Friday 28 February 2014

World's oldest cheese recovered from mummies

Ancient cheese has been collected from the neck and chest of a female mummy known as the 'Beauty of Xiaohe'. The archaeologists have unearthed world's oldest cheese from necks and chests of perfectly preserved mummies buried in China's desert sand. The 3,600-year-old cheese was discovered during archaeological excavations at the Xiaohe cemetery in the inhospitable Taklamakan desert. The researchers lead by Chinese team leader Changsui Wang from the University of Chinese Academy of Sciences collected 13 samples of the yellowish organic material from 10 tombs and mummies. Dating back as early as 1615 BC, the lumps of yellowish organic material have provided direct evidence for the oldest known dairy fermentation method. The individuals were buried with the cheese so they could savour it in the afterlife, said the study. 'Beauty of Xiaohe' is a 3,800-year-old female mummy wrapped in a finely crafted shroud, bearing Caucasian features such as a long nose and light hair. Until now, no remains of ancient cheeses had been found.

Tuesday 25 February 2014

Soon, cheap second-generation biofuel for cars

In a breakthrough, scientists have developed a new technique to produce cheap and environmentally friendly second-generation biofuel from dead plant tissue. The process as used today needs expensive enzymes, and large companies dominate this market, researchers said. Now Danish and Iraqi researchers have developed a new technique that avoids the expensive enzymes. Researchers said the production of second generation biofuels thus becomes cheaper, probably attracting many more producers and competition, and this may finally bring the price down. Bioethanol, which is made from the remains of plants after other parts have been used as food or other agricultural products, and therefore termed "second generation," is seen as a strong potential substitute candidate. Corn cubs and sugar canes are in fact plant parts that can also be used directly as food, so there is a great public resistance to accept producing this kind of bioethanol. A big challenge is therefore to become able to produce bioethanol from plant parts, which cannot be used for food. The goal is to produce bioethanol from cellulose. Cellulose is very difficult to break down, and therefore cannot directly be used as a food source, researchers said. "But the patented enzymes are expensive to buy. We are proud to now introduce a completely enzyme-free technique that is not patented and not expensive. The technique can be used by everybody," said Per Morgen from University of Southern Denmark. Together with colleagues from the University of Baghdad and Al-Muthanna University in Iraq, he said that it is not an enzyme, but an acid that plays the main role in the new technique. The acid is called RHSO3H, and it is made on the basis of rice husks. The ashes from burnt rice husks have a high content of silicate, and this is the important compound in the production of the new acid. The scientists paired silicate particles with chlorosulfonic acid and this made the acid molecules attach themselves to the silicate compounds. "The result was an entirely new molecule - the acid RHSO3H - which can replace the enzymes in the work of breaking down cellulose to sugar," said Morgen.

Saturday 22 February 2014

Giant solar flare welcomes earth

Don't miss the strongest solar flare of the year that sent out giant bursts of light and radiation into the space. Nasa's Interface Region Imaging Spectrograph (IRIS) captured its strongest solar flare since its launch in the summer of 2013. IRIS looks into chromosphere, a layer of the sun's lower atmosphere just above the surface, with unprecedented resolution. Chromosphere regulates the flow of energy and material as they travel from the sun's surface out into space. On January 28, scientists spotted a magnetically active region on the sun and focused IRIS on it to see how the solar material behaved under intense magnetic forces. They noticed a moderate flare, labeled an M-class flare - which is the second strongest class flare after X-class - erupted from the area, sending light and x-rays into space. IRIS is equipped with an instrument called a spectrograph that can separate out the light it sees into its individual wavelengths, which in turn correlates to material at different temperatures, velocities and densities. The spectrograph on IRIS was pointed right into the heart of this flare when it reached its peak. The data obtained can help determine how different temperatures of material flow, giving scientists more insight into how flares work, said a Nasa release. http://timesofindia.indiatimes.com/home/science/Giant-solar-flare-welcomes-earth/articleshow/30842404.cms

Wednesday 19 February 2014

Activity videos may boost brain power: Study

Watching activity videos before carrying simple tasks may boost the brain's plasticity and increase motor skills, shows research. Brain plasticity is the brain's ability to flex and adapt, allowing for better learning. The brain loses plasticity as it ages. "The study lends that even as an adult, your brain is able to better learn skills just by watching the activity take place. With a dramatic increase of videos available through mobile phones, computers, and other newer technology, this topic should be the focus of more research," explained Paolo Preziosa from San Raffaele Hospital in Milan, Italy. The results might also contribute to reducing disability and improving quality of those who are impaired or who are undergoing physical rehabilitation. The researchers put 36 right-handed healthy adults in 40-minute training sessions five times a week for two weeks. Half the group watched videos of a specific task, such as writing with a pen, cutting with scissors or handling coins, then were asked to complete the task themselves. The other half watched videos of landscapes and then were asked to complete the same tasks. The groups were tested for strength and hand skills and also underwent 3-D MRI brain scans. The researchers found that the group who completed the training along with watching the activity videos had 11 times greater improvement of motor skill abilities - mainly in terms of strength - compared to those who watched the landscape videos. The detailed study is scheduled to be presented at the American Academy of Neurology's 66th Annual Meeting in Philadelphia April 26-May 3.

Tuesday 18 February 2014

First animals lived with almost no oxygen?

The most primitive animals may have thrived in water that contained almost zero or little oxygen, a new study suggests, challenging a long held theory about the evolution of life on earth. One of science's strongest dogmas is that complex life on Earth could only evolve when oxygen levels in the atmosphere rose close to modern levels. But now studies of a small sea sponge fished out of a Danish fjord - the westernmost inlet of the Baltic Sea - shows that complex life does not need high levels of oxygen in order to live and grow. The origin of complex life is one of science's greatest mysteries. Researchers wondered how the first small primitive cells evolve into the diversity of advanced life forms that exists on Earth today. The explanation in all textbooks is: Oxygen. Complex life evolved because the atmospheric levels of oxygen began to rise about 630-635 million years ago, researchers said. However, new studies of a common sea sponge from Denmark shows that this explanation needs to be reconsidered. The sponge studies show that animals can live and grow even with very limited oxygen supplies. In fact animals can live and grow when the atmosphere contains only 0.5 per cent of the oxygen levels in today's atmosphere. "Our studies suggest that the origin of animals was not prevented by low oxygen levels," said Daniel Mills, PhD at the Nordic Centre for Earth Evolution at the University of Southern Denmark. The emergence of animals coincided with a significant rise in atmospheric oxygen, and therefore it seemed obvious to link the two events and conclude that the increased oxygen levels had led to the evolution of animals, researchers said. "But nobody has ever tested how much oxygen animals need - at least not to my knowledge. Therefore we decided to find out", said Mills who worked with lead author Lewis M Ward from the California Institute of Technology. The living animals that most closely resemble the first animals on Earth are sea sponges. "When we placed the sponges in our lab, they continued to breathe and grow even when the oxygen levels reached 0.5 per cent of present day atmospheric levels," said Mills. This is lower than the oxygen levels we thought were necessary for animal life, researchers said. The research was published in the journal PNAS.

Saturday 15 February 2014

Tracing ancestry, researchers produce a genetic atlas of human mixing events

The rise and fall of empires, the march of armies, the flow of trade routes, the practice of slavery — all these events have led to a mixing of populations around the world. Such episodes have left a record in the human genome, but one that has so far been too complex to decipher on a global scale. Now, geneticists applying new statistical approaches have taken a first shot at both identifying and dating the major population mixture events of the last 4,000 years, with the goal of providing a new source of information for historians. Some of the hundred or so major mixing events they describe have plausible historical explanations, while many others remain to be accounted for. For instance, many populations of the southern Mediterranean and Middle East have segments of African origin in their genomes that were inserted at times between AD 650 and 1900, according to the geneticists' calculations. This could reflect the activity of the Arab slave trade, which originated in the seventh century, and the absorption of slaves into their host populations. The lowest amount of African admixture occurs in the Druse, a religious group of the Middle East that prohibited slavery and has been closed to converts since AD 1043. Another mixing event is the injection of European-type DNA into the Kalash, a people of Pakistan, at some time between 990 and 210 BC This could reflect the invasion of India by Alexander the Great in 326 BC The Kalash claim to be descended from Alexander's soldiers, as do several other groups in the region. The genetic atlas of human mixing events was published on Thursday in the journal Science by a team led by Simon Myers of Oxford University, Garrett Hellenthal of University College London and Daniel Falush of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Having sampled genomes from around the world, they found they could detect about 95 distinguishable populations. Though all humans have the same set of genes, their genomes are studded with mutations, which are differences in the sequence of DNA units in the genome. These mutations occur in patterns because whole sets of mutations are passed down from parent to child and hence will be common in a particular population. Based on these patterns, geneticists can scan a person's genome and assign the ancestry of each segment to a particular race or population. The team led by Dr Myers has developed a statistical technique for identifying the chromosomal segments with particular precision. This enables them to perform a second feat, that of assigning a date to the one or more mixing events that have affected a population. The dating system is based on measuring the length of chromosome segments of a particular ancestry that occur in a population. When people of two different populations intermarry, their children's genomes carry large chunks of DNA of one parent's ancestry interspersed with large chunks from the other's. In each successive generation, the average size of the chunks becomes smaller because when DNA is swapped between the parents' genomes in making the eggs or sperm, the cuts needed to generate the swapped sections are made in different places. Therefore, from the average size of the chunks in a person's genome, the geneticists can calculate the number of generations since the mixing event. "We are among the first to try to date ancestry events, and we have more ability to determine the source populations," Dr Myers said. One of the most widespread events his group has detected is the injection of Mongol ancestry into populations within the Mongol empire, such as the Hazara of Afghanistan and the Uighur Turks of Central Asia. The event occurred 22 generations ago, according to genetic dating, which corresponds to the beginning of the 14th century, fitting well with the period of the Mongol empire. In another example, the European colonization of America is recorded in the genomes of the Maya and Pima Indians. And Cambodian genomes mark the fall of the Khmer empire in the form of ancestral DNA from the invading Tai people. Dr Myers and his colleagues have detected European ancestry that entered the Tu people of central China between the 11th and 14th centuries; this, they surmise, could be from traders traveling the Silk Road. They find among Northern Italians an insertion of Middle Eastern DNA that occurred between 776 BC and AD 550, and may represent the Etruscans, a mysterious people said by the ancient Greek historian Herodotus to have emigrated from Lydia in Turkey. The Myers group has posted its results on a web page that records the degree of admixture in each population. The English, however, known to be a rich medley of Celts with invaders such as the Angles, Saxons, Jutes, Danes and Norwegians, carry the notation "No strong evidence of admixture." Dr Myers said his method cannot yet detect genetic mixing between very similar populations, as was the case with the English and their invaders from Scandinavia and Northern Germany. He said he hoped to distinguish all these groups in a separate project on British ancestry. Dr Hellenthal said, "We're fairly confident that increasing our sample size will help us follow local migrations." John Novembre, a geneticist at the University of Chicago, described the new genetic atlas as a "landmark study" because of its scale and the fact that the authors had been able to extract complex signatures from the data. "The detailed historical interpretations may need further questioning and testing," he said. Dr Myers and Dr Hellenthal said that they hoped historians would find their work useful, but that they had not collaborated with historians. "In some sense we don't want to talk to historians," Dr Falush said. "There's a great virtue in being objective: You put the data in and get the history out. We do think this is a way of reconstructing history by just using DNA."

Saturday 8 February 2014

Here is what Earth looks like from Mars

Nasa's Curiosity rover has taken a photograph of Earth from the surface of Mars, showing what our planet looks like from 100 million miles away. It's rare that a single dot on a computer screen can elicit such a strong reaction, but there is something mind-blowing about Earth's diminutive appearance in the image. While we are used to seeing vivid greens and blues and swirling cloud when the Earth is photographed from space, from this distance the planet and its moon appear like no more than a couple of bright 'evening stars'. http://timesofindia.indiatimes.com/home/science/Here-is-what-Earth-looks-like-from-Mars/articleshow/30054065.cms

Wednesday 5 February 2014

Scientists find planet drunkenly dancing around two 'suns'

It doesn't get weirder than this in the cosmic zoo: a gas planet that is going around two 'suns', one orange and the other red, all the time wobbling drunkenly so much that 'seasons' would flash past. This strange world was discovered 2300 light years away by Nasa's planet-hunting Kepler space telescope. The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin axis, much like a child's top. The tilt of the planet's spin axis can vary by as much as 30 degrees over 11 years, leading to rapid and erratic changes in seasons. In contrast, Earth's rotational precession is 23.5 degrees over 26,000 years. Researchers are amazed that this far-off planet is precessing on a human timescale. Kepler 413-b is located in the constellation Cygnus. It circles a close pair of orange and red dwarf stars every 66 days. The planet's orbit around the binary stars appears to wobble, too, because the plane of its orbit is tilted 2.5 degrees with respect to the plane of the star pair's orbit. As seen from Earth, the wobbling orbit moves up and down continuously. Kepler finds planets by noticing the dimming of a star or stars when a planet transits, or travels in front of them. Normally, planets transit like clockwork. Astronomers using Kepler discovered the wobbling when they found an unusual pattern of transiting for Kepler-413b. "Looking at the Kepler data over the course of 1,500 days, we saw three transits in the first 180 days -- one transit every 66 days -- then we had 800 days with no transits at all. After that, we saw five more transits in a row," said Veselin Kostov, the principal investigator on the observation. Kostov is affiliated with the Space Telescope Science Institute and Johns Hopkins University in Baltimore, Md. The next transit visible from Earth's point of view is not predicted to occur until 2020. This is because the orbit moves up and down, a result of the wobbling, in such a great degree that it sometimes does not transit the stars as viewed from Earth. Astronomers are still trying to explain why this planet is out of alignment with its stars. There could be other planetary bodies in the system that tilted the orbit. Or, it could be that a third star nearby that is a visual companion may actually be gravitationally bound to the system and exerting an influence. "Presumably there are planets out there like this one that we're not seeing because we're in the unfavorable period," said Peter McCullough, a team member with the Space Telescope Science Institute and Johns Hopkins University. "And that's one of the things that Veselin is researching: Is there a silent majority of things that we're not seeing?" Even with its changing seasons, Kepler-413b is too warm for life as we know it. Because it orbits so close to the stars, its temperatures are too high for liquid water to exist, making it inhabitable. It also is a super Neptune -- a giant gas planet with a mass about 65 times that of Earth -- so there is no surface on which to stand.

Tuesday 4 February 2014

Pyramid older than Great Pyramid Of Giza discovered in Egypt

Archaeologists have discovered a 4600-year-old mysterious step pyramid in Egypt, which was built at least a few decades before the Great Pyramid of Giza. Scientists are unsure as to why this pyramid was built and speculate it could have been a symbol of the king's power. Working near the ancient settlement of Edfu, in southern Egypt, archaeologists unearthed the step pyramid that predates the Great Pyramid of Giza by at least a few decades. The pyramid, which was once 13 meters in height, is one of seven so-called "provincial" pyramids built by either the pharaoh Huni (2635-2610 BC) or Snefru (2610-2590 BC). The step pyramid's stone blocks were pillaged over time, and the monument was exposed to weathering, so it is only about 5 metre tall now, 'LiveScience' reported. The provincial pyramids are scattered throughout central and southern Egypt and are located near major settlements. They have no internal chambers and were not intended for burial purposes. Six of the seven pyramids have almost identical dimensions, including the newly uncovered one at Edfu. The purpose of these seven pyramids remains a mystery, the report said. "The similarities from one pyramid to the other are really amazing, and there is definitely a common plan," said Gregory Marouard, a research associate at the University of Chicago's Oriental Institute who led the work.