Surface ornamentation of the echinoid test and its ecologic significance

Paleobiology ◽  
1976 ◽  
Vol 2 (2) ◽  
pp. 122-130 ◽  
Author(s):  
Susan C. Oldfield
Keyword(s):  
Growth Rate ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Outer Surface ◽  
High Growth ◽  
High Energy ◽  
Low Energy ◽  
Plate Surface ◽  
Surface Ornamentation ◽  
Scanning Electron

A scanning electron microscope survey of the regular echinoid test reveals that the outer surface of its component coronal plates may be sculptured with a fine-relief ornament that is species-characteristic for those species presently surveyed. Structural resemblances in surface ornamentation are more marked in species living in similar habitats than in those species that are apparently phyletically related. Plate ornament is related to skeletal magnesium levels. It is tentatively suggested that low growth rate echinoids that inhabit “low-energy” environments (and exhibit low total skeletal magnesium levels) and “high-energy” habitat-exploiting species with high growth rates (and relatively high skeletal magnesium levels) may have differential patterns of plate growth that can be distinguished by the degree of ornamentation of the plate surface.

scholarly journals A design for a subminiature, low energy scanning electron microscope with atomic resolution

2009 ◽  
Vol 105 (1) ◽  
pp. 014702 ◽  
Author(s):  
D. A. Eastham ◽  
P. Edmondson ◽  
S. Greene ◽  
S. Donnelly ◽  
E. Olsson ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Low Energy ◽  
Atomic Resolution ◽  
Scanning Electron

SEM OBSERVATIONS ON 'TAWARA-SHIBO' (A SERIES OF SWELLINGS ALONG THE AXIS) STEMS OF CHAMAECYPARIS OBTUSA

IAWA Journal ◽  
2002 ◽  
Vol 23 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Ryogo Nakada ◽  
Kaichiro Kawamura
Keyword(s):  
Growth Rate ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Growth Rates ◽  
Light Microscope ◽  
Chamaecyparis Obtusa ◽  
Stem Form ◽  
Anatomical Features ◽  
Hormonal Secretion ◽  
Scanning Electron

The anatomy of tawara-shibo stems of Chamaecyparis obtusa (Siebold & Zucc.) Endl. was observed using a scanning electron microscope (SEM) and a light microscope. Tawara-shibo is a strange stem form with a series of swellings that appear at regular intervals along the stem axis. Multiseriate rays, trabeculae and related structures, and modified tracheids were frequently observed at swollen portions. These features were less frequent at non-swollen portions.We conclude that abnormal cambial activities, occurring at regular longitudinal intervals, cause the formation and development of these three anatomical features and higher growth rates at swollen portions. As a result of differences in growth rate between swollen and non-swollen portions, the stem form of tawara-shibo develops. It is suggested that formation of the characteristics observed in tawara-shibo stems is genetically controlled by hormonal secretion into or within the cambium.

scholarly journals Contribution to the systematic knowledge of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey

2020 ◽  
Vol 27 (1) ◽  
pp. 27-35
Author(s):  
Emrah Şirin ◽  
Mehmet Cengiz Karaismailoğlu
Keyword(s):  
Electron Microscope ◽  
Chromosome Number ◽  
Scanning Electron Microscope ◽  
Geographical Distribution ◽  
Anatomical Structures ◽  
Seed Surface ◽  
Cytological Data ◽  
Surface Ornamentation ◽  
Systematic Knowledge ◽  
Scanning Electron

The aim of this study was to document the taxonomical, morphological, anatomical, palynological and cytological characters, and geographical distribution of endemic Aubrieta pinardii Boiss. (Brassicaceae) from Turkey. The description of the taxon was revised as a consequence of comprehensive assessments of many specimens. The surface pictures belonging to seed and pollen of the taxon were obtained by Scanning Electron Microscope. The seed surface ornamentation was rugose. The pollen was radially and isopolar and prolate in forms, with polar axes of 19.52 ± 0.29 μm and equatorial axes of 13.04 ± 0.22 μm, with oval outlines in the equatorial axes, and elliptical in the polar axes. They were three–colpate and colpus sizes varied between 12.98 μm and 13.29 μm in length, and between 1.33 and 2.09 μm in width. Also, the anatomical structures of the root, stem and leaf of species were studied. In cytological studies, the chromosome number of species was found as 2n = 16 (x =8). This was the first work including taxonomical, morphological (macro and micro), anatomical and cytological data of endemic Aubrieta pinardii. Bangladesh J.Plant Taxon. 27(1): 27-35, 2020 (June)

MICRO-FOUR-POINT PROBES IN A UHV SCANNING ELECTRON MICROSCOPE FOR IN-SITU SURFACE-CONDUCTIVITY MEASUREMENTS

2000 ◽  
Vol 07 (05n06) ◽  
pp. 533-537 ◽  
Author(s):  
ICHIRO SHIRAKI ◽  
TADAAKI NAGAO ◽  
SHUJI HASEGAWA ◽  
CHRISTIAN L. PETERSEN ◽  
PETER BØGGILD ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Defects ◽  
High Energy ◽  
Surface Conductivity ◽  
Conductivity Measurements ◽  
Surface Domains ◽  
Unambiguous Detection ◽  
Scanning Electron

For in-situ measurements of surface conductivity in ultrahigh vacuum (UHV), we have installed micro-four-point probes (probe spacings down to 4 μm) in a UHV scanning electron microscope (SEM) combined with scanning reflection–high-energy electron diffraction (RHEED). With the aid of piezoactuators for precise positioning of the probes, local conductivity of selected surface domains of well-defined superstructures could be measured during SEM and RHEED observations. It was found that the surface sensitivity of the conductivity measurements was enhanced by reducing the probe spacing, enabling the unambiguous detection of surface-state conductivity and the influence of surface defects on the electrical conduction.

Perimicropylar filaments in eggs of Cyprinodontidae (Pisces, Teleostei)

1992 ◽  
Vol 70 (5) ◽  
pp. 1064-1068 ◽  
Author(s):  
Omar Thiom Thiaw ◽  
Xavier Mattei
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Animal Pole ◽  
Surface Ornamentation ◽  
Scanning Electron

We used a scanning electron microscope to observe the eggs of eight species of fishes belonging to the Cyprinodontidae: Aphyosemion geryi, Aphyosemion riggenbachi, Aphyosemion splendopleure, Epiplatys ansorgei, Epiplatys chaperi, Epiplatys fasciolatus, Epiplatys spilargyreus, and Fundulosoma thierryi. The secondary envelope organizes ornamentations on its surface, except for a localized zone at the animal pole that corresponds to the micropylar region. In certain species the micropyle closes on contact with water but can be identified by the absence of surface ornamentation in the area. The eggs of these fishes possess adhesive filaments that seem to be distributed over the whole surface. In the species studied here, the adhesive filaments are almost exclusively perimicropylar. In F. thierryi, the filaments are even present in the vestibule.

Stroboscopic testing of LSIs with LVSEM

1984 ◽  
Vol 42 ◽  
pp. 464-467
Author(s):  
H. Todokoro ◽  
S. Yoneda ◽  
K. Yamaguchi
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Radiation Damage ◽  
Packing Density ◽  
Low Voltage ◽  
Low Energy ◽  
Electron Radiation ◽  
Optical Aberration ◽  
Voltage Scanning ◽  
Scanning Electron

Recently, the low-voltage scanning electron microscope (LVSEM) has become the center of wide interest. This is because the SEM has become an indispensable instrument in the field of semiconductor production, where packing density is increasing and device geometry is shrinking to a few microns or less. However, application of the SEM in the semiconductor industries presents two serious problems: (i) electron radiation damage to transistor functions and (ii) charge-up of electrons on insulators. Various reports concerning electron radiation damage have been published (1,2,3), and it has been found that electron energy must be less than 2 kV to minimize radiation damage. Such low energy also avoids the charge-up effect. However, it is quite difficult to get a fine probe at such low energy due to insufficient source brightness and electron optical aberration.

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