scholarly journals The multicellular incoherent feedforward loop motif generates spatial patterns

2019 ◽  
Author(s):  
Marcos Rodríguez Regueira ◽  
Jesús Daza García ◽  
Alfonso Rodríguez-Patón Aradas
Keyword(s):  
Spatial Patterns ◽  
Pattern Generation ◽  
Genetic Circuit ◽  
Distributed Robotics ◽  
Stripe Pattern ◽  
Feedforward Loop ◽  
Spatial Computing ◽  
Individual Based Models ◽  
Spatially Distributed ◽  
Multi Agent

The multicellular incoherent feedforward loop (mIFFL) is an extension of the traditional intracellular IFFL gene motif where the interacting nodes no longer need to be genes inside the same cell but can be spatially distributed in different cells. We studied for the first time the spatial computing abilities of these mIFFL through in silico simulations done with individual-based models (run in Morpheus and GRO software). We observed that: 1) a genetic circuit working as a mIFFL can behaves as an edge detector of the border of an infection, and 2) a mIFFL can be the inner mechanism generating the complex 7 stripe pattern of eve in D. melanogaster embryogenesis. So, in this work, we show that multicellular IFFL architectures can produce spatial patterns and are a promising spatial computing motif that deserves to be incorporated into the toolbox of pattern generation and multicellular coordination mechanisms. This study opens several future lines of research: multi-agent IFFL applied in ecology as a tool to predict spatial position of interacting animals or in distributed robotics.

scholarly journals Estimating spatially distributed soil water content at small watershed scales based on decomposition of temporal anomaly and time stability analysis

2016 ◽  
Vol 20 (1) ◽  
pp. 571-587 ◽  
Author(s):  
W. Hu ◽  
B. C. Si
Keyword(s):  
Stability Analysis ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Spatial Patterns ◽  
Watershed Scale ◽  
Small Watershed ◽  
Time Stability ◽  
Spatially Distributed ◽  
Space Variant

Abstract. Soil water content (SWC) is crucial to rainfall-runoff response at the watershed scale. A model was used to decompose the spatiotemporal SWC into a time-stable pattern (i.e., temporal mean), a space-invariant temporal anomaly, and a space-variant temporal anomaly. The space-variant temporal anomaly was further decomposed using the empirical orthogonal function (EOF) for estimating spatially distributed SWC. This model was compared to a previous model that decomposes the spatiotemporal SWC into a spatial mean and a spatial anomaly, with the latter being further decomposed using the EOF. These two models are termed the temporal anomaly (TA) model and spatial anomaly (SA) model, respectively. We aimed to test the hypothesis that underlying (i.e., time-invariant) spatial patterns exist in the space-variant temporal anomaly at the small watershed scale, and to examine the advantages of the TA model over the SA model in terms of the estimation of spatially distributed SWC. For this purpose, a data set of near surface (0–0.2 m) and root zone (0–1.0 m) SWC, at a small watershed scale in the Canadian Prairies, was analyzed. Results showed that underlying spatial patterns exist in the space-variant temporal anomaly because of the permanent controls of static factors such as depth to the CaCO3 layer and organic carbon content. Combined with time stability analysis, the TA model improved the estimation of spatially distributed SWC over the SA model, especially for dry conditions. Further application of these two models demonstrated that the TA model outperformed the SA model at a hillslope in the Chinese Loess Plateau, but the performance of these two models in the GENCAI network (∼  250 km2) in Italy was equivalent. The TA model can be used to construct a high-resolution distribution of SWC at small watershed scales from coarse-resolution remotely sensed SWC products.

A Multi-Agent Solution to Distributed Fault Diagnosis of Preheater Cement Cyclone

2016 ◽  
Vol 15 (04) ◽  
pp. 209-221 ◽  
Author(s):  
O. Chouhal ◽  
H. L. Mouss ◽  
K. Benaggoune ◽  
R. Mahdaoui
Keyword(s):  
Fault Diagnosis ◽  
Health Management ◽  
Engineering Systems ◽  
Distributed Approach ◽  
Development Framework ◽  
Diagnostic Agents ◽  
Spatially Distributed ◽  
Multi Agent ◽  
Systematic Solution ◽  
Diagnostic Agent

Systems health monitoring is essential to guaranteeing the safe, efficient, and reliable operation of engineering systems. Integrated systems health management methodologies include fault diagnosis mechanism. Diagnosis involves detecting when a fault has occurred, isolating the true fault, and identifying the true damage to the system. This important issue is even harder when the systems to be diagnosed are dynamic and spatially distributed systems with their successively increasing complexity. For such systems, a single diagnostic entity having a model of the whole system approach is inappropriate. Whereas a distributed approach of multiple diagnostic agents can offer a solution. An overall systematic solution for these issues could be obtained by an artificial intelligent mechanism called the multi-agent system (MAS). This paper presents a MAS model for fault diagnosis based on logical theory of diagnosis. In this approach, each local diagnostic agent has knowledge above its subsystem and an abstract view of the neighboring subsystems and it is able to determine the local minimal diagnoses that are consistent with global diagnoses. The multi-agent models are simulated in Java Agent Development Framework and are applied to the preheated cement cyclone in the workshop of SCIMAT clinker.

scholarly journals Optimal spatial patterns in feeding, fishing, and pollution

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Hannes Uecker
Keyword(s):  
Spatial Patterns ◽  
Time Horizon ◽  
Optimal Control Problems ◽  
Steady States ◽  
Control Problems ◽  
Optimal Controls ◽  
Infinite Time ◽  
Distributed Optimal Control ◽  
Distributed Optimal Control Problems ◽  
Spatially Distributed

<p style='text-indent:20px;'>Infinite time horizon spatially distributed optimal control problems may show so–called optimal diffusion induced instabilities, which may lead to patterned optimal steady states, although the problem itself is completely homogeneous. Here we show that this can be considered as a generic phenomenon, in problems with scalar distributed states, by computing optimal spatial patterns and their canonical paths in three examples: optimal feeding, optimal fishing, and optimal pollution. The (numerical) analysis uses the continuation and bifurcation package <inline-formula><tex-math id="M1">\begin{document}$\mathtt{pde2path} $\end{document}</tex-math></inline-formula> to first compute bifurcation diagrams of canonical steady states, and then time–dependent optimal controls to control the systems from some initial states to a target steady state as <inline-formula><tex-math id="M2">\begin{document}$ t\to\infty $\end{document}</tex-math></inline-formula>. We consider two setups: The case of discrete patches in space, which allows to gain intuition and to compute domains of attraction of canonical steady states, and the spatially continuous (PDE) case.</p>

Biological Circuit Components

2014 ◽  
Author(s):  
Richard M. Murray
Keyword(s):  
Synthetic Biology ◽  
Bacterial Chemotaxis ◽  
Dynamical Model ◽  
Genetic Circuit ◽  
Toggle Switch ◽  
Simple Circuit ◽  
Natural Systems ◽  
E Coli ◽  
Feedforward Loop ◽  
Circuit Components

This chapter describes some simple circuit components that have been constructed in E. coli cells using the technology of synthetic biology and then considers a more complicated circuit that already appears in natural systems to implement adaptation. It first analyzes the negatively autoregulated gene fabricated in E. coli bacteria, before turning to the toggle switch, which is composed of two genes that mutually repress each other. The chapter next illustrates a dynamical model of a “repressilator”—an oscillatory genetic circuit consisting of three repressors arranged in a ring fashion. The activator–repressor clock is then considered, alongside an incoherent feedforward loop (IFFL). Finally, the chapter examines bacterial chemotaxis, which E. coli use to move in the direction of increasing nutrients.

scholarly journals Modelling the transfer of supraglacial meltwater to the bed of Leverett Glacier, southwest Greenland

2014 ◽  
Vol 8 (4) ◽  
pp. 4243-4280 ◽  
Author(s):  
C. C. Clason ◽  
D. W. F. Mair ◽  
P. W. Nienow ◽  
I. D. Bartholomew ◽  
A. Sole ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Greenland Ice Sheet ◽  
Temporal And Spatial Patterns ◽  
Distributed Modelling ◽  
Supraglacial Lakes ◽  
Ice Surface ◽  
Air Temperatures ◽  
Spatially Distributed ◽  
Temporal And Spatial ◽  
Efficient Transfer

Abstract. Meltwater delivered to the bed of the Greenland Ice Sheet is a driver of variable ice-motion through changes in effective pressure and enhanced basal lubrication. Ice surface velocities have been shown to respond rapidly both to meltwater production at the surface and to drainage of supraglacial lakes, suggesting efficient transfer of meltwater from the supraglacial to subglacial hydrological systems. Although considerable effort is currently being directed towards improved modelling of the controlling surface and basal processes, modelling the temporal and spatial evolution of the transfer of melt to the bed has received less attention. Here we present the results of spatially-distributed modelling for prediction of moulins and lake drainages on the Leverett Glacier in south-west Greenland. The model is run for the 2009 and 2010 ablation seasons, and for future increased melt scenarios. The temporal and spatial patterns of modelled lake drainages are qualitatively comparable with those seen from analyses of satellite imagery. The modelled timings and locations of delivery of meltwater to the bed match well with observed temporal and spatial patterns of ice surface speed ups. This is particularly true for the lower catchment (< 1000 m a.s.l.) where both the model and observations indicate that the development of moulins is the main mechanism for the transfer of surface meltwater to the bed. At higher elevations (e.g. 1250–1500 m a.s.l.) the development and drainage of supraglacial lakes becomes increasingly important. At these higher elevations, the delay between modelled melt generation and subsequent delivery of melt to the bed matches the observed delay between the peak air temperatures and subsequent velocity speed ups. Although both moulins and lake drainages are predicted to increase in number for future warmer climate scenarios, the lake drainages play an increasingly important role in both expanding the area over which melt accesses the bed and in enabling a greater proportion of surface melt to reach the bed.

scholarly journals Topological conditions for propagation of spatially-distributed neural activity

2021 ◽  
Author(s):  
Àlex Tudoras ◽  
Alex D Reyes
Keyword(s):  
Nervous System ◽  
Spatial Patterns ◽  
Neural Activity ◽  
Large Population ◽  
Simplicial Complexes ◽  
Brain Regions ◽  
Important Task ◽  
Active Population ◽  
Spatially Distributed ◽  
Target Layer

An important task of the nervous system is to transmit information faithfully and reliably across brain regions, a process that involves the coordinated activity of a relatively large population of neurons. In topographically organized networks, where the entering and exiting axons of neurons terminate in confined areas, successful propagation depends on the spatial patterns of activity: the firing neurons in a presynaptic or source layer must be located sufficiently close to each other to ensure that cells in the postsynaptic or target layer receive the requisite number of convergent inputs to fire. Here, we use principles of topology to define the conditions for transmitting information across layers. We show that simplicial complexes formed by source neurons can be used to: 1) determine whether target neurons receive suprathreshold inputs; 2) identify neurons within the active population that contribute to firing; and 3) discriminate between single and multiple active clusters of neurons.

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