Amphipods (Amphipoda, Gammaridea) at the Gorevoy Utes oil and methane seep, Lake Baikal

Crustaceana ◽  
2014 ◽  
Vol 87 (13) ◽  
pp. 1500-1520 ◽  
Author(s):  
Irina V. Mekhanikova ◽  
Irina V. Mekhanikova ◽  
Tatiana Ya. Sitnikova
Keyword(s):  
Electron Microscopy ◽  
Lake Baikal ◽  
Additional Data ◽  
Maximum Density ◽  
Depth Range ◽  
Methane Seep ◽  
Flat Bottom ◽  
Bacterial Mats ◽  
Entire Lake ◽  
Scanning Electron

We examined amphipods collected from aboard the deepwater manned submersibles “Mir-1” and “Mir-2” at oil and methane seeps near Cape Gorevoy Utes (Central Baikal). Most of the 23 taxa registered inhabit the entire Lake Baikal within a wide depth range. Two species of the genus Echiuropus are probably new. Leptostenus leptocerus (Dybowsky, 1874), that, until now, was regarded as a rare species, is likely to be an indicator for methane and oil discharge areas. Additional data on the morphology of this species were obtained; cuticular sensory (lateral line organs) and nonsensory microstructures were examined by scanning electron microscopy. The density of nectobenthic amphipods was 5-6 times higher on bitumen mounds than that at neighbouring sites with flat bottom. Maximum density of benthic amphipods was recorded on bacterial mats. No amphipods were observed at the bottom with large oil patches. High density of amphipods at the oil-methane seep is attributed to highly structured habitats and food abundance.

scholarly journals Pollen morphology of the genus Eremanthus Less. (Vernonieae, Asteraceae)

2012 ◽  
Vol 26 (1) ◽  
pp. 46-57 ◽  
Author(s):  
BenoÎt Loeuille ◽  
Raquel Maria Batista Souza-Souza ◽  
Vanessa Holanda Righetti Abreu ◽  
Cláudia Barbieri Ferreira Mendonça ◽  
Vania Gonçalves-Esteves
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pollen Morphology ◽  
Additional Data ◽  
Phylogenetic Reconstruction ◽  
Pollen Grains ◽  
Prolate Spheroidal ◽  
Oblate Spheroidal ◽  
Quantitative Characters ◽  
Scanning Electron

In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae), and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits.

scholarly journals The diatom genus Gomphoneis Cleve (Bacillariophyceae) from Lake Baikal, Russia

Phytotaxa ◽  
2013 ◽  
Vol 154 (1) ◽  
pp. 1 ◽  
Author(s):  
JOHN P. KOCIOLEK ◽  
MAXIM S. KULIKOVSKIY ◽  
CÜNEYT N. SOLAK
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lake Baikal ◽  
Western North America ◽  
The West ◽  
Nw China ◽  
The World ◽  
Diatom Genus ◽  
Scanning Electron ◽  
Species Flocks

We describe 22 new species of Gomphoneis, and report several previously described taxa, from historical and recently made collections from Lake Baikal, Russia. We use light microscopy to document all taxa, and scanning electron microscopy to illustrate several of the species from the lake. All of the species present in Lake Baikal are part of the Elegans subgroup of the genus. Despite previous reports, we could find no representatives of the Herculeana subgroup in Baikal. We provide comparisons between the taxa, and document variability in the features found in the species. Two groups within the Elegans subgroup are present; most have 4 (or more) stigmoids, while a minority of the species lack stigmoids. We suggest that the species in Lake Baikal have two origins; one from the West, where an arc of related species spans Mongolia, NW China to Macedonia, and the second from western North America. Radiation of the two groups has resulted in species flocks. The number of Gomphoneis species in Lake Baikal is the largest number of species of the genus anywhere in the world.

Rediscovery of the poorly known Scorzonera argyria and its relationships in Turkey

Biologia ◽  
2008 ◽  
Vol 63 (6) ◽  
Author(s):  
Muhittin Dinç ◽  
Ahmet Duran ◽  
Esra Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Scientific Community ◽  
Additional Data ◽  
Conservation Status ◽  
Distinct Species ◽  
Turkish Flora ◽  
Vegetative Characters ◽  
Associated Species ◽  
Scanning Electron

AbstractScorzonera argyria Boiss. has been a poorly known endemic species classified within DD category of IUCN. It has not been collected since its introduction to the scientific community in 1843. Scorzonera argyria in the Turkish flora might be considered to be a synonymy of S. eriophora. Based on the specimens collected from the type locality environs, Scorzonera argyria’s detailed morphological, karyological and palynological descriptions are presented. Its two allies, S. eriophora DC. and S. pisidica Hub.-Mor., are morphologically and palynologically studied and compared to Scorzonera argyria. After the comparison conducted in the present study, S. argyria is clearly determined to be a distinct species. Consequently, in addition to some vegetative characters S. argyrea basically differs from the allied species by its typical achenes. S. argyrea and the two allied species are generally palynologically similar, but minor differences exist between them on account of their spine shapes and micro-ornamentations observed under scanning electron microscopy. The habitat S. argyrea and its typically associated species are briefly discussed. Additional data on the ecology and the conservation status of S. argyria are also given.

scholarly journals The Influence of Laser Defocusing in Selective Laser Melted IN 625

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3447
Author(s):  
Alexandru Paraschiv ◽  
Gheorghe Matache ◽  
Mihaela Raluca Condruz ◽  
Tiberius Florian Frigioescu ◽  
Ion Ionică
Keyword(s):  
Electron Microscopy ◽  
Tensile Testing ◽  
Maximum Density ◽  
The Other ◽  
Melting Depth ◽  
Sem Images ◽  
Pool Shape ◽  
Melt Pool ◽  
Melt Pool Size ◽  
Scanning Electron

Laser defocusing was investigated to assess the influence on the surface quality, melt pool shape, tensile properties, and densification of selective laser melted (SLMed) IN 625. Negative (−0.5 mm, −0.3 mm), positive (+0.3 mm, +0.5 mm), and 0 mm defocusing distances were used to produce specimens, while the other process parameters remained unchanged. The scanning electron microscopy (SEM) images of the melt pools generated by different defocusing amounts were used to assess the influence on the morphology and melt pool size. The mechanical properties were evaluated by tensile testing, and the bulk density of the parts was measured by Archimedes’ method. It was observed that the melt pool morphology and melting mode are directly related to the defocusing distances. The melting height increases while the melting depth decreases from positive to negative defocusing. The use of negative defocusing distances generates the conduction melting mode of the SLMed IN 625, and the alloy (as-built) has the maximum density and ultimate tensile strength. Conversely, the use of positive distances generates keyhole mode melting accompanied by a decrease of density and mechanical strength due to the increase in porosity and is therefore not suitable for the SLM process.

scholarly journals Longevity of Apis mellifera workers fed on a diet incorporating entomopathogens

2019 ◽  
Vol 86 ◽  
Author(s):  
Fernanda Caroline Colombo ◽  
Rodrigo Mendes Antunes Maciel ◽  
Gabriela Libardoni ◽  
Fernanda Raulino ◽  
Everton Ricardi Lozano ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Apis Mellifera ◽  
Tween 80 ◽  
Distilled Water ◽  
Flat Bottom ◽  
Morphological Alterations ◽  
Glass Tubes ◽  
Qualitative Analyses ◽  
Scanning Electron

ABSTRACT: The present study had the objective of evaluating the longevity of A. mellifera workers fed on a diet incorporating commercial entomopathogens, Beauveria bassiana, and Bacillus thuringiensis. It also aimed at verifying possible morphological alterations in the midgut. To this purpose, the entomopathogens used were B. bassiana (Product A) (5.0 × 1011 viable conidia.kg-1), B. thuringiensis (Product B) (2.5 × 109 viable spores.g-1), and B. thuringiensis (Product C) (1.0 × 109 viable spores.g-1); and two controls: T1: sterilized distilled water, and T2: sterilized distilled water + Tween 80® (0.01%). For the bioassays, 2 mL of each treatment were incorporated into Candy paste. For each treatment, 80 bees were individually in flat bottom glass tubes (2.5 cm Ø) covered with voile, containing a piece of cotton soaked in water and Candy paste. These tubes were stored in a B.O.D (30 ± 2°C, R.H 70% ± 10%, 12 h), and mortality was evaluated every six hours, for 10 days. Soon after verifying mortality, two bees per treatment were selected for the removal of their midgut. Midgut samples were processed using standard methodology for Scanning Electron Microscopy (SEM). It was verified that products A, B, and C reduced the longevity of bees when compared to T1 and T2 controls. In the qualitative analyses carried out using SEM, it was not possible to observe external or internal morphological alterations to midgut tissues. Although products A, B, and C cause a reduction in longevity, their presence was not verified when tissues were analyzed using SEM.

Nematodes of the order Rhabditida from Andalucía Oriental, Spain. The genus Cervidellus Thorne, 1937 (Cephalobidae) with additional data on C. hamatus Thorne, 1937

Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 753-776 ◽  
Author(s):  
Oleksandr Holovachov ◽  
Joaquín Abolafia ◽  
Sven Boström ◽  
Reyes Peña-Santiago
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Iberian Peninsula ◽  
Additional Data ◽  
Identification Key ◽  
Natural Areas ◽  
The Usa ◽  
Se Iberian Peninsula ◽  
Scanning Electron

AbstractThree known species of the genus Cervidellus Thorne, 1937 are described from natural areas in the SE Iberian Peninsula on the basis of light and scanning electron microscopy, viz., C. neftasiensis, C. vexilliger and C. hamatus. In addition, data on C. hamatus from the USA are given. Descriptions, measurements and illustrations, including SEM photographs, are provided for all three species. The systematics of the genus is briefly discussed and an identification key to the species is provided.

The diatom genus Gomphonema Ehrenberg in Lake Baikal. II. Revision of taxa from Gomphonema acuminatum and Gomphonema truncatum-capitatum complexes

Phytotaxa ◽  
2015 ◽  
Vol 233 (3) ◽  
pp. 251 ◽  
Author(s):  
Maxim Sergeevich Kulikovskiy ◽  
John Patrick Kociolek ◽  
Cuneyt Nadir Solak ◽  
Irina Kuznetsova
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Central Asia ◽  
Lake Baikal ◽  
Wide Distribution ◽  
Species Complexes ◽  
Diatom Genus ◽  
Scanning Electron

We document the diversity of diatom taxa from the G. acuminatum and truncatum-capitatum species complexes in Lake Baikal using light and scanning electron microscopy. This investigation revealed four species new to Science, namely G. pseudacuminatum sp. nov., G. microlaticollum sp. nov., G. paracapitatum sp. nov., and G. microcapitatum sp. nov. In addition, we consider seven previously described species that are part of these ‘typical Gomphonema’ complexes. Some of the taxa treated here were previously observed from other regions, especially from Mongolia. These data show a wide distribution of species from these complexes in waterbodies of Central Asia, and confirm the presence of some cosmopolitan taxa within Lake Baikal.

Nematodes from the Gulf of California. Part 2. Ceramonema nasobema sp. n. (Nematoda: Ceramonematidae)

Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 835-844 ◽  
Author(s):  
Oleksandr Holovachov ◽  
Manuel Mundo-Ocampo ◽  
Irma Tandingan De Ley ◽  
Paul De Ley
Keyword(s):  
Electron Microscopy ◽  
South Africa ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Sexual Dimorphism ◽  
Gulf Of California ◽  
Additional Data ◽  
Scanning Electron

AbstractAn unusual new ceramonematid, Ceramonema nasobema sp. n., is described using light and scanning electron microscopy. It is particularly characterised by the presence of a perioral tube projecting 5.5-7.0 μm anterior to the lips, moderately long body (0.86-1.09 mm), relatively small number of body annules (121-134), weakly developed zygapophyses, absence of intracuticular vacuoles, pronounced sexual dimorphism in amphid shape with the male ventral amphidial branch extending as far posterior as the 55-80th annule (no extension in females), barrel-shaped stoma, sigmoid and anteriorly inclined vagina without sclerotisations, gubernaculum with dorsal apophyses and relatively uniform cloacal annules. The new species differs from all other known species of Ceramonema especially by the shape of the amphid in males, the strongly projecting perioral tube and the inclined, sigmoid, vagina. Additional data on morphology of Ceramonema algoensis (from Natal Bay, South Africa) are also provided as this species has the most prominent perioral tube among previously described members of the genus.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

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