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Development Of Real-Time Pcr Assays For Rapid Detection Of Pfiesteria Piscicida And Related Dinoflagellates, Torstein Tengs

Dr. Torstein Tengs

Pfiesteria complex species are heterotrophic and mixotrophic dinoflagellates that have been recognized as harmful algal bloom species associated with adverse fish and human health effects along the East Coast of North America, particularly in its largest (Chesapeake Bay in Maryland) and second largest (Albermarle- Pamlico Sound in North Carolina) estuaries. In response to impacts on human health and the economy, monitoring programs to detect the organism have been implemented in affected areas. However, until recently, specific identification of the two toxic species known thus far, Pfiesteria piscicida and P. shumwayae (sp. nov.), required scanning electron microscopy (SEM). SEM is a …

Eight Ways To Be A Colonizer; Two Ways To Be An Invader., Mark Davis, K Thompson

Mark Davis

No abstract provided.

An Outline Of A Theory Of The Constructional Constraints Governing Early Organismic Evolution, Winfried S. Peters, Bernd Herkner

Winfried S. Peters

This paper has no abstract; this is the first paragraph. The origin of life is one of the most fascinating biological enigmas (Dyson 1985, de Duve 1991). A multitude of hypotheses is available, ranging from the classical "primordial broth" (Haldane 1929) to the "genetic takeover" (Cairns-Smith 1982). Most of these models center on biochemical, metabolic, or genetic aspects. To our knowledge a comprehensive investigation into the mechanical constraints governing the early development of organismic constructions is not available to date. Attempting to close this gap, we here present an outline of a theory of the transformation of constructions in early …

Phylogenetic Resolution Within The Tribe Episcieae (Gesneriaceae): Congruence Of Its And Ndhf Sequences From Parsimony And Maximum-Likelihood Analyses, James F. Smith

James F. Smith

Generic relationships within Episcieae were assessed using ITS and ndhF sequences. Previous analyses of this tribe have focused only on ndhF data and have excluded two genera, Rhoogeton and Oerstedina, which are included in this analysis. Data were analyzed using both parsimony and maximum-likelihood methods. Results from partition homogeneity tests imply that the two data sets are significantly incongruent, but when Rhoogeton is removed from the analysis, the data sets are not significantly different. The combined data sets reveal greater strength of relationships within the tribe with the exception of the position of Rhoogeton. Poorly or unresolved relationships based exclusively …

Phylogenetic Analyses Indicate That The 19'Hexanoyloxy-Fucoxanthin-Containing Dinoflagellates Have Tertiary Plastids Of Haptophyte Origin, Torstein Tengs

Dr. Torstein Tengs

The three anomalously pigmented dinoflagellates Gymnodinium galatheanum, Gyrodinium aureolum, and Gymnodinium breve have plastids possessing 199-hexanoyloxy-fucoxanthin as the major carotenoid rather than peridinin, which is characteristic of the majority of the dinoflagellates. Analyses of SSU rDNA from the plastid and the nuclear genome of these dinoflagellate species indicate that they have acquired their plastids via endosymbiosis of a haptophyte. The dinoflagellate plastid sequences appear to have undergone rapid sequence evolution, and there is considerable divergence between the three species. However, distance, parsimony, and maximum-likelihood phylogenetic analyses of plastid SSU rRNA gene sequences place the three species within the haptophyte clade. …

A Homeostatic Set Point For Branching In Neurospora Crassa, Michael Watters, Christine Humphries, Ingrid De Vries, Anthony Griffiths

Michael Watters

The mechanisms responsible for controlling hyphal extension and branching are still poorly understood. We have investigated these processes by studying their dependence on temperature and nutrient concentration. Tip growth is highly responsive to temperature change, increasing linearly from 4 to 37 °C. Over this range of temperatures the branching pattern shows virtually no response. Likewise, varying nutrient concentration does not affect branch distribution. Colonies subjected to rapid extreme temperature downshifts (for example from 25 to 4°) display a strong and highly predictable branching response. There are three stages to this response. First there is an initial lag phase of growth …

Test Of Intron Predictions Reveals Novel Splice Sites, Alternatively Spliced Mrnas And New Introns In Meiotically Regulated Genes Of Yeast, Carrie A. Davis, Leslie Grate, Marc Spingola, Manuel Ares

Marc Spingola

Heteroduplex Mobility Assay-Guided Sequence Discovery: Elucidation Of The Small Subunit (18s) Rdna Sequences Of Pfiesteria Piscicida And Related Dinoflagellates From Complex Algal Culture And Environmental Sample Dna Pools, Torstein Tengs

Dr. Torstein Tengs

The newly described heterotrophic estuarine dinoflagellate Pfiesteria piscicida has been linked with fish kills in field and laboratory settings, and with a novel clinical syndrome of impaired cognition and memory disturbance among humans after presumptive toxin exposure. As a result, there is a pressing need to better characterize the organism and these associations. Advances in Pfiesteria research have been hampered, however, by the absence of genomic sequence data. We employed a sequencing strategy directed by heteroduplex mobility assay to detect Pfiesteria piscicida 18S rDNA ‘‘signature’’ sequences in complex pools of DNA and used those data as the basis for determination …

Xenopus Laevis Gelatinase B (Xmmp-9): Development, Regeneration, And Wound Healing, Brian Walter, Maria Carinato, Jonathan Henry

Brian Walter

It has been argued that matrix metalloproteinases play important roles in cellular differentiation and regeneration in certain systems. While studying changes in gene expression associated with the phenomena of cornea/lens transdifferentiation ("lens regeneration"), which takes place in the larva of Xenopus laevis, we identified the Xenopus gelatinase B gene. The open reading frame is homologous to other gelatinase B genes identified in other species and encodes all of the domains characteristic of this protein. Xenopus gelatinase B (Xmmp-9) is first expressed during early tail-bud stages in a subset of mesodermal cells scattered throughout the body. Expression is also seen in …

Metals And Metallothionein In The Liver Of Raccoons: Utility For Environmental Assessment And Monitoring, Joanna Burger, Christine G. Lord, Edward J. Yurkow, Lynn Mcgrath, Karen F. Gaines, I. Lehr Brisbin Jr., Michael Gochfeld

Karen F. Gaines

The relationship between metallothionein levels and concentrations of several metals and radionuclides was examined in liver tissues of raccoons (Procyon lotor, n = 47) from the Department of Energy’s Savannah River Site in South Carolina to determine the applicability of metallothioneins as an initial screening device for exposure assessment in free-living mammals and environmental monitoring. Using a fluorescent marker and a cell sorter to measure metallothionein, a significant positive correlation was found across animals between levels of metallothioneins and concentrations of selenium (Pearson’s r = .30) , mercury (Pearson’s r = .31) , and copper (Pearson’s r = .30) in …

Raccoons As Potential Vectors Of Radionuclide Contamination To Human Food Chains From A Nuclear Industrial Site, Karen F. Gaines, Christine G. Lord, C. Shane Boring, I. Lehr Brisbin Jr., Michael Gochfeld, Joanna Burger

Karen F. Gaines

Although the raccoon (Procyon lotor) is commonly harvested and consumed throughout the southeastern United States, little is known regarding the fate and effects of environmental pollutants to this species, and the potential for it to act as a contaminant vector to humans or other predators. Muscle and liver tissues were collected from 76 raccoons from locations on and near the Department of Energy's Savannah River Site (SRS) in South Carolina and analyzed for radiocesium (137Cs). Raccoons were trapped from areas near a former reactor cooling reservoir known to be contaminated from former nuclear production activities, a stream drainage system also …

Binding Of Urate And Caffeine To Hemocyanin Of The Lobster Homarus Vulgaris (E.) As Studied By Isothermal Titration Calorimetry †, Michael A. Menze, Nadja Hellmann, Heinz Decker, Manfred K. Grieshaber

Michael Menze

Hemocyanin serves as an oxygen carrier in the hemolymph of the European lobster Homarus Vulgaris. The oxygen binding behavior of the pigment is modulated by metabolic effectors such as lactate and urate. Urate and caffeine binding to 12-meric hemocyanin (H. Vulgaris) was studied using isothermal titration calorimetry (ITC). Binding isotherms were determined for fully oxygenated hemocyanin between pH 7.55 and 8.15. No pH dependence of the binding parameters could be found for either effector. Since the magnitude of the Bohr effect depends on the urate concentration, the absence of any pH dependence of urate and caffeine binding to oxygenated hemocyanin …

Foraging Ecology Of The Endangered Wood Stork Recorded In The Stable Isotope Signature Of Feathers, Christopher S. Romanek, Karen F. Gaines, A. L. Bryan Jr., I. L. Brisbin Jr.

Karen F. Gaines

Down feathers and regurgitant were collected from nestling wood storks (Mycteria americana) from two inland and two coastal breeding colonies in Georgia. The stable isotopic ratios of carbon ( 13 C/12 C) and nitrogen ( 15N/ 14N) in these materials were analyzed to gain insights into the natal origins of juvenile storks and the foraging activities of adults. Down feathers differed in δ 13 C between inland and coastal colonies, having average isotopic values that reflected the sources of carbon fixed in biomass at the base of the food web. Feathers from the inland colonies differed between colonies in δ …

The Effects Of Drought On Foraging Habitat Selection Of Breeding Wood Storks In Coastal Georgia, Karen F. Gaines, A. Lawrence Bryan Jr., Philip M. Dixon

Karen F. Gaines

Foraging habitat use by Wood Storks (Mycteria americana) during the breeding season was studied for three coastal colonies during a drought year and compared to habitat use during normal rainfall years. Information on the distribution of wetland habitat types was derived using U.S. Fish and Wildlife Service National Wetland In- ventory (NWI) data within a Geographic Information System (GIS). Foraging locations were obtained by following storks from their colonies in a fixed-winged aircraft. Differences in hydrologic condition and, the resulting prey availability in coastal zone freshwater wetlands greatly affected foraging habitat use and breeding success of the three stork colonies. …

Water Fog For Repelling Birds, Larry Clark, Thomas Nachtman, John Hull

Larry Clark

No abstract provided.

Size Selectivity Of Crappie Angling, Leandro E. Miranda, Brian S. Dorr

Brian S Dorr

Abstract.—Over 6,000 black crappies Pomoxis nigromaculatus and white crappies P. annularis were tagged in five lakes and reservoirs to quantify size selectivity of angling. Total length of fish tagged ranged from 20.0 to 39.8 cm; fish caught by anglers ranged from 20.0 to 38.8 cm. Return rates were low at lengths near 20 cm, increased gradually to a peak between 26 and 32 cm, and decreased for longer fish. This pattern was consistent among the five lakes and reservoirs and did not differ between species. Observed size-selective exploitation resulted in the lopsided removal of intermediate age-classes, thereby simulating a reversed …

Vocal Tract Function In Birdsong Production: Experimental Manipulation Of Beak Movements, Jeffrey Podos, W. J. Hoese, N. C. Boetticher, S. Nowicki

Jeffrey Podos

Kinematic analyses have demonstrated that the extent to which a songbird's beak is open when singing correlates with the acoustic frequencies of the sounds produced, suggesting that beak movements function to modulate the acoustic properties of the vocal tract during song production. If motions of the beak are necessary for normal song production, then disrupting the ability of a bird to perform these movements should alter the acoustic properties of its song. We tested this prediction by comparing songs produced normally by white-throated sparrows and swamp sparrows with songs produced when the beak was temporarily immobilized. We also observed how …

F-Actin Is Concentrated In Nonrelease Domains At Frog Neuromuscular Junctions, Elizabeth A. Connor, A. Duneavsky

Elizabeth A. Connor

To gain insight into the role of F-actin in the organization of synaptic vesicles at release sites, we examined the synaptic distribution of F-actin by using a unique synaptic preparation of frog target-deprived nerve terminals. In this preparation, imaging of the synaptic site was unobstructed by the muscle fiber cytoskeleton, allowing for the examination of hundreds of synaptic sites in their entirety in whole mounts. At target-deprived synaptic sites F-actin was distributed in a ladder-like pattern and was colocalized with β-fodrin. Surprisingly, F-actin stain, which we localized to the nerve terminal itself, did not overlap a synaptic vesicle marker, suggesting …

Stunted Plant 1 Mediates Effects Of Cytokinin, But Not Of Auxin, On Cell Division And Expansion In The Root Of Arabidopsis Thaliana, Tobias Baskin, G.T.S. Beemster

Tobias Baskin

Plants control organ growth rate by adjusting the rate and duration of cell division and expansion. Surprisingly, there have been few studies where both parameters have been measured in the same material, and thus we have little understanding of how division and expansion are regulated interdependently. We have investigated this regulation in the root meristem of the stunted plant 1(stp1) mutation of Arabidopsis, the roots of which elongate more slowly than those of the wild type and fail to accelerate. We used a kinematic method to quantify the spatial distribution of the rate and extent of cell division and expansion, …

Organic Carbon Supply And Metabolism In A Shallow Groundwater Ecosystem, Michelle A. Baker

Michelle A. Baker

In groundwater ecosystems, in situ primary production is low, and metabolism depends on organic matter inputs from other regions of the catchment. Heterotrophic metabolism and biogeochemistry in the floodplain groundwater of a headwater catchment (Rio Calaveras, New Mexico, USA) were examined to address the following questions: (1) How do groundwater metabolism and biogeochemistry vary spatially and temporally? (2) What factors influence groundwater metabolism? (3) What is the energy source for groundwater metabolism?

Additive And Nonadditive Effects Of Herbivory And Competition On Tree Seedling Mortality, Growth, And Allocation, Scott J. Meiners, Steven N. Handel

Scott J. Meiners

The interaction between simulated cotyledon herbivory and interspecific competition was studied in a greenhouse experiment using two species of trees, Acer rubrum and Quercus palustris, which commonly invade abandoned agricultural fields. Herbivory treatments were applied as a gradient of cotyledon removal for A. rubrum with 0, 25, 50, 75, and 100% of cotyledon tissue removed. Cotyledons from Q. palustris were clipped and removed (control, early, and late removal) to create a gradient of seed reserve availability. The competition treatment consisted of plugs of old-field vegetation that filled the pots with perennial cover. Mortality of seedlings was higher with competition. There …

Predation Rates On Real And Artificial Nests Of Grassland Birds, William B. Davison, Eric K. Bollinger

Eric K. Bollinger

We estimated nesting success at real and artificial nests of grassland birds to test the influence of nest type, nest position, and egg size on predation rates. We distributed wicker nests and realistic woven-grass nests baited with a clay egg and either a Northern Bobwhite (Colinus virginianus) egg or a House Sparrow (Passer domesticus) egg in four grasslands that were part of the Conservation Reserve Program in east-central Illinois. Nesting success averaged 86.5% for 12 days of exposure for artificial nests. For real nests, nesting success was markedly lower, averaging 39% over the entire nesting cycle and 59% during approximately …

Season And Distance From Forest - Old Field Edge Affect Seed Predation By White-Footed Mice, Scott J. Meiners, James T. Mccormick

Scott J. Meiners

We studied the spatial pattern of seed predation across a forest-old field edge in both fall and winter to assess the potential for seed predators to influence plant spatial patterns. We used a 100 x 100 m grid that began 30 m inside the forest and extended 60 m into the old field. Inside this grid we placed seed stations at regular 10 m intervals and monitored seed removal. Seed predation varied significantly across the edge gradient in both fall and winter with the highest rate of seed removal at the edge in both trials. The spatial pattern of seed …

Sagina (Caryophyllaceae) In Illinois: An Update, Gordon C. Tucker

Gordon C. Tucker

No abstract provided.

Heterogeneity In Water Availability Alters Cellular Development And Hydraulic Conductivity Along Roots Of A Desert Succulent, Gretchen North, P. Nobel

Gretchen North

Plants of the desert succulent Agave deserti were grown in partitioned containers to determine whether heterogeneity in soil moisture leads to differences in cellular development and hydraulic conductivity along individual roots. Roots from containers with a dry distal compartment (furthest from the shoot), a wet middle compartment, and a dry proximal compartment had distal regions (including the root tips) that were more suberized and lignified in the endodermis and adjacent cell layers than were root regions from the wet middle compartment. Proximal root regions about 40 mm from the succulent shoot base were also relatively unsuberized, suggesting that both external …

The Effects Of Drought In The Solidago Altissima - Eurosta Solidaginis - Natural Enemy Complex: Population Dynamics, Local Extirpations, And Measures Of Selection Intensity Of Gall Size, D Sumerford, Warren Abrahamson, A Weis

Warren G. Abrahamson, II

No abstract provided.

Review Of The Cynipid Gall Wasps Of The Genus Loxaulus (Hymenoptera: Cynipidae) With Descriptions Of New Species, Warren Abrahamson

Warren G. Abrahamson, II

No abstract provided.

Adaptive Amplification, An Inducible Chromosomal Instability Mechanism, P. Hastings, H. Bull, Jennifer Kowalski, S. Rosenberg

Jennifer Kowalski

Adaptive mutation is an induced response to environmental stress in which mutation rates rise, producing permanent genetic changes that can adapt cells to stress. This contrasts with neo-Darwinian views of genetic change rates blind to environmental conditions. DNA amplification is a flexible, reversible genomic change that has long been postulated to be adaptive. We report the discovery of adaptive amplification at the lac operon in Escherichia coli. Additionally, we find that adaptive amplification is separate from, and does not lead to, adaptive point mutation. This contradicts a prevailing alternative hypothesis whereby adaptive mutation is normal mutability in amplified DNA. Instead, …

Review Of The Cynipid Gall Wasps Of The Genus Loxaulus (Hymenoptera Cynipidae) With Descriptions Of New Species, G. Melika, Warren Abrahamson

Warren G. Abrahamson, II

No abstract provided.

Historical Review And Current State Of The World Generic Classification Of Oak Galls (Hymenoptera: Cynipidae: Cynipini, Warren Abrahamson, G. Melika

Warren G. Abrahamson, II

No abstract provided.