scholarly journals Revision of Icacinaceae from the Early Eocene London Clay flora based on X-ray micro-CT

Botany ◽  
2016 ◽  
Vol 94 (9) ◽  
pp. 713-745 ◽  
Author(s):  
Gregory W. Stull ◽  
Neil F. Adams ◽  
Steven R. Manchester ◽  
Dan Sykes ◽  
Margaret E. Collinson
Keyword(s):  
Evolutionary History ◽  
3D Structure ◽  
Early Eocene ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Material ◽  
Technological Advances ◽  
London Clay ◽  
Clay Formation

The Early Eocene (Ypresian) London Clay Formation contains one of the most important fruit and seed assemblages from the Paleogene, including a large diversity of taxa (>350 spp.) preserved as pyrite permineralizations retaining 3D structure as well as anatomical detail. Despite the importance of the flora for understanding angiosperm biogeographic and evolutionary history, the majority of the fossil material has not been revisited since the original taxonomic treatments by E.M. Reid and M.E.J. Chandler. Given subsequent advances in our understanding of angiosperm phylogeny and fruit morphology, coupled with technological advances in imaging/visualizing fossil material, many of the taxa represented in the flora deserve further study. Here we present a revision of the pantropical family Icacinaceae using X-ray micro-computed tomography (micro-CT) images of 21 species from the flora. Based on the results, four new combinations are made, a new fossil-genus is established for a distinctive species with affinities to the Phytocreneae, and emended diagnoses are provided for eight taxa. Of the seven genera recognized from the flora, only one, Iodes Blume, is extant. This study offers important insights on the biogeographic and evolutionary history of Icacinaceae, which is one of the most abundant and diverse components of the flora from the London Clay Formation.

scholarly journals Revision of Icacinaceae from the Early Eocene London Clay flora based on X-ray micro-CT1

2017 ◽  
Author(s):  
Gregory W. Stull ◽  
Neil F. Adams ◽  
Steven R. Manchester ◽  
Dan Sykes ◽  
Margaret E. Collinson
Keyword(s):  
Evolutionary History ◽  
3D Structure ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Material ◽  
Technological Advances ◽  
History Of ◽  
London Clay ◽  
Clay Formation

The Early Eocene (Ypresian) London Clay Formation contains one of the most important fruit and seed assemblages from the Paleogene, including a large diversity of taxa (>350 spp.) preserved as pyrite permineralizations retaining 3D structure as well as anatomical detail. Despite the importance of the flora for understanding angiosperm biogeographic and evolutionary history, the majority of the fossil material has not been revisited since the original taxonomic treatments by E.M. Reid and M.E.J. Chandler. Given subsequent advances in our understanding of angiosperm phylogeny and fruit morphology, coupled with technological advances in imaging/visualizing fossil material, many of the taxa represented in the flora deserve further study. Here we present a revision of the pantropical family Icacinaceae using X-ray micro-computed tomography (micro-CT) images of 21 species from the flora. Based on the results, four new combinations are made, a new fossil-genus is established for a distinctive species with affinities to the Phytocreneae, and emended diagnoses are provided for eight taxa. Of the seven genera recognized from the flora, only one, Iodes Blume, is extant. This study offers important insights on the biogeographic and evolutionary history of Icacinaceae, which is one of the most abundant and diverse components of the flora from the London Clay Formation.

scholarly journals X-ray micro-computed tomography (micro-CT) of pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian) conserved in silicone oil: a critical evaluation

Botany ◽  
2016 ◽  
Vol 94 (9) ◽  
pp. 697-711 ◽  
Author(s):  
Margaret E. Collinson ◽  
Neil F. Adams ◽  
Steven R. Manchester ◽  
Gregory W. Stull ◽  
Fabiany Herrera ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Silicone Oil ◽  
Critical Evaluation ◽  
Minimal Risk ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
London Clay ◽  
Clay Formation ◽  
Made In

Pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian; England) in the NHMUK are stored in silicone oil to retard decay processes. X-ray micro-computed tomography (micro-CT) has revealed internal morphology for multiple holotypes (including severely cracked and encrusted specimens) scanned in the protective fluid. Silicone oil alone has a similar X-ray attenuation to parts of the specimens, causing minor uncertainty for digitally rendered surfaces, but key systematic characters are readily visualized. Further work is needed to optimize visualization of fine-scale cellular detail. Labelling and segmentation to visualize important structures is achievable with these micro-CT datasets. However, manual labelling of individual slices is required, and defining boundaries between features can be difficult due to differential pyritization and silicone oil permeation. Digital sections through specimens can be made in any orientation and digital locule casts can be produced for studies in virtual taphonomy. These achievements have been accomplished with minimal risk to specimens, which remained in silicone oil and were studied within the museum. The datasets provide a potentially permanent record of at-risk specimens, can be made widely available to researchers unable to visit the collections and to other interested parties, and they enable monitoring for future conservation.

scholarly journals X-ray micro-computed tomography (micro-CT) of pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian) conserved in silicone oil: a critical evaluation1

2017 ◽  
Author(s):  
Margaret E. Collinson ◽  
Neil F. Adams ◽  
Steven R. Manchester ◽  
Gregory W. Stull ◽  
Fabiany Herrera ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Silicone Oil ◽  
Minimal Risk ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Internal Morphology ◽  
London Clay ◽  
Clay Formation ◽  
Made In

Pyrite-permineralized fruits and seeds from the London Clay Formation (Ypresian, England) in the NHMUK are stored in silicone oil to retard decay processes. X-ray micro-computed tomography (micro-CT) has revealed internal morphology for multiple holotypes (including severely cracked and encrusted specimens) scanned in the protective fluid. Silicone oil alone has a similar X-ray attenuation to parts of the specimens, causing minor uncertainty for digitally rendered surfaces, but key systematic characters are readily visualised. Further work is needed to optimise visualization of fine-scale cellular detail. Labelling and segmentation to visualise important structures is achievable with these micro-CT datasets. However, manual labelling of individual slices is required and defining boundaries between features can be difficult due to differential pyritization and silicone oil permeation. Digital sections through specimens can be made in any orientation and digital locule casts can be produced for studies in virtual taphonomy. These achievements have been accomplished with minimal risk to specimens, which remained in silicone oil and were studied within the museum. The datasets provide a potentially permanent record of at-risk specimens, can be made widely available to researchers unable to visit the collections and to other interested parties, and they enable monitoring for future conservation.

Morphology and Affinities of Ampelocissites Seeds (Vitaceae: Ampelopsis clade) from the Paleogene of Texas, USA

2020 ◽  
Vol 45 (3) ◽  
pp. 478-482
Author(s):  
Steven R. Manchester
Keyword(s):  
Computed Tomography ◽  
Cross Sections ◽  
Seed Coat ◽  
Ct Scanning ◽  
Seed Morphology ◽  
Early Eocene ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fossil Seeds ◽  
Fossil Genus

Abstract—The type material on which the fossil genus name Ampelocissites was established in 1929 has been reexamined with the aid of X-ray micro-computed tomography (μ-CT) scanning and compared with seeds of extant taxa to assess the relationships of these fossils within the grape family, Vitaceae. The specimens were collected from a sandstone of late Paleocene or early Eocene age. Although originally inferred by Berry to be intermediate in morphology between Ampelocissus and Vitis, the newly revealed details of seed morphology indicate that these seeds represent instead the Ampelopsis clade. Digital cross sections show that the seed coat maintains its thickness over the external surfaces, but diminishes quickly in the ventral infolds. This feature, along with the elliptical chalaza and lack of an apical groove, indicate that Ampelocissites lytlensis Berry probably represents Ampelopsis or Nekemias (rather than Ampelocissus or Vitis) and that the generic name Ampelocissites may be useful for fossil seeds with morphology consistent with the Ampelopsis clade that lack sufficient characters to specify placement within one of these extant genera.

scholarly journals Endogenous Production of n-3 Polyunsaturated Fatty Acids Promotes Fracture Healing in Mice

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yuhui Chen ◽  
He Cao ◽  
Dawei Sun ◽  
Changxin Lin ◽  
Liang Wang ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Fracture Healing ◽  
Histological Analysis ◽  
Callus Formation ◽  
Healing Process ◽  
Proximal Femoral Fracture ◽  
Fracture Repair ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray

Bone fracture is a global healthcare issue for high rates of delayed healing and nonunions. Although n-3 polyunsaturated fatty acid (PUFA) is considered as a beneficial factor for bone metabolism, only few studies till date focused on the effects of n-3 PUFAs on fracture healing. In this study, we investigated the effect of endogenous n-3 PUFAs on fracture healing by measuring femur fracture repair in bothfat-1transgenic mice and WT mice. Proximal femoral fracture model was established infat-1transgenic mice and WT mice, respectively, and then the fracture was analyzed by using X-ray, micro-computed tomography (micro-CT), and histological assessment at 7, 14, 21, 28, and 35 days after fixation. The results showed that compared with WT mice,fat-1mice exhibited acceleration in fracture healing through radiographic and histological analysis (18–21 days versus 21–28 days postfracture). Meanwhile, X-ray and micro-CT analysis that showed better remodeling callus formation were in thefat-1group compared to WT group. Furthermore, histological analysis revealed that endogenous n-3 PUFAs promoted local endochondral ossification and accelerated the remodeling of calcified calluses after fracture. In conclusion, the present study indicated that endogenously produced n-3 PUFAs promote fracture healing process and accelerate bone remodeling in mice, and supplementation of n-3 PUFAs was positively associated with fracture healing.

scholarly journals Investigating the Evolution of Fractures in Clay–based Ceramics During Repeated Freeze-Thawing Cycles Using Micro X-Ray Computed Tomography and Image Analysis

2020 ◽  
Author(s):  
Carlo Porfido ◽  
Roberto Rizzo ◽  
David Healy ◽  
Matteo Spagnuolo ◽  
Roberto Terzano ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Methodological Approach ◽  
Fracture Initiation ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Freeze Thaw ◽  
Fracture Length ◽  
Grain Distribution ◽  
Fracture Damage

<div><div><div><p>This work presents a study on the fracturing behaviour of a quartz tempered clay-based ceramic subjected to damage in freeze-thaw cycles. X-ray micro-computed tomography (micro-CT) provided high-resolution imaging of the ceramic before and during the freeze-thaw treatment, allowing to analyse a fully water-saturated sample using a special thermal stage designed to keep the sample frozen during analyses. Micro-CT 3D renderings showed the internal features of the specimen (i.e., quartz grain distribution), the increment of fracture count and size, and the detachment of ceramic and/or temper fragments from the edges of the sample over the cycles. Selected 2D micrographs, before and after freeze-thawing treatment, were analysed using the MATLAB toolbox FracPaQ. This software provided detailed data on fracture length, intensity, density, orientation and connectivity, and enabled to interpret the process of fracture initiation and propagation inside the material. These results showed that the temper plays a crucial role in ceramic fracturing behaviour under freeze- thawing conditions, as damage propagation is influenced by quartz grain distribution and orientation within the material. The study described in this work, not only offers new insights into the fracture dynamics of freeze-thawed clay-based ceramics, but also presents a new methodological approach to quantitatively measure fracture damage in porous materials.</p></div></div></div>

scholarly journals Generalized Pulp Stones of Primary Dentition in a Patient with Molar-Incisor Malformation : A Case Report

2020 ◽  
Vol 47 (3) ◽  
pp. 337-343
Author(s):  
Dongyun Lee ◽  
Jisun Shin
Keyword(s):  
Case Report ◽  
Primary Dentition ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Second Molar ◽  
New Type ◽  
Mandibular First Molar ◽  
Pulp Stones ◽  
Scanning Electron

Molar-incisor malformation (MIM) is a new type of root anomaly reported recently. The characteristics of MIM are dysplastic root formations, constriction of pulp chambers and presence of calcified matrices at the level of cementoenamel junction in permanent first molars and primary second molars. In some cases, permanent maxillary incisors are also affected.The permanent first molars of the patient in this case report were affected with MIM. Generalized pulp stones were observed in overall primary dentition. Micro-computed tomography (micro-CT) imaging and scanning electron microscope-energy dispersive X-ray spectrometer analysis were performed on the extracted mandibular first molar and maxillary primary second molar of the patient. Micro-CT images revealed the discontinuity of enamel directly connected to an accessory canal of the root.

scholarly journals Topographical evaluation of laser generated surfaces using statistical analysis of surface-normal vector distributions

2021 ◽  
Vol 1135 (1) ◽  
pp. 012023
Author(s):  
Rickard Olsson ◽  
John Powell ◽  
Jan Frostevarg ◽  
Alexander F.H. Kaplan
Keyword(s):  
Surface Roughness ◽  
Measurement Techniques ◽  
Considerable Effect ◽  
Normal Vector ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
New Techniques ◽  
X Ray ◽  
Independent Analysis ◽  
Surface Profiles

Abstract Surfaces generated by Additive Manufacturing or laser texturing can involve the solidification of droplets of liquid, which can give rise to overhanging features on the solidified surface. Overhanging features add a layer of complexity to the surface topography and are undetectable by standard surface roughness measurement techniques such as profilometry. Such features are important because they can have a considerable effect on surface properties such as wettability. New techniques and algorithms are therefore required to analyse and quantify convoluted surfaces with overhanging (re-entrant) features. Earlier work by the authors introduced the concept of using X-ray micro-computed tomography (Micro-CT) to identify the directions of vectors normal to the surface at any point and thus indicate the presence or absence of overhanging features. This paper divides overhanging features into two types; simple and compound, and introduces new, size independent, analysis techniques which measure what proportion of each type is on the surface. Another extension of the analysis is the comparison of surface profiles taken in different directions in order to identify any surface roughness anisotropies.

scholarly journals A Review of Current Challenges and Case Study toward Optimizing Micro-Computed X-Ray Tomography of Carbon Fabric Composites

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3606
Author(s):  
Armin Rashidi ◽  
Tina Olfatbakhsh ◽  
Bryn Crawford ◽  
Abbas S. Milani
Keyword(s):  
Computed Tomography ◽  
Woven Fabric ◽  
Fiber Reinforced Polymers ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Fabric Composites ◽  
Low X ◽  
Composite Fabrics

X-ray computed tomography provides qualitative and quantitative structural and compositional information for a broad range of materials. Yet, its contribution to the field of advanced composites such as carbon fiber reinforced polymers is still limited by factors such as low imaging contrast, due to scarce X-ray attenuation features. This article, through a review of the state of the art, followed by an example case study on Micro-computed tomography (CT) analysis of low X-ray absorptive dry and prepreg carbon woven fabric composites, aims to highlight and address some challenges as well as best practices on performing scans that can capture key features of the material. In the case study, utilizing an Xradia Micro-CT-400, important aspects such as obtaining sufficient contrast, an examination of thin samples, sample size/resolution issues, and image-based modeling are discussed. The outcome of an optimized workflow in Micro-CT of composite fabrics can assist in further research efforts such as the generation of surface or volume meshes for the numerical modeling of underlying deformation mechanisms during their manufacturing processes.

scholarly journals Micro-CT study of Middle Ordovician Spumellaria (radiolarians) from western Newfoundland, Canada

2020 ◽  
Vol 94 (3) ◽  
pp. 417-435 ◽  
Author(s):  
Sarah Kachovich ◽  
Jonathan C. Aitchison
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Detailed Examination ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Lower Paleozoic ◽  
X Ray ◽  
Middle Ordovician ◽  
Radiolarian Assemblage ◽  
Taxonomic Groups

AbstractA new, previously undescribed Middle Ordovician (middle Darriwilian: Dw2) radiolarian assemblage has been recovered from the Table Cove Formation at Piccadilly Quarry, western Newfoundland. Constituents of the fauna described herein are both distinctive and exceptionally well preserved. Three-dimensional X-ray micro-computed tomography (μ-CT) is used to make a detailed examination of four key spumellarian specimens. This technology enables visualization of hitherto ambiguous details of the internal morphologies of key lower Paleozoic taxonomic groups, among which a lack of knowledge has impeded resolution of higher taxonomic rankings.

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