The secrets of cryptochromes: photoreceptors, clock proteins, and magnetic sensors

Neuroforum ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rabea Bartölke ◽  
Heide Behrmann ◽  
Katharina Görtemaker ◽  
Chad Yee ◽  
Jingjing Xu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Potential Interaction ◽  
Magnetic Sensors ◽  
Receptor Protein ◽  
Signaling Cascade ◽  
Screening Methods ◽  
Clock Proteins ◽  
Migratory Songbirds ◽  
Interaction Partners ◽  
Phototransduction Pathway

Abstract A class of light-activated proteins in the eyes of birds, called cryptochromes, are thought to act as the primary magnetic sensors allowing night-migratory songbirds to navigate over thousands of kilometers using the earth’s magnetic field. Having evolved from DNA-repairing photolyases, cryptochromes have redirected the energy from light to fuel a variety of other functions: as photoreceptors, as regulators of the circadian clock – and, in some species, most likely as sensors of the magnetic field. While the quantum effects of magnetic fields on cryptochromes are already being studied in detail, almost nothing is known about the signaling cascade involving cryptochrome as the primary receptor protein. Two different screening methods have identified potential interaction partners that suggest an involvement of the visual phototransduction pathway, the visual cycle, potassium channels or glutamate receptors, but more pioneering research is needed to unravel the signaling cascade responsible for transducing the magnetic signal.

Magnetic Emission Mapping for Passive Integrated Components Characterisation

2003 ◽  
Author(s):  
O. Crépel ◽  
Y. Bouttement ◽  
P. Descamps ◽  
C. Goupil ◽  
P. Perdu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mobile Phone ◽  
Printed Circuit Board ◽  
Magnetic Sensors ◽  
Circuit Board ◽  
Magnetic Disturbance ◽  
Passive Components ◽  
Printed Circuit ◽  
Integrated Inductor ◽  
The Magnetic Field

Abstract We developed a system and a method to characterize the magnetic field induced by circuit board and electronic component, especially integrated inductor, with magnetic sensors. The different magnetic sensors are presented and several applications using this method are discussed. Particularly, in several semiconductor applications (e.g. Mobile phone), active dies are integrated with passive components. To minimize magnetic disturbance, arbitrary margin distances are used. We present a system to characterize precisely the magnetic emission to insure that the margin is sufficient and to reduce the size of the printed circuit board.

scholarly journals A Feasibility Study of a Noncontact Torque Sensor with Multiple Hall Sensors

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Kyungshik Lee ◽  
Chongdu Cho
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
Power Transmission ◽  
Magnetic Sensors ◽  
Torque Sensor ◽  
Torque Measurement ◽  
Test Range ◽  
Variable Power ◽  
Hall Sensors ◽  
The Magnetic Field

The feasibility of a noncontact sensor is investigated. This type of sensor can potentially be used for torque measurement in a speed-variable power transmission system. Torque can be read by examining the phase difference between two induction signals from respective magnetic sensors that detect the magnetic field intensity of permanent magnets mounted on the surface of a shaft in rotation. A real-time measuring algorithm that includes filtering and calibration is adopted to measure the torque magnitude. It is shown that this new torque sensor can perform well under rotation speeds ranging from 300 rpm to 500 rpm. As an interim report rather than a complete development, this work demonstrates the feasibility of noncontact torque measurement by monitoring a magnetic field. The result shows an error of less than 2% within the full test range, which is a sufficient competitive performance for commercial sensors. The price is very low compared to competitors in the marketplace, and the device does not require special handling of the shaft of the surface.

scholarly journals A broadband two axis flux-gate magnetometer

1998 ◽  
Vol 41 (3) ◽  
Author(s):  
P. Palangio
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
High Sensitivity ◽  
Magnetic Sensors ◽  
Frequency Range ◽  
Field Station ◽  
Low Weight ◽  
Highly Sensitive ◽  
Flux Gate ◽  
Magnetic Field Variations

A broadband two axis flux-gate magnetometer was developed to obtain high sensitivity in magnetotelluric measurements. In magnetotelluric sounding, natural low frequency electromagnetic fields are used to estimate the conductivity of the Earth's interior. Because variations in the natural magnetic field have small amplitude(10-100 pT) in the frequency range 1 Hz to 100 Hz, highly sensitive magnetic sensors are required. In magnetotelluric measurements two long and heavy solenoids, which must be installed, in the field station, perpendicular to each other (north-south and east-west) and levelled in the horizontal plane are used. The coil is a critical component in magnetotelluric measurements because very slight motions create noise voltages, particularly troublesome in wooded areas; generally the installation takes place in a shallow trench. Moreover the coil records the derivative of the variations rather than the magnetic field variations, consequently the transfer function (amplitude and phase) of this sensor is not constant throughout the frequency range 0.001-100 Hz. The instrument, developed at L'Aquila Geomagnetic Observatory, has a flat response in both amplitude and phase in the frequency band DC-100 Hz, in addition it has low weight, low power, small volume and it is easier to install in the field than induction magnetometers. The sensivity of this magnetometer is 10 pT rms.

scholarly journals TECHNOLOGY AND MEASUREMENTS OF MAGNETORESISTANCE IN THIN-LAYERED FERROMAGNETIC STRUCTURES

2020 ◽  
Vol 10 (1) ◽  
pp. 44-47
Author(s):  
Jakub Kisała ◽  
Karolina Czarnacka ◽  
Mateusz Gęca ◽  
Andrzej Kociubiński
Keyword(s):  
Magnetic Field ◽  
Constant Magnetic Field ◽  
Spatial Arrangement ◽  
Field Vector ◽  
Magnetic Sensors ◽  
Layer Structures ◽  
Mems Technology ◽  
Nife Layer ◽  
The Individual ◽  
Neodymium Magnets

The paper presents the technology for obtaining NiFe/Ti/NiFe layer structures in MEMS technology using magnetron purge with the assumption of being used as semi-magnetic sensors. A series of samples was made on a glass substrate with a sandwich structure, where the individual layers were 100 nm NiFe, 10 nm Ti and on top again NiFe with a thickness of 100 nm. Measurements of DC resistance of the obtained structures in a constant magnetic field, which was produced by neodymium magnets and an electromagnet, were carried out. The obtained results confirm the occurrence of phenomena known as the magnetoresistance effect. The influence of the spatial arrangement of structures relative to the constant magnetic field vector was checked and proved.

scholarly journals The development of the magnetic system of sensor for PMR-analyser

2020 ◽  
Vol 22 (4) ◽  
pp. 115-122
Author(s):  
A. Y. Svinin ◽  
R. S. Каshaev ◽  
O. V. Коzelkov
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic System ◽  
Scientific Paper ◽  
Magnetic Sensors ◽  
Measuring Instruments ◽  
Main Task ◽  
Magnetic Field Homogeneity ◽  
Nuclear Magnetic

The enhancement of the measuring instruments accuracy has always been the most crucial task for engineers and scientists. In particular, in the field of nuclear magnetic resonance, the creation of uniform magnetic field often defines the results of measurements, therefore the main task of this study is to develop Halbach magnet array based on design characteristics of developing NMR-analyzer. The research describes the development process of the main sensor’s magnetic system components for continuous-flow portable NMR-analyzer. The scientific paper makes a different variations analysis of Halbach magnet arrays on the degree of the magnetic field homogeneity, shows the process of development and production of the 3D-framework for Halbach magnet array for NMR-analyzer. The article also gives information on the design of quartz generator based on Pierce oscillator circuit for receiver-transmitter coil of the NMR-analyzer’s sensor. The results could be useful for the magnetic sensors design with high degree of homogeneity, measuring instruments and devices using the method of nuclear magnetic resonance in its foundation.

Two-step calibration method for three-axis magnetic sensor error based on particle swarm optimization

Sensor Review ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 577-583
Author(s):  
Yanxia Liu ◽  
Zhikai Hu ◽  
JianJun Fang
Keyword(s):  
Magnetic Field ◽  
Fitness Function ◽  
Particle Swarm ◽  
Calibration Method ◽  
Magnetic Sensors ◽  
Earth’S Magnetic Field ◽  
Swarm Optimization ◽  
Error Matrix ◽  
Content Type ◽  
Earth's Magnetic Field

Purpose The three-axis magnetic sensors are mostly calibrated by scalar method such as ellipsoid fitting and so on, but these methods cannot completely determine the 12 parameters of the error model. A two-stage calibration method based on particle swarm optimization (TSC-PSO) is proposed, which makes full use of the amplitude invariance and direction invariance of Earth’s magnetic field vector. Design/methodology/approach The TSC-PSO designs two-stage fitness function. Stage 1: design a fitness function of the particle swarm by the amplitude invariance of the Earth’s magnetic field to obtain a preliminary error matrix G and the bias error B. Stage 2: further design the fitness function of the particle swarm by the invariance of the Earth’s magnetic field to obtain a rotation matrix R, thereby determining the error matrix uniquely. Findings The proposed TSC-PSO can completely determine 12 unknown parameters in error model and further decrease the maximum fluctuation error of the Earth’s magnetic field amplitude and the absolute error of heading. Practical implications The proposed TSC-PSO provides an effective solution for three-axis magnetic sensor error compensation, which can greatly reduce the price of magnetic sensors and be used in the fields of Earth’s magnetic survey, drilling and Earth’s magnetic integrated navigation. Originality/value The proposed TSC-PSO has significantly improved the magnetic field amplitude and heading accuracy and does not require additional heading reference. In addition, the method is insensitive to noise and initialization conditions, has good robustness and can converge to a global optimum.

scholarly journals Performance Validation of a Planar Hall Resistance Biosensor through Beta-Amyloid Biomarker

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 434 ◽  
Author(s):  
SungJoon Kim ◽  
Sri Ramulu Torati ◽  
Artem Talantsev ◽  
ChangYeop Jeon ◽  
SungBae Lee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Second Harmonic ◽  
Signal To Noise Ratio ◽  
Point Of Care ◽  
Magnetic Sensors ◽  
Hall Resistance ◽  
Field Mode ◽  
Mode Method ◽  
Performance Validation

Magnetic sensors have great potential for biomedical applications, particularly, detection of magnetically-labeled biomolecules and cells. On the basis of the advantage of the planar Hall effect sensor, which consists of improved thermal stability as compared with other magnetic sensors, we have designed a portable biosensor platform that can detect magnetic labels without applying any external magnetic field. The trilayer sensor, with a composition of Ta (5 nm)/NiFe (10 nm)/Cu (x = 0 nm~1.2 nm)/IrMn (10 nm)/Ta (5 nm), was deposited on a silicon wafer using photolithography and a sputtering system, where the optimized sensor sensitivity was 6 μV/(Oe∙mA). The detection of the magnetic label was done by comparing the signals obtained in first harmonic AC mode (1f mode) using an external magnetic field and in the second harmonic AC mode (2f mode) with a self-field generated by current passing through the sensor. In addition, a technique for the β-amyloid biomarker-based antibody-antigen sandwich model was demonstrated for the detection of a series of concentrations of magnetic labels using the self-field mode method, where the signal-to-noise ratio (SNR) was high. The generated self-field was enough to detect an immobilized magnetic tag without an additional external magnetic field. Hence, it could be possible to reduce the device size to use the point-of-care testing using a portable circuit system.

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