Observation d'un sol forestier (rendzine) en microscopie electronique

1979 ◽  
Vol 25 (8) ◽  
pp. 943-946 ◽  
Author(s):  
G. Kilbertus ◽  
J. Proth
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Forest Soil ◽  
Clay Minerals ◽  
The Other ◽  
Soil Suspension ◽  
Microscopie Électronique ◽  
Fungal Hyphae ◽  
Ultrathin Sections ◽  
Scanning Electron

Scanning electron microscopy was used to evidence the aggregated structure of a forest soil as well as the presence of fungal hyphae external to soil aggregates.The supernatant of soil suspension in water mainly contained isolated bacteria, while ultrathin sections of aggregates frequently revealed groups of bacteria surrounded by a sheath of mucilage with adhering clay minerals on the outside.These results confirm the existence of two particular biotopes in the soil studied: one is located inside aggregates, and the other, in the inter-aggregate spaces. [Translated by the journal]

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 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.

scholarly journals Effect of denture surface glazing on denture plaque formation

2005 ◽  
Vol 16 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Newton Sesma ◽  
Dalva Cruz Laganá ◽  
Susana Morimoto ◽  
Carlos Gil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacterial Colonization ◽  
Plaque Formation ◽  
The Other ◽  
Bacterial Plaque ◽  
The Right ◽  
Clinical Experiment ◽  
Scanning Electron

This study evaluated, in vivo, the efficacy of a denture glazing material (Palaseal) in modifying plaque colonization of dentures. Ten subjects were selected and received maxillary temporary partial removable dentures, with complete acrylic palatal coverage. The right half of the fitting surface of the denture bases were glazed with Palaseal, whereas the other half was not glazed. One month after insertion, two fragments of the resin base of all dentures were removed (one from the glazed side and another from the non-glazed side). These samples were prepared and examined by scanning electron microscopy. Three months after insertion, other fragments were obtained and analyzed. Microscopic observation at 1 month revealed that, for all patients, the plaque film was thinner on the treated side in comparison to the non-treated side. However, at the 3-month evaluation, some areas of the glaze showed cracking, and both glazed and non-glazed sides were covered by a dense bacterial plaque film. In conclusion, the findings of this clinical experiment showed that glazing denture's fitting surface did not prevent bacterial colonization, but favored plaque removal while the glaze layer remained intact. After three months, glaze cracks created microretentive areas that increased plaque accumulation.

Silica deposition in the inflorescence bracts of wheat (Triticum aestivum). I. Scanning electron microscopy and light microscopy

1988 ◽  
Vol 66 (5) ◽  
pp. 829-838 ◽  
Author(s):  
M. J. Hodson ◽  
A. G. Sangster
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Triticum Aestivum ◽  
Light Microscopy ◽  
Triticum Aestivum L ◽  
The Other ◽  
Deposition Pattern ◽  
Membranous Structure ◽  
Silica Deposition ◽  
Scanning Electron

Silica deposition in the lower glume, lemma, and palea of wheat (Triticum aestivum L. cv. Highbury) was investigated using scanning electron microscopy and light microscopy. Silica was present in the outer walls of all the epidermal cells including prickles and papillae of the glume and lemma awns. The glume and the lemma were similar in epidermal silica deposition pattern, both having numerous silicified short trichomes and papillae on inner and outer surfaces. Epidermal long cells and short cells were also silicified. Macrohairs were restricted to isolated areas in these bracts, particularly on the inner surfaces just beneath the awns. The palea was a thin membranous structure differing markedly from the other two bracts. Most of the palea is pressed between the caryopsis and the next floret, and both surfaces are almost devoid of trichomes in these areas. However, at the apex and margins of the palea, macrohairs and papillae were abundant. The results are discussed with respect to possible taxonomic, anatomical, medical, and archaeological implications.

Structure of the cephalic end of two little-known oxyuroid genera, Travnema Pereira, 1938 and Cosmoxynemoides Travassos, 1949, parasites of fishes, as revealed by SEM

1994 ◽  
Vol 68 (4) ◽  
pp. 319-322 ◽  
Author(s):  
F. Moravec ◽  
A. Kohn ◽  
B.M.M. Fernandes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Type Species ◽  
Freshwater Fishes ◽  
The Other ◽  
New Host ◽  
The Family ◽  
Cephalic Extremity ◽  
New Host Records ◽  
Scanning Electron

AbstractThe cephalic end of the type species of pharyngodonid genera Travnema and Cosmoxynemoides, T. travnema Pereira, 1938 and C. aguirrei Travassos, 1949, parasites of Brazilian freshwater fishes, was studied by scanning electron microscopy. The mouth aperture of Travnema was found to be circular, surrounded by four cephalic papillae and two lateral amphids and the cuticle of the cephalic end had a conspicuous dense sculpture. On the other hand, the mouth aperture of Cosmoxynemoides was triangular, surrounded by three lip-like elevations covering the whole surface of the relatively flat cephalic extremity, each with two inner lobes separated one from another by a short groove; the lip-like elevations bore four medium-sized, kidney-shaped cephalic papillae and two minute amphids (two papillae on the dorsal elevation and one papilla and one amphid on each of two ventrolateral elevations); the cuticle of the cephalic end was smooth. Both species were noted for the absence of oral lamellae and the presence of lateral alae. Both genera are listed in the family Pharyngodonidae but Travnema (and also Hakynema), due to its morphological peculiarities, is considered to represent a distinct subfamily Travnematinae within the Pharyngodonidae. The finding of both T. travnema and C. aguirrei in the characid fish Astyanax bimaculatus lacustris represents new host records.

Comparison of Hydrogen Sulfide Sensing Properties between Multiple-Walled Carbon Nanotubes (MWNTs) and MWNTs-HAuCl4 Materials

2014 ◽  
Vol 936 ◽  
pp. 310-314
Author(s):  
Si Xuan He ◽  
Guang Zhong Xie ◽  
Ya Dong Jiang ◽  
Guang Di Zhang ◽  
Yong Zhou
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Hydrogen Sulfide ◽  
Response Time ◽  
Room Temperature ◽  
The Other ◽  
High Toxicity ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

The rapid and precise detection of hydrogen sulfide (H2S) has great significance due to its high toxicity. In this work, the response properties of multiple-walled carbon nanotubes (MWNTs) and MWNTs-HAuCl4 to H2S at room temperature were compared. Scanning electron microscopy (SEM) technique was used to characterize MWNTs and MWNTs-HAuCl4 films. It was found that sensors with MWNTs-HAuCl4 exhibited much higher response value. On the other hand, sensors with MWNTs were observed to have faster response time and better recovery properties.

scholarly journals Scanning Electron Microscopy Reveals Different Response Pattern of Four Vitis Genotypes to Xylella fastidiosa Infection

Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Felix B. Fritschi ◽  
Hong Lin ◽  
M. Andrew Walker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Xylella Fastidiosa ◽  
Systemic Infection ◽  
The Other ◽  
Enzyme Linked Immunosorbent Assay ◽  
Treatment Comparisons ◽  
Different Response ◽  
Scanning Electron ◽  
Tylose Formation

The xylem-limited bacterium Xylella fastidiosa causes Pierce's disease (PD), whose disease symptoms are primarily the result of xylem vessel blockage in susceptible grapevines. Stem internode and petiole tissues from infected and uninfected control plants of four grape genotypes (Vitis vinifera, V. rufotomentosa, V. smalliana, and V. arizonica/candicans) differing in PD susceptibility were examined using scanning electron microscopy (SEM). Tyloses, fibrillar networks, and gum plugs were observed in lumens of tracheary elements in petioles and internodes of both water-inoculated control plants and X. fastidiosa–inoculated plants of all genotypes. Bacteria were not observed in control plants. In both petiole and internode tissues, the greatest number of occluded xylem vessels were observed in V. vinifera and the smallest number in V. arizonica/candicans. The number of xylem vessels infested with X. fastidiosa was greatest in V. vinifera and did not differ among the other three genotypes. Systemic infection was found in all genotypes. The frequency with which X. fastidiosa infested vessels were observed using SEM corresponded well with bacterial levels estimated by enzyme-linked immunosorbent assay. Among infected plants, tylose formation in internodes was lowest in V. arizonica/candicans and did not differ among the other three genotypes. Infection with X. fastidiosa strongly induced tylose formation in V. vinifera and V. smalliana but not in V. arizonica/candicans. Analysis across tissues and genotypes indicated an induction of fibrillar networks and gum occlusions in response to X. fastidiosa infection, whereas treatment comparisons within genotypes were not significant except for V. vinifera petioles. Limiting the spread of X. fastidiosa infection by xylem conduit occlusions does not appear to be the mechanism conferring PD resistance or tolerance to V. arizonica/candicans, V. smalliana, or V. rufotomentosa. In contrast, the strong induction of tyloses may be detrimental rather than beneficial for V. vinifera survival after X. fastidiosa infection.

Morphology and ultrastructure of Hippodonta qinghainensis sp. nov. (Bacillariophyceae), a new diatom from Lake Qinghai, China

Phytotaxa ◽  
2014 ◽  
Vol 186 (2) ◽  
pp. 61 ◽  
Author(s):  
YUMEI PENG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
The Other ◽  
Similar Species ◽  
Unique Combination ◽  
Lake Qinghai ◽  
Geometric Morphometric ◽  
Morphometric Analyses ◽  
Scanning Electron

A new medium-sized species of Hippodonta (Bacillariophyceae) is described from Lake Qinghai, China. The morphology and ultrastructure of Hippodonta qinghainensis sp. nov. are described using light and scanning electron microscopy. This new species is compared with similar species of Hippodonta using conventional and geometric morphometric analyses. Hippodonta qinghainensis can be separated from the other species of Hippodonta by a unique combination of characters that include an elliptic-lanceolate to rhombic-lanceolate valve shape, non protracted apices, the absence of fascia, relatively coarse, uniseriate striae and the presence of two rows of lineolae around the valves apices.

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