Intimidation and threats are common throughout society, whether it’s in the school playground, sporting arena or boardroom. Threatening behaviour is equally widespread among non-human animals.

Individuals signal their superior strength to competitors to obtain food, resolve territorial disputes and acquire mates. Current theory insists that signals of strength should be honest. Surprisingly researchers have found that dishonest signals are used routinely during dominance disputes by male Australian crayfish.

Bacteria must talk to each other, in a sense. They use signals to inform neighbors whether to switch certain genes on or off and this allows them to adapt to changing circumstances.

Scientists have identified three different signals that indicate damage to chloroplasts— the photosynthetic factories of plant cells that give plants their green color —but little is known about how the signal gets passed on to the nucleus. Scientists at the Salk Institute for Biological Studies made a big step towards explaining how chloroplasts let a cell's nucleus know when things start to go wrong at the periphery so nuclear gene expression can be adjusted accordingly.

Combining precise observations obtained by ESO's Very Large Telescope with those gathered by a network of smaller telescopes, astronomers have described in unprecedented detail the double asteroid Antiope, which is shown to be a pair of rubble-pile chunks of material, of about the same size, whirling around one another in a perpetual pas de deux. The two components are egg-shaped despite their very small sizes.

Picture the flow of water over a rock. At very low speeds, the water looks like a smooth sheet skimming the rock's surface. As the water rushes faster, the flow turns into turbulent, roiling whitewater that can overturn your raft.

DNA testing carried out by University of Leicester geneticists and funded by The Wellcome Trust has thrown new light on the ancestry of one of the USA’s most revered figures, the third President, Thomas Jefferson.

Almost 10 years ago, the University of Leicester team, led by Professor Mark Jobling, together with international collaborators, showed that Thomas Jefferson had fathered at least one of the sons of Sally Hemings, a slave of Jefferson’s.

For the very first time, astronomers have witnessed the speeding up of an asteroid's rotation, and have shown that it is due to a theoretical effect predicted but never seen before. The international team of scientists used an armada of telescopes to discover that the asteroid's rotation period currently decreases by 1 millisecond every year, as a consequence of the heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system and even break apart.

Nanomechanical oscillators -- tiny strips of vibrating silicon only a few hundred atoms thick -- are the subject of extensive study by nanotechnology researchers. They could someday replace bulky quartz crystals in electronic circuits or be used to detect and identify bacteria and viruses.

Despite the attractive electrical properties and physical features of single-walled carbon nanotubes, incorporating them into scalable integrated circuits has proven to be a challenge because of difficulties in manipulating and positioning these molecular scale objects and in achieving sufficient current outputs.

Now, researchers at the University of Illinois, Lehigh University and Purdue University have developed an approach that uses dense arrays of aligned and linear nanotubes as a thin-film semiconductor material suitable for integration into electronic devices.

Marine and freshwater organisms could be facing damage due to increasing levels of ultraviolet (UV) radiation, according to a United Nations (UN) commissioned review.

The news is reported in the latest edition of the Royal Society of Chemistry journal Photochemical & Photobiological Sciences.

Aquatic ecosystems produce over half the biomass of the Earth and are an integral part of the planet’s biosphere.