scholarly journals Mechanical vibration patterns elicit behavioral transitions and habituation in crawlingDrosophilalarvae

2021 ◽  
Author(s):  
Alexander Berne ◽  
Tom Zhang ◽  
Joseph Shomar ◽  
Anggie J. Ferrer ◽  
Aaron Valdes ◽  
...  
Keyword(s):  
Mechanical Vibration ◽  
Vertical Vibration ◽  
Electrical Circuit ◽  
Mechanical Stimuli ◽  
Molecular Processes ◽  
Mechanical Agitation ◽  
Time Constants ◽  
Behavioral Transitions ◽  
Behavioral States ◽  
Behavior Profiles

AbstractHow animals respond to repeatedly applied stimuli, and how animals respond to mechanical stimuli in particular, are important questions in behavioral neuroscience. We study adaptation to repeated mechanical agitation using theDrosophilalarva. Vertical vibration stimuli elicit a discrete set of responses in crawling larvae: continuation, pause, turn, and reversal. Through high-throughput larva tracking, we characterize how the likelihood of each response depends on vibration intensity and on the timing of repeated vibration pulses. By examining transitions between behavioral states at the population and individual levels, we investigate how the animals habituate to the stimulus patterns. We identify time constants associated with desensitization to prolonged vibration, with re-sensitization during removal of a stimulus, and additional layers of habituation that operate in the overall response. Known memory-deficient mutants exhibit distinct behavior profiles and habituation time constants. An analogous simple electrical circuit suggests possible neural and molecular processes behind adaptive behavior.

A Dynamical Model for Studying the Stability of Thermo-Solutal Convection Under the Effect of Vertical Vibration

2005 ◽  
Author(s):  
Y. P. Razi ◽  
M. Mojtabi ◽  
K. Maliwan ◽  
M. C. Charrier-Mojtabi ◽  
A. Mojtabi
Keyword(s):  
Stability Analysis ◽  
Mechanical Vibration ◽  
Stability Limit ◽  
Lewis Number ◽  
Vertical Vibration ◽  
Wave Number ◽  
Dimensionless Wave Number ◽  
Non Linear ◽  
Linear Differential ◽  
The Stability

This paper concerns the thermal stability analysis of porous layer saturated by a binary fluid under the influence of mechanical vibration. The linear stability analysis of this thermal system leads us to study the following damped coupled Mathieu equations: BH¨+B(π2+k2)+1H˙+(π2+k2)−k2k2+π2RaT(1+Rsinω*t*)H=k2k2+π2(NRaT)(1+Rsinω*t*)Fε*BF¨+Bπ2+k2Le+ε*F˙+π2+k2Le−k2k2+π2NRaT(1+Rsinω*t*)F=k2k2+π2RaT(1+Rsinω*t*)H where RaT is thermal Rayleigh number, R is acceleration ratio (bω2/g), Le is the Lewis number, k is the dimensionless wave-number, ε* is normalized porosity and N is the buoyancy ratio (H and F are perturbations of temperature and concentration fields). In the follow up, the non-linear behavior of the problem is studied via a generalization of the Lorenz model (five coupled non-linear differential equations with periodic coefficients). In the presence or absence of gravity, the stability limit for the onset of stationary as well as Hopf bifurcations is determined.

Dynamics of a three-parameter electromagnetic vibration energy harvester considering electromechanical coupling

2019 ◽  
Vol 234 (7) ◽  
pp. 1323-1339
Author(s):  
Haiping Liu ◽  
Dongmei Zhu
Keyword(s):  
Energy Harvester ◽  
Mechanical Vibration ◽  
Average Power ◽  
Electrical Circuit ◽  
Single Frequency ◽  
Vibration Energy ◽  
Electrical Load ◽  
Vibration Energy Harvester ◽  
Analytical Expressions ◽  
Frequency Harmonic

The paper concerns the dynamic responses and vibration energy harvesting characteristics in an electromagnetic vibration energy harvester comprising three-parameter mechanical vibration subsystem. For completeness and comparison, a two-parameter vibration energy harvester is also presented. The analytical expressions of the amplitude-frequency and phase-frequency responses of the inertial mass and the current in the electrical circuit are respectively derived by applying dimensionless method to the studied two- and three-parameter dynamic systems. Considering the effects of different types of ambient excitation, a single-frequency harmonic load and a periodic load are introduced into the analytical expressions on the dynamic performance of the vibration energy harvester. First of all, the influences of the designing parameters from the mechanical vibration subsystem and the electrical circuit subsystem on the vibration energy harvester are investigated. For evaluating the effects due to introducing the three-parameter mechanical vibration component, comparisons are made between two- and three-parameter vibration energy harvesters to convert the ambient excitations into electrical energy. And then, the expressions of the dimensionless average power which delivered into an electrical load under a single-frequency harmonic excitation or a periodic excitation are derived. The calculating results show that the energy conversion efficiency is enhanced significantly by changing the mechanical damping efficiency and the stiffness ratio for the three-parameter mechanical component of the energy harvester. At the same time, the average power of the three-parameter vibration energy harvester, which delivered into the electrical load, is also improved. However, the influences of the electrical circuit component on the ambient energy harvesting can be omitted when keeping the designing parameters of the mechanical part constant.

A Study of Mechanosensing of an Osteoblast at Focal Adhesions Under Cyclic Strain Using Magnetic Micropillars

2019 ◽  
Author(s):  
Toshihiko Shiraishi ◽  
Kota Nagai
Keyword(s):  
Calcium Ion ◽  
Mechanical Vibration ◽  
Focal Adhesions ◽  
Cyclic Strain ◽  
Mechanical Stimuli ◽  
Osteoblast Cells ◽  
Intracellular Calcium Ion ◽  
A Cell ◽  
Sense And Respond ◽  
Biochemical Signals

Abstract It has been reported that cells sense and respond to mechanical stimuli. Mechanical vibration promotes the cell proliferation and the cell differentiation of osteoblast cells at 12.5 Hz and 50 Hz, respectively. It indicates that osteoblast cells have a mechansensing system for mechanical vibration. There may be some mechanosensors and we focus on cellular focal adhesions through which mechanical and biochemical signals may be transmitted from extracellular matrices into a cell. However, it is very difficult to directly apply mechanical stimuli to focal adhesions. We developed a magnetic micropillar substrate on which micron-sized pillars are deflected according to applied magnetic field strength and focal adhesions adhering to the top surface of the pillars are given mechanical stimuli. In this paper, we focus on intracellular calcium ion as a second messenger of cellular mechanosensing and investigate the mechanosensing mechanism of an osteoblast cell at focal adhesions under cyclic strain using a magnetic micropillar substrate. The experimental results indicate that the magnetic micropillars have enough performance to response to an electric current applied to a coil in an electromagnet and to apply the cyclic strain of less than 3% to a cell. In the cyclic strain of less than 3%, the calcium response of a cell was not observed.

scholarly journals An Electromechanical Pendulum Robot Arm in Action: Dynamics and Control

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
A. Notué Kadjie ◽  
P. R. Nwagoum Tuwa ◽  
Paul Woafo
Keyword(s):  
Control Strategies ◽  
Dynamical Behavior ◽  
Mechanical Vibration ◽  
High Amplitude ◽  
Electrical Signal ◽  
Electrical Circuit ◽  
Robot Arm ◽  
Dynamics And Control ◽  
Short Time ◽  
And Control

The authors numerically investigate the dynamics and control of an electromechanical robot arm consisting of a pendulum coupled to an electrical circuit via an electromagnetic mechanism. The analysis of the dynamical behavior of the electromechanical device powered by a sinusoidal power source is carried out when the effects of the loads on the arm are neglected. It is found that the device exhibits period-n T oscillations and high amplitude oscillations when the electric current is at its smallest value. The specific case which considers the effects of the impulsive contact force caused by an external load mass pushed by the arm is also studied. It is found that the amplitude of the impulse force generates several behaviors such as jump of amplitude and distortions of the mechanical vibration and electrical signal. For more efficient functioning of the device, both piezoelectric and adaptive backstepping controls are applied on the system. It is found that the control strategies are able to mitigate the signal distortion and restore the dynamical behavior to its normal state or reduce the effects of perturbations such as a short time variation of one component or when the robot system is subject to noises.

scholarly journals Mechanical impact stimulation platform tailored for high-resolution light microscopy

2019 ◽  
Vol 10 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Heidi T. Halonen ◽  
Jari A.K. Hyttinen ◽  
Teemu O. Ihalainen
Keyword(s):  
High Resolution ◽  
Epithelial Cells ◽  
Light Microscopy ◽  
Mechanical Stimulation ◽  
Cellular Response ◽  
Mechanical Vibration ◽  
Stem Cell Differentiation ◽  
Live Cell ◽  
Mechanical Stimuli

Abstract High frequency (HF) mechanical vibration has been used in vitro to study the cellular response to mechanical stimulation and induce stem cell differentiation. However, detailed understanding of the effect of the mechanical cues on cellular physiology is lacking. To meet this limitation, we have designed a system, which enables monitoring of living cells by high-resolution light microscopy during mechanical stimulation by HF vibration or mechanical impacts. The system consists of a commercial speaker, and a 3D printed sample vehicle and frame. The speaker moves the sample in the horizontal plane, allowing simultaneous microscopy. The HF vibration (30–200 Hz) performances of two vehicles made of polymer and aluminum were characterized with accelerometer. The mechanical impacts were characterized by measuring the acceleration of the aluminum vehicle and by time lapse imaging. The lighter polymer vehicle produced higher HF vibration magnitudes at 30–50 Hz frequencies than the aluminum vehicle. However, the aluminum vehicle performed better at higher frequencies (60–70 Hz, 90–100 Hz, 150 Hz). Compatibility of the system in live cell experiments was investigated with epithelial cells (MDCKII, expressing Emerald-Occludin) and HF (0.56 Gpeak, 30 Hz and 60 Hz) vibration. Our findings indicated that our system is compatible with high-resolution live cell microscopy. Furthermore, the epithelial cells were remarkable stable under mechanical vibration stimulation. To conclude, we have designed an inexpensive tool for the studies of cellular biophysics, which combines versatile in vivo like mechanical stimuli with live cell imaging, showing a great potential for several cellular applications.

Effects of Mechanical Stimuli on Adaptive Remodeling of Condylar Cartilage

2009 ◽  
Vol 88 (5) ◽  
pp. 466-470 ◽  
Author(s):  
D. Sriram ◽  
A. Jones ◽  
I. Alatli-Burt ◽  
M.A. Darendeliler
Keyword(s):  
High Frequency ◽  
Mechanical Vibration ◽  
Mechanical Stimuli ◽  
Micro Computed Tomography ◽  
Condylar Cartilage ◽  
Endochondral Bone ◽  
Hypertrophic Cartilage ◽  
C3h Mice ◽  
Experimental Group ◽  
Low Magnitude

Trabecular bone has been shown to be responsive to low-magnitude, high-frequency mechanical stimuli. This study aimed to assess the effects of these stimuli on condylar cartilage and its endochondral bone. Forty female 12-week-old C3H mice were divided into 3 groups: baseline control (killed at day 0), sham (killed at day 28 without exposure to mechanical stimuli), and experimental (killed following 28 days of exposure to mechanical stimuli). The experimental group was subjected to mechanical vibration of 30 Hz, for 20 minutes per day, 5 days per week, for 28 days. The specimens were analyzed by micro-computed tomography. The experimental group demonstrated a significant decrease in the volume of condylar cartilage and also a significant increase in bone histomorphometric parameters. The results suggest that the low-magnitude, high-frequency mechanical stimuli enhance adaptive remodeling of condylar cartilage, evidenced by the advent of endochondral bone replacing the hypertrophic cartilage.

scholarly journals Horizontal spin of ratchet motor by vertical agitation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshinobu Takahashi ◽  
Erika Okita ◽  
Daigo Yamamoto ◽  
Yasunao Okamoto ◽  
Akihisa Shioi
Keyword(s):  
Simple Model ◽  
Vibration Frequency ◽  
Potential Field ◽  
Granular Matter ◽  
Vertical Motion ◽  
Vertical Vibration ◽  
Random Motion ◽  
Energy Harvest ◽  
Granular Bed ◽  
Mechanical Agitation

AbstractThe horizontal spin of a ratchet motor by vertical vibration is reported. A macroscopic ratchet gear is placed on a granular bed, where nearly half of the gear is penetrated in the bed. The gear and granular bed are mechanically vibrated. The gear shows a random motion or one-way spin that depend on the diameter of the granules, vibration frequency, and degree of vertical motion allowed for the gear. Even when one-way spin is observed, the spin direction depends on the abovementioned factors. Although the dependency is complicated, it is deterministic because the motion or flows of granular matter determines it. The characteristics observed in the experiments are explained by a simple model that accounts for the statistical variance in the motion of the granular matter. Extraction of systematic motion from small and non-useful motions such as mechanical agitation will be developed into energy harvest technology and may facilitate the science of a spontaneously moving system in a uniform potential field.

Mouse embryo motion and embryonic development from the 2-cell to blastocyst stage using mechanical vibration systems

2014 ◽  
Vol 26 (5) ◽  
pp. 733 ◽  
Author(s):  
Yuka Asano ◽  
Koji Matsuura
Keyword(s):  
Embryonic Development ◽  
Mechanical Vibration ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
Physical Factors ◽  
Mechanical Stimuli ◽  
Negative Effects ◽  
Factors Affecting ◽  
Comparison Of The Results ◽  
Static Conditions

We investigated the effect of mechanical stimuli on mouse embryonic development from the 2-cell to blastocyst stage to evaluate physical factors affecting embryonic development. Shear stress (SS) applied to embryos using two mechanical vibration systems (MVSs) was calculated by observing microscopic images of moving embryos during mechanical vibration (MV). The MVSs did not induce any motion of the medium and the diffusion rate using MVSs was the same as that under static conditions. Three days of culture using MVS did not improve embryonic development. MVS transmitted MV power more efficiently to embryos than other systems and resulted in a significant decrease in development to the morula or blastocyst stage after 2 days. Comparison of the results of embryo culture using dynamic culture systems demonstrated that macroscopic diffusion of secreted materials contributes to improved development of mouse embryos to the blastocyst stage. These results also suggest that the threshold of SS and MV to induce negative effects for mouse embryos at stages earlier than the blastocyst may be lower than that for the blastocyst, and that mouse embryos are more sensitive to physical and chemical stimuli than human or pig embryos because of their thinner zona pellucida.

Effect of external mechanical stimuli on human bone: a narrative review

2021 ◽  
Author(s):  
Megan E Mancuso ◽  
Andrew R. Wilzman ◽  
Kyle E. Murdock ◽  
Karen Troy
Keyword(s):  
Mechanical Loading ◽  
Bone Structure ◽  
Mechanical Vibration ◽  
Human Bone ◽  
Mechanical Stimuli ◽  
Exercise Interventions ◽  
Clinical Scenarios ◽  
Cord Injury ◽  
Pulsed Electromagnetic ◽  
External Stimuli

Abstract Bone is a living composite material that has the capacity to adapt and respond to both internal and external stimuli. This capacity allows bone to adapt its structure to habitual loads and repair microdamage. Although human bone evolved to adapt to normal physiologic loading (for example from gravitational and muscle forces), these same biological pathways can potentially be activated through other types of external stimuli such as pulsed electromagnetic fields, mechanical vibration, and others. This review summarizes what is currently known about how human bone adapts to various types of external stimuli. We highlight how studies on sports-specific athletes and other exercise interventions have clarified the role of mechanical loading on bone structure. We also discuss clinical scenarios, such as spinal cord injury, where mechanical loading is drastically reduced, leading to rapid bone loss and permanent alterations to bone structure. Finally, we highlight areas of emerging research and unmet clinical need.

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