Digital Commons Network^™

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 …

Atomic Force Microscopy And Optical Studies Of Organic Thin Films With Hydrogen-Bonded Networks, Arkadi L. Litvin, Valery N. Bliznyuk, Vladimir V. Tsukruk, Suresh Valiyaveettil, David L. Kaplan

Scanning Microscopy

Brewster angle microscopy and atomic force microscopy were used to characterize the surface morphology of thin films in situ or after transfer onto solid supports. Two acids were studied, differing in carboxylic acid head groups, resulting in significantly different morphological features for thin films formed from these two amphiphiles on a Langmuir trough. Differences in self-assembly and domain sizes were correlated with the formation of hydrogen-bonded networks. The influence of surface hydrophobicity or hydrophilicity during deposition on morphology was also characterized, with spherulitic features appearing in some samples.

Monte Carlo Simulation Of Electron Backscattering In Solids Using A General-Purpose Computer Code, E. Acosta, E. Coleoni, G. Castellano, J. A. Riveros, J. M. Fernández-Varea, F. Salvat

Scanning Microscopy

A Monte Carlo study of backscattering of kilovolt electrons in solids, a process of primary importance in electron microscopy and surface analytical techniques, is carried out. Simulations have been performed using the general-purpose simulation code PENELOPE (an acronym for "Penetration and ENErgy LOss of Positrons and Electrons"), which generates electron-photon showers in arbitrary materials. A systematic comparison of results from PENELOPE with available experimental data, and with results from simulations with a much more sophisticated code, is given for electron beams with energies between 2.5 and 60 keV and elemental solids with atomic numbers Z = 4 to 92. It …

Effects Of Castration Upon The Morphology Of The Accessory Sex Organs Of The Male Rat - A Scanning Electron Microscopy Study, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

A systematic, comparative study of the accessory sex glands of the adult male rat after androgen withdrawal was carried out. The changes were investigated by using scanning electron microscopy at different intervals after surgical castration. The main common signs of epithelial cell involution were flattening of the cell surface, reduction of the size and number of microvilli, some blurring of the cell borders, cessation of secretory activity and diminution of the luminal volume of the glands. Overall, confident signs of atrophy were evident after one week, and complete epithelial involution was reached by the third week. The epithelial cell atrophy …

Emerging Applications Of Fluorescence Spectroscopy To Cellular Imaging: Lifetime Imaging, Metal-Ligand Probes, Multi-Photon Excitation And Light Quenching, Joseph R. Lakowicz

Scanning Microscopy

Advances in time-resolved fluorescence spectroscopy can be applied to cellular imaging. Fluorescence lifetime imaging microscopy (FLIM) creates image contrast based on the decay time of sensing probes at each point in a two-dimensional image. FLIM allows imaging of Ca²⁺ and other ions without the need for wavelength-ratiometric probes. Ca²⁺ imaging can be performed by FLIM with visible wavelength excitation. Instrumentation for FLIM is potentially simple enough to be present in most research laboratories. Applications of fluorescence are often limited by the lack of suitable fluorophores. New, highly photostable probes allow off-gating of the prompt autofluorescence, and measurement of …

Scanning Electron Microscopy Of The Accessory Sex Glands Of The Adult Male Rat, R. Wahlqvist, E. Dahl, K. J. Tveter

Scanning Microscopy

This study describes the morphology of the accessory sex glands of the adult male rat as observed by scanning electron microscopy (SEM). The purpose was to obtain a systematic and comparative SEM description of these glands and to evaluate different preparation techniques. A common morphological feature is polyhedral delineation of the cells, which exhibited a variable convexity of their apical surface. The cell apices were more or less studded with microvilli. Nevertheless, it was possible to distinguish the glands by their surface morphology. In the ventral prostate, there was a considerable heterogeneity in cell surface appearance. The lateral lobe bad …

Pearling And Aquaculture In The Dampier Archipelago - Existing And Proposed Operations - A Report For Public Comment, Ben Fraser

Fisheries Management Papers

This discussion paper has been prepared by the Fisheries Department of WA as part of a consultative process to enable the public to comment on existing and proposed pearling and aquaculture activities in the Dampier Archipelago. This report follows on from Fisheries Management Report 90 - the Driscoll Report - and provides more detailed information about pearling and aquaculture to enable the public to consider and comment on individual projects.

Characterization Of Experimentally Induced, Nonaflatoxigenic Variant Strains Of Aspergillus Parasiticus., Shubha Kale Ireland, J. W. Cary, D. Bhatnagar, J. W. Bennett

Faculty and Staff Publications

Six previously isolated, nonaflatoxigenic variants of Aspergillus parasiticus, designated sec mutants, were characterized morphologically by electron microscopy, biochemically by biotransformation studies with an aflatoxin precursor, and genetically by Northern (RNA) hybridization analysis of aflatoxin biosynthetic gene transcripts. Scanning electron micrographs clearly demonstrated that compared with the parental sec+ forms, the variant sec forms had an abundance of vegetative mycelia, orders of magnitude reduced number of conidiophores and conidia, and abnormal metulae. Conidiospores were detected in sec cultures only at higher magnifications (x500), in contrast to the sec+ (wild-type) strain, in which abundant conidiospores (masking the vegetative mycelia) were observed even …

Hydrogen Atom Extraction And Redeposition On Hydrogen-Terminated Silicon Surface With Scanning Tunneling Microscope At Room Temperature, D. H. Huang, Y. Yamamoto

Scanning Microscopy

We have previously demonstrated that hydrogen atoms on the hydrogen-terminated Si(100)-2xl:H surface can be extracted by applying either positive or negative voltage pulses between an STM tip and the sample surface with a certain tunneling current. This phenomenon suggests that electron excitation and field evaporation both play a role in atom transfer. Under our experimental conditions, hydrogen atoms are extracted in pairs from either a single dimer or from two adjacent dimers in neighboring rows. Hydrogen atoms can also be redeposited onto the Si(100)-2xl:H surface from a tungsten tip, which has picked up hydrogen from the sample surface through the …

Applications Of Laser Microprobe Mass Spectrometry In Biology And Medicine, Annette Bakker, Luc Van Vaeck, Wim Jacob

Scanning Microscopy

Laser microprobe mass spectrometry (LMMS) provides spot analysis with a lateral resolution of 1-5 μm. Focused laser ionisation, combined with mass spectrometry, yields information on elements, molecular identification of inorganic substances, and structural characterisation of organic molecules of typically less than 2-3 kDa. Quantification in complex heterogeneous systems, such as biological materials, is not possible at the present state of the art. The strength of the method lies in the qualitative information on the molecular composition of the analyte, not just element detection, with a lateral resolution at the light microscopy level. The applications of this technique in the field …

Influence Of Bleeding On Post-Mortem Tenderization Of Fish Muscle During Chilled Storage, M. Ando, A. Nishiyabu, T. Nakagawa, Y. Makinodan

Scanning Microscopy

The influence of bleeding on post-mortem tenderization of fish muscle during storage was studied. Six fish species were used for the present study. Among them, delay of post-mortem tenderization of muscle by bleeding was shown in the pelagic fishes: yellowtail, horse mackerel, and striped jack. On the other hand, bleeding had no influence on the muscle firmness of the bottom fishes: red sea bream, flatfish, and rudder-fish. According to transmission electron microscopy, degradation of pericellular collagen fibrils was delayed in bled yellowtail and horse mackerel. In the case of striped jack, though, collagen fibril degradation could not be observed; slower …

The Role Of Calcium In The Regulation Of Apoptosis, David J. Mcconkey

Scanning Microscopy

The recognition that apoptosis is regulated by an evolutionarily conserved set of polypeptides from the nematode Caenorhabditis elegans to humans suggests that a conserved set of biochemical mechanism(s) may also be involved in the response. Early evidence suggested that the endogenous endonuclease implicated in apoptosis in most model systems is Ca2+ -dependent, and subsequent work from a number of independent laboratories suggests that alterations in cytosolic Ca2+ homeostasis are one of the conserved biochemical pathways regulating the response. Molecular targets for Ca2+ are now being identified and include signal transduction intermediates, endonuclease(s) and proteases, and the enzymes involved in the …

Contact Force Dependence On Relative Humidity: Investigations Using Atomic Force Microscopy, E. Finot, E. Lesniewska, J. -C. Mutin, S. I. Hosain, J. -P. Goudonnet

Scanning Microscopy

This paper deals with the ability of scanning force microscopy to determine contact forces of various materials. Indeed, with high spring constants at low relative humidity, the nature of the material can be determined by measurement of the contact force as the tip approaches. Cantilevers with a high spring constant are used to achieve solid-solid contact for the tip-sample system. The capillary force estimation provides information on the development of the height of the water meniscus formed between the tip and different surfaces depending on the relative humidity. Finally, we focus our attention on measurements of moduli of elasticity which …

Covalent Labeling Of Proteins With Fluorescent Compounds For Imaging Applications, Darl R. Swartz

Scanning Microscopy

The labeling of proteins with fluorescent compounds for microscopy has allowed a greater understanding of biological processes. The preparation of fluorescent proteins is the first step in development of their use in microscopy. Methods are described to label and characterize a protein as an example of the general approach for other proteins. Skeletal muscle alpha-actinin was labeled with either fluorescein-5-maleimide or 5-iodoaceamidofluorescein and the reaction characterized. The maleimide reaction was much more rapid and efficient than the iodoacetamide reaction giving a coupling efficiency of 65% under the given ration conditions. The fluorescein-5-maleimide alpha-actinin was functionally characterized and there was essentially …

Pelage Coloration In Oldfield Mice (Peromyscus Polionotus): Antipredator Adaptation?, Mark C. Belk, Michael H. Smith

Faculty Publications

Reflectance spectra (in full light and moonlight) of dorsal pelage of 469 adult oldfield mice (Peromyscus polionotus) comprising nine regional samples were compared to reflectance spectra of corresponding surface and subsurface soil samples to test for a selective effect of predation on color of pelage. Mice were slightly more reddish in hue, generally had more chroma, and were less reflective than soil at all locations. Color of pelage within locations was not significantly correlated with color of soil. Among all locations, brightness of pelage and soil were significantly positively correlated. Among mainland locations, there was a significant positive …

Labeling With Nanogold And Undecagold: Techniques And Results, James F. Hainfeld

Scanning Microscopy

A significant new development in gold labeling for microscopy has been achieved through the use of gold cluster compounds that are covalently attached to antibodies or other probe molecules. These unique gold probes are smaller than most colloidal gold conjugates and exhibit improved penetration into tissues, higher labeling densities, and allow many new probes to be made with peptides, nucleic acids, lipids, drugs, and other molecules. A new fluorescent-gold conjugate is useful for examining localization by fluorescence microscopy, then visualizing the same label at the ultrastructural level in the electron microscope.

Quantitative Analyses Of Microwear And Honing On The Sloping Crest Of The P3 In Female Japanese Monkeys (Macaca Fuscata), Teruyuki Hojo

Scanning Microscopy

Female wild Japanese monkeys (Macaca fuscata), as with all male cercopithecoids, use the mesiobuccal surfaces or the elongated crests of the mandibular third premolars (P3s), as cutting blocks that wear against edges of maxillary canines during threat manifestation or food-eating. In other words, the crests of their P3s are honed with the maxillary canines. The crests become sloped during growth and more heavily striated with the advance of age. The number, directions, lengths, and widths of these striations have been analyzed quantitatively using scanning electron microscopy (SEM). Two samples showed two distinct types of parallel striations, one longer and thicker …

The Neonatal Chinchilla Cochlea: Morphological And Functional Study, R. V. Harrison, J. R. Cullen, S. Takeno, R. J. Mount

Scanning Microscopy

The developmental time scale of the cochlea varies from species to species. We investigate here the condition of the neonatal cochlea in the chinchilla, a species increasingly used in auditory research. We have examined the morphology of cochlear hair cells using scanning microscopy, and the development of auditory function during the first postnatal month by monitoring auditory brainstem evoked responses (ABR). We find that although there were some outer hair cell kinocilia present in middle and apical areas, the hair cells otherwise were mature at 24 hours after birth. Furthermore, cochlear auditory thresholds are adult-like at birth. However, whilst there …

Cytoskeletal Changes During Radiation-Induced Neoplastic Transformation Of Human Prostate Epithelial Cells, S. C. Prasad, P. J. Thraves, J. S. Rhim, M. R. Kuettel

Scanning Microscopy

We recently reported tumorigenic transformation of SV 40-immortalized neonatal human prostate epithelial cells (267Bl) by exposure to fractionated doses of X-rays. Altered morphology and anchorage independence were observed following two successive fractions of 2 Gy each (F3-SAC). Additional 2 Gy treatments to these non-tumorigenic cells to a total dose of 30 Gy resulted in radiation-transformed tumorigenic colonies (267Bl-SXR). Malignant transformation of parental 267B 1 cells was also achieved by consecutive 2 Gy exposures to a total dose of 30 Gy (267Bl-XR). This study discusses the cytoskeletal changes in the F3-SAC, 267Bl-XR and 267Bl-SXR derivatives of these human prostate epithelial cells. …

Advanced Instrumentation And Methodology Related To Cryoultramicrotomy: A Review, H. Sitte

Scanning Microscopy

This review is concerned with the considerable progress in the field of cryo-ultramicrotomy (cryofixation, cryosectioning, investigation and analysis of cryosections) during recent years. This progress includes both more efficient instrumentation and methodology. The article is mainly directed to the investigation and analysis of frozen-hydrated sections in the low dose cryo-transmission electron microscopy (TEM) and cryo-energy filtered TEM (EFTEM). A general survey is followed by an evaluation of the different relevant procedures. Both cryo-ultramicrotomy for macromolecular cytochemistry (Tokuyasu technique) and cryo-ultramicrotomy for element analysis are only shortly mentioned without discussion of the chemical and analytical approach. Because of lack of first …

Evaluation Of A Rapid-Screening Toxicity Test Using The Ciliate, Colpoda Inflata (Stokes): Sensitivity And Bioavailability To Model Compounds, Daria Galina Mochan

Dissertations and Theses

Standard toxicity tests often require high costs for maintaining healthy cultures, so few test species are employed in routine ecotoxicological analysis. An alternative is the "battery of tests" approach involving using rapid toxicity tests for screening. Rapid-screening toxicity tests must display organism sensitivity, similarity in responses to other test organisms, relevancy to many circumstances, and repeatability. Protozoa are ideal candidates for rapid-screening bioassays. They are cosmopolitan, play important roles in ecosystems, and have high reproductive rates. Many protozoa can form a resting stage (cyst) that remains viable during adverse conditions, eliminating the need for maintaining continuous cultures for testing.

The …

Thermal Preference Of Spring And Fall Chinook Salmon (Oncorhynchus Tshawytscha) During Smoltification, Sally T. Sauter

Dissertations and Theses

Innate species-specific temperature preferences of fish are subjected to fluctuations under a variety of environmental, physiological, and developmental conditions. The temperature preference patterns of two ecologically distinct races of chinook salmon (Oncorhynchus tshawytscha) were investigated as laboratory held animals underwent smoltification. Smoltification is a distinct developmental stage in the life history of anadromous salmonids when juvenile fish undergo profound behavioral, morphological, and physiological differentiation prepatory to seawater entry. A group of spring and fall chinook salmon were held under identical conditions of increasing water temperature over the course of smoltification. Another group of spring and fall chinook salmon were held …

Mutations In Two Ku Homologs Define A Dna End-Joining Repair Pathway In Saccharomyces Cerevisiae, George Todd Milne, Shengfang Jin, Katie Shannon, David T. Weaver

Biological Sciences Faculty Research & Creative Works

DNA double-strand break (DSB) repair in mammalian cells is dependent on the Ku DNA binding protein complex. However, the mechanism of Ku-mediated repair is not understood. We discovered a Saccharomyces cerevisiae gene (KU80) that is structurally similar to the 80-kDa mammalian Ku subunit. Ku80 associates with the product of the HDF1 gene, forming the major DNA end-binding complex of yeast cells. DNA end binding was absent in ku80Δ, hdf1Δ, or ku80Δ hdf1Δ strains. Antisera specific for epitope tags on Ku80 and Hdf1 were used in supershift and immunodepletion experiments to show that both proteins …

A Protocol For Ecosystem Management, Jack A. Stanford, G. C. Poole

Biological Sciences Faculty Publications

No abstract provided.

The Flora And Ecology Of Seidman Park, Kent County, Michigan, Pamela J. Laureto

Masters Theses

A floristic study of Seidman Park, Kent County, Michigan was performed. The study identified 521 vascular plants belonging to 96 families and 284 genera. The plant communities of Seidman Park were delimited by identification of dominant species and observation of the physical environment. It was believed that communities existed within the upland forest that could not be identified by observation alone. The use of Non-Metric Multidimensional Scaling (NMS) ordination techniques identified three communities within the upland forest. These were a xeric community, a dry-mesic community and a nutrient-rich community. Three sub-communities of the dry-mesic community were also identified.

The Effects Of 2,4-Dichlorophenoxyacetic Acid On The Diazotrophic Soil Microbial Community, Denise M. Brown

Master's Theses

This study measures the effects of 2,4- dichlorophenoxyacetic acid (2,4-D) on growth and nitrogen fixation capabilities of the native microbial soil community during eight field trials conducted over an eight month period. After application of 2,4-D, soil samples were analyzed for enumeration of diazotrophic and general microbial communities, and for nitrogenase activity as measured by the acetylene reduction assay (ARA). Statistical analyses were conducted using Minitab. Results show that 2,4-D significantly stimulated growth of diazotrophic microbes in 87.5% of the trials and was found to have a stimulatory growth effect on the general microbes in 62.5% of the trials. A …

The Effect Of Thyroid Hormone On The Expression Of A7 Myosin Heavy Chain Mrna In Xenopus Laevis, Bradley Thomas Butkovich

Master's Theses

It has long been known that thyroid hormone (TH) is responsible for metamorphosis in tadpoles. It is also known that A7 MHC, an adult muscle isoform, is expressed in adult Xenopus laevis frogs, but not in larvae. Furthermore, the appearance of A7 corresponds with the onset of metamorphosis. The present study investigated the relationship between TH and the expression of A7 MHC mRNA in Xenopus laevis. Isolated tails in culture and 6-n-propyl 2-thiouracil (PTU) treated tails were treated with TH and the presence of A7 mRNA analyzed with in-situ hybridization, and RT-PCR. It was found that TH caused substantial …

Osteology, Morphology, And Female Choice In Species Of The Genus Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro Barrella

Master's Theses

Relationships among the species of the annual fish Cynolebias are unclear. An analysis of the utility of different osteological and morphological characters for phylogenetic analyses was done using clear and double stained specimens and measurements of morphometric parameters respectively. Scanning electron microscopy was used to study the morphology of the egg chorion. Female choice tests were also conducted to test male traits that may be preferred by females. The osteological analysis showed that some characters previously unreported may be phylogenetically useful. Head scalation patterns were found to be intraspecifically variable, making them inappropriate to use in systematics. Each morphometric parameter …

Feasibility Of Stocking Grass Carp (Ctenopharyngodon Idella; Cyprinidae) To Control Hydrilla (Hydrilla Verticillata; Hydrocharitaceae) In Lake Anna, Virginia, Paul Matthew Overton

Master's Theses

The goal of this study was to demonstrate the feasibility of using triploid ·Ctenopharvngodon idella (grass carp) to control Hydrilla verticillata in the Waste Heat Treatment Facility (WHTF) in Lake Anna, Virginia. The four objectives were to determine: the frequency of occurrences of grass carp over hydrilla; the proportions of hydrilla to other aquatic macrophytes in the guts of grass carp; effects of physical and chemical factors on movement of grass carp; and a theoretical stocking rate of grass carp for the WHTF. Frequency of occurrence of grass carp over hydrilla was calculated to be 84% and correlated with impoundment …