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Role Of Iron, Light, And Silicate In Controlling Algal Biomass In Subantarctic Waters Se Of New Zealand, Robert Michael Mckay, Philip Boyd, Julie Laroche, Mark Gall, Russell Frew

Biological Sciences Faculty Publications

Phytoplankton processes in subantarctic (SA) waters southeast of New Zealand were studied during austral autumn and spring 1997. Chlorophyll a (0.2–0.3 μg L⁻¹) and primary production (350–650 mg C m⁻² d⁻¹) were dominated by cells μm (cyanobacteria) in both seasons. The photochemical efficiency of photosystem II (F_υ/F_m) of cells was low (0.3), indicating physiological stress. Dissolved Fe (DFe) levels in surface waters were subnanomolar, and the molecular marker flavodoxin indicated that cells were iron stressed. In contrast, Subtropical Convergence (STC) and subtropical waters had higher algal biomass/production levels, particularly …

Variation Of Total Lipid And Fatty Acid Amount And Compositions Inmuscles Of Capoeta Trutta And Barbus Rajanorum Mystaceus Duringreproduction Period, Vahi̇t Konar, Ayhan Canpolat, Ökkeş Yilmaz, Feri̇t Gürsu

Turkish Journal of Biology

In this study, the variation of total lipid and fatty acid composition in muscle tissues of females and males of Copoeta trutta and Barbus rajanorum mystaceus living in Keban Dam Lake (Elazig) were examined. It was observed that the amount of total lipid in muscle tissues of C. trutta (p

Bacterial Growth State Distinguished By Single-Cell Protein Profiling: Does Chlorination Kill Coliforms In Municipal Effluent?, David Rockabrand, Teresa Austin, Robyn Kaiser, Paul H. Blum

School of Biological Sciences: Faculty Publications

Municipal effluent is the largest reservoir of human enteric bacteria. Its public health significance, however,

depends upon the physiological status of the wastewater bacterial community. A novel immunofluorescence

assay was developed and used to examine the bacterial growth state during wastewater disinfection. Quantitative

levels of three highly conserved cytosolic proteins (DnaK, Dps, and Fis) were determined by using

enterobacterium-specific antibody fluorochrome-coupled probes. Enterobacterial Fis homologs were abundant

in growing cells and nearly undetectable in stationary-phase cells. In contrast, enterobacterial Dps homologs

were abundant in stationary-phase cells but virtually undetectable in growing cells. The range of variation in

the abundance of …

Obtaining And Sampling Of High Quality Energetic-Protein Mixtures (Pottages) Of Tuber-Cereal-Leguminous Bases In The Candelaria Area, Maria Lilian Maldonado Chavez

Theses and Dissertations

Specially designed foodstuffs destined for children of weaning age in the community of Candelaria were developed and evaluated biologically. These victuals had as bases combinations of tubers-cereals-legumes of high nutritional quality to be implemented in the home. Based on the availability of food and alimentary habits of the region, seven mixtures were formulated of triples and quadruples containing tubers (potato, oca, papaliza, and isano); cereals (rice, wheat, corn, and quinua); and legumes (tarwi, broad bean, and peanut). The cereal-leguminous proportion was maintained as one complement and the addition of the tubers. These mixes were subjected to biological tests, obtaining incremental …

Limitation Of Algal Growth By Iron Deficiency In The Australian Subantarctic Region, Peter N. Sedwick, Giacomo R. Ditullio, David A. Hutchins, Philip W. Boyd, F. Brian Griffiths, A. Clive Crossley, Thomas W. Trull, Bernard Queguiner

OES Faculty Publications

In March 1998 we measured iron in the upper water column and conducted iron- and nutrient-enrichment bottle-incubation experiments in the open-ocean Subantarctic region southwest of Tasmania, Australia. In the Subtropical Convergence Zone (∼42°S, 142°E), silicic acid concentrations were low (< 1.5μM) in the upper water column, whereas pronounced vertical gradients in dissolved iron concentration (0.12-0.84 nM) were observed., presumably reflecting the interleaving of Subtropical and Subantarctic waters, and mineral aerosol input. Results of a bottle-incubation experiment performed at this location indicate that phytoplankton growth rates were limited by iron deficiency within the iron-poor layer of the euphotic zone. In the Subantarctic water mass (∼46.8°S, 142°E), low concentrations of dissolved iron (0.05-0.11nM) and silicic acid (< 1μM) were measured throughout the upper water column, and our experimental results indicate that algal growth was limited by iron deficiency. These observations suggest that availability of dissolved iron is a primary factor limiting phytoplankton growth over much of the Subantarctic Southern Ocean in the late summer and autumn.

Metamorphis Is Not A New Beginning, Jan A. Pechenik, Dean E. Wendt, Jeremiah N. Jarrett

Biological Sciences

No abstract provided.

Grizzly Bear Digging: Effects On Subalpine Meadow Plants In Relation To Mineral Nitrogen Availability, Sandra E. Tardiff, Jack Arthur Stanford

Biological Sciences Faculty Publications

Grizzly bears (Ursus arctos horribilis) affect plant distributions and mineral nitrogen availability when they forage by digging for the bulbs of glacier lilies (Erythronium grandiflorum) growing in subalpine meadows of Glacier National Park, Montana, United States. Our working hypothesis is that grizzly bears structure plant communities and influence nitrogen availability when they selectively dig for preferred plants. In this paper, we report on differences found in recently disturbed digs (<5 yr old) when compared to adjacent, undisturbed meadow.

We used ion exchange resin bags to determine the availability of mineral nitrogen in grizzly bear digs compared to undisturbed meadow. Soil in digs contained significantly …

Effective Recovery Of Bacterial Dna And Percent-Guanine-Plus-Cytosine-Based Analysis Of Community Structure In The Gastrointestinal Tract Of Broiler Chickens, Juha H. A. Apajalahti, Laura K. Särkilahti, Brita R. E. Mäki, J. Pekka Heikkinen, Päivi H. Nurminen, William E. Holben

Biological Sciences Faculty Publications

A DNA-based, direct method for initial characterization of the total bacterial community in ileum and cecum of the chicken gastrointestinal (GI) tract was developed. The efficiencies of bacterial extraction and lysis were >95 and >99%, respectively, and therefore the DNA recovered should accurately reflect the bacterial communities of the ileal and cecal digesta. Total bacterial DNA samples were fractionated according to their percent G+C content. The profiles reflecting the composition of the bacterial community were reproducible within each compartment, but different between the compartments of the GI tract. This approach is independent of the culturability of the bacteria in the …

Increased Photosynthesis Offsets Costs Of Allocation To Sapwood In An Arid Environment, Eileen V. Carey, Ragan M. Callaway, Evan H. Delucia

Biological Sciences Faculty Publications

We assessed the effect that varying patterns of biomass allocation had on growth of ponderosa pine (Pinus ponderosa) growing in the desert climate of the Great Basin and the montane climate of the eastern Sierra Nevada. Prior work established that desert trees have lower leaf:sapwood area ratios than montane trees (0.104 and 0.201 m²/cm², respectively) and proportionally greater stem respiration. Sapwood:leaf mass ratios are also greater and increase more as a function stem diameter in desert than in montane trees. We hypothesized that this increased allocation of carbon to stem sapwood and stem respiration …

Bacterial Stress Responses To 1-Megahertz Pulsed Ultrasound In The Presence Of Microbubbles, Amy Cheng Vollmer, Sylvia D. Sakyiama Kwakye , '98, Matthew Evan Halpern , '98, E. Carr Everbach

Engineering Faculty Works

Members of a panel of stress-responsive biosensors have been used to study the effect of megahertz frequency ultrasound onEscherichia coli. Insonification causes acoustic cavitation, the collapse of oscillating microbubbles in solution, which can damage bacterial cells. A focused 1-MHz ultrasound transducer, capable of generating a spatial peak pulse average intensity of 500 W/cm2, was used to treat liquid bacterial cultures. Stress-responsive promoters fused to luxCDABE allowed the continuous measurement of light produced as a result of protein damage, DNA damage, oxidative stress, and membrane perturbation. A promoter responsive to ammonia limitation was not transcriptionally activated under test conditions. In contrast …

Identification Of A Functional Homolog Of The Yeast Copper Homeostasis Gene Atx1 From Arabidopsis, Edward Himelblau, Helena Mria, Su-Ju Lin, Valeria Cizewski Culotta, Lola Penarrubia, Richard M. Amasino

Biological Sciences

A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1 (ATX1) has been identified from Arabidopsis. This gene, referred to as Copper CHaperone (CCH), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1-deficient yeast (atx1) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating that CCH is a functional homolog of ATX1 …

Photoadaptation Rate Of Synechococcus Wh7803 Cultures At Two Iron Concentrations, Jon Daniel Moulton

Dissertations and Theses

The marine cyanobacterium Synechococcus WH7803 adapts to changes in light intensity by changing its photosynthetic physiology. This work is a study o f the rate o f photoadaptation of Synechococcus WH7803 in laboratory cultures. Cultures were shifted from constant 8 µEm^-2s^-1 light to constant 80 µEm^-2s^-1 light, from constant 80 µEm^-2s^-1 light to 8 µEm^-2s^-1 light and from different light regimes to a single fluctuating light regime. The response of high iron cultures grown in modified aquil culture medium at 5*10^-6M Fe was compared with the …

Insect Herbivory Above- And Belowground: Individual And Joint Effects On Plant Fitness, John L. Maron

Biological Sciences Faculty Publications

Understanding of the selective effects of insect herbivory on plants comes primarily from studies of herbivory aboveground. The impact of belowground herbivory, either in isolation or in concert with herbivory aboveground, on plant fitness is only beginning to be understood.

I reduced the densities of root-boring ghost moth (Hepialus californicus) larvae and/or flower- and seed-feeding insects of bush lupine (Lupinus arboreus), a woody shrub, and followed fecundity and survival of plants for three years. In year one, suppression of aboveground herbivores increased mean seed output by 31%, but suppression of belowground herbivores had no significant effect …

Identification Of A Family Of Zinc Transporter Genes From Arabidopsis That Respond To Zinc Deficiency, Natasha Grotz, Tama Fox, Erin Connolly, Walter Park, Mary Lou Guerinot, David Eide

Dartmouth Scholarship

Millions of people worldwide suffer from nutritional imbalances of essential metals like zinc. These same metals, along with pollutants like cadmium and lead, contaminate soils at many sites around the world. In addition to posing a threat to human health, these metals can poison plants, livestock, and wildlife. Deciphering how metals are absorbed, transported, and incorporated as protein cofactors may help solve both of these problems. For example, edible plants could be engineered to serve as better dietary sources of metal nutrients, and other plant species could be tailored to remove metal ions from contaminated soils. We report here the …

Ecosystem Responses To Internal And Watershed Organic Matter Loading: Consequences For Hypoxia In The Eutrophying Neuse River Estuary, North Carolina, Usa, Hans W. Paerl, James L. Pinckney, John M. Fear, Benjamin L. Peierls

Faculty Publications

The contrasting impacts of externally supplied (runoff) and internally generated (nutrient stimulated phytoplankton blooms) organic matter on oxygen (0₂) depletion were examined and evaluated in the eutrophic, salinity-stratified Neuse River Estuary, North Carolina, USA. This nitrogen (N)- limited estuary is experiencing increasing anthropogenic N loading from expanding urban, agricultural and industrial development in its watershed. Resultant algal blooms, which provided organic matter loads capable of causing extensive low 0₂ (hypoxic) and depleted 0₂ (anoxic) conditions, have induced widespread mortality of resident fin- and shellfish. Phytoplankton blooms followed periods of elevated N loading, except during extremely high …

Shrimp Aquaculture: An Analysis Of Its Evolution And Organization; And The Development Of A Shrimp Growth Model, Adam Rana

Honors Theses

This paper examines the impetus for the development and subsequent rise of the shrimp aquaculture industry and continues by exploring a model that seeks to improve shrimp farmers' harvests by identifying specific variables affecting shrimp growth. Evidence reviewed from 1980 through today suggest that technological advancements, reduced prices, and increases in both the supply and demand for shrimp are positively associated with the industry's rapid ascent. The introduction of vertically integrated shrimp farms along with the ability for shrimp farmers to differentiate their products are also correlated with the industry's growth. Variables affecting shrimp growth were also studied to determine …

Phytotoxicity Of Pseudomonas Chlororaphis Strain O6: Role Of Phenazines And Implications For Biocontrol, Elizabeth Thomas

Biology

Phenazines, the water-soluble pigments produced naturally by bacteria with distinct antimicrobial properties, have been implicated in the biological control of several plant diseases. Pseudomonas chlororaphis strain O6, obtained from the rhizosphere of wheat, is known to produce at least three different phenazines, which include phenazine-1-carboxylic acid, 2-hydroxyphenazine-1-carboxylic acid, and 2-hydroxyphenazine. A field trial conducted in the fall of 1994 to test the biocontrol properties of O6 indicated that this strain inhibited wheat seed germination, which led me to hypothesize that phenazines cause phytotoxicity. Mutants of O6 created by Tn5 lux insertion (Phz^- mutants) that did not produce the pigments …

Phylogenetic Characterization Of Endosymbionts In Psyllids (Hemiptera: Sternorrhyncha), Allen W. Spaulding

Biology

Most sternorrhynchan insects harbor endosymbiotic bacteria in specialized cells (bacteriocytes) near the gut, which provide essential nutrients for hosts. In lineages investigated so far with molecular methods (aphids, mealybugs, whiteflies), endosymbionts apparently have arisen from independent infections of common host ancestors and cospeciated with their hosts. Some endosymbionts also exhibit putatively negative genetic effects from their symbiotic association. In this study, the identity of endosymbionts in one major sternorrhynchan lineage, psyllids (Psylloidea), was investigated to determine their position in eubacterial phylogeny and relationship to other sternorrhynchan endosymbionts. Small-subunit ribosomal RNA genes (16S rDNA) from bacteria in three psyllid species (families …

Parameter Estimation Of The Mountain Pine Beetle-Host Tree System, Zy Frederick Biesinger

Undergraduate Honors Capstone Projects

The spatial redistribution of organisms in an ecosystem is often a complex process. Many ecosystems exhibit spatial complexity on a broad range of scales, driven by the physical environment and biotic interactions [1]. As different species aggregate and disperse in spatially complex ways, even an initially uniform environment will soon evolve spatial heterogeneity.

Grandmothering, Menopause, And The Evolution Of Human Life Histories, K. Hawkes, J.F. O'Connell, N.G. Blurton Jones, H. Alvarez, Eric Charnov

Biology Faculty & Staff Publications

Long postmenopausal lifespans distinguish humans from all other primates. This pattern may have evolved with mother—child food sharing, a practice that allowed aging females to enhance their daughters fertility, thereby increasing selection against senescence. Combined with Charnov's dimensionless assembly rules for mammalian life histories, this hypothesis also accounts for our late maturity, small size at weaning, and high fertility. It has implications for past human habitat choice and social organization and for ideas about the importance of extended learning and paternal provisioning in human evolution.

Effects Of Fertilization On Water Quality In Grayson Lake, Kentucky., Albert W. Remley Ii

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Albert W. Remley II on January 15, 1998.

Differences In Lean And Obese Skeletal Muscle Myoblasts Of Adult And Post-Natal La/N (Faf) Rats: A Confocal Description Of The Skeletal Muscle Myoblast, J. Adam Noah

Theses, Dissertations and Capstones

Mutant strains of obese rats are currently being studied to reveal the mechanisms of increased lipid synthesis and decreased lipid oxidation in these rats. It was originally thought that much of the fat production that leads to obesity is the result of metabolic processes in the liver and adipose tissue. Studies by Kahle et al.³ showed that the liver and adipose tissue account for only 22% and 7% respectively, of total fatty acid synthesis. It was also shown that 21 % of total de novo fatty acid was localized in the postural skeletal muscle.

The dry weight of the …

Natural And Genetic Engineering Of The Heat-Shock Protein Hsp70 In Drosophila Melanogaster: Consequences For Thermotolerance, Martin E. Feder, Robert A. Krebs

Biological, Geological, and Environmental Faculty Publications

Larvae of the fruit fly, Drosophila melanogaster, live within necrotic fruit, a challenging environment in which larvae can experience severe thermal stress. One response to thermal stress, the expression of heat-shock proteins (Hsps), has evolved distinctively in this species; the gene encoding Hsp70 has undergone extensive duplication and accounts for the bulk of Hsps that are expressed upon heat shock. Genetic engineering of hsp70 copy number is sufficient to affect thermotolerance at some (but not all) life stages. Increases in Hsp70, moreover, can protect intact larvae against thermal inactivation of the enzyme alcohol dehydrogenase and thermal inhibition of feeding. …

Molecular Mapping Of The Fatty (F) (Formerly Corpulent) Gene In The La/N Rat Obesity Model, Kenneth G. Butz

Theses, Dissertations and Capstones

The LA/N-corpulent (cp) rat obesity model was a congenic rat strain developed at the National Institutes of Health by C. T. Hansen . The LA/N-cp rat originated from breeding the Koletsky rat, possessing the corpulent gene, with the normotensive LA/N inbred rat. The autosomal recessive single gene mutation, cp, produces obesity with hyperphagia, hyperinsulinemia and elevated activities of liver and skeletal muscle lipogenic enzymes in the LA/N-cp rat model. The Zucker-fatty mutation, which was mapped to rat chromosome , resulted in a comparable, but not identical obesity syndrome. Breeding experiments by Yen et al …

Bacterial Analysis Of Refrigerated Human Milk Following Infant Feeding, Rachel Renee Brusseau

CUP Undergraduate Research

The number of infants who are breastfed is on the rise, as is the number of women in the workforce. Many women who choose breastfeeding after returning to work, express milk during the day and store this milk for a future feeding. When infants do not finish a bottle of expressed breastmilk, doctors recommend unfinished portions be thrown away. This study examined bacterial levels in expressed, partially consumed breastmilk that was stored for 48 hours at 4-6° C. A portion of unconsumed milk was examined as a control. Samples were taken every 12 hours for bacterial analysis. Tests were performed …

The Components Of Feeeding Behavior In The Rotifer Asplanchna Herricki: Attack, Capture, Consumption, Selectivity, And Trophi Morphology, Tony Baumert

Honors Theses, 1963-2015

The rotifer Asplanchna herricki (A. herricki) is an integral predatory species impacting rotifer and algae populations of fresh water lake habitats. In order to determine the feeding behavior and mechanism of A. herricki, stomach content analysis was performed and predator/prey interactions were observed. A. herricki encountered prey randomly, only attacking after physical contact of the prey with the corona. It was found that A. herricki prefers small rotifer prey as opposed to algae. Algae such as Volvox and Pediastrum appeared to deter ingestion due to size or shape. Rotifers such as Keratella cochlearis, Brachionus patulus, …

Body Condition And The Adrenal Stress Response In Captive American Kestrel Juveniles, Julie A. Heath, Alfred M. Dufty Jr.

Biology Faculty Publications and Presentations

We examined the adrenal response to handling stress of birds in different body conditions. In order to affect the birds’ body condition, young (73-d old) female American kestrels (Falco sparverius) were maintained for 6 wk on one of three diets: a control diet (fed ad lib.) and two calorically restricted diets. To invoke a stress response, we removed birds from their cages and took repeated blood samples over the course of an hour. All birds responded to handling stress with an increase in plasma corticosterone, but control birds (in good body condition) showed a more rapid increase to …

The Algal Flora Of The Littoral Region In Lake Akşehir, Ayşe Elmaci, Olcay Obali

Turkish Journal of Biology

In this study, composition and seasonal variations of littoral algae in Lake Akşehir were investigated from June 1992- November 1993. In the littoral region, the algal flora were composed of 115 species belonging to Bacillariophyta, Charophyta, Chlorophyta, Cyanophyta, Euglenophyta. Bacillariophyta was predominant in respect to species diversity and density. Cyanophyta and Chlorophyta were in minority. In general, the most of the identified species of the algal flora of Lake Akşehir are considered as the members of eutrophic lakes which are rich in nutritional salts.

Wound Repair, Raymond E. Sicard, Jeffry D. Shearer, Michael D. Caldwell

Journal of the Minnesota Academy of Science

Following injury, a series of events is initiated that includes global and local reactions. Global reactions, such as inflammatory and immunological responses as well as adjustments in neural and endocrine status, are directed at marshaling the organism's resources for dealing with changes in its integrity and the potential threat of infection or other complications. Injury entails cell and tissue damage and often a physical breach in the barrier against the outside world (e.g., skin). Local reactions are exemplified by immediate hemostatic (e.g., blood clotting) events followed by changes in local cellular composition created by the inflammatory infiltrate and adjustments in …

Environmental Stress Effects On Vigor, Mortality, And Growth In Northern Hardwood Forests Along A Pollution-Climate Gradient, Neil W. Macdonald, John A. Witter, David R. Reed, Andrew J. Burton, Kurt S. Pregitzer, Hal O. Liechty

Peer Reviewed Publications

Concern exists over the effects of interacting environmental stresses on the ecological integrity of temperate forests. Coincidence of sensitivity to drought, increasing occurrence of defoliation, and elevated pollutant deposition has produced speculation that northern hardwood forests may be susceptible to the increased climatic stresses projected for the Great Lakes region. The objective of our study was to examine relationships among environmental stress factors, vigor, mortality, and growth in northern hardwood forests located along a pollution-climate gradient in the Great Lakes region. Between 1987 and 1993, we quantified climatic variables, pollutant deposition, insect defoliation, and tree vigor and growth at five …