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Molecular Fluorescence, Phosphorescence, And Chemiluminescence Spectrometry, Kristin A. Fletcher, Sayo O. Fakayode, Mark Lowry, Sheryl A. Tucker, Sharon L. Neal, Irene W. Kimaru, Matthew E. Mccarroll, Gabor Patonay, Philip B. Oldham, Oleksandr Rusin, Robert M. Strongin, Isiah M. Warner Jun 2006

Molecular Fluorescence, Phosphorescence, And Chemiluminescence Spectrometry, Kristin A. Fletcher, Sayo O. Fakayode, Mark Lowry, Sheryl A. Tucker, Sharon L. Neal, Irene W. Kimaru, Matthew E. Mccarroll, Gabor Patonay, Philip B. Oldham, Oleksandr Rusin, Robert M. Strongin, Isiah M. Warner

Faculty Publications

No abstract provided.

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Will Lowering Estuarine Salinity Increase Gulf Of Mexico Oyster Landings?, R. Eugene Turner Jun 2006

Will Lowering Estuarine Salinity Increase Gulf Of Mexico Oyster Landings?, R. Eugene Turner

Faculty Publications

Previous studies provide conflicting opinions on whether lower than average salinities in Gulf of Mexico (GOM) estuaries are likely to increase or decrease oyster harvests (Crassostrea virginica), which represented 69% and 54% of the United States oyster landings by weight, and dockside value, respectively, in 2003. The present study examined a 54-yr record (1950–2003) of oyster harvests and river discharge in five major estuaries in GOM states (Florida, Alabama, Mississippi, Louisiana, and Texas). Oyster landings were inversely related to freshwater inflow. Peaks in landings, 21 of 23 in West Florida, Alabama, Mississippi, and Texas combined, were coincidental with …

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Origin And Health Impacts Of Emissions Of Toxic By-Products And Fine Particles From Combustion And Thermal Treatment Of Hazardous Wastes And Materials, Stephania A. Cormier, Slawo Lomnicki, Wayne Backes, Barry Dellinger Jun 2006

Origin And Health Impacts Of Emissions Of Toxic By-Products And Fine Particles From Combustion And Thermal Treatment Of Hazardous Wastes And Materials, Stephania A. Cormier, Slawo Lomnicki, Wayne Backes, Barry Dellinger

Faculty Publications

High-temperature, controlled incineration and thermal treatment of contaminated soils, sediments, and wastes at Superfund sites are often preferred methods of remediation of contaminated sites under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and related legislation. Although these methods may be executed safely, formation of toxic combustion or reaction by-products is still a cause of concern. Emissions of polycyclic aromatic hydrocarbons (PAHs); chlorinated hydrocarbons (CHCs), including polychlorinated dibenzo-p-dioxins and dibenzofurans; and toxic metals (e.g., chromium VI) have historically been the focus of combustion and health effects research. However, fine particulate matter (PM) and ultrafine PM, which have been …

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Pivotal Advance: Eosinophil Infiltration Of Solid Tumors Is An Early And Persistent Inflammatory Host Response, Stephania A. Cormier, Anna G. Taranova, Carrie Bedient, Thanh Nguyen, Cheryl Protheroe, Ralph Pero, Dawn Dimina, Sergei I. Ochkur, Katie O'Neill, Dana Colbert, Theresa R. Lombari, Stephanie Constant, Michael P. Mcgarry, James J. Lee, Nancy A. Lee Jun 2006

Pivotal Advance: Eosinophil Infiltration Of Solid Tumors Is An Early And Persistent Inflammatory Host Response, Stephania A. Cormier, Anna G. Taranova, Carrie Bedient, Thanh Nguyen, Cheryl Protheroe, Ralph Pero, Dawn Dimina, Sergei I. Ochkur, Katie O'Neill, Dana Colbert, Theresa R. Lombari, Stephanie Constant, Michael P. Mcgarry, James J. Lee, Nancy A. Lee

Faculty Publications

Tumor-associated eosinophilia has been observed in numerous human cancers and several tumor models in animals; however, the details surrounding this eosinophilia remain largely undefined and anecdotal. We used a B16-F10 melanoma cell injection model to demonstrate that eosinophil infiltration of tumors occurred from the earliest palpable stages with significant accumulations only in the necrotic and capsule regions. Furthermore, the presence of diffuse extracellular matrix staining for eosinophil major basic protein was restricted to the necrotic areas of tumors, indicating that eosinophil degranulation was limited to this region. Antibody-mediated depletion of CD4+ T cells and adoptive transfer of eosinophils suggested, respectively, …

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Positive Selection On Nucleotide Substitutions And Indels In Accessory Gland Proteins Of The Drosophila Pseudoobscura Subgroup, Sheri Dixon Schully, Michael E. Hellberg Jun 2006

Positive Selection On Nucleotide Substitutions And Indels In Accessory Gland Proteins Of The Drosophila Pseudoobscura Subgroup, Sheri Dixon Schully, Michael E. Hellberg

Faculty Publications

Genes encoding reproductive proteins often diverge rapidly due to positive selection on nucleotide substitutions. While this general pattern is well established, the extent to which specific reproductive genes experience similar selection in different clades has been little explored, nor have possible targets of positive selection other than nucleotide substitutions, such as indels, received much attention. Here, we inspect for the signature of positive selection in the genes encoding five accessory gland proteins (Acps) (Acp26Aa, Acp32CD, Acp53Ea, Acp62F, and Acp70A) originally described from Drosophila melanogaster but with recognizable orthologues in the D. pseudoobscura subgroup. We compare patterns of selection within the …

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Ir-Maldi-Ldi Combined With Ion Mobility Orthogonal Time-Of-Flight Mass Spectrometry, Amina S. Woods, Micheal Ugarov, Shelley N. Jackson, Thomas Egan, Hay Yan J. Wang, Kermit K. Murray, J. Albert Schultz Jun 2006

Ir-Maldi-Ldi Combined With Ion Mobility Orthogonal Time-Of-Flight Mass Spectrometry, Amina S. Woods, Micheal Ugarov, Shelley N. Jackson, Thomas Egan, Hay Yan J. Wang, Kermit K. Murray, J. Albert Schultz

Faculty Publications

Most MALDI instrumentation uses UV lasers. We have designed a MALDI-IM-oTOF-MS which employs both a Nd:YAG laser pumped optical parametric oscillator OPOTEK, λ = 2.8-3.2 μm at 20 Hz) to perform IR-LDI or IR-MALDI and a Nd:YLF laser (Crystalaser, λ = 249 nm at 200 Hz) for the UV. Ion mobility (IM) gives a fast separation and analysis of biomolecules from complex mixtures in which ions of similar chemical type fall along well-defined "trend lines". Our data shows that ion mobility allows multiply charged monomers and multimers to be resolved; thus, yielding pure spectra of the singly charged protein ion …

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Initiation Of Apoptosis And Autophagy By Photodynamic Therapy, David Kessel, M. Graça H. Vicente, John J. Reiners Jun 2006

Initiation Of Apoptosis And Autophagy By Photodynamic Therapy, David Kessel, M. Graça H. Vicente, John J. Reiners

Faculty Publications

Background and Objectives: This study was designed to examine modes of cell death after photodynamic therapy (PDT). Study Design: Murine leukemia L1210 cells and human prostate Bax-deficient DU145 cells were examined after PDT-induced photodamage to the endoplasmic reticulum (ER). Phase contrast, fluorescence and electron microscopy were used to identify changes in cellular morphology, chromatin condensation, loss of mitochondrial membrane potential, and formation of phagolysosomes. Western blots were used to assess the processing of LC3-I to LC3-II, a marker for autophagy. Inhibitors of apoptosis and/or autophagy were used to delineate the contributions of the two pathways to the effects of PDT. …

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Do Geese Fully Develop Brood Patches? A Histological Analysis Of Lesser Snow Geese (Chen Caerulescens Caerulescens) And Ross's Geese (C. Rossii), Jón Einar Jónsson, Alan D. Afton, Dominique G. Homberger, William G. Henk, Ray T. Alisauskas Jun 2006

Do Geese Fully Develop Brood Patches? A Histological Analysis Of Lesser Snow Geese (Chen Caerulescens Caerulescens) And Ross's Geese (C. Rossii), Jón Einar Jónsson, Alan D. Afton, Dominique G. Homberger, William G. Henk, Ray T. Alisauskas

Faculty Publications

Most birds develop brood patches before incubation; epidermis and dermis in the brood patch region thicken, and the dermal connective tissue becomes increasingly vascularized and infiltrated by leukocytes. However, current dogma states that waterfowl incubate without modifications of skin within the brood patch region. The incubation periods of lesser snow geese (Chen caerulescens caerulescens; hereafter called snow geese) and Ross's geese (C. rossii) are 2-6 days shorter than those of other goose species; only females incubate. Thus, we hypothesized that such short incubation periods would require fully developed brood patches for sufficient heat transfer from incubating parents to eggs. We …

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Systematics And Historical Biogeography Of Greater Antillean Cichlidae, Prosanta Chakrabarty Jun 2006

Systematics And Historical Biogeography Of Greater Antillean Cichlidae, Prosanta Chakrabarty

Faculty Publications

A molecular phylogenetic analysis recovers a pattern consistent with a drift vicariance scenario for the origin of Greater Antillean cichlids. This phylogeny, based on mitochondrial and nuclear genes, reveals that clades on different geographic regions diverged concurrently with the geological separation of these areas. Middle America was initially colonized by South American cichlids in the Cretaceous, most probably through the Cretaceous Island Arc. The separation of Greater Antillean cichlids and their mainland Middle American relatives was caused by a drift vicariance event that took place when the islands became separated from Yucatan in the Eocene. Greater Antillean cichlids are monophyletic …

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Total Nitrogen Inflow And Outflow From A Large River Swamp Basin To The Gulf Of Mexico, Y. Jun Xu Jun 2006

Total Nitrogen Inflow And Outflow From A Large River Swamp Basin To The Gulf Of Mexico, Y. Jun Xu

Faculty Publications

River corridor wetland restoration and freshwater diversion from the lower Mississippi River are being considered as two major options to reduce nitrogen input to the Gulf of Mexico. However, it is largely uncertain how much nitrogen can actually be retained from the overflowing waters by these wetland systems. This study quantified the nitrogen inflow and outflow for the largest distributary basin of the Mississippi River, the Atchafalaya River Swamp basin. The goal of the study was to seek answers to three critical questions: (a) Does the Atchafalaya River Swamp remove a significant amount of nitrogen from the overflowing water, or …

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Reproductive Behavior Of The Yellow-Crowned Parrot (Amazona Ochrocephala) In Western Panama, Angélica M. Rodríguez Castillo, Jessica R. Eberhard Jun 2006

Reproductive Behavior Of The Yellow-Crowned Parrot (Amazona Ochrocephala) In Western Panama, Angélica M. Rodríguez Castillo, Jessica R. Eberhard

Faculty Publications

We studied the breeding biology of the Panamanian subspecies of the Yellow-crowned Parrot, Amazona ochrocephala panamensis, during 1997-1999 in the province of Chiriquí, Panama, to provide basic information regarding the breeding behavior and reproductive success of these parrots in their natural habitat. We recorded parrot behaviors throughout the reproductive period, monitored nest success, and characterized occupied and non-occupied tree cavities. All breeding attempts involved a male-female pair. Clutch size ranged from 2 to 4 eggs, which were incubated only by the female, beginning when the first egg was laid. Incubation averaged 25 days and the eggs hatched asynchronously. During the …

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Toxic And Contaminant Concerns Generated By Hurricane Katrina, Danny D. Reible, Charles N. Haas, John H. Pardue, William J. Walsh Jun 2006

Toxic And Contaminant Concerns Generated By Hurricane Katrina, Danny D. Reible, Charles N. Haas, John H. Pardue, William J. Walsh

Faculty Publications

No abstract provided.

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Induction Of Socs-3 Is Insufficient To Confer Irs-1 Protein Degradation In 3t3-L1 Adipocytes, Fang He, Jacqueline M. Stephens May 2006

Induction Of Socs-3 Is Insufficient To Confer Irs-1 Protein Degradation In 3t3-L1 Adipocytes, Fang He, Jacqueline M. Stephens

Faculty Publications

Insulin receptor substrate (IRS)-1 is a key protein in insulin signaling. Several studies have shown that the expression of IRS-1 can be modulated by protein degradation via the proteasome and the degradation of IRS-1 can be related to insulin-resistant states. The degradation of IRS-1 has been shown to be induced by SOCS-1 and SOCS-3 via the ubiquitin pathway. The goal of our study was to determine if the induction of SOCS-3 correlated with increased IRS-1 degradation in cultured 3T3-L1 adipocytes. Interestingly, our studies have shown that there is little correlation between the induction in SOCS-3 expression and the degradation of …

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Recently Integrated Alu Retrotransposons Are Essentially Neutral Residents Of The Human Genome, Richard Cordaux, Jungnam Lee, Liv Dinoso, Mark A. Batzer May 2006

Recently Integrated Alu Retrotransposons Are Essentially Neutral Residents Of The Human Genome, Richard Cordaux, Jungnam Lee, Liv Dinoso, Mark A. Batzer

Faculty Publications

Alu elements represent the largest family of human mobile elements in copy number. A controversial issue with implications for both Alu biology and human genome evolution is whether selective pressures are affecting Alu elements on a large scale. To address this issue, we analyzed the genomic distribution of the three youngest known human Alu subfamilies (Ya5a2, Ya8 and Yb9) in conjunction with their insertion polymorphism status in the human population, since selection can only act on polymorphic elements. Our results indicate that: (i) polymorphic and fixed recently integrated Alu elements are found in genomic regions whose GC contents are statistically …

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Estimating The Retrotransposition Rate Of Human Alu Elements, Richard Cordaux, Dale J. Hedges, Scott W. Herke, Mark A. Batzer May 2006

Estimating The Retrotransposition Rate Of Human Alu Elements, Richard Cordaux, Dale J. Hedges, Scott W. Herke, Mark A. Batzer

Faculty Publications

Mobile elements such as Alu repeats have substantially altered the architecture of the human genome, and de novo mobile element insertions sometimes cause genetic disorders. Previous estimates for the retrotransposition rate (RR) of Alu elements in humans of one new insertion every ∼100-125 births were developed prior to the sequencing of the human and chimpanzee genomes. Here, we used two independent methods (based on the new genomic data and on disease-causing de novo Alu insertions) to generate refined Alu RR estimates in humans. Both methods consistently yielded RR on the order of one new Alu insertion every ∼20 births, despite …

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Birth Of A Chimeric Primate Gene By Capture Of The Transposase Gene From A Mobile Element, Richard Cordaux, Swalpa Udit, Mark A. Batzer, Cédric Feschotte May 2006

Birth Of A Chimeric Primate Gene By Capture Of The Transposase Gene From A Mobile Element, Richard Cordaux, Swalpa Udit, Mark A. Batzer, Cédric Feschotte

Faculty Publications

The emergence of new genes and functions is of central importance to the evolution of species. The contribution of various types of duplications to genetic innovation has been extensively investigated. Less understood is the creation of new genes by recycling of coding material from selfish mobile genetic elements. To investigate this process, we reconstructed the evolutionary history of SETMAR, a new primate chimeric gene resulting from fusion of a SET histone methyltransferase gene to the transposase gene of a mobile element. We show that the transposase gene was recruited as part of SETMAR 40-58 million years ago, after the insertion …

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A Time-Resolved Vibrational Spectroscopy Glimpse Into The Oxygen-Evolving Complex Of Photosynthesis, Terry M. Bricker May 2006

A Time-Resolved Vibrational Spectroscopy Glimpse Into The Oxygen-Evolving Complex Of Photosynthesis, Terry M. Bricker

Faculty Publications

No abstract provided.

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Nitric Oxide Transiently Converts Synaptic Inhibition To Excitation In Retinal Amacrine Cells, Brian Hoffpauir, Emily Mcmains, Evanna Gleason May 2006

Nitric Oxide Transiently Converts Synaptic Inhibition To Excitation In Retinal Amacrine Cells, Brian Hoffpauir, Emily Mcmains, Evanna Gleason

Faculty Publications

Nitric oxide (NO) is generated by multiple cell types in the vertebrate retina, including amacrine cells. We investigate the role of NO in the modulation of synaptic function using a culture system containing identified retinal amacrine cells. We find that moderate concentrations of NO alter GABAA receptor function to produce an enhancement of the GABA-gated current. Higher concentrations of NO also enhance GABA-gated currents, but this enhancement is primarily due to a substantial positive shift in the reversal potential of the current. Several pieces of evidence, including a similar effect on glycine-gated currents, indicate that the positive shift is due …

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Small-Scale Fuel Variation Alters Fire Intensity And Shrub Abundance In A Pine Savanna, Jarrod M. Thaxton, William J. Platt May 2006

Small-Scale Fuel Variation Alters Fire Intensity And Shrub Abundance In A Pine Savanna, Jarrod M. Thaxton, William J. Platt

Faculty Publications

Small-scale variation in fire intensity and effects may be an important source of environmental heterogeneity in frequently burned plant communities. We hypothesized that variation in fire intensity resulting from local differences in fuel loads produces heterogeneity in pine savanna ground cover by altering shrub abundance. To test this hypothesis, we experimentally manipulated prefire fuel loads to mimic naturally occurring fuel-load heterogeneity associated with branch falls, needle fall near large pines, and animal disturbances in a frequently burned longleaf pine (Pinus palustris) savanna in Louisiana, USA. We applied one of four fuel treatments (unaltered control, fine-fuel removal, fine-fuel addition, wood addition) …

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Lipid Trafficking To The Outer Membrane Of Gram-Negative Bacteria, William T. Doerrler May 2006

Lipid Trafficking To The Outer Membrane Of Gram-Negative Bacteria, William T. Doerrler

Faculty Publications

The envelope of Gram-negative bacteria is composed of two distinct lipid membranes: an inner membrane and outer membrane. The outer membrane is an asymmetric bilayer with an inner leaflet of phospholipids and an outer leaflet of lipopolysaccharide. Most of the steps of lipid synthesis occur within the cytoplasmic compartment of the cell. Lipids must then be transported across the inner membrane and delivered to the outer membrane. These topological features combined with the ability to apply the tools of biochemistry and genetics make the Gram-negative envelope a fascinating model for the study of lipid trafficking. In addition, as lipopolysaccharide is …

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The Shoot-Specific Expression Of Γ-Glutamylcysteine Synthetase Directs The Long-Distance Transport Of Thiol-Peptides To Roots Conferring Tolerance To Mercury And Arsenic, Yujing Li, Om Parkash Dankher, Laura Carreira, Aaron P. Smith, Richard B. Meagher May 2006

The Shoot-Specific Expression Of Γ-Glutamylcysteine Synthetase Directs The Long-Distance Transport Of Thiol-Peptides To Roots Conferring Tolerance To Mercury And Arsenic, Yujing Li, Om Parkash Dankher, Laura Carreira, Aaron P. Smith, Richard B. Meagher

Faculty Publications

Thiol-peptides synthesized as intermediates in phytochelatin (PC) biosynthesis confer cellular tolerance to toxic elements like arsenic, mercury and cadmium, but little is known about their long-distance transport between plant organs. A modified bacterial γ-glutamylcysteine synthetase (ECS) gene, S1pt::ECS, was expressed in the shoots of the ECS-deficient, heavy-metal-sensitive cad2-1 mutant of Arabidopsis (Arabidopsis thaliana). S1pt::ECS directed strong ECS protein expression in the shoots, but no ECS was detected in the roots of transgenic plant lines. The S1pt::ECS gene restored full mercury tolerance and partial cadmium tolerance to the mutant and enhanced arsenate tolerance significantly beyond wild-type levels. After arsenic treatment, the …

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Comparing Tropical Forest Tree Size Distributions With The Predictions Of Metabolic Ecology And Equilibrium Models, Helene C. Muller-Landau, Richard S. Condit, Kyle E. Harms, Christian O. Marks, Sean C. Thomas, Sarayudh Bunyavejchewin, George Chuyong, Leonardo Co, Stuart Davies, Robin Foster, Savitri Gunatilleke, Nimal Gunatilleke, Terese Hart, Stephen P. Hubbell, Akira Itoh, Abd Rahman Kassim, David Kenfack, James V. Lafrankie, Daniel Lagunzad, Hua Seng Lee, Elizabeth Losos, Jean Remy Makana, Tatsuhiro Ohkubo, Cristian Samper, Raman Sukumar, I. Fang Sun, M. N. Nur Supardi, Sylvester Tan, Duncan Thomas, Jill Thompson, Renato Valencia, Martha Isabel Vallejo, Gorky Villa Muñoz May 2006

Comparing Tropical Forest Tree Size Distributions With The Predictions Of Metabolic Ecology And Equilibrium Models, Helene C. Muller-Landau, Richard S. Condit, Kyle E. Harms, Christian O. Marks, Sean C. Thomas, Sarayudh Bunyavejchewin, George Chuyong, Leonardo Co, Stuart Davies, Robin Foster, Savitri Gunatilleke, Nimal Gunatilleke, Terese Hart, Stephen P. Hubbell, Akira Itoh, Abd Rahman Kassim, David Kenfack, James V. Lafrankie, Daniel Lagunzad, Hua Seng Lee, Elizabeth Losos, Jean Remy Makana, Tatsuhiro Ohkubo, Cristian Samper, Raman Sukumar, I. Fang Sun, M. N. Nur Supardi, Sylvester Tan, Duncan Thomas, Jill Thompson, Renato Valencia, Martha Isabel Vallejo, Gorky Villa Muñoz

Faculty Publications

Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing …

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Testing Metabolic Ecology Theory For Allometric Scaling Of Tree Size, Growth And Mortality In Tropical Forests, Helene C. Muller-Landau, Richard S. Condit, Jerome Chave, Sean C. Thomas, Stephanie A. Bohlman, Sarayudh Bunyavejchewin, Stuart Davies, Robin Foster, Savitri Gunatilleke, Nimal Gunatilleke, Kyle E. Harms, Terese Hart, Stephen P. Hubbell, Akira Itoh, Abd Rahman Kassim, James V. Lafrankie, Hua Seng Lee, Elizabeth Losos, Jean Remy Makana, Tatsuhiro Ohkubo, Raman Sukumar, I. Fang Sun, M. N. Nur Supardi, Sylvester Tan, Jill Thompson, Renato Valencia, Gorky Villa Muñoz, Christopher Wills, Takuo Yamakura, George Chuyong, Handanakere Shivaramaiah Dattaraja, Shameema Esufali, Pamela Hall May 2006

Testing Metabolic Ecology Theory For Allometric Scaling Of Tree Size, Growth And Mortality In Tropical Forests, Helene C. Muller-Landau, Richard S. Condit, Jerome Chave, Sean C. Thomas, Stephanie A. Bohlman, Sarayudh Bunyavejchewin, Stuart Davies, Robin Foster, Savitri Gunatilleke, Nimal Gunatilleke, Kyle E. Harms, Terese Hart, Stephen P. Hubbell, Akira Itoh, Abd Rahman Kassim, James V. Lafrankie, Hua Seng Lee, Elizabeth Losos, Jean Remy Makana, Tatsuhiro Ohkubo, Raman Sukumar, I. Fang Sun, M. N. Nur Supardi, Sylvester Tan, Jill Thompson, Renato Valencia, Gorky Villa Muñoz, Christopher Wills, Takuo Yamakura, George Chuyong, Handanakere Shivaramaiah Dattaraja, Shameema Esufali, Pamela Hall

Faculty Publications

The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that …

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A Comprehensive Catalog Of Human Krab-Associated Zinc Finger Genes: Insights Into The Evolutionary History Of A Large Family Of Transcriptional Repressors, Stuart Huntley, Daniel M. Baggott, Aaron T. Hamilton, Mary Tran-Gyamfi, Shan Yang, Joomyeong Kim, Laurie Gordon, Elbert Branscomb, Lisa Stubbs May 2006

A Comprehensive Catalog Of Human Krab-Associated Zinc Finger Genes: Insights Into The Evolutionary History Of A Large Family Of Transcriptional Repressors, Stuart Huntley, Daniel M. Baggott, Aaron T. Hamilton, Mary Tran-Gyamfi, Shan Yang, Joomyeong Kim, Laurie Gordon, Elbert Branscomb, Lisa Stubbs

Faculty Publications

Krüppel-type zinc finger (ZNF) motifs are prevalent components of transcription factor proteins in all eukaryotes. KRAB-ZNF proteins, in which a potent repressor domain is attached to a tandem array of DNA-binding zinc-finger motifs, are specific to tetrapod vertebrates and represent the largest class of ZNF proteins in mammals. To define the full repertoire of human KRAB-ZNF proteins, we searched the genome sequence for key motifs and then constructed and manually curated gene models incorporating those sequences. The resulting gene catalog contains 423 KRAB-ZNF protein-coding loci, yielding alternative transcripts that altogether predict at least 742 structurally distinct proteins. Active rounds of …

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Modelling Responses Of Pine Savannas To Climate Change And Large-Scale Disturbance, Brian Beckage, Louis J. Gross, William J. Platt May 2006

Modelling Responses Of Pine Savannas To Climate Change And Large-Scale Disturbance, Brian Beckage, Louis J. Gross, William J. Platt

Faculty Publications

Global warming can potentially influence ecological communities through altered disturbance regimes in addition to increased temperatures. We investigate the response of pine savannas in the southeastern United States to global warming using a simple Lotka-Volterra competition model together with predicted changes to fire and hurricane disturbance regimes with global climate change. In the southeastern United States, decreased frequency of both fires and hurricanes with global warming will shift pine savannas toward a forested state. A CO2 fertilization effect that increases the growth rate of tree populations will also push southeastern landscapes from open savannas towards closed forests. Transient dynamics associated …

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Natural Disturbances And The Physiognomy Of Pine Savannas: A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet May 2006

Natural Disturbances And The Physiognomy Of Pine Savannas: A Phenomenological Model, Frank S. Gilliam, William J. Platt, Robert K. Peet

Faculty Publications

Question: The decline of the Pinus palustris ecosystems has resulted from anthropogenic influences, such as conversion to pine plantation forestry, agriculture and land development, all of which are closely related to increases in human populations. Other effects, however, have arisen from alterations in disturbance regimes that maintain the structure and function of these ecosystems. How have alterations of the disturbance regime altered the physiognomy of 'old-growth' stands, and what are the implications for ecosystem conservation and restoration? Methods: In contrast to models that emphasize close interactions among the vertically complex strata, we develop a conceptual phenomenological model for the physiognomic …

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Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt May 2006

Conservation And Restoration Of The Pinus Palustris Ecosystem, Frank S. Gilliam, William J. Platt

Faculty Publications

The well-documented decline of the Pinus palustris ecosystem has resulted from several anthropogenic influences, such as forest clearing (e.g. pine plantation forestry, agriculture) and urban development, both of which are closely related to increases in human populations. Other impacts have arisen from alterations in disturbance regimes responsible for maintaining the structure and function of these ecosystems. Restoration and management of degraded pine savanna ecosystems is critical. Identification of ecological processes that determine the structure and function of the intact system are important because successful restoration efforts should be based on sound scientific understanding. In this paper, we introduce this special …

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Pine Savanna Overstorey Influences On Ground-Cover Biodiversity, William J. Platt, Susan M. Carr, Matthew Reilly, Jean Fahr May 2006

Pine Savanna Overstorey Influences On Ground-Cover Biodiversity, William J. Platt, Susan M. Carr, Matthew Reilly, Jean Fahr

Faculty Publications

Question: Does the overstorey of pine savannas influence plant species biodiversity in the ground cover? Location: Camp Whispering Pines (30°41' N; 90°29' W), eastern Louisiana (USA). Methods: We used ecologically sensitive restoration logging to remove patches of Pinus palustris (longleaf pine) in a second-growth loess plain Pinus palustris savanna managed using frequent lightning season fires. Five years later, we measured numbers of vascular plant species and transmitted light in replicated 100-m2 plots. Treatments involved three different overstorey conditions: no overstorey for 5 years, no overstorey for several decades, and overstorey pines present for decades. Results: Both recent and long-term openings …

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Characterization Of A Branchial Epithelial Calcium Channel (Ecac) In Freshwater Rainbow Trout (Oncorhynchus Mykiss), A. Shahsavarani, B. Mcneill, F. Galvez, C. M. Wood, G. G. Goss, P. P. Hwang, S. F. Perry May 2006

Characterization Of A Branchial Epithelial Calcium Channel (Ecac) In Freshwater Rainbow Trout (Oncorhynchus Mykiss), A. Shahsavarani, B. Mcneill, F. Galvez, C. M. Wood, G. G. Goss, P. P. Hwang, S. F. Perry

Faculty Publications

The entry of calcium (Ca2+) through an apical membrane epithelial calcium channel (ECaC) is thought to a key step in piscine branchial Ca2+ uptake. In mammals, ECaC is a member of the transient receptor potential (TRP) gene family of which two sub-families have been identified, TRPV5 and TPRV6. In the present study we have identified a single rainbow trout (Oncorhynchus mykiss) ECaC (rtECaC) that is similar to the mammalian TRPV5 and TRPV6. Phylogenetic analysis of the protein sequence suggests that an ancestral form of the mammalian genes diverged from those in the lower vertebrates prior to the gene duplication event …

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Sauria Sines: Novel Short Interspersed Retroposable Elements That Are Widespread In Reptile Genomes, Oliver Piskurek, Christopher C. Austin, Norihiro Okada May 2006

Sauria Sines: Novel Short Interspersed Retroposable Elements That Are Widespread In Reptile Genomes, Oliver Piskurek, Christopher C. Austin, Norihiro Okada

Faculty Publications

SINEs are short interspersed retrotransposable elements that invade new genomic sites. Their retrotransposition depends on reverse transcriptase and endonuclease activities encoded by partner LINEs (long interspersed elements). Recent genomic research has demonstrated that retroposons account for at least 40% of the human genome. Hitherto, more than 30 families of SINEs have been characterized in mammalian genomes, comprising ∼4600 extant species; the distribution and extent of SINEs in reptilian genomes, however, are poorly documented. With more than 7400 species of lizards and snakes, Squamata constitutes the largest and most diverse group of living reptiles. We have discovered and characterized a novel …

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