River otter hair structure facilitates interlocking to impede penetration of water and allow trapping of air

2005 ◽  
Vol 83 (5) ◽  
pp. 649-655 ◽  
Author(s):  
John W Weisel ◽  
Chandrasekaran Nagaswami ◽  
Rolf O Peterson
Keyword(s):  
Light Microscopy ◽  
Thick Layer ◽  
Air Bubbles ◽  
River Otter ◽  
Adjacent Level ◽  
River Otters ◽  
Lutra Canadensis ◽  
Microscopy Images ◽  
Scanning Electron ◽  
Size And Structure

Unlike many other mammals spending a considerable amount of time in water, river otters (Lutra canadensis (Schreber, 1777)) do not have a thick layer of body fat. Instead, they have a very densely packed layer of thin underhairs. The structure of river otter hair was examined by scanning electron microscopy and polarizing light microscopy. Guard hairs were hollow and became thicker distally and then tapered to a point and had different cuticle scales in proximal and distal regions. The cuticle of the thin underhairs had a striking pattern of sharply sculpted fins with deep grooves between them; usually there were four fins at each level, rotated 45° with respect to those at an adjacent level. Underhairs varied in diameter and the scales were sometimes petal-shaped. Polarizing light microscopy images showed interlocking arrangements of the underhairs that help to impede the penetration of water. Also, these images showed that the grooves between fins or petals of underhairs entrap air bubbles. The structure of the hairs allows them to interact loosely with each other, despite variations in size and structure. Furthermore, the nature of the interactions between the fins and depressions allows space between the hairs that can trap air bubbles to increase the thermal insulation of the otter's coat.

Food habits of the river otter Lutra canadensis in the marine environment of British Columbia

1984 ◽  
Vol 62 (1) ◽  
pp. 88-91 ◽  
Author(s):  
G. B. Stenson ◽  
G. A. Badgero ◽  
H. D. Fisher
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Food Habits ◽  
River Otter ◽  
River Otters ◽  
Two Samples ◽  
Lutra Canadensis ◽  
Fish Remains ◽  
Coastal British Columbia

Food habits of river otters (Lutra canadensis) inhabiting coastal British Columbia were studied by examining scat and stomach samples. Fish remains occurred in 99.4% of the scats while crustacean and bird remains were encountered in 7.2 and 4.2%, respectively. The majority of fish identified belong to six groups: Embiotocidae (occurring in 42.2% of the scats), Cottidae (40.5%), Pleuronectiformes (40.0%), Blennioidea (33.3%), Scorpaenidae (30.1%), and Hexagrammidae (13.1%). Of 69 stomachs collected by trappers, 86.9% contained remains of fish and 13% contained bird remains. Only two samples (2.9%) contained crustacean remains. Similar families of fish were found in both scat and stomach samples. Scat samples, collected on 10 consecutive visits to 55 sites from May 1977 through February 1978, indicated that, with the possible exception of bird remains, food types do not appear to vary seasonally. Otters in the marine environment utilize their habitat in the same manner that freshwater otters do; they are opportunistic feeders and rely primarily on midsize, slower moving fish that occur in the intertidal and subtidal regions close to shore.

Intraocular muscles of the Canadian river otter and Canadian beaver and their optical function

1989 ◽  
Vol 67 (2) ◽  
pp. 469-474 ◽  
Author(s):  
K. A. Ballard ◽  
J. G. Sivak ◽  
H. C. Howland
Keyword(s):  
Ciliary Body ◽  
Castor Canadensis ◽  
Optical Function ◽  
River Otter ◽  
Microscopic Anatomy ◽  
River Otters ◽  
Refractive Power ◽  
Lutra Canadensis ◽  
Corneal Refractive Power

The gross morphology and microscopic anatomy of the ciliary and iris musculature of the Canadian river otter (Lutra canadensis) and Canadian beaver (Castor canadensis) were studied to help evaluate whether either species has an exaggerated accommodative mechanism for use underwater. The intraocular muscles of the otter are of a size and organization indicative of an extreme lens-deforming accommodative ability involving both the ciliary body and iris. By contrast, the intraocular muscles of the beaver eye indicate that accommodation is not significant in this animal. Thus, the intraocular musculature of the class Mammalia is not homogeneous, even within the amphibious mammals. Refractive and corneal measurements on two living river otters confirm that this animal is capable of an accommodative range that can neutralize the loss of corneal refractive power when the eye is in water.

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).

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

Examination of Schistosome Cercariae and Schistosomules by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 50-51
Author(s):  
D. Johnson ◽  
P. Moriearty
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Light Microscopy ◽  
Surface Structure ◽  
Extensive Study ◽  
Scanning Microscopy ◽  
Host Parasite ◽  
Conventional Electron Microscopy ◽  
Scanning Electron

Since several species of Schistosoma, or blood fluke, parasitize man, these trematodes have been subjected to extensive study. Light microscopy and conventional electron microscopy have yielded much information about the morphology of the various stages; however, scanning electron microscopy has been little utilized for this purpose. As the figures demonstrate, scanning microscopy is particularly helpful in studying at high resolution characteristics of surface structure, which are important in determining host-parasite relationships.

SEM Observations on the Germination of Euonymous Americanus

1985 ◽  
Vol 43 ◽  
pp. 508-509
Author(s):  
D.R. Hill ◽  
J.R. McCurry ◽  
L.P. Elliott ◽  
G. Howard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Filter Paper ◽  
Room Temperature ◽  
Food Source ◽  
Environmental Chamber ◽  
Dormant Stage ◽  
Scanning Electron

Germination of Euonymous americanus in the laboratory has previously been unsuccessful. Ability to germinate Euonymous americanus. commonly known as the american strawberry bush, is important in that it represents a valuable food source for the white-tailed deer. Utilizing the knowledge that its seeds spend a period of time in the rumin fluid of deer during their dormant stage, we were successful in initiating germination. After a three month drying period, the seeds were placed in 25 ml of buffered rumin fluid, pH 8 at 40°C for 48 hrs anaerobically. They were then allowed to dry at room temperature for 24 hrs, placed on moistened filter paper and enclosed within an environmental chamber. Approximately four weeks later germination was detected and verified by scanning electron microscopy; light microscopy provided inadequate resolution. An important point to note in this procedure is that scarification, which was thought to be vital for germination, proved to be unnecessary for successful germination to occur. It is believed that germination was propagated by the secretion of enzymes or prescence of acids produced by microorganisms found in the rumin fluid since sterilized rumin failed to bring about germination.

New diagnostic characters of Kolhymorbis angarensis (Dybowski & Grochmalicki, 1925) (Gastropoda: Pulmonata: Planorbidae)

2009 ◽  
Vol 18 (2) ◽  
pp. 191-195
Author(s):  
E.V. Soldatenko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Light Microscopy ◽  
Diagnostic Characters ◽  
Copulatory Apparatus ◽  
Scanning Electron

The radula morphology and the anatomy of the copulatory apparatus in Kolhymorbis angarensis were examined using light microscopy, scanning electron microscopy (SEM) and histological methods. Kolhymorbis angarensis was shown to have the stylet and the penial sac with a glandular appendage (flagellum), the characteristics, previously unknown for any species of this genus. The significance of these findings for the taxonomy of the genus is discussed.

scholarly journals Clay-Based Brick Porosity Estimation Using Image Processing Techniques

2019 ◽  
Vol 29 (1) ◽  
pp. 1226-1234
Author(s):  
Safa Jida ◽  
Hassan Ouallal ◽  
Brahim Aksasse ◽  
Mohammed Ouanan ◽  
Mohamed El Amraoui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Computer Vision ◽  
Image Processing Techniques ◽  
Processing Techniques ◽  
Porosity Estimation ◽  
Microscopy Images ◽  
Scanning Electron

Abstract This work intends to apprehend and emphasize the contribution of image-processing techniques and computer vision in the treatment of clay-based material known in Meknes region. One of the various characteristics used to describe clay in a qualitative manner is porosity, as it is considered one of the properties that with “kill or cure” effectiveness. For this purpose, we use scanning electron microscopy images, as they are considered the most powerful tool for characterising the quality of the microscopic pore structure of porous materials. We present various existing methods of segmentation, as we are interested only in pore regions. The results show good matching between physical estimation and Voronoi diagram-based porosity estimation.

scholarly journals Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Nanocomposite Coating ◽  
Superhydrophobic Coating ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

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