Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Satellite images reveal key to predicting outbreaks of plague

Normally percolation theory is used to describe the movement of liquid through porous material. A good example of percolation is when hot water is forced through ground coffee in an espresso or Senseo machine.

By moving through the coffee via the empty spaces between the ground coffee particles, the water picks up the flavour of the coffee. Stephen Davis and colleagues at the Faculty of Veterinary Medicine, Utrecht University, report in Nature their discovery that the spread of the bubonic plague bacteria in Central Asia by gerbils, works much the same way.

Plague bacteria percolate through the landscape transmitted by fleas from one great gerbil family to the next, from burrow system to burrow system. It’s the first time percolation theory is used to accurately describe the natural dynamics of an infectious disease. The discovery might be helpful to understand how outbreaks of disease occur in other populations. It may, for example, shed new light on spread of bovine tuberculosis in badgers, and spread of viral diseases in populations of African lions.

Spread of infection predictable

Like making a good cup of coffee, there are conditions for successful percolation of the plague through gerbils. In the case of coffee, if you pack it too tightly the water will not move through and the coffee just burns. In the case of plague, if there are too few gerbils, the fleas won’t be able to move from one burrow to another, and the spread halts. The use of percolation theory by Davis can predict the final size of an outbreak of plague, starting with one infected family group. It has also determined the so called ‘abundance threshold’ necessary to be exceeded before percolation occurs, in this case the percentage of available burrows populated by gerbils.

Russian ‘Plague Archives’ show plague dynamics

In Kazakhstan and elsewhere in central Asia, the plague bacterium Yersinia pestis, source of human cases of bubonic plague, still circulates in wild populations of gerbils and other small mammals. Intensive surveillance systems established by Soviet scientists in Kazakhstan at the end of World War II appear to have successfully reduced human cases. These programs also resulted in vast amounts of data, referred to as ‘The Plague Archives’, recording the dynamics of plague in wild animals. The data for the research done by Davis comes from one of the desert plague foci in Kazakhstan where great gerbils play a central role as a plague host.

A remarkable feature of these gerbils is their complex burrow systems that create discs of bare earth, typically 30 metres in diameter and visible from space on satellite images like the ones from Google Earth. The vast tracts of land inhabited by connecting burrows of great gerbils contrast starkly with the relatively short distances of about 200 metres travelled by fleas responsible for transmission of plague. This difference in scales means that connectivity of the population is key.

Peter van der Wilt | alfa
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

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...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

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...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

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...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>