Shrinking Leaves Point to Climate Change

University of Adelaide researchers have discovered that recent climate change is causing leaves of some Australian plants to narrow in size.

The study, which is the first of its kind in the world, highlights that plant species are already responding to changes in climate. The results are published online July 4 in the Royal Society journal Biology Letters.

Researchers analysed leaves from herbarium specimens of Narrow-leaf Hopbush (Dodonaea viscosa subsp. angustissima) dating from the 1880s to the present. The study focused on specimens from South Australia's Flinders Ranges.

The analysis revealed a 2mm decrease in leaf width (within a total range of 1-9mm) over 127 years across the region. Between 1950 and 2005, there has been a 1.2ºC increase in maximum temperatures in South Australia but little change in rainfall in the Flinders Ranges.

"Climate change is often discussed in terms of future impacts, but changes in temperature over recent decades have already been ecologically significant," says Dr Greg Guerin, a Postdoctoral Fellow with the University of Adelaide's School of Earth and Environmental Sciences and lead author of the study.

"Climate change is driving adaptive shifts within plant species and leaf shape has demonstrated adaptive significance in relation to climate.

"Our results indicate that leaf width is closely linked to maximum temperatures, and plants from warmer latitudes typically have narrower leaves.

"In the case of Narrow-leaf Hopbush, we can significantly link the changes in leaf width to changes in climate."

Dr Guerin says some Australian plant species have greater potential to respond to and cope with increasing temperatures than others. "It's important to understand how plants cope with changing climates, because species that are more adaptive to change may be good candidates for environmental restoration efforts.

Read more at Science Daily

Game, Set and Match to Strawberries: The Superfruit

Strawberries, the traditional summer treat associated with Wimbledon could be serving up some unexpected health benefits.

Scientists at the University of Warwick have been studying the beneficial effects of strawberries on our cardiovascular health, particularly around how they prevent the development of heart disease and diabetes.

Professor Paul Thornalley from Warwick Medical School heads the team that discovered extracts from strawberries positively activate a protein in our bodies called 'Nrf2' which is shown to increase antioxidant and other protective activities. This protein works to decrease blood lipids and cholesterol, the very things which can lead to cardiovascular problems.

Eating strawberries has previously been found to counter post-meal blood glucose and low density lipoprotein, or 'bad' cholesterol and therefore decrease risk of diabetes and heart disease, but this is the first time that strawberry extracts have been proved to actively stimulate proteins that offer us protection against disease.

Professor Thornalley explained: "We've discovered the science behind how strawberries work to increase our in-built defences to keep cells, organs and blood vessels healthy and which can reduce the risk of developing cardiovascular problems such as heart disease and diabetes.

"So don't feel guilty about serving up strawberries and cream … although I'd suggest more strawberries and less or even no cream!"

Screening and mathematical modelling techniques developed at the University of Warwick can now take this research further to help identify the best varieties of strawberries, how they are served or processed and how many strawberries should be eaten for optimum health benefit.

Read more at Science Daily

Fetal Solar System Aborted

For a long while, it looked like the young star known as TYC 8241 2652 1 was getting ready to make some planets.

The sun-like star, located about 450 light-years from Earth in the constellation Centaurus was encircled by a disk of warm, brightly glowing dust located about as far away from the star as Mercury orbits the sun.

But something strange happened between 2008, when the star was observed by a powerful ground-based infrared telescope in Chile, and 2010 when NASA's WISE infrared space telescope took a look: The dust was gone.

"We said 'Whoa, what's going on here?'" astronomer Ben Zuckerman, with the 
University of California Los Angeles, told Discovery News.

The discovery has scientists wondering anew about the path from dust to planet.

"It doesn't look like it is quite a monotonic progression from tiny dust grains to full-fledge rocky planets as we and others might have believed. There may be bumps and wiggles and holes along the road," Zuckerman said.

The dust that once orbited around the star likely came from two small rocky bodies that were destroyed when they smashed into each other. Astronomers have found no evidence of any planets around the star.

As far as what happened to the dust, no one knows. One theory is that friction with intervening gas caused the dust to slow and fall onto the star, lured by gravity. Another idea is that the dust grains continued crashing into each other until, too small to remain in orbit, they got blasted out of the system. But whatever happened, happened fast.

"The disappearance ... in less than two years is incredibly fast by our current understanding, and the impact of this is difficult to predict," astronomer Margaret Moerchen, with the European Southern Observatory in Chile, wrote in an analysis of the research published in Nature.

Astronomers plan to keep an eye on the star to see if another dust disk forms.

"My guess is that the star can and will make planets in the future because in order to produce so much dust a few decades ago it must have been pretty well along the way," Zuckerman said. "This was just a bit of glitch."

The star most likely has other proto-planets in orbit, similar to what produced the dust in the first place, which could be the source of a new dust disk.

Read more at Discovery News

Particle 'Consistent' With Higgs Boson Discovered

The discovery of a particle consistent with the Higgs boson has been announced by physicists from the Large Hadron Collider's CMS and ATLAS detectors.

The discovery was detailed at a major conference to update the world on the continuing efforts by CERN scientists to find the last remaining piece of the Standard Model that underpins the foundations of our Universe. The Higgs boson mediates the "Higgs field" that ultimately endows all matter with mass -- finding the Higgs is therefore imperative for physicists to understand what gives the Universe substance.

When reports first surfaced that Peter Higgs -- one of the six physicists who, in the 1960s, developed the theory behind Higgs boson -- had been invited to CERN for this morning's announcement, the event became hard to ignore: something historic was about to happen.

And sure enough, at 9 a.m. in Geneva, Switzerland (3 a.m. EST), the news we had all been waiting for was spelled out by Joe Incandela, lead scientist of the CMS experiment: "We have observed a new boson."

This "new boson" revealed itself in the CMS data as a "bump" at 125 GeV/c2, a value that places it at over 130 times more massive than a proton.

After combining all the results gathered over many different channels in the CMS, the level of certainty -- 4.9-sigma -- came tantalizingly close to the "Gold Standard" (5-sigma) for subatomic particle discovery. This means there is a one-in-2 million chance of the result being a random fluctuation, or noise. For all intents and purposes, this is a discovery of a particle that acts very much like a Higgs boson.

"This is very preliminary result, but it's very strong," added Incandela.

Following the CMS announcement, ATLAS' Fabiola Gianotti said: "We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV." A 5-sigma result represents a one-in-3.5 million chance of the result being noise. This is undeniable proof that a boson, with very Higgs-like qualities, has been discovered by the two detectors.

However, more work needs to be done to figure out if this is indeed a Higgs boson or some unexpected renegade particle that just acts like the Higgs (although the latter is highly unlikely). Also, if it is a Higgs boson, is it a part of a larger Higgs family of particles?

In this high-stakes game of quantum mechanics, statistics and landmark particle discoveries, it can be hard to pronounce a definitive discovery of any subatomic particle, especially if it happens to be a particle that underpins the Universe's very existence.

The ATLAS and CMS detectors are located at strategic locations around the 17-mile (27-kilometer) circumference ring of superconducting electromagnets of the LHC. Both detectors are looking for, amongst a myriad of other things, evidence for the Higgs. And both, according to this announcement, have found that evidence to a very high degree of statistical certainty.

During all the excitement of a round of LHC results announced in December 2011, physicists pointed to an "excess" of particles around the predicted energy range for one type of theoretical Higgs boson. The energy range was 115 to 130 GeV/c2 and the statistical certainty was 2.4-sigma. 2.4-sigma means that there is a 98 percent chance that the signal is real and not caused by experimental error.

Read more at Discovery News

First Photo of Shadow of Single Atom

In an international scientific breakthrough, a Griffith University research team has been able to photograph the shadow of a single atom for the first time.

"We have reached the extreme limit of microscopy; you can not see anything smaller than an atom using visible light," Professor Dave Kielpinski of Griffith University's Centre for Quantum Dynamics in Brisbane, Australia.

"We wanted to investigate how few atoms are required to cast a shadow and we proved it takes just one," Professor Kielpinski said.

Published this week in Nature Communications, "Absorption imaging of a single atom "is the result of work over the last 5 years by the Kielpinski/Streed research team.

At the heart of this Griffith University achievement is a super high-resolution microscope, which makes the shadow dark enough to see.

Holding an atom still long enough to take its photo, while remarkable in itself, is not new technology; the atom is isolated within a chamber and held in free space by electrical forces.

Professor Kielpinski and his colleagues trapped single atomic ions of the element ytterbium and exposed them to a specific frequency of light. Under this light the atom's shadow was cast onto a detector, and a digital camera was then able to capture the image.

"By using the ultra hi-res microscope we were able to concentrate the image down to a smaller area than has been achieved before, creating a darker image which is easier to see," Professor Kielpinski said.

The precision involved in this process is almost beyond imagining.

"If we change the frequency of the light we shine on the atom by just one part in a billion, the image can no longer be seen," Professor Kielpinski said.

Research team member, Dr Erik Streed, said the implications of these findings are far reaching.

"Such experiments help confirm our understanding of atomic physics and may be useful for quantum computing," Dr Streed said.

There are also potential follow-on benefits for biomicroscopy.

"Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics."

"This is important if you want to look at very small and fragile biological samples such as DNA strands where exposure to too much UV light or x-rays will harm the material.

"We can now predict how much light is needed to observe processes within cells,under optimum microscopy conditions, without crossing the threshold and destroying them."

Read more at Science Daily

Bees Can 'Turn Back Time,' Reverse Brain Aging

Scientists at Arizona State University have discovered that older honey bees effectively reverse brain aging when they take on nest responsibilities typically handled by much younger bees. While current research on human age-related dementia focuses on potential new drug treatments, researchers say these findings suggest that social interventions may be used to slow or treat age-related dementia.

In a study published in the scientific journal Experimental Gerontology, a team of scientists from ASU and the Norwegian University of Life Sciences, led by Gro Amdam, an associate professor in ASU's School of Life Sciences, presented findings that show that tricking older, foraging bees into doing social tasks inside the nest causes changes in the molecular structure of their brains.

"We knew from previous research that when bees stay in the nest and take care of larvae -- the bee babies -- they remain mentally competent for as long as we observe them," said Amdam. "However, after a period of nursing, bees fly out gathering food and begin aging very quickly. After just two weeks, foraging bees have worn wings, hairless bodies, and more importantly, lose brain function -- basically measured as the ability to learn new things. We wanted to find out if there was plasticity in this aging pattern so we asked the question, 'What would happen if we asked the foraging bees to take care of larval babies again?"

During experiments, scientists removed all of the younger nurse bees from the nest -- leaving only the queen and babies. When the older, foraging bees returned to the nest, activity diminished for several days. Then, some of the old bees returned to searching for food, while others cared for the nest and larvae. Researchers discovered that after 10 days, about 50 percent of the older bees caring for the nest and larvae had significantly improved their ability to learn new things.

Amdam's international team not only saw a recovery in the bees' ability to learn, they discovered a change in proteins in the bees' brains. When comparing the brains of the bees that improved relative to those that did not, two proteins noticeably changed. They found Prx6, a protein also found in humans that can help protect against dementia -- including diseases such as Alzheimer's -- and they discovered a second and documented "chaperone" protein that protects other proteins from being damaged when brain or other tissues are exposed to cell-level stress.

In general, researchers are interested in creating a drug that could help people maintain brain function, yet they may be facing up to 30 years of basic research and trials.

"Maybe social interventions -- changing how you deal with your surroundings -- is something we can do today to help our brains stay younger," said Amdam. "Since the proteins being researched in people are the same proteins bees have, these proteins may be able to spontaneously respond to specific social experiences."

Read more at Science Daily

Gold and DNA Could Create New Dark Matter Detector

A combined team of physicists and biologists aim to build a directional dark matter detector using strands of DNA and gold.

Dark matter is a hypothesized type of matter which accounts for much of the mass of the universe. It cannot be seen, but its existence is inferred from its gravitational influence on visible matter and the structure of the universe. Some of the most popular models of dark matter suggest that it exerts itself on galaxy clusters and surrounds the Earth like a sea as it travels around the Sun, which in turn is slowly traveling towards the constellation Cygnus as it rotates around the galactic center.

If this is the case, Earth should experience a “headwind” of dark matter in front of it (coming form the direction of Cygnus) for half of the year and a tailwind for the other half of the year, depending on where it is on its orbit around the Sun.

Many different groups are working to try and detect dark matter using expensive detectors in deep underground caverns, which protect them from radiation that could otherwise pollute the signal. They are focusing on finding the unique signature that the “sea” of dark matter supposedly produces as the Earth orbits the Sun. This should change depending on what point in the year it is and also throughout the day as the Earth rotates on its axis. A dark matter detector should be able to sense the direction change as the Earth rotates each day.

A combined team including Katherine Freese, an astrophysicist from the University of Michigan and geneticist George Church from Harvard say they can overcome challenges with detecting dark matter by using DNA to find the dark matter particles, called weakly interacting massive particles, or WIMPs.

They have created a detector using a thin gold sheet with many single strands of DNA hanging from it. The theory is that a particle of dark matter will smash into the heavy gold nucleus, pushing it out of the gold sheet and through into the DNA “forest”, knocking the strands out as it travels.

These strands fall onto a collection tray. Each of them has a unique identifier showing where they were located on the gold sheet, so researchers can reconstruct the path of the gold particle with incredible precision. The detector is made up of hundreds of thousands of these sheets placed between Mylar sheets, using around a kilogram of gold and 100g of single-strand DNA on a square-meter array.

DNA is useful in this context because its structure will separate vertically with nanometer resolution — it wills separate to the nearest nucleotide — the smallest structural units of DNA. This is many orders of magnitude better than is currently possible. Secondly, the detector can work at room temperature, rather than needing cooling. Finally, the Mylar sheets make the detector directional — each sheet should be able to absorb the gold nucleus of its energy after it has passed through the “DNA forest”. Higher energy nuclei from background radiation would pass through several of the leaves of Mylar, allowing them to be identified and excluded.

If a dark matter particle hits a gold nucleus in on direction, it will propel it into the DNA forest. If it strikes in the other direction, it will head straight into the Mylar sheet and be absorbed.

Read more at Wired Science

Spectacularly Preserved Fossil Suggests Most Dinosaurs Were Feathered

The discovery of a fantastically preserved, bushy-tailed fossil theropod has cloaked the dinosaur world in feathers.

Named Sciurumimus -- Latin for "squirrel-mimic" -- albersdoerferi, the dinosaur lived 150 million years ago in what is now Germany. When it died, it came to rest in sediments so fine-grained that they preserved an almost photographic impression of the filaments covering its body.

Other feathered theropods, the taxonomic clade including all two-legged dinosaurs and their bird descendants, have been found previously, inspiring fantastic artist renditions and speculation that plumes rather than scales were the dinosaur norm.

Those fossils, however, belonged to a relative latecomer group known as coelurosaurs. Whether most theropods were feathered, or just a few recent evolutionary offshoots, was an open question. The new fossil find, described July 3 in Proceedings of the National Academy of Sciences and led by paleontologist Oliver Rauhut of Germany's Ludwig Maximilian University, gives a resounding answer.

Compared to the coelurosaurs, S. albersdoerferi was "significantly more basal in the evolutionary tree of theropods," or a trunk rather than a branch, wrote Rauhut and colleagues. If it had feathers, so did the rest of the theropods.

The plumage didn't end there. Other paleontologists have found feathers in beaked, quadrupedal dinosaurs. Combine those observations with S. albersdoerferi's taxonomic significance, and "a filamentous body covering obviously represents the plesiomorphic state for dinosaurs in general," wrote Rauhut's team.

Plesiomorphic is another way of saying "ancestrally typical." In short, it was feathers all the way down.

Read more at Wired Science

World's Smallest Fly Decapitates Ants

A newly discovered species, Euryplatea nanaknihali, is the world's smallest fly, and has the rather unsavory habit of biting off the heads of ants, according to a paper in the latest issue of the Annals of the Entomological Society of America.

At just .4 millimeters in length, the fly is only a fraction of an inch in size. A house fly is 15 times bigger. A fruit fly is 5 times larger.

The new member to the insect record books is also the first of its genus to be discovered in Asia. Members of its fly family (Phoridae) are all believed to decapitate ants. The process isn't a simple bite and patooie either.

Members of the Phoridae family lay eggs in the bodies of ants. The resulting larvae feed in the ants' heads, eventually causing decapitation. Not easy being an ant! On the upside, from a "pest" control perspective, some of these phorid flies are being used to try to control fire ants in the southern United States.

Nature seems to have pitted the world's smallest flies against the world's smallest ants.

Author Brian Brown of the Natural History Museum of Los Angeles County explained that the newfound flies can probably decapitate ants that have heads as small as .5 millimeters. Although this is speculation at now for the new species, Brown believes it's highly likely because the fly's only known relative, Euryplatea eidmanni, is known to parasitize ants in Equatorial Guinea.

Read more at Discovery News

Why Do Chimps Attack?

Chimpanzees have made headlines in recent years for several unprovoked attacks against humans, the latest last week at the Jane Goodall Institute Chimpanzee Eden in South Africa. The severely injured victim, University of Texas graduate student Andrew Oberle, remains in intensive care.

Oberle was mauled by chimpanzees as he gave a lecture to about a dozen tourists. The brutal attack prompted many to wonder what, if anything, provoked the animals? Experts suggest that multiple reasons could explain the attack.

Eugene Cussons, managing director of the sanctuary and host of the Animal Planet show Escape to Chimp Eden, said Oberle received training prior to the incident, but broke the rules when he went through two fences separating the primates from humans. A male chimpanzee grabbed Oberle and pulled him under one of the fences, which was electrified.

Aside from that dangerous misstep, the fact that the attackers were male is not surprising to those who study chimpanzees. Sylvia Amsler, a lecturer in the Anthropology Program at the University of Arkansas at Little Rock, told Discovery News that male chimps in the wild commonly engage in war-like behavior to defend or acquire territory.

“Such attacks can be severe and fatal,” she said. “In the case of an adult victim, the attacking males take turns beating and jumping on the victim. Attackers use their canines to bite and tear at the victim, so that any body parts that stick out, such as testes and ears, are often ripped off during an attack.”

Jenny Short, assistant director of colony management and research services at the California National Primate Research Center, reminded that chimpanzees and other primates are not domesticated animals.

“You have to be reactive and extremely careful around them,” she told Discovery News. “We work with rhesus macaques, which are much smaller than chimpanzees, and even they require strict precautions. If you go to a zoo and look at chimps, it takes your breath away because they are so big and strong.”

Paleoanthropologist Alan Walker of Penn State University thinks that even if a human and a chimp were somehow evenly matched in size, chimpanzees wind up using all of their muscle strength, whereas humans tend to hold back.

Relative to body mass, chimpanzees have less grey matter in their spinal cords than humans have. This matter contains large numbers of nerve cells that connect to muscle fibers and regulate muscle movement.

The finely tuned motor system in humans gives us the ability to do things like make complex tools, throw accurately, and manipulate small objects. Conversely, when a chimp uses its muscles, particularly in a defense or attack mode, the action is more “all or nothing,” with each neuron triggering a higher number of muscle fibers, Walker explained.

“That is the reason apes seem so strong relative to humans,” he added.

Read more at Discovery News