Fall 2010

Changing Landscapes Shape Contemporary Lake Systems on the Coastal Plain of North Carolina

Dr. Matthew Waters
Department of Biology
Valdosta State University

Hosting Dept: Biology

Abstract:  Trophic structure in shallow aquatic ecosystems has been linked to internal and external loading of nutrients from surrounding landscapes. However, less attention has been given to the amount and type of organic material entering these ecosystems. Here, a paleolimnological investigation was conducted on three lakes located on the coastal plain of North Carolina, USA. Lake Mattamuskeet, Pungo Lake and Lake Phelps are similar in nutrient inputs, depth and geography, but they currently contain tropic structures of hypereutrophic, dystrophic and oligotrophic, respectively. Multiple chemical and biological proxies were measured on sediment cores from each lake, including sedimentary photosynthetic pigments, lignin-phenols, nutrients and metals, in order to investigate changes in organic matter inputs and trophic responses throughout the Holocene. Results show that trophic alterations are linked to organic matter inputs resulting from anthropogenic and climatic stressors.

Thursday,  August 26, 2010 4pm

Light-induced Charge Separation in Ligand-modified Nanoparticulate Semiconductor Films

Dr. Linda de la Garza
Valdosta State University

Hosting Dept: Chemistry

Abstract:  One way to improve solar energy to electrical energy conversion is to enhance the charge separation by multi-step electron transfer, similar to the initial mechanisms that occur in photosynthetic systems. Semiconductor crystals such as titanium dioxide on the nanoscale conserve the band-gap properties of bulk semiconductor, have large surface area available for chemical modification, and form charge-transfer complexes with surface modifiers. Films of titanium dioxide nanoparticles have been assembled and modified with enediol ligands. The light-induced current production of the films is enhanced upon surface modification and has been found to be further improved by the linking of a conductive polymer.

Thursday,  September 2, 2010 4pm

Educating Engineers/Scientists for Sustainable Development

Abdol R. Chini, Ph.D., P.E.
Director and Professor
Rinker School of Building Construction
University of Florida

Hosting Dept: Department of Physics, Astronomy, Environmental Geosciences & Engineering Studies

Abstract:  In the last three decades, the environmental movement toward sustainability in industrialized countries has motivated researchers and industry coalitions to seek ways to minimize the negative environmental impacts of the built environment and find ways to build green. Education and training are essential components in the dynamics of environmental protection, especially in science and engineering. In the higher education, a university culture should be created with a core philosophy of environmental stewardship, sustainable development, and critical examination of all activities in light of their environmental impacts. This requires an environmentally knowledgeable faculty, a research program that develops clean, resource efficient technologies with low environmental impacts, and a university with a small ecological footprint. Educating a new generation of scientists, engineers, and technologist with highly developed knowledge of the environment and natural systems and their contributions to human well-being is an essential element of environmental sustainability. This presentation reviews the fundamental concepts of sustainability that should be integrated with the engineering and science education. Several strategies used in the University of Florida to integrate principles of sustainable development are discussed to provide an example of what can be used in other universities.

Thursday,  September 9, 2010 4pm

Why are Homicides and Homicide Arrests Decreasing?

Dr. Charles Wellford
Department of Criminology and Criminal Justice
University of Maryland

Hosting Dept: Sociology, Anthropology, and Criminal Justice

Abstract:  This presentation considers the reasons the homicide rate has decreased in the United States and why at the same time the clearances of homicides has also been decreasing. Special consideration is given to the role of policing strategies and the role of firearms in these trends. Drawing on research conducted over the past ten years the talk concludes with specific recommendations to further the decrease in homicides and reverse the trend for homicide clearances.

Thursday,  September 16, 2010 4pm

Defensive symbionts in aphids

Dr. Kerry Oliver
University of Georgia-Athens Department of Entomology

Hosting Dept: Biology

Abstract:  Aphids engage in symbiotic associations with a diverse assemblage of heritable bacteria. In addition to their obligate nutrient-provisioning symbiont, Buchnera aphidicola aphids may also carry one or more facultative symbionts. Facultative symbionts are not generally required for survival or reproduction but can invade and persist in host lineages by conferring benefits to hosts. Experiments on pea aphids (Acyrthosiphon pisum) have demonstrated that the facultative symbiont Hamiltonella confers protection against attack by the prevalent parasitoid Aphidius ervi by causing mortality to developing wasps. I will review the experimental evidence demonstrating a protective role for Hamiltonella, followed by a discussion of more recent work investigating the contribution of bacteriophages to the protective phenotype and to the maintenance of the tripartite symbiosis.

Thursday,  September 23, 2010 4pm

This seminar will be held in the Union Ballroom

Mathematics, thermodynamics and modeling to address common misconceptions about proteins in undergraduate biology and biochemistry courses

Dr. Srebrenka Robic
Assistant Professor of Biology
Agnes Scott College

Hosting Dept: Biology

Abstract:  To fully understand the roles proteins play in cellular processes, students need to grasp complex ideas about protein structure, folding and stability. Our current understanding of these topics is based on mathematical models and experimental data. However, protein structure, folding and stability are often introduced as descriptive, qualitative phenomena in undergraduate classes. In the process of learning about these topics, students often form incorrect ideas. For example, by learning about protein folding in the context of protein synthesis, students may come to an incorrect conclusion that once synthesized on the ribosome, a protein spends its entire cellular life time in its fully folded native confirmation. This is clearly not true; proteins are dynamic structures that undergo both local fluctuations and global unfolding events. To prevent and address such misconceptions, basic concepts of protein science can be introduced in the context of simple mathematical models and hands-on explorations of publicly available data sets. Some common misconceptions about proteins, along with suggestions for using equations, models, sequence, structure and thermodynamic data to help students gain a deeper understanding of basic concepts relating to protein structure, folding and stability. Examples of incorporating such activities in classes ranging form first-year introductory courses to upper level classes, seminars and undergraduate research projects will be presented and discussed.

Thursday,  September 30, 2010 4pm

Phylogeny, Biogeography, & Morphological Evolution of the Gaultherieae 

Dr. Catherine Bush
Valdosta State University

Hosting Dept: Biology

Abstract:  The plant tribe Gaultherieae (Ericaceae: subfamily Vaccinioideae) comprises seven genera with a total of approximately 250 species. The group exhibits an amphi-Pacific distribution, that is, temperate and tropical regions of the Americas, eastern Asia, Southeast Asia, and New Guinea, Australia, and New Zealand. Phylogenetic analyses using DNA sequence data have shown that the Gaultherieae and the wintergreen group are monophyletic. Several strongly supported clades within the wintergreen group (i.e., Gaultheria s.s.) include members from a particular geographic region. Phylogenetic relationships within Gaultheria L. from Australia and New Zealand were examined by using DNA sequence data and it was found that all Australia/New Zealand species form a clade that is sister to a clade of temperate South American species. The disjunct Brazilian species of Gaultheria were also analyzed in a molecular phylogeny. Six species of Gaultheria are endemic to the Mata Atlantica (Atlantic rainforest) in Brazil, several of which exhibit unique morphological characters within Gaultheria.  A strongly supported clade of five Brazilian endemics was recovered (corresponding to the currently recognized G. ser. Myrtilloideae clade) and is sister to a clade of Gaultheria from temperate South America. Gaultheria serrata, another endemic Gaultheria species and two other Gaultheria that exhibit distributions in Brazil and the Andes are closely related to each other and other species from the Andes/Mexico. These results support the hypothesis that some Brazilian species of Gaultheria are derived from Andean ancestors.  However, the G. ser. Myrtilloideae clade is imbedded within a clade containing species from temperate South America, indicating that the Andes may not have served as the only source area for the species in the Mata Atlantica of Brazil.

Thursday, October 7, 2010 4pm

Evolution and molecular mechanisms of fungicide resistance in peanut leaf spot pathogens

Dr. Katherine Stevenson
Department of Plant Pathology
University of Georgia

Hosting Dept: Biology

Abstract:  Large scale commercial production of peanuts in the humid southeastern US relies on fungicides for management of foliar and soilborne fungal diseases. However, effectiveness of some fungicides has declined significantly over the past 10 years, due to the development of resistance in pathogen populations. Results of in vitro bioassays have confirmed a gradual, but significant decline in sensitivity of the peanut leaf spot pathogens to the sterol biosynthesis-inhibiting fungicide tebuconazole, in particular. Further investigations of the molecular and physiological mechanisms of DMI resistance in the early leaf spot pathogen have revealed mutations in the CYP51 gene of the fungus that may be responsible for resistance of some isolates to tebuconazole.

Thursday,October 14, 2010 4pm

On Certain Divisibility Property of Polynomials

Dr. Jose Velez-Marulanda
Valdosta State University

Hosting Dept: Math & Computer Sciences

Abstract:  We review the definition of D-rings introduced by H. Gunji & D. L. MacQuillan in 1975. We provide alternative characterizations for such rings that allows us to give an elementary proof of that a ring of integers over a quadratic field is a D-ring and give a criteria to determine divisibility of polynomials using polynomial evaluations.

Thursday, October 21, 2010 4pm

When Georgia Had Volcanoes: The Earliest Phases of Appalachian Mountain Building

Dr. Clint Barineau
Department of Earth and Space Sciences
Columbus State University

Hosting Dept: Department of Physics, Astronomy, Environmental Geosciences & Engineering Studies

Abstract:  On a geologically active planet such as Earth, changes in the physical character of continents and oceans are the norm. Although the Georgia of today, like much of the east coast of North America, consists of a deeply eroded and topographically low mountain chain (Appalachians) flanked on the east-southeast by flat lying sedimentary rocks (Atlantic and Gulf Coastal Plains), Georgia's geologic past was far more tectonically active. The Georgia of 480 million years ago was home to active volcanoes associated with a convergent plate margin, not dissimilar to portions of the west coast of North America and much of the Pacific Rim. Geologists have recognized for the better part of a century that many rocks within the Piedmont and Blue Ridge physiographic provinces were magmatic-volcanic in origin. However, in recent decades the geologic relationship between these rocks and the continent of North America has come into question. Researchers from the New England and Canadian segment of the Appalachians have long suggested that North America was subducted beneath one or more volcanic island arcs during the Ordovician, resulting in the accretion of volcanic terranes to the ancient North American margin. However, research from the Appalachians of Alabama, Georgia, and North Carolina suggests that a very different tectonic setting is needed to account for the geologic history and geometry of lithotectonic terranes in this region. Contrasts between the northern and southern ends of the Appalachian Mountains suggests that a major transform plate boundary must have accommodated subduction zones of opposite polarity during the Ordovician – not unlike modern day New Zealand and Taiwan – implying that the earliest phases of Appalachian mountain building (orogeny) involved the development of volcanoes directly on the ancient North American plate.

Thursday, October 28, 2010 4pm

Fungal Endophytes: The “Ad Infinitum” of Plant-Fungal Symbiotic Associations

Dr. Anthony Glenn
USDA-ARS Toxicology and Mycotoxin Research Unit, Athens, GA

Hosting Dept: Biology

Abstract:  Fungi are truly everywhere in our environment. On land, in sea, and in air. Whether it be growing in landscaping mulch, sprouting from our lawns, floating through the air, growing in buildings, or infecting a huge range of organism such as plants, coral, and humans, fungi are around us daily and impact our lives in significant ways, both positively and negatively. Plant pathogenic fungi cause significant damage to crops, costing the US farming industry hundreds of millions of dollars annually. However, not all fungi that infect plants cause disease. Some have adapted to infect and grow within plants without causing disease, and in some cases are actually very beneficial to plants in terms of drought tolerance and resistance to plant pathogenic fungi, herbivorous insects, and even extreme temperatures. This seminar will discuss such “endophytic” fungi in detail, with an emphasis on their basic biology and ecology as well as their production of a wide range of secondary metabolites, many of which are toxic to animals and humans (i.e., mycotoxins). The biological diversity exhibited by endophytic fungi has only recently become an area of intense study and discovery. Nearly every plant species examined has been found to harbor endophytic fungi. This broader appreciation of fungal diversity and host-associations has impacted the scientific community’s estimate of the total number of fungal species (1.5 million) that may exist on the planet. Such diversity has potential utility since fungi are a source for pharmaceuticals and industrial chemicals and enzymes, but there is also reason for concern since global movement of fungi can result in new plant disease issues that weren’t previously of concern.

Thursday, November 4, 2010 4pm

A goliath success story: Recovery of the endangered goliath grouper in Florida

Dr. Christopher C. Koenig
Reef Fish Ecology Group
Florida State University Coastal and Marine Laboratory

Hosting Dept: Biology

AbstractThe goliath grouper (Epinephelus itajara) population of Florida has recovered significantly over the past 20 years of total protection by federal and state fishery management agencies.  In this talk, I will present the highlights of our research documenting goliath grouper distribution in the southeastern U.S., ecological relationships, spawning and nursery patterns, and the regional recovery of this ‘critically endangered’ species (IUCN designation).  I will also use scientific information to address the opinions and concerns of recreational fishermen of Florida, many of whom have assumed that population increases of goliath grouper have negatively impacted their own reef fish fisheries. 

Thursday, November 11, 2010 4pm

Rare Herbarium Specimens Reveal the Phylogeny of Schoenocaulon (Melanthiaceae)

Dr. Wendy Zomlefer
Department of Plant Biology
University of Georgia

Hosting Dept: Biology

Abstract:  Schoenocaulon is an odd plant, characterized by bulbs covered with dark scales, long wand-like flower clusters, and winged seeds. The 24 species in the genus are mainly endemic to Mexico, often restricted to a single mountain range. Species delimitations have been problematic. Analyses of ITS sequence data support recognition of several new species, and some resolution of relationships. The phylogeny, correlated with geography and morphology, allows insight into the evolution of unusual morphological characters. This series of studies would not have been possible without careful sampling of properly vouchered herbarium specimens of these rarely collected species.

Thursday, November 18, 2010 4pm

Thanksgiving Break

The Evolutionary History of Macadamias and their Relatives

Dr. Austin Mast
Florida State University

Hosting Dept: Biology 

Abstract:  The Macadamia nut family (Proteaceae; ca. 1800 species in 80 genera) is widespread across the southern hemisphere on all major fragments of what was once the super-continent Gondwana, and it has played a central role in our historical interpretation of the interplay of continental drift and biotic evolution. I will weave together phylogenetic inferences, molecular age estimates, and fruit evolution reconstructions from my lab to propose new interpretations of the role that continental drift played in generating biogeographic patterns and ecological diversity in the southern hemisphere. I will also discuss unexpected discoveries related to the evolutionary history of macadamia nuts, in particular.

Thursday, December 2, 2010 4pm

End of semester