A scientist who studies the phsyics of sperm "as a hobby" is challenging the current understanding of how sperm swim towards an egg. At the Society for Experimental Biology conference today Dr Christopher Lowe will present the results of his modelling of a sperm`s tail, suggesting we may need to re-think our assumptions of how sperm move through fluid.
Experimental studies of sperm have generated a fairly well established database of parameters on sperm movement. The frequency and wavelength of the tail movement is estimated at around 50 hertz down the tail. The low speed at which sperm swim is well known - perhaps suprisingly low given the urgency of the mission, but understandable because of the sheer force of the fluid it is moving in. "If you were a sperm it would be the equivalent of swimming in a liquid a thousand million times more viscous than air. There is not a substance known to man that is that viscous - even swimming in a pool of thick syrup would be easy going compared to the Olympic feats performed by sperm," says Dr Lowe.
The fluids in which sperm swim are also well-characterised. Using both the sperm and fluid parameters Dr Lowe constructed a computer model which accurately recreated the shape and movement of the sperm`s tail as it swims towards the egg. The simulation also correctly reproduced the swimming speed. But to Dr Lowe`s surprise, he discovered a discrepancy between the computer model and the established theory, related to how stiff the sperm`s tail needs to be to counteract the resistance or drag of the surrounding fluid. "Either the tail is significantly stiffer when the sperm is swimming than previous experiments suggest, or the sperm is doing something very clever indeed to overcome the sticky forces exerted on it by the surrounding fluid. On the grounds that sperm, being on a kamikaze mission, are unlikely to be over-endowed in the brains department, I prefer the former explanation," says Dr Lowe. He suggests the discrepancy arises because many of the previous studies have been performed on sperm parts or on dead sperm. His findings are wholly based on the simulation of a live sperm.
Jenny Gimpel | alphagalileo
International team discovers novel Alzheimer's disease risk gene among Icelanders
24.10.2016 | Baylor College of Medicine
New bacteria groups, and stunning diversity, discovered underground
24.10.2016 | DOE/Lawrence Berkeley National Laboratory
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Power and Electrical Engineering
24.10.2016 | Life Sciences
24.10.2016 | Life Sciences