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2008

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Articles 451 - 480 of 647

Full-Text Articles in Biology

Structure-Function Analysis Of The Drosophila Stubble Type Ii Transmembrane Serine Protease, Rachel Morgan Jan 2008

Structure-Function Analysis Of The Drosophila Stubble Type Ii Transmembrane Serine Protease, Rachel Morgan

Electronic Theses and Dissertations

Hormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important roles in the development and homeostasis of a number of mammalian tissues. Aberrant expression of TTSPs is linked to several human disorders, including deafness, heart and respiratory disease and cancer. However, the …

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Tmdl Bioassessment Sampling Of Benthic Macroinvertebrates For Lake Jesup And Lake Seminary, Gloria Eby Jan 2008

Tmdl Bioassessment Sampling Of Benthic Macroinvertebrates For Lake Jesup And Lake Seminary, Gloria Eby

Electronic Theses and Dissertations

The objective of this study was to obtain a bioassessment using benthic macroinvertebrates to meet TMDL (Total Maximum Daily Load) criteria for an oligotrophic (Lake Seminary) and an eutrophic (Lake Jesup) freshwater system in Seminole County, Florida. Monthly sampling of the benthic macroinverterbrate communities provided important biological data necessary to construct TMDL protocol and trophic state. Since macroinvertebrates are near the base of the food chain, they not only provide a critical role in the natural flow of energy and cycling of nutrients through the food web, but also provide a good indication of water quality by their presence and …

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Growth And Survival Of Bacteria In Simulated Martian Conditions, Bonnie Berry Jan 2008

Growth And Survival Of Bacteria In Simulated Martian Conditions, Bonnie Berry

Electronic Theses and Dissertations

Escherichia coli and Serratia liquefaciens, two common microbial spacecraft contaminants known to replicate under low atmospheric pressures of 25 mb, were tested for growth and survival in simulated martian conditions. Stressors of high salinity, low temperature, and low pressure were screened alone and in combination to determine how they might affect microbial activity. Growth and survival of E. coli and S. liquefaciens under low temperatures (30, 20, 10, or 5 °C) with increasing concentrations (0, 5, 10, or 20 %) of three salts believed to be present on the surface of Mars (MgCl2, MgSO4, NaCl) were monitored over 7 d. …

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Cis-Regulatory Analysis Of The Pigment Cell Differentiation Gene Polyketide Synthase, David Rogers Jan 2008

Cis-Regulatory Analysis Of The Pigment Cell Differentiation Gene Polyketide Synthase, David Rogers

Electronic Theses and Dissertations

The analysis of Gene Regulatory Networks (GRNs) is essential to understanding the complete process of embryo development. Elucidating every gene regulatory circuit from maternal regulatory inputs all the way to the activation of differentiation gene batteries is an important step in increasing our understanding of developmental biology. In this work I study the cis-regulatory architecture of a pigment cell differentiation gene, polyketide synthase (SpPks) in the sea urchin Strongylocentrotus purpuratus. SpPks encodes an enzyme that is responsible for the biosynthesis of the sea urchin pigment echinochrome in larval pigment cells. The analysis of the promoter of a differentiation gene will …

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Leptodactylus Cunicularius Sazima And Bokermann Rabbit-Burrow Frog, W. R. Heyer, M. M. Heyer, Rafael O. De Sá Jan 2008

Leptodactylus Cunicularius Sazima And Bokermann Rabbit-Burrow Frog, W. R. Heyer, M. M. Heyer, Rafael O. De Sá

Biology Faculty Publications

Adult Leptodactylus cunicularius are moderately small. The head is longer than wide and the hind limbs are long (Table 1; Heyer and Thompson 2000 provided definitions of adult size and leg length categories for Leptodactylus). Male vocal sacs are internal, not externally expanded. The snout is protruding, not sexually dimorphic. Male forearms are not hypertrophied and males lack asperities on the thumbs and chest. The dorsum is variegated with small, often confluent, spots and blotches. There is a very thin interrupted mid-dorsal light stripe (pinstripe). Usually, there is a noticeable light, irregular, elongate, mid-dorsal blotch in the scapular region. …

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Is The Amphibian Tree Of Life Really Fatally Flawed?, Darrel R. Frost, Taran Grant, Julian Faivovich, Raoul H. Bain, Alexander Haas, Celio F.B. Haddad, Rafael O. De Sá, Et Al. Jan 2008

Is The Amphibian Tree Of Life Really Fatally Flawed?, Darrel R. Frost, Taran Grant, Julian Faivovich, Raoul H. Bain, Alexander Haas, Celio F.B. Haddad, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Wiens (2007, Q. Rev. Biol. 82, 55–56) recently published a severe critique of Frost et al.'s (2006, Bull. Am. Mus. Nat. Hist. 297, 1–370) monographic study of amphibian systematics, concluding that it is “a disaster” and recommending that readers “simply ignore this study”. Beyond the hyperbole, Wiens raised four general objections that he regarded as “fatal flaws”: (1) the sampling design was insufficient for the generic changes made and taxonomic changes were made without including all type species; (2) the nuclear gene most commonly used in amphibian phylogenetics, RAG-1, was not included, nor were the morphological characters that had justified …

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Factors Influencing The Distribution Of Overwintered Bullfrog Tadpoles (Rana Catesbeiana) In Two Small Ponds, S. E. Hargis, M.-K. Harr, C. J. Henderson, W. J. Kim, Geoffrey R. Smith Jan 2008

Factors Influencing The Distribution Of Overwintered Bullfrog Tadpoles (Rana Catesbeiana) In Two Small Ponds, S. E. Hargis, M.-K. Harr, C. J. Henderson, W. J. Kim, Geoffrey R. Smith

Faculty Publications

No abstract provided.

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Diet And Sexual Dimorphism Of The Desert Iguana, Dipsosaurus Dorsalis, From Sonora, Mexico, C. J. Dibble, Geoffrey R. Smith, J. A. Lemos-Espinal Jan 2008

Diet And Sexual Dimorphism Of The Desert Iguana, Dipsosaurus Dorsalis, From Sonora, Mexico, C. J. Dibble, Geoffrey R. Smith, J. A. Lemos-Espinal

Faculty Publications

No abstract provided.

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A Tribute To Robert Benson Gordon, Gerard Hertel, Virginia Gordon Hatch, Robert L. Gordon Jan 2008

A Tribute To Robert Benson Gordon, Gerard Hertel, Virginia Gordon Hatch, Robert L. Gordon

Gordon Natural Area History & Strategic Plan Documents

No abstract provided.

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Cytotoxicity Of Diepoxybutane And Epichlorohydrin In Relation To Stages Of The Cell Cycle, Megan L. Watts Jan 2008

Cytotoxicity Of Diepoxybutane And Epichlorohydrin In Relation To Stages Of The Cell Cycle, Megan L. Watts

Honors Theses

Work conducted in the Millard Biochemistry Research Laboratory examines the dual nature of molecules as carcinogens and anti-tumor agents through the molecular mechanisms of duplex DNA damage by bifunctional alkylating agents. Diepoxybutane (DEB) and epichlorohydrin (ECH) are polar molecules that form covalent DNA interstrand lesions by cross-linking the N7 position of deoxyguanosine residues. A recent experiment indicated that ECH preferentially targets nuclear DNA over mitochondrial DNA, whereas DEB shows similar rates of lesion formation for both loci. It was concluded that preferential targeting of nuclear DNA results from relatively poor uptake of ECH across the mitochondrial membrane. The objective of …

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Gliotoxin Production In Aspergillus Fumigatus, Susan Musyimi Jan 2008

Gliotoxin Production In Aspergillus Fumigatus, Susan Musyimi

Theses and Dissertations

Aspergillus fumigalus is a ubiquitous fungus that causes an infection called aspergillosis in immune-compromised surgery patients (Latge, 2001, 384; Bok et al. 2006). Aspergillosis cases have increased in the past decade due to the increasing number of patients undergoing immunosuppressive therapy and receiving organ transplants (Bok et al. 2006). Although there is still disagreement as to the causative agent of the symptoms accompanying aspergillosis, many scientists suspect that the compound, gliotoxin, plays a major role, hi this study, we compared the amounts of gliotoxin produced from clinical and environmental isolates of A. fumigatus. We hypothesized that the amount of gliotoxin …

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Microhabitat Selection By The Tortoiseshell Limpet, Tectura Testudinalis (Müller), In Tide Pools On The Mid-Maine Coast, Emily R. Lyczkowski Jan 2008

Microhabitat Selection By The Tortoiseshell Limpet, Tectura Testudinalis (Müller), In Tide Pools On The Mid-Maine Coast, Emily R. Lyczkowski

Honors Theses

Microhabitat selection of the limpet Tectura testudinalis, an important grazer along the rocky Maine coast is examined using both mensurative and manipulative experiments. T. testudinalis substrate selection is essential to its survival in the unpredictable and harsh regime of the intertidal zone. At three sites studied in the Gulf of Maine, T. testudinalis selectively inhabits tidal pools and vertically oriented substrates. Both of these microhabitats reduce the degree of environmental stress (desiccation, extreme temperature, and hypersaline conditions) and predation experienced by individuals. Differences among sites are common, indicating the importance of varying environmental factors in regulating and influencing habitat selection …

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A Genetic Assessment Of The Red Squirrel In Illinois: Natives, Immigrants, Or Exotics?, William Beatty Jan 2008

A Genetic Assessment Of The Red Squirrel In Illinois: Natives, Immigrants, Or Exotics?, William Beatty

Masters Theses

A small population ofred squirrels (Tamiasciurus hudsonicus) has existed in Iroquois County, Illinois since the 1970' s. The origin of this population is unknown, but some accounts suggest they are the offspring of released red squirrels from Minnesota. Alternatively, they may be a remnant Illinois population or more recent immigrants from Indiana. Finally, this population could reflect a mixed ancestry of the above scenarios. Mitochondrial DNA (mtDNA) was utilized to determine the genetic relationships among red squirrel populations in Illinois, Indiana, Michigan, Minnesota, and Wisconsin. My results showed low levels of haplotype diversity and nucleotide diversity in the Illinois sample. …

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Beneficial Effects Of Estradiol Are Mediated Through Apoe, Aseem Hussain Jan 2008

Beneficial Effects Of Estradiol Are Mediated Through Apoe, Aseem Hussain

Masters Theses

Estradiol is the primary premenopausal hormone circulating in women. It is a powerful hormone in the female body since it sends signals to the brain, regulates ovulation and menstrual cycle and acts on the nervous syste~ heart, breast and many other tissues in the body. However all estradiol production is stopped after menopause. Post menopausal women can develop a host of neurodegenerative diseases such as Alzheimer's disease. If the onset of progressive dementia is after menopause during loss of estradiol, it seems logical to assume that the lack of estradiol should have a big role to play in the pathogenesis …

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Tracing Sperm In Multiply-Mated Female Anastrepha Suspensa, (Diptera:Tephridae), Preeti Dhakal Jan 2008

Tracing Sperm In Multiply-Mated Female Anastrepha Suspensa, (Diptera:Tephridae), Preeti Dhakal

Masters Theses

Anastrepha suspensa females have four different sites of sperm storage in their reproductive tract, may mate with more than one male, and store sperm in differing amounts in each organ after copulation. In order to study the dynamics of sperm storage patterns and subsequent paternity outcomes, a method was developed for both genotyping and quantifying sperm in the spermathecae. Spermathecae were isolated and sonicated to remove maternal cells, and subsequently crushed between two microslides to release sperm from the capsule. After DNA isolation, microsatellite loci could be amplified by PCR for fragment analysis. A newly developed method was then used …

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Artificial Riffles As A Stream Remediation Technique, Bethany S. Harrington Jan 2008

Artificial Riffles As A Stream Remediation Technique, Bethany S. Harrington

Masters Theses

No abstract provided.

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Influence Of Seed Source On Vegetative And Reproductive Performance Of Three Common Prairie Grasses Common In Grassland Restoration, Matt Burmeister Jan 2008

Influence Of Seed Source On Vegetative And Reproductive Performance Of Three Common Prairie Grasses Common In Grassland Restoration, Matt Burmeister

Masters Theses

Though tallgrass prairie once covered 250 million acres of the midwestem U.S, now less than one percent· of this original area is left. In recent years the restoration and reconstruction of tallgrass prairie has become more popular throughout the prairie region. There is evidence that local and distant populations may both be practical seed sources for ecological restoration projects. To address this basic issue in restoration, I tested the how performance of three grass species from different locations was affected by the distance from the restored area. Three species, Andropogon gerardii, Sorghastrum nutans and Panicum virgatum, of perennial grasses common …

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Comparative Study Between Wild Rice (Oryza Rufipogon) And Domesticated Rice (Oryza Sativa Ssp Japonica) Chromosome 8 Centromere, Soham Aso Jan 2008

Comparative Study Between Wild Rice (Oryza Rufipogon) And Domesticated Rice (Oryza Sativa Ssp Japonica) Chromosome 8 Centromere, Soham Aso

Theses, Dissertations and Culminating Projects

Rice has one of the simplest of the monocotyledonous genomes analyzed to date. The Oryza sativa genome is made of 12 chromosomes and has a total length of 430 MB. It is highly syntenic amongst other cereals. Therefore, genetic distances of these organisms are surprisingly very similar, meaning that genomic recombinations in each cereal occur at much the same frequency despite the differences in their genome size. The reason for this synchrony in recombinations may be due to similar lengths of gene-rich and gene-rare regions. This study focuses on the gene-rare repetitive centromeric region of rice chromosome 8. Although the …

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Proxy-Based Reconstructions Of Hemispheric And Global Surface Temperature Variations Over The Past Two Millennia, Michael E. Mann, Scott Rutherford Jan 2008

Proxy-Based Reconstructions Of Hemispheric And Global Surface Temperature Variations Over The Past Two Millennia, Michael E. Mann, Scott Rutherford

Arts & Sciences Faculty Publications

Following the suggestions of a recent National Research Council report [NRC (National Research Council) (2006) Surface Temperature Reconstructions for the Last 2,000 Years (Natl Acad Press, Washington, DC).], we reconstruct surface temperature at hemispheric and global scale for much of the last 2,000 years using a greatly expanded set of proxy data for decadal-to-centennial climate changes, recently updated instrumental data, and complementary methods that have been thoroughly tested and validated with model simulation experiments. Our results extend previous conclusions that recent Northern Hemisphere surface temperature increases are likely anomalous in a long-term context. Recent warmth appears anomalous for at least …

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Assessment Of Synaptic Function During Short-Term Facilitation In Motor Nerve Terminals In The Crayfish, Mohati Desai-Shah, Kert Viele, G. Sparks, J. Nadolski, B. Hayden, V. K. Srinivasan, Robin L. Cooper Jan 2008

Assessment Of Synaptic Function During Short-Term Facilitation In Motor Nerve Terminals In The Crayfish, Mohati Desai-Shah, Kert Viele, G. Sparks, J. Nadolski, B. Hayden, V. K. Srinivasan, Robin L. Cooper

Biology Faculty Publications

An enhanced buildup of [Ca2+]i occurs during short-term facilitation (STF) at the crayfish neuromuscular junction (NMJ). As a model system, this NMJ allows discrete postsynaptic quantal events to be counted and characterized in relation to STF. Providing 10 pulses, at 20 and 40Hz, we monitored postsynaptic quantal events over a discrete region of a nerve terminal with a focal macropatch electrode. Characteristics of quantal events were clustered into groups by peak amplitude and time to the peak amplitude. Since the synapses at this NMJ have varied spacing of active zones, number of active zones and synaptic size, the …

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Presynaptic Depression In Phasic Motor Nerve Terminals And Influence Of 5-Ht On Vesicle Dynamics, A. F. M. Johnstone, S. S. Kellie, Robin L. Cooper Jan 2008

Presynaptic Depression In Phasic Motor Nerve Terminals And Influence Of 5-Ht On Vesicle Dynamics, A. F. M. Johnstone, S. S. Kellie, Robin L. Cooper

Biology Faculty Publications

Synaptic depression that is induced by electrical stimulation of the glutamatergic neuromuscular junction (NMJ) of the crayfish can be offset by recruitment of vesicles from a presynaptic reserve pool. This recruitment occurs following treatment of the NMJ with serotonin (5-HT), which results in a delay in the onset of synaptic depression induced by high frequency stimulation. The results of this study demonstrate that the releasable vesicles are insufficiently replenished during high frequency stimulation and that the readily releasable pool of vesicles (RRP) can be enhanced by the reserve pool (RP) in the presence of 5-HT. Anatomical visualization of vesicular pools …

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Mojave Applied Ecology Notes Winter 2008, Scott R. Abella, E. Cayenne Engel, Jill E. Craig Jan 2008

Mojave Applied Ecology Notes Winter 2008, Scott R. Abella, E. Cayenne Engel, Jill E. Craig

Mojave Applied Ecology Notes

Mojave Desert collaborative projects, fire history in Spring Mountains, Northshore Road rehabilitation, wildfires and invasive plants in American deserts conference, weed sentry surveys

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In Vitro Antimicrobial Activity Of Salvadora Persica L. Extracts Against Some Isolated Oral Pathogens In Iraq, Firas A. Al-Bayati, Khudir D. Sulaiman Jan 2008

In Vitro Antimicrobial Activity Of Salvadora Persica L. Extracts Against Some Isolated Oral Pathogens In Iraq, Firas A. Al-Bayati, Khudir D. Sulaiman

Turkish Journal of Biology

Aqueous and methanol extracts of Salvadora persica L., a plant used in Iraq for oral hygiene, was investigated for its antimicrobial activities against 7 isolated oral pathogens: Staphylococcus aureus, Streptococcus mutans, Streptococcus faecalis, Streptococcus pyogenis, Lactobacillus acidophilus, Pseudomonas aeruginosa, and Candida albicans using disc diffusion and micro-well dilution assays. According to both antimicrobial assays the aqueous extract inhibited all isolated microorganisms, especially the Streptococcus species, and was more efficient than the methanol extract, which was resisted by Lacto. acidophilus and Ps. aeruginosa. The strongest antibacterial activity was observed using the aqueous extract against Strep. faecalis (zone of inhibition: 22.3 mm; …

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Effects Of Population Size And Density On Pollinator Visitation, Pollinator Behavior, And Pollen Tube Abundance In Lupinus Perennis, Christopher E. Bernhardt, Randall J. Mitchell, Helen J. Michaels Jan 2008

Effects Of Population Size And Density On Pollinator Visitation, Pollinator Behavior, And Pollen Tube Abundance In Lupinus Perennis, Christopher E. Bernhardt, Randall J. Mitchell, Helen J. Michaels

Biology Faculty Research

Both the number and the density of flowering plants in a population can be important determinants of pollinator abundance and behavior. We report the joint effects of population size and density on pollinator visitation and pollination success for Lupinus perennis (Fabaceae). Focusing on five pairs of populations, we matched one small population (125-800 flowering plants) with one distinctly larger population (1000-3000 flowering plants). In these pairs, population size did not affect pollinator communities or pollination success. All measures of pollination success increased significantly with density. Only bee behavior (number of flowers probed per inflorescence) exhibited a significant interaction of size …

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Annual Secondary Production Of Fungal And Bacterial Decomposers Associated With Standing And Benthic Litter Of The Freshwater Emergent Macrophyte, Typha Angustifolia , Brian Matthew Ohsowski Jan 2008

Annual Secondary Production Of Fungal And Bacterial Decomposers Associated With Standing And Benthic Litter Of The Freshwater Emergent Macrophyte, Typha Angustifolia , Brian Matthew Ohsowski

Master's Theses and Doctoral Dissertations

Fungi and bacteria are significant decomposers of plants within wetlands, but annual secondary production investigations are lacking. Microbial carbon assimilation into biomass and CO2 mineralization may contribute considerably to wetland biogeochemical cycling and energy flow. Naturally-occurring Typha angustifolia detritus was collected to determine annual areal carbon flow through secondary decomposers. Two decay phases, standing-dead and benthic litter, were analyzed concurrently to determine fungal (14C-acetate incorporation) and bacterial (3H-leucine incorporation) production estimates. Gradual collapse of the 2004 cohort standing-dead stocks resulted in lowest litter biomass at study's end while benthic detrital stocks displayed little biomass fluctuation. …

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How The Turtle Gets Its Shell, Scott F. Gilbert, J. A. Cebra-Thomas, A. C. Burke Jan 2008

How The Turtle Gets Its Shell, Scott F. Gilbert, J. A. Cebra-Thomas, A. C. Burke

Biology Faculty Works

No abstract provided.

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Insertion Of The Enzyme Cyclopropane Fatty Acid Synthase Into Plastids Through Agrobacterium Mediated Transformation, Jason L. Rush Jan 2008

Insertion Of The Enzyme Cyclopropane Fatty Acid Synthase Into Plastids Through Agrobacterium Mediated Transformation, Jason L. Rush

Undergraduate Honors Thesis Collection

Under natural conditions, Agrobacterium is a plant pathogen that infects plants by inserting genes into the plant's genome that are desirable to the bacterium itself. A tumor is then formed and the infected plant tissue makes molecules that the bacterium uses as food.

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Investigation Of Kalanchoe Homeobox 1 (Kh1) Gene In Apical Meristems Of Kalanchoe Pinnatum, Jessica Lynn Kirkpatrick Jan 2008

Investigation Of Kalanchoe Homeobox 1 (Kh1) Gene In Apical Meristems Of Kalanchoe Pinnatum, Jessica Lynn Kirkpatrick

Undergraduate Honors Thesis Collection

Kalanchoe pinnatum (syn. Bryophyllum pinnatum) is a succulent plant that is notable for developing small plantlets on the outer edges of its leaves, when its leaves are detached (Kulka 2006). These plantlets eventually drop off and root, which is a unique way for the plant to asexually reproduce. In most other plants, leaves exhibit determinate growth, meaning once they reach their maturity, they do not continue to grow.

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Macrofungal Diversity At The Gordon Natural Area, Lauryn Levy, Greg Turner, Gerard Hertel Jan 2008

Macrofungal Diversity At The Gordon Natural Area, Lauryn Levy, Greg Turner, Gerard Hertel

Gordon Natural Area Biodiversity Studies Documents

No abstract provided.

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Antipyretic Activity Of Peperomia Pellucida Leaves In Rabbit, Alam Khan, Moizur Rahman, Shariful Islam Jan 2008

Antipyretic Activity Of Peperomia Pellucida Leaves In Rabbit, Alam Khan, Moizur Rahman, Shariful Islam

Turkish Journal of Biology

Antipyretic effects of petroleum ether and ethyl acetate soluble fractions of ethanol extract of the leaves of Peperomia pellucida (Linn.) HBK (Fam. Piperaceae) were investigated. Intraperitoneal administration of boiled milk at a dose of 0.5 ml/kg body weight in albino rabbit leads to pyrexia. Intraperitoneal (i.p.) administration of petroleum ether and ethyl acetate soluble fractions of ethanol extract of the leaves of P. pellucida at a dose of 80 mg/kg body weight significantly reduced the elevated body temperature of rabbit. This antipyretic effect has been compared with antipyretic effect of standard aspirin and the solvent used.

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