Physical Sciences and Mathematics Commons^™

Insights Into Forest Soil Carbon Dynamics From Nuclear Magnetic Resonance Spectroscopy, Chris E. Johnson

Civil and Environmental Engineering

No abstract provided.

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …

Imaginenative 2012: Ecocinema And The Indigenous Film Festival, Salma Monani, Miranda Brady

Environmental Studies Faculty Publications

Much scholarship points to how ecological concerns are never far from Indigenous struggles for political sovereignty and public participation. In this paper we turn to the Indigenous film festival as a relatively understudied yet rich site to explore such ecological concerns. Specifically, we highlight the ImagineNATIVE 2012 film festival based in Toronto, Canada.

Creating An Interdisciplinary Research Course In Mathematical Ecology, Glenn Ledder, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

An integrated interdisciplinary research course in biology and mathematics is useful for recruiting students to interdisciplinary research careers, but there are difficulties involved in creating and implementing it. We describe the genesis, objectives, design policies, and structure of the Research Skills in Theoretical Ecology course at the University of Nebraska–Lincoln and discuss the difficulties that can arise in designing and implementing interdisciplinary courses.

Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones

OES Faculty Publications

Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …

Phosphorus Cycling In The Sargasso Sea: Investigation Using The Oxygen Isotopic Composition Of Phosphate, Enzyme-Labeled Fluorescence, And Turnover Times, Karen Mclaughlin, Jill A. Sohm, Gregory A. Cutter, Michael W. Lomas, Adina Paytan

OES Faculty Publications

Dissolved inorganic phosphorus (DIP) concentrations in surface water of vast areas of the ocean are extremely low (<10 nM) and phosphorus (P) availability could limit primary productivity in these regions. We explore the use of oxygen isotopic signature of dissolved phosphate (δ¹⁸O_PO4) to investigate biogeochemical cycling of P in the Sargasso Sea, Atlantic Ocean. Additional techniques for studying P dynamics including ³³P-based DIP turnover time estimates and percent of cells expressing alkaline phosphatase (AP) activity as measured by enzyme-labeling fluorescence are also used. In surface waters, δ¹⁸O_PO4 values were lower than equilibrium by 3–6%, indicative of dissolved organic phosphorous (DOP) remineralization by extracellular enzymes. An isotope mass balance model using a variety of possible combinations of …

Does Pitcher Plant Morphology Affect Spider Residency?, Marc A. Milne, Deborah A. Waller

Biological Sciences Faculty Publications

Spiders are often found as residents in association with Sarracenia purpurea ( Purple Pitcher Plant). Many spiders choose web locations based on environmental cues such as vegetation structure and composition, prey density, temperature, and humidity. To determine if spiders use cues from the Purple Pitcher Plant to build their webs, we conducted a field study using variants of the plant that separated various morphological features: nectar, pigment, and the presence of prey. There was no difference in spider residency across all treatments and no difference in male/female or mature/immature residency. Linyphiids were the most common residents, possibly due to pitcher …

Heritable Melanism And Parasitic Infection Both Result In Black-Spotted Mosquitofish, Lisa Horth, David Gauthier, Wolfgang Vogelbein

Biological Sciences Faculty Publications

Male Gamhusia holhrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism approximate to 99% of males are silver, and only approximate to 1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater …

Range Maps For Nebraska's Threatened And Endangered Species, Nebraska Natural Heritage Program

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

This document includes maps and associated information on the ranges of Nebraska’s federal and state-listed species. The information is current as of January 2013. The information is updated as needed. Contact the Nebraska Game and Parks Commission to determine if a more current version is available. The species treated are as follows: American Burying Beetle (Nicrophorus americanus), Salt Creek Tiger Beetle (Cicindela nevadica lincolniana), Swift Fox (Vulpes velox), River Otter (Lutra canadensis), Southern Flying Squirrel (Glaucomys volans), Pallid Sturgeon (Scaphirhyncus albus), Topeka Shiner (Notropis topeka), Sturgeon Chub (Macrhybopsis gelida), Blacknose Shiner (Notropis heterolepis), Lake Sturgeon (Acipenser fulvescens), Northern Redbelly Dace …

Multiscale Analysis Of Factors That Affect The Distribution Of Sharks Throughout The Northern Gulf Of Mexico, J. Marcus Drymon, Laure Carassou, Sean P. Powers, Mark Grace, John Dindo, Brian Dzwonkowski

University Faculty and Staff Publications

Identification of the spatial scale at which marine communities are organized is critical to proper management, yet this is particularly difficult to determine for highly migratory species like sharks. We used shark catch data collected during 2006–09 from fishery- independent bottom-longline surveys, as well as biotic and abiotic explanatory data to identify the factors that affect the distribution of coastal sharks at 2 spatial scales in the northern Gulf of Mexico. Centered principal component analyses (PCAs) were used to visualize the patterns that characterize shark distributions at small (Alabama and Mississippi coast) and large (northern Gulf of Mexico) spatial scales. …

Gulf-Wide Decreases In The Size Of Large Coastal Sharks Documented By Generations Of Fishermen, Sean P. Powers, F. Joel Frodrie, Steven B. Scyphers, J. Marcus Drymon, Robert L. Shipp, Gregory W. Stunz

University Faculty and Staff Publications

Large sharks are top predators in most coastal and marine ecosystems throughout the world, and evidence of their reduced prominence in marine ecosystems has been a serious concern for fisheries and ecosystem management. Unfortunately, quantitative data to document the extent, timing, and consequences of changes in shark populations are scarce, thwarting examination of long-term (decadal, century) trends, and reconstructions based on incomplete data sets have been the subject of debate. Absence of quantitative descriptors of past ecological conditions is a generic problem facing many fields of science but is particularly troublesome for fisheries scientists who must develop specific targets for …

Mutation From Arginine To Lysine At The Position 189 Of Hemagglutinin Contributes To The Antigenic Drift In H3n2 Swine Influenza Viruses, Jianqiang Ye, Yifei Xu, Jillian Harris, Hailiang Sun, Andrew S. Bowman, Fred L. Cunningham, Carol Cardona, Kyoungjin J. Yoon, Richard D. Slemons, Xiu-Feng Wan

United States Department of Agriculture Wildlife Services: Staff Publications

Two distinct antigenic clusters were previously identified among the H3N2 swine influenza A viruses (IAVs) and were designated H3N2SIV-alpha and H3N2SIV-beta (Feng et al., 2013. Journal of Virology 87(13), 7655–7667). A consistent mutation was observed at the position 189 of hemagglutinin (R189K) between H3N2SIV-alpha and H3N2SIV-beta fair isolates. To evaluate the contribution of R189K mutation to the antigenic drift from H3N2SIV-alpha to H3N2SIV-beta, four reassortant viruses with189R or189K were generated. The antigenic cartography demonstrated that the R189K mutation in the hemagglutinin of H3N2IAV contributed to the antigenicdrift, separating these viruses into H3N2SIV-alpha to H3N2SIV- beta. This R189K mutation was also …

Global Attracting Equilibria For Coupled Systems With Ceiling Density Dependence, Eric A. Eager, Mary Hebert, Elise Hellwig, Francisco Hernandez, Richard Rebarber, Brigitte Tenhumberg, Bryan Wigianto

School of Biological Sciences: Faculty Publications

In this paper, we present a system of two difference equations modeling the dynamics of a coupled population with two patches. Each patch can house only a limited number of individuals (called a carrying capacity) because resources like food and breeding sites are limited in each patch. We assume that the population in each patch is governed by a linear model until reaching a carrying capacity in each patch, resulting in map which is nonlinear and not sublinear. We analyze the global attractors of this model.

An Interdisciplinary Research Course In Theoretical Ecology For Young Undergraduates, Glenn Ledder, Brigitte Tenhumberg, G. Travis Adams

School of Biological Sciences: Faculty Publications

As part of an interdepartmental effort to attract promising young students to research at the interface between mathematics and biology, we created a course in which groups of recent high school graduates and first-year college students conducted a research project in insect population dynamics. The students set up experiments, collected data, used the data to develop mathematical models, tested their models against further experiments, and prepared their results for dissemination. The course was self-contained in that the lecture portion developed the mathematical, statistical, and biological background needed for the research. A special writing component helped students learn the principles of …

Daily Temperature Fluctuations Unpredictably Influence Developmental Rate And Morphology At A Critical Early Larval Stage In A Frog, Juliana M. Arrighi, Ezra S. Lencer, Advait Jukar, Daesik Park, Patrick C. Phillips, Robert H. Kaplan

Systems Science Faculty Publications and Presentations

Background: Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized the influence of temperature on development in amphibians have failed to incorporate the realities of diel temperature fluctuations (DTF), which can be considerable for pond-breeding amphibians.

Results: We evaluated the effects of different ecologically relevant ranges of DTF compared with effects of constant temperatures on development of embryos and larvae of the Korean fire-bellied toad (Bombina orientalis). We constructed thermal reaction norms for developmental stage, snout- vent length, and tail length by fitting …

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Antioch University Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …

Bacterial Colonization And Extinction On Marine Aggregates: Stochastic Model Of Species Presence And Abundance, Andrew M. Kramer, M. Maille Lyons, Fred C. Dobbs, John M. Drake

OES Faculty Publications

Organic aggregates provide a favorable habitat for aquatic microbes, are efficiently filtered by shellfish, and may play a major role in the dynamics of aquatic pathogens. Quantifying this role requires understanding how pathogen abundance in the water and aggregate size interact to determine the presence and abundance of pathogen cells on individual aggregates. We build upon current understanding of the dynamics of bacteria and bacterial grazers on aggregates to develop a model for the dynamics of a bacterial pathogen species. The model accounts for the importance of stochasticity and the balance between colonization and extinction. Simulation results suggest that while …