Life Sciences Commons^™

Phylogenetic Implications Of Sporangial Ultrastructure In The Subfamily Lithophylloideae (Corallinales, Rhodophyta), Mark T. Bedell

Dissertations, Theses, and Masters Projects

No abstract provided.

Evolutionary Relationships Among The Protostrongylidae (Nematoda: Metastrongyloidea) As Inferred From Morphological Characters, With Consideration Of Parasite-Host Coevolution, Ramon A. Carreno, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

The phylogeny of nematodes in the family Protostrongylidae (Nematoda: Metastrongyloidea) was reconstructed by cladistic analysis of 28 binary and multistate characters derived from comparative morphology. Analyses were hierarchical, and examined (1) relationships among genera, including 13 ingroup taxa and Metastrongylidae as an outgroup (single tree, 78 steps, consistency index [CI]=0.705); and (2) relationships among genera and species groups including 21 ingroup taxa and Metastrongylus apri as an outgroup (single tree, 76 steps, CI=0.582). In the species-level tree, Protostrongylidae was divided into 2 major clades, one containing the subfamilies Muelleriinae (including the recently described Umingmakstrongylus pallikuukensis) Elaphostrongylinae, and the Varestrongylinae …

Experimental Infections Of Muskoxen (Ovibos Moschatus) And Domestic Sheep With Umingmakstrongylus Pallikuukensis (Nematoda: Protostrongylidae): Parasite Development, Population Structure, And Pathology, Susan J. Kutz, Eric P. Hoberg, Lydden Polley

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Three captive muskoxen (Ovibos moschatus) were successfully infected with third-stage larvae of Umingmakstrongylus pallikuukensis digested or emerged from the slugs Deroceras reticulatum and D. laeve, for the first time completing the life cycle of this parasite under experimental conditions. The course of parasite development and patency was followed for 26 months post infection (p.i.) using fecal examinations and radiography. The prepatent periods in two of the muskoxen were 91 and 95 days and the patent period in one extended for 23 months. Larval production peaked 13–14 months p.i. On postmortem of two of the muskoxen at months …

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Biological Sciences Faculty Publications

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Biological Sciences Faculty Publications

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasglow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al, 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …

Bacterial Dynamics And Community Structure In The York River Estuary, Gary Edward Schultz Jr

Dissertations, Theses, and Masters Projects

Bacterial community dynamics were investigated over seasonal and basin scales within the York River, VA, estuary. Various parameters characterizing bacterioplankton dynamics were measured weekly at a single station (March 1996 through May 1997) and monthly at six stations (June 1996 through May 1997) spanning the entire salinity gradient (0 - ca. 20 psu over 60 km). Bacterial abundance and production were found to be high throughout the estuary. Bacterial abundance ranged from 4.4 x 108 to 1.3 x 1010 cells-liter-1Incorporation of 3H-thymidine ranged from 10 to 863 pmol-liter-1-hr-1 while 3H-leucine incorporation rates ranged from 25 to 1963 pmol-liter -1-hr-1. Clear …

Alarm Calls Affect Foraging Behavior In Eastern Chipmunks (Tamias Striatus), Jessica K. Baack

Masters Theses

I used playback experiments to test whether alarm calls affected the foraging behavior of Eastern chipmunks (Tamias striatus). I subjected chipmunks, foraging at artificial feeding stations, to three playback treatments (silent, control noise, and alarm call) and examined changes in vigilant and foraging behavior. Chipmunks responded to alarm calls with a greater degree and duration of vigilant behavior, such as look-ups and alert postures. Chipmunks also ran a shorter distance to cover, ran more directly to cover, and took longer to re-emerge from the burrow after hearing an alarm call. Alarm calls caused individuals to spend more time …

Characterization And Improvement Of Eos Land Products Using Measurements At Ameriflux Grassland And Wheat Sites In The Arm/Cart Region: Research Annual Performance Report For Period March 1, 1999- February 29, 2000., E. A. Walter-Shea, S. B. Verma

School of Natural Resources: Documents and Reviews

No abstract provided.

Influence Of Prairie Dogs On Vegetation In Kansas Shortgrass Prairie, Stephen L. Winter, Jack F. Cully Jr., Jeffrey S. Pontius

United States Fish and Wildlife: Staff Publications

We quantified plant species richness, frequency, percent cover and percent bare ground on black-tailed prairie dog colonies and non-colonized areas in southwest Kansas in 1996 and 1997. In 1996 field sampling occurred after 12 months of below-average precipitation, while field sampling in 1997 occurred after 10 months of above-average precipitation. In 1996 prairie dog colonies were characterized by lower percentages of grass cover and higher percentages of forb cover than non-colonized sites, but there was no difference in percent bare ground. In 1997 percent grass cover, forb cover and bare ground was similar for prairie dog colonies and non-colonized areas. …

Growth And Yield-Per-Recruit Modeling Of Spot (Leiostomus Xanthurus) In The Chesapeake Bay, And A Comparison Of Biological Reference Points, Kevin Ray Piner

Biological Sciences Theses & Dissertations

Spot were sampled from the Chesapeake Bay commercial fishery from 1993–1995 to determine if spot are overfished. Transversely sectioned otoliths were determined to be the most appropriate structure for ageing spot. It was determined that spot have a high natural mortality rate (M = 0.9) and fast growth (K = 0.6). This combination of M and K makes spot relatively impervious to growth overfishing as determined by yield-per-recruit modeling. Because spot are nearly impervious to growth overfishing, management thresholds based on yield-per-recruit modeling may be inappropriate. In addition, the combination of high M and fast K makes it possible to …

The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins

OES Theses and Dissertations

The Eastern Shore of Virginia (Greens Creek) as well as a large portion of the North Atlantic coastline is characterized by estuarine systems not dominated by large river systems. Instead, small freshwater creeks influence many coastal systems yet little information has been documented on their ecological significance. The focus of this research is to identify the biogeochemical and physical interactions within an estuarine water-column and understand the importance of freshwater sources in governing phytoplankton production. The hypothesis of this research is that increases in external nutrient loading into Greens Creek will not result in an increase in primary production. The …

The Genetics And Evolution Of The Mariner Transposable Element In Drosophila Simulans: Worldwide Distribution And Experimental Population Dynamics, Amy L. Russell, R. C. Woodruff

Amy L. Russell

Relationship Between The Bacillus Subtilis Clades Associated With Strains 168 And W23: A Proposal For B. Subtilis Subsp. Subtilis And B. Subtilis Subsp. Spizizenii, L. K. Nakamura, M. S. Roberts, Frederick M. Cohan

Frederick M. Cohan

No abstract provided.

Dna Sequence Similarity Requirements For Interspecific Recombination In Bacillus, J. Majewski, Frederick M. Cohan

Frederick M. Cohan

No abstract provided.