Biology Commons^™

Assessment Of Fecal Bacteria Contamination In Sewage And Non-Sewage Impacted Mangrove Ecosystems Along The Coast Of Dar Es Salaam, A. A. Abbu, Thomas J. Tj Lyimo

Tanzania Journal of Science

Microbiological quality of the intertidal pool water was evaluated in sewage impacted (Mtoni Kijichi) and non-sewage impacted (Rasi Dege) mangrove forest sites along the coast of Dar es Salaam, Tanzania. The Most Probable Number method was used for estimating the total coliform (TC), fecal coliform (FC) and fecal enterococci (ENT) levels. In addition, physicochemical parameters (temperature, pH, salinity and nutrients) were measured. The results for microbial fecal indicators were compared to the World Health Organisation (WHO) and United States Environmental Protection Agency (USEPA) guidelines for marine recreational and shellfish harvesting waters. Fecal bacteria contamination was significantly higher at Mtoni Kijichi …

Characteristics And Dyes Biodegradation Potential Of Crude Lignolytic Enzymes From White-Rot Fungus Crepidotus Variabilis Isolated In Coastal Tanzania, G. Y. S. Gys Mtui

Tanzania Journal of Science

Lignocellulosic enzymes from Crepidotus variabilis collected from mangrove forests of coastal Tanzania were investigated by using standard methods, and their ability to degrade aromatic compounds were elucidated. The fungal crude enzyme filtrates had maximum laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP) activities of 70 U/mL, 16 U/mL and 8, U/mL respectively. The crude enzyme extracts were able to oxidize rhemazol brilliant blue-R (RBB-R) dye, phenol, "-naphthol and pyrogallol. Also, they could remove up to 58% and 92% color from raw textile effluent and aromatic dyes, respectively, after 14 days of incubation at 30ºC and pH 4.5. Desalted and …

Chemical Constituents And Biological Activity Of Three Tanzanian Wild Mushroom Species, L.D. Baraza, C. C. Joseph, M. J. Moshi, M. H. H. Nkunya

Tanzania Journal of Science

The three Tanzanian wild mushroom species Termitomyces letestui, Lactarius edulis and Agaricus sp. aff. arvensis yielded ergosterol, 5,8-peroxyergosterol and ergosta-5,22-dien-3β-ol, and a mixture of ergosterol, ergosta-7,22-dien-3β-ol and ergosta-7-en-3β-ol whose composition was deduced from gas chromatography/mass spectroscopic (GC/MS) analysis of the trimethysilylated mixture. GC/MS analysis of the lipid fraction from T. letestu revealed the presence of linoleic (C18:2), stearic (C18:0), oleic (C18:1), palmitic (C16:0), pentadecanoic (C15:0) and myristic (C14:0) acid. Polar T. letestui and L. edulis fractions yielded α,α,1'trehalose andmannitol. Some of the crude extracts from the three mushroom species showed mild antimicrobial, mosquito larvicidal and cytotoxic activities. The chemical composition …

Effect Of High Pressurized Carbon Dioxide On Escherichia Coli, I. P. Bateebe, O Kibazohi

Tanzania Journal of Science

Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high pressurised carbon dioxide at 15, 25 and 35 bar, and varying exposure times of 20, 40, 60 and 90 minutes at room temperature (27 oC). Microbial inactivation increased with pressure and exposure time. For the first 20 minutes reduction of viable microbial cells was 18%, 30% and 36% at 15, 25 and 35 …

Natal Dispersal And New Group Formation In Capybaras (Hydrochoerus Hydrochaeris) In A Seasonally Flooded Savanna Of Venezuela, Elizabeth Rae Congdon

Dissertations

This study examines natal dispersal and new group formation in capybaras (Hydrochoerus hydrochaeris) in a seasonally flooded savanna in Venezuela. The first section describes a novel approach to the study of dispersal that could be applied to many taxa. Dispersal is considered in three stages (emigration, transience, and immigration) and its proximate and ultimate mechanisms are clearly differentiated. The second chapter describes dispersal behavior in capybaras, including which individuals disperse, when, and to where. In the third chapter, I evaluate dispersal in capybaras with respect to social subordination and social cohesion hypotheses. In this population, some support was …

Arabian Sea Response To Monsoon Variations, Raghu Murtugudde, Richard Seager, Prasad Thoppil

Faculty Publications

This study aims to quantify the impact of strong monsoons on the mixed layer heat budget in the Arabian Sea by contrasting forced ocean general circulation model simulations with composite strong and weak monsoon winds. Strong (weak) monsoons are defined as years with zonal component of the Somali Jet being greater (smaller) by more than a standard deviation of the long-term mean of the National Centers for Environmental Prediction reanalysis winds. Coastal upwelling is shown to be demonstrably stronger for strong monsoons leading to significant surface cooling, shallower thermoclines, and deeper mixed layers. A coupled ecosystem model shows that surface …

Analysis Of Hg And Stable Isotope Concentrations In Bald Eagle Feathers From The Great Lakes And Voyageurs National Park, Minnesota, Jennifer Thomsen

All Theses

Bald eagles (Haliaeetus leucocephalus) feed on a variety of aquatic and terrestrial wildlife. As top predators in their food chain, they may accumulate harmful concentrations of pollutants such as mercury, which can have detrimental effects on populations of this species. The stable isotope composition of feathers provides useful information about the food resources assimilated by bald eagles. The connection between mercury, (Hg), concentration and stable isotope concentration ( 13C and 15N) of feathers were measured to better understand the potential sources and pathways of Hg uptake by bald eagles living in the Great Lakes region of Michigan and Voyageurs National …

The Role Of Carcinine In Signaling At The Drosophila Photoreceptor Synapse, Brendan A. Gavin, Susan E. Arruda, Patrick J. Dolph

Dartmouth Scholarship

The Drosophila melanogaster photoreceptor cell has long served as a model system for researchers focusing on how animal sensory neurons receive information from their surroundings and translate this information into chemical and electrical messages. Electroretinograph (ERG) analysis of Drosophila mutants has helped to elucidate some of the genes involved in the visual transduction pathway downstream of the photoreceptor cell, and it is now clear that photoreceptor cell signaling is dependent upon the proper release and recycling of the neurotransmitter histamine. While the neurotransmitter transporters responsible for clearing histamine, and its metabolite carcinine, from the synaptic cleft have remained unknown, a …

In-Vitro Investigations On Ultrasonic Control Of Water Chestnut, Meiyin S Wu, J. Wu

Department of Biology Faculty Scholarship and Creative Works

Water chestnut (Trapa natans L.) is native to southern Europe and tropical Africa and Asia and was first introduced into North America in 1874. Since then, wild populations have quickly become established in many locations in the northeastern United States. T. natans is referred to as a noxious aquatic weed since its aggressive growth usually results in complete coverage of the water surface with floating rosettes of leaves. This study investigated the potential of the ultrasonic control of water chestnut since ultrasound has been documented to effectively damage plant cells and tissues. Various frequencies and amplitudes of ultrasound waves generated …

The Family Fuselloviridae : Diversity And Replication Of A Hyperthermic Virus Infecting The Archaeon Genus Sulfolobus, Adam Joseph Clore

Dissertations and Theses

The virus family Fuselloviridae infects the hyperthermophilic and acidophilic Crenarchaeon genus Sulfolobus and has been isolated from terrestrial hotsprings worldwide. Two previously uncharacterized Fuselloviruses, SSV-13 and SSV-L1, were isolated and sequenced and are compared to the five fully sequenced viruses presently in the public databases. Conserved promoters in all viruses and similar putative origins of replication suggest that these viruses use a transcriptional and genomic replication program similar to the relatively well-characterized SSV1. Pairwise comparisons of conserved genes in the seven virus genomes show that, like its host Sulfolobus, these viruses' genetic divergence correlates with geographic separation. Genome rearrangements, horizontal …

Phylogeography Of The Livebearer Xenophallus Umbratilis (Teleostei: Poeciliidae): Glacial Cycles And Sea Level Change Predict Diversification Of A Freshwater Tropical Fish, Carissa Poole Jones

Theses and Dissertations

The biogeography of Central America is considered a classical case study in understanding the impact of vicariant events on patterns of biotic dispersal. While many biogeographers have focused on community composition and geographic limits of species at broad scales across Central America, much less work has focused on post-colonization diversification patterns at finer scales. The livebearing freshwater fish Xenophallus umbratilis presents an ideal system for determining the impact of recent earth history events on biodiversity in northern Costa Rica. Here, we test the hypothesis that marine inundation of the San Carlos and Northern Limón basins during the Miocene has caused …

A Quantitative Synthesis Of The Medicinal Ethnobotany Of The Malinké Of Mali And The Asháninka Of Peru, With A New Theoretical Framework, Nathaniel Bletter

Publications and Research

Background: Although ethnomedically and taxonomically guided searches for new medicinal plants can improve the percentage of plants found containing active compounds when compared to random sampling, ethnobotany has fulfilled little of its promise in the last few decades to deliver a bounty of new, laboratory-proven medicinal plants and compounds. It is quite difficult to test, isolate, and elucidate the structure and mechanism of compounds from the plethora of new medicinal plant uses described each year with limited laboratory time and resources and the high cost of clinical trials of new drug candidates.

Methods: A new quantitative theoretical framework of mathematical …

Niche Separation Along Environmental Gradients As A Mechanism To Promote The Coexistence Of Native And Invasive Species, Edmund R. Priddis

Theses and Dissertations

Niche separation may be the key to promoting the long-term coexistence of introduced and native species. Physical alterations to the environment (habitat manipulation) or re-introducing native species to former habitats can exploit the maladapted traits of introduced species to create a refuge for native species. No two species have identical niches because evolutionary constraints differ between species with different evolutionary histories. Our objectives were to determine if cold temperatures could promote coexistence between native least chub and introduced western mosquitofish. We used individual scale and population scale experiments to test four hypotheses: 1) colder temperatures would reduce the aggressive behavior …

Effects Of An Inserted Endoscope On Chyme Movement In Small Intestine – A Theoretical Model, V. P. Srivastava

Applications and Applied Mathematics: An International Journal (AAM)

The effects of an inserted endoscope on chyme movement in small intestine (gastrointestinal tract) have been investigated. The flow of chyme is induced by a progressive wave of area contraction along the length of intestinal wall under long wavelength approximation. It is found that the chyme movement is significantly influenced due to the presence of the endoscope. The pressure drop assumes lower values for higher values of the endoscope radius for small flow rates but the property reverses with increasing flow rates. The friction forces at intestinal wall and endoscope possess character similar to the pressure drop for any given …

Lichens Of Pine Hill, A Peridotite Outcrop In Eastern North America, Tanner B. Harris, Fred C. Olday, Nishanta Rajakaruna

Biological Sciences

Despite a large body of work on the serpentine-substrate effect on vascular plants, little work has been undertaken to describe lichen communities growing on serpentine soils derived from peridotite and other ultramafic rocks. Most such work has been conducted in Europe and western North America. Only one study to date has examined the lichen flora of an ultramafic outcrop in eastern North America. The current paper examines the lichen flora of a peridotite outcrop from Deer Isle, Hancock County, Maine, U.S.A. The lichen flora is presented along with relevant ecological and geochemical data. Sixty-three species were found, comprising 35 genera. …

Diatom Species Composition And Ecology Of The Animas River Watershed, Colorado, Usa, Gerald V. Sgro, John B. Poole, Jeffrey R. Johansen

Biology

The diatom flora of selected sites in the Animas River Watershed, San Juan County, Colorado, was studied. Eighty diatom taxa were identified from 10 sites: 8 sites on the Animas River and 1 site each on the Cement and Cascade tributaries. The sample diatom abundance was dominated by Achnanthidium minutissimum, Encyonema silesiacum, Aulacoseira distans, Hannaea arcus, and Diatoma mesodon. The presence of teratologic specimens of Fragilaria and Achnanthidium in the samples indicated the possibility of metals contamination. Diatom diversity was low and Lange-Bertalot pollution index scores indicated little organic pollution evidenced from diatom composition. There was evidence that diatom composition …

A Novel Zinc-Binding Domain Is Essential For Formation Of The Functional Junin Virus Envelope Glycoprotein Complex, Joanne York, Jack H. Nunberg

Biological Sciences Faculty Publications

The envelope glycoprotein of the Junin arenavirus (GP-C) mediates entry into target cells through a pH-dependent membrane fusion mechanism. Unlike other class I viral fusion proteins, the mature GP-C complex retains a cleaved, 58-amino-acid signal peptide (SSP) as an essential subunit, required both for trafficking of GP-C to the cell surface and for the activation of membrane fusion. SSP has been shown to associate noncovalently in GP-C via the cytoplasmic domain (CTD) of the transmembrane fusion subunit G2. In this report we investigate the molecular basis for this intersubunit interaction. We identify an invariant series of six cysteine and histidine …

Quantitative Dissection Of Clone-Specific Growth Rates In Cultured Malaria Parasites, Heather B. Reilly Ayala, Hongjian Wang, John A. Steuter, Anastasia M. Marx, Michael T. Ferdig

Faculty Publications - Department of Biological & Molecular Science

Measurement of parasite proliferation in cultured red blood cells underpins many facets of malaria research, from drug sensitivity assays to assessing the impact of experimentally altered genes on parasite growth, virulence, and fitness. Pioneering efforts to grow Plasmodium falciparum in cultured red blood cells revolutionized malaria research and spurred the development of semi-high throughput growth assays using radio-labeled hypoxanthine, an essential nucleic acid precursor, as a reporter of whole-cycle proliferation (Trager and Jensen, 1976; Desjardins et al., 1979). Use of hypoxanthine (Hx) and other surrogate readouts of whole-cycle proliferation remains the dominant choice in malaria research. While amenable to high-throughput …

Cellular Targets Involved In Reovirus-Induced Oncolysis Of Ras-Transformed Cells, Jung Hwa Chung

Biology Theses - Archive

Reovirus is a ubiquitous virus with demonstrated oncolytic properties. In this study, we investigate the pathways which reovirus produces a lytic infection in SV-40 transformed WI-38 cells and the noncytocidal infection of normal WI-38 cells using microarray technology. The analysis revealed that reovirus infection induced changes in 178 genes, of which 112 genes were up regulated and 66 genes down regulated. Of the 112 up regulated genes, 13 of the WI-38 2RA genes were shown to be involved in apoptosis or inhibition of cellular DNA synthesis. Of the 66 genes down regulated, seven of the WI-38 genes displayed effects involved …

Rcd-1 Related:A Positively Selected Retrogene With Spermatogenesis Function In Drosophila, Taniya Muliyil

Biology Theses - Archive

Gene duplication is one of the major forces in driving genome evolution. Our study focuses on a particular retrogene Rcd-1 related (Rcd-1r) that originated through retroposition of the parental gene Required for cell differentiation 1 (Rcd-1) about 5-13 million years ago. Rcd-1r is present in D. melanogaster, D. simulans, D. sechellia and D. mauritiana whereas the parental gene is present in all the Drosophila species. Rcd-1r is inserted in the 3' UTR of the gene CG13102 and it is encoded in the complementary strand. Previous studies by Castrillion et al. showed that a P element inserted in the 5' UTR …

A Sticky Situation: Functional Responses Of Mast Cells To Acidic Ph, Nicole Conaway Grose

Biology Dissertations - Archive

Precise regulation of extracellular pH is critical for proper function of many cellular activities. Minor fluctuations in pH can have profound effects on ion transport, receptor function, and cellular secretions. This work examines the impact of acidic pH, universal at sites of inflammation, on the activation status of mast cells. The mast cell line HMC-1 was used to explore activation by acidic pH. Activation of HMC-1 cells was characterized in cell adhesion, secretion of cytokines, and changes in cell morphology. HMC-1 adhesion to two substrates, collagen and laminin was measured at 0, 1 hr, 2 hrs, 4 hrs, and 6 …

Efficacy Of A Series Of Organotin Polymers As Anticancer And Antiviral Drugs, Kimberly Rae Shahi

Biology Dissertations - Archive

Anticancer drugs have been shown to have antiviral abilities as well. The two types of diseases are similar in that they hold the cell in a continued growth phase. Therefore, if a drug has anticancer activity, it could have antiviral activity as well. I was interested in drugs that could inhibit DNA replication, since both cancer cells and cells infected with a DNA virus have increased DNA replication. Organotins are known to have anticancer activity and are thought to inhibit DNA replication. In this study, four cancer cell lines (from the NCI 60) and two DNA viruses, HSV-1 and vaccinia, …

Development Of New Simple Sequence Repeat Markers For Pearl Millet, O. P. Yadav, S. E. Mitchell, A. Zamora, Theresa M. Fulton, Stephen Kresovich

Faculty Publications

No abstract provided.

Species Invasion Shifts The Importance Of Predator Dependence, Blaine D. Griffen, David G. Delaney

Faculty Publications

The strength of interference between foraging individuals can influence per capita consumption rates, with important consequences for predator and prey populations and system stability. Here we demonstrate how the replacement of a previously established invader, the predatory crab Carcinus maenas, by the recently invading predatory crab Hemigrapsus sanguineus shifts predation from a species that experiences strong predator interference (strong predator dependence) to one that experiences weak predator interference (weak predator dependence). We demonstrate using field experiments that differences in the strength of predator dependence persist for these species both when they forage on a single focal prey species only (the …

Occurrence And Biological Effect Of Exogenous Steroids In The Elkhorn River, Nebraska, Usa, Alan S. Kolok, Daniel D. Snow, Satomi Kohno, Marlo K. Sellin, Louis J. Guillette Jr.

Biology Faculty Publications

Recent studies of surface waters in North America, Japan, and Europe have reported the presence of steroidogenic agents as contaminants. The current study has three objectives: 1) to determine if steroidogenic compounds are present in the Elkhorn River, 2) to determine if sediments collected from the Elkhorn River can act as a source of steroidogenic compounds to aquatic organisms, and 3) to determine if site-specific biological effects are apparent in the hepatic gene expression of fathead minnows. Evidence was obtained using three approaches: 1) deployment of polar organic chemical integrative samplers (POCIS), 2) deployment of caged fathead minnows, and 3) …

Cold Responsive Earli1 Type Hyprps Improve Freezing Survival Of Yeast Cells And Form Higher Order Complexes In Plants, Yi Zhang, Michael Schläppi

Biological Sciences Faculty Research and Publications

Plants have large families of proteins sharing a conserved eight-cysteine-motif (8CM) domain. The biological functions of these proteins are largely unknown. EARLI1 is a cold responsive Arabidopsis gene that encodes a hybrid proline-rich protein (HyPRP) with a three-domain architecture: a putative signal peptide at the N-terminus, a proline-rich domain (PRD) in the middle, and an 8CM domain at the C-terminus. We report here that yeast cells expressing different EARLI1 genes had significantly higher rates of freezing survival than empty-vector transformed controls. Arabidopsis plants with knocked down EARLI1 genes had an increased tendency for freezing-induced cellular damage. EARLI1-GFP Fluorescence in …

The Ecological Boundaries Of Six Carolina Bays: Community Composition And Ecotone Distribution, Lorrie Laliberte, James O. Luken, John J. Hutchens Jr., Kevin S. Godwin

Biology

Community and environmental gradients within the ecological boundaries of Carolina bay wetlands may provide important information on the interaction between Carolina bays and associated uplands, and may also provide guidance for improved management. We established twelve 30-m transects on the sloping rims of each of six Carolina bays in northeastern South Carolina to characterize the community gradient, as well as important environmental factors producing this gradient. Mid-points of the transects were placed on jurisdictional wetland boundaries. Hydrology, soil properties, and plant species composition were measured within these transects. On average, transects included an elevation change of 0.6 m that corresponded …

Pattern Analysis Of Microtubule-Polymerizing And -Depolymerizing Agent Combinations As Cancer Chemotherapies, Carol A. Heckman, S. O. Uppal, Y. Li, E. Wendt, M. L. Cayer, J. Barnes, D. Conway, N. Boudreau

Biological Sciences Faculty Publications

Subcellular distribution of mass can be analyzed by a technique that involves culturing cells on interferometers and digitizing their interference contours. Contour sampling resulted in 102 variables per cell, which were predictors of oncogenic transformation. Cell phenotypes can be deconstructed by use of latent factors, which represent the covariance of the real variables. The reversal of the cancertype phenotype by a combination of microtubule- stabilizing and -depolymerizing agents was described previously. The implications of these results have been explored by clinicians who treated patients with the combination of docetaxel and vinorelbine (Navelbine®). The current study was performed to determine the …

Evalution Of The Efficacy Of The Photosystem Ii Inhibitor Dcmu In Periphyton And Its Effects On Nontarget Microorganisms And Extracellular Enzymatic Reactions, Steven N. Francoeur, Audrey C. Johnson, Kevin A. Kuehn, Robert K. Neely

Faculty Publications

We examined the efficacy of the photosystem II inhibitor 3-(3,4-diclorophenyl)-1,1-dimethyl urea (DCMU) for inhibition of algal photosynthesis in periphyton associated with submerged decomposing litter of Typha angustifolia. We also investigated the possible nontarget effects of DCMU exposure on heterotrophic microorganisms (i.e., bacteria and fungi) and extracellular enzyme activity associated with decaying litter. Standing-dead Typha leaf litter was submerged for 34 and 73 d, returned to the laboratory, and used for controlled laboratory experiments that examined the effect of DCMU on algal ([¹⁴C]bicarbonate, pulse-amplitude modulated fluorometry), bacterial ([³H]leucine), and fungal ([¹⁴C]acetate) production. Simultaneous assays …

Mapk Survival Signaling In Melanoma, Matthew W. Vanbrocklin

Dissertations

Extracellular signals activate mitogen-activated protein kinase (MAPK) cascades potentiating biological activities such as cell proliferation, differentiation, and survival. Constitutive activation of MAPK signaling pathways is implicated in the development and progression of many human cancers, including melanoma. Mutually exclusive activating mutations in NRAS or BRAF are found in ∼85% of all melanomas resulting in constitutive activation of the MAPK pathway (RAS-BRAF-MEK-ERK-RSK). We have previously demonstrated that inhibition of this pathway with small molecule MEK inhibitors selectively induces apoptosis in human melanoma cells both in vitro and in vivo, but not in normal melanocytes. These results support the notion that the …