Biology Commons^™

Drosophila Has A Single Copy Of The Gene Encoding A Highly Conserved Histone H2a Variant Of The H2a.F/Z Type, Angela Van Daal, E White, M Gorovsky, Sarah C.R. Elgin

Biology Faculty Publications & Presentations

The Tetrahymena histone H2A variant designated hv1 is localized exclusively in the transcriptionally active macronucleus and is absent from the quiescent micronucleus (1). A cDNA clone of the hv1 gene (2) was used to screen a Drosophila cDNA library. A cross-hybridizing clone was recovered and shown by sequence analysis to code for a protein homologous to hv1 as well as to the chicken H2A variant, H2A.F (3), the sea urchin H2A variant, H2A.F/Z (4) and the mammalian H2A variant H2A.Z (5). Southern analysis of Drosophila genomic DNA indicates that the H2AvD (H2A variant Drosophila) gene is present in one copy. …

Ultrastructural And Functional Effects Of Lipopolysaccharide And Interleukin-2 On Human Nk Cells, Yuan-Hsu Kang, Mitchell Carl, Lorrita P. Watson

Scanning Microscopy

Bacterial endotoxin (lipopolysaccharide, LPS) and interleukin-2 (IL-2) are known to stimulate NK cell mediated cytotoxicity against tumor cells. In the present report we sought to correlate the stimulatory effect of LPS and IL-2 on NK cell activity with ultrastructural changes which occurred as a result of such stimulation. Peripheral blood mononuclear cells (PBMC) were purified from healthy donors by a Ficoll-Hypaque density gradient technique. Leu-11a⁺ NK cells were isolated by flow microfluorometry using a monoclonal FITC conjugated anti-Leu-11a antibody and a FACS II cell sorter. The PBMC were incubated, respectively, with E. coli LPS or recombinant IL-2 (IL-2) for …

Crystal Associated Diseases: Role Of Scanning Electron Microscopy In Diagnosis, K. P. H. Pritzker, P. -T. Cheng, M. D. Grynpas, D. P. Holmyard

Scanning Microscopy

As crystals are important etiologic agents for disease, their accurate identification in tissues and body fluids is of utmost importance. This paper surveys the roles of crystals in disease process and outlines current analytical techniques for crystal detection and identification in bone tissues. The value of multiple correlated techniques is demonstrated including scanning electron microscopy, x-ray energy spectroscopy and powder diffraction analysis. The current feasibility of utilizing intermediate voltage scanning transmission analytical electron microscopy to integrate these analytical techniques on the same tissue sample is emphasized.

Clinical Applications Of Electron Microscopy In The Analysis Of Collagenous Biomaterials, Arthur J. Wasserman, Charles J. Doillon, Alvin I. Glasgold, Y. Pedro Kato, David Christiansen, Azam Rizvi, Eric Wong, Jack Goldstein, Frederick H. Silver

Scanning Microscopy

Scanning and transmission electron microscopy are of clinical value in assessing the interaction between biomaterials and ingrowing tissues. Ultrastructural information allows the clinician and biomaterials specialist to determine events occurring during wound healing and the biocompatibility of prosthetic devices. This paper reviews some of the experimental and clinical studies done in our laboratory on the use of natural and reconstituted collagen as replacements for connective tissues. Consideration is given to collagen flakes used for the treatment of dermal ulcers, a collagen fiber prosthesis used for tendon and ligament replacement, the effects of chemical preservatives on cartilage used for replacement of …

Scanning Tunneling Microscopy Methods For Spectroscopic Imaging Of Subsurface Interfaces, L. D. Bell, W. J. Kaiser

Scanning Microscopy

A new method for spatially-resolved, spectroscopic investigation of subsurface interface structure has been developed. The method, Ballistic Electron Emission Microscopy (BEEM), is based on Scanning Tunneling Microscopy (STM) techniques. BEEM combines STM vacuum tunneling with unique ballistic electron spectroscopy capabilities. BEEM enables, for the first time, direct imaging of subsurface interface electronic properties with nanometer spatial resolution. STM topographic images of surface structure and BEEM images of subsurface properties are obtained simultaneously. BEEM capabilities are demonstrated by investigation of important metal-semiconductor interfaces.

Effect Of Fluoride And Cobalt On Forming Enamel: Scanning Electron Microscope And X-Ray Microanalysis Study, S. H. Ashrafi, D. R. Eisenmann, A. E. Zaki, R. Liss

Scanning Microscopy

The forming surfaces of enamel of rat incisors were examined by scanning electron microscope one hour after injection of either 5 mg/100 g body weight of sodium fluoride or 12 mg/100 g body weight of cobalt chloride. The cell debris from the surfaces of the separated incisors was either gently wiped off with soft facial tissues or chemically removed by treating with NaOH, NaOCl or trypsin. Best results to remove cell debris were obtained from 0.25% trypsin treatment.

SEM studies revealed that the surface of the normal secretory enamel was characteristic in appearance with well-developed smooth prism outlines. In fluoride …

Double-Axis Rotary Shadowing For High-Resolution Scanning Electron Microscopy, R. Hermann, J. Pawley, T. Nagatani, M. Müller

Scanning Microscopy

Thin continuous metal coatings and a scanning electron microscope-generated spot size in the range of the visualized particles, are necessary prerequisites if one hopes to extract high-resolution topographic information in the scanning electron microscope. Chemical fixation and dehydration in organic solvents at room temperature lead to severe ultrastructural artifacts which can be avoided by cryofixation and freeze-drying of the specimen. 0.9 to 2.7 nm thick homogeneous layers of chromium and germanium can be deposited onto the surface of cryofixed and freeze-dried specimens at high sub-zero temperatures by electron beam evaporation using "double-axis rotary shadowing". Theoretical calculations of the layer geometry …

Detectors For Quantitative Electron Beam Voltage Measurements, A. R. Dinnis

Scanning Microscopy

Qualitative voltage contrast is produced without difficulty in any SEM. Complete separation of the voltage contrast from other sources of contrast is not a straightforward matter because of the nonlinear relations between the phenomena causing contrast and the video signal.

Quantitative measurements depend on the availability of electron energy analysers which can detect accurately the shift in secondary electron energies due to potentials appearing on integrated circuit tracks, without being affected by transverse fields due to potentials on other conductors or insulators. The principles underlying existing detectors are explained, their effectiveness assessed, and a new form of electron detector is …

Signal Of Backscattered Electrons From Multiple Marks In Dependence On Mark Profile, D. Kaczmarek, Z. Czyżewski

Scanning Microscopy

The backscattered electron signal can be detected using a solid state detector system. Because this signal is affected by the surface topography it is necessary to determine the optimal detection condition for a registration mark detection in the electron-beam lithography and for an automatic topographical surface reconstruction.

The BSE signal from surface marks has been measured using semiconductor detectors with a small collection angle. Calculations of the BSE signal have been carried out by means of a simplified model of electron backscattering. The signal shape depends on some parameters of the mark profile, such as length, height and inclination angle …

Contribution Of Densely Distributed Electron Beam Induced Current Contrasts In Annealed Cz Silicon To Bulk Recombination, M. Kittler, W. Seifert

Scanning Microscopy

The paper presents a detailed analysis of Electron Beam Induced Current (EBIC) diffusion-length and contrast data for samples containing defect accumulations. The formulae given allow one to estimate to which extent the average diffusion length is determined by recombination-active defects showing EBIC contrast.

This analysis may be used to identify essential sources of bulk recombination in annealed silicon. In the light of our results stacking faults are an essential source of bulk recombination in intrinsically gettered p-type Cz silicon.

Mounting Materials For Automated Image Analysis Of Coals Using Backscattered Electron Imaging, W. E. Straszheim, K. A. Younkin, R. T. Greer, R. Markuszewski

Scanning Microscopy

In order to apply SEM-based automated image analysis (AIA) to the characterization of not only minerals in coal but to the coal itself, sample preparation methods need to be developed beyond common practice. A significant consideration is the degree of contrast achievable between the mount media chosen and the coal. Four low-atomic number materials (epoxy, polyethylene, polystyrene and carnauba wax) were compared for their potential as suitable mounting media for coal samples. Epoxy is satisfactory only for characterization of mineral particles since the contrast between epoxy and coal particles is negligible. Polyethylene or polystyrene have marginal application for use as …

The Use Of Backscattered Electron Imaging, X-Ray Microanalysis And X-Ray Microscopy In Demonstrating Physiological Cell Death, I. D. Bowen, N. A. Worrill, C. A. Winters, K. Mullarkey

Scanning Microscopy

The cytochemical localization of enzymatic activity by means of backscattered electron imaging (BEi) is reviewed and the application of BEI to changes in acid phosphatase and ATPase distribution during physiological (programmed) cell death in Heliothis midgut is explored. Programmed cell death entails the release of nascent free acid phosphatase as extracisternal hydrolase. This shift can readily be detected by means of the atomic number contrast imparted by BEI of the lead phosphatase reaction product, thus enabling the distribution of dying cells to be mapped. BEI is particularly useful in this context as it allows the examination of bulk specimens at …

Scanning Electron Microscopic Autoradiography Of Lung, K. E. Lauhala, C. L. Sanders, K. E. Mcdonald

Scanning Microscopy

Scanning electron microscopic (SEM) autoradiography of the lung is being used to determine the distribution of inhaled, alpha particle-emitting, plutonium dioxide particles. SEM autoradiography provides high visual impact views of alpha activity. Particles irradiating the bronchiolar epithelium were detected both on the bronchiolar surface and in peribronchiolar alveoli. The technique is being used to obtain quantitative data on the clearance rates of plutonium particles from bronchi and bronchioles.

The Influence Of Analyser Geometry Effects In Scanning Electron Microscope Voltage Contrast Measurements, Daniel S.H. Chan, Teck Seng Low, Wai Kin Chim, Jacob C. H. Phang

Scanning Microscopy

A computer simulation model used to study specimen dependent and analyser geometry dependent effects is described in this paper. With this model, the influence of the specimen dependent effect on quantitative voltage contrast measurements can be isolated from the analyser geometry dependent effect. Linearization error voltages in quantitative voltage contrast measurements arising from the individual influences of the specimen dependent and analyser geometry dependent effects are presented. The results show that the error component due to very narrow analysers dominate the total linearization error. The same situation arises when the voltage measurement point on the specimen is very near to …

Secondary Ion Mass Spectrometry Studies Of Isotope Effect In Diffusion, U. Södervall, H. Odelius, A. R. E. Lodding

Scanning Microscopy

The mass effect of diffusion is of interest in connection with interactions between defects and impurities and with the mechanisms of atomic displacements in the condensed states. The delineation entails the precise measurement of the isotope ratio as function of tracer concentration, varying within several orders of magnitude along the diffusion profile. The measurement by SIMS (secondary ion mass spectrometry), using stable isotopes, has proved to possess advantages compared to familiar techniques with radiotracers. However, the aims require the utmost counting economy and optimal precision available in SIMS, including the control of the mass fractionation and of some features peculiar …

An Electron Microscopic Study Of Hemopoietic Tissues In The Course Of Lewis Lung Carcinoma, Cheryl Hardy, Yuzhi Wang, Bettye Collier, Mehdi Tavassoli

Scanning Microscopy

Lewis lung carcinoma of C57Bl/6 mice causes a progressive anemia with reticulocytosis and splenomegaly, metastasizes to lungs, liver, and kidneys but does not invade hemopoietic tissues. The cause of this anemia is uncertain. We studied the structure of spleen and bone marrow in these tumor hosts by light and electron microscopy. Splenic congestion of the red pulp with numerous erythropoietic islands and marrow hyperplasia characterized the hemopoietic tissues of these mice, which, when coupled with other hematological parameters suggested a hemolytic condition. However, the erythropoietic response appeared to be in part ineffective as evidenced by phagocytosis of immature as well …

Kinematics And Estimated Thrust Production Of Swimming Harp And Ringed Seals, Frank E. Fish, S Innes, K Ronald

Frank E. Fish

No abstract provided.

Radar And Visual Observations Of Autumnal (Southward) Shorebird Migration On Guam, Timothy C. Williams , '64, J. M. Williams

Biology Faculty Works

Several species of shorebirds migrate between eastern Asia and the southern Pacific islands, Australia, and New Zealand. Observations made from Guam (13°25′N, 144°45′E) during autumn 1983 indicate that a significant number of birds take a direct route over the western Pacific Ocean. Radar observations and ground counts of migrants on Guam showed two periods of autumnal migratory activity. The first, largely adult birds, was in August and September. The second, largely juveniles, was in late September and October. Radar indicated that large numbers of birds passed over the island to the south with no evidence of compensation for drift by …

Ua66/6/2 Bionews From The Hill, Wku Biology

WKU Archives Records

Newsletter created by and about the WKU Biology department highlighting students, faculty and alumni activities.

Comparative Analysis Of The Effects Of Visual And Auditory Stimuli On Avian Mobbing Behavior, C. Ray Chandler, Robert K. Rose

Biological Sciences Faculty Publications

Both visual and auditory stimuli elicit avian mobbing behavior, but there is little comparative information on their isolated and additive effects. Using three combinations of two experimental stimuli (mount and tape of an Eastern Screech-Owl, Otus asio) we tested the effects of stimuli on the frequency, intensity, and duration of avian mobbing behavior. Of 169 mount-only trials, only 11 (6.5%) were successful in attracting birds. Tape-only (n = 169) and mount-and-tape (n = 170) were equally successful in attracting birds (approximately 85% of all trials), but mount-and-tape trials were more likely to initiate mobbing behavior. Birds responding …

Basis Of The Structure And Development Of Mammalian Enamel As Seen By Scanning Electron Microscopy, A. Boyde, M. Fortelius, K. S. Lester, L. B. Martin

Scanning Microscopy

Mature enamel is the most mineralized of mammalian tissues, contains the least water and therefore does not present problems of shrinkage on preparation for SEM. However, the developing enamel is highly hydrated and presents severe problems in preparation.

The structure of enamel is determined by the activity of its individual formative cells and their group behaviour. The peculiar, unequal secretion of matrix at the distal pole of the ameloblast leads to the presence of characteristically shaped pits in the surface of the formative tissue. Crystals grow in a special relationship to this surface. Sharp changes in orientation of the surface …

Bovine Aorta Endothelial Cell Incubation With Interleukin 2: Morphological Changes Correlate With Enhanced Vascular Permeability, Corazon D. Bucana, Joann Trial, Audrey C. Papp, Kenneth K. Wu

Scanning Microscopy

Interleukin 2 induced alterations in the morphology of bovine aortic endothelial cells in vitro. The changes observed in confluent cultures of bovine aortic endothelial cells included retraction and elongation of eel ls leading to enlarged gaps between cells quantified by image analysis. Purified IL-2 (1 U/ml medium) increased the gaps between endothelial cells 3-4-fold compared with control cultures. The effect was transient, since the cells reverted to their original morphology 6-12 hours after the removal of lL-2. Correlative scanning electron microscopy (SEM) studies using fresh bovine aorta showed a dose-dependent alteration of the endothelial surface by IL-2 characterized by rounding …

Topographic Evolution In The Atomic Scale Growth And Erosion Continuum, G. Carter, I. V. Katardjiev, M. J. Nobes, J. L. Whitton

Scanning Microscopy

This review gives a detailed survey of the range of fascinating surface features which develop under growth or erosion conditions under the combined influence of thermal and more energetic atomic particle fluxes. Collisionally induced atomic ejection and migration, and thermally and radiation induced atom and defect diffusion processes are outlined and their relevance to topographic initiation and evolution explored. A range of experimental observations of surface feature elaboration is discussed from net growth to net erosion conditions and models for their explanation are considered. It is concluded that while much data have been accumulated, much of these have been in …

Quantitative Analysis Of Particulate Burden In Lung Tissue, J. P. Mastin, L. E. Stettler, J. D. Shelburne

Scanning Microscopy

Numerous methods have been used in the preparation and analysis of the particulate matter deposited in human lungs. Preparation techniques include those for particle isolation and for in situ analysis. Analytical techniques include bulk and particle-by-particle analysis. In this paper, a general discussion of many of these methods is presented along with examples of how two specific techniques have been used. In one study, individual particles from the lungs of 75 randomly selected autopsy cases were analyzed using an automated scanning electron microscopy (SEM)/ energy dispersive X-ray microanalysis (EDX) system. An average of 613 million particles, of exogenous origin, per …

Defect Detection And Thickness Mapping Of Passivation Layers On Integrated Circuits Using Energy Dispersive X-Ray Analysis And Image Processing Techniques, Richard G. Sartore

Scanning Microscopy

The relative thickness of passivation layers has been mapped for integrated circuits by utilizing the penetration voltage method, in conjunction with energy dispersive x-ray analysis (EDXA) and a scanning electron microscope (SEM), to detect defects and map film thickness. The thickness mapping technique was evaluated for area coverage and correlated to size of defective areas. The purpose of this study was to determine optimal operational conditions for fast and accurate defect detection on an integrated circuit for failure analysis and non-destructive process evaluation. Image processing was required to enhance the acquired map and to obtain a calibrated image for relative …

Application Of Photovoltage Imaging To Semiconductor Wafer Characterization, Kanji Kinameri, Chusuke Munakata, Noriaki Honma, Hiromichi Shimizu

Scanning Microscopy

A technique for imaging the distribution of ac surface photovoltages induced in a semiconductor wafer by the irradiation with a blue or near-infrared chopped photon beam is applied to non-destructive inspection of faults in Si or GaAs wafers. Faults detected include crystal defects, radiation damage, surface charge-up, striation and junction inhomogeneity. The principles of inspecting for the above mentioned wafer faults are quantitatively presented by numerical analyses of dependence of ac surface photovoltage on wafer electronic characteristics. The minimum detectable changes in minority carrier lifetime, interface trap density, fixed oxide charge density and resistivity for a depleted p-type Si wafer …

Determination Of Nitrogen In Stainless Steel By Auger Electron Spectroscopy, H. Hantsche, H. J. Dudek

Scanning Microscopy

Application properties of steel can be improved considerably by alloying with nitrogen. The nitrogen may be present both as dissolved nitrogen and as nitride precipitate. It is well-known that the determination of low nitrogen content by means of X-ray microprobe analyses (EMPA) is not easy, consequently it seemed only logical to try to perform these measurements with the method of Auger electron spectroscopy ( AES) which is more sensitive as far as detection of light elements is concerned. After determining the line shape and line position of the nitrogen KLL-peak the detection limit was calculated at 0.02 at .% using …

Studies Of Intestinal Lymphoid Tissue. Xi – The Immunopathology Of Cell-Mediated Reactions In Gluten Sensitivity And Other Enteropathies, Michael N. Marsh

Scanning Microscopy

Computerised image-analysis was used to quantitate small intestinal mucosae from celiac sprue and dermatitis herpetiformis patients, Gambian children with tropical-sprue-like malabsorption, first-degree celiac sprue relatives, and treated celiac sprue patients during challenge with a peptic-tryptic digest of gluten. A wide range of mucosal appearances was observed. Typically, 'flat' lesions (Type 2) revealed a reduced number of epithelial lymphocytes that were large and mitotically active. At the other extreme, mucosal architecture was relatively well preserved (Type 1) but surface epithelium contained an expanded population of small, non-mitotic lymphocytes, with or without crypt hyperplasia. Similar changes were observed in one-third of celiac …

Energetics Of The Lizard Cnemidophorus Tigris And Life History Consequences Of Food-Acquisition Mode, Roger A. Anderson, William H. Karasov

Biology Faculty and Staff Publications

Energy budgets for the wide-foraging "arthropodivorous" lizard Cnemi­dophorus tigris were constructed for the reproductive season using doubly labeled water measurements of field metabolic rate (FMR). Rates of body mass change, clutch sizes, and clutch intervals were also investigated. FMRs of both sexes (males, 298 J·g^{- 1}·d^-1 ; females, 247 J·g^{- 1}·d- ¹) were greater in the reproductive season than during the postreproductive season. This was not due to differences in resting metabolism, but, instead, was due to higher activity costs during the reproductive season. Although males had signficantly higher FMR than females, males …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines.

Because …