Science news, Anthropology, Physics, Agriculture - Scicornwall

Particle Physicists Discover Lowest Energy "Bottomonium" Particle

Particle physicists working with the BaBar detector at Stanford Linear Accelerator Center have discovered a new particle in the bottomonium family of "quarkonium" particles. Technically it isn't a "new particle" it is a previously unobserved state of particle, but when we are talking about subatomic particles, their energy states become a big deal (and their names get very cool). We are in the realms of the vanishingly small and the discovery of the lowest energy bottomonium particle may not seem very significant. But in the world of quantum chromodynamics, this completes the long quest to find experimental evidence for this elusive meson and may help explain why there is more matter than anti-matter in the Universe…

Quarkonia are types of mesons containing two quarks: one quark and its anti-quark (they are therefore "colourless"). They belong to one of two families: "bottomonium" or "charmonium". As the names suggest, bottomonium contains a bottom quark and anti-bottom quark; charmonium contains a charm quark and anti-charm quark. Groups of three quarks (interacting via the strong force) are baryons (i.e. protons and neutrons) whereas groups of two quarks are mesons. Mesons are all thought to be made from a quark-antiquark pair and are therefore of huge importance when studying why there is more matter than anti-matter in the Universe.

This is where the BaBar detector at the Stanford Linear Accelerator Center (SLAC), CA, comes in. The BaBar international collaboration investigates the behaviour of particles and anti-particles during the production of the bottomonium meson (bottom-antibottom quark pairs) in the aim of explaining why there is an absence of anti-particles in everyday life.

For each particle of matter there exists an equivalent particle with opposite quantum characteristics, called an anti-particle. Particle and anti-particle pairs can be created by large accumulations of energy and, conversely, when a particle meets an anti-particle they annihilate with intense blasts of energy. At the time of the big-bang, the large accumulation of energy must have created an equal amount of particles and anti-particles. But in everyday life we do not encounter anti-particles. The question, therefore, is "What has happened to the anti-particles?" - From the BaBar/SLAC collaboration pages.

All matter has a "ground state", or the lowest energy the system is trying to attain. As particles for instance try to reach this ground state, they lose energy, often in the form of electromagnetic radiation. Once reached, the ground state determines the baseline at which measurements can be made for higher energy states of those particles. And this is what the BaBar team has done, they have been able to isolate the lowest possible energy state for the bottomonium particle (which is far from easy). So what have they named the ground state of bottomonium? Quite simply: ηb, pronounced "eta-sub-b".

The bottomonium particle was generated during a collision between an electron and positron. The energy generated by this collision created a bottom quark and an anti-bottom quark bound together. At this point, the bottomonium particle was of too high an energy, but it very quickly decayed, emitting a gamma ray leaving the ηb behind. However, ηb's are highly unstable and will quickly decay into other particles, plus they are very rare and difficult to detect. This particular decay event only occurs once in every two or three thousand higher energy bottomonium decays, so many collisions had to be measured and a huge amount of data had to be gathered by the BaBar detector before a precise measurement of the ηb ground state could be gained.

"This very significant observation was made possible by the tremendous luminosity of the PEP-II accelerator and the great precision of the BaBar detector, which was so well calibrated over the BaBar experiment's 8-plus years of operation. These results were highly sought after for over 30 years and will have an important impact on our understanding of the strong interactions." - Hassan Jawahery, BaBar Spokesperson, University of Maryland.

If you want to find out more, you can check out the BaBar team's publication (with the longest list of co-authors I've ever seen!) or the SLAC press release.

Source

Watch out for a killer slugs at large in your garden

A CARNIVOROUS slug that sucks worms in “like spaghetti” and which has never been seen before in Western Europe, has been discovered in Welsh gardens, biologists revealed yesterday.

The slug, which boasts blade-like teeth, has turned up in a garden in Caerphilly to the amazement of experts.A  similar type of creature – which is completely white and without eyes – is normally found in Turkey and Georgia. The bizarre subterranean beast has since become the first creature to boast a scientific name based on a Welsh word.

A spokeswoman for the National Museum in Cardiff said the origin of this particular slug, named Selenochlamys ysbryda by museum experts, is a mystery as to how it got to Britain.

The slugs came to the attention of the museum after being found by a gardener, who wishes to remain anonymous. The spokeswoman believed the creatures could be more widespread in South Wales. She added: “Unlike most slugs, the ghost slug is carnivorous and kills earthworms at night with powerful, blade-like teeth, sucking them in like spaghetti. “It has no eyes, is completely white, and lives underground, squeezing its flexible body into cracks to get at the worms.”

Ben Rowson, a biologist at the National Museum in Cardiff, said: “The ghost slug belongs to an obscure and almost unpronounceable group of slugs – the Trigonochlamydidae.

“We had to thumb through lots of old publications in Russian and German to find anything like them – but then discovered they were something entirely new.”

He added: “They may well eat other slugs too.”

Unlike others from the group of creatures which are larger, have no eyes and a different internal anatomy, the scientists realised it was an undescribed species that had no scientific name. They decided to name the creature Selenochlamys ysbryda, partly from the Welsh word ysbryd meaning ghost, a name which appears with the species’ description in June’s edition of the Journal of Conchology. Mr Rowson added: “Selenochlamys ysbryda seemed appropriate for this spooky, nocturnal hunter and indicates where it was first found.

“We think this is the first time a Welsh word has been used in an animal’s scientific name.”

Bill Symondson, an ecologist at Cardiff University, added: “The lack of eyes and body colour could indicate the species evolved in a cave system. “It was probably introduced to Britain in plant pots, making it an ‘alien’ species, although we can’t be certain. We’re concerned that it might become a pest, but we need to find out more about it first.”

John Humphries, Western Mail gardening columnist, urged garden centres and gardeners to inspect plants for such creatures, before they escape and breed in the wider environment. “I’ve never heard of the ghost slug but I assume it is one of these pests that come into the UK on container plants and get introduced accidentally.

“There are more and more such pests coming in.

“And no matter how much we may hate our indigenous slugs and snails that eat our produce – and there have been an awful lot of them this year – it is better the devil you know.

“Without earthworms our soil would be rock hard and they do a lot of good for the garden.

“Once here, the pests can cause a lot of damage which can be difficult to stop and they could upset the balance of things.”

To monitor the ghost slug’s trail, the museum has produced a simple identification guide available from their website www.museumwales.ac.uk/

Super atoms turn the periodic table upside down

Researchers at Delft University of Technology in The Netherlands have developed a technique for generating atom clusters made from silver and other metals. Surprisingly enough, these so-called super atoms (clusters of 13 silver atoms, for example) behave in the same way as individual atoms and have opened up a whole new branch of chemistry.

If a silver thread is heated to around 900 degrees Celsius, it will generate vapour made up of silver atoms. The floating atoms stick to each other in groups. Small lumps of silver comprising for example 9, 13 and 55 atoms appear to be energetically stable and are therefore present in the silver mist more frequently that one might assume. Prof. Andreas Schmidt-Ott and Dr. Christian Peineke of TU Delft managed to collect these super atoms and make them suitable for more detailed chemical experiments.

The underlying mechanism governing this stability in super atoms was described in Science by scientists from Virginia Commonwealth University in 2005. They had discovered metal super atoms, but from aluminium. Their aluminium clusters of 13, 23 and 37 atoms reacted in the same way as individual atoms because they comprised electrons that revolved around the atom cluster as a whole. These so-called outer layers were strikingly similar to the outer layers of elements from the periodic table.

The super atoms gave the periodic table a third dimension as it were, according to Schmidt-Ott: 'The chemical properties of the super atoms that have been identified up until now are very similar to those of elements in the periodic table, because their outer layers are much the same. However, we may yet discover super atoms with a different outer layer, giving us another set of completely new properties.'

Schmidt-Ott hopes to find atom clusters with new unique magnetic, optical or electrical properties, which would also be stable enough to create crystals or other solid forms. Potential applications include catalysts in fuel and extra-conductive crystals.

So although super atoms are nothing new, thanks to TU Delft the particles can now be collected in a very pure form and selected according to size, thereby making them suitable for chemical experiments.

Full article can be read in the new edition of TU Delft magazine Delft Outlook. See http://www.delftoutlook.tudelft.nl

Geologists study China earthquake for glimpse into future

The May 12 earthquake that rocked Sichuan Province in China was the first there in recorded history and unexpected in its magnitude. Now a team of geoscientists is looking at the potential for future earthquakes due to earthquake-induced changes in stress.

Around the world, earthquakes like the one in China are associated with triggered aftershocks that are very large. In 1999, a 7.1 earthquake in Duzce, Turkey, followed a 7.4 magnitude earthquake in Izmit, Turkey. In 2004, an 8.7 magnitude earthquake struck three months after the Sumatra Andaman earthquake of magnitude 9.2. While analysis of the Turkish earthquakes was not timely enough to shed light on the second earthquake there, the researchers believe that information on the Sumatra Andaman earthquake did illuminate the situation.

For the May 12 earthquake, the researchers performed analysis of co-seismic stress transfer onto Sichuan basin faults using broad ranges because at this time, exact values for all the various factors are unknown. The researchers report in today's (July 6) advanced online edition of Nature that "this approach enables rapid mapping of faults with heightened rupture likelihood."

"We knew that the fault was there and we knew it was active," says Eric Kirby, associate professor of geosciences at Penn State. "I had done some previous work in the area, but I do not think anyone would have anticipated the size of this earthquake."

The May earthquake in Sichuan Provence was 7.9 in magnitude and collapsed buildings, destroyed villages and killed thousands of people. The earthquake occurred in the area where the Sichuan basin and the Longmen Mountains meet. This is on the eastern edge of the Tibetan Plateau in an area deformed by the collision of the Indian and Asian tectonic plates. The area is crisscrossed with fault lines.

The researchers, who include Tom Parsons, research geophysicist, U.S. Geological Survey, Chen Ji, assistant professor of Earth sciences, University of California-Santa Barbara, and Kirby, used a model to see how the Sichuan earthquake, which took place on the Beichuan fault, affected other portions of that fault and others in the area. They looked at physical characteristics of the faults including the directions and amounts of movement of the faults – whether and how much they moved up and down and side to side, and the estimates of the frictional resistance to motion along the fault.

"The Sichuan earthquake seemed to rupture on the northern portion of the Beichuan fault," says Kirby. "It does not seem to have involved the southwestern branch."

According to the model, after the May 12 earthquake, stress increased on faults running parallel to the Wenchuan-Maowen fault and the two major faults that are perpendicular and to the north of the fault. Some smaller faults south of the earthquake zone show a decrease in stress. However, according to the model, the majority of the faults in the area are still stressed.

"The occurrence of triggered earthquakes after a major earthquake can be months, years or decades," says Kirby. "Sumatra seems to be a really nice example. Also, the historic record in Turkey shows a series of earthquakes that progress from east to west over 60 years."

The data used in the model consists of ranges rather than actual measurements because of the difficulty of obtaining information from that area of China at the moment. The models always use a range of friction because the movement of the faults changes the friction sometimes in unknown or unexpected ways.

"The model takes what we think we know about the faults in the region and asks what was the change to stress associated with the earthquake," says Kirby. "The model shows where an increase in the potential for failure may occur, but we do not know the trigger point for these faults. The analysis does not say there is going to be an earthquake, just that the potential exists on some of the faults."

Want to fly? Don't copy the birds and the bees

Since earliest recorded history, and presumably beyond, humans have always wanted to fly. First attempts involved imitation of winged creatures around them, and unfailingly ended in disaster. No workable flying machines have ever looked particularly similar to nature's fliers, and today there is little comparison between a top of the range military chopper and the humble bumblebee, despite similar flight patterns. In an era in which engineers are increasingly exploiting designs from nature, understanding this paradox is becoming ever more important. Dr Jim Usherwood, from the Royal Veterinary College, has studied the reasons behind these differences in aerodynamics and concluded that scientists should, in this instance, be more hesitant before imitating nature. He will be presenting his results on Sunday 6th July at the Society for Experimental Biology's Annual Meeting in Marseille [Session A3].

Dr Usherwood believes the reason that flying creatures don't look like man made machines is all to do with the need to flap. "Animals' wings, unlike propellers, have to keep stopping and starting in order produce lift (animals have forgotten to invent propellers, just as they forgot wheels)," he explains. "Think of vigorous waving, or perhaps exuberant rattling of a cocktail shaker - this takes a fair amount of power to overcome inertia. So, the idea is that both wing shape and how wings are used can be understood better if the effort of flapping is remembered, which explains why vultures don't look like gliders, and most winged creatures, from insects to pigeons, fly so inefficiently."

His research has centred on creatures as diverse as dragonflies and quails. Currently he is investigating the compromise winged creatures face between meeting aerodynamic requirements and overcoming inertia in order to generate lift, by loading wings of racing pigeons with lead fishing weights. He believes that lessons from all of these studies lead to the same conclusion. "My work should act as a reminder to be cautious in copying nature. There is lots of interest in making MAVs/UAVs (micro/unmanned air vehicles) that flap, which may present all sorts of advantages in terms of maneuverability, speed and so on. However, there is a tendancy to presume that biology is efficient, and I would say that, even at very small sizes, if you want to hover efficiently, be a helicopter not a flapper…"

For more information please visit Society for Experimental Biology

Slow exercise (not fast) is better for menopausal women

It's an inevitable truth: as we get older, our muscles deteriorate and we become weaker. Not only can this be an immensely frustrating change, but it can also have many other, more serious implications. We become clumsier and begin to have more falls, often resulting in broken bones or even more severe injuries. There is wide interest in this phenomenon, but to date, the majority of research has focussed on therapies for older patients with advanced symptoms. Now one study, led by Dr Alexandra Sänger from the University of Salzburg, is taking a new approach: scientists are examining the effects of different exercise regimes in menopausal women, with the aim of developing new strategies for delaying and reducing the initial onset of age related muscle deterioration. Results will be presented on Monday 7th July at the Society for Experimental Biology's Annual Meeting in Marseille [Poster Session A5].

Dr Sänger's research group has investigated two particular methods of physical training. Hypertrophy resistance training is a traditional approach designed to induce muscle growth whereas 'SuperSlow®' is a more recently devised system which involves much slower movement and fewer repetitions of exercises, and was originally introduced especially for beginners and for rehabilitation. "Our results indicate that both methods increase muscle mass at the expense of connective and fatty tissue, but contrary to expectations, the SuperSlow® method appears to have the greatest effect," reveals Dr Sänger. "These findings will be used to design specific exercise programmes for everyday use to reduce the risk of injury and thus significantly contribute to a better quality of life in old age."

The study focussed on groups of menopausal women aged 45-55 years, the age group in which muscle deterioration first starts to become apparent. Groups undertook supervised regimes over 12 weeks, based on each of the training methods. To see what effect the exercise had, thigh muscle biopsies were taken at the beginning and end of the regimes, and microscopically analysed to look for changes in the ratio of muscle to fatty and connective tissue, the blood supply to the muscle, and particularly for differences in the muscle cells themselves. "The results of our experiments have significantly improved our understanding of how muscles respond to different forms of exercise," asserts Dr Sänger. "We believe that the changes that this new insight can bring to current training systems will have a considerable effect on the lives of both menopausal and older women," she concludes.

Source

Tree-Killing Fungus Officially Named by Scientists

The USDA Forest Service Southern Research Station (SRS) today announced that an SRS scientist and other researchers have officially named the fungus responsible for killing redbay and other trees in the coastal plains of northeastern Florida, Georgia, and South Carolina.

Lead author and Iowa State University Plant Pathologist Tom Harrington, co-author and SRS Plant Pathologist Stephen Fraedrich, and Azerbaijan National Academy of Sciences Researcher D.N. Aghayeva unveiled the name, Raffaelea lauricola, in an article published in the April-June 2008 issue of Mycotaxon, the international journal of fungal taxonomy and nomenclature.

“Until now, the fungus was known as ‘the laurel wilt pathogen’ because of the devastating disease it causes in redbay trees and other laurel species like sassafras and avocado trees in the Southeast,” said Fraedrich, based in Athens, GA. “Now arborists, foresters, researchers, and regulatory officials have a formal, scientific name and description of the fungus, as well as a detailed explanation of how the pathogen compares to similar fungi."

Raffaelea lauricola is one of many species of fungi carried by ambrosia beetles, a group of highly specialized wood-boring insects that feed on symbiotic fungi, which they carry from tree to tree in specialized sacs. The beetles feed on their own special ambrosia fungi, much as the Greek gods were believed to exist on their "ambrosia." R. lauricola is the principle ambrosia fungus of an invasive species from Asia, the redbay ambrosia beetle. R. lauricola is the only known tree pathogen among the ambrosia fungi and differs from other Raffaelea species in its DNA sequence and spore sizes. The fungus also grows faster than similar fungi.

Ambrosia beetles introduce the fungus into redbay or other laurel tree species by burrowing into the trees and laying eggs. The fungus serves as a food source for beetle larvae. The pathogen moves through a tree’s vessels causing a vascular wilt disease similar to Dutch elm disease.

In an April 3 press release, SRS announced the first description of the fungus and its association with the redbay ambrosia beetle and laurel wilt. The press release, posted online at http://www.srs.fs.fed.us/news/153, provides more information about the fungus and the threat it poses to the laurel family.

Source

Happiness is rising around the world: U-M study

People in most countries around the world are happier these days, according to newly released data from the World Values Survey based at the University of Michigan Institute for Social Research.

Data from representative national surveys conducted from 1981 to 2007 show the happiness index rose in an overwhelming majority of nations studied.

"It's a surprising finding," said U-M political scientist Ronald Inglehart, who directs the World Values Surveys and is the lead author of an article on the topic to be published in the July 2008 issue of the journal Perspectives on Psychological Science. "It's widely believed that it's almost impossible to raise an entire country's happiness level."

The 2007 wave of the surveys also provides a ranking of 97 nations containing 90 percent of the world's population. The results indicate that Denmark is the happiest nation in the world and Zimbabwe the unhappiest. The United States ranks 16th on the list, immediately after New Zealand.

During the past 26 years, the World Values Surveys have asked more than 350,000 people how happy they are, using the same two questions.

"Taking all things together, would you say you are very happy, rather happy, not very happy, not at all happy?" And, "All things considered, how satisfied are you with your life as a whole these days?"

Combining responses to these two questions, Inglehart and colleagues constructed an index of subjective well-being that reflects both happiness and general life satisfaction.

In the 52 countries for which a substantial time series is available (covering 17 years on average), this index rose in 40 countries and fell in only 12. The average percentage of people who said they were "very happy" increased by almost seven points.

"Most earlier research has suggested that happiness levels are stable," Inglehart said. "Important events like winning the lottery or learning you have cancer can lead to short-term changes, but in the long run most previous research suggests that people and nations are stuck on a 'hedonic treadmill.' The belief has been that no matter what happens or what we do, basic happiness levels are stable and don't really change."

The new findings from the World Values Surveys not only show that during the past 25 years, happiness has in fact risen substantially in most countries. Fully as important as the fact that happiness rose is the reason why. In recent decades, low-income countries such as India and China have experienced unprecedented rates of economic growth, dozens of medium-income countries have democratized and there has been a sharp rise of gender equality and tolerance of ethnic minorities and gays and lesbians in developed societies.

Economic growth, democratization and rising social tolerance have all contributed to rising happiness, with democratization and rising tolerance having even more impact than economic growth. All of these changes have contributed to providing people with a wider range of choice in how to live their lives---which is a key factor in happiness.

The people of rich countries tend to be happier than those of poor countries, but even controlling for economic factors, certain types of societies are much happier than others.

"The results clearly show that the happiest societies are those that allow people the freedom to choose how to live their lives," Inglehart said.

As an example, Inglehart points to the tolerant social norms and democratic political systems in Denmark, Iceland, Switzerland, the Netherlands and Canada all of which rank among the 10 happiest countries in the world.

"The events of the past 25 years have brought a growing sense of freedom that seems to be even more important than economic development in contributing to rising happiness," Inglehart said. "Moreover, the most effective way to maximize happiness seems to change with rising levels of economic development. In subsistence-level societies, happiness is closely linked with in-group solidarity, religiosity and national pride. At higher levels of economic security, free choice has the largest impact on happiness."

He also notes that the largest recent increases on the subjective well-being index, measuring both happiness and life-satisfaction, occurred in the Ukraine, followed by Moldova, Slovenia, Nigeria, Turkey and Russia.

"While most ex-communist countries show low levels of happiness, many of them show large recent increases in subjective well-being," Inglehart said. "The collapse of communism was generally followed by a sharp decline in well-being, which tended to rise again with economic recovery."

Useful Links

For more information on the World Values Survey: www.worldvaluessurvey.org
Happiness Trends