scholarly journals Signal transmission through seawater for MHz frequencies and medium distances (0–30 m) using ionic current waves

2019 ◽  
Vol 36 (3) ◽  
pp. 53-61
Author(s):  
Emeritus J Lucas
Keyword(s):  
Signal Transmission ◽  
Full Range ◽  
Ionic Current ◽  
Electrical Energy ◽  
Ionic Currents ◽  
Signal Propagation ◽  
Signal Loss ◽  
Deep Seawater ◽  
Sonar Systems ◽  
Submarine Communications

Electromagnetic (EM) signals can only be transmitted through seawater for short distances (<1 m) for frequencies (>1 MHz). Therefore a new technique, the ionic current wave (ICW), has been developed for signal propagation at MHz frequency. This technique uses the conduction current produced in seawater as a result of thermal ionisation releasing H+ and OH– ions. A small voltage (<1.5 V pk) is applied between two metal electrodes submerged in the seawater to avoid ionisation by the input electrical energy.<br/> A detailed theoretical analysis of the ICW process has shown that ionic currents can be transmitted at MHz frequency over distances of 10 m with low signal loss per decade. For longer propagation distances of 100 m the theory predicts a signal loss of –20 dB per decade.<br/> Propagation experiments have been carried out in Liverpool dock seawater for distances of 2 m–28 m between parallel 0.5 m × 0.3 m electrodes placed vertically in the seawater at a depth of 2 m. Signal frequencies within the range of 1 MHz–8 MHz have been investigated. In each experiment the received propa gated signal power was approximately –67 dBm (well above the dock electrical noise of –140 dBm) and only showed a small power loss over the full range of propagation.<br/> The ICW system will be able to measure longer propagation distances in deep seawater conditions suitable for ship and submarine communications. Its performance is comparable to that of sonar systems.

Analysis of Characteristic of Microstrip Signal Loss in Course of Signal Transmission

2011 ◽  
Vol 194-196 ◽  
pp. 2229-2232
Author(s):  
Qing Song Xiong ◽  
Zhao Hua Wu ◽  
Pin Chen ◽  
Sheng Zhang
Keyword(s):  
Line Width ◽  
Transmission Lines ◽  
Coupling Effect ◽  
Signal Transmission ◽  
Characteristic Impedance ◽  
Signal Loss ◽  
Scattering Parameters ◽  
Scattering Parameter ◽  
Conductor Loss ◽  
Strip Lines

The effect of loss of transmission line on the transmission signal can’t be ignored in microwave circuits. Based on the theory of loss and microwave network principle, the effect of the width, parallel length and space of transmission lines on the scattering parameters’ insertion loss is analyzed in perspective of scattering parameters of the odd mode and even mode. The simulation results show that: when the other parameters are fixed, both the characteristic impedance and the conductor loss decrease non-linearly with the line width broadening; due to the coupling effect between micro-strip lines, the first trough frequency of the scattering parameter S21 curved line, that is the point the signal energy attenuate most seriously, decreases linearly with line width broadening and increases non- linearly with line spaces broadening.

Signal Propagation Along Unidimensional Neuronal Networks

2005 ◽  
Vol 94 (5) ◽  
pp. 3406-3416 ◽  
Author(s):  
Ofer Feinerman ◽  
Menahem Segal ◽  
Elisha Moses
Keyword(s):  
Large Scale ◽  
Signal Transmission ◽  
Signal Propagation ◽  
High Amplitude ◽  
Adhesive Material ◽  
One Dimensional ◽  
Calcium Indicator ◽  
Scale Population ◽  
Population Burst ◽  
Linear Signal

Dissociated neurons were cultured on lines of various lengths covered with adhesive material to obtain an experimental model system of linear signal transmission. The neuronal connectivity in the linear culture is characterized, and it is demonstrated that local spiking activity is relayed by synaptic transmission along the line of neurons to develop into a large-scale population burst. Formally, this can be treated as a one-dimensional information channel. Directional propagation of both spontaneous and stimulated bursts along the line, imaged with the calcium indicator Fluo-4, revealed the existence of two different propagation velocities. Initially, a small number of neighboring neurons fire, leading to a slow, small and presumably asynchronous wave of activity. The signal then spontaneously develops to encompass much larger and further populations, and is characterized by fast propagation of high-amplitude activity, which is presumed to be synchronous. These results are well described by an existing theoretical framework for propagation based on an integrate-and-fire model.

scholarly journals Anoctamin 5/TMEM16E facilitates muscle precursor cell fusion

2018 ◽  
Vol 150 (11) ◽  
pp. 1498-1509 ◽  
Author(s):  
Jarred M. Whitlock ◽  
Kuai Yu ◽  
Yuan Yuan Cui ◽  
H. Criss Hartzell
Keyword(s):  
Cell Fusion ◽  
Ionic Current ◽  
Ionic Currents ◽  
Muscle Physiology ◽  
Muscle Repair ◽  
Hek 293 ◽  
293 Cells ◽  
Phospholipid Scrambling ◽  
Muscle Precursor Cell

Limb-girdle muscular dystrophy type 2L (LGMD2L) is a myopathy arising from mutations in ANO5; however, information about the contribution of ANO5 to muscle physiology is lacking. To explain the role of ANO5 in LGMD2L, we previously hypothesized that ANO5-mediated phospholipid scrambling facilitates cell–cell fusion of mononucleated muscle progenitor cells (MPCs), which is required for muscle repair. Here, we show that heterologous overexpression of ANO5 confers Ca2+-dependent phospholipid scrambling to HEK-293 cells and that scrambling is associated with the simultaneous development of a nonselective ionic current. MPCs isolated from adult Ano5−/− mice exhibit defective cell fusion in culture and produce muscle fibers with significantly fewer nuclei compared with controls. This defective fusion is associated with a decrease of Ca2+-dependent phosphatidylserine exposure on the surface of Ano5−/− MPCs and a decrease in the amplitude of Ca2+-dependent outwardly rectifying ionic currents. Viral introduction of ANO5 in Ano5−/− MPCs restores MPC fusion competence, ANO5-dependent phospholipid scrambling, and Ca2+-dependent outwardly rectifying ionic currents. ANO5-rescued MPCs produce myotubes having numbers of nuclei similar to wild-type controls. These data suggest that ANO5-mediated phospholipid scrambling or ionic currents play an important role in muscle repair.

scholarly journals Differential Inhibitory Actions of Multitargeted Tyrosine Kinase Inhibitors on Different Ionic Current Types in Cardiomyocytes

2020 ◽  
Vol 21 (5) ◽  
pp. 1672 ◽  
Author(s):  
Wei-Ting Chang ◽  
Ping-Yen Liu ◽  
Kaisen Lee ◽  
Yin-Hsun Feng ◽  
Sheng-Nan Wu
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
Ionic Current ◽  
Small Animal ◽  
Ionic Currents ◽  
Neonatal Rat ◽  
Delayed Rectifier ◽  
Qtc Prolongation ◽  
The Impact

Lapatinib (LAP) and sorafenib (SOR) are multitargeted tyrosine kinase inhibitors (TKIs) with antineoplastic properties. In clinical observations, LAP and SOR may contribute to QTc prolongation, but the detailed mechanism for this has been largely unexplored. In this study, we investigated whether LAP and SOR affect the activities of membrane ion channels. Using a small animal model and primary cardiomyocytes, we studied the impact of LAP and SOR on Na+ and K+ currents. We found that LAP-induced QTc prolongation in mice was reversed by isoproterenol. LAP or SOR suppressed the amplitude of the slowly activating delayed-rectifier K+ current (IK(S)) in H9c2 cells in a time- and concentration-dependent fashion. The LAP-mediated inhibition of IK(S) was reversed by adding isoproterenol or meclofenamic acid, but not by adding diazoxide. The steady-state activation curve of IK(S) during exposure to LAP or SOR was shifted toward a less negative potential, with no change in the gating charge required to activate the current. LAP shortened the recovery from IK(S) deactivation. As rapid repetitive stimuli, the IK(S) amplitude decreased; however; the LAP-induced inhibition of IK(S) remained effective. LAP or SOR alone also suppressed inwardly rectifying K+ and voltage-gated Na+ current in neonatal rat ventricular myocytes. The inhibition of ionic currents during exposure to TKIs could be an important mechanism underlying changes in QTc intervals.

Analysis on Signal Transmission Methods for Rapid Searching in Active SONAR Systems

2018 ◽  
Vol 55 (8) ◽  
pp. 83-93
Author(s):  
Woo-Sung Son ◽  
Young Kwang Seo ◽  
Wan-Jin Kim ◽  
Hyoung-Nam Kim
Keyword(s):  
Signal Transmission ◽  
Active Sonar ◽  
Sonar Systems

Modeling and Simulation of the Propagation Characteristics by Underground Current Field

2013 ◽  
Vol 385-386 ◽  
pp. 1568-1571
Author(s):  
Yi Dong Xu
Keyword(s):  
Mathematical Model ◽  
Signal Transmission ◽  
Signal Propagation ◽  
Underground Mines ◽  
Constant Current ◽  
Propagation Characteristics ◽  
Current Field ◽  
Channel Characteristics ◽  
Underground Communication ◽  
The Mathematical Model

It's one of the effective channels for short-distance wireless communications through stratum in underground mines on emergency communications. The geologic structure is complex in mines, in practical environments. It means there is a considerable difference in conductance property and channel characteristics. In order to realize effective communication through stratum, its necessary to explore and study underground signal transmission by establishing mathematical model of underground signal propagation characteristics based on the theory of constant current field and simulating the mathematical model with MATLAB. We established a simulation model of underground communication channel physics experiments and obtained the amplitude frequency characteristic of the channel, with which we can get the error comparison between theory and test.

Harvesting Natural Salinity Gradient Energy for Hydrogen Production Through Reverse Electrodialysis Power Generation

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Mohammadreza Nazemi ◽  
Jiankai Zhang ◽  
Marta C. Hatzell
Keyword(s):  
Energy Efficiency ◽  
Power Density ◽  
External Load ◽  
Salinity Gradient ◽  
Electrical Power ◽  
Ionic Current ◽  
Electrical Energy ◽  
Hydrogen Energy ◽  
Mixing Processes ◽  
Reverse Electrodialysis

There is an enormous potential for energy generation from the mixing of sea and river water at global estuaries. Here, we model a novel approach to convert this source of energy directly into hydrogen and electricity using reverse electrodialysis (RED). RED relies on converting ionic current to electric current using multiple membranes and redox-based electrodes. A thermodynamic model for RED is created to evaluate the electricity and hydrogen which can be extracted from natural mixing processes. With equal volume of high and low concentration solutions (1 L), the maximum energy extracted per volume of solution mixed occurred when the number of membranes is reduced, with the lowest number tested here being five membrane pairs. At this operating point, 0.32 kWh/m3 is extracted as electrical energy and 0.95 kWh/m3 as hydrogen energy. This corresponded to an electrical energy conversion efficiency of 15%, a hydrogen energy efficiency of 35%, and therefore, a total mixing energy efficiency of nearly 50%. As the number of membrane pairs increases from 5 to 20, the hydrogen power density decreases from 13.6 W/m2 to 2.4 W/m2 at optimum external load. In contrast, the electrical power density increases from 0.84 W/m2 to 2.2 W/m2. Optimum operation of RED depends significantly on the external load (external device). A small load will increase hydrogen energy while decreasing electrical energy. This trade-off is critical in order to optimally operate an RED cell for both hydrogen and electricity generation.

Messenger RNA from bovine retina induces kainate and glycine receptors in Xenopus oocytes

1985 ◽  
Vol 225 (1238) ◽  
pp. 99-106 ◽  
Keyword(s):  
Messenger Rna ◽  
Xenopus Oocytes ◽  
Signal Transmission ◽  
Ionic Current ◽  
Kainate Receptors ◽  
Equilibrium Potential ◽  
Bovine Retina ◽  
Neurotoxic Effects ◽  
Chemical Synapses ◽  
Oocyte Membrane

The retina contains several types of nerve cells that communicate through chemical synapses. The transmitter and receptor molecules that mediate signal transmission across these synapses need further characterization. For this purpose, poly (A) + mRNA was isolated from bovine retinas and injected into Xenopus laevis oocytes. Translation of the foreign mRNA induced the oocyte membrane to acquire functional receptors to kainate and, to a lesser extent, also receptors to glycine, γ -aminobutryic acid (GABA), aspartate and glutamate. Thus, the cells in the retina must contain different messengers coding for these neurotransmitter receptors. Activation of the kainate receptors opens membrane channels, generating an ionic current which has an equilibrium potential close to 0 mv. The current is well maintained during prolonged application of kainate, and hence these receptors may be involved in the neurotoxic effects produced by kainate in the retina.

scholarly journals Optimal information transfer in enzymatic networks: A field theoretic formulation

2017 ◽  
Author(s):  
Himadri S. Samanta ◽  
Michael Hinczewski ◽  
D. Thirumalai
Keyword(s):  
Linear Theory ◽  
Chemical Reactions ◽  
Information Transfer ◽  
Signal Transmission ◽  
Control Variable ◽  
Signal Propagation ◽  
Umbral Calculus ◽  
Theoretic Approach ◽  
Optimal Information ◽  
Enzymatic Networks

AbstractSignaling in enzymatic networks is typically triggered by environmental fluctuations, resulting in a series of stochastic chemical reactions, leading to corruption of the signal by noise. For example, information flow is initiated by binding of extracellular ligands to receptors, which is transmitted through a cascade involving kinase-phosphatase stochastic chemical reactions. For a class of such networks, we develop a general field-theoretic approach in order to calculate the error in signal transmission as a function of an appropriate control variable. Application of the theory to a simple push-pull network, a module in the kinase-phosphatase cascade, recovers the exact results for error in signal transmission previously obtained using umbral calculus (Phys. Rev. X.,4, 041017 (2014)). We illustrate the generality of the theory by studying the minimal errors in noise reduction in a reaction cascade with two connected push-pull modules. Such a cascade behaves as an effective three-species network with a pseudo intermediate. In this case, optimal information transfer, resulting in the smallest square of the error between the input and output, occurs with a time delay, which is given by the inverse of the decay rate of the pseudo intermediate. Surprisingly, in these examples the minimum error computed using simulations that take non-linearities and discrete nature of molecules into account coincides with the predictions of a linear theory. In contrast, there are substantial deviations between simulations and predictions of the linear theory in error in signal propagation in an enzymatic push-pull network for a certain range of parameters. Inclusion of second order perturbative corrections shows that differences between simulations and theoretical predictions are minimized. Our study establishes that a field theoretic formulation of stochastic biological signaling offers a systematic way to understand error propagation in networks of arbitrary complexity.

scholarly journals Single-Molecule Dynamics and Discrimination between Hydrophilic and Hydrophobic Amino Acids in Peptides, through Controllable, Stepwise Translocation across Nanopores

2018 ◽  
Author(s):  
Alina Asandei ◽  
Isabela S. Dragomir ◽  
Giovanni Di Muccio ◽  
Mauro Chinappi ◽  
Yoonkyung Park ◽  
...  
Keyword(s):  
Amino Acids ◽  
Single Molecule ◽  
Ionic Current ◽  
Ionic Currents ◽  
Alpha Hemolysin ◽  
Time Discrimination ◽  
Voltage Dependent ◽  
Hydrophobic Amino Acids ◽  
Molecular Brake ◽  
Oppositely Charged

In this work we demonstrate the proof-of-concept of real-time discrimination between patches of serine or isoleucine monomers in the primary structure of custom-engineered, macro-dipole-like peptides, at uni-molecular level. We employed single-molecule recordings to examine the ionic current through the &alpha;-hemolysin (&alpha;-HL) nanopore, when hydrophilic serine or hydrophobic isoleucine residues, flanked by segments of oppositely charged arginine and glutamic amino acids functioning as a voltage-dependent &lsquo;molecular brake&rsquo; on the peptide, were driven at controllable rates across the nanopore. The observed differences in the ionic currents blockades through the nanopore, visible at time resolutions corresponding to peptide threading through the &alpha;-HL&rsquo;s constriction region, was explained by a simple model of the volumes of electrolyte excluded by either amino acid species, as groups of three serine or isoleucine monomers transiently occupy the &alpha;-HL. To provide insights into the conditions ensuring optimal throughput of peptide readout through the nanopore, we probed the sidedness-dependence of peptide association to and dissociation from the electrically and geometrically asymmetric &alpha;-HL.

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