scholarly journals Unlocking the secrets of multi-flagellated propulsion: drawing insights from Tritrichomonas foetus

2014 ◽  
Vol 11 (93) ◽  
pp. 20131149 ◽  
Author(s):  
Scott C. Lenaghan ◽  
Stefan Nwandu-Vincent ◽  
Benjamin E. Reese ◽  
Mingjun Zhang
Keyword(s):  
High Speed ◽  
Experimental Approach ◽  
Flexural Rigidity ◽  
Tritrichomonas Foetus ◽  
Propulsive Force ◽  
High Speed Imaging ◽  
Resistive Force ◽  
Thrust Generation ◽  
Run And Tumble ◽  
Resistive Force Theory

In this work, a high-speed imaging platform and a resistive force theory (RFT) based model were applied to investigate multi-flagellated propulsion, using Tritrichomonas foetus as an example. We discovered that T. foetus has distinct flagellar beating motions for linear swimming and turning, similar to the ‘run and tumble’ strategies observed in bacteria and Chlamydomonas . Quantitative analysis of the motion of each flagellum was achieved by determining the average flagella beat motion for both linear swimming and turning, and using the velocity of the flagella as inputs into the RFT model. The experimental approach was used to calculate the curvature along the length of the flagella throughout each stroke. It was found that the curvatures of the anterior flagella do not decrease monotonically along their lengths, confirming the ciliary waveform of these flagella. Further, the stiffness of the flagella was experimentally measured using nanoindentation, allowing for calculation of the flexural rigidity of T. foetus' s flagella, 1.55×10 −21 N m 2 . Finally, using the RFT model, it was discovered that the propulsive force of T. foetus was similar to that of sperm and Chlamydomonas , indicating that multi-flagellated propulsion does not necessarily contribute to greater thrust generation, and may have evolved for greater manoeuvrability or sensing. The results from this study have demonstrated the highly coordinated nature of multi-flagellated propulsion and have provided significant insights into the biology of T. foetus .

scholarly journals Dynamics of flagellar force generated by a hyperactivated spermatozoon

Reproduction ◽  
2011 ◽  
Vol 142 (3) ◽  
pp. 409-415 ◽  
Author(s):  
Sumio Ishijima
Keyword(s):  
Zona Pellucida ◽  
High Speed ◽  
Beat Frequency ◽  
Transverse Force ◽  
Sperm Head ◽  
Propulsive Force ◽  
Resistive Force ◽  
High Speed Video ◽  
Sperm Penetration ◽  
Resistive Force Theory

The flagellar force generated by a hyperactivated monkey spermatozoon was evaluated using the resistive force theory applied to the activated (nonhyperactivated) and hyperactivated flagellar waves that were obtained using high-speed video microscopy and digital image processing in order to clarify the mechanism of sperm penetration through the zona pellucida. No difference in the maximum propulsive force, which was parallel to the longitudinal sperm head axis, was found between the activated and hyperactivated spermatozoa. The maximum transverse force (45 pN), which was perpendicular to the longitudinal sperm head axis, of the hyperactivated spermatozoon was ∼2.5 times its propulsive force. As the beat frequency of the flagellar beating remarkably decreased during the hyperactivation, the slowly oscillating transverse force (5 Hz) by the hyperactivated spermatozoon seems to be most effective for sperm penetration through the zona pellucida.

scholarly journals Разрушение эмульсий вода в масле" при воздействии неоднородного переменного электрического поля

2020 ◽  
Vol 46 (5) ◽  
pp. 52
Author(s):  
Э.С. Батыршин ◽  
А.И. Муллаянов ◽  
С.П. Саметов
Keyword(s):  
Electric Field ◽  
Optical Microscopy ◽  
Quantitative Estimate ◽  
High Speed ◽  
Experimental Approach ◽  
High Speed Imaging ◽  
Alternating Electric Field ◽  
Oil Emulsions

The paper presents an experimental approach using microfluidics methods, optical microscopy and high-speed imaging for studying a destruction of water-in-oil emulsions under a non-uniform alternating electric field. A quantitative estimate of parameters characterizing the emulsion destruction dynamics was made. The method can be used for developing effective techniques for water-in-oil emulsions destruction including combined with other affecting methods: chemical, acoustic, thermal, etc.

Experimental Measurement of In-Plane Rolling Nonpneumatic Tire Vibrations Using High-Speed Imaging

2019 ◽  
Vol 47 (3) ◽  
pp. 196-210
Author(s):  
Meghashyam Panyam ◽  
Beshah Ayalew ◽  
Timothy Rhyne ◽  
Steve Cron ◽  
John Adcox
Keyword(s):  
High Speed ◽  
Image Correlation ◽  
Dynamic Mode Decomposition ◽  
Dynamic Mode ◽  
High Speed Imaging ◽  
Correlation Algorithm ◽  
Mode Decomposition ◽  
Series Of Experiments ◽  
Plane Deformations ◽  
Dominant Frequencies

ABSTRACT This article presents a novel experimental technique for measuring in-plane deformations and vibration modes of a rotating nonpneumatic tire subjected to obstacle impacts. The tire was mounted on a modified quarter-car test rig, which was built around one of the drums of a 500-horse power chassis dynamometer at Clemson University's International Center for Automotive Research. A series of experiments were conducted using a high-speed camera to capture the event of the rotating tire coming into contact with a cleat attached to the surface of the drum. The resulting video was processed using a two-dimensional digital image correlation algorithm to obtain in-plane radial and tangential deformation fields of the tire. The dynamic mode decomposition algorithm was implemented on the deformation fields to extract the dominant frequencies that were excited in the tire upon contact with the cleat. It was observed that the deformations and the modal frequencies estimated using this method were within a reasonable range of expected values. In general, the results indicate that the method used in this study can be a useful tool in measuring in-plane deformations of rolling tires without the need for additional sensors and wiring.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

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