scholarly journals Fractal Model of the Protoplant's Appearance

2016 ◽  
Vol 11 (2) ◽  
pp. 225-232
Author(s):  
В.В. Галицкий ◽  
V.V. Galitskii
Keyword(s):  
Seed Germination ◽  
Exponential Growth ◽  
Fractal Geometry ◽  
Higher Plants ◽  
Eukaryotic Cell ◽  
Fractal Model ◽  
Fixed Number ◽  
Set Of Points ◽  
Allometric Parameter ◽  
Plant Embryogenesis

Sectional model of the tree's system branches, which was published earlier, was extended on the range (0.1) of model's allometric parameter μ, relating the magnitude of the green biomass of a tree and its size (for spruce μ ≈ 1.83). The model showed the presence of a green biomass in this range. According to the statements of fractal geometry this points out a possibility to interpret the placement of green biomass as a set of photosynthesis points. In turn according to contemporary notions about endosymbiotic character of appearance of organelles in eukaryotic cell this was interpreted as begin of endosymbiosis of cyanobacteria and a host (protist). This has been modeled by the groups’ placement of growing number of points on an interval under initial limitation of the number of points per group. The limitation is connected to the initial absence in protist an infrastructure which is need for the growing number of cyanobacteria. It was demonstrated that initially in course of increasing total points number the parameter μ decreases from 1.0 to 0.25 under the fixed number of points per group and then increases to 1.0 under the fixed number of groups. This gives an initial braking (slowdown) of growth of protoplant's size (a characteristic geometrical dimension of set of points) and then exponential growth after deleting limitation of point number per group in evolution's course of host endosymbiosis similarly to higher plants. Morphological analogy of situations of begin of plant embryogenesis and begin of seed germination with the situation described by the model of protoplant appearance is discussed.

RECENT ADVANCES ON FRACTAL MODELING OF PERMEABILITY FOR FIBROUS POROUS MEDIA

Fractals ◽  
2015 ◽  
Vol 23 (01) ◽  
pp. 1540006 ◽  
Author(s):  
JIANCHAO CAI ◽  
LIANG LUO ◽  
RAN YE ◽  
XIANGFENG ZENG ◽  
XIANGYUN HU
Keyword(s):  
Porous Media ◽  
Pore Structure ◽  
Fractal Geometry ◽  
Influence Factor ◽  
Fractal Model ◽  
Fibrous Materials ◽  
Permeability Model ◽  
Fractal Modeling ◽  
Fibrous Porous Media ◽  
Future Work

Permeability is an important hydraulic parameter for characterizing heat and mass transfer properties of fibrous porous media. However, it is difficult to be quantitatively predicted due to the complex and irregular pore structure of fibrous porous media. Fractal geometry has been verified to be an effective method for determining the permeability of fibrous porous media. In this study, recent works on the permeability of fibrous porous media by means of fractal geometry are reviewed, the advances for each presented fractal model are analyzed and summarized, parameter equations used in available fractal permeability models are also briefly compared and reviewed. Future work for more generalized permeability model of fibrous porous media need to conducted by considering the special characters of fibrous materials, uniform pore structure parameter model and the influence factor of capillary pressure, electrokinetic phenomena, etc.

Seed Germination Syndromes in Higher Plants

1979 ◽  
pp. 188-206 ◽  
Author(s):  
Mark W. Angevine ◽  
Brian F. Chabot
Keyword(s):  
Seed Germination ◽  
Higher Plants

scholarly journals iTRAQ-Based Analysis of Proteins Co-Regulated by Brassinosteroids and Gibberellins in Rice Embryos during Seed Germination

2018 ◽  
Vol 19 (11) ◽  
pp. 3460 ◽  
Author(s):  
Qian-Feng Li ◽  
Jin-Dong Wang ◽  
Min Xiong ◽  
Ke Wei ◽  
Peng Zhou ◽  
...  
Keyword(s):  
Seed Germination ◽  
Regulatory Network ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Higher Plants ◽  
Absolute Quantification ◽  
Rice Seed ◽  
Differentially Expressed Proteins ◽  
Search Tool ◽  
Isobaric Tags

Seed germination, a pivotal process in higher plants, is precisely regulated by various external and internal stimuli, including brassinosteroid (BR) and gibberellin (GA) phytohormones. The molecular mechanisms of crosstalk between BRs and GAs in regulating plant growth are well established. However, whether BRs interact with GAs to coordinate seed germination remains unknown, as do their common downstream targets. In the present study, 45 differentially expressed proteins responding to both BR and GA deficiency were identified using isobaric tags for relative and absolute quantification (iTRAQ) proteomic analysis during seed germination. The results indicate that crosstalk between BRs and GAs participates in seed germination, at least in part, by modulating the same set of responsive proteins. Moreover, most targets exhibited concordant changes in response to BR and GA deficiency, and gene ontology (GO) indicated that most possess catalytic activity and are involved in various metabolic processes. Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analysis was used to construct a regulatory network of downstream proteins mediating BR- and GA-regulated seed germination. The mutation of GRP, one representative target, notably suppressed seed germination. Our findings not only provide critical clues for validating BR–GA crosstalk during rice seed germination, but also help to optimise molecular regulatory networks.

Structural, physiological and molecular aspects of heterogeneity in seeds: a review

2005 ◽  
Vol 15 (2) ◽  
pp. 63-76 ◽  
Author(s):  
Angel Matilla ◽  
Mercedes Gallardo ◽  
María Isabel Puga-Hermida
Keyword(s):  
Abscisic Acid ◽  
Seed Germination ◽  
Seed Bank ◽  
Higher Plants ◽  
Hormonal Control ◽  
Individual Plant ◽  
Shape Parameters ◽  
Action Mechanism ◽  
Seed Population ◽  
Molecular Aspects

Higher plants have several strategies to perpetuate themselves under adequate ecophysiological conditions. The production of heterogeneous seeds is one such strategy. That is, to ensure the survival of the next generation, an individual plant might produce seeds that are heterogeneous with respect to the extent of dormancy, dispersion and persistence within the seed bank. Heterogeneity can affect not only certain physiological and molecular properties related to seed germination, but also such characteristics as colour, size and shape, parameters commonly used to differentiate morphs within a heterogeneous seed population. In heterogeneous seeds, the above features determine seed behaviour and alter their mechanism of germination. In this work, emphasis is placed on the existence of seed mutants having major alterations in characteristics of the testa and hormonal response. These mutants constitute a valuable tool for elucidating the mechanism of dormancy, germination and perpetuation of seeds. Finally, ontogeny and heterogeneity are reviewed, providing the first data related to the possible hormonal control of heterogeneity in seeds. These results raise the hypothesis that one of the factors triggering differences in germination among heterogeneous seeds may be an alteration in the signalling and action mechanism of ethylene and abscisic acid (ABA).

MINIMUM POLYGON TRANSVERSALS OF LINE SEGMENTS

1995 ◽  
Vol 05 (03) ◽  
pp. 243-256 ◽  
Author(s):  
DAVID RAPPAPORT
Keyword(s):  
Convex Hull ◽  
General Problem ◽  
Line Segment ◽  
Simple Polygon ◽  
Fixed Number ◽  
Line Segments ◽  
Geometric Objects ◽  
Finite Set ◽  
Minimum Perimeter ◽  
Set Of Points

Let S be used to denote a finite set of planar geometric objects. Define a polygon transversal of S as a closed simple polygon that simultaneously intersects every object in S, and a minimum polygon transversal of S as a polygon transversal of S with minimum perimeter. If S is a set of points then the minimum polygon transversal of S is the convex hull of S. However, when the objects in S have some dimension then the minimum polygon transversal and the convex hull may no longer coincide. We consider the case where S is a set of line segments. If the line segments are constrained to lie in a fixed number of orientations we show that a minimum polygon transversal can be found in O(n log n) time. More explicitely, if m denotes the number of line segment orientations, then the complexity of the algorithm is given by O(3mn+log n). The general problem for line segments is not known to be polynomial nor is it known to be NP-hard.

scholarly journals A Raf-like kinase is required for smoke-induced seed dormancy in Arabidopsis thaliana

2021 ◽  
Vol 118 (14) ◽  
pp. e2020636118
Author(s):  
Inhye Lee ◽  
Eunsun Kim ◽  
Soobin Choi ◽  
Dayoung Kim ◽  
Wangyu Hong ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Seed Germination ◽  
Seed Dormancy ◽  
Higher Plants ◽  
Critical Role ◽  
Phenotypic Analysis ◽  
Genetic Components ◽  
Dependent Inhibition ◽  
Molecular Aspects

Plants sense and integrate diverse stimuli to determine the timing for germination. A smoke compound, 3,4,5-trimethylfuran-2(5H)-one (trimethylbutenolide, TMB), has been identified to inhibit the seed germination of higher plants. To understand the mode of action, we examined various physiological and molecular aspects of the TMB-dependent inhibition of seed germination in Arabidopsis thaliana. The results indicated that the effect of TMB is due to the enhanced physiological dormancy, which is modulated by other dormancy regulatory cues such as after-ripening, stratification, and ABA/GA signaling. In addition, gene expression profiling showed that TMB caused genome-wide transcriptional changes, altering the expression of a series of dormancy-related genes. Based on the TMB-responsive physiological contexts in Arabidopsis, we performed mutant screening to isolate genetic components that underpin the TMB-induced seed dormancy. As a result, the TMB-RESISTANT1 (TES1) gene in Arabidopsis, encoding a B2 group Raf-like kinase, was identified. Phenotypic analysis of the tes1 mutant implicated that TES1 has a critical role in the TMB-responsive gene expression and the inhibition of seed germination. Taken together, we propose that plants have been equipped with a TMB sensory pathway through which the TMB induces the seed dormancy in a TES1-dependent way.

scholarly journals Parameter identification for fractional-fractal model of filtration-consolidation dynamics using artificial neural networks

2021 ◽  
pp. 52-57
Author(s):  
Vsevolod Bohaienko ◽  
Volodymy y Bulavatsky ◽  
Anatolij Gladky
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Fractional Derivatives ◽  
Identification Problem ◽  
Fractal Model ◽  
Fixed Number ◽  
Data Sets ◽  
Noise Levels ◽  
Filtration Consolidation ◽  
Artificial Neural

Artificial neural networks are applied to solve parameters identification problem for one-dimensional fractional-fractal model of filtration consolidation processes in geo-porous media in the conditions of salt transfer. Based on the indicators of the state of the process in a fixed number of observation points, the values of the orders of fractional derivatives with respect to time and space variables were restored. Testing results based on data sets obtained from noised solutions of the direct problem show the adequacy of fractional derivatives orders restoration with at least 25 observation points and noise levels less than 10%.

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