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Caprine Sperm Cells As Vectors For Gene Transfer., Yongxin Sun Jan 1997

Caprine Sperm Cells As Vectors For Gene Transfer., Yongxin Sun

LSU Historical Dissertations and Theses

Goat sperm cells were used as a model to evaluate sperm-mediated gene transfer. Fresh and frozen-thawed goat sperm cells were co-incubated with radio-labelled foreign DNA. After 10 extensive washings, the compacted sperm retained foreign DNA. Confocal microscopy confirmed that the position on the sperm cell responsible for binding of foreign DNA was located in both the anterior and the posterior heads of caprine sperm cells. Furthermore, confocal longitudinal sections of the sperm cells showed that foreign DNA had penetrated into goat sperm nuclei. In this study, 37% of the fresh goat sperm and 33% of the frozen-thawed goat sperm cells …

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Relative Rates Of Molecular Evolution In Rodents And Their Symbionts., Theresa Ann Spradling Jan 1997

Relative Rates Of Molecular Evolution In Rodents And Their Symbionts., Theresa Ann Spradling

LSU Historical Dissertations and Theses

The focus of this dissertation is the relative tempo of molecular evolution among organisms of varying levels of relatedness. Because this is a rapidly expanding area of research, Chapter 1 is devoted to a review of the current state of knowledge on rates of molecular evolution. In Chapter 2, I present an analysis of relative rates of evolution among several distantly related rodents. The heterogeneity in rate of evolution of the cytochrome b gene observed here cannot be explained by metabolic rate, body size, generation time, or nucleotide-generation time. Likewise, there is no evidence that these differences in rate of …

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Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar Jan 1997

Cloning And Expression Of Capsid Proteins Of Hepatitis A Virus In Escherichia Coli., Lingaiah Chandrashekar

LSU Historical Dissertations and Theses

Hepatitis A virus (HAV), the causative agent of food and water borne acute hepatitis worldwide, is very difficult and expensive to propagate in tissue culture. Large scale production of HAV proteins in E. coli by recombinant DNA techniques would be invaluable for antisera production, biochemical analyses and in developing sensitive diagnostic tests. Therefore, PCR amplified DNA fragments encoding the HAV capsid proteins were cloned individually into prokaryotic expression vectors for production of either recombinant fusion or non-fusion proteins. Cloning and expression of HAV capsid genes, which induced toxic effects in certain host E. coli, was tolerated better by protease-deficient host …

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Dna Wrapping And The Nature Of Interaction Between E. Coli Rna Polymerase And Promoter Dna., Parisa Jazbi Jan 1997

Dna Wrapping And The Nature Of Interaction Between E. Coli Rna Polymerase And Promoter Dna., Parisa Jazbi

LSU Historical Dissertations and Theses

Regulation of transcription most often occurs at the stage of initiation. RNA polymerase binding to the transcription start site, the promoter, is influenced by many nucleotide sequence elements. The predominant recognition sequences are those bound by the $\sigma$ subunit of RNA polymerase located at $-$10 and $-$35 relative to initiation site of most promoters. Another element involved in this regulation is intrinsic DNA curvature. In this study, the contribution of intrinsically curved DNA immediately upstream of the promoter to the interaction between Escherichia coli RNA polymerase and this DNA was examined. DNase I footprinting analysis confirmed that RNA polymerase wraps …

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Pest Status And Management Of Beet Armyworm, Spodoptera Exigua (Hubner), On Cotton In Louisiana., Victor James Mascarenhas Jan 1997

Pest Status And Management Of Beet Armyworm, Spodoptera Exigua (Hubner), On Cotton In Louisiana., Victor James Mascarenhas

LSU Historical Dissertations and Theses

Field cage studies were conducted to measure the effects of late season beet armyworm, Spodoptera exigua (Hubner), infestations (0, 1, 3, and 6 egg masses per 5.1 row m) on defoliation, fruit damage, and yield of cotton. Light penetration through the canopy was significantly higher in infested plots. Although a trend for increased numbers of damaged fruiting forms with increases in egg mass density was observed, there were no significant differences between infested and control plots. There were no significant differences in the cumulative number of shed fruiting forms or yield between infested and control plots. Field tests were conducted …

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Metamorphosis Of The Hawaiian Stream Goby Sicyopterus Stimpsoni: A Structural, Functional, And Behavioral Analysis., Heiko Lars Schoenfuss Jan 1997

Metamorphosis Of The Hawaiian Stream Goby Sicyopterus Stimpsoni: A Structural, Functional, And Behavioral Analysis., Heiko Lars Schoenfuss

LSU Historical Dissertations and Theses

The endemic goby Sicyopterus stimpsoni is unique among five species of Hawaiian freshwater fishes because it undergoes rapid metamorphosis of cranial structures during postlarval development. These fishes are amphidromous and return after a prolonged stay in the ocean to streams where they are confined to estuaries until completion of cranial restructuring. Within 48 hours after entering fresh water, head width increases significantly, while total length and head length remains unchanged. Weight decreases by approximately 15% during this period. The upper lip enlarges greatly, and the mouth position shifts from terminal to nearly ventral. Shape analysis of radiographs taken from a …

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Aerenchyma Development In The Freshwater Marsh Species Sagittaria Lancifolia L., Elisabeth Ellen Schussler Jan 1997

Aerenchyma Development In The Freshwater Marsh Species Sagittaria Lancifolia L., Elisabeth Ellen Schussler

LSU Historical Dissertations and Theses

Aerenchyma tissue consists of gas channels that provide a pathway for O$\sb2$ transport to waterlogged roots. Aerenchyma gas spaces are formed by cell separation or cell lysis during development. Light microscopy was used to determine how aerenchyma develops in Sagittaria lancifolia, a freshwater marsh species, when plants were grown in hydroponic solution. Petiole aerenchyma was formed by cell separation caused by differential cell expansion and division. In the root cortex, certain radial files of cells separated slightly from adjacent files and then lysed to form gas spaces. Development of root aerenchyma was characterized in S. lancifolia, Zea mays, and Oryza …

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Law And Biology: Toward An Integrated Model Of Human Behavior, Owen D. Jones Jan 1997

Law And Biology: Toward An Integrated Model Of Human Behavior, Owen D. Jones

Vanderbilt Law School Faculty Publications

As first year law students unhappily discover, the meaning of "law" is frustratingly protean, shifting by usage and user. Depending on whom you ask, law is a system of rules, a body of precedents, a legislative enactment, a collection of norms, a process by which social goals are pursued, or some dynamic mixture of these. Law's principal purpose is to define and protect individual rights, to ensure public order, to resolve disputes, to redistribute wealth, to dispense justice, to prevent or compensate for injury, to optimize economic efficiency, or perhaps to do something else. And yet one thing is irreducibly …

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Evaluation Of The Effects Of Afff Inputs On The Vip Biological Nutrient Removal Process And Pass-Through Toxicity. Phase 1a. Volume Ii. Appendix Vii. Acute Toxicity Test Results, Mujde Erten-Unal, Gary C. Schafran Jan 1997

Evaluation Of The Effects Of Afff Inputs On The Vip Biological Nutrient Removal Process And Pass-Through Toxicity. Phase 1a. Volume Ii. Appendix Vii. Acute Toxicity Test Results, Mujde Erten-Unal, Gary C. Schafran

Civil & Environmental Engineering Faculty Publications

This report discusses the results of a bench scale study conducted to evaluate the potential inhibitory effects of untreated AFFF wastewater to the Virginia Initiative Plant VIP biological nutrient removal process. A bench-scale study was conducted to evaluate the potential inhibitory effects of untreated AFFF wastewater to the nitrification process of the Virginia Initiative Plant biological nutrient removal system. Under this testing, bench-scale reactors simulating the nitrification process were loaded at various AFFF concentrations and the influence on the process performance was evaluated. The purpose of this effort was to determine the level of AFFF that could be incorporated into …

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The Effects Of Adrenergic And Cholinergic Stimulation On Skin Gland Secretions In The Dwarf African Frog Hymenochirus Curtipes, Daniel H. Gong Jan 1997

The Effects Of Adrenergic And Cholinergic Stimulation On Skin Gland Secretions In The Dwarf African Frog Hymenochirus Curtipes, Daniel H. Gong

University of the Pacific Theses and Dissertations

Many studies have been done on the neural control of serous gland secretion in the skin of frogs and newts. However, no studies have been published on the effects of adrenergic and cholinergic neurotransmitters on the sexually dimorphic breeding glands of male frogs. The present study examined the effects of neurotransmitters on the serous and breeding glands of Hymenochirus curtipes. Explants of dorsal skin and postaxial skin (containing whole breeding glands) were incubated in vitro with epinephrine, norepinephrine or acetylcholine for 30 minutes. The explants were then preserved and examined histologically for signs of secretion. The area and perimeter of …

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Yellagonga Wetlands: A Study Of The Water Chemistry And Aquatic Fauna, Adrianne Kinnear, Patrick Garnett, Hugo Bekle, K. Upton Jan 1997

Yellagonga Wetlands: A Study Of The Water Chemistry And Aquatic Fauna, Adrianne Kinnear, Patrick Garnett, Hugo Bekle, K. Upton

Research outputs pre 2011

Wetlands worldwide are continually threatened by urbanisation and Western Australia is no exception. Since European settlement in 1829, it has been estimated that at least 75% of the wetlands of the Swan Coastal Plain have disappeared (Halse, 1988). The remaining 25% continue to be threatened by eutrophication and pollution, changes in hydrology and water level patterns, clearing of riparian vegetation, aesthetic disruption and weed invasion (CALM, 1980; Davis and Rolls, 1987; Wrigley et al., 1991; Balla and Davis, 1995). These degradation components are interrelated and largely the consequence of the extensive removal of surrounding vegetation...

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Integrated Pest Management Tactics For Control Of Cabbage Looper And Diamondback Moth In Cabbage., Paul Wesley Ivey Jan 1997

Integrated Pest Management Tactics For Control Of Cabbage Looper And Diamondback Moth In Cabbage., Paul Wesley Ivey

LSU Historical Dissertations and Theses

Population density estimates, yield data, damage rating, and marketability of cabbage were used to assess the effectiveness of integrating several control tactics--an action threshold, host plant resistance, intercropping (companion planting), microbial control, and pesticide use reduction--for managing the diamondback moth (DBM), Plutella xylostella (L.), and the cabbage looper (CL), Trichoplusia ni (Hubner), in cabbage and in protecting beneficial arthropods. An action threshold of six DBM larvae per plant was inadequate for making insecticide application decisions because cabbage plots treated based on this action threshold had significantly higher densities of CL and DBM larvae, higher damage rating and yield loss, and …

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The Evolution Of Landscapes And Lineages In Pitcher Plants And Their Moths., Margaret Ellen Oard Jan 1997

The Evolution Of Landscapes And Lineages In Pitcher Plants And Their Moths., Margaret Ellen Oard

LSU Historical Dissertations and Theses

Pitcher plants and pitcher plant moths exhibit two prominent themes in the long evolutionary history between plants and insects. These themes are carnivory and herbivory. In pitcher plants, the leaf has been modified into an elegant pitfall trap enabling these plants to subsist at both the producer and consumer trophic levels. Of the numerous insect species intimately associated with pitcher plants, pitcher plant moths are the only inquilines which have evolved the capacity to disrupt both the carnivore and photosynthetic functions of the host plant. The carnivorous habit, considered an adaptation for nutrient deficient environments, has contributed to species radiations …

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Activity Of Selected Insecticides Against The Soybean Looper, Pseudoplusia Includens (Walker), Using An Artificial Diet Overlay Bioassay Technique: Dosage Mortality, Discriminating Concentrations, And Resistance Monitoring., Rosanne Nicholson Mascarenhas Jan 1997

Activity Of Selected Insecticides Against The Soybean Looper, Pseudoplusia Includens (Walker), Using An Artificial Diet Overlay Bioassay Technique: Dosage Mortality, Discriminating Concentrations, And Resistance Monitoring., Rosanne Nicholson Mascarenhas

LSU Historical Dissertations and Theses

Diet overlay bioassays were conducted, evaluating insecticides requiring ingestion, on 3rd instar soybean loopers, Pseudoplusia includens (Walker). Laboratory reference and field strains were exposed to several insecticide concentrations, and LC$\sb{50}$s were compared. Field strains had significantly greater LC$\sb{50}$s than the reference strain when evaluating standard insecticides. Bioassays with experimental insecticides revealed few differences among strains. The diet overlay technique appears to be a viable method for monitoring insecticide resistance to these insecticides. Insecticide discriminating concentrations were determined using diet overlay bioassays to evaluate susceptibility of field and F1 generation, laboratory and field soybean looper strains. Field strains, exposed to permethrin …

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Phylogeny Of The Characeae (Charophyta) And Biogeography Of Chara (Characeae) Inferred From Ribosomal Rna Genes., Susan T. Meiers Jan 1997

Phylogeny Of The Characeae (Charophyta) And Biogeography Of Chara (Characeae) Inferred From Ribosomal Rna Genes., Susan T. Meiers

LSU Historical Dissertations and Theses

This dissertation examined generic, subsection, and infraspecific aspects of the phylogeny of the Characeae, and biogeography of Chara subsections and Chara haitensis. These relationships were inferred from cladistic and maximum likelihood analyses of sequence data for 18S and ITS regions of nuclear-encoded ribosomal RNA genes. Morphologically-based phylogenetic hypotheses of Wood and Imahori (1965) and Khan and Sarma (1984) concerning the six extant members of Characeae were tested. The analyses supported: monophyly of family Characeae, tribe Chareae, and of Lamprothamnium; placement of Nitellopsis basal to tribe Chareae; and an unresolved relationship between Lamprothamnium and Chara. Neither the hypothesis of Wood and …

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Development Of Diagnostic Technology For Monitoring Pyrethroid Resistance Mechanisms In The Tobacco Budworm, Heliothis Virescens (F.)., Guomin Shan Jan 1997

Development Of Diagnostic Technology For Monitoring Pyrethroid Resistance Mechanisms In The Tobacco Budworm, Heliothis Virescens (F.)., Guomin Shan

LSU Historical Dissertations and Theses

Metabolic resistance was studied in the tobacco budworm, Heliothis virescens (F.) using pyrethroid analogs, insecticide synergists, and an in vitro assay with $\sp{14}$C-cypermethrin. In initial studies, the phenoxybenzyl moiety of conventional pyrethroid, a major site of oxidative metabolism in resistant H. virescens, was replaced with P450 monooxygenase-inhibiting or oxidatively blocked groups. Isomers (1R/1S, cis/trans) of the resulting chrysanthemates were separated and tested as insecticides against pyrethroid-susceptible (LSU) and -resistant H. virescens (Pyr-R). A number of compounds with pentafluorophenyl (PFP), methylenedioxyphenyl (MDP), and propargyloxyphenyl (PP) groups were insecticidal and activity was dependent on both geometric and stereochemical configuration of the acid …

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Rickettsia Felis, A Newly Discovered Rickettsia Associated With The Cat Flea (Ctenocephalides Felis Bouche)., Jimmy Wedincamp Jr Jan 1997

Rickettsia Felis, A Newly Discovered Rickettsia Associated With The Cat Flea (Ctenocephalides Felis Bouche)., Jimmy Wedincamp Jr

LSU Historical Dissertations and Theses

A study was performed to determine the life cycle of Rickettsia felis, a novel bacterium associated with cat fleas (Ctenocephalides felis Bouche). Cat flea populations maintain R. felis in successive generations by efficient transovarial transmission. Transovarial transmission was demonstrated in our study up to 12 generations. The mean infection rate for the progeny of fleas maintained on both cats and an artificial membrane system were comparable (64.3% and 58% respectively). Cats with no prior exposure to fleas were exposed to fleas infected with Rickettsia felis and monitored monthly for seroconversion via IFA. Blood samples were assayed for the presence of …

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The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo Jan 1997

The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo

LSU Historical Dissertations and Theses

The extracellular capsule polysaccharide (CPS) of Vibrio vulnificus is a primary virulence factor which allows survival of the bacteria in the human host. To study the genes involved in the production of the polysaccharide capsule, 23 mutants were generated that lost their ability to produce CPS due to the insertion of a mini-transposon into the genome of the encapsulated clinical strain V. vulnificus 1003 (O). The mutants were examined by Southern blot analysis to ensure the transposon had inserted only once in the chromosome. Exoenzymes, which are believed to contribute to the virulence of the organism, produced by all 23 …

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The Use Of Secondarily Treated Wastewater Effluent For Forested Wetland Restoration In A Subsiding Coastal Zone., John M. Rybczyk Jan 1997

The Use Of Secondarily Treated Wastewater Effluent For Forested Wetland Restoration In A Subsiding Coastal Zone., John M. Rybczyk

LSU Historical Dissertations and Theses

Insufficient sedimentation, coupled with high rates of relative sea-level rise (RSLR), are two important factors contributing to wetland loss in coastal Louisiana. I hypothesized that adding nutrient rich, secondarily treated, wastewater effluent to subsiding coastal wetlands in Louisiana could promote vertical accretion in these systems through increased organic matter production and subsequent deposition, and allow accretion to keep pace with estimated rates of RSLR (subsidence plus eustatic sea-level rise). To test this hypothesis, I measured processes affecting wetland elevation including, organic matter decomposition, sediment accretion, aboveground primary production, and, plant tissue nutrient (N, P, K, Ca, Mg, Fe) concentrations, in …

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Growth And Mortality Of Fish Larvae In The Northcentral Gulf Of Mexico And Implications To Recruitment., Bruce Henry Comyns Jan 1997

Growth And Mortality Of Fish Larvae In The Northcentral Gulf Of Mexico And Implications To Recruitment., Bruce Henry Comyns

LSU Historical Dissertations and Theses

Extensive plankton collections were taken during September for several years along the northcentral Gulf of Mexico's inner continental shelf. Significant differences in growth rates were found for both vermilion snapper and Atlantic bumper larvae collected at stations where hydrographic conditions were similar, indicating the probable existence of small-scale patchily-distributed feeding conditions. Such variability in growth rates is probably inevitable given the high variability in the observed spatial and temporal distribution of surface chlorophyll a levels, macrozooplankton biomass, copepod abundance, and dispersion of fish larvae. Cruise estimates of mortality coefficients (Z) for larval vermilion snapper, red drum, and Atlantic bumper were …

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The Radioresistance Of Deinococcus Radiodurans., Valerie Mattimore Jan 1997

The Radioresistance Of Deinococcus Radiodurans., Valerie Mattimore

LSU Historical Dissertations and Theses

Deinococcus radiodurans is a remarkably ionizing radiation resistant bacterium. As a vegetative cell it is capable of withstanding 5,000 Gy ionizing radiation without evidence of death or mutation. D. radiodurans survives irradiation by repairing DNA damage via an extremely efficient DNA repair system. However, this DNA repair system has not been completely defined. In addition, the selective process allowing the evolution of high level radioresistance has remained a question. This dissertation bolsters the understanding of the DNA repair system of D. radiodurans by characterizing a collection of ionizing radiation sensitive (IRS) mutants. The level of radioresistance is quantified and transformation …

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An Analysis Of Two Tests For Diesel Contamination In The Environment When Considering The Impact On Hydrocarbon Degrading Bacteria, Chris Wedding Dec 1996

An Analysis Of Two Tests For Diesel Contamination In The Environment When Considering The Impact On Hydrocarbon Degrading Bacteria, Chris Wedding

Mahurin Honors College Capstone Experience/Thesis Projects

No abstract provided.

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Biology: What One Needs To Know, Ursula Goodenough Dec 1996

Biology: What One Needs To Know, Ursula Goodenough

Biology Faculty Research

Biology on this planet represents an astonishing experiment in carbon-based chemistry which, over billions of years, has generated billions of species adapted to countless major and minor fluctuations in ecological circumstances. In one sense there is no way to generalize about biology. While biological activities can all be ultimately explained by physical laws (like everything else in the universe), it is the emergent intensely particular properties of organisms that most interest us. This essay represents an attempt to describe some of the more prominent patterns that emerge from the sea of biological particularities, patterns that present many opportunities for religious …

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Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin Oct 1996

Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin

Faculty Publications

In marine soft-sediment habitats, the sediment surface is altered by activities of sediment dwellers (infauna). Such biogenic disturbance can influence recruitment success if settling larvae and juveniles avoid disturbed sites or if juveniles die as a result of disturbance after settling. Because infauna commonly lose exposed body parts to browsing predators and disturb less sediment as a result, we developed a simulation model to examine the interactions between browsing predation, infaunal adult activity, and recruitment. Sediment disturbance in the model was based on data for the polychaete Abarenicola pacifica. We simulated the activity of two general types of predators: prey …

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Characterization Of An Octopamine Receptor Gene In Drosophila Melanogaster., Kelley Lynn Colvin Aug 1996

Characterization Of An Octopamine Receptor Gene In Drosophila Melanogaster., Kelley Lynn Colvin

Student Work

The biogenic amine octopamine is a versatile signaling molecule that acts in essential physiological functions in invertebrates. Its roles in neurotransmission, neurohormone regulation and neuromodulation are achieved through interaction with G-protein coupled receptors. Such invertebrate receptors are structurally and functionally analogous to vertebrate adrenergic receptors. A human brain β2-adrenergic receptor cDNA clone was used as a hybridization probe to identify a Drosophila gene encoding an octopamine/tyramine receptor. This 367 base pair fragment of Drosophila genomic DNA, homologous to the putative sixth and seventh transmembrane regions of adrenergic receptors, was used to isolate an octopamine/tyramine receptor 3.3 Kb cDNA clone from …

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The Spatial Distribution Of A Transcript Of A Drosophila Octopamine/Tyramine Receptor., Laura M. Mckay Aug 1996

The Spatial Distribution Of A Transcript Of A Drosophila Octopamine/Tyramine Receptor., Laura M. Mckay

Student Work

Two specific receptor subtypes for octopamine, a biogenic amine found in both vertebrates and invertebrates, have been pharmacologically defined in insects. These receptors mediate responses involved in the regulation of movement, feeding and mating behaviors by inducing a rise in intracellular cAMP levels via adenylate cyclase stimulation or by increasing intracellular calcium levels via an undetermined mechanism. Recent studies on a putative octopamine/tyramine Drosophila receptor cDNA permanently expressed in mammalian cells have suggested the existence of an additional novel octopamine receptor subtype. This receptor binds multiple agonists (i.e. octopamine and tyramine) and can differentially couple to two different secondary messenger …

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The Effects Of Selected Lichen Extracts And Purified Compounds On The Rat Heart., Richard C. Witt Jul 1996

The Effects Of Selected Lichen Extracts And Purified Compounds On The Rat Heart., Richard C. Witt

Student Work

Extracts from Letharia vulpina, Umbilicaria americana, Cladina subtenuis, Xanthoparmelia cumberlandia, Rimelia reticulata, and Parmotrema austrosinense were used to study their electrophysiological effects on rat heart ventricular tissue. Additionally, solutions of four purified lichen metabolites ---- vulpinic acid, usnic acid, stictic acid, and atranorin ---- were studied in the same manner. The action potential duration at 50% and 90% of repolarization was significantly reduced by two of the extracts and metabolites, those containing vulpinic acid and usnic acid and the purified forms of those compounds. A positive relationship between the effects of extracts and purified compounds was exhibited. These data suggest …

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1: "To Know Ourselves", The U.S. Department Of Energy, The Human Genome Project Jul 1996

1: "To Know Ourselves", The U.S. Department Of Energy, The Human Genome Project

Genomics: Past & Future

AT THE END OF THE ROAD in Little Cottonwood Canyon, near Salt Lake City, Alta is a place of near-mythic renown among skiers. In time it may well assume similar status among molecular geneticists. In December 1984, a conference there, co-sponsored by the U.S. Department of Energy, pondered a single question: Does modern DNA research offer a way of detecting tiny genetic mutations—and, in particular, of observing any increase in the mutation rate among the survivors of the Hiroshima and Nagasaki bombings and their descendants? In short the answer was, Not yet. But in an atmosphere of rare intellectual fertility, …

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A Comparison Of Vegetation In Restored And Natural Wetlands In The Nebraska Sandhills., Warren Thomas Weaver Jul 1996

A Comparison Of Vegetation In Restored And Natural Wetlands In The Nebraska Sandhills., Warren Thomas Weaver

Student Work

Plant composition was compared between 3 restored and 3 natural Nebraska sandhill wetlands using plot data collected from each wetland in July and August of 1995 along five randomly placed, 25m transects. A total of 126 species were identified, of which 72 were found only in the natural area and 23 only in the restored area; the natural wetlands average 58 species and their restored 31. Cluster analysis of mean cover values, at a Euclidean Distance of 1000, identified five vegetative associations in the natural and three in the restored wetlands. In addition, cluster analysis of combined data indicated a …

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Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey Jun 1996

Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey

Faculty Publications

We predicted that both refuge dimension and growth form would influence settlement and short-term post-settlement success (≤7 d) of sessile marine invertebrates that live attached to hard substrata in low energy environments. Individuals with unlimited attachment to the substrata should rapidly be protected by their growth form, thus decreasing their need to settle in refuges and limiting the length of time any locations on heterogeneous substrata act as refuges. Alternatively, organisms with limited attachment to the substrata should remain susceptible to the causes of mortality for a longer time, and as a result should settle in high quality refuges (sites …

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