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Posts Tagged ‘Vesta’

Science Sunday #27

Posted by Don McLenaghen on December 18, 2011

– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. This week’s top stories:

This week’s top stories:

 

Gold 2.0, valuable and harder than steel -

EPFL scientists have created 18-karat gold that’s harder than tempered steel and virtually unscratchable.

By combining a gold alloy with boron carbide, an extremely hard ceramic that’s used in bulletproof vests, a team of EPFL researchers has succeeded in making the world’s toughest 18-karat gold (75% gold). With a Vickers hardness number of 1000, it’s harder than most tempered steels (600 Vickers) and thus almost impossible to scratch, except with a diamond. This discovery is the result of a three-year collaboration between the Mechanical Metallurgy Laboratory in EPFL’s Institute of Materials, under the leadership of Professor Andreas Mortensen, and the Swiss watchmaking company Hublot.

The process for developing this material is relatively complicated. Powdered boron carbide is heated to almost 2000°C, where it forms a rigid, porous structure by a process called sintering. A liquid molten alloy of gold is infiltrated under very high pressure into the pores of this structure, and then solidified, yielding a pore-free composite material. The final material is thus made up of two kinds of crystals that are intimately interconnected in space, like two three-dimensional labyrinths. Because the molten gold used is a previously-made alloy based on 24-karat gold and aluminum (3%) for strength, the final gold is thus 3% aluminum, 75% gold and 22% boron carbide.

By definition, gold is very soft. Managing to harden it to this degree while still maintaining 18-karat purity was a real challenge for the EPFL scientists. They overcame the obstacle by taking the ceramic-metal composite approach. Composite materials are created by artificially combining several materials that conserve their individual characteristics even after they’re assembled. In this they are different from alloys, in which atoms mix together to form a new, homogeneous, material.

Zeitnews

EPFL creates unscratchable gold

 

New rules for ethical treatment of research primates  -

Given that chimpanzees are so closely related to humans and share similar behavioral traits, the National Institutes of Health should allow their use as subjects in biomedical research only under stringent conditions, including the absence of any other suitable model and inability to ethically perform the research on people, says a new report from the Institute of Medicine and National Research Council. In addition, use of these animals should be permissible only if forgoing their use will prevent or significantly hinder advances necessary to prevent or treat life-threatening or debilitating conditions, said the committee that wrote the report. Based on these criteria, chimpanzees are not necessary for most biomedical research.

“The report’s recommendations answer the need for a uniform set of criteria for assessing the scientific necessity of chimpanzees in biomedical, comparative genomics, and behavioral research,” said committee chair Jeffrey Kahn, senior faculty member, Johns Hopkins Berman Institute of Bioethics, Baltimore. “The committee concluded that research use of animals that are so closely related to humans should not proceed unless it offers insights not possible with other animal models and unless it is of sufficient scientific or health value to offset the moral costs. We found very few cases that satisfy these criteria”.

The committee would not close the door on the possibility that chimpanzees may be needed in future research to develop treatments or preventive tools against as yet unknown diseases or disorders. It is impossible to say in advance whether other animal models or research tools will always serve effectively and quickly enough in the face of a novel health threat.

The report’s recommendations focus on the scientific necessity of the chimpanzee as a research subject, but also take ethical issues into account. Chimpanzees’ genetic closeness to humans and their similar biological and behavioral characteristics not only make chimpanzees a uniquely valuable species for certain types of research but also demand greater justification for conducting research with them, the committee said.

Science Daily

IOM Report Recommends Stringent Limits On Use Of Chimpanzees in Biomedical and Behavioral Research

Chimpanzees in Biomedical and Behavioral Research: Assessing the Necessity

Should Vesta be reclassified a planet? -

On Vista “we’re seeing enormous mountains, valleys, hills, cliffs, troughs, ridges, craters of all sizes, and plains,” says Chris Russell, Dawn principal investigator from UCLA. “Vesta is not a simple ball of rock. This is a world with a rich geochemical history. It has quite a story to tell!”

In fact, the asteroid is so complex that Russell and members of his team are calling it the “smallest terrestrial planet.”  Vesta has an iron core, notes Russell, and its surface features indicate that the asteroid is “differentiated” like the terrestrial planets Earth, Mercury, Mars, and Venus.

Researchers believe this process also happened to Vesta. The story begins about 4.57 billion years ago, when the planets of the Solar System started forming from the primordial solar nebula. As Jupiter gathered itself together, its powerful gravity stirred up the material in the asteroid belt so objects there could no longer coalesce. Vesta was in the process of growing into a full-fledged planet when Jupiter interrupted the process.

Although Vesta’s growth was stunted, it is still differentiated like a true planet. “We believe that the Solar System received an extra slug of radioactive aluminum and iron from a nearby supernova explosion at the time Vesta was forming,” explains Russell. “These materials decay and give off heat. As the asteroid was gathering material up into a big ball of rock, it was also trapping the heat inside itself.”

As Vesta’s core melted, lighter materials rose to the surface, forming volcanoes and mountains and lava flows. “We think Vesta had volcanoes and flowing lava at one time, although we’ve not yet found any ancient volcanoes there,” says Russell. “We’re still looking. Vesta’s plains seem similar to Hawaii’s surface, which is basaltic lava solidified after flowing onto the surface.

Science Daily

A small step for lungfish, a big step for the evolution of walking

Behavioral evidence for the evolution of walking and bounding before terrestriality in sarcopterygian fishes

 

The real Star War’s Midichloria  -

The work, published in this month’s issue of Molecular Biology and Evolution, challenges traditional explanations of how the ancestors of mitochondria first entered our cells between one and a half and two billion years ago. It also sheds new light on a process recognised as one of the major transitions in the history of life on earth.

“Our results challenge the paradigm – shown in every biology textbook – that mitochondria were passive bacteria gobbled up by a primordial cell,” says co-author Dr Nathan Lo from the University of Sydney’s School of Biological Sciences.

“We have found instead that the mitochondrial ancestor most likely had a flagellum, so was able to move, and possibly acted as a parasite, rather than prey, on early eukaryotic cells,” added Dr Lo, who collaborated with scientists from Italy and Spain on the research.

“We studied M. mitochondrii because its genome has never been analysed and because it is the only bacterium known to be able to enter into the mitochondria of living cells,” said Dr Lo.

After determining the DNA sequence of M. mitochondrii’s entire genome, Dr Lo and collaborators found the bacterium contained 26 genes coding for an entire flagellum – including all the key components such as hook, filament and basal body.

He also found a second set of genes which coded for enzymes that would allow the bacterium to survive in low-oxygen environments. These genes have never been seen before in bacterial relatives of mitochondria.

Dr Lo says: “We found these two sets of genes were inherited from the common ancestor shared by M. mitochondrii and our own mitochondria. Mitochondria’s ancestor most likely possessed a flagellum, which is a key characteristic of many parasitic bacteria.

“Our results show the ancestor of mitochondria probably played a much more active, even parasitic, role in the early interactions with its eukaryotic host than previously thought. They also explain how the relationship could have evolved in the low-oxygen environments of two billion years ago.

“This should cause a rethink of how the symbiosis between mitochondria and eukaryotic cells originally developed – one of the most controversial topics in biology.”

Science Alert

Star Wars-inspired bacterium provides glimpse into life

 

Women are worse at math than men, really?  -

A major study of recent international data on school mathematics performance casts doubt on some common assumptions about gender and math achievement — in particular, the idea that girls and women have less ability due to a difference in biology.

“We tested some recently proposed hypotheses that try to explain a supposed gender gap in math performance and found they were not supported by the data,” says Janet Mertz, lead author in a new study published in Notices of the American Mathematical Society. The study looked at data from 86 countries, which the authors used to test the “greater male variability hypothesis” famously expounded in 2005 by Lawrence Summers, then president of Harvard, as the primary reason for the scarcity of outstanding women mathematicians.

That hypothesis holds that males diverge more from the mean at both ends of the spectrum and, hence, are more represented in the highest-performing sector. But, using the international data, the Wisconsin authors observed that greater male variation in math achievement is not present in some countries, and is mostly due to boys with low scores in some other countries, indicating that it relates much more to culture than to biology.

The Wisconsin study also debunked the idea proposed by Steven Levitt of “Freakonomics” fame that gender inequity does not hamper girls’ math performance in Muslim countries, where most students attend single-sex schools. Levitt claimed to have disproved a prior conclusion of others that gender inequity limits girls’ mathematics performance. He suggested, instead, that Muslim culture or single-sex classrooms benefit girls’ ability to learn mathematics.

To measure the status of females relative to males within each country, the authors relied on a gender-gap index, which compares the genders in terms of income, education, health and political participation. Relating these indices to math scores, they concluded that math achievement at the low, average and high end for both boys and girls tends to be higher in countries where gender equity is better. In addition, in wealthier countries, women’s participation and salary in the paid labor force was the main factor linked to higher math scores for both genders.

“We found that boys — as well as girls — tend to do better in math when raised in countries where females have better equality, and that’s new and important,” says Kane. “It makes sense that when women are well-educated and earn a good income, the math scores of their children of both genders benefit.”

Science Daily

Zeitnews

Study debunks myths about gender and math performance

Study challenges conventional wisdom about gender and math performance

Feet before lungs -

Extensive video analysis, published in the Proceedings of the National Academy of Sciences, reveal that the African lungfish can use its thin pelvic limbs to not only lift its body off the bottom surface but also propel itself forward. Both abilities were previously thought to originate in early tetrapods, the limbed original land-dwellers that appeared later than the lungfish’s ancestors.

The observation reshuffles the order of evolutionary events leading up to terrestriality, the adaptation to living on land. It also suggests that fossil tracks long believed to be the work of early tetrapods could have been produced instead by lobe-finned ancestors of the lungfish.

“In a number of these trackways, the animals alternate their limbs, which suggested that they must have been made by tetrapods walking on a solid substrate,” said Melina Hale, PhD, associate professor of Organismal Biology and Anatomy. “We’ve found that aquatic animals with fundamentally different morphologies and that aren’t tetrapods could potentially make very similar track patterns”.

The discovery suggests that many of the developments necessary for the transition from water to land could have occurred long before early tetrapods, such as Tiktaalik, took their first steps on shore. Lobe-finned ancestors of the lungfishes as well as tetrapods could have evolved hind limb propulsion and the ability to walk on the substrate at the bottom of a lake or marsh millions of years before limbs with digits and land-dwelling animals appeared.

“This shows us — pardon the pun — the steps that are involved in the origin of walking,” Shubin said. “What we’re seeing in lungfish is a very nice example of how bottom-walking in fish living in water can easily come about in a very tetrapod-like pattern”.

Science Daily

A small step for lungfish, a big step for the evolution of walking

Behavioral evidence for the evolution of walking and bounding before terrestriality in sarcopterygian fishes

 

What makes a buttercup Yellow? –

The researchers discovered that the buttercup petal’s unique bright and glossy appearance is the result of the interplay between its different layers. In particular, the strong yellow reflection responsible for the chin illumination is mainly due to the epidermal layer of the petal that reflects yellow light with an intensity that is comparable to glass.

Scientists have been interested in how the buttercup flower works for over a century. They have previously shown that the reflected colour is yellow due to the absorption of the colours in the blue-green region of the spectrum by the carotenoid pigment in the petals. As the blue-green light is absorbed, the light in the other spectral regions (in this case, primarily yellow) is reflected. It has also been known for many years that the epidermal layer of the petals is composed of very flat cells, providing strong reflection.

This new study shows how the buttercup’s exceptionally bright appearance is a result of a special feature of the petal structure. The epidermal layer of cells has not one but two extremely flat surfaces from which light is reflected. One is the top of the cells, the other exists because the epidermis is separated from the lower layers of the petal by an air gap. Reflection of light by the smooth surface of the cells and by the air layer effectively doubles the gloss of the petal, explaining why buttercups are so much better at reflecting light under your chin than any other flower.

The researchers also found that the buttercup reflects a significant amount of UV light. As many pollinators, including bees, have eyes sensitive in the UV region, this provides insight into how the buttercup uses its unique appearance to attract insects.

Science Daily

New Scientist

Directional scattering from the glossy flower of Ranunculus: how the buttercup lights up your chin

Why buttercups reflect yellow on chins

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Science Sunday #5

Posted by Don McLenaghen on July 17, 2011

– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. This week’s top stories:

Words of the Week:

Ichnology – the branch of geology that deals with traces of organismal behavior, such as burrows and footprints.

Paracancerous – (Could not find this outside medical journals, but from the context and prefix I reconstruct this defintion) – located near or adjacent to cancerous cells.

 

New Mexico ‘spaceport’ in the works –

Under the authority of the newly created New Mexico Spaceport Authority and Spaceport America, plans for the new space are set for a site outside Truth or Consequences, a tiny desert town.

The U.S.’s manned shuttle missions have been put to an end, and the hope is that the private sector will pick up, and a new tourism industry will be born. Virgin Galactic, the first space tourism company, has already been created, and Boeing also reportedly plans to get in on the action. The project has already cost the state of New Mexico $200 million.

NPR – Space Port

RawStory – Space Port

NASA spacecraft to enter orbit of large asteroid -
NASA’s Dawn spacecraft is about to be captured into orbit around the giant asteroid Vesta. Meanwhile, a new paper argues that Vesta and Ceres, another huge asteroid set to be visited by Dawn, are the main stumbling blocks to predicting the long-term fate of the solar system.

At 530 kilometres across, Vesta is one of the biggest denizens of the asteroid belt, the junkyard of leftover planetary building blocks found between Mars and Jupiter. Vesta, thought to have finished growing long before Earth and the other planets, could reveal clues about the era of early planet formation. After a year in orbit, Dawn will head to Ceres, the solar system’s biggest asteroid.

New Scientist – Probe’s targets cloud ‘crystal ball’

RawStory – NASA orbits asteroid

 

Fossil Forensics: Wasps setup home in Dino eggs - 

The approximately 70 million year old eggs, from gigantic titanosaur sauropod dinosaurs were discovered in 1989 in the Patagonia region of Argentina, well known for yielding fossils of sauropod dinosaur eggs and even embryonic dinosaurs. Only recently it was discovered that one of the broken eggs contained tiny sausage-shaped structures, 2-3cm long and 1cm wide. The structures closely resembled fossilised insect cocoons, and were most similar in size and shape to the cocoons of some species of modern wasp.

There are many records of fossilised dinosaur eggs, and even several records of fossil cocoons, but, as author Dr Jorge Genise of the Museo Argentino de Ciencias Naturales states “this is the first time that these cocoons are found closely associated with an egg.”

ScienceDaily – How Wasps Populated Rotting Dinosaur Eggs

 

Early Talking Doll Recording Discovered  -

Scientists managed to recover the sound from what is thought to be the earliest ever talking doll – 123 years old, singing ‘Twinkle Twinkle Little Star’. It was recorded by Thomas Edison himself, and probably has not been heard since his lifetime. We find out how this recording was made.

The artifact is a ring-shaped cylinder phonograph record made of solid metal. The metal record is significantly bent out of its original round, cylindrical shape.  At the Lawrence Berkeley National Laboratory, Senior Scientist Carl Haber and Computer Systems Engineer Earl Cornell used a three-dimensional optical scanning technology to create a digital model of the surface of the record. With this digital model, they used modern image analysis methods to reproduce the audio stored on the record, saving it as a WAV-format digital audio file.

NPS – Early Talking Doll Recording Discovered

Science in Action

 

Tough at the top - 

These days, the expression “it’s tough at the top” is usually used ironically. But it turns out that being a top ranking, or alpha male could be a lot more stressful than we realised, particularly if you are a monkey. Researchers have just published work involving a nine year study of baboon populations in Africa. They found that alpha males have higher levels of stress hormones and lower levels of testosterone than males ranked below them. So could the same hold true for humans?

In social hierarchies, dominant individuals experience reproductive and health benefits, but the costs of social dominance remain a topic of debate. Prevailing hypotheses predict that higher-ranking males experience higher testosterone and stress hormone levels than lower-ranking males when hierarchies are unstable but not otherwise. In this long-term study of rank-related stress in a natural population of savannah baboons, high-ranking males had higher testosterone and lower glucocorticoid levels than other males, regardless of hierarchy stability. The singular exception was for the highest-ranking (alpha) males, who exhibited both high testosterone and high glucocorticoid levels. In particular, alpha males exhibited much higher stress hormone levels than second-ranking (beta) males, suggesting that being at the very top may be more costly than previously thought.

Science – Life at the Top

Science in Action

 

CRYPTOZOOLOGY - 

The Yeti, the Loch Ness Monster, giant sea serpents – these are all examples of creatures rumoured to exist but never proven. Dr Charles Paxten of St Andrews University discussed the science of cryptozoology at a meeting at the Zoological Society of London this week. But is it a valid science? Can anecdotal reports tell us about real monsters, rare species or just human psychology?

Speculation as to the nature of large unknown aquatic animals has generally occurred in the absence of quantitative data and relied almost solely on eyewitness testimonial. This need not be the case. I estimated the number of unknown large open water marine animals awaiting discovery by science based on an assumption that the scientific description rate for unknown large aquatic animals from 1830 could be extrapolated into the future. If this is true then the cumulative species description rate can be modelled as a rectangular hyperbola and an estimate of the number of large unknown open water marine animals could be made.

Material World
Predicting Aquatic Monsters

 

Piece of Mind: Is the Internet Replacing Our Ability to Remember - 

Has the Internet dumbed down society or simply become an external storage unit that enhances the human brain’s memory capacity? With Google, Internet Movie Database and Wikipedia at our beck and call via smart phones, tablets and laptops, the once essential function of committing facts to memory has become little more than a flashback to flash cards.

The results of four studies suggest that when faced with difficult questions, people are primed to think about computers and that when people expect to have future access to information, they have lower rates of recall of the information itself and enhanced recall instead for where to access it. The Internet has become a primary form of external or transactive memory, where information is stored collectively outside ourselves.

Scientific American – Piece of Mind

Science – Google Effects on Memory

 

Funding For James Webb Space Telescope In Jeopardy - 

A bill approved by the House Committee on Appropriations cuts funding for NASA’s James Webb Space Telescope in 2012. (The bill has not yet been approved by the full House and Senate). Ira Flatow and guests discuss the status of the telescope and what happens if funding is cut.

Science Friday

James Webb Space Telescope

 

Rise in Risk Inequality - 

A new study of political polarization in the United States suggests that changes in the labor market since the 1970s has helped create more Republican and Democratic partisans and fewer independents..

In a study published recently in the British Journal of Political Science, Philipp Rehm estimated that slightly more than half of Americans could be counted as natural partisans in 1968, based on their income and job security. But by 2008, the number of natural partisans had climbed to include nearly two-thirds of all Americans.

Rehm said that, traditionally, many political scientists have thought that Americans’ income played a large role in which political party they supported. Rehm argues that Americans’ political preferences are shaped not just by their current income, but also by the risk they perceive that they could lose their current income level.

ScienceDaily – Polarized US Voters

 

A field guide to bullshit - 

How do people defend their beliefs in bizarre conspiracy theories or the power of crystals? Philosopher Stephen Law has tips for spotting their strategies.

“Intellectual black holes are belief systems that draw people in and hold them captive so they become willing slaves of claptrap. Belief in homeopathy, psychic powers, alien abductions – these are examples of intellectual black holes. As you approach them, you need to be on your guard because if you get sucked in, it can be extremely difficult to think your way clear again.

You identify some strategies people use to defend black hole beliefs. Tell me about one of them – “playing the mystery card“?

This involves appealing to mystery to get out of intellectual hot water when someone is, say, propounding paranormal beliefs. They might say something like: “Ah, but this is beyond the ability of science and reason to decide. You, Mr Clever Dick Scientist, are guilty of scientism, of assuming science can answer every question.” This is often followed by that quote from Shakespeare’s Hamlet: “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy”. When you hear that, alarm bells should go off.

How can science test these mysteries?

Psychologist Christopher French at Goldsmiths, University of London, ran an experiment into the effects of crystals to explore claims that holding “real” crystals from a New Age shop while meditating has a powerful effect on the psyche, more so than just holding “fake” ones. But French found no difference in participants using real and fake crystals. This was good evidence that the effect people report is down to the power of suggestion, not the crystals.

Of course, this study provoked comments such as: “Not being able to prove the existence of something does not disprove its existence. Much is yet to be discovered.” This is just a smokescreen. But because the mantra “it’s-beyond-the-ability-of-science-to-establish…” gets repeated so often, it is effective at lulling people back to sleep – even if they have been stung into entertaining a doubt for a moment or two.”

New Scientist

Stephen Law

 

Why the universe wasn’t fine-tuned for life – 

In recent years many such examples of how the laws of physics have been “fine-tuned” for us to be here have been reported. Some religious people claim these “cosmic coincidences” are evidence of a grand design by a Supreme Being. In The Fallacy of Fine-tuning, physicist Victor Stenger makes a devastating demolition of such arguments.

A general mistake made in search of fine-tuning, he points out, is to vary just one physical parameter while keeping all the others constant. Yet a “theory of everything” – which alas we do not yet have – is bound to reveal intimate links between physical parameters. A change in one may be compensated by a change in another, says Stenger.

In addition to general mistakes, Stenger deals with specifics. For instance, British astronomer Fred Hoyle discovered that vital heavy elements can be built inside stars only because a carbon-12 nucleus can be made from the fusion of three helium nuclei. For the reaction to proceed, carbon-12 must have an energy level equal to the combined energy of the three helium nuclei, at the typical temperature inside a red giant. This has been touted as an example of fine-tuning. But, as Stenger points out, in 1989, astrophysicist Mario Livio showed that the carbon-12 energy level could actually have been significantly different and still resulted in a universe with the heavy elements needed for life.

New Scientist

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