Fall 2012 Asa Gray Seminar Series
September 10, 2012
Monkeypox virus: From emergence and evolution to the development of anti-viral strategies
Sara C. Johnston, Ph.D., Research Microbiologist, United States Army Medical Research Institute of Infectious Diseases, Virology Division
The Orthopoxvirus genus of family Poxviridae contains numerous virus species that are capable of causing severe disease in humans, including variola virus (the etiological agent of smallpox) and monkeypox virus. Monkeypox is endemic in the Democratic Republic of the Congo (DRC) and is characterized by systemic lesion development and prominent lymphadenopathy. Monkeypox prevalence in the DRC has increased dramatically since the cessation of active smallpox vaccination. Like variola virus, it is a high priority pathogen due to its potential to cause serious disease with significant health impacts following zoonotic, accidental, or deliberate introduction into a naïve population. Although a vaccine exists, it is highly reactogenic and contraindicated for a growing number of people. Current efforts have focused on the development of safer alternatives and therapeutics to treat active infections. Recently, we showed the in vitro efficacy of IFN-β against monkeypox virus. In addition, we found that IFN-β was effective when administered up to 12 hours post infection, demonstrating its therapeutic potential. Collectively, the data support the continued development of IFN-β as a treatment for monkeypox virus as well as other Orthopoxviruses including variola virus.
October 1, 2012
Excitation-contraction coupling in normal and failing hearts
Jonathan M. Cordeiro, Ph.D, Research Scientist, Masonic Medical Research Laboratory
Heart failure (HF) is one of the most common causes of death and disability in United States, affecting about 2.5 million in this country alone. HF is associated with extensive structural, functional and electrophysiological remodeling that ultimately results in a reduced cardiac output. Associated with HF are a number of other problems such as cardiac arrhythmias. Altered intracellular Ca2+ handling appears to play a central role during the progression of heart failure as well as in the development of cardiac arrhythmias. I will present data showing the extent to which electrical and mechanical differences in ventricle are altered in the failing myocardium. I will also show recent experiments demonstrating how a class of ion channel activators may prove beneficial in the failing myocardium. The results provide a proof of principal that some aspects of the electrical remodelling encountered during the development of heart failure can be pharmacologically reversed.
October 22, 2012
Environmental phytotechnologies
Lee A. Newman, Ph.D., Assistant Professor, Biotechnology and Phytoremediation, Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry
When we think of plants, we think food, housing, and paper. But plants can play many other roles in our lives, sometimes without our even knowing about it. They can remediate toxic waste, they can play multiple roles in reducing carbon dioxide levels due to fossil fuel uses, and can help us to understand potential environmental toxicity issues. In this talk, we will explore some of these novel areas. Phytoremediation, or the use of plants to degrade or sequester environmental toxins, is a major part of the work that will be presented. We will also discuss plant microbe interactions, and how understanding these can help us in a variety of areas, and we will also learn how plants can play a vital role in our new energy economy. Finally, we will discuss how plants can help us to learn about potential toxicological risks related to the emerging field of nanotechnology.
November 12, 2012
Identification of Merkel cell progenitors in developing and adult mice
Margaret C. Wright, Graduate Student, Maricich Lab, Case Western Reserve University, Department of Neuroscience,
Merkel cells are specialized epidermal cells that are intimately associated with large, slowly-adapting peripheral nerve fibers. These Merkel cell-neurite complexes are important for the detection of certain light touch stimuli. Merkel cells are derived from the skin lineage and constantly turn over throughout life. However, the immediate precursor of these cells and the processes that govern their genesis and maintenance are unknown. The transcription factor Atoh1 is required for Merkel cell production and its expression is maintained in mature Merkel cells. We found that a small fraction of Atoh1GFP+ cells express the proliferative marker Ki67 at embryonic and adult ages and that these cells are found within the most superficial regions of whisker and guard hair follicles. In addition, fate-mapping of Atoh1-lineal cells in adulthood using an inducible Atoh1CreER;ROSALacZ reporter resulted in persistent reporter gene expression exclusively in Merkel cells up to nine months after tamoxifen treatment. These experiments demonstrate that the immediate Merkel cell progenitor expresses Atoh1, and that these progenitors are committed solely to the Merkel cell lineage. Furthermore, we found that perturbations of Notch signaling during embryonic development resulted in increased numbers of Merkel cells within whisker follicles, suggesting a critical role for Notch-dependent pathways in controlling precursor specification. Our results provide new insights into the origins and genetic pathways that control Merkel cell development.
December 3, 2012
Chestnut blight, an old problem with new solutions
William A. Powell, Ph.D., Director, Council on Biotechnology in Forestry, SUNY College of Environmental Science and Forestry
The American chestnut (Castanea dentate) was once a keystone species in the forests of the eastern United States, accounting for approximately 25% of the mature trees. A healthy American chestnut tree could grow up to 100 feet tall and measure up to 10 feet in diameter. It was super at producing nuts for wildlife; important for agriculture for human consumption of the nuts; very important for the lumber industry, making a rot-resistant, fast-growing wood product; and it was also important part of our history. The mission of the American Chestnut Research and Restoration Center at the SUNY College of Environmental Science & Forestry is to conduct basic and applied research that will lead to the development of a blight-resistant American chestnut tree. Our ultimate goal is to reintroduce a population of these resistant trees back into forest ecosystems of New York and then the rest of the eastern United States. The project has evolved from basic research into a multifaceted endeavor which includes such areas as the identification of plant pathogen resistance-enhancing genes, the development of American chestnut tissue culture, field testing chestnut trees from tissue culture, public participation through the identification of rare remnant survival chestnut trees, collection and exchange of viable nuts and the establishment of large restoration plantations throughout New York State. This presentation will provide a brief history of the chestnut blight and current status of the efforts to develop a blight resistant tree that would lead to restoration of this important tree species.
Fall 2011 Asa Gray Seminars
September 12, 2011
Restoration of Solvay waste sites using threatened and endangered plant communities
Tony Eallonardo, Ph.D., Scientist at O'Brien & Gere
Lime waste sites are areas that have received alkaline refuse from industrial processes using limestone and basic reagents. These sites are typified by alkaline soils with high concentrations of base cations and extremely low concentrations of available nitrogen and phosphorus. They often re-vegetate naturally—to at least 50% cover within 10 years following dumping, and they often support a mix of native and non-native early successional species as well as rare species from calcareous, infertile or otherwise stressful habitats. The goal of this study was to restore a seasonally flooded lime waste (i.e., Solvay waste) site near Syracuse, NY that had remained largely barren for over 30 years. Native plant communities from infertile, stressful and calcareous settings (i.e., alvar grassland, inland salt marsh, Great Lakes dune, and marl fen) were targeted for the restoration as well as a collection of stress tolerant emergent species from fresh to salt marsh communities. Species were mainly introduced to the 2.1 ha site by planting: from 2008 to 2010 approximately 55,000 plants were installed. Over this time period 8.96 metric tons of pelletized 5-10-5 fertilizer was applied, and invasive species were controlled by a variety of means. As of 2010, 172 vascular plant species have been observed on site, 85 of which were planted or sown and eight of which are classified as threatened or endangered in New York. Since 2008, the following variables have been on a positive trajectory over time: total cover (%), cover of target species (%), and species richness per square meter
Relative cover of the highly invasive Phragmites australis and Lythrum salicaria are on negative trajectories. Analysis of soils and species traits shows that the weathering of magnesium oxide (a key constituent in Solvay waste) drives a soil process that suppresses competitive exclusion and favors species with traits associated with stress tolerance and efficient nutrient use. Historic flooding of the project site in 2011 has modified the initial trajectory of vegetation development with robust emergent vegetation increasing, perhaps temporarily, in importance. This project demonstrates that stressful growing conditions provided by Solvay waste simulate stresses provided by saline or alkaline groundwater discharge, enabling the restoration of marl fen and inland salt marsh plant communities. Lessons learned from this project will be discussed in the context of restoring other post industrial and stressful urban sites.
October 3, 2011
“Girdling, Splitting and Rearing to Know: Insights into New York Invasive Forest Insects”
Melissa K. Fierke, Ph.D., Assistant Professor, Forest Entomology - Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry
Research in my lab centers around two invasive wood-borers in New York State, emerald ash borer and Sirex noctilio, the European woodwasp. With emerald ash borer, we are investigating different management techniques in order to slow ash mortality as new infestations are identified in NY. We are looking at parasitism of the woodwasp by native hymenopterans as well as interactions with our native woodwasps. This presentation will give an overview of these insects as well as some of the insights we’ve gained over the past couple of years.
October 24, 2011
“Improving Bifunctional Intrabodies Against the Huntingtin Protein”
David Butler, Ph.D., Postdoctoral Fellow, Wadsworth Center, NYS Department of Health
Single-chain antibodies (scFvs) that bind Huntingtin (HTT) protein show promise as possible immunotherapeutics for Huntington's Disease (HD). Intrabodies directed at the N-17 domain of HTT are capable of minimizing the toxic effects of protein misfolding in cell culture, ex vivo cultures, and Drosophilamelanogaster models of HD. Additionally, intrastriatal delivery of scFv-C4 has been shown to significantly reduce the size and number of aggregates in HD transgenic mice; however, this protective effect diminished with age and time after injection. Additional optimization of scFv-C4 is required for this intrabody to be of future use in clinical applications.
Proteins that contain enriched regions of amino acids Proline (P), Glutamic Acid (E) or Aspartic Acid (D), Serine (S), and Threonine (T), otherwise known as PEST regions, are targeted for proteasomal degradation and generally have a short half life. This talk will summarize the data which suggest that fusion of the C-terminal PEST region to scFv-C4, a bifunctional intrabody, reduces soluble and insoluble httex1-72Q fragments in vitro.
November 7, 2011
"Use of Model Organisms to Study Gene Regulation"
Steven D. Hanes, Ph.D., Professor of Biochemistry and Molecular Biology, SUNY-Upstate Medical University
Gene Regulation in Development and Disease: My laboratory is interested in how cells control the activity of genes during early development of the embryo and during the cell cycle. One key point of regulation is the synthesis of an RNA copy of individual genes. This process is carried out by RNA polymerase II (RNA pol II). We study RNA pol II in two distinct contexts. Each project uses a different model organism to its best advantage, where we can apply sophisticated genetic, molecular, and biochemical tools to discover important mechanisms of gene regulation. Our findings are relevant to understanding similar mechanisms that occur in human cells, and whose disruption is often associated with disease.
Homeobox genes: In the first project we study homebox transcription regulators in Drosophila melanogaster (fruit fly). For example, we study a homeobox gene called bicoid, which encodes a protein (Bicoid) that directs development of the head and thorax in early embryos. Bicoid works by recruiting RNA pol II to selected target genes, and how exactly it does this is the subject of our work. Our results have been important for understanding how homeobox genes function in normal cells and how their disruption causes certain human cancers (e.g. childhood leukemias). We also discovered proteins that interact with Bicoid (Sap18 and Bin3). These proteins have human counterparts and we are trying to understand how they function.
Prolyl isomerases: In a second project, we study a called ESS1 in Saccharomyces cerevisiae (yeast) which encodes an enzyme known as a prolyl cis/trans isomerase. ESS1 is essential for growth in yeast and cells that lack ESS1 arrest in mitosis. A counterpart of ESS1 is found in humans and is called PIN1. We are learning how yeast ESS1 and human PIN1 control cell growth. We discovered that Ess1 works by controlling the conformation of RNA pol II. This understanding might lead to the development of antifungal drugs against ESS1 (or anticancer drugs against PIN1).
November 28, 2011
“Exposure to Polychlorinated Biphenyls Causes Alterations in Brain Serotonin Concentrations in Swiss-Webster Mice”
Dr. Terri Provost, Ph.D.Biology Department, Utica College and Megan Peppenelli, Graduate Student, SUNY Upstate Medical University
Spring 2011 Asa Gray Seminars
January 31, 2011
How cells control pH
Dr. Patricia Kane, Department of Biochemistry and Molecular Biol., SUNY Upstate Medical University
My laboratory works on a proton-pumping ATPase, the V-ATPase, that is found in lysosomes, endosomes, and Golgi apparatus of all eukaryotic cells. This enzyme is responsible for using the energy from ATP hydrolysis to acidify these compartments, which are maintained at pH 4.5-6.5 in a cytosol that is at near-neutral pH. We use yeast cells to better understand how V-ATPase activity is controlled, since V-ATPases in human and yeast cells are very similar. We are able to measure cytosolic and organelle pH in living yeast cells with fluorescent pH sensors, and to test how the pH of these compartments responds to conditions outside the cell. We have also found that V-ATPases inside the cell change their activity in response to pH changes outside the cell, and that V-ATPases actively collaborate with other proton pumps to ensure proper cellular pH regulation. This raises the interesting question of how cells "measure" pH in different compartments and respond appropriately to altered conditions. Perturbed V-ATPase activity is implicated in numerous diseases, including neurodegeneration, cancer, and osteoporosis, so understanding V-ATPase regulation is highly significant.
February 28, 2011
Microclimate benefits for Monarch Butterflies overwintering in Mexico
Dr. Ernest H. Williams, Jr. and Christian A. Johnson, Department of Biology, Hamilton College
The extraordinary migration of monarch butterflies from eastern North America to the mountains of central Mexico protects them from freezing during wintertime. The microclimate varies within these mountain-top forests, however, so monarchs cluster in specific locations under the forest canopy. Recent studies I've done with collaborators show how the microclimate varies and how the butterflies take advantage of the least hazardous places to cluster. I'll describe temperature patterns within the forest and show photos of dense over-wintering aggregations of monarchs.
March 28, 2011
Trophic control of a temperate grassland ecosystem: Elk, bison, and wolves in Yellowstone National Park
Dr. Douglas A. Frank, Department of Biology, Syracuse University
Climate is the primary factor controlling terrestrial ecosystems. However, when abundant, large herbivores also can play a central role. During this talk I will summarize research that colleagues and I have conducted over a 22 year span in Yellowstone National Park that documents important effects that large migratory herds of elk and bison have on grassland production and soil carbon and nitrogen processes. I will then describe how the re-introduction of the gray wolf in 1995 has altered the influence of ungulates on ecosystem dynamics and has resulted in profound and wide-spread changes in the ecology of Yellowstone National Park.
April 11, 2011
Forest management changes plant community composition, diversity, and stability in the Pacific Northwest
Dr. Martin Dovciak, Department of Environmental & Forest Biology, SUNY College of Environmental Science & Forestry
Global changes in land-use are the leading threat to biological diversity world-wide. Forests provide a unique habitat for many species, but they also serve as a source of wood and other materials used in a multitude of products important for humans, and they compete with other land-uses such as agriculture and human settlement. Consequently, the spatial extent of forests has dramatically decreased in modern times and most forests are now directly managed by humans. Forest management, and especially timber harvest, can negatively affect many forest species and lead to changes in the character of biological communities, loss of biological diversity, and decline in ecosystem services and ecosystem stability. Dr. Dov?iak will discuss how forest ecosystem management affects the composition, diversity and stability of forest understory plant communities in the Pacific Northwest, using analyses of long-term datasets from the Andrews Long-Term Ecological Research (LTER) site in Oregon and U.S. Forest Service long-term plots in the Cascade Mts. in Washington. Work to date suggests that while forest timber harvest decreases the abundance and richness of sensitive forest interior herbs and bryophytes, it can increase the abundance and richness of non-forest species, including invasive species. The stability of forest understory plant communities was positively related to community richness, and negatively to the proportion of colonizing non-forest species. Consequently, forest timber harvest appears to dramatically change the character and temporal stability of forest understory plant communities. Applications of these findings to the management of Pacific Northwest forests are discussed, including alternative strategies for green-tree retention harvests that have been adopted or are currently under investigation as a part of the Demonstration of Ecosystem Management Options (DEMO) study funded by the U.S. Forest Service.
Fall 2011 Asa Gray Seminars
September 12, 2011
Restoration of Solvay waste sites using threatened and endangered plant communities
Tony Eallonardo, Ph.D., Scientist at O'Brien & Gere
Lime waste sites are areas that have received alkaline refuse from industrial processes using limestone and basic reagents. These sites are typified by alkaline soils with high concentrations of base cations and extremely low concentrations of available nitrogen and phosphorus. They often re-vegetate naturally—to at least 50% cover within 10 years following dumping, and they often support a mix of native and non-native early successional species as well as rare species from calcareous, infertile or otherwise stressful habitats. The goal of this study was to restore a seasonally flooded lime waste (i.e., Solvay waste) site near Syracuse, NY that had remained largely barren for over 30 years. Native plant communities from infertile, stressful and calcareous settings (i.e., alvar grassland, inland salt marsh, Great Lakes dune, and marl fen) were targeted for the restoration as well as a collection of stress tolerant emergent species from fresh to salt marsh communities. Species were mainly introduced to the 2.1 ha site by planting: from 2008 to 2010 approximately 55,000 plants were installed. Over this time period 8.96 metric tons of pelletized 5-10-5 fertilizer was applied, and invasive species were controlled by a variety of means. As of 2010, 172 vascular plant species have been observed on site, 85 of which were planted or sown and eight of which are classified as threatened or endangered in New York. Since 2008, the following variables have been on a positive trajectory over time: total cover (%), cover of target species (%), and species richness per square meter
Relative cover of the highly invasive Phragmites australis and Lythrum salicaria are on negative trajectories. Analysis of soils and species traits shows that the weathering of magnesium oxide (a key constituent in Solvay waste) drives a soil process that suppresses competitive exclusion and favors species with traits associated with stress tolerance and efficient nutrient use. Historic flooding of the project site in 2011 has modified the initial trajectory of vegetation development with robust emergent vegetation increasing, perhaps temporarily, in importance. This project demonstrates that stressful growing conditions provided by Solvay waste simulate stresses provided by saline or alkaline groundwater discharge, enabling the restoration of marl fen and inland salt marsh plant communities. Lessons learned from this project will be discussed in the context of restoring other post industrial and stressful urban sites.
October 3, 2011
“Girdling, Splitting and Rearing to Know: Insights into New York Invasive Forest Insects”
Melissa K. Fierke, Ph.D., Assistant Professor, Forest Entomology - Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry
Research in my lab centers around two invasive wood-borers in New York State, emerald ash borer and Sirex noctilio, the European woodwasp. With emerald ash borer, we are investigating different management techniques in order to slow ash mortality as new infestations are identified in NY. We are looking at parasitism of the woodwasp by native hymenopterans as well as interactions with our native woodwasps. This presentation will give an overview of these insects as well as some of the insights we’ve gained over the past couple of years.
October 24, 2011
“Improving Bifunctional Intrabodies Against the Huntingtin Protein”
David Butler, Ph.D., Postdoctoral Fellow, Wadsworth Center, NYS Department of Health
Single-chain antibodies (scFvs) that bind Huntingtin (HTT) protein show promise as possible immunotherapeutics for Huntington's Disease (HD). Intrabodies directed at the N-17 domain of HTT are capable of minimizing the toxic effects of protein misfolding in cell culture, ex vivo cultures, and Drosophilamelanogaster models of HD. Additionally, intrastriatal delivery of scFv-C4 has been shown to significantly reduce the size and number of aggregates in HD transgenic mice; however, this protective effect diminished with age and time after injection. Additional optimization of scFv-C4 is required for this intrabody to be of future use in clinical applications.
Proteins that contain enriched regions of amino acids Proline (P), Glutamic Acid (E) or Aspartic Acid (D), Serine (S), and Threonine (T), otherwise known as PEST regions, are targeted for proteasomal degradation and generally have a short half life. This talk will summarize the data which suggest that fusion of the C-terminal PEST region to scFv-C4, a bifunctional intrabody, reduces soluble and insoluble httex1-72Q fragments in vitro.
November 7, 2011
"Use of Model Organisms to Study Gene Regulation"
Steven D. Hanes, Ph.D., Professor of Biochemistry and Molecular Biology, SUNY-Upstate Medical University
Gene Regulation in Development and Disease: My laboratory is interested in how cells control the activity of genes during early development of the embryo and during the cell cycle. One key point of regulation is the synthesis of an RNA copy of individual genes. This process is carried out by RNA polymerase II (RNA pol II). We study RNA pol II in two distinct contexts. Each project uses a different model organism to its best advantage, where we can apply sophisticated genetic, molecular, and biochemical tools to discover important mechanisms of gene regulation. Our findings are relevant to understanding similar mechanisms that occur in human cells, and whose disruption is often associated with disease.
Homeobox genes: In the first project we study homebox transcription regulators in Drosophila melanogaster (fruit fly). For example, we study a homeobox gene called bicoid, which encodes a protein (Bicoid) that directs development of the head and thorax in early embryos. Bicoid works by recruiting RNA pol II to selected target genes, and how exactly it does this is the subject of our work. Our results have been important for understanding how homeobox genes function in normal cells and how their disruption causes certain human cancers (e.g. childhood leukemias). We also discovered proteins that interact with Bicoid (Sap18 and Bin3). These proteins have human counterparts and we are trying to understand how they function.
Prolyl isomerases: In a second project, we study a called ESS1 in Saccharomyces cerevisiae (yeast) which encodes an enzyme known as a prolyl cis/trans isomerase. ESS1 is essential for growth in yeast and cells that lack ESS1 arrest in mitosis. A counterpart of ESS1 is found in humans and is called PIN1. We are learning how yeast ESS1 and human PIN1 control cell growth. We discovered that Ess1 works by controlling the conformation of RNA pol II. This understanding might lead to the development of antifungal drugs against ESS1 (or anticancer drugs against PIN1).
November 28, 2011
“Exposure to Polychlorinated Biphenyls Causes Alterations in Brain Serotonin Concentrations in Swiss-Webster Mice”
Dr. Terri Provost, Ph.D. Biology Department, Utica College and Megan Peppenelli, Graduate Student, SUNY Upstate Medical University
Spring 2011 Asa Gray Seminars
January 31, 2011
How cells control pH
Dr. Patricia Kane, Dept. of Biochemistry and Molecular Biol., SUNY Upstate Medical Univ.
My laboratory works on a proton-pumping ATPase, the V-ATPase, that is found in lysosomes, endosomes, and Golgi apparatus of all eukaryotic cells. This enzyme is responsible for using the energy from ATP hydrolysis to acidify these compartments, which are maintained at pH 4.5-6.5 in a cytosol that is at near-neutral pH. We use yeast cells to better understand how V-ATPase activity is controlled, since V-ATPases in human and yeast cells are very similar. We are able to measure cytosolic and organelle pH in living yeast cells with fluorescent pH sensors, and to test how the pH of these compartments responds to conditions outside the cell. We have also found that V-ATPases inside the cell change their activity in response to pH changes outside the cell, and that V-ATPases actively collaborate with other proton pumps to ensure proper cellular pH regulation. This raises the interesting question of how cells "measure" pH in different compartments and respond appropriately to altered conditions. Perturbed V-ATPase activity is implicated in numerous diseases, including neurodegeneration, cancer, and osteoporosis, so understanding V-ATPase regulation is highly significant.
February 28, 2011
Microclimate benefits for Monarch Butterflies overwintering in Mexico
Dr. Ernest H. Williams,Jr. and Christian A. Johnson, Department of Biology, Hamilton College
The extraordinary migration of monarch butterflies from eastern North America to the mountains of central Mexico protects them from freezing during wintertime. The microclimate varies within these mountain-top forests, however, so monarchs cluster in specific locations under the forest canopy. Recent studies I've done with collaborators show how the microclimate varies and how the butterflies take advantage of the least hazardous places to cluster. I'll describe temperature patterns within the forest and show photos of dense over-wintering aggregations of monarchs.
March 28, 2011
Trophic control of a temperate grassland ecosystem: Elk, bison, and wolves in Yellowstone National Park
Dr. Douglas A. Frank, Department of Biology, Syracuse University
Climate is the primary factor controlling terrestrial ecosystems. However, when abundant, large herbivores also can play a central role. During this talk I will summarize research that colleagues and I have conducted over a 22 year span in Yellowstone National Park that documents important effects that large migratory herds of elk and bison have on grassland production and soil carbon and nitrogen processes. I will then describe how the re-introduction of the gray wolf in 1995 has altered the influence of ungulates on ecosystem dynamics and has resulted in profound and wide-spread changes in the ecology of Yellowstone National Park.
April 11, 2011
Forest management changes plant community composition, diversity, and stability in the Pacific Northwest
Dr. Martin Dovciak, Department of Environmental & Forest Biology, SUNY College of Environmental Science & Forestry
Global changes in land-use are the leading threat to biological diversity world-wide. Forests provide a unique habitat for many species, but they also serve as a source of wood and other materials used in a multitude of products important for humans, and they compete with other land-uses such as agriculture and human settlement. Consequently, the spatial extent of forests has dramatically decreased in modern times and most forests are now directly managed by humans. Forest management, and especially timber harvest, can negatively affect many forest species and lead to changes in the character of biological communities, loss of biological diversity, and decline in ecosystem services and ecosystem stability. Dr. Dov?iak will discuss how forest ecosystem management affects the composition, diversity and stability of forest understory plant communities in the Pacific Northwest, using analyses of long-term datasets from the Andrews Long-Term Ecological Research (LTER) site in Oregon and U.S. Forest Service long-term plots in the Cascade Mts. in Washington. Work to date suggests that while forest timber harvest decreases the abundance and richness of sensitive forest interior herbs and bryophytes, it can increase the abundance and richness of non-forest species, including invasive species. The stability of forest understory plant communities was positively related to community richness, and negatively to the proportion of colonizing non-forest species. Consequently, forest timber harvest appears to dramatically change the character and temporal stability of forest understory plant communities. Applications of these findings to the management of Pacific Northwest forests are discussed, including alternative strategies for green-tree retention harvests that have been adopted or are currently under investigation as a part of the Demonstration of Ecosystem Management Options (DEMO) study funded by the U.S. Forest Service.
Fall 2010 Asa Gray Seminars
September 13th, 2010
“Estrogen Signaling and Regulation of Primordial Follicle Formation”
Melissa Pepling, Ph.D., Associate Professor, Department of Biology, Syracuse University
In mammals, the pool of primordial follicles present at birth represents the total population of germ cells available to a female during her entire reproductive life. Oocytes develop as clusters of interconnected cells called germ cell cysts in embryonic mouse ovaries. During the perinatal period, oocyte cysts break apart and granulosa cells surround individual oocytes to form primordial follicles. As the cysts break down, some oocytes in each cyst die with only a third of the initial number surviving. Mechanisms regulating cyst breakdown and follicle assembly to establish the pool of primordial follicles are not well understood. In addition, it is unclear why some oocytes die during cyst breakdown. Recent work from several groups suggests that estrogens may inhibit cyst breakdown. Treatment of neonatal mice with natural or synthetic estrogens results in abnormal multiple oocyte follicles in adult ovaries. Neonatal estrogen treatment inhibits cyst breakdown suggesting multiple oocyte follicles are cysts that did not break apart. Estrogen works through nuclear hormone receptors, estrogen receptor (ER) α and ERβ. To understand how estrogen signals in neonatal ovaries, three approaches were taken. First, we examined the expression of ERs in neonatal mouse ovaries and detected ERα in granulosa cells and ERβ in oocyte nuclei. Second, ovaries in organ culture were treated with ER selective agonists. We found that ERα and ERβ agonists inhibited cyst breakdown, suggesting that estrogen can signal through either receptor in the developing ovary. Third, we examined oocyte development in mice lacking either ERα or ERβ. Surprisingly, cyst breakdown and follicle assembly was normal in both mutant strains suggesting that one receptor could compensate for the other. Cyst breakdown was only slightly altered ER mutants lacking both receptors implying that another receptor may be involved. Supporting this, estradiol modified so that it can only exert effects at the membrane, was able to inhibit cyst breakdown, implying that estrogen can also function through a novel membrane bound estrogen receptor. Understanding how oocytes develop will give insight into premature ovarian failure, reproductive lifespan, menopause and ovarian cancer and contribute to potential treatments of female infertility.
October 25, 2010
“Many variations on a few themes: A broad look at structure and development of insect scales and bristles.”
H. Ghiradella, Ph.D., Professor of Biology, The University at Albany
The arthropod integument is noted for its outgrowths, in particular, its hairs, bristles and scales. These start as hollow cuticular projections templated on projections (microvilli or filopodia for hairs and larger projections for scales and bristles) from parent epidermal cells. Bristles and scales in particular are usually noted for their complex architecture, study of whose development yields insights into more general mechanisms of cellular pattern formation.
We will consider what is known of these developmental mechanisms, in particular those that appear to be guided by two cellular systems, the actin cytoskeleton and the smooth endoplasmic reticulum (SER), which appear multitalented to the extreme in their ability to orchestrate very different structures and functions in what would seem to be otherwise unremarkable cells.
November 8, 2010
“Polysaccharide-Based Strategies for Improving the Therapeutic Efficacy of Disease-Modifying Anti-Rheumatic Drugs”
Rebecca A. Bader, Ph.D., Assistant Professor Biomedical & Chemical Engineering, Syracuse Biomaterials Institute, Syracuse University
Historically, rheumatoid arthritis (RA) has been treated with gold salts that have anti-rheumatic properties, such as auranofin, immunosuppressants that are typically used following organ transplantation, including cyclosporine A, or with cytotoxic cancer therapeutics that have immunosuppressive side effects, particularly methotrexate. These so called disease-modifying anti-rheumatic drugs (DMARDs) have severe, potentially life threatening, consequences due to non-specific targeting and impaired immune function. In recent years, paradigms have shifted towards combining toxic drugs with molecular vehicles intended to promote delivery exclusively to the diseased region, thereby increasing efficacy and reducing side effects. To further enhance this specificity, the carrier systems are often combined with targeting moieties such as antibodies, small peptides, and natural ligands. This talk will describe our approaches towards improving the delivery of both hydrophilic and hydrophobic DMARDs to the inflamed joint tissue. We use polysaccharide-based materials for direct conjugation or encapsulation of common drugs used in the treatment of rheumatoid arthritis. Recent studies have focused on the use of polysialic acid and hyaluronic acid to improve circulatory stability and/or actively target cells within the diseased region. This talk will also highlight in vitro methods used to assess the efficacy of drug delivery systems. In sum, the work described provides insight into how drug delivery technology can be used to improve the lives of those that suffer from rheumatoid arthritis.
November 22, 2010
“Secondary Bacterial Infections as the Cause of Death from Influenza”
Dennis Metzger, Ph.D., Professor and Theobald Smith Alumni Chair, Director Center for Immunology and Microbial Disease, Albany Medical College
Dr. Metzger's research program concentrates on examining new approaches for immune protection in the respiratory tract. The mechanisms responsible for viral-bacterial synergy in the lung are of particular interest. It is well known that secondary bacterial infection often follows pulmonary virus infection and is a major cause of severe disease, especially during influenza pandemics in humans, including the 1918 Spanish flu pandemic that killed over 50 million people worldwide. Combined infection with a highly virulent influenza virus and a bacterial strain such as pneumococcus can create a “perfect storm” that leads to very high rates of mortality. However, the reasons for this are only poorly understood. Dr. Metzger's laboratory has now demonstrated that pulmonary interferon (IFN)-gamma produced during T cell responses to influenza infection inhibits scavenger receptor expression by alveolar macrophages and hence, bacterial clearance from the lung. This suppression of phagocytosis then leads to enhanced susceptibility to secondary bacterial infection, which can be prevented by IFN-gamma neutralization following influenza infection Thus, the hypothesis of the work is that induction of an adaptive immune response against an intracellular pathogen in the lung (virus) results in significant impairment of innate alveolar macrophage-mediated protection against extracellular pathogens (bacteria). Current work is focused on characterizing functional changes in alveolar macrophages induced by influenza virus infection and determining the mechanisms responsible for the inhibition of alveolar macrophage-mediated bacterial clearance. The ultimate goal is to develop novel, safe and efficacious strategies for biodefense against potential pandemic threats.
December 6, 2010
“Smart material substrates for cell culture”
James Henderson, Ph.D., Department of Biomedical and Chemical Engineering, Syracuse University
Living cells are remarkably complex, dynamic, and versatile systems, but the material substrates currently used to culture them are not. Although properties of the material substrate, such as surface geometry and stiffness, can direct cell lineage specification, cell growth kinetics, cell orientation, cell migration, and cell traction, the polymeric materials commonly used in cell culture, such as polystyrene, offer attached cells only a 2D surface of unchanging properties. This physical stasis of current cell culture materials severely limits our ability to control cell-material interactions during cell culture and, therefore, our ability to advance understanding of fundamental cell processes. This seminar will present current work in which we are developing “active” cell culture technologies that allow dynamic control of cell-material interactions. The potential for these approaches to control cell-material interactions during 2D cell culture for biological and bioengineering research and applications will be discussed.
Spring 2010 Asa Gray Seminar Series
February 8, 2010
Interactions between Complementary Sex Determination and Wolbachia in Parasitoid Wasps
Laura Anne Weiser Erlandson, Ph.D., Assistant Professor of Biology, Department of Biology, SUNYIT
As in many other hymenopterans, sex in Habrobracon hebetor (Say) (Hymenoptera: Braconidae) is determined by single-locus complementary sex determination. Thus, unfertilized eggs become haploid males and fertilized eggs that are homozygous and heterozygous at the sex locus develop into diploid males and females, respectively. We investigated the effects of Wolbachia on the production of diploid males.
March 8, 2010
Correlation of Documented Historical Long-Term Changes in the Macrophyte Community at Put-in-Bay, Ohio in western Lake Erie with Dated Sediment Core Pollen Analysis
David Moore, Ph.D., Professor of Biology, Department of Biology, Utica College
The first comprehensive survey and baseline comparison for future interpretations of the aquatic macrophyte communities of western Lake Erie was completed in 1898, by Adrian J. Pieters as part of the first US comprehensive lake survey. Those observations were supplemented by a series of collections and documented observations from Pieters’ time into the 21th century by a succession of scientists including my work over the last 40 years. From that long-term data base we have a detailed history of the aquatic macrophyte community of the Lake Erie Island Flora. My research over the last four years has examined the pollen records of that same area, confirming historical records and providing a glimpse into the nature of and diversity of the western Lake Erie macrophyte communities extending back approximately 5,400 years, when western Lake Erie exhibited somewhat different plant distribution.
March 29, 2010
The Tell-tale Heart: Innate Immune Responses to Mammalian Orthoreovirus Infection
Geoffrey H. Holm, Ph.D., Assistant Professor of Biology, Department of Biology, Colgate University
Mammalian orthoreoviruses (reovirus) are non-enveloped viruses characterized by a genome composed of multiple segments of double-stranded RNA. Reoviruses infect multiple mammalian species, including humans, though disease is limited to the very young. In newborn mice, reovirus infection causes myocarditis, or inflammation of the heart. Apoptosis, or programmed cell death, is a pathologic hallmark of reovirus-induced myocarditis. Additionally, reovirus-induced myocarditis is greatly influenced by functions of the innate immune system, cellular mechanisms that detect and respond to pathogens prior to the induction of pathogen-specific adaptive immune responses. My laboratory examines the relationships between innate immune responses to reovirus infection and the induction of programmed cell death. Our data indicate that in cell-culture models, the innate immune transcription factors IRF-3 and NF-κB enhance reovirus-induced apoptosis. However, this function appears to be distinct from the role of these transcription factors in inducing expression of the antiviral cytokine, IFN-β. In vivo, these pathways function to limit reovirus-induced myocarditis and facilitate viral clearance. These results suggest that the interface between innate immune responses and cell death pathways is a critical nexus of viral pathogenesis.
April 26, 2010
Neptune’s Nematodes: Searching for the Root of the Nematode Phylogeny in the Sea
Ashleigh Smythe, Ph.D., Visting Assistant Professor of Biology, Department of Biology, Hamilton College
Nematodes, commonly called roundworms, are among the most diverse metazoans on the planet. Only 25,000 species have been described, but estimates of the true number of species range from 500,000 into the millions. Molecular phylogenies over the past decade have suggested that there are three major lineages of nematodes: Chromadoria, Dorylaimia, and Enoplia. The order of appearance in evolutionary time of these lineages remains unclear, however. Morphological and developmental evidence suggest that Enoplia may have emerged first. Members of Enoplia are found in marine and estuarine sediments worldwide and may represent the root of the nematode phylogeny. In this talk I will discuss my work constructing a phylogeny of the Enoplia using 18S and 28 rDNA and its implications for the evolution of Nematoda.
Fall 2009 Asa Gray Seminars
September 28, 2009
Lake Sediment and Biological Response to both Intrabasinal and Extrabasinal Changes over the Past 350 Years, Fulton Chain of Lakes, South-Central Adirondack Mountains
Sharon L. Kanfoush, Ph.D., Associate Professor and Chair, Department of Geology, Utica College
Many lakes in the Adirondacks have been impacted by nutrient influx associated with land development and recreation. Studies from other regions have shown that lakes are affected also by changes in climate. Global temperature has increased since the end of the Little Ice Age (mid-to-late 1800s) due to both natural and human factors, and instrumental data suggests the Adirondack region has experienced similar warming as well as a decline in precipitation over the past century. Sediments from Fourth Lake near Old Forge, New York were examined to ascertain if and how the lake has been impacted by climate change. Changes in organic carbon, abundance of total diatoms, and relative abundance of individual diatom taxa in Fourth Lake are observed that correlate with large-scale conditions outside of the lake basin such as northern hemisphere temperature, atmospheric carbon dioxide, and solar irradiance. Such relationships have implications for watershed and lake management as policies intended to lessen the effects of human-induced nutrient loading may need to be made increasingly stringent to compensate for ongoing upward trends in these variables.
October 5, 2009
Discovery of New Bacterial Species from Clinical Specimens
Bill Wolfgang, Ph.D., Division of Infectious Disease, New York State Department of Health, Wadsworth Center
Every month some 50 new species of bacteria are discovered. Most are from an environmental source such as air, soil, and even permafrost; only about 3% are from patients. In our role as a reference laboratory, the Bacteriology Laboratory at the Wadsworth Center receives hundreds of bacterial cultures each month, isolated from patients that hospitals and clinics are unable to identify. Using classical culture methodology and molecular DNA sequencing we are able to identify most of these bacteria. None-the-less and despite our best efforts, about 5% remain unidentified. It is within this group we have begun the hunt for new species.
October 19, 2009
Army ants - Studies in Molecular Ecology and Evolution
Daniel Kronauer, Ph.D., Junior Fellow at Harvard Society of Fellows, Harvard University, Museum of Comparative Zoology Labs
Army ants are dominant social hunters of invertebrates and thereby play an integral role in tropical ecosystems. They are defined by a suite of evolutionarily interrelated physiological, behavioural and morphological traits, the army ant adaptive syndrome: they are obligate group predators, they frequently relocate their nests, and their permanently wingless queens found new colonies accompanied by workers. Furthermore, army ants typically have extremely male-biased numerical sex-ratios, and queens are inseminated by many males. In this talk I will discuss recent advances in understanding the evolutionary causes and consequences of this unusual life-history.
October 26, 2009
Variation within a summer season in bacteria resistant to antibiotics in the upper Susquehanna River
Mary E. Allen, Ph.D., Chair and Associate Professor of Biology, Department of Biology, Hartwick College
Increasingly bacteria are acquiring resistance to antibiotics, making these compounds ineffective for treatment of disease. Antibiotics enter natural environments from agricultural and municipal water sources. Some bacteria in soils have also been shown to consume antibiotics and use them for growth. These bacteria could help us to clean-up environments polluted with antibiotics, or serve as mechanisms for antibiotic-resistance to spread to bacteria that cause diseases in humans. In either case, knowledge of these microbes in natural settings is important. This presentation will describe efforts to investigate the incidence of antibiotic-resistant bacteria in the upper Susquehanna River over the course of a summer season. Two groups of bacteria were investigated: microbes that commonly inhabit the human intestine and serve as indicators of pollution and naturally occurring microbes that use antibiotics for growth.
November 9, 2009
The Evolution of Bird Eggs and Songs
David C. Lahti, Ph.D., Postdoctoral Research Fellow, Department of Biology, Morrill Science Center, University of Massachusetts
Birds are valuable study organisms for understanding the evolution of complex traits, especially those that involve learning. They have relatively short generation times for a vertebrate, and are easily studied both in the wild and (for some species) in the laboratory. I describe two studies that show how complex traits that involve learning can evolve by natural selection. First, the village weaverbird (Ploceus cucullatus) has distinctive eggs in Africa, in order to tell when a parasitic cuckoo lays eggs in its nest. After the weaver was introduced to islands without cuckoos, however, they lost some of the distinctiveness of their eggs, and became less able to discriminate against foreign eggs. In the other case study, male swamp sparrows (Melospiza georgiana) sing songs of repeated notes (trills). Faster songs are harder to sing, and females like them better. These birds learn their songs during a narrow time window as juveniles. We brought nestlings into the laboratory and trained them on songs that we experimentally slowed relative to their natural (wild-recorded) rate, in order to see how well birds would learn these lower performance training models. Swamp sparrows memorized the training models regardless of their speed, but they demonstrate two kinds of unlearned and adaptive biases during development: they speed up slower songs, and they reproduce faster songs more accurately. Both of these studies show how inheritance and learning interact to produce the final form of a behavior.
November 16, 2009
“Deceptive Imprinting”-the next major decade in Systems Immunobiology
Peter L. Nara, M.Sc., DVM, Ph.D., W. Eugene Lloyd Endowed Chair, Director for the Center of Advanced Host Defenses, Immunobiotics and Translational Comparative Medicine, Iowa State University, Department of Biomedical Sciences, College of Veterinary Medicine, and President and CEO, Biological Mimetics, Inc.
The list of disease-causing microbial pathogens is significantly longer than the list of microbes currently controlled or eliminated by vaccine development. It appears that current research and development directed at antigen delivery, vectors, presentation, expression systems and cytokine steering approaches although important, have not fully addressed the problem. As such, it stands that selected genetic instability of the pathogen leading to antigenic variation, coupled with non-protective immunodominance stands as one of the major obstacles in vaccine design today. The immune defense system of the host operates by surveying the “antigenic space” through shapes and linear sequences of chemical information. It appears that microbial pathogens have continued the evolution of selecting for and presenting chemical shapes and sequences on their surfaces (epitopes), which are more immunogenic relative to other biochemically conserved structures on the microbes and structurally dissociated in such a way as to tolerate significant sequence modifications (immunodominant non-protective epitopes-IDNPs). These IDNPs may be deeper in our B and T cell repertoire and act to decoy, misdirect and dysregulate the host’s immune system (Deceptive Imprinting). The technology of Immune Dampening/Refocusing maps, identifies and through site-directed mutagenesis techniques selectively immune dampens the IDNP T and B cell epitopes. New vaccines and therapeutic monoclonal antibodies made by this technology are purposely lacking IDNPs which when used as immunogens induce a new type of antibody with different specificity which convey new immunological and biological properties often conveying broader cross-strain neutralizing antibodies and cell-mediated immune responses and protection.
Spring 2009 Asa Gray Seminars
March 2, 2009
Circadian Photoreception: More than meets the eye
Steven W. Lockley, Ph.D., Assistant Professor of Medicine, Division of Sleep Medicine, Harvard Medical School;Associate Neuroscientist, Division of Sleep Medicine, Brigham and Women’s Hospital
Many aspects of human physiology and behavior are dominated by 24-hour rhythms that have a major impact on our health and well-being, including the sleep-wake cycle, alertness and performance patterns, and the production of hormones such as melatonin and cortisol. These rhythms are generated by an endogenous near-24-hour oscillator in the suprachiasmatic nuclei of the hypothalamus and are reset each by the 24-hour light-dark cycle. Failure to detect light, due to total blindness or loss of eyes, results in the circadian pacemaker ‘free-running’ on its own internal time and becoming desynchronized with the 24-hour world, inducing a chronic cyclic sleep disorder.
Recently, major advances have been made in understanding how light is detected by the eye to reset circadian rhythms. A novel photoreceptor system has been discovered in the mammalian eye, including humans, that is anatomically and functionally distinct from the visual system. A novel photopigment, melanopsin, primarily mediates these responses to light via a small number of intrinsically photosensitive retinal ganglion cells. These cells, and therefore our ‘non-visual’ responses to light, are most sensitive to short-wavelength blue light.
This lecture will review the organization of the human circadian system, how light and lack of light affects our physiology and behavior and the evidence for a novel photoreceptor system in the mammalian eye. Potential clinical and occupational applications of these discoveries will also be discussed.
WOLFGANG SEMINAR CANCELLED - Will Present in Fall 2009
Discovery of New Bacterial Species from Clinical Specimens.
Bill Wolfgang Ph.D, Division of Infectious Disease, New York State Dept. of Health, Wadsworth Center
Every month some 50 new species of bacteria are discovered. Most are from an environmental source such as air, soil, and even permafrost; only about 3% are from patients. In our role as a reference laboratory, the Bacteriology Laboratory at the Wadsworth Center receives hundreds of bacterial cultures each month, isolated from patients that hospitals and clinics are unable to identify. Using classical culture methodology and molecular DNA sequencing we are able to identify most of these bacteria. None-the-less and despite our best efforts, about 5% remain unidentified. It is within this group we have begun the hunt for new species.
April 6, 2009
Are There Gender Differences in the Human Axillary Secretions Produced in Response to Visual Stimuli?
David Hornung, St. Lawrence University
The overall objective of this study was to test the hypothesis that axillary responses produced when viewing pornographic videos are gender specific. This test was accomplished by evaluating the differences in the axillary secretions produced when humans watched pornographic, romantic, action or documentary videos. For this evaluation, a golden-retriever (Canis familiaris) was trained to recognize a target gauze pad worn while human subjects viewed the pornographic video. After sampling three test boxes, the dog exhibited a sit/stay response in front of the box containing the target. The dog first learned to correctly identify the target from unscented pads. Then distracters, the gauze pads worn while the same subject watched the other genres of videos, were introduced as possible choices. An error analysis was used to judge the commonality between the various distracters and the target smell. In other words, the more often the dog confused a particular distracter for the target, the more similar that distracter was assumed to be to the target. For male subjects, the smell produced while watching the action video was more often confused with the pornographic target than was the smell produced from the other distracters (p < 0.05). However, for females, the smell produced while watching the romantic video was more often confused with the pornographic target (p < 0.05). These observations are consistent with the hypothesis that the axillary response produced when viewing pornographic videos are gender specific. An analysis of heart rate changes recorded while subjects watched these videos suggests the effect does not simply reflect cardiac acceleration. Likewise an exercise distracter was not confused with the target from either men or women. Data from menopausal women suggests some of the smells females produce while watching videos are estrogen dependent.
April 20, 2009
Tales from Siberia: Climate Change and the World's Greatest Lake
Marianne Moore, Associate Professor, Dept Biological Sciences at Wellesley College
Lake Baikal in subarctic Siberia is the world’s largest, oldest, deepest, and most biodiverse lake in the world; yet, this aquatic version of the Galapagos Islands is poorly known to Western scientists. Analyses of an extraordinary data set collected by 3 generations of a Russian scientific family show that this lake is responding strongly to contemporary climate change despite its enormous volume and thermal inertia. Surface waters have warmed significantly to a depth of 25 m and the rate of warming exceeds that of regional air temperatures. In addition, biological changes consistent with this warming have occurred. By mid-century, changes in ice dynamics will likely elicit greater ecological change than warmer water temperatures in this remarkable ecosystem, harboring more than 1500 endemic species and the world's only freshwater seal.
Fall 2008 Asa Gray Seminars
October 6, 2008
Paul Kent, Associate Professor Neurology, SUNY Upstate Medical University
TBA
October 27, 2008
The role of prediction in prey interception by dragonflies
Andrea Worthington, Professor of Biology, Department of Biology, Siena College.
In an act of elegant precision, a dragonfly swoops up to pluck a flying insect from the air. The entire event, from takeoff to capture, often takes only one or two tenths of a second. It’s over so quickly that the flying insect usually takes no evasive maneuvers. By the time we humans can register that we saw something happen, it’s over. How does the dragonfly recognize its prey? How does it so quickly send the necessary information from eyes to brain to wings to guide the behavior? How does it so accurately plot its deadly course? These questions and more have occupied our interest for much of our professional lives as we have sought to understand the neural basis of this deadly accurate behavior. Our attempts to answer these questions has led us from inserting tiny electrodes into the dragonfly brain, to videotaping the natural behavior in the field, and finally to dissecting the behavior in a flight cage with high speed video.
November 10, 2008
The Behavioral and Evolutionary Responses of Native Tadpoles to Introduced Predators
Martin Schlaepfer, Assistant Professor of Environmental and Forest Biology, SUNY-ESF, Syracuse
Tadpoles can generally increase their probability of survival in the presence of known predators by reducing their foraging activities or modifying their tail shape to increase swimming speed or lure attacks away from the head. It is unknown, however, to what extent tadpoles can induce such behavioral and morphological plasticity in response to evolutionarily unfamiliar predators. Lowland Leopard Frogs (Rana yavapaiensis) are native to Arizona and are currently declining due to various introduced predators. Here I present results from mesocosm experiments in which I test whether tadpoles have evolved in response to the novel selective pressures of non-native predators. mschlaepfer@esf.edu
November 24, 2008
Position Preferences within Swarms and Flocks
Dr. W.L. Romey, Associate Professor of Biology, SUNY Potsdam
Large groups of birds, fish, or insects appear to be randomly mixed. But how might individual differences in gender, hunger, size, and defenses influence position preferences? And, do animals respond to only one of these state variables at a time? For example, it has been found that hungry fish go to the outside of schools where the edge represents a trade-off between feeding opportunity and predation risk. Dr. Romey presents evidence from controlled experiments with whirligig beetles and simulation models showing that animals appear to take a variety of these factors into account when choosing positions within a group. Males tend to go to the outside in many species because of increased food needs. However, if they are bucking a current, they position themselves in the back where it is easier to swim. He also shows how simulation models suggest a proximate explanation for the above behaviors; a simple rule such as “defend a larger interpersonal space” can lead individuals to optimal positions. These experiments suggest some principles which may apply generally to flocks, schools, and other swarms.romeywl@potsdam.edu
Spring 2008 Asa Gray Seminar Series
February 11, 2008
Using 'Designer Mice' to Study Human Viruses
Jennifer F. Moffat, PhD, Associate Professor, Department of Microbiology and Immunology, SUNYUpstateMedicalUniversity
Some viruses only infect humans, such as AIDS (HIV), chicken pox (VZV), and certain lymphomas (HTLV-1). It has been difficult to study these diseases without a small animal model for biomedical research. To address this problem, models were created that graft human tissues into mice that lack an immune system. Using these "designer mice", much progress has been made in understanding how human viruses cause disease, and new antiviral drugs have been tested. Technology has been developed to measured virus infection in living mice using bioluminescent imaging. These tools are important for developing better treatments and vaccines.
March 3, 2008
DOES MOTHER NATURE ALWAYS KNOW BEST? The contribution of fetal ethanol experience to adolescent alcohol abuse
Steven Youngentob, Ph.D, Professor and Vice-Chair, Department of Neuroscience and Physiology, SUNY Upstate Medical University
A substantial literature has documented the extensive negative consequences associated with prenatal exposure to ethanol in terms of the drugs toxic effects on the developing nervous system. For example, prenatal exposure to ethanol can cause behavioral changes such as hyperactivity, and learning and memory deficits. Further, gestational exposure is a leading known cause of mental retardation. These observations notwithstanding, there are subtler, yet potentially just as detrimental long-term consequences. Clinical and epidemiological studies provide strong evidence for a relationship between prenatal ethanol exposure and the risk for ethanol abuse in adolescent and young adults. In fact, gestational exposure in humans is considered, perhaps, the best predictor of later ethanol abuse during adolescence. Thus far, there is little evidence regarding the underlying factors contributing to these long-term ingestive consequences. In this respect, there is extensive data demonstrating the general finding that olfactory (smell) and gustatory (taste) experiences influences sensory function, that postnatal behaviors controlled by chemical stimuli can be influenced by fetal experiences with the odorant or tastant, and these early experiences can later modulate intake and preferences for the substance. We have begun testing the theory that altered olfactory and gustatory system responsiveness to ethanol, as a consequence fetal exposure, acts as a potential contributing risk factor for postnatal preference. To accomplish this, we have been applying behavioral and neurophysiological methods to examine the response of early postnatal, adolescent and adult animals to ethanol. The developing data from these studies provide evidence that fetal ethanol experience induces developmental changes in the chemosensory systems involved in the preference for ethanol odor and the perception of ethanol’s flavor: thereby contributing to the risk of initial ethanol ingestion and continued abuse in adolescence.
March 10, 2008
Autism and Alcohol. What's the Connection?
Sandra M. Mooney, Ph.D, Assistant Professor, Department of Neuroscience and Physiology, SUNY Upstate Medical University
Autism is a developmental disorder that is diagnosed based on abnormal social behaviors. The underlying cause of autism is unknown. Based on family histories, there is a clear genetic component to autism; however, it is also likely that there is an environmental contribution. One example is that prenatal exposure to compounds (such as drugs or alcohol) alter fetal development and also cause autistic-like changes in social behaviors. We have been examining how timing of the exposure to alcohol affects social behaviors. Pregnant rats were given a single exposure to alcohol either at a time equivalent to the fourth week of pregnancy (i.e., before may women know they are pregnant) or a time equivalent to the tenth week of pregnancy in humans. We examined the behavior of the offspring and found that not only did both groups of rats exhibit abnormal social behaviors compared to controls, but that the two alcohol groups were different from each other. This suggests that (1) even a short exposure to alcohol can have long-term (possibly permanent) effects on social behavior, (2) the time when the alcohol is given can dictate the behavioral change(s), and (3) exposure to environmental toxins, such as alcohol, may be one of the many causes of autism.
April 14, 2008
Little brown bats (Myotis lucifigus) recognize individual identity of conspecifics using sonar cells
Tammy Kenny, MS, Merck Division of Science and Technology, Southern Vermont College
Bats use sonar calls to locate prey and orient in their environment but they may also be used by conspecifics to obtain information about a caller. Statistical analysis of sonar calls provides evidence that variation carries social information about a caller, including individual identity. We hypothesized that little brown bats (Myotis lucifigus) would be able to recognize individuals given the potential fitness benefits of doing so. We performed playback trials using a habituation-discrimination design to determine whether little brown bats are able to recognize the individual identity of a caller based on variation in their sonar calls. Each subject bat was played the calls of Bat A until they habituated (defined as a 50% decrease from the initial call rate) then the calls of Bat B or a new call sequence of Bat A (a control, referred to as Bat A’) was played. Each subject received a unique pair of playback recordings (Bat A and B) from adult female bats from the same colony (but a different colony than the subject) and the order of trials was randomized. The response measures were habituation time (s) and call rate (call/s). Within a trial, subjects habituated to calls of Bat A and transferred this habituation to the Bat A’ sequence, in addition, they increased their call rates when played calls of Bat B. Comparing between trials, subjects increased their call rate to the calls of Bat B to a greater relative extent than to the calls of Bat A’. These results provide the first evidence that bats recognize individual identity of conspecifics (as opposed to discrimination of groups) which has implications for the social interactions of bats.
Kazial, K.A., Kenny, T.L., & Burnett, S.C. Little brown bats (Myotis lucifugus) recognize individual identity of conspecifics using sonar calls. In review, Ethology.
Fall 2007 Asa Gray Seminars
September 17, 2007
“Bioengineering Approaches to Nerve Regeneration after Spinal Cord Injury”
Julie M. Hasenwinkel, Ph.D., Assistant Professor, Department of Biomedical and Chemical Engineering, Syracuse University
There are approximately 250,000 spinal cord injured people living in the United States today, with nearly 12,000 new injuries occurring each year. Spinal cord injury (SCI), and the resulting paralysis, is not only physically and emotionally devastating for these patients and their families; the lifetime costs associated with caring for these individuals is significant as well. Nerve regeneration, to the point of functional recovery, fails in the spinal cord and central nervous system after injury. This is primarily due to the formation of the glial scar, which inhibits neuronal outgrowth due to the presence of a number of inhibitory molecules, including chondroitin sulfate proteoglycans (CSPGs). The glial scar has been cited as a biochemical and mechanical barrier to regeneration; however, the mechanism by which CSPGs inhibit neuronal outgrowth is unclear.
Our laboratory is exploring many aspects of this complex injury and our work is currently guided by the following questions:
1. How does the mechanical environment change in spinal cord tissue following injury, and does this correlate with biochemical changes at the site of the glial scar?
2. Can we modulate the environment, both from a biochemical and mechanical standpoint?
3. Can we promote regeneration by further optimizing the environment through the use of biomaterials-based substrates?
We are using a combination of microindentation techniques, nanosphere-based drug delivery, and mechanically-tuned, micropatterned hydrogels to explore these questions, in order to better understand spinal cord injury and develop therapies to treat it.
September 24, 2007
“Fetal Programming and the Etiology of Fetal Alcohol Syndrome”
Michael W. Miller, Ph.D., Professor and Chair
Department of Neuroscience and Physiology,
Upstate Medical University
The salient features of fetal alcohol syndrome (FAS) are a diagnostic set of craniofacial malformations, intrauterine growth retardation, and mentaldysfun ction. Indeed, FAS is the most common cause of mental retardation in the United States and the rest of the Western world. FAS-associated problems result from disruptions of early development. The brain, because it develops over such an extended period of time, is particularly vulnerable to alcohol toxicity. Our studies have focused on mechanisms by which alcohol can interrupt early brain development. In particular, we have focused on processes of cell production, migration, and survival, processes that determine the number of neurons in the brain. Each process depends
upon genetic regulation as well as environmental agents such as growth factors. Alcohol can affect any and all processes of brain development. The effect is defined by the ongoing ontogenetic events and the effect of alcohol on the normally balanced contributions of nature and nurture in sculpting the developing brain.
October 15, 2007
“The Ecological and Evolutionary Effects of Hayfield Management on Grassland Songbirds”
Noah Perlut, Ph.D., Professor of Biology
The Rubenstein School of Environment and Natural Resources,
University of Vermont
Over the last 40 years North American grassland bird populations have declined more than any other bird guild. This trend is especially evident in Vermont, where species experiencing precipitous declines include the Savannah Sparrow (Passerculus sandwichensis) and Bobolink (Dolichonyx oryzivorus). These declines are linked to habitat loss due to reforestation and suburbanization as well as the intensification of grassland management.
Modern grassland management includes earlier first-haying dates (late-May) and shorter intervals between haying events (35 days). These management practices have severe repercussions for songbird populations because 1) early-haying results in complete nest failure (99% Savannah Sparrow and 100% Bobolink nests), 2) the interval between the first and second haying is too short for birds to renest, and 3) intensively managed fields comprise a significant portion of the total available habitat (as much as 40%).
In 2002-2007, I examined how hayfield and pasture management affected grassland songbird ecological and evolutionary behavior in the agricultural landscape of the Champlain Valley, Vermont and New York. I studied songbirds in four grassland management types: early-hayed fields harvested in late-May or early-June and again in mid-July; middle-hayed fields harvested in late-June or early-July; late-hayed fields harvested after 1 August; rotationally-grazed pastures, a matrix of small paddocks where cows are moved after the grass in a paddock is eaten to a low point. I addressed the following objectives:
1. Determined the annual productivity, survival, and recruitment of Bobolinks and Savannah Sparrows in the four treatment types.
2. Identified the effects of early-haying on the social and genetic mating systems of Savannah Sparrows.
This study provides information on how agricultural management affects the ecology, evolution, and viability of grassland birds. It will help inform landowners, managers, and law-makers about management practices and habitat requirements needed to sustain populations.
October 22, 2007
“Bacterial multicellular behaviors as a target for new therapies”
Dr. Dacheng Ren, Assistant Professor, Department of Biomedical and Chemical Engineering, Syracuse University
Bacteria have evolved complex multicellular behaviors, such as biofilm formation and quorum sensing, to initiate infections and to survive in competitive environments. These systems involve coordinated gene expression and lead to serious problems such as persistent infections and contamination of medical devices. In this presentation, we will discuss our progress in understanding the genetic basis of bacterial multicellular behaviors and drug resistance as well as the development of novel control strategies.
November 5, 2007
“The Water-Lilies of Australia”
C. Barre Hellquist, Ph.D., Professor of Biology, Massachusetts College of Liberal Arts
Until the last twenty years the native tropical water-lilies of Australia consisted of four species in three different subgenera. Today three subgenera are still recognized with Nymphaea pubescens in the subgenus Lotos, N. nouchali in the subgenus Brachycerus, and ten species in the truly Australia, New Guinea subgenus Anecphya. Extensive work in the past 20 years by Surrey Jacobs (Royal Botanic Gardens, Sydney), Barre Hellquist, John Wiersema, Cornelia Lohne, and Thomas Borsch have brought about the greater understanding of the Anecphya. This subgenus consists of some of the most beautiful water-lilies in the world. They may be white, blue, lavender, dark purple, pink, and changeable. The blossoms may stand 18 inches above the water surface with leaves up to 30 inches in diameter. The Anecphya is divided into two main groups, the large-seeded (N. gigantea group)and the small-seeded (N. violacea group). Extensive fieldwork continues, as recent as the summer of 2007, on the subgenus Anecphya in tropical Queensland. Both the large-seeded and small-seeded groups still need extensive work with as many as five more possible species to be described.
November 19, 2007
“Wind turbines and birds: observations from a land-based wind turbine on Cape Cod”
Lucy Vlietstra, Ph.D., Assistant professor of Marine Safety & Environmental Protection, Department of Marine Safety and Environmental Protection, Massachusetts Maritime Academy
Wind power is the fastest growing energy industry in the world, a trend embraced by some scientists promoting clean and renewable energy. Others, however, challenge the benefits of wind development citing concern that wind turbines threaten avian populations. Their view is supported by the large number of birds killed by wind turbine rotors in some parts of the country. Conflicts surrounding these issues are a daily part of life on Cape Cod, Massachusetts, where two large wind farms have been proposed for offshore waters that support numerous migratory and resident waterbirds. When Massachusetts Maritime Academy recently constructed a single, commercial-grade wind turbine on the shoreline of Cape Cod, we had an opportunity to assess its potential impact on the survivorship of local birds, including one endangered species, roseate terns. In this presentation, I discuss our findings in light of the issues surrounding wind turbines and avian conservation.
Spring 2007 Asa Gray Seminars
February 26, 2007
"Genome Organization in Spirotrichous Ciliates (Protozoa)"
Wei-Jen Chang, Ph.D. Assistant Professor of Biology, Department of Biochemistry and Molecular Biology, Hamilton College
Spirotrichous ciliates undergo massive DNA elimination and genome rearrangement to construct gene-sized chromosomes in their somatic nucleus (1). An example is the extensively scrambled DNA polymerase a gene, which is broken into 48 pieces and distributed between two unlinked loci in Stylonychia (2, 3). To understand the emergence of this complex phenomenon during evolution, we examined DNA polymerase a genes in several related species, representing evolutionary intermediates. Mapping these data onto an evolutionary tree suggests that this gene became fragmented and scrambled through a series of steps, each leading to greater complexity (4). I will also discuss our recent efforts to find new scrambled genes, in addition to the three cases that have been broadly studied in the past. We have so far found three additional scrambled genes, each with novel features (5, 6). Our data suggest that 20-30% of genes in some spirotrichous ciliates may be scrambled-similar to a previous estimation. While the molecular mechanisms that scramble and unscramble genes and the evolutionary advantages/disadvantages associated with this are still largely unknown, we are making progress toward understanding this unorthodox system.
1. D. M. Prescott,Microbiol Rev 58, 233 (Jun, 1994).
2. L. F. Landweber, T. C.Kuo, E. A. Curtis, Proc Natl Acad Sci U S A 97, 3298 (Mar28, 2000).
3. D. H. Ardell, C. A.Lozupone, L. F. Landweber, Genetics 165, 1761 (Dec,2003).
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March 26, 2007
"The Physiological Ecology of Avian Magnetoreception"
Mark Deutschlander, Ph.D. Assistant Professor of Biology, Department of Biology, Hobart and William Smith Colleges
For almost 50 years, scientists have known that birds are able to sense the earth’s magnetic field for orientation and navigation. Research has focused on elucidating the sensory receptor(s) responsible for the magnetic sense and determining the functional aspects of magnetoreception for migration. Directional choices based on the geomagnetic field depend not only on season, but also on the age and condition of birds, as well as calibration of the magnetic field with other available compass cues. Evidence suggests that birds have two different sensory systems for detection of the magnetic field: a light-dependent sense implicating the eyes in magnetoreception and a magnetite-based magnetic sense transmitted via the trigeminal nerve. Although the suggestion for more than one magnetic sense may seem far-fetched, the functional properties of these two systems are consistent with two different age-dependent uses of the magnetic field in orientation: obtaining a compass bearing and determining geographic position. Although both juvenile and adult birds possess a functional magnetic compass sense, adult birds appear to be able determine geographic position based on subtle variations in magnetic intensity and inclination. In this presentation, I will provide an overview of magnetoreception in birds with a focus on age-dependent and condition-dependent factors that affect the expression of magnetic orientation.
April 2, 2007
"Engineering New Models of Human Retinal Degenerative Disease"
Gustav A. Engbretson, Ph.D. Professor and Chairman, Department of Biomedical and Chemical Engineering, Syracuse University
Retinal degenerative diseases such as retinitis pigmentosa and macular degeneration are crippling human disorders in which the photoreceptors responsible for vision degenerate relatively slowly. Typically, a mutation in one of several rod-specific genes leads to death of the rod photoreceptors and subsequent degeneration of the cones. The reasons for the cone degeneration are not well understood. The patient progresses through night-blindness to total blindness. Though mammalian models of these degenerative diseases do exist, they all suffer from one or another shortcoming. My laboratory has been using transgenesis to develop additional models in the amphibian, Xenopus laevis. We have used the restriction enzyme mediated insertion (REMI) method to insert a variety of genes with the intent to develop frogs with “rodless” retinas in which we hope to study the interactions of rods and cones that appear to underlie the degenerative condition.
April 9, 2007
"It's a Jungle Out There: Approaches to Enhance Axonal Regeneration After Spinal Cord Injury"
Dennis J. Stelzner, Ph.D. Professor of Cell and Developmental Biology and Medical Humanities, Department of Cell and Developmental Biology, SUNY Upstate Medical University
Axonal regeneration does not occur in the central nervous system (CNS) after it is injured, although, in spite of many mistakes, regeneration does occur in the periphery. Axons of at least some neurons within the CNS are able to regenerate within peripheral nerve grafts, showing that factors in the PNS environment enhance and/or CNS environment inhibit axonal growth. These factors will be reviewed, and experiments described using two approaches attempting to promote axonal regeneration after spinal cord injury (olfactory ensheathing cell implants, and nanosphere injections of chondroitinase). It is likely that a combined approach using several therapeutic interventions will be needed to stimulate axonal regeneration leading to functional recovery.
Fall 2006 Asa Gray Seminars
September 18, 2006
"Population Structure and Conservation of Three Rare Butterflies"
Ernest H. Williams, Ph.D., Leonard C. Ferguson Professor and Chair, Department of Biology, Hamilton College
Rare butterflies often live in separate, small colonies, with limited interpopulation dispersal. To conserve such species, we must understand the factors that regulate growth of individual populations and limit the establishment of new colonies. Gillett's Checkerspot is found in the Rocky Mountains in meadow patches along streams (studied in Wyoming), while Frosted Elfin and Karner Blue butterflies occupy sandy patches in the East where wild blue lupine grows (studied in the Rome, NY, Sand Plains). Conservation of these species depends on a deeper understanding of their population dynamics. I'll describe the research underway on these insects and their habitats.
September 25, 2006
"The Relation between Cues and Perceived Stereo Depth in Relative Disparity Studies"
Yu-Chin Chai, Ph.D., Institute for Sensory Research, Department of Biomedical & Chemical Engineering, Syracuse University
Models of stereo vision are primary models of absolute disparity. It's usually assumed that the relative disparity between two stimuli is computed simply by differencing their absolute disparities, which are the only stimulus variables included in this computation. However, previous research in our lab (VSS 2003,
2004) has shown that thresholds for discriminating relative disparity vary greatly with the similarity of stimuli on other variables, such as orientation and spatial frequency, which are independent of absolute disparity. The ongoing research uses the stereo plaids made of superimposed sinusoids to measure how perceived depth depends on the relative orientation and disparity directions. Our studies show that component orientation matters for perceived depth, even for stimuli that are not themselves obviously oriented, indicating that disparity maps onto perceived depth within orientation channels. The parameters of the 2-D disparity vector metric for determining perceived depth will be discussed.
October 16, 2006
"Hormone Signaling in Mouse Oocyte Differentiation and Follicle Formation"
Melissa Pepling, Ph.D., Assistant Professor of Biology, Biological Research Labs, Syracuse University
Early in ovarian differentiation, female mouse germ cells develop in clusters called oocyte nests or germ cell cysts. After birth, mouse germ cell cysts break down into individual oocytes that are surrounded by somatic pre-granulosa cells to form primordial follicles. At the same time, around two thirds of the oocytes die by apoptosis with only one third surviving. The factors responsible for cyst breakdown and selective oocyte survival are unknown. Treatment of neonatal mice with natural estrogens such as estradiol, or the phytoestrogen genistein or synthetic estrogens results in abnormal multiple oocyte follicles (MOFs). To determine if genistein treatment leads to MOFs by inhibiting breakdown of oocyte cysts, mice were treated neonatally with genistein for 5 days and the differentiation of the ovary compared with untreated controls. Mice treated with genistein had fewer single oocytes and a higher percentage of oocytes not enclosed in follicles. There was also an increase in the number of oocytes that survived during the cyst breakdown period. These data taken together suggest that genistein exposure during development alters ovarian differentiation by inhibiting oocyte nest breakdown and attenuating oocyte cell death. However, the major endogenous estrogen present in the maternal circulation is 17-?-estradiol (E2). To investigate the role of E2 in cyst breakdown and oocyte survival, a neonatal ovary organ culture system was used. Newborn mouse ovaries were cultured with E2 for seven days and analyzed by confocal microscopy. In untreated ovaries, the total oocyte number dropped while the percent of single oocytes increased similar to in vivo. The E2 treated ovaries showed a similar drop in oocyte number except at the highest concentration. However, E2 treated ovaries had a significantly reduced cyst breakdown rate, manifested by persistent large cysts at PND8. E2 treatment also inhibited primordial follicle assembly. Thus, treatment with the endogenous estrogen, estradiol, inhibits cyst breakdown and at the highest concentration tested, increases cell survival supporting the model that the dramatic drop at birth in the level of estrogen that the fetus is exposed to causes oocyte cysts to begin breaking down and follicles to assemble.
November 6, 2006
"Descriptive, Experimental, and Modeling Approaches for Studying Wildlife Biology: Case Histories from the Vermont Cooperative Fish and Wildlife Research Unit"
Therese Donovan, Ph.D., USGS Vermont Cooperative Fish and Wildlife Research Unit, University of Vermont
Understanding the factors that influence distribution, survival, and reproduction of organisms is a central question in ecology. We use a variety of scientific approaches (descriptive, experimental, and modeling) to understand how landuse pattern and management activities affect a variety of wildlife species. Descriptive studies focus on bobcats, black bears, and fisher. Experimental studies focus 1) identifying the proximate cues used by forest-nesting songbirds in selecting breeding territories, and their fitness consequences; 2) understanding how wildlife management activities alter the population
dynamics of double-crested cormorant, and 3) determining the effects of hayfield management on grassland songbirds. Overviews of these studies will be presented.
Spring 2006 Asa Gray Seminars
February 6, 2006
“The Effects of Photoperiod on the Behavioral Patterns in Green Tree Frogs.”
Hannah Cleary, Jennifer Warner, and Dr. Mary S. Rea,Department of Biology, Russell Sage College
My students and I have been studying the circadian behavior of American green treefrogs, Hyla cinerea. We have found that treefrogs entrained to 12L:12D cycles exhibit crepuscular behavior with most activity occurring during the dawn and dusk transition times. This activity is significantly suppressed in continuous light and continuous dark with a loss of rhythmicity during the first 24 hours. When given a pulse of light during the dark phase of a 12L:12D cycle frog activity was phase-advanced. Our preliminary studies measuring spectral sensitivity indicate that light levels at or near 6 Lux are too low to phase-advance frog activity.
February 13, 2006
Bottom-up and top-down control of a grazing ecosystem: drought and wolves in Yellowstone National Park.
Dr. Douglas Frank, Syracuse University
Terrestrial ecosystems are regulated by (a) bottom-up effects that directly influence plants, then ascend up the food chain, and (b) top-down effects of predators that directly influence prey, then cascade down to lower trophic levels. In this talk I will review 17 years of research that has examined the effects of large herds of migratory ungulates, drought, and the introduction in 1995 of the gray wolf on grassland production and nutrient cycling in grasslands of Yellowstone National Park. Results indicate that all three factors have important and interacting effects on grassland processes.
March 6, 2006
“Age-related Patterns of Reproductive Success in House Sparrows.”
Dr. Margaret Hatch, Pennsylvania State University - Worthington Scranton
A common life history pattern in several taxa is that reproductive success increases with age. We found a similar pattern in house sparrows (Passer domesticus), and tested one hypothesis concerning the potential mechanisms underlying the observed increase in offspring production with age. For most measures of reproductive success, older individuals performed better than yearlings. Older males and females began breeding earlier in a given season and fledged more young than their yearling counterparts. Individual males also fledged more young at two years of age than they did at one year of age, but individual females did not show consistent improvement from year one to two. A path analysis indicated that the effect of age was primarily through the timing of breeding and number of nesting attempts. A path analysis indicated that earlier breeding within a season was associated with more young fledged. For both males and females, age was negatively related to the date the first egg was laid earlier by older individuals in the nest. Neither male nor female age was directly related to the number of young fledged. Path analysis indicated that the effect of age was primarily through the timing of breeding and not on other aspects of fledging success such as hatching or survival from hatching to fledging. Increased reproductive success with age may arise from high quality individuals surviving to be older (selection hypothesis). Contrary to this hypothesis we found survival from one year of age to two years of age was negatively related to reproductive success. Additionally, individuals that survived to breed as two-year-olds did not differ in reproductive performance in their first year from those that did not survive to breed as two-year-olds.
March 20, 2006
The Contributions of Bacteria and Biogenic Magnetite to Carbon Tetrachloride Degradation in a Model Iron-Reducing System
Dr. Michael L. McCormick, Assistant Professor of Biology, Hamilton College
It has long been recognized that both cell-mediated (biotic) and mineral-mediated (abiotic) reactions may participate in the reductive transformation of select contaminants in iron-reducing environments. Yet attempts to quantify the magnitude of these biotic and abiotic reactions are rare. For this reason, we often have little knowledge of the predominant agents responsible for contaminant degradation in these complex systems. In this work, the contributions of cell-mediated and mineral-mediated reactions to carbon tetrachloride (CT) transformation were studied in a model iron-reducing system. The results indicate that when cells and minerals are present together, CT transformation is due, almost entirely, to abiotic surface-mediated reactions. These findings suggest that reactive biogenic minerals could play a significant role in the natural attenuation of chlorinated solvents in iron-reducing environments. The research also suggests that a novel approach for remediating alkyl halides, and other groundwater contaminants, may be to engineer the formation of reactive biogenic minerals in-situ.
April 3, 2006
"Exploring implications of the risk allocation hypothesis: sex and death"
Dr. Tom McCarthy, Assistant Professor of Biology, Utica College
This talk will examine how both mating and predator-prey interactions are influenced by variations in the temporal patterns of exposure to chemical cues that indicate the occurrence of previous predation events. Hundreds of studies have examined factors that influence the mating systems of many different types of organisms. Likewise, many studies have examined factors that influence predator-prey interactions. Furthermore, there are numerous studies that have integrated these fields and considered how predation risk influences the mating systems of prey species. A set of recent theory (the ‘risk allocation hypothesis’) predicts that animals always at risk of being killed (e.g. high predator density) will behave differently than animals that are rarely in danger (low predator density) when under similar conditions. For example, animals accustomed to predators should have less intense avoidance behaviors than naive animals when they perceive predation risk; conversely, animals accustomed to predators should have higher activity rates when no risk is perceived. Thus, current prey behavior should be influenced by the temporal patterns of predation risk that prey have experienced in the past. Several experimental studies have tested the predictions of this theory and found that prey behaviors can be influenced by temporal patterns of predation risk. I will discuss several experiments that are, directly or indirectly, relevant to the risk allocation hypothesis. I also propose a series of field and laboratory experiments that extend the predictions of the risk allocation hypothesis to consider mating behaviors of prey, foraging behaviors of predators, and the results of interactions between predators and prey.
Fall 2005 Asa Gray Seminars
September 19, 2005
“Science and Conservation in the Serengeti Ecosystem, East Africa .”
Dr. Samuel J. McNaughton, Professor Emeritus
Professor McNaughton has been studying one of Earth’s great ecosystems for over 30 years. He will present results of those studies and their application to conservation policy.
September 26, 2005
"Invasive Worms Clashing in North American Soils: Everyone's Problem."
Dr. Peter K. Ducey, Department, Department of Biological Sciences, SUNY Cortland
The familiar earthworms of the family Lumbricidae have a major influence on physical and biological features of soils in agricultural, horticultural, and natural habitats. The status of these earthworms is currently under threat in parts of North America. Within the last 100 years, exotic, terrestrial flatworms (broadhead planarians) that eat earthworms have been spread across much of the continent. The natural history, evolution, and ecological interactions of these interesting predators will determine the extent of their impact on the earthworms. Scientific study of the flatworms is finally beginning to reveal their biology. An additional recent threat to the lumbricid earthworms is coming from a distinctly different group of worms, the invasive megascolecid earthworms from Asia. Some megascolecids can greatly alter soil structure and compete with the lumbricids for space and food. One ecological battleground for the three groups of worms is here in central New York. The desired outcomes, from a human perspective, of these ecological and evolutionary interactions remain open to considerable debate.
October 17, 2005
“Population Dynamics of Mutualism: Ants, Treehoppers, and Goldenrod.”
Dr. Manuel Morales, Department of Biology, Williams College
Mutualism is an interaction between species where both species benefit. I study the ecology and evolution of mutualism using the interaction between ants and treehoppers as a model system. Treehoppers are insects that feed on plant sap and excrete a sugary waste product called "honeydew." Ants collect this honeydew as a food source, and in exchange benefit treehoppers by protection from predators and by enhancing feeding. My research shows that the relative attractiveness of treehoppers to ants is the primary factor controlling the dynamics of this system. I discuss this work in the context of the evolution of interspecific signaling (e.g. communication between ants and treehoppers) and the ecology of spatial pattern formation.
November 14, 2005
“Integrating the quality and quantity of mutualistic service to contrast ant species visiting a plant with extrafloral nectaries."
Dr. Josh Ness, Department of Biology, Skidmore College
Mutualisms (reciprocally beneficial interactions between two species) are often characterized by great variation in the benefits provided by different partner species. This variation may be due to differences among species in the quality and quantity of their interactions, as well as the costs incurred during those interactions. Many plant species produce extrafloral nectar, a carbohydrate-rich resource, to attract ant species that can act as bodyguards against a plants natural enemies. Here, I explore differences in the quality and quantity of protective service that ants can provide a plant by contrasting the four most common ant visitors to Ferocactus wislizeni, an extrafloral nectary-bearing cactus in southern Arizona. I also ask whether the indirect costs of these plant bodyguards differ. Specifically, I ask whether these aggressive ants deter other beneficial visitors to the plant, such as pollinators. Last, I explore two strategies by which plants may increase the benefits and decrease the costs of their interactions with the ants, thereby increasing the plants net benefit from participating in the mutualism.
November 21, 2005
"Embryonic Stem Cells: Role of genetic manipulation on differentiation”
Dan O'Bryan, Department of Anatomy and Neuroscience, University of Wisconsin, Madison
The use of Embryonic Stem Cells (ESC) offers hope to many fields, including cell-replacement therapy and developmental biology. By genetically manipulating ESCs, key events of cell specification and differentiation can be identified. In this talk, the role of genetic manipulations on specification and differentiation of oligodendrocytes from ESCs will be analyzed.
November 28, 2005
"Francisella tularensis: It’s Re-emergence as a Weapon of Bioterrorism"
Dr. Chandra Shekhar Bakshi, Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York
For rogue governments and terrorists, Francisella tularensis’s allure is that of a weapon of mass disruption. High infectivity, ease of intentional aerosol dissemination and its tinted past during the cold war has made it one of the latest targets of the U.S. government's massive R&D effort to defend against a potential bioweapon attacks. It is still unknown where this bacterium lives in the wild, how exactly it is transmitted, or even how it makes people sick. Thus, there are plenty of puzzles for the researchers to tackle. The focus of our research efforts is to elucidate the cellular and molecular mechanism(s) responsible for the development of innate immunity which, play a key role in the control of F. tularensis proliferation and alleviation of inflammation-mediated tissue damage. In order to achieve this, we are assessing the clinical course and severity of pneumonic tularemia in mice deficient for various pattern recognition receptors such as Toll like receptor-2 (TLR-2) and TLR-4. Our results have shown that TLRs play a critical role in determining the nature of innate immune response in the lungs to aerosol infection by F. tularensis live vaccine strain. Another focus of our research is to genetically manipulate F. tularensis in order to develop attenuated strains that could be used as a vaccine to populations at risk from F. tularensis infection, either from natural sources or from a biological attack. The ultimate goal is to develop novel, safe and efficacious strategies for biodefense against this potential bioterrorism agent.
