Digital Commons Network^™

Modeling The Acquisition Of Social Rank In Crayfish: Winner And Loser Effects And Self-Structuring Properties, Karlo Hock, Robert Huber

Robert Huber

No abstract provided.

Climatic Unpredictability And Parasitism Of Caterpillars: Implications Of Global Warming, John O. Stireman Iii, Lee A. Dyer, D. H. Janzen, M. S. Singer, J. T. Lill, R. J. Marquis, R. E. Ricklefs, G. L. Gentry, W. Hallwachs, P. D. Coley, J. A. Barone, H. F. Greeney, H. Connahs, P. Barbosa, H. C. Morais, I. R. Diniz

Robert Marquis

The Three Dimensional Detection Of Microvasculatory Bed In The Brain Of White Rat Rattus Norvegicus By A Ca2+ -Atpase Method., Amaiak Chilingaryan, Amayak Chilingaryan, Gary Martin

Gary Martin

A procedure is described which allows for the selective and non-injectional staining of the three-dimensional microvasculatory bed (MVB) in thick sections (60–140 μm) of formalin-fixed brain tissue of white rats Rattus norvegicus. This histochemical method detects ATPase activity and takes place between pH 10.5 and 11.2. Calcium ion is used to capture inorganic phosphate, calcium phosphate is converted to lead phosphate, and subsequently converted to black or dark brown lead sulfide. All vessels are revealed due to a precipitate on the endothelium and smooth muscle cells of arterioles. In some vessels, red blood cells also stain. The background is transparent …

Spiroplasma Penaei Sp. Nov., Associated With Mortalities In Penaeus Vannamei, Pacific White Shrimp, Linda M. Nunan, Donald V. Lightner, Marietta A. Oduori, Gail E. Gasparich

Gail Gasparich

Spiroplasma Leucomae Sp. Nov., Isolated In Poland From White Satin Moth (Leucoma Salicis L.) Larvae, Marietta A. Oduori, Jerzy J. Lipa, Gail E. Gasparich

Gail Gasparich

Callose (Β-1,3 Glucan) Is Essential For Arabidopsis Pollen Wall Patterning, But Not Tube Growth, Rob Swanson

Rob Swanson

Background: Callose (β-1,3 glucan) separates developing pollen grains, preventing their underlying walls (exine) from fusing. The pollen tubes that transport sperm to female gametes also contain callose, both in their walls as well as in the plugs that segment growing tubes. Mutations in CalS5, one of several Arabidopsis β-1,3 glucan synthases, were previously shown to disrupt callose formation around developing microspores, causing aberrations in exine patterning, degeneration of developing microspores, and pollen sterility. Results: Here, we describe three additional cals5 alleles that similarly alter exine patterns, but instead produce fertile pollen. Moreover, one of these alleles (cals5-3) resulted in the …

Problem Solving: A Foundation For Modeling, Janet Hodder, George Middendorf, D. Ebert-May

George Middendorf

No abstract provided.

Regulatory Functions Of Phospholipase D And Phosphatidic Acid In Plant Growth, Development, And Stress Responses, Xuemin Wang

Xuemin (Sam) Wang

No abstract provided.

Graduate Colloquium, Borbala Mazzag

Borbala Mazzag

No abstract provided.

Expression Of G-Protein Inwardly Rectifying Potassium Channels (Girks) In Lung Cancer Cell Lines, Howard Plummer 3rd, Madhu Dhar, Maria Cekanova Ms, Rndr, Phd, Hildegard Schuller

Maria Cekanova MS, RNDr, PhD

BACKGROUND: Previous data from our laboratory has indicated that there is a functional link between the beta-adrenergic receptor signaling pathway and the G-protein inwardly rectifying potassium channel (GIRK1) in human breast cancer cell lines. We wanted to determine if GIRK channels were expressed in lung cancers and if a similar link exists in lung cancer. METHODS: GIRK1-4 expression and levels were determined by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. GIRK protein levels were determined by western blots and cell proliferation was determined by a 5-bromo-2'-deoxyuridine (BrdU) assay. RESULTS: GIRK1 mRNA was expressed in three of six small …

Digenic Control Of Colouration In The Two-Spot Gourami Trichogaster Trichopterus Trichopterus, Jack Frankel

Jack Frankel

Gli Function Is Essential For Motor Neuron Induction In Zebrafish, Rolf O. Karlstrom, Gary Vanderlaan, Oksana V. Tyurina, Anand Chandrasekhar

Rolf O Karlstrom

The Gli family of zinc-finger transcription factors mediates Hedgehog (Hh) signaling in all vertebrates. However, their roles in ventral neural tube patterning, in particular motor neuron induction, appear to have diverged across species. For instance, cranial motor neurons are essentially lost in zebrafish detour (gli1−) mutants, whereas motor neuron development is unaffected in mouse single gli and some double gli knockouts. Interestingly, the expression of some Hh-regulated genes (ptc1, net1a, gli1) is mostly unaffected in the detour mutant hindbrain, suggesting that other Gli transcriptional activators may be involved. To better define the roles of the zebrafish gli genes in motor …

Hedgehog Regulated Slit Expression Determines Commissure And Glial Cell Position In The Zebrafish Forebrain, Michael J. F. Barresi, Lara D. Hutson, Chi-Bin Chien, Rolf O. Karlstrom

Rolf O Karlstrom

Three major axon pathways cross the midline of the vertebrate forebrain early in embryonic development: the postoptic commissure (POC), the anterior commissure (AC) and the optic nerve. We show that a small population of Gfap+ astroglia spans the midline of the zebrafish forebrain in the position of, and prior to, commissural and retinal axon crossing. These glial `bridges' form in regions devoid of the guidance molecules slit2 and slit3, although a subset of these glial cells express slit1a. We show that Hh signaling is required for commissure formation, glial bridge formation, and the restricted expression of the guidance molecules slit1a, …

Cobra, An Arabidopsis Extracellular Glycosyl-Phosphatidyl Inositol-Anchored Protein, Specifically Controls Highly Anisotropic Expansion Through Its Involvement In Cellulose Microfibril Orientation, François Roudier, Anita G. Fernandez, Miki Fujita, Regina Himmelspach, Georg H.H. Borner, Gary Schindelman, Shuang Song, Tobias Baskin, Paul Dupree, Geoffrey O. Wasteneys, Philip N. Benfey

Tobias Baskin

The orientation of cell expansion is a process at the heart of plant morphogenesis. Cellulose microfibrils are the primary anisotropic material in the cell wall and thus are likely to be the main determinant of the orientation of cell expansion. COBRA (COB) has been identified previously as a potential regulator of cellulose biogenesis. In this study, characterization of a null allele, cob-4, establishes the key role of COB in controlling anisotropic expansion in most developing organs. Quantitative polarized-light and field-emission scanning electron microscopy reveal that loss of anisotropic expansion in cob mutants is accompanied by disorganization of the orientation of …

Evolution Of Cyrtandra (Gesneriaceae) In The Pacific Ocean: The Origin Of A Supertramp Clade, Quentin C. B. Cronk, Michael Kiehn, Warren L. Wagner, James F. Smith

James F. Smith

Cyrtandra comprises at least 600 species distributed throughout Malesia, where it is known for many local endemics and in Polynesia and Micronesia, where it is present on most island groups, and is among the most successfully dispersing genera of the Pacific. To ascertain the origin of the oceanic Pacific island species of Cyrtandra, we sequenced the internal transcribed spacers of nuclear ribosomal DNA of samples from throughout its geographical range. Because all oceanic Pacific island species form a well-supported clade, these species apparently result from a single initial colonization into the Pacific, possibly by a species from the eastern rim …

Zebrafish Bandoneon Mutants Display Behavioral Defects Due To A Mutation In The Glycine Receptor Β Subunit, Gerald B. Downes, Hiromi Hirata, Louis Saint-Amant, Wilson W. Cui, Weibin Zhou, Michael Granato, John Y. Kuwada

Gerald B. Downes

Bilateral alternation of muscle contractions requires reciprocal inhibition between the two sides of the hindbrain and spinal cord, and disruption of this inhibition should lead to simultaneous activation of bilateral muscles. At 1 day after fertilization, wild-type zebrafish respond to mechanosensory stimulation with multiple fast alternating trunk contractions, whereas bandoneon (beo) mutants contract trunk muscles on both sides simultaneously. Similar simultaneous contractions are observed in wild-type embryos treated with strychnine, a blocker of the inhibitory glycine receptor (GlyR). This result suggests that glycinergic synaptic transmission is defective in beo mutants. Muscle voltage recordings confirmed that muscles on both sides of …

Quasistatic And Continuous Dynamic Characterization Of The Mechanical Properties Of Silk From The Cobweb Of The Black Widow Spider Latrodectus Hesperus, Todd A. Blackledge, John E. Swindeman, Cheryl Y. Hayashi

Todd A. Blackledge

Spider silks are among the strongest and toughest known materials, but investigation of these remarkable properties has been confined largely to orb-weaving spiders. We investigated the mechanical performance of silk from the cobweb-weaving spider Latrodectus hesperus. Both silk from the scaffolding region of the web and sticky gumfooted capture lines had material properties similar to the major ampullate silk that orb weavers use as the framework for their orb webs. Major ampullate fibers obtained from anaesthetized Latrodectus spiders were similar, but exhibited increased stiffness and reduced extensibility. Novel continuous dynamic analysis of the silks revealed that the loss tangent (tan …

Regulation Of Prokineticin 2 Expression By Light And The Circadian Clock, Michelle Y. Cheng, Eric L. Bittman, Samer Hattar, Qun Yong Zhou

Eric L. Bittman

Background: The suprachiasmatic nucleus (SCN) contains the master circadian clock that regulates daily rhythms of many physiological and behavioural processes in mammals. Previously we have shown that prokineticin 2 (PK2) is a clock-controlled gene that may function as a critical SCN output molecule responsible for circadian locomotor rhythms. As light is the principal zeitgeber that entrains the circadian oscillator, and PK2 expression is responsive to nocturnal light pulses, we further investigated the effects of light on the molecular rhythm of PK2 in the SCN. In particular, we examined how PK2 responds to shifts of light/dark cycles and changes in photoperiod. …

A Porpoise For Power, Frank E. Fish

Frank E. Fish

No abstract provided.

What Communities Should Do Pre-Event To Support Public Health Post-Event Assessments, Surveillance And Monitoring, Thomas Lyons Carr Iii

Thomas Lyons (Thom) Carr III Appl.Sc., CEM

[Abstract written March 2008, TLC] Under worst-case planning assumptions used by some major metropolitan areas, a Neighbor-to-Neighbor self-help program model is the primary link between citizens and the professional response personnel of the responsible government agencies.

In the Neighbor-to-Neighbor self-help program model or a Community Emergency Management Plan (CEMP) calls on the citizens in neighborhoods to identify and establish cluster emergency preparedness committees, Cluster Emergency Coordination Centers (CECC) and Community Emergency Response Teams (CERT). Missing from these plans or what is not articulated is how constant Public Health Post-Event Surveillance, Monitoring and Assessments will be done. Given the worst-case planning …

Biogeography Of The Nearshore Rocky-Reef Fishes At The Southern And Baja California Islands, Daniel Pondella, Brooke Gintert, Jana Cobb, Larry Allen

Daniel Pondella

No abstract provided.

Rodents As Receptor Species At A Tritium, Angel Kelsey-Wall, John C. Seaman, Charles H. Jegoe, Cham E. Dallas, Karen F. Gaines

Karen F. Gaines

New methods are being employed on the Department of Energy’s Savannah River Site to deal with the disposal of tritium, including the irrigation of a hardwood/pine forest with tritiated water from an intercepted contaminant plume to reduce concentrations of tritium outcropping into Fourmile Branch, a tributary of the Savannah River. The use of this system has proven to be an effective means of tritium disposal. To evaluate the impact of this activity on terrestrial biota, rodent species were captured on the tritium disposal site and a control site during two trapping seasons in order to assess tritium exposure resulting from …

Cryopreservation Of Human Hematopoietic Stem And Progenitor Cells Loaded With Trehalose: Transient Permeabilization Via The Adenosine Triphosphatedependent P2z Receptor Channel, Sandhya S. Buchanan, Michael A. Menze, Steven C. Hand, David W. Pyatt, John F. Carpenter

Michael Menze

Hematopoietic stem and progenitor cells (HPCs) are a heterogenic population of cells used to treat a number of human diseases. Multilineage differentiation is a required function in successful hematopoietic reconstitution after transplantation of cryopreserved grafts. Conventional use of the cryoprotectant dimethyl sulfoxide (DMSO) has resulted in some reports of infusion related toxicity attributed to DMSO and/or damage to cells during freezethawing procedures. The purpose of this study was to explore the use of trehalose, a nontoxic disaccharide of glucose, as an alternative cryoprotectant. Trehalose was introduced into HPCs using the P2Z receptor, known to form nonselective pores in the presence …

Allosteric Models For Multimeric Proteins: Oxygen-Linked Effector Binding In Hemocyanin, Michael A. Menze, Nadja Hellman, Heinz Decker, Manfred K. Grieshaber

Michael Menze

In many crustaceans, changing concentrations of several low molecular weight compounds modulates hemocyanin oxygen binding, resulting in lower or higher oxygen affinities of the pigment. The nonphysiological effector caffeine and the physiological modulator urate, the latter accumulating in the hemolymph of the lobster Homarus Vulgaris during hypoxia, increase hemocyanin oxygen affinity and decrease cooperativity of oxygen binding. To derive a model that describes the mechanism of allosteric interaction between hemocyanin and oxygen in the presence of urate or caffeine, studies of oxygen, urate, and caffeine binding to hemocyanin were performed. Exposure of lobster hemocyanin to various pH values between 7.25 …

Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang-Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner

Michael Menze

Trehalose has extensively been used to improve the desiccation tolerance of mammalian cells. To test whether trehalose improves desiccation tolerance of mammalian mitochondria, we introduced trehalose into the matrix of isolated rat liver mitochondria by reversibly permeabilizing the inner membrane using the mitochondrial permeability transition pore (MPTP). Measurement of the trehalose concentration inside mitochondria using high perfOrmance liquid chromatography showed that the sugar permeated rapidly into the matrix upon opening the MPTP. The concentration of intra matrix trehalose reached 0.29 mmoVmg protein (-190 mM) in 5 min. Mitochondria, with and without trehalose loaded into the matrix, were desiccated in a …

A Spatially Explicit Model Of The Wild Hog For Ecological Risk Assessment Activities At The Department Of Energy's Savannah River Site, Karen F. Gaines, Dwayne E. Porter, Tracy Punshon, I. Lehr Brisbin Jr.

Karen F. Gaines

In North America, wild hogs (Sus scrofa) are both sought after as prime game and despised due to their detrimental impacts to the environment from their digging and rooting behavior. They are also a potentially useful indicator species for environmental health for both ecological- and human-based risk assessments. An inductive approach was used to develop probabilistic resource selection models using logistic regression to quantify the likelihood of hogs being in any area of the Department of Energy’s 805 km2 Savannah River Site (SRS) in west-central South Carolina. These models were derived by using available SRS hog hunt data from 1993–2000 …

The Development Of A Spatially Explicit Model To Estimate, Karen F. Gaines, C. Shane Boring, Dwayne E. Porter

Karen F. Gaines

A spatially explicit model of raccoon (Procyon lotor) distribution for the U.S. Department of Energy’s (DOE) Savannah River Site (SRS) in west-central South Carolina was developed using data from a raccoon radio-telemetry study and visualized within a Geographic Information System (GIS). An inductive approach was employed to develop three sub-models using the ecological requirements of raccoons studied in the following habitats: (1) man-made reservoirs, (2) bottomland hardwood/ riverine systems, and (3) isolated wetland systems. Logistic regression was used to derive probabilistic resource selection functions using habitat compositional data and landscape metrics. The final distribution model provides a spatially explicit probability …

Temporal Patterns In Fall Migrant Communities In Yucatan, Mexico, Jill L. Deppe, John T. Rotenberry

Jill L Deppe

We quantified temporal turnover in the composition of fall migrant landbird communities along the northern coast of the Yucatan Peninsula using Detrended Correspondence Analysis. The presence of winter residents of many migrant species at the site prevented turnover from being complete. However, early and late season transient communities shared few, if any, species in common. Point-count surveys showed greater compositional change than net surveys that included winter residents. The rate of species turnover was generally slow until the middle of the season, when it reached a maximum, and decreased again toward the end of the season as species composition began …

Habitat And Exposure Modelling For Ecological Risk Assessment: A, T. Edwin Chow, Karen F. Gaines, Michael E. Hodgson, Machelle D. Wilson

Karen F. Gaines

Contamination has a dramatic impact on the health of ecosystem and habitat suitability for the inhabited flora and fauna. The Environmental Protection Agency (EPA) mandates an ecological risk assessment (ERA) that evaluates the potential adverse impact of any anthropogenic activities on the ecosystem (US Environmental Protection Agency, 1997. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessment. EPA/630/R-021011, Washington, DC). This study provides a general framework and specific procedures to predict the contaminant exposure of midsized mammals using a geographical information system (GIS)-based Monte Carlo simulation model. The model was applied to the raccoons (Procyon …

Influence Of Stem Cutting And Glyphosate Treatment Of Lonicera Maackii, An Exotic And Invasive Species, On Stem Regrowth And Native Species Richness, Henry R. Owen, A. L. Mcdonnell, A. M. Mounteer, B. L. Todd

Henry R. Owen

Lonicera maackii (Rupr.) Herder (Caprifoliaceae), Amur honeysuckle, is an exotic and invasive species in the United States that has quickly overtaken disturbed habitats in the eastern and midwestern United States, as well as in Ontario, Canada. A reduction of light due to its dense canopy, extended growing season compared to native species, and production of numerous basal sprouts allow L. maackii to outcompete its native counterparts. Eradication of this species can be difficult and time-consuming. This research was undertaken to identify how L. maackii influences species diversity and species re-establishment and to determine an efficient and effective eradication method. A …