The External Morphology of the Eggs of Culex (Culex) saltanensis (Diptera: Culicidae) Under Scanning Electron Microscopy

Author(s):  
J R Santos-Mallet ◽  
T D Balthazar ◽  
A A Oliveira ◽  
W A Marques ◽  
A Q Bastos ◽  
...  

Abstract The aim of the present study was to describe the morphology of the eggs of Culex (Culex) saltanensis Dyar that occurs in the Neotropical region. Eggs of the Cx. (Cux.) saltanensis were collected at the Mata Atlântica FIOCRUZ campus, fixed in 1% osmium tetroxide, prepared for mounting on metal supports, observed under a scanning electron microscope, and described morphologically. The eggs had a coniform shape with a length of approximately 0.5 mm (505–510 µm) and a width in the median portion of 117 µm (113–123 µm). Upper portion is lined with tubers of irregular shape and varying sizes (0.64–1.31 µm), located on a cross-linked matrix forming bands observed under optical microscopy. The micropyle is encased in a necklace of approximately 6.6-µm plates arranged in a flower-like shape. Comparing Cx. (Cux.) saltanensis eggs with several species of different genera, important divergent characteristics can be observed. However, this study points to the need for new descriptions of eggs of species belonging to the same subgenus in order to analyze if there will be differences between them. Culex (Cux.) saltanensis eggs have particular characteristics not observed in eggs of other Culicidae genera.

2001 ◽  
Vol 36 (4) ◽  
pp. 335-341 ◽  
Author(s):  
Ai-Ping Liang

The external morphology of the sensilla on the antennae of the adult spittlebug, Prosapia bicincta (Say) (Hemiptera: Cercopidae), is described for the first time, using scanning electron microscope observations. The sensilla include one peg-like basiconic sensillum (about 65.05 to 65.90 μ in length and 13.33 to 14.08 μ in width at base), 18 to 23 porous coeloconic sensilla (mostly 7.38 to 8.94 μ in diam), one campaniform sensillum and a cluster of trichoid sensilla (about 45 to 55 (μ long). The first two types of sensilla are located on the expanded flagellar base, while the latter two sensilla are on the pedicel.


1980 ◽  
Vol 58 (15) ◽  
pp. 1700-1703 ◽  
Author(s):  
E. C. Quattlebaum ◽  
G. R. Carner

Vapor fixation for 96 h with 1% osmium tetroxide (OsO4) and 3–4 days air drying produced distortion-free specimens of Beauveria spp. for examination with the scanning electron microscope. A combination of 4 h OsO4 vapor fixation and freeze-drying also reduced disruption satisfactorily but specimens were not as well preserved as with the first method. Preparation methods that were ineffective in preventing collapse of hydrophilic structures were Cling Free® sprayed on specimens prior to examination, freeze-drying, critical-point drying (of unfixed material), and vapor fixation with glutaraldehyde.


1989 ◽  
Vol 67 (4) ◽  
pp. 831-838 ◽  
Author(s):  
N. N. Kapoor

The external morphology and distribution of various types of sensilla on the mouthparts of the nymphs of Paragnetina media are described, based on light and scanning electron microscopy. Hairs of various types are arranged in distinctive patterns on each mouthpart. Scolopophorous sensilla, each consisting of a pore canal and two bipolar neurons, are present in the mandibular teeth. The elliptical type of campaniform sensilla, multiporous columnar pegs, and nonporous sensilla are concentrated on the segments of the maxillary and labial palps. The tips of the maxillary and labial palps bear a cluster of uniporous multidigitate pegs, a multiporous peg, a circular type campaniform sensillum, and several nonporous sensilla. Nonsocketed uniporous pegs crown the tip of galeae and are also scattered over the surface of the glossae and paraglossae. Possible functions of these sensilla are discussed. A cleaning method is described to visualize details with the scanning electron microscope.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 487
Author(s):  
Hana Běhalová ◽  
Bohuslava Tremlová ◽  
Ludmila Kalčáková ◽  
Matej Pospiech ◽  
Dani Dordevic

The aim of the research was to verify the necessity of secondary fixation with osmium tetroxide in various types of meat products and evaluation of structural changes of products using different fixation procedures. The material for the study consisted of 11 types of meat products that were analyzed using a scanning electron microscope (SEM) with two different methods of chemical fixation. The first method included the usual processing of biological samples: glutaraldehyde primary fixation, the use of a buffer, secondary fixation by osmium tetroxide (OsO4), buffer, and dehydration using ethanol of increasing concentrations. The second method comprised the glutaraldehyde primary fixation and dehydration using the ethanol of increasing concentrations only. The results unambiguously suggest that the main difference between these methods is in fixation and visibility of fat. Our analysis principally suggests that fixation of the product with OsO4 allows the tracking of all components (fat droplets, muscle fibers, connective tissue) in meat products. At the same time, our results also support the possibility that the secondary fixation can be skipped during the analysis, where the main objection is an observation of lipid-free structures of the meat products (e.g., connection between muscle and starches or spices) or meat products with an insignificant amount of fat.


Author(s):  
David Joy ◽  
James Pawley

The scanning electron microscope (SEM) builds up an image by sampling contiguous sub-volumes near the surface of the specimen. A fine electron beam selectively excites each sub-volume and then the intensity of some resulting signal is measured. The spatial resolution of images made using such a process is limited by at least three factors. Two of these determine the size of the interaction volume: the size of the electron probe and the extent to which detectable signal is excited from locations remote from the beam impact point. A third limitation emerges from the fact that the probing beam is composed of a finite number of discrete particles and therefore that the accuracy with which any detectable signal can be measured is limited by Poisson statistics applied to this number (or to the number of events actually detected if this is smaller).


Author(s):  
Mamaeva S.N. ◽  
Vinokurov R.R. ◽  
Munkhalova Ya.A. ◽  
Dyakonova D.P. ◽  
Platonova V.A. ◽  
...  

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.


1972 ◽  
Vol 3 (3) ◽  
pp. 181-188 ◽  
Author(s):  
Christine Dahl

AbstractA method for preparation of alcohol-preserved culicid larvae for Scanning Electron Microscope (SEM) studies is described. It is based on dehydration by ethanol-xylol and fast evaporation of xylol in +8o° C. for ten minutes. For taxonomic studies such as examination of pecten teeth, comb scales and microtrichiae in magnifications up to 6oooX the method is suitable. For studies of receptor structures on hair-tufts and microstructures of the body integument alcohol preserved material is less satisfactory. The microstructure of the comb scales is figured and their function discussed. Differences in the ultrastructure of the abdominal hair-tufts are pointed out.


1988 ◽  
Vol 62 (2) ◽  
pp. 141-147 ◽  
Author(s):  
F. J. Kruger ◽  
V. L. Hamilton-Attwell

ABSTRACTSchistosoma haematobium miracidia were collected from a locality with a high prevalence of human infection with the animal parasite, S. mattheei, which hybridizes with S. haematobium, and from 2 localities with negligible infection rates. The terebratoria of the miracidia from these localities were compared with each other, with laboratory maintained S. haematobium and with four populations of S. mattheei by means of scanning electron microscopy. It was found that the terebratorial membrane of certain of the S. haematobium miracidia from the locality with a high S. mattheei prevalence in humans, resembled the more intricate membrane of S. mattheei. This suggests introgressive hybridization between S. haematobium and S. haematobium x S. mattheei.


1994 ◽  
Vol 40 (134) ◽  
pp. 195-197
Author(s):  
E. W. Wolff ◽  
A. P. Reid

AbstractA snow crystal has been successfully collected on to a scanning electron microscope (SEM) stub in central Greenland. It was preserved at liquid-nitrogen temperature for 5 months, prior to examination in the SEM. This is believed to be the first time a snow crystal has been observed directly in the SEM and offers some new experimental methods for understanding crystals and their chemistry.


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