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A Gene Expression Study Of The Tgf-\Beta Signaling Pathway Components In Differentiating Pc12 Cells, Işil Aksan Kurnaz

Turkish Journal of Biology

The neuronal differentiation process has been studied in great detail from many aspects. In the PC12 system, NGF was found to induce neuronal differentiation as measured by neurite extensions and neuronal marker expression. This effect was seen to be mainly conducted through the Ras/MAPK pathway; however, additional pathways are suspected to play a significant role in this cellular response. One such pathway is Smad signaling - NGF was previously reported to induce the expression of the TGF-\beta signal, although the physiological relevance of this was not completely understood. In this study, we analyzed the expression profiles of several TGF-\beta pathway …

The Effect Of Acid Adaptation Conditions On Acid Tolerance Response Of Escherichia Coli O157: H7, Hali̇l Tosun, Şahi̇ka Aktuğ Gönül

Turkish Journal of Biology

This study examined the effects of acid shock and acid adaptation on acid tolerance of E. coli O157: H7 932 strain. E. coli O157: H7 were exposed to acid at pH 4.5, 5.0 or 5.5 for acid adaptation or acid shock in tryptic soy broth (acidified with 6 N HCI). Acid shocked cells were incubated for 1, 2, 3 or 4 h while acid adapted cells were incubated for 18 h at 37°C and then acid tolerance of acid shocked and acid adapted cells were determined by exposing to acid challenge of pH 2.5 or 3.0 in tryptic soy broth. …

Efficacy Of Aqueous And Methanol Extracts Of Some Medicinal Plants For Potential Antibacterial Activity, Jigna Parekh, Darshana Jadeja, Sumitra Chanda

Turkish Journal of Biology

Twelve medicinal plants were screened, namely Abrus precatorius L., Caesalpinia pulcherrima Swartz., Cardiospermum halicacabum L., Casuarina equisetifolia L., Cynodon dactylon (L.) Pers., Delonix regia L., Euphorbia hirta L., Euphorbia tirucalli L., Ficus benghalensis L., Gmelina asiatica L., Santalum album L., and Tecomella undulata (Sm.) Seem, for potential antibacterial activity against 5 medically important bacterial strains, namely Bacillus subtilis ATCC6633, Staphylococcus epidermidis ATCC12228, Pseudomonas pseudoalcaligenes ATCC17440, Proteus vulgaris NCTC8313 and Salmonella typhimurium ATCC23564. The antibacterial activity of aqueous and methanol extracts was determined by agar disk diffusion and agar well diffusion method. The methanol extracts were more active than the aqueous …

Phylogenetic Analysis Of Vascular Endothelial Growth Factor Diversity, Murat Kasap

Turkish Journal of Biology

The secreted glycoprotein vascular endothelial growth factor (VEGF) is a potent and specific mitogen for vascular endothelial cells, capable of stimulating angiogenesis during embryonic development and tumor formation. Despite intensive research, the functions of several VEGF family members remain a mystery. Insight into their evolutionary relationships could profoundly improve our understanding of why there are so many VEGFs and why we have not been able to dissect their function to our satisfaction. It appears from the presence of several structurally related VEGF proteins that VEGF proteins do have a long divergence history. We investigated the evolution and phylogenetic relationships among …

Ecology Of Larval Fishes And Large Zooplankton In The Keweenaw Current Region Of Lake Superior, With Special Focus On Lake Herring, Coregonus Artedi, Jason K. Oyadomari

Dissertations, Master's Theses and Master's Reports - Open

I assessed the influence of the Keweenaw Current and spring thermal bar on the distribution of larval fishes and large zooplankton in Lake Superior. In 1998 and 1999, samples were collected from inshore (0.2 – 3.0 km from shore) and offshore (5.0 – 9.0 km from shore) locations on three transects off the western coast of the Keweenaw Peninsula, Michigan. For larval fishes, density and size distribution patterns of lake herring (Coregonus artedi), rainbow smelt (Osmerus mordax), burbot (Lota lota), deepwater sculpin (Myoxocephalus thompsoni), and spoonhead sculpin (Cottus ricei) suggest …

Flying Squirrel Is Seldom Seen, Often Misunderstood Member Of Arkansas Wildlife, Aldemaro Romero Jr., Thomas S. Risch

Publications and Research

No abstract provided.

Reproductive Effort Is Inversely Proportional To Average Adult Life Span., Eric Charnov

Biology Faculty & Staff Publications

Background: Forty years ago, G.C. Williams predicted that reproductive effort should be inversely related to the average adult life span across species. Aim: Use allometric life-history theory to refine that prediction. Result: Reproductive effort should be inversely proportional to average adult life span, a −1 scaling rule.

Mammal Life-History Evolution With Size-Dependent Mortality, Eric Charnov

Biology Faculty & Staff Publications

Size dependence of mortality over the ontogeny is added to life-history optimization schemes for mammals

Interspecific Competition For Pollination Lowers Seed Production And Outcrossing In Mimulus Ringens, John M. Bell, Jeffrey D. Karron, Randall J. Mitchell

Biology Faculty Research

Sympatric plant species with similar flowering phenologies and floral morphologies may compete for pollination, and as a consequence potentially influence each other's reproductive success and mating system. Two likely competitors are Mimulus ringens and Lobelia siphilitica, which co-occur in wet meadows of central and eastern North America, produce blue zygomorphic flowers, and share several species of bumble bee pollinators. To test for effects of competition for pollination, we planted experimental arrays of Mimulus ringens, each consisting of genets with unique combinations of homozygous marker genotypes. In two arrays we planted mixtures of Mimulus and Lobelia. and in two additional arrays …

Biochemical And Molecular Nutrition Blocks As Dietary Supplements In Llamas (Lama Glama) In The Last Third Of The Gestation Period Of The Ceac, Janette Illanes Callejas

Theses and Dissertations

The present work consisted in the use of biochemical and molecular nutrition blocks (BMN) in llamas during the last third of the gestation period, at the Agricultural Experiment Center of Condori (CEAC), located 49 km north of the city of Oruro, and 12 km north of the Caracollo population, in the province of Cercado. For this research work, we used 20 pregnant llamas in the last third of their gestation period, between the ages of 2 and 3 years old, 10 of which belonged to the Khara breed, and 10 to the Thampulli breed. Two corrals of 7 x 7 …

Cascading Effects Of Predator Removal On The Ecology Of Sea Turtle Nesting Beaches, Brandon Barton

Electronic Theses and Dissertations

Traditional views of food web dynamics have characterized species interactions as linear and direct. However, modern food web theory suggests that interactions can also be nonlinear and indirect, so that disturbance at one trophic level is transmitted throughout the community. Many previous studies have demonstrated that the removal of top predators from terrestrial ecosystems can have broad-scale impacts on community ecology. I examined the direct and indirect effects of raccoon removal from sea turtle nesting beaches in east-central Florida during the summers of 2003 and 2004. Raccoon and ghost crab predation are among the highest causes of egg mortality for …

Confocal Laser Scanning Microscopy As A Tool For The Investigation Of Tetracycline Fluorescence In Archaeologicalhuman Bone, Corey Maggiano

Electronic Theses and Dissertations

Fluorochromes such as tetracycline have been used to label bone for histomorphometric analysis, measuring bone formation, growth, maintenance, and pathology. More recently, similar fluorescence has been observed in ancient human bone. Attributed to tetracycline (TC) exposure, this phenomenon could affect various aspects of health during life and/or preservation of remains postmortem. Standard epifluorescence microscopy is the most common tool employed in the analysis of these labels. Though valuable, this technique is limited by its inability to penetrate bone three-dimensionally and its inclusion of out-of-focus light, possibly disrupting accurate analysis. Confocal Laser Scanning Microscopy (CLSM) has been demonstrated as a valuable …

Haemophilus Influenzae Modulins In Chronic Obstructive Pulmonary Disease Airway Inflammation, Gitanjali Kundu

Master's Theses and Doctoral Dissertations

Nontypeable H. influenzae (NTHi) causes repeated respiratory infections characterized by a brisk inflammatory response that results in the expression and secretion of proinflammatory cytokines. We hypothesized that secreted and cell asssociated NTHi proteins mediate cellular interactions with respiratory epithelial cells, leading to the production of interleukin (IL)-8. We exposed human tracheal epithelial cells to H. influenzae strain Rd and compared the resulting profiles of IL-8 secretion. Putative H. influenzae Rd modulins were enriched from culture supernatant fluid. Proteome analysis of the enriched fractions revealed 27 candidate proteins. Further analysis of four proteins, ClpB, OmpP2, TonB, and RelA, suggested a potential …

Diet: Charina Bottae, T. J. Devitt, Ryan I. Hill, S. E. Cameron

College of the Pacific Faculty Articles

No abstract provided.

Omnivory By The Small Cosmopolitan Hydromedusa Aglaura Hemistoma, Sean Colin, John H. Costello, William M. Graham, John Higgins Iii

Arts & Sciences Faculty Publications

We investigated the feeding of the small hydromedusa, Aglaura hemistoma (bell diameter < 4 mm), to determine if it occupies a trophic position similar to that of large medusae. Feeding was examined using gut-content analysis of preserved and unpreserved medusae and by analyzing prey-capture events using microvideographic techniques. Analysis of gut contents and prey-capture events revealed that A. hemistoma fed heavily on protistan prey and that it possessed a prey-capture mechanism, specifically a feeding current,that is effective at entraining and capturing protists with low motility. We suggest that many species of small hydromedusae possess prey-capture mechanisms adapted to capture small protistan prey and that many of these small hydromedusae feed omnivorously on microplanktonic prey. The trophic roles of small hydromedusae in different systems are not understood and more studies are needed. However, based on their often high abundances and the cosmopolitan nature, if small hydromedusae …

Flow Patterns Generated By Oblate Medusan Jellyfish: Field Measurements And Laboratory Analyses, John O. Dabiri, Sean Colin, John H. Costello, Morteza Gharib

Arts & Sciences Faculty Publications

Flow patterns generated by medusan swimmers such as jellyfish are known to differ according the morphology of the various animal species. Oblate medusae have been previously observed to generate vortex ring structures during the propulsive cycle. Owing to the inherent physical coupling between locomotor and feeding structures in these animals, the dynamics of vortex ring formation must be robustly tuned to facilitate effective functioning of both systems. To understand how this is achieved, we employed dye visualization techniques on scyphomedusae (Aurelia aurita) observed swimming in their natural marine habitat. The flow created during each propulsive cycle consists of …

Prorocentrum Minimum(Clone Exuv) Is Nutritionally Insufficient, But Not Toxic To The Copepod Acartia Tonsa, Hans G. Dam, Sean Colin

Arts & Sciences Faculty Publications

This study tested whether the dinoflagellate Prorocentrum minimum is nutritionally insufficient or toxic to the copepod Acartia tonsa. Experiments were carried out with adult female A. tonsa and the P. minimum clone Exuv, both isolated from Long Island Sound. Initially, the functional and numerical responses of A. tonsa feeding on exponentially growing P. minimum cells were characterized. These experiments revealed that A. tonsa readily ingested P. minimum cells, up to the equivalent of 200% of body carbon day⁻¹, but egg production was relatively low, with a maximum egg production rate of 22% of body carbon day …

A Fossil Reef From The Last Interglacial, Western Australia, Benjamin J. Greenstein, John M. Pandolfi, David R. Blakeway

Arts & Sciences Faculty Publications

We report an initial investigation of a Devils Point Event (DPE) style surface exposed approximately 1.5 m above present sea level in a spectacularly preserved reef sequence in southern Exmouth Gulf, Western Australia.

Gene Set Coregulated By The Saccharomyces Cerevisiae Nonsense-Mediated Mrna Decay Pathway, Rachel Taylor, Bessie Wanja Kebaara, Tara Nazarenus, Ashley Jones, Rena Yamanaka, Rachel Uhrenholdt, Jason P. Wendler, Audrey L. Atkin

School of Biological Sciences: Faculty Publications

The nonsense-mediated mRNA decay (NMD) pathway has historically been thought of as an RNA surveillance system that degrades mRNAs with premature translation termination codons, but the NMD pathway of Saccharomyces cerevisiae has a second role regulating the decay of some wild-type mRNAs. In S. cerevisiae, a significant number of wild-type mRNAs are affected when NMD is inactivated. These mRNAs are either wild-type NMD substrates or mRNAs whose abundance increases as an indirect consequence of NMD. A current challenge is to sort the mRNAs that accumulate when NMD is inactivated into direct and indirect targets. We have developed a …

Characterization Of Different Crystal Forms Of The Α-Glucosidase Mala From Sulfolobus Solfataricus, Heidi Asschenfeldt Ernst, Martin Willemoës, Leila Lo Leggio, Gordon Leonard, Paul H. Blum, Sine Larsen

School of Biological Sciences: Faculty Publications

MalA is an _-glucosidase from the hyperthermophilic archaeon Sulfolobus

solfataricus. It belongs to glycoside hydrolase family 31, which includes several

medically interesting α-glucosidases. MalA and its selenomethionine derivative

have been overproduced in Escherichia coli and crystallized in four different

crystal forms. Microseeding was essential for the formation of good-quality

crystals of forms 2 and 4. For three of the crystal forms (2, 3 and 4) full data sets

could be collected. The most suitable crystals for structure determination are the

monoclinic form 4 crystals, belonging to space group P21, from which data sets

extending to 2.5 Å resolution …

Upf1p, A Highly Conserved Protein Required For Nonsense-Mediated Mrna Decay, Interacts With The Nuclear Pore Proteins Nup100p And Nup116p, Tara Nazarenus, Rebecca Cedarberg, Ryan Bell, Joseph Cheatle, Amanda Forch, Alexis Haifley, Ann Hou, Bessie Wanja Kebaara, Christina Shields, Kate Stoysich, Rachel Taylor, Audrey L. Atkin

School of Biological Sciences: Faculty Publications

Saccharomyces cerevisiae Upf1p is a 971-amino-acid protein that is required for the nonsense-mediated mRNA decay (NMD) pathway, a pathway that degrades mRNAs with premature translational termination codons. We have identified a two-hybrid interaction between Upf1p and the nuclear pore (Nup) proteins, Nup100p and Nup116p. Both nucleoporins predominantly localize to the cytoplasmic side of the nuclear pore and participate in mRNA transport. The two-hybrid interaction between Upf1p and the nuclear pore proteins, Nup100p and Nup116p, is dependent on the presence of the C-terminal 158 amino acids of Upf1p. Nup100p and Nup116p can be coimmunoprecipitated from whole-cell extracts with Upf1p, confirming in …

Effects Of Endogenous Steroid Hormone Levels On Annual Survival In Cliff Swallows, Charles R. Brown, Mary Bomberger Brown, Samrrah A. Raouf, Linda C. Smith, John C. Wingfield

School of Biological Sciences: Faculty Publications

The hormone corticosterone is an important part of animals’ response to environmental stress, modulating short-term adaptive changes in behavior and physiology. The hormone testosterone is also critical, especially for males, in regulating the expression of sexual behavior and parental care. These hormones can have costly consequences, however, and within populations individuals show variation in endogenous levels of both corticosterone and testosterone. We studied how annual survival varied as a function of natural levels of these hormones in colonially breeding Cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, USA, in 2000–2003. We sampled hormone levels of birds caught at colonies …

Testosterone And Group Size In Cliff Swallows: Testing The “Challenge Hypothesis” In A Colonial Bird, Linda C. Smith, Samrrah A. Raouf, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown

School of Biological Sciences: Faculty Publications

The “challenge hypothesis” states that increases in testosterone levels of male animals during the breeding season are directly related to the extent of intrasexual competition for resources or mates that they experience. Although often tested in territorial species, the challenge hypothesis has not been evaluated for colonial animals that live in groups of different sizes and that thus experience different intensities of intrasexual competition. We measured circulating testosterone levels of male and female cliff swallows (Petrochelidon pyrrhonota) in southwestern Nebraska, where these birds nest in colonies of widely different sizes. Males had significantly higher testosterone levels than females, …

Comparison Of Phytoplankton And Autotrophic Picoplankton Populations Over A 24-Hour Period From A Pond's Surface And Subsurface Waters, Harold G. Marshall, Lubomira Burchardt, Elżbieta Wilk-Woźniak

Biological Sciences Faculty Publications

Phytoplankton abundance and composition relationships within the surface layer changed over short time periods (4-6 hours) in comparison with more constant associations at 2 cm below the surface. Both strata had a diverse algal flora (>50 taxa), but no distinct neuston assemblage characterized the surface layer algal composition over the 24-hour study. The similarity between the two strata indicated the floral composition of the surface layer came from the water column algae below the surface. Chlorophytes, diatoms, cyanobacteria, and cryptophytes represented the most abundant algal categories for both strata with a total mean phytoplankton abundance of 3,566 cells ml …

Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera, Alan H. Savitzky, Jeffrey A. Hinkley

Biological Sciences Faculty Publications

The evolution of the ophidian feeding mechanism has involved substantial morphological restructuring associated with the ability to ingest relatively large prey. Previous studies examining the morphological consequences of macrophagy have concentrated on modifications of the skull and cephalic musculature. Although it is evident that macrophagy requires highly compliant skin, the mechanical properties of the ophidian integument have received limited attention, particularly in the context of feeding. We examined mechanical properties of skin along the body axis in Thamnophis sirtalis (Colubridae). Data were collected from tensile tests and were analyzed using a multivariate analysis of variance (MANOVA) and post-hoc multiple comparison …

The Architecture Of A Proteomic Network In The Yeast, Emad Ramadan, Christopher Osgood, Alex Pothern

Biological Sciences Faculty Publications

We describe an approach to clustering the yeast protein-protein inter-action network in order to identify functional modules, groups of proteins forming multi-protein complexes accomplishing various functions in the cell. We have developed a clustering method that accounts for the small-world nature of the network. The algorithm makes use of the concept of k-cores in a graph, and employs recursive spectral clustering to compute the functional modules. The computed clusters are annotated using their protein memberships into known multi-protein complexes in the yeast. We also dissect the protein interaction network into a global subnetwork of hub proteins (connected to several clusters), …

3,4-Methylenedioxymethamphetamine Activates Nuclear Factor- Κb, Increases Intracellular Calcium, And Modulates Gene Transcription In Rat Heart Cells, David A. Tiangco, Frank A. Lattanzio Jr., Christopher J. Osgood, Stephen J. Beebe, Julie A. Kerry, Barbara Y. Hargrave

Biological Sciences Faculty Publications

3,4-Methylenedioxymethamphetamine (MDMA) is an illicit psychoactive drug that has gained immense popularity among teenagers and young adults. The cardiovascular toxicological consequences of abusing this compound have not been fully characterized. The present study utilized a transient transfection/dual luciferase genetic reporter assay, fluorescence confocal microscopy, and gene expression macroarray technology to determine nuclear factor-κB (NF-κB) activity, intracellular calcium balance, mitochondrial depolarization, and gene transcription profiles, respectively, in cultured rat striated cardiac myocytes (H9c2) exposed to MDMA. At concentrations of 1×10⁻³ M and 1×10⁻² M, MDMA significantly enhanced NF-κB reporter activity compared with 0 M (medium only) control. This …

A Defensin-Like Gene Expressed In The Black-Legged Tick, Ixodes Scapularis (Acari: Ixodidae), Wayne L. Hynes, S. M. Ceraul, S. M. Todd, K. C. Seguin, Daniel E. Sonenshine

Biological Sciences Faculty Publications

The black-legged tick Ixodes scapularis linnaeus (Acari: Ixodidae) is an important vector of microbial pathogens. Knowledge of the tick's innate immune response, particularly defensin and other antimicrobial peptides, is important for understanding how microbes survive in this tick. A defensin gene (slnA) from I. scapularis was obtained by reverse transcription-polymerase chain reaction (RT-PCR) using mRNA extracted from tissues of female ticks. RT-PCR indicated the gene was expressed in the midgut, haemocytes, and fat-body, although no evidence of a peptide was found. Sequencing a cloned cDNA fragment revealed a 225 bp open reading frame encoding a 74 amino acid pre-prodefensin, including …

The Bipartite Structure Of The Trna M1A58 Methyltransferase From S. Cerevisiae Is Conserved In Humans, Sarah G. Ozanick, Annette M. Krecic, Joshua Andersland, James T. Anderson

Biological Sciences Faculty Research and Publications

Among all types of RNA, tRNA is unique given that it possesses the largest assortment and abundance of modified nucleosides. The methylation at N₁ of adenosine 58 is a conserved modification, occurring in bacterial, archaeal, and eukaryotic tRNAs. In the yeast Saccharomyces cerevisiae, the tRNA 1-methyladenosine 58 (m¹A58) methyltransferase (Mtase) is a two-subunit enzyme encoded by the essential genes TRM6 (GCD10) and TRM61 (GCD14). While the significance of many tRNA modifications is poorly understood, methylation of A58 is known to be critical for maintaining the stability of initiator tRNA^Met in yeast. …

Molecular Identification Of Anopheles Spp. (Diptera: Culicidae) In The Chapare/Carrasco Valleys, Cochabamba, Bolivia, Corey Brelsfoard

Masters Theses

Studies on malaria in our "backyard," the Neotropics, have been hampered by the lack of an accurate means of species identification for mosquito vectors of the human malaria parasite (i.e. Plasmodium spp). Mosquitoes in the genus Anopheles are the principle malaria vectors in the Neotropics and are often composed of closely related morphologically similar species complexes. This thesis describes three polymerase chain reaction (PCR) protocols to aid in identifying four anopheline mosquitoes for any life stage, of which three have been incriminated as vectors of human malaria in several locations throughout S. America and might be potential vectors of human …