Pattern Formation Research Articles

Network topology and double delays in turing instability and pattern formation

Network topology and double delays in turing instability and pattern formation

Pattern formation in reaction-diffusion information propagation model on multiplex simplicial complexes

Turing patterns for explaining spatial distribution in nature mostly focus on continuous media and existing networks, but only few attempts exist to study them on systems with high-order interactions. Considering that high-order interactions have a particularly significant impact on rumor propagation, this study establishes a generalized reaction-diffusion rumor propagation model based on a multiplex network, where simplicial complexes are employed to describe high-order structures. It aims to provide the spatial distribution patterns of the population participating in rumor propagation and identify the structural factors that affect such patterns. We theoretically provide the necessary conditions for Turing instability in single-layer and multiplex networks by considering high-order interactions. In the numerical simulation, we demonstrate that the Turing pattern could be controlled by adjusting the diffusion coefficient, high-order structure intensity, and average degree of the network. The results indicate that: (i) in a single-layer network, the Turing pattern only exists when high-order interactions appear, and the difference in diffusion rate plays a decisive role, (ii) in a multiplex network, the Turing pattern can still be observed under the same diffusion rates, which are affected by the difference in higher-order intensity between the two layers, and (iii) in existing networks, the average degree of the network has an important impact on Turing pattern. These findings contribute toward comprehending the impact of network structure on pattern formation, particularly the high-order interactions on the Turing pattern.

Omniphobic Photoresist‐Assisted Patterning of Porous Polymethacrylate Films

AbstractPatterning of various surface properties, including roughness, wettability, adhesiveness, and mechanical properties, can markedly enhance the functionality of test systems. Thus, porous polymethacrylates prepared by polymerization‐induced phase separation (PIPS) represent a promising class of functional materials for the construction of miniaturized test systems. Different porosity, surface chemistry, and wettability are achieved in porous polymethacrylates with different precursor compositions. Nevertheless, only wettability microstructuring has been highlighted for these materials thus far. Here, the study presents a novel method for the direct and selective deposition of porous polymethacrylate films with different surface chemistry and porosity. The selective adhesion of omniphobic–omniphilic wettability patterns is used to facilitate the polymer pattern formation. The feasibility of patterning with different monomers and porogenic solvents is demonstrated. The topological study confirms the selective application of polymer structures with different thickness and roughness. The wettability characterization of the omniphobic material shows no significant changes caused by the operations performed. Thus, a new pattern with a greater difference in the wettability of the areas is produced in the process. Discontinuous dewetting of different liquids is performed. The use of poly(2‐hydroxyethyl methacrylate‐co‐ethylene dimethacrylate) (HEMA‐EDMA) modified patterns for precise living cell patterning is also demonstrated.

Transport of topological defects in a biphasic mixture of active and passive nematic fluids

Collectively moving cellular systems often contain a proportion of dead cells or non-motile genotypes. When mixed, nematically aligning motile and non-motile agents are known to segregate spontaneously. However, the role that topological defects and active stresses play in shaping the distribution of the two phases remains unresolved. In this study, we investigate the behaviour of a two-dimensional binary mixture of active and passive nematic fluids to understand how topological defects are transported between the two phases and, ultimately, how this leads to the segregation of topological charges. When the activity of the motile phase is large, and the tension at the interface of motile and non-motile phases is weak, we find that the active phase tends to accumulate +1/2 defects and expel −1/2 defects so that the motile phase develops a net positive charge. Conversely, when the activity of the motile phase is comparatively small and interfacial tension is strong, the opposite occurs so that the active phase develops a net negative charge. We then use these simulations to develop a physical intuition of the underlying processes that drive the charge segregation. Lastly, we quantify the sensitivity of this process on the other model parameters, by exploring the effect that anchoring strength, orientational elasticity, friction, and volume fraction of the motile phase have on topological charge segregation. As +1/2 and −1/2 defects have very different effects on interface morphology and fluid transport, this study offers new insights into the spontaneous pattern formation that occurs when motile and non-motile cells interact.

An epigenetically mediated double negative cascade from EFD to HB21 regulates anther development

Epigenetic modifications are crucial for plant development. EFD (ExineFormationDefect) encodes a SAM-dependent methyltransferase that is essential for the pollen wall pattern formation and male fertility in Arabidopsis. In this study, we find that the expression of DRM2, a de novo DNA methyltransferase in plants, complements for the defects in efd, suggesting its potential de novo DNA methyltransferase activity. Genetic analysis indicates that EFD functions through HB21, as the knockout of HB21 fully restores fertility in efd mutants. DNA methylation and histone modification analyses reveal that EFD represses the transcription of HB21 through epigenetic mechanisms. Additionally, we demonstrate that HB21 directly represses the expression of genes crucial for pollen formation and anther dehiscence, including CalS5, RPG1/SWEET8, CYP703A2 and NST2. Collectively, our findings unveil a double negative regulatory cascade mediated by epigenetic modifications that coordinates anther development, offering insights into the epigenetic regulation of this process.

Exploring the Element of Form Based on Traditional Chinese Auspicious Patterns

Chinese traditional auspicious patterns, which date back more than 5,000 years, are a vital component of national art and traditional culture. These patterns have special meanings and are often associated with good wishes and blessings. Their development reached its peak in the Ming and Qing Dynasties. This research on auspicious patterns focuses mainly on the creation method and classification, with few forms. It seeks to ascertain the features of the traditional auspicious pattern form in China. This study adopts qualitative analysis, specifically in analyzing patterns by observation. Based on Panofsky's theory of iconography, the study selected six common Chinese traditional auspicious patterns and analyzed them to determine their classification, layout, composition and elements. It can be concluded that their form is characterized by various elements, specifically figurative and complete, complex pattern formations, full layout designs, balanced or symmetrical compositions, and single or fit patterns. Thus, this study summarized the pattern form analysis model or the PFC-Model. By addressing this gap in knowledge, the study enhances understanding of auspicious patterns. At the same time, the pattern analysis model can be used to analyze similar patterns, which makes it easier to analyze other pattern forms and brings the study of traditional Chinese patterns to a new height. In the meantime, this research only studies the external form of auspicious patterns. In this regard, as form and color is the first layer of research mentioned in Panofsky's image theory, it needs to be more comprehensive. In the future, researchers can continue to explore its color characteristics and extend the research into the content of the first layer of the theories. Undoubtedly, researchers can also expand the analysis of auspicious patterns using the theory's second and third layers.

Dimensionality reduction in bulk-boundary reaction-diffusion systems.

Intracellular protein patterns regulate many vital cellular functions, such as the processing of spatiotemporal information or the control of shape deformations. To do so, pattern-forming systems can be sensitive to the cell geometry by means of coupling the protein dynamics on the cell membrane to dynamics in the cytosol. Recent studies demonstrated that modeling the cytosolic dynamics in terms of an averaged protein pool disregards possibly crucial aspects of the pattern formation, most importantly concentration gradients normal to the membrane. At the same time, the coupling of two domains (surface and volume) with different dimensions renders many standard tools for the numerical analysis of self-organizing systems inefficient. Here, we present a generic framework for projecting the cytosolic dynamics onto the lower-dimensional surface that respects the influence of cytosolic concentration gradients in static and evolving geometries. This method uses a priori physical information about the system to approximate the cytosolic dynamics by a small number of dominant characteristic concentration profiles (basis), akin to basis transformations of finite element methods. As a proof of concept, we apply our framework to a toy model for volume-dependent interrupted coarsening, evaluate the accuracy of the results for various basis choices, and discuss the optimal basis choice for biologically relevant systems. Our analysis presents an efficient yet accurate method for analyzing pattern formation with surface-volume coupling in evolving geometries.

Role of Membrane H+ Transport and Plasmalemma Excitability in Pattern Formation, Long-Distance Transport and Photosynthesis of Characean Algae

Role of Membrane H+ Transport and Plasmalemma Excitability in Pattern Formation, Long-Distance Transport and Photosynthesis of Characean Algae

Structure, function and formation of the amniote skin pattern

From feather and hair dotted arrays to pigmented stripes and spots, the spatial distribution of skin appendages and colouration often forms visible ornaments crucial for fitness in the coat of birds and mammals. These geometrical motifs are extremely diverse in nature. Yet, phenotypic surveys evidenced common themes in variation: the orientation, appendage-specificity or pigmentation of a given region may be conserved across groups or species. Here, we review naturalist observations of natural variation in the anatomy and ecological function of the skin pattern in amniotes. We then describe several decades of genetics, mathematical modelling and experimental embryology work aiming at understanding the molecular and morphogenetic mechanisms responsible for pattern formation. We discuss how these studies provided evidence that the morphological trends and differences representative of the phenotypic landscape of skin patterns in wild amniote species is rooted in the mechanisms controlling the production of distinct compartments in the embryonic skin.

Deriving Flow Velocity and Initial Concentration From Liesegang‐Like Patterns

AbstractZebra rocks, characterized by their striking reddish‐brown stripes, rods, and spots of hematite (Fe‐oxide), showcase complex self‐organized patterns formed under far‐from‐equilibrium conditions. Despite their ease of recognition, the underlying mechanisms of pattern‐forming processes remain elusive. We introduce a novel advection‐dominated phase‐field model that effectively replicates the Liesegang‐like patterns observed in Zebra rocks. This numerical model leverages the concept of phase separation, a well‐established principle governing Liesegang phenomena in a two‐dimensional setting. Our findings reveal that initial solute concentration and fluid flow velocity are critical determinants in pattern morphologies. We quantitatively explain the spacing and width of a specific Liesegang‐like pattern category. Furthermore, the model demonstrates that vanishingly low initial concentrations promote the formation of oblique patterns, with inclination angles influenced by rock heterogeneity. Additionally, we establish a quantitative relationship between band thickness and geological parameters for orthogonal bands. This enables the characterization of critical geological parameters based solely on static patterns observed in Zebra rocks, providing valuable insights into their formation environments. The diverse patterns in Zebra rocks share similarities with morphologies observed on early Earth and Mars, such as banded iron formations and hematite spherules. Our model, therefore, offers a plausible explanation for the formation mechanisms of these patterns and presents a powerful tool for deciphering the geochemical environments of their origin.

The Black Death, Girl Power, and the Emergence of the European Marriage Pattern in England

This article critiques the debate over the extent to which labor shortages caused by the Black Death and subsequent epidemics empowered women economically, and whether this had significant implications for overall demographic behavior and long-term economic performance. Some historians have argued that after ca. 1350 women in the North Sea region were drawn into the land and labor markets to a far greater extent than women in other parts of Europe, and in particular into employment as single live-in servants, which led to a rise in the average age of women at first marriage and the proportion of women never marrying. This in turn led to the formation of the European Marriage Pattern (EMP), which is associated with fertility restriction and higher levels of household income. The evidence and arguments underpinning this viewpoint are critically evaluated for England, where by 1600 the EMP was certainly established. The extant sources do not enable us to measure the extent of women's financial gains after the Black Death, or to assess changes in their marital choices. There is no convincing evidence for any rise in the proportion of single female servants in the century after the Black Death or for the existence of the EMP before 1550. Young women did not increase their participation in the land market in order to construct a marriage fund. The article concludes by assessing the possible chronologies of England's transition to the EMP, and by suggesting new lines of enquiry about structural changes in women's work during the sixteenth century.

Investigation of transverse exchange-springs in electrodeposited nano-heterostructured films through first-order reversal curve analysis

The prerequisite of efficient exchange-spring nano-heterostructures, i.e., tuning both hard and soft phases at a nanometer level, has posed significant preparation challenges to ensure effective exchange-coupling. Here, we present a novel approach to fabricate transverse exchange-spring nano-heterostructures using single starting material through an “in situ” electrodeposition technique at room temperature. Utilizing modified acidic bath chemistry and controlled hydrogen evolution, we successfully prepared stress-free, shiny, fine-grained amorphous, and nanocrystalline Co-rich cobalt phosphorus films. These nano-heterostructured films exhibit a unique non-collinear anisotropy-driven transverse exchange-spring behavior, investigated systematically under ambient conditions. The comprehensive functional analyses reveal that intricate interplay between in-plane (IP) anisotropy of amorphous phase and out-of-plane (OOP) anisotropy generating from a nanocrystalline structure compete with each other, while producing characteristic stripe domain structures to novel corrugated stripe domain shapes. The angle-dependent first-order reversal curve distributions demonstrate new insights into the magnetic reversal mechanisms, further confirming the non-exchange-spring and exchange-spring nature of the films depending on the prevalent interfacial exchange coupling. Formation of anisotropy-driven metastable-state due to competition between IP and OOP anisotropy at a particular OOP orientation has led the normal exchange-spring structures to a transverse exchange-spring structure. Micromagnetic simulations, in excellent agreement with experimental data, further elucidate the formation of characteristic stripe domain patterns and the influence of anisotropy on the magnetic properties. The innovative methodology and detailed functional analysis presented here offer significant understanding to the field of exchange-spring magnetic materials, including anisotropy-driven metastable states, demonstrating the potential for scalable and cost-effective fabrication of advanced nano-heterostructures with tailored magnetic properties.

Economic growth and national security: Patterns of European countries’ resistance to global turbulences

Macroeconomic stability and national security are core measurement indicators of country performance. Historical, economic, social and other prerequisites contribute to the formation of country-specific patterns of these performance indicators resistance to global turbulences such as COVID-19 pandemic. Pandemic proved that considering of public health issues in promoting economic prosperity, social welfare and environmental security is crucially important. The aim of the research is to identify country-specific (for 34 European countries) patterns of socio-economic (internal) and public health (external) drivers and inhibitors of ensuring economic growth, macroeconomic stability and national security resistance to global turbulences similar to COVID-19 pandemic. Realization of the research objectives involves the implementation of the following stages: 1) identification of the general and country-specific the most influential internal impetus indicators fostering volatility socio-economic development and national security based on multivariate analysis; 2) formation of general and country-specific matrix of influential determinants of ensuring macroeconomic stability and national security resistance to global turbulences similar to COVID-19 pandemic; 3) formalization general and country-specific external drivers and inhibitors of macroeconomic stability and national security volatility within public health determinants. The study is carried out on a sample of 34 European countries for 2000-2022.

Processes and mechanisms of the evolution of container port system in the Yangtze River Delta: An analysis from spatial and network perspectives

the Yangtze River Delta (YRD) has established a large-scale container port system with seaports and Yangtze ports as the mainstay and including other riverports and dry ports, occupying a prominent position in the pattern of national and even the global shipping development. Considering the new trend that the theoretical paradigm of port research has shifted from “spatial” to “network”, and that the focus of research goes from seaports to both seaports and inland ports, this study brings the complexity and uniqueness of the development of the port system in the YRD into the picture. By analyzing the influence of globalization, specialization, marketization, transportation, and greenization on port system development and its pattern formation, this paper elaborates on the gradient process of transportation and services allocation from the coast to the riverside and then to the inland. The evolution of port system is considered to have a temporal gradient between spatial-level transportation expansion and network-level services upgrading, and it is also believed that there is a spatial gradient in logistics supply chain terminalization between coastal and inland areas. Combined with the quantitative analysis from 200 5 to 2020, after entering the stage of port regionalization in the YRD, the container volume is distributed from coastal concentration to inland decentralization at the spatial level, while at the network level, port and shipping service enterprises (PSSEs) maintain a relatively centralized distribution along the coastal areas. At the same time, container volume growth rate fluctuates down, number of PSSEs growth rate fluctuates up, which trend is notable in the seaport. Currently, port regionalization in the YRD is still incomplete; the degree of logistics supply chain terminalization of ports in inland areas is relatively low; and the synergy between spatial and network in the entire YRD region has not yet been formed. This study tries to answer the question of the relationship between different types of ports in the complex port system, which can enrich the theoretical and empirical results of port system research and guide the practice of port and shipping in the YRD.

Understanding the spatial pattern and structural characteristics of cities in late feudal China: evidence from the local chronicle maps of the qing dynasty (1644–1911)

ABSTRACT Our study analyzes the spatial pattern and structural characteristics of cities in late feudal China based on multiple correlation and geographic information system spatial analysis, using 58 local Chinese chronicle maps of Jiangsu in the Qing Dynasty as research material. The elements in the city map were dominated by the types of official buildings, transportation facilities, and religious buildings. The urban spatial pattern can be classified into four types, such as extraverted and introverted, with each type having an aggregated spatial distribution and a gradual introverted orientation in time. The urban spatial structure can also be divided into four types: traditional, axial, random, and composite. Spatial distribution of each type is relatively stable, with little change over time. The geographic environment and the traditional concept of city building are the basic reasons for the formation of the spatial pattern and structure. The flood disaster, commercial and military factors contribute to the diverse structures. Our study demonstrates the feasibility of quantifying the ancient Chinese chronicles’ city maps. The findings have important value for contemporary ancient city restoration and shaping urban characteristics.

KAJIAN KONSEPTUAL SILABEL RITME GANDANG MINANGKABAU

This article tryes to initiate the concept of Minangkabau rhythm syllables, which is a method in music learning related to audiation in rhythm learning, the urgency in this study explores the basic elements of the audiation system that can be applied to music learning related to rhythm syllables based on local approaches, taking into account previous concepts that have been popular in recent schools. In West Sumatra, the concepts of syllable rhythm such as Zoltan Kodaly, Kannokol, American Style Syllables, and Edwin Gordon are not so popular, but environments such as schools and art studios have their own ways of approaching learning music related to pronouncing sounds, so that in this study it is addressed as an interesting and crucial thing to study and formulate further into formulations. The method used in this research uses a qualitative paradigm with a literature review approach. Where the concept of previous rhythmic syllables is used as a reference in analyzing, bringing up findings, and juxtaposing the findings with the initiated Minangkabau rhythmic syllable formula, so that the Minangkabau rhythmic syllables can be generalized and adapted, but still referring to the habits of the local community material. Based on the results of the analysis, like Gordon’s concept, it is found that syllables or audiation appear after the formation of rhythms, patterns and sound colors from an instrument, which can then strengthen the form of audiation into verbal form.

Pattern Formation and Bistability in a Synthetic Intercellular Genetic Toggle.

Differentiation within multicellular organisms is a complex process that helps to establish spatial patterning and tissue formation within the body. Often, the differentiation of cells is governed by morphogens and intercellular signaling molecules that guide the fate of each cell, frequently using toggle-like regulatory components. Synthetic biologists have long sought to recapitulate patterned differentiation with engineered cellular communities, and various methods for differentiating bacteria have been invented. Here, we couple a synthetic corepressive toggle switch with intercellular signaling pathways to create a "quorum-sensing toggle". We show that this circuit not only exhibits population-wide bistability in a well-mixed liquid environment but also generates patterns of differentiation in colonies grown on agar containing an externally supplied morphogen. If coupled to other metabolic processes, circuits such as the one described here would allow for the engineering of spatially patterned, differentiated bacteria for use in biomaterials and bioelectronics.

RESPIRATORY BURST OXIDASE HOMOLOG 5.1 regulates H3K4me3 deposition and transcription after cold priming in cucumber.

Plants can maintain acquired cold tolerance for a long period after cold priming, even after the resumption of warmer temperatures. However, the transcriptional mechanisms active during the recovery period after cold priming remain unknown. Here, we found that in cucumber (Cucumis sativus), cold priming altered the Histone H3 lysine 4 trimethylation (H3K4me3) signal of sustainably-induced (memory) and non-sustainably-induced (NSI) genes during recovery. In addition, H3K4me3 marks on upregulated memory genes exhibited a specific epigenetic memory during recovery. However, the rank of the H3K4me3 signal on memory and NSI genes in the genome was independent of cold priming, which always contributed to and inhibited the formation of transcription patterns of memory and NIS genes, respectively. Furthermore, the short-lived increase of RESPIRATORY BURST OXIDASE HOMOLOG 5.1 (CsRBOH5.1) expression during recovery after cold priming was essential to maintain high levels of NADPH oxidase activity and apoplastic H2O2, causing cucumber to acquire cold priming and enhancing the maintenance of acquired cold tolerance (MACT). Interestingly, the expression of some key H3K4me3 methyltransferase genes and the accumulation of H3K4me3 on memory genes depended on CsRBOH5.1. Surprisingly, CsRBOH5.1 was essential for almost all genes to form the normal H3K4me3 signaling patterns during recovery, and the necessity was more obvious as recovery progressed. Moreover, transcriptional memory was completely lost in Csrboh5.1 mutants, and the transcriptional patterns of about 80% of NSI genes were disrupted. Overall, our results show that CsRBOH5.1 governs H3K4me3 deposition and cold-induced transcription during recovery after cold priming, affecting the acquisition of cold priming and the intensity of MACT.

The role of supporting afferentation in the formation of muscle synergies patterns in locomotion

The role of supporting afferentation in the formation of muscle synergies patterns in locomotion

Gamma-protocadherins regulate dendrite self-recognition and dynamics to drive self-avoidance

Neurons form cell-type-specific morphologies that are shaped by cell-surface molecules and their cellular events governing dendrite growth. One growth rule is dendrite self-avoidance, whereby dendrites distribute uniformly within a neuron's territory by avoiding sibling branches. In mammalian neurons, dendrite self-avoidance is regulated by a large family of cell-recognition molecules called the clustered protocadherins (cPcdhs). Genetic and molecular studies suggest that the cPcdhs mediate homophilic recognition and repulsion between self-dendrites. However, this model has not been tested through direct investigation of self-avoidance during development. Here, we performed live imaging and four-dimensional (4D) quantifications of dendrite morphogenesis to define the dynamics and cPcdh-dependent mechanisms of self-avoidance. We focused on the mouse retinal starburst amacrine cell (SAC), which requires the gamma-Pcdhs (Pcdhgs) and self/non-self-recognition to establish a stereotypic radial morphology while permitting dendritic interactions with neighboring SACs. Through morphogenesis, SACs extend dendritic protrusions that iteratively fill the growing arbor and contact and retract from nearby self-dendrites. Compared to non-self-contacting protrusions, self-contacting events have longer lifetimes, and a subset persists as loops. In the absence of the Pcdhgs, non-self-contacting dynamics are unaffected but self-contacting retractions are significantly diminished. Self-contacting bridges accumulate, leading to the bundling of dendritic processes and disruption to the arbor shape. By tracking dendrite self-avoidance in real time, our findings establish that the γ-Pcdhs mediate self-recognition and retraction between contacting sibling dendrites. Our results also illustrate how self-avoidance shapes stochastic and space-filling dendritic outgrowth for robust pattern formation in mammalian neurons.