Biology Commons^™

Preparation Of Cultured Smooth Muscle Cells From Human Myometrium For X-Ray Microanalysis, Jarin Hongpaisan, Godfried M. Roomans

Scanning Microscopy

Methodological aspects of the use of X-ray microanalysis in physiological and pharmacological experiments on cultured myometrial cells were investigated. Cultured human myometrial cells were grown from biopsies after detaching the fibroblasts. Of the cultured cells, 95-98% showed desmin-like immunoreactivity. Transmission electron microscopy showed that subcultured cells were different from myometrial cells in situ. The effects of washing the cells to remove external salt-rich medium were investigated. All solutions removed the external medium, resulting in lower concentrations of Na and Cl. In the cells washed with 0.3 M mannitol, most of the elemental concentrations were significantly lower than in their …

Morphological And Chemical Properties Of Plastic Residues In Composts, Charles R. Krause, Leona E. Horst, Harry A. J. Hoitink

Scanning Microscopy

The relative quantity of plastic film residues and other man-made materials in composts prepared from municipal solid wastes (MSW), biosolids, yard wastes, and pine bark was evaluated utilizing light and scanning electron microscopy equipped with energy dispersive X-ray analyzer. MSW composts screened through a 4 mm screen contained significant but highly variable quantities of plastic film residues and other man-made materials that escaped detection with the unaided eye. The other composts were free of such particles. We conclude that the database for evaluation of man-made materials in MSW composts is inadequate and must be developed further.

Phenology Of Apothecium Production In Populations Of Monilinia Vaccinii-Corymbosi From Early- And Late-Maturing Blueberry Cultivars, Jeffrey Lehman

Biology and Earth Science Faculty Scholarship

Pseudosclerotia were evaluated for differences in timing of apothecium development in four controlled experiments conducted over a 2-year period. In a separate experiment, conidia from 10 randomly selected isolates from both of the fungal populations were used to inoculate open flowers. Germination of pseudosclerotia produced from these artificial inoculations also was evaluated. The timing and rate of shoot elongation for cvs. Weymouth and Jersey were assessed in one greenhouse and two field experiments. Average development times for the fungal population from cv. Weymouth were 8 to 15 days earlier or 33 to 42% less than those for the population from …

Relative Intranuclear Magnesium And Phosphorus Contents In Normal And Tumor Cells Of The Human Thyroid Gland As Revealed By Energy-Dispersive X-Ray Microanalysis, Geza L. Lukacs, Imre Zs.-Nagy, Janos Steiber, Ferenc Gyori, Gyorgy Balazs

Scanning Microscopy

Energy dispersive X-ray microanalysis was performed on altogether 42 surgically removed tissue specimens of 32 patients, which were taken either from intact thyroid parts or various histopathologically verified tumors of the thyroid gland. The tissue specimens were processed with the freeze-fracture-freeze-drying technique and then analyzed in the so-called bulk specimen form. The studies were carried out during the years 1980-81, when intranuclear monovalent ionic composition was studied in detail. From the retained total elemental peak list, it was possible to calculate retrospectively the relative intranuclear Mg and P contents. The data processed by nested (hierarchical) analysis of variance show that …

Imaging The Electrocyte Of Torpedo Marmorata By Scanning Force Microscopy, L. I. Pietrasanta, A. Schaper, G. Q. Fox, F. J. Barrantes, T. M. Jovin

Scanning Microscopy

Scanning force microscopy (SFM) and scanning electron microscopy (SEM) were used to examine the tissue structure of the electric organ of Torpedo marmorata in air and in liquid after applying fracturing and cryosectioning techniques and chemical fixation. The electric organ is organized in columns of stacked electrocytes, arranged in a honeycomb pattern. The columns were cut along a plane normal to the cell stack and thin sections were transferred to polylysine coated glass coverslips. The polarity of the electrocytes was made apparent by immunofluorescence microscopy directed to different domains of the acetylcholine receptor (AChR), thus revealing the innervated face of …

Paleomicrobiological Study In Dental Calculus: Streptococcus Mutans, A. Linossier, M. Gajardo, J. Olavarria

Scanning Microscopy

Morphological types of bacterial remains preserved in ancient tartar of teeth from extinct human groups, which included some communities of coastal gatherers, fishermen, hunters, and farmers, and those practicing a mixed economy, were analyzed. Previous studies have shown the presence of bacteria in ancient tartar. The aim of this work was to determine whether Streptococcus mutans was present in ancient populations (500-12,000 years old). Teeth samples were from ancient skulls obtained from different anthropological collections: the north and south of Chile (before the Spanish conquest), Palencia, Spain, and an eastern Mediterranean region (Levant). Optical microscopy showed Gram positive and Gram …

Hair Bundle Morphology On Surviving Hair Cells Of The Chick Basilar Papilla Exposed To Intense Sound, J. S. Erulkar, D. A. O'Brien, J. C. Saunders

Scanning Microscopy

Exposure to intense sound produces a well-defined "patch" lesion on the chick basilar papilla in which 30-35% of the short hair cells are lost. The present study compares various aspects of sensory hair bundle morphology on surviving hair cells in the patch lesion with hair bundles from matched locations on nonexposed control papilla immediately after removal from the exposure and 12-days post exposure. The height and thickness of the hairs, the total number of hairs in the bundle, the width of the bundle, and the area and perimeter of the apical surface of the hair cell were quantified from scanning …

Video Rate Confocal Laser Scanning Reflection Microscopy In The Investigation Of Normal And Neoplastic Living Cell Dynamics, Pavel Vesely, Alan Boyde

Scanning Microscopy

The introduction of video rate confocal laser scanning microscopes (VRCLSM) used in reflection mode with high magnification, high aperture objective lenses and with further magnification by a zoom facility allowed the first detailed observations of the activity of living cytoplasm and offered a new tool for investigation of the structural transition from the living state to the specimen fixed for electron microscopy (EM). We used a Noran Odyssey VRCLSM in reflection (backscattered) mode. A greater degree of oversampling and more comfortable viewing of the live or taped video image was achieved at zoom factor 5, giving a display monitor field …

Azorhizobium Caulinodans Uses Both Cytochrome Bd (Quinol) And Cytochrome Cbb3 (Cytochrome C) Terminal Oxidases For Symbiotic N2 Fixation, Alexandre Kaminski, Christopher L. Kitts, Zachary Zimmerman, Robert A. Ludwig

Biological Sciences

Azorhizobium caulinodans employs both cytochrome bd (cytbd; quinol oxidase) and cytcbb3 (cytc oxidase) as terminal oxidases in environments with very low O2 concentrations. To investigate physiological roles of these two terminal oxidases both in microaerobic culture and in symbiosis, knockout mutants were constructed. As evidenced by visible absorbance spectra taken from mutant bacteria carrying perfect gene replacements, both the cytbd- and cytcbb3- mutations were null alleles. In aerobic culture under 2% O2 atmosphere, Azorhizobium cytbd- and cytcbb3- single mutants both fixed N2 at 70 to 90% of wild-type rates; in root nodule symbiosis, both single mutants fixed N2 at 50% …

Shark Bay World Heritage Property: Summary Of Public Submissions To The Draft Management Plan For Fish Resources, Kevin A. Francesconi

Fisheries Management Papers

In November 1994, the draft management plan for fish resources for the Shark Bay World Heritage Area (Fisheries Management Paper no 72) was released for public comment. This report summarises and analyses the 28 written public submissions received to the draft fisheries management plan.

Shark Bay Management Paper For Fish Resources, Fisheries Department Of Western Australia, Department Of Conservation And Land Management

Fisheries Management Papers

This paper deals with the management of fish resources in the Shark Bay World Heritage Property which are the responsibility of the Fisheries Department of Western Australia. It was prepared by the Fisheries Department in close liaison with the Department of Conservation and Land Management. The policies and guidelines proposed in this paper will be followed for a period not exceeding 10 years.

Directed Insertion Of A Selectable Marker Into A Circular Plasmid Of Borrelia Burgdorferi, Patricia Rosa, D. Scott Samuels, Daniel Hogan, Brian Stevenson, Sherwood Casjens, Kit Tilly

Biological Sciences Faculty Publications

Studies of the biology of Borrelia burgdorferi and the pathogenesis of Lyme disease are severely limited by the current lack of genetic tools. As an initial step toward facile genetic manipulation of this pathogenic spirochete, we have investigated gene inactivation by allelic exchange using a mutated borrelial gyrB gene that confers resistance to the antibiotic coumermycin A(1) as a selectable marker. We have transformed B. burgdorferi by electroporation with a linear fragment of DNA in which this selectable marker was flanked by sequences from a native borrelial 26-kb circular plasmid. We have identified coumermycin A(1)-resistant transformants in which gyrB had …

Modeling Nutrient And Plankton Processes In The California Coastal Transition Zone: 3. Lagrangian Drifters, J. R. Moisan, Eileen E. Hofmann

CCPO Publications

Two types of numerical Lagrangian drifter experiments were conducted, using a set of increasingly complex and sophisticated models, to investigate the processes associated with the plankton distributions in the California coastal transition zone (CTZ). The first experiment used a one-dimensional (1-D; vertical) time-dependent physical-bio-optical model, which contained a nine-component food web. Vertical velocities, along the track of simulated Lagrangian drifters, derived from a three-dimensional (3-D), primitive equation circulation model developed to simulate the flow observed within the CTZ; were used to parameterize the upwelling and downwelling processes. The second experiment used 880 simulated Lagrangian drifters from a 3-D primitive equation …

Competition And Facilitation: Contrasting Effects Of Artemisia Tridentata On Desert Vs Montane Pines, Ragan M. Callaway, Eh Delucia, Darrin Moore, R Nowak, W. H. Schlesinger, Brenda J. Moor

Biological Sciences Faculty Publications

Circumstantial evidence suggests that Artemisia tridentata may out-compete Pinus ponderosa and P. jefferyi for water at ecotones between shrub steppe and montane forest vegetation in the Great Basin. Other studies indicate that within the shrub steppe Artemisia may act as a nurse plant for a third species of pine, P. monophylla. We used field experiments to study these contrasting effects of Artemisia on P, ponderosa and P. monophylla within the contest of the distributional patterns in western Nevada of all three species on andesite, and on sites where hydrothermal activity has altered the andesite. At intermediate elevations in the Great …

Modeling Interactions Of Browsing Predation, Infaunal Activity And Recruitment In Marine Soft-Sediment Habitats, Sara M. Lindsay, David S. Wethey, Sarah A. Woodin

Faculty Publications

In marine soft-sediment habitats, the sediment surface is altered by activities of sediment dwellers (infauna). Such biogenic disturbance can influence recruitment success if settling larvae and juveniles avoid disturbed sites or if juveniles die as a result of disturbance after settling. Because infauna commonly lose exposed body parts to browsing predators and disturb less sediment as a result, we developed a simulation model to examine the interactions between browsing predation, infaunal adult activity, and recruitment. Sediment disturbance in the model was based on data for the polychaete Abarenicola pacifica. We simulated the activity of two general types of predators: prey …

Secondary Electron Emission From Simple Metals: Comparative Studies For Al, Mg, And Be, M. Rosler

Scanning Microscopy

In the secondary electron emission (SEE) from solids, the role of different excitation processes is now as ever of special interest from both the theoretical and the experimental points of view. Depending on the primary energy, the relative importance of different excitation mechanisms related to conduction as well as core electrons will be discussed for different simple metals. So far, first principles results are available only for Al for primary energies up to 10 keV. Starting from a microscopic description of the SEE based on the transport equation formalism, calculations were performed for other nearly-free-electron metals (Mg, Be) up to …

Deposition Of Supercoiled Dna On Mica For Scanning Force Microscopy Imaging, B. Samori, I. Muzzalupo, G. Zuccheri

Scanning Microscopy

The deposition of DNA molecules on mica is driven and controlled by the ionic densities around DNA and close to the surface of the substrate. Dramatic improvements in the efficiency and reproducibility of DNA depositions were due to the introduction of divalent cations in the deposition solutions. The ionic distributions on DNA and on mica determine the mobility of adsorbed DNA molecules, thus letting them assume thermodynamically equilibrated conformations, or alternatively trapping them in non-equilibrated conformations upon adsorption.

With these prerequisites, mica does not seem like an inert substrate for DNA deposition for microscopy, and its properties greatly affect the …

Simultaneous Identification Of A Specific Gene Protein Product And Transcript Using Combined Immunocytochemistry And In Situ Hybridization With Non-Radioactive Probes, Gwen V. Childs

Scanning Microscopy

Simultaneous identification of messenger RNA (mRNA) and proteins in the same cells or tissues is a valuable tool to help the cell biologist evaluate the cell secretory cycle. Some cells may produce the mRNA and delay the production of the proteins. Alternatively, the proteins may be rapidly secreted. Other cells may produce both in sequence within the same time frame. Because of this difference, some cells can only be identified by their mRNA product. Others may have both products. This presentation describes a non-radioactive approach to the detection of both products with dual-peroxidase labeling protocols in use in this laboratory …

Electrical Characterization Of Submicrometer Silicon Devices By Cross-Sectional Contact Mode Atomic Force Microscopy, P. De Wolf, T. Trenkler, T. Clarysse, M. Caymax, W. Vandervorst, J. J. Snauwaert, L. Hellemans

Scanning Microscopy

Two contact mode atomic force microscopic (AFM) techniques under ambient conditions are presented for the electrical evaluation of cross sectioned silicon devices. In the first technique, a conductive AFM tip is used as a voltage probe to determine the local potential distribution on the cross section of a silicon device under operation. The electrical potential is measured simultaneously with the surface topography with nanometer resolution and mV accuracy, offering an easy way of correlating topographic and electrical features. A second method, nanometer spreading resistance profiling (nano-SRP), performs localized spreading resistance measurements to determine the spatial distribution of charge carriers in …

Fluorescence Imaging And Spectroscopy Of Biomaterials In Air And Liquid By Scanning Near-Field Optical/Atomic Force Microscopy, H. Muramatsu, N. Chiba, K. Nakajima, T. Ataka, M. Fujihira, J. Hitomi, T. Ushiki

Scanning Microscopy

We have developed scanning near-field optical/atomic force microscopy (SNOM/AFM). The SNOM/AFM uses a bent optical fiber simultaneously as a dynamic force AFM cantilever and a SNOM probe. Resonant frequency of the optical fiber cantilever is 15-40 kHz. Optical resolution of the SNOM/AFM images shows less than 50 nm. The SNOM/ AFM system contains photon counting system and polychrometer/intensified coupled charge devise (ICCD) system to observe fluorescence image and spectrograph of micro areas, respectively. Cultured cells were stained with fluorescein isothiocyanate (FITC)-labeled anti-keratin antibody or FITC-labeled phalloidin after treatment with Triton X-100. Fluorescence and topographic images were obtained in air and …

Nucleic Acid Detection By In Situ Molecular Immunogold Labeling Procedures, Marc Thiry

Scanning Microscopy

We have recently combined immunogold labeling procedures with molecular biology methods to pinpoint the precise locations of nucleic acids in biological material at the ultrastructural level. These new immunocytological approaches involve the incorporation of labeled nucleotides in the nucleic acids present at the surface of ultrathin sections prior to immunogold labeling. The antibodies used recognize a nucleoside analogue (bromodeoxyuridine) or a hapten (biotin) employed to label nucleotides. Examples of high-resolution detection include DNA or RNA present in different substructures of cell nuclei, and in particular, in adenovirus-induced intranuclear regions of HeLa cells. In addition to being highly sensitive and specific, …

Freeze-Dried Human Leukocytes Stabilized With Uranyl Acetate During Low Temperature Embedding Or With Oso4 Vapor After Embedding, L. Edelmann, A. Ruf

Scanning Microscopy

Two new simple stabilization procedures for freeze-dried biological material are introduced which are compatible with low temperature embedding (LTE) in Lowicryl. The first method uses a Lowicryl K11M/HM20 mixture supplemented with 0.3% uranyl acetate for LTE. For the second method polymerized Lowicryl blocks containing the freeze-dried material are exposed to OsO₄ vapor which penetrates into the Lowicryl block and stabilizes the embedded specimen. The quality of structural preservation is demonstrated with human leukocytes.

X-Irradiation-Induced Changes Of The Prelysosomal And Lysosomal Compartments And Proteolysis In Ht-29 Cells, Z. Somosy, A. Takáts, G. Bognár, A. L. Kovács, Á. Telbisz, A. Rácz, J. Kovács, G. J. Köteles

Scanning Microscopy

As a consequence of external and internal ionizing radiation, lysosome-like bodies have been observed to increase both in size and number in some cell types. We investigated this process by morphological methods (electron microscopy, cationized ferritin uptake, acid phosphatase histochemistry, morphometry) in cultured HT-29 cells. In parallel with these studies, we measured the rate of protein degradation on the basis of 14C-valine release from prelabeled cellular proteins. We found that at 2 and 4 Gy doses of X-irradiation the volume of the vacuolar (probably lysosomal) compartment increased without detectable changes of acid phosphatase activity. A 2 Gy irradiation dose did …

Towards In Situ Atomic Force Microscopy Imaging Of Biofilm Growth On Stainless Steel, D. T. Goddard, A. Steele, I. B. Beech

Scanning Microscopy

Atomic force microscopy (AFM) has been used to visualise the formation of bacterial biofilms on polished surfaces of 316 stainless steel. Imaging under ambient conditions revealed both the bacterial cells and the matrix of exopolymeric substances (EPS). These images exhibited good resolution with cell surface features as small as 30 nm distinguishable. In situ imaging was also carried out, and although the resolution was considerably reduced, images revealing the process of bacteria division have been obtained.

Ion And Electron Emission From Liquid Metal Sources, H. Niedrig

Scanning Microscopy

In liquid metal ion sources, the emission is located at the apex of a liquid cone (the often so-called Taylor cone), formed by electrostatic forces and surface tension. Reversal of the extraction voltage polarity results in electron emission from the liquid metal surface. For small apex radii, ≤ 1 μm, steady field emission of electrons has been observed, whereas for apex radii ≥ 10 μm, explosive pulsed emission occurs. Since the onset voltage for electron emission has been found to be considerably lower than the critical voltage for the formation of the Taylor cone, it has been concluded that dc …

A Comparison Of The Renal Structures Of The Anaconda And The Ball Python, H. Ditrich

Scanning Microscopy

The renal vascular system of the Ball python (Python regius) and the anaconda (Eunectes noteus; Serpentes - Squamata) has been investigated using light microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) of vascular corrosion casts and critical-point dried non-corroded specimens. The average glomerular diameters of these two species differ significantly (anaconda: 59.1 μm, python: 124.3 μm). Also, the relative proportions of the renal tubules are different. These findings can be related to the different habitats of the two species (aquatic versus terrestrial environment).

Atomic Force Microscopy Investigation Of Radiation-Induced Dna Double Strand Breaks, D. Pang, G. Popescu, J. Rodgers, B. L. Berman, A. Dritschilo

Scanning Microscopy

We have used atomic force microscopy (AFM) to study radiation-induced DNA double strand breaks. Double-stranded plasmid DNA was irradiated with 18-MeV electrons in aqueous buffer, using a medical linear accelerator. Doses of 50, 100, 150, and 200 Gy were delivered to DNA samples, and atomic force microscopy was used to measure the length of each DNA fragment. From these measurements, we obtained the average length of the irradiated DNA for each sample and found a linear-quadratic relationship between the average length and radiation dose.

A Micro-Raman Spectroscopic Study Of Hydrazine-Treated Human Dental Calculus, H. Tsuda, W. L. Jongebloed, I. Stokroos, J. Arends

Scanning Microscopy

Hydrazine has been used to remove organic components and to isolate the mineral(s) from human calculus. Micro-Raman measurements were performed on the mineral phase. After the hydrazine-treatment, not only a large reduction in fluorescence but also an increase in Raman signal was observed. The treatment was essential in minimizing thermally-induced chemical changes which could otherwise occur to the original calculus mineral due to the intense laser light. The Raman spectral features of the mineral were nearly all identical among the Raman spectra obtained at many randomly-selected sites by the micro-Raman microbe with a lateral resolution of approximately 1 μm, and …

Combined Bronchoalveolar-Vascular Casting Of The Canine Lung, John A. Nettum

Scanning Microscopy

Canine bronchoalveolar and vascular corrosion casts were prepared using unfixed tissue and Dow-Corning Room Temperature Vulcanizing Silastic® 734. The casts were observed using stereo light microscopy and scanning electron microscopy. The casts show the relationship between the vasculature and airway and demonstrate intricate microanatomical details. Also, microvasculature filling was enhanced using unfixed tissue as compared to my previously described technique using fixed tissue. Prewashing the microvasculature with cold phosphate buffered saline appeared to facilitate microvascular filling with silicone rubber. The described method is useful for rapidly making durable models for studying the normal respiratory airway and microvasculature. It should be …

Application Of Monte Carlo Simulations To Critical Dimension Metrology In A Scanning Electron Microscope, Jeremiah R. Lowney

Scanning Microscopy

The state of the art in Monte Carlo simulations of scanning electron microscope (SEM) signals is reviewed. Two Monte Carlo computer codes were written to simulate the transmitted-, backscattered-, and secondary-electron signals from targets in a scanning electron microscope. The first, MONSEL-11, is applied to semi-infinite lines produced lithographically on multi-layer substrates. The second, MONSEL-111, is an extension to fully three-dimensional targets. Results for a 1 μm step, etched in a silicon substrate are compared with experimental data. The comparisons show that it is possible to obtain edge locations to an uncertainty of less than 10 nm. Simulations were performed …