Digital Commons Network^™

Changes In Rat And Mouse Salivary Glands And Pancreas After Chronic Treatment With Diuretics: A Potential Animal Model For Cystic Fibrosis, Samuel Sagström, Edward B. Mcmillan, Monique Marijianowski, Helmy Mulders, Godfried M. Roomans

Scanning Microscopy

Defective transepithelial chloride and water transport is thought to be the cellular basis of the disease cystic fibrosis (CF). Therefore, it was attempted to develop an animal model for this disease by chronically inhibiting transepithelial chloride transport in experimental animals by long term treatment with high doses of diuretics. In the present study, changes in the salivary glands and pancreas after such treatment were investigated by X-ray microanalysis and electron microscopy.

Treatment of rats for one month with diuretics caused a significant decrease in chloride and an increase in calcium in the acinar cells of the submandibular gland. This increase …

Studies Of Irritant Reactions On Epidermis: The Application Of Energy Dispersive X-Ray Microanalysis, Magnus Lindberg

Scanning Microscopy

Modern man is exposed to an increasing amount of chemicals in the environment. The skin is a complex tissue with regards to both structure and function. Contact with external stimuli can lead to various responses in the skin depending on the type of stimuli, the dose and time of exposure and the status of the exposed individual. The electron probe microanalytic technique can be used to obtain information on physiological alterations within the skin and especially the epidermis when the normal homeostasis is disturbed by contact with external stimuli. The present paper presents a review of some aspects of contact …

Correlative Light, Transmission, And High Resolution (Se-I) Scanning Electron Microscopy Studies Of Rhesus Adrenocortical Vascular Morphology, R. P. Apkarian, N. L. L' Hernault

Scanning Microscopy

A detailed correlative morphologic description using light microscopy (LM), transmission electron microscopy (TEM) and high resolution SE-I scanning electron microscopy (SEM) was conducted on the capillary endothelium of the zona-fasciculata (Z-F) in juvenile male rhesus monkeys. The glucocorticoid synthesis and release phenomena, associated with stress stimulated release of adrenocorticotropic hormone (ACTH) via the hypothalamic-pituitary axis, intimately involves capillaries of the Z-F. A comprehensive study of all the ultrastructural features implicated in the transendothelial uptake of steroidogenic precursors and release of glucocorticoids in perfused rhesus adrenals has not previously been made. This report presents correlative images of transendothelial openings that include …

Surface Corrections To Bulk Energy Losses In Scanning Transmission Electron Microscopy Of Spheres, A. Rivacoba, P. M. Echenique

Scanning Microscopy

The interaction of a fast electron penetrating a spherical target is studied, in the frame of the classical dielectric theory. Expressions for ω the Fourier component of the induced scalar field and energy loss probability are obtained. The reduction in the bulk loss probability due to the surface boundary correction is calculated to all orders in a multipole expansion. The dependence of this correction on the impact parameter and on the radius of the sphere is also studied and compared with the results for films.

Azimuthal Variations Of Sensitivity In The Coaxial Scanning Auger Microprobe, L. Frank

Scanning Microscopy

Experiments with the PHI 595 Multiprobe have revealed a pronounced asymmetry of the energy filtered image (the shape of the line-scan curve) obtained with an isolated sphere lying on a flat surface. The effect is explained as a consequence of transmission efficiency variations along the circumference of the ring-shaped detector assembly, and is probably caused by deviations from coaxiality of the adjustable parts of the entrance annular aperture controlling the energy resolution. A quantitative model provides realistic results and has indicated the emission anisotropy of Auger electrons as being much larger than that of the energy filtered background emission at …

Comparative Analysis Of The Proliferative Response Of The Rat Urinary Bladder To Sodium Saccharin By Light And Scanning Electron Microscopy And Autoradiography, Samuel M. Cohen, Maria J. Fisher, Takao Sakata, Martin Cano, Gerald P. Schoenig, Clifford I. Chappel, Emily M. Garland

Scanning Microscopy

Three methods used to detect proliferative changes in the rat urothelium, light microscopy, scanning electron microscopy, and autoradiography, were compared for their sensitivity in detecting changes produced by administration of sodium saccharin. Weanling male F344 rats were fed sodium saccharin as 0, 3, 5, or 7.5% of the diet, and the bladders were evaluated after 4, 7, and 10 wks of feeding. Light microscopic changes and an increase in labeling index were seen at all time points in rats fed 7.5 % sodium saccharin, but not at the lower doses. A slight increase in labeling index was also observed at …

Development Of Sorghum (Sorghum Bicolor (L.) Moench) Endosperm In Varieties Of Varying Hardness, J. M. Shull, A. Chandrashekar, A. W. Kirleis, G. Ejeta

Food Structure

Factors responsible for grain hardness in sorghum are not well understood. Therefore, a study was undertaken to observe differences in the developmental processes of three sorghum varieties which vary in endosperm texture: hard, intermediate, and soft. Grain samples were collected at 5 day intervals beginning at 5 days after half-bloom (DAHB) until physiological maturity (40 DAHB) and prepared for viewing with scanning electron microscopy and transmission electron microscopy.

Comparisons were made between vitreous and floury endosperm portions of each variety and among the three varieties. The major difference between vitreous and floury endosperm was the degree to which the protein …

9th Biennial Cheese Industry Conference, Various Authors

Cheese Industry Conference

No abstract provided.

Scattering From Atoms And Molecules In The Free State By Electrons With Energies Below 10 Kev., Russell A. Bonham

Scanning Microscopy

A survey of electron scattering from a free atom or molecule by incident electrons with energies below 10 keV is best accomplished by viewing a Bethe surface. This surface presents a global picture of nearly all observable phenomena obtained from the investigation of the angular and energy dependence of scattered electrons. An absolute, comprehensive and accurate surface for molecular nitrogen, obtained from electron energy loss spectroscopic experiments, illustrates the major points to be made. Two general uses of such scattering information are: (i) the inference of various aspects of the electronic structure of the target through the observation of spectral …

Monte Carlo Calculations Of Secondary Electron Emission, Suichu Luo, David C. Joy

Scanning Microscopy

Monte Carlo calculations of secondary electron (SE) generation have been performed using a hybrid model of the exponential decay law and cascade multiplication process. The contributions of both valence and core electron excitations, and the production of secondaries by the volume plasmon decay, have been included. The calculation has been extended to include SE's with energies up to half the incident beam energy. The SE yield δ_SE1 component due to excitation by primary electrons, the SE yield δ_SE2 due to excitation by backscattered electrons, and the β coefficient are estimated using this model. Calculated SE yields, energy distributions, …

Murphy's Law And The Uncertainty Of Electron Probes, Linn W. Hobbs

Scanning Microscopy

The electron microscope has brought over the last fifty years a wealth of information about the structure of solids, from surface topography to the details of atomic arrangements. Like any probe, however, the electron beam is subject to the epistomological constraint that the investigator inevitably perturbs what is being investigated, and from its beginnings questions were raised about the integrity of the ·images generated in the microscope from a specimen which was subjected to such an aggressive probe. A fast electron is about as likely to be scattered inelastically as elastically from a collection of atoms, and the density of …

Transmission And Scanning Electron Microscopy Of Peanut (Arachis Hypogaea L. Cv. Florigiant) Cotyledon After Roasting, Clyde T. Young, William E. Schadel

Food Structure

Changes in the microstructure of peanut (Arachis~ L. cv. Florigiant) cotyledon after roasting at a temperature of 160°C for 16 minutes were investigated with transmission and scanning electron microscopy. Thermal modifications were documented with photomicrographs of t he cytoplasmic network , protein bodies, starch grains and cell-to-cell junctions after oven roasting. These thermal modifications include disruption of the cytoplasmic network, distension of protein bodies, decreased stain affinity of starch grains , and disintegration of middle lamellae in some cell-t o-cell junctions.

Microscopic Measurement Of Apple Bruise, N. K. Kim, Y. C. Hung

Food Structure

Microstructural differences between unbruised and bruised apple tissues were evaluated. Cell connections appeared to be looser in bruised tissue than in unbruised tissue. Bruised tissue exhibited more empty regions which are not occupied by cells than unbruised tissue. Empty reg ions in unbruised and bruised tissues were about 0.7 and 2.4 per mm2, respectively, comprising 0.7% and 2.7% of the respective total volume. Stereology is a body of mathematical methods relating three-dimensional parameters defining a structure to two- dimensional measurements. Two methods based on a stereological principle were also used to quantify the fraction of total volume occupied by cells. …

Food Microstructure

Food Structure

No abstract provided.

Extracting Chemical Information From Auger Line Shapes, David E. Ramaker

Scanning Microscopy

We have developed a generally applicable, semi-empirical approach for quantitatively interpreting Auger line shapes. Detailed information on hybridization, electron delocalization and correlation, screening effects, bonding, and covalency can be obtained from the line shape. Methods for extracting the Auger line shape from the experimental data are briefly described. We summarize our recent results from the C KVV Auger line shapes of five different gas phase hydrocarbons (methane, ethane, cyclo-hexane, benzene, and ethylene), three solids (polyethylene, diamond, and graphite), and a molecularly chemisorbed system (ethylene/ Ni). The normal kvv component accounts for only about half of the total experimental KVV intensity …

Secondary Electron Emission From Solids. Ii. Theoretical Descriptions, Michel Cailler, Jean-Pierre Ganachaud

Scanning Microscopy

A primary beam impinging on a solid target suffers elastic and inelastic collisions with the components of the solid. These collisions can be incorporated into a Monte-Carlo simulation model if all the cross sections associated with the various types of collisions are known.

Elastic diffusion effects are mainly related to the interactions of the particles with the real potential V(r) surrounding each ionic core. An essential simplification of the inelastic interactions is to consider that the solid reacts as a whole to an external probe, which is the incident electron beam. The linear response of the solid to an external …

Sage Grouse Status And Recovery Plan For Strawberry Valley, Utah, United States Department Of Agriculture, Forest Service

Wildlife Conservation and Management

Since 1939, an estimated 3,000 sage grouse in Strawberry Valley, UT, have declined to some 180 birds, mainly because of reservoir construction and eradication of big sagebrush to promote livestock forage. A 4-year study of numbers and movements of radio-tagged grouse has provided the basis for a recovery program calling for rejuvenation of big sagebrush and forbs important to grouse, replacement of mating grounds lost to human activities, consideration of sage grouse biology in management decisions, and formation of a sage grouse recovery team.

Facts And Feelings Series For Parents, Unknown Unknown

All Archived Publications

Packet that gives instructions to parents about talking to teens about common issues they face.

Assessment Of Nongame Bird Habitat Using Forest Survey Data, United States Department Of Agriculture, Forest Service

Wildlife Conservation and Management

Forest Survey data have potential for use in obtaining information on the condition and diversity of the Nation's forest resources relevant to wildlife habitat that is needed for planning and monitoring at State and regional levels. In this study, Forest Survey data were used to assess nongame bird habitat potential based on food and shelter requirements on 24 plots. These assessments were then evaluated using bird numbers. Results of the analyses showed some correlation of bird numbers with tree canopy variables, and illustrate the potential for using Forest Survey data for wildlife habitat assessment, for identifying opportunities to improve habitat …

Bird Populations In And Adjacent To A Beaver Pond Ecosystem In Idaho, United States Department Of Agriculture, Forest Service

Wildlife Conservation and Management

We compared breeding bird populations and community organization between a beaver pond habitat dominated by willows (Salix spp.) and an adjacent nonwillow riparian habitat on Summit Creek in east-central Idaho. For the previous 14 years both habitats had been protected from livestock grazing by a fenced excloser (122-ha). Bird populations were determined by spot-mapping on 9-ha plots in spring 1989. Structural (physiognomic) differences in vegetation between the two habitats and the availability of impounded water on the beaver pond site were reflected in associated breeding bird populations. Total bird density in the beaver pond habitat was three times that of …

Plasmons In Scanning Transmission Electron Microscopy Electron Spectra, R. H. Ritchie, A. Howie, P. M. Echenique, G. J. Basbas, T. L. Ferrell, J. C. Ashley

Scanning Microscopy

A general self-energy formulation of the interaction between an electron in a scanning transmission electron microscope (STEM) and a localized target is given. We prove a theorem relating the probability of energy transfer to that calculated classically. Local dielectric theory of target excitation for various geometries is discussed. The problem of localization of initially unlocalized excitations in the valence band of solids is treated by transforming cross sections differential in momentum transfer into dependence on an impact parameter variable. We are thereby able to account for experimental data in scanning electron microscopy (SEM) that show high spatial resolution.

Energy Loss Of Electrons Below 10 Kev, Hans Bichsel

Scanning Microscopy

Monte Carlo calculations are used to obtain the energy loss and spatial distribution of electrons penetrating matter. For this purpose, reliable cross section for the inelastic collisions must be known. As an approximation valid for large energy losses, the Coulomb cross section can be used. It can be modified in a simple way to account for the binding of electrons and for the exchange effect. In the Gryzinski model, collisions with moving electrons are assumed. In the quantum mechanical Bethe approximation, σ is closely related to the dipole oscillator strength (DOS), and its extension to finite momentum transfers, the generalized …

Slowing Down Of Positrons And Applications To Solid Surfaces, Peter J. Schultz, L. R. Logan, W. N. Lennard, G. R. Massoumi

Scanning Microscopy

When monoenergetic positrons enter a solid they scatter and lose energy via processes similar to those for electrons. Theoretical details of these processes have been well established for decades, but experimental results using low energy positron beams are only now becoming available for comparison. We review the theoretical results for elastic and inelastic scattering of positrons and the predictions that follow for backscattering, inner-shell ionization, energy loss and stopping profiles. In this presentation, emphasis is given to specific comparisons with calculations for electrons. We discuss recent experimental results in each of these areas, and conclude with two examples of applications …

Slowing Down And Scattering Of Ions In Solids, W. Heiland, H. Derks, T. Bremer

Scanning Microscopy

The interaction of particle beams with solids yields three parts, i.e. reflected particles, penetrating particles and trapped particles. At very low energies particle reflection is dominant, at very high energies penetration is the most important effect. Trapped particles are the result of energy loss processes, which on the other hand cause radiation damage in the solid. In the energy range discussed here, i.e. above energies where quantum effects, diffraction etc. are important and below energies where nuclear reactions, relativistic effects etc. may occur, the particle trajectories are classical. The energy loss process can be treated separately as nuclear and electronic …

Conditioned Flavor Aversion: A Mechanism For Goats To Avoid Condensed Tannins In Blackbrush, Frederick D. Provenza, Elizabeth A. Burritt, T. P. Clausen, J. P. Bryant, P. B. Reichardt, Roberto A. Distel

Behavioral Education for Human, Animal, Vegetation, and Ecosystem Management (BEHAVE)

It has been hypothesized that herbivores instinctively avoid tannin-containing plant parts in response to the adverse effects of tannins on forage digestion. However, we found that goats learned to avoid condensed tannins (CTs) from blackbrush current season's growth by associating the flavor of foods containing CTs with aversive postingestive consequences. The aversive consequences experienced by goats apparently are not related to digestion inhibition and may depend on the structure of CTs and on how CTs are bound with other cell constituents. These observations suggest several areas of inquiry related to the interaction between CTs and herbivores. A better understanding of …

Angular And Energy Distributions Of Electrons Emitted From Gases And Thin Foils During Light Ion Bombardment, L. H. Toburen

Scanning Microscopy

The energy and angular distributions of electrons ejected by fast charged particles in ionizing collisions provide detailed information regarding the effects of atomic, molecular, and condensed-phase structure on the energy loss process. Analysis of the wide range of available data has lead to several general conclusions. For ionization of atomic and molecular targets by protons having energies above a few hundred keV, the cross sections for electron production have been found to scale as the number of loosely bound target electrons. The more subtle features of the ejected electron energy spectra are, however, dependent on the electronic structure of the …

Electron Stimulated Surface Chemistry, Miles J. Dresser

Scanning Microscopy

When an electron beam of less than 1000 eV interacts with a surface layer a variety of phenomena may occur. In this paper I will discuss those interactions that lead to either chemical changes on the surface and/or desorption of species or fragments from the surface. Theoretical models of electron stimulated desorption, (ESD) will be presented, specifically the Menzel, Gomer, and Redhead model, the Knotek, Feibelman model and the Ramaker, White and Murday model. Experiments that display the angular distribution of the desorbing ionic or metastable fragments, (referred to as ESDIAD for Electron Stimulated Desorption: Ion Angular Distributions) are the …

Physical Sputtering Of Metallic Systems By Charged-Particle Impact, Nghi Q. Lam

Scanning Microscopy

The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. …

Ion-Induced Electron Emission From Solids, Wolfgang O. Hofer

Scanning Microscopy

A review of ion-induced electron emission is presented which concentrates on the mechanisms relevant to imaging, analysis, and processing of surfaces by ion beams. In this field of applications, the main interest in electron emission lies in kinetic emission by heavy, i.e. multi-electron (Z > 2) ions of energy ≤ 100 keV.

Interband Transitions In Electron Energy Loss Spectrometry, P. Schattschneider, P. Pongratz

Scanning Microscopy

Electron energy loss spectrometry (EELS) allows one to experimentally obtain the dielectric permittivity 𝜀:(ω, q) as a function of frequency ω and wave vector if. From 𝜀 information on inter band transitions in the probed medium can be drawn. In EELS, inter band transitions are screened by the movement of the loosely bound valence or conduction electrons. The screening effect may enhance or attenuate the strength of transitions, and tends to shift the frequencies of resonant oscillations. Another aspect of screening is the occurrence of longitudinal modes in the spectrum. So, great care has to be taken in interpreting …