Digital Commons Network^™

Effect Of Larval Swimming Duration On Success Of Metamorphosis And Size Of The Ancestrular Lophophore In Bugula Neritina (Bryozoa), Dean E. Wendt

Biological Sciences

There is a growing realization that events during one portion of an organism's life cycle can have both subtle and dramatic effects on other stages in the life history. Lethal and sublethal effects associated with the duration of larval swimming in marine invertebrates were examined for the bryozoan Bugula neritina. Larvae were kept swimming up to a maximum of 28 h at 20{deg}C by exposure to continuous bright fluorescent illumination. At 4-h intervals, samples of 20-40 larvae were removed from bright illumination and were exposed to seawater containing 10 mM excess KCI, an inducer of metamorphosis in this species. …

Analysing Ancient Dna, Raúl J. Cano

Biological Sciences

Much of what we know about extinct organisms comes from traits that are not preserved in the fossil record. Until recently, morphological analysis was the only tool available for scientists to determine relationships for extinct fossil organisms. We now know that ‘ancient’ DNA can be preserved in the remains of extinct organisms. By targeting specific gene sequences, it may be possible to deduce biochemical characteristics and through sequence comparisons, to estimate the extent of evolutionary divergence. By comparing the amount and type of these changes, one could estimate how quickly some DNA ‘evolves’ relative to other segments, or which genes …

The Texture Of Surficial Sediments In Central Long Island Sound Off Milford, Connecticut., Roman Zajac, Larry J. Poppe, B B. Taylor, Dann Blackwood, Ralph S. Lewis, Mary L. Digiacomo-Cohen

Biology and Environmental Science Faculty Publications

The purpose of this study was to determine the grain-size distributions and associated statistical parameters of the surficial sediment samples from central Long Island Sound off Milford, Connecticut. These grain-size data, which help to ground-truth a pre-existent sidescan sonar survey (Poppe and others, 1995a; Twichell and others, in press), will eventually be used to describe the sedimentary processes active in this portion of central Long Island Sound. Other potential uses for these textural data include benthic biologic studies that evaluate faunal distributions and relate them to habitats (Zajac and others, 1995), and geochemical studies involving the distribution, transport and deposition …

Organic Carbon, Hydrogen, And Nitrogen Concentrations In Surficial Sediments From Western Long Island Sound, Connecticut And New York, Roman Zajac, Larry J. Poppe, Ralph S. Lewis, S E. Pratt, Zofia J. Mlodzinska, B. B. Taylor, Mary L. Digiacomo-Cohen

Biology and Environmental Science Faculty Publications

Total organic carbon, hydrogen, and nitrogen (CHN) analyses were performed on 147 surficial sediment samples from study areas off the Norwalk Islands and Milford, Connecticut, in western Long Island Sound. The CHN data and gross lithologic descriptions of the sediments are reported herein. The concentrations of total organic carbon (TOC), hydrogen, and nitrogen in these samples average 1.54, 1.40, and 0.17 weight percent, respectively. The individual CHN concentrations vary inversely with grain size, with CHN values increasing with the percent fines. Increasing nutrient inputs and decreasing circulation cause TOC and nitrogen values to generally increase westward within the Sound. C/N …

The Texture Of Surficial Sediments In Western Long Island Sound Off The Norwalk Islands, Connecticut, Roman Zajac, Larry J. Poppe, B. B. Taylor, Dann Blackwood, A. E. Harmon

Biology and Environmental Science Faculty Publications

Grain-size analyses were performed on 69 samples from western Long Island Sound. The relative grain-size frequency distributions and related statistics are reported herein. Descriptions of the benthic character from video tapes and still camera photographs of the bottom at these stations, and 33 others, are also presented. The southern and eastern parts of the study area are dominated by poorly sorted clayey silts that have nearly symmetrical distributions. Gravelly sediments are prevalent in the shallow northwestern part of the study area, but are also present in central part of the study area. Bands of sand, silty sand, and sand-silt-clay occur …

An Nmr Investigation Of The Effect Of Hydrogen Bonding On The Rates Of Rotation About The C-N Bonds In Urea And Thiourea, Karl A. Haushalter, Janice Lau, John D. Roberts

All HMC Faculty Publications and Research

The interaction between urea and tetrabutylammonium acetate was investigated in dimethylformamide/ dimethyl sulfoxide solutions using ¹H and 15^N NMR. The chemical-shift behavior of the urea protons is consistent with a urea-acetate hydrogen-bonded complex involving both carboxylate oxygens and the urea hydrogens trans to the carbonyl oxygen with K_assoc = 120 ± 10. Line shape analysis of the temperature-dependent ¹H NMR spectra show that ∆G^‡ for rotation about the C-N bond of urea changes only slightly from 11.0 ± 0.1 to 11.2 ± 0.1 kcal/mol on 1:1 molar addition of tetrabutylammonium acetate to a dilute solution of urea. A parallel investigation …

Book Review - Caddisflies (Trichoptera) Of The Interior Highlands Of North America, John C. Morse

Publications

No abstract provided.

Seeing Double: Crystal Structures Of The Type I Tnf Receptor, James H. Naismith, Barbara J. Brandhuber, Tracey Q. Devine, Stephen R. Sprang

Biological Sciences Faculty Publications

The crystal structure of the extracellular domain of the type I tumor necrosis factor receptor (sTNF-R1) has been determined to 2.25 Å at pH 7.5. We have also solved the structure of sTNF-R1 at pH 3.7. sTNF-R1 is an elongated molecule consisting of a linear combination of four cysteine-rich motifs. Interestingly, the crystal structure reveals two distinct dimers of the receptor. One dimer is formed by a parallel arrangement of receptors, the other by an antiparallel arrangement of receptors. In the parallel arrangement of the receptors, the tumor necrosis factor (TNF) binding face of the receptor is completely exposed to …

Scaling Of Muscle Composition, Wing Morphology, And Intermittent Flight Behavior In Woodpeckers, Bret W. Tobalske

Biological Sciences Faculty Publications

Existing theory and empirical evidence suggest that body size should have a profound influence upon the composition of flight muscles and the performance of intermittent flight in birds. I examine the relationships between functional morphology and intermittent flight behavior within a closely-related group of birds using six species of woodpeckers (Picidae): Downy Woodpecker (Picoides pubescens, 27.2 g), Red-naped Sapsucker (Sphyrapicus nuchalis, 47.4 g), Hairy Woodpecker (P. villosus, 70.5 g), Lewis' Woodpecker (Melanerpes lewis, 106.6 g), Northern Flicker (Colaptes auratus, 148.1 g), and Pileated Woodpecker (Dryocopus pileatus, 262.5 g). In woodpeckers with a body mass less than 100 g, the pectoralis …

Book Review - The Adult Limnephilus Leach (Trichoptera:Limnephilidae) Of The New World, John C. Morse

Publications

No abstract provided.

The Effect Of The Mammalian Hormone Estrogen On The Yeast C̲A̲N̲D̲I̲D̲A̲ A̲L̲B̲I̲C̲A̲N̲S̲, Marcia Clifton Finucane

Theses, Dissertations and Capstones

Changes in the balance between commensal microbes and mammalian hosts can cause disease if the scales tip in favor of the microbe. Although usually caused by a defective host immune response, overgrowth of or changes in the microbe may also be responsible for opportunistic infections. Clinical and laboratory investigations have indicated that mammalian hormones, including estrogen, can influence the production of symptomatic disease and the virulence attributes of Candida albicans.

This study demonstrated enhanced growth of some strains of C. albicans when 17β-estradiol was added to the growth medium. Measurement of extracellular protein under the influence of estradiol did …

Characterization Of A Basolateral Electroneutral Na+/H+ Antiporter In Atlantic Lobster (Homarus Americanus) Hepatopancreatic Epithelial Vesicles, Jeff Duerr, Gregory A. Ahearn

Faculty Publications - Department of Biological & Molecular Science

Purified basolateral membrane vesicles (BLMVs) were prepared from Atlantic lobster (Homarus americanus) hepatopancreas using a Percoll density gradient technique. Enrichments of the Na+/K+-ATPase and alkaline phosphatase activities of these vesicles were 15.4- and 1.2- fold, respectively. The presence of amiloride-sensitive Na+/H+ exchange was demonstrated. Contrary to electrogenic 2Na+/1H+ exchange on apical membranes from the same tissue, kinetic studies of Na+ transport by these basolateral membranes indicate an electroneutral antiport with a Km of 28±1.7 mmol l21 and a Jmax of 1.74±0.13 mmol mg21 min21. Amiloride interacted at a single binding site (Ki=39mmol l21) and external Li+ was shown to be …

Relationship Between Morphology And Hydrodynamics During Swimming By The Hydromedusae Aequorea Victoria And Aglantha Digitale, Sean Colin, John H. Costello

Arts & Sciences Faculty Publications

No abstract provided.

Neotropical Bird Migration During The Ice Ages: Orientation And Ecology, Timothy C. Williams , '64, T. Webb Iii

Biology Faculty Works

Reconstruction of breeding habitat of North American Neotropical migrants 18,000 years ago and 9,000 years ago indicated major shifts in both location and composition of plant communities relative to present conditions. Increased vegetation in xeric areas may have compensated, at least in part, for the reduction in breeding habitat due to glaciation. Autumnal flights of Neotropical passerine migrants flying on constant headings from North America to Central and South America were simulated under present wind conditions and for winds during periods of glaciation at 18,000 and 9,000 years ago. The 155 degrees average headings currently observed for Atlantic migrants were …

Allometry Of Litter Mass In Bats: Maternal Size, Wing Morphology, And Phylogeny, Virginia Hayssen, T. H. Kunz

Biological Sciences: Faculty Publications

We examine how litter mass in bats varies with respect to wing loading, an important aerodynamic aspect of flight. From geometric proportions, litter mass should scale to wing loading by an exponent of three. Conversely, analysis of aerodynamic consequences of carrying extra mass suggests that an exponent significantly less than three would be selectively advantageous. Our results show that Megachiroptera and Microchiroptera differ in the relationship between litter mass and wing loading. Litter mass in megachiropterans scales as expected by geometric proportions, whereas litter mass in microchiropterans, as a group, and for individual families, scales as expected if aerodynamic consequences …

Top-Down Cascade From A Bitrophic Predator In An Old-Field Community, Matthew D. Moran, Thomas P. Rooney, L. E. Hurd

Biological Sciences Faculty Publications

We tested the hypothesis that a bitrophic (third and fourth level) arthropod predator can exert a cascading, top-down influence on other arthropods and plants in an early successional old field. First-stadium mantids, Tenodera sinensis, were added to replicated open-field plots in numbers corresponding to naturally occurring egg hatch density and allowed to remain for ≈ 2 mo. Sticky-trap dispersal barriers around both control and mantid-addition plots allowed us to monitor emigration of arthropods continuously during the experiment. Biomass of herbivores, carnivores, and plants, and abundances of arthropod taxa within plots were determined at the beginning, middle, and end of …

Post-Conflict Behavior In Japanese Macaques At The Indianapolis Zoo: Age Of Opponents Influences Reconciliation, Scott Kight

Department of Biology Faculty Scholarship and Creative Works

In many primate species, opponents may affiliate soon after an agonistic encounter. This study examined how the individual characteris- tics of opponents affected post-conflict interactions in a captive group of Japan- ese macaques (Macaca fuscata). Reconciliation and selective attraction of opponents was shown to occur following agonistic encounters. The factor most strongly influencing post-conflict interactions was age. Juveniles were significantly more likely than adults to initiate reconciliation. Sex, kinship, and dominance status were not associated with contact initiation. Because juveniles were the most likely victims of aggression, juvenile reconciliatory contact initiative may reduce the threat of further aggression.

Streamnet: An Integrated Information System Serving Fisheries Scientists And Managers In The Columbia River Basin - Or - Is Innovation Possible When Differing Traditions Collide?, Gretta E. Siegel

Library Faculty and Staff Publications and Presentations

StreamNet is a project which brings together fisheries information collected by state agencies, federal agencies, and Indian tribes in a system of interconnected sets of data about anadromous fish in the Columbia River Basin. The data are used to observe trends in stock abundance escapement, hatchery production, etc. Each data point is linked to corresponding literature which can be searched separately in a references database. Plans are in progress to make this system available via the Internet. Data entry for the reference module is done via Microsoft Access. The application has been designed to include features of both a catalog …

Mile-A-Minute Weed, (Polygonum Perfoliatum L.), An Invasive Vine In Natural And Disturbed Sites, J. Douglas Oliver

Faculty Publications and Presentations

Polygonum perfoliatum L. (Polygonaceae) or mile-a-minute weed, from eastern Asia, has been spreading through wild and disturbed areas of the mid-Atlantic United States. It has a wide ecological amplitude and is found on stream banks, moist thickets, roadsides, nurseries, wood-piles, clearings, and ditches. Polygonum perfoliatum presents serious problems for reforestation because it thrives where forests are clear-cut. A southward direction of spread indicates that the species will probably proliferate in at least some southern states. Mechanical control is not likely to be completely effective because seeds are often left behind. No appropriate biocontrols are known. The plant poses a threat …

Caulobacter Lon Protease Has A Critical Role In Cell-Cvcle Cbntrol Of Dna I Methylation, Craig Stephens, Rachel Wright, Gary Zweiger, Lucy Shapiro, M.R.K. Alley

Biology

CcrM, an adenine DNA methyltransferase, is essential for viability in Caulobacter crescentus. The CcrM protein is present only in the predivisional stage of the cell cycle, resulting in cell-cycle-dependent variation of the DNA methylation state of the chromosome. The availability of CcrM is controlled in two ways: (1) the ccrM gene is transcribed only in the predivisional cell, and (2) the CcrM protein is rapidly degraded prior to cell division. We demonstrate here that CcrM is an important target of the Lon protease pathway in C. crescentus. In a lon null mutant, ccrM transcription is still temporally regulated, but the …

The Potential For Ontogenetic Vertical Migration By Larvae Of Bathyal Echinoderms, William Jaeckle, Craig M. Young, Michael G. Devin, Suki U.K. Ekaratne, Sophie B. George

Scholarship

Planktotrophy is a relatively common developmental mode among bathyal and abyssal echinoderms, but the sources of food used by deep-sea planktotrophic larvae remain generally unknown. Very few deep-sea echinoderm larvae have been collected in plankton samples, so we do not know whether larvae migrate to the euphotic zone to feed or if they rely on bacteria or detritus at greater depths. We approached this question indirectly by investigating whether larvae of bathyal echinoids can tolerate the temperatures they would encounter in the euphotic zone and whether they possess sufficient energy stores to migrate to the euphotic zone without feeding. Twenty-four …

Book Review Of "The Battle Of Beginnings: Why Neither Side Is Winning The Creation-Evolution Debate" By Del Ratzsch, Carl J. Bajema

Other Scholarly Publications

The book is interesting for two reasons. First, the author presents numerous brief negative critiques of many of the arguments that creationists and scientists have employed in debates. Second, this book is an example of the recent strategy by Phillip Johnson and others to redirect the creation-evolution debate to such religious issues as intelligent design. This review will concentrate on Ratszch's discussion of (1) the imperfect nature of science, (2) design arguments and (3) who is entitled to be called a "creationist."

Communities Of Cloacal Bacteria In Tree Swallow Families, Michael P. Lombardo, Patrick A. Thorpe, R. Cichewicz, M. Henshaw, C. Millard, C. Steen, T. K. Zeller

Peer Reviewed Publications

Our aim in this study was to survey the communities of bacteria found in the cloacae of adult and nestling Tree Swallows (Tachycineta bicolor), determine if there were familial patterns of prevalence, and determine if there were relationships between bacteria loads and nestling size when 12 days old and fledging success.

Effects Of Regional Origin And Genotype On Intraspecific Root Communication In The Desert Shrub Ambrosia Dumosa (Asteraceae), Bruce E. Mahall, Ragan M. Callaway

Biological Sciences Faculty Publications

Previous work has shown that the contact inhibition that occurs among roots of Ambrosia dumosa shrubs has a self/nonself recognition capability. In the current study, we investigated some of the geographic and genotypic dimensions of this recognition capability by using root observation chambers to observe the effects of encounters of individual roots on root elongation rates. We measured such effects in encounters between roots of plants from the same region and compared these to effects in encounters between roots of plants from two different regions. We also measured effects of encounters between roots of plants from the same clones and …

Variation In Leaf Structure And Function In Quercus Douglasii Trees Differing In Root Architecture And Drought History, Ragan M. Callaway, Bruce E. Mahall

Biological Sciences Faculty Publications

Seasonal changes in leaf specific mass, nitrogen, chlorophyll, and photosynthetic properties were measured for two groups of spatially intermixed Quercus douglasii trees with different drought histories and apparently different root architectures. One group, referred to as ''high-psi(pd) trees, included trees with low amounts of fine root biomass in the upper 50 cm of soil and high predawn xylem pressure potentials (psi(pd)) during summer drought. These two characteristics indicate that trees in this group have deep roots, which may reach the water table. The second group, referred to as ''low-psi(pd) trees, had three to five times higher fine root biomass in …

On The Mutability Of Genes And Geneticists: The "Americanization" Of Richard Goldschmidt And Victor Jollos, Michael Dietrich

Dartmouth Scholarship

No abstract provided.

Use Of Conductance Technology To Determine The Bioactivity Of Oxytetracycline-Hydrochloride, Michael Mc Donagh

Theses

The biological activity of oxytetracycline-hydrochloride was investigated using the indirect conductivity method which is based on the measurement of metabolically generated CO2. A number of laboratory strains and a fresh natural inoculum were exposed to oxytetracycline in the presence and absence of 12% sterile sediment. Results comparing sediment and sediment free systems for all test cultures revealed elevated minimum inhibitory concenrations (MIC) of the agent in the presence of sediment; percentage bioactivity results ranged between 0.50 and 2.07%. pH differences betw'een sediment and sediment-free systems were found not to effect MIC results, and the use of different buffers resulted in …

Captive Environmental Influences On Behavior In Zoo Drills And Mandrills (Mandrillus), A Threatened Genus Of Primate, Erik Terdal

Dissertations and Theses

Drills (Mandrillus leucophaeus) are an endangered species of African monkey (Cercopithecidae), and their sole congener the mandrill (Mandrillus sphinx) is vulnerable to extinction. Both species are threatened in the wild by deforestation and hunting.

Drills have a poor record of captive reproduction. Many individuals appear to have behavioral deficiencies which interfere with reproduction. Thus, the zoo population of drills does not serve as a “hedge” against the species’ total extinction: drills are endangered in captivity as well as in the wild. Mandrills, by contrast, reproduce well in captivity. Information on the behavior of mandrills in captivity may help zoo managers …

A Pcr Assay For The Detection Of Wuchereria Bancrofti In Blood, Min Zhong, James Mccarthy, Lou Ann Bierwert, Michelle Lizotte-Waniewski, Suzanne Chanteau, Thomas Nutman, Eric A. Ottesen, Steven A. Williams

Biological Sciences: Faculty Publications

To identify Wuchereria bancrofti DNA sequences that could be used as the basis for a simple and rapid parasite detection assay, a genomic library of W. bancrofti was constructed and screened for highly repeated DNA. The repeat found with the highest copy number was 195 basepairs (bps) long, 77% AT, and 300 copies per haploid genome. This sequence was designated the Ssp I repeat because it has a unique recognition site for that restriction endonuclease in all or most of the repeat copies. The Ssp I repeat DNA family is dispersed, genus-specific, and exists in all of the different geographic …

Reproductive Ecology Of Pinckneya Bracteata (Bartram) Raflnesque (Rubiaceae), George H. Rountree

College of Graduate Studies: Theses & Dissertations (1964–2006)

Pinckneya bracteata is a small tree or large shrub that is indigenous to the coastal plain of extreme southern South Carolina, Georgia, and northern Florida. It in occurs in sunny, wet habitats and in small populations that are usually separated by distances of kilometers. This study examined the mating, dispersal, and germination systems of the species. Pinckneya bracteata was found to be protandrous and self incompatible. Ruby-throated Hummingbirds and bumblebees ( Bombus spp. appear to be the primary pollinators. Seed fall velocity is important to the wind dispersal of seeds and decreases as seed size increases. Fall velocity is also …