Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sporty Sperm: A Stiff One Gets the Job Done More Quickly

10.04.2002


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

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>