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Full-Text Articles in Life Sciences
Misregulation Of Genomic Imprinting Drives Abnormal Seed Development In Hybrid Monkeyflowers (Mimulus), Taliesin Kinser
Misregulation Of Genomic Imprinting Drives Abnormal Seed Development In Hybrid Monkeyflowers (Mimulus), Taliesin Kinser
Dissertations, Theses, and Masters Projects
Genomic imprinting is the preferential expression of one allele over the other. It is an epigenetic phenomenon that occurs in the placentas of mammals and the endosperm of angiosperms. Endosperm, like placentas, is a nutrient rich tissue that supports the growing embryo within the seed. All grains are predominantly composed of this tissue. It is the product of a second fertilization event, resulting in both maternal and paternal alleles. Some alleles are regulated differentially, resulting in imprinted genes. There are both paternally expressed imprinted genes (PEGs) and maternally expressed imprinted genes (MEGs) in the endosperm. In general PEGs tend to …
The Influence Of Environmental Factors And Resource Availability On Zostera Marina Flowering Intensity, Andrew J. Johnson
The Influence Of Environmental Factors And Resource Availability On Zostera Marina Flowering Intensity, Andrew J. Johnson
Dissertations, Theses, and Masters Projects
Sexual reproduction and the production of seeds are important for the resilience of all angiosperm species. For clonal species, such as the seagrass Zostera marina, resource allocation is complicated because these species reproduce both asexually and sexually, and the factors contributing to allocation to these two processes remains unknown. The goal of this study was, therefore, to investigate the importance of critical light, nutrient, and rhizome resources on Z.
marina sexual reproduction and flowering intensity. To evaluate the importance of sediment nutrients on Z. marina flowering intensity two distinct field manipulative experiments and one field survey were initiated: 1. Sediments …
The Roles Of Dispersal And Predation In Determining The Seedling Recruitment Patterns Of A Zostera Marina System, Stephen R. Manley
The Roles Of Dispersal And Predation In Determining The Seedling Recruitment Patterns Of A Zostera Marina System, Stephen R. Manley
Dissertations, Theses, and Masters Projects
Seed dispersal and seed predation are two important processes in the early life history of plants. The interaction between these two processes influences the population recruitment from a parent plant. These mechanisms have been studied extensively in terrestrial plants and have resulted in various models to describe plant recruitment (e.g. Janzen-Connell, Hubbell, McCanny). However, seed dispersal and predation may also influence the population recruitment of marine angiosperms, such as Zostera marina (eelgrass). The objectives of this study were to determine: 1.) the patterns of seed dispersal as a function of distance from the seed source, 2.) the predation pressure on …
The Fruits Of Their Labors: Exploring William Hamilton's Greenhouse Complex And The Rise Of American Botany In Early Federal Philadelphia, Sarah Jane Chesney
The Fruits Of Their Labors: Exploring William Hamilton's Greenhouse Complex And The Rise Of American Botany In Early Federal Philadelphia, Sarah Jane Chesney
Dissertations, Theses, and Masters Projects
This dissertation explores the world of early American botany and the transatlantic community of botanical enthusiasts from the perspective of William Hamilton, gentleman botanical collector in late eighteenth and early nineteenth century Philadelphia. Drawing on both existing documentary sources and three seasons of archaeological excavation at The Woodlands, Hamilton's country estate on the west bank of the Schuylkill River, I analyze both the physical requirements of botanical collecting as well as the more nuanced social, cultural, and economic elements of this trade and its early modern participants.;The personal experiences of individual participants in this exchange are often traced through the …
The Effects Of Salinity Pulses Of Varying Duration And Intensity On Three Freshwater Submerged Aquatic Vegetation Species, Rebecca Wright
The Effects Of Salinity Pulses Of Varying Duration And Intensity On Three Freshwater Submerged Aquatic Vegetation Species, Rebecca Wright
Dissertations, Theses, and Masters Projects
No abstract provided.
The Effects Of Seagrass Species And Trophic Interactions In Experimental Seagrass Communities, Althea F. P. Moore
The Effects Of Seagrass Species And Trophic Interactions In Experimental Seagrass Communities, Althea F. P. Moore
Dissertations, Theses, and Masters Projects
No abstract provided.
Vascular Flora Of The Totuskey Creek Watershed, Richmond County, Virginia, Christopher W. Johnstone
Vascular Flora Of The Totuskey Creek Watershed, Richmond County, Virginia, Christopher W. Johnstone
Dissertations, Theses, and Masters Projects
No abstract provided.
Investigation Of Relationships Between Short-Term Photosynthetic Performance And Long-Term Growth Of Zostera Marina, Elizabeth Amy Lewis
Investigation Of Relationships Between Short-Term Photosynthetic Performance And Long-Term Growth Of Zostera Marina, Elizabeth Amy Lewis
Dissertations, Theses, and Masters Projects
No abstract provided.
Vegetation Dynamics Of A Tidal Freshwater Marsh: Long-Term And Inter-Annual Variability And Their Relationship To Salinity, Sarah B. Davies
Vegetation Dynamics Of A Tidal Freshwater Marsh: Long-Term And Inter-Annual Variability And Their Relationship To Salinity, Sarah B. Davies
Dissertations, Theses, and Masters Projects
No abstract provided.
Microevolutionary Processes In Chesapeake Bay (Virginia, Usa) Eelgrass, Zostera Marina L, Jennifer Michelle Rhode
Microevolutionary Processes In Chesapeake Bay (Virginia, Usa) Eelgrass, Zostera Marina L, Jennifer Michelle Rhode
Dissertations, Theses, and Masters Projects
Eelgrass (Zostera marina L.) is the northern hemisphere's dominant marine angiosperm, a species with both ecological and economic importance. Initial allozyme surveys of eelgrass populations in Chesapeake Bay (Virginia, USA) revealed substantial amounts of geographically-partitioned genetic variation, which could be the result of nonselective demographic processes, including founder events and drift. However, strong spatial variation in the environment and in eelgrass morphology suggests that differential adaptation of isolated beds to local environmental conditions could also produce these patterns. This dissertation used three sets of studies to investigate microevolutionary processes might produce the observed variation among Chesapeake eelgrass beds: (1) an …
Allozyme Variation In American Ginseng, Panax Quinquefolius L (Araliaceae): Implications For Management Of Wild And Cultivated Populations, Holly Jean Grubbs
Allozyme Variation In American Ginseng, Panax Quinquefolius L (Araliaceae): Implications For Management Of Wild And Cultivated Populations, Holly Jean Grubbs
Dissertations, Theses, and Masters Projects
No abstract provided.
Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer
Application Of The Genetic Algorithm To An Ecological Simulation, William J. Seufzer
Dissertations, Theses, and Masters Projects
A computational framework is built and demonstrated which is capable of testing plant growth strategies. The framework consists of Vgrass, a carbon based simulation model of a single Zostera marina plant, and the genetic algorithm (GA). Vgrass is based on published seagrass models, published photosynthetic data, and general plant physiology information. The model grows individual leaves whose initiation times are based on degree-day intervals. Leaf size is computed and combined with shoot density to compute population self shading. Leaf length is an emergent property since leaf growth is limited by light attenuation caused by self shading. The model is able …
Effects Of Light And Salinity Stress On Vallisneria Americana (Wild Celery), Gail T. French
Effects Of Light And Salinity Stress On Vallisneria Americana (Wild Celery), Gail T. French
Dissertations, Theses, and Masters Projects
No abstract provided.
Spatial And Temporal Variation In Plant Communities Of Three Tidal Salt Marshes Along The York River, Virginia, Rosemary E. Laird
Spatial And Temporal Variation In Plant Communities Of Three Tidal Salt Marshes Along The York River, Virginia, Rosemary E. Laird
Dissertations, Theses, and Masters Projects
No abstract provided.
Plant Species Of The Virginia Coastal Plain Flora That Are Disjunct From The Mountains: Their Distribution, Abundance And Substrate Selectivity, Leah E. Mcdonald
Plant Species Of The Virginia Coastal Plain Flora That Are Disjunct From The Mountains: Their Distribution, Abundance And Substrate Selectivity, Leah E. Mcdonald
Dissertations, Theses, and Masters Projects
No abstract provided.
Ecological Dispersal Mechanisms, Reproductive Ecology, And The Importance Of Scale In Zostera Marina In Chesapeake Bay, Matthew C. Harwell
Ecological Dispersal Mechanisms, Reproductive Ecology, And The Importance Of Scale In Zostera Marina In Chesapeake Bay, Matthew C. Harwell
Dissertations, Theses, and Masters Projects
Previous knowledge of the seed ecology of the clonal seagrass Zostera marina L. (eelgrass) suggests that sexual reproduction is not very important to the population dynamics of eelgrass; however, researchers have hypothesized long-distance dispersal for nearly a century. From a bay-wide sampling effort, viable eelgrass seeds in the seed bank were found throughout most of the lower and middle Chesapeake Bay, but abundance of seeds was highly variable. Lower seed-bank densities were found in middle Chesapeake Bay, the region with slow recovery of eelgrass populations. From natural and artificially created eelgrass populations, regional environmental conditions were found to have a …
Systematic And Population Genetic Analyses Of Northern Vs Southern Yellow Lady's Slippers (Cypripedium Parviflorum Vars Parviflorum, Pubescens, And Makasin): Inference From Isozyme And Morphological Data, Lisa Ellen Wallace
Dissertations, Theses, and Masters Projects
No abstract provided.
Studies On Processes Controlling The Input Of Agricultural Chemicals In Groundwater To Surface Waters, Edward Laurence Libelo
Studies On Processes Controlling The Input Of Agricultural Chemicals In Groundwater To Surface Waters, Edward Laurence Libelo
Dissertations, Theses, and Masters Projects
This dissertation describes several studies of groundwater quality, the fate and transport of nutrients and atrazine in groundwater systems and physical processes at the sediment-water interface which impact on groundwater discharge. Groundwater monitoring wells were installed at the Goodwins Island and Catlett Island NERRS sites in Virginia and agricultural, suburban and forest land use sites in the York and James River Basins. Groundwater was analyzed for nutrients, pH, salinity and trace organics. Shoreline land use, associated nutrient loading and an estimate of total groundwater flux suggest that groundwater contributes up to 30% of the total nitrogen input to the Chesapeake …
The Vascular Flora Of The Carrotoman River Watershed, Lancaster County, Virginia, Troy W. Weldy
The Vascular Flora Of The Carrotoman River Watershed, Lancaster County, Virginia, Troy W. Weldy
Dissertations, Theses, and Masters Projects
No abstract provided.
Phylogenetic Implications Of Sporogenesis Ultrastructure In The Genus Bossiella (Corallinales, Rhodophyta), Kimberly Joy Karnas
Phylogenetic Implications Of Sporogenesis Ultrastructure In The Genus Bossiella (Corallinales, Rhodophyta), Kimberly Joy Karnas
Dissertations, Theses, and Masters Projects
No abstract provided.
An Ultra Structural Study Of Sporogenesis, Vegatative Morphology, And Host-Parasite Interactions In Choreonema Thuretii (Corallinales, Rhodophyta), Elizabeth Anne Lapointe
An Ultra Structural Study Of Sporogenesis, Vegatative Morphology, And Host-Parasite Interactions In Choreonema Thuretii (Corallinales, Rhodophyta), Elizabeth Anne Lapointe
Dissertations, Theses, and Masters Projects
No abstract provided.
Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer
Measurement Of In Situ Eelgrass Community Metabolism In Standing And Flowing Waters: Methods And Models, William James Seufzer
Dissertations, Theses, and Masters Projects
No abstract provided.
The Vascular Flora Of The Tar Bay And Powell Creek Watersheds, Prince George County, Virginia, Mark Eugene Mort
The Vascular Flora Of The Tar Bay And Powell Creek Watersheds, Prince George County, Virginia, Mark Eugene Mort
Dissertations, Theses, and Masters Projects
No abstract provided.
The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman
The Role Of Predation On Zostera Marina L (Eelgrass) Seed Abundance, James Fishman
Dissertations, Theses, and Masters Projects
No abstract provided.
Reproductive Strategies In Asclepias Syriaca And Apocynum Cannabinum, Mariellen J. Soltys
Reproductive Strategies In Asclepias Syriaca And Apocynum Cannabinum, Mariellen J. Soltys
Dissertations, Theses, and Masters Projects
No abstract provided.
Growth Response Of Eelgrass (Zostera Marina L) To Root-Rhizome And Whole Plant Exposure To Atrazine, Arthur C. Schwarzschild
Growth Response Of Eelgrass (Zostera Marina L) To Root-Rhizome And Whole Plant Exposure To Atrazine, Arthur C. Schwarzschild
Dissertations, Theses, and Masters Projects
No abstract provided.
Adaptive Significance Of Ray Florets In Asteraceae, Gail Taber Steele
Adaptive Significance Of Ray Florets In Asteraceae, Gail Taber Steele
Dissertations, Theses, and Masters Projects
No abstract provided.
Photosynthetic Responses Of Eelgrass (Zostera Marina L) To Light And Sediment Sulfide In A Shallow Barrier Island Lagoon, Jill Lynn Goodman
Photosynthetic Responses Of Eelgrass (Zostera Marina L) To Light And Sediment Sulfide In A Shallow Barrier Island Lagoon, Jill Lynn Goodman
Dissertations, Theses, and Masters Projects
No abstract provided.
A Vegetational Analysis Of Interdunal Swale Communities Of False Cape State Park, Currituck Spit, Virginia, Heather A. Jones
A Vegetational Analysis Of Interdunal Swale Communities Of False Cape State Park, Currituck Spit, Virginia, Heather A. Jones
Dissertations, Theses, and Masters Projects
No abstract provided.
Vegetation Ecology Of Tidal Freshwater Swamps Of The Lower Chesapeake Bay, United States Of America, Richard D. Rheinhardt
Vegetation Ecology Of Tidal Freshwater Swamps Of The Lower Chesapeake Bay, United States Of America, Richard D. Rheinhardt
Dissertations, Theses, and Masters Projects
Woody and herbaceous vegetation were sampled in 23 tidal swamps along a tidal freshwater tributary of lower Chesapeake Bay. Four vegetative categories were ordinated with Detrended Correspondence Analysis (DECORANA). Species distribution patterns of each strata were compared with respect to edaphic factors, a wetness index, and mean water table depth. Woody species are restricted to hummocks (topographic highs). Hummocks drain as quickly as the tide drops and so are partially inundated for only short periods each day. Although low in canopy diversity, tidal swamps are floristically rich in herbaceous and woody understory species, ranking them among the most speciose in …