Life Sciences Commons^™

Molecular Mechanism Of Cyanobacteria Circadian Clock Oscillator And Effect Of Co Factors On Its Oscillation, Manpreet Kaur

Dissertations

The circadian rhythms arise as an adaptation to the environmental 24-hour day and night cycle due to Earth's rotation. These rhythms prepare organisms to align their internal biological activities and day to day behavior or events with the environmental change of the 24-hour day and night cycle. Circadian rhythms are found widely in all living kingdoms of life on Earth. Cyanobacteria are photosynthetic prokaryotes which first used to study these circadian rhythms. Among cyanobacterial species, Synechococcus elongatus PCC 7942 (henceforth, S. Elongatus) is the simplest organism with a durable and sturdy circadian clock and is study as a model organism. …

Molecular Studies On The Interactions Between Biomphalaria Snails And Schistosoma Mansoni, Lijun Lu

Biology ETDs

Biomphalaria snails serve as vectors for Schistosoma mansoni, a trematode causing human schistosomiasis. Control of Schistosoma mansoni involves chemotherapy of affected people, but new control methods built on improved understanding of schistosome-snail interactions are needed. My dissertation applies molecular and bioinformatics approaches to understand such interactions. Chapter 1 shows that significant differences exist among Biomphalaria species in Africa with respect to their ability to support schistosome development. Chapters 2 and 3 reveal the transcriptional responses of Biomphalaria glabrata susceptible (SUS) or resistant (RES) to Schistosoma mansoni. Chapter 2 identifies a new family of snail immune factors, the AIG …

The Future Of Maine's Forests Under Alternative Socioeconomic, Climate And Conservation Pathways, Jianheng Zhao

Electronic Theses and Dissertations

Maine is a historically important timber supply region in North America and understanding the potential change in forestlands and their product industries affected by climate change and various socio-economic conditions can better improve the forest healthy and sustain a sustainable product industry. A statistical harvest choice model for the state of Maine was developed in chapter 1. It was estimated using a multinomial logit model of two products, under varying management intensities, and ownership classifications across varying market conditions. Results indicate that stumpage prices have a significant effect on forest landowners' harvest decisions and that the expansion of conservation land …

A Historical Ecology Of Aridland Springs In Desert National Wildlife Refuge, Nuwu/Nuwuvi (Southern Paiute/Chemehuevi) Ancestral Territory, Nevada, Yarrow Sarah Valentine Geggus

Dissertations and Theses

Aridland springs are among the most threatened ecosystems in the world. Vital to desert ecologies and Indigenous cultures, these complex and individualistic ecosystems have layered histories. To inform management in the changing landscape of Desert National Wildlife Refuge, a 1.6 million acre protected area in Southern Nevada, I conducted a historical ecology study of a sample of ten upland springs. Through a six-part interdisciplinary methodology including interviews, archaeological survey, botanical survey, and archival research, I summarize findings into three broad eras: the Nuwu/Nuwuvi pre-Contact Era, the Settler Era, and the U.S. Fish and Wildlife Service Era.

For millennia, Nuwu/Nuwuvi drank …

A Phenomenological Study On The Impact Of Servant Leadership For Establishing A Culture Of High Performance As Perceived By High School Principals, Darrick Rice

Dissertations

Purpose: The purpose of this phenomenological study was to explore and describe the perceived impact of Patterson’s (2003) 7 servant leadership constructs on high school principals in establishing a culture of high performance.

Methodology: The qualitative phenomenological study described the lived experiences of high school principals who lead schools that have implemented Patterson's (2003) 7 servant leadership constructs for establishing a culture of high performance in Los Angeles County, California. The researcher was a part of 8 peer researchers and 2 faculty advisors. The data collection included virtual face-to-face semi structured interviews using a protocol developed by the thematic team. …

Neuromodulation By Endogenous Interlukin-1Β In Hippocampus Of The Murine Brain: Regulation Of Neuronal Excitation, Spandita Seouli Dutta

Dissertations - ALL

The pro-inflammatory cytokine, Interleukin-1β (IL-1β), is well known for its ability to initiate and propagate inflammatory responses at sites of infection and tissue injury. Paradoxically at odds with this classic view, it is now clear that IL-1β signaling modulates a number of physiological functions in the central nervous system. In this regard, IL-1β is involved in sleep and body fluid regulation in the basal forebrain and hypothalamus, respectively, and plasticity changes that underlie cognition in the hippocampus. Evidence from a previous study in my laboratory further suggests that IL-1β regulates the innate seizure threshold, which arguably is a reflection of …

Genetic Determinants Of Increased Outcrossing In Caenorhabditis Elegans Following Dauer Diapause, Rose Al-Saadi

Theses - ALL

Mating strategies, whether sexual or asexual, confer unique costs and benefits to populations and species that facilitate evolutionary processes. In wild isolates of Caenorhabditis elegans, mating strategies are dependent on developmental history. Outcrossing levels significantly increase when both hermaphrodites and males have transiently passed through the stress-resistant dauer diapause stage (postdauers). However, the molecular mechanisms of how life history can alter mating strategies have not been systematically explored. Mating behaviors of C. elegans can be attributed, in part, to sex-specific responses to ascaroside pheromone components. For example, high concentrations of the pheromone ascr#3 results in a strong avoidance response in …

Identification Of Blda As A Major Regulator Of Virulence In The Sweetpotato Soil Rot Pathogen Streptomyces Ipomoeae And Characterization Of Distinct Clostridium Sweetpotato Soft Rot Isolates, Kuei-Ting Yang

LSU Doctoral Dissertations

Streptomyces ipomoeae is the causative agent of Streptomyces soil rot on sweetpotato, a disease characterized by extensive necrosis of both adventitious and storage roots. While Streptomyces potato scab pathogens produce a phytotoxin (thaxtomin A), which is induced in the presence of cellobiose and suberin, S. ipomoeae produces a less-modified, phytotoxin (thaxtomin C), whose inducer has not been identified. To investigate transcriptional regulation of thaxtomin C production, we inserted a promoter involved in thaxtomin C synthesis upstream of the gusA reporter in an S. ipomoeae strain. Reporter gene expression was significantly upregulated in the presence of size-fractionated sweetpotato extract (SPE). The …

Exploring Behavioral Flexibility, Problem-Solving, And Innovation In Captive Asian Elephants (Elephas Maximus), Amanda Puitiza

Theses and Dissertations

Asian elephants encounter and adapt to changing environments by problem-solving and innovating. In this study, we assessed behavioral measures, such as persistence and motivation, to determine potential predictors of problem-solving success. This is the first examination of problem-solving in elephants with a multi-solution puzzle box.

Variation In Personality Among Semi-Wild Myanmar Timber Elephants, Sateesh Venkatesh

Theses and Dissertations

This study examines two personality traits: exploration and neophobia, which could influence human-elephant conflicts. Thirty-one semi-wild elephants were tested over two trials using a custom novel puzzle tube containing three tasks and three rewards. Our studies show that elephants do vary significantly between individuals in both exploration and neophobia.

A Cophylogenetic Analysis Of Fungus Gardening Ants And Their Symbiotic Fungi, Katherine Beigel

Biology Theses

Fungus-growing ants (Tribe Attini) and their fungal cultivars share a 50-million-year coevolutionary history. Large scale phylogenetic analyses depict a strong co-phyletic signal among ants and their farmed fungi yet fungus sharing among unrelated ant lineages is somewhat widespread. An overview of sharing has been hampered by a lack of genetic markers that exhibit intraspecific variation and surveys across geographic regions. For example, previous studies have shown similar sequences of the internal transcribed spacer (ITS) region of fungus in different species of Trachymyrmex, suggesting that these ant species are farming the same fungal clone. To examine whether this was a …

A Molecular Toolset For The In Vivo Detection Of A Sulfolobus Islandicus Leucyl Trna Synthetase Paralog, Nicholas Michael Bretz

Theses and Dissertations

An ancient and ubiquitous set of enzymes known as the aminoacyl-tRNA synthetases are required for the viability of all organisms. The aminoacyl-tRNA synthetases catalyze the attachment of amino acids onto tRNA molecules. The aminoacylated, or charged, tRNA is then transported and utilized at the ribosome for the synthesis of proteins. The genome of the hyperthermophilic microorganism Sulfolobus islandicus (S. islandicus) harbors a unique leucyl-tRNA synthetase paralog, LeuRS-I, of unknown function. While its duplicate, LeuRS-F, carries out all the classical functions of LeuRS-family enzymes, LeuRS-I fails to charge leucine onto tRNALeu, despite its ability to activate this amino acid and bind …

Evaluating Lignosulfonates Potential As Legume Hay And Silage Preservatives, Angela Yenny Leon-Tinoco

Electronic Theses and Dissertations

The aim was to screen and optimize low-cost lignosulfonates (LST) as legume silage and hay preservatives to decrease losses of DM and nutritive value due to spoilage. In experiment 1, we evaluated the effects of untreated silage (0%), sodium lignosulfonate (NaL) and magnesium lignosulfonate (MgL) applied independently at 0.5, 1, and 1.5 (% w/w, fresh basis) and INO (Pediococcus pentosaceus and Lactobacillus plantarum; 5 and 4 log cfu/fresh alfalfa g, on high moisture alfalfa (Medicago sativa L.) silage nutrient preservation. Data were analyzed as a randomized complete block design (RCBD; 5 blocks) and linear and quadratic polynomial contrasts were used …

Sustainable Production Of Feed For Recirculating Aquaculture Using Black Solider Flies And Microalgae, Patrick Erbland

Electronic Theses and Dissertations

The demand for high-quality, nutritious food continues to increase as human populations grow. As wild fisheries are depleted, aquaculture production is growing to meet the demand for seafood. Sustainable alternatives to wild caught fish meal are increasingly valued for aquaculture feed production. Microalgae and insect larvae are both valuable sources of fatty acids in aquaculture feed. Black soldier fly larvae, Hermetia illucens (L.) are used to convert organic waste streams into insect-based animal feeds. We tested their ability to retain alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) from feeding substrates, which has important implications for their use …

Development, Design, And Utilization Of A Reflective Based Photoplethysmography Sensor, Madeline Mazjanis

Electronic Theses and Dissertations

Plethysmography refers to the dynamic measurement of biological tissue volumes that, for example, may change due to fluctuations in blood volume. Photoplethysmography (PPG) makes use of the attenuation of light penetrating into vascular tissues to determine these changes in blood volume. Modern PPG is an optical technique involving low cost photosensors and light emitting diodes (LED), and is capable of measuring multiple biological vitals simultaneously. For example, in addition to heart rate determination, PPG devices can be used as pulse oximeters, capable of calculating the blood oxygen saturation (SpO2) through a series of simple optical calculations performed on either reflectance …

Holistic Monitoring Of Maine Sea Lice (Lepeoptheirus Salmonis, Kroyer, 1837) Sensitivities To Therapies: Developing A Novel Assay To Examine Lice Behavior, Kathryn Liberman

Electronic Theses and Dissertations

Sea lice (Lepeoptheirus salmonis) present significant economic and animal welfare challenges to salmon aquaculture globally. Chemical delousing agents are used in many countries, with each nation eventually reporting sea lice developing reduced sensitivities to treatments. While some countries have in place sea lice sensitivity monitoring programs, that is not the case in Maine, USA. Although chemical delousing agents are not currently used in Maine, they have been used in the past and are currently used in neighboring Canadian salmon farms. Different bay management areas (BMAs) were sampled during different seasons to determine if there is a seasonal or spatial component …

Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich

Senior Honors Projects, 2020-current

Female mimicry in the red-sided garter snake, Thamnophis sirtalis parietalis, is described in several well-studied evolutionary advantages, but an aspect that remains elusive is how reproductive traits are linked to the 3-fold higher circulating androgens in males with this phenotype. In this study, we implanted male garter snakes (n=15 per group) with either a blank implant (SHAM; control) or a T implant, the latter simulating the female mimic phenotype. Following simulated low-temperature dormancy, males were scored for courtship intensity over three days of behavioral trials with females housed in the same facility. Males were sacrificed, and sperm were collected …

The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson

Electronic Thesis and Dissertation Repository

Up to 22.6% of pregnant women consume cannabis during pregnancy despite the uncertainty of teratogenicity of the main ingredients in cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This study tested the hypothesis that gestational THC and CBD exposure leads to heart abnormalities. Daily, oral THC exposure induced heart abnormalities in 68% of offspring with three main phenotypes including thickened semilunar valves, ventricular myocardial hypertrophy and hypoplastic coronary arteries in fetuses, and postnatal cardiac dysfunction. Altered gene expression of key cardiogenic regulators, increased proliferation, and reduced epicardial epithelial-to-mesenchymal-transition were demonstrated implicating potential mechanisms responsible for these abnormalities. Also, maternal CBD exposure resulted …

Investigation Of Shot1-Binding Atpases In Arabidopsis Thaliana, Sam Zelman

Masters Theses

Mitochondria play critical roles not only in primary metabolism as a central organelle for ATP generation, but also in responding to abiotic stresses. We identified a mutation in the MTERF18 (Mitochondrial Transcription Termination factor)/SHOT1 (Suppressor of hot1-4 1) gene in Arabidopsis thaliana that enables plants to better tolerate heat and oxidative stresses, presumably due to reduced oxidative damage, but the exact molecular mechanism of the heat tolerance is unknown. In order to reveal the stress tolerance mechanisms of mterf18/shot1 mutations, it is critical to understand the molecular defects of the mutant and to identify …

Exploration Of The Association Between Muscle Volume And Bone Geometry Reveals Surprising Relationship At The Genetic Level, Prakrit Subba

Masters Theses

The evolution of jaws in cichlid fishes of the East African Great Lakes is a textbook example of adaptive radiation in vertebrates. Karl Liem postulated that this adaptive radiation has been possible due to the functional decoupling of two cichlid functional units – the pharyngeal jaw (PJ) and the oral jaw (OJ). This functional decoupling of the jaws has enabled the OJ to be relieved of its dual role of prey capturing and processing and has allowed the PJ to take on the role of prey processing. As a result, African cichlids have adapted the morphology of their functional units …

In-Vitro Propagation And Fish Assessments To Inform Restoration Of Dwarf Wedgemussel (Alasmidonta Heterodon), Jennifer Ryan

Masters Theses

The dwarf wedgemussel (Alasmidonta heterodon) is a federally endangered freshwater mussel that once ranged from New Brunswick to North Carolina, but now only exists in isolated populations throughout its diminished range. Laboratory propagation in conjunction with augmentation or reintroduction is considered a critical component of dwarf wedgemussel restoration. My thesis aimed to I) develop in-vitro propagation techniques including methods to minimize microbial contamination for two Alasmidonta species and II) compile and assess critical fish assemblage information at existing dwarf wedgemussel presence and absence locations to inform future restoration activities. For the first objective (Chapter 2) I assessed three …

Effects Of Berberine On Development In Caenorhabditis Elegans, Zhuojia Qian

Masters Theses

Berberine is an isoquinoline alkaloid found in some plants and has many bioactivities including anti-microbial, lipid- and glucose-lowering, anti-cancer, anti-inflammatory, etc. However, there is limited knowledge about berberine’s effects on development and locomotive activity. Herein, in vivo studies were conducted to determine these effects of berberine using Caenorhabditis elegans as an in vivo model. Treatment of berberine at 50 μM starting at L1 stage significantly retarded the growth rate of nematodes, and reduced the length, width and moving speed of worms by 19%, 12% and 29%, respectively, compared to the control. In addition, triglycerides (TG) and protein content in worms …

Assessing Stress Tolerance Of Organelle Small Heat Shock Protein Mutants In Arabidopsis Thaliana, Parth Patel

Masters Theses

Molecular chaperones are proteins found in virtually every organism and are essential to cell survival. When plants are heat stressed, they upregulate and downregulate multiple genes, many of which are associated with the heat shock response. Small heat shock proteins (sHSPs) are one class of molecular chaperones that are upregulated during heat shock. They are proposed to act as the first line of defense by binding to heat sensitive proteins and preventing their irreversible aggregation. However, many details of sHSP function remain to be discovered and exactly what proteins they protect is unresolved. In addition to cytosolic sHSPs found in …

From Intentional Awareness To Environmental Action: The Relationship Between Mindfulness And Pro-Environmental Behaviors, Nischal Neupane

Masters Theses

Mindfulness is defined as the ‘awareness that arises through paying attention to the present moment, on purpose, non-judgmentally’. Despite ample empirical evidence of its efficacy in inducing positive behavior change, almost no work has investigated the viability of using mindfulness-based interventions (MBIs) to promote pro-environmental behavior. Some recent studies have demonstrated consistent correlational relationships between mindfulness levels and pro-environmental attitudes (e.g., connectedness to nature), intentions, and some pro-environmental behaviors (e.g., recycling, “green” purchasing decisions), but no past work has explicitly examined mindfulness in the context of energy saving behaviors. Results from both quantitative and qualitative research conducted as part of …

Does Invasion Science Encompass The Invaded Range? A Comparison Of The Geographies Of Invasion Science Versus Management In The U.S., Lara Munro

Masters Theses

Biases in invasion science lead to a taxonomic focus on plants, particularly a subset of well-studied plants, and a geographic focus on invasions in Europe and North America. Geographic biases could also cause some branches of invasion science to focus on a subset of environmental conditions in the invaded range, potentially leading to an incomplete understanding of the ecology and management of plant invasions. While broader, country-level geographic biases are well known, it is unclear whether these biases extend to a finer scale and thus affect research within the invaded range. This study assessed whether research sites for ten well-studied …

The Shape Of U: Mapping Out Protective Elements In Mrna Escapees, Jacob Miles

Masters Theses

A crucial step of the viral life cycle of Kaposi’s Sarcoma Herpesvirus (KSHV) lytic infection is the triggering of a massive RNA decay event termed “Host Shutoff”. Host Shutoff is driven by the viral endonuclease SOX which leads to the destruction of over 70% of the total transcriptome. This process cripples cellular gene expression and allows for viral reprograming of the cell for the purpose of viral replication. Co-evolution has led to the host developing a multitude of antiviral defenses aimed at preserving certain cellular RNAs linked to antiviral responses. One such defense are RNA secondary structures located within the …

Effect Of Jackfruit-Derived Extract Consumption On Colitis-Associated Colon Tumorigenesis In Mice, Jingwen Lin

Masters Theses

Colorectal cancer is the third most common cancer and the fourth most common cause of cancer-related death in the world. The global burden of colorectal cancer is also expected to increase by 60%, to over 2.2 million new cases and 1.1 million annual deaths, by the year 2030. Jackfruit is known for its packed nutrition including many antioxidants: vitamin C, carotenoids and flavanones. It has also been used in traditional medicine due to its potential protection against many chronic diseases. However, there is limited research studying the potential effect of jackfruit on colorectal cancer. Here, we used a well-established AOM/DSS …

New England’S Underutilized Seafood Species: Defining And Exploring Marketplace Potential In A Changing Climate, Amanda Davis

Masters Theses

New England’s seafood industry has been searching for opportunities to diversify their landings and build resilience as it faces socio-economic challenges from a changing climate. Developing markets for underutilized species is one way the New England community could help their seafood industry build resilience. This thesis identified New England’s underutilized fish species and explored their marketplace potential by examining their availability in a changing climate, current availability to consumers, and consumers’ responses. In Chapter I, I account how New England’s seafood preferences have changed over time. In Chapter II, I identify New England’s seven underutilized seafood species: 1) Acadian redfish …

Impact Of Extremely Low-Frequency Magnetic And Electric Stimuli On Vestibular-Driven Outcomes, Nicolas Bouisset

Electronic Thesis and Dissertation Repository

The vestibular system is extremely sensitive to electric fields (E-fields). Indeed, vestibular hair cells are graded potential cells and this property makes them very susceptible to small membrane potential modulations. Studies show that extremely low-frequency magnetic fields (ELF-MF) induced E-fields impact postural control in which the vestibular system plays an important role. However, the knowledge of whether this is indeed a vestibular specific effect is still pending.

Considering its crucial role and the specific neurophysiological characteristics of its hair cells, the vestibular system emerges as an ELF-MF likely target

The three studies presented in this thesis aimed to further address …

Impact Of Predators On Hemlock Woolly Adelgid (Hemiptera: Adelgidae) In The Eastern And Western United States, Ryan Crandall

Masters Theses

Hemlock woolly adelgid, Adelges tsugae, native to Asia and the Pacific Northwest of North America (Pacific Northwest), has devastated eastern hemlock (Tsuga canadensis) in a major portion of its range in the eastern U.S. After many years and much effort directed towards rearing and releasing biological control agents to manage HWA, one of these agents, Laricobius nigrinus, native to the Pacific Northwest, is now well-established in sites from the southern to the mid-Atlantic states of the eastern U.S. However, there have yet to be studies of its efficacy in lowering A. tsugae densities, and there has …