scholarly journals Wnt/β-catenin regulates an ancient signaling network during zebrafish scale development

2018 ◽  
Author(s):  
Andrew J. Aman ◽  
Alexis N. Fulbright ◽  
David M. Parichy
Keyword(s):  
Scale Development ◽  
Three Dimensional ◽  
Collective Cell Migration ◽  
Cell Behaviors ◽  
Skin Appendage ◽  
Rigorous Testing ◽  
Regulatory Module ◽  
Developmental Patterning ◽  
A Cell ◽  
Appendage Patterning

ABSTRACTUnderstanding how patterning influences cell behaviors to generate three dimensional morphologies is a central goal of developmental biology. Additionally, comparing these regulatory mechanisms among morphologically diverse tissues allows for rigorous testing of evolutionary hypotheses. Zebrafish skin is endowed with a coat of precisely patterned bony scales. We use in-toto live imaging during scale development and manipulations of cell signaling activity to elucidate core features of scale patterning and morphogenesis. These analyses show that scale development requires the concerted activity of Wnt/β-catenin, Ectodysplasin (Eda) and Fibroblast growth factor (Fgf) signaling. This regulatory module coordinates Hedgehog (HH) dependent collective cell migration during epidermal invagination, a cell behavior not previously implicated in skin appendage morphogenesis. Our analyses demonstrate the utility of zebrafish scale development as a tractable system in which to elucidate mechanisms of developmental patterning and morphogenesis, and suggest a single, ancient origin of skin appendage patterning mechanisms in vertebrates.

scholarly journals Wnt/β-catenin regulates an ancient signaling network during zebrafish scale development

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Andrew J Aman ◽  
Alexis N Fulbright ◽  
David M Parichy
Keyword(s):  
Scale Development ◽  
Three Dimensional ◽  
Collective Cell Migration ◽  
Cell Behaviors ◽  
Skin Appendage ◽  
Rigorous Testing ◽  
Regulatory Module ◽  
Developmental Patterning ◽  
A Cell ◽  
Appendage Patterning

Understanding how patterning influences cell behaviors to generate three dimensional morphologies is a central goal of developmental biology. Additionally, comparing these regulatory mechanisms among morphologically diverse tissues allows for rigorous testing of evolutionary hypotheses. Zebrafish skin is endowed with a coat of precisely patterned bony scales. We use in-toto live imaging during scale development and manipulations of cell signaling activity to elucidate core features of scale patterning and morphogenesis. These analyses show that scale development requires the concerted activity of Wnt/β-catenin, Ectodysplasin (Eda) and Fibroblast growth factor (Fgf) signaling. This regulatory module coordinates Hedgehog (HH) dependent collective cell migration during epidermal invagination, a cell behavior not previously implicated in skin appendage morphogenesis. Our analyses demonstrate the utility of zebrafish scale development as a tractable system in which to elucidate mechanisms of developmental patterning and morphogenesis, and suggest a single, ancient origin of skin appendage patterning mechanisms in vertebrates.

A Three-Dimensional Viscous Transonic Inverse Design Method

2000 ◽  
Author(s):  
W. T. Tiow ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscous Effects ◽  
Flow Equations ◽  
Flow Solution ◽  
Turbomachinery Blades ◽  
A Cell ◽  
Inverse Design Method ◽  
Euler Solver

The development and application of a three-dimensional inverse methodology is presented for the design of turbomachinery blades. The method is based on the mass-averaged swirl, rV~θ distribution and computes the necessary blade changes directly from the discrepancies between the target and initial distributions. The flow solution and blade modification converge simultaneously giving the final blade geometry and the corresponding steady state flow solution. The flow analysis is performed using a cell-vertex finite volume time-marching algorithm employing the multistage Runge-Kutta integrator in conjunction with accelerating techniques (local time stepping and grid sequencing). To account for viscous effects, dissipative forces are included in the Euler solver using the log-law and mixing length models. The design method can be used with any existing solver solving the same flow equations without any modifications to the blade surface wall boundary condition. Validation of the method has been carried out using a transonic annular turbine nozzle and NASA rotor 67. Finally, the method is demonstrated on the re-design of the blades.

scholarly journals Weakening of resistance force by cell–ECM interactions regulate cell migration directionality and pattern formation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Masaya Hagiwara ◽  
Hisataka Maruyama ◽  
Masakazu Akiyama ◽  
Isabel Koh ◽  
Fumihito Arai
Keyword(s):  
Cell Migration ◽  
Pattern Formation ◽  
Epithelial Cells ◽  
Optical Tweezers ◽  
Three Dimensional ◽  
Lung Epithelial Cells ◽  
Resistance Force ◽  
Collective Cell Migration ◽  
Physical Forces ◽  
Cellular Movement

AbstractCollective migration of epithelial cells is a fundamental process in multicellular pattern formation. As they expand their territory, cells are exposed to various physical forces generated by cell–cell interactions and the surrounding microenvironment. While the physical stress applied by neighbouring cells has been well studied, little is known about how the niches that surround cells are spatio-temporally remodelled to regulate collective cell migration and pattern formation. Here, we analysed how the spatio-temporally remodelled extracellular matrix (ECM) alters the resistance force exerted on cells so that the cells can expand their territory. Multiple microfabrication techniques, optical tweezers, as well as mathematical models were employed to prove the simultaneous construction and breakage of ECM during cellular movement, and to show that this modification of the surrounding environment can guide cellular movement. Furthermore, by artificially remodelling the microenvironment, we showed that the directionality of collective cell migration, as well as the three-dimensional branch pattern formation of lung epithelial cells, can be controlled. Our results thus confirm that active remodelling of cellular microenvironment modulates the physical forces exerted on cells by the ECM, which contributes to the directionality of collective cell migration and consequently, pattern formation.

The Development of an Automatic Three-Dimensional Mesh Generator via Modified Ray Casting

1992 ◽  
Author(s):  
Cengiz Yeker ◽  
Ibrahim Zeid
Keyword(s):  
Finite Elements ◽  
Cell Structure ◽  
Three Dimensional ◽  
Ray Casting ◽  
Solid Object ◽  
Casting Technique ◽  
Element Size ◽  
A Cell ◽  
Conforming Meshes ◽  
Representation Scheme

Abstract A fully automatic three-dimensional mesh generation method is developed by modifying the well-known ray casting technique. The method is capable of meshing objects modeled using the CSG representation scheme. The input to the method consists of solid geometry information, and mesh attributes such as element size. The method starts by casting rays in 3D space to classify the empty and full parts of the solid. This information is then used to create a cell structure that closely models the solid object. The next step is to further process the cell structure to make it more succinct, so that the cells close to the boundary of the solid object can model the topology with enough fidelity. Moreover, neighborhood relations between cells in the structure are developed and implemented. These relations help produce better conforming meshes. Each cell in the cell structure is identified with respect to a set of pre-defined types of cells. After the identification process, a normalization process is developed and applied to the cell structure in order to ensure that the finite elements generated from each cell conform to each other and to other elements produced from neighboring cells. The last step is to mesh each cell in the structure with valid finite elements.

Contractual Complexity in Construction Projects

2018 ◽  
Vol 49 (3) ◽  
pp. 46-61 ◽  
Author(s):  
Wenqian Wang ◽  
Yongqiang Chen ◽  
Shuibo Zhang ◽  
Yu Wang
Keyword(s):  
Structural Equation Modeling ◽  
Scale Development ◽  
Structural Equation ◽  
Construction Projects ◽  
Construction Project ◽  
Three Dimensional ◽  
Modeling Technique ◽  
Equation Modeling ◽  
Empirical Testing ◽  
Item Scale

Building on the multifunctional perspective from current contract theory, we conceptualize contractual complexity as a three-dimensional construct to depict the explicitness and elaborateness of control, coordination, and adaptation provisions in a construction project contract. A 13-item scale with construction project features is developed for measuring the different aspects of contractual complexity following rigorous scale development procedures. Using the structural equation modeling technique, empirical testing results demonstrate that all of the three components contribute significantly to contractual complexity. Further analysis indicated that treating contractual complexity in the three-functional way outperforms the unidimensional one regarding power to explain satisfaction and strong-form opportunism.

The Crystal Structure of KIO3.HIO3

1971 ◽  
Vol 49 (3) ◽  
pp. 468-476 ◽  
Author(s):  
Lilian Y. Y. Chan ◽  
F. W. B. Einstein
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
X Ray ◽  
R Factor ◽  
Octahedral Environment ◽  
Distorted Octahedral ◽  
Potassium Hydrogen ◽  
A Cell ◽  
Least Squares Techniques

The crystal structure of potassium hydrogen di-iodate (bi-iodate) KIO3.HIO3 was determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.0 % for the 1392 observed reflexions. The salt crystallizes in the monoclinic space group P21/c with eight formula units in a cell of dimension a = 7.028(1) Å, b = 8.203(1) Å, c = 21.841(3) Å, β = 98.03(1)°.The iodate units are all basically pyramidal; weak interionic I—O contacts complete a very distorted octahedral environment around three iodine atoms. There is a capped octahedral (7-coordinate) environment around the remaining iodine atom. The I—O bonds are in the range 1.75–1.82 Å and the I—OH bonds are 1.91 and 1.95 Å, variations in length can be correlated with differences in the degree of involvement in (a) hydrogen bonding and (b) interaction with adjacent iodine atoms.

Ascertaining the “Halalness” of restaurants – scale development and validation

2019 ◽  
Vol 10 (2) ◽  
pp. 426-439 ◽  
Author(s):  
Ghazala Khan ◽  
Faiza Khan
Keyword(s):  
Scale Development ◽  
Discriminant Validity ◽  
Three Dimensional ◽  
Reliability And Validity ◽  
Total Sample ◽  
Measurement Scale ◽  
Content Type ◽  
Three Dimensional Measurement ◽  
Average Variance ◽  
Development Literature

PurposeThe purpose of this study is to develop and validate a measurement scale for determining the “Halalness” of restaurants and related behaviour among Muslim consumers in the absence of the halal logo. The study responded to scholarly calls for further research in exploring the consumption practices of Muslims.Design/methodology/approachThe scale was developed and validated using a rigorous methodology recommended in the scale development literature. The study used a total sample of 438 (66 respondents for pilot study, 208 for exploratory survey and 164 for the confirmatory survey) to collect the data. Reliability and validity of the measurement scale was established through average variance extracted, Cronbach’s alpha, composite reliability, critical ratios and discriminant validity.FindingsThe results from the exploratory factor analysis and confirmatory analysis propose a three-dimensional measurement scale with 14 items for establishing the “Halalness” of restaurants and including social servicescape; neighbourhood and behaviour.Research limitations/implicationsThe study was unable to validate a number of cues and behaviour such as the presence of images in the restaurant or consumer responses to the presence of alcohol. The researchers are therefore encouraged to test these cues.Originality/valueThe study addresses a gap in Islamic literature, and it is among the first to provide conceptualisation and empirically validate a scale for measuring the “Halalness” of restaurants. The scale was tested and validated based on samples drawn from two different countries, thereby allowing for generalizability.

Three-Dimensional Microfabrication System for Biodegradable Microdevices With High-Resolution and Bio-Applicability

2005 ◽  
Author(s):  
Akira Yamada ◽  
Fuminori Niikura ◽  
Koji Ikuta
Keyword(s):  
Tensile Strength ◽  
Biodegradable Polymers ◽  
Conventional Method ◽  
Three Dimensional ◽  
Single Layer ◽  
Batch Process ◽  
Potential Applications ◽  
A Cell ◽  
The One ◽  
Almost All

Biodegradable polymers are employed in medicine and its further application is expected with eagerness. But the lack of an appropriate processing method retards the progress. To overcome this problem, we have developped a novel three-dimensional microfabrication system. The system design allows us the processing of the free three-dimensional micro-level forms by stacking up melted polymers from the nozzle. Different from the conventional method, we adopted a batch process to supply materials in order to eliminate the prior process that required toxic solvents. In addition, it is possible to handle almost all biodegradable thermoplastic resins by adopting this system. A single layer from the piled-up layers of extruded lines was observed to evaluate the resolution. The lateral and depth resolutions attained are 40 μm and 45 μm, respectively. Biodegradable polymers enable three-dimensional microstructures such as micro-pipes, micro-bends, and micro-coil springs to be manufactured in less than 15 min. The biocompatibility of the newly fabricated structure was evaluated using a cell line (PC12). For this purpose, a small vessel, with a transparent base, was fabricated using PLA and cells were cultivated in it. The results were then compared with the results obtained using the standard method. The mechanical strength of our microstructures was evaluated using a tensile strength test. The tensile strength of the microstructure was lower than the one obtained from the conventional method, but has enough strength for fabrication of medical devices. Our system renders it possible to produce toxic-free, as well as transparent and leakage-free devices. Our system is expected to have potential applications in optimum design and fabrication of implantable devices, especially in tissue engineering.

scholarly journals Podophyllotoxin and Quercetin in Silico Derivatives Docking Analysis with Cyclooxygenase-2 and Aminopeptidase-N

2021 ◽  
Author(s):  
A.E. Manukyan ◽  
A.A. Hovhannisyan
Keyword(s):  
In Silico ◽  
Biological Activities ◽  
Three Dimensional ◽  
Aminopeptidase N ◽  
Docking Analysis ◽  
Quercetin Derivatives ◽  
Pubchem Database ◽  
A Cell ◽  
Cox 2 ◽  
High Level

ABSTRACTThe cyclooxygenase (COX) enzymes are tumor markers, the inhibition of which can be used in the prevention and therapy of carcinogenesis. It was found that COX-2 IS considered as targets for tumor inhibition. Aminopeptidase N (APN) is a type II membrane-bound metalloprotease associated with cancer, being identified as a cell marker on the surface of malignant myeloid cells and reached a high level of expression in progressive tumors. In anticancer therapy, plant compounds are considered that can inhibit their activity. Modeling of the COX-2 and APN enzymes was carried out on the basis of molecular models of three-dimensional structures from the PDB database [PDB ID: 5f19, 4fyq] RCSB. For docking analysis, 3D ligand models were created using MarvinSketch based on the PubChem database [CID: 5280343, 5281654]. In silico experiments, for the first time, revealed the possible interaction and inhibition of COX-2 and APN by quercetin and quercetin derivatives. Aspirin and Marimastat were taken to compare the results. Possible biological activities and possible side effects of the ligands have been identified.

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