On the role of the plasmodial cytoskeleton in facilitating intelligent behavior in slime mold Physarum polycephalum

Router design for nano-communication using actin quantum cellular automata

Logic expressions can be designed from actin filaments. It is a protein that makes the cellular structure and plays an important role in intracellular communication. Nano communication technique has been established using actin cellular automata. Among several rules, (1, 30) and (4, 27) rules have been used to design 2 to 1 multiplexer, 4 to 1 multiplexer, 1 to 2 demultiplexer and 1 to 4 demultiplexer. Router or data selector has been made of using multiplexer and demultiplexer. Three novel circuits such as multiplexer, demultiplexer and nano-router have been designed using the projected mechanism. The primary focus of this proposed technique is on different designs of the multiplexer, demultiplexer and minimum cell count with minimum time steps. The different router circuits have been simulated with the help of Simulink by which output has been verified for different circuits. Stuck at fault analysis is also done in this study. Device density and power consumption have also been included in this study. A comparative analysis of the different designs of the router provides a better concept of circuit optimisation. Furthermore, this study analyses convenient forthcoming applications in nano-technology and nano-bio-molecular systems involving the proposed parameters.

Neuromorphic Liquid Marbles with Aqueous Carbon Nanotube Cores

Neuromorphic computing devices attempt to emulate features of biological nervous systems through mimicking the properties of synapses toward implementing the emergent properties of their counterparts, such as learning. Inspired by recent advances in the utilization of liquid marbles (LMs, microliter quantities of fluid coated in hydrophobic powder) for the creation of unconventional computing devices, we describe the development of LMs with neuromorphic properties through the use of copper coatings and 1.0 mg mL-1 carbon nanotube (CNT)-containing fluid cores. Experimentation was performed through sandwiching the LMs between two cup-style electrodes and stimulating them with repeated dc pulses at 3.0 V. Our results demonstrate that "entrainment" of CNT-filled copper LMs via periodic pulses can cause their electrical resistance to rapidly switch between high to low resistance profiles upon inverting the polarity of stimulation: the reduction in resistance between high and low profiles was approximately 88% after two rounds of entrainment. This effect was found to be reversible through reversion to the original stimulus polarity and was strengthened by repeated experimentation, as evidenced by a mean reduction in time to switching onset of 43%. These effects were not replicated in nanotube solutions not bound inside LMs. Our electrical characterization also reveals that nanotube-filled LMs exhibit pinched loop hysteresis IV profiles consistent with the description of memristors. We conclude by discussing the applications of this technology to the development of unconventional computing devices and the study of emergent characteristics in biological neural tissue.

Design of binary subtractor using actin quantum cellular automata

Actin is a biological protein that provides support to the cellular structure and plays a crucial role in cytoskeletal and intra‐cellular signalling events. Logic circuits can be designed with actin filaments with the help of actin quantum automata. The authors use a rule (4,27) to implement some novel designs of logic subtractor circuits on this automata to achieve the difference in two binary bits. Logic design of both half and full binary subtractors is proposed in this study. Actin‐based quantum cellular automata can be used in different combinations of input to get optimised results from the circuits. The authors focus on consolidating the designs inside single automata block to generate output in a less number of timesteps and less overheads. The designs are simulated with Simulink and this way output is verified for these different design approaches. Reliability and fault‐tolerance check is another interesting part of this study. To get a better idea of the optimisation achieved, the authors have also presented a comparative study between the proposed designs in terms of circuit size and efficiency. With all these parameters involved, this study explores opportunities for future implementation of unconventional computing in nano‐scale and cost‐effective bio‐molecular networks.

East-West paths to unconventional computing

Unconventional computing is about breaking boundaries in thinking, acting and computing. Typical topics of this non-typical field include, but are not limited to physics of computation, non-classical logics, new complexity measures, novel hardware, mechanical, chemical and quantum computing. Unconventional computing encourages a new style of thinking while practical applications are obtained from uncovering and exploiting principles and mechanisms of information processing in and functional properties of, physical, chemical and living systems; in particular, efficient algorithms are developed, (almost) optimal architectures are designed and working prototypes of future computing devices are manufactured. This article includes idiosyncratic accounts of 'unconventional computing' scientists reflecting on their personal experiences, what attracted them to the field, their inspirations and discoveries.

Particle sorting by Paramecium cilia arrays

Motile cilia are cell-surface organelles whose purposes, in ciliated protists and certain ciliated metazoan epithelia, include generating fluid flow, sensing and substance uptake. Certain properties of cilia arrays, such as beating synchronisation and manipulation of external proximate particulate matter, are considered emergent, but remain incompletely characterised despite these phenomena having being the subject of extensive modelling. This study constitutes a laboratory experimental characterisation of one of the emergent properties of motile cilia: manipulation of adjacent particulates. The work demonstrates through automated videomicrographic particle tracking that interactions between microparticles and somatic cilia arrays of the ciliated model organism Paramecium caudatum constitute a form of rudimentary 'sorting'. Small particles are drawn into the organism's proximity by cilia-induced fluid currents at all times, whereas larger particles may be held immobile at a distance from the cell margin when the cell generates characteristic feeding currents in the surrounding media. These findings can contribute to the design and fabrication of biomimetic cilia, with potential applications to the study of ciliopathies.

On the Computing Potential of Intracellular Vesicles

Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca²⁺-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal ‘circuitry’ and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a ‘vesicle modification’ of the archetypal CBC ‘billiard ball model’ of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle ‘programming’ in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.