46 million year old Blood-filled mosquito fossil found.

A Unique 46-million-year-old mosquito fossil with a belly full of dried blood has been found in a Montana riverbed, US researchers say.

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“It is an extremely rare fossil, the only one of its kind in the world,” said Dale Greenwalt, lead author of the study in the Proceedings of the National Academy of Sciences, on Monday.

Cutting-edge instruments detected the unmistakable traces of iron in her engorged abdomen, but just what creature that blood came from is a mystery since DNA cannot be extracted from a fossil that old.

Greenwalt said it might have been blood from a bird, since the ancient mosquito resembles a modern one from the genus Culicidae, which likes to feed on our feathered friends.

“But that would be pure speculation,” said Greenwalt, a retired biochemist who volunteers at the Smithsonian Museum of Natural History in Washington.

Greenwalt said he became fascinated with fossilised insects several years ago.

He learned about Master’s student Kurt Constenius, who described his discoveries of fossilised insects along a remote Montana riverbed in an obscure geological journal more than two decades ago.

Greenwalt and Constenius discussed the fossil grounds, which lie near the Flathead River along the western boundary of Glacier National Park.

The fossil described in PNAS came from a collection of fossilised insects languishing in Constenius’s basement since the 1980s, and which he and his family had donated to the Smithsonian museum.

“As soon as I saw it, I knew it was different,” Greenwalt said.

The mosquito itself is only about 0.5cm in size. Somehow, the fragile creature ate its last meal, filling its abdomen until it was nearly ready to burst like a balloon.

Then, perhaps as the mosquito was flying over an algae-coated lake, it became caught in that mucus, enveloped in microbes that protected it from degrading, and eventually sank deep into the sediment of the lake.

Despite its impressive age it is far from the oldest known mosquito fossil. That honour goes to a 95-million-year-old mosquito in amber in Myanmar.

 

Astronomers find wandering planet, and a planet with signs of water and rocky surfaces

A Lonely planet, wandering through space without a star or companions, has caught the eye of astronomers searching for alien life.

The gaseous exoplanet, dubbed PSO J318.5-22, is just 80 light years from Earth and has a mass only six times that of Jupiter.

Having formed 12 million years ago, the planet is considered a newborn among its peers.

“We have never before seen an object free-floating in space that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” said research team leader Michael Liu of the Institute for Astronomy at the University of Hawaii at Manoa.

“I had often wondered if such solitary objects exist, and now we know they do.”

The researchers, whose study was published in the Astrophysical Journal Letters, identified the planet from its faint and unique heat signature using the Pan-STARRS 1 wide-field survey telescope on the Haleakala volcano of Hawaii’s Maui island.

The discovery comes at the same time that a planetary “graveyard” some 150 light years away reveals it once had the right conditions for life – and planets like Earth may have orbited the star known as GD 61, British astronomers reported in the journal Science.

990436-pso-j318-5-22 But it is the wanderer that has caught the public’s imagination.

The Astronomers suggest the newly found planet may have the lowest mass of all known freely floating objects.

Other telescopes in Hawaii showed that the planet has similar properties to those of gas giants orbiting around young stars, but PSO J318.5-22 is nowhere near a host star.

During the past decade, researchers have found about a thousand extrasolar planets using indirect methods, including planet-induced wobbling or dimming of their host stars.

But only a handful of these planets have been observed directly since most are orbiting around young stars less than 200 million years old and thus very bright.

PSO J318.5-22 “is going to provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth,” said co-author Niall Deacon of the Max Planck Institute for Astronomy in Germany.
Meanwhile, the discovery of the “planetary graveyard” raises hopes of observing a system with life-supporting conditions.

“This planetary graveyard swirling around the embers of its parent star is a rich source of information about its former life,” said co-author Boris Gansicke of the Department of Physics at the University of Warwick.

Around 200 million years ago, GD 61 lost its power and began sucking in the nearest planets with its extreme gravitational pull, devouring them to pieces.

Now that Sun is what is known as a white dwarf, or a dying star that is circled by planetary debris.

Astronomers have typically studied living stars and the planets that circle them in the search for other worlds that are a reasonable distance from their stars and therefore not too cold or too hot for life.

But a handful of promising far-away discoveries by the NASA Kepler mission have been limited to the size and density of planets in this so-called Goldilocks zone.

Their compositions, whether rocky like Earth or gassy like Jupiter, have remained a mystery because astronomers couldn’t get close enough to peer at their surfaces, or inside them.

The latest analysis focused on a dead planet that has been broken to bits, allowing scientists to analyse the fragments and actually see inside the contents.

Previous research has examined 12 destroyed exoplanets orbiting white dwarves in this way, but never before has the signature of water been found.

Using ultraviolet spectroscopy data, scientists have shown that the fragments contain about 26 per cent water by mass, far greater than the Earth’s 0.02 per cent.

The team detected magnesium, silicon, iron and oxygen in the white dwarf’s atmosphere, making up the main components of rocks.

The high proportion of oxygen indicates the presence of water.

“Those two ingredients – a rocky surface and water – are key in the hunt for habitable planets outside our solar system so it’s very exciting to find them together for the first time outside our solar system,” said Mr Gansicke.

The findings are based on data from the Hubble Space Telescope and the W.M. Keck Observatory on Mauna Kea on Hawaii on planets far beyond the solar system.

“The finding of water in a large asteroid means the building blocks of habitable planets existed – and maybe still exist – in the GD 61 system, and likely also around substantial number of similar parent stars,” said lead author Jay Farihi, from Cambridge’s Institute of Astronomy.

“A system cannot create things as big as asteroids and avoid building planets, and GD 61 had the ingredients to deliver lots of water to their surfaces,” Mr Farihi said.

“Our results demonstrate that there was definitely potential for habitable planets in this exoplanetary system.”

While the findings offer fresh hope of someday locating other planets where life exists, they also provides a sobering reminder of what lies ahead for Earth, perhaps six billion years from now, when alien astronomers may be studying the fragments of our solar system.

Nano-Dissection Identifies Genes Involved in Kidney Disease

131004154808-largeUnderstanding how genes act in specific tissues is critical to our ability to combat many human diseases, from heart disease to kidney failure to cancer. Yet isolating individual cell types for study is impossible for most human tissues.

A new method developed by researchers at Princeton University and the University of Michigan called “in silico nano-dissection” uses computers rather than scalpels to separate and identify genes from specific cell types, enabling the systematic study of genes involved in diseases.

The team used the new method to successfully identify genes expressed in cells known as podocytes — the “work-horses” of the kidney — that malfunction in kidney disease. The investigators showed that certain patterns of activity of these genes were correlated with the severity of kidney impairment in patients, and that the computer-based approach was significantly more accurate than existing experimental methods in mice at identifying cell-lineage-specific genes. The study was published in the journal Genome Research.

Using this technique, researchers can now examine the genes from a section of whole tissue, such as a biopsied section of the kidney, for specific signatures associated with certain cell types. By evaluating patterns of gene expression under different conditions in these cells, a computer can use machine-learning techniques to deduce which types of cells are present. The system can then identify which genes are expressed in the cell type in which they are interested. This information is critical both in defining novel disease biomarkers and in selecting potential new drug targets.

By applying the new method to kidney biopsy samples, the researchers identified at least 136 genes as expressed specifically in podocytes. Two of these genes were experimentally shown to be able to cause kidney disease. The authors also demonstrated that in silico nano-dissection can be used for cells other than those found in the kidney, suggesting that the method is useful for the study of a range of diseases.

The computational method was significantly more accurate than another commonly used technique that involves isolating specific cell types in mice. The nano-dissection method’s accuracy was 65% versus 23% for the mouse method, as evaluated by a time-consuming process known as immunohistochemistry which involves staining each gene of interest to study its expression pattern.

The research was co-led by Olga Troyanskaya, a professor of computer science and the Lewis-Sigler Institute for Integrative Genomics at Princeton, and Matthias Kretzler, a professor of computational medicine and biology at the University of Michigan. The first authors on the study were Wenjun Ju, a research assistant professor at the University of Michigan, and Casey Greene, now at the Geisel School of Medicine at Dartmouth and a former postdoctoral fellow at Princeton.

Where did we come from?

 

One of the big questions is: “Where did we come from?” Well, thanks to a strange fusion of a few different sciences, we’re getting closer to finding out — and the answer is pretty surprising.

The scientists included palaeontologists (the fossil dudes), geneticists (the DNA dudes) and archaeologists (the dudes who try to understand artifacts from our human past).

So here we are today, Homo sapiens, the only species of human left. But 100,000 years ago, there were at least three different species of human, and possibly six. So, to understand this, let’s look at the timeline of our evolution.

Well, the story begins in Africa about six to eight million years ago, when there was the big split between the line that led to us, and the line that led to the chimpanzees. Around 2.6 million years, our ancestors had invented rock tools and had a brain around 400 to 500 cubic centimeters or cc.

Via evolution, the brain size gradually increased, and by around 600,000 years ago, our direct ancestor was Homo heidelbergensis. They were not that different from us — the brain was only about 100cc smaller, at around 1,200cc, and there’s very strong evidence that they had language.

Around 500,000 years ago, a group of hominins (almost certainly Homo heidelbergensis) walked out of Africa forever, heading north for Europe and Asia. By around 300,000 years ago, they had evolved into two different species.

Now, one species was the Neanderthals, who headed west, towards Europe. About 100,000 years ago, they got itchy feet and began spreading east, towards Asia. The last Neanderthals died out as recently as 30,000 years ago, in caves in Gibraltar. We’ve known about the existence of the Neanderthals for nearly two centuries.

The other species (who also descended from Homo heidelbergensis) headed east towards Asia. They are also our long-lost cousins, but we’ve known about them only since 2010, when some remains were found in a cave in the Altai Mountains. Now, these mountains are in Southern Siberia, about 2600 kilometres north of Dhaka, the capital of Bangladesh.

In the 18th century, a hermit named Denis lived in this very cave and in 2008, an archaeologist exploring this cave found a tiny 40,000 year-old bone. It was a chip of the middle section of a little finger and when DNA was analysed, there was a huge surprise — it was human, but it was not Neanderthal, and it wasn’t us, Homo sapiens. So this new species of extinct human was called Denisovan, after the hermit, Denis.

So getting back to our timeline, about a quarter-of-a-million years ago, there were at least three species of humans on the planet. There was Homo heidelbergensis, still hanging around in Africa, the Neanderthals who had gone West to Europe, and the Denisovans in the East.

Then, in Africa, by around 200,000 years ago, Homo heidelbergensis had gradually evolved into us, Homo sapiens and, about 65 to 70,000 years ago, Homo sapiens left Africa, and spread across the world. They walked into Europe, and, to a very limited degree, they interbred with the Neanderthals.

Now, by this time, the Neanderthals had walked across to the east, in fact, to that very same cave that Denis the Hermit lived in. But the Neanderthals never walked back into Africa. So, all of us, except for Africans, today carry some Neanderthal DNA. About 2.5 per cent of our DNA (excluding Africans) is Neanderthal DNA.

Early Homo sapiens, when they left Africa, about 65 to 70,000 years ago, also went East and West. To a limited degree, the early Homo sapiens interbred with the Denisovans. So today, in the Melanesians of Papua New Guinea and of Bougainville, and in the Australian Aborigines, there’s some Denisovan DNA — up to five per cent.

But these answers, of course, lead to more questions.

First, if our Homo sapiens ancestors bred with the Denisovans, you can see how the Australian Aborigines and the Melanesians could have some Denisovan DNA. But how come hardly anybody else in Asia has any Denisovan DNA?

Second, we know that there were a few other species of humans around in the past — such as the Neanderthals and the Denisovans, and almost certainly Homo floresiensis. Why did they die out?

We don’t know.

But, this cave, now it was home to the Neanderthals and the Denisovans and to us Homo sapiens and, not to mention, Denis the Hermit. Here’s the big question: What’s so great about this cave?

Thanks to Dr Karl

Spinning star has a split personality

Astronomers have found a neutron star that can switch from being a rotating radio wave beacon to a weight-gaining x-ray emitter, in a relatively short space of time.

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The finding may explain an intermediate phase in the life of these powerful objects.

The discovery was made in a binary star known as IGR J18245-2452, which creates a bright x-ray source. One star is a puffy low-mass star; the other a rapidly-spinning neutron star, a super-dense stellar corpse that pulls in material from its companion.

As material from the large, low-mass star is pulled into a hot accretion disk swirling around its companion and interacts with its magnetic field, powerful x-rays are emitted, detectable as a “low-mass binary” by x-ray-sensitive telescopes like NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton.

But as the neutron star absorbs material from the spinning accretion disk it gains momentum, spinning faster and faster and ramping-up its magnetic field even further.

The flow of material from the low-mass star slows, the neutron star — now spinning madly, up to 254 times a second — throws much of the material in the disk out of the system entirely.

With the x-ray emitting material gone, the neutron star is free to blast jets of radio waves out into space from its poles. It’s now a millisecond pulsar, and to anything aligned with its poles it flashes in the radio spectrum like a lighthouse beacon on overdrive.

The full transition of a low-mass x-ray binary to millisecond pulsar is a process that’s thought to take place over billions of years. But IGR J18245-2452 has given astronomers evidence that switches — in both directions — can occur much more rapidly… within a period of just a few days, in fact.

It’s the first time that the transition between these particular two stages of stellar evolution has been directly observed.

“We’ve been fortunate enough to see all stages of this process, with a range of ground and space telescopes. We’ve been looking for such evidence for more than a decade,” says Dr Alessandro Papitto of ther Institute of Space Sciences, Spain, lead author of the paper published in the journal Nature.

“It’s like a teenager who switches between acting like a child and acting like an adult,” says John Sarkissian, a co-author who observed the system with CSIRO’s Parkes radio telescope in Australia.

And since some scientists think this same process could actually “rejuvenate” older pulsars by increasing their rotation rates via accretion, it could also be compared to an adult acting like a kid again.

Eventually, over the course of millions of years, the larger companion star will become a white dwarf and will have no more material to share with its spinning companion, leaving it to remain as a millisecond pulsar.

Novel Technology to Produce Gasoline by a Metabolically-Engineered Microorganism

Scientists succeeded in producing 580 mg of gasoline per litre of cultured broth by converting in vivo generated fatty acid.

For many decades, we have been relying on fossil resources to produce liquid fuels such as gasoline, diesel, and many industrial and consumer chemicals for daily use. However, increasing strains on natural resources as well as environmental issues including global warming have triggered a strong interest in developing sustainable ways to obtain fuels and chemicals.

Gasoline, the petroleum-derived product that is most widely used as a fuel for transportation, is a mixture of hydrocarbons, additives, and blending agents. The hydrocarbons, called alkanes, consist only of carbon and hydrogen atoms. Gasoline has a combination of straight-chain and branched-chain alkanes (hydrocarbons) consisted of 4-12 carbon atoms linked by direct carbon-carbon bonds.

Previously, through metabolic engineering of Escherichia coli (E. coli), there have been a few research results on the production of long-chain alkanes, which consist of 13-17 carbon atoms, suitable for replacing diesel. However, there has been no report on the microbial production of short-chain alkanes, a possible substitute for gasoline.

In the paper (entitled “Microbial Production of Short-chain Alkanes”) published online in Nature on September 29, a Korean research team led by Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering at the Korea Advanced Institute of Science and Technology (KAIST) reported, for the first time, the development of a novel strategy for microbial gasoline production through metabolic engineering of E. coli.

The research team engineered the fatty acid metabolism to provide the fatty acid derivatives that are shorter than normal intracellular fatty acid metabolites, and introduced a novel synthetic pathway for the biosynthesis of short-chain alkanes. This allowed the development of platform E. coli strain capable of producing gasoline for the first time. Furthermore, this platform strain, if desired, can be modified to produce other products such as short-chain fatty esters and short-chain fatty alcohols.

In this paper, the Korean researchers described detailed strategies for 1) screening of enzymes associated with the production of fatty acids, 2) engineering of enzymes and fatty acid biosynthetic pathways to concentrate carbon flux towards the short-chain fatty acid production, and 3) converting short-chain fatty acids to their corresponding alkanes (gasoline) by introducing a novel synthetic pathway and optimization of culture conditions. Furthermore, the research team showed the possibility of producing fatty esters and alcohols by introducing responsible enzymes into the same platform strain.

Professor Sang Yup Lee said, “It is only the beginning of the work towards sustainable production of gasoline. The titre is rather low due to the low metabolic flux towards the formation of short-chain fatty acids and their derivatives. We are currently working on increasing the titre, yield and productivity of bio-gasoline. Nonetheless, we are pleased to report, for the first time, the production of gasoline through the metabolic engineering of E. coli, which we hope will serve as a basis for the metabolic engineering of microorganisms to produce fuels and chemicals from renewable resources.”

Pain ray makes your skin tingle

At first it feels like a giant invisible hairdryer is blowing hot air on you. But a few seconds later you feel as though you are burning all over your skin. Welcome to the ‘pain ray’, or the ‘heat ray’, or to use the proper military term, ‘active denial’.

Active denial falls into the category of ‘non-lethal’ weapons. It was designed to control or subdue people in war zones, supposedly with little or no injury. It’s claimed to be less harmful than batons, rubber bullets or tasers. It’s basically just a super-powerful microwave beam.

We all know that a microwave oven warms up last night’s Thai takeaway leftovers by blasting them with microwaves. The food absorbs the microwaves, and the energy they carry gets turned into heat.

In your home, the power output of your microwave oven is about 1 kilowatt, and the microwaves usually have a frequency of around 2.45 gigahertz — which corresponds to a wavelength around 122 millimetres. Thanks to this long wavelength, the microwaves can penetrate deeply into your food.

Back in the late 1980s, the US military began thinking about how to use microwave energy as a non-lethal weapon. This research was done at the Air Force Research Laboratory at Kirtland Air Force Base in Albuquerque, New Mexico. The key was to use microwaves with a frequency of around 95 gigahertz, corresponding to a much shorter wavelength of around 3.2 millimetres. They also cranked up the power to around 1000 kilowatts. These microwaves penetrated the skin to a depth of only about 0.4 millimetres. Water in that thin layer of skin absorbs the microwave energy and turns it into heat.

Luckily for the military, we humans have a very sensitive heat receptor in that outer layer of our skin. It’s called a thermal nocioceptor.

From an evolutionary point of view, it’s very important that we are sensitive to heat, because our skin is so fragile. You can get a very nasty full-thickness burn from water at the surprisingly low temperature of only 55°C.

The first version of the active denial weapon was called ‘System O’ and was delivered in the year 2000. It worked, but it was seriously overweight at 7.5 tonnes. The current system is lighter, but still has to be carried by a truck. It looks like a large satellite dish and produces a beam about two metres across, and has a range of several hundred metres. It fires in repeated bursts, each about three to five seconds long.

In 2012, Spencer Ackerman, a reporter for Wired magazine, volunteered at a media event to stand in the beam of the pain ray. He says: “My shoulder and upper chest … felt like they were being roasted, with what can be likened to a super-hot tingling feeling”.

Most people can stand the beam for three seconds or less — and then their reflexes take over and they run away.

The active denial system was sent to Afghanistan in 2010, but for various reasons was never used. Raytheon (the fifth largest military contractor in the world) designed and built the active denial system, and has built a few smaller versions — for use in prison cells, as hand-held weapons, and to be fired from aircraft.

As well as being large and cumbersome at the moment, another problem is that the pain ray doesn’t work very well when it’s raining, snowing or whipping up a dust storm. Another problem is that it doesn’t turn on instantly like a light bulb — instead, it takes 16 hours to be fully operational from a cold start. You could keep it running all the time, but it would burn up a lot of fuel.

The heat delivered to the skin by the pain ray depends on the power produced, the distance to the victim, and the length of time for which the power was delivered.

So far in controlled trials, it appears to be relatively safe. There have been only eight burn injuries from the more than 11,000 volunteers who have been exposed to the beam in experimental tests. But in one of those, the power was accidentally reset to maximum, and the burns were so severe that the volunteer apparently needed skin grafts. Furthermore, a ‘controlled trial’ is very different from ‘out in the field’.

And what about permanent injuries?

Consider an oppressive government that wants to stop a legitimate peaceful demonstration or a workers’ strike — they could simply run the pain ray for 10 seconds, instead of five, causing severe burns.

What if the pain ray were used upon a crowd who simply could not leave the area, because the exits were blocked? In that case you would expect that some people would be zapped by the beam several times over — again causing a horrible disfiguring roasting of the skin.

And what about torture?

Overly enthusiastic police officers have been known to use tasers over and over again on people who were already restrained and who posed no threat. If you leave enough time between exposures, the pain ray will cause intense pain, but won’t leave any marks.

Will we be able to trust the authorities never to misuse the pain ray?

Maybe yes, maybe no.

But look on the bright side. When you’re next at a peaceful legitimate demonstration, take last night’s Thai leftovers, in case they pull out the pain ray …