Early limb development of Xenopus laevis

Development ◽  
1971 ◽  
Vol 26 (2) ◽  
pp. 169-179
Author(s):  
D. Tarin ◽  
A. P. Sturdee
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Xenopus Laevis ◽  
Limb Development ◽  
The Other ◽  
Similar Function ◽  
Histological Techniques ◽  
Marginal Sinus ◽  
Limb Morphogenesis ◽  
Scanning Electron

This investigation has used histological techniques and the scanning electron microscope to establish the presence of an apical ectodermal ridge in the developing limbs of Xenopus laevis. The ridge appeared at stage 50, reached its maximal size at stage 51, and subsequently disappeared by stage 53. The course of the ridge was consistently related to a marginal sinus in the underlying mesenchyme. The other features of limb morphogenesis, such as the formation of a paddle and the sequence of condensation of skeletal rudiments in the mesenchyme, corresponded closely to those seen in other vertebrates. It remains to be seen whether the ridge we have demonstrated in Xenopus exercises a similar function to that claimed for its counterpart in the chick.

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

Synthesis of ZrO2 Nanotubes by Anodization of Zr Foil

2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno
Keyword(s):  
Aqueous Solution ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Preparation ◽  
The Other ◽  
Preparation Methods ◽  
X Ray ◽  
Anodization Time ◽  
Other Hand ◽  
Scanning Electron

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.

The study on antennal sensilla of eight Acrididae species  (Orthoptera: Acridoidea) in Northeast China

Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Northeast China ◽  
The Other ◽  
Antennal Sensilla ◽  
Male And Female ◽  
Trichoid Sensilla ◽  
Basiconic Sensilla ◽  
Scanning Electron

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.

A new species of Tabularia (Kützing) Williams & Round from Poyang Lake, Jiangxi Province, China, with a cladistic analysis of the genus and their relatives

Phytotaxa ◽  
2018 ◽  
Vol 373 (3) ◽  
pp. 169 ◽  
Author(s):  
YUE CAO ◽  
PAN YU ◽  
QINGMIN YOU ◽  
REX L. LOWE ◽  
DAVID M. WILLIAMS ◽  
...  
Keyword(s):  
Electron Microscope ◽  
New Species ◽  
Scanning Electron Microscope ◽  
Poyang Lake ◽  
Cladistic Analysis ◽  
The Other ◽  
Jiangxi Province ◽  
A New Species ◽  
Scanning Electron

A new species of Tabularia, Tabularia sinensis, is described from the inland Poyang Lake (Jiangxi Province), the largest lake in China. The description is based on light and scanning electron microscope observations of valve and girdle elements. Given the diversity of forms in the genus, the relationships and status of the genus was investigated in the context of the other known species in the genus and to ascertain if Tabularia, as originally circumscribed, remains monophyletic.

Micro-Structural Studies of Leached SON-68-Type Glasses

2001 ◽  
Author(s):  
N. Ollier ◽  
G. Panczer ◽  
B. Champagnon ◽  
P. Jollivet
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Rare Earth Element ◽  
Earth Element ◽  
The Other ◽  
Structural Studies ◽  
Microscopic Features ◽  
Precipitated Phases ◽  
Scanning Electron

Abstract Two types of borosilicate leached SON68-type glasses were studied, one doped with uranium and the other with rare-earth element (Nd, Eu). Photoluminescence and cathodoluminescence properties of U doped samples have been correlated to microscopic features of the corroded glass. Nuclear analysis, Electronic Microprobe and Scanning Electron Microscope investigations revealed the heterogeneous composition of the gels with differentiated phases. Enriched U phases (crystallised or not) and phosphorus precipitated phases in rare earth gel have been detected.

A redescription of Metopa species (Amphipoda, Stenothoidae) based on the type material. 1. Zoological Museum, Copenhagen (ZMUC)

Zootaxa ◽  
2009 ◽  
Vol 2093 (1) ◽  
pp. 1-36 ◽  
Author(s):  
ANNE HELENE S. TANDBERG ◽  
WIM VADER
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Taxonomic Position ◽  
Type Material ◽  
Zoological Museum ◽  
Type Specimens ◽  
Line Drawings ◽  
New Material ◽  
Scanning Electron

This paper presents redescriptions of amphipods in the genus Metopa (Stenothoidae) in the type-collections of the Zoological Museum of Copenhagen. For Metopa clypeata and M. abyssalis we redescribe the type-specimens, for M. glacialis and M. groenlandica the redescriptions are based on new material and checked against the type-specimens. For all except M. abyssalis a combination of new line drawings and scanning electron microscope (SEM) pictures is provided, for M. abyssalis, line drawings only. A summary of the other species having earlier been designed to Metopa in the Copenhagen collections is given, with a list of their present taxonomic position.

Choosing a Scanning Electron Microscope

1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Selection Process ◽  
The Other ◽  
Hard Data ◽  
Methodical Approach ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
First Time ◽  
Scanning Electron

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.

Additional taxonomic studies on Avena fatuoids: some morphological attributes seen using the scanning electron microscope

1971 ◽  
Vol 49 (5) ◽  
pp. 647-649 ◽  
Author(s):  
Bernard R. Baum
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Avena Fatua ◽  
The Other ◽  
Electron Microscopic ◽  
Morphological Attributes ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Taxonomic Studies ◽  
Scanning Electron

This paper describes and evaluates the results of a scanning electron microscopic study of the sculpture of the surfaces of caryopses, glumes, lemmas, awn columns, and awn subules of Avena fatua, normal cultivated oats (A. sativa), fatuoids, and F1 hybrids A. fatua × sativa. Only qualitative differences were sought, and none were detected in the glumes and on the caryopses. The prickles on the lemmas, on the awn columns, and on the awn subules all appear in two character states. In the case of the lemmas one state is found in the normal cultivated oats, fatuoids, and F1 hybrids, and the other in A. fatua. On the other hand in the awn subules one state is found in the normal cultivated oats and the other in fatuoids, F1 hybrids, and A. fatua, while in the awn columns one state occurs in cultivated oats and the other in A. fatua, but in the F1 hybrids and fatuoids both states occur. These findings provide taxonomic evidence additional to that described earlier based on lodicules coupled with traditional characters.

scholarly journals Combining Focused Ion Beam and Scanning Electron Microscopy for IC Fab Support and Defect Review

1996 ◽  
Vol 4 (3) ◽  
pp. 18-19
Author(s):  
Janet Tashima ◽  
Jay Lindquist
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
The Other ◽  
High Resolution Imaging ◽  
Resolution Imaging ◽  
Twin Beam ◽  
Edge Tool ◽  
Scanning Electron

The cutting-edge tool for IC fab support and defect review brings together the Focused Ion Beam (FIB) technology with the Scanning Electron Microscope (SEM) into a single workstation. The twin beam FIB/SEM workstation, FEI Company's DualBeam™ 820 for example, combines the unique micromachining, microdeposition, and analysis capabilities of a FIB with the high resolution imaging power of a Schottky field emission scanning electron microscope (FE SEM). The full functionality of both instruments is available and neither is compromised by the other.

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