scholarly journals Surface tension determines tissue shape and growth kinetics

2019 ◽  
Vol 5 (9) ◽  
pp. eaav9394 ◽  
Author(s):  
S. Ehrig ◽  
B. Schamberger ◽  
C. M. Bidan ◽  
A. West ◽  
C. Jacobi ◽  
...  
Keyword(s):  
Physical Environment ◽  
Constant Mean Curvature ◽  
Three Dimensional ◽  
Feedback Mechanism ◽  
Self Organization ◽  
Biological Feedback ◽  
Cell Contractility ◽  
Mechanical Signaling ◽  
Fluid Behavior ◽  
Cellular Forces

The collective self-organization of cells into three-dimensional structures can give rise to emergent physical properties such as fluid behavior. Here, we demonstrate that tissues growing on curved surfaces develop shapes with outer boundaries of constant mean curvature, similar to the energy minimizing forms of liquids wetting a surface. The amount of tissue formed depends on the shape of the substrate, with more tissue being deposited on highly concave surfaces, indicating a mechano-biological feedback mechanism. Inhibiting cell-contractility further revealed that active cellular forces are essential for generating sufficient surface stresses for the liquid-like behavior and growth of the tissue. This suggests that the mechanical signaling between cells and their physical environment, along with the continuous reorganization of cells and matrix is a key principle for the emergence of tissue shape.

In-Between and Through: Architecture and Complexity

2005 ◽  
Vol 3 (3) ◽  
pp. 335-354 ◽  
Author(s):  
Clarissa Ribeiro Pereira de Almeida ◽  
Anja Pratschke ◽  
Renata La Rocca
Keyword(s):  
Complex System ◽  
Software Engineering ◽  
Complex Systems ◽  
Design Process ◽  
Three Dimensional ◽  
Self Organization ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Complex Thought ◽  
Basic Characteristics

This paper draws on current research on complexity and design process in architecture and offers a proposal for how architects might bring complex thought to bear on the understanding of design process as a complex system, to understand architecture as a way of organizing events, and of organizing interaction. Our intention is to explore the hypothesis that the basic characteristics of complex systems – emergence, nonlinearity, self-organization, hologramaticity, and so forth – can function as effective tools for conceptualization that can usefully extend the understanding of the way architects think and act throughout the design process. To illustrate the discussions, we show how architects might bring complex thought inside a transdisciplinary design process by using models such as software engineering diagrams, and three-dimensional modeling network environments such as media to integrate, connect and ‘trans–act’.

Simplified Development Method of FEA Code for Sloshing of Floating Roof Tanks (Lagrangian Formulation for Axisymmetric Linear Problem)

2014 ◽  
Author(s):  
Shoichi Yoshida
Keyword(s):  
Linear Problem ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Computational Time ◽  
Storage Tanks ◽  
Coupling Vibration ◽  
Development Method ◽  
Oil Storage ◽  
Fluid Behavior ◽  
Computer Codes

Floating roofs are widely used to prevent evaporation of content in large cylindrical aboveground oil storage tanks. The 2003 Hokkaido Earthquake caused severe damages to the floating roofs due to sloshing. These accidents became a cause to establish structural integrity of the floating roof tanks in sloshing. However, many designers do not have a solution for the sloshing of floating roof tanks except for three-dimensional FEA computer codes. The three-dimensional FEA requires a long computational time and expenses. The sloshing of floating roof tanks is a coupling vibration problem with fluid and structure. The simplified and convenient method has been desired for this solution. This paper presents a simplified development method of a FEA code in the axisymmetric linear problem. It is performed to modify an existing structural analysis code. The fluid behavior is formulated in terms of displacement as the Lagrangian approach.

Integral criteria for closed surfaces with constant mean curvature

2007 ◽  
Vol 463 (2081) ◽  
pp. 1199-1210
Author(s):  
Luca Guzzardi ◽  
Epifanio G Virga
Keyword(s):  
Mean Curvature ◽  
Constant Mean Curvature ◽  
Three Dimensional ◽  
Dimensional Euclidean Space ◽  
Second Variation ◽  
Closed Surfaces ◽  
Area Functional ◽  
Symmetric Surface ◽  
The Second Variation ◽  
Integral Identities

We propose three integral criteria that must be satisfied by all closed surfaces with constant mean curvature immersed in the three-dimensional Euclidean space. These criteria are integral identities that follow from requiring the second variation of the area functional to be invariant under rigid displacements. We obtain from them a new proof of the old result by Delaunay, to the effect that the sphere is the only closed axis-symmetric surface.

scholarly journals What you see is where you go: visibility influences movement decisions of a forest bird navigating a three-dimensional-structured matrix

2021 ◽  
Vol 17 (1) ◽  
pp. 20200478
Author(s):  
Job Aben ◽  
Johannes Signer ◽  
Janne Heiskanen ◽  
Petri Pellikka ◽  
Justin M. J. Travis
Keyword(s):  
Physical Environment ◽  
Visual Cues ◽  
Three Dimensional ◽  
Forest Birds ◽  
Lidar Data ◽  
Perceptual Range ◽  
Movement Data ◽  
Structured Matrix ◽  
Viewshed Analysis ◽  
Step Selection

Animal spatial behaviour is often presumed to reflect responses to visual cues. However, inference of behaviour in relation to the environment is challenged by the lack of objective methods to identify the information that effectively is available to an animal from a given location. In general, animals are assumed to have unconstrained information on the environment within a detection circle of a certain radius (the perceptual range; PR). However, visual cues are only available up to the first physical obstruction within an animal's PR, making information availability a function of an animal's location within the physical environment (the effective visual perceptual range; EVPR). By using LiDAR data and viewshed analysis, we modelled forest birds' EVPRs at each step along a movement path. We found that the EVPR was on average 0.063% that of an unconstrained PR and, by applying a step-selection analysis, that individuals are 1.55 times more likely to move to a tree within their EVPR than to an equivalent tree outside it. This demonstrates that behavioural choices can be substantially impacted by the characteristics of an individual's EVPR and highlights that inferences made from movement data may be improved by accounting for the EVPR.

scholarly journals Tuning cell migration: contractility as an integrator of intracellular signals from multiple cues

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 1819 ◽  
Author(s):  
Francois Bordeleau ◽  
Cynthia A. Reinhart-King
Keyword(s):  
Cell Migration ◽  
Growth Factors ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Multiple Cues ◽  
Cell Contractility ◽  
Cell Matrix ◽  
Intracellular Signals ◽  
Physical Cues ◽  
The Matrix

There has been immense progress in our understanding of the factors driving cell migration in both two-dimensional and three-dimensional microenvironments over the years. However, it is becoming increasingly evident that even though most cells share many of the same signaling molecules, they rarely respond in the same way to migration cues. To add to the complexity, cells are generally exposed to multiple cues simultaneously, in the form of growth factors and/or physical cues from the matrix. Understanding the mechanisms that modulate the intracellular signals triggered by multiple cues remains a challenge. Here, we will focus on the molecular mechanism involved in modulating cell migration, with a specific focus on how cell contractility can mediate the crosstalk between signaling initiated at cell-matrix adhesions and growth factor receptors.

Three-dimensional SWCNT and MWCNT hybrid networks for extremely high-loading and high rate cathode materials

2019 ◽  
Vol 7 (29) ◽  
pp. 17412-17419 ◽  
Author(s):  
Dae-wook Kim ◽  
Nobuyuki Zettsu ◽  
Katsuya Teshima
Keyword(s):  
Cathode Materials ◽  
Three Dimensional ◽  
Hybrid Networks ◽  
High Rate ◽  
Self Organization ◽  
High Loading ◽  
Dimensional Network

Extremely high-loading LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode materials (up to 99.5 wt%) were achieved through self-organization of a three-dimensional network of multi-walled and single-walled CNT hybrids.

scholarly journals Constant mean curvature spheres in homogeneous three-manifolds

2020 ◽  
Author(s):  
William H. Meeks ◽  
Pablo Mira ◽  
Joaquín Pérez ◽  
Antonio Ros
Keyword(s):  
Mean Curvature ◽  
Constant Mean Curvature ◽  
Three Dimensional ◽  
Complete Classification ◽  
Homogeneous Manifolds ◽  
The Mean

Abstract We prove that two spheres of the same constant mean curvature in an arbitrary homogeneous three-manifold only differ by an ambient isometry, and we determine the values of the mean curvature for which such spheres exist. This gives a complete classification of immersed constant mean curvature spheres in three-dimensional homogeneous manifolds.

scholarly journals Control of cellular responses to mechanical cues through YAP/TAZ regulation

2019 ◽  
Vol 294 (46) ◽  
pp. 17693-17706 ◽  
Author(s):  
Ishani Dasgupta ◽  
Dannel McCollum
Keyword(s):  
Cell Fate ◽  
Wound Repair ◽  
Hippo Pathway ◽  
Three Dimensional ◽  
Focal Adhesions ◽  
Mechanical Stimuli ◽  
Cell Contractility ◽  
Cell Fate Decisions ◽  
Disease States ◽  
The Hippo Pathway

To perceive their three-dimensional environment, cells and tissues must be able to sense and interpret various physical forces like shear, tensile, and compression stress. These forces can be generated both internally and externally in response to physical properties, like substrate stiffness, cell contractility, and forces generated by adjacent cells. Mechanical cues have important roles in cell fate decisions regarding proliferation, survival, and differentiation as well as the processes of tissue regeneration and wound repair. Aberrant remodeling of the extracellular space and/or defects in properly responding to mechanical cues likely contributes to various disease states, such as fibrosis, muscle diseases, and cancer. Mechanotransduction involves the sensing and translation of mechanical forces into biochemical signals, like activation of specific genes and signaling cascades that enable cells to adapt to their physical environment. The signaling pathways involved in mechanical signaling are highly complex, but numerous studies have highlighted a central role for the Hippo pathway and other signaling networks in regulating the YAP and TAZ (YAP/TAZ) proteins to mediate the effects of mechanical stimuli on cellular behavior. How mechanical cues control YAP/TAZ has been poorly understood. However, rapid progress in the last few years is beginning to reveal a surprisingly diverse set of pathways for controlling YAP/TAZ. In this review, we will focus on how mechanical perturbations are sensed through changes in the actin cytoskeleton and mechanosensors at focal adhesions, adherens junctions, and the nuclear envelope to regulate YAP/TAZ.

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