Alkenes warn ants of invaders
Animal biologists and chemists have joined forces to solve a century-long insect mystery: discovering the chemical cues that ants use to tell friend from foe. It’s long been assumed that ants’ recognition of their nestmates - and their enemies - has a chemical basis, but pinning down the exact compounds responsible has been a difficult task.
UK and Finnish researchers publishing in Proceedings of the Royal Society B(DOI: 10.1098/rspb.2007.1708), picked out Formica exsecta ants, which are known to produce a simple collection of alkanes and alkenes.
For these ants, the team’s chemists found that a delicately balanced profile of C23-C29 alkenes alone was specific to each colony. They used glass beads to simulate dummy ant invaders - making exact copies of nestmate and invader alkene profiles to coat the beads.
’When beads with the colony odour were introduced they were investigated then ignored, but the ants behaved aggressively towards the beads with the foreign odour, trying to remove them,’ said lead author Stephen Martin, from the University of Sheffield, UK.
Nanoparticles emitted by low-emission diesel engines may be more harmful to human health than the dark exhaust fumes produced by older models, researchers in Germany and Italy have found.
In vitro tests suggested that newer diesel engines (conforming to 2005 Euro-IV low emission standards) emit 5-20nm particles that penetrate lung tissue more deeply than older engine exhaust particles, which are around twice as large.
The optimised combustion of low-emission engines, which almost completely burn diesel, could be to blame, said the researchers, who published in Environmental Science & Technology (2008, 42, 1761, DOI: 10.1021/es0716554). In older engines small amounts of unburned fuel lead to more - and bigger - soot particles.
A separate study carried out in Sweden on human volunteers (Particle and Fibre Toxicology, DOI: 10.1186/1743-8977-5-4) found that diesel fumes can trigger stress-related changes in the brain’s electrical activity. Lead researcher Paul Borm, from Zuyd University in the Netherlands, suggested nanoparticles - which rat studies have
shown can enter the brain from nerves in the nose - were to blame.
Metal markets upset
Smelter shutdowns following power plant blackouts in South Africa have led to shortages of platinum, mainly used in catalytic converters to lower exhaust pollution. South Africa supplies over three-quarters of the world’s platinum, and prices of the metal passed an unprecedented $2000 per troy ounce at the end of February 2008.
Copper mining in Chile, which accounts for a third of the world’s copper production, has also been affected after droughts brought by La Ni?a. But prices of these and other increasingly expensive precious metals - such as silver and gold - are likely to be volatile, as power shortages occur alongside concerns over a US recession.
Fakes and frauds
South Korean scientist Tae Kook Kim has been suspended by the Korean Advanced Institute of Science and Technology (KAIST) over scientific misconduct. Kim has admitted fabricating - and has now retracted - research published in Sciencein 2005, on using nanoparticles to probe cell behaviour, and in Nature Chemical Biology in 2006,
on using proteins identified by the nanoparticle technique to reset cell aging clocks. KAIST’s investigation had not been concluded as Chemistry World went to press.
After his Science publication in 2005, Kim told a local newspaper he wanted to be as famous as fellow countryman Woo Suk Hwang - the stem cell researcher who in 2006 was dismissed after admitting to faking research on cloning.
Meanwhile, chemistry professor Pattium Chiranjeevi, of Sri Venkateswara University in Tirupati, India, has been accused of faking over 70 research papers published in a variety of journals, many of which have now been retracted by publishers.
Electric cars are seen as eco-friendly, but they could stress scarce water resources, US scientists have warned. Michael Webber and Carey King, from the University of Texas at Austin, calculate in Environmental Science & Technology (DOI: 10.1021/es0716195) that electric cars consume three times more water per mile than those running on gasoline (petrol). That’s because water is the main coolant in the coal, gas, or nuclear power plants that largely supply vehicles with electricity. Biofuels derived from irrigated crops are even more water-intensive, the researchers say.
The added water demands might not be very significant, commented Peter Gleick, president of the environmental think-tank the Pacific Institute in Oakland, California - especially if there was greater uptake of solar electricity, which uses less water. But he agreed that the link between water use and energy had been neglected amid understandable concerns about security and carbon-costs of energy supplies.
Legal options for open access
The Scholarly Publishing and Academic Resources Coalition (SPARC), Science Commons, and the Association of Research Libraries have released a white paper helping university administrators meet the US National Institutes of Health open access rules that come into force on 7 April 2008. The new requirement means NIH-funded researchers must deposit their articles in the agency’s free online archive, PubMedCentral, within 12 months of publication (see Chemistry World, March 2008, p14). Attorney Michael Carroll spells out the options for copyright management in a freely available paper at www.arl.org/sparc/advocacy/nih/copyright
Nanotube bed sheets
New Hampshire, US-based company Nanocomp Technologies has unveiled the world’s largest sheet of carbon nanotubes. The one metre by two metre foldable sheet contains around 1017 nanotubes, conducts electricity, and is reportedly as strong as steel, but thirty times less dense.
To make the sheet, manufacturers wove millimetre-long nanotubes into 30nm-wide bundles, then assembled these together into layers on a rotating drum. Sheets like these could be used in composite coatings, to dissipate heat, protect objects from lightning strikes by steering charge around them, or to shield devices from electromagnetic interference, Nanocomp says. The sheets are coated to prevent black specks rubbing off on your hands.
Australia rejigs numbers game
Australia’s minister for the Department of Innovation, Industry, Science and Research, Kim Carr, has announced a new system to assess the country’s research quality. It replaces the previous government’s mooted Research Quality Framework (RQF) which Carr scrapped just before Christmas (see Chemistry World, January 2008, p8).
The Excellence in Research for Australia (ERA) initiative will rely on a combination of peer review and metrics - such as citation statistics - to evaluate research quality. The scheme will not immediately be coupled to research funding, but will be overseen by the Australian Research Council (who award grants, so have expertise in judging university research) in order to reduce costs and bureaucracy - contentious issues of the old RQF.
Chemists share Descartes prize
A nanotechnology research consortium led by David Leigh, of Edinburgh University, UK, has won a third-part share of the prestigious ?1.8 million Descartes prize for transnational collaborative research at the European Science Awards. Leigh’s team was cited for the SynNanoMotors project, which developed the first examples of synthetic motors on a molecular scale (see also Chemistry World, March 2007, p23).
US budget woes
The disappointing budgets allocated to US government science agencies (see Chemistry World, February 2008, p13) are beginning to cut into chemistry. ’We’re squeezed and unable to implement the plans that we had,’ says Luis Echegoyen, who directs the National Science Foundation’s (NSF) division of chemistry. The NSF will award fewer grants to university chemists, while the National Institute of Standards and Technology (NIST) is cancelling a key nanoscience exploratory research programme for FY08 at its Chemical Science and Technology Laboratory. Science lobby groups are hoping Congress will pass a $500 million supplemental budget in April.