Biology Commons^™

Subjective, Cultural, And Natural Ecology, Ursula Goodenough

Biology Faculty Research

No abstract provided.

Complement Resistance In Agrobacterium Tumefaciens Isolates, Michael E. Mccormick

Honors Theses

The word "pathogen" ofen brings to mind morose images and other words such as "illness," "malaria," and "outbreak": words associated with animal pathogens, in particular, the ones that make us humans sick. However, some pathogens also affect another major kingdom, plants, and one of the more devastating pathogens to the plant kingdom is the bacteria Agrobacterium tumefaciens. This organism has a Type IV Secretion System that allows it to transfer a piece of t-DNA into the host cell; this DNA integrates into the eukaryotic genome and establishes in ction by utilizing the host's transcription machinery. This unique and effective means …

Imaginal Discs: The Genetic And Cellular Logic Of Pattern Formation, Michael Dietrich

Dartmouth Scholarship

Review of Imaginal Discs: The Gneetic and Cellular Logic of Pattern Formation by Lewis I. Held, Jr., Cambridge University Press, 2002.

Embryology In Wax, Michael Dietrich

Dartmouth Scholarship

Book review of Embryos in Wax: Models from the Ziegler Studio by Nick Hopwood Whipple Museum of the History of Science, 2002.

The Response Of Mice To Infection By The Parasitic Nematode Trichinella: A Comparison Of Trichinella Spiralis And Trichinella Pseudospiralis, Barry Clayton Anderson

Dissertations and Theses

The intracellular parasite Trichinella is a genus in phylum Nematoda that contains six named species including Trichinella spiralis and Trichinella pseudospiralis. These parasites infect a large variety of wild and domestic animals, human beings and a few species of birds. The parasitic strategies and the pathological effects on the host between trichinella spiralis and Trichinella pseudospiralis are quite different.

The purpose of this study is to gain an understanding of the physiological, immunological and pathological differences between these two species of Trichinella using infections in the mouse as a model. In the course of this research I have attempted to …

Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum

Dartmouth Scholarship

Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass …

Specimen Catalog, Part 4, Brian D. Frank

Division of Mammals - Field Notes and Catalogs

No abstract provided.

Using Ecological Land Units In A Gap Analysis For Conservation Planning In A Southwestern Ohio Watershed, Christopher Lee Zimmerman

Browse all Theses and Dissertations

Gap analysis is a method to identify insufficiency in biodiversity protection. In degraded agricultural landscapes, it requires information on the past, present, and the potential natural distribution of forest vegetation to construct a comprehensive nature reserve network. Using Geographic Information Systems (GIS), I conducted a biodiversity gap analysis to assess the representation of ecological land units (ELUs) supporting forest vegetation both within and external to the current reserve network in the Lower Twin Creek Watershed (LTCW), southwestern Ohio. I used this analysis to make conservation planning recommendations to the local park district. ELUs are based on relatively stable associations of …

Graininess Of Spatial Distribution In House Sparrows And House Finches: Implications For Interspecific Competition, Carol A. Heaverlo

Dissertations and Theses @ UNI

In Iowa, the House Sparrow (Passer domesticus) is a non-indigenous avian species commonly found in areas inhabited by humans. During the past 10 years the House Sparrow population numbers have declined 54%. Competition for resources between the House Sparrow and House Finch has been cited as the reason for the decline. It has also been suggested that interspecific competition between the House Sparrow and House Finch is not the primary reason for the decline because the two perceive the environment on different scales: the House Sparrow is a coarse-grained species and the House Finch a fine-grained species. In three urban …

Familial Amyotrophic Lateral Sclerosis-Associated Mutations Decrease The Thermal Stability Of Distinctly Metallated Species Of Human Copper/Zinc Superoxide Dismutase, Jorge A. Rodriguez, Joan S. Valentine, Daryl K. Eggers, James A. Roe, Ashutosh Tiwari, Robert H. Brown Jr., Lawrence J. Hayward

Chemistry and Biochemistry Faculty Works

We report the thermal stability of wild type (WT) and 14 different variants of human copper/zinc superoxide dismutase (SOD1) associated with familial amyotrophic lateral sclerosis (FALS). Multiple endothermic unfolding transitions were observed by differential scanning calorimetry for partially metallated SOD1 enzymes isolated from a baculovirus system. We correlated the metal ion contents of SOD1 variants with the occurrence of distinct melting transitions. Altered thermal stability upon reduction of copper with dithionite identified transitions resulting from the unfolding of copper-containing SOD1 species. We demonstrated that copper or zinc binding to a subset of “WT-like” FALS mutants (A4V, L38V, G41S, G72S, D76Y, …

Conformational Strictness Required For Maximum Activity And Stability Of Bovine Pancreatic Ribonuclease A As Revealed By Crystallographic Study Of Three Phe120 Mutants At 1.4 Å Resolution, Eri Chatani, Rikimaru Hayashi, Hideaki Moriyama, Tatzuo Ueki

School of Biological Sciences: Faculty Publications

The replacement of Phe120 with other hydrophobic residues causes a decrease in the activity and thermal stability in ribonuclease A (RNase A). To explain this, the crystal structures of wild-type RNase A and three mutants—F120A, F120G, and F120W—were analyzed up to a 1.4 Å resolution. Although the overall backbone structures of all mutant samples were nearly the same as that of wild-type RNase A, except for the C-terminal region of F120G with a high B-factor, two local conformational changes were observed at His119 in the mutants. First, His119 of the wild-type and F120W RNase A adopted an A position, whereas …

In Vivo Effect Of Leukemia Inhibitory Factor (Lif) And An Anti-Lif Polyclonal Antibody On Murine Embryo And Fetal Development Following Exposure At The Time Of Transcervical Blastocyst Transfer, Michael H. Mitchell, R. James Swanson, Sergio Oehninger

Biological Sciences Faculty Publications

Leukemia inhibitory factor (LIF) enhances in vitro murine preimplantation development in a time- and dose-dependent fashion. Knockout experiments have demonstrated that endometrial LIF is essential for in vivo murine implantation. We assessed the impact of LIF and an anti-LIF polyclonal antibody (pab) on in vivo development and developed a novel and successful nonsurgical method of embryo transfer for this species, a transcervical blastocyst transfer technique. The objectives of this study were to evaluate the effects of LIF and the anti-LIF pab on 1) implantation, resorption, pregnancy, and viability rates and 2) the overall structural and skeletal development. Two-cell embryos were …

A Novel Family Of Mobile Genetic Elements Is Limited To The Germline Genome In Tetrahymena Thermophila, Jeffrey D. Wuitschick, Jill A. Gershan, Andrew J. Lochowicz, Shuqiang Li, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

In the ciliated protozoan Tetrahymena thermophila, extensive DNA elimination is associated with differentiation of the somatic macronucleus from the germline micronucleus. This study describes the isolation and complete characterization of Tlr elements, a family of approximately 30 micronuclear DNA sequences that are efficiently eliminated from the developing macronucleus. The data indicate that Tlr elements are comprised of an ∼22 kb internal region flanked by complex and variable termini. The Tlr internal region is highly conserved among family members and contains 15 open reading frames, some of which resemble genes encoded by transposons and viruses. The Tlr termini appear to …

Leptodactylus Silvanimbus, W. R. Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Adult Leptodactylus silvanimhus are of moderate sized, the head is about as wide as long, and the hind limbs are moderate in length (see Table; also see Heyer and Thompson 2000 for definitions of adult size and leg length categories for Leptodacrylus). The male vocal sac is single and internal. Male forearms are hypertrophied in larger individuals. Adult males have two black thumb spines on each hand and lack chest spines. Individuals lack dorsolateral folds. The toe tips are narrow, not expanded. Females have weakly developed lateral toe fringes and males either have lateral toe ridges or weakly developed fringes. …

Analysis Of Protein Localization And Secretory Pathway Function Using The Yeast Saccharomyces Cerevisiae, Elizabeth Ann Vallen

Biology Faculty Works

The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a chimeric protein. The chimera contains a signal sequence fused to histidinol dehydrogenase. A strain with a defect in the translocation of secretory proteins into the endoplasmic reticulum (ER) accumulates sufficient histidinol dehydrogenase in the cytoplasm to grow on media lacking histidine. In contrast, yeast proficient for secretion, or …

Investigation Of Four Classes Of Non-Nodulating White Sweetclover (Melilotus Alba Annua Desr.) Mutants And Their Responses To Arbuscular-Mycorrhizal Fungi, Michelle Lum

Biology Faculty Works

The nitrogen-fixing symbiosis between Rhizobiaceae and legumes is one of the best-studied interactions established between prokaryotes and eukaryotes. The plant develops root nodules in which the bacteria are housed, and atmospheric nitrogen is fixed into ammonia by the rhizobia and made available to the plant in exchange for carbon compounds. It has been hypothesized that this symbiosis evolved from the more ancient arbuscular mycorrhizal (AM) symbiosis, in which the fungus associates with roots and aids the plant in the absorption of mineral nutrients, particularly phosphate. Support comes from several fronts: 1) legume mutants where Nod- and Myc- co-segregate, and 2) …

"A New Genus And Species Of Freshwater Crab From Northern Madagascar, And A Second New Species Associated With Pandanus Leaf Axils" , Neil Cumberlidge, Christopher B. Boyko, Harvey Wallace

Journal Articles

No abstract provided.

Meiotic Cohesion Requires Accumulation Of Ord On Chromosomes Before Condensation., Eric M. Balicky, Matthew W. Endres, Cary Lai, Sharon E. Bickel

Biology Faculty Publications

Cohesion between sister chromatids is a prerequisite for accurate chromosome segregation during mitosis and meiosis. To allow chromosome condensation during prophase, the connections that hold sister chromatids together must be maintained but still permit extensive chromatin compaction. In Drosophila, null mutations in the orientation disruptor (ord) gene lead to meiotic nondisjunction in males and females because cohesion is absent by the time that sister kinetochores make stable microtubule attachments. We provide evidence that ORD is concentrated within the extrachromosomal domains of the nuclei of Drosophila primary spermatocytes during early G2, but accumulates on the meiotic chromosomes by mid to late …

Potent Immunosuppressive Activities Of Cytomegalovirus-Encoded Interleukin-10, Juliet V. Spencer, Kristen M. Lockridge, Peter A. Barry, Gaofeng Lin, Monica Tsang, Mark E.T. Penfold, Thomas J. Schall

Biology Faculty Publications

Cytomegalovirus (CMV) has highly evolved mechanisms for avoiding detection by the host immune system. Recently, in the genomes of human and primate CMV, a novel gene comprising segments of noncontiguous open reading frames was identified and found to have limited predicted homology to endogenous cellular interleukin-10 (IL-10). Here we investigate the biological activities of the CMV IL-10-like gene product and show it to possess potent immunosuppressive properties. Both purified bacterium-derived recombinant CMV IL-10 and CMV IL-10 expressed in supernatants of human cells were found to inhibit proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMCs), with specific activity comparable to that …

Behavioral Evidence For Chemosensory And Thermosensory Pathway Convergence In The Caenorhabditis Elegans Nervous System, Bowman O. Davis Jr., Lewis Vanbrackle, Darren Pittard

Faculty Articles

The nematode, Caenorhabditis elegans, is an established model system to explore the ways simple nervous systems detect and direct organismal responses to environmental changes. C. elegans possesses specialized receptor cells for the detection of a variety of environmental stimuli. Separate cell types respond to volatile chemical and thermal stimuli and the neural pathways for these show anatomical evidence of convergence. This work reports findings from behavioral assays during simultaneous exposure of nematodes to both thermal differences and attractant volatile chemicals. Combined exposure to benzaldehyde and cold neutralized the behavioral responses to both stimuli in 24°C acclimated worms. Diacetyl and mild …

Regulation And Measurement Of Nitrification In Terrestrial Systems, D. R. Smart, S. C. Hart, K. A. Haubensak, John M. Stark

Biology Faculty Publications

Nitric oxide (NO) is a relatively short-lived trace gas that reacts with oxygen in the troposphere to produce the air pollutant ozone. It also reacts with water vapor to form nitric and nitrous acids, which acidify precipitation and increase N deposition. Models currently used to predict soil NO fluxes are based on the assumption that NO flux is proportional to the gross rate of nitrification or N mineralization; however, this assumption has not been tested because of the difficulty in measuring gross N-cycling rates in situ. We measured soil NO fluxes, gross and net N-cycling rates, and a variety of …

Type-Specific Inositol 1,4,5-Trisphosphate Receptor Localization In The Vomeronasal Organ And Its Interaction With A Transient Receptor Potential Channel, Trpc2, Jessica H. Brann, John C. Dennis, Edward E. Morrison, Debra A. Fadool

Biology: Faculty Publications and Other Works

The vomeronasal organ (VNO) is the receptor portion of the accessory olfactory system and transduces chemical cues that identify social hierarchy, reproductive status, conspecifics and prey. Signal transduction in VNO neurons is apparently accomplished via an inositol 1,4,5-trisphosphate (IP3)-activated calcium conductance that includes a different set of G proteins than those identified in vertebrate olfactory sensory neurons. We used immunohistochemical (IHC) and SDS-PAGE/western analysis to localize three IP3 receptors (IP3R) in the rat VNO epithelium. Type-I IP3R expression was weak or absent. Antisera for type-II and -III IP3R recognized appropriate molecular weight proteins by SDS-PAGE, and labeled protein could be …

Length-At-Age In Juvenile Patagonian Toothfish (Dissostichus Eleginoides), J. Ashford, C. Jones, S. Bobko, I. Everson

OES Faculty Publications

We used the otoliths from a sample of Dissostichus eleginoides pre-recruits, whose length density was distinctly polymodal, to see whether ages estimated by reading otoliths were congruent with the length modes observed. Length densities by age were compared graphically with the overall length density observed. Additionally, ages were predicted for each fish based on length, and compared with ages estimated from reading otoliths in a goodness-of-fit test. The majority of the otoliths (83.6%) were estimated to be from fish 1+ or 2+ years old, with mean total lengths of 32.5 cm and 41.3 cm respectively. No difference was found between …

Morphology, Swimming Performance And Propulsive Mode Of Six Co-Occurring Hydromedusae, Sean Colin, John H. Costello

Arts & Sciences Faculty Publications

Jet propulsion, based on examples from the Hydrozoa, has served as a valuable model for swimming by medusae. However, cnidarian medusae span several taxonomic classes (collectively known as the Medusazoa) and represent a diverse array of morphologies and swimming styles. Does one mode of propulsion appropriately describe swimming by all medusae? This study examined a group of co-occurring hydromedusae collected from the waters of Friday Harbor, WA, USA, to investigate relationships between swimming performance and underlying mechanisms of thrust production. The six species examined encompassed a wide range of bell morphologies and swimming habits. Swimming performance (measured as swimming acceleration …

Testing For Toxic Effects Of Prey On Zooplankton Using Sole Versus Mixed Diets, Sean Colin, Hans G. Dam

Arts & Sciences Faculty Publications

No abstract provided.

Prey Resource Utilization By Coexistent Hydromedusae From Friday Harbor, Washington, Usa, John H. Costello, Sean Colin

Arts & Sciences Faculty Publications

Prey selection patterns were quantified for a sympatric group of hydromedusae from Friday Harbor, WA. Selection patterns varied between species, but were largely replicable between sample dates and resembled dietary patterns found in similar studies from neighboring regions. Ambush-foraging medusae (Aglantha digitale, Sarsia tubulosa, and Proboscidactyla flavicirrata) fed primarily on crustacean and ciliated prey but the dietary niches of these hydromedusan species centered on different fractions of the available plankton. Consequently, little dietary overlap occurred between the ambush foraging hydromedusae. In contrast, the dietary niches of cruising predators (Aequorea victoria, Mitrocoma cellularia, and …

Behavioral And Reproductive Aspects Of Captive Maxwell's Duiker (Cephalophus Mawellii) Husbandry, Janet Mcneill Mackinnon

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

Female Maxwell's duikers (Cephalophus maxwellii) were studied at the Wildlife Survival Center on St. Catherine's Island, Georgia. The objectives were to quantify the effects of housing on activity budgets and progesterone cycling. Four animals were studied across two housing situations: housed individually versus housed in a grouped setting. Behavioral observations revealed no significant change in access to resources, rumination, or repetitive behaviors, once animals were housed together. Fecal samples were collected in order to determine levels of progesterone through radioimmunoassay (RIA). Fluctuations in progesterone levels revealed no clear estrous cycles. Animals showed less variability in progesterone levels and …

Effects Of Indoleacetic Acid And Kinetin On Lipid Peroxidation Levels In Various Rat Tissues, İsmai̇l Çeli̇k, Yasi̇n Tülüce, Necati̇ Özok

Turkish Journal of Biology

This study was carried out to investigate whether plant growth regulators (PGRs) could affect lipid peroxidation (Malondialdehyde = MDA level) in erythrocyte, muscle, liver, heart and kidney tissue. Eighteen Sprague-Dawley albino rats were divided into three experimental groups: control and PGR-treated (indoleacetic acid and kinetin). Seventy-five ppm of PGRs, indoleacetic acid (IAA), and kinetin were administered orally to 6 rats ad libitum for 25 days. The hormone treatments caused different effects on the level of malondialdehyde (MDA) to those of the control rats. According to the results, while liver and kidney MDA levels were increased significantly by IAA administration in …

Antimicrobial And Cytotoxic Activities Of Ceratonia Siliqua L. Extracts, Bi̇jen Kivçak, Tuba Mert, H. Tansel Öztürk

Turkish Journal of Biology

The antimicrobial and cytotoxic activities of n-hexane, methanol, ethanol, ethyl acetate and water extracts of Ceratonia siliqua L. leaves were evaluated in this study. The antimicrobial activities of the extracts were reported against Escherichia coli ATCC 29998, Escherichia coli ATCC 25922, Escherichia coli ATCC 11230, Staphylococcus aureus ATCC 6538P, Staphylococcus aureus ATCC6538P, Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 12228, Salmonella thyphimurium CCM 5445, Enterobacter cloacae ATCC 13047, Enterococcus faecalis ATCC 29212, Pseudomonas aeroginosa ATCC 27853 as bacteria and Candida albicans ATCC 10239 as yeast-like fungi by the disc diffusion method. The cytotoxic activity of the extracts was evaluated by …

Antimicrobial Peptides: A Potential Therapeutic Alternative For The Treatment Of Fish Diseases, Ali̇ye Sarmaşik

Turkish Journal of Biology

Fish losses from infectious diseases are a significant problem in aquaculture worldwide. However, peptide antibiotics show potent activity against a broad range of pathogens including fish pathogens. Therefore, the ability of antimicrobial peptides to protect fish against infections caused by fish pathogens clearly shows the potential for utilisation of antimicrobial peptides for the treatment of fish diseases. The strategy of overexpressing the antimicrobial peptide genes in transgenic fish may provide a method of decreasing fish disease problems in aquaculture.