Digital Commons Network^™

The Response Phase - The First Six Hours After Acute Airway Injury By So2 Inhalation: An In Vivo And In Vitro Study, W. C. Hulbert, S. F. P. Man, M. K. Rosychuk, G. Braybrook, J. G. Mehta

Scanning Microscopy

We have identified an airway epithelial response following acute injury that cannot be termed 'repair' or regeneration. It precedes these well characterized events and it is termed the 'response phase'. We tested the hypothesis that for the first 6 h following acute injury to the tracheal mucosa, the initial cellular events of the response phase will continue as in vivo even if the tissue is maintained in vitro in an Ussing chamber. The tracheal mucosa of anesthetized, intubated mongrel dogs was injured by the inhalation of SO₂ 500 ppm for 1 h (7 dogs); controls (3 dogs) breathed filtered, …

X-Ray Microanalysis Of Calcium Containing Organelles In Resin Embedded Tissue, G. Nicaise, I. Gillot, A. K. Julliard, E. Keicher, S. Blaineau, J. Amsellem, J. C. Meyran, M. L. Hernandez-Nicaise, B. Ciapa, C. Gleyzal

Scanning Microscopy

The localization of calcium in cell organelles at the electron microscope level is often achieved through cytochemical techniques, and verified by X-ray microanalysis. Various methods have been used to cytochemically detect calcium or calcium-binding sites : calcium loading, calcium substitution by strontium, barium, or even lead, and calcium precipitation by oxalate, phosphate, fluoride, or pyroantimonate. Their results may have heuristic value, particularly in preliminary studies of poorly known cell types. A complementary and more physiological approach is offered by quantitative measurement of the total calcium content of organelles after cryofixation.

Resin embedding is less demanding than cryomicrotomy and gives better …

Design And Applications Of In-Situ Differential Scanning Electron Microscopy, A. Sicignano, M. Vaez Iravani

Scanning Microscopy

Contrast enhancement in the scanning electron microscope (SEM) is usually achieved by either of the two techniques of black level suppression, and differential imaging. This paper is mainly concerned with the latter method. Differential imaging of SEM images is commonly accomplished by either using a selective electronic filtering circuit (time sensitive) on the video signals, or the post processing of a collected digitized image (application of special kernel operatives). A technique is described that is capable of generating true in-situ SEM differential video signals of local sample features. Characteristics of this method are enhanced sample feature-boundary sensitivity, suppression of large …

Mechanism Of Hydrolysis Of Octacalcium Phosphate, B. B. Tomazic, M. S. Tung, T. M. Gregory, W. E. Brown

Scanning Microscopy

The chemical and structural properties of hydrolyzed octacalcium phosphate (OCP) appear to be of high relevance to tooth, bone and pathological bioapatites. Hydrolysis of synthetic well-crystallized OCP was studied at constant pH by using the pH stat method over the 6.1 to 8.6 range at 50°C and to a lesser extent at 37°C. Hydrolytic transformation proceeds according to thermodynamic requirements except for some retardation at the highest pH value as a consequence of decreased solubility of OCP which may be rate determining. The product of hydrolysis, OCP-hydrolyzate (OCPH), was characterized by chemical analysis, scanning electron microscopy, x-ray diffraction, electron microprobe …

Sodium Lauryl Sulfate Enhances Nickel Penetration Through Guinea-Pig Skin. Studies With Energy Dispersive X-Ray Microanalysis, Magnus Lindberg, Samuel Sagström, Godfried M. Roomans, Bo Forslind

Scanning Microscopy

The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis ( EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na. Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX …

A Report On Marron Fishing In Western Australia., Doug Wenn

Fisheries Management Papers

The marroning experience is one enjoyed by many Western Australians. A rapid increase in fishing effort evidenced by the increase in number of recreational fishing licences issued, combined with low rainfall in the last few years resulted in a dramatic reduction of marron catch rates during 1986/87. In view of the state of marron stocks, the Minister for Fisheries considered it appropriate to close the 1987/88 marron season.

Methylation Of Replicating And Nonreplicating Dna In The Ciliate Tetrahymena Thermophila, Gail Singer Harrison, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

Methylation of adenine in replicating and nonreplicating DNA of the ciliate Tetrahymena thermophila was examined. In growing cells, 87% of the methylation occurred on the newly replicated daughter strand, but methylation was also detectable on the parental strand. Methylation of nonreplicating DNA from starved cells was demonstrated.

Scanning Electron Microscope And X-Ray Diffraction Investigations Of Mudrock Fabrics, Textures And Mineralogy, J. M. Huggett

Scanning Microscopy

Mudstones from a broad range of depositional environments have been investigated to determine whether fabric, texture or mineralogy may (1) be used to identify the environment of deposition and (2) be correlated with poroperm. The diversity of fabrics and textures reflects features of the detrital mudstone composition, compaction and diagenesis, rather than environment of deposition. Preferred orientation has been disturbed by bioturbation and growth of post-compactional authigenic minerals; these factors have reduced to nil any correlation which may have existed between fabric, measured as the illite orientation ratio (O/R) and environment of deposition.

It is mineralogy rather than fabric or …

Preparation Of Dipteran Larvae For Scanning Electron Microscopy With Special Reference To Myiasigen Dipteran Species, I. Ruiz-Martinez, M. D. Soler-Cruz, R. Benitez-Rodriguez, M. Diaz Lopez, J. M. Perez-Jimenez

Scanning Microscopy

Although controversy exists concerning the role of chemical fixatives in scanning electron microscopy (SEM) studies of Dipteran larvae, we have observed that filtered 10% formaldehyde solution gives excellent results as a preservative. After immersing in vivo in formaldehyde, the larvae material is preserved for prolonged periods (up to 8 months), before examination with SEM. As a fixative, formaldehyde preserves the structure of the larval cuticle and produces no visible artifacts. Moreover, postfixation is not necessary.

Due to pecularities of the way of life of Wohlfahrtia magnifica (principally the accumulations of necrotic tissue, purulent particles, and other types of substances that …

The Vascular System Of Xenotransplanted Tumors -Scanning Electron And Light Microscopic Studies-, M. A. Konerding, F. Steinberg, V. Budach

Scanning Microscopy

A widely used model for investigating basic tumor characteristics and different treatment modalities preclinically is the immune-deficient, athymic nude mouse. This model offers many morphological parallelisms to the clinical situation.

The aim of this study is to demonstrate the vascularization pattern of xenotransplanted human melanomas and sarcomas using different methods. Xenotransplanted tumors of 62 congenital thymusaplastic nude mice were examined ultrastructurally and topographically after corrosion cast and tissue preparation. Quantitative measurements of tumors injected with India ink were carried out to obtain comparable information on the vascular densities in the tumors.

Quantitative measurements showed that there is no zonal, topographic …

Altered Fungal Morphogenesis During Early Stages Of Ectomycorrhiza Formation In Eucalyptus Pilularis, P. F. Jacobs, R. L. Peterson, H. B. Massicotte

Scanning Microscopy

Scanning electron microscopy (SEM) of Eucalyptus pilularis roots inoculated with Pisolithus tinctorius, under controlled conditions, revealed altered morphogenesis of fungal hyphae in contact with the root surface. These changes occurred prior to the formation of a full fungal mantle and resulted in the formation of a compact fungal layer as a consequence of fusion of proliferating, branching hyphae. Although similar growth patterns have been observed in the inner mantle of fully developed ectomycorrhizae using contrast interference microscopy, this is the first time this feature has been observed during early mantle formation using SEM. Changes in fungal morphology during early …

Quantitative Microanalysis Of Nitrogen Distribution In Carpospores Of Gracilaria Secundata With Scanning Auger Microscopy, Åke Lignell, Rein Kalm, Godfried M. Roomans, Angelica Von Hofsten, Olof Vingsbo

Scanning Microscopy

Quantitative microanalysis has been performed with a JAMP 10 Scanning Auger Microscope at 0.5 μm spot size, on carpospores of Gracilaria secundata Harv.. Samples were fixed in glutaraldehyde and osmium tetroxide and embedded in plastic material. Thin sections were placed on solid copper discs. the surfaces of which had been smoothed by electropolishing.

Quantification of the nitrogen content was performed using a standard with known content of nitrogen.

Nitrogen was localized in the nucleus, chloroplasts and osmiophilic inclusions of the carpospore. Trace amounts of nitrogen were also found in cell walls, starch grains and in the embedding material.

The use …

Ultrastructural Variation In Enamel Of Australian Marsupials, C. F. Gilkeson, K. S. Lester

Scanning Microscopy

This paper initiates a survey of the enamel of fossil and extant Australian marsupials by scanning electron microscopy. Enamel was examined from 17 extant and 11 extinct marsupials. Assessment was made of prism packing pattern, prism course, tubule presence, tubule size and distribution. Values calculated were: prism diameter; prism axis ratio; cross-sectional prism area; cross-sectional ameloblast area; and numerical prism density.

Three different prism packing arrangements were found for extant and fossil marsupials within the classical Pattern 2. The Pattern 1 arrangement found in three extant species was relatively unexpected given the general acceptance of Marsupialia as having Pattern 2 …

Surface Studies Of Calcium Oxalate Dihydrate Single Crystals During Dissolution In The Presence Of Stone-Formers' Urine, M. Akbarieh, R. Tawashi

Scanning Microscopy

Dissolution of calcium oxalate dihydrate (COD) single crystals was studied at different pH levels and in different dilutions of stone formers' (SF) urine. The Fourier descriptors of the contour were determined during dissolution of COD using a quantitative morphological technique. The surface ruggedness of COD single crystals was determined from fractal analysis. The results obtained were compared with COD single crystals behavior in different dilutions of normal urine previously reported. The shape parameters and surface geometry of the dissolving COD crystals were significantly different in normal and SF urine. The data suggest that the shape descriptors and fractal geometry is …

Dentin: A Dynamic Substrate - A Review, David H. Pashley

Scanning Microscopy

The structure of dentin is unusual in that the number and size of its tubules changes as one moves from the periphery toward the pulp chamber. Near the pulp, the tubules are very close together and the water con tent of this deep dentin is high. Near the enamel, the tubules are far apart, occupying less than 1% of the surface area. When enamel or dentin is cut, the surface becomes covered by an adherent layer of cutting debris called the smear layer. Its composition presumably reflects the composition of the underlying dentin. It is only about 1 μm thick …

Scanning Optical Microscopy Of Semiconductor Materials And Devices, C. J. R. Sheppard

Scanning Microscopy

In the scanning optical microscope a focused light spot is used to illuminate the object and some property monitored as the spot is scanned relative to the object to build up an image. By monitoring different properties it is thus possible to use the scanning optical microscope in a wide range of imaging modes, which can be used to give much information concerning the structure and properties of semiconductor materials and devices. In the optical-beam induced current method the focused light spot generates electronic carriers in a semiconductor specimen, and the resultant current monitored. The technique can be used to …

Vascular "Sphincter" And Microangioarchitecture In The Central Nervous System: Constriction Of Intraparenchymal Blood Vessels Following A Treatment Of Vasoconstrictive Neurotransmitter, K. Nakai, Y. Naka, H. Yokote, T. Ikatura, H. Imai, N. Komai, T. Maeda

Scanning Microscopy

The site of action of neuropeptide Y (NPY), a potent vasoconstrictive neurotransmitter, on the intraparenchymal blood vessels in the rat parietal cortex was demonstrated using a corrosion cast technique with scanning electron microscopy. Our observations were confined to the cortical area where the regional cerebral blood flow (rCBF) had been reduced significantly by in situ application of NPY. A striking finding in that area was the diffuse narrowing of the perforating arteries in the upper cortical layers. Ring-like compressions on the corrosion casts, presumably formed by active vascular sphincters along the arteries, capillaries and venules within the brain parenchyma, seemed …

Patterns Of Species Co-Occurrence In The Antillean Bat Fauna, Donald A. Mcfarlane

WM Keck Science Faculty Papers

The bat fauna of 25 Antillean islands is presented as a species presence-absence matrix, and used to construct a large population of randomized null-model matrices by Monte-Carlo simulation techniques. Comparison of the observed data matrix with the randomized population reveals a statistically significant departure from randomness which is interpreted as evidence of community structure. The Antillean bat fauna is marked by a pattern of high species co-occurrence, with endemics dominating in the northern Antilles and undifferentiated South American taxa dominating in the southern Antilles. The 'checkerboard' distributions which have been identified in the bird populations of some tropical archipelagos are …

The Distribution Of Minnesota Fishes And Late Pleistocene Glaciation, James C. Underhill

Journal of the Minnesota Academy of Science

No abstract provided.

The Genera Of Commelinaceae In The Southeastern United States, Gordon C. Tucker

Faculty Research & Creative Activity

No abstract provided.

Historical Biogeography: Geography As Evolution, Evolution As Geography, Charles H. Smith

DLPS Faculty Publications

Despite a number of advances in recent years, biogeography remains a field with a poorly developed philosophical core. As a result, its historical and ecological sides remain as isolated from one another as ever. In this essay I argue that a more unified approach to biogeographic studies will become possible only when workers realise that it is necessary to reject absolute space, "geography as handmaiden" approaches to distribution problems in favour of structuralist models compatible with both probabilistic spatial interaction and deterministic phylogenetic kinds of thinking. Pros and cons of regionalist, vicariance, and panbiogeographic approaches are weighed in this regard; …

Ultrastructure Of The Early Stages Of Infection Of Peanut Leaves By The Rust Fungus Puccinia Srachidis [Abstract], C. W. Mims, Josephine Taylor, E. A. Richardson

Faculty Publications

No abstract provided.

Genetic Variability Within And Among Wintering Populations Of Brant, James M. Novak, L. M. Smith, L. D. Vangilder

Faculty Research & Creative Activity

No abstract provided.

The Genera Of Commelinaceae In The Southeastern United States, Gordon Tucker

Faculty Research & Creative Activity

No abstract provided.

Plant Photosensitizers: A Survey Of Their Occurrence In Arid And Semiarid Plants From North America, Kelsey R. Downum, Sergio Villegas, Eloy Rodriguez, David J. Keil

Biological Sciences

No abstract provided.

Wolves: A Bibliography And Guide To The Literature, 1968-1987 [Pdf Version], Michael Knee

University Libraries Faculty Scholarship

The purpose of this bibliography is to provide comprehensive, worldwide coverage of the scientific literature about wolves for the years 1968 through 1987. The bibliography does not contain references published after 1987. It updates the bibliographies appearing in S. P. Young and E. A. Goldman's 1944 classic work, The wolves of North America (American Wildlife Institute, Washington) and L. D. Mech's The wolf: The ecology and behavior of an endangered species [see entry 1.030] as well as B. Fodor's The wolf in southeastern United States: A bibliography [see entry 7.009].

The Prey Of Common Barn Owls (Tyto Alba) In Dry Limestone Scrub Forest Of Southern Jamaica, Donald A. Mcfarlane, Kimball L. Garrett

WM Keck Science Faculty Papers

A collection of common barn-owl (Tyto alba Scopoli) pellets from caves on the Portland Ridge of Jamaica reveals that whereas introduced rodents constitute approximately 90% of the total prey, bats and birds are also frequent prey items. Of the bats, frugivorous species predominate with Ariteus flavescens Gray and Artibeus jamaicensis Leach accounting for the largest portion of the bat prey. Insectivorous bats are markedly under-represented with respect to the known diversity of insectivorous species in the habitat.

Field Notes, Joseph A. Cook

Division of Mammals - Field Notes and Catalogs

No abstract provided.

Feeding By A “Nonfeeding” Larva: Uptake Of Dissolved Amino Acids From Seawater By Licithotrophic Larvae Of The Gastropod Haliotis Refescens, William Jaeckle

Scholarship

No abstract provided.

Sex Change And Population Fluctuations In Pandalid Shrimp, Paul Anderson, Eric Charnov

Biology Faculty & Staff Publications

No abstract provided.