scholarly journals Revision of the genus Niphta (Diptera, Thaumaleidae) Theischinger of South America, with descriptions of nine new species and a new immature morphotype

ZooKeys ◽  
2021 ◽  
Vol 1063 ◽  
pp. 49-104
Author(s):  
Robert J. Pivar ◽  
Bradley J. Sinclair ◽  
John K. Moulton
Keyword(s):  
Electron Microscopy ◽  
South America ◽  
South American ◽  
Immature Stages ◽  
Key To Species ◽  
Distribution Maps ◽  
Phylogenetic Affinities ◽  
Microscopy Images ◽  
First Descriptions ◽  
Scanning Electron

The Niphta Theischinger fauna of South America is revised to include 11 species, nine of which are described as new to science (N. acus Pivar, sp. nov., N. bifurcata Pivar & Moulton, sp. nov., N. bispinosa Pivar & Sinclair, sp. nov., N. brunnea Pivar, sp. nov., N. courtneyi Pivar, sp. nov., N. daniellae Pivar, sp. nov., N. downesi Pivar, sp. nov., N. eurydactyla Pivar, sp. nov., N. mapuche Pivar, sp. nov.). The genus Niphta is redefined, both previously described Chilean species are redescribed, N. halteralis (Edwards) and N. nudipennis (Edwards), and females are described or redescribed where possible. The first descriptions of the immature stages of South American Niphta are provided, which represent a new larval morphotype in Thaumaleidae, as larvae and pupae possess ventral adhesive structures. Furthermore, these larvae were collected from vegetation rather than rocky substrates. Illustrations and micrographs are provided for all species, and scanning electron microscopy images are included for select immatures. A key to species, distribution maps, and discussions regarding phylogenetic affinities and habitat are also included.

scholarly journals Morphological aspects of immature stages of Migonemyia migonei (Diptera: Psychodidae, Phlebotominae), an important vector of Leishmaniosis in South America, described by scanning electron microscopy

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242163
Author(s):  
Eric Fabrício Marialva ◽  
Nágila F. Secundino ◽  
Fernando F. Fernandes ◽  
Helena R. C. Araújo ◽  
Claudia M. Ríos-Velásquez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
South America ◽  
Leishmania Infantum ◽  
Immature Stages ◽  
Vector Species ◽  
Future Studies ◽  
Larval Stages ◽  
Morphological Aspects ◽  
Scanning Electron

We describe the immature stages of Migonemyia migonei, which is the vector of Leishmania (Viannia) braziliensis, the etiological agent of cutaneous leishmaniasis in South America, and a putative vector of Leishmania infantum chagasi. Scanning Electron Microscopy (SEM) was used to refine the description of the structures of the egg, all instar larvae, and the pupa. The eggs have polygonal cells on the egg exochorion, and differences between larval and pupal chaetotaxy have been highlighted. Different sensillary subtypes—trichoidea, basiconica, coelonica and campanoformia—were observed in the larval stages. The results presented herein contribute to the taxonomy of Mg. migonei and may contribute to future studies on the phylogeny of this important vector species.

Revision of the South American species of Austrothaumalea Tonnoir (Diptera: Thaumaleidae)

Zootaxa ◽  
2020 ◽  
Vol 4853 (4) ◽  
pp. 509-526
Author(s):  
ROBERT J. PIVAR ◽  
BRADLEY J. SINCLAIR ◽  
JOHN K. MOULTON
Keyword(s):  
South America ◽  
Junior Synonym ◽  
South American ◽  
The South ◽  
South American Species ◽  
Distribution Maps ◽  
Phylogenetic Affinities

The Austrothaumalea fauna of South America is revised and includes five species: A. apicalis Edwards, A. chilensis Edwards, A. fredericki Pivar sp. nov., A. setipennis Edwards stat. rev. and A. spatulata Schmid. The genus Oterere McLellan syn. nov. is considered a new junior synonym of Austrothaumalea Tonnoir on the basis of several shared apomorphic characters. All previously described South American species are redescribed, including females where possible. Illustrations and micrographs of all species are provided, as well as distribution maps, keys to genera and species, and discussions regarding phylogenetic affinities. 

scholarly journals Taxonomic revision of Galeocharax (Characiformes: Characidae: Characinae)

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Victor Giovannetti ◽  
Mônica Toledo-Piza ◽  
Naércio A. Menezes
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Taxonomic Revision ◽  
South American ◽  
Morphometric Data ◽  
Key To Species ◽  
Madre De Dios ◽  
Rio Negro ◽  
Scanning Electron ◽  
Rio Madeira

ABSTRACT The taxonomy of Galeocharax, a genus of freshwater fishes distributed in most South American cis-Andean river systems, except the rio Negro, rio São Francisco and rio Xingu basins and the eastern drainages of Brazil, is herein revised. A total of 1229 specimens were examined from which 680 had meristic and morphometric data taken. Osteological and morphological features were also examined through radiographs, scanning electron microscopy and in cleared and stained specimens. Three of the four species previously considered as valid are herein recognized: Galeocharax humeralis from rio Paraguay and lower rio Paraná basins; Galeocharax goeldii, from rio Madeira basin, with records of geographical distribution expanded to the río Madre de Dios, río Beni, rio Mamoré and rio Guaporé basins and Galeocharax gulo, which is widespread throughout rio Amazonas, río Orinoco, rio Tocantins, and upper rio Paraná basins. Galeocharax knerii is herein considered a junior synonym of Galeocharax gulo. A key to species of Galeocharax is presented.

scholarly journals Recognition of two morpho-types in eastern South American brackens (Pteridium—Dennstaedtiaceae—Polypodiopsida)

Phytotaxa ◽  
2014 ◽  
Vol 170 (2) ◽  
pp. 103 ◽  
Author(s):  
PEDRO B. SCHWARTSBURD ◽  
PEDRO L. R. DE MORAES ◽  
KARINA L. B. LOPES-MATTOS
Keyword(s):  
South America ◽  
Morphological Characteristics ◽  
South American ◽  
Morphological Pattern ◽  
Early 19Th Century ◽  
Distribution Maps ◽  
Eastern Brazil ◽  
North Eastern ◽  
Stomatal Guard Cells ◽  
Microscopy Images

In this work we propose the recognition of two well defined morpho-types of Pteridium from eastern South America: P. arachnoideum subsp. arachnoideum s. str., wide-spread from north-eastern Brazil southwards to north-eastern Argentina and Uruguay, and P. arachnoideum subsp. campestre, comb. et stat. nov., endemic to north-eastern Brazil. Inevitably, we propose a narrower circumscription for P. arachnoideum subsp. arachnoideum, being restricted to eastern South America and characterized by free lobes between the distal segments, veins abaxially lanose with lax arachnoid hairs, and laminar tissue between the veins abaxially without farinose appearance, glabrous and visible (total absence of gnarled hairs). This morphological pattern is constant and stable in all 191 specimens studied (including living specimens), and geographically related. Plants from western South America and Central America, previously ascribed to P. arachnoideum s.l., shall be better reclassified into at least one other subspecies—for which no published name is current available. This is morphologically distinct and geographically segregated from P. arachnoideum subsp. arachnoideum s. str. by the South American Dry Diagonal. Based on stomatal guard-cells length, the two morpho-types from eastern South America are presumably diploid. We provide lectotypifications for the two taxa, complete and new synonymies, descriptions, illustrations, light microscopy images, distribution maps, and detailed information about the Pteridium specimens gathered in Brazil by Maximilian, the Prince of Wied, in the early 19th Century. We also indicate overlooked morphological characteristics with taxonomical value within the genus.

scholarly journals Morphological aspects of immature stages of Migonemyia migonei (Diptera: Psychodidae, Phlebotominae) an important vector of Leishmaniosis in South America by scanning electron microscopy

2020 ◽  
Author(s):  
Eric F. Marialva ◽  
Nágila F. Secundino ◽  
Fernando F. Fernandes ◽  
Helena R. C. Araújo ◽  
Claudia M. Ríos-Velásquez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
South America ◽  
Immature Stages ◽  
Important Species ◽  
Future Studies ◽  
Larval Stages ◽  
Morphological Aspects ◽  
Species Vector ◽  
Scanning Electron

We describe the immature stages of Migonemyia migonei, which is the vector of Leishmania (Viannia) braziliensis, the aetiological agent of cutaneous leishmaniasis in South America, and a putative vector of Leishmania infantum chagasi. Scanning Electron Microscopy (SEM) was used to refine the description of the structures of eggs, all instar larvae and pupa. The eggs have polygonal cells on the egg exochorion, and differences between larval and pupal chaetotaxy are highlighted. Different sensillary subtypes were observed in the larval stages, among the types trichoidea, basiconica, coelonica and campanoformia. These results contribute to the taxonomy of Mg. migonei and may contribute to future studies on the phylogeny of this important species vector.

scholarly journals Clay-Based Brick Porosity Estimation Using Image Processing Techniques

2019 ◽  
Vol 29 (1) ◽  
pp. 1226-1234
Author(s):  
Safa Jida ◽  
Hassan Ouallal ◽  
Brahim Aksasse ◽  
Mohammed Ouanan ◽  
Mohamed El Amraoui ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Computer Vision ◽  
Image Processing Techniques ◽  
Processing Techniques ◽  
Porosity Estimation ◽  
Microscopy Images ◽  
Scanning Electron

Abstract This work intends to apprehend and emphasize the contribution of image-processing techniques and computer vision in the treatment of clay-based material known in Meknes region. One of the various characteristics used to describe clay in a qualitative manner is porosity, as it is considered one of the properties that with “kill or cure” effectiveness. For this purpose, we use scanning electron microscopy images, as they are considered the most powerful tool for characterising the quality of the microscopic pore structure of porous materials. We present various existing methods of segmentation, as we are interested only in pore regions. The results show good matching between physical estimation and Voronoi diagram-based porosity estimation.

scholarly journals Corrosion Behavior and Mechanical Properties of a Nanocomposite Superhydrophobic Coating

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 652
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Lutfun Nipa ◽  
Ian Lian ◽  
Gary Twu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Nanocomposite Coating ◽  
Superhydrophobic Coating ◽  
Force Microscopy ◽  
Atomic Force ◽  
Microscopy Images ◽  
Scanning Electron

In this work, a mechanically durable anticorrosion superhydrophobic coating is developed using a nanocomposite coating solution composed of silica nanoparticles and epoxy resin. The nanocomposite coating developed was tested for its superhydrophobic behavior using goniometry; surface morphology using scanning electron microscopy and atomic force microscopy; elemental composition using energy dispersive X-ray spectroscopy; corrosion resistance using atomic force microscopy; and potentiodynamic polarization measurements. The nanocomposite coating possesses hierarchical micro/nanostructures, according to the scanning electron microscopy images, and the presence of such structures was further confirmed by the atomic force microscopy images. The developed nanocomposite coating was found to be highly superhydrophobic as well as corrosion resistant, according to the results from static contact angle measurement and potentiodynamic polarization measurement, respectively. The abrasion resistance and mechanical durability of the nanocomposite coating were studied by abrasion tests, and the mechanical properties such as reduced modulus and Berkovich hardness were evaluated with the aid of nanoindentation tests.

scholarly journals Microscopic Cords, a Virulence-Related Characteristic of Mycobacterium tuberculosis, Are Also Present in Nonpathogenic Mycobacteria

2010 ◽  
Vol 192 (7) ◽  
pp. 1751-1760 ◽  
Author(s):  
Esther Julián ◽  
Mónica Roldán ◽  
Alejandro Sánchez-Chardi ◽  
Oihane Astola ◽  
Gemma Agustí ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Trehalose Dimycolate ◽  
Cord Factor ◽  
Ideal Tool ◽  
Colonial Morphology ◽  
Related Characteristic ◽  
Microscopy Images ◽  
Scanning Electron ◽  
The Ideal

ABSTRACT The aggregation of mycobacterial cells in a definite order, forming microscopic structures that resemble cords, is known as cord formation, or cording, and is considered a virulence factor in the M ycobacterium tuberculosis complex and the species M ycobacterium marinum. In the 1950s, cording was related to a trehalose dimycolate lipid that, consequently, was named the cord factor. However, modern techniques of microbial genetics have revealed that cording can be affected by mutations in genes not directly involved in trehalose dimycolate biosynthesis. Therefore, questions such as “How does mycobacterial cord formation occur?” and “Which molecular factors play a role in cord formation?” remain unanswered. At present, one of the problems in cording studies is the correct interpretation of cording morphology. Using optical microscopy, it is sometimes difficult to distinguish between cording and clumping, which is a general property of mycobacteria due to their hydrophobic surfaces. In this work, we provide a new way to visualize cords in great detail using scanning electron microscopy, and we show the first scanning electron microscopy images of the ultrastructure of mycobacterial cords, making this technique the ideal tool for cording studies. This technique has enabled us to affirm that nonpathogenic mycobacteria also form microscopic cords. Finally, we demonstrate that a strong correlation exists between microscopic cords, rough colonial morphology, and increased persistence of mycobacteria inside macrophages.

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