Teaching Fields: Organic Evolution, Population Biology, Experimental Design

Research Interests: My research involves both ecological and genetic approaches to plant populations. We are currently studying two rare species: Panax quinquefolius (American Ginseng) and Spiranthes cernua (Nodding ladies' tresses). Both are long-lived, herbaceous plants. American ginseng grows in the deciduous forests in eastern Nebraska while Spiranthes is found in prairies. To examine patterns of genetic variation within and between populations, we have applied nuclear DNA markers and allozymes to both species.

Long-term demographic monitoring allows us to evaluate the present status and model the future of both of these threatened species. Recently, we have investigated the role of light on growth and reproduction in Panax quinquefolius. Transplanted seedlings of Spiranthes cernua have been successfully established at Nine-mile Prairie, providing a test of re-introduction procedures. The importance of mycorrhizae for the growth of terrestrial orchids is also being investigated.

A new area of research is the evaluation of a prairie restoration project at Stolley Prairie in west Omaha.

Research Interests: My research specialty is paleobotany with interests in paleoecosystem dynamics and plant macroevolution during the Mesozoic, paleophytogeography of the Southern Hemisphere, plant structural and developmental responses to paleoenvironmental changes, and physical and biological constraints on the evolution of plant structures. I am currently pursuing three major projects: 1. Plant species diversity and abundance in paleoenvironments influenced the evolution of major plant groups, including the origin and radiation of the flowering plants.   2. The Permian-Triassic (245 Ma) biotic transition is a critical interval in evolutionary history since the largest mass extinction occurs at this boundary.   3. Physical and biological constraints influence the evolution of plant form and function.

Teaching Fields: Ecology, Plant Ecology, Fire Ecology, and Communities and Ecosystems.

Research Interests: Research in North America focuses on plant community dynamics and diversity of Tallgrass Prairie (native and restored), Loess Hills Prairie, Nebraska Sandhills Prairie, Eastern Deciduous Forests, and Loess Hill Savanna (restoration). The specific focus is on the season and frequency of burning. Research includes assessing historic fire return intervals from fire-scarred trees using dendrochronological techniques. Research projects in Australia focus on fire effects on plant community dynamics of Western Australian desert grasslands as part of a larger study aimed at reintroducing mid-sized mammals to their historic range.

UNO field sites (Allwine, Davis):
http://www.unomaha.edu/prairie/home.php

Prescribed Burn Home Page:
http://www.unomaha.edu/biology/Fire/

Teaching Fields: General Biology; General and Advanced Genetics; Genetics, Evolution and Development; Bioinformatics; Neuroscience

Research Interests: I am interested in understanding the genetic contributions to neurodegenerative diseases such as Parkinson's disease and Multiple Sclerosis, developing biomarkers that can aid in early diagnosis and classification of neurodegenerative disorders, and elucidating gene networks involved in neuronal development and maintenance. My research employs genetic analyses in experimental models of disease that include flies and transgenic mice, and, in collaboration with clinical investigators, molecular genetic and bioinformatic analyses of human samples.

Teaching Fields: Principles of Biology, Endocrinology, Writing in Biology, Human Physiology

Research Interests: Avian physiology and endocrinology
Studies tracking seasonal changes in blood lipids in free-living and captive populations of White-crowned Sparrows documented dramatic metabolic adaptations attending preparations for migration. Work with Harris' Sparrows, a migratory visitor to eastern Nebraska, dealt with the control of lipid mobilization, particularly the role of the pancreatic hormone glucagon. Additional studies in this species focused on metabolic adaptations during fasting under winter conditions, the importance of lipid reserves, and the role of glucocorticoid hormones. More recent work described dramatic plasma volume expansion associated with postnuptial molting in Harris' Sparrows. Collaborative work with J. French and S. Hendricks (Psychology, UNO) included radioimmunoassay of LH in golden lion tamarins and studies of feedback control of its release.

Teaching Fields: General Biology, Lichenology, and Non-vascular Plant Morphology

Research Interests: My research interests include the systematics, ecology and phytogeography of the lichen-forming fungi.  My current research utilizes traditional morphological approaches as well as data from TLC chemical analyses and is centered around floristic and taxonomic studies of the lichens of Wyoming's Snowy Range, the Big Thicket National Preserve in East Texas, and the Lichen family Parmeliaceae in Mexico.  I maintain a lichen herbarium of approximately 17,000 identified specimens, cataloged on computer databases, and have a lichen exchange program. I also maintain computer database files on more than 28,000 lichen literature references published since 1950.

My Site: http://avalon.unomaha.edu/lichens/

Teaching Fields: Herpetology, Vertebrate Embryology, Comparative Anatomy of Vertebrates, Histology, Human Anatomy and Physiology

Research Interests: Anatomy, ecology, behavior, and reproductive biology of amphibians and reptiles; vertebrate histology and embryology. In particular, I am interested in the structure-function and hormonal control of the lepidosaurian oviduct and uterus, and the ecology and conservation of the amphibians and reptiles of Nebraska. I also maintain a bibliographic database on tuatara, lizards and leiopelmatid frogs of New Zealand. Current graduate student studies include 1)Population dynamics of two sympatric softshell turtles and implications for river flow regulation, 2) Spatial ecology and natural history of the western massasauga rattlesnake in Nebraska, 3) Histology and histochemistry of the stomach and intestine of an anoline lizard, and 4) Population dynamics, demographics and conservation of the Osage copperhead in Nebraska.

Teaching Fields: Introductory Biology, Environmental Science, Mammalogy, Natural History of the Vertebrates

Research Interests: All aspects of mammalian biology with an emphasis on ecology and ecophysiology. My current projects involve studying renal form and function in shrews and moles, effects of pesticides on bats, effects of prairie fires on small mammals, and the natural history of Nebraskan and New Mexican mammals.

Teaching Fields: Animal Physiology, Environmental Physiology, Toxicology, Environmental Biology

Research Interests: the physiological response of fish to environmental stressors. Ongoing projects in the laboratory include:

- The effects of Cadmium on the reproductive physiology and liver gene expression of fathead minnows.
- The physiological response of fathead minnows to effluent from four different wastewater treatment plants in Nebraska.
- The physiological response of fathead minnows to runoff from Nebraska cattle feedlots.
- The effect of a trematode brain parasite on the reproductive physiology of fathead minnows.
- The effect of development, reproduction and diet on the liver gene expression in fathead minnows.

Teaching Fields: Molecular Biology of the Cell, Cell Biology, Writing in Biology, Introductory Biology

Research Interests: Gene silencing is an important regulatory mechanism for controlling cell development, aging, and cell proliferation. It allows a brain cell to develop different traits than a red blood cell, and aids in removing obsolete cells by triggering cell death. Inappropriate gene activation, or inappropriate silencing, can lead to development of cancers, developmental abnormalities, and premature cell death. Recently, a new RNA helicase from Drosophila has been shown to be capable of overcoming gene silencing at telomeres, suggesting a functional role for this helicase in regulating gene silencing..

My lab aims to characterize the yeast homolog of this Drosophila RNA helicase, the S. cerevisiae SUB2 gene.

Teaching Fields: Introductory Biology, Flora of the Great Plains, Phylogenetic Systematics.

Research Interests: I study the systematics of the plant family Apocynaceae (the milkweed family). Systematics is the field of biology primarily concerned with the study of the Earth's biodiversity.  I have two on-going projects.

1) Many species of Dischidia grow in the nests of arboreal ants, and some species have modified leaves that function as ant houses. I am studying how ant associations and ant-house leaves evolved in Dischidia and preparing a monograph, a complete account of all species, of the genus.

2) Some Apocynaceae, such as the species of Asclepias, or milkweeds, have among the most highly-modified flowers of all flowering plants while others have much simpler flowers. I have recently completed an analysis of DNA sequences that rejects the long-accepted hypothesis of how the highly-modified flowers of Asclepias evolved. I am currently collecting additional data to further test these results.

Teaching Fields: all about bioinformatics, including Intro to Bioinformatics, Applied Bioinformatics,Bioinformatics Algorithms, and Seminar in Bioinformatics.

Research Interests: I am interested in bioinformatics. My lab has been developing biological databases and new algorithms for understanding better how genes or non-coding regions give each organism unique characteristics. Currently we have several ongoing research projects that cover different aspects in evolutionary bioinformatics as below:

Phylomarker - an in silico data mining tool for predicting gene regions that are likely to reflect the true evolutionary history and thus can be used as genetic markers for constructing species phylogeny. In collaboration with Dr C. Li at UNL. Website: http://bioinfo-srv1.awh.unomaha.edu/phylomarker/index.php.

GenomeBLAST - a Web tool for comparative genomics analysis. This tool is particularly useful for organisms with small genome size, e.g., viruses. GenomeBlast uses a novel parameter, namely coverage, for homologous gene prediction. Website: http://bioinfo-srv1.awh.unomaha.edu/genomeblast/.

FluGenome - a Web server for genotyping influenza A virus using genome sequences. In collaboration with Dr. Ruben Donis at CDC (http://www.cdc.gov/), we are developing an application for genotyping Avian flu viruses. FluGenome provides functions for the user to interrogate the database in different modalities and get detailed reports on lineages and genotypes.

My Site: http://bioinfo-srv1.awh.unomaha.edu/glu/index.htm

Teaching Fields: Ornithology, Environmental Biology, Environmental Field Methods

Research Interests: My research focuses on the ecology and conservation of birds.  I am especially interested in designing research that meets the needs of policy-makers and resource managers, while also addressing basic questions in ecology. The current focus of my lab is on the ecology of birds in ecosystems heavily modified by agriculture. This research includes work on grassland birds that combines population-level studies of Dickcissels (Spiza americana) with community-level work looking at the grassland bird community in relation to vegetation and food supply. My lab is also actively working on the ecology of shorebirds that migrate through the agro-ecosystem of Nebraska's Rainwater Basin region.

My Site http://www.unomaha.edu/environmental_studies/JPM_Home.html

Teaching Fields: Developmental Biology, Intro to Immunology

Research Interests: With Raychel A. Watkins and Aelita J. Pinter, conducted a search for an invertebrate host for Hepatozoon sp. infecting the montane vole (Microtus montanus), we collected fleas, ticks, and mites from live-trapped voles and searched squash preparations for Hepatozoon oocysts. From 1989 through 1996, we identified six species of fleas in Grand Teton National Park: Megabothris abantis, Megabothris asio megacolpus, Aetheca wagneri, Peromyscopsylla selenis, Peromyscopsylla. hesperomys, and Hystrichopsylla dippiei dippiei. We found Hepatozoon oocysts only in M. abantis; we found no oocysts in mites or ticks. We conclude that M. abantis is an invertebrate host of Hepatozoon sp. and is likely to be the definitive host for theHepatozoon spp. of M. montanus.

Teaching Fields: Ecology, Behavioral Ecology, Environmental Biology

Research Interests:My research focuses on the ecology and evolution of social behavior and life histories. The subsocial burying beetles (Nicrophorus spp.) are an ideal system to study social behavior and life histories from the perspective of behavioral ecology, quantitative genetics, and evolutionary biology. My current research projects focus on indirect genetic effects of parental care and brood size as well as on the environmental and genetic factors causing variation in parental care and brood size.

Teaching Fields: microbiology, pathenogenic microorganisms, principles of biology

Research Interests: how microorganisms such as bacteria and fungi sense and adapt to changing environmental conditions, particularly stressful conditions, and how pathogenic microorganisms cause disease.  Currently, I am studying regulation of production of extracellular sugar coating alginate in bacterium Pseudomonas aeruginosa.  Production of alginate contributes to the ability of Pseudomonas to cause chronic lung infections in cystic fibrosis patients.  Production of alginate is regulated by environmental conditions and is normally induced in response to stressful conditions.  Students in my lab work to identify and characterize regulatory factors in this bacterium that play a role in sensing environmental conditions and altering alginate production. I also have interests in the effectiveness of an antimicrobial chemical used by dentists and oral surgeons, monitoring the changes in the population of bacteria in a polluted aquifer during a trial bioremediation treatment, the regulation of nitrogen utilization genes in response to the availability of nitrogen-containing compounds in baker’s yeast Saccharomyces cerevisae.

Teaching Fields: plant physiology, molecular, and cellular biology, molecular plant-microbe interactions and plant stress physiology, molecular methods and research strategies, plant biology and the history of agriculture, undergraduate research experience, writing in biology, general biology

Research Interests: Physiology and metabolism of parasitic and carnivorous plants, especially Cuscuta pentagona (dodder) and Dionaea muscipula (Venus flytrap); carbon and nitrogen metabolism, RNA metabolism, and plant growth and development.

My Site: http://myweb.unomaha.edu/~mschoenbeck/

Teaching Fields: Biology II, parasitology

Research Interests: My research interests are broad and encompass parasite biodiversity, parasite biogeography and host-parasite coevolution. I examine these aspects of biology by focusing on the parasites of turtles, specifically Australian turtles. Dr. Vasyl Tkach and I have been funded by the National Science Foundation to examine parasite biodiversity in Australian turtles. We are currently collecting parasites, identifying the few that are known, and describing the species that are new to science. As our biodiversity research proceeds we conduct evolutionary examinations of Australian turtle parasites and other turtle worms from around the world. These evolutionary examinations use morphological, molecular and life history information and I am keenly interested in the role of hosts in driving parasite cladogenesis. My approach combines field work, microscopy, experimental biology and molecular techniques and is very amenable to student participation.

My Site:http://avalon.unomaha.edu/parasite/

Teaching Fields: chthyology, limnology, stream ecology, fauna of the great plains, parasitology, biosystematics, biogeography

Research Interests: Ichthyology/aquatic ecology: life history, ecology and systematics of North American fishes. Studies of reproduction in the minnow genus Phoxinus have demonstrated a parthenogenetic polyploid/mosaic complex in the Nebraska Sa ndhills. Ecological studies have been made on many Nebraskan fishes including pearl and blacknose dace, sicklefin and sturgeon chub, plains topminnow, tadpole madtom, orangethroat and Iowa darters. Field records from the past 25 years document the distr ibution of the state's fishes; data on population levels allows the compilation of a threatened/endangered species list. Morphological, electrophoretic, and DNA techniques have been used to investigate systematic relationships in several groups of midwes tern fishes. Studies of predator/prey relationships revealed changes in behavior and physiology in Daphnia and relative spine length in sticklebacks in bodies of water without fishes.

Teaching Fields: Genetics and Molecular Genetics

Research Interests: Our research focuses on the response of yeast cells to amino acid deprivation. All cells respond to external stimuli or changes in internal conditions by altering patterns of gene expression. Starvation for amino acids in yeast leads to the induction of the General Amino Acid Control (GAAC) pathway. The cell senses the lack of amino acids and produces a signal that leads to increased translation of Gcn4p, a potent activator protein that controls the expression of many genes encoding amino acid biosynthetic enzymes. During activation of GAAC, bulk mRNA translation decreases while the translation of Gcn4p target gene mRNAs is maintained. Gcn4p controls the expression of its many target genes through the recruitment of several transcription coactivator complexes that have seemingly overlapping functions.

Our studies seek to answer the following questions: 1)What functions do the coactivator complexes provide to Gcn4p target gene expression once recruited to a promoter? 2) How are Gcn4p target genes inactivated as cells recover from amino acid starvation? 3) How are Gcn4p target genes repressed in non-starvation conditions? 4) How can the cell distinguish between Gcn4p target gene messages and mRNA from other genes when GAAC is activated?

Teaching Fields: Molecular Biology, Virology, Nucleic Acids Biochemistry, Protein Structure

Research Interests: The overall goal of our research is to understand the structure and function of RNA molecules. Most of our early work focused on ribosomal RNA (rRNA), characterizing the role of the RNA in protein synthesis (Vila et al 1994, Thompson et al 2001). We have recently embarked on a new area of investigation studying the structure and function of viral RNA molecules, particularly enteroviral genomic RNA. Many of the approaches that we used for determining the structure of rRNA are also applicable to viral RNA. We have initiated studies to learn the structure of the internal ribosome entry site (IRES) RNA found in picornaviruses (Kim et al., 2005, Bailey and Tapprich 2007). This work is significant because virulence is determined by IRES structure. In our initial studies we have used chemical modification and primer extension to deduce the secondary structure of the IRES elements in coxsackievirus B3. This analysis has been completed for virulent wild type viruses and for attenuated mutant viruses. We have shown localized structural changes in the IRES RNA that correlate with virulence. Theses shifts in structure occur in regions of the IRES known to be important for the binding of key cellular proteins. The results show that viral replication and viral virulence is critically dependent on discrete structures in the RNA. Further characterization of these structures will lead to strategies to develop antiviral compounds and vaccines.

My Site: http://www.unomaha.edu/biology/tapprich.php

Teaching Fields: Microbial Physiology, Fungi, Microbiology, Genetics

Research Interests: My research interests are in understanding the regulation of development in microorganisms. We are concentrating our research efforts on Dictyostelium as the model organism for these investigations. In Dictyostelium, independently growing cells, upon receiving the appropriate signal, cooperate to produce one of two multicellular structures: spore-bearing sorocarps or macrocysts.  We are investigating the processes that control the choice between sorocarp and macrocyst development. Monoclonal antibodies are used to follow temporal, spatial and quantitative aspects of stage-specific proteins. cDNA libraries provide the starting point for identifying genes expressed at the earliest stages of multicellular development.  The indentity of these genes and their requirement for normal development are being studied.

Teaching Fields: Conservation Biology, Fauna of the Great Plains

Research Interests: Dr. Wolfenbarger conducts research on the ecology and conservation of grassland species and communities in the agricultural landscape of the Great Plains. She also devotes research time to synthesizing information for policymakers and resource managers so that scientific results are readily available for decision makers.

My Site: http://www.unomaha.edu/environmental_studies/LLWolfenbarger.html

Carl E. Nordahl
Assistant Professor Emeritus
Retired May 2005
Ph.D., University of Iowa, 1969
cnordahl@mail.unomaha.edu

Teaching Fields: plant physiology, cellular biology, botany, plant anatomy, microtechnique

Research Interests: Plant growth hormones and/or regulators; the use of plant tissue culture to study various hormonal effects; the use of light and electron microscopy to study regulator effects at the cellular and tissue levels; studies dealing with chloroplast development and function in gibberellin treated tissues.

Teaching Fields: microbiology, pathogenic microbiology, parasitology

Research Interests: parasitic protists

Teaching Fields: plant systematics, general biology, plant morphology, writing and communicating in biology

Research Interests: Floristics, taxonomic treatments of genera, vegetative characteristics of grasses. Wrote treatments of 75 genera of Poaceae and 11 genera of Ranunculaceae for Great Plains Flora. Wrote several legume genera, Dalea, Errazurizia, Psorothamnus, and Marina, for Flora of North America. Wrote and edited many parts of Flora of Nebraska (with Robert Kaul and Steven Rolfsmeier).

Teaching Fields: Animal Behavior, Experimental Methodology, Behavioral Endocrinology

Research Interests: The focus of my research program is the analysis of the proximate physiological and behavioral mechanisms underlying the unusual life-history characteristics of cooperatively-breeding mammals: delayed dispersal, reproduction suppression, and helping behavior. We also are exploring the underlying nature of long-term heterosexual relationships in purportedly monogamous mammals. Currently we are addressing these issues in two species, the black tufted-ear marmoset (Callithrix kuhli) and the Mongolian gerbil (Meriones unguiculatus).

Teaching Fields: Landscape Design, Landscape Plant Identification, Landscape/Environmental Appreciation

Research Interests: Landscape sustainability, visual resources assessment and the role of landscape design in quality-of-life perceptions. Present research fosuses on assessing the role of horticulture and quality residential landscaping in personal and family quality-of-life.

Teaching Fields: Molecular Virology, Molecular Viral Pathogenesis, Viral Evolution

Research Interests: This laboratory focuses on the molecular biology of a common human enterovirus, called coxsackievirus B3 (CVB3). CVB3 is a common viral cause of acute inflammatory heart disease or myocarditis. Based upon the detection of viral RNA in diseased heart muscle, it is believed that CVB3 may also induce a condition termed dilated cardiomyopathy or DCM. DCM is often a terminal disease, and is one of the most common reasons for seeking heart transplantation. There are no vaccines against CVBs or any other enterovirus except the polioviruses. It is not known how CVB3 or related enteroviruses naturally determine the virulence phenotype: that is, the viral genetics that determine whether a virus strain is cardiovirulent (able to induce disease) or avirulent in man. The well-studied poliovirus system examined the genetics of artificially-induced vaccine strain attenuation, a much different story than the genetics of virulence in wild-type viruses.