Sunday, 6 December 2009

Plumbing key to flowering plants’ evolutionary success

The evolution of an efficient water transport system may be how flowering plants came to dominate terrestrial plant life 60-70 million years ago.


Wednesday, 13 May 2009

Energy bubble could enable warp speed travel

Einstein, eat your heart out: a space-time bubble could enable travel at light speed and beyond.

Physicists at Baylor University in Texas are working on a method to make the theoretical Alcubierre ('warp') drive a reality.

Proposed in 1994, the Alcubierre drive expands the fabric of space behind a spaceship into a bubble, while shrinking space-time in front of the ship.

The ship would not actually move; rather, space would move around the ship. The theory thus complies with Einstein’s Theory of Relativity, which states that it would take an infinite amount of energy to accelerate an object faster than the speed of light.

Warp drives have, so far, remained in the realm of science fiction due to there being no known methods to create a warp bubble.

Now, the Baylor University researchers theorise that such a bubble could be formed by manipulating the 11th dimension to create dark energy.

Dark energy is a hypothetical form of energy that is said to be responsible for accelerating the expansion of the universe.

The researchers estimate that the amount of energy needed to influence the extra dimensions is equivalent to the entire mass of Jupiter being converted into energy.

“That is an enormous amount of energy,” said Gerald Cleaver, an associate professor of Physics at Baylor. “We are still a very long ways off before we could create something to harness that type of energy.”

More information is available from Baylor University's press release.


Friday, 1 May 2009

New doubt cast on dinosaur-killing asteroid theory

The asteroid blamed for a mass extinction event 65 million years ago could actually predate the demise of dinosaurs by 300,000 years.

By analysing sediments near the asteroid's site of impact, called the Chicxulub crater, researchers have found that the impact did not cause the extinction of any species.

In the Mexican town of El Penon, Princeton University geologist Gerta Keller and her research team found evidence of 52 species in sediments that were deposited both before, and after, the impact.

"We found that not a single species went extinct as a result of the Chicxulub impact," she said.

Keller's report contradicts the popular theory that the Chicxulub impact heralded the extinction of 65 percent of all species, including plants, dinosaurs, and other animals.

She expects her findings to be unsurprising, as no other great mass extinctions are associated with an impact, and no other large craters are known to have caused a significant extinction event.

Keller suggests that the massive volcanic eruptions at the Deccan Traps in India may be responsible for the extinction.

Huge amounts of dust and gases from the eruptions could have blocked out sunlight and brought about a significant greenhouse effect, she said.

More information is available from the National Science Foundation's press release.


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.


Monday, 30 March 2009

Plastic containers could contaminate drinking water

Potent, man-made hormones could be leaching out of plastic water bottles into bottled drinking water, German researchers have found.

In an analysis of 20 brands of mineral water available in Germany, researchers from the Goethe University detected estrogen contamination in 60 percent of the samples.

Estrogen functions as the primary female sex hormone. In humans, it promotes the formation of breasts and is used in some oral contraceptives.

The researchers tested the extent and effect of estrogen contamination by breeding New Zealand mud snails in both plastic and glass water bottles.

Mud snails in plastic bottles were found to produce more than double the number of embryos of those in glass bottles.

Specifically, one third of the glass bottled samples showed what researchers called 'significant hormonal activity', compared with nearly 80 percent of water in plastic bottles.

More information is available from Martin Wagner and Jörg Oehlmann's online journal article.


Thursday, 26 March 2009

Scientists scavenge power from body movements

Researchers have developed a minuscule generator that converts energy from the slightest of movements into usable electricity.

The nanogenerator consists of zinc oxide nanowires, and is based on a phenomenon called piezoelectricity.

Piezoelectric properties of zinc oxide causes the material to generate an electric current when subjected to mechanical stress.

Scientists plan to embed the nanowires in clothes, shoes and even human muscles to harvest energy from users' movements.

The technology is expected to hit the market in five years' time, after the Georgia Tech research team resolves issues to do with increasing the generator's output voltage.

More information is available from Liz Tay's article on


Wednesday, 25 March 2009

Directing kids not just wasted breath

Frustrated parents rejoice: instructions to toddlers may not just be going 'in one ear, out the other' after all.

According to psychologist Christopher Chatham, young children tend to store instructions and recall them after the fact, rather than act on them instantly.

"For example, let's say it's cold outside and you tell your three-year-old to go get his jacket out of his bedroom and get ready to go outside," said Chatham, who is a doctoral student at the University of Colorado at Boulder.

"You might expect the child to plan for the future, think 'okay it's cold outside so the jacket will keep me warm'," he explained.

"But what we suggest is that this isn't what goes on in a three-year-old's brain. Rather, they run outside, discover that it is cold, and then retrieve the memory of where their jacket is, and then they go get it."

With psychology professor Yuko Munakata, Chatham conducted a study of three-and-a-half to six year olds.

The children were presented with a computer game that required them to press a button when the image appeared on screen.

Meanwhile, the researchers measured the diameter of the pupil of each child's eye to determine the mental effort of the child.

While older children completed the tasks relatively effortlessly, preschoolers were found to have more difficulty.

"The older kids found this sequence easy, because they can anticipate the answer before the object appears," Chatham said.

"But preschoolers fail to anticipate in this way. Instead, they slow down and exert mental effort after being presented with the [image], as if they're thinking back to the character they had seen only after the fact."

The researchers concluded that young children neither plan for the future nor live completely in the present. Instead, they call up the past as they need it.

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


Thursday, 19 March 2009

New fingerprinting technology heats up forensics

Two student scientists have developed a new fingerprint imaging technique that uses heat to produce images cheaply and effectively.

While current methods rely on dyes and chemicals to stain fingerprints, the new technique requires only the application of heat to produce images in a matter of seconds.

The technique was accidentally discovered by honours students Adam Brown and Daniel Sommerville, both of the University of Technology, Sydney.

"Originally the aim was to make fingerprints coloured using chemicals," said Brian Reedy, a senior lecturer at the University, "but the students noticed that the application of heat alone could actually develop fingerprints."

"Our team refined the thermal technique, exposing fingerprints to hot air with temperatures of up to 300 degrees Celsius for periods of 10 to 20 seconds, which produced well-defined images."

"We also observed that after shorter heating times, fluorescent prints could be observed," he said.

Besides Brown and Sommerville's work, there has been little research done regarding the application of heat to fingerprints to date, as heat generally is considered impractical and inferior to other fingerprint imaging techniques, Reedy explained.

More information is available from the University of Technology, Sydney's press release.


Tuesday, 17 March 2009

Silicon-organic hybrid material could speed Internet access

A newly developed silicon-organic hybrid material could be key to superfast, all-optical networks of the future, researchers say.

The material combines silicon with a small organic molecule called DDMEBT that enables light-to-light interactions due to its nonlinear properties.

Materials are said to exhibit a ‘nonlinear optical response’ if their properties are affected by the intensity of light, which in turn affect how the light propagates.

This nonlinear response enables the light-to-light interactions necessary for data processing in all-optical networks.

Because DDMEBT is difficult to flexibly structure into optical circuitry, the researchers have combined it with silicon technology.

Similar to how snowflakes during a heavy storm tend to fill all the gaps between bricks, the small DDMEBT molecules are deposited into gaps between separate silicon waveguides on an integrated optical circuit.

These slots measure only tens of nanometres wide and control the propagation of light beams.

“With pure silicon,” explained Lehigh University physicist Ivan Biaggio, "you can build waveguides that enable you to control light beam propagation, but you cannot get ultrafast light-to-light interaction.”

"We need higher-speed switching to achieve a higher bit rate. Organic materials can do this, but they are not terribly good for building waveguides that control propagation of tightly confined light beams."

"We have combined the two approaches," he said in a press release.

"We start from a silicon waveguide designed to guide the light between two silicon ridges. Then we use molecular beam deposition to fill the space between the ridges with the organic material [DDMEBT], creating a dense plastic with high optical quality and high nonlinearity where the light propagates.”

The resultant device is said to demonstrate the best all-optical demultiplexing rate yet recorded for a silicon-organic hybrid device.

Demultiplexing is the process of deciphering and splitting a combined signal into its component data streams.

More information is available from Lehigh University’s press release.


Friday, 13 March 2009

A drug to end fear

Scientists may be a step closer to eliminating the emotional fear response by using a drug called propranolol.

In a recent study, psychologist Merel Kindt and a team of researchers from the University of Amsterdam showed images of two different spiders to 60 human volunteers.

One of the images was accompanied by a mild electric shock until the volunteers learned to exhibit fear and anxiety for the spider even without the shock being administered.

The following day, some of the volunteers were administered propranolol, while a control group of volunteers was given a placebo. The volunteers were then showed the spider images again.

While no difference was found between the fear response of the control group and those who had taken propranolol initially, differences became apparent on the third day.

On the third day, those who had received propranolol were found no longer to exhibit a fear response on seeing the spider, unlike those who had received the placebo.

While the volunteers could remember the association between the spider and the pain of an electric shock, this was found no longer to elicit any emotional response.

The researchers plan to investigate the long-term effects of administering propranolol, which currently is used to treat high-blood pressure.

They expect their results to contribute to a new procedure for the treatment of patients with anxiety disorders.

More information is available from the Netherlands Organisation for Scientific Research


Tuesday, 10 March 2009

Older men may father less intelligent kids

Children of older fathers perform less well in a range of cognitive tests during infancy and early childhood, a recent study has found.

Queensland Brain Institute researcher John McGrath analysed data about 33,437 children who were born between 1959 and 1965 in the United States.

Children were subject to cognitive testing at 8 months, 4 years and 7 years of age to measure the ability to think and reason, including concentration, learning, memory, speaking and reading skills.

The study found that the older the father, the more likely the child was to have lower scores on the various tests -– with the exception of one measure of physical coordination.

In contrast, the study found that children with older mothers gained higher scores in the same tests.

While previous researchers have suggested that older mothers may provide a more nurturing home environment, the Queensland Brain Institute study suggests that children of older fathers do not necessarily experience the same benefit.

McGrath and his colleagues hypothesise that the link between paternal age and a child's cognitive ability could be due to inferior sperm.

Unlike a woman's eggs, which are formed when she herself is in the womb, a man's sperm accumulates over his lifetime, which previous studies have suggested can mean increased incidence of mutations in the sperm at an older age.

More information is available from the research paper, which was published this week in PLoS Medicine.


Friday, 6 March 2009

Martian mountain could imply life

A study of the Martian volcano Olympus Mons has found that pockets of ancient water may still be trapped under the mountain.

Conducted by Rice University geophysicists Patrick McGovern and Julia Morgan, the study could help answer the question of whether the Red Planet ever had -- or still supports -- life.

Olympus Mons is about three times the height of Mount Everest and stands almost 15 miles high. It slopes gently for a distance of more than 150 miles from the foothills to the caldera.

The researchers modelled the formation of Olympus Mons with an algorithm known as particle dynamics simulation and determined that only the presence of ancient clay sediments could account for the volcano's asymmetric shape.

The presence of sediment indicates water was or is involved.

"What we were analyzing was the structure of Olympus Mons, why it's shaped the way it is," said McGovern, an adjunct assistant professor of Earth science and staff scientist at the NASA-affiliated Lunar and Planetary Institute.

"What we found has implications for life -- but implications are what go at the end of a paper," he noted.

Similar to volcanoes in Hawaii, Olympus is expected to have been able to grow to its size because of the clay's friction-reducing effect.

The researchers suspect that if they were able to stand on the northwest side of Olympus Mons and start digging, they'd eventually find clay sediment deposited there billions of years ago, before the mountain was even a molehill.

The researchers are interested in what may be trapped underneath the mountain, as there may still be fluids, and potentially life, embedded in the clay sediment.

"This deep reservoir, warmed by geothermal gradients and magmatic heat and protected from adverse surface conditions, would be a favored environment for the development and maintenance of thermophilic organisms," they wrote in a report that was published in February's issue of the journal Geology.

More information is available from Rice University's press release.


Saturday, 7 February 2009

Young people may risk over-caffeination

The growing popularity of energy drinks among 18- to 24-year-olds could have a negative impact on the young people's health, researchers warn.

According to Stéphanie Côté, a nutritionist at the Université de Montréal in Canada, energy drinks are 'the coffee of a new generation', used to fuel late night study sessions, all-night parties, and physical activity.

A 2008 report by Agriculture and Agri-Food Canada estimates 1.5 billion cans of the Red Bull energy drink to have been sold in the United States in 2004. Consumption is said to be a growing trend for 18- to 24-year-olds, and younger children also are beginning to consume caffeine-rich drinks before doing physical activity.

But energy drinks are not recommended to either athletes or children under the age of twelve. Furthermore, researchers warn that the strong doses of caffeine found in these drinks can increase hypertension, cause heart palpitations, provoke irritability and anxiety as well as cause headaches and insomnia.

"These [energy] drinks are made up of sugar and caffeine and can have a negative impact on health," Côté said. "Energy drinks don't hydrate the body efficiently because they have too much sugar, and caffeine doesn't necessarily improve physical performance."

"In high quantities it [caffeine] can increase the risks of fatigue and dehydration," she said, noting that Health Canada does not recommend consuming more than two cans of energy drinks per day.

More information is available from the Université de Montréal's press release (in French).