scholarly journals A reexamination of Yuknessia from the Cambrian of British Columbia and Utah

2015 ◽  
Vol 89 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Steven T. LoDuca ◽  
Jean-Bernard Caron ◽  
James D. Schiffbauer ◽  
Shuhai Xiao ◽  
Anthony Kramer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
National Park ◽  
Red Alga ◽  
Fine Scale ◽  
Burgess Shale ◽  
Phylogenetic Affinity ◽  
New Material ◽  
Scanning Electron

AbstractTo investigate the phylogenetic affinity of Yuknessia simplex Walcott, 1919, scanning electron microscopy was applied to the Burgess Shale (Cambrian Series 3, Stage 5) type material and to new material from the Trilobite Beds (Yoho National Park) and specimens from the Cambrian of Utah. On the basis of fine-scale details observed using this approach, including banding structure interpreted as fusellae, Yuknessia Walcott, 1919 is transferred from the algae, where it resided for nearly a century, to the extant taxon Pterobranchia (Phylum Hemichordata). Considered as such, Yuknessia specimens from the Trilobite Beds and Spence Formation (Utah) are amongst the oldest known colonial pterobranchs. Two morphs regarded herein as two different species are recognized from the Trilobite Beds based on tubarium morphology. Yuknessia simplex has slender erect tubes whereas Yuknessia stephenensis n. sp., which is also known in Utah, has more robust erect tubes. The two paratypes of Y. simplex designated by Walcott (1919) are formally removed from Yuknessia and are reinterpreted respectively as an indeterminate alga and Dalyia racemata Walcott, 1919, a putative red alga.

Isoetes × marensis, a new interspecific hybrid from western Canada

1995 ◽  
Vol 73 (9) ◽  
pp. 1345-1353 ◽  
Author(s):  
Donald M. Britton ◽  
Daniel F. Brunton
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Key Words ◽  
North American ◽  
Interspecific Hybrid ◽  
Western Canada ◽  
Hybrid Plants ◽  
Surface Ornamentation ◽  
Scanning Electron

A new interspecific hybrid in Isoetes, I. maritima Underw. × I. howellii Engelm., is delineated and described from the Shuswap Highlands region of British Columbia by means of cytology and scanning electron microscopy of spores. Isoetes × marensis D.M. Britton and D.F. Brunton, hyb.nov. is the name proposed for this taxon. It is triploid (3x; 2n = 33) and is believed to produce only sterile and (or) aborted spores. Hybrid plants have polymorphic spores that demonstrate size and surface ornamentation features intermediate between those of the putative parents. Three populations were examined, each growing with both of the putative parents in silt and sand among granite cobble over clay along an emergent lakeshore. Isoetes × marensis is the first described North American hybrid involving an amphibious Isoetes. It is expected to be a rare taxon owing to the restricted sympatric area of the putative parents and their tendency to occupy different habitats. Key words: Isoetes, Isoetes howellii, Isoetes maritima, hybrid, British Columbia.

Redescription of Lamproglena Clariae Fryer, 1956 (Copepoda, Lernaeidae), With Notes On Its Occurrence and Distribution

Crustaceana ◽  
1996 ◽  
Vol 69 (4) ◽  
pp. 509-523 ◽  
Author(s):  
A. Avenant-Oldewage ◽  
Hazel M. Marx
Keyword(s):  
Electron Microscopy ◽  
South Africa ◽  
Scanning Electron Microscopy ◽  
National Park ◽  
Kruger National Park ◽  
Gill Parasite ◽  
Morphological Findings ◽  
Olifants River ◽  
First Time ◽  
Scanning Electron

AbstractThe morphology of the gill parasite Lamproglena clariae Fryer, 1956, from the Olifants River, Kruger National Park, South Africa, was studied with the aid of light and scanning electron microscopy. Ultrastructural details of all appendages are given as well as a table and map with information on the occurrence and distribution of L. clariae in Africa. Important morphological findings include: the observation of only one claw on the maxilla; first time findings and descriptions of the nuchal organ, upper and lower lips, the fifth pair of legs and circular openings on all appendages.

scholarly journals Supplemental Material: Early formation and taphonomic significance of kaolinite associated with Burgess Shale fossils

2020 ◽  
Author(s):  
Ross Anderson ◽  
et al.
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antibacterial Properties ◽  
Energy Dispersive ◽  
Burgess Shale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Early Formation ◽  
Data Tables ◽  
Scanning Electron

Supplemental methodological details, antibacterial properties of clays, other minerals with distinct fossil/matrix distributions, summaries of mineralogy by taxon, data tables, statistical summaries, and light/scanning electron microscopy–energy-dispersive X-ray spectroscopy images of fossil specimens showing X-ray diffraction selected areas.<br>

Morphology of Chrysastrella paradoxa stomatocysts from the Subpolar Urals (Russia) with comments on related morphotypes

Phytotaxa ◽  
2019 ◽  
Vol 402 (6) ◽  
pp. 295
Author(s):  
DMITRY KAPUSTIN ◽  
IRINA STERLYAGOVA ◽  
ELENA PATOVA
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
National Park ◽  
Type Species ◽  
Subpolar Urals ◽  
Mass Development ◽  
Scanning Electron

For many years Chrysastrella Chodat has been a cyst genus but recently it has been re-instated and re-defined. Currently, Chrysastrella contains Ochromonas-like flagellates including O. tuberculata Hibberd which was synonymized with the type species, Chrysastrella paradoxa Chodat. A mass development of stomatocysts, which we identified as Ch. paradoxa, was observed in a bog on the territory of “Yugyd va” National Park (the Subpolar Urals, Russia). The morphology of stomatocysts was studied by scanning electron microscopy and compared with previously described similar morphotypes. Stomatocysts #80 Hansen, #1 Wołowski & Płachno and #4 Bai & Chen seem to be identical to Chrysastrella paradoxa stomatocysts and we propose to reduce them to synonymy.

Ovine pericardium as a new material for duraplasty

1996 ◽  
Vol 84 (3) ◽  
pp. 508-513 ◽  
Author(s):  
Jan Pařízek ◽  
Zdeněk Husěk ◽  
Pavel Měřička ◽  
Josef Téra ◽  
Stanislav Němeček ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Host Tissue ◽  
Γ Irradiation ◽  
Content Type ◽  
Dural Substitute ◽  
Freeze Dried ◽  
New Material ◽  
Fine Print ◽  
Scanning Electron

✓ The authors report on their 2 1/2-year clinical experience using a dural substitute, ovine pericardium, stabilized with 0.3% glutaraldehyde, flat freeze-dried, and sterilized with γ-irradiation. Packaging of the ovine pericardium in double-plastic transparent bags allows simple storage in operating rooms and the opportunity for the surgeon to choose an ideal graft according to its shape, size, and plasticity. The ovine pericardia were examined histologically and by transmission and scanning electron microscopy in their native, freeze-dried, and irradiated forms. The final product is composed solely of pericardium fibrosum interwoven with artificially formed extracellular microcavities that serve as natural pores for the ingrowth of host tissue. The surfaces of the grafts appear smooth on the inner and rough on the outer sides. Sixteen grafts were examined macroscopically at autopsy and four of these were also examined histologically to illustrate their successful healing with no adhesion to the underlying brain. As a new dural substitute, ovine pericardium proved to be superior to bovine and allogeneic pericardia because of its workability, flexibility, and reduced thickness. In a study of 120 grafts, all but one healed without complications.

Phyllodistomum umblae (Fabricius) (Digenea, Gorgoderidae) from British Columbia salmonids: a description based on light and scanning electron microscopy

1987 ◽  
Vol 65 (7) ◽  
pp. 1703-1712 ◽  
Author(s):  
T. A. Bakke ◽  
R. E. Bailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Electron Microscope ◽  
Salmo Salar ◽  
Electron Microscope Study ◽  
Salvelinus Fontinalis ◽  
Salmo Gairdneri ◽  
Scanning Electron Microscope Study ◽  
Scanning Electron

Specimens of Phyllodistomum umblae (Fabricius, 1780) from Oncorhynchus nerka (Walbaum) from the Nautley River, British Columbia, and Salmo gairdneri Richardson from the Stuart River, British Columbia, are described and figured using light microscopy and scanning electron microscopy. Particular emphasis is placed on describing the numbers, types, and arrangement of papillae as seen with scanning electron microscopy. No significant differences were observed between the present Canadian material from O. nerka and S. gairdneri and specimens of P. umblae described from Norway, Sweden, and the U.S.S.R. Thus, P. umblae has a holarctic distribution in salmonids. Phyllodistomum limnosa Sandeman and Pippy, 1967, described from Salmo salar L. and Salvelinus fontinalis (Mitchill) from Newfoundland, is regarded as a synonym of P. umblae. Phyllodistomum lachancei Choquztte, 1947, described from S. fontinalis in Quebec, probably is also a synonym of P. umblae, but a more detailed scanning electron microscope study of the papillae in P. lachancei is required for confirmation.

Pestalotiopsis guepinii, a Taxol-producing Endophyte of the Wollemi Pine, Wollemia nobilis

1997 ◽  
Vol 45 (6) ◽  
pp. 1073 ◽  
Author(s):  
Gary A. Strobel ◽  
W. M. Hess ◽  
Jia-Yao Li ◽  
Eugene Ford ◽  
Joe Sears ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Anticancer Drug ◽  
Endophytic Fungi ◽  
National Park ◽  
Hydrophobic Surfaces ◽  
Taxus Brevifolia ◽  
Native Birds ◽  
Scanning Electron ◽  
Sydney Australia

Wollemia nobilis (Wollemi pine), an araucariaceous plant, whose closest known relatives are from the Jurassic period, occurs in the Wollemi National Park near Sydney, Australia. This tree is host to many endophytic fungi, including Pestalotiopsis guepinii which produces taxol, an important anticancer drug. It was shown by immunological, spectroscopic and chromatographic means to be identical with authentic taxol obtained from Taxus brevifolia (Pacific yew). Since the Wollemi pine does not produce taxol, how might a taxol-producing fungus be present in this unusual tree? Spores of P. guepinii possess several appendages which strongly interact with hydrophobic surfaces including plastics and the pinnae of birds’ feathers. Scanning electron microscopy of the conidia of P. guepinii clearly shows the spores on the feathers of a green-checked conure and a cockatiel. Conceivably, the fungus may have acquired the ability to produce taxol from a foreign or local yew and then is carried to the Wollemi pine site by native birds.

Trichodina truttae Mueller, 1937 (Ciliophora: Peritrichida), a common pathogenic ectoparasite of cultured juvenile salmonid fishes in British Columbia: redescription and examination by scanning electron microscopy

1984 ◽  
Vol 62 (9) ◽  
pp. 1842-1848 ◽  
Author(s):  
J. R. Arthur ◽  
L. Margolis
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
British Columbia ◽  
Pacific Salmon ◽  
Salmo Gairdneri ◽  
Diagnostic Features ◽  
Detailed Surface ◽  
Juvenile Pacific Salmon ◽  
Oral Surface ◽  
Scanning Electron

The trichodinid ciliate Trichodina truttae Mueller, 1937 is redescribed from silver-impregnated specimens collected from the skin of cultured juvenile Pacific salmon (Oncorhynchus spp.) and steelhead trout (Salmo gairdneri) from British Columbia, and its detailed surface topography was examined by scanning electron microscopy (SEM). Diagnostic features evident by light microscopy are the large size (body diameter 114–179 μm), high denticle number (28–30), and high number (about 20) of radial pins per denticle. Especially noteworthy characters revealed by SEM that may be important for species identification are the presence of radial ridges on the oral surface and two markedly different lengths of cilia within the adoral ciliary spiral. This is the first verified report of T. truttae from Canada.

Stomatocysts of Chrysastrella paradoxa Chodat (Chrysophyceae) from herb-mosses mire at the western slope of the Subpolar Urals (Russia)

2021 ◽  
pp. 80-84
Author(s):  
Irina N. Sterlyagova ◽  
Elena N. Patova ◽  
Dmitry A. Kapustin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
National Park ◽  
Western Slope ◽  
Subpolar Urals ◽  
Scanning Electron

Stomatocysts of Chrysastrella paradoxa was observed in a herb-mosses mire on the territory of “Yugyd va” National Park (the Subpolar Urals, Russia). The morphology of stomatocysts was studied by scanning electron microscopy. This is the second record of Ch. paradoxa in Russia.

Supplemental Material: Early formation and taphonomic significance of kaolinite associated with Burgess Shale fossils

2020 ◽  
Author(s):  
Ross Anderson ◽  
et al.
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antibacterial Properties ◽  
Energy Dispersive ◽  
Burgess Shale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Early Formation ◽  
Data Tables ◽  
Scanning Electron

Supplemental methodological details, antibacterial properties of clays, other minerals with distinct fossil/matrix distributions, summaries of mineralogy by taxon, data tables, statistical summaries, and light/scanning electron microscopy–energy-dispersive X-ray spectroscopy images of fossil specimens showing X-ray diffraction selected areas.<br>

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