Kellie Woodard May 2021

Characterizing The Gene Regulatory Network Required To Specify The Excitatory Neurotransmitter Phenotype Of V0v Spinal Interneurons, Amber Kellie Woodard

Theses - ALL

The majority of neurons within the spinal cord are interneurons. Interneurons make important connections with other cells that allow signals to be relayed between the brain and the rest of the body, and aid in functions such as locomotion. One key functional characteristic of interneurons is the neurotransmitter that they use to communicate with other cells. Interneurons that use GABA or glycine neurotransmitters to communicate have an inhibitory phenotype, while interneurons that use glutamate neurotransmitters have an excitatory neurotransmitter phenotype. Without the correct neurotransmitter phenotype, connections within the central nervous system will malfunction. It is therefore important to understand how …


Effects Of Covid-19 On Global Healthcare Research And Management, Stephanie Autore, Santanu De May 2021

Effects Of Covid-19 On Global Healthcare Research And Management, Stephanie Autore, Santanu De

Biology Faculty Articles

The Coronavirus Infectious Disease 2019 (COVID-19) pandemic has affected most nations at all levels of functioning, individual to governmental. Therefore, it is imperative to evaluate the effects the virus has had on one of the most important socioeconomic global sectors – healthcare. This comprehensive literature review explores key, recent research and management strategies that have been undertaken in healthcare systems around the world in order to make meaningful attempts at identifying the etiology, diagnosis, and treatment the disease, and combating the spread of this deadly virus. Healthcare facilities have implemented a variety of changes, all geared towards reducing non-emergency patient …


Androgen Receptor, Although Not A Specific Marker For, Is A Novel Target To Suppress Glioma Stem Cells As A Therapeutic Strategy For Glioblastoma, Nan Zhao, Fei Wang, Shaheen Ahmed, Kan Liu, Chi Zhang, Sahara J. Cathcart, Dominick J. Dimaio, Michael Punsoni, Bingjie Guan, Ping Zhou, Shuo Wang, Surinder K. Batra, Tatiana Bronich, Tom K. Hei, Chi Lin, Chi Zhang May 2021

Androgen Receptor, Although Not A Specific Marker For, Is A Novel Target To Suppress Glioma Stem Cells As A Therapeutic Strategy For Glioblastoma, Nan Zhao, Fei Wang, Shaheen Ahmed, Kan Liu, Chi Zhang, Sahara J. Cathcart, Dominick J. Dimaio, Michael Punsoni, Bingjie Guan, Ping Zhou, Shuo Wang, Surinder K. Batra, Tatiana Bronich, Tom K. Hei, Chi Lin, Chi Zhang

School of Biological Sciences: Faculty Publications

Targeting androgen receptor (AR) has been shown to be promising in treating glioblastoma (GBM) in cell culture and flank implant models but the mechanisms remain unclear. AR antagonists including enzalutamide are available for treating prostate cancer patients in clinic and can pass the blood–brain barrier, thus are potentially good candidates for GBM treatment but have not been tested in GBM orthotopically. Our current studies confirmed that in patients, a majority of GBM tumors overexpress AR in both genders. Enzalutamide inhibited the proliferation of GBM cells both in vitro and in vivo. Although confocal microscopy demonstrated that AR is expressed but …


Fungi Associated With Herbaceous Plants In Coastal Northern California, Greg Huffman May 2021

Fungi Associated With Herbaceous Plants In Coastal Northern California, Greg Huffman

Natural Sciences and Mathematics | Biological Sciences Master's Theses

The presence of fungal species associated with herbaceous plants was monitored in coastal Marin County, California, USA. The research involved a combination of field sampling surveys and data collection using a stratified random design, pathogen identification through microbiological and molecular analysis, and descriptive analysis and ordination of results. A total of two years of repeated sampling (four times a year) was organized to allow for the detection of seasonal differences in pathogen presence on aerial plant parts. The objective of this study was to identify microbial species present on herbaceous plants using ITS1 sequence analysis. Throughout March of 2018 to …


Evaluating Kin And Group Selection As Tools For Quantitative Analysis Of Microbial Data, Jeff Smith, Fredrik Inglis May 2021

Evaluating Kin And Group Selection As Tools For Quantitative Analysis Of Microbial Data, Jeff Smith, Fredrik Inglis

Biology Department Faculty Works

Kin selection and multilevel selection theory are often used to interpret experiments about the evolution of cooperation and social behaviour among microbes. But while these experiments provide rich, detailed fitness data, theory is mostly used as a conceptual heuristic. Here, we evaluate how kin and multilevel selection theory perform as quantitative analysis tools. We reanalyse published microbial datasets and show that the canonical fitness models of both theories are almost always poor fits because they use statistical regressions misspecified for the strong selection and non-additive effects we show are widespread in microbial systems. We identify analytical practices in empirical research …


Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg May 2021

Synthesis Of Thresholds Of Ocean Acidification Impacts On Echinoderms, N. Bednaršek, P. Calosi, R. A. Feely, R. Ambrose, M. Byrne, Kit Yu Karen Chan, S. Dupont, J. L. Padilla-Gamiño, J. I. Spicer, F. Kessouri, M. Roethler, M. Sutula, S. B. Weisberg

Biology Faculty Works

Assessing the vulnerability of marine invertebrates to ocean acidification (OA) requires an understanding of critical thresholds at which developmental, physiological, and behavioral traits are affected. To identify relevant thresholds for echinoderms, we undertook a three-step data synthesis, focused on California Current Ecosystem (CCE) species. First, literature characterizing echinoderm responses to OA was compiled, creating a dataset comprised of >12,000 datapoints from 41 studies. Analysis of this data set demonstrated responses related to physiology, behavior, growth and development, and increased mortality in the larval and adult stages to low pH exposure. Second, statistical analyses were conducted on selected pathways to identify …


Coxiella Burnetii And Related Tick Endosymbionts Evolved From Pathogenic Ancestors, Amanda E. Brenner, Sebastián Muñoz-Leal, Madhur Sachan, Marcelo B. Labruna, Rahul Raghavan May 2021

Coxiella Burnetii And Related Tick Endosymbionts Evolved From Pathogenic Ancestors, Amanda E. Brenner, Sebastián Muñoz-Leal, Madhur Sachan, Marcelo B. Labruna, Rahul Raghavan

Biology Faculty Publications and Presentations

Both symbiotic and pathogenic bacteria in the family Coxiellaceae cause morbidity and mortality in humans and animals. For instance, Coxiella-like endosymbionts (CLEs) improve the reproductive success of ticks—a major disease vector, while Coxiella burnetii causes human Q fever, and uncharacterized coxiellae infect both animals and humans. To better understand the evolution of pathogenesis and symbiosis in this group of intracellular bacteria, we sequenced the genome of a CLE present in the soft tick Ornithodoros amblus (CLEOA) and compared it to the genomes of other bacteria in the order Legionellales. Our analyses confirmed that CLEOA is more closely related to …


Infectious Disease Transmission By Arline Travel, Daniele Provenzano, Sofy Barocio May 2021

Infectious Disease Transmission By Arline Travel, Daniele Provenzano, Sofy Barocio

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Improvements in aviation technology have led to considerable growth of domestic and international flights worldwide especially during the past four decades. Commercial flights have increased the movement of and have connected people from virtually all corners of the globe since the end of World War II to exceed 3 billion passengers a year since 2013: a sizable proportion of the global human population. Flight times have decreased considerably from the onset of commercial aviation and the range of airliners has extended substantially. A passenger harboring an infectious agent embarking a flight on one continent can be deplaning on another continent …


Evolution Of Extreme Habitat Specialists In The Dark: Cavefishes And Anglerfishes, Pamela Hart May 2021

Evolution Of Extreme Habitat Specialists In The Dark: Cavefishes And Anglerfishes, Pamela Hart

LSU Doctoral Dissertations

Extremophilic organisms are fascinating in that they thrive in physiologically demanding environments. Extreme habitats include subsurface caves and the deep sea, which share several qualities like low light and cold temperatures. Extremophiles have adapted bizarre characteristics that allow them to thrive in such harsh environments including eye and pigment loss (cavefishes) and development of a lure in anglerfishes. These traits are integral to the health and fitness of these organisms, yet the evolutionary history of these traits is unclear.

Cave adaptation has evolved repeatedly across the Tree of Life, famously leading to eye degeneration and loss, yet its macroevolutionary implications …


The Impacts Of Disturbance On Submerged Aquatic Macrophytes Populations Of The Jemez Mountains, New Mexico, Virginia Frances Thompson May 2021

The Impacts Of Disturbance On Submerged Aquatic Macrophytes Populations Of The Jemez Mountains, New Mexico, Virginia Frances Thompson

Biology ETDs

This dissertation investigates the effects of disturbance (a catastrophic forest fire and decadal-level multi-day flood) on populations of submerged aquatic macrophytes (SAMs) in the streams and rivers of the Jemez Mountains of northern New Mexico, USA. Research conducted and reported in this dissertation addresses the following research questions: 1.) What factors influence the presence or absence of SAMs in Jemez Mountain streams? 2.) How does disturbance (catastrophic wildfire and decadal-level flood) change the amount of aboveground SAM biomass? and 3.) How does that disturbance change the nutrient content (%C, %N, %P) and nutrient stoichiometry of SAMs? These disturbance events had …


Beyond The Kármán Gait: Knifefish Swimming In Periodic And Irregular Vortex Streets, Victor M. Ortega-Jiménez, Christopher P. Sanford May 2021

Beyond The Kármán Gait: Knifefish Swimming In Periodic And Irregular Vortex Streets, Victor M. Ortega-Jiménez, Christopher P. Sanford

Faculty Articles

Neotropical freshwater fishes such as knifefishes are commonly faced with navigating intense and highly unsteady streams. However, our knowledge on locomotion in apteronotids comes from laminar flows, where the ribbon fin dominates over the pectoral fins or body bending. Here, we studied the 3D kinematics and swimming control of seven black ghost knifefish (Apteronotus albifrons) moving in laminar flows (flow speed U∞≈1-5 BL s-1) and in periodic vortex streets (U∞≈2-4 BL s-1). Two different cylinders (∼2 and ∼3 cm diameter) were used to generate the latter. Additionally, fish were exposed to an irregular wake produced by a free oscillating cylinder …