Life Sciences Commons^™

Nitrogen Budgets Of Phloem-Feeding Bark Beetles With And Without Symbiotic Fungi, Matthew P. Ayres, Richard T. Wilkens, Jonathan J. Ruel, María J. Lombardero, Erich Vallery

Dartmouth Scholarship

The nitrogen content of plant tissue is low relative to that of herbivores; as a consequence, dietary N can limit the growth and reproduction of herbivores and select for attributes that increase N acquisition. Bark beetles face a particularly severe challenge because the phloem that they consume is very low in nitrogen and phosphorus relative to their requirements. We quantified variation in the phloem concentrations of N and P in the host tree, Pinus taeda, and evaluated the following hypotheses regarding the role of symbiotic fungi in nutrient budgets of the herbivore Dendroctonus frontalis: D. frontalis experience variation …

High Efficiency Separation Of Microbial Aggregates Using Capillary Electrophoresis, J. M. Schneiderheinze, Daniel W. Armstrong, G. Schulte, David J. Westenberg

Chemistry Faculty Research & Creative Works

Recent advances in the technique of capillary electrophoresis have demonstrated fast, highly efficient separation of mixtures of intact microbes. This paper describes the application of this technique for the separation of microbial aggregates of Micrococcus luteus, Saccharomyces cerevisiae, or Alcaligenes faecalis. The aggregates of these microbes were resolved into several highly efficient peaks with analysis times under 10 min and efficiencies approaching 1 000 000 plates m-1 in some cases. A reproducible relationship was found between the electrophoretic mobility and the aggregation number or size of the cluster under a given set of experimental conditions. Often, cellular aggregation was reversible …

La Notion De Danger, Jean M. Kanellopoulos, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Pendant de nombreuses années, les recherches en immunologie ont été centrées sur la réponse immunitaire adaptative, et la plupart des immunologistes considéraient que sa fonction principale était de faire la distinction entre soi et non soi. Plus récemment, plusieurs équipes ont proposé que la fonction principale du système immunitaire est en réalité d’éliminer les agents pathogènes. Or, c’est le système immunitaire inné, longtemps négligé, qui joue un rôle essentiel dans l’induction d’une réponse contre les microorganismes. Ce système réagit précocement aux infections, voire instantanément, puis il induit et oriente la réponse du système adaptatif. Plusieursthéories ont été élaborées pour expliquer …

The Role Of Nf-Кb Activation In Breast Carcinoma And Glioblastoma Cell Lines, Kelly T. Murphy

Masters Theses

The nuclear factor-КB (NF-КB)/Rel family of inducible dimeric transcription factors regulates numerous genes associated with the immune, mitogenic, and apoptotic responses. Investigations were made into the role of NF-КB in breast carcinoma (MCF-7, T47D, MDA-MB-231) and glioblastoma (U87MG, U373MG, Ul 18MG) cell lines. NF-КB binding to DNA was quantified using both gel mobility shift assays and transient transfections of a vector containing a luciferase gene under the control of 4 tandem copies of the NF-КB binding sequence. To determine the correlation between NF-КB activation, cellular proliferation, and foci formation, the tumor cells were cultured and analyzed in the presence of …

Baseline Susceptibility Of The Corn Earworm (Lepidoptera: Noctuidae) To The Cry1ab Toxin From Bacillus Thuringiensis, Blair D. Siegfried, Terrence A. Spencer, Jessica Nearman

Department of Entomology: Faculty Publications

Susceptibility to Cry1Ab toxin from Bacillus thuringiensis (Bt) was determined for 12 field populations of neonate corn earworm, Helicoverpa zea (Boddie), from the United States. Earworm larvae were exposed to artificial diet treated with increasing Bt concentrations, and mortality and growth inhibition were evaluated after 7 d. The range of variation in Bt susceptibility indicated by growth inhibition was very similar to that indicated by mortality. Although interpopulation variation in susceptibility to both proteins was observed, the magnitude of the differences was small (less than or equal to fivefold). These results suggest that the observed susceptibility differences reflect natural variation …

Nuclear Localization Of Turnip Crinkle Virus Movement Protein P8, Yuval Cohen, Feng Qu, Andreas Gisel, Thomas Jack Morris, Patricia Zambryski

Department of Plant Pathology: Faculty Publications

Turnip crinkle virus (TCV) is a single-stranded positive-sense RNA virus of the Carmovirus genus. Two of its five open reading frames (ORFs), encoding proteins of 8 and 9 kDa, are required for cell-to-cell movement of the virus. These movement proteins (MPs) were fused to green fluorescent protein (GFP) to determine their cellular localization. In protoplasts, p9-GFP, like GFP itself, is found throughout the cytoplasm, as well as in cell nuclei. In contrast, p8-GFP was confined to the cell nucleus. Similar localization patterns were observed when specific small peptide epitopes were fused to p8 and p9 proteins instead of GFP. The …

Utility Of The Mitochondrial Cytochrome Oxidase Ii Gene For Resolving Relationships Among Black Flies (Diptera: Simuliidae), K. P. Pruess, B. J. Adams, T. J. Parsons, X. Zhu, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

The complete mitochondrial cytochrome oxidase II gene was sequenced from 17 black flies, representing 13 putative species, and used to infer phylogenetic relationships. A midge (Paratanytarsus sp.) and three mosquitoes (Aedes aegypti, Anopheles quadrimaculatus, and Culex quinquefasciatus) were used as outgroup taxa. All outgroup taxa were highly divergent from black flies. Phylogenetic trees based on weighted parsimony (a priori and a posteriori), maximum likelihood, and neighbor-joining (log-determinant distances) differed topologically, with deeper nodes being the least well-supported. All analyses supported current classification into species groups but relationships among those groups were poorly resolved. The majority of phylogenetic …

Emergence Of Third-Stage Larvae Of Umingmakstrongylus Pallikuukensis From Three Gastropod Intermediate Host Species, Susan K. Kutz, Eric P. Hoberg, Lydden Polley

Harold W. Manter Laboratory of Parasitology: Faculty Publications

We investigated the emergence of third-stage larvae (L3) of Umingmakstrongylus pallikuukensis from the slugs Deroceras laeve, Deroceras reticulatum, and the snail Catinella sp. in the laboratory and from D. laeve on the tundra. Third-stage larvae emerged from 8 of 8 D. laeve and 8 of 8 D. reticulatum housed at 20°C in darkness and from 9 of 10 D. laeve and 5 of 5 Catinella sp. housed at 21°C with 10-12 hours of light/day. Larvae emerged from D. laeve and D. reticulatum over a wide range of infection intensities (2-179 and 20-65, respectively), and the patterns of emergence …

Before You Say Yes: A Planning Guide For Speakers, Charles A. Francis, Heidi Carter, Cris Carusi, James W. King

Department of Agronomy and Horticulture: Faculty Publications

We need guidelines to help us decide whether to accept invitations to speak, whether to a class on campus or a special interest group outside. As educators and workshop organizers, we could also use suggestions on how to approach potential speakers. This article describes a single-page format that can be used to guide the planning process. Essential elements include contact information, location and organization of the activity, audience, learning goals, expected content, conclusions, and evaluation. Use of this planning sheet can give organization to an often haphazard process of planning, and enhance the potential of achieving the learning goals of …

Early Instar Growth And Survivorship In The Common Baskettail Dragonfly Epitheca Cynosura (Anisoptera: Corduliidae)., Bryan Arthur Reece

Electronic Theses and Dissertations

Egg masses of Epitheca cynosura were collected from Bays Mountain Park, Tennessee, USA, in June, 1999. Newly hatched individuals were placed into enclosures and sampled at scheduled time intervals throughout the summer. Enclosures were exposed to combinations of high and low densities and presence/absence of a second-year class E. cynosura predator. Survivorship, mean head widths, and mean dry masses were compared across treatments. Due to poor recovery of early-instar larvae, survivorship showed no significant differences in mortality among treatments. The predator present treatment caused significantly smaller head widths and dry masses only on days 42 and 55. The density treatment …

Characterization Of 50s Ribosomal Subunit Assembly Inhibition In Erythromycin Treated Escherichia Coli Cells., Jerry Edward Usary

Electronic Theses and Dissertations

Erythromycin has long been recognized for its ability to inhibit protein synthesis by interfering with mRNA translation on the bacterial ribosome. We have recently shown that erythromycin also inhibits the assembly of the 50S ribosomal subunit in growing bacterial cells. The nature of this assembly inhibition has been investigated using ³H-uridine pulse-chase labeling of control and erythromycin treated E. coli cells.

Subunit assembly was examined by sucrose gradient centrifugation of labeled cell lysates. Normal assembly kinetics of subunit assembly were observed in control cells at 37°C. Formation of the 30S subunit was completed by 7.5 minutes and assembly of …

Practicality Of Large Mylar Bags To Store Corn And Beans In Kenya, Byu Food Quality Assurance Laboratory

Faculty Publications

The purpose of this study is to determine the practicality of using extra large zip-lock mylar bags with oxygen absorber packets to store corn and beans in Chyulu, Kenya. Weevil usually gets in the food after about 5 months, so if the oxygen can be maintained at a low level, the corn and beans could be stored for longer than that. The goal is to be able to store the food for 18 months. In order to determine the practicality of using the mylar bags to store corn and beans, the following questions will need to be answered: · Are …

Vibrio Cholerae H-Ns Silences Virulence Gene Expression At Multiple Steps In The Toxr Regulatory Cascade, Melinda B. Nye, James D. Pfau, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

H-NS is an abundant nucleoid-associated protein involved in the maintenance of chromosomal architecture in bacteria. H-NS also has a role in silencing the expression of a variety of environmentally regulated genes during growth under nonpermissive conditions. In this study we demonstrate a role for H-NS in the negative modulation of expression of several genes within the ToxR virulence regulon ofVibrio cholerae. Deletion of hns resulted in high, nearly constitutive levels of expression of the genes encoding cholera toxin, toxin-coregulated pilus, and the ToxT virulence gene regulatory protein. For the cholera toxin- and ToxT-encoding genes, elevated expression in an …

A Plant Virus Vector For Systemic Expression Of Foreign Genes In Cereals, Il-Ryong Choi, Drake C. Stenger, Thomas Jack Morris, Roy C. French

Department of Plant Pathology: Faculty Publications

Inserts bearing the coding sequences of NPTll and P-glucuronidase (GUS) were placed between the nuclear inclusion b (Nlb) and coat protein (CP) domains of the wheat streak mosaic virus (WSMV) polyprotein ORF. The WSMV Nlb-CP junction containing the nuclear inclusion a (Nla) protease cleavage site was duplicated, permitting excision of foreign protein domains from the viral polyprotein. Wheat, barley, oat and maize seedlings supported systemic infection of WSMV bearing NPTII. The NPTII insert was stable for at least 18-30 days post-inoculation and had little effect on WSMV CP accumulation. Histochemical assays indicated the presence of functional GUS protein in systemically …

Isolation And Characterization Of A Genetic Locus That Confers Tolerance To Cadmium And Zinc In Pseudomonas Fluorescens, Szi Fei Feng

Masters Theses

This thesis describes the isolation and characterization of a region containing several genes involved in metal tolerance in the common soil bacterium, Pseudomonas fluorescens ATCC 13525. The DNA region was identified in a cadmium and zinc sensitive mutant, 45-B10, which contains a lacZ-based reporter gene transposon Tn5-B20 inserted in the chromosome. The DNA surrounding the transposon was cloned from this mutant strain and DNA sequencing of this region revealed seven genes that share similarity with genes whose products are involved in the cation-proton antiporter efflux system of other Gram-negative bacteria. Complete DNA sequence was obtained from four of these …

Identifying Areas Of Agricultural Significance, Ian Kininmonth

Agriculture reports

The protection of productive agricultural land and the avoidance of land use conflicts in rural areas are important objectives of the Western Australian Government. They are reflected in the State Planning Strategy, Agriculture Western Australia’s strategic plan, ‘Focus on the Future’ and draft Statement of Planning Policy (SPP) No. 11 – Agricultural and Rural Land Use Planning Policy. However, agricultural land is required for a variety of purposes and so it is important that agriculture is able to identify those areas which are irreplaceable in terms of existing and future production and those areas which may be used for other …

Physiology Of A Microgravity Environment Invited Review: Microgravity And Skeletal Muscle, Robert H. Fitts, Danny R. Riley, Jeffrey J. Widrick

Biological Sciences Faculty Research and Publications

Spaceflight (SF) has been shown to cause skeletal muscle atrophy; a loss in force and power; and, in the first few weeks, a preferential atrophy of extensors over flexors. The atrophy primarily results from a reduced protein synthesis that is likely triggered by the removal of the antigravity load. Contractile proteins are lost out of proportion to other cellular proteins, and the actin thin filament is lost disproportionately to the myosin thick filament. The decline in contractile protein explains the decrease in force per cross-sectional area, whereas the thin-filament loss may explain the observed postflight increase in the maximal velocity …

The Impact Of Lianas On Tree Regeneration In Tropical Forest Canopy Gaps: Evidence For An Alternative Pathway Of Gap‐Phase Regeneration, Stefan A. Schnitzer, James W. Dalling, Walter P. Carson

Biological Sciences Faculty Research and Publications

1 Regeneration in forest canopy gaps is thought to lead invariably to the rapid recruitment and growth of trees and the redevelopment of the canopy. Our observations, however, suggest that an alternate successional pathway is also likely, whereby gap‐phase regeneration is dominated by lianas and stalled in a low‐canopy state for many years. We investigated gap‐phase regeneration in an old‐growth tropical forest on Barro Colorado Island (BCI) in Panama to test the following two hypotheses: (i) many gaps follow a pathway in which they remain at a low canopy height and are dominated by lianas and (ii) the paucity of …

Physiology Of A Microgravity Environment Invited Review: Microgravity And Skeletal Muscle, Robert H. Fitts, Danny R. Riley, Jeffrey J. Widrick

Biological Sciences Faculty Research and Publications

Spaceflight (SF) has been shown to cause skeletal muscle atrophy; a loss in force and power; and, in the first few weeks, a preferential atrophy of extensors over flexors. The atrophy primarily results from a reduced protein synthesis that is likely triggered by the removal of the antigravity load. Contractile proteins are lost out of proportion to other cellular proteins, and the actin thin filament is lost disproportionately to the myosin thick filament. The decline in contractile protein explains the decrease in force per cross-sectional area, whereas the thin-filament loss may explain the observed postflight increase in the maximal velocity …

Aintegumenta Promotes Petal Identity And Acts As A Negative Regulator Of Agamous, Beth A. Krizek, Valerie Prost, Anthony Macias

Faculty Publications

The Arabidopsis AINTEGUMENTA (ANT) gene has been shown previously to be involved in ovule development and in the initiation and growth of floral organs. Here, we show that ANT acts in additional processes during flower development, including repression of AGAMOUS (AG) in second whorl cells, promotion of petal epidermal cell identity, and gynoecium development. Analyses of ap2-1 ant-6 double mutants reveal that ANT acts redundantly with AP2 to repress AG in second whorl cells. The abaxial surface of ant petals contains features such as stomata and elongated, interdigitated cells that are not present on wild-type petals. …

Myrica Pensylvanica Mirb., Gordon C. Tucker

Specimens by Name

No abstract provided.

Fraxinus Americana L., Gordon C. Tucker, Edwin H. Horning

Specimens by Name

No abstract provided.

Fraxinus Pennsylvanica Marsh., Gordon C. Tucker

Specimens by Name

No abstract provided.

Comptonia Peregrina (L.) J.M. Coult., Gordon C. Tucker, Edwin H. Horning, Maria Figueroa, P. R. Lagname

Specimens by Name

No abstract provided.

The Dynamics Of The Planktonic Communities Of Two Oregon Reservoirs, Miguel Angel Estrada

Dissertations and Theses

From June 1998 to July 1999, the dynamics of the plankton in Hagg Lake and Barney Reservoir were studied with the purpose to identify the succession dynamics of the planktonic species, to test the Plankton Ecology Group (PEG) model, and to explore the relationships between these successions and the physical and chemical variables.

Industrialization And Globalization: A Battle Over Values?, Gary D. Lynne

Cornhusker Economics

About a year ago a French farmer proclaimed, while he checked himself into jail for his part in vandalizing a new McDonald’s restaurant, “My struggle remains the same . . . the battle against globalization, and for the right of people to feed themselves as they choose'' (New York Times, August 29, 1999). Such protests reflect even more fundamental underlying concerns for food produced in ways not always meeting higher level needs, e.g., not satisfying the cultural needs for the French, a country in which the event of a meal is often just as important as the food itself. The …

Ampelopsis Brevipedunculata (Maxim.) Trautv., Gordon C. Tucker

Specimens by Name

No abstract provided.

Ampelopsis Brevipedunculata (Maxim.) Trautv., Gordon C. Tucker, Daniel M. Tucker

Specimens by Name

No abstract provided.

Ampelopsis Cordata Michx., John E. Ebinger

Specimens by Name

No abstract provided.

Verbena Stricta Vent., John E. Ebinger

Specimens by Name

No abstract provided.