scholarly journals Geometric Packing under Nonuniform Constraints

2017 ◽  
Vol 46 (6) ◽  
pp. 1745-1784
Author(s):  
Alina Ene ◽  
Sariel Har-Peled ◽  
Benjamin Raichel
Keyword(s):  
Geometric Packing

scholarly journals Structural and Electronic Properties of Gold Clusters

2005 ◽  
Vol 1 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Denitsa Alamanova ◽  
Yi Dong ◽  
Habib ur Rehman ◽  
Michael Springborg ◽  
Valeri G. Grigoryan
Keyword(s):  
Total Energy ◽  
Electronic Properties ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Gold Clusters ◽  
Structural And Electronic Properties ◽  
Geometric Packing

We study the structure and energetics of AuN clusters by means of parameterfree density-functional calculations (N ≤ 8), jellium calculations (N ≤ 60), embeddedatom calculations (N ≤ 150), and parameterized density-functional calculations (N ≤ 40) in combination with different methods for determining the structure of the lowest total energy. By comparing the results from the different approaches, effects due to geometric packing and those due to the electronic orbitals can be identified. Different descriptors that highlight the results of the analysis are presented and used.

scholarly journals Bimodal Spindle Orientation Drives Tissue Regularity in a Proliferating Epithelium

2017 ◽  
Author(s):  
Tara M. Finegan ◽  
Daxiang Na ◽  
Austin V. Skeeters ◽  
Nicole S. Dawney ◽  
Patrick W. Oakes ◽  
...  
Keyword(s):  
Cell Shape ◽  
Tissue Expansion ◽  
Follicular Epithelium ◽  
Spindle Orientation ◽  
Epithelial Tissue ◽  
Interphase Cell ◽  
Cortical Tension ◽  
Geometric Packing ◽  
Summary Statement ◽  
The Relationship

AbstractWe investigated the relationship between proliferation and tissue topology in an epithelial tissue undergoing elongation. We found that cell division is not required for elongation of the early Drosophila follicular epithelium, but does drive the tissue towards optimal geometric packing. To increase tissue regularity, cell divisions are oriented in the planar axis, along the direction of tissue expansion. Planar division orientation is governed by apico-cortical tension, which aligns with tissue expansion but not with interphase cell shape elongation. Hertwig’s Rule, which holds that cell elongation determines division orientation, is therefore broken in this tissue. We tested whether this observation could be explained by anisotropic activity of the conserved Pins/Mud spindle-orienting machinery, which controls division orientation in the apical-basal axis. We found that Pins/Mud does not participate in planar division orientation. Rather, tension translates into planar division orientation in a manner dependent on Canoe/Afadin, which links actomyosin to adherens junctions. These findings demonstrate that division orientation in different axes - apical-basal and planar - is controlled by distinct, independent mechanisms in a proliferating epithelium.Summary StatementRegularity in a proliferating epithelium requires cells to divorce division orientation from interphase shape, which they accomplish by using distinct mechanisms to orient divisions in the apical-basal and planar axes.

Hydrophobically-Driven Self-Assembly:  A Geometric Packing Analysis

Nano Letters ◽  
2003 ◽  
Vol 3 (5) ◽  
pp. 623-626 ◽  
Author(s):  
Stefan Tsonchev ◽  
George C. Schatz ◽  
Mark A. Ratner
Keyword(s):  
Self Assembly ◽  
Geometric Packing ◽  
Packing Analysis

scholarly journals The developing kidney actively negotiates geometric packing conflicts to avoid defects

2021 ◽  
Author(s):  
Louis S Prahl ◽  
John M Viola ◽  
Jiageng Liu ◽  
Alex James Hughes
Keyword(s):  
Packing Density ◽  
Geometric Constraints ◽  
Material Modeling ◽  
Limited Area ◽  
Surface Imaging ◽  
Vertical Orientation ◽  
Geometric Packing ◽  
Developing Kidney ◽  
Physical Limitations ◽  
Necessary And Sufficient

The physiological functions of several organs rely on branched tubular networks, but little is known about conflicts in development between building enough tubules for adequate function and geometric constraints imposed by organ size. We show that the mouse embryonic kidney epithelium negotiates a physical packing conflict between tubule tip duplication and limited area at the organ surface. Imaging, computational, and soft material modeling of tubule 'families' identifies six geometric packing phases, including two defective ones. Experiments in kidney explants show that a retrograde tension on tubule families is necessary and sufficient for them to avoid defects by switching to a vertical orientation that increases packing density. These results reveal developmental contingencies in response to physical limitations, and create a framework for classifying kidney defects.

scholarly journals Exact algorithms for a geometric packing problem (extended abstract)

1993 ◽  
pp. 317-322 ◽  
Author(s):  
L. Kučera ◽  
K. Mehlhorn ◽  
B. Preis ◽  
E. Schwarzenecker
Keyword(s):  
Packing Problem ◽  
Exact Algorithms ◽  
Geometric Packing
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