Digital Commons Network^™

Development Of Ocular Inserts For Cattle, R. T. Greer, J. P. Ryoo

Scanning Microscopy

Ring shaped ocular inserts have been developed to administer a therapeutic level of tylosin tartrate throughout a five day period to treat pinkeye in cattle. The inserts are based on polyvinyl chloride rings which are dip coated with a copolymer containing the antibiotic (tylosin tartrate). Scanning electron microscope (SEM) characterization of surfaces has been of value to evaluate the presence and extent of surface flaws in the hydrogel coating, and to contribute to improvement in fabrication of the rings to insure the establishment of satisfactory seals at joints, uniformity of microporosity and cross sections, and the absence of significant cracking …

A Scanning Electron Microscopy Study Of Human Spleen: Relationship Between The Microcirculation And Functions, Makoto Kashimura, Tsuneo Fujita

Scanning Microscopy

This paper reviews scanning electron microscope (SEM) observation of the circulatory system of the human spleen, based on our findings on freeze-cracked surfaces and vascular casts of the spleen.

Central arteries ran straight in the white pulp without branching out follicular arteries and became penicillar arteries in the red pulp. Some penicillar arteries returned to the marginal zone. Some of their branches ended by opening there, whereas others passed through the marginal zone, entered the white pulp and became follicular arteries. Some of them took the shape of an "arteriolar-capillary bundle". Most of the follicular capillaries ended opening into the …

A Comparative Study On In Vitro Invasion Rates By Melanoma Cells In The Human Amniotic Basement Membrane Model Versus In Vivo Tumor Nodule Formation In C57bl6 Mice, B. Persky, G. W. Chmielewski

Scanning Microscopy

Invasion by murine B16-F10 melanoma cells was studied using the human amniotic basement membrane (HABM) assay. B16-F10 cells were collected after a single passage through the amnion and grown to near confluency. The cycle of plating, passaging, collecting, and culturing B16-F10 cells was repeated five times. The invasion rate for B16-F10 cells remained relatively unchanged after six passages through the amnion. Injection of first-passage B16-F10 cells into C57BL6 mice resulted in 29 lung tumors per animal whereas sixth-passage cells resulted in 300+ lung tumors. While there exists no correlation of the number of cells penetrating the amnion with colonization number, …

The Cytotoxic Effects Of Trimethylpentane On Rat Renal Tissue, William N. Norton, David R. Mattie

Scanning Microscopy

The primary objective of the investigation was to determine the acute cytopathologic effects of 2,3,4 -trimethylpentane, a major constituent of gasoline, on renal tissue of the mature male rat. Three groups of 9 Fischer-344 rats each were administered trimethylpentane by gavage twice weekly for 7, 14, or 28 days at a concentration of 1.5 ml/kg body weight. The tissues were fixed by perfusion, and subsequently processed for scanning and transmission electron microscopy. Al though the manifestations of hydrocarbon toxicity were evident in all experimental tissues examined, the extent and magnitude of cellular lesions increased as the exposure period progressed. The …

Exploring Folk Art, Michael Owen Jones

All USU Press Publications

Jones explores the human impulse to create, the necessity for having aesthetically satisfying experiences, and the craving for tradition. He also considers topics such as making chairs, remodeling houses, using and preserving soda-fountain slang, preparing and eating food, and sculpting lifelike figures out of cement.

Theoretical Study Of The Effect Of Ionospheric Return Currents On The Electron Temperature, Robert W. Schunk, Jan Josef Sojka, M. D. Bowline

All Physics Faculty Publications

An electron heat flow can occur in a partially ionized plasma in response to either an electron temperature gradient (thermal conduction) or an electron current (thermoelectric heat flow). The former process has been extensively studied, while the latter process has received relatively little attention. Therefore a time-dependent three-dimensional model of the high-latitude ionosphere was used to study the effect of field-aligned ionospheric return currents on auroral electron temperatures for different seasonal and solar cycle conditions as well as for different upper boundary heat fluxes. The results of this study lead to the following conclusions: (1) The average, large-scale, return current …

Food Microstructure

Food Structure

No abstract provided.

Insites, Winter 1987, Utah State University

inSites

Magazine of the Department of Landscape Architecture and Environmental Planning

Western Spruce Budworm, M. H. Brooks, J. J. Colbert, R. G. Mitchell, R. W. Stark

The Bark Beetles, Fuels, and Fire Bibliography

No abstract provided.

A Prototype For Quality: Bryce Canyon National Park Interpretive Prospectus, 1987, United States Department Of The Interior, National Park Service

Parks and Reserves

To ensure maximum coordination of message delivery, personal service efforts should be orchestrated as a result of annual (winter season) planning sessions involving TW Services, Bryce/Zion Trail Rides, and park personnel. Such planning should coordinate general summer season schedules, brainstorm new program ideas and service proposals, and establish procedures for monitoring and evaluation. This is also an opportunity to identify high priority messages regarding resources, events, new services, and park management pertinent in the coming season; in this manner, emphases for seasonal training are established.

Aerial Photography Comparison Of 1983 High Flow Impact To Vegetation At Eight Colorado River Beaches, Nancy J. Brian

Elusive Documents

No abstract provided.

Food Microstructure

Food Structure

No abstract provided.

Internal Porosity Of Corn Extrudate Air Cell Wall, Samuel H. Cohen, Charles A. Voyle

Food Structure

Transmission electron microscopy was used to observe structures within the air cell wall of a corn-based extrudate. Modified fixation and embedding techniques were employed to obtain optimum thin sections. Photomicrographs from these sections showed minute air cells measuring approximately 5 um or less. The size of air cells might impose a limiting factor on the infusion of particulate materials throughout the extrudate matrix.

Bear River Water Quality: Phosphorus Control And The Impacts Of Exchanging Water With Willard Reservoir, Darwin L. Sorensen, Craig Caupp, Kenneth W. Barker, Jean M. Ihnat

Reports

No abstract provided.

Influence Of Rufuging Consumers (Pikas: Ochotona Princeps) On Subalpine Meadow Vegetation, Nancy J. Huntly

Biology Faculty Publications

Talus slopes in western North America frequently are bordered by vegetation that differs in biomass, cover, height, and species composition from vegetation located farther from talus. These areas are grazed by pikas (Ochotona princess, which nest in that talus. Foraging theory predicts that pikas will produce a gradient of grazing pressure, which could produce the observed vegetational zonation. In a subalpine meadow in west-central Colorado, pikas produced the predicted gradient of grazing pressure, along which plant groups varied clinally in abundance. The effects of pikas on talus-border vegetation were tested by excluding pikas from small plots at several distances from …

Human Health Effects Assays, Ronald C. Sims, J. L. Sims, R. R. Dupont

Biological Engineering Faculty Publications

Health risk assessment of individual environmental chemicals, risks of drinking water supplies, methods for evaluating toxicity, and structure-activity relationships and response-surface methodology represent the focus for 1986. A report of the Steering Committee on Identification of Toxic and Potentially Toxic Chemicals for Consideration by the National Toxicology Pro gram found that, for the majority of substances they examined, data essential for human health hazard assessment were lacking.¹ Milestone publications concerning human health effects aspects include works by Mortelmans et al,² Busch et al,³ Hartman et al,⁴ Rein,⁵ Gentile,⁶ Hodgson,⁷ and Tagashira and Omura. …

Morphological Characterization Of Materials Using Low Voltage Scanning Electron Microscopy (Lvsem), Jesse Hefter

Scanning Microscopy

The use of lower energy (0.5 to 10 keV) electron beams in the scanning electron microscope (LVSEM) provides a number of advantages in the imaging of materials, including increased topographic contrast and reduced specimen charging. Application of LVSEM to materials analysis was difficult in the past due to a number of instrumental difficulties, including low gun brightness, the increased effect of chromatic aberration upon lower energy beams, and the increased sensitivity of such electron beams to stray fields. Improvements in design have led to commercial instruments which provide the microscopist with the capability to analyze materials in this low-energy regime. …

Applications Of Cathodoluminescence Of Quartz And Feldspar To Sedimentary Petrology, Leslie F. Ruppert

Scanning Microscopy

Cathodoluminescence (CL), the emission of visible light during electron bombardment, was first used in sandstone petrology in the mid-1960's. CL techniques are especially useful for determining the origin and source of quartz and feldspar, two of the most common constituents in elastic rocks. CL properties of both minerals are dependent on their temperature of crystallization, duration of cooling, and/or history of deformation. Detrital quartz and feldspar are typically derived from igneous and metamorphic sources and luminesce in the visible range whereas authigenic quartz and feldspar form at low temperatures and do not luminesce. Quantification of luminescent and non-luminescent quartz and …

Replica-Immunogold Technique Applied To Studies On Measles Virus Morphogenesis, W. Bohn, K. Mannweiler, H. Hohenberg, G. Rutter

Scanning Microscopy

The replica technique was applied to studies on the dynamic process of measles virus budding on infected HeLa cells. Virus structures were identified by labeling with anti-measles antibodies and protein A-gold. The combination of these two methods enabled us (1) to characterize the sequence of virus budding at the plasma membrane, (2) to localize virus structures on cytoskeletons of infected cells, and (3) to study the influence of Ca²⁺ ions on virus structures at the plasma membrane. Studies on platinum carbon surface replicas suggest that the process of virus budding is similar to the genesis of cellular microvilli. Replicas …

Low Load Vickers Hardness Measurements Of Nonconducting Materials In A Scanning Electron Microscope, H. Bangert, X. Cai, A. Wagendristel, A. Kaminitschek

Scanning Microscopy

Vickers hardness tests on microscopic small bodies, e.g., fibers, powder particles, thin layers, etc., require imprint dimensions near or even below the resolution limits of light microscopes. Hence, to detect and evaluate these miniature imprints a scanning electron microscope (SEM) has to be used. For such observations in a SEM, nonconducting samples have to be coated with a thin conductive layer. The influence of these films on the imprint size and thus on the hardness value can be rather significant. On the basis of a systematic investigation in the case of a layer much softer than the sample to be …

Nature And Properties Of Cardiovascular Deposits, B. B. Tomazic, E. S. Etz, W. E. Brown

Scanning Microscopy

Mineral deposits from human aortas and bioprosthetic devices implanted in experimental animals show close similarities in chemical composition, solubility and structural characteristics. Chemical analyses show compositions corresponding to a Na, Mg, CO₃ substituted apatitic calcium phosphate. Synergistic XRO, FT-IR and Raman Mi crop robe spectroscopic data provided coherent indication of Type-B CO₃^2- incorporation. Microscopic and electron microprobe microanalyses, however, indicate substantial morphological and spatial heterogeneity in the deposits.

Solubility and kinetic dissolution data of the mineral fraction of deposits can be compared with the corresponding data of octacalcium phosphate (OCP). This may indicate that OCP is a …

Interaction Between X-Irradiated Plateau-Phase Bone Marrow Stromal Cell Lines And Co-Cultivated Factor-Dependent Cell Lines Leading To Leukemogenesis In Vitro, E. Naparstek, P. Ankleasria, T. J. Fitzgerald, M. A. Sakakeeny, J. S. Greenberger

Scanning Microscopy

Plateau-phase mouse clonal bone marrow stromal cell lines D2XRII and C3H c1 II produce decreasing levels of M-CSF (CSF-I), a specific macrophage progenitor cell humoral regulator, following x-irradiation in vitro. The decrease did not go below 40% of control levels, even after irradiation doses of 50,000 rad (500 Gy). In contrast, a distinct humoral regulator stimulating growth of GM-CSF/IL-3 factor-dependent (FD) hematopoietic progenitor cell lines was detected following radiation to doses above 2,000 rad. This humoral factor was not detectable in conditioned medium from irradiated cells, weakly detected using factor-dependent target cell populations in agar overlay, and was prominently detected …

Scanning Electron Microscopy Of Microcorrosion Casts: Applications In Ophthalmologic Research, Peter C. Burger, David B. Chandler, Andrzeji W. Fryczkowski, Gordon K. Klintworth

Scanning Microscopy

In light of the complicated nature of the ocular vasculature, it has been difficult to define the normal ocular anatomy by reference to two-dimensional tissue sections. Since it provides three-dimensional replicas, scanning electron microscopy (SEM) of vascular corrosion casts has therefore been an invaluable addition to the study of ocular vasculature. This technique also often permits identification of a normal vessel's arterial, venous, or capillary nature by its surface features. In addition, this technique is finding increased use in defining anatomical features of human vascular disease and is especially well suited for the study of experimental neovascularization as it relates …

The Ultrastructure Of Membranes In Sympathetic Ganglia, Catarina Andersson Forsman, Lars-Gösta Elfvin

Scanning Microscopy

This review presents some recent observations made on membranes in the mammalian sympathetic ganglia after application of freeze-fracturing and histochemistry. After freeze-fracture clear differences have been found between the neuronal and the satellite cell plasmalemma. The satellite cell plasma membrane exhibits specialized intramembrane particles not found in the neuronal membrane. Freeze-fracture cytochemistry reveals a further difference between the neurons and satellite cells i.e., a higher density of 𝛃-hydroxysterols is present in the satellite cell membrane than in the neuronal membrane.

Histochemical methods to localize 5'-nucleotidase, Ca²⁺-ATPase and Na⁺/K⁺-ATPase in the membranes have been utilized. …

Chiropteran Enamel Structure, K. S. Lester, S. J. Hand

Scanning Microscopy

We have examined sectioned and whole teeth of Hipposideros diadema in order to provide a baseline description of bat enamel at electron microscope level. Intact and worn surfaces of whole teeth from representatives of all superfamilies of the suborder Microchiroptera, representatives of the suborder Megachiroptera, and the Ditjimanka fossil tooth have been surveyed.

Whole chiropteran teeth lend themselves well to non-destructive SEM examination; all except Dobsonia sp. showing evidence of prismatic structure at the outer surface. The majority of prisms in chiropteran enamel are horse-shoe shaped becoming rounded and complete only towards the outer enamel surface. Prism packing is typically …

Review Of Fossil Eggs And Their Shell Structure, Karl F. Hirsch, Mary J. Packard

Scanning Microscopy

Of the established eggshell groups (membrane-like, pliable, and rigid), the rigid eggshell group has the best chance of fossilizing. Fossils of this group, with modern-type structure, extend back into the Eocene (crocodiles, gecko) and even into the Cretaceous (birds, turtles).

Structural types which differ from modern types are found as late as the Eocene, and in the Cretaceous they are numerous. These Cretaceous eggshells have, for the most part, been assigned to dinosaurs often without consideration of other egg-laying animals of that time. Only a few eggs and eggshells have been reported from the Jurassic and older periods.

Polarizing and …

Vasospastic Phenomena On The Luminal Replica Of Rat Brain Vessels, Enrico D. F. Motti, Hans-Georg Imhof, Jesus Martinez Garza, Gazi M. Yasargil

Scanning Microscopy

Strikingly localized ring-like constrictions (other than sphincters, cushions and offshoot furrows) have appeared on the casted vessels of some of our preparations. Morphology of the phenomena reveals diverse degree of active contraction of the vessel wall, ranging from corrugation of the luminal surface to near severance of the acrylic cast. Distribution of the vasospastic phenomena reveals as particularly affected the arteries in the diameter range between 25 and 75 μm, that belong either to intra-arterial anastomoses between the branches of each of the three major cerebral arteries or to their terminal junctions in the border zones (inter-arterial anastomoses). Among the …

Early Scanning Electron Microscopic Studies Of Hard Tissue Resorption: Their Relation To Current Concepts Reviewed, A. Boyde, S. J. Jones

Scanning Microscopy

This paper highlights some observations made by the authors in SEM studies of hard tissue resorption and considers their significance in relation to current concepts. All mammalian mineralised tissues may undergo physiological resorption, the resulting surface reflecting the density of mineralisation and the organic matrix chemistry, organisation and orientation. Resorption-repair coupling may follow the resorption of any tissue, but SEM studies first noted this process in the case of the dental tissues. The difference between fetal and adult bone formation and resorption provided evidence against the concept of osteocytic osteolysis. SEM stereophotogrammetric methods for the quantitation of individual resorption lacunae …

Matrix Effects In Secondary Ion Mass Spectrometric Analysis Of Biological Tissue, Margaret S. Burns, David M. File, Vaughn Deline, Pierre Galle

Scanning Electron Microscopy

We have made several observations during the course of our studies that show the presence of matrix effects in soft biological tissue and standards. The sputtering rate of gelatin is approximately twice that of epoxy resin, but the ion yield of lithium in gelatin is an order of magnitude less than in epoxy. Osmium impregnation of freeze-dried material significantly alters the localization of calcium, but not potassium and barium. The absolute count rate for calcium in osmicated tissue is increased several-fold above that in freeze-dried tissue. Scanning electron microscopy of sputtered material shows the formation of cones during sputtering, which …

Studies Of Otoconial Development In A “Giant-Crystal” Strain Of Chicks Using Scanning Electron Microscopy, Polarized Light Microscopy, And X-Ray Crystallography, Joanne Ballarino, Howard C. Howland

Scanning Electron Microscopy

Otolith formation was studied in a mutant strain of low-fertility Delaware chicks which exhibit an otolithic defect. In all chicks of this strain, otoliths were present as a fused crystal mass which contained abnormally large (giant) otoconia. Studies of the formation of such otoliths during embryonic development revealed that from the very earliest stages the otoconia were much larger than normal, and in the saccular and utricular otoliths formed a fused mass. These results are interpreted as supporting a hypothesis of the de novo formation of giant otoconia in this giant-crystal strain as opposed to the recrystallization hypothesis proposed for …