Digital Commons Network^™

Pre-Embedding Staining Of Single Muscle Fibers For Light And Electron Microscopy Studies Of Subcellular Organization, Evelyn Ralston, Thorkil Ploug

Scanning Microscopy

Skeletal muscle fibers are large, multinucleated cells which pose a challenge to the morphologist. In the course of studies of the distribution of the glucose transporter GLUT4, in muscle, we have compared different preparative procedures, for both light (LM) and electron microscopy (EM) immunocytochemistry. Here we show that pre-embedding staining of single teased fibers, or of single enzymatically dissociated fibers, has several advantages over the use of sections for observing discrete patterns that extend over long distances in the cells. We report on an optimization study carried out to establish fixation and permeabilization conditions for EM immunogold labeling of the …

X-Ray Microscopy: Preparations For Studies Of Frozen Hydrated Specimens, A. Osanna, C. Jacobsen, A. Kalinovsky, J. Kirz, J. Maser, S. Wang

Scanning Microscopy

X-ray microscopes provide higher resolution than visible light microscopes. Wet, biological materials with a water thickness of up to about 10 μm can be imaged with good contrast using soft X-rays with wavelengths between the oxygen and carbon absorption edges (at 24 and 43 Å). The Stony Brook group has developed and operates a scanning transmission X-ray microscope (STXM) at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The microscope is used for imaging with a current resolution of 50 nm, and for elemental and chemical state mapping.

Radiation damage imposes a significant limitation upon high resolution X-ray …

Reproductive Ecology, Population Genetics, And Clonal Distribution Of The Narrow Endemic: Mirabilis Macfarlanei (Nyctaginaceae), Jennifer L. Barnes

Biology

I examined the reproductive biology and population genetics of the narrow endemic, Mirabilis macfarlanei (Nyctaginaceae) Constance and Rollins, from the Snake and Salmon Rivers in Idaho and Oregon. The results of this study provide further evidence for the proposed effects of rarity on plant reproductive systems and population genetics. Breeding system results indicated that M. macfarlanei is self-compatible, but requires a pollen vector for fertilization. Seed set was not pollen limited, but may be resource limited during others. The major floral visitors were long-tongued bees such as Anthophora spp. and Bombus spp., unlike other species of Mirabilis, which are …

Imaging Molecular Structure Of Channels And Receptors With An Atomic Force Microscope, Ratneshwar Lal

Scanning Microscopy

Biological membranes contain specialized protein macromolecules such as channels, pumps and receptors. Physiologically, membranes and their constituent macromolecules are the interface surfaces toward which most of the regulatory biochemical and other signals are directed. Yet very little is known about these surfaces. The structure of biological membranes has been analyzed primarily using imaging techniques that are limited in their resolution of surface topology. An atomic force microscope (AFM) developed by Binnig, Quate and Gerber, can image molecular structures on specimen surfaces with subnanometer resolution, under diverse environmental conditions. Also, AFM can manipulate surfaces with molecular precision: it can nanodissect, translocate, …

The Texture Of Surficial Sediments In Central Long Island Sound Off Milford, Connecticut., Roman Zajac, Larry J. Poppe, B B. Taylor, Dann Blackwood, Ralph S. Lewis, Mary L. Digiacomo-Cohen

Biology and Environmental Science Faculty Publications

The purpose of this study was to determine the grain-size distributions and associated statistical parameters of the surficial sediment samples from central Long Island Sound off Milford, Connecticut. These grain-size data, which help to ground-truth a pre-existent sidescan sonar survey (Poppe and others, 1995a; Twichell and others, in press), will eventually be used to describe the sedimentary processes active in this portion of central Long Island Sound. Other potential uses for these textural data include benthic biologic studies that evaluate faunal distributions and relate them to habitats (Zajac and others, 1995), and geochemical studies involving the distribution, transport and deposition …

The Texture Of Surficial Sediments In Western Long Island Sound Off The Norwalk Islands, Connecticut, Roman Zajac, Larry J. Poppe, B. B. Taylor, Dann Blackwood, A. E. Harmon

Biology and Environmental Science Faculty Publications

Grain-size analyses were performed on 69 samples from western Long Island Sound. The relative grain-size frequency distributions and related statistics are reported herein. Descriptions of the benthic character from video tapes and still camera photographs of the bottom at these stations, and 33 others, are also presented. The southern and eastern parts of the study area are dominated by poorly sorted clayey silts that have nearly symmetrical distributions. Gravelly sediments are prevalent in the shallow northwestern part of the study area, but are also present in central part of the study area. Bands of sand, silty sand, and sand-silt-clay occur …

Atomic Force Microscopy Of Nucleoprotein Complexes, Y. L. Lyubchenko, B. L. Jacobs, S. M. Lindsay, A. Stasiak

Scanning Microscopy

Recent data on the AFM studies of nucleoprotein complexes of different types are reviewed in this paper. The first section describes the progress in the sample preparation methods for AFM studies of nucleic acids and nucleoprotein complexes. The second part of this paper reviews AFM data on studies of complexes of DNA with regulatory proteins. These studies include two different types of DNA distortion induced by proteins binding: local bending of DNA at sites of protein binding and formation of large loops due to protein-protein interactions between molecules bound to distant sites along the DNA molecules (DNA looping). The prospects …

An Improved Method For Chemical Devitellinization Of X-Gal Stained Drosophila Embryos, Amit Singh, Madhuri Kango-Singh, P. Sinha

Biology Faculty Publications

In Drosophila developmental biological studies, X-gal staining is commonly employed to study the spatio-temporal expression of the lacZ reporter gene in the transformed flies or their embryos. Study of the lacZ pattern in embryos often suffers from the lack of an efficient and high yieldirrg technique for devitellinization of X-gal stained embryos. Devitellinization techniques employed during antibody staining, in situ hybridization or embryonic cuticular preparations generally do not give satisfactory results when used for similar purpose in X-gal stained embryos. This results in the flaky appearance of the blue stain. We present here an improved chemical devitellinization technique which gives …

The Principles Of Proton Probe Microanalysis In Biology, G. J. F. Legge, M. Cholewa

Scanning Microscopy

The proton microprobe, more correctly described as an ion microprobe which operates at MeV energies, complements its parent instrument the electron microprobe. This paper compares the basic principles and performance of the two instruments and relates the evolution of biological analysis on such ion microprobes to that on electron microprobes, covering the development of sample handling techniques and of data handling techniques and comparing beam damage studies. The paper describes the variety of techniques available to the ion microprobe - the initial techniques of Energy Dispersive X-ray analysis, Rutherford Back Scattering and Nuclear Reaction Analysis and the rapid evolution of …

Quantitative Dark-Field Mass Analysis Of Ultrathin Cryosections In The Field-Emission Scanning Transmission Electron Microscope, S. Brian Andrews, Roger A. Buchanan, Richard D. Leapman

Scanning Microscopy

The availability of a cryotransfer stage, highly efficient electron energy loss spectrometers, and ultrathin-window energy-dispersive x-ray spectrometers for the VG Microscopes HB501 field-emission scanning transmission electron microscope (STEM) provides this instrument with the potential for high resolution biological microanalysis. Recent technical advances offer cryosections that are thin enough to take advantage of the analytical capabilities of this microscope. This paper first discusses the quantitative characterization of freeze-dried, ultrathin cryosections of directly frozen liver and brain by low-dose dark-field STEM imaging. Such images reveal high-quality sections with good structural detail, mainly due to reduced preparation artifacts and electron beam damage. These …

Analysis Of High Quality Monatomic Chromium Films Used In Biological High Resolution Scanning Electron Microscopy, Robert P. Apkarian

Scanning Microscopy

During the recent employment of field emission (FE) in-lens scanning electron microscopes (SEMs), refractory metal deposition technology has co-evolved to provide enhanced contrast of 1-10 nm hydrocarbon based biological structures imaged at high magnifications (> 200,000 times). Pioneer development employing the Penning sputter system in a high vacuum chamber proved that imaging of chromium (Cr) coated biological specimens contained enriched secondary electron (SE)-(I) contrasts. Single nanometer size fibrillar and particulate ectodomains within the context of complex biological membranes were accurately imaged without significant enlargement using the high resolution SE-I mode (HRSEM). This paper reports the transmission electron microscopy (TEM) testing …

The Preparation Of Cultured Cells For X-Ray Microanalysis, Alice Warley

Scanning Microscopy

X-ray microanalysis of cells in culture is being used increasingly for the study of relationships between element (ion) content and cell function. There is, however, no one single method which can be used for the preparation of all different cell types for study by microanalysis. Cells in suspension are usually concentrated by centrifugation, before cryofixation, cryosectioning, and freeze drying. On the other hand cells grown as monolayers are more often studied as whole cell mounts, which are washed to remove the external medium before cryofixation and freeze drying. The alternative approach, sectioning of cell monolayers is rarely used. Some of …

Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority

Publications (WR)

The purpose of Task 010A15M of the Southern Nevada Water Authority (SNWA) Treatment and Transmission Facility (TTF) contract is to conduct a study of existing information concerning water quality within Lake Mead and identify additional water quality studies that are needed to supplement existing data. The objective of this task is not to discuss treatability of the raw water source; this is addressed by Task 010A18M, "Define Water Treatment Requirements." In addition, a narrative on the effect of pending Safe Drinking Water Act amendments and a determination of treated water quality goals is included in Task 010A16M, "Review Safe Drinking …

Ion Microscopy In Biology, George H. Morrison, Isabelle Gay, Subhash Chandra

Scanning Microscopy

Ion microscopy, a mass spectrometry based isotopic imaging technique, is uniquely suited for ion transport-related problems in biological systems. Due to its high sensitivity, it can image the transport and distribution of both major and minor elements (isotopes) at subcellular resolutions. The images of major elements such as K, Na, Cl, etc., can be viewed directly and recorded in real-time from the microchannel plate-fluorescent screen detector of the instrument. The low concentration physiologically important elements, such as Ca, need about one minute of integration for good quality imaging. The isotopic imaging capability of ion microscopy provides a unique approach for …

Modelling Avian Distributions Of The Navarrese Region In Northern Spain With A Geographic Information System, Samuel Soret-Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

GIS (Geographic information Systems) technology was used for identifying relations between environmental characteristics and the breeding distributions of nine avian species of the Navarrese region in northern Spain. Data overlays of multiple GIS layers derived the explanatory variables for modelling the breeding distributions from logistic regressions. A spatial autocorrelation analysis was conducted to characterize the distribution patterns and to incorporate spatial factors (neighborhood effects) into their analysis.

All nine patterns analyzed exhibited a high level of spatial autocorrelation. Accordingly, the basic hypothesis of spatial randomness was rejected in favor of spatial clustering for the sample data. The breeding distributions strongly …

Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall

Biological Sciences Faculty Publications

A twelve-month phytoplankton study was conducted in Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Four dominant phytoplankton groups were identified at these sites. These were the Bacillariophyceae, Cyanophyceae, Cryptophyceae and an autotrophic picoplankton component. Over the past 20 years there has been a decrease in the mean pH levels of Lake Drummond and the replacement of one its former major components, the Chlorophyceae, by the Cyanophyceae. Based on water quality analysis results and species diversity indices, Lake Drummond is classified as in an early eutrophic stage of development.

The Expression Pattern Of The Tonoplast Intrinsic Protein Γ-Tip In Arabidopsis Thaliana Is Correlated With Cell Enlargement, Edward Himelblau, Herman Hofte, Dolors Ludevid, Maarten J. Chrispeels

Biological Sciences

The vacuolar membrane (tonoplast) contains an abundant intrinsic protein with six membrane-spanning domains that is encoded by a small gene family. Different isoforms of tonoplast intrinsic protein (TIP) are expressed in different tissues or as a result of specific signals. Using promoter-β-glucuronidase (GUS) fusions and in situ hybridization, we have examined the expression of γ-TIP in Arabidopsis thaliana. GUS staining of plants transformed with promoter-GUS fusions showed that γ-TIP gene expression is high in recently formed tissues of young roots. In the shoot, γ-TIP gene expression was highest in the vascular bundles of stems and petioles, as well as …

Effect Of Hindlimb Unweighting On Tissue Blood Flow In The Rat, Kerry S. Mcdonald, M. D. Delp, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The purpose of this study was to characterize the distribution of blood flow in the rat during hindlimb unweighting (HU) and post-HU standing and exercise and examine whether the previously reported (Witzmann et al., J. Appl. Physiol. 54: 1242–1248, 1983) elevation in anaerobic metabolism observed with contractile activity in the atrophied soleus muscle was caused by a reduced hindlimb blood flow. After either 15 days of HU or cage control, blood flow was measured with radioactive microspheres during unweighting, normal standing, and running on a treadmill (15 m/min). In another group of control and experimental animals, blood flow was measured …

A Review Of Graphite And Gold Surface Studies For Use As Substrates In Biological Scanning Tunneling Microscopy Studies, Carol R. Clemmer, Thomas P. Beebe Jr.

Scanning Microscopy

The current status of biological Scanning Tunneling Microscopy (STM) investigations and the importance of using a well-characterized substrate are discussed. The findings of over two years of experiments and over 1,000 images obtained on gold substrates prepared by a variety of different methods are statistically summarized and compared to a very flat reference substrate, highly oriented pyrolytic graphite (HOPG). In an effort to begin to corroborate STM results with those obtained from other more established techniques, the results of Auger Electron Spectroscopy (AES) and Electron Spectroscopy for Chemical Analysis (ESCA) of biomolecular STM samples are presented.

Integrated Single Crystal Detector For Simultaneous Detection Of Cathodoluminescence And Backscattered Electrons In Scanning Electron Microscopy, Rudolf Autrata, Josef Jirák, Jiří Špinka, Otakar Hutař

Scanning Microscopy

The design of the majority of the available high efficiency cathodoluminescence (CL) detection systems allows the secondary electron (SE) and backscattered electron (BSE) image modes to be detected simultaneously to a limited degree only. The described CL-BSE detector is based on the single crystal YAG scintillator shaped as a spherical mirror which reflects photons emitted from the CL specimen and focuses them on to the entrance surface of a fibre optic light guide connected to the photomultiplier tube (PMT I). The backscattered electrons emitted from the CL specimen move through the reflecting layer of the mirror into the YAG scintillator …

A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart

Scanning Microscopy

A common problem with electron micrographs of biological objects is that fine details are usually faint and, moreover, tend to be obscured by background noise from stain and support film. Filtering is a useful way to improve the signal-to-noise ratio and is particularly important when trying to detect small changes (conformational or due to labelling) or when examining frozen hydrated objects, where the statistical definition of the image has been reduced because of the low-dose conditions needed to prevent radiation damage. Filtering can also be used to address the superposition effects that result from the large depth of focus of …

Microbeam Studies Of The Sensitivity Of Structures Within Living Cells, L. A. Braby

Scanning Microscopy

Determining the biological effects of low doses of radiation with high linear energy transfer (LET) is complicated by the stochastic nature of charged-particle interactions. Populations of cells exposed to very low radiation doses contain a few cells which have been hit by a charged particle, while the majority of the cells receive no radiation damage. At somewhat higher doses, a few cells receive two or more events. Because the effects of damage produced by separate events can interact in the cell, we have had to make assumptions about the nature of these interactions in order to interpret the results of …

A Review Of Scanning Tunneling Microscope And Atomic Force Microscope Imaging Of Large Biological Structures: Problems And Prospects, B. L. Blackford, M. H. Jericho, P. J. Mulhern

Scanning Microscopy

The application of the scanning tunneling microscope (STM) and the atomic force microscope (AFM) to the study of small biological molecules, such as DNA and smaller molecules, has received considerable attention in the literature. This paper reviews STM and AFM studies of larger biological structures such as bacterial membranes, bacteriophages, viruses, antibodies, etc. The problems encountered in these applications are emphasized, with particular reference to the unknown conduction mechanism, tip-sample interaction forces, and tip-sample convolution artifacts in the images. The latter problem is illustrated by new results from IgG antibody complexes attached to a bacterial sheath layer. A new conduction …

Terminal Differentiation Of Human Fibroblasts Is Induced By Radiation, H. Peter Rodemann, Hans-Peter Peterson, Karla Schwenke, K. -Hartmut Von Wangenheim

Scanning Microscopy

In order to analyze the effect of various kinds of radiation on the terminal differentiation processes of fibroblasts in culture, both human skin and lung fibroblasts were irradiated with electromagnetic non ionizing as well as ionizing radiation in clonal and sparse mass culture systems. As analyzed by cell biological (cell type frequencies), biochemical (collagen synthesis) and molecular markers (expression of protein PIVa) human skin and lung fibroblasts are induced to differentiate prematurely into terminal postmitotic cells. Thus, both electromagnetic and ionizing radiation induce terminal differentiation in cultured cells. These data add some new aspects for the interpretation of radiation effects …

Ted Hall And The Science Of Biological Microprobe X-Ray Analysis: A Historical Perspective Of Methodology And Biological Dividends, Brij L. Gupta

Scanning Microscopy

This review surveys the emergence of electron probe X-ray microanalysis as a quantitative method for measuring the chemical elements in situ. The extension of the method to the biological sciences under the influence of Ted Hall is reviewed. Some classical experiments by Hall and his colleagues in Cambridge, UK, previously unpublished, are described; as are some of the earliest quantitative results from the cryo-sections obtained in Cambridge and elsewhere. The progress of the methodology is critically evaluated from the earliest starts to the present state of the art. Particular attention has been focused on the application of the method in …

"Introduction" (To Alfred Russel Wallace; An Anthology Of His Shorter Writings), Charles H. Smith

DLPS Faculty Publications

No abstract provided.

Age And Growth Of King Mackerel, Scomberomorus Cavalla, From The Atlantic Coast Of The United States, Mark R. Collins, David J. Schmidt, C. Wayne Waltz, James L. Pinckney

Faculty Publications

Whole sagittae from 683 and sectioned sagittae from 773 "adult" (age> 0 ; 437-1.310 mm FL), and lapilli from 29 larval (2-7 mm SL) and 69 young-of-the-year (79-320 mm FL) king mackerel, were examined. All fish were from waters off the Atlantic coast of the southeastern United States (Cape Canaveral, Florida to Cape Fear. North Carolina). Back-calculated lengths at ages and von Bertalanffy growth equations were calculated from both whole and sectioned sagittae. Ages determined from sectioned sagittae were significantly greater than ages determined from whole sagittae, and the magnitude of the difference increased with age (from sections). Rings on …

Proton Microprobe And Particle Induced X-Ray Emission (Pixe) Analysis For Studies Of Pathological Brain Tissue, K. G. Malmqvist, A. Brun, K. Inamura, E. Martins, L. G. Salford, B. K. Siesjö, U. A. S. Tapper, K. Themner

Scanning Microscopy

Particle Indiced X-ray Emission and proton microprobe analyses have been applied for the investigation of regional elemental distributions in connection with various pathological states in the brain. Malignant brain tumours and adjacent histologically intact tissue removed during surgery were analysed with PIXE. Systematic elemental variations, e.g., for calcium and selenium, were observed in the tumour front. The proton microprobe was applied to study the Ca and K concentrations in various cell strata in hippocampus following transient ischaemia in rat brain. Significant increases in the Ca level occurred in selectively vulnerable cells within 48 h after the ischaemia.

Cellular Politics: Ernest Everett Just, Richard B. Goldschmidt, And The Attempt To Reconcile Embryology And Genetics, Scott F. Gilbert

Biology Faculty Works

No abstract provided.

Electron Energy Loss Spectroscopic Imaging In Biology, G. T. Simon, Y. M. Heng

Scanning Microscopy

One of the goals in biology is to relate the ultrastructure with the movement of elements to under stand better physiological and pathophysiological mechanisms. Electron energy loss spectroscopy (EELS) imaging, which was developed in the last decade, appears to be an ideal technique to make such correlation.

EELS takes advantage of the energy distribution of transmitted electrons which interacted with the specimen. All these electrons are collected and can be displayed as an energy loss spectrum for analytical purposes. Images can be produced from selected regions from the energy distribution allowing the mapping of specific elements. The main advantage of …