On Periodic Distribution Groups

1981 ◽  
pp. 53-61 ◽  
Author(s):  
Ioana Ciorănescu
Keyword(s):  
Periodic Distribution

Nanoscale periodic distribution of energy dissipation at the shear band plane in a Zr-based metallic glass

2021 ◽  
Vol 197 ◽  
pp. 113784
Author(s):  
D.P. Wang ◽  
H.T. Zhang ◽  
P.Y. Guo ◽  
B.A. Sun ◽  
Y.X. Wang
Keyword(s):  
Energy Dissipation ◽  
Shear Band ◽  
Metallic Glass ◽  
Periodic Distribution

Catalytic activity of CuGHK peptide-based porous material

2021 ◽  
Author(s):  
Francisco G. Cirujano ◽  
Nuria Martin ◽  
Neyvis Almora-Barrios ◽  
Carlos Martí-Gastaldo
Keyword(s):  
Catalytic Activity ◽  
Porous Material ◽  
Active Sites ◽  
Room Temperature ◽  
Side Chain ◽  
Periodic Distribution ◽  
Lysine Side Chain ◽  
One Step

Room temperature one-step synthesis of the peptide-based porous material with a periodic distribution of pockets decorated with lysine side chain active sites behaves as a heterogeneous organocatalyst. The pockets are...

Periodic Distribution of Troponin along the Thin Filament*

1967 ◽  
Vol 61 (6) ◽  
pp. 817-819 ◽  
Author(s):  
IWAO OHTSUKI ◽  
TOMOH MASAKI ◽  
YOSHIAKI NONOMURA ◽  
SETSURO EBASHI
Keyword(s):  
Thin Filament ◽  
Periodic Distribution

Sound Attenuation in a Flow Duct Periodically Loaded With Micro-Perforated Patches Backed by Helmholtz Resonators

2018 ◽  
Author(s):  
T. Bravo ◽  
C. Maury
Keyword(s):  
Separation Distance ◽  
Side Branch ◽  
Optimal Choice ◽  
Sound Attenuation ◽  
Limited Area ◽  
Frequency Noise ◽  
Matrix Formulation ◽  
Wave Regime ◽  
Helmholtz Resonators ◽  
Periodic Distribution

Mitigating the propagation of low frequency noise sources in ducted flows represents a challenging task since wall treatments have often a limited area and thickness. Loading the periphery of a duct with a periodic distribution of side-branch Helmholtz resonators broadens the bandwidth of the noise attenuated with respect to a single resonator and generates stop bands that inhibit wave propagation. However, significant flow pressure drop may occur along the duct axis that could be reduced using micro-perforated patches at the duct-neck junctions. In this study, a transfer matrix formulation is derived to determine the sound attenuation properties of a periodic distribution of MPPs backed by Helmholtz resonators along the walls of a duct in the plane wave regime. In the no-flow case, it is shown that an optimal choice of the MPP parameters and resonators separation distance lowers the frequencies of maximal attenuation while maintaining broad stopping bands. As observed in the no-flow and low-speed flow cases, these frequencies can be further decreased by coiling the acoustic path length in the resonators cavity, albeit at the expense of narrower bands of low pressure transmission. The achieved effective wall impedances are compared against Cremer optimal impedance at the first attenuation peak.

scholarly journals Phyllotaxic diversity in Magnolia flowers

2014 ◽  
Vol 63 (2) ◽  
pp. 117-137 ◽  
Author(s):  
Beata Zagórska-Marek
Keyword(s):  
Genetic Factor ◽  
Wide Spectrum ◽  
Periodic Distribution ◽  
Pattern Diversity ◽  
First Time

Impermanent initials and thus the shift of the axis in the stochastic meristems are postulated to be responsible for ontogenetic phyllotactic diversity in plants. In the gynoecium of <i>Magnolia acuminata</i> the main Fibonacci pattern develops in much less than 50% of individual generative shoots. There is also an extremely wide spectrum of other patterns, among them even the rarest I, 3, 8, 11 ... pattern is present. Regarded sometimes as "impossible", the pattern has been documented in SEM for the first time. Beside the presence of various patterns, frequent ontogenetic transformations of phyllotaxis have been found in <i>Magnolia</i>. These are indicated by dislocations in the periodic distribution of carpel primordia. In other magnolias, exemplified by <i>M. soulangeana</i>, the Fibonacci pattern prevails, but not as much as in coniferous vegetative shoots, where, as demonstrated earlier, it reaches 95%. Other pattern numbers are also different. This suggests the involvement of the genetic factor and may be attributed to the higher frequency of discontinuous phyllotactic transformations in some species. The stochastic character of the meristem is perhaps more pronounced in some plants, which leads in turn to more frequent transitions and greater pattern diversity.

scholarly journals A species-specific nucleosomal signature defines a periodic distribution of amino acids in proteins

Open Biology ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 140218 ◽  
Author(s):  
Luis Quintales ◽  
Ignacio Soriano ◽  
Enrique Vázquez ◽  
Mónica Segurado ◽  
Francisco Antequera
Keyword(s):  
Amino Acids ◽  
Protein Composition ◽  
Open Reading Frames ◽  
Yeast Genome ◽  
Relative Distribution ◽  
Periodic Distribution ◽  
Wide Range ◽  
Average Distribution ◽  
Species Specific ◽  
High Degree

Nucleosomes are the basic structural units of chromatin. Most of the yeast genome is organized in a pattern of positioned nucleosomes that is stably maintained under a wide range of physiological conditions. In this work, we have searched for sequence determinants associated with positioned nucleosomes in four species of fission and budding yeasts. We show that mononucleosomal DNA follows a highly structured base composition pattern, which differs among species despite the high degree of histone conservation. These nucleosomal signatures are present in transcribed and non-transcribed regions across the genome. In the case of open reading frames, they correctly predict the relative distribution of codons on mononucleosomal DNA, and they also determine a periodicity in the average distribution of amino acids along the proteins. These results establish a direct and species-specific connection between the position of each codon around the histone octamer and protein composition.

scholarly journals Patterns in melanocytic lesions: impact of the geometry on growth and transport inside the epidermis

2014 ◽  
Vol 11 (97) ◽  
pp. 20140339 ◽  
Author(s):  
Thibaut Balois ◽  
Clément Chatelain ◽  
Martine Ben Amar
Keyword(s):  
Tumour Growth ◽  
Basal Layer ◽  
Biomechanical Model ◽  
Cell Aggregation ◽  
Periodic Distribution ◽  
Clinical Observations ◽  
Melanocytic Lesions ◽  
Biological Studies ◽  
Specific Geometry

In glabrous skin, nevi and melanomas exhibit pigmented stripes during clinical dermoscopic examination. They find their origin in the basal layer geometry which periodically exhibits ridges, alternatively large (limiting ridges) and thin (intermediate ridges). However, nevus and melanoma lesions differ by the localization of the pigmented stripes along furrows or ridges of the epidermis surface. Here, we propose a biomechanical model of avascular tumour growth which takes into account this specific geometry in the epidermis where both kinds of lesions first appear. Simulations show a periodic distribution of tumour cells inside the lesion, with a global contour stretched out along the ridges. In order to be as close as possible to clinical observations, we also consider the melanin transport by the keratinocytes. Our simulations show that reasonable assumptions on melanocytic cell repartition in the ridges favour the limiting ridges of the basal compared with the intermediate ones in agreement with nevus observations but not really with melanomas. It raises the question of cell aggregation and repartition of melanocytic cells in acral melanomas and requires further biological studies of these cells in situ .

EFFECT OF THERMAL NOISE ON THE CURRENT-VOLTAGE CHARACTERISTICS OF JOSEPHSON JUNCTIONS

1996 ◽  
Vol 10 (22) ◽  
pp. 1095-1102 ◽  
Author(s):  
A.K. CHATTAH ◽  
C.B. BRIOZZO ◽  
O. OSENDA ◽  
M.O. CÁCERES
Keyword(s):  
Josephson Junctions ◽  
Thermal Noise ◽  
Planck Equation ◽  
Resonance Problem ◽  
Shapiro Steps ◽  
Periodic Distribution ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Path Integral Method ◽  
Asymptotic Time

We analyze the influence of thermal noise on the Shapiro steps appearing in the current-voltage characteristics of Josephson junctions. We solve the Fokker-Planck equation describing the system by a path integral method in the steepest-descent approximation, previously applied to the stochastic resonance problem. We obtain the Asymptotic Time-Periodic Distribution Pas(ϕ, t), where ϕ∈[0, 2π] and compute from it the voltage [Formula: see text], constructing the I-V characteristics. We find a defined “softening” of the Shapiro steps as temperature increases, for values of the system parameters in the experimentally accessible range.

scholarly journals Prevalent presence of periodic actin–spectrin-based membrane skeleton in a broad range of neuronal cell types and animal species

2016 ◽  
Vol 113 (21) ◽  
pp. 6029-6034 ◽  
Author(s):  
Jiang He ◽  
Ruobo Zhou ◽  
Zhuhao Wu ◽  
Monica A. Carrasco ◽  
Peri T. Kurshan ◽  
...  
Keyword(s):  
Glial Cell ◽  
Animal Species ◽  
Homo Sapiens ◽  
Neuronal Cell ◽  
Cell Types ◽  
Membrane Skeleton ◽  
Brain Regions ◽  
Inhibitory Neurons ◽  
Periodic Distribution ◽  
Neuronal Types

Actin, spectrin, and associated molecules form a periodic, submembrane cytoskeleton in the axons of neurons. For a better understanding of this membrane-associated periodic skeleton (MPS), it is important to address how prevalent this structure is in different neuronal types, different subcellular compartments, and across different animal species. Here, we investigated the organization of spectrin in a variety of neuronal- and glial-cell types. We observed the presence of MPS in all of the tested neuronal types cultured from mouse central and peripheral nervous systems, including excitatory and inhibitory neurons from several brain regions, as well as sensory and motor neurons. Quantitative analyses show that MPS is preferentially formed in axons in all neuronal types tested here: Spectrin shows a long-range, periodic distribution throughout all axons but appears periodic only in a small fraction of dendrites, typically in the form of isolated patches in subregions of these dendrites. As in dendrites, we also observed patches of periodic spectrin structures in a small fraction of glial-cell processes in four types of glial cells cultured from rodent tissues. Interestingly, despite its strong presence in the axonal shaft, MPS is disrupted in most presynaptic boutons but is present in an appreciable fraction of dendritic spine necks, including some projecting from dendrites where such a periodic structure is not observed in the shaft. Finally, we found that spectrin is capable of adopting a similar periodic organization in neurons of a variety of animal species, including Caenorhabditis elegans, Drosophila, Gallus gallus, Mus musculus, and Homo sapiens.

Sign in / Sign up

Export Citation Format

Share Document