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Abiotic Stress And The Relative Importance Of Interference And Facilitation In Montane Bunchgrass Communities In Western Montana, John T. Greenlee, Ragan M. Callaway

Biological Sciences Faculty Publications

No abstract provided.

Molecular Studies Of Restriction Genes In Enteric Bacteria, Obed B. Rutebuka

Loma Linda University Electronic Theses, Dissertations & Projects

Bacterial cells contain various restriction-modification (R-M) systems to protect themselves from incoming foreign DNA. Most bacteria have at least one such system. In this study, the restriction genes and the location of the genes on the chromosome were examined in three enteric bacteria. Salmonella typhimurium LT2, Klebsiella pneumoniae GM 236, and Klebsiella pneumoniae M5al. The 98 minute region of the Salmonella typhimurium LT2 chromosome comprises at least two R-M systems. From genetic data this region was previously thought to be only one minute in length but was found to be larger than two minutes using a physical mapping technique, pulsed …

Effects Of Fatiguing Stimulation On Intracellular Na+ And K+ In Frog Skeletal Muscle, Edward Michael Balog, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The purpose of this study was to describe the alterations in the intracellular concentrations of sodium ([Na⁺]_i) and potassium ([K⁺]_i) and the membrane potential (E_m) as a result of fatiguing stimulation of the frog semitendinosus muscle and to relate these changes to the alterations in the sarcolemma action potential and force-generating ability of the muscle. [Na⁺]_i and [K⁺]_i were measured by using ion-selective microelectrodes. Before stimulation (100-ms trains at 150 Hz, 1 stimulus/s for 5 min), [Na⁺]_i, [K⁺] …

Pre-Embedding Staining Of Single Muscle Fibers For Light And Electron Microscopy Studies Of Subcellular Organization, Evelyn Ralston, Thorkil Ploug

Scanning Microscopy

Skeletal muscle fibers are large, multinucleated cells which pose a challenge to the morphologist. In the course of studies of the distribution of the glucose transporter GLUT4, in muscle, we have compared different preparative procedures, for both light (LM) and electron microscopy (EM) immunocytochemistry. Here we show that pre-embedding staining of single teased fibers, or of single enzymatically dissociated fibers, has several advantages over the use of sections for observing discrete patterns that extend over long distances in the cells. We report on an optimization study carried out to establish fixation and permeabilization conditions for EM immunogold labeling of the …

Structural And Calcification Patterns Of The Neonatal Line In The Enamel Of Human Deciduous Teeth, Tetsuo Kodaka, Tsuneyoshi Sano, Shohei Higashi

Scanning Microscopy

The neonatal line of the enamel in human deciduous teeth was observed by scanning electron microscopy using secondary and backscattered electron signals. The neonatal line containing irregular structures of enamel prisms with disordered crystal arrangements was basically formed by the abrupt bending of the prisms towards the root. Usually, the prisms gradually bent back again to regain their previous orientation, but the prisms in the inner and the surface layer sometimes ran straight ahead after bending. The prism sheath regions showing hypocalcification contained a relatively large amount of organic material as shown by treatment with chromium sulfate. When etched with …

Monte Carlo Simulation Of Secondary Electron Emission From Thin Film/Substrate Targets, K. Murata, M. Yasuda, H. Kawata

Scanning Microscopy

We have developed a Monte Carlo simulation model of secondary electron emission from thin film/substrate samples, taking into consideration their exact boundary condition. First, the validity of the model is checked in comparison with the experimental data reported such as the secondary electron emission and backscattering yields from thick Al, thick Au targets and Al thin films on a Au substrate, the energy distribution of secondary electrons, and the contribution of backscattering to the secondary electron emission yield. The agreement is relatively good. Next, we have applied the model to the secondary electron emission from Au films on an Al …

Interactive Effects Of Inducible Defense And Resource Availability On Phlorotannins In The North Atlantic Brown Alga Fucus Vesiculosus, P. Peckol, J. M. Krane, J. L. Yates

Biological Sciences: Faculty Publications

Research seeking to explain the ecological role of polyphenolics (phlorotannins) in plants and brown algae has largely focused on 2 alternative concepts, the carbon/nutrient (C/N) balance and the inducible defense models. We tested the hierarchy of effects of both models on phlorotannin production in the brown alga Fucus vesiculosus (Fucales) by simultaneously manipulating the N environment and simulating herbivory for 2 oceanic (high and low intertidal) and estuarine populations. We measured phlorotannin levels in algae under control, grazed, N-enriched, and grazed + N-enriched treatments with time (0 to 14 d) throughout the year to determine onset and duration of the …

Generation Of High Efficiency Ssdna Hybridization Probes By Linear Polymerase Chain Reaction (Lpcr), Gregory W. Konat

Scanning Microscopy

The polymerase chain reaction (PCR) methodology can be employed to produce DNA hybridization probes. The major advantages of this paradigm over other techniques include superior specific activity of the probes, the versatility of sequence selection, the ability to produce short probes, and the simplicity of the procedure. We have further improved the efficiency of PCR probes by generating single stranded (ssDNA) probes that do not reanneal with themselves in solution, and hence, their availability for the interaction with the complementary sequences of the target is profoundly increased. Protocols for ³²P-dCTP labeled and digoxigenin-dUTP labeled probes have been elaborated to …

Evidence For Acquisition In Nature Of A Chromosomal 2,4-Dichlorophenoxyacetic Acid/(Alpha)-Ketoglutarate Dioxygenase Gene By Different Burkholderia Spp., V. Grace Matheson, Larry J. Forney, Yuichi Suwa, Cindy H. Nakahatsu, Alan J. Sexstone, William E. Holben

Biological Sciences Faculty Publications

We characterized the gene required to initiate the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) by the soil bacterium Burkholderia sp. strain TFD6, which hybridized to the tfdA gene of the canonical 2,4-D catabolic plasmid pJP4 under low-stringency conditions. Cleavage of the ether bond of 2,4-D by cell extracts of TFD6 proceeded by an (alpha)-ketoglutarate-dependent reaction,characteristic of TfdA (F. Fukumori and R. P. Hausinger, J. Bacteriol. 175:2083-2086, 1993). The TFD6 tfdA gene was identified in a recombinant plasmid which complemented a tfdA transposon mutant of TFD6 created by chromosomal insertion of Tn5. The plasmid also expressed TfdA activity in Escherichia coli …

Characterization Of A Chromosomally Encoded 2,4-Dichlorophenoxyacetic Acid/A-Ketoglutarate Dioxygenase From Burkholderia Sp. Strain Rasc, Yuichi Suwa, Alice D. Wright, Fumitasu Fukimori, Kathy A. Nummy, Robert P. Hausinger, William E. Holben, Larry J. Forney

Biological Sciences Faculty Publications

The findings of previous studies indicate that the genes required for metabolism of the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) are typically encoded on broad-host-range plasmids. However, characterization of plasmid-cured strains of Burkholderia sp. strain RASC, as well as mutants obtained by transposon mutagenesis, suggested that the 2,4-D catabolic genes were located on the chromosome of this strain. Mutants of Burkholderia strain RASC unable to degrade 2,4-D (2,4-D- strains) were obtained by insertional inactivation with Tn5. One such mutant (d1) was shown to have Tn5 inserted in tfdA_RASC, which encodes 2,4-D/alpha-ketoglutarate dioxygenase. This is the first reported example of a …

Oxidative Stress Detection With Escherichia Coli Harboring A Katg'::Lux Fusion, S. Belkin, D. R. Smulski, Amy Cheng Vollmer, T. K. Van Dyk, R. A. Larossa

Biology Faculty Works

A plasmid containing a transcriptional fusion of the Escherichia coli katG promoter to a truncated Vibrio fischeri lux operon (luxCDABE) was constructed. An E. coli strain bearing this plasmid (strain DPD2511) exhibited low basal levels of luminescence, which increased up to 1,000-fold in the presence of hydrogen peroxide, organic peroxides, redox-cycling agents (methyl viologen and menadione), a hydrogen peroxide-producing enzyme system (xanthine and xanthine oxidase), and cigarette smoke. An oxyR deletion abolished hydrogen peroxide-dependent induction, confirming that oxyR controlled katG'::lux luminescence. Light emission was also induced by ethanol by an unexplained mechanism. A marked synergistic response was observed when cells …

Impact Of A Parasitic Plant On The Structure And Dynamics Of Salt Marsh Vegetation, Steven C. Pennings, Ragan M. Callaway

Biological Sciences Faculty Publications

We investigated the effect of a native parasitic plant, Cuscuta salina, on the structure and dynamics of the plant community in a California salt marsh. Cuscuta was common in the middle marsh zones. The abundance of Cuscuta was positively correlated with the abundance of Limonium californicum at two sampling scales (0.25— and ≈\approx40—m² quadrats). Sampling at the scale of individual plants indicated that the dominant plant in the marsh, Salicornia virginica, was preferred by Cuscuta as a host over Arthrocnemum subterminale, Limonium californicum, and Frankenia salina. This result was confirmed with host—choice experiments in the field. Based on spatial …

Morphometry Of Juvenile And Subadult Loligo Pealei And L. Plei From The Northern Gulf Of Mexico, Guillermo Sánchez, Harriet M. Perry, Christine B. Trigg, Michael Vecchione, Clyde Roper, Patricia M. Biesot

Faculty Publications

Two species of Loligo are abundant in northern Gulf waters: the long-finned squid, Loligo pealei. and the arrow squid, Loligo plei. Variability within species and similarities between the species often hamper accurate identification. The two species more closely resemble each other in areas of sympatry. and there is overlap in almost all of the diagnostic characters. Small specimens of Loligo are not easily identified. and there are few studies detailing their morphometry. Because of the taxonomic uncertainties associated with the identification of juveniles and subadults of L. pealei and L. plei, the species were differentiated by isoelectric …

Characterization Of A Newly Cloned Dna Damage- Inducible Gene From Saccharomyces Cerevisiae Strain D43, June-Home Chen

Master's Theses

The identification and characterization of DNA damage-inducible genes is an important topic in the study of the integrity of the cellular genome. Previously, a TnlO-lacZ derivative was inserted randomly into yeast cells and the resulting mutants were screened for insertions in DNA damage-inducible genes. S. cerevisiae strain D43 was identified as one such TnlO-lacZ insertion mutant. DNA sequencing results show the insertion in D43 is located within the TDH2 gene, which encodes glyceraldehyde-3-phosphate dehydrogenase. Treatment of strain D43 with DNA damaging agents and heat shock suggest TDH2 is responsive to DNA damage, but not to heat shock. Haploid mutants carrying …

Female Choice In Sage Grouse: The Roles Of Attraction And Active Comparison, Robert M. Gibson

School of Biological Sciences: Faculty Publications

Previous studies of female choice in sage grouse Centrocercus urophasianus have implicated both the acoustic quality and repetition rate of the stereotyped strut display as putative cues for female choice. Stages in the choice process at which specific components of male courtship display influence female decisions were investigated using field observations of female premating behavior. Females visited a subset of territorial males and then actively chose one of these as a mate. The order in which males were visited suggested that females searched until an acceptable mate was found, rather than employing a “best-of-n” tactic. Numbers of females visiting a …

Microhardness And Scanning Electron Microscopy Analysis Of Nd:Yag Laser And Acid Treatment Effects In Dentin, J. M. White, G. L. Adams

Scanning Microscopy

Laser irradiation at and above parameters producing the modification threshold for dentin causes structural changes to the dentin surface. This study determined the microhardness of dentin before and after laser modification and acid treatment using a repeated-measures de-sign. Seven dentin sections (4 mm in thickness) were cut from freshly extracted non-carious third molars using a diamond saw. The middle occlusal third was used as the test dentin surface. One section served as a control (C); three received laser modification (L) and then acid treatment (L + A); and three received acid (A) and then laser treatment (A + L). Laser …

Experimental Nephrolithiasis In Rats: The Effect Of Ethylene Glycol And Vitamin D3 On The Induction Of Renal Calcium Oxalate Crystals, R. De Water, E. R. Boevé, P. P. M. C. Van Miert, G. Deng, L. C. Cao, Th. Stijnen, W. C. De Bruijn, F. H. Schröder

Scanning Microscopy

Using ethylene glycol (EG) and vitamin D3 as crystal-inducing diet (CID) in rats, we investigated the effect of the dosage of EG on the generation of chronic calcium oxalate (CaOx) nephrolithiasis. We collected weekly 24 hour urines and measured herein the amount of oxalate, calcium, glycosaminoglycans (GAG's), creatinine, protein, alkaline phosphatase (AP), 𝝲-glutamyl transpeptidase (𝝲GT), and N-acetyl-𝝱-glucosaminidase (NAG). The potential of these urines to inhibit crystal growth and agglomeration was also evaluated. After four weeks, the kidneys were screened by histology and radiography for the presence of CaOx crystals and the amount of kidney-associated oxalate was biochemically measured. Using 0.5 …

Settlement And Early Post-Settlement Survival Of Sessile Marine Invertebrates On Topographically Complex Surfaces: The Importance Of Refuge Dimensions And Adult Morphology, Linda J. Walters, David S. Wethey

Faculty Publications

We predicted that both refuge dimension and growth form would influence settlement and short-term post-settlement success (≤7 d) of sessile marine invertebrates that live attached to hard substrata in low energy environments. Individuals with unlimited attachment to the substrata should rapidly be protected by their growth form, thus decreasing their need to settle in refuges and limiting the length of time any locations on heterogeneous substrata act as refuges. Alternatively, organisms with limited attachment to the substrata should remain susceptible to the causes of mortality for a longer time, and as a result should settle in high quality refuges (sites …

Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam

Faculty Publications

The interaction of bacteria with particulate organic matter has implications for organic matter cycling and bacterial ecology in the ocean. Until recently, the focus has been on 'classical' particles visible by unaided eye (marine snow) or light microscopy. Recent discoveries of several new types of abundant particles, from sub-micrometer to sub-marine snow, are changing our ideas of the physical and chemical nature of the particle field with which pelagic bacteria interact. Previous workers have discovered polysaccharide-containing (Alcian Blue stainable) transparent exopolymer particles (TEP) ranging from 3 to 100s of micrometers. Looking for additional components of the sub-marine snow particle field, …

Problems In Preparation Of Chromosomes For Scanning Electron Microscopy To Reveal Morphology And To Permit Immunocytochemistry Of Sensitive Antigens, A. T. Sumner

Scanning Microscopy

Although much information about chromosome structure and behaviour has been obtained using light microscopy, greater resolution is needed for a thorough understanding of chromosome organisation. Scanning electron microscopy (SEM) can provide valuable data about these three-dimensional organelles. The introduction of methods using osmium impregnation of methanol-acetic acid-fixed chromosome spreads revolutionised matters, producing life-like images of chromosomes. Nevertheless, it became clear that osmium impregnation introduced various artefacts, although the resulting images were still useful. Methanol-acetic acid-fixed chromosomes are, in fact, flattened on the glass substratum, and the 3-dimensional appearance obtained after osmium impregnation is the result of swelling during this process. …

Preparation Of Plasmid Dna In Transfection Complexes For Fluorescence And Electron Spectroscopic Imaging, Marek Malecki

Scanning Microscopy

The aim of this project was to develop procedures necessary to study mechanisms of receptor mediated gene transfer by means of integrated microscopy.

Plasmid DNA was incorporated into a transfection complex consisting of poly(L)lysine and transferrin to which the nuclear localization signal was conjugated. This complex was presented to cultured glioma cells. Preparation of the transfected DNA for imaging was pursued by two methods. In the first method tetramethylrhodamine, nanogold, and ferritin were linked through streptavidin to the biotinylated plasmid DNA. Trafficking of the fluorescent derivatives was studied in living cells with fluorescence microscopy. Then, selected cells were rapidly cryo-immobilized. …

Common Epidermal Lesions Of The Bowhead Whale, Balaena Mysticetus, William G. Henk, Dianna L. Mullan

Scanning Microscopy

Samples of common skin abnormalities from 23 subsistence-harvested bowhead whales (Balaena mysticetus) were examined. Most lesions fell into three broad classes: shallow lacerations, circular depressions, and epidermal sloughing. Both circular depression lesions and epidermal sloughing lesions may be divided into more than one subgroup based on morphological criteria. Examination of each of the subgroups using light and scanning electron microscopy suggests relationships among the subgroups of a class. These proposed relationships are discussed, as are some possible etiologies. Scanning electron microscopy reveals abundant bacteria and diatoms present in association with each lesion class but no evidence of a particular association …

Adhesion And Endocytosis Of Calcium Oxalate Crystals On Renal Tubular Cells, Y. Kohjimoto, S. Ebisuno, M. Tamura, T. Ohkawa

Scanning Microscopy

The present investigation was designed to study interactions between Madin-Darby canine kidney (MOCK) cells and calcium oxalate monohydrate (COM) crystals and to clarify the significance of these crystal-cell interactions in stone pathogenesis.

MOCK cells cultured in the presence of COM crystals showed a time-dependent uptake of crystals; this was specific for COM crystals. In the dynamic model system designed to study these phenomena under more physiological conditions, COM crystals adhered to the cell surface and were subsequently internalized. In this endocytotic process, the microvilli of the cell appeared to play an important role. The observation by scanning electron microscopy of …

Potential New Method: A Comparability Study Of M-Coliblue24 And M-Endo Les For The Verified Recoveries Of Total Coliforms And E. Coli, Kevin Robert Geotz

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Kevin Robert Goetz on June 10, 1996.

X-Ray Microscopy: Preparations For Studies Of Frozen Hydrated Specimens, A. Osanna, C. Jacobsen, A. Kalinovsky, J. Kirz, J. Maser, S. Wang

Scanning Microscopy

X-ray microscopes provide higher resolution than visible light microscopes. Wet, biological materials with a water thickness of up to about 10 μm can be imaged with good contrast using soft X-rays with wavelengths between the oxygen and carbon absorption edges (at 24 and 43 Å). The Stony Brook group has developed and operates a scanning transmission X-ray microscope (STXM) at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The microscope is used for imaging with a current resolution of 50 nm, and for elemental and chemical state mapping.

Radiation damage imposes a significant limitation upon high resolution X-ray …

Offshore Constitutional Settlement 1995, H. G. Brayford, G. E. Lyon

Fisheries Management Papers

The Offshore Constitutional Settlement OCS is a legal arrangement between the Commonwealth and State Governments, and defines control over the fisheries which operate off each State of Australia. For the Western Australian coast, the first set of arrangements took effect in 1987. The OCS of 1995 specifies five arrangements, under which the fisheries inside the 200 nautical mile approximately 370 km limit of the Australian Fishing Zone AFZ come under either State, Commonwealth, or joint control.

Temperature-Driven Variation In Substrate Oxygenation And The Balance Of Competition And Facilitation, Ragan M. Callaway, Leah King

Biological Sciences Faculty Publications

Emergent wetland plants often alleviate the effects of anaerobic soils on root respiration by passively transporting oxygen belowground through continuous air spaces (aerenchyma) in leaves and roots. Oxygen leaked from the roots into the rhizosphere may oxidize minerals in the soil or become available to other plants. Some spatial patterns in marsh plant communities suggest interspecific facilitative interactions, but there is little experimental evidence for interplant facilitation via soil oxygenation. We investigated the capability of the widespread, highly aerenchymous wetland plant, Typa latifolia, to aerate sediments and affect the growth of two non—aerenchymous neighbors, Salix exigua and Myosotis laxa, both …

Analysis Of Linear Plasmid Dimers In Borrelia Burgdorferi Sensu Lato Isolates: Implications Concerning The Potential Mechanism Of Linear Plasmid Replication, Richard T. Marconi, Sherwood Casjens, Ulrike G. Munderloh, D. Scott Samuels

Biological Sciences Faculty Publications

The Borrelia genome is composed of a linear chromosome and a number of variable circular and linear plasmids. Atypically large linear plasmids of 92 to 105 kb have been identified in several Borrelia burgdorferi sensu lato isolates and characterized. These plasmids carry the p27 and ospAB genes, which in other isolates reside on a 50-kb plasmid. Here we demonstrate that these plasmids are dimers of the 50-kb ospAB plasmid (pAB50). The 94-kb plasmid from isolate VS116, pVS94, was an exception and did not hybridize with any plasmid gene probes. When this plasmid was used as a probe, homologous sequences in …

Low Calcium Diet In Hypercalciuric Calcium Nephrolithiasis: First Do No Harm, Bernhard Hess

Scanning Microscopy

Many studies indicate that up-regulated production of 1,25(OH)2-vitamin D3 (calcitriol) with increased intestinal absorption of calcium is the primary event causing idiopathic hypercalciuria. Thus, a low calcium diet appears to be a straightforward strategy in calcium stone formers with hypercalciuria (HCSF). However, the efficacy of such a regimen has never been established, and lowering calcium intake from 1000 to 400 mg/day further enhances calcitriol production. On a diet chronically restricted in calcium, many stone formers increase their intake of animal flesh protein. The latter is known to increase renal mass, and calcitriol levels indeed are positively correlated with renal mass …

Rust Diseases Of Apple, John R. Hartman

Agriculture and Natural Resources Publications

Three related rust diseases occur on apple trees in Kentucky: cedar-apple rust, cedar-hawthorn rust, and cedarquince rust. Crabapple, hawthorn, mountain ash, pear, and serviceberry are also susceptible to these diseases. All three rusts are caused by different species of the fungus Gymnosporangium, each of which must spend a phase of its life cycle as a parasite on Juniperus species such as native red cedars or ornamental junipers.

Although cedar rusts can cause unsightly growths on Juniperus, they do not usually cause serious damage to these plants. Rust diseases can cause serious losses on apples, however, as a result …