Digital Commons Network^™

Denitrification, Nutrient Regeneration And Carbon Mineralization In Sediments Of Galveston Bay, Texas, Usa, Andrew R. Zimmerman, Ronald Benner

Faculty Publications

Rates of benthic denitrification, oxygen consumption and nutrient regeneration were measured during winter, spring and summer in Galveston Bay (Texas, USA) sediments. Denitrification ranged from 0 to 47 µmol N₂ m^-2 h^-1 with maximal rates generally occurring in the summer and the upper estuary. Oxygen consumption rates ranged from 38 µmol O₂ m^-2 h^-1 in the winter to 353 µmol O₂ m^-2 h^-1 in the summer and were correlated with denitrification rates. Variations in bay water temperature accounted for 52 % of the variability associated with denitrification rates whereas only 28% …

The Identification, Distribution, Impacts, Biology And Management Of Noxious Rangeland Weeds, Roger L. Sheley

All U.S. Government Documents (Utah Regional Depository)

This document provides a discussion of the biology and management of exotic rangeland weeds which are a threat to native ecosystems of the western United States. Chapter 1 describes a generalized approach for managing noxious weed infested rangeland, while Chapter 2 focuses on preventing noxious weed invasion. In some cases, noxious weeds readily invade riparian areas, and because of the sensitive nature of these ecosystems Chapter 3 is devoted to riparian weed management. The following 13 chapters describe the identification, origin, history, distribution, potential invasion, impacts, biology and ecology, and management of specific noxious rangeland weeds.

1994 Ieee Computer Society Press Reprint, James W. Brunt

Long Term Ecological Research Network

Effective management of ecological research data can insure the security and accessibility of data that cannot be collected again under the same conditions and plays a key role in every aspect of the research project from experimental design to publication. Commercial relational database management software, developed an adequate solution for long-term scientific data management. An archive file format provides the standard around which a data file management system is implemented. The system works within the parameters of existing components of the operating system software. Data filters and data engines are used to communicate data to and from applications. This paper …

On Lexical And Syntactic Processing Of Bangla Language By Computer., Probal Sengupta Dr.

Doctoral Theses

A distinctive intelligent trait of human beings is the ability to carry out meaningful communication through language. The communication may be direct as in spoken conversation or indirect as in written form, through the audio-visual media, etc. Linguistic ability in humans have fascinated scholars ever since man first learnt to use language. Linguistics, the branch of study involved in studying the nature of human linguistic communication, is perhaps as old as language itself. The invention of the computer added a new dimension to linguistics. Making the computer emu- late human linguistic behaviour was taken up as a challenge by computer …

Working Draft, University Of South Florida Botanical Garden Blueprint For The Future, August 1994, Frederick B. Essig

USF University Archives and Documents

Working draft of the University of South Florida Botanical Garden Blueprint for the Future dated August 1994. Topics include overview of and history of the University of South Florida Botanical Garden, facilities, funding, staffing, master plan for the Garden, mission statement, site maps, and proposal for tropical plant Conservatory.

Determination Of The Transcriptional Start Site And In Vitro Translation Of The A-11 Mrna In Dictyostelium Mucoroides., Weilie Ma

Student Work

Previous studies in Dictyostelium mucoroides have sought to identify genes specific for macrocyst development. A gene named A-11, previously isolated as a cDNA, appears to be one of these genes. The cDNA of A-11 was made from macrocyst (8h) mRNA, and Northern analysis did not detect any A-11 transcript during sorocarp formation. The cDNA sequence for A-11 has been obtained. To determine if the cDNA of A-11 is complete, primer extension and RNA sequencing were performed using an end-labeled oligonucleotide complementary to positions 1221 to 1239 of A-11 cDNA. The two longest extension products were 102 bases in 101 bases. …

Characterization Of Cdnas Encoding Potential Drosophila Acetylcholine Receptors., Gang Wu

Student Work

In the central nervous system (CNS) of insects and other invertebrates, acetylcholine (Ach) functions as a major neurotransmitter and acts upon a number of different types of receptors. One approach is to the identification of acetylcholine receptors (AChR) is to use cross-homology between vertebrate and invertebrate AChRs. To this end, monoclonal antibodies (mAbs) to the well-characterized nicotinic vertebrate AChR that cross-react with Drosophila tissues have been developed. One of them, mAb 16.42, was used to screen a lambda-ZAP expression vector library in which Drosophila adult head cDNAs were inserted, and three cDNAs that may encode nAChRs were identified.

Activity And Distribution Of Attached Bacteria In Chesapeake Bay, Peter Griffith, Fuh-Kwo Shiah, Kathryn Gloersen, Hugh W. Ducklow, Madilyn Fletcher

Faculty Publications

The purpose of this study was to further our understanding of the role of particle-associated bacteria in phytoplankton degradation in the Chesapeake Bay, USA, and to identify environmental parameters that control production by free and particle-associated bacteria. Surface and bottom waters at 10 stations along the length of the Bay were sampled over a 2 yr period. Samples were analyzed for temperature, salinity, chlorophyll, phaeophytin, particulate protein, thymidine incorporation (an estimate of bacterial growth rate), and bacterial total direct counts. Results demonstrated that freeliving bacteria were responsible for most of the total bacterial production, which was correlated with temperature and …

Lter Correspondence & Letters, Jerry F. Franklin

Long Term Ecological Research Network

1st. Letter written by Jerry F. Franklin, chair of LTER Network, addressed to David Greenland of the department of Geography. Franklin extends an invitation to the upcoming Coordinating Committee meeting taking place from October 19-21.

2nd. Letter written by Jerry F. Franklin, chair of LTER Network, addressed to Joshua Greenberg of he College of Forest Resources. Franklin extends an invitation to the upcoming Coordinating Committee meeting taking place from October 19-21.

3rd. Letter written by Jerry F. Franklin, chair of LTER Network, he writes on the significant decisions taken place over the LTER/CC meeting held on April 22-24.

4th. Letter …

Report, University Of South Florida Botanical Garden Mission Statement And Summary Of Activities And Goals, March 1994, Frederick B. Essig

USF University Archives and Documents

Mission statement and summary of activities and goals of the University of South Florida Botanical Gardens dated March 1994. Topics include goals, communities served, facilities, educational outreach, collection development priorities, staffing, and design.

Multiple Modes Of Asexual Reproduction By Tropical And Subtropical Sea Star Larvae: An Unusual Adaptation For Genet Dispersal And Survival, William Jaeckle

Scholarship

Sea star larvae (Echinodermata: Asteroidea), collected from the subtropical Northwest Atlantic Ocean, exhibited three distinct modes of asexual reproduction. A number of different bipinnariae and brachiolariae reproduced by paratomous cloning of the posterolateral arms. This morphogenesis was identical to that of larvae assignable to the genus Luidia. A second mode of asexual reproduction involves the autotomization of an anterior portion of the preoral lobe. Primary larvae with preoral lobes of varying sizes and free-swimming preoral lobes of various stages of morphological development were simultaneously collected. The free-swimming preoral lobes developed complete digestive systems and ultimately assumed the form of …

G94-1220 Controlling Ticks, John B. Campbell, Gustave D. Thomas

University of Nebraska-Lincoln Extension: Historical Materials

Identification and control of ticks common to Nebraska.

Ticks are members of the same phylum (Arthropoda) of the animal kingdom as insects, but are in a different class (Arachnida). The main difference is the body of a tick is composed of only two sections while insect bodies have three sections.

There are over 800 species of ticks, 100 of which are important to man and animals because of economic losses or disease transmission. Fortunately in the United States, only about 12 species are economically important because they transmit disease organisms (viral, bacterial, protozoan, and rickettsial) or cause economic losses to …

Status, Biology, And Management Of Ferruginous Hawks: A Review, United States Bureau Of Land Management

All U.S. Government Documents (Utah Regional Depository)

The purpose of this paper is to promote the wise management of ferruginous hawk habitat to enable the species to maintain or increase its population levels. Twenty-seven recommendations are presented, supported by reviews of population status, nesting chronology, nest site characteristics, food habits, and spatial considerations. This is followed by discussion of the impacts of human activities on the ferruginous hawk, such as urbanization, cultivation, grazing, land conversion, poisoning and small mammal control, mining, fire and fire management, and other activities.

Mechanisms Of Adenosine Receptor-Mediated Inhibition Of Tachykinin Release In The Enteric Nervous System, Robert Michael Broad

Digitized Theses

Interactions with the A{dollar}\sb1{dollar} subtype of adenosine receptors in the enteric nervous system (ENS) have previously been shown to lead to inhibition of ACh release from nerves of the myenteric plexus. Similar inhibition of release of the major contractile neuropeptide, substance P (SP), has only been demonstrated indirectly. Although the mechanism of adenosine-mediated neuroinhibition in the CNS has been elucidated, similar mechanisms in the ENS remain unknown.;The objective of this thesis was to directly examine the inhibitory effects of A{dollar}\sb1{dollar} receptor interactions on the release of substance P from enteric neurons and to identify the intracellular mechanisms involved in this …

Central Neuronal Circuits Involved In The Reflex Control Of The Cardiovascular System, Douglas James Mckitrick

Digitized Theses

To reveal central nervous system (CNS) structures involved in the reflex control of the cardiovascular system, the distribution of Fos protein-like immunoreactivity (FLI) was examined in the brains of urethane anesthetized rats following stimulation of the aortic depressor (ADN) and femoral (FN) nerves. First, the ADN was cut bilaterally in 13 rats, the central ends were placed on stimulating electrodes and stimulated for 1 h. CNS sections were incubated in anti-Fos antibody and prepared immunohistochemically for visualization of FLI. Label was found on the side ipsilateral to the side of stimulation in discrete nuclei in the hindbrain, midbrain and forebrain …

Thyroid Hormone-Induced Changes In Gene Expression In The Bullfrog, Rana Catesbeiana, Tadpole Liver, Caren Christiane Helbing

Digitized Theses

During spontaneous and 3,5,3{dollar}\sp\prime{dollar}-triiodothyronine (T{dollar}\sb3{dollar})-induced metamorphosis, the Rana catesbeiana tadpole undergoes an obligatory transition from ammonotelism to ureotelism. Although this ultimately results from marked increases in the activities and/or de novo synthesis of urea cycle enzymes in the liver, the precise molecular means governing this tissue-specific response are unknown. T{dollar}\sb3{dollar} acts primarily on gene transcription by interacting with specific nuclear receptors (TRs). Recent reports suggest a strong correlation between TR{dollar}\beta{dollar} mRNA up-regulation and gross metamorphic changes. To address whether or not this same relationship exists within a T{dollar}\sb3{dollar}-responsive tissue, cDNA sequences encoding three Rana catesbeiana urea cycle enzymes, carbamyl phosphate …

Topics In Forward Stepwise Logistic Regression, Kang-In Lee

Digitized Theses

In this dissertation, five topics related to the process and prediction of forward stepwise logistic regression are investigated.;Forward stepwise logistic regression is involved with selection and stopping criteria. Seven selection criteria are used: the likelihood ratio statistic, Lawless and Singhal (1978)'s statistic, the Wald statistic, the score statistic, Peduzzi, Hardy, and Holford (1980)'s statistic, Lee and Koval's statistic (LK), and a sweep operator's statistic (SW). Five stopping criteria are used: {dollar}\chi\sp2{dollar} test based on a fixed {dollar}\alpha{dollar} level, minimum value of ERR, minimum value of the C{dollar}\sb{lcub}\rm p{rcub}{dollar} statistic (Hosmer, 1989), minimum value of the Akaike information criterion (Akaike, 1974), …

Binocular Vision And The Kinematics Of Human Prehension, Philip Raymond Servos

Digitized Theses

A series of experiments was devised to examine the contribution of binocular depth and distance cues to skilled reaching and grasping movements in humans. These movements were monitored using a high resolution opto-electronic recording device.;In the initial experiment, subjects reached out and grasped oblong blocks under conditions of either monocular or binocular vision. Kinematic analyses revealed that grasping movements made under monocular viewing conditions showed longer movement times, lower peak velocities, proportionately longer deceleration phases, and smaller grip apertures than movements made under binocular viewing. In short, subjects appeared to be underestimating the distance of objects (and as a consequence, …

Tests Of The Effect Of Treatment In Stratified Cluster Randomization Trials, Neil S. Klar

Digitized Theses

It is becoming increasingly common for epidemiologists to consider randomizing intact social units (e.g. families, schools, communities) rather than individuals in experimental trials. Reasons are diverse, but include administrative convenience, a desire to reduce the effect of treatment contamination and the need to avoid ethical issues that might otherwise arise. Dependencies among cluster members typical of such designs must be considered when determining sample size and analysing the resulting data.;The primary focus of this thesis is on comparisons of tests of the effect of treatment in trials where clusters are randomly assigned to treatment groups after stratifying on cluster-level baseline …

Pre-Cataractous Loss Of Cellular Antioxidants And Atp In The Diabetic Rat Lens, Kenneth Patrick Mitton

Digitized Theses

The in vivo streptozotocin-induced diabetic rat model of cataract is one of the oldest animal models of cataractogenesis available, however investigation of diabetic lenses before the formation of liquid-filled vacuoles, is lacking. Using analysis specific for glutathione, it was found that pre-vacuolar diabetic rat lenses lost glutathione (GSH) (85%) compared to normal lenses. Glutathione disulphide (GSSG) did not appear in diabetic lenses. Lens ascorbate concentration was also decreased by 48% in pre-vacuolar diabetic lenses compared to normal lenses.;ATP loss, previously demonstrated only in post-vacuolar diabetic lenses, was found in pre-vacuolar diabetic lenses compared to normal lenses. It is possible that …

Ribosomal Rna-Protein Interactions In Escherichia Coli: Binding Of Ribosomal Protein S20 To 16 Srrna And Processing Of 5 Srrna By Ribonuclease E, Robert Stephen Cormack

Digitized Theses

Specific ribonucleotides within the 5{dollar}\sp\prime{dollar} domain of 16 S rRNA were altered by deletion and/or substitution by site-directed mutagenesis of cloned DNA to assess the importance of these particular residues in defining the binding site for ribosomal protein S20. Gel filtration and sucrose gradient centrifugation were employed to measure the binding of S20 to synthetic transcripts containing various alterations. RNA transcripts containing residues 1-402 were sufficient for optimal S20 binding. The removal or the substitution of bulges at 250-251, 278-280 or 321/332 reduced S20-16 S rRNA association significantly. A variety of mutations was introduced into the stem and loop residues …

Transcriptional Regulation And Autogenous Control Of The Genes For The Beta And Beta' Subunits Of Escherichia Coli Rna Polymerase, Keith L. Steward

Digitized Theses

The transcriptional control of the two genes rpoB and rpoC encoding the {dollar}\beta{dollar} and {dollar}\beta\sp\prime{dollar} subunits of RNA polymerase was examined in a systematic fashion in order to evaluate the contribution of such control to the autogenous regulation of RNA polymerase synthesis. Numerous transcriptional fusions were constructed by placing restriction fragments of the rplKaJLrpoBC gene cluster upstream of the lacZ reporter gene on {dollar}\lambda{dollar} phage vectors. Assaying {dollar}\beta{dollar}-galactosidase activity from monolysogens of the recombinant phage permitted a high resolution scan of the gene cluster for transcriptional controls. The results precisely quantitate the efficiencies of two strong promoters, rplKp and rplJp, …

Corticosteroid-Binding Globulin In Fetal And Adult Sheep, Edward Terry Berdusco

Digitized Theses

In the ovine fetus, plasma cortisol is bound by its high affinity binding protein corticosteroid-binding globulin (CBG). Plasma CBG concentrations increase during late gestation, but the stimulus for this increase and its consequences in the fetal sheep are not known. These studies were undertaken to examine the stimulus for an increase in fetal plasma CBG, the mechanism of this increase, and the physiological significance of the increase.;Chronically catheterized fetal and adult sheep were used to examine the changes in late gestation of plasma CBG concentrations, plasma CBG glycosylation, total and free cortisol, and effects of glucocorticoids on plasma CBG. An …

Uterine Vascular Permeability, Extracellular Fluid Volume And Blood Flow Following Deciduogenic Stimulation Of Rats, Gavin Scot Hamilton

Digitized Theses

The present study examined the possible importance of uterine vascular permeability (VP), extracellular fluid volume (ECFV) and blood flow (BF) in the enhanced accumulation of serum proteins in uterine tissue destined to undergo decidualization. This process is identifiable by endometrial blueing after intravenous (i.v.) injection of Evans blue dye. It was hypothesized that VP, ECFV and BF must increase to promote the enhanced intrauterine accumulation of serum proteins and that these uterine vascular and perivascular changes require optimal endometrial sensitization and prostaglandins (PGs).;ECFV was estimated by the uterine volume of distribution of i.v. injected {dollar}\sp{lcub}51{rcub}{dollar}Cr-EDTA, VP by the rate of …

The Role Of Locally-Produced Growth Factors On Human Placental Growth And Invasion, Jeffrey John Lysiak

Digitized Theses

ABSTRACT HAS BEEN ARCHIVED 07/12/97;

The Molecular Genetics Of Mouse Catalase, Dorothy L. Reimer

Digitized Theses

Catalases provide cellular protection against the effects of oxygen free radicals. In mice, catalase is coded for by a single gene, Cas-1, located on Chromosome 2, 48 cM from the centromere. A number of genetic strains with variable tissue-specific expression patterns permit the evaluation of molecular mechanisms for the regulation of this housekeeping enzyme.;Transcriptional and post-transcriptional mechanisms of catalase regulation were investigated. The first complete cDNA sequence of Cas-1 is presented and includes 1584 nucleotides encoding 528 amino acids. In addition, 659 bp of 5{dollar}\sp\prime{dollar} genomic upstream region of Cas-1 were sequenced revealing a "CG island", two putative CCAAT boxes, …

Molecular Taxonomy Of The Sporopachydermia Cereana Complex, Jody Elise Kaden

Digitized Theses

The delimitation of phenotypically similar species is often problematic. Increasingly, molecular methods of taxonomy are called upon to resolve closely related taxa. DNA reassociation is a method capable of distinguishing between sibling species. This method has been used to clarify the genetic group boundaries that exist within the Sporopachydermia cereana species complex.;The yeast genus Sporopachydermia currently comprises three species, Sp. lactativora, Sp. quercuum, and Sp. cereana. These yeasts are unusual ascomycetes that assimilate inositol, lack the ability to ferment sugars, and may give a positive diazonium blue B reaction. Preliminary studies indicated that Sp. cereana contained 4 or 5 genetically …

The Roles Ofmrna Stability And Secondary Structure In The Differential Expression Of The Escherichia Coliunc Genes, Ashok M. Patel

Digitized Theses

The genes of the Escherichia coli unc operon are differentially expressed according to the subunit requirements in the mature {dollar}\rm F\sb1F\sb0{dollar}-ATPase complex. The experiments described in this thesis were designed to elucidate how mRNA processing, degradation, and structure regulate the differential expression of the unc genes. Studies were focused on the uncBE region, near the 5{dollar}\sp\prime{dollar} end of the transcript, and uncDC region at the 3{dollar}\sp\prime{dollar} end of the transcript.;Northern blot analysis of uncC mRNA, the last gene of the operon, suggested that the unc transcription terminator protected the uncC message against exonucleolytic degradation, and that this stabilization was important …

The Ribosomal Rna Phylogeny Of Kluyveromyces, Ming Zhan

Digitized Theses

The Phylogeny of Kluyveromyces was studied by partial sequencing the ribosomal RNA gene.;The gene coding for the divergent domain II (D2) of nuclear LSU rRNA was amplified by polymerase chain reaction (PCR) for Kluyveromyces and other yeasts. The PCR products were cloned and sequenced. The sequence data were analyzed by the neighbour-joining, Fitch-Margoliash, maximum likelihood, parsimony and compatibility methods of phylogenetic inference. The final conclusions of the analyses were drawn from the consensus of the various phylogenies confirmed to be reliable by bootstrap tests.;The genus Kluyveromyces is polyphyletic. The species of this genus probably evolved from three distinct ancestries: one …

Developmental, Hormonal And Neural Aspects Of Spatial Learning In Rodents, Liisa Ann Galea

Digitized Theses

Developmental, neural and hormonal aspects of sexually-dimorphic spatial learning (Morris water-maze) in meadow voles (Microtus pennsylvanicus) and deer mice (Peromyscus maniculatus) were examined in this thesis. The first study examined seasonal changes in sexually-dimorphic spatial ability in adult deer mice. A sex difference in spatial learning favoring males was evident during breeding season, while there was no evidence of a sex difference during the non-breeding season. Male spatial performance was increased during the breeding season relative to the non-breeding season while the reverse pattern was observed in females. The second study examined developmental changes in spatial learning in voles. Postweaning …