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Articles 1 - 14 of 14

Full-Text Articles in Life Sciences

Thyroid Histology And Reproductive Function In The Prairie Deer Mouse And In The White-Footed Mouse, Jennifer M. Dolan Jan 1990

Thyroid Histology And Reproductive Function In The Prairie Deer Mouse And In The White-Footed Mouse, Jennifer M. Dolan

Dissertations, Theses, and Masters Projects

No abstract provided.


Determination Of Macrophage Chemiluminescent Response In Fundulus Heteroclitus As A Function Of Pollution And Temperature Stress, Karen Kelly Reay Jan 1990

Determination Of Macrophage Chemiluminescent Response In Fundulus Heteroclitus As A Function Of Pollution And Temperature Stress, Karen Kelly Reay

Dissertations, Theses, and Masters Projects

No abstract provided.


Population Dynamics Of Young-Of-The-Year Striped Bass, Morone Saxatilis, Populations, Based On Daily Otolith Increments, Lisa L. Kline Jan 1990

Population Dynamics Of Young-Of-The-Year Striped Bass, Morone Saxatilis, Populations, Based On Daily Otolith Increments, Lisa L. Kline

Dissertations, Theses, and Masters Projects

Validation of daily increment deposition in otoliths of juvenile striped bass up to 80 days of age was provided through sequential sacrifice of known age hatchery-reared fish in 1987 and 1989, and through tetracycline marking of otoliths of cage-cultured striped bass in 1989. Ages of fish between 80-110 days old were consistently underestimated by 1-3 growth increments. Known age juvenile striped bass were raised in the laboratory in 1989 under controlled environmental conditions. These experiments provided evidence of an endogenous circadian rhythm controlling daily increment deposition in juvenile striped bass otoliths. Juvenile striped bass were collected in the 4 Virginia …


Relative Effects Of Nutrient Enrichment And Grazing On Epiphyton-Macrophyte (Zostera Marina L.) Dynamics, Hilary A. Neckles Jan 1990

Relative Effects Of Nutrient Enrichment And Grazing On Epiphyton-Macrophyte (Zostera Marina L.) Dynamics, Hilary A. Neckles

Dissertations, Theses, and Masters Projects

Dissolved nutrient concentrations and invertebrate grazing activity regulate epiphytic biomass. Because epiphyton may limit light and carbon at leaf surfaces and the consequent productivity of submerged macrophytes, factors which influence epiphytic biomass may indirectly affect macrophyte abundance. I measured the simultaneous effects of water column nutrients (ambient or 3x ambient concentrations of nitrogen and phosphorus) and grazing (presence or absence of epifaunal community) on epiphyton and macrophytes seasonally in eelgrass (Zostera marina L.) microcosms on lower Chesapeake Bay. Grazing was more important than nutrients in controlling accrual of total epiphytic biomass, although effects on epiphytic components varied; numbers of diatoms …


The Gametogenic Cycle Of Placopecten Magellanicus (Gmelin) In The Mid-Atlantic Bight, Anne Catherine Schmitzer Jan 1990

The Gametogenic Cycle Of Placopecten Magellanicus (Gmelin) In The Mid-Atlantic Bight, Anne Catherine Schmitzer

Dissertations, Theses, and Masters Projects

No abstract provided.


Habitat Quality And Seasonal Foraging Patterns Of The Red-Cockaded Woodpecker (Picoides Borealis) In Southeastern Virginia, Dana Seward Bradshaw Jan 1990

Habitat Quality And Seasonal Foraging Patterns Of The Red-Cockaded Woodpecker (Picoides Borealis) In Southeastern Virginia, Dana Seward Bradshaw

Dissertations, Theses, and Masters Projects

No abstract provided.


Adrenal Histology And Reproductive Function In Peromyscus Maniculatus Bairdii And Peromyscus Leucopus Noveborocensis, Peggy Alicia Rouleau Jan 1990

Adrenal Histology And Reproductive Function In Peromyscus Maniculatus Bairdii And Peromyscus Leucopus Noveborocensis, Peggy Alicia Rouleau

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effect Of Nitrogen And Phosphorus Supply Ratios And Dilution Rate On Phosphorus Uptake And Mineralization In Continuous Flow Microcosms, Peter M. Eldridge Jan 1990

The Effect Of Nitrogen And Phosphorus Supply Ratios And Dilution Rate On Phosphorus Uptake And Mineralization In Continuous Flow Microcosms, Peter M. Eldridge

Dissertations, Theses, and Masters Projects

Continuous flow microcosms (50L volume, salinity 18-24 ppt) were used to examine the roles of heterotrophic protozoa and bacteria as phosphorus mineralizers. Nitrogen limitation was regulated by N:P supply ratios (5:1, 16:1) and growth rate was regulated by dilution rate (0.5, 0.25 volumes day&\sp{lcub}-1{rcub}&). Rates of carbon and phosphorus uptake from dissolved inorganic pools were determined using &\sp{14}&C and &\sp{lcub}32{rcub}&P tracer experiments and pre- and post-fractionation incubations. Based on uptake rates and on POP and POC values of the bacteria in the &<&1.0 &\mu&m fraction, mass balance estimates of bacterial mineralization were determined. An isotope dilution method was used to determine phosphorus mineralization in the unfractionated sample. Heterotrophic protozoan mineralization was calculated as the difference. Results showed that bacteria had a minor role as remineralizers of phosphorus, more often taking-up inorganic phosphorus than remineralizing it. Heterotrophic protozoa were the major remineralizers of phosphorus. Microcosm treatments with a greater supply of inorganic phosphorus over nitrogen had increased POP concentrations and increased phosphorus remineralization. The effect of dilution on phosphorus remineralization was temperature dependent. Greater remineralization occurred in the high dilution rate in the July through October experiments and less remineralization occurred in the high dilution rate treatments in the December and January experiments.


The Vascular Flora Of Western Isle Of Wight County, Virginia, Gregory Michael Plunkett Jan 1990

The Vascular Flora Of Western Isle Of Wight County, Virginia, Gregory Michael Plunkett

Dissertations, Theses, and Masters Projects

No abstract provided.


Growth Rate And Grazing Dynamics Of Coccoid Cyanobacteria In The Lower Chesapeake Bay, Carol J. Falkenhayn Jan 1990

Growth Rate And Grazing Dynamics Of Coccoid Cyanobacteria In The Lower Chesapeake Bay, Carol J. Falkenhayn

Dissertations, Theses, and Masters Projects

No abstract provided.


Comparative Community Structure Of Surf-Zone Fishes In The Chesapeake Bight And Southern Brazil, Cassiano Monteiro-Neto Jan 1990

Comparative Community Structure Of Surf-Zone Fishes In The Chesapeake Bight And Southern Brazil, Cassiano Monteiro-Neto

Dissertations, Theses, and Masters Projects

The structure of surf-zone fish communities at Cassino (western South Atlantic, WSA) and the Chesapeake Bight (western North Atlantic, WNA) is described using historical beach seine data, to examine similarities between geographically isolated fish communities. Numerical classification, ANCOVA, Shanon-Wiener diversity and its components, and species rarefaction are used to describe fish community structure: (a) within habitat (Cassino); (b) within region (Chesapeake Bight); (c) within the western Atlantic (comparison between Cassino and the Chesapeake Bight). The surf-zone fish community at Cassino had a low diversity and was dominated by a few species. Seasonal periods identified by cluster analysis correlated well with …


Frna Coliphages As A Viral Indicator Of Sewage Pollution In An Estuary, David Miller Boyd Jan 1990

Frna Coliphages As A Viral Indicator Of Sewage Pollution In An Estuary, David Miller Boyd

Dissertations, Theses, and Masters Projects

No abstract provided.


The Effects Of Shading By Open-Pile Structures On The Density Of Spartina Alterniflora, Heather L. Mcguire Jan 1990

The Effects Of Shading By Open-Pile Structures On The Density Of Spartina Alterniflora, Heather L. Mcguire

Dissertations, Theses, and Masters Projects

No abstract provided.


Patterns Of Habitat Utilization In 0-Age Summer Flounder (Paralichthys Dentatus), David M. Wyanski Jan 1990

Patterns Of Habitat Utilization In 0-Age Summer Flounder (Paralichthys Dentatus), David M. Wyanski

Dissertations, Theses, and Masters Projects

No abstract provided.