scholarly journals Epidermal micromorphology of floret parts in Aeluropus (Poaceae)

2021 ◽  
Vol 65 (1) ◽  
pp. 35-45
Author(s):  
Samaneh Mosaferi ◽  
Maryam Keshavarzi

Aeluropus from Poaceae comprises 5 species in the world and 3 species in Iran. This halophytic perennial is distributed in salty and dry soils of Asia, Europe, and Africa. In addition to being used as fodder, it can stabilize the soil by its rhizome or stolon. These features make Aeluropus a valuable plant. In this study, lemma and palea of 10 populations of Aeluropus were studied micromorphologically by scanning electron microscope (SEM) to determine diagnostic features among species studied. Eight characters as micro-prickle, macro-hair, long cell outline, cork and silica cells, papilla, salt gland, and epicuticular wax were studied. The occurrence of salt glands and silica cells in populations/taxa studied showed the ability of Aeluropus to tolerate harsh habitats. Our result showed the taxonomic value of floret micromorphological features to separate Aeluropus species.

Author(s):  
Hadi M. Hamza Al-Mayali ◽  
Hind A. Abdul Kadhim

Introduction: Echinococcosis and hydatidosis caused by the metacestode of Echinococcus granulosus are among the most important zoonotic diseases in the world. This study aims to study the ultrastructure of fertile hydatid cysts that infect humans using a scanning electron microscope (SEM). Materials and Methods: Twenty samples of human fertile hydatid cysts were collected from the human liver and lung after performing surgery operations and examined with an SEM. Results: The results of the electron microscopy with different magnifications revealed that the laminated layer (LL) consists of sheets that appeared more compact and aligned. The brood capsules appeared, consisting of a net of finger-shaped structures that emerged from bulges of various sizes and shapes. Conclusion: Under a transmission electron microscope, it was found that the LL had a coherent and flexible structure, settling on a three-dimensional microscopic network of hydrophilic fibers, with high humidity. These fibers were arranged irregularly and had a diameter of about 10 nm; therefore, the fibers adjacent to the germinal layer (GL) were possibly attached to microtriches of tegument, which reached a thickness of 1 mm in the LL.


2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.


1998 ◽  
Vol 44 ◽  
pp. 331-347 ◽  
Author(s):  
K. C. A. Smith

Charles Oatley made three outstanding contributions to the engineering sciences: he was one of the brilliant team that developed radar in Britain during the Second World War; he revolutionized the teaching of electronics at Cambridge University; and he developed the scanning electron microscope. It is for the last of these that he will be chiefly remembered. He stands with Manfred von Ardenne as one of the two great pioneers of scanning electron microscopy His involvement with the instrument began shortly after the war when, fresh from his experience in the development of radar, he perceived that new techniques could be brought to bear which would overcome some of the fundamental problems encountered by von Ardenne in his pre–war research. Oatley's work led directly to the launch of the world's first series production instrument—the Stereoscan—in 1965. Thousands of scanning electron microscopes have since been manufactured and are to be found in practically every research laboratory in the world. The striking three–dimensional images of microscopic organisms produced have been used to illustrate countless newspaper and magazine articles, as well as scientific research papers, giving the general public a new perspective and appreciation of the world that lies beyond the resolution of the human eye. The scanning electron microscope is, arguably, the single most important scientific instrument of the post-war era.


2014 ◽  
Vol 14 (2) ◽  
pp. 83-91
Author(s):  
Karol Latowski ◽  
Cezary Toma ◽  
Magdalena Dąbrowska ◽  
Egita Zviedre

AbstractResearch was carried out on fruits and seeds of Nymphaea and Nuphar taxa collected from Poland, Latvia and Estonia. The aim of the research was to establish diagnostic features which could enable identification of the examined taxa on the basis of the fruit and seed structure and creating a key to identify them. The examined organs were observed through an optic microscope and scanning electron microscope (SEM). New diagnostic features were discovered: spotting of fresh pericarp, the range of the fruit shape coefficient, the colour of the rays in the fruit stigma disc, the thickness of the seed testa, ribs in the seeds, and occurrence of the “puzzle shaped” cells on the surface of the testa. The discovered features were used in the taxonomic characteristics.


Phytotaxa ◽  
2016 ◽  
Vol 243 (2) ◽  
pp. 185 ◽  
Author(s):  
Letícia Donadel ◽  
Lezilda Carvalho Torgan

Falcula hyalina Takano (1983: 24) is an epizoic diatom commonly associated with coastal copepods in many parts of the world (Takano 1983, Mahoney & Gibson 1983, Hiromi et al. 1985, Prasad et al. 1989, Souza-Mosimann et al. 1989, Fernandes & Calixto-Feres 2012, Li et al. 2014). The species was described and illustrated using the transmission electron microscope by Takano (1983) who differentiated it from other taxa of the genus—F. rogallii Voigt (1960: 86), F. media Voigt (1960: 87), F. semiundulata Voigt (1960: 87), F. paracelsiana Voigt (1961: 54) and F. media var. subsalina Proshkina-Lavrenko (1963: 36)—by the morphometric features of the valve (length, width, and stria and areolae density). Some years later, Prasad et al. (1989) improved the morphological features of F. hyalina using the scanning electron microscope and discussed the relation of the species with similar taxa. Round et al. (1990), in the diacritic description of the genus, raised the question that F. hyalina had some features that could not match with Falcula, such as the wider sternum and poroidal apical pore field (ocellulimbus), as opposed to a series of slits at the apices. Therefore, the taxonomic position of F. hyalina still remains uncertain.


Author(s):  
Unueroh Ufuoma Georgina ◽  
Basil Onyekpe

Corrosion is a major problem all over the world. A lot of researches on corrosion are ongoing all over the world and will continue to go on. This paper investigates the effect of corrosion on the tensile properties of AISI 1040 steel in seawater. The samples were austenised at 8300C, 9300C, and 10300C, while some were not. The austenised samples were quenched in water and tempered at 5000C. The samples were further machined into tensile test specimens and then exposed to stagnant aerated seawater. Two samples each from each austenised temperature were tested using a tensile test machine at every 15-days interval, for a duration of 90 days. Some of the fracture surfaces were examined using scanning electron microscope. The results shows a 25% decrease in tensile strength for as received sample, 20.1% decrease for samples austenised at 8300C, 20.9% decrease for samples austenised at 9300C and 22.4% decrease for samples austenised at 10300C at the end of the 90thday.


Author(s):  
E. Eichen ◽  
D. R. Fitchmun ◽  
L. R. Sefton

In the past two years, there has been a great increase in interest in the scanning electron microscope as a research tool. Coupled with this has been a large increase in the number of instruments being used throughout the world. The reasons for this popularity stems from the unique abilities of this form of in strumentation which include: (a) a large depth of field which allows one to view a very rough surface; (b) a minimal requirement of specimen preparation; and (c) its ability to make use of voltage contrast in the study of semiconductors.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

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.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


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