Search results for: microautoradiography-and-electron-probe-analysis

Microautoradiography and Electron Probe Analysis

Author : U. Lüttge
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In biological literature, several definitions of quantitative autoradio graphy are given. The term is defined as either the determination and com parison of the density of silver grains above various structures or under varying conditions, or the determination of absolute quantities of radio activity. In both these cases, photometric measurement serves for more rapid and more exact evaluation of grain densities than would be possible by visual counting of the grains. The equipment generally used for the photometric measurement of silver grains consists of a microscope, a photocell, an electronic amplifier system and a display unit. Grains can be made accessible to photometric evaluation by various kinds of microscopic illumination: 1. Substage bright-field illumination. 2. Substage dark-field illumination. 3. Incident dark-field illumination. 4. Vertical bright-field illumination. With all these types of illumination, the relationship between the luminous flux I absorbed by the film, scattered into the objective and reflected or diffracted, and the flux 10 which is not affected by the film is used as a measure of grain density. Since these are differential measurements, the light beam I transmitted by the film is in itself a measure of grain density if the luminous flux 10 incident on the grains is kept constant. This approach has been used in a large number of measuring setups.

Microautoradiography and Electron Probe Analysis

Author : Ulrich Lüttge
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Zeitschrift F r Naturforschung

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Electron Probe Microanalysis

Author : Karl Zierold
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The aim of electron probe microanalysis of biological systems is to identify, localize, and quantify elements, mass, and water in cells and tissues. The method is based on the idea that all electrons and photons emerging from an electron beam irradiated specimen contain information on its structure and composition. In particular, energy spectroscopy of X-rays and electrons after interaction of the electron beam with the specimen is used for this purpose. However, the application of this method in biology and medicine has to overcome three specific problems: 1. The principle constituent of most cell samples is water. Since liquid water is not compatible with vacuum conditions in the electron microscope, specimens have to be prepared without disturbing the other components, in parti cular diffusible ions (elements). 2. Electron probe microanaly sis provides physical data on either dry specimens or fully hydrated, frozen specimens. This data usually has to be con verted into quantitative data meaningful to the cell biologist or physiologist. 3. Cells and tissues are not static but dynamic systems. Thus, for example, microanalysis of physiolo gical processes requires sampling techniques which are adapted to address specific biological or medical questions. During recent years, remarkable progress has been made to overcome these problems. Cryopreparation, image analysis, and electron energy loss spectroscopy are key areas which have solved some problems and offer promise for future improvements.

Advanced Techniques in Biological Electron Microscopy

Author : J.K. Koehler
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The past decade has seen a remarkable increase in the use of electron microscopy as a researm tool in biology and medicine. Thus, most institu tions of higher learning now boast several electron optical laboratories having various levels of sophistication. Training in the routine use of elec tron optical equipment and interpretation of results is no longer restricted to a few prestigious centers. On the other hand, temniques utilized by researm workers in the ultrastructural domain have become extremely diverse and complex. Although a large number of quite excellent volumes of electron microscopic temnique are now dedicated to the basic elements available whim allow the novice to acquire a reasonable introduction to the field, relatively few books have been devoted to a discussion of more ad vanced temnical aspects of the art. It was with this view that the present volume was conceived as a handy reference for workers already having some background in the field, as an information source for those wishing to shift efforts into more promising temniques, or for use as an advanced course or seminar guide. Subject matter has been mosen particularly on the basis of pertinence to present researm activities in biological electron microscopy and emphasis has been given those areas whim seem destined to greatly expand in useful ness in the near future.

Membrane Transport in Plants

Author : U. Zimmermann
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In February, 1974, an 'International Workshop on Membrane Transport in Plants' was held at the Nuclear Research Centre, JLiI ich, West Germany. More than two hundred and fifty people, from fourteen countries, took part in this highly successful meeting. A somewhat similar meeting took place in Liverpool, England, two years ago and it became clear there that progress in the field of membrane transport in plants was now so marked that a second, and wider, meeting in Germany was more than fully justified. The members of our pro gramme committee (U. Zimmermann, Chairman, JLilich (FRG); J. Dainty,

Transport in Plants III

Author : C.R. Stocking
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The problems associated with the movement of water and solutes throughout the plant body have intrigued students of plants since Malpighi's conclusions in 1675 and 1679 that nutrient sap flows upward and downward in stems through vessels in both wood and bark. Steven Hale's ingenious experiments on the movement of water in plants in 1726 and Hartig's observations of sieve-tube exudation in the mid-19th century set the stage for continued intensive studies on long-range transport in plants. In spite of this interest for more than 200 years in the movement of solutes and water in plants, it has only been within the last 20 to 30 years that extensive research effort has been directed toward a critical evaluation of the interactions among the various cellular organelles. The important roles played by the exchange of metabolites in the control and regulation of cellular processes is now widely recognized, but in most instances poorly understood.

Microwave Techniques and Protocols

Author : Richard T. Giberson
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Richard Giberson and Richard Demaree, Jr, have collected a wide range of time-saving microwave techniques for processing biological samples for evaluation by many different microscopic methods. Described in step-by-step detail by hands-on researchers, these readily reproducible protocols include both optimized classic methods and such state-of-the art techniques as in vivo labeling, formalin fixation of fresh tissue, vacuum processing, and processing for scanning electron microscopy. Each stand-alone microwave method has been handcrafted by a researcher who regularly uses it to ensure processing success and the brightest quality result.

Methods in Plant Electron Microscopy and Cytochemistry

Author : William V. Dashek
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Hands-on experimentalists describe the cutting-edge microscopical methods needed for the effective study of plant cell biology today. These powerful techniques, all described in great detail to ensure successful experimental results, range from light microscope cytochemistry, autoradiography, and immunocytochemistry, to recent developments in fluorescence, confocal, and dark-field microscopies. Important advances in both conventional and scanning electron microscopies are also fully developed, together with such state-of-the-art ancillary techniques as high-resolution autoradiography, immunoelectron microscopy, X-ray microanalysis, and electron systems imaging. Easy-to-use and up-to-date, Methods in Plant Electron Microscopy and Cytochemistry offers today's plant scientists a first class collection of readily reproducible light and electron microscopical methods that will prove the new standard for all working in the field.

U S Environmental Protection Agency Library System Book Catalog Holdings as of July 1973

Author : United States. Environmental Protection Agency. Library Systems Branch
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Plant Nutrition from Genetic Engineering to Field Practice

Author : J. Barrow
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Plant Nutrition - From Genetic Engineering to Field Practice, the 12th International Colloquium on Plant Nutrition, is the latest in a series which began in 1954. Early meetings were mainly concerned with the practical problems of soil fertility, with soil assessment, fertilizer requirements and methods of analysis. As the colloquia have progressed, the emphasis has slowly changed. The practical problems are still important, but there is increasing emphasis on plant physiology, plant biochemistry, membrane biochemistry, and even on the chemistry of genes which control the proteins which transfer nutrient ions to the inside of cells. The meetings therefore provide a valuable opportunity for each half of the science of plant nutrition to interact with, and learn from the other half. This volume begins with five papers which review current knowledge in important fields: the rhizosphere, molecular biology, electron microscopy, location and function of elements in vivo, and modelling nutrient responses in the field. These themes are continued in groups of shorter papers which follow. In addition, there are sections on nutrient dynamics and partitioning, diagnostic techniques, plant survival strategies, mycorrhizas, and on nutrients such as P, N, S, K, Ca, Mg, and micronutrients. A large section is devoted specifically to boron - reflecting the considerable current interest in this element. In total there are 177 refereed papers providing both a broad overview and a detailed picture of the latest developments in pure and applied plant nutrition.

Laboratory Procedures and Their Applications

Author : Indra Vasil
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Laboratory Procedures and Their Applications

Fixation for Electron Microscopy

Author : M.A. (Eric) Hayat
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Fixation for Electron Microscopy presents how to better understand the effects of fixatives on the molecular structure of the cell. This book attempts to consider each aspect of fixation, including chemical interactions between fixatives and individual cellular substances. The chemistry of fixative interactions that are discussed in the book is based primarily on the reactions of a fixative with isolated proteins, lipids, nucleic acids, and carbohydrates. The book shows that the correct interpretation of information retrieved from electron micrographs depends on the knowledge of the basic principles underlying the fixation procedure. Also, the book presents the fixation of both eukaryotic and prokaryotic specimens. The special fixation conditions for plant specimens are discussed in detail and have been allotted a whole chapter. Also emphasized in this book is the connection between morphology and biochemical aspects of preparatory treatments and the chemical basis of the formation of artifacts. This topic is useful in understanding the modifications of cell structures introduced during their processing. A guide for recognizing and minimizing major artifacts and fixation faults that are usually encountered is also presented in the book. This valuable resource will prove useful to both students and professionals in the field of biology and clinical medicine. Specimen preservation researchers can also benefit from this book.

Catalog of Copyright Entries Third Series

Author : Library of Congress. Copyright Office
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Transport in Plants I

Author : M.H. Zimmermann
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When WILHELM RUHLAND developed his plan for an Encyclopedia of Plant Physiol ogy more than three decades ago, biology could still be conveniently subdivided into classical areas. Even within plant physiology, subdivisions were not too difficult to make, and general principles could be covered sufficiently in the two introductory volumes of the Encyclopedia on the physical and chemical basis of cell biology. But the situation changed rapidly even during the 12-year publication period of the Encyclopedia (1955-1967). The new molecular direction of genetics and structural research on biopolymers had an integrating effect on all other biological fields, including plant physiology, and it became increasingly difficult to keep previously distinct areas separated. RUHLAND'S overall plan included 18 volumes and about 22,000 pages. It covered the entire field of plant physiology, in most cases from the very beginning. But, as each volume appeared, it was clear that its content would soon be outdated.

Progress in Botany

Author : Joachim W. Kadereit
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With one volume each year, this series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences. The present volume includes reviews on genetics, cell biology, and vegetation science.

Principles and Techniques of Scanning Electron Microscopy

Author : M. A. Hayat
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Transient Processes in Cell Proliferation Kinetics

Author : Andrej Yu. Yakovlev
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A mathematician who has taken the romantic decision to devote himself to biology will doubtlessly look upon cell kinetics as the most simple and natural field of application for his knowledge and skills. Indeed, the thesaurus he is to master is not so complicated as, say, in molecular biology, the structural elements of the system, i. e. ceils, have been segregated by Nature itself, simple considerations of balance may be used for deducing basic equations, and numerous analogies in other areas of science also superficial add to one"s confidence. Generally speaking, this number of impression is correct, as evidenced by the very great theoretical studies on population kinetics, unmatched in other branches of mathematical biology. This, however, does not mean that mathematical theory of cell systems has traversed in its development a pathway free of difficulties or errors. The seeming ease of formalizing the phenomena of cell kinetics not infrequently led to the appearance of mathematical models lacking in adequacy or effectiveness from the viewpoint of applications. As in any other domain of science, mathematical theory of cell systems has its own intrinsic logic of development which, however, depends in large measure on the progress in experimental biology. Thus, during a fairly long period running into decades activities in that sphere were centered on devising its own specific approaches necessitated by new objectives in the experimental in vivo and in vitro investigation of cell population kinetics in different tissues.

Plant Carbohydrates II

Author : W. Tanner
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In 1958, a single volume in the original series of this Encyclopedia adequately summarized the state of knowledge about plant carbohydrates. Expansion into two volumes in the New Series highlights the explosive increase in information and the heightened interest that attended this class of compounds in the interven ing years. Even now the search has just begun. Much remains to be accom plished; e.g., a full description of the plant cell wall in chemical terms. Why this growing fascination with plant carbohydrates? Clearly, much credit goes to those who pioneered the complex chemistry of polyhydroxylated compounds and to those who later sorted out the biochemical features of these molecules. But there is a second aspect, the role of carbohydrates in such biological func tions as host-parasite and pollen-pistil interactions, the mating reaction in fungi, symbiosis, and secretion to name a few. Here is ample reason for anyone concerned with the plant sciences to turn aside for a moment and consider how carbohydrates, so many years neglected in favor of the study of proteins and nucleic acids, contribute to the physiological processes of growth and devel opment in plants.

Micromethods in Molecular Biology

Author : Volker Neuhoff
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This book is based on practical experience and is therefore written as a prac tical manual. The fore-runners of the book were the manuals of the first and second EMBO-Courses on "Micromethods in Molecular Biology" which were held in G6ttingen in the spring of 1970 and the autumn of 1971. This book may serve as a manual not only for the participants of the third EMBO-Course to be held in G6ttingen in autumn 1973, but also for all experimenters who are interested in using micromethods. It must be emphasized from the outset that this book is conceived as a "cook book" and not as a monograph which attempts to revue the literature on micromethods critically. The methods described here in detail are performed routinely in the authors' laboratories and include all the practical details necessary for the successful appli cation of the micromethods. There are many other sensitive and excellent micro methods which are not included in this book, because the authors feel that in a "cook book" only methods for which they have personal experience and profi ciency should be described. Some readers may feel that the title promises more than the present contents of this book; however, if sufficient interest is shown in this volume, it may be possible to remedy such deficiencies in future editions.