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Full-Text Articles in Life Sciences

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman Dec 2022

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …


Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan Aug 2019

Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan

Electronic Theses and Dissertations

Thermotolerance limit in aquatic organism is set by the ability to sustain aerobic scope to sudden temperature shifts. This study tested the genetic and plastic differences in thermotolerance of Daphnia that can be explained by the differences in the ability to retain mitochondrial integrity at high temperatures. Five genotypes with different biogeographic origins were acclimated to 18C and 25C. We developed a rhodamine 123 in-vivo assay to measure mitochondrial membrane potential and observed higher fluorescent in heat damaged tissues as the disruption of the mitochondrial membrane potential. Significant effects on temperature tolerance were observed with CCCP …


Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner May 2019

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …


Investigating The Interaction Of Monoamines And Diel Rhythmicity On Anti-Predator Behavior In An Orb-Weaving Spider, Larinioides Cornutus (Araneae: Araneae), Rebecca Wilson Aug 2018

Investigating The Interaction Of Monoamines And Diel Rhythmicity On Anti-Predator Behavior In An Orb-Weaving Spider, Larinioides Cornutus (Araneae: Araneae), Rebecca Wilson

Electronic Theses and Dissertations

Circadian rhythms are ubiquitous among organisms, influencing a wide array of physiological processes and behaviors including aggression. While many neurophysiological mechanisms are involved in the regulation of aggressive behaviors, relatively few studies have investigated the underlying components involved in the interplay between circadian rhythms and aggression. Spiders are an ideal model system for studying circadian regulation of aggression as they are ecologically both predators and prey. Recent studies have revealed a nocturnal orb- weaving spider Larinioides cornutus exhibits a diel and circadian rhythm in anti-predator behavior (i.e. boldness) that can be manipulated by administration of octopamine (OA) and serotonin (5- …


Venom Peptides Lasioglossin Ii And Mastoparan B As Escherichia Coli Atp Synthase Inhibitors, Rafiat Ajoke Bello Aug 2016

Venom Peptides Lasioglossin Ii And Mastoparan B As Escherichia Coli Atp Synthase Inhibitors, Rafiat Ajoke Bello

Electronic Theses and Dissertations

The inhibitory effects on Escherichia coli ATPase activity by two venom peptides, lasioglossin II and mastoparan B. Membrane bound F1FO ATP synthase was isolated from E. coli strain pBWU13.4/DK8 and treated with varied concentrations of lasioglossin II and mastoparan B. Lasioglossin II caused very low inhibition of ATPase activity, but the inhibition profile of mastoparan B was suggestive of an interesting biological effect. A relatively shorter total length, a smaller net positive charge, and a reduced amphipathic character of both peptides, as compared to previously tested antimicrobial peptides, may account for the limited degree of inhibition observed …


Characterization Of A Putative Phospholipase D ´ Like Gene As A Lipid Signaling Modulator And Its Role In Salicylic Acid Mediated Defense Pathway In Nicotiana Tabacum, Phillip T. Dean Dec 2014

Characterization Of A Putative Phospholipase D ´ Like Gene As A Lipid Signaling Modulator And Its Role In Salicylic Acid Mediated Defense Pathway In Nicotiana Tabacum, Phillip T. Dean

Electronic Theses and Dissertations

Plants are in a perpetual evolutionary arms race with a wide range of pathogens. Their sessile nature has led plants to evolve defense mechanisms that can quickly recognize a unique stressor and deploy a resistance tailored for a specific attack. The salicylic acid (SA) mediated defense pathway has been shown to be one of the major defense tactics plants can initiate to defend themselves against microbial pathogens. Following a pathogen attack high levels of methyl salicylate (MeSA) are produced that can be converted to SA by the enzyme salicylic acid binding protein 2 (SABP2). A yeast two-hybrid screening was performed …