scholarly journals The foregut of the Mysida (Crustacea, Peracarida) and its phylogenetic relevance

1998 ◽  
Vol 353 (1368) ◽  
pp. 559-581 ◽  
Author(s):  
Wulf Kobusch
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Histological Techniques ◽  
Ground Pattern ◽  
Neomysis Integer ◽  
Probable Function ◽  
Mesopodopsis Slabberi ◽  
Scanning Electron

The foreguts of the mysids Antarctomysis maxima , A. ohlinii , Hansenomysis antarctica , Heteromysis formosa , Mesopodopsis slabberi , Neomysis integer , Paramysis kessleri , Praunus flexuosus , and Siriella jaltensis were examined by maceration methods, histological techniques, and scanning electron microscopy. Their morphology, their connection with the midgut glands, and probable function are described and summarized. Previous stomach investigations on mysids and the results of the present study are tabulated; a list of foregut characters, common to all Mysida, is presented. The phylogenetic relevance of these characters within the Malacostraca, especially within the Peracarida, is discussed. Most features are inherited from the ground pattern of the Malacostraca or Eumalacostraca. The bulbous cardia with its dorsal fold, the armature of the lateralia, and the construction of the funnel region are apomorphies for the Mysida. The results suggest that characters of mysidan and other peracaridan foreguts might also be useful in the elucidation of the phylogeny of the Mysida and Peracarida, respectively.

A review of freshwater species of Diphyllobothrium with redescriptions and the distribution of D. dendriticum (Nitzsch, 1824) and D. ditremum (Creplin, 1825) from North America

1987 ◽  
Vol 65 (9) ◽  
pp. 2216-2228 ◽  
Author(s):  
Karin Andersen ◽  
Hilda Lei Ching ◽  
Rolf Vik
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
North America ◽  
Freshwater Species ◽  
Histological Techniques ◽  
Diphyllobothrium Dendriticum ◽  
Fish Samples ◽  
Diphyllobothrium Latum ◽  
Scanning Electron

Plerocercoids of Diphyllobothrium were studied from fish samples representing eight species of salmonids from British Columbia, Wyoming, Quebec, and Maine. Adults were studied mainly from experimental infections of golden hamsters, Mesocricetus auratus (Waterhouse). Using scanning electron microscopy and histological techniques, the plerocercoids and adults were identified as Diphyllobothrium dendriticum or Diphyllobothrium ditremum. Morphological comparisons were made with European specimens of these two species and those of Diphyllobothrium latum (Linnaeus, 1758). Among the nine freshwater species reviewed, Diphyllobothrium cordiceps (Leidy, 1872), Diphyllobothrium sebago (Ward, 1910), and Diphyllobothrium ursi Rausch, 1954, are considered synonyms of Diphyllobothrium dendriticum.

scholarly journals Description of the glochidium of Margaritifera auricularia (Spengler 1793) (Bivalvia, Unionoidea)

1998 ◽  
Vol 353 (1375) ◽  
pp. 1553-1559 ◽  
Author(s):  
R. Araujo ◽  
M. A. Ramos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Histological Techniques ◽  
Oral Plate ◽  
The Family ◽  
Anterior Position ◽  
First Time ◽  
Margaritifera Auricularia ◽  
Scanning Electron

The glochidium of Margaritifera auricularia is described for the first time by using light microscopy, scanning electron microscopy and histological techniques. The larval mantle is formed by only two layers of cells; the inner one being much thicker, with microvilli. All cell masses of the glochidium are temporary aggregations that are the rudiments of organs of the subsequent juveniles which will be released after metamorphosis in the host tissues. In the glochidium there are three main masses of cells: (i) the muscle, which is in an anterior position; (ii) the oral plate in the centre of the larva; and (iii) the more ventrally and posteriorly situated ventral plate, or foot rudiment, flanged with lateral pits all bearing dense cilia. No rudimentary organs such as the pericardium, the kidney, the heart or nerve ganglia have developed. There are no visible hooks in the valve margins, but by using light microscopy we observed minute teeth covered by a rim of the periostracum. Near the margin of the shell there are two pairs of sensory hair tufts only observable by scanning electron microscopy. The glochidium of M. auricularia is the largest of the family Margaritiferidae and intermediate between the glochidium of the known species of this family and those of Unionidae.

Fine structure and development of the zygospore of Rhizopus sexualis (Smith) Callen

1971 ◽  
Vol 263 (848) ◽  
pp. 71-100 ◽  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Probable Function ◽  
Cytoplasmic Organelles ◽  
Transmission Electron ◽  
Scanning Electron ◽  
Number Form

The development of the zygospore of Rhizopus sexualis (Smith) Callen was followed by light microscopy, transmission electron microscopy and scanning electron microscopy. Details of all stages, including dissolution of the fusion wall, delimitation of the gametangia by septa, and formation of the complex wall of the zygospore are described and illustrated. Changes in number, form and distribution of the organelles and the behaviour of the nuclei are described. The probable function of the cytoplasmic organelles and the possible mechanisms controlling development are discussed.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Microbulldozing and Microchiseling

1969 ◽  
Vol 27 ◽  
pp. 134-135
Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Material Handling ◽  
Microprobe Analysis ◽  
Foreign Matter ◽  
Specific Location ◽  
Potential Problems ◽  
Knoop Indenter ◽  
Scanning Electron ◽  
Microhardness Tester

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.

A New Image Processing Technique for STEM

1974 ◽  
Vol 32 ◽  
pp. 432-433
Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Elastic Scattering ◽  
Field Emission ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Energy Analyzer ◽  
Scanning Microscope ◽  
Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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