scholarly journals Minerals in the gut: scoping a Cambrian digestive system

2016 ◽  
Vol 3 (11) ◽  
pp. 160420 ◽  
Author(s):  
K. M. Strang ◽  
H. A. Armstrong ◽  
D. A. T. Harper
Keyword(s):  
Calcium Phosphate ◽  
Digestive System ◽  
Three Dimensional ◽  
Elemental Mapping ◽  
Burgess Shale ◽  
High Concentration ◽  
Acidic Conditions ◽  
Electron Imaging ◽  
Crystal Seed ◽  
North Greenland

The Sirius Passet Lagerstätte of North Greenland contains the first exceptionally preserved mat-ground community of the Cambrian, dominated, in terms of abundance, by trilobites but particularly characterized by iconic arthropods and lobopods, some also occurring in the Burgess shale. High-resolution photography, scanning electron imaging and elemental mapping have been carried out on a variety of specimens of the non-mineralized arthropod Campanamuta mantonae (Budd 2011 J. Syst. Palaeontol. 9 , 217–260 ( doi:10.1080/14772019.2010.492644 )) which has three-dimensional gut and muscle preservation. Results show that the guts contain a high concentration of calcium phosphate (approximating to the mineral francolite), whereas the adjacent muscles are silicified. This indicates a unique, tissue-specific taphonomy for this Cambrian taxon. We hypothesize that the precipitation of calcium phosphate in the guts occurs rapidly after death by ‘crystal seed’ processes in suboxic, slightly acidic conditions; critically, the gut wall remained intact during precipitation. We postulate that the calcium phosphate was derived from ingested cellular material. Silicification of the muscles followed as the localized water chemistry became saturated in silica, high in Fe 2+ , and low in oxygen and sulfate. We document here the unique occurrence of two distinct but mechanistically similar taphonomic pathways within a diverse suite of possibilities in an Early Cambrian Lagerstätte.

scholarly journals Arthropods from North Greenland: exceptional data in the ‘Cambrian explosion’ debate

1992 ◽  
Vol 6 ◽  
pp. 44-44
Author(s):  
Graham E. Budd
Keyword(s):  
Morphological Changes ◽  
Three Dimensional ◽  
Cambrian Explosion ◽  
Burgess Shale ◽  
Phylogenetic Methods ◽  
Fossil Material ◽  
Body Patterning ◽  
Bare Bones ◽  
Early Metazoan ◽  
North Greenland

'Sirius Passet’ fauna arthropods from the Lower Cambrian Buen Formation of North Greenland form the major component of this exceptionally preserved biota. Early mineralisation of body cavities led to internal anatomy being preserved more readily than external structures such as limbs. Musculature and gut are known in three dimensional form. Many of the taxa present are more easily compared to extant arthropods than to flattened fossil material such as from the Burgess Shale.The most common arthropod is represented by some 1600 specimens. Although widely differing in preservational style, these specimens may be reconciled to provide a coherent model of the three-dimensional anatomy of the arthropod. The affinities of this arthropod lie with the ‘Cheliceromorph’ rather than the Crustacean biramous-limbed arthropods, and may represent a fairly advanced lineage within the clade.Recent discussions of the patterns produced by the early metazoan radiations have concentrated on data available from the Burgess Shale. The continuing discovery and description of other Cambrian lagerstätten such as from North Greenland and Chengjiang has highlighted the degree to which the Burgess Shale fauna should be considered to be an aliquot taken from the foment of the ‘Cambrian Explosion’. The discovery of more taxa is tending to flesh out the bare bones of the Burgess fauna. Conclusions about phylogentic patterns drawn from the Burgess Shale alone may thus be premature.Body patterning in the arthropods, and the validity of the ‘Bauplan’ concept may be investigated by consideration of the actual mechanisms available for profound morphological change. One promising route is provided by the ‘homeotic’ and other hierarchically arranged developmental genes. When the mode of action of these genes is considered in conjunction with phylogenetic methods, it may prove possible to assess evolutionary pathways in terms of the feasibility of the morphological changes required by them rather than relying on what seems inherently reasonable or on marginal advantages in parsimony. Exceptionally preserved biotas also contain the evidence for the evolution of the developmental mechanisms themselves.

Study of the resistor material of an automotive spark plug by use of the charge-up effect along with elemental mapping in an electron microprobe

1991 ◽  
Vol 49 ◽  
pp. 742-743
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
J. S. Park ◽  
B. N. Juterbock
Keyword(s):  
Electron Microprobe ◽  
Present Report ◽  
Coated Sample ◽  
Valuable Insight ◽  
Elemental Mapping ◽  
Spark Plug ◽  
Carbon Coated ◽  
Electron Image ◽  
Electron Imaging ◽  
Insight Into

The electric and thermal properties of the resistor material in an automotive spark plug should be stable during its service lifetime. Containing many elements and many phases, this material has a very complex microstructure. Elemental mapping with an electron microprobe can reveal the distribution of all relevant elements throughout the sample. In this work, it is demonstrated that the charge-up effect, which would distort an electron image and, therefore, is normally to be avoided in an electron imaging work, could be used to advantage to reveal conductive and resistive zones in a sample. Its combination with elemental mapping can provide valuable insight into the underlying conductivity mechanism of the resistor.This work was performed in a CAMECA SX-50 microprobe. The spark plug used in the present report was a commercial product taken from the shelf. It was sectioned to expose the cross section of the resistor. The resistor was known not to contain the precious metal Au as checked on the carbon coated sample. The sample was then stripped of carbon coating and re-coated with Au.

scholarly journals Biphasic Calcium Phosphate Biomaterials: Stem Cell-Derived Osteoinduction or In Vivo Osteoconduction? Novel Insights in Maxillary Sinus Augmentation by Advanced Imaging

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2159
Author(s):  
Giovanna Iezzi ◽  
Antonio Scarano ◽  
Luca Valbonetti ◽  
Serena Mazzoni ◽  
Michele Furlani ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Maxillary Sinus ◽  
Biphasic Calcium Phosphate ◽  
Calcium Phosphates ◽  
Three Dimensional ◽  
Sinus Augmentation ◽  
Native Bone ◽  
Maxillary Sinus Augmentation ◽  
Posterior Maxilla

Maxillary sinus augmentation is often necessary prior to implantology procedure, in particular in cases of atrophic posterior maxilla. In this context, bone substitute biomaterials made of biphasic calcium phosphates, produced by three-dimensional additive manufacturing were shown to be highly biocompatible with an efficient osteoconductivity, especially when combined with cell-based tissue engineering. Thus, in the present research, osteoinduction and osteoconduction properties of biphasic calcium-phosphate constructs made by direct rapid prototyping and engineered with ovine-derived amniotic epithelial cells or amniotic fluid cells were evaluated. More in details, this preclinical study was performed using adult sheep targeted to receive scaffold alone (CTR), oAFSMC, or oAEC engineered constructs. The grafted sinuses were explanted at 90 days and a cross-linked experimental approach based on Synchrotron Radiation microCT and histology analysis was performed on the complete set of samples. The study, performed taking into account the distance from native surrounding bone, demonstrated that no significant differences occurred in bone regeneration between oAEC-, oAFMSC-cultured, and Ctr samples and that there was a predominant action of the osteoconduction versus the stem cells osteo-induction. Indeed, it was proven that the newly formed bone amount and distribution decreased from the side of contact scaffold/native bone toward the bulk of the scaffold itself, with almost constant values of morphometric descriptors in volumes more than 1 mm from the border.

Articulated halkieriids from the Lower Cambrian of North Greenland and their role in early protostome evolution

1995 ◽  
Vol 347 (1321) ◽  
pp. 305-358 ◽  
Keyword(s):  
Body Size ◽  
Molecular Biology ◽  
Lower Cambrian ◽  
Burgess Shale ◽  
Internal Anatomy ◽  
Middle Cambrian ◽  
Functional Consequence ◽  
Primitive State ◽  
North Greenland

Articulated halkieriids of Halkieria evangelista sp. nov. are described from the Sirius Passet fauna in the Lower Cambrian Buen Formation of Peary Land, North Greenland. Three zones of sclerites are recognizable: obliquely inclined rows of dorsal palmates, quincuncially inserted lateral cultrates and imbricated bundles of ventro-lateral siculates. In addition there is a prominent shell at both ends, each with radial ornamentation. Both sclerites and shells were probably calcareous, but increase in body size led to insertion of additional sclerites but marginal accretion of the shells. The ventral sole was soft and, in life, presumably muscular. Recognizable features of internal anatomy include a gut trace and possible musculature, inferred from imprints on the interior of the anterior shell. Halkieriids are closely related to the Middle Cambrian Wixaxia , best known from the Burgess Shale: this clade appears to have played an important role in early protostome evolution. From an animal fairly closely related to Wixaxia arose the polychaete annelids; the bundles of siculate sclerites prefigure the neurochaetae whereas the dorsal notochaetae derive from the palmates. Wixaxia appears to have a relic shell and a similar structure in the sternaspid polychaetes may be an evolutionary remnant. The primitive state in extant polychaetes is best expressed in groups such as chrysopetalids, aphroditaceans and amphinomids. The homology between polychaete chaetae and the mantle setae of brachiopods is one line of evidence to suggest that the latter phylum arose from a juvenile halkieriid in which the posterior shell was first in juxtaposition to the anterior and rotated beneath it to provide the bivalved condition of an ancestral brachiopod. H. evangelista sp. nov. has shells which resemble those of a brachiopod; in particular the posterior one. From predecessors of the halkieriids known as siphogonuchitids it is possible that both chitons (polyplacophorans) and conchiferan molluscs arose. The hypothesis of halkieriids and their relatives having a key role in annelid—brachiopod—mollusc evolution is in accord with some earlier proposals and recent evidence from molecular biology. It casts doubt, however, on a number of favoured concepts including the primitive annelid being oligochaetoid and a burrower, the brachiopods being deuterostomes and the coelom being an archaic feature of metazoans. Rather, the annelid coelom arose as a functional consequence of the transition from a creeping halkieriid to a polychaete with stepping parapodial locomotion.

scholarly journals The role of a mid-air collision in drifting snow

2018 ◽  
Author(s):  
Shuming Jia ◽  
Zhengshi Wang ◽  
Shumin Li
Keyword(s):  
Friction Velocity ◽  
Global Climate ◽  
Three Dimensional ◽  
Particle Collision ◽  
High Concentration ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Drifting Snow ◽  
Collision Mechanism

Abstract. Drifting snow, a common two-phase flow movement in high and cold areas, contributes greatly to the mass and energy balance of glacier and ice sheets and further affects the global climate system. Mid-air collisions occur frequently in high-concentration snow flows; however, this mechanism is rarely considered in current models of drifting snow. In this work, a three-dimensional model of drifting snow with consideration of inter-particle collisions is established; this model enables the investigation of the role of a mid-air collision mechanism in openly drifting snow. It is found that the particle collision frequency increases with the particle concentration and friction velocity, and the blown snow with a mid-air collision effect produces more realistic transport fluxes since inter-particle collision can enhance the particle activity under the same condition. However, the snow saltation mass flux basically shows a cubic dependency with friction velocity, which distinguishes it from the quadratic dependence of blown sand movement. Moreover, the snow saltation flux is found to be largely sensitive to the particle size distribution since the suspension snow may restrain the saltation movement. This research could improve our understanding of the role of the mid-air collision mechanism in natural drifting snow.

Ceramic calcium phosphate materials obtained by technology adapted to three-dimensional printing on inkjet printer

2013 ◽  
Vol 4 (4) ◽  
pp. 336-339 ◽  
Author(s):  
V. V. Smirnov ◽  
A. Yu. Fedotov ◽  
E. N. Antonov ◽  
V. N. Bagratashvili ◽  
S. M. Barinov ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Inkjet Printer ◽  
Dimensional Printing

Cosmetic potential of boiled water of Hijiki (Sargassum fusiforme) grown in the ocean in Okinawa, Japan

2021 ◽  
Author(s):  
Hanagasaki Takashi
Keyword(s):  
Marine Algae ◽  
Three Dimensional ◽  
Raw Material ◽  
Cosmetic Products ◽  
High Concentration ◽  
Melanin Pigmentation ◽  
Sargassum Fusiforme ◽  
Cladosiphon Okamuranus ◽  
High Possibility ◽  
Boiled Water

Abstract Okinawa has most beautiful ocean that attracts tourists and it was recorded over 10 million foreign tourists visited Okinawa in 2018. The ocean surrounding Okinawa has various species of marine algae that could be raw material for cosmetic products because it has high concentration of phenolic compounds contributing antioxidant activity. There is an urgent need to create Okinawa’s unique brands for cosmetic products using marine algae grown in the ocean of Okinawa. Some of marine algae including popular seaweed food, Mozuku (Cladosiphon okamuranus Tokida) and Hijiki (Sargassum fusiforme), had high oxygen radical absorbance capacity and tyrosinase inhibition. In the food processing of Hijiki, there is a boiling step needed. And this Hijiki liquor is wasted 15 tons per year. To take advantage of this residue, development of cosmetic products derived from Hijiki liquor should be required. Hijiki liquor had the effect of decreasing melanin pigmentation and no cytotoxicity in a three-dimensional human skin model. Therefore, there is a high possibility that Hijiki liquor is a great material for cosmetic products.

scholarly journals Untargeted Metabolomic Profile for the Detection of Prostate Carcinoma—Preliminary Results from PARAFAC2 and PLS–DA Models

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3063 ◽  
Author(s):  
Amante ◽  
Salomone ◽  
Alladio ◽  
Vincenti ◽  
Porpiglia ◽  
...  
Keyword(s):  
Specific Antigen ◽  
Three Dimensional ◽  
Classification Model ◽  
Variables Selection ◽  
Electron Impact Mass ◽  
Full Scan ◽  
Acidic Conditions ◽  
New Biomarkers ◽  
Targeted Approach ◽  
Impact Mass

Prostate-specific antigen (PSA) is the main biomarker for the screening of prostate cancer (PCa), which has a high sensibility (higher than 80%) that is negatively offset by its poor specificity (only 30%, with the European cut-off of 4 ng/mL). This generates a large number of useless biopsies, involving both risks for the patients and costs for the national healthcare systems. Consequently, efforts were recently made to discover new biomarkers useful for PCa screening, including our proposal of interpreting a multi-parametric urinary steroidal profile with multivariate statistics. This approach has been expanded to investigate new alleged biomarkers by the application of untargeted urinary metabolomics. Urine samples from 91 patients (43 affected by PCa; 48 by benign hyperplasia) were deconjugated, extracted in both basic and acidic conditions, derivatized with different reagents, and analyzed with different gas chromatographic columns. Three-dimensional data were obtained from full-scan electron impact mass spectra. The PARADISe software, coupled with NIST libraries, was employed for the computation of PARAFAC2 models, the extraction of the significative components (alleged biomarkers), and the generation of a semiquantitative dataset. After variables selection, a partial least squares–discriminant analysis classification model was built, yielding promising performances. The selected biomarkers need further validation, possibly involving, yet again, a targeted approach.

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