Digital Commons Network^™

Antisense Expression Of The Peptide Transport Gene Atptr2-B Delays Flowering And Arrests Seed Development In Transgenic Arabidopsis Plants, Wei Song, Serry Koh, Mihály Czakó, László Márton, Eliana Drenkard, Jeffrey M. Becker, Gary Stacey

Faculty Publications

Previously, we identified a peptide transport gene, AtPTRZ-B, from Arabidopsis thaliana that was constitutively expressed in all plant organs, suggesting an important physiological role in plant growth and development. To evaluate the function of this transporter, transgenic Arabidopsis plants were constructed expressing antisense or sense AtPTRZ-B. Genomic Southern analysis indicated that four independent antisense and three independent sense AtPTRZ-B transgenic lines were obtained, which was confirmed by analysis of the segregation of the kanamycin resistance gene carried on the T-DNA. RNA blot data showed that the endogenous AtPJRZ-B mRNA levels were significantly reduced in transgenic leaves and …

Nebraska's Flying Mammals, Patricia W. Freeman, Kenneth N. Geluso, J. Scott Altenbach

Biology Faculty Publications

They flit around at dusk in crazy patterns. They fly around street lights and dive at rocks thrown in the air. They have high-pitched squeaks and turn up in unexpected places. They have strange, little faces and bizarre ears. They have soft fur and a thin rubbery membrane across their long fingers. They are bats, Nebraska's only flying mammals.

Bats are mysterious. Is it because they come out at night and we come out in the daytime? Maybe it is because we associate flying with birds, not mammals. Bats are dark and foreboding, not brightly colored. At first, these mysterious …

Properties And Regulation Of The Mink Potassium Channel Protein, Leonard K. Kaczmarek, Edward M. Blumenthal

Biological Sciences Faculty Research and Publications

The minK gene encodes a protein of 130 amino acids that has a single transmembrane segment and is expressed in many tissues including heart, uterus, and kidney. When Xenopus oocytes are injected with minK mRNA, a very slowly activating voltage-dependent potassium current is induced in these cells. The induced channels appear to result from the interaction of the minK protein with other channel-forming subunits such as the KvLQT1 channel. The minK protein is intimately associated with the structure of the resultant channels, and mutations in minK can alter ion selectivity and modulation by second messengers. Strong candidates for native currents …

Structural And Successional Analysis Of Woodland Vegetation In Tualatin Hills Nature Park, Christopher J. Dobson

Dissertations and Theses

Tualatin Hills Nature Park is an urban woodland located in Beaverton, Oregon. The park is owned and managed by Tualatin Hills Park & Recreation District. Vegetation in the park is in a state of secondary succession following a long history of disturbance. The site provided an excellent opportunity to study the recovery of a natural woodland in an urban setting in the northern Willamette Valley.

The purpose of this study was to analyze the species composition, structure, and successional trends of the woodland vegetation in Tualatin Hills Nature Park. A secondary purpose was to determine if there were any natural …

The Mayfly Newsletter, Peter M. Grant

The Mayfly Newsletter

The Mayfly Newsletter is the official newsletter of the Permanent Committee of the International Conferences on Ephemeroptera.

The Aquaculture Of Non-Endemic Species In Western Australia, Tina Thorne

Fisheries Management Papers

This Management Paper has been drafted in liaison with the Department of Environmental Protection in accordance with the principles of risk assessment and taking into account translocation issues of non-endemic species such as redclaw (Cheras quadricarninatus). It is considered that the implementation of this policy will protect the natural environment and native crayfish species. It will also allow for the development of a redclaw industry, and provide the first step towards self regulation of that industry.

Effect Of Intermittent Weight Bearing On Soleus Fiber Force-Velocity-Power And Force-Pca Relationships, J. J. Bangart, Jeffrey J. Widrick, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Rat permeabilized type I soleus fibers displayed a 33% reduction in peak power output and a 36% increase in the free Ca²⁺ concentration required for one-half maximal activation after 14 days of hindlimb non-weight bearing (NWB). We examined the effectiveness of intermittent weight bearing (IWB; consisting of four 10-min periods of weight bearing/day) as a countermeasure to these functional changes. At peak power output, type I fibers from NWB animals produced 54% less force and shortened at a 56% greater velocity than did type I fibers from control weight-bearing animals while type I fibers from the IWB rats produced …

Development Of Fetal Putative Blue Retinal Ganglion Cells Of Rhesus Macaque, Michael Snyder

Loma Linda University Electronic Theses, Dissertations & Projects

Steineke and Kirby (1994) reported that arbors of parasol ganglion cells that ramify in the middle layers of the inner plexiform layer (IPL) are transiently bistratified, becoming unistratified during late fetal periods. In this study I examined cells that ramify in the extreme inner and outer layers of the IPL, in fetal macaque, and compared their dendritic growth to cells ramifying in the middle IPL layers.

Timed dated fetal monkeys were delivered by C-section, euthanized, and their retinas rapidly removed and horseradish peroxidase stained using diaminobenzidine. Dendritic arbors were measured in wholemounts with quantification of the area and depth of …

The Periphyton Community Of A Second Order Subalpine Stream Following Salmon Carcass Decomposition, Jonathan Micheal Honea

Dissertations and Theses

To protect and manage Pacific Northwest salmonid stocks, sound management programs must be developed that incorporate knowledge of the ecological processes critical to their survival. One such process is the nutrient dynamic in headwater spawning streams. It is essential that we understand the trophic relationships among the spawners, the I to 3 year-old juveniles, the invertebrates, and the primary producers in these streams.

The hypothesis that I tested is that photoautotrophic production increases due to the decomposition of salmon carcasses. Increased primary production would stimulate the production of invertebrates which are an important food resource of juvenile salmonid species. The …

Trade-Off-Invariant Rules For Evolutionarily Stable Life Histories, Eric Charnov

Biology Faculty & Staff Publications

Optimization models have been widely and succesfully used in evolutionary ecology to predict the attributes of organisms. Most such models maximize darwinian fitness in the face of trade-offs and constraints; the numerical results usually depend on the exact form of the trade-offs or constraints. But not always : for example, earlier work predicted that the optimal range in offspring size ought to show a -1 scaling with small litter size, independent of most details of the underlying offspring-survival/offspring-size trade-off relation. Here I report that in non-growing (stationary) age-structured populations, three major life-history attributes (age at first breeding, size of an …

Isolation Of A Cdna Encoding A Kex2-Like Endoprotease With Homology To Furin From The Nematode Caenorhabditis Elegans, Eduardo Gomez-Saladin, Anne E. Luebke, David L. Wilson, Ian M. Dickerson

Biology Articles and Papers

A cDNA was isolated from the nematode Caenorhabditis elegans that encodes an endoprotease which is a member of the Kex2 family of serine endoproteases. Degenerate oligonucleotide primers were designed based on conserved regions within the active sites of known Kex2-like endoproteases, and were used for reverse transcription-polymerase chain reaction (RT-PCR) of poly(A)⁺RNA isolated from C. elegans. A PCR product was isolated that had homology to the active sites of known furin endoproteases, and was used as a probe to screen a C. elegans cDNA library. A Kex2-like endoprotease (CelfurPC) which encoded a 692-amino-acid preproendoprotease, was identified. The …

The Role Of Alfalfa Weevil Larvae As Prey In Adult Maintenance And Reproduction By Two Ladybird Beetle Species, Douglas R. Richards

Biology

Ladybird beetles (Coccinella spp.) are important predators of pea aphids (Acyrthosiphon pisum) in alfalfa. Adult ladybird beetles also consume alternative foods such as alfalfa weevil larvae (Hypera postica) and nectar. I compared egg production and ovariole condition of Coccinella septempunctata (an Old World species introduced to North America) and Coccinella transversoguttata (an indigenous North American species) that were maintained on diets of pea aphids, alfalfa weevil larvae, sugar water ("artificial nectar"), or various combinations of these foods. In the first experiment, gravid females of both species continued to lay many eggs and had large ovarioles …

Results And Analyses Of A Landscape Scale Random Point Avian Census, Eric R. Cannon

Biology

We conducted an avian census at 897 random points documenting the presence and relative abundance of breeding bird species across 11 cover types in the Manti-La Sal National Forest. We detected 85 bird species varying in abundance from Dark-eyed Juncos (Junco hyemalis) encountered at 33% of the points to 11 species that were detected only once. Relative abundances of all species by cover type were reported. We found a significant linear relationship between MacArthur's alpha diversity (species number) and the structural complexity of the cover types. However, we failed to find a relationship between sampling effort and the …

Isolation And Characterization Of Four Linear Plasmids In Ascosphaera Aggregata, Dakun Xu

Biology

Four extrachromosomal DNA plasmids were isolated from the entomopathogenic fungus Ascosphaera aggregata and named as pAaL10, pAaL8, pAaL2.8, and pAaL2.6 based on their host, morphology and size. DNA hybridization results suggested that pAaL10, pAaL8, pAaL2.8, and pAaL2.6 are not homologous with pAaL, a plasmid isolated from Ascosphaera apis. Extraction of DNA from intact mitochondria followed by gel electrophoretic analysis suggests pAaL10, pAaL8, pAaL2.8, and pAaL2.6 are located within the mitochondria. From hybridization results it was concluded that each of pAaL10, pAaL8, pAaL2.8, and pAaL2.6 is not homologous to mitochondrial DNA. This implies that these plasmids are all self-replicating. Restriction …

The Behavior Of Dippers (Family Cinclidae) In Relation To Food Acquisition, Roarke E. Donnelly

Biology

Individuals and populations are likely to optimize methods of food harvest and synchronize reproduction with local peaks in food supply, because animals exhibiting greater efficiency at acquiring energy or energy intensive tasks will often achieve greater survival, growth, and reproduction. Although this statement implies that foraging efficiency is optimized by selection for better foragers and optimal foraging theory owes much of its development and refinement to studies of free-living birds, the positive association of foraging proficiency and fitness has not been documented for free-ranging birds. Furthermore, the synchrony of reproduction and the peak in food resources has been examined within …

Discovery, Identification, And Evaluation Of Antifungal Compounds Produced By Pseudomonas Syringae, Kevin N. Sorensen

Biology

New antifungal agents are needed to combat the increasing incidence of fungal diseases. Strains of Pseudomonas syringae produce cyclic lipodepsinonapeptides (CLPs) such as syringomycin, syringostatin, and syringotoxin, which could be developed as therapeutic antifungal agents. Of these CLPs, syringostatin has been difficult to produce in vitro. Syringostatin production was achieved using syringomycin minimal medium supplemented with arbutin and D-fructose, and a high cell density. Syringostatin A (SS-A) was purified in quantities sufficient to evaluate its antifungal activities. The antifungal activities and erythrocyte toxicities of syringomycin E (SR-E), SS-A, and syringotoxin B (ST-B) were evaluated. All showed fungicidal activities against most …

The Biophysics Of Voltage-Gated Skeletal Muscle Sodium Channels And Muscle Excitability, David E. Featherstone

Biology

Voltage-gated skeletal muscle sodium channels are large transmembrane proteins that are responsible for the initiation and propagation of skeletal muscle action potentials. Sodium channels undergo three kinetically and pharmacologically distinct processes: activation/deactivation, fast inactivation, and slow inactivation. The work in this dissertation characterized each of these processes in heterologously expressed voltage-gated skeletal muscle sodium channels, then examined biophysical changes in mutant sodium channels responsible for paramyotonia congenita, an inherited human disease of muscle hyperexcitability. All sodium channel kinetic processes were studied, with particular emphasis on slow inactivation, which had not previously been well characterized. Paramyotonia congenita appears to result from …

Management Arrangements For The Western Rock Lobster Fishery For The 1997/98 Season, F. B. Prokop

Fisheries Management Papers

This paper deals with the proposed management strategies for the 1997/98 seasons. The purpose of this paper is to present the views of RLIAC on management arrangements for the 1997/98 rock lobster season and to indicate the strategic directions that long term management of this important fishery might take so as to ensure both its biological sustainability and the optimisation of product value for both the State and the participants in the fishery.

Homology Among The Autosomal Chromosomes Of Boophilus Annulatus (Say) And B. Microplus (Canestrini), Bonnie S. Gunn

Theses and Dissertations - UTB/UTPA

Autosomes of Boophilus annulatus and B. microplus were compared using C- and G-bands to establish the degree of homology. Karyotypes of both species consisted of 20 autosomes and an XX:XO sex determination system with the X being the largest chromosome. All chromosomes of B. annulatus were acrocentric with heterochromatin limited to centromeric regions. The B. microplus karyotype was acrocentric with one band of noncentromeric heterochromatin occurring in three chromosome pairs. Interspecific comparisons indicated seven pairs of G-band homologous autosomes and three G-band homologous pairs when added interstitial heterochromatin was considered. The number three chromosome of both species showed variation in …

Patterns Of Root Colonization By The Arbuscular Mycorrhizal Fungus Glomus Intraradices And Host Plant Responses, Kristopher A. Blee

Biology

Mycorrhizal hyphae were directed in their growth pattern in roots. Arbuscules produced by a single isolate of Glomus intraradices Schenck & Smith in roots of corn, wheat, carrot, clover, mung bean, and bean (Phaseolus vulgaris L.) were consistently limited to cortical cells immediately adjacent to the endodermis. Two hypotheses for controlled growth of arbuscular mycorrhizal fungi in plants were examined: (1) activation of plant defenses by the fungus, and (2) availability of host-derived carbon to the fungus. Accumulations of mRNAs for the defense-related genes phenylalanine ammonia-lyase (PAL), chalcone synthase, chitinase (CHT), glucanese, and hydroxyproline-rich glycoprotein were examined in the …

Polar Distribution Of Neurofilaments In A Nonspiking Central Nervous System Neuron, David Dale Cole

Biology

Immunolabelling of phosphorylated and nonphosphorylated neurofilaments in teleost retinal horizontal cells, which are nonspiking neurons, is described. Light microscopy (postembedding immunolabelling) of retinal tissue sections revealed nonphosphorylated neurofilaments localized to regions where horizontal cell axon terminals, dendrites, and somata are located. In contrast, phosphoneurofilaments were localized to regions where axons and axon terminals of various retinal neurons, including horizontal cells, are found, as in typical spiking central nervous system neurons. Electron microscopy (preembedding immunolabelling) demonstrated that phosphoneurofilaments were localized to cone horizontal cell axons and axon terminals. Immunolabelling of primary cell cultures, however, revealed that axon-specific distribution of phosphoneurofilaments in …

Foraging Strategies Of Migrant Bald Eagles Exploiting A Seasonally Concentrated Food Source, Marco Restani

Biology

Generalizations regarding the relationship between age and foraging proficiency in birds may be incomplete and potentially misleading because most were formulated from studies of seabirds and shorebirds. Therefore, I examined three aspects of Bald Eagle (Haliaeetus leucocephalus) foraging behavior: numerical and functional responses, patch residence time, and producing-scrounging behavior. The study was conducted during autumn migration when hundreds of eagles congregate at Hauser Reservoir, Montana, to feed on spawning kokanee salmon (Oncorhynchus nerka). I determined eagle numerical and functional responses from 1991-1995. Eagles tracked the number of salmon during four of five autumns, and immigration and …

Effects Of Plant Architecture On The Foraging Behavior And Prey Capture Success Of Two Generalist Predators Attacking The Russian Wheat Aphid, Teresa L. Clark

Biology

This research investigated the effects of plant architecture on the foraging behavior and prey capture success of two generalist predators of the Russian wheat aphid, Diuraphis noxia (Mordvilko). One study examined plant architectural effects on the behavior of a native predator, the common green lacewing, Chrysoperla plorabunda Fitch; a second study examined host plant effects on larvae and adults of the fourteen-spotted ladybird beetle, Propylea quatuordecimpunctata (L.), which is native to Eurasia and has been released in the United States for potential control of D. noxia. Behavioral observations of each of these predators were conducted on two architecturally diverse …

Hnk-1 Immunoreactivity In In Situ Adult Teleost Retina, Kie Hoon Jung

Biology

To identify HNK-1 bearing molecules, anti-HNK-1 was used to probe adult hybrid bass retina, including mature, central retina and the circumferential germinal margin (CGM), where new cells are constantly added to the neural circuitry. The HNK-1 antigen was heavily distributed in both of the plexiform (synaptic) layers, in tufts of Müller cell microvilli at the outer limiting membrane, throughout the optic fiber layer, and in tubular processes surrounding cone horizontal cells in the inner nuclear layer. A differential fixation scheme suggested that the Müller cell microvillar and tubular process HNK-1 immunoreactivity was due primarily to glycoproteins, with the remainder possibly …

Hybrid Bass Retinal Cells In Situ And In Vitro: Structure And Immunocytochemistry, Kyeongsuk Ki

Biology

The morphologies of intact retina and acutely isolated retinal neurons are described for a relatively newcomer model for studies of visual physiology, the hybrid bass (Morone chrysops x M. saxatilus). These features are indistinguishable from the white bass (M. chrysops) at the light microscopic level. In situ immunolocalization patterns for several glial and neuronal markers also match previous work in the white bass. Carbonic anhydrase is found in retinal layers corresponding to Müller (glial) cells and horizontal cells; glial fibrillary acidic protein (GFAP) and glutamine synthetase are found in Müller cells only; and the intermediate M, …

Secondary Reproductive Strategies Of The Eastern Kingbird (Tyrannus Tyrannus), Assessed By Dna Fingerprinting And Egg Physiognomy, Diane L. Rowe

Biology

Extra-pair fertilization, a secondary breeding strategy, was detected in the eastern kingbird (Tyrannus tyrannus) using multi-locus DNA fingerprinting. I assessed the genetic parentage of 20 broods in a population of kingbirds in central New York. Two DNA probes were used to test for exclusion of nestlings as true offspring of one or both social parents. Band-sharing coefficients and the number of novel bands were used to discern which parent was not a first-degree relative of the nestling in question. No cases of conspecific brood parasitism or quasi-parasitism were documented. However, extra-pair paternity was found to be very common, …

Plant- Versus Predator-Mediated Interactions Between Cereal Aphids On A Shared Host Plant, Erin Bergeson

Biology

This research investigates plant- and predator-mediated effects of the bird cherry-oat aphid, Rhopalosiphum padi (L.) on the Russian wheat aphid, Diuraphis noxia (Mordvilko). I combined a suite of population-level experiments with behavioral observations to determine whether the two aphids interacted principally through a common host, crested wheatgrass (Agropyron desertorum [Fisher ex Link] Schultes), or a common predator, larvae of the green lacewing (Chrysoperla plorabunda [Fitch]). The population-level experiments revealed some evidence of host-mediated interspecific competition but only at extremely high aphid densities (>2000 individuals per greenhouse seedling). In addition, some of these experiments suggested that the bird …

Intraspecific And Diffuse Competition: The Response Of Nassella Pulchra In A California Grassland, Andrew R. Dyer, Kevin J. Rice

Faculty Publications

In inland California grasslands, the high densities of alien annual species have altered the growing environment for native perennial grasses. Using variable-density plots, we measured the influence of intraspecific competition (conspecifics only) and diffuse competition (mixed-composition neighborhoods that include conspecifics) on growth and survival of Nassella pulchra, purple needlegrass. We assessed the effects of intraspecific and diffuse competition in weeded plots and unweeded plots, respectively, across a density gradient of N. pulchra plants (16–356 plants/m2). We used summer fire and spring sheep grazing to reduce diffuse competition in unweeded plots. The potential effect of rooting volume on competitive interactions …

Semipermeable Membrane Devices Are Effective Surrogates Of Fish In Concentrating Polychlorinated Biphenyls, Christopher Gardner Collins

Master's Theses

This study examined the effectiveness of Semipermeable Membrane Devices (SPMDs) as surrogates for fish in concentrating polychlorinated biphenyls. Golden shiners (Notemigonus crysolucas) and SPMDs were exposed to three different concentrations (0.5, 1.5, and 3.0ppm) of Aroclor 1254 for 1, 3, and 5 days under laboratory conditions. Concentrations of Aroclor 1254 were measured in the SPMDs and fish tissue using extraction techniques and gas chromatography. The concentrations of PCB in SPMDs and N. crysolucas were positively correlated. This relationship compared favorably with data from other studies. The relationship between the concentration of PCB in SPMDs and tissue offish and …

Interaction Of The Human Serine Protease Inhibitor Alpha-1-Antitrypsin With Cryptosporidium Parvum, John Russell Forney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The human serine protease inhibitor (serpin) alpha-1-antitrypsin (AAT) was studied for potential interaction with components of the protozoan parasite Cryptosporidium parvum. A homogenate prepared from C. parvum oocysts was incubated with purified human AAT, and complexes formed between the serpin and components of the homogenate were detected using an enzyme-linked immunosorbent assay (ELISA). Serpin:parasite infections were effectively blocked by preincubating AAT with a cognate target enzyme, porcine pancreatic elastase, prior to performing the ELISA on the homogenate. Incubation of a mixture of C. parvum oocysts and sporozoites with AAT demonstrated preferential fluorescence labeling of the sporozoite surface membrane by indirect …