scholarly journals Pentaradial eukaryote suggests expansion of suspension feeding in White Sea-aged Ediacaran communities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kelsie Cracknell ◽  
Diego C. García-Bellido ◽  
James G. Gehling ◽  
Martin J. Ankor ◽  
Simon A. F. Darroch ◽  
...  
Keyword(s):  
White Sea ◽  
Three Dimensional ◽  
Research Area ◽  
Cambrian Explosion ◽  
Suspension Feeding ◽  
Ecological Strategy ◽  
Feeding Mode ◽  
Ecological Innovation ◽  
Benthic Ecosystems ◽  
Marine Biosphere

AbstractSuspension feeding is a key ecological strategy in modern oceans that provides a link between pelagic and benthic systems. Establishing when suspension feeding first became widespread is thus a crucial research area in ecology and evolution, with implications for understanding the origins of the modern marine biosphere. Here, we use three-dimensional modelling and computational fluid dynamics to establish the feeding mode of the enigmatic Ediacaran pentaradial eukaryoteArkarua. Through comparisons with two Cambrian echinoderms,CambrasterandStromatocystites, we show that flow patterns aroundArkaruastrongly support its interpretation as a passive suspension feeder.Arkaruais added to the growing number of Ediacaran benthic suspension feeders, suggesting that the energy link between pelagic and benthic ecosystems was likely expanding in the White Sea assemblage (~ 558–550 Ma). The advent of widespread suspension feeding could therefore have played an important role in the subsequent waves of ecological innovation and escalation that culminated with the Cambrian explosion.

scholarly journals Inference of facultative mobility in the enigmatic Ediacaran organism Parvancorina

2017 ◽  
Vol 13 (5) ◽  
pp. 20170033 ◽  
Author(s):  
Simon A. F. Darroch ◽  
Imran A. Rahman ◽  
Brandt Gibson ◽  
Rachel A. Racicot ◽  
Marc Laflamme
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Suspension Feeder ◽  
Evolutionary Significance ◽  
Suspension Feeding ◽  
Current Direction ◽  
Feeding Mode ◽  
Recirculating Flow ◽  
Competing Models ◽  
Benthic Ecosystems

Establishing how Ediacaran organisms moved and fed is critical to deciphering their ecological and evolutionary significance, but has long been confounded by their non-analogue body plans. Here, we use computational fluid dynamics to quantitatively analyse water flow around the Ediacaran taxon Parvancorina , thereby testing between competing models for feeding mode and mobility. The results show that flow was not distributed evenly across the organism, but was directed towards localized areas; this allows us to reject osmotrophy, and instead supports either suspension feeding or detritivory. Moreover, the patterns of recirculating flow differ substantially with orientation to the current, suggesting that if Parvancorina was a suspension feeder, it would have been most efficient if it was able to re-orient itself with respect to current direction, and thus ensure flow was directed towards feeding structures. Our simulations also demonstrate that the amount of drag varied with orientation, indicating that Parvancorina would have greatly benefited from adjusting its position to minimize drag. Inference of facultative mobility in Parvancorina suggests that Ediacaran benthic ecosystems might have possessed a higher proportion of mobile taxa than currently appreciated from trace fossil studies. Furthermore, this inference of movement suggests the presence of musculature or appendages that are not preserved in fossils, but which would noneltheless support a bilaterian affinity for Parvancorina .

A THREE-DIMENSIONAL GEOLOGIC CONCEPTUAL MODEL BENEATH THE IDAHO NATIONAL LAB’S GEOTHERMAL RESOURCE RESEARCH AREA

2016 ◽  
Author(s):  
James T. St. Clair ◽  
◽  
Michael Janis ◽  
Robert K. Podgorney ◽  
Michael McCurry ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Three Dimensional ◽  
Research Area ◽  
Geothermal Resource ◽  
Resource Research

scholarly journals An Overview on the Rheology, Mechanical Properties, Durability, 3D Printing, and Microstructural Performance of Nanomaterials in Cementitious Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2950
Author(s):  
Hongwei Song ◽  
Xinle Li
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Three Dimensional ◽  
Cementitious Materials ◽  
Research Area ◽  
Cementitious Composites ◽  
Split Tensile Strength ◽  
Contour Crafting ◽  
Wide Range ◽  
Active Research

The most active research area is nanotechnology in cementitious composites, which has a wide range of applications and has achieved popularity over the last three decades. Nanoparticles (NPs) have emerged as possible materials to be used in the field of civil engineering. Previous research has concentrated on evaluating the effect of different NPs in cementitious materials to alter material characteristics. In order to provide a broad understanding of how nanomaterials (NMs) can be used, this paper critically evaluates previous research on the influence of rheology, mechanical properties, durability, 3D printing, and microstructural performance on cementitious materials. The flow properties of fresh cementitious composites can be measured using rheology and slump. Mechanical properties such as compressive, flexural, and split tensile strength reveal hardened properties. The necessary tests for determining a NM’s durability in concrete are shrinkage, pore structure and porosity, and permeability. The advent of modern 3D printing technologies is suitable for structural printing, such as contour crafting and binder jetting. Three-dimensional (3D) printing has opened up new avenues for the building and construction industry to become more digital. Regardless of the material science, a range of problems must be tackled, including developing smart cementitious composites suitable for 3D structural printing. According to the scanning electron microscopy results, the addition of NMs to cementitious materials results in a denser and improved microstructure with more hydration products. This paper provides valuable information and details about the rheology, mechanical properties, durability, 3D printing, and microstructural performance of cementitious materials with NMs and encourages further research.

Combining Serial Sectioning, EBSD Analysis, and Image-Based Finite Element Modeling

MRS Bulletin ◽  
2008 ◽  
Vol 33 (6) ◽  
pp. 597-602 ◽  
Author(s):  
G. Spanos ◽  
D.J. Rowenhorst ◽  
A.C. Lewis ◽  
A.B. Geltmacher
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Electron Backscatter Diffraction ◽  
Three Dimensional ◽  
Research Area ◽  
Polycrystalline Materials ◽  
Serial Sectioning ◽  
3D Fem ◽  
Element Modeling ◽  
The Status

AbstractThis article first provides a brief review of the status of the subfield of three-dimensional (3D) materials analyses that combine serial sectioning, electron backscatter diffraction (EBSD), and finite element modeling (FEM) of materials microstructures, with emphasis on initial investigations and how they led to the current state of this research area. The discussions focus on studies of the mechanical properties of polycrystalline materials where 3D reconstructions of the microstructure—including crystallographic orientation information—are used as input into image-based 3D FEM simulations. The authors' recent work on a β-stabilized Ti alloy is utilized for specific examples to illustrate the capabilities of these experimental and modeling techniques, the challenges and the solutions associated with these methods, and the types of results and analyses that can be obtained by the close integration of experiments and simulations.

scholarly journals Polymorphy and extinction of the Late Cretaceous burrowing shrimp Protocallianassa faujasi and first record of the genera Corallianassa and Calliax (Crustacea, Decapoda, Thalassinoidea) from the Cretaceous

2001 ◽  
Vol 70 (2) ◽  
pp. 85-98 ◽  
Author(s):  
Krista Swen ◽  
René H.B. Fraaije ◽  
Gijsbert J. van der Zwaan
Keyword(s):  
New Species ◽  
First Record ◽  
Suspension Feeding ◽  
Feeding Mode ◽  
Male And Female ◽  
Immature Male ◽  
Type Area ◽  
Mode Of Life ◽  
Burrow Morphology

A biometric study of chelae of the burrowing shrimp Protocallianassa faujasi ( Desmarest, 1822), from the late Maastrichtian of the Maastrichtian type area, The Netherlands, has revealed three morphotypes. These types are interpreted as sexual dimorphs (male and female) and earliest ecdysis stages (immature male). Among the studied material are fifteen specimens of a new Cretaceous callianassid, Corallianassa acucurvata new species, one specimen provisionally assigned to the genus Calliax and a callianassid from the Danian. Burrows preserving callianassid chelae in situ are discussed. Based on burrow morphology a suspension feeding mode of life for P.faujasi is inferred, whereas C. acucurvata n. sp. probably was an active omnivorous analogue of its closest Recent relatives. The extinction of P. faujasi in the Meerssen Member appears to correspond to the increase in seagrass vegetation. The Protocallianassa-Corallianassa faunal changeover took place about 100,000 yrs before the K/T boundary in this region.

scholarly journals 50 nm Scale Alignment Method for Hybrid Manufacturing Processes for Full 3D Structuring

2020 ◽  
Vol 21 (12) ◽  
pp. 2407-2417
Author(s):  
Ki-Hwan Jang ◽  
Hae-Sung Yoon ◽  
Hyun-Taek Lee ◽  
Eunseob Kim ◽  
Sung-Hoon Ahn
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Research Area ◽  
Manufacturing Processes ◽  
Alignment Error ◽  
Alignment Method ◽  
Major Research ◽  
Hybrid Processes

AbstractIn micro-/nano-scale, multi-material three-dimensional (3D), structuring has been a major research area for making various applications. To overcome dimensional and material limitations, several hybrid processes have been proposed. The hybrid processes were performed in the same or different numerically controlled stages. If the stages differed, the substrate was moved and locked to the stage before fabrication. During the locking, alignment error occurred. This error became problematic because this significantly compromised the quality of final structures. Here, an alignment method for a hybrid process consisted of a focused ion beam milling, aerodynamically focused nanoparticle printing, and micro-machining was developed. Two sets of collinear marks were placed at the edges of the substrate. Rotational and translational errors were calculated and compensated using the marks. Processes having different scales were bridged through this alignment method. Various materials were utilized, and accuracy was less than 50 nm when the length of the substrate was less than 13 mm. The alignment method was employed to fabricate a V-shaped structure and step-shaped structure using polymer, ceramic, and metal.

scholarly journals Prediction of Aerosol Deposition in the Human Respiratory Tract via Computational Models: A Review with Recent Updates

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 137 ◽  
Author(s):  
Vu Khac Hoang Bui ◽  
Ju-Young Moon ◽  
Minhe Chae ◽  
Duckshin Park ◽  
Young-Chul Lee
Keyword(s):  
Respiratory Tract ◽  
Particle Deposition ◽  
Computational Models ◽  
Aerosol Particles ◽  
Three Dimensional ◽  
Aerosol Deposition ◽  
Research Area ◽  
Human Respiratory Tract

The measurement of deposited aerosol particles in the respiratory tract via in vivo and in vitro approaches is difficult due to those approaches’ many limitations. In order to overcome these obstacles, different computational models have been developed to predict the deposition of aerosol particles inside the lung. Recently, some remarkable models have been developed based on conventional semi-empirical models, one-dimensional whole-lung models, three-dimensional computational fluid dynamics models, and artificial neural networks for the prediction of aerosol-particle deposition with a high accuracy relative to experimental data. However, these models still have some disadvantages that should be overcome shortly. In this paper, we take a closer look at the current research trends as well as the future directions of this research area.

Research on Types of Oil Reservoirs and Character of Oil-Water Distribution in Heidimiao Layer

2013 ◽  
Vol 772 ◽  
pp. 789-794
Author(s):  
Gui You Lv
Keyword(s):  
Water Distribution ◽  
Oil And Gas ◽  
Dominant Role ◽  
Three Dimensional ◽  
Physical Property ◽  
Research Area ◽  
Oil Reservoir ◽  
Well Testing ◽  
Testing Data ◽  
Oil Water

This paper takes Yingtai area which is located in the south of Qijia-Gulong sag and part of central sag area in the north of the Songliao Basin as the research area. Then combining all information of core, logging, three-dimensional seism and well testing data, it studies the reservoir type and oil-water distribution characteristics of Heidimiao by analyzing the comparison charts of sandstone, profile map of reservoir, T07 structure diagram, well testing data, stratum thickness, sandstone thickness, ratio of sandstone thickness to stratum thickness, porosity values, permeability contour maps. The reservoir lithology of Heidimiao oil layer is siltstone-oriented with poor physical property. The main controlling factor of oil-water distribution is the lithology, followed by the structure. Heidimiao oil layer mainly includes three types, lithological oil reservoir, lithological - structural oil reservoir and structural oil reservoir, among which lithological reservoir plays a dominant role. Its oil-water distribution is characterized by the pattern of upper-water and bottom-oil; when the fault acts as the pathway for the longitudinal migration of oil and gas, the pattern changes to the upper-oil and bottom-water. This research could provide reliable geological basis for the research of old well re-examination, favorable area evaluation and horizontal well drilling design.

scholarly journals A superarmored lobopodian from the Cambrian of China and early disparity in the evolution of Onychophora

2015 ◽  
Vol 112 (28) ◽  
pp. 8678-8683 ◽  
Author(s):  
Jie Yang ◽  
Javier Ortega-Hernández ◽  
Sylvain Gerber ◽  
Nicholas J. Butterfield ◽  
Jin-bo Hou ◽  
...  
Keyword(s):  
South China ◽  
Cambrian Explosion ◽  
Suspension Feeding ◽  
Early Cambrian ◽  
Early Paleozoic ◽  
Crown Group ◽  
Morphological Disparity ◽  
Stem Group ◽  
Velvet Worms ◽  
Mode Of Life

We describe Collinsium ciliosum from the early Cambrian Xiaoshiba Lagerstätte in South China, an armored lobopodian with a remarkable degree of limb differentiation including a pair of antenna-like appendages, six pairs of elongate setiferous limbs for suspension feeding, and nine pairs of clawed annulated legs with an anchoring function. Collinsium belongs to a highly derived clade of lobopodians within stem group Onychophora, distinguished by a substantial dorsal armature of supernumerary and biomineralized spines (Family Luolishaniidae). As demonstrated here, luolishaniids display the highest degree of limb specialization among Paleozoic lobopodians, constitute more than one-third of the overall morphological disparity of stem group Onychophora, and are substantially more disparate than crown group representatives. Despite having higher disparity and appendage complexity than other lobopodians and extant velvet worms, the specialized mode of life embodied by luolishaniids became extinct during the Early Paleozoic. Collinsium and other superarmored lobopodians exploited a unique paleoecological niche during the Cambrian explosion.

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