Micromagnetic modeling of silicate-hosted magnetic inclusions using SEM-FIB slice-and-view nanotomography

2020 ◽  
Author(s):  
Even. S. Nikolaisen ◽  
Richard. J. Harrison ◽  
Suzanne. A. McEnroe ◽  
Karl Fabian
Keyword(s):  
Morphological Data ◽  
Magnetic Minerals ◽  
Preparation Methods ◽  
Thin Sections ◽  
Dual Beam ◽  
Platinum Layer ◽  
3D Volume ◽  
Volume Mesh ◽  
Magnetic Inclusions

<p><span>Slice-and-view nanotomography uses a dual beam SEM-FIB to reconstruct the 3D volume of a mineralogical sample using a sequential series of nanoscale slices created with a focussed beam of Ga ions. This method reveals the true shapes and forms of naturally occurring magnetic inclusions hosted by the silicate minerals feldspar and pyroxene. High-resolution 3D morphological data for the magnetic minerals is extracted, converted to tetrahedral meshes, and micromagnetically modelled using the MERRILL software. </span></p><p><span>This study optimises the step-by-step process of extracting and processing micromagnetic data from polished thin-sections to generate a full rock magnetic classification of the remanence carriers in silicates. Slice-and-view nanotomography follows known preparation methods with a protective platinum layer, carbon rod guides and trenches, but also introduces a carbon slab along the Z-direction for e-beam alignment. This method reduces the need for auto focus, as the e-beam alignment will have a constant imaging distance and generates a good reference point for stack alignment. Image processing is limited to 3D a gaussian blur and 3D mean filters. Paraview is used to set the correct voxel dimensions and to generate the surface mesh. Freeware software Meshmixer and Meshlab are used for their powerful smoothing, mesh interaction tools and geometric calculations. The tetrahedral volume mesh is produced with iso2mesh in Matlab. </span></p><p><span>Micromagnetic hysteresis and back-field simulations of >400 inclusions with a broad range of morphologies have been performed using MERRILL using 20 different field directions, enabling average magnetic properties to be calculated for a random ensemble. The results give a detailed and direct description of the micromagnetic structure of naturally formed magnetic minerals that compliments macroscopic approaches, such as FORC analysis. </span></p>

Hydrogel-Based Bioinks for Three-Dimensional Bioprinting: Patent Analysis

2021 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Ahmed Fatimi
Keyword(s):  
Tissue Engineering ◽  
Detailed Analysis ◽  
State Of The Art ◽  
Three Dimensional ◽  
Patent Analysis ◽  
The State ◽  
Driving Factors ◽  
3D Bioprinting ◽  
Preparation Methods

There are a variety of hydrogel-based bioinks commonly used in three-dimensional bioprinting. In this study, in the form of patent analysis, the state of the art has been reviewed by introducing what has been patented in relation to hydrogel-based bioinks. Furthermore, a detailed analysis of the patentability of the used hydrogels, their preparation methods and their formulations, as well as the 3D bioprinting process using hydrogels, have been provided by determining publication years, jurisdictions, inventors, applicants, owners, and classifications. The classification of patents reveals that most inventions intended for hydrogels used as materials for prostheses or for coating prostheses are characterized by their function or properties Knowledge clusters and expert driving factors show that biomaterials, tissue engineering, and biofabrication research is concentrated in the most patents.

scholarly journals Classification of Streptomyces griseus (Krainsky 1914) Waksman and Henrici 1948 and related species and the transfer of ‘Microstreptospora cinerea’ to the genus Streptomyces as Streptomyces yanii sp. nov.

2005 ◽  
Vol 55 (4) ◽  
pp. 1605-1610 ◽  
Author(s):  
Zhiheng Liu ◽  
Yanlin Shi ◽  
Yamei Zhang ◽  
Zhihong Zhou ◽  
Zhitang Lu ◽  
...  
Keyword(s):  
Streptomyces Griseus ◽  
Taxonomic Status ◽  
Morphological Data ◽  
Rrna Gene ◽  
Phenotypic Properties ◽  
Phenotypic Data ◽  
Genus Streptomyces ◽  
Actinomycete Strain ◽  
Soil Actinomycete

A soil actinomycete, strain 80-133T, with the non-validly published name ‘Microstreptospora cinerea’, was the subject of a polyphasic study designed to clarify its taxonomic status. Comparative 16S rRNA gene sequence studies indicated that the organism belonged to the genus Streptomyces, a result in line with previous chemotaxonomic and morphological data. The strain belonged to the Streptomyces griseus clade, but could be distinguished from representatives of species assigned to this taxon by using DNA–DNA relatedness and phenotypic data. In light of these findings, it is proposed that the organism should be recognized as a novel species of the genus Streptomyces. The name proposed for this taxon is Streptomyces yanii sp. nov., with isolate 80-133T (=AS 4.1146T=JCM 3331T) as the type strain. It was also shown that representative strains of Streptomyces argenteolus, Streptomyces caviscabies, S. griseus and Streptomyces setonii belong to the same genomic species and have key phenotypic properties in common. It is proposed that S. caviscabies and S. setonii should be considered as later heterotypic synonyms of S. griseus and that S. argenteolus AS 4.1693T should also be assigned to this taxon.

EXISTING AND POSSIBLE NEW GLEYSOLIC ORDER CRITERIA APPLIED TO FIVE PEDONS FROM BRITISH COLUMBIA

1986 ◽  
Vol 66 (2) ◽  
pp. 323-336 ◽  
Author(s):  
J. A. McKEAGUE ◽  
C. TARNOCAI ◽  
H. A. LUTTMERDING
Keyword(s):  
British Columbia ◽  
Thin Sections ◽  
Soil Water Regime ◽  
Reducing Conditions ◽  
Current Classification ◽  
Bulk Chemical ◽  
Iron Manganese ◽  
Iron And Manganese ◽  
Do So

Use of the current criteria for distinguishing Gleysolic soils from gleyed intergrades to other soil classes resulted in the apparent misclassification of some soils in British Columbia. Pedologists of the area selected five pedons encompassing several degrees of expression of gley features. Current classification criteria based on soil color and possible new differentiating features based on chemical and micromorphological analyses were applied in considering the classification of the soils. Application of the current specific color criteria involving low chromas and prominent mottling result in the classification of three pedons in the Gleysolic order and two in gleyed subgroups of other orders. This classification was appropriate in the view of B.C. pedologists except for one Gleysolic pedon in which the water table is rarely within 1 m of the surface. Prior to drainage, however, the soil was probably saturated to the surface and under reducing conditions for prolonged periods each year. Thus, classification as a Gleysolic soil is appropriate as it probably reflects the prevailing conditions and processes during most of the period of soil genesis.Segregation of iron and manganese as nodules and coatings was most marked in the Gleysolic pedons. Walls of some voids were bleached due to depletion of iron oxides. Though study of thin sections, bulk chemical analysis and analysis of specific features by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDXRA) were useful in providing information on soil properties, they did not indicate an improved basis for differentiating Gleysolic soils from others. The color criteria used to distinguish soils of the Gleysolic order do not necessarily reflect the current soil water regime, and they are not intended to do so. The current criteria resulted in the appropriate classification of the five soils. Key words: Gleying, reduction, iron, manganese, micromorphology, SEM-EDXRA

New insights on the taxonomy and phylogenetic relationships of the Neotropical genus Phoebis (Pieridae: Coliadinae) revealed by molecular and morphological data

Zootaxa ◽  
2018 ◽  
Vol 4457 (1) ◽  
pp. 179 ◽  
Author(s):  
LEIDYS MURILLO-RAMOS ◽  
RENZO HERNÁNDEZ TORRES ◽  
RAYNER NÚÑEZ ÁGUILA ◽  
ROGER AYAZO
Keyword(s):  
Morphological Characters ◽  
Point Of View ◽  
Morphological Data ◽  
Caribbean Region ◽  
Greater Antilles ◽  
Data Set ◽  
Mitochondrial Coi ◽  
The Matrix ◽  
Taxonomic Point

Phoebis Hübner (1819) is a genus of the Neotropical subfamily Coliadinae (Lepidoptera: Pieridae). The highest diversity is found in the Greater Antilles islands in the Caribbean region. Although from the taxonomic point of view, Phoebis seems to be a stable genus, there is no phylogenetic hypothesis corroborating the monophyly of the genus. In this study, we used both morphological characters and a genetic dataset consisting of one mitochondrial (COI) and three nuclear markers (RpS5, MDH, Wingless). The matrix was concatenated and analysed with parsimony under implied weights (IW). Also, the concatenated data set was analysed using maximum likelihood and Bayesian inference evolutionary methods, and ancestral states reconstruction with characters traditionally used for classification of Phoebis was carried out. The same topology was recovered by Parsimony, ML and BI analysis, and suggest that Phoebis is not a monophyletic genus, with Aphrissa and Rhabdodryas nested within it. Our findings allow us to consider the genera Rhabdodryas syn.rev. and Aphrissa syn.rev. to be synonyms of Phoebis. These results have implications for the systematics of Phoebis and the genera that should be accepted in Coliadinae.

CONVOLUTIONAL NEURAL NETWORKS AS AN AID TO BIOSTRATIGRAPHY AND MICROPALEONTOLOGY: A TEST ON LATE PALEOZOIC MICROFOSSILS

Palaios ◽  
2020 ◽  
Vol 35 (9) ◽  
pp. 391-402 ◽  
Author(s):  
RAFAEL PIRES DE LIMA ◽  
KATIE F. WELCH ◽  
JAMES E. BARRICK ◽  
KURT J. MARFURT ◽  
ROGER BURKHALTER ◽  
...  
Keyword(s):  
Machine Learning ◽  
Cross Validation ◽  
Network Models ◽  
Late Paleozoic ◽  
Neural Network Models ◽  
Thin Sections ◽  
Machine Learning Approach ◽  
Taxonomic Groups ◽  
And Training

ABSTRACT Accurate taxonomic classification of microfossils in thin-sections is an important biostratigraphic procedure. As paleontological expertise is typically restricted to specific taxonomic groups and experts are not present in all institutions, geoscience researchers often suffer from lack of quick access to critical taxonomic knowledge for biostratigraphic analyses. Moreover, diminishing emphasis on education and training in systematics poses a major challenge for the future of biostratigraphy, and on associated endeavors reliant on systematics. Here we present a machine learning approach to classify and organize fusulinids—microscopic index fossils for the late Paleozoic. The technique we employ has the potential to use such important taxonomic knowledge in models that can be applied to recognize and categorize fossil specimens. Our results demonstrate that, given adequate images and training, convolutional neural network models can correctly identify fusulinids with high levels of accuracy. Continued efforts in digitization of biological and paleontological collections at numerous museums and adoption of machine learning by paleontologists can enable the development of highly accurate and easy-to-use classification tools and, thus, facilitate biostratigraphic analyses by non-experts as well as allow for cross-validation of disparate collections around the world. Automation of classification work would also enable expert paleontologists and others to focus efforts on exploration of more complex interpretations and concepts.

On the morphology and classification of larval water mites (Hydrachnidia, Acari) from springs in Luxembourg

Zootaxa ◽  
2006 ◽  
Vol 1138 (1) ◽  
pp. 1 ◽  
Author(s):  
PETER MARTIN
Keyword(s):  
Morphological Data ◽  
Water Mites ◽  
Water Mite ◽  
Question Mark ◽  
First Time

Morphological data on the larvae of 37 species of freshwater mites (Hydrachnidia) known from springs in Luxembourg are reported. Larvae of Sperchon insignis (Walter, 1906), S. longissimus K.Viets, 1920, Lebertia holsatica K. Viets, 1920, Atractides fonticolus (K.Viets, 1920) and, with a question mark, A. pennatus (K.Viets, 1920) are described for the first time; re-descriptions are presented for Sperchon squamosus Kramer, 1879 and S. setiger Thor, 1898. Previous larval descriptions are listed and commented on for all species. Two species are recorded as new for the Luxembourgian fauna: Panisellus thienemanni (K.Viets, 1920) and Pseudofeltria scourfieldi Soar, 1904. A further taxon previously not recorded from springs in Luxembourg is described, probably Tiphys Koch, 1836 sp. An illustrated key is presented suitable for the determination of most parasitic water mite larvae attached to insect hosts from Luxembourgian springs.

Phylogenetic relationships and classification of the Malagasy pseudoxyrhophiine snake genera Geodipsas and Compsophis based on morphological and molecular data

Zootaxa ◽  
2007 ◽  
Vol 1517 (1) ◽  
pp. 53-62 ◽  
Author(s):  
FRANK GLAW ◽  
ZOLTÁN T. NAGY ◽  
MIGUEL VENCES
Keyword(s):  
Dna Sequences ◽  
Phylogenetic Relationships ◽  
Close Relationships ◽  
Original Description ◽  
Molecular Data ◽  
Morphological Data ◽  
Molecular Phylogenetic ◽  
Species Groups ◽  
Morphological And Molecular Data

Based on a specimen found at Montagne d'Ambre in northern Madagascar morphologically agreeing with Compsophis albiventris Mocquard, 1894, we report on the rediscovery of this enigmatic snake genus and species and its molecular phylogenetic relationships. Compsophis albiventris, considered to be the only representative of its genus and unreported since its original description, bears strong morphological similarities to species of Geodipsas Boulenger, 1896. A molecular phylogeny based on DNA sequences of three mitochondrial and nuclear genes (complete cytochrome b, fragments of 16S rRNA and c-mos) in Compsophis albiventris and three Geodipsas species corroborated close relationships between C. albiventris and Geodipsas boulengeri, and showed that the genera Compsophis and Geodipsas together form a monophyletic unit. Despite the general similarities, morphological data and chromatic features support the existence of two species groups, corresponding to Compsophis and Geodipsas. We consequently consider Geodipsas as a subgenus of Compsophis and transfer all species currently in Geodipsas into the genus Compsophis.

Morphological cladistic analysis resolves the generic limits of the Neotropical potter wasp genera Minixi Giordani Soika and Pachyminixi Giordani Soika (Hymenoptera : Vespidae : Eumeninae)

2016 ◽  
Vol 30 (3) ◽  
pp. 187 ◽  
Author(s):  
Marcel G. Hermes ◽  
Letícia A. de Oliveira
Keyword(s):  
Cladistic Analysis ◽  
Morphological Data ◽  
Past Century ◽  
New Combinations ◽  
Key To Species ◽  
Natural Classification ◽  
The Past ◽  
Constituent Species ◽  
A New Species

The generic classification of Neotropical Eumeninae has been termed chaotic, and synonymisation of taxa has become constant in recent years. Recognition of some generic limits are problematic due to features showing a great deal of variation, such as the length of the first metasomal tergum. This applies to the Neotropical Alphamenes van der Vecht, Minixi Giordani Soika and Pachyminixi Giordani Soika. Minixi has already been demonstrated to be paraphyletic in regards to Pachyminixi. These taxa are the focus of the present study, which used morphological data to infer the phylogenetic relationships among their constituent species. A total of 14 taxa and 34 characters were subjected to cladistic analysis under implied weighting. A single most-parsimonious cladogram was obtained, recovering Pachyminixi as monophyletic. Minixi, however, was paraphyletic relative to Pachyminixi and they are thus synonymised, with the former name having priority. A new species from Mexico, Minixi mariachii, sp. nov., is described. Minixi joergenseni bicingulatus (Zavattari, 1912) is synonymised under M. joergenseni (Schrottky, 1909), comb. nov. Additional new combinations are: Minixi arechavaletae (Brèthes, 1903), comb. nov., M. bifasciatum (von Schulthess, 1904), comb. nov., M. brethesi (Bertoni, 1927), comb. nov., M. sumichrasti (de Saussure, 1875), comb. nov., and M. uruguyense (de Saussure, 1855), comb. nov. Illustrations and a new key to species of Minixi are provided. The present study enhances our knowledge on Neotropical potter wasp systematics, providing one further step into a natural classification for a group whose taxonomy has suffered from irrational splitting of genera in the past century.

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