The functional morphology of the retractor lentis muscle of a teleost fish, Astronotus ocellatus

1994 ◽  
Vol 72 (11) ◽  
pp. 1880-1886 ◽  
Author(s):  
M. E. Andison ◽  
J. G. Sivak
Keyword(s):  
Smooth Muscle ◽  
Light Microscopy ◽  
Relative Size ◽  
Lens Capsule ◽  
Scanning Electron Micrographs ◽  
Anatomical Basis ◽  
Astronotus Ocellatus ◽  
Muscle Scanning ◽  
Scanning Electron

Visual teleost species such as the oscar, Astronotus ocellatus, accommodate by moving the lens within the eye. This movement is controlled by a smooth muscle, the retractor lentis. We observed two components in the accommodative lens movement: a nasotemporal and a mediolateral component. In the present study, the anatomical basis of these two components was investigated. Photographs of freshly dissected specimens were used to determine the position and relative size of the retractor lentis muscle in situ. Light microscopy sections reveal two fibre orientations within the muscle. Scanning electron micrographs illustrate that the muscle ligament fans out in two primary directions where it inserts into the lens capsule. The observation that two independent lens movements occur during accommodation is supported anatomically by the orientation of the fibres within the muscle and by the nature of the insertion of the ligament into the lens capsule.

Study on Mechanical Properties of AA6351 Alloy Reinforced with Titanium Di-Boride (TiB2) Composite by In Situ Casting Method

2015 ◽  
Vol 787 ◽  
pp. 583-587 ◽  
Author(s):  
V. Mohanavel ◽  
K. Rajan ◽  
K.R. Senthil Kumar
Keyword(s):  
Tensile Strength ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Scanning Electron Micrographs ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
In Situ Reaction ◽  
Halide Salts ◽  
Scanning Electron

In the present study, an aluminum alloy AA6351 was reinforced with different percentages (1, 3 and 5 wt %) of TiB2 particles and they were successfully fabricated by in situ reaction of halide salts, potassium hexafluoro-titanate and potassium tetrafluoro-borate, with aluminium melt. Tensile strength, yield strength and hardness of the composite were investigated. In situ reaction between the inorganic salts K2TiF6 and KBF4 to molten aluminum leads to the formation of TiB2 particles. The prepared aluminum matrix composites were characterized using X-ray diffraction and scanning electron microscope. Scanning electron micrographs revealed a uniform dispersal of TiB2 particles in the aluminum matrix. The results obtained indicate that the hardness and tensile strength were increased with an increase in weight percentages of TiB2 contents.

Removing the Barriers to Next Generation'S Dielectric Films: In Situ Void-Free Planarized Films

1990 ◽  
Vol 203 ◽  
Author(s):  
J.R. Monkowski ◽  
M.A. Logan ◽  
L.F. Wright
Keyword(s):  
Aspect Ratio ◽  
Ion Chromatography ◽  
Field Measurements ◽  
Dielectric Films ◽  
Breakdown Field ◽  
Scanning Electron Micrographs ◽  
Aspect Ratios ◽  
New Process ◽  
Scanning Electron

ABSTRACTIn the next generation of semiconductor devices, minimum dimensions will be smaller, aspect ratios (height to width) of devices features will be larger, and BPSG dielectrics will be challenged to deal with these changes. A new process, which integrates deposition, flow, and anneal of BPSG films, and allows void-free filling of high-aspect-ratio trenches with excellent surface planarization, is presented in this paper. Scanning electron micrographs are used to show the extent of film coverage and planarization. Additional characterization includes ion chromatography, ellipsometry, stress measurements, and breakdown field measurements.

Three new species of Calliandra in section Monticola (Leguminosae, Mimosoideae) from Chapada Diamantina, Bahia, Brazil

Phytotaxa ◽  
2014 ◽  
Vol 164 (2) ◽  
pp. 104
Author(s):  
Elvia Rodrigues Souza ◽  
Adelina Vitória Ferreira Lima ◽  
Luciano Paganucci Queiroz ◽  
Francisco A. Ribeiro Santos
Keyword(s):  
New Species ◽  
Light Microscopy ◽  
Electron Micrographs ◽  
Pollen Morphology ◽  
Identification Key ◽  
Similar Species ◽  
Scanning Electron Micrographs ◽  
Chapada Diamantina ◽  
Three New Species ◽  
Scanning Electron

Three new species of Calliandra section Monticola are described and illustrated: C. bromelioides, C. lewisii and C. oroboensis. All of them are endemic to the Chapada Diamantina, Bahia, Brazil. In addition we present a study of the pollen morphology using light microscopy and scanning electron micrographs. An identification key for the three new species and the most morphologically similar species in section Monticola is also provided. 

Methanosaeta fibers in anaerobic migrating blanket reactors

2000 ◽  
Vol 41 (4-5) ◽  
pp. 35-39 ◽  
Author(s):  
L.T. Angenent ◽  
D. Zheng ◽  
S. Sung ◽  
L. Raskin
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Scanning Electron Microscopy ◽  
In Situ Hybridization ◽  
Light Microscopy ◽  
Volatile Fatty Acids ◽  
Dense Structure ◽  
Scanning Electron ◽  
Granular Blanket

An anaerobic migrating blanket reactor (AMBR) was seeded with flocculent biomass from a digester and fed a substrate consisting of volatile fatty acids and sucrose to study granulation. After three months of operation, a mature granular blanket developed in the reactor. Moreover, fibers of approximately 1 cm long had become prevalent in the AMBR. Scanning electron microscopy (SEM) and light microscopy revealed a very dense structure consisting of bundles of filaments resembling Methanosaeta cells. Further studies with fluorescence in-situ hybridization (FISH), showed that Methanosaeta concilii was the predominant microorganism in these fibers.

Pollen morphology of Pacific Northwestern Polemonium species in relation to paleoecology and taxonomy

1979 ◽  
Vol 57 (21) ◽  
pp. 2428-2442 ◽  
Author(s):  
Rolf W. Mathewes
Keyword(s):  
Light Microscopy ◽  
Electron Micrographs ◽  
Pollen Analysis ◽  
Pollen Morphology ◽  
Scanning Electron Micrographs ◽  
Taxonomic Treatment ◽  
Close Affinity ◽  
Pollen Types ◽  
Quaternary Paleoecology ◽  
Scanning Electron

Six morphological types of Polemonium pollen are described, including P. micranthum which is the only taxon considered to be consistently identifiable to species. A key to the pollen types as seen in light microscopy is presented along with light and scanning electron micrographs of each type. The palynological evidence supports the taxonomic treatment of P. uciitiflorum and P. occidentale as subspecies of P. caeruleum, and supports a close affinity between P. pectinatum and P. foliosissimum. Brief summaries of the present-day ecology and distribution of Pacific Northwestern Polemonium species are presented. The application of indicator pollen analysis in Quaternary paleoecology is discussed, with special references to examples of paleoenvironmen-tal inference using Polemonium pollen types.

In-situ Tensile Straining of Metal Films on Polymer Substrates under an AFM

2013 ◽  
Vol 1527 ◽  
Author(s):  
M.J. Cordill ◽  
V.M. Marx
Keyword(s):  
Optical Microscope ◽  
Metal Films ◽  
Scanning Electron Micrographs ◽  
Adhesion Properties ◽  
Polymer Substrates ◽  
Fragmentation Test ◽  
First Occurrence ◽  
Film Substrate ◽  
Scanning Electron

ABSTRACTMetal films on polymer substrates are commonly used in flexible electronic devices and as gas barrier coatings. One way to evaluate the fracture and adhesion properties of such film systems is the fragmentation test. In the fragmentation test a film-substrate system is strained in tension under an optical microscope or inside a scanning electron microscope to observe the cracking and delamination events in situ. The technique works very well for brittle metal and ceramic films. However, when ductile films are strained they deform plastically before cracks and buckles appear. Therefore, a tensile straining device was developed to fit under an AFM for in situ observation of ductile metal films on polymer substrates. With the new in situ device the first occurrence of plastic deformation in the form of localized thinning of the film and channel cracks are visible. These features can only be detected through a height difference in the AFM images and not with optical or scanning electron micrographs. A comparison to brittle Cr films on polymer substrates was performed.

Preparing plant chromosomes for scanning electron microscopy

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 333-339 ◽  
Author(s):  
John E. Dillé ◽  
Douglas C. Bittel ◽  
Kathleen Ross ◽  
J. Perry Gustafson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
In Situ Hybridization ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Plant Chromosomes ◽  
Cellular Debris ◽  
Scanning Electron

The scanning electron microscope may be useful in the analysis of plant chromosomes treated with in situ hybridization, especially when the probes and (or) chromosomes are near or beyond the resolution of the light microscope. Usual methods of plant chromosome preparation are unsuitable for scanning electron microscope observation as a result of cellular debris, which also interferes with probe hybridization. A method is described whereby protoplasts are obtained from fixed root tips by enzymatic digestion and applied to slides in a manner that produces little or no cellular debris overlying the chromosomes. The slides were examined by scanning electron microscopy and light microscopy after C-banding and in situ hybridization with a rye nucleolus organizer region spacer probe. This technique, which allows for scanning electron microscope visualization of bands and probes not easily identified with light microscopy, should prove useful in the physical mapping of low copy number or unique DNA sequences.Key words: protoplasts, rice, wheat, rye, physical maps, in situ hybridization.

Production and Microstructure of In Situ Synthesized (Ti,W)C Reinforced Iron Matrix Composite

2012 ◽  
Vol 457-458 ◽  
pp. 7-10 ◽  
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Yuan Hui Li
Keyword(s):  
Matrix Composite ◽  
In Situ Synthesis ◽  
Scanning Electron Micrographs ◽  
Matrix Interface ◽  
Powder Metallurgy Technique ◽  
X Ray Diffraction ◽  
Iron Matrix ◽  
X Ray ◽  
Scanning Electron

A powder metallurgy technique combined with in-situ synthesis technique was applied to produce (Ti,W)C particulates reinforced iron matrix composite. The sintered composites were characterized by X-ray diffraction and scanning electron microscopy. (Ti,W)C and α-Fe were detected by X-ray diffraction analysis. The scanning electron micrographs revealed the morphology and distribution of the reinforcements. The results show that the rectangular (Ti,W)C carbides are distributed uniformly in the composite. The (Ti,W)C/Fe matrix interface is found to be free from cracks and deleterious phases. The reasons for the formation of coarse (Ti,W)C particles were also discussed .

Apothecium morphogenesis in Peziza quelepidotia: scanning electron and light microscopy

1976 ◽  
Vol 54 (19) ◽  
pp. 2254-2267 ◽  
Author(s):  
K. L. O'Donnell ◽  
G. R. Hooper ◽  
W. G. Fields ◽  
Arthur O. Ackerson
Keyword(s):  
Light Microscopy ◽  
Unique Feature ◽  
Spatial Relationship ◽  
Scanning Electron Micrographs ◽  
Electron Microscopic ◽  
Functional Image ◽  
Scanning Electron Microscopic ◽  
Electron And Light Microscopy ◽  
Whole Mounts ◽  
Scanning Electron

This study on Peziza quelepidotia Korf & O'Donnell, a homothallic operculate Discomycete (Pezizales, Pezizaceae), presents the first detailed correlative light microscopic and scanning ultrastructural observations of any species in this genus. This investigation was possible because P. quelepidotia. unlike other Peziza spp., produces fertile ascomata in pure culture. A complete structural and functional image of apothecium morphogenesis was obtained by combining scanning electron micrographs of the initial stages with light micrographs of whole mounts and thick sections of apothecia embedded in plastic at all stages of development. The temporal–spatial relationship between the ascogonia and the Botrytis-like imperfect state suggests that the ascogonial coils may be under chemotrophic control of the conidiophores. Although functional ascogonia are present, sexuality is apparently parthenogenetic since antheridia were never observed. A unique feature of paragymnohymenial apothecium development in this species is the elevation of the ascogonial coil as the stipe develops. Scanning electron microscopic observations on longitudinally cryofractured ascocarps are presented.

Evaluation of the emerging coleorhiza and radicle of Bromus tectorum using SEM and light microscopy

1995 ◽  
Vol 53 ◽  
pp. 980-981
Author(s):  
Maren Christensen ◽  
John S. Gardner ◽  
Phil S. Allen
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Bromus Tectorum ◽  
Root Hairs ◽  
Freeze Substitution ◽  
Soil Surface ◽  
Limited Attention ◽  
Freeze Dried ◽  
Scanning Electron

The coleorhiza is a nonvascular sheath that encloses the embryonic radicle in Gramineae, and is generally the first tissue to emerge during germination. Coleorhiza cells develop extensions similar to root hairs, which are difficult to study quantitatively in situ because they are extremely sensitive to desiccation and breakage. Protective, absorptive and adhesive roles have been postulated for this tissue, but have received limited attention, This study used scanning electron microscopy (SEM) and light microscopy (LM) to characterize the coleorhiza and radicle during germination of Bromus tectorum, a species that often emerges from the soil surface in semiarid habitats.Caryopses (seeds) were imbibed at various water potentials over solutions of polyethylene glycol (PEG) or in soil until coleorhizae had emerged. For SEM, seeds imbibed over PEG were frozen in liquid freon and then freeze dried, Seeds imbibed in soil were frozen in liquid nitrogen and then freeze dried. For LM, seeds imbibed over PEG were subjected to freeze substitution in dry acetone with 1% OSO4 at -80°C for 19 days.

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