Morphological and experimental studies of the somitomeric organization of the segmental plate in snapping turtle embryos

Development ◽  
1984 ◽  
Vol 84 (1) ◽  
pp. 35-48
Author(s):  
David S. Packard ◽  
Stephen Meier
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Final Stage ◽  
Experimental Studies ◽  
The Other ◽  
Chelydra Serpentina ◽  
Microscopy Imaging ◽  
Snapping Turtle ◽  
Somite Formation ◽  
Scanning Electron

The segmental plate mesoderm of snapping turtle embryos (Chelydra serpentina) was examined with stereoscanning electron microscopy imaging. A metameric pattern was detected along the entire length of the segmental plates. This pattern consisted of a tandem sequence of mesodermal units, called somitomeres. Each somitomere was oval to cubic in shape and the processes of the constituent mesodermal cells tended to be arranged in concentric rings about the centre of the somitomere. Several experiments from a previous study (Packard, 1980b) of snapping turtle segmental plates were repeated, but, instead of culturing the explants and observing the numbers of somites that formed, the explants were fixed immediately for scanning electron microscopy and the number of somitomeres was counted. The segmental plates were found to contain an average of 6·5 ± 0·7 somitomeres, which is almost identical to the average number of somites formed by such segmental plates when cultured (6·6 ± 1·2). Furthermore, the number of somitomeres was identical in right and left explants removed from the same embryo, and the number of somitomeres was consistent regardless of the length of the segmental plate. Both of these observations are identical to those made previously for somite formation in culture. This association between numbers of somitomeres and somites strongly suggests that one gives rise to the other. Finally, it was demonstrated that for each somite formed by a segmental plate in culture, the segmental plate contained one less somitomere. This showed in a direct manner that turtle somitomeres become somites. It was concluded that the segmental plate mesoderm of snapping turtle embryos is already segmented, and that the ‘segmentation’ seen under a dissecting microscope is actually the final stage of somitomere differentiation into an epithelial somite.

ADVANCES IN FILLER DISPERSION MEASUREMENTS

2016 ◽  
Vol 89 (1) ◽  
pp. 142-153 ◽  
Author(s):  
Leszek Nikiel ◽  
Russell Mason ◽  
Wesley Wampler
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrical Resistivity ◽  
The Other ◽  
Microscopy Imaging ◽  
Rubber Compounds ◽  
Filler Dispersion ◽  
Varying Dispersion ◽  
Mineral Fillers ◽  
Scanning Electron

ABSTRACT It is well documented throughout the literature that filler dispersion significantly influences rubber performance. However, there is no single experimental method to measure dispersion precisely. By presenting new experimental techniques and reviewing several existing ones that measure dispersion at different length scales, steps are undertaken to close the knowledge gap in understanding dispersion. Some methods, such as electrical resistivity, are able to probe only the conductive carbon black network; the others take into consideration all compounding ingredients including mineral fillers and chemicals. One of the techniques discussed in more detail will be surface profilometry, which is based on the noncontact optical interferometry principle. The other technique reviewed in more detail is based on high-resolution field emission scanning electron microscopy imaging. These different techniques were employed to evaluate multiple rubber compounds with varying dispersion levels, and the data will be presented and discussed.

scholarly journals Intraocular lens biofilm formation supported by scanning electron microscopy imaging

2019 ◽  
Vol 67 (10) ◽  
pp. 1708
Author(s):  
Dipankar Das ◽  
Harsha Bhattacharjee ◽  
Krishna Gogoi ◽  
JayantaK Das ◽  
Puneet Misra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Intraocular Lens ◽  
Biofilm Formation ◽  
Microscopy Imaging ◽  
Scanning Electron

Problems associated with ageing squid from their statoliths: towards a more structured approach

1994 ◽  
Vol 6 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Marek R. Lipinski ◽  
M. Deon Durholtz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Regression Analysis ◽  
Light Microscopy ◽  
The Other ◽  
Etching Solution ◽  
Significant Difference ◽  
Structured Approach ◽  
Fish Otoliths ◽  
Scanning Electron

It appears that squid statoliths cannot yet be regarded as accurate an ageing tool as fish otoliths. Statoliths from the same pair, prepared differently for viewing and counting increments, were compared. Increment counts do not imply age in days, because this was not validated. One statolith from each pair was examined by light microscopy (LM) after preparation following a new method. The other was viewed by Scanning Electron microscopy (SEM) with a modified etching solution. Shape of each statolith was similar when compared by multiple regression analysis (11 variables, n=53). There was a weak but significant difference between sexes (statoliths of females were slightly larger). All other differences were insignificant. Microscopic observation and increment counts of increments were successfully carried out for 37 pairs of statoliths. Significant differences between two independent counts were found for the LM method, but no significant differences were found between two independent SEM counts. Counts were significantly different when interpreted by both LM and SEM, probably because of poor resolution in the LM readings and over-resolution (growth layers prominent and numerous) in those read by SEM. Recommendations are made on how ageing studies, based on statoliths, should be structured and the results evaluated.

Pollen morphology of Sabinaria magnifica (Cryosophileae, Coryphoideae, Arecaceae)

Phytotaxa ◽  
2015 ◽  
Vol 207 (1) ◽  
pp. 135 ◽  
Author(s):  
Giovanni Raul Bogota ◽  
Carina Hoorn ◽  
Wim Star ◽  
Rob Langelaan ◽  
Hannah Banks ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
The Other ◽  
Transmission Electron ◽  
Palm Species ◽  
Scanning Electron

Sabinaria magnifica is so far the only known species in the recently discovered tropical palm genus Sabinaria (Arecaceae). Here we present a complete description of the pollen morphology of this palm species based on light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We also made SEM-based comparisons of Sabinaria with other genera within the tribe Cryosophileae. Pollen grains of Sabinaria magnifica resemble the other genera in the heteropolar, slightly asymmetric monads, and the monosulcate and tectate exine with perforate surface. Nevertheless, there are some clear differences with Thrinax, Chelyocarpus and Cryosophila in terms of aperture and exine. S. magnifica differs from its closest relative, Itaya amicorum, in the exine structure. This study shows that a combination of microscope techniques is essential for the identification of different genera within the Cryosophileae and may also be a necessary when working with other palynologically less distinct palm genera. 

scholarly journals Correlation of X-ray Computed Nanotomography and Scanning Electron Microscopy Imaging of Collagen Scaffolds

2018 ◽  
Vol 24 (S2) ◽  
pp. 104-105
Author(s):  
Dominika Kalasova ◽  
Veronika Pavlinakova ◽  
Tomas Zikmund ◽  
Lucy Vojtova ◽  
Jozef Kaiser
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Collagen Scaffolds ◽  
Microscopy Imaging ◽  
X Ray ◽  
X Ray Computed ◽  
Scanning Electron

Sutureless nonocclusive bypass surgery in combination with an expanded polytetrafluoroethylene graft

2007 ◽  
Vol 107 (6) ◽  
pp. 1190-1197 ◽  
Author(s):  
Jochem P. Bremmer ◽  
Bon H. Verweij ◽  
Albert van der Zwan ◽  
Michael M. Reinert ◽  
Hendricus J. Mansvelt Beck ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bypass Surgery ◽  
Experimental Studies ◽  
Cerebral Aneurysms ◽  
Ease Of Use ◽  
Repair Tissue ◽  
Eptfe Graft ◽  
Expanded Polytetrafluoroethylene ◽  
Scanning Electron

Object Cerebral aneurysms that cannot be treated by clip or coil placement can be treated with high-flow bypass surgery using techniques such as the excimer laser–assisted nonocclusive anastomosis (ELANA). To simplify the technique, a sutureless ELANA (SELANA) was developed in combination with an expanded polytetrafluoroethylene (ePTFE) graft. Methods In 18 rabbits a bypass was constructed on the abdominal aorta using the SELANA technique with an ePTFE graft, resulting in 18 bypasses and 36 anastomoses. Short-term effects were analyzed in the first 2 weeks and at 2 and 3 months after the procedure. Patency was evaluated using quantitative ultrasound flowmetry. The anastomotic sites were studied using scanning electron microscopy. Results Construction of the bypass using the SELANA technique was easier and faster (15–25 minutes) compared with bypasses made with the ELANA technique (> 90 minutes). At the end of follow-up, 16 of 18 bypasses were patent. Of 36 SELANA anastomoses, 32 could be completed without short temporary occlusion of the recipient vessel. Scanning electron microscopy showed complete coverage of all anastomoses with neointimal repair tissue after 10 days. Conclusions The SELANA technique provides further advantages over the conventional ELANA technique in ease of use and shortening of procedure time. The patency rate in this series was 89% and neointima repair tissue at the anastomosis site was complete after 10 days. Further experimental studies of the long-term patency and safety of this technique are necessary before clinical application.

scholarly journals In VitroAdherence of Oral Bacteria to Different Types of Tongue Piercings

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lucas Pereira Borges ◽  
Julio Cesar Campos Ferreira-Filho ◽  
Julia Medeiros Martins ◽  
Caroline Vieira Alves ◽  
Bianca Marques Santiago ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Adhesion ◽  
Oral Bacteria ◽  
The Other ◽  
Control Group ◽  
Colony Forming Units ◽  
Different Types ◽  
Scanning Electron

The purpose of this work was to verifyin vitroadherence ofE. corrodensandS. oralisto the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU) and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type) were individually incubated in 5 mL of BHI broth and 50 μL of inoculum at 37°C/24 h. The other 96 piercings formed the control group and were individually incubated in 5 mL of BHI broth at 37°C/24 h. Plates were incubated at 37°C/48 h for counting of CFU/mL and data were submitted to statistical analysis (pvalue<0.05). ForE. corrodens, difference among types of material was observed (p<0.001) and titanium and surgical steel showed lower bacterial adherence. The adherence ofS. oralisdiffered among piercings, showing lower colonization (p<0.007) in titanium and surgical steel piercings. The four types of piercings were susceptible to colonization byE. corrodensandS. oralis, and bacterial adhesion was more significant in those made of Bioplast and Teflon. The piercings presented bacterial colonies on their surface, being higher in plastic piercings probably due to their uneven and rough surface.

Fine morphology of the cuticle surface of Chordodes anthophorus and reinterpretation of C. aquaeductus, C. ferganensis and C. oscillatus (Gordiida Nematomorpha)

Zootaxa ◽  
2007 ◽  
Vol 1397 (1) ◽  
pp. 39-45 ◽  
Author(s):  
CRISTINA DE VILLALOBOS ◽  
FERNANDA ZANCA ◽  
SERGEI SPIRIDONOV
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Central Asia ◽  
The Other ◽  
Species Status ◽  
Taxonomic Descriptions ◽  
Former Ussr ◽  
Fine Morphology ◽  
Scanning Electron

We reinvestigate four species of the genus Chordodes from Central Asia and one from Georgia (Transcaucasian part of former USSR) in order to certify the taxonomic descriptions and verify the species status. By scanning electron microscopy, we demonstrate characteristic cuticular patterns for Chordodes anthophorus. The other three species, C. aquaeductus, C. ferganensis and C. oscillatus are synonymized with C. anthophorus because no differences were detected.

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