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Computational Prediction Of The Sporulation Network In Clostridium Thermocellum, Changyi Jiang Jan 2013

Computational Prediction Of The Sporulation Network In Clostridium Thermocellum, Changyi Jiang

Dissertations, Master's Theses and Master's Reports - Open

Sporulation is a process in which some bacteria divide asymmetrically to form tough protective endospores, which help them to survive in a hazardous environment for a quite long time. The factors which can trigger this process are diverse. Heat, radiation, chemicals and lacking of nutrition can all lead to the formation of endospores. This phenomenon will lead to low productivity during industrial production. However, the sporulation mechanism in a spore-forming bacterium, Clostridium theromcellum, is still unclear. Therefore, if a regulation network of sporulation can be built, we may figure out ways to inhibit this process. In this study, a …


Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey Jan 2013

Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey

UNF Graduate Theses and Dissertations

Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning …


Identification Of Kinase Signaling Pathways Inducing Morphological Changes In Dendritic Cells Upon Leptin Treatment, Marisol Ann O'Neill Jan 2013

Identification Of Kinase Signaling Pathways Inducing Morphological Changes In Dendritic Cells Upon Leptin Treatment, Marisol Ann O'Neill

Open Access Theses & Dissertations

Leptin is a pleiotropic hormone secreted by white adipose tissue. Obesity leads to overexpression of leptin as a result of leptin receptor desensitization. Obese leptin serum levels (160ng/ml) have been found to enhance immune functions in macrophages, natural killer cells, B cells, T cells, and dendritic cells. Previous data from our lab suggests that obese concentrations of leptin cause morphological changes in DCs, although further studies are required to verify these results. We hypothesized that leptin promotes DC cytoskeletal changes though activation of PI3K signaling. Morphological and functional changes were evaluated in JAWS II immortalized DCs though microscopy, transwell migration, …


Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino Jan 2013

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino

UNF Graduate Theses and Dissertations

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its …


Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes Jan 2013

Associational Resistance And Competition In The Asphondylia - Borrichia - Iva System, Keith Stokes

USF Tampa Graduate Theses and Dissertations

Indirect ecological effects such as associational resistance and resource competition have the potential to affect ecological interactions and influence the structure of ecological communities. Although resource competition is commonly studied, the effects of associational resistance are not as evident if studies are not designed to detect them. Additionally, the relative strengths of different ecological mechanisms ought to be measured in studies, rather than the strength of singular mechanisms. This permits proper attribution of causes and effects in community structure and detection of higher order interactions in a way that naïve reductionism will not.

In a series of experiments, I looked …


Effect Of Buckwheat (Fagopyrum Esculentum) On Soil Phosphorus Availability And Organic Acids, Angela R. Possinger, Loren B. Byrne, Nancy Breen E. Breen Jan 2013

Effect Of Buckwheat (Fagopyrum Esculentum) On Soil Phosphorus Availability And Organic Acids, Angela R. Possinger, Loren B. Byrne, Nancy Breen E. Breen

Arts & Sciences Faculty Publications

As a cover crop, buckwheat (Fagopyrum esculentum) may increase soil-P availability. Buckwheat was grown in low-P and P-fertilized field plots, and organic anions were measured in rhizosphere soil. Soil-P availability was not affected by buckwheat, but the concentration of rhizosphere tartrate2– was significantly higher (p < 0.005) in low-P vs. P-fertilized plots. This suggests that organic-anion root exudation may have a role in buckwheat-rhizosphere P dynamics.


Feeding Modes Of Larvae Of Nematostella Vectensis (Cnidaria: Anthozoa), Amanda Kehr Smith '13, William Jaeckle Jan 2013

Feeding Modes Of Larvae Of Nematostella Vectensis (Cnidaria: Anthozoa), Amanda Kehr Smith '13, William Jaeckle

Students' Professional Presentations and Publications

We assessed the ability of larvae of the starlet sea anemone, Nematostella vectensis, to assimilate dissolved organic material (DOM) and ingest artificial and natural particles from seawater. Planulae were exposed to the proteins ferritin and labeled bovine serum albumin (FITC-BSA) and the polysaccharides iron dextran and labeled dextran (FITC-dextran) at solute concentrations between 0.25-1.0 mg/mL for 1-5 hours at 22°C. Other larvae were incubated with polystyrene beads (0.5 μm, 106 beads/mL and 4.5 μm and 6 μm, 103 beads/mL) or with algal cells (Dunaliella tertiolecta, 5 ' 103 cells/mL) for 2.5-5 h. The label from all provided macromolecules …


Phenotypic Characterization Of The Pancreatic-Derived Factor (Pander) Knockout Mouse On Pure C57bl/6 Background, Shari Moak Jan 2013

Phenotypic Characterization Of The Pancreatic-Derived Factor (Pander) Knockout Mouse On Pure C57bl/6 Background, Shari Moak

USF Tampa Graduate Theses and Dissertations

PANcreatic-DERived Factor (PANDER), or FAM3B, is a 235-amino acid protein strongly expressed within and secreted from the endocrine pancreas. Research surrounding PANDER has revealed a large role for the protein in maintaining glucose homeostasis, as evidenced by several Ad-PANDER overexpressing murine models, our lab's pancreas-specific PANDER transgenic overexpressor, and most recently our mixed genetic C57/129J PANDER knockout (PANKO) mouse. However, PANDER's overall role in glycemic regulation and glucose homeostasis has yet to be studied in a purebred C57BL/6J PANDER knockout model. Here we present the first phenotypic characterization of our global PANDER knockout mouse on a C57BL/6J background (PANKO-C57) where …


Growth And Herbivory Of The Black Mangrove, Avicennia Germinans, Along A Salinity Gradient, Danielle Neveu Jan 2013

Growth And Herbivory Of The Black Mangrove, Avicennia Germinans, Along A Salinity Gradient, Danielle Neveu

USF Tampa Graduate Theses and Dissertations

Coastal communities will be most affected by global climate change and are important to study to understand current and future ecological processes. The current model for global climate change predicts a change in rainfall, which will alter the salinity of coastal systems. Given the presence of eutrophication in many coastal waters, it is important to understand the effects that this increase in nutrients, coupled with changes in salinity, will have on these communities. This study was conducted to understand the effect of salinity increase on the growth and herbivory of the black mangrove, Avicennia germinans, in the presence of …


Full Issue: Volume 6, Number 2 Jan 2013

Full Issue: Volume 6, Number 2

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.


Thymoquinone Decreases Oxidative Dna Damage (8-Ohdg) In Dmba Treated Female Sprague Dawley Rats, Abrar A. Sindi Jan 2013

Thymoquinone Decreases Oxidative Dna Damage (8-Ohdg) In Dmba Treated Female Sprague Dawley Rats, Abrar A. Sindi

EWU Masters Thesis Collection

"Tamoxifen (TAM) is used widely for treatment and prevention of breast cancer. However, TAM has been reported to have a negative effect on glutathione (GSH) levels and 8-hydroxydeoxyguanosine (8-OHdG). Thymoquinone (TQ), the main active ingredient of Nigella sativa, or Black seeds, is used in the Middle East for treatment of several diseases, especially cancer. The aim of my research was to investigate the role of thymoquinone in improving 8-OHdG and GSH compared with tamoxifen in female Sprague Dawley rats treated with 7,12 dimethylbenz (a)anthracene (DMBA, a drug that induces mammary cancer). 8-OHdG is the most commonly assayed fingerprint of free …


Factors Shaping The Ontogeny Of Vocal Signals In A Wild Parrot, Karl S. Berg, Steven R. Beissinger, Jack W. Bradbury Jan 2013

Factors Shaping The Ontogeny Of Vocal Signals In A Wild Parrot, Karl S. Berg, Steven R. Beissinger, Jack W. Bradbury

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

Parrots rely heavily on vocal signals to maintain their social and mobile lifestyles. We studied vocal ontogeny in nests of wild green-rumped parrotlets (Forpus passerinus) in Venezuela. We identified three successive phases of vocal signaling that corresponded closely to three independently derived phases of physiological development. For each ontogenetic phase, we characterized the relative importance of anatomical constraints, motor skills necessary for responding to specific contexts of the immediate environment, and the learning of signals that are necessary for adult forms of communication. We observed shifts in the relative importance of these three factors as individuals progressed from …


Opportunistic Pathogenic Bacteria Colonize Thorns Of Native Rio Grande Valley Plants, Felicia A. Charles, Sergio Cepeda, J. Andrew Mcdonald, Kristine L. Lowe Jan 2013

Opportunistic Pathogenic Bacteria Colonize Thorns Of Native Rio Grande Valley Plants, Felicia A. Charles, Sergio Cepeda, J. Andrew Mcdonald, Kristine L. Lowe

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

Thorns serve as mechanical defenses of plants against herbivory. However, plant thorns harbor microorganisms that are potentially pathogenic. These pathogens may be transferred to herbivores and other animals and provide an additional defense for the plants. Thorns from 5 plant species native to the Rio Grande Valley of South Texas were collected and used to isolate bacteria colonizing the thorn surface. Thorns, leaves and stems of plants were visualized using Scanning Electron Microscopy (SEM) to observe any bacteria on the plant surface. Isolated bacteria were tested for their ability to grow in aerobic versus anaerobic environments, to produce hemolysis, carbon …


A Comparison Of Placental Tissue In The Skinks Eulamprus Tympanum And E. Quoyii, Lauren Yates Dec 2012

A Comparison Of Placental Tissue In The Skinks Eulamprus Tympanum And E. Quoyii, Lauren Yates

Honors Theses

The species Eulamprus tympanum and Eulamprus quoyii are viviparous skinks that are said to have a Type I placenta. This research compared histological characteristics of the oviduct during pregnancy in E. tympanum and E. quoyii and assessed whether structural features are consistent with a Type I placentation. A similarity was seen in both of these species and was not consistent with a Type I placenta. Extreme folding of the uterine tissue was observed in the early stages. An increase in glands around the later stages was observed while there was no change in blood vessel density over the course of …


Lipophilic And Hydrophilic Quantitative Analysis Of Antioxidant Activity In Tomatoes And Tomato Products, Anna Tran Dinh Dec 2012

Lipophilic And Hydrophilic Quantitative Analysis Of Antioxidant Activity In Tomatoes And Tomato Products, Anna Tran Dinh

Masters Theses, 2010-2019

The amount of antioxidants present in food varies depending on environmental conditions in which produce was grown and how products were processed prior to consumption. It would, therefore, be useful to quantify antioxidant activities in these foods. This study focused on quantitative analysis of antioxidant activities in commercially produced whole tomatoes and processed tomato products. For commercially processed tomatoes, diced tomatoes had total antioxidant activities (TAA) ranging from 1.243 to 2.243 μmol TE/g fresh weight (fw), juice 1.573 to 6.86 μmol TE/g fw, paste 6.3 to 13.248 μmol TE/g fw, sauce 1.62 to 3.168 μmol TE/g fw, and soup 1.073 …


Traversing Swanton Road, 10th Ed., James A. West Dec 2012

Traversing Swanton Road, 10th Ed., James A. West

Academic, Government & Associated Organizational Research Resources

Situated at the northwest end of Santa Cruz County and occupying circa 30 square miles of sharply contrasted terrain, the Scott Creek Watershed concentrates within its geomorphological boundaries, at least 10-12% of California's flora, both native and introduced. Paradoxically, the use/abuse that the watershed has sustained over the past 140+ years, has not necessarily diminished the biodiversity and perhaps parallels the naturally disruptive but biologically energizing processes (fire, flooding, landslides and erosion), which have also been historically documented for the area for +60 years. This is an early edition of an extensive document by James A. West. Please visit the …


Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker Dec 2012

Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker

Dissertations

Marine fungi are an important but often overlooked component of marine ecosystems. Primarily saprotrophic, they are vital to coastal nutrient cycling processes and food webs. However, basic marine fungal distribution data are lacking in many parts of the world, as is knowledge of the sampling intensity required to characterize the biodiversity of these communities. The roles of substrate, season and latitude in shaping intertidal ascomycete community structure were examined for the U.S. Gulf of Mexico, and the role of sampling frequency on species richness estimates was also addressed. Best sampling practices were developed and 750 collections of beach detritus, sand …


Management Of Biological And Chemical Constituents For The Advancement Of Intensive, Minimal-Exchange, Biofloc-Based Shrimp (Litopenaeus Vannamei) Aquaculture, Andrew James Ray Dec 2012

Management Of Biological And Chemical Constituents For The Advancement Of Intensive, Minimal-Exchange, Biofloc-Based Shrimp (Litopenaeus Vannamei) Aquaculture, Andrew James Ray

Dissertations

Intensive, minimal-exchange, biofloc-based shrimp aquaculture systems may provide a sustainable alternative to traditional shrimp culture. Through a series of experiments, this document explores the effects of several key management strategies on water quality, isotopic distribution, and shrimp production.

An experiment evaluated the effects of managing suspended solids (biofloc) concentration at two levels. It was found that using a higher flow rate to larger settling chambers resulted in significantly lower biofloc and nitrate concentrations, and significantly improved shrimp growth rate. A second experiment compared systems with clear water and systems with biofloc. The filters in the clear water systems prevented biofloc …


Influences Of A Cladophora Bloom On The Diets Of Amblema Plicata And Elliptio Dilatata In The Upper Green River, Kentucky, Jennifer Maria Yates Dec 2012

Influences Of A Cladophora Bloom On The Diets Of Amblema Plicata And Elliptio Dilatata In The Upper Green River, Kentucky, Jennifer Maria Yates

Masters Theses & Specialist Projects

Freshwater mussels are the most imperiled group of freshwater invertebrates globally. Recent research suggests a better understanding of mussel feeding ecology may facilitate and improve conservation efforts. The use of stable isotopes is becoming an increasingly common method to study aquatic food webs. Carbon (C) and nitrogen (N) are two of the most frequently employed elements in food web studies. Differences in natural abundance of 13C/12C can indicate which food sources are the basal sources of carbon incorporated into a consumer’s tissue, while the ratio of 15N /14N provides a method of assessing trophic …


A Symbiotic View Of Life: We Have Never Been Individuals, Scott F. Gilbert, J. Sapp, A. I. Tauber Dec 2012

A Symbiotic View Of Life: We Have Never Been Individuals, Scott F. Gilbert, J. Sapp, A. I. Tauber

Biology Faculty Works

The notion of the "biological individual" is crucial to studies of genetics, immunology, evolution, development, anatomy, and physiology. Each of these biological subdisciplines has a specific conception of individuality, which has historically provided conceptual contexts for integrating newly acquired data. During the past decade, nucleic acid analysis, especially genomic sequencing and high-throughput RNA techniques, has challenged each of these disciplinary definitions by finding significant interactions of animals and plants with symbiotic microorganisms that disrupt the boundaries that heretofore had characterized the biological individual. Animals cannot be considered individuals by anatomical or physiological criteria because a diversity of symbionts are both …


The Effects Of Temperature On Energy Utilization By Marine Invertebrate Larvae, Elizabeth Whitehill Dec 2012

The Effects Of Temperature On Energy Utilization By Marine Invertebrate Larvae, Elizabeth Whitehill

All Dissertations

Most ectothermic organisms are larger when reared at lower temperatures and temperature can greatly affect an organism's physiological state, so understanding how temperature affects larval size and quality can provide insight into how the larval thermal environment affects post-metamorphic success. Because quality is often defined in terms of size and energy content, I focused on how temperature affects energy utilization by larvae and how differences in energy accumulation and utilization may carry over into the juvenile stage. Marine invertebrate larvae are often classified into two groups: larvae from smaller eggs that must obtain food from the environment in order to …


Influence Of Nitrogen And Phosphorus On Ecosystem Co2 Exchange In A Restored Temperate Grassland, Lynn M. Socha Dec 2012

Influence Of Nitrogen And Phosphorus On Ecosystem Co2 Exchange In A Restored Temperate Grassland, Lynn M. Socha

Biology Theses

Nitrogen (N) and phosphorus (P) affect the structure and function of grasslands by altering plant competitive interactions, shifting patterns of above- and belowground biomass allocation, and by increasing net primary production. However, the influence of N and P on net ecosystem productivity is poorly understood. In the context of a field-based factorial N- and P-addition experiment, I measured soil moisture, leaf area index and component fluxes of ecosystem CO2 exchange throughout the growing season in a restored temperate grassland near Buffalo, New York. I predicted that N-addition would enhance ecosystem CO2 uptake (GEE) while P-addition would stimulate ecosystem …


Natural And Lignocellulose-Enriched Microbial Communities In Great Boiling Spring, Nv, Jessica Cole Dec 2012

Natural And Lignocellulose-Enriched Microbial Communities In Great Boiling Spring, Nv, Jessica Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

The natural microbial communities present in Great Boiling Spring were investigated and contrasted against those present after in situ enrichment with lignocellulose. High-throughput cultivation-independent DNA sequencing of the V8 region of the small subunit (SSU) rRNA gene generated a total of 274,119 quality-filtered pyrosequencing fragments. Twelve natural spring samples were analyzed, including four high-temperature water samples and eight sediment samples ranging from 87 - 62 °C. Eight lignocellulosic enrichments incubated in the spring sediment and water at two high-temperature sites were analyzed. The natural water communities were found to be extremely uneven but relatively constant throughout time. The natural sediment …


Fungal Biofilm Colonization And Succession On Artificial Reefs In The North-Central Gulf Of Mexico, Amy Leigh Salamone Dec 2012

Fungal Biofilm Colonization And Succession On Artificial Reefs In The North-Central Gulf Of Mexico, Amy Leigh Salamone

Master's Theses

This study represents the first characterization of natural mixed-species fungal biofilm communities on artificial reefs in the marine environment. Previous fungal biofilm studies have failed to observe the naturally-occurring biodiversity in coastal areas, which comprise the most utilized zone of the marine environment. Artificial reefs can increase fishing yields, amplify oyster habitats, contribute to shoreline stabilization, promote good water quality, and deter pollution. Proper management practices of artificial reefs require knowledge of the colonization of these new habitats by marine organisms and their subsequent succession. Fungi, along with bacteria, archaea, protists, algae, and diatoms, quickly form a complex biofilm on …


The Rise And Fall Of Kin Structure In The Neotropical, Family-Living Buff-Breasted Wren (Cantorchilus Leucotis) In Gamboa, Panama, Sarah C. Alessi Dec 2012

The Rise And Fall Of Kin Structure In The Neotropical, Family-Living Buff-Breasted Wren (Cantorchilus Leucotis) In Gamboa, Panama, Sarah C. Alessi

Masters Theses

Family-living species provide an exciting model to examine how natal dispersal and kin structure influence genetic structuring within local populations. Juvenile buff-breasted wrens (Cantorchilus leucotis) of both sexes delay dispersal and exhibit short-distance natal dispersal, which should lead to kin-structured populations in which relatives of both sexes occupy neighboring territories. Blood samples collected from juvenile and adult wrens in Gamboa, Panama were analyzed using microsatellite markers to determine whether related individuals are spatially clustered on neighboring territories, spatial clusters of relatives change over time, and if kin structure is sex-specific. Global and local spatial autocorrelation analyses detected genetic …


Gene Duplication And The Evolution Of Hemoglobin Isoform Differentiation In Birds, Michael T. Grispo Dec 2012

Gene Duplication And The Evolution Of Hemoglobin Isoform Differentiation In Birds, Michael T. Grispo

School of Biological Sciences: Dissertations, Theses, and Student Research

The majority of bird species co-express two functionally distinct hemoglobin (Hb) isoforms in definitive erythrocytes: HbA (the major adult Hb isoform, with α-chain subunits encoded by the αA-globin gene) and HbD (the minor adult Hb isoform, with α-chain subunits encoded by the αD-globin gene). The αD-globin gene originated via tandem duplication of an embryonic α-like globin gene in the stem lineage of tetrapod vertebrates, which suggests the possibility that functional differentiation between the HbA and HbD isoforms may be attributable to a retained ancestral character state in HbD that harkens back to a primordial, …


Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga Dec 2012

Community Structure And Ecological Specialization In Plant-Ant Interactions, Paola Barriga

Graduate Theses and Dissertations

Positive associations among species have contributed to the maintenance of biodiversity. These interactions are typically studied in pairwise fashion where two interacting organisms are the focus. This dissertation uses network theory to analyze positive plant-ant associations in three Neotropical forests. Obligate plant-ant mutualisms were used, where plants host the ants in domatia and provide food bodies while the ants protect the plants and can feed them. A network approach was used to depict all obligate plant-ant interactions within a community. The main questions asked at the community level were: 1) Do network structure and levels of specialization change geographically and, …


Proteome Analyses Of Strains Cyanothece Atcc 51142 And Pcc 7822 Of The Diazotrophic Cyanobacterium Cyanothece Sp. Under Culture Conditions Resulting In Enhanced H2 Production., Uma K. Aryal, Stephen J. Callister, Sujata Mishra, Xiaohui Zhang, Janani I. Shutthanandan, Thomas E. Angel, Anil K. Shukla, Matthew E. Monroe, Ronald J. Moore, David W. Koppenhaal, Richard D. Smith, Louis A. Sherman Nov 2012

Proteome Analyses Of Strains Cyanothece Atcc 51142 And Pcc 7822 Of The Diazotrophic Cyanobacterium Cyanothece Sp. Under Culture Conditions Resulting In Enhanced H2 Production., Uma K. Aryal, Stephen J. Callister, Sujata Mishra, Xiaohui Zhang, Janani I. Shutthanandan, Thomas E. Angel, Anil K. Shukla, Matthew E. Monroe, Ronald J. Moore, David W. Koppenhaal, Richard D. Smith, Louis A. Sherman

Department of Biological Sciences Faculty Publications

Cultures of the cyanobacterial genus Cyanothece have been shown to produce high levels of biohydrogen. These strains are diazotrophic and undergo pronounced diurnal cycles when grown under N2-fixing conditions in light-dark cycles. We seek to better understand the way in which proteins respond to these diurnal changes, and we performed quantitative proteome analysis of Cyanothecesp. strains ATCC 51142 and PCC 7822 grown under 8 different nutritional conditions. Nitrogenase expression was limited to N2-fixing conditions, and in the absence of glycerol, nitrogenase gene expression was linked to the dark period. However, glycerol induced expression of nitrogenase during …


Ornamental Bill Color Rapidly Signals Changing Condition, M. F. Rosenthal, Troy G. Murphy, N. Darling, K. A. Tarvin Nov 2012

Ornamental Bill Color Rapidly Signals Changing Condition, M. F. Rosenthal, Troy G. Murphy, N. Darling, K. A. Tarvin

Biology Faculty Research

Ornamental bill color is postulated to function as a condition-dependent signal of individual quality in a variety of taxonomically distant bird families. Most red, orange, and yellow bill colors are derived from carotenoid pigments, and carotenoid deposition in ornamentation may trade off with their use as immunostimulants and antioxidants or with other physiological functions. Several studies have found that bill color changes in response to physiological perturbations, but how quickly such changes can occur remains unclear. We tested the hypothesis that carotenoid-based orange bill color of American goldfinches Spinus tristis responds dynamically to rapid changes in physiological stress and reflects …


Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas Oct 2012

Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas

Biology Faculty Publications

We characterized soil communities in the Mojave Desert across an elevation gradient. Our goal was to test the hypothesis that as soil quality improved with increasing elevation (due to increased productivity), the diversity of soil prokaryotes and nematodes would also increase. Soil organic matter and soil moisture content increased with elevation as predicted. Soil salinity did not correlate to elevation, but was highest at a mid-gradient, alluvial site. Soil nematode density, community trophic structure, and diversity did not show patterns related to elevation. Similar results were obtained for diversity of bacteria and archaea. Relationships between soil properties, nematode communities, and …