Locusts - breaking up the party

Locust swarms could become a thing of the past, thanks to UK scientists who have discovered that serotonin is the key to their swarming behaviour. 

The team found that locusts with high serotonin levels tend to swarm, and that blocking their serotonin receptors can stop this behaviour, turning them back into harmless loners.

The group worked out that the insects get agitated when they see or smell too many other locusts, triggering a rise in their levels of serotonin (the same neurotransmitter that's linked to depression in humans). This causes a drastic switch in behaviour - as well as their colour - transforming locusts that were harmless on their own into swarming plagues that can devastate crops.

The team discovered that doping the locusts with the serotonin receptor antagonistsketanserin and methiothepin, or with alpha-methyltryptamine, which blocks serotonin production, stops the swarming behaviour - ensuring the insects remained resolutely solitary. 

The team say in principle these products could be used as a method of locust crowd control in areas where their populations are growing. The findings are published in  Science  (DOI: 10.1126/science.1165939). 

Topical treatment wipes out herpes

US scientists have developed a topical viricide which they say could be used to prevent the spread of sexually transmitted viral infections.     

The team based at the Harvard Medical School have developed a topic treatment that disables the key genes used in the spread of the herpes virus in mice. Using RNA interference, the technique that won a Nobel Prize in 2006, the team were able to simultaneously disable both the virus's ability to replicate and the host's ability to take up the virus.  

They showed that the ointment could be applied one week before and up to a few hours after exposure, and still remains effective.   

The team, who published these results in Cell Host and Microbe  (DOI: 10.1016/j.chom.2008.12.003), are now looking into how the same concept could be used to halt the spread of HIV.  

Safer rail travel for chemicals  

The US Department of Transport has introduced new standards to make the railway cars used to transport hazardous chemicals such as chlorine and ammonia safer in the event of a crash.  

The rule, which affects all new tank cars built after 15 March 2009, will improve the durability of the tank car if it is involved in an accident. All cars will need to have better resistance to punctures, as well as stronger inner shells or outer jackets - depending on the chemical they carry. A 50 mile per hour speed limit has also been imposed on trains hauling the most dangerous chemicals. 

Plastic chemical hangs around

The controversy over bisphenol A (BPA) - a chemical found in reusable plastic bottles - continues. Publishing in Environmental Health Perspectives  (DOI: 10.1289/ehp.0800376), a US team have found that the chemical remains in the body at high levels even after fasting for 24 hours.  

These new results question previous assumptions that food is our main source of exposure, and that BPA is excreted quickly from the body.   

With studies linking the chemical to diseases such as breast cancer and heart disease, the team's findings could influence the US Food and Drug Administration's ongoing re-evaluation of its position on the safety of BPA (see  Chemistry World  , February 2009, p5).  

Plutonium unearthed

The oldest known sample of man-made plutonium has been found during the clean up of the decommissioned US nuclear production plant where second world war atomic weapons research was carried out.  

While excavating the Hanford site, several hundred milligrams of plutonium was found. Scientists from the Pacific Northwest National Laboratory in Richland used a range of analytical techniques - including isotopic age dating - and reactor model simulations to date the plutonium.   

Reporting in  Analytical Chemistry  (DOI: 10.1021/ac802286a), the team say that the sample was part of the first industrial-sized batch of plutonium separated at Hanford on 9 December 1944. 

Ozone recovery delay predicted

Global warming may delay the recovery of the ozone layer, claim US scientists. The atmospheric models, developed by a team at Johns Hopkins University in Baltimore, suggest that the increase in greenhouse gases could adversely affect the regeneration of stratospheric ozone in some regions. 

Reporting in Geophysical Research Letters (DOI: 10.1029/2008GL036223), they predict that climate change could cause the circulation of air to speed up in the lower stratosphere in a band of the Earth including Australia and Brazil. And that if air is passing through the region more quickly, less ozone will be formed, meaning that the amount of ozone in these regions would never return to their pre-1960 levels. 

However, they do predict better news for some, saying that restoration of ozone in the polar regions and northern mid-latitudes should not be impacted by an increase in greenhouse gases.  

Ultra-pure boron structure unveiled

US scientists have characterised a new form of elemental boron - a notoriously difficult element to synthesis in a pure form - and were surprised to find that ionic bonding helps hold the structure together.

The team from Stony Brook University, New York, who published their findings in Nature   (DOI: 10.1038/nature07736), have added this new form - termed gamma-boron - to the 16 polymorphs of boron already known. 

Gamma-boron is made up of two well known forms of boron clusters, B₂pairs and B₁₂icosahedra - where 12 boron atoms are arranged in a regular 20 sided polyhedron.

The group unexpectedly found that differences in electronegativity between the two forms led to a significant amount of ionic bonding. The B₂pairs and B₁₂icosahedra act as anions and cations, respectively, forming a sodium chloride type structure. The ionic component was shown to affects properties such as the electronic bandgaps and IR spectrum.  

This new form has also shed light on the element's previously unknown phase diagram, helping to map the element's phase changes in response to pressure and temperature. 

Polymer improves plastic transistors

The prospect of powerful electronic circuits made from printable plastics has moved a step closer with the discovery of a cheap, stable organic polymer that carries charge through the movement of electrons.  

The semiconductor created by the Polyera Corporation in Illinois, US, complements the printable organic semiconductors that operate by conducting positive charges or 'holes' - opening the possibility of far faster printed circuits based on transistors which combine the two types of materials. 

The group also showed that their electron-transporting polymer, based on naphthalene-bis(dicarboximide), can be readily processed by a range of printing technologies, including ink-jet and gravure printing.  

The team, who published their research in Nature  (DOI: 10.1038/nature07727), say that the new transistors may find applications in organic display devices and sensors. 

UK research budget debated   

The UK science minister has called for a debate on whether the national research budget should be rethought, directing funds into areas that could help the UK recover from the economic downturn, provoking a concerned response from scientists.  

During a Foundation for Science and Technology lecture in London on 4 February 2009, Lord Drayson questioned whether funds should be moved away from 'blue skies' research, and directed towards areas that were likely to make more money in the immediate future, such as life sciences, green energy and digital communications.  

Lord Rees, president of The Royal Society, responded that blue skies research did not short change the public and was crucial for the future - a view supported by other scientists including Peter Ringrose, chairman of the Biotechnology and Biological Sciences Research Council (BBSRC).