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An Evaluation Of Bacterial And Fungal Contributions To Organic Matter Decomposition Along A Soil Moisture Gradient, Morgan Rawls Jul 2009

An Evaluation Of Bacterial And Fungal Contributions To Organic Matter Decomposition Along A Soil Moisture Gradient, Morgan Rawls

Theses and Dissertations

The decomposition of plant litter is a critical biological function that aids in nutrient cycling and energy transfers within and between ecosystems. The primary decomposers of dead leaf material are bacteria and fungi, though there is no consensus as to which of these groups is dominant, nor is it known how the abundance and composition of these communities changes over time. The objectives of this study were to examine the relative contributions of bacterial and fungal populations to leaf organic matter (OM) decomposition and to consider the effect of moisture availability on the microbial community. The study was conducted across …

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Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott Jul 2009

Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott

Theses and Dissertations

Understanding why some species coexist and others do not remains one of the fundamental challenges of ecology. While several lines of evidence suggest that closely related species are unlikely to occupy the same habitat because of competitive exclusion, there are many cases where closely related species do co-occur. Research comparing sympatric and allopatric populations of co-occurring species provides a framework to understand the role of phenotypic diversification in species coexistence. In this study I focus on the livebearing fish Poeciliopsis baenschi and ask if differences in phenotypic traits among populations can be explained by the presence or absence of the …

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A Bac-Based Physical Map Of The Hessian Fly Genome Anchored To Polytene Chromosomes, Rajat Aggarwal, Thiago R. Benatti, Navdeep Gill, Chaoyang Zhao, Ming-Shun Chen, John P. Fellers, Brandon J. Schemerhorn, Jeff J. Stuart Jul 2009

A Bac-Based Physical Map Of The Hessian Fly Genome Anchored To Polytene Chromosomes, Rajat Aggarwal, Thiago R. Benatti, Navdeep Gill, Chaoyang Zhao, Ming-Shun Chen, John P. Fellers, Brandon J. Schemerhorn, Jeff J. Stuart

Biology Faculty Articles

Background: The Hessian fly (Mayetiola destructor) is an important insect pest of wheat. It has tractable genetics, polytene chromosomes, and a small genome (158 Mb). Investigation of the Hessian fly presents excellent opportunities to study plant-insect interactions and the molecular mechanisms underlying genome imprinting and chromosome elimination. A physical map is needed to improve the ability to perform both positional cloning and comparative genomic analyses with the fully sequenced genomes of other dipteran species. Results: An FPC-based genome wide physical map of the Hessian fly was constructed and anchored to the insect's polytene chromosomes. Bacterial artificial chromosome (BAC) clones corresponding …

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Presence Of Haemosporidia And Flaviviruses In Breeding Prothonotary Warblers (Protonotaria Citrea): An Analysis Of Spatial And Temporal Trends In Infection Prevalence And Associations With Reproductive Success, Elena Grillo Jul 2009

Presence Of Haemosporidia And Flaviviruses In Breeding Prothonotary Warblers (Protonotaria Citrea): An Analysis Of Spatial And Temporal Trends In Infection Prevalence And Associations With Reproductive Success, Elena Grillo

Theses and Dissertations

As Neotropical migratory birds, Prothonotary Warblers are exposed to parasites in both tropical and temperate regions and may act as dispersal agents between geographic areas. This study identifies the prevalence of Haemosporidia, West Nile Virus (WNV), and St. Louis Encephalitis virus (SLEV) in this species. A total of 71.6% of captured Prothonotary Warblers were infected with Haemosporidia during the 2008 breeding season, and infection prevalence increased throughout the season. This temporal change in prevalence is likely due to infection relapse and transmission of new infections. No correlations between reproductive effort and infection status were observed, nor were any associations between …

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Heterosternuta Sulphuria (Coloptera: Dytiscidae) Occurence In The Sulphur Springs Headwater System And In Buffalo National River Tributaries (Arkansas, Usa): Current Distribution, Habitat Conditions, And Biomonitoring Framework, S.D. Longing, B.E. Haggard Jul 2009

Heterosternuta Sulphuria (Coloptera: Dytiscidae) Occurence In The Sulphur Springs Headwater System And In Buffalo National River Tributaries (Arkansas, Usa): Current Distribution, Habitat Conditions, And Biomonitoring Framework, S.D. Longing, B.E. Haggard

Arkansas Water Resources Center Technical Reports

Heterosternuta sulphuria is an endemic aquatic species of concern in Arkansas, with a priority score of 80 out of 100 and a conservation rank of S1and G1. A need of the Arkansas Wildlife Action Plan (AWAP) was to obtain baseline information on distribution and population status of H. sulphuria. Here, we report new H. sulphuria records for 39 sites across 10 counties in the Ozark Highlands and Boston Mountain ecoregions and a determined habitat type of shallow margins and small bedrock pools of perennial streams and spring seeps. Few habitat patches were observed per site because detection was typically rapid …

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Assessing Organic Matter Breakdown And Associated Macroinvertebrate Community Structure In Headwater Streams: Effects Of Hydrologic Gradients And Upland Timber Harvesting, Miller Scott Jarrell Jul 2009

Assessing Organic Matter Breakdown And Associated Macroinvertebrate Community Structure In Headwater Streams: Effects Of Hydrologic Gradients And Upland Timber Harvesting, Miller Scott Jarrell

Masters Theses & Specialist Projects

I examined the effects of hydrologic gradients and upland timber harvesting with different streamside management zone widths on yellow-poplar (Liriodendron tulipifera) processing and the associated macroinvertebrate community structure in the Cumberland Plateau ecophysic region, U.S.A. Prior to upland timber harvesting, 5.0 ± 0.1 g yellow-poplar leaf packs were constructed, zip-tied to gutter nails, and placed into 7 perennial and 6 temporary stream reaches with similar physiochemical and geomorphic characteristics. From December 2007 to May 2008, 3–5 leaf packs were collected per reach monthly. I found significant differences in the functional feeding group composition. Temporary reaches contained higher shredder, gathering-collector, predator, …

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A Continent-Wide Clone: Population Genetic Variation Of The Invasive Plant Hieracium Aurantiacum (Orange Hawkweed; Asteraceae) In North America, Eli S. Loomis, Lila Fishman Jul 2009

A Continent-Wide Clone: Population Genetic Variation Of The Invasive Plant Hieracium Aurantiacum (Orange Hawkweed; Asteraceae) In North America, Eli S. Loomis, Lila Fishman

Biological Sciences Faculty Publications

We investigated the population genetic structure of the invasive plant Hieracium aurantiacum (Asteraceae), a facultative apomict. We generated amplified fragment length polymorphism fingerprints for H. aurantiacum samples from across its invasive range in North America (N = 226) and from six other North American native and invasive Hieracium species (N = 60). Almost no genetic variability was found in the North American H. aurantiacum across locations from Alaska and Oregon to Pennsylvania and Ontario (clonal diversity = 0.035). In contrast, other Hieracium species showed a range of clonal diversities (range = 0.154-1.0). The single H. aurantiacum genotype that dominated the …

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Bar-Coded Pyrosequencing Reveals Shared Bacterial Community Properties Along The Temperature Gradients Of Two Alkaline Hot Springs In Yellowstone National Park, Scott R. Miller, Aaron L. Strong, Kenneter L. Jones, Mark C. Ungerer Jul 2009

Bar-Coded Pyrosequencing Reveals Shared Bacterial Community Properties Along The Temperature Gradients Of Two Alkaline Hot Springs In Yellowstone National Park, Scott R. Miller, Aaron L. Strong, Kenneter L. Jones, Mark C. Ungerer

Biological Sciences Faculty Publications

An understanding of how communities are organized is a fundamental goal of ecology but one which has historically been elusive for microbial systems. We used a bar-coded pyrosequencing approach targeting the V3 region of the bacterial small-subunit rRNA gene to address the factors that structure communities along the thermal gradients of two alkaline hot springs in the Lower Geyser Basin of Yellowstone National Park. The filtered data set included a total of nearly 34,000 sequences from 39 environmental samples. Each was assigned to one of 391 operational taxonomic units (OTUs) identified by their unique V3 sequence signatures. Although the two …

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Differential Interactions Of The Catalytic Subunits Of Adenylyl Cyclase With Forskolin Analogs, Cibele Pinto, Melanie Hübner, Andreas Gille, Mark Richter, Tung-Chung Mou, Stephen R. Sprang, Roland Seifert Jul 2009

Differential Interactions Of The Catalytic Subunits Of Adenylyl Cyclase With Forskolin Analogs, Cibele Pinto, Melanie Hübner, Andreas Gille, Mark Richter, Tung-Chung Mou, Stephen R. Sprang, Roland Seifert

Biological Sciences Faculty Publications

The diterpene forskolin (FS) binds to, and activates, mammalian membranous adenylyl cyclase (AC) isoforms I-VIII. Diterpenes without C(1)-OH group do not activate ACs. The C(1)-OH group forms a hydrogen bond with the backbone oxygen of Val506 of the C1 catalytic subunit of AC (isoform V numbering). To better understand the mechanism of AC activation we examined the interactions of FS and eight FS analogs with purified catalytic AC subunits C1 (AC V) and C2 (AC II) by fluorescence spectroscopy, using 2',3'-O-(N-methylanthraniloyl)-guanosine 5'-triphosphate (MANT-GTP) as fluorescent reporter probe, and by enzymatic activity. FS analogs induced C1/C2 assembly as assessed by fluorescence …

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Molluscan Models In Evolutionary Biology: Apple Snails (Gastropoda: Ampullariidae) As A System For Addressing Fundamental Questions, Kenneth Hayes Jul 2009

Molluscan Models In Evolutionary Biology: Apple Snails (Gastropoda: Ampullariidae) As A System For Addressing Fundamental Questions, Kenneth Hayes

Department of Biology Faculty Publications

Molluscs constitute the second largest phylum in terms of the number of described species and possess a wide array of characteristics and adaptations for living in marine, terrestrial, and freshwater habitats. They are morphologically diverse and appear in the fossil record as far back as the early Cambrian (-560 mybp). Despite their high diversity and long evolutionary history, molluscs are often underused as models for the study of general aspects of evolutionary biology. Freshwater snails in the family Ampullariidae have a global tropical and subtropical distribution and high diversity with more than 150 species in nine currently recognized genera, making …

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Was Climate The Prime Releaser For Encephalization? An Editorial Comment, David Schwartzman, George Middendorf, Miranda Armour-Chelu Jul 2009

Was Climate The Prime Releaser For Encephalization? An Editorial Comment, David Schwartzman, George Middendorf, Miranda Armour-Chelu

Department of Biology Faculty Publications

Kleidon (2009) concludes that warm climates impose important constraints on the evolution of large brains relative to body size, confirming our previous hypothesis (Schwartzman and Middendorf 2000). Here we update the case for our hypothesis and present a first approximation estimate of the cooling required for hominin brain size increase using a simple model of heat loss. We conclude that Pleistocene glacial episodes were likely sufficient to serve as prime releasers for emergence of Homo habilis and Homo erectus. In addition, we propose that atmospheric oxygen levels may been an analogous constraint on insect encephalization.

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Mojave Applied Ecology Notes Summer 2009, Kevin E. Oliver, Dianne N. Bangle, E. Cayenne Engel, Lindsay P. Chiquoine, Scott R. Abella Jul 2009

Mojave Applied Ecology Notes Summer 2009, Kevin E. Oliver, Dianne N. Bangle, E. Cayenne Engel, Lindsay P. Chiquoine, Scott R. Abella

Mojave Applied Ecology Notes

BLM and wildfire protection in the Mojave, studies of the sticky ringstem flowering phenology in Lake Mead NRA, restoration work within gypsum soils, post-fire response synthesis for Mojave and Sonoran deserts

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Drosophila Risc Component Vig And Its Homolog Vig2 Impact Heterochromatin Formation, Elena Gracheva, Monica Dus, Sarah C.R. Elgin Jul 2009

Drosophila Risc Component Vig And Its Homolog Vig2 Impact Heterochromatin Formation, Elena Gracheva, Monica Dus, Sarah C.R. Elgin

Biology Faculty Research

Heterochromatin formation plays an important role in gene regulation and the maintenance of genome integrity. Here we present results from a study of the D. melanogaster gene vig, encoding an RNAi complex component and its homolog vig2 (CG11844) that support their involvement in heterochromatin formation and/or maintenance. Protein null mutations vig(EP812) and vig2(PL470) act as modifiers of Position Effect Variegation (PEV). VIG and Vig2 are present in polytene chromosomes and partially overlap with HP1. Quantitative immunoblots show depletion of HP1 and HP2 (large isoform) in isolated nuclei from the vig(EP812) mutant. The vig2(PL470) mutant strain demonstrates a decreased level of …

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American Kestrel Reproduction: Evidence For The Selection Hypothesis And The Role Of Dispersal, Karen Steenhof, Julie A. Heath Jul 2009

American Kestrel Reproduction: Evidence For The Selection Hypothesis And The Role Of Dispersal, Karen Steenhof, Julie A. Heath

Biology Faculty Publications and Presentations

Many hypotheses attempt to explain why younger, less experienced birds have relatively low reproductive output. We evaluated reproductive patterns of marked American Kestrels Falco sparverius nesting in boxes in southwestern Idaho from 1992 to 2006 to test predictions of these hypotheses. Results were consistent with the selection (differential mortality) hypothesis and did not support the constraint, restraint or recruitment hypotheses. Most known-age Kestrels nested in their first year of life, and there was no apparent short-term or long-term reproductive advantage to delayed breeding. The number of years that Kestrels nested in study area boxes ranged from 1 to 6 years, …

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Section Abstracts: Biology And Microbiology & Molecular Biology Jul 2009

Section Abstracts: Biology And Microbiology & Molecular Biology

Virginia Journal of Science

Abstracts of the Biology Section and Microbiology & Molecular Biology for the 87th Annual Meeting of the Virginia Academy of Science, May 27th-29th, 2009, Virginia Commonwealth University, Richmond, VA.

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Ontogeny And Individual Variation In The Adrenocortical Response Of Zebra Finch (Taeniopygia Guttata) Nestlings, Haruka Wada, Katrina G. Salvante, Emily Wagner, Tony D. Williams, Creagh W. Breuner Jul 2009

Ontogeny And Individual Variation In The Adrenocortical Response Of Zebra Finch (Taeniopygia Guttata) Nestlings, Haruka Wada, Katrina G. Salvante, Emily Wagner, Tony D. Williams, Creagh W. Breuner

Biological Sciences Faculty Publications

Numerous studies indicate interspecies variation in the ontogeny of the adrenocortical response in birds; however, little is known about the extent of interindividual variation in avian young. Toward this end, we examined the ontogeny and interindividual variation in the adrenocortical response in zebra finch (Taeniopygia guttata) nestlings. We measured baseline and stress-induced total (bound and free) corticosterone, corticosteroid binding globulin capacity, and resulting estimated free corticosterone levels in nestlings of four different ages ( days 5, 10, 16, and 21). In addition, we investigated the potential correlates of interindividual variation (brood size and mass). Nestlings at days 5 and 10 …

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Bushmeat Poaching Reduces The Seed Dispersal And Population Growth Rate Of A Mammal-Dispersed Tree, Jedidiah F. Brodie, Olga E. Helmy, Warren Y. Brockelman, John L. Maron Jul 2009

Bushmeat Poaching Reduces The Seed Dispersal And Population Growth Rate Of A Mammal-Dispersed Tree, Jedidiah F. Brodie, Olga E. Helmy, Warren Y. Brockelman, John L. Maron

Biological Sciences Faculty Publications

Myriad tropical vertebrates are threatened by overharvest. Whether this harvest has indirect effects on nonhunted organisms that interact with the game species is a critical question. Many tropical birds and mammals disperse seeds. Their overhunting in forests can cause zoochorous trees to suffer from reduced seed dispersal. Yet how these reductions in seed dispersal influence tree abundance and population dynamics remains unclear. Reproductive parameters in long-lived organisms often have very low elasticities; indeed the demographic importance of seed dispersal is an open question. We asked how variation in hunting pressure across four national parks with seasonal forest in northern Thailand …

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No Evolutionary Response To Four Generations Of Laboratory Selection On Antipredator Behavior Of Aedes Albopictus: Potential Implications For Biotic Resistance To Invasion, Banugopan Kesavaraju, Steven A. Juliano Jul 2009

No Evolutionary Response To Four Generations Of Laboratory Selection On Antipredator Behavior Of Aedes Albopictus: Potential Implications For Biotic Resistance To Invasion, Banugopan Kesavaraju, Steven A. Juliano

Faculty Publications – Biological Sciences

Aedes albopictus (Skuse) is an invasive container-dwelling mosquito and an important disease vector that co-occurs with the native mosquito, Aedes triseriatus (Say), and the predatory midge, Corethrella appandiculata (Grabham). Larval Ae. triseriatus show significantly greater antipredatory responses when compared to larval Ae. albopictus in the presence of predation cues from C. appendiculata. The potential for evolution of antipredatory behavioral responses to C. appendiculata in Ae. albopictus is unknown. We used a controlled laboratory selection experiment to test whether Ae. albopictus could evolve antipredatory behavioral responses to C. appendiculata predation. We subjected replicate Ae. albopictus populations to four generations of predation …

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Biotic And Abiotic Characteristics Influencing Nest Location And Trophic Relationships Of The Fungus-Growing Ant Trachymyrmex Septentrionalis (Formicidae: Attini), Jonathan Paul Howell Jul 2009

Biotic And Abiotic Characteristics Influencing Nest Location And Trophic Relationships Of The Fungus-Growing Ant Trachymyrmex Septentrionalis (Formicidae: Attini), Jonathan Paul Howell

Biological Sciences Theses & Dissertations

Trachymyrmex septentrionalis represents the only species of fungus-growing ant in the southeastern United States. T. septentrionalis cultivates a symbiotic fungus on which the ants feed. Worker ants collect plant and animal debris to feed the fungus. These ants are common in Florida, but increasingly scarce as they near the northern extent of their range in New Jersey. Colonies of T. septentrionalis occur in patches throughout Blackwater Ecological Preserve, a longleaf pine forest in southeastern Virginia. Blackwater Ecologic Preserve is a 129 hectare tract of land, located in Isle of Wight county, that is undergoing a regimen of controlled burning to …

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Ic97 Is A Novel Intermediate Chain Of I1 Dynein That Interacts With Tubulin And Regulates Interdoublet Sliding, Maureen Wirschell, Chun Yang, Pinfen Yang, Laura Fox, Haru-Aki Yanagisawa, Ritsu Kamiya, George B. Witman, Mary E. Porter, Winfield S. Sale Jul 2009

Ic97 Is A Novel Intermediate Chain Of I1 Dynein That Interacts With Tubulin And Regulates Interdoublet Sliding, Maureen Wirschell, Chun Yang, Pinfen Yang, Laura Fox, Haru-Aki Yanagisawa, Ritsu Kamiya, George B. Witman, Mary E. Porter, Winfield S. Sale

Biological Sciences Faculty Research and Publications

Our goal is to understand the assembly and regulation of flagellar dyneins, particularly the Chlamydomonas inner arm dynein called I1 dynein. Here, we focus on the uncharacterized I1-dynein IC IC97. The IC97 gene encodes a novel IC without notable structural domains. IC97 shares homology with the murine lung adenoma susceptibility 1 (Las1) protein—a candidate tumor suppressor gene implicated in lung tumorigenesis. Multiple, independent biochemical assays determined that IC97 interacts with both α- and β-tubulin subunits within the axoneme. I1-dynein assembly mutants suggest that IC97 interacts with both the IC138 and IC140 subunits within the I1-dynein motor complex and that IC97 …

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Correction For Ic97 Is A Novel Intermediate Chain Of I1 Dynein That Interacts With Tubulin And Regulates Interdoublet Sliding, Maureen Wirschell, Chun Yang, Pinfen Yang, Laura Fox, Haru-Aki Yanagisawa, Ritsu Kamiya, George B. Witman, Mary E. Porter, Winfield S. Sale Jul 2009

Correction For Ic97 Is A Novel Intermediate Chain Of I1 Dynein That Interacts With Tubulin And Regulates Interdoublet Sliding, Maureen Wirschell, Chun Yang, Pinfen Yang, Laura Fox, Haru-Aki Yanagisawa, Ritsu Kamiya, George B. Witman, Mary E. Porter, Winfield S. Sale

Biological Sciences Faculty Research and Publications

Our goal is to understand the assembly and regulation of flagellar dyneins, particularly the Chlamydomonas inner arm dynein called I1 dynein. Here, we focus on the uncharacterized I1-dynein IC IC97. The IC97 gene encodes a novel IC without notable structural domains. IC97 shares homology with the murine lung adenoma susceptibility 1 (Las1) protein—a candidate tumor suppressor gene implicated in lung tumorigenesis. Multiple, independent biochemical assays determined that IC97 interacts with both α- and β-tubulin subunits within the axoneme. I1-dynein assembly mutants suggest that IC97 interacts with both the IC138 and IC140 subunits within the I1-dynein motor complex and that IC97 …

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Srs2 Disassembles Rad51 Filaments By A Protein-Protein Interaction Triggering Atp Turnover And Dissociation Of Rad51 From Dna, Edwin Antony, Eric J. Tomko, Qi Xiao, Lumir Krejci, Timothy M. Lohman, Tom Ellenberger Jul 2009

Srs2 Disassembles Rad51 Filaments By A Protein-Protein Interaction Triggering Atp Turnover And Dissociation Of Rad51 From Dna, Edwin Antony, Eric J. Tomko, Qi Xiao, Lumir Krejci, Timothy M. Lohman, Tom Ellenberger

Biological Sciences Faculty Research and Publications

Rad51 is a DNA recombinase functioning in the repair of DNA double-strand breaks and the generation of genetic diversity by homologous recombination (HR). In the presence of ATP, Rad51 self-assembles into an extended polymer on single-stranded DNA to catalyze strand exchange. Inappropriate HR causes genomic instability, and it is normally prevented by remodeling enzymes that antagonize the activities of Rad51 nucleoprotein filaments. In yeast, the Srs2 helicase/translocase suppresses HR by clearing Rad51 polymers from single-stranded DNA. We have examined the mechanism of disassembly of Rad51 nucleoprotein filaments by Srs2 and find that a physical interaction between Rad51 and the C-terminal …

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Co2, Nitrogen, And Diversity Differentially Affect Seed Production Of Prairie Plants, J. Hillierislambers, W. S. Harpole, Stefan A. Schnitzer, D. Tilman, P. B. Reich Jul 2009

Co2, Nitrogen, And Diversity Differentially Affect Seed Production Of Prairie Plants, J. Hillierislambers, W. S. Harpole, Stefan A. Schnitzer, D. Tilman, P. B. Reich

Biological Sciences Faculty Research and Publications

Plant species composition and diversity is often influenced by early life history stages; thus, global change could dramatically affect plant community structure by altering seed production. Unfortunately, plant reproductive responses to global change are rarely studied in field settings, making it difficult to assess this possibility. To address this issue, we quantified the effects of elevated CO2, nitrogen deposition, and declining diversity on inflorescence production and inflorescence mass of 11 perennial grassland species in central Minnesota, USA. We analyzed these data to ask whether (1) global change differentially affects seed production of co‐occurring species; (2) seed production responses …

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Liana Communities In Three Tropical Forest Types In Xishuangbanna, South-West China, Zhi-Quan Cai, Stefan A. Schnitzer, Yu-Long Zheng, Frans Bongers Jul 2009

Liana Communities In Three Tropical Forest Types In Xishuangbanna, South-West China, Zhi-Quan Cai, Stefan A. Schnitzer, Yu-Long Zheng, Frans Bongers

Biological Sciences Faculty Research and Publications

Lianas are an important growth form in tropical forests around the world. However, they are relatively unknown in south-east Asia. We identified, measured and determined the climbing and dispersal modes for lianas in five 0.1-ha plots in three common forest types at the tropical-temperate transitional zone in Xishuangbanna, SW China, namely, montane forest, evergreen broad-leaved forest and seasonally wet forest. Liana diversity in the three forests combined was high; we found a total of 147 liana species, representing 48 families and 75 genera. The mean density of lianas was 3407 ha-1 and varied significantly between the three forests, with 445, …

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The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas Jul 2009

The Influence Of Environmental Factors On The Activity And Movement Of Bufo Nebulifer (Coastal Plain Toad) In A Disturbed Area, Crystal Salinas

Theses and Dissertations - UTB/UTPA

Toads in the family Bufonidae are poorly studied in southern Texas. Bufo nebulifir, a native bufonid, has been studied in its northern and southern range limits (east Texas and northern Mexico). South Texas' sub-tropical climate could impact the length of the activity period for B. nebulifer in yet unrecorded ways. This study resolves whether environmental factors correlate to Bufo nebulifer's activity, presence, and movement, using a mark-recapture method. The study was conducted for one year during February 2008 to March 2009. Environmental factors, especially rainfall and temperature were significantly correlated (PB. nebulifer . The active period of B. …

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Modulation Of Lps-Induced Activation Of Hepatic Map Kinases, Oliver Surriga Jul 2009

Modulation Of Lps-Induced Activation Of Hepatic Map Kinases, Oliver Surriga

Seton Hall University Dissertations and Theses (ETDs)

Lipopolysaccharide (LPS) is a potent inflammagen that has been found to be primarily responsible for many symptoms caused by gram-negative bacterial infections. The LPS-initiated signal transduction pathways involve several terminal kinases, mainly p42/44 mitogen-activated protein kinase (MAPK), p38 MAPK and c-Jun N-terminal kinase (JNK), ultimately leading to increased expression of genes encoding such inflammatory cytokines as interleukin (IL )-1 �. IL-6 and tumor necrosis factors (TNF)-u. In this study, the effects of age on LPS-induced activation of MAPKs in the liver of rats were examined. Results show that the basal level of phosphorylated p42/44 MAPK was increased in postnatal day …

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Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez Jul 2009

Genetic And Phenotypic Characterization Of Plant Pathogen Inhibitory Streptomyces Isolates, Uylissa A. Rodriguez

Theses and Dissertations - UTB/UTPA

Streptomyces are Gram-positive, filamentous bacteria that are readily isolated from soil and produce diverse secondary metabolites such as pigments and antibiotics. A survey of indigenous soil microbes from Rio Grande Valley agricultural soils revealed several isolates with broad inhibitory abilities against a range of soil-borne plant pathogens. The goal of this study was to characterize eleven of these potential biocontrol isolates both biochemically and genetically. Nutrient utilization profiles, 16S rDNA sequencing, and the presence of genes involved in antibiotic biosynthesis pathways (strBl, strR, strF, strN, strS and KS) on plasmids or the chromosome were investigated. Nutrient utilization profiling revealed that …

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Environmental Regulation Of Carbon Isotope Discrimination And Internal Co2 Conductance In C3 Leaves, Christopher Paul Bickford Jul 2009

Environmental Regulation Of Carbon Isotope Discrimination And Internal Co2 Conductance In C3 Leaves, Christopher Paul Bickford

Biology ETDs

Stable carbon isotopes are powerful tools for elucidating leaf- and ecosystem- level processes, and recent technological developments provide new opportunities to assess the isotopic flux during leaf gas exchange. In these studies I used a tunable diode laser spectroscope coupled to a infra-red gas analyzer to measure the isotopic composition of leaf gas exchange at high frequency in both field and greenhouse settings and assess environmental regulation of carbon isotope discrimination (Δ) and internal conductance of CO2 to sites of carboxylation (gi). I measured Δ and gi across diurnal and seasonal periods in field-grown Juniperus monosperma trees and used these …

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Description Of Thermonectus Nigrofasciatus And Rhantus Binotatus (Coleoptera:-Dytiscidae) Mating Behavior, Lauren M. Cleavall Jul 2009

Description Of Thermonectus Nigrofasciatus And Rhantus Binotatus (Coleoptera:-Dytiscidae) Mating Behavior, Lauren M. Cleavall

Biology ETDs

Models of sexual conflict predict that diving beetles should respond morphologically and behaviorally during mating events to overcome the opposing sex. Morphological and behavioral adaptations may result from pressures by one sex to overcome resistance to mating attempts of the opposite sex. Morphological data supports an evolutionary arms race in diving beetles (Dytiscidae) exhibited in a series of adaptations attributable to sexual conflict between males and females. Males of certain Dytiscinae have sucker shaped adhesion setae on their front and mid tarsi to improve attachment to the females elytra prior to and during mating, whereas females have evolved grooves, ridges, …

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Transient De-Coupling Of Photosynthesis And Stomatal Conductance In Response To Leaf Primary Vein Cut In Helianthus Annuus, Laura Elizabeth Green Jul 2009

Transient De-Coupling Of Photosynthesis And Stomatal Conductance In Response To Leaf Primary Vein Cut In Helianthus Annuus, Laura Elizabeth Green

Biology ETDs

Control of stomatal aperture is the primary way plants regulate gas exchange in the short-term, but what triggers stomatal responses to water stress is still debated. Chlorophyll-a fluorescence imaging, local leaf temperature, and gas exchange were measured simultaneously following a cut to primary leaf vein of Helianthus annuus to access the effect of local leaf xylem cavitation on leaf function. The treatment was repeated under 3 different vapor pressure deficit (VPD) conditions. Surprisingly, photosynthesis (A) and stomatal conductance (gs) responded inversely immediately following the treatment, indicating that A was not CO2 limited by stomatal closure. Comparisons of fluorescence images and …

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