scholarly journals Exceptional preservation of soft tissue in a new specimen of Eoconfuciusornis and its biological implications

2017 ◽  
Vol 4 (3) ◽  
pp. 441-452 ◽  
Author(s):  
Xiaoting Zheng ◽  
Jingmai K. O’Connor ◽  
Xiaoli Wang ◽  
Yanhong Pan ◽  
Yan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Soft Tissues ◽  
Support Network ◽  
Sexually Dimorphic ◽  
Remarkable Similarity ◽  
Exceptional Preservation ◽  
Internal Support ◽  
Scanning Electron

Abstract We report on an exceptional specimen of Eoconfuciusornis preserving rare soft-tissue traces of the ovary and wing. Ovarian follicles preserve a greater hierarchy than observed in Jeholornis and enantiornithines, suggesting confuciusornithiforms evolved higher rates of yolk deposition in parallel with the neornithine lineage. The preserved soft tissues of the wing indicate the presence of a propatagium and postpatagium, whereas an alular patagium is absent. Preserved remnants of the internal support network of the propatagium bear remarkable similarity to that of living birds. Soft tissue suggests the confuciusornithiform propatagium could maintain a cambered profile and generate lift. The feathers of the wing preserve remnants of their original patterning; however, this is not strongly reflected by observable differences under scanning electron microscopy (SEM). The tail plumage lacks elongate rectrices, suggesting that the earliest known confuciusornithiforms were sexually dimorphic in their plumage.

scholarly journals What Is Considered a Variation of Biomechanical Parameters in Tensile Tests of Collagen-Rich Human Soft Tissues?—Critical Considerations Using the Human Cranial Dura Mater as a Representative Morpho-Mechanic Model

Medicina ◽  
2020 ◽  
Vol 56 (10) ◽  
pp. 520
Author(s):  
Johann Zwirner ◽  
Mario Scholze ◽  
Benjamin Ondruschka ◽  
Niels Hammer
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Dura Mater ◽  
Soft Tissues ◽  
Tensile Tests ◽  
Interquartile Range ◽  
Tissue Structure ◽  
Mechanical Parameters ◽  
Scanning Electron

Background and Objectives: Profound knowledge on the load-dependent behavior of human soft tissues is required for the development of suitable replacements as well as for realistic computer simulations. Regarding the former, e.g., the anisotropy of a particular biological tissue has to be represented with site- and direction-dependent particular mechanical values. Contrary to this concept of consistent mechanical properties of a defined soft tissue, mechanical parameters of soft tissues scatter considerably when being determined in tensile tests. In spite of numerous measures taken to standardize the mechanical testing of soft tissues, several setup- and tissue-related factors remain to influence the mechanical parameters of human soft tissues to a yet unknown extent. It is to date unclear if measurement extremes should be considered a variation or whether these data have to be deemed incorrect measurement outliers. This given study aimed to determine mechanical parameters of the human cranial dura mater as a model for human soft tissues using a highly standardized protocol and based on this, critically evaluate the definition for the term mechanical “variation” of human soft tissue. Materials and Methods: A total of 124 human dura mater samples with an age range of 3 weeks to 94 years were uniformly retrieved, osmotically adapted and mechanically tested using customized 3D-printed equipment in a quasi-static tensile testing setup. Scanning electron microscopy of 14 samples was conducted to relate the mechanical parameters to morphological features of the dura mater. Results: The here obtained mechanical parameters were scattered (elastic modulus = 46.06 MPa, interquartile range = 33.78 MPa; ultimate tensile strength = 5.56 MPa, interquartile range = 4.09 MPa; strain at maximum force = 16.58%, interquartile range = 4.81%). Scanning electron microscopy revealed a multi-layered nature of the dura mater with varying fiber directions between its outer and inner surface. Conclusions: It is concluded that mechanical parameters of soft tissues such as human dura mater are highly variable even if a highly standardized testing setup is involved. The tissue structure and composition appeared to be the main contributor to the scatter of the mechanical parameters. In consequence, mechanical variation of soft tissues can be defined as the extremes of a biomechanical parameter due to an uncontrollable change in tissue structure and/or the respective testing setup.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Corrigendum to: Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Vol 34 (8) ◽  
pp. 906
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

Plastic embedding and surface erosion techniques in soft tissue scanning electron microscopy

1973 ◽  
Vol 99 (1) ◽  
pp. 69-74 ◽  
Author(s):  
I. G. S. Alexander ◽  
P. M. Capicchiano ◽  
B. C. Ritchie ◽  
J. E. Maloney
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissue ◽  
Surface Erosion ◽  
Plastic Embedding ◽  
Scanning Electron

scholarly journals Ossicle development of the crinoid Florometra serratissima through larval stages

2017 ◽  
Vol 95 (3) ◽  
pp. 183-192 ◽  
Author(s):  
Ariane Comeau ◽  
Cory D. Bishop ◽  
Christopher B. Cameron
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soft Tissues ◽  
Sister Group ◽  
Coralline Algae ◽  
Rapid Radiation ◽  
Larval Stages ◽  
Evolution And Development ◽  
Feather Star ◽  
Scanning Electron

Crinoids are the oldest living class of echinoderm and sister group to the remaining eleutherozoan clade and so are key to discussions on the evolution and development of the echinoderm skeleton. Here we present the intraspecific variation of ossicle development of the feather star Florometra serratissima (A.H. Clark, 1907) during its three larval stages: doliolaria, cystidean, and early pentacrinoid. To induce settlement, larvae were cultured on a sea table in glass bowls containing coralline algae. The soft tissues of 60 larvae were dissolved to isolate and to observe the ossicles with compound microscopy and scanning electron microscopy. From the late doliolaria stage to 56-day-old pentacrinoids, a total of four types of ossicle developed: oral plates, basal plates, columnar stalk ossicles, and an attachment disk. Occasionally, an additional plate was found under the basal plates, which may represent a vestigial infrabasal plate. The shape of the attachment disk was plastic to accommodate the substrate. Crinoid ossicle development is variable in size, shape, and number, and the timing of development is asynchronous; traits that may have contributed to the early rapid radiation and phenotypic disparity of echinoderms.

Mechanical and Corrosion Behaviour of Some Devices for Ostheosinthesis

2007 ◽  
Vol 23 ◽  
pp. 257-260 ◽  
Author(s):  
Brandusa Ghiban
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Femoral Fracture ◽  
Soft Tissues ◽  
Corrosion Behaviour ◽  
Structural Features ◽  
X Rays ◽  
Hard Tissues ◽  
Mechanical Devices ◽  
Scanning Electron

Orthopaedic implants represent mechanical devices which may be used for different purposes in human skeleton. such as either repairing of soft tissues (ligaments) or hard tissues (fractures. osteotomy. partial or total replacements). The aim of present paper is to put in evidence some macro and micro structural features revealed at state of surface after 5 months of implant in a female femoral fracture. Investigated surfaces were analyzed by optical and scanning electron microscopy and by X-Rays diffraction.

Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

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