Tunable directivity in metamaterials with reconfigurable cell symmetry

2015 ◽  
Vol 106 (9) ◽  
pp. 091905 ◽  
Author(s):  
Paolo Celli ◽  
Stefano Gonella
Keyword(s):  
Cell Symmetry

Actinellopsis murphyi gen. et spec. nov.: A new small celled freshwater diatom (Bacillariophyta, Eunotiales) from Zambia

Phytotaxa ◽  
2014 ◽  
Vol 178 (2) ◽  
pp. 128 ◽  
Author(s):  
Jonathan Charles Taylor ◽  
BALASUBRAMANIAN KARTHICK ◽  
J. PATRICK KOCIOLEK ◽  
CARLOS E. WETZEL ◽  
CHRISTINE COCQUYT
Keyword(s):  
Morphological Characteristics ◽  
Distinguishing Characteristic ◽  
Cell Symmetry ◽  
Freshwater Diatom

In this paper we describe Actinellopsis murphyi gen. et spec. nov. a small heteropolar and dorsiventral diatom from a seep habitat in Zambia. This novel taxon has the chief distinguishing characteristic, along with its cell symmetry, of having the raphe positioned wholly in the valve face and not extending onto the mantle. It is further placed within the Peroniaceae as it possesses a straight raphe on the valve face and rimoportulae, and the frustules are heteropolar with regard to the length of the raphe. We also transfer the fossil diatom Actinella giraffensis to Actinellopsis as the morphological characteristics of this taxon are consistent with those of the generitype.

scholarly journals Grid cell symmetry is shaped by environmental geometry

Nature ◽  
2015 ◽  
Vol 518 (7538) ◽  
pp. 232-235 ◽  
Author(s):  
Julija Krupic ◽  
Marius Bauza ◽  
Stephen Burton ◽  
Caswell Barry ◽  
John O’Keefe
Keyword(s):  
Grid Cell ◽  
Cell Symmetry ◽  
Environmental Geometry

scholarly journals Regulation of Cell Diameter, For3p Localization, and Cell Symmetry by Fission Yeast Rho-GAP Rga4p

2007 ◽  
Vol 18 (6) ◽  
pp. 2090-2101 ◽  
Author(s):  
Maitreyi Das ◽  
David J. Wiley ◽  
Saskia Medina ◽  
Helen A. Vincent ◽  
Michelle Larrea ◽  
...  
Keyword(s):  
Cell Growth ◽  
Growth Control ◽  
Cell Diameter ◽  
Dependent Manner ◽  
Cell Symmetry ◽  
Actin Cable ◽  
Growing Cell ◽  
Development And Differentiation ◽  
Negative Role ◽  
Cell Growth Control

Control of cellular dimensions and cell symmetry are critical for development and differentiation. Here we provide evidence that the putative Rho-GAP Rga4p of Schizosaccharomyces pombe controls cellular dimensions. rga4Δ cells are wider in diameter and shorter in length, whereas Rga4p overexpression leads to reduced diameter of the growing cell tip. Consistent with a negative role in cell growth control, Rga4p protein localizes to the cell sides in a “corset” pattern, and to the nongrowing cell tips. Additionally, rga4Δ cells show an altered growth pattern similar to that observed in mutants of the formin homology protein For3p. Consistent with these observations, Rga4p is required for normal localization of For3p and for normal distribution of the actin cytoskeleton. We show that different domains of the Rga4p protein mediate diverse morphological functions. The C-terminal GAP domain mediates For3p localization to the cell tips and maintains cell diameter. Conversely, overexpression of the N-terminal LIM homology domain of Rga4p promotes actin cable formation in a For3p-dependent manner. Our studies indicate that Rga4p functionally interacts with For3p and has a novel function in the control of cell diameter and cell growth.

scholarly journals The Role of Branch Cell Symmetry and Other Critical Nanoscale Design Parameters in the Determination of Dendrimer Encapsulation Properties

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 642 ◽  
Author(s):  
Donald A. Tomalia ◽  
Linda S. Nixon ◽  
David M. Hedstrand
Keyword(s):  
Drug Delivery ◽  
Metal Cluster ◽  
Design Parameters ◽  
Void Space ◽  
The Past ◽  
Cell Symmetry ◽  
Family Types ◽  
Approved Drugs

This article reviews progress over the past three decades related to the role of dendrimer-based, branch cell symmetry in the development of advanced drug delivery systems, aqueous based compatibilizers/solubilizers/excipients and nano-metal cluster catalysts. Historically, it begins with early unreported work by the Tomalia Group (i.e., The Dow Chemical Co.) revealing that all known dendrimer family types may be divided into two major symmetry categories; namely: Category I: symmetrical branch cell dendrimers (e.g., Tomalia, Vögtle, Newkome-type dendrimers) possessing interior hollowness/porosity and Category II: asymmetrical branch cell dendrimers (e.g., Denkewalter-type) possessing no interior void space. These two branch cell symmetry features were shown to be pivotal in directing internal packing modes; thereby, differentiating key dendrimer properties such as densities, refractive indices and interior porosities. Furthermore, this discovery provided an explanation for unimolecular micelle encapsulation (UME) behavior observed exclusively for Category I, but not for Category II. This account surveys early experiments confirming the inextricable influence of dendrimer branch cell symmetry on interior packing properties, first examples of Category (I) based UME behavior, nuclear magnetic resonance (NMR) protocols for systematic encapsulation characterization, application of these principles to the solubilization of active approved drugs, engineering dendrimer critical nanoscale design parameters (CNDPs) for optimized properties and concluding with high optimism for the anticipated role of dendrimer-based solubilization principles in emerging new life science, drug delivery and nanomedical applications.

Impact of intra- and inter-unit cell symmetry breaking on the optical response of the arrays of nanotrimers

2019 ◽  
Vol 44 (21) ◽  
pp. 5169
Author(s):  
Ning Wang ◽  
Matthias Zeisberger ◽  
Uwe Hübner ◽  
Markus A. Schmidt
Keyword(s):  
Symmetry Breaking ◽  
Optical Response ◽  
Unit Cell ◽  
Cell Symmetry
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