Electroreception, electrogenesis and electric signal evolution

Abstract With the ever-increasing density and performance of integrated circuits, non-invasive, accurate, and high spatial and temporal resolution electric signal measurement instruments hold the key to performing successful diagnostics and failure analysis. Sampled electrostatic force microscopy (EFM) has the potential for such applications. It provides a noninvasive approach to measuring high frequency internal integrated circuit signals. Previous EFMs operate using a repetitive single-pulse sampling approach and are inherently subject to the signal-to-noise ratio (SNR) problems when test pattern duty cycle times become large. In this paper we present an innovative technique that uses groups of pulses to improve the SNR of sampled EFM systems. The approach can easily provide more than an order-ofmagnitude improvement to the SNR. The details of the approach are presented.

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Neurofilament Proteins as Prognostic Biomarkers in Neurological Disorders

Current Pharmaceutical Design ◽

10.2174/1381612825666191210154535 ◽

2020 ◽

Vol 25 (43) ◽

pp. 4560-4569 ◽

Cited By ~ 7

Author(s):

Yichen Lee ◽

Bo H. Lee ◽

William Yip ◽

Pingchen Chou ◽

Bak-Sau Yip

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Nervous System ◽

Trinucleotide Repeat ◽

Muscular Atrophy ◽

Electric Signal ◽

Motor Neuropathy ◽

Post Translational Modification ◽

Neurofilament Proteins ◽

Type Iv ◽

Lateral Sclerosis

Neurofilaments: light, medium, and heavy (abbreviated as NF-L, NF-M, and NF-H, respectively), which belong to Type IV intermediate filament family (IF), are neuron-specific cytoskeletal components. Neurofilaments are axonal structural components and integral components of synapses, which are important for neuronal electric signal transmissions along the axons and post-translational modification. Abnormal assembly of neurofilaments is found in several human neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), infantile spinal muscular atrophy (SMA), and hereditary sensory-motor neuropathy (HSMN). In addition, those pathological neurofilament accumulations are known in α-synuclein in Parkinson’s disease (PD), Aβ and tau in Alzheimer’s disease (AD), polyglutamine in CAG trinucleotide repeat disorders, superoxide dismutase 1 (SOD1), TAR DNA-binding protein 43 (TDP43), neuronal FUS proteins, optineurin (OPTN), ubiquilin 2 (UBQLN2), and dipeptide repeat protein (DRP) in amyotrophic lateral sclerosis (ALS). When axon damage occurs in central nervous disorders, neurofilament proteins are released and delivered into cerebrospinal fluid (CSF), which are then circulated into blood. New quantitative analyses and assay techniques are well-developed for the detection of neurofilament proteins, particularly NF-L and the phosphorylated NF-H (pNF-H) in CSF and serum. This review discusses the potential of using peripheral blood NF quantities and evaluating the severity of damage in the nervous system. Intermediate filaments could be promising biomarkers for evaluating disease progression in different nervous system disorders.

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Functionally Tailored Electro-Sensitive Poly(Acrylamide)-g-Pectin Copolymer Hydrogel for Transdermal Drug Delivery Application: Synthesis, Characterization, In-vitro and Ex-vivo Evaluation

Drug Delivery Letters ◽

10.2174/2210303110666200206114632 ◽

2020 ◽

Vol 10 (3) ◽

pp. 185-196

Author(s):

Sudha B. Patil ◽

Syed Z. Inamdar ◽

Kakarla R. Reddy ◽

Anjanapura V. Raghu ◽

Krishnamachari G. Akamanchi ◽

...

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Transdermal Drug Delivery ◽

Ex Vivo ◽

Transmission Rate ◽

Electric Signal ◽

Poly Vinyl Alcohol ◽

Electric Stimulus ◽

Copolymer Hydrogel ◽

Transdermal Drug Delivery Systems

Background and Objectives: To develop electro-sensitive transdermal drug delivery systems (ETDDS) using polyacrylamide-grafted-pectin (PAAm-g-PCT) copolymer hydrogel for rivastigmine delivery. Methods: Free radical polymerization and alkaline hydrolysis technique was employed to synthesize PAAm-g-PCT copolymer hydrogel. The PAAm-g-PCT copolymeric hydrogel was used as a reservoir and cross-linked blend films of PCT and poly(vinyl alcohol) as rate-controlling membranes (RCMs) to prepare ETDDS. Results: The pH of the hydrogel reservoir was found to be in the range of 6.81 to 6.93 and drug content was 89.05 to 96.29%. The thickness of RCMs was in the range of 51 to 99 μ and RCMs showed permeability behavior against water vapors. There was a reduction in the water vapor transmission rate as the glutaraldehyde (GA) concentration was increased. The drug permeation rate from the ETDDS was enhanced under the influence of electric stimulus against the absence of an electric stimulus. The increase in flux by 1.5 fold was recorded with applied electric stimulus. The reduction in drug permeability observed when the concentration of GA was increased. Whereas, the permeability of the drug was augmented as an electric current was changed from 2 to 8 mA. The pulsatile drug release under “on– off” cycle of electric stimulus witnessed a faster drug release under ‘on’ condition and it was slow under ‘off’ condition. The alteration in skin composition after electrical stimulation was confirmed through histopathology studies. Conclusion: The PAAm-g-PCT copolymer hydrogel is a useful carrier for transdermal drug delivery activated by an electric signal to provide on-demand release of rivastigmine.

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Development of a Self-Powered Piezo-Resistive Smart Insole Equipped with Low-Power BLE Connectivity for Remote Gait Monitoring

Sensors ◽

10.3390/s21134539 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4539

Author(s):

Roberto de Fazio ◽

Elisa Perrone ◽

Ramiro Velázquez ◽

Massimo De Vittorio ◽

Paolo Visconti

Keyword(s):

Low Power ◽

Smart Materials ◽

Applied Pressure ◽

Pressure Sensors ◽

Complete Characterization ◽

Electric Signal ◽

Sensing Matrix ◽

Capacitive Accelerometer ◽

Gait Parameters ◽

Smart Insole

The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters; indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3-axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., ) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section.

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Negative Pressure Provides Simple and Stable Droplet Generation in a Flow-Focusing Microfluidic Device

Micromachines ◽

10.3390/mi12060662 ◽

2021 ◽

Vol 12 (6) ◽

pp. 662

Author(s):

Nikita A. Filatov ◽

Anatoly A. Evstrapov ◽

Anton S. Bukatin

Keyword(s):

Microfluidic Device ◽

Negative Pressure ◽

Low Cost ◽

Control Valve ◽

Droplet Microfluidics ◽

Droplet Generation ◽

Electric Signal ◽

Absolute Pressure ◽

Flow Focusing ◽

Wide Range

Droplet microfluidics is an extremely useful and powerful tool for industrial, environmental, and biotechnological applications, due to advantages such as the small volume of reagents required, ultrahigh-throughput, precise control, and independent manipulations of each droplet. For the generation of monodisperse water-in-oil droplets, usually T-junction and flow-focusing microfluidic devices connected to syringe pumps or pressure controllers are used. Here, we investigated droplet-generation regimes in a flow-focusing microfluidic device induced by the negative pressure in the outlet reservoir, generated by a low-cost mini diaphragm vacuum pump. During the study, we compared two ways of adjusting the negative pressure using a compact electro-pneumatic regulator and a manual airflow control valve. The results showed that both types of regulators are suitable for the stable generation of monodisperse droplets for at least 4 h, with variations in diameter less than 1 µm. Droplet diameters at high levels of negative pressure were mainly determined by the hydrodynamic resistances of the inlet microchannels, although the absolute pressure value defined the generation frequency; however, the electro-pneumatic regulator is preferable and convenient for the accurate control of the pressure by an external electric signal, providing more stable pressure, and a wide range of droplet diameters and generation frequencies. The method of droplet generation suggested here is a simple, stable, reliable, and portable way of high-throughput production of relatively large volumes of monodisperse emulsions for biomedical applications.

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Electric signal synchronization as a behavioural strategy to generate social attention in small groups of mormyrid weakly electric fish and a mobile fish robot

Biological Cybernetics ◽

10.1007/s00422-021-00892-8 ◽

2021 ◽

Author(s):

Martin Worm ◽

Tim Landgraf ◽

Gerhard von der Emde

Keyword(s):

Small Groups ◽

Electric Fish ◽

Social Attention ◽

Weakly Electric Fish ◽

Electric Signal ◽

Fish Robot ◽

Wide Range ◽

Signal Synchronization ◽

Weakly Electric ◽

Attention Hypothesis

AbstractAfrican weakly electric fish communicate at night by constantly emitting and perceiving brief electrical signals (electric organ discharges, EOD) at variable inter-discharge intervals (IDI). While the waveform of single EODs contains information about the sender’s identity, the variable IDI patterns convey information about its current motivational and behavioural state. Pairs of fish can synchronize their EODs to each other via echo responses, and we have previously formulated a ‘social attention hypothesis’ stating that fish use echo responses to address specific individuals and establish brief dyadic communication frameworks within a group. Here, we employed a mobile fish robot to investigate the behaviour of small groups of up to four Mormyrus rume and characterized the social situations during which synchronizations occurred. An EOD-emitting robot reliably evoked social following behaviour, which was strongest in smaller groups and declined with increasing group size. We did not find significant differences in motor behaviour of M. rume with either an interactive playback (echo response) or a random control playback by the robot. Still, the robot reliably elicited mutual synchronizations with other fish. Synchronizations mostly occurred during relatively close social interactions, usually when the fish that initiated synchronization approached either the robot or another fish from a distance. The results support our social attention hypothesis and suggest that electric signal synchronization might facilitate the exchange of social information during a wide range of social behaviours from aggressive territorial displays to shoaling and even cooperative hunting in some mormyrids.

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Improving Turret Control on Military Vehicles

Volume 10: Mechanical Systems and Control, Parts A and B ◽

10.1115/imece2009-11821 ◽

2009 ◽

Author(s):

Thomas W. Anderson ◽

Nathaniel A. Clark ◽

Wesley E. Kotz ◽

Briana D. Stremick ◽

O¨zer Arnas ◽

...

Keyword(s):

Hall Effect ◽

Output Voltage ◽

Magnetic Force ◽

Electric Signal ◽

Similar Response ◽

Hall Effect Sensor ◽

Military Vehicles ◽

Tactical Vehicle ◽

The Magnetic Field ◽

Mechanical Assistance

Recent additions of armor have made light tactical vehicle turrets heavy enough that mechanical assistance is required for them to rotate. The Army’s solution is the Battery Powered Motorized Traversing Unit (BPMTU) which uses a joystick to traverse the turret. Use of the joystick distracts the gunner and prevents the gunner from continuously engaging the target while rotating the turret. This paper presents a modification to the weapon mount that allows the turret to be controlled by the position of the weapon itself and emphasizes the design process used to develop the inovation. With this design, the gunner can now maintain contact with a target, while rotating the turret, without fiddling with the joystick. The Weapon Activated and Controlled Turret (WACT) consists of two primary components; the bottom component is stationary relative to the turret and contains a Hall effect sensor and the top component rotates with the weapon and holds a linear magnet. As the position of the sensor relative to the magnet changes, the corresponding strength of the magnetic field also varies. This change in magnetic force induces a similar response in the output voltage of the Hall effect sensor, effectively translating rotational motion into an electric signal able to control the turret motor.

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Experimental Learning of Digital Power Controller for Photovoltaic Module Using Proteus VSM

Journal of Solar Energy ◽

10.1155/2014/736273 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Abhijit V. Padgavhankar ◽

Sharad W. Mohod

Keyword(s):

System Modeling ◽

Maximum Power ◽

Digital Controller ◽

Electric Signal ◽

Photovoltaic Module ◽

Boost Converters ◽

Learning Platform ◽

Pv Module ◽

Experimental Learning ◽

Virtual System

The electric power supplied by photovoltaic module depends on light intensity and temperature. It is necessary to control the operating point to draw the maximum power of photovoltaic module. This paper presents the design and implementation of digital power converters using Proteus software. Its aim is to enhance student’s learning for virtual system modeling and to simulate in software for PIC microcontroller along with the hardware design. The buck and boost converters are designed to interface with the renewable energy source that is PV module. PIC microcontroller is used as a digital controller, which senses the PV electric signal for maximum power using sensors and output voltage of the dc-dc converter and according to that switching pulse is generated for the switching of MOSFET. The implementation of proposed system is based on learning platform of Proteus virtual system modeling (VSM) and the experimental results are presented.

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Sensory-based niche partitioning in a multiple predator–multiple prey community

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0520 ◽

2015 ◽

Vol 282 (1808) ◽

pp. 20150520 ◽

Cited By ~ 23

Author(s):

Jay J. Falk ◽

Hannah M. ter Hofstede ◽

Patricia L. Jones ◽

Marjorie M. Dixon ◽

Paul A. Faure ◽

...

Keyword(s):

Species Interactions ◽

Prey Species ◽

Niche Partitioning ◽

Signal Evolution ◽

Signal Design ◽

Predator Species ◽

Mate Attraction ◽

Communication Signals ◽

Signal Features ◽

The Impact

Many predators and parasites eavesdrop on the communication signals of their prey. Eavesdropping is typically studied as dyadic predator–prey species interactions; yet in nature, most predators target multiple prey species and most prey must evade multiple predator species. The impact of predator communities on prey signal evolution is not well understood. Predators could converge in their preferences for conspicuous signal properties, generating competition among predators and natural selection on particular prey signal features. Alternatively, predator species could vary in their preferences for prey signal properties, resulting in sensory-based niche partitioning of prey resources. In the Neotropics, many substrate-gleaning bats use the mate-attraction songs of male katydids to locate them as prey. We studied mechanisms of niche partitioning in four substrate-gleaning bat species and found they are similar in morphology, echolocation signal design and prey-handling ability, but each species preferred different acoustic features of male song in 12 sympatric katydid species. This divergence in predator preference probably contributes to the coexistence of many substrate-gleaning bat species in the Neotropics, and the substantial diversity in the mate-attraction signals of katydids. Our results provide insight into how multiple eavesdropping predator species might influence prey signal evolution through sensory-based niche partitioning.

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