Analysis of Phonetic Soliton Propagation in Neutral Weyl Fermion-sea

We propose application of Machine Learning (ML) and Neural Network (NN) technique for the analysis of ultrasonic Time Reversal based Nonlinear Elastic Wave Spectroscopy (TR-NEWS). In order to acquire topological features, we adopt the $(2+1)D$ lattice simulation with fixed point (FP) actions. We consider 7 A type loops which sit on $2D$ spacial plane spanned by $e_1, e_2$ and 13 B type loops which contain links parallel to $e_1\wedge e_2$ and to -$e_1\wedge e_2$. We consider propagation of bosonic phonons in Fermi-sea of neutral Weyl spinors which are described by Clifford algebra. Configurations in momentum space is transformed to real position space via Clifford Fourier Transform. We consider A-type without hysteresis effects and B-type with hysteresis effects, and via ML or NN technique search optimal weight of 7 A-type FP actions and 13 B-type FP actions using the Monte-Carlo method.Comment: 5 pages, 4 figure

Clifford Fourier Transforms in (2+1)D Lattice Simulations of Soliton Propagations

Monte Carlo simulation of solitonic phonon propagation on a 2D plane in Weyl fermion-sea is analyzed. We assume materials are filled with Weyl spinors located on $256\times 256$ 2D lattice points, which are expressed by quaternions ${\bf H}$. The topology of solitonic phonon propagation is defined by modifying fixed point actions of 4D Quantum Chromo Dynamics action to (2+1)D action, replacing Dirac fermions by Weyl fermions, and changing the electric charge current flow to the energy flow. We consider $A$ type loops whose path are on a 2D plane, and $B$ type loops which contain two parallel links that connect two 2D plane on different time slices. The length of loops are restricted to be less than or equal to 8 lattice units. At the moment spatial lattice unit and time lattice unit are same. They can be chosen arbitrarily when one compares hysteresis effects with experimental data. Using the quaternion expression of Porteous, we calculate the plaquette part of loop actions and the link part of loop actions. Link actions of $A$ type loops cancel with each other, but those of $B$ type loops depends on whether the spin rotation is clockwise or that is counterclockwise. In the present work we consider average of clockwise rotating and counterclockwise rotating loop contributions.Comment: 9 pages, 7 figures, The 39th International Symposium on Lattice Field Theory, 8th-13th August, 2022, Rheinische Friedrich-Wilhelms-Universit\"at Bonn, Bonn, German

Application of Quaternion Neural Network to Time Reversal Based Nonlinear Elastic Wave Spectroscopy

Identification of crack positions or anomalies in materials using the time reversal based nonlinear elastic wave spectroscopy (TR-NEWS) is an established method. We propose a system using transducers which emit forward propagating solitonic wave and time-reversed propagating solitonic wave produced by memristers placed on a side of a rectangle and scattered by cracks in the material and received by receivers which are placed on the opposite side of the rectangle. By minimizing the difference of the scattered forward propagating wave and the scattered TR wave, we get information of the position of the crack by using the neural network technique. Route of the solitons are expressed by 2 dimensional projective quaternion functions, and parameters for getting the optimal route from signals are expected to be reduced. We consider the wave is expressed by a soliton which is conformal, and discuss symmetry protected topological impurities and gravitational effects using the Atiyah-Patodi-Singer's index theorem.Comment: 15 pages, 19 figure

FRET: a tool to study the interaction between apatite and collagen ?

Fluorescence Resonance Energy Transfer, FRET, is largely used in biology to demonstrate the occurrence of molecular interactions. In order to investigate the vicinity between collagen and calcium phosphate in bone substitute biomaterial, composites constituted of autofluorescent collagen and apatite doped by europium were synthesized by a precipitation method. The first results show a fluorescence energy transfer between the two fluorescent components and are very promising

Modeling Acoustically Driven Microbubbles by Macroscopic Discrete-Mechanical Analogues

[EN] The dynamics of continuous systems that exhibit circular or spherical symmetry like drops, bubbles or some macromolecules, under the influence of some external excitation, develop surface patters that are hard to predict in most practical situations. In the particular case of acoustically driven microbubbles (ultrasound contrast agent), the study of the behavior of the bubble shell requires complex modeling even for describe the most simple oscillation patterns. Furthermore, due to the smallness of the spatio-temporal scale of the problem, an experimental approach requires expensive hardware setup. Despite the complexity of the particular physical problem, the basic dynamical features of some continuous physical systems can be captured by simple models of coupled oscillators. In this work we consider an analogy between a shelled-gas bubble cavitating under the action of an acoustic field and a discrete mechanical system. Thus, we present a theoretical and experimental study of the spatial instabilities of a circular ring of coupled pendulums parametrically driven by a vertical harmonic force. The system is capable of wave propagation and exhibit nonlinearities and dispersion, so manifest rich dynamics: normal oscillation modes (breathing, dipole, quadrupole...) and localized patterns of different types (breathers and kinks) witch are predicted by finite-differences numerical solutions and observed experimentally. On the basis of this analogy, the oscillation patterns and localized modes observed experimentally in acoustically driven bubbles are interpreted and discussed.[ES] La dinámica de sistemas continuos que muestran simetría circular o esférica como gotas, burbujas, o algunas macromoléculas, bajo la influencia de una excitación externa desarrollan patrones de superficie que en muchas situaciones prácticas son difíciles de predecir. En el caso particular de una microburbuja bajo la acción de un campo acústico (agente de contraste ultrasónico), el estudio de la dinámica de la burbuja requiere un complejo modelado incluso para describir los modos de oscilación más simples. Además, debido a la pequeña escala espacio-temporal del problema, el estudio experimental requiere un hardware extremadamente sofisticado y costoso. Por otro lado, la dinámica de muchos sistemas complejos continuos puede ser modelada por medio de agrupaciones de osciladores acoplados. Así, en este trabajo se considera una analogía entre la microburbuja cavitando bajo la acción del campo acústico y un sistema de discreto de osciladores mecánicos excitados paramétricamente. De esta manera, se presenta un estudio teórico y experimental de las inestabilidades de un anillo de péndulos acoplados paramétricamente excitados por una fuerza armónica vertical. Así, el sistema presenta propagación de ondas, exhibiendo no linealidad y dispersión, por lo que una rica dinámica se observa: modos propios, como el modo radial o “breathing mode”, dipolar, cuadripolar, etc. y estructuras localizadas como breathers o modos intrínsecos localizados, kinks, etc. Todos ellos han sido observados experimentalmente y numéricamente obtenidos mediante diferencias finitas. A la vista de los resultados, el presente experimento es un excelente banco de pruebas para el estudio de sistemas no lineales en un curso de grado o máster. La presencia de forzamiento paramétrico y pérdidas, así como la interacción entre linealidad y dispersión provoca que el sistema presente la rica dinámica el amplio abanico de fenómenos estudiados de una manera muy visual e intuitiva para el estudiante.The authors acknowledge financial support from the Spanish Ministry of Science and Innovation and European Union FEDER through project FIS2011-29731-C02-02.Sánchez-Morcillo, V.; Jiménez, N.; González, N.; Dos Santos, S.; Bouakaz, A.; Chaline, J. (2013). Modeling Acoustically Driven Microbubbles by Macroscopic Discrete-Mechanical Analogues. Modelling in Science Education and Learning. 6(3):75-87. doi:10.4995/msel.2013.1985SWORD75876

Six1 homeoprotein drives myofiber type IIA specialization in soleus muscle

International audienceAbstractBackgroundAdult skeletal muscles are composed of slow and fast myofiber subtypes which each express selective genes required for their specific contractile and metabolic activity. Six homeoproteins are transcription factors regulating muscle cell fate through activation of myogenic regulatory factors and driving fast-type gene expression during embryogenesis.ResultsWe show here that Six1 protein accumulates more robustly in the nuclei of adult fast-type muscles than in adult slow-type muscles, this specific enrichment takes place during perinatal growth. Deletion of Six1 in soleus impaired fast-type myofiber specialization during perinatal development, resulting in a slow phenotype and a complete lack of Myosin heavy chain 2A (MyHCIIA) expression. Global transcriptomic analysis of wild-type and Six1 mutant myofibers identified the gene networks controlled by Six1 in adult soleus muscle. This analysis showed that Six1 is required for the expression of numerous genes encoding fast-type sarcomeric proteins, glycolytic enzymes and controlling intracellular calcium homeostasis. Parvalbumin, a key player of calcium buffering, in particular, is a direct target of Six1 in the adult myofiber.ConclusionsThis analysis revealed that Six1 controls distinct aspects of adult muscle physiology in vivo, and acts as a main determinant of fast-fiber type acquisition and maintenance

Septins restrict inflammation and protect zebrafish larvae from Shigella infection

Shigella flexneri, a Gram-negative enteroinvasive pathogen, causes inflammatory destruction of the human intestinal epithelium. Infection by S. flexneri has been well-studied in vitro and is a paradigm for bacterial interactions with the host immune system. Recent work has revealed that components of the cytoskeleton have important functions in innate immunity and inflammation control. Septins, highly conserved cytoskeletal proteins, have emerged as key players in innate immunity to bacterial infection, yet septin function in vivo is poorly understood. Here, we use S. flexneri infection of zebrafish (Danio rerio) larvae to study in vivo the role of septins in inflammation and infection control. We found that depletion of Sept15 or Sept7b, zebrafish orthologs of human SEPT7, significantly increased host susceptibility to bacterial infection. Live-cell imaging of Sept15-depleted larvae revealed increasing bacterial burdens and a failure of neutrophils to control infection. Strikingly, Sept15-depleted larvae present significantly increased activity of Caspase-1 and more cell death upon S. flexneri infection. Dampening of the inflammatory response with anakinra, an antagonist of interleukin-1 receptor (IL-1R), counteracts Sept15 deficiency in vivo by protecting zebrafish from hyper-inflammation and S. flexneri infection. These findings highlight a new role for septins in host defence against bacterial infection, and suggest that septin dysfunction may be an underlying factor in cases of hyper-inflammation