Digital Commons Network^™

Does Light Control Algal Abundance In Large River Systems?, Amy Macdonald

Theses and Dissertations

A limited amount of research has been done to investigate the factors influencing algal abundance in large river systems. This study examines light as the primary factor that controls algal abundance in the Upper Mississippi, Missouri and Ohio Rivers. Data were collected for 2004 in conjunction with the Environmental Monitoring Assessment Program- Great River Ecosystems EMAP-GRE project using EPA approved methods. Chlorophyll a concentrations were 34.6 µg•L-1 in the Upper Mississippi, 19.8 µg•L-1 in Missouri River and 9 µg•L-1 in the Ohio River for 2004. Chlorophyll a concentrations were significantly different among the three rivers (p<0.0001) but not between years. Inter-river variation could be loosely correlated with light availability: mean Average Irradiance Dosages, which consider factors that affect light climate (depth, transparency, velocity, surface irradiance), by river corresponded with mean chlorophyll a levels by river. Intra-river variation seemed to be due to both the influence of light and nutrients.

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota, Jennifer Borgo

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.

Diets Of Ladybird Beetles (Coleoptera: Coccinellidae) In Utah Alfalfa Fields, Lynette Nicole Davidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aphidophagous lady beetles rely on multiple sources of food in their environment. Alfalfa fields provide both aphids and many alternate foods, such as other arthropod prey, pollen, and fungi. Alfalfa fields (Medicago sativa L.) in Utah have low aphid densities, which may require lady beetles to consume alternative sources of food. Many methods can be used to determine these diets; frass analysis is used here to compare the diets of the introduced species Coccinella septempunctata L. with two native species, C. transversoguttata richardsoni Brown and Hippodamia convergens Guérin-Méneville, that occur in the Utah alfalfa habitat.

In initial laboratory experiments …

Mountain Pine Beetle Fecundity And Offspring Size Differ Among Lodgepole Pine And Whitebark Pine Hosts, Donovan Gross

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, lodgepole pine (Pinus contorta Engelmann), and whitebark pine. We tested the effects of natal host and brood host on beetle fecundity, offspring size, and brood sex-ratio. We reared mountain pine beetles …

Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant^-1 s^-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO₂ uptake. Diurnal cycles in ethylene synthesis were present in …

Neuroendocrine Peptides Neuropeptide-Y (Npy) And Peptide-Yy (Pyy) Suppress Cl- Secretion And K+ Secretion In Guinea Pig Distal Colon Through Action At Y2-Receptors, Susan T. Halm, Jin Zhang, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

Electrogenic Cl^– and K⁺ secretion in isolated mucosa from guinea pig distal colon measured as short-circuit current (I_sc) and transepithelial conductance (G_t) were stimulated by epinephrine (epi), prostaglandin-E₂ (PGE₂) and carbachol (CCh). neuropeptide-Y (NPY) and peptide-YY (PYY) inhibited by 60% Cl^– secretion activated by either PGE₂ or PGE₂+CCh with EC₅₀’s of 16nM and 6nM, respectively. Neither peptide markedly inhibited the transient component of the PGE₂+CCh response. Immunoreactivity (IR) for NPY was present in enteric ganglia and in proximity with crypts. Basolateral membranes of …

Ambient Temperature Influences Diet Selection And Physiology Of An Herbivorous Mammal, Neotoma Albigula, M. D. Dearing, Jennifer S. Forbey, J. D. Mclister, L. Santos

Biology Faculty Publications and Presentations

The whitethroat woodrat (Neotoma albigula) eats juniper (Juniperus monosperma), but the amount of juniper in its diet varies seasonally. We tested whether changes in juniper consumption are due to changes in ambient temperature and what the physiological consequences of consuming plant secondary compounds (PSCs) at different ambient temperatures might be. Woodrats were acclimated to either 20ºC or 28ºC. Later, they were given two diets to choose from (50% juniper and a nontoxic control) for 7 d. Food intake, resting metabolic rate (RMR), and body temperature (T_b) were measured over the last 2 d. Woodrats at 28ºC …

Corallivorous Reef Fishes As Potential Vectors Of Coral Disease Based On A Study Of Dietary Preferences, Tanya Rogers

Independent Study Project (ISP) Collection

The prevalence of coral disease appears to be increasing worldwide, although little is known about how these diseases are transmitted between coral colonies. To examine whether corallivorous fishes could potentially act as disease vectors, this study examined whether and which fish species feed on diseased coral, and whether these fishes actively target diseased coral sections. Branches of Acropora muricata with brown band disease were filmed in the field, and bites taken by fishes on different sections of the coral (live tissue, tissue margin, disease band, dead skeleton, and algae) were recorded. For each fish species, electivity indices were calculated for …

Breakdown And Invertebrate Colonization Of Dead Wood In Wetland, Upland, And River Habitats, Amy Braccia, Darold P. Batzer

Biological Sciences Faculty and Staff Research

Breakdown of woody debris in river and upland habitats as well as the interactions between wood and invertebrates have been well described. Studies of wood in wetlands are rare, and far less is known about breakdown and invertebrate use of wood in these transitional habitats. This study experimentally assessed breakdown and invertebrate colonization of wood in a floodplain wetland and directly related patterns in the wetland to adjacent river and upland habitats. Over a 2.7 year period, we monitored breakdown and invertebrate presence in 10 cm diameter × 150 cm long sweetgum (Liquidambar styraciflua L.) logs in a floodplain wetland …

Shrub-Interspace Dynamics Alter Relationships Between Microbial Community Composition And Belowground Ecosystem Characteristics, Rebecca E. Drenovsky, Z. T. Aanderud, M. I. Shuldman, J. H. Richards

Biology

In desert ecosystems, belowground characteristics are influenced chiefly by the formation and persistence of “shrub-islands of fertility” in contrast to barren plant interspaces. If soil microbial communities are exclusively compared between these two biogeochemically distinct soil types, the impact of characteristics altered by shrub species, especially soil C and N, are likely to be overemphasized and overshadow the role of other characteristics in structuring microbial composition. To determine how belowground characteristics influence microbial community composition, and if the relative importance of these characteristics shifts across the landscape (i.e., between and within shrub and interspace soils), changes in microbial communities across …

The Leaf Ionome As A Multivariable System To Detect A Plant's Physiological Status, Ivan R. Baxter, Olga Vitek, Brett Lahner, Balasubramaniam Muthukumar, Monica Borghi, Joe Morrissey, Mary Lou Guerinot, David E. Salt

Dartmouth Scholarship

The contention that quantitative profiles of biomolecules contain information about the physiological state of the organism has motivated a variety of high-throughput molecular profiling experiments. However, unbiased discovery and validation of biomolecular signatures from these experiments remains a challenge. Here we show that the Arabidopsis thaliana (Arabidopsis) leaf ionome, or elemental composition, contains such signatures, and we establish statistical models that connect these multivariable signatures to defined physiological responses, such as iron (Fe) and phosphorus (P) homeostasis. Iron is essential for plant growth and development, but potentially toxic at elevated levels. Because of this, shoot Fe concentrations are …

No Evidence For Trade-Offs: Centaurea Plants From America Are Better Competitors And Defenders, Wendy M. Ridenour, Jorge M. Vivanco, Yulong Feng, Jun-Ichiro Horiuchi, Ragan M. Callaway

Biological Sciences Faculty Publications

The natural enemies hypothesis has led to a number of ideas by which invaders might evolve superior competitive ability. In this context, we compared growth, reproduction, competitive effect, competitive response, and defense capabilities between invasive North American populations of Centaurea maculosa and populations in Europe, where the species is native. We found that Centaurea from North America were larger than plants from European populations. North American Centaurea also demonstrated stronger competitive effects and responses than European Centaurea. However, competitive superiority did not come at a cost to herbivore defense. North American plants were much better defended against generalist insect …

Dietary Intakes Of Swedish Children And Adolescents: The European Heart Study, Emma Patterson

Masters

What children eat is important both for their health now and for their risk of chronic non communicable diseases, such as cardiovascular disease, in the future. The diets of 1,121 children (aged 9 y, n=552) and adolescents (aged 15 y, n=569) were assessed by an interviewer mediated 24-hour recall, as part of the European Youth Heart Study. Group macronutrient intakes and their food sources were described, and dietary energy density (ED) and breakfast habits were employed as markers of dietary quality. The effect of socioeconomic status on these markers was investigated. The adequacy of energy-reporting in this population was also …

Cloning Of The Neurodegeneration Gene Drop-Dead And Characterization Of Additional Phenotypes Of Its Mutation, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

Mutations in the Drosophila gene drop-dead (drd) result in early adult lethality and neurodegeneration, but the molecular identity of the drd gene and its mechanism of action are not known. This paper describes the characterization of a new X-linked recessive adult-lethal mutation, originally called lot's wife (lwf¹) but subsequently identified as an allele of drd (drd^lwf); drd^lwf mutants die within two weeks of eclosion. Through mapping and complementation, the drd gene has been identified as CG33968, which encodes a putative integral membrane protein of unknown function. The drd^lwf allele is associated …

The Effect Of Ginseng On Biofilm Formation By Wild Type And Mutant Strains Of Pseudomonas Aeruginosa, Premi Shekar

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Premi Shekar on June 25, 2008.

A Reverse Transcriptase-Pcr Assay For Detecting Filarial Infective Larvae In Mosquitoes, Sandra J. Laney, Caitlin J. Buttaro, Sabato Visconti, Nils Pilotte, Reda M.R. Ramzy, Gary J. Weil, Steven A. Williams

Biological Sciences: Faculty Publications

Background: Existing molecular assays for filarial parasite DNA in mosquitoes cannot distinguish between infected mosquitoes that contain any stage of the parasite and infective mosquitoes that harbor third stage larvae (L3) capable of establishing new infections in humans. We now report development of a molecular L3-detection assay for Brugia malayi in vectors based on RT-PCR detection of an L3-activated gene transcript.

Methodology/Principal Findings: Candidate genes identified by bioinformatics analysis of EST datasets across the B. malayilife cycle were initially screened by PCR using cDNA libraries as templates. Stage-specificity was confirmed using RNA isolated from infected mosquitoes. Mosquitoes were collected daily …

Plumage Ornamentation As An Indicator Of Female Age And An Influence In Male Mate Choice In Protonotaria Citrea, The Prothonotary Warbler In Virginia., Terry Smith

Theses and Dissertations

Flamboyant plumage and ornamentation is common and well-known in male birds; it serves as a sexual display to attract potential mates. While flamboyant plumage is less common and usually more subtle in female birds, it does occur in some species such as Dark-Eyed Juncos (Junco hyemalis) and Prothonotary Warblers (Protonotaria citrea). Prothonotary Warblers display relatively subtle sexual dimorphism. This study examines variations in tail spot patterns in Prothonotary Warblers and relates those variations to age in females. Females with fewer than six spots tend to be two years old or younger; females with six spots or more tend to be …

Separating Developmental And Environmental Effects On Fluctuating Asymmetry In Lythrum Salicaria And Penthorum Sedoides, Jennifer R. Milligan, Robert A. Krebs, Tarun K. Mal

Biological, Geological, and Environmental Faculty Publications

Environmental stress can disrupt developmental processes on biological, physiological, and chemical levels and thereby affect the symmetry of a trait. For this reason, fluctuating asymmetry is often proposed as a measure of stress encountered by an individual. One problem is that asymmetry may have multiple causes, including developmental noise and genetic background, and genetic differences may interact with any physiological stress imposed by the environment. The main objective of this research was to determine whether developmental noise and genetic stress can be separated from environmental effects on leaf asymmetry. The experiments were conducted on two wetland plants, Lythrum salicaria (purple …

Differential Exposure, Duration, And Sensitivity Of Unionoidean Bivalve Life Stages To Environmental Contaminants, W. Gregory Cope, Robert B. Bringolf, David B. Buchwalter, Teresa J. Newton, Christopher G. Ingersoll, Ning Wang, Tom Augspurger, F. James Dwyer, M. Christopher Barnhart, For Complete List Of Authors, See Publisher's Website., Edward Hammer

College of Natural and Applied Sciences

Freshwater mussels (superfamily Unionoidea) are in serious global decline and in urgent need of protection and conservation. The declines have been attributed to a wide array of human activities resulting in pollution and water-quality degradation, and habitat destruction and alteration. Linkages among poor water quality, pollutant sources, and mussel decline in rivers and streams have been associated with results of laboratory-based tests of specific pollutants. However, uncertainties remain about the relationship of laboratory data to actual contaminant exposure routes for various mussel species, life stages, and in the habitats occupied during these exposures. We evaluated the pathways of exposure to …

Soil Morphology, Depth And Grapevine Root Frequency Influence Microbial Communities In A Pinot Noir Vineyard, Rebecca E. Drenovsky, K. L. Steenwerth, J. J. Lambert, D. A. Kluepfel, K. M. Scow, D. R. Smart

Biology

The composition of microbial communities responds to soil resource availability, and has been shown to vary with increasing depth in the soil profile. Soil microorganisms partly rely on root-derived carbon (C) for growth and activity. Roots in woody perennial systems like vineyards have a deeper vertical distribution than grasslands and annual agriculture. Thus, we hypothesized that vineyard soil microbial communities along a vertical soil profile would differ from those observed in grassland and annual agricultural systems. In a Pinot noir vineyard, soil pits were excavated to ca. 1.6–2.5m, and microbial community composition in ‘bulk’ (i.e., no roots) and ‘root’ (i.e., …

Variation In Resource Acquisition And Utilization Traits Between Native And Invasive Perennial Forbs, Rebecca E. Drenovsky, Christina E. Martin, Molly R. Falasco, Jeremy J. James

Biology

Understanding the functional traits that allow invasives to outperform natives is a necessary first step in improving our ability to predict and manage the spread of invaders. In nutrient-limited systems, plant competitive ability is expected to be closely tied to the ability of a plant to exploit nutrient-rich microsites and use these captured nutrients efficiently. The broad objective of this work was to compare the ability of native and invasive perennial forbs to acquire and use nutrients from nutrient-rich microsites. We evaluated morphological and physiological responses among four native and four invasive species exposed to heterogeneous (patch) or homogeneous (control) …

Undetected Species Losses, Food Webs, And Ecological Baselines: A Cautionary Tale From The Greater Yellowstone Ecosystem, Usa, Joel Berger

Biological Sciences Faculty Publications

Large protected areas are often considered natural yet outside pressures may compromise ecological integrity. This paper points to a problem in assessing ecological baselines: what if species' extirpations go undetected? I present a data set spanning 130 years that demonstrates the loss of white-tailed jack rabbits Lepus townsendii from two National Parks in the well studied 60,000 km(2) Greater Yellowstone Ecosystem, USA. While these extirpations have been unnoticed until now, an ecological consequence may be elevated predation on juvenile ungulates. A critical challenge we face is how to apply better the concept of shifting baselines to the restoration of functional …

Behavioral And Physiological Ecology Of Scorpion Venom Expenditure: Stinging, Spraying, And Venom Regeneration, Zia Nisani

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I reviewed the functional aspects of venom from a behavioral perspective to develop a comprehensive understanding of the behavioral ecology of venom. To explore the behavioral and physiological ecology of venom expenditure by scorpions, I conducted four studies of the medically significant Buthid scorpion Parabuthus transvaalicus. The first two experiments revealed that scorpions regulate their venom expenditure during defensive stinging and squirting in the most complex manner yet described for any venomous organism. When stinging, these scorpions can choose between delivering a dry or wet sting. Should they deliver a wet sting, they meter the volume …

The Role Of Mitochondria Atp-Sensitive Potassium Channel In Cardioprotection, Ksenia Andrukhiv Everton

Dissertations and Theses

Mitochondrial ATP-sensitive potassium channel (mitoK_ATP) has been suggested to be the mediator of cardiac preconditioning. All of the diverse pharmacological and physiological agents that open mitoK_ATP provide protection against ischemia-reperfusion injury. Some investigators have pointed out that some of these mitoK_ATP channel openers also inhibit succinate dehydrogenase (SDH), complex II of the electron transport chain. Based on this observation they suggest that it is the inhibition of SDH, and not the opening of mitoK_ATP channel, that mediates the observed cardioprotection. In this study, I examined four chemically distinct and unrelated pharmacological agents, diazoxide, 3-Nitropropionic Acid …

The Reproductive Ecology Of Graptemys Geographica In The Central Canal, Kati Keppen Rush

Undergraduate Honors Thesis Collection

Life for all organisms involves carefully managing a limited amount of resources. In many cases these resources affect how organisms Jive on a daily basis. In addition to competition from other species, organisms face competition within their own species, populations, and niches. Those individuals that manage their resources effectively will increase their chances of survival, reproduction, and the continuation of their genes in the gene pool. Studies that focus on life history characteristics of organisms aim to understand the mechanisms used by organisms to increase the chances that their genes will remain in thegenepoolpasttheirown Iifetime.Thegoal ofthesemechanisms istoensuresurvival and maximize reproduction. …

Revisiting A Model Of Ontogenetic Growth: Estimating Model Parameters From Theory And Data, Melanie E. Moses, Chen Hou, William H. Woodruff, Geoffrey B. West, Jeffery C. Nekola, Wenyun Zuo, James H. Brown

Biological Sciences Faculty Research & Creative Works

The ontogenetic growth model (OGM) of West et al. provides a general description of how metabolic energy is allocated between production of new biomass and maintenance of existing biomass during ontogeny. Here, we reexamine the OGM, make some minor modifications and corrections, and further evaluate its ability to account for empirical variation on rates of metabolism and biomass in vertebrates both during ontogeny and across species of varying adult body size. We show that the updated version of the model is internally consistent and is consistent with other predictions of metabolic scaling theory and empirical data. The OGM predicts not …

Analysis Of The Cyc1 Promoter In Candida Albicans, Tomica Blocker

McCabe Thesis Collection

Scientists are considering two factors that may be important in the pathogenesis of C. albicans', it's capability to morph from yeast to hyphal phase, and its differences in colony morphology, cell shape, cell surface and cell permeability. (5) Unfortunately, unlike the bacteria, yeasts do not yet have proven virulence factors. However, science is suggesting that some of the major factors which contribute to the virulence of Candida are its ability to form hyphae, its ability to resist phagocytosis, its ability to adhere to epithelial cell surfaces, its ability to grow well at 37 degrees Celsius, and its ability to secrete …

Integrating Across Life-History Stages: Consequences Of Natal Habitat Effects On Dispersal, Michael F. Benard, Shannon J. Mccauley

Biological Sciences

Ecological and evolutionary processes are affected by forces acting at both local and regional scales, yet our understanding of how these scales interact has remained limited. These processes are fundamentally linked through individuals that develop as juveniles in one environment and then either remain in the natal habitat or disperse to new environments. Empirical studies in a diverse range of organisms have demonstrated that the conditions experienced in the natal habitat can have profound effects on the adult phenotype. This environmentally induced phenotypic variation can in turn affect the probability that an individual will disperse to a new environment and …

The Relationship Of Oribatid Soil Mite Abundance To Abiotic And Biotic Factors, Carolyn Hess

Biology Theses - Archive

Oribatid soil mites primarily feed on fungi and dead organisms. They belong to the arthropod subclass, Acari, that are believed to contribute to soil processes such as plant litter breakdown and nutrient release. In order to facilitate more accurate predictions about obscure soil processes, research has been done that has attempted to correlate soil mite abundance and diversity to more easily measured aboveground biota. The present study examined monthly Oribatid soil mite abundance and its relationship to four different plant communities in North Texas: mowed grass monoculture, un-managed field, riparian, and woodland, during one growing season. Due to the nutritional …

Granivores And Restoration: Implications Of Invasion And Considerations Of Context-Dependent Seed Removal, Steven M. Ostoja

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Granivores are important components of sagebrush communities in western North America. These same regions are being altered by the invasion of the exotic annual Bromus tectorum (cheatgrass) that alters physical and biological dynamics in ways that appear to promote its persistence. This research directly relates to the restoration of B. tectorum-dominated systems in two inter-related ways. First, because these landscapes have large quantities of seeds applied during restoration, it is important to determine the major granivore communities in intact sagebrush communities and in nearby cheatgrass-dominated communities. Second, it is important to develop an understanding of patterns of seed harvest …