scholarly journals Morphometric Variations in Caryopses and Seedlings of Two Grass Species Growing Under Contrasting Habitats

2015 ◽  
Vol 7 (3) ◽  
pp. 355-360
Author(s):  
Dhara GANDHI ◽  
Susy ALBERT
Keyword(s):  
Light Microscopy ◽  
Fresh Water ◽  
Grass Species ◽  
Morphometric Traits ◽  
Electron Microscopic ◽  
Contrasting Habitats ◽  
Characteristic Features ◽  
Periclinal Walls ◽  
Urochondra Setulosa ◽  
Sem Studies

Urochondra setulosa grows in marine conditions, while Sporobolus indicus grows near fresh water and sometimes also close to moist places along roadside areas. Both species belong to the same tribe and same family. The two grass species growing under different habitats showed characteristic variations in their morphometric traits of the caryopsis and seedlings. U. setulosa growing in salty area had characteristic features, e.g. leaf and culm with salt deposition, rigid leaf blade with pointed leaf tip, while S. indicus growing near fresh water showed glabrous nodes and internodes. Morphometric analysis of caryopses of both species showed very similar features, without prominent differences in their length, breadth and thickness. But light microscopy and scanning electron microscopic (SEM) studies showed variations. Under light microscopy, features like colour, shape and compression of caryopses showed differences among the species. SEM studies of caryopses revealed a reticulate type of pattern of sculpturing on both dorsal and ventral surfaces, whereas anticlinal and periclinal walls in U. setulosa were elevated with folded walls, while in S. indicus had non elevated undulating walls. In conclusion, each individual grass ecotype evolves some characteristic morphological features to thrive well under a particular environment. Both species studied hereby, grown in different habitats, showed remarkable differentiations in their characters, thus indicating that habitats play a major role in traits of the plant growth.

Immunocytochemistry. A Review of Methodology for Electron Microscopic Applicaiton

1974 ◽  
Vol 32 ◽  
pp. 328-329
Author(s):  
Joseph E. Mazurkiewicz
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Ultrastructural Level ◽  
Electron Microscopic ◽  
Biological Interest ◽  
Investigative Approach ◽  
Immunologic Activity ◽  
Dense Label

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.

A Method for Electron Microscopic Study of Tissue Culture Cell Monolayers Grown in Tubes

1967 ◽  
Vol 25 ◽  
pp. 132-133
Author(s):  
R. Stephens ◽  
G. Schidlovsky ◽  
S. Kuzmic ◽  
P. Gaudreau
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Light Microscopy ◽  
Cell Sheet ◽  
Culture Cell ◽  
Tissue Culture Cell ◽  
Electron Microscopic ◽  
Cell Sheets ◽  
Morphological Alterations ◽  
Culture Cells

The usual method of scraping or trypsinization to detach tissue culture cell sheets from their glass substrate for further pelletization and processing for electron microscopy introduces objectionable morphological alterations. It is also impossible under these conditions to study a particular area or individual cell which have been preselected by light microscopy in the living state.Several schemes which obviate centrifugation and allow the embedding of nondetached tissue culture cells have been proposed. However, they all preserve only a small part of the cell sheet and make use of inverted gelatin capsules which are in this case difficult to handle.We have evolved and used over a period of several years a technique which allows the embedding of a complete cell sheet growing at the inner surface of a tissue culture roller tube. Observation of the same cell by light microscopy in the living and embedded states followed by electron microscopy is performed conveniently.

Ultrastructural modification of cellular interactions in cancer tumor

1978 ◽  
Vol 36 (2) ◽  
pp. 318-319
Author(s):  
N. P. Dmitrieva
Keyword(s):  
Cancer Cells ◽  
Human Thyroid ◽  
Adjacent Cell ◽  
Main Role ◽  
Cellular Interactions ◽  
Electron Microscopic ◽  
Cancer Tumor ◽  
Normal Human ◽  
Characteristic Features

One of the most characteristic features of cancer cells is their ability to metastasia. It is suggested that the modifications of the structure and properties of cancer cells surfaces play the main role in this process. The present work was aimed at finding out what ultrastructural features apear in tumor in vivo which removal of individual cancer cells from the cell population can provide. For this purpose the cellular interactions in the normal human thyroid and cancer tumor of this gland electron microscopic were studied. The tissues were fixed in osmium tetroxide and were embedded in Araldite-Epon.In normal human thyroid the most common type of intercellular contacts was represented by simple junction formed by the parallelalignment of adjacent cell membranees leaving in between an intermembranes space 15-20 nm filled with electronlucid material (Fig. 1a). Sometimes in the basal part of cells dilatations of the intercellular space 40-50 nm wide were found (Fig. 1a). Here the cell surfaces may form single short microvilli.

Correlative video enhanced differential interference contrast light microscopy (VDIC)-LM), low-voltage high-resolution SEM (LV-HR-SEM), and high-voltage electron microscopy (HVEM) in the observation of gold-labelled surface antigens and the subjacent cytoskeletal matrix

1989 ◽  
Vol 47 ◽  
pp. 904-905
Author(s):  
Ralph M. Albrecht ◽  
Scott R. Simmons ◽  
Marek Malecki
Keyword(s):  
High Resolution ◽  
Light Microscopy ◽  
Low Voltage ◽  
Microscopic Analysis ◽  
Cell Labelling ◽  
Video Technology ◽  
Electron Microscopic ◽  
Image Capture ◽  
High Voltage Electron Microscopy ◽  
Fluorescence Studies

The development of video-enhanced light microscopy (LM) as well as associated image processing and analysis have significantly broadened the scope of investigations which can be undertaken using (LM). Interference/polarization based microscopies can provide high resolution and higher levels of “detectability” especially in unstained living systems. Confocal light microscopy also holds the promise of further improvements in resolution, fluorescence studies, and 3 dimensional reconstruction. Video technology now provides, among other things, a means to detect differences in contrast difficult to detect with the human eye; furthermore, computerized image capture, processing, and analysis can be used to enhance features of interest, average images, subtract background, and provide a quantitative basis to studies of cells, cell features, cell labelling, and so forth. Improvements in video technology, image capture, and cost-effective computer image analysis/processing have contributed to the utility and potential of the various interference and confocal microscopic instrumentation.Electron microscopic technology has made advances as well. Microprocessor control and improved design have contributed to high resolution SEMs which have imaging capability at the molecular level and can operate at a range of accelerating voltages starting at 1KV. Improvements have also been seen in the HVEM and IVEM transmission instruments. As a whole, these advances in LM and EM microscopic technology provide the biologist with an array of information on structure, composition, and function which can be obtained from a single specimen. Corrrelative light microscopic analysis permits examination of living specimens and is critical where the “history” of a cell, cellular components, or labels needs to be known up to the time of chemical or physical fixation. Features such as cytoskeletal elements or gold label as small as 0.01 μm, well below the 0.2 μm limits of LM resolution, can be “detected” and their movement followed by VDIC-LM. Appropriate identification and preparation can then lead to the examination of surface detail and surface label with stereo LV-HR-SEM. Increasing the KV in the HR-SEM while viewing uncoated or thinly coated specimens can provide information from beneath the surface as well as increasing Z contrast so that positive identification of surface and subsurface colloidal gold or other heavy metal labelled/stained material is possible. Further examination of the same cells using stereo HVEM or IVEM provides information on internal ultrastructure and on the relationship of labelled material to cytoskeletal or organellar distribution, A wide variety of investigations can benefit from this correlative approach and a number of instrumentational configurations and preparative pathways can be tailored for the particular study. For a surprisingly small investment in time and technique, it is often possible to clear ambiguities or questions that arise when a finding is presented in the context of only one modality.

Progressive Mucinous Histiocytosis: Importance of Electron Microscopy to Confirm Diagnosis

2010 ◽  
Vol 14 (5) ◽  
pp. 245-248 ◽  
Author(s):  
Iman Hemmati ◽  
W. Alastair McLeod ◽  
Richard I. Crawford
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Clinical Examination ◽  
Crucial Role ◽  
Langerhans Cell Histiocytosis ◽  
Langerhans Cell ◽  
History Of ◽  
Characteristic Features ◽  
Immunohistochemical Studies

Background: Progressive mucinous histiocytosis (PMH) is a benign, non-Langerhans cell histiocytosis with characteristic ultrastructural features that can be used for diagnosis. Once an important tool in dermatologic diagnosis, electron microscopy has been largely replaced by immunohistochemistry and immunofluorescence techniques today. However, electron microscopy occasionally still plays a crucial role in the diagnosis of dermatologic conditions. We report a case of PMH as an example of a dermatologic disorder that requires electron microscopy for its diagnosis. Methods: A 60-year-old woman presented to our clinic with a history of small, sharply demarcated, skin-colored papules ranging from 2 to 5 mm in diameter distributed over the arms, forearms, and dorsal hands. The results of light microscopy, immunohistochemical studies, and clinical examination were inconclusive. Another biopsy for electron microscopy showed the characteristic features of PMH. Conclusion: This case demonstrates that a dermatopathology service still needs to have access to electron microscopy for diagnostic purposes to successfully diagnose a small number of rare conditions.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

IV.—Physiography of the Lower Trias

1889 ◽  
Vol 6 (12) ◽  
pp. 549-558 ◽  
Author(s):  
T. Mellard Reade
Keyword(s):  
Fresh Water ◽  
Freshwater Lakes ◽  
Characteristic Features

The origin of the Triassic rocks of Britain is a question that has excited from time to time much interest and varied speculation. The entire absence of fossils in the Lower Trias or Bunter Sandstone has led the majority of geological reasoners to look to causes other than marine action for an explanation of its characteristic features. The late Mr. Godwin-Austen was of opinion that the whole of the Triassic rocks were laid down in freshwater lakes which, passing through the brackish stage, become finally saturated with saline matter through evaporation exceeding the inflow of fresh water. It has been felt, however, by other geologists, that this theory, while accounting fairly well for the upper deposits of the Triassic age, does not fit in with the phenomena of current bedding, the presence and distribution of the numerous quartzite and other well-rounded pebbles, and the comparative absence of marl-beds, which distinguish the Lower Trias or Bunter Sandstones.

Electrostatic Removal of Loose Particulate Surface Contamination from Historical Photographs / Elektrostatische Abnahme lose aufliegender partikulärer Verunreinigungen von historischen Photographien / Dissolution électrostatique des particules libres contaminant la surface de photographies historiques

2013 ◽  
Vol 34 (3) ◽  
Author(s):  
Marie-Louise Frank ◽  
Ernst Becker ◽  
Julia Schultz ◽  
Ulrike Hähner ◽  
Irene Brückle ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Microbial Contamination ◽  
Surface Contamination ◽  
Visual Evaluation ◽  
Microbiological Methods ◽  
Microbial Contaminants ◽  
Characteristic Features ◽  
Cleaning Technology ◽  
Historical Photographs ◽  
Particulate Surface

AbstractThis article discusses the use of electrostatic cleaning technology to remove loose particulate surface contamination - which here includes microbial contaminants such as spores, conidia and hyphal fragments - from two 19th century albumen photographs mounted on cardboard. The results of this study, obtained using light microscopy, SEM/EDX and microbiological methods, as well as conservators' visual evaluation, show that the technology is fundamentally suitable for removing microbial contamination from photographic prints and their cardboard mounts. Cleaning the surface four times with electrostatically charged foils reduced the microbial contamination by up to 70%. The surface of the albumen print, which is sensitive to abrasion, was not harmed, and its characteristic features were not changed. The photographs, which were partly delaminated from the cardboard support and the mechanically weakened cardboard, could be treated without creating any additional damage.

Staining methods for sections of epon-embedded tissues for light microscopy

1970 ◽  
Vol 48 (1) ◽  
pp. 189-191 ◽  
Author(s):  
C. Roland Leeson ◽  
Thomas S. Leeson
Keyword(s):  
Light Microscopy ◽  
Synthetic Resin ◽  
Electron Microscopic ◽  
Glass Slides ◽  
Staining Methods

Sections 0.5–2 μ thick are mounted on clean glass slides and allowed to dry. A number of staining procedures are described. After the sections are stained, permanent preparations are made by mounting them in a synthetic resin. The methods result in sections which are suitable for routine light microscopy and for comparison with adjacent electron microscopic sections.

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