Entire DC Network | Open Access Articles | Digital Commons Network™

The Benefits Of Bathing Buds: Water Calyces Protect Flowers From A Microlepidopteran Herbivore, Jane E. Carlson, Kyle E. Harms

Faculty Publications

Protective floral structures may evolve in response to the negative effects of floral herbivores. For example, water calyces - liquid-filled, cup-like structures resulting from the fusion of sepals - may reduce floral herbivory by submerging buds during their development. Our observations of a water-calyx plant, Chrysothemis friedrichsthaliana (Gesneriaceae), revealed that buds were frequently attacked by ovipositing moths (Alucitidae), whose larvae consumed anthers and stigmas before corollas opened. Almost 25% of per-plant flower production was destroyed by alucitid larvae over two seasons, far exceeding the losses to all other floral herbivores combined. Experimental manipulation of water levels in calyces showed that …

Go to article

Investigation Of The Summer Kara Sea Circulation Employing A Variational Data Assimilation Technique, G. Panteleev, A. Proshutinsky, M. Kulakov, Dmitri A. Nechaev, W. Maslowski

Faculty Publications

[ 1] The summer circulations and hydrographic fields of the Kara Sea are reconstructed for mean, positive and negative Arctic Oscillation regimes employing a variational data assimilation technique which provides the best fit of reconstructed fields to climatological data and satisfies dynamical and kinematic constraints of a quasi-stationary primitive equation ocean circulation model. The reconstructed circulations agree well with the measurements and are characterized by inflow of 0.63, 0.8, 0.51 Sv through Kara Gate and 1.18, 1.1, 1.12 Sv between Novaya Zemlya and Franz Josef Land, for mean climatologic conditions, positive and negative AO indexes, respectively. The major regions of …

Go to article

Whole Genome Duplications And Contracted Breakpoint Graphs, Max A. Alekseyev, Pavel A. Pevzner

Faculty Publications

The genome halving problem, motivated by the whole genome duplication events in molecular evolution, was solved by El-Mabrouk and Sankoff in the pioneering paper [SIAM J. Comput., 32 (2003), pp. 754–792]. The El-Mabrouk–Sankoff algorithm is rather complex, inspiring a quest for a simpler solution. An alternative approach to the genome halving problem based on the notion of the contracted breakpoint graph was recently proposed in [M. A. Alekseyev and P. A. Pevzner, IEEE/ACM Trans. Comput. Biol. Bioinformatics, 4 (2007), pp. 98–107]. This new technique reveals that while the El-Mabrouk–Sankoff result is correct in most cases, it does not hold in …

Go to article

Adult Phyllophaga Ephilida Host Plant Feeding Preference, Aboubacar Diagne, Richard N. Story, Abner M. Hammond

Faculty Publications

Limited biological information about Phyllophaga ephilida, a major sweet potato pest in Louisiana, is available. In 2001 and 2002, a study was conducted in the laboratory to investigate the feeding preference of adult Phyllophaga ephilida (Say) (Coleoptera: Scarabaeidae) for the foliage of eight woody plant species: water oak (Quercus nigra L.), live oak (Quercus virginiana Mill.), red maple (Acer rubrum L.), slash pine (Pinus caribaea Morelet), pecan (Carya illinoensis (Wangenh) K. Koch), sweetgum (Liquidambar styraciflua L.), southern magnolia (Magnolia grandiflora L.), and American elm (Ulmus americana L.). Beetles were placed in an arena with the eight host plants and allowed …

Go to article

Cellular Efflux Of Auxin Catalyzed By The Arabidopsis Mdr/Pgp Transporter Atpgp1, Markus Geisler, Joshua J. Blakeslee, Rodolphe Bouchard, Ok Ran Lee, Vincent Vincenzetti, Anindita Bandyopadhyay, Boosaree Titapiwatanakun, Wendy Ann Peer, Aurèlien Bailly, Elizabeth L. Richards, Karin F.K. Ejendal, Aaron P. Smith, Célia Baroux, Ueli Grossniklaus, Axel Müller, Christine A. Hrycyna, Robert Dudler, Angus S. Murphy, Enrico Martinoia

Faculty Publications

Directional transport of the phytohormone auxin is required for the establishment and maintenance of plant polarity, but the underlying molecular mechanisms have not been fully elucidated. Plant homologs of human multiple drug resistance/P-glycoproteins (MDR/PGPs) have been implicated in auxin transport, as defects in MDR1 (AtPGP19) and AtPGP1 result in reductions of growth and auxin transport in Arabidopsis (atpgp1, atpgp19), maize (brachytic2) and sorghum (dwarf3). Here we examine the localization, activity, substrate specificity and inhibitor sensitivity of AtPGP1. AtPGP1 exhibits non-polar plasma membrane localization at the shoot and root apices, as well as polar localization above the root apex. Protoplasts from …

Go to article

Antifungal Activity Of Camptothecin, Trifolin, And Hyperoside Isolated From Camptotheca Acuminata, Shiyou Li, Zhizhen Zhang, Abigail Cain, Bo Wang, Melissa Long, Josephine Taylor

Faculty Publications

Leaf spots and root rots are major fungal diseases in Camptotheca acuminata that limit cultivation of the plant for camptothecin (CPT), a promising anticancer and antiviral alkaloid. Bioassays showed that pure CPT and flavonoids (trifolin and hyperoside) isolated from Camptotheca effectively control fungal pathogens in vitro, including Alternaria alternata, Epicoccum nigrum, Pestalotia guepinii, Drechslera sp., and Fusarium avenaceum, although antifungal activity of these compounds in the plant is limited. CPT inhibited mycelial growth by approximately 50% (EC₅₀) at 10−30 μg/mL and fully inhibited growth at 75−125 μg/mL. The flavonoids were less effective than CPT …

Go to article

Error As Means To Discovery, Kevin C. Elliott

Faculty Publications

This paper argues, first, that recent studies of experimentation, most notably by Deborah Mayo, provide the conceptual resources to describe scientific discovery’s early stages as error-probing processes. Second, it shows that this description yields greater understanding of those early stages, including the challenges that they pose, the research strategies associated with them, and their influence on the rest of the discovery process. Throughout, the paper examines the phenomenon of ‘‘chemical hormesis’’ (i.e., anomalous low-dose effects from toxic chemicals) as a case study that is important not only for the biological sciences but also for contemporary public policy. The resulting analysis …

Go to article

Evolution, Theology, And Method - Part 2: Scientific Method And Evolution, Fernando L. Canale

Faculty Publications

No abstract provided.

Go to article

Determination And Consideration Of Flight Potential In A Laboratory Population Of True Armyworm (Lepidoptera: Noctuidae), Lizhi Luo, S. J. Johnson, A. M. Hammond, J. D. Lopez, J. P. Geaghan, K. R. Beerwinkle, J. K. Westbrook

Faculty Publications

Flight potential, a poorly understood phenomenon in the migratory true armyworm, Pseudaletia unipuncta (Haworth), was investigated in a laboratory population using tethered-flight techniques. True armyworm exhibited strong flight potential relative to other known migratory noctuids whose flight potentials were previously determined by similar techniques. Flight potential was generally low for 1-d-old moths and increased with age to day 5 of adult life. Flight speed and distance flown decreased for female moths from day 5 to day 10 as their reproductive system developed. The greatest average flight speed, total flight duration, and distance flown was exhibited by 5-d-old females and 10-d-old …

Go to article

Microscale Patchiness Of Bacterioplankton Assemblage Richness In Seawater, Richard A. Long, Farooq Azam

Faculty Publications

We sought to test the hypothesis that bacterial species richness and composition vary at the millimeter scale in the marine pelagic environment, in response to the heterogeneous distribution of organic matter. To test this hypothesis, it was necessary to design and test a protocol to sample, lyse and analyze (by polymerase chain reaction/denaturing gradient gel electrophoresis [PCR-DGGE]) bacterioplankton species richness in a single microliter of seawater. Significant variation in bacterial species richness was found amongst 1 μl samples. Greater species richness was seen when seawater was enriched with diatom detritus. Examination of species richness at 2 mm intervals over a …

Go to article

Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam

Faculty Publications

The relationship between bacterial 16S rRNA gene composition and carbon metabolism was analyzed during an intense dinoflagellate bloom off the Southern California coast during the spring of 1997. Bacterial numbers and rate processes, chlorophyll a, and the dissolved and particulate organic matter pools were measured during the bloom to provide a framework within which to assess bacterial community composition. Free bacteria were numerically dominant, generally comprising >90% of the total, and were responsible for >70% of bacterial production. Attached bacteria had higher cell-specific growth rates than free bacteria (range = 0.5 to 15.1 and 0.7 to 2.5 d^{-1 …}

Go to article

Development Of A Protein-Free Chemically Defined Culture Medium For The Propagation Of The Oyster Pathogen Perkinsus Marinus, J. F. La Peyre, M. Faisal

Faculty Publications

In the present study we describe a protein-free, chemically defined culture medium, designated JL-ODRP-3, which supports the propagation of Perkinsus marinus, a parasite of the eastern oyster, Crassostrea virginica. P. marinus adapted rapidly to the defined medium and the growth rate of the protozoan increased significantly following a few subcultures. Two isolates of P. marinus, one from the Chesapeake Bay (Virginia) and the other from the Gulf of Mexico (Texas) were cultured for at least ten passes. The doubling times for the isolates from Virginia and Texas, in log phase, were 18 ± 1.2 and 28.6 ± 3.2 hours respectively, …

Go to article

Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney

Faculty Publications

Whole sagittae from 683 and sectioned sagittae from 773 "adult" (age> 0 ; 437-1.310 mm FL), and lapilli from 29 larval (2-7 mm SL) and 69 young-of-the-year (79-320 mm FL) king mackerel, were examined. All fish were from waters off the Atlantic coast of the southeastern United States (Cape Canaveral, Florida to Cape Fear. North Carolina). Back-calculated lengths at ages and von Bertalanffy growth equations were calculated from both whole and sectioned sagittae. Ages determined from sectioned sagittae were significantly greater than ages determined from whole sagittae, and the magnitude of the difference increased with age (from sections). Rings on …

Go to article

Changes In The Submerged Macrophytes Of Lake Pontchartrain (Louisiana): 1954-1973, R. Eugene Turner, Rezneat M. Darnell, Judy Bond

Faculty Publications

No abstract provided.

Go to article

Digital Commons Network^™

Full-Text Articles in Entire DC Network

The Benefits Of Bathing Buds: Water Calyces Protect Flowers From A Microlepidopteran Herbivore, Jane E. Carlson, Kyle E. Harms

Faculty Publications

Investigation Of The Summer Kara Sea Circulation Employing A Variational Data Assimilation Technique, G. Panteleev, A. Proshutinsky, M. Kulakov, Dmitri A. Nechaev, W. Maslowski

Faculty Publications

Whole Genome Duplications And Contracted Breakpoint Graphs, Max A. Alekseyev, Pavel A. Pevzner

Faculty Publications

Adult Phyllophaga Ephilida Host Plant Feeding Preference, Aboubacar Diagne, Richard N. Story, Abner M. Hammond

Faculty Publications

Faculty Publications

Antifungal Activity Of Camptothecin, Trifolin, And Hyperoside Isolated From Camptotheca Acuminata, Shiyou Li, Zhizhen Zhang, Abigail Cain, Bo Wang, Melissa Long, Josephine Taylor

Faculty Publications

Error As Means To Discovery, Kevin C. Elliott

Faculty Publications

Evolution, Theology, And Method - Part 2: Scientific Method And Evolution, Fernando L. Canale

Faculty Publications

Determination And Consideration Of Flight Potential In A Laboratory Population Of True Armyworm (Lepidoptera: Noctuidae), Lizhi Luo, S. J. Johnson, A. M. Hammond, J. D. Lopez, J. P. Geaghan, K. R. Beerwinkle, J. K. Westbrook

Faculty Publications

Microscale Patchiness Of Bacterioplankton Assemblage Richness In Seawater, Richard A. Long, Farooq Azam

Faculty Publications

Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam

Faculty Publications

Development Of A Protein-Free Chemically Defined Culture Medium For The Propagation Of The Oyster Pathogen Perkinsus Marinus, J. F. La Peyre, M. Faisal

Faculty Publications

Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney

Faculty Publications

Changes In The Submerged Macrophytes Of Lake Pontchartrain (Louisiana): 1954-1973, R. Eugene Turner, Rezneat M. Darnell, Judy Bond

Faculty Publications