Monday, 27 April 2009

Universal flu vaccine in the making

Researchers are developing an influenza vaccine that protects against different strains of the flu, including potential pandemic viruses.

While drug companies currently manufacture different flu vaccines each year to match the strains of influenza that researchers predict to circulate, a universal influenza vaccine could improve protection against strains of the virus as they change.

According to Robert Belshe, who is leading the research at the Saint Louis University, scientists have taken a 'significant first step' in creating the universal vaccine.

Belshe and his colleagues studied a vaccine made with proteins from two of the five main strains of inflenza: influenza viruses A and B.

377 healthy adults received three injections of the vaccine, known as Bivalent Influenza Peptide Conjugate Vaccine (BIPCV), over a six month period.

Researchers found that a low dose of the vaccine is well tolerated and safe. The low dose vaccine also evoked an immune response, high antibody titers, that is similar to levels associated with protecting small animals infected with influenza from serious disease and death.

“This is a significant first step in developing a universal vaccine to help protect against pandemic influenza,” Belshe said, noting that more testing is needed.

More information is available from the Saint Louis University Medical Center's press release.


Friday, 17 April 2009

Gloomy moods better for memory

People are more likely to accurately remember details about their surroundings when in a gloomy mood, researchers have found.

The study was conducted over a two-month period at a suburban newsagency in Sydney, where 73 shoppers were asked to recall small background objects that they had encountered on the check-out counter.

On rainy, cloudy days, the researchers arranged for sad music to be played in the store to reinforce shoppers' negative moods. On bright, sunny days, customers heard happy music.

Researchers found that customers on rainy, cloudy days could list three times as many objects as those on sunny days. More importantly, the negative group's recall was far more accurate as well.

"Mild, fleeting moods can have a profound yet subconscious influence on how people think and deal with information," said Joe Forgas, a University of New South Wales professor who conducted the research.

"Being happy tends to promote a thinking style that is less focused on our surroundings. In a positive mood, we are more likely to make more snap judgments about people we meet," he said. "We are more forgetful and yet we are paradoxically far more likely to be over-confident that our recall is correct."

"Mild negative mood, in turn, tends to increase attention to our surroundings and produce a more careful, thorough thinking style," he said.

Forgas noted that accurately remembering mundane, everyday scenes is a demanding task and one that can be of crucial importance in certain situations, for example in forensic and legal practice.

More information is available from the University of New South Wales's press release.


Thursday, 16 April 2009

Nanochip technology could revolutionise medicine

Photons, instead of electrons, are key to a newly developed nanochip manufacture technique that is three times as precise as conventional methods.

The technique has been dubbed ‘absorption modulation’. It is based on photochromism, which is the ability of some materials to change their colour in response to certain wavelengths of light.

By exposing the photochromic material to patterns created by interfering beams of light, researchers have created lines just 36 nanometres wide -- approximately one-tenth as thick as the wavelength of light used to create them.

The patterned photochromatic material is then used on top of a conventional ‘photoresist’ that is used to coat a silicon wafer, forming a chip.

Lead researcher Rajesh Menon explained that the absorption modulation method creates patterns on a photoresist in a similar manner to how black and white photos are printed from negatives.

“We are creating an image of a pattern on a photosensitive material using light,” said Menon, who is a research engineer at the Massachusetts Institute of Technology.

“[This is] analogous to old-school photography, but, of course at the nanoscale,” he said.

Menon expects his method to be competitive with scanning-electron-beam lithography, which is commonly used to pattern photoresists in today’s semi-conductor industry.

However, by using light instead of electrons, Menon said his technique could be faster, more accurate, and less likely to interfere with fragile samples such as biological samples.

The technology will be commercialised via an MIT spin-off company, LumArray. Already, the researchers have had ‘some discussion’ with chip manufacturers, and Menon expects to achieve commercial production within five years.

The researchers also are pursuing ways of using the technique to create even smaller patterns, down to the scale of individual molecules.

As well as paving the way for advances in nanophotonics, nanofluidics and nanoelectronics, the technology could significantly improve optical microscopy, allowing future researchers to make more detailed biological or material observations.

“The impact here could be substantial as this would enable biologists to peer at proteins with nanoscale resolution, potentially revolutionising medicine,” Menon said.


Friday, 10 April 2009

'Sex-bias' hormone identified

Scientists have identified a hormone that could be responsible for non-reproductive differences in male and female brains.

The hormone, called Müllerian Inhibiting Substance (MIS), occurs only in men, and has previously been thought to have the sole function of preventing the formation of a uterus.

However, according to a new study of male and female mice, MIS may contribute to sex-linked behavioural traits that the researchers call 'sex-biases'.

"The sex-biases in the body do not define a person's sex or sexuality," explained neurobiologist Ian McLennan, who conducted the research at the University of Otago, New Zealand.

"Empathy, for example, has a female bias, but some of the greatest men are empathetic. Likewise, girls engage in less rough and tumble play than boys, but a boy who shuns rough and tumble play is still a boy," he said.

McLennan and his colleague Kyoko Koishi found most neurons in mice to have an MIS receptor. They then charted the behaviours of particular male and female mice that were missing either the gene for MIS or its receptor.

Male mice missing either of these showed a feminisation of some behavioral traits. The researchers noted differences in the 'male tendency' to explore and spatial processing.

Further work is needed to determine which human traits are regulated by MIS; however, the researchers hope that their findings contribute towards a greater understanding of human diversity.

More information is available from the University of Otago's press release.


Thursday, 9 April 2009

Ancient nickel famine may have birthed complex life

Almost 3 million years ago, a subtle geochemical change in volcanic lava may have set the stage for complex life to evolve.

According to geologist Mark Barley, nickel levels in lava and in the sea water began to drop approximately 2.7 million years ago, decreasing by more than half within the subsequent 200,000 years.

Decreased nickel levels were detrimental to the methane-producing microbes that inhabited Earth at the time, paving the way for the proliferation of oxygen-producing bacteria that eventually oxygenated the atmosphere.

"Methane-producing microbes, [which are called] methanogens, require the element nickel for their life and for the formation of methane," explained Barley, who is a professor in the University of Western Australia's School of Earth and Environment.

“The nickel crash after its early boom 2.7 billion years ago helped make our planet habitable by complex life,” he said.

Barley and his colleagues say their findings could explain the puzzling 'Great Oxidation Event' that led to a dramatic rise of oxygen in Earth's atmosphere approximately 2.4 billion years ago.

The researchers' report was published today in the international weekly journal, Nature.

More information is available from the Carnegie Institution's press release.