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Atomic Resolution Electron Holography, K. Ishizuka, T. Tanji, A. Tonomura

Scanning Microscopy

It has been demonstrated that electron holography is a very powerful tool to investigate an electromagnetic potential in medium resolution, since the phase of an electron wave is approximately proportional to the potential. Now, electron holography is at the second stage of development: to establish holography at atomic resolution and further to realize Gabor's idea to improve the resolution restricted by the spherical aberration of the objective lens. We investigate the possibility of electron holography to get information at atomic resolution by computer simulations as well as by digital processing of electron holograms. We show that the phase distribution has …

Holography - Just Another Method Of Image Processing?, Hannes Lichte

Scanning Microscopy

The advantage of all different kinds of electron holography lies in the fact that in addition to the image intensity they make use of the phase in real space and in Fourier space. Therefore, they are in principle superior to conventional imaging techniques, even if these are supported by highly sophisticated methods of image processing. The technique of electron off-axis holography, under development in Tübingen for more than 20 years, now enters atomic resolution domain. After correction of aberrations, amplitudes and phases can be determined quantitatively, both in real space and Fourier space, opening up novel facilities for the analysis …

Image Delocalisation And High Resolution Transmission Electron Microscopic Imaging With A Field Emission Gun, W. Coene, A. J. E. M. Jansen

Scanning Microscopy

The high spatial and temporal coherence of a field emission gun (FEG) increases the information limit of high-resolution transmission electron microscopes (HRTEM), but has also its implications on the localisation of the high resolution information in the image. In this paper, we present the results of a combined theoretical and experimental study of delocalisation in HRTEM. First, we derive a spatial frequency analysis of the delocalisation for crystal defects. Next, the delocalisation is studied from a real-space point of view, in terms of the impulse-response function, for which an instructive asymptotic mathematical analysis has been set up. Finally, we present …

Partial Characterization Of The Major Lipooligosaccharide From A Strain Of Haemophilus Ducreyi, The Causative Agent Of Chancroid, A Genital Ulcer Disease, William Melaugh, Nancy J. Phillips, A A. Campagnari, R Karalus, B W. Gibson

Chemistry Faculty Publications

The first preliminary structure of a surface lipooligosaccharide from Haemophilus ducreyi has been determined. The major oligosaccharide was released by mild acid hydrolysis and analyzed by liquid secondary ion and tandem mass spectrometry. The mass spectral data combined with composition and methylation analysis yielded the most probable structure; Gal1----4GlcNAc1----3Gal1----4Hep1----6Glc1----( Hep1----2Hep1----)3,4Hep1---- KDO, where the reducing terminal 3-deoxy-D-manno-octulosonic acid (or KDO) exists in an anhydro form. This anhydro species results from the elimination of a phosphate from C-4 of KDO during mild acid hydrolysis. The core heptose trisaccharide consists of L-glycero-D-manno-heptose, but analysis of the peracetylated sugars indicated that the 1,4-linked heptose …

Effects Of Moose Foraging On Browse Availability In New Hampshire Deer Yards, Michael T. Pruss, Peter J. Pekins

New Hampshire Agricultural Experiment Station Publications

Food habits of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) overlap in northern New Hampshire during autumn and winter. High moose and deer densities in deer yards, where deer may be confined for extended periods, could result in competition for limited deciduous forage. The purpose of this study was to investigate possible impacts by moose on browse availability in deer yards, and the potential effects on deer. Fifteen deer yards were studied in northern New Hampshire during spring and fall, 1990-91. Unbrowsed and browsed deciduous twigs, and deer and moose pellet groups were counted on 900 permanent plots to …

Automatic Orientation Analysis Of Microfabric, N. K. Tovey, P. Smart, M. W. Hounslow, J. P. Desty

Scanning Microscopy

The orientation of features in digitized scanning electron micrographs may be estimated using a technique which examines the changes in intensity in two orthogonal directions about each pixel. Typically, over 250, 000 estimates of orientation may be made generating an output image where the pixel value relates to the orientation direction of the feature at the corresponding pixel in the original image. At the same time, a rosette histogram may be generated to give a visual impression of any preferred alignment. These data may be reduced to two parameters specifying the direction and degree of orientation.

A new algorithm involving …

Image-Matching As A Means Of Atomic Structure Evaluation In High Resolution Transmission Electron Microscopy, John C. Barry

Scanning Microscopy

Two of the major applications of the high resolution transmission electron microscope (HRTEM) image-matching technique are: a) to refine the structure of defects and interfaces in crystals, and b) to identify minority phases in multi-phase materials. An important advantage of the technique is that it provides spatial information at the atomic level; but an important disadvantage is that the results are often hard to quantify. There are many factors which affect the precision of the image-matching technique, and methods for measuring the pertinent experimental parameters are discussed in this paper. It is shown that if the experimental parameters are known, …

Sub-Angstrom Microscopy Through Incoherent Imaging And Image Reconstruction, S. J. Pennycook, D. E. Jesson, M. F. Chisholm, A. G. Ferridge, M. J. Seddon

Scanning Microscopy

Z-contrast scanning transmission electron microscopy (STEM) with a high-angle annular detector breaks the coherence of the imaging process, and provides an incoherent image of a crystal projection. Even in the presence of strong dynamical diffraction, the image can be accurately described as a convolution between an object function, sharply peaked at the projected atomic sites, and the probe intensity profile. Such an image can be inverted intuitively without the need for model structures, and therefore provides the important capability to reveal unanticipated interfacial arrangements. It represents a direct image of the crystal projection, revealing the location of the atomic columns …

Segmentation Of Pores In Backscattered Images Of Sediments And Soils And Their Relationship To Domain Structure, M. W. Hounslow, N. K. Tovey

Scanning Microscopy

A new technique to quantify variations in pore structure across an image is described in this paper. The method involves several stages as the original images are rarely suitable for simple segmentation by the selection of a single threshold. The processing first involves the application of a Wiener filter to remove imaging artefacts and to sharpen the edge of void/particle contacts. This image reconstruction is followed by the selection of a global threshold based on the relative contrast method, to create a binary image separating the voids from the particles. Such an image can be used to evaluate pore structure …

Cathodoluminescence Image Processing Of High Tc Superconductors, Z. Barkay, G. Deutscher, E. Grunbaum

Scanning Microscopy

Cathodoluminescence (CL) in the Scanning Electron Microscope (SEM) was performed for both ceramic pellets and thin films of YBaCuO high T_C superconductors. Image processing provided additional quantitative information. For single phase films, we demonstrated the possibility to create thickness maps in real time from the CL pictures. The gradual thickness variation within the sample was revealed by the histogram of the thickness image. The continuity of the film was observed at a few threshold thicknesses values, defined by the fraction of the occupied area. At the conduction threshold value, the location and width of the conducting paths could be …

Biochemical Systematics Of Notothenioid Fishes From Antarctica, Mara A. Mcdonald, Michael H. Smith, Michael W. Smith, James M. Novak, Paul E. Johns, Arthur L. Devries

Faculty Research & Creative Activity

Genetic variation at 30 protein-coding loci was examined in seven forms of notothenioid fishes from Antarctica. Multilocus heterozygosity varied from 0.018 to 0.078 across taxa. An analysis of the allozyme data revealed the probable existence of an unrecognized cryptic species within Trematomu5 bemacchii. Pagothenia borchgrevinki is as closely related to some species of Trematomus as are some species of Trematomus to each other. Speciation among the species of Trematomus and Pagothenia appears to have taken place primarily after the separation of Antarctica from Australia.

Direct Methods In High Resolution Electron Microscopy, D. Van Dyck, M. Op De Beeck

Scanning Microscopy

New approaches are proposed to retrieve the wavefunction at the object and from this, to retrieve the projected structure of the object. The wavefunction is retrieved by capturing images at a series of closely spaced focus values and to process the whole 3D data. The structure of the object is retrieved using a formalism based on electron channelling.

Morphological Three-Dimensional Analysis, C. Gratin, F. Meyer

Scanning Microscopy

This paper presents the main results of our research on mathematical morphology for three-dimensional images. The first issue is to decide which grid must be used. The face-centred cubic grid and the centred cubic grid seem to be more suitable than the cubic grid in terms of possible rotations. For these two grids we derive the formulae for the basic Minkovski measures. Then we show through several examples that extension from 2D to 3D is straightforward for most transformations. The efficiency of direct 3D processing is illustrated by applications to filtering, overlapping particle separation and grey-scale image segmentation.

An Optical Moiré Technique For The Analysis Of Displacements In Lattice Images, C. J. D. Hetherington, U. Dahmen

Scanning Microscopy

High resolution electron microscopy is a means for imaging not only the local structure at a defect or interface but also the displacement field in the surrounding lattice. However, in general it is difficult or tedious to analyse this field which can extend across the entire micrograph. The optical moiré technique, which is based on interference effects between the experimental lattice image and an artificial reference lattice, allows a rapid and accurate measurement of the displacements. Small violations of translation, rotation or mirror symmetries give rise to large changes in the periodicity or orientation of the moiré pattern.

The spacing …

Pleistocene Terrestrial Vertebrates From Near Point San Luis, And Other Localities In San Luis Obispo County, California, George T. Jefferson, Harry L. Fierstine, John R. Wesling, Teh-Lung Ku

Biological Sciences

Terrestrial vertebrate remains were recovered from sediments that lie on remnants of the lowest marine wave-cut platform between Point Buchon and Point San Luis. Uranium series ages of these samples, which range from 83 to about 49 ka suggest a correlation to late Pleistocene climatic and eustatic events associated with marine oxygen isotope substage 5a, and establish a maximum age of ≈80 ka for the occurrence of terrestrial mammal fossils. The Point San Luis area assemblage appears typical of the late Pleistocene regional vertebrate paleofauna fauna from west-central California. Five mammalian taxa are added to the Pleistocene record from San …

Palmer Lter Program: Spatial Variability In Phytoplankton Distribution And Surface Photosynthetic Potential Within The Peninsula Grid, November 1991, Barbara B. Prezelin, Nicholas P. Boucher, Mark A. Moline, Elise Stephens, Keith Seydel, Kai Scheppe

Biological Sciences

No abstract provided.

Palmer Lter: Temporal Variability In Hplc Pigmentation And Inorganic Nutrient Distribution In Surface Waters Adjacent To Palmer Station, December 1991-February 1992, Barbara B. Prezelin, Mark A. Moline, Keith Seydel, Kai Scheppe

Biological Sciences

No abstract provided.

New Combinations In Gnaphalium (Asteraceae: Inuleae), G. Ledyard Stebbins, David J. Keil

Biological Sciences

Because of extensive morphological intermediacy, plants formerly distinguished at the species level as Gnaphalium beneolens, G. microcephalum, G. thermale, and G. wrightii are treated as intergrading races of the widespread G. canescens. The new combinations, G. canescens subsp. beneolens, G. canescens subsp. microcephalum and G. canescens subsp. thermale are made.

Application Of Slow-Scan Charge-Coupled Device (Ccd) Cameras To On-Line Microscope Control, O. L. Krivanek, G. Y. Fan

Scanning Microscopy

Autotuning methods for transmission electron microscopy are reviewed, and a distinction is drawn between predictive and non-predictive methods. The predictive methods make better use of the input data and therefore need fewer images to carry out complete autotuning. They typically require high quality of input data, which can be best provided by cooled slow-scan charge-coupled device (CCD) cameras. Two predictive methods are considered in more detail. These are the tilt-induced image shift (TIS) method of Koster, van der Mast and de Ruijter, and a new automated diffractogram analysis (ADA) method, which is introduced in this paper. The ADA method is …

Measurement Of Electron-Optical Parameters For High-Resolution Electron Microscopy Image Interpretation, A. F. De Jong, A. J. Koster

Scanning Microscopy

A method is presented to measure various electron-optical parameters needed for high-resolution electron microscopy image interpretation with high accuracy. The method is based on the measurement of a series of beam-tilt induced image displacements. The displacements are calculated via cross-correlation of the images, and subsequently fitted to a third-order polynomal in the beam tilt. From two series of images (using the x and y beam tilt coils), the spherical aberration constant of the microscope can be measured, as well as the current values of defocus, beam tilt and astigmatism. The spherical aberration constant of three Philips microscopes is measured with …

Imaging Deformed Proteins: Characterising The State Fully, W. O. Saxton

Scanning Microscopy

By analysing the positions of individual unit cells in the image of a distorted macromolecular crystal, it is possible to achieve considerably more than is achieved by the correlation averaging or unbending now widely practised. It is possible partly to compensate for individual molecular distortion; and it is possible to identify molecules in equivalent environments (which can be expected to be in equivalent states of strain), selective averaging of which yields images that show how strain is accommodated at the sub-molecular level. The possible presence of surface forces applied to the crystal by its support film complicates the analysis and …

The Watershed Transformation Applied To Image Segmentation, Serge Beucher

Scanning Microscopy

Image segmentation by mathematical morphology is a methodology based upon the notions of watershed and homotopy modification.This paper aims at introducing this methodology through various examples of segmentation in materials sciences, electron microscopy and scene analysis.

First, we defined our basic tool, the watershed transform. We showed that this transformation can be built by implementing a flooding process on a greytone image. This flooding process can be performed by using elementary morphological operations such as geodesic skeleton and reconstruction. Other algorithms are also briefly presented (arrows representation).

Then, the use of this transformation for image segmentation purposes is discussed. The …

Phase Space Methods In Image Formation Theory, Victor Castaño, Gustavo Vásquez-Polo, Ramón Gutiérrez-Castrejón

Scanning Microscopy

A review of the basic mathematical principles and properties of some phase space functions (Wigner and Ambiguity functions) is first presented in a more general mathematical context. Then, we deal in detail with three applications : image formation in optical systems (specifically cascading systems of lenses), image formation in Transmission Electron Microscopy, by taking advantage of some formal similarities with the previous examples and, finally, contrast transfer functions in Electron Microscopy in order to obtain 2-dimensional plots which provide information on the behavior of a transmission electron microscope. Also, the relations of these functions with other mathematical tools utilized in …

Ua1d Thomas Coohill Personnel File, Wku Human Resources

WKU Administration Documents

Personnel file of Biology professor Thomas Coohill.

Evidence For The Location Of Aviral Protease & Protease Cleavage Sites In The 105 Kilodalton Protein Of Southern Bean Mosaic Virus, Timothy Shannon

Masters Theses & Specialist Projects

Southern Bean Mosaic Virus (SBMV) codes for a large polyprotein which is subsequently cleaved into smaller functional proteins. A virally encoded protease is suspected of mediating the cleavages. SBMV, picornaviruses and picornavirus-like viruses appear to have similar genomic organizations, which would place the protease region of the genome between the VPg and RNA dependen,, RNA polymerase regions. Protein sequence comparisons revealed homology between SBMV putative protease and the known proteases from foot and mouth disease virus, encephlamyocarditis virus, poliovirus, and cowpea mosaic virus. Experimental evidence provides little information on the exact location of the protease; however, protein sequence analysis suggests …

An Examination And Correction Of Plant Tissue Culture Basal Medium Formulations, Henry R. Owen, A. Raymond Miller

Faculty Research & Creative Activity

The inorganic formulations of fourteen common plant tissue culture basal media were examined from the primary literature. Inaccuracies and errors were found for molecular formulae, chemical hydrations, and molar equivalences for iron/EDTA complexation. A comparison with published basal medium formulations from six commercial suppliers uncovered additional inaccuracies, modifications, and errors, thereby emphasizing the need for investigators to examine and describe medium formulations precisely in future publications.

Random Image Models For Microstructure Analysis And Simulation, Dominique Jeulin

Scanning Microscopy

A wide spectrum of Random Function models, based on the theory of Random sets, are introduced to simulate single or multivariate signals as encountered in the common practice of electron probe microscopy.

These models are built in three steps, combining the choice of a family of primary random functions and of Poisson varieties in the n-dimensional space for their implantation. For electron microscopy images, they can describe the following situations:

- topography (as obtained from stereo pair images in fractography) simulated by Boolean and by alternate sequential random functions;

- thick slices (as in the case of Transmission Electron Microscope …

Some Applications Of Image Analysis To Materials Science, François Grillon

Scanning Microscopy

We have presented four applications of Image Analysis to material science. The first one is on a yarn composite SiC where we want to know the relative proportion of matrix, fibers, porosity and the size of the fibers. The results are used to estimate mechanical properties of the composite.

The second one is to measure the residual porosity after a laser shock on powder metallurgy steel. The knowledge of the depth of the affected zone is necessary to optimise the laser treatment.

The third one uses Fourier transformation to analyse plastic deformation on grains. Values are obtained from Fourier transform …

Diffraction And Imaging Theory Of Inelastically Scattered Electrons - A New Approach, Z. L. Wang, J. Bentley

Scanning Microscopy

A new dynamical theory is developed for describing inelastic electron scattering in thin crystals. Compared to existing theories, the first advantage of this new theory is that the incoherent summation of the diffracted intensities contributed by electrons after exciting vast numbers of degenerate excited states has been evaluated before any numerical calculation. The second advantage is that only the modulus squared of the transition matrix elements are needed in the final computation. This greatly reduces the effort in searching for "phase shifts" in inelastic scattering matrix calculations. By iterative operation of this single-inelastic scattering theory, multiple-inelastic electron scattering of phonons, …

The Application Of Multispectral Techniques To Analytical Electron Microscopy, P. G. Kenny, M. Prutton, R. H. Roberts, I. R. Barkshire, J. C. Greenwood, M. J. Hadley, S. P. Tear

Scanning Microscopy

The York multispectral analytical electron microscope (MULSAM) was the first instrument specifically designed to acquire and process multiple Auger, X-ray, backscattered electron, elastically scattered electron, scanning electron microscopy (SEM) and specimen absorption current images simultaneously. Analyzing combinations of these signals with multispectral correlation techniques yields more information than would normally be obtained by treating each image separately. This paper reports some of the multispectral methods we have investigated at York which may be of use to other workers. Included are (1) a method that corrects for beam current fluctuations during long acquisition runs which is based on the anti-correlation between …