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By Stephen Luntz

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Gamma Ray Burst at the Gates of Dawn
A 2009 gamma ray burst 500 million years after the Big Bang has been estimated as the oldest event ever observed.

Prof Brian Schmidt of the Australian National University’s Research School of Astronomy and Astrophysics says it is not easy to measure the age of such distant events, particularly those that don’t last long enough for detailed study. “What we definitely know is that this gamma-ray explosion was incredibly bright for a short period of time billions of light years ago, at the dawning of the birth of the universe, and that is certainly very exciting,” he says.

GRB 090429B was observed in the infrared by NASA’s Swift satellite. With no optical observations it was not possible to conduct the spectroscopy that would indicate its red shift precisely.

However, the absence of light at optical wavelengths is indicative of a very high red shift, with the cut-off caused by the absorption of light from gases located between Earth and the original explosion.

The location of the shortest wavelength of light Swift picked up from GRB 090429B suggests that its red shift is around 9.2, according to an Astrophysical Journal paper co-authored by Schmidt. The previous oldest event is estimated at a red shift of 8.4.

“With recent advances in technology, we are now getting to a stage where we are discovering what the far reaches of the universe look like, and that’s bringing us closer to the Big Bang, which is believed to have occurred 13.7 billion years ago,” Schmidt says. “GRB 090429B exploded when the universe was less than 4% its present age, just 520 million years old, and it tells us that stars were already being formed and exploding at that time.”

Bee Vision Controls Aerodynamics
Bees determine how to hold their abdomen in flight based on what they see rather than the motion of the air.

Dr Tien Luu of the University of Queensland’s Vision Centre discovered this after tethering bees to a piece of metal so they were free to flap their wings and adjust their body angle but could not move through the air. “We created a simulated scene by running images rapidly past its eyes so the bee thinks that it’s flying forward down a tunnel,” Luu says.

Luu reported in The Journal of Experimental Biology that the bees adjusted the position of their abdomen, lifting it into a more aerodynamic position when the images moved faster and letting it drop when they slowed down. “While previous research has demonstrated that insects lift their abdomens during flight, we have found that visual stimulus alone is powerful enough to provoke the streamlining response,” Luu says.

“Bees fly at a high speed, typically 35 km/h, yet they seldom collide with obstacles or crash land,” Luu says. “This is because their eyes have lots of photo­receptors – vision cells – which focus on objects as they fly past and so detect motion very clearly. When their eyes signal that they can fly faster, they streamline their bodies to reduce the aerodynamic drag that would otherwise be caused by the abdomen.”

The bees flapped their wings while airborne, even though the tether kept them aloft. Luu says that bee wings usually beat at 200–250 Hz irrespective of speed, and adjust the power of their strokes to speed up or slow down. Since the amplitude of each wing stroke is hard to measure, Luu is unsure whether this was also adjusted to match the images’ apparent speed.

While the advantages of an aero­dynamic body shape at high speed are obvious, Luu is not sure why the bees prefer to let their abdomen drop at low speed. “Drooping may be less energy-consuming,” she says.

Luu notes that bees assess their speed based on how fast the angle of an object’s position changes. While this can be distorted if something appears closer or further than its true position, they judge distances well enough for flight in most circumstances.

“The research could be useful in designing control systems for aircraft that rely on vision to control aircraft,” Luu says, although she does not think it is likely to replace other systems of aircraft control.

Baby Formula Fails
Supposedly hypoallergenic baby formulae do not reduce a child’s risk of developing allergies, a study has found. The results are particularly interesting because the research was funded by a subsidiary of Nestle, which was no doubt hoping for the reverse result.

“Over the last 40–50 years, rates of allergic diseases have increased dramatically,” says Dr Adrian Lowe of the University of Melbourne. Breast-feeding substantially protects against allergy development, but supposedly hypoallergenic baby formulae have been introduced for children considered at risk of allergies when breastfeeding is discontinued for any reason.

Lowe explains that hypoallergenic formulae include partially hydrolysed whey in which proteins in cows’ milk are cleaved into small pieces. “It was hoped introducing them in this form might induce tolerance,” says Lowe. This idea was supported by animal trials and a clinical study now known to have been fabricated.

A 2009 study providing weak evidence supporting hydrolysed whey led the Australasian Society of Clinical Immunology and Allergy to recommend the use of hypoallergenic formulae.

Lowe gave children either hypoallergenic formulae, cow’s milk or soy formula after breastfeeding ceased, and tested for allergies at 6–24 months and again at 6–7 years.

“Our results are definitive,” Lowe says. “If you add this to the previous weak evidence it no longer supports formula.” Lowe considers this unfortunate because the hydrolysis of whey is easy and, had it worked, the formula would have been a “cheap solution”.

As it is, the only solidly based methods Lowe can offer for parents to help their children avoid allergies are to breastfeed as long as possible and avoid exposure to tobacco smoke.

Left Turn in Pregnancy
Pregnant women may improve their prospects of a successful birth by sleeping on their left side late in pregnancy, a study published in the British Medical Journal suggests. The author, Ms Tomasina Stacey, says the results are not conclusive, but a correlation was found between stillbirth and other sleeping positions.

Stacey, a PhD student in midwifery at the University of Auckland, says: “We had a hypothesis that sleeping on your back during pregnancy might not be so good, because it makes snoring worse. We thought sleep apnoea might affect a baby’s oxygen levels.”

Stillbirth is so rare that Stacey says any attempt to follow women through pregnancy to see if sleeping patterns predict stillbirth rates would have required “us to follow tens of thousands of women”. Instead she interviewed 155 women who had given birth to a stillborn baby after 28 weeks, as well as a control group, and asked them about the position in which they slept on the last night before giving birth, as well as 1 week and 1 month before.

“I was quite surprised how many remembered,” Stacey says. “Some said they had changed places with their husbands because they liked sleeping facing out, or facing him.”

The sample suggests that there was no difference between the outcomes for those who slept on their back and slept on their right. However, women who spent the last night on their left had half the rate of stillbirth of the others. Sleeping on the left in the month and week leading up to the birth also showed a trend that Stacey says was “close to significance”. Stacey stresses that the work needs corroboration, preferably from a larger study.

Since the difference between left and right sides was un­expected, she doesn’t have a clear explanation but thinks that lying on the right may squash the larger blood vessels, reducing oxygen flow to the baby. She also notes that caesarean deliveries have a higher success rate when the mother is tilted slightly to the left.

Women who went to the toilet once or not at all on the last night were also more likely to suffer stillbirth, but Stacey says it is not clear whether getting up improved blood flow or if the mother had an undisturbed night in cases where the baby had died.

A British Medical Journal editorial notes that stillbirths in the developed world are ten times more common than SIDS deaths and four times more frequent than babies born with Down’s syndrome, yet are the subject of far less research.

Reindeer See in Ultraviolet
If Rudolph wanted to guide Santa’s sleigh he needed a nose that glowed in the ultraviolet range rather than emitting red light. International research has found that reindeer are capable of seeing light with wavelengths that are too short for the human eye, although how they do it remains unclear.

“The human cornea cuts out sharply at 400 nm,” says Prof David Hunt of the University of Western Australia’s Neuro­ecology Group. “There is evidence from people who have had their lens removed that the retina can detect wavelengths slightly shorter than that, but normally they are completely blocked out.”

Shorter wavelength light releases free radicals in the cells of the retina, like UVB light in skin cells, leading to long-term damage. Although the body produces enzymes that can scavenge these oxidising chemicals, most long-lived diurnal animals protect the retina by having the front of their eyes block the penetration of UV light. Animals that are nocturnal, live underwater or have short life spans may detect UV since they will seldom be exposed enough to send themselves blind before they die.

There are exceptions, however, most notably parrots that see in the UV range. Hunt says it is not known how they avoid retinal damage.

Now Hunt has co-authored a paper in the Journal of Experimental Biology examining the surprising discovery that reindeer are similarly capable. The team led by Dr Christopher Hogg and Prof Glen Jeffrey of University College, London were interested in the fact that pigments in the eye respond to a 24-hour cycle, and wanted to observe the effect of long periods of light and darkness.

The UV discovery was made by chance, but makes some sense. UV light is scattered off snow, but lichen and wolf fur both absorb UV. Consequently, in the winter half-light each would stand out as dark. Reindeer sustain themselves on lichen during the winter, while wolves represent their main predators.

Hunt says the discovery suggests that other northern animals might also benefit from UV vision, but he’s not keen to conduct the testing required on polar bears.

Reindeer have only recently adopted their current lifestyle, so the trait must have evolved quickly. Hunt doesn’t know if it appeared in one sudden shift, but thinks it more likely that it appeared gradually as evolution selected reindeer capable of seeing further and further into the UV.

Childhood on a Farm Is Baaad for the Blood
Growing up on a livestock farm represents a health risk for New Zealand children, with a 22% increased risk of dying from blood cancers like leukaemia.

Dr Andrea ‘t Mannetje of Massey University’s Centre for Public Health analysed 114,000 death certificates for New Zealanders between the ages of 35 and 85. New Zealand death certificates include an individual’s occupation and that of their parents. While ‘t Mannetje acknowledges that some parents may have changed jobs to make the certificate misleading, in most cases these provide a good indication of childhood environment.

“We wanted to check the hypothesis that early exposure to some things can alter the immune system, and this can affect blood cancers in later life,” ‘t Mannetje says. “However, since we had the data we also checked for other sorts of cancer and found the effect was unique for blood cancers.”

Poultry farms represent the greatest danger, with three times the rates of leukaemia, multiple myeloma and non-Hodgkin’s lymphoma. While the sample size here was small compared with all livestock farms, ‘t Mannetje acknowledges that it was still large enough to make the finding significant.

Pesticide use has been suggested as a possible cause for cancers among farmers, but ‘t Mannetje notes that at the time when many of the people in the study were growing up pesticides were used far less widely than in more recent times. Instead ‘t Mannetje believes that biological exposures are more likely to provide the explanation, although she says: “At this stage we’re just hypothesising”.

New Zealanders who grew up on crop farms or orchards had a risk of dying from blood cancers that was almost 20% lower than the population as a whole, even though adult farm work in these places has been associated with greater risk of the diseases. According to ‘t Mannetje: “Growing up on a farm is probably healthier as a background than in a city,” if pesticide use and biological triggers from association with animals can be removed.

A Knight on Shining Treadmill
The knights of old found it hard to do battle vigorously inside armour, and now we know just how hard, thanks to a study published in the Proceedings of the Royal Society of London, Biological Sciences.

“The steel plate armour worn by soldiers in medieval Europe weighed 30–50 kg, and there was a real trade-off between increased protection and reduced mobility,” says Dr Federico Formenti of the University of Auckland. Carrying a 40 kg weight is hard enough, but Dr Graham Askew of Leeds University explains that armour was worse. “In a suit of armour, the limbs are loaded with weight,” he says, “which means it takes more effort to swing them with each stride”.

Moreover, Formenti points out that the helmet and breastplate could constrict breathing, particularly when forced to run or do some forceful smiting.

Presumably knights knew this and figured that the safety provided was worth the limitations, but they may not always have been right. Historians attribute the English victory at Agincourt to the fact that the French knights were too weighed down for the muddy conditions and were overcome by more nimble English and Welsh soldiers.

The French might have benefited from Formenti’s work with volunteers at the Royal Armouries Museum in Leeds, who were tested on treadmills to see how much harder exercise is inside a suit of armour. “Our research showed that wearing a suit of armour doubled the amount of energy that a soldier used to walk or run, and substantially reduced their speed,” Formenti says. He also found that the kinematics of knights were relatively unchanged.

The study was performed on people who had extensive experience using armour made specifically to suit them, but Formenti acknowledges that the Royal Armourers would have had less time training for the challenges of battle in armoured suits than medieval knights. Although three different styles of armour were studied all were from the same era, so Formenti says he cannot compare the merits of lighter but less protective defences.

The work is of more than amusement value. Formenti says that robotic exo­skeletons are being designed for people with disabilities and modern soldiers. However, the energy required for their operation limit their range. Formenti says his work serves as a reminder that the distribution of weight, as well as the overall mass, needs to be considered in these designs.

Microwaves Open Bacterial Pores
Microwave radiation opens the pores of E. coli cells, allowing substances to enter or leave the cell, Swinburne researchers have found.

Microwave radiation can cause cell linings to collapse. However, scientists were unsure if this was purely a result of the liquid inside the cell boiling or if there were non-temperature-related effects.

In research published in Applied and Environmental Microbiology, Prof Russell Crawford’s team reported that even with peak temperatures below 40°C E. coli bacteria leak intracellular fluid when exposed to microwave radiation of 18 GHz.

The team also discovered that the microwaves caused sugar molecules to cross the cellular membrane, opening up potential medical applications.

“For instance, the pore-forming effect could help doctors deliver antibiotics to infection sites, such as open wounds or surfaces around medical implants,” Crawford says. “By focusing microwave treatment on the site, this would open up pores in the bacterial cells, allowing the drugs to enter. And because the microwave treatment would be done at a low temperature it wouldn’t damage any of the patient’s surrounding cells.”

Dr Rodney Croft of the University of Wollongong’s Centre for Radio Frequency Bioeffects Research says: “In terms of the safety, the energy produced by the exposure is much larger than safety standards permit, and so we cannot be confident that no damage could result from the technique”. Nevertheless, he hopes that safe doses could be administered, possibly through brief radiation pulses.

Prof Elena Ivanova of Swinburne University initiated the research and says it is not known over what frequencies the effect occurs. She adds: “One of our previous projects gave evidence that the mechanical properties of tissue cells were not affected. However, more work is required in this direction.” So far it is not known whether other forms of bacteria respond the same way was E. coli.

Microwave radiation would not be a common feature of the environments in which E. coli live, so it is unclear how the trait evolved.

Beware the Moon Snail
It sounds like a horror movie parody, but snails have been discovered that ambush soldier crabs by lying in wait beneath the sand, surging up to grab the fast-moving crustaceans even if the prey are larger than themselves. The discovery was published in Molluscan Research.

“Moon snails are well-known for attacking other snails and bivalves and, until now, moon snails have been thought to feed almost exclusively on shelled molluscs,” says Dr Thomas Huelsken of the University of Queensland. “This observation that they also prey on crabs is a total surprise. Moon snails have now secured their status as top predators of the intertidal sand flats.”

Moon snails are best-known for their beautiful shells and the neat circular holes they drill through the shells of other molluscs or bivalves. The holes allow moon snails to eat their prey alive inside the shell.

Evidence of the long history of this activity is clearly written in the fossil record. “Now, we can surmise that palaeo-moon snails were probably eating crabs too, but have somehow not left a fossil record for that part of their diet,” Huelsken says.

The explanation for this absence, Huelsken believes, lies partly in the fact that crustacean carapaces don’t fossilise well. Moreover, he points out that their brittle nature is known “to anyone who has eaten them for dinner”. While the moon snails leave a circular hole on a bivalve, on crabs their holes are “more toothy looking” and have not been recognised as being from the same source.

Huelsken says he first observed a moon snail catching a soldier crab while sampling a specimen for a study on genetic connectivity between molluscs. Having then observed the same behaviour on a Victorian beach he returned to Stradbroke Island, the site of the first observation, to see how common the behaviour is. “I found it is normal behaviour for this species, not aberrant.”

Capturing the fast-moving crabs is not easy, and Huelsken says that larger prey, in relation to the predator, have more chance of escaping. Nevertheless, soldier crabs sometimes bury themselves in sand to feed or hide, and the moon snails have developed a technique for grabbing them as they come to the surface.

Impact of Fishing Small Species
Removing the top predators from an ecosystem can have dramatic consequences, but an international study published in Science shows that the same can be true for species near the bottom of the food chain.

Lead author Dr Anthony Smith of CSIRO’s Wealth from Oceans Flagship refers to sardines, anchovies, krill and others who fill similar niches as low-trophic level (LTL) species. “They’re mostly plankton feeders,” he says. “Some also feed on the larvae of other fish at some stages in their lifecycle.”

Removing LTL fish isn’t always devastating for an ecosystem. “The reality of marine ecosystems is that there is a certain amount of primary production, and if you remove particular species the overall productivity is not usually affected,” he says.

That doesn’t mean, however, that there are not huge effects on individual species within the system. Prey and species that compete with those targeted for fishing may actually benefit when pressure is intense, but for other species the effects can be disastrous.

Smith and colleagues around the world modelled the effect of different levels of fishing of LTL species in five marine ecosystems, including off south-eastern Australia. “These are well-studied ecosystems, and the models have been confirmed against experimental data for them,” Smith says. “Subsequently we checked the results for marine mammals and seabirds against the observations resulting from mostly natural fluctuations in LTL species.”

The authors conclude that current sustainable catch limits are often too high to prevent damage to species at other trophic levels, particularly when the species being targeted is either the dominant form of biomass in the fishery, or is highly connected with many species that prey on it or are preyed on by it.

“Halving exploitation rates would result in much lower impacts on marine ecosystems, while still achieving 80% of maximum sustainable yield,” the paper claims. Smith explains that exploitation rates in this context refer to the effort put into fishing. While catches may fall, costs will fall faster if such limits can be imposed.

A reduction in fishing for LTL fish does not mean that anchovies will disappear from the planet’s pizzas or sardines from toast. Roughly 80% of the LTL fish captured are made into fishmeal to be used in aquaculture or fed to livestock.

History of Baleen Whales Revised
The second known fossil of Janjucetus, an early form of baleen whale, has upended ideas about the development of these giants.

Janjucetus hunderi was named after the discovery of the first fossil found at Jan Juc in Victoria. An amateur fossil collector, Mr Brian Crichton, had previously found a jaw that turned out to be from Janjucetus nearby. He showed his discovery to Dr Erich Fitzgerald of Museum Victoria, who realised that the early whale had a rigid lower jaw joint – unlike modern baleen whales.

Flexible jaw joints are essential for baleen whales to draw in huge amounts of water in the process of filter feeding. The discovery, combined with the absence of certain features observed in all baleen whales, indicates that Janjucetus did not feed by forcing water against the baleen in front of its mouth and then consuming the krill or small fish captured in the bristles, as its descendents do.

Nevertheless, Fitzgerald says the way in which the upper jawbone connects to the braincase and the anatomy of the facial region still place Janjucetus in the suborder Mysticeti, in which all living members use baleen to feed.

Moreover, while Janjucetus was just 3 metres long, it had the same wide mouth, in proportion to its body size, of modern baleen whales. “When fully expanded, a blue whale’s mouth could park a Kombi van,” Fitzgerald says.

It seems these large mouths were a predecessor of filter feeding, and probably one that made it possible for whales to capture this unique ecological niche.

Fitzgerald believes Janjucetus used suction to capture fish or squid in a manner similar to the modern leopard seal. As with these seals, Janjucetus had teeth that were presumably suited to grasping prey while water was flushed out.

“Their skull, mouth and lips may have acted like vacuum cleaners, hoovering up larger animals,” Fitzgerald says. Wide mouths create the opportunity for a larger vacuum when the tongue is depressed, increasing the pressure difference that forces prey into the predator’s mouth.

Fitzgerald is keen to discover when Janjucetus’ descendents developed baleen, and whether their astonishing size evolved before or after this event. “The paucity of whale fossils has prevented us answering this, but developments are happening all the time.”

UV Boosts Crop Growth
Lettuce seedlings exposed to ultraviolet light grow larger once they are transplanted, according to research published in Plant, Cell and Environment.

Dr Jason Wargent of Massey University says that 1980s concerns about ozone depletion led to investigations of the way plants protect themselves against UV radiation. “The Southern Hemisphere has much higher UV, not just because of ozone depletion,” Wargent says. “We have less pollution, the Earth’s orbit takes us closer to the Sun during summer, and the transportation of ozone from the tropics to the poles is more efficient in the Southern Hemisphere.”

It is known, however, that UV light is not all bad. Desirable red colours in some fruits are a form of UV protection, so Wargent and colleagues in the UK decided to study whether the exclusion of UV light early in a plant’s life might be unhealthy.

Replacing the films in a greenhouse with a screen that allows some UV through led initially to smaller lettuces. However, when these plants were transferred to farm conditions they were 29% larger at harvest time. Even while in the greenhouse the UV-exposed vegetables showed evidence of greater photosynthesis, and they subsequently coped better with heat stress.

Wargent compares the findings to vaccinating children against disease: “It appears that a little bit of a bad thing – in this case UV light – does you good.”

The use of greenhouses for seedlings before transplantation to the open air is common for many foods, and Wargent says that studies on the model plant Arabidopsis suggest the benefits are likely to be widespread.

While in some cases a loss of taste or other disadvantages may make the methodology he trialled inappropriate, Wargent believes that experimentation with different sorts of early exposure to light, including the use of LEDs, may produce many benefits.

Already one farmer in the UK who witnessed the trials has changed the plastic on his greenhouses to allow some UV through, and Wargent says he is aware of one New Zealand farmer experimenting in this direction.

Dope Loses Gateway Drug Tag
While cannabis may be reviled as a gateway drug that leads users towards more dangerous substances, those who quit in their twenties are less likely to go on to other drugs.

The National Drug and Alcohol Research Centre at the University of New South Wales has reported in the Journal of Epidemiological and Community Health that former cannabis users who quit in their twenties were only one-third as likely as those who continued using to take up other illicit drugs. Unsurprisingly, heavy users were more than twice as likely to start using other drugs as those who were occasional users.

The data were drawn from 2000 Victorian school students who have been interviewed many times over a 13-year period from the early 1990s.

Lead author Dr Wendy Swift says that most studies of cannabis users have focused on adolescents, and there is a paucity of information on what happens among those in their twenties. Through this decade the number of people using cannabis fell, but the proportion of heavy users nearly doubled.

Malaria Threatens Tigers
Tiger populations are threatened by malaria, Ms Nandini Velho of James Cook University has found – not because the parasite infects the tigers but through its impact on human guardians.

In the Pakke tiger reserve in India, 70% of the forest staff had a bout of malaria during a 4-year study period. “Malaria made many of the guards too sick to carry out their duties, and this likely led to an increase in wildlife poaching in the park,” Velho says.

With most reserves already understaffed, guard sickness makes the animals deeply vulnerable. The mistaken belief that tiger body parts are protective against malaria contributes to the economic drivers of poaching.

Insecticide-treated mosquito nets are the most cost-effective method of combating malaria, particularly in areas such as north-east India where the parasite is resistant to most anti-malarial drugs. Velho distributed these nets to guards in the Pakke Reserve, leading to a 90% reduction in new infections.

Candida Caught Quick
The fungal disease candidaemia, popularly known as Candida after the genus that causes it, kills 60 New Zealanders per annum, mostly those with compromised immune systems such as pre­mature babies.

“Candidaemia is a disease that is time-consuming and difficult to diagnose,” said Dr Jan Schmid of Massey University’s Institute of Molecular Biosciences. “It affects patients who are already quite sick, and by the time it is diagnosed through blood analysis it is often too late.”

Schmid has identified a strain of Candida that is particularly lethal in young patients. In the Journal of Clinical Microbiology he reported the creation of a PCR assay for this strain, allowing swift identification of patients who are particularly vulnerable to Candida, which can be treated with anti-fungal drugs if caught in time.

Lobster Captive Breeding
The Australian Institute of Marine Science (AIMS) has made a step forward for aquaculture by breeding tens of thousands of ornate rock lobsters from a female who was herself born in captivity. AIMS researchers believe it will now be possible to selectively breed this commercially valuable species.

“Much of this research progress has been possible because of the AIMS research vessel, the RV Ferguson, which has given us the platform to study the secret life of the lobster in its natural habitat in the Coral Sea,” says AIMS researcher Dr Mike Hall.

Australia imports four times as much seafood as it exports, and wild fisheries are straining under a combination of overfishing and environmental damage.

Challenges overcome include raising larvae on artificial diets and identifying a new species of disease-causing bacteria.

The Cost of Calamari
The New Zealand sea lion is declining in its main breeding grounds of the Auckland Islands, and squid fishing may be to blame.

In Mammal Review, Dr Bruce Robertson of Otago University’s Zoology Department compared the halving of the number of pups born in the Auckland Islands since 1998 with a slow increase at Campbell Island. Robertson says the most likely explanation for the difference is that the sea lions are often caught as by-catch in the squid nets of Auckland Islands-based trawlers.

“This research is not about apportioning blame,” he says. “Rather, I was interested in what is the cause of the observed decline. Understanding the cause should allow managers to address the decline.”

Cockatoos on Campus
Murdoch University ornithologists have brought their research close to home, with the establishment of a successful artificial nesting hollow on campus attracting a near-threatened subspecies of the red-tailed black cockatoo.

“The forest red-tails have a very different breeding biology to the other well-known cockatoos,” says Prof Ron Johnstone. “The forest red-tails breed only on a 2–3-year cycle; they lay a single egg; they mate for life; they don’t breed until around 6 years of age and they return back to the same breeding hollow each breeding season – assuming that the hollow is still there.”

One of the major threats to forest red-tails has been the takeover of their nests by feral bees, but Johnstone found that the cockatoos consider PVC nests acceptable while the bees don’t like them.

One lecturer is seeking students to monitor the nest boxes as an Honours project, providing a chance for a wildlife biologist to conduct field studies with unusually little travel.

Cattle Vaccine Just a Tick Away
The identification of antigens to tick infection could lead to a vaccine of great benefit to the cattle industry and the environment.

“In 2008, Meat and Livestock Australia pinpointed tick infestation as the ‘number one’ cattle health problem in the country,” says Dr Ala Lew-Tabor of the Queensland Alliance for Agriculture and Food Innovation. The cost to the beef and dairy industries is estimated at $175 million per year. Current methods rely on pesticides carrying environmental risks.

Lew-Tabor says that ticks are developing resistance to these pesticides, reducing their effectiveness. She has identified tick genes that might represent weak points, and fed ticks with appropriate antibodies. A trial vaccine based on successful antibodies has reduced infection by 50–87% depending on conditions, while also reducing the capacity of surviving ticks to lay eggs.

The work was published in the International Journal of Parasitology.

SPIDER by Nature
A paper in Nature Photonics has announced the development of Spectral Phase Interferometry for Direct Electric Field Reconstruction (SPIDER) on a chip. SPIDER technology is not new, but this chip integrates with silicon chips and is made in the same way, allowing dramatic reductions in cost and power consumption.

The SPIDER chip allows the measurement of the intensity and phase of the optical pulses used to transmit information through fibre or for applications such as high-precision spectroscopy.

“The ability to monitor and characterise these signals has, until now, been restricted to optical laboratories,” explains A/Prof David Moss of the University of Sydney’s Physics Department.

Why Willows Spread
A study of willow reproduction has revealed how the pest species Salix cinerea has managed to spread so dramatically through Australia’s river systems. “We discovered this species of willow is pollinated by both insects and wind, and the average willow tree can make 330,000 seeds in a season,” said Tara Hopley of CSIRO Plant Industry.

Previous research has found that 1 hectare of willows with permanent access to water evaporates 5.5 ML per year, 17 times the water consumption of an average house (AS, March 2011, p.10). “Over half the pollen and seed is moving more than 15 km between rivers,” Hopley found. This occurred through a combination of wind and insect pollination.

While these findings indicate just how hard it is for farmers to prevent rapid willow reinfestation, Hopley identified a chink in the armour. “We also found a small proportion of sites studied were producing a large proportion of the seed. In practical terms this means that clearing just 20% of sites could see a 50% reduction in seed production.”