An immortal creature found

The Turritopsis Nutricula is able to revert back to a juvenile form once it mates after becoming sexually mature.

Marine biologists say the jellyfish numbers are rocketing because they need not die.

Dr Maria Miglietta of the Smithsonian Tropical Marine Institute said: "We are looking at a worldwide silent invasion."

The jellyfish are originally from the Caribbean but have spread all over the world.

Turritopsis Nutricula is technically known as a hydrozoan and is the only known animal that is capable of reverting completely to its younger self.

It does this through the cell development process of transdifferentiation.

Scientists believe the cycle can repeat indefinitely, rendering it potentially immortal.

While most members of the jellyfish family usually die after propagating, the Turritopsis nutricula has developed the unique ability to return to a polyp state.

Having stumbled upon the font of eternal youth, this tiny creature which is just 5mm long is the focus of many intricate studies by marine biologists and geneticists to see exactly how it manages to literally reverse its aging process.

Source: http://www.telegraph.co.uk

Read more »

How many orange slices to charge an Iphone ?

It takes almost 2300+ slices of oranges to be able to charge an Iphone !

Read more »

Human Sperm May 'Smell'

Human sperm may literally sniff their way to an egg in their quest for fertilisation.

Scientists have discovered that a smell receptor on the sperm apparently causes them to zoom in on their target.

"This receptor may be important for the path finding from sperm to egg," says study author Marc Spehr, a neuroscientist at Ruhr University Bochum in Germany.

Although very preliminary, the finding could one day lead to new forms of contraception and new fertility treatments.

"It's speculative, but it's an intriguing possibility," cautions Donner Babcock, author of an accompanying article in the March 28 issue of Science.

A scientific first

In addition to the nose, olfactory receptors are found in certain parts of the brain and, only occasionally, on the skin. Certain olfactory receptors are expressed mostly or exclusively in human spermatogenic cells, scientists have discovered. This is the first time the function of such a sperm receptor has been decoded.

Spehr and his colleagues conducted molecular, cellular and behavioural tests to try to determine the role of the receptor in question, called hOR17-4.

The tests revealed the sperm swam toward elevated levels of a substance called "bourgeonal." A compound called "undecanal," on the other hand, appeared to block the attracting effect. What this means is that signalling from hOR17-4 may control communication between the egg and sperm.

The scent of a woman

One remaining question is where the attracting compound comes from within the female. Is it the egg itself, or some other part of the female reproductive tract? "It could be that the egg is releasing an attractant that helps guide the sperm to the egg, but the problem is that we don't yet know whether, in fact, the egg is the source of that attractant," Babcock says.

Though it won't be easy finding the answers to those questions, at least researchers have a new avenue to try. "The exciting part is it gives us a way of addressing those questions," Babcock says. "A major barrier in the past was that you had to find something that was released by the egg that would attract sperm. Human eggs are few in number and almost impossible to get."

An alternative to hormone-based contraception?
In practical terms, this could one day mean an alternative to hormone-based contraceptive methods.

"It opens new doors to exploration," Babcock adds. "If this is an important mechanism to ensure fertilization, then one could think about new ways of interfering with it and thus new contraceptives."

On the other hand, if scientists discovered a bourgeonal-like compound in the female genital tract that attracts sperm, they might be able to use that to incubate an egg to make it easier for the sperm to find the egg or to increase the number of sperm that are able to fertilize the egg, Spehr says.

For now, researchers are trying to determine the function of other olfactory receptors expressed in sperm, and discovering a complementary process in the egg.

Read more here

Read more »

Your fat may help you heal

It frequently happens in science that what you throw away turns out to be most valuable. It happened to Deepak Nagrath, but not for long.
The Rice assistant professor in chemical and biomolecular engineering was looking for ways to grow cells in a scaffold, and he discarded the sticky substance secreted by the cells.
"I thought it was contamination, so I threw the plates away," said Nagrath, then a research associate at Harvard Medical School.

Nagrath, who joined Rice in 2009, and his co-authors have since built a biological scaffold that allows cells to grow and mature. He hopes the new material, when suffused with stem cells, will someday be injected into the human body, where it can repair tissues of many types without fear of rejection.
The research by Nagrath and his co-authors appeared last week in the Federation of American Societies for Experimental Biology (FASEB) Journal.
The basic idea is simple: Prompt fat cells to secrete what bioengineers call "basement membrane." This membrane mimics the architecture tissues naturally use in cell growth, literally a framework to which cells attach while they form a network. When the cells have matured into the desired tissue, they secrete another substance that breaks down and destroys the scaffold.
Structures that support the growth of living cells into tissues are highly valuable to pharmaceutical companies for testing drugs in vitro. Companies commonly use Matrigel, a protein mixture secreted by mouse cancer cells, but for that reason it can't be injected into patients.
"Fat is one thing that is in excess in the body. We can always lose it," Nagrath said. The substance derived from the secretions, called Adipogel, has proven effective for growing hepatocytes, the primary liver cells often used for pharmaceutical testing.
"My approach is to force the cells to secrete a natural matrix," he said. That matrix is a honey-like gel that retains the natural growth factors, cytokines (substances that carry signals between cells) and hormones in the original tissue.
Nagrath's strategy for growing cells isn't the only approach being pursued, even at Rice: Another method reported last week in Nature Nanotechnology uses magnetic levitation to grow three-dimensional cell cultures.

But Nagrath is convinced his strategy is ultimately the most practical for rebuilding tissue in vivo, and not only because it may cost significantly less than Matrigel. "The short-term goal is to use this as a feeder layer for human embryonic stem cells. It's very hard to maintain them in the pluripotent state, where they keep dividing and are self-renewing," he said.
Once that goal is achieved, Adipogel may be just the ticket for transplanting cells to repair organs. "You can use this matrix as an adipogenic scaffold for stem cells and transplant it into the body where an organ is damaged. Then, we hope, these cells and the Adipogel can take over and improve their functionality."
Source <www.scienceblog.com>

Read more »

Meet X-woman: a possible new species of human

The human family tree may be in for a dramatic rewrite. DNA collected from a fossilised finger bone from Siberia shows it belonged to a mysterious ancient hominid – perhaps a new species.

"X-woman", as the creature has been named, last shared an ancestor with humans and Neanderthals about 1 million years ago but is probably different from both species. She lived 30,000 to 50,000 years ago.

"This is the tip of the iceberg," says Chris Stringer, a palaeoanthropologist at the Natural History Museum in London who was not involved in the find. More hominids that are neither Neanderthal nor human are likely to be discovered in coming years, particularly in central and eastern Asia, he says.

Roaming Asia

Previously, anthropologists thought that Neanderthals and humans were the only hominids roaming Europe and Asia during the late Pleistocene. The discovery of 17,000-year-old Homo floresiensis – the "hobbit" – dispelled that notion, but many anthropologists look on H. floresiensis as an anomaly, isolated from the human–Neanderthal hegemony on the mainland.

The newly discovered creature, which probably lived in close proximity to humans and Neanderthals, suggests that things were not that simple. "The picture that's going to emerge in the next years is a much more complex one," says Svante Pääbo, a palaeogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Pääbo and colleague Johannes Krause discovered the specimen in the Denisova cave in southern Siberia, and sequenced DNA from its mitochondria. It is impossible to say what the creature would have looked like based on a single pinkie bone, so Pääbo and Krause are hesitant to call it a new species.

Though the creature's sex is not known, they are for now referring to her as X-woman because mitochondria are inherited maternally. "No one really knows what she would look like," Pääbo says.

X-woman's mitochondria differ from a human's at nearly 400 DNA letters; Neanderthals show only half as many differences.

Read more here

Read more »

Other Suns and Planets May Provide Better Conditions for Life than Our Own

While our sun and Earth have allowed for the development of a relative bounty of life, many astronomers are starting to believe that the conditions they provide aren't unique, or even ideal, suggesting we may not be alone after all.


At this year's meeting of the General Assembly of the International Astronomical Union, at a panel titled "Solar and Stellar Variability ― impact on Earth and Planets," a multidisciplinary group of experts discussed the evolving research into the types of suns and planets that would be hospitable to the development of life.

Edward Guinan, a professor of astronomy at Villanova University, claims that our sun provided better conditions for the formation of life in its youth. Over four billion years ago, the sun rotated ten times faster than it does today, causing the sun to generate a stronger magnetic field and considerably more radiation than it does today. These conditions have aided the formation of life, but other stars exist that maintain such a rapid rotation for a much longer duration:

Jean-Mathias Grießmeier of ASTRON's research similarly suggests that the Earth may not be an ideal planet for the formation and development of life. Grießmeier examined planetary magnetic fields, finding that a planet with a stronger magnetic field is less likely to have its atmosphere blown away by cosmic debris and is also better able to shield its surface from cosmic radiation. Guinan suggests that planets larger than Earth might be better able to protect any burgeoning life forms:

The Sun does not seem like the perfect star for a system where life might arise. Although it is hard to argue with the Sun's ‘success' as it so far is the only star known to host a planet with life, our studies indicate that the ideal stars to support planets suitable for life for tens of billions of years may be a smaller slower burning ‘orange dwarf' with a longer lifetime than the Sun ― about 20-40 billion years. These stars, also called K stars, are stable stars with a habitable zone that remains in the same place for tens of billions of years. They are 10 times more numerous than the Sun, and may provide the best potential habitat for life in the long run.

Jean-Mathias Grießmeier of ASTRON's research similarly suggests that the Earth may not be an ideal planet for the formation and development of life. Grießmeier examined planetary magnetic fields, finding that a planet with a stronger magnetic field is less likely to have its atmosphere blown away by cosmic debris and is also better able to shield its surface from cosmic radiation. Guinan suggests that planets larger than Earth might be better able to protect any burgeoning life forms:

On the more speculative side we have also found indications that planets like Earth are also not necessarily the best suited for life to thrive. Planets two to three times more massive than the Earth, with a higher gravity, can retain the atmosphere better. They may have a larger liquid iron core giving a stronger magnetic field that protects against the early onslaught of cosmic rays. Furthermore, a larger planet cools more slowly and maintains its magnetic protection. This kind of planet may be more likely to harbour life.

That K stars are relatively common may offer new hope for the possibility of extraterrestrial life, although astronomers are quick to note they don't fully understand how common or fragile life in the universe may be. But their findings do suggest that, on a cosmological scale, Earth can't support life much longer. Says Guinan:

The Earth's period of habitability is nearly over ― on a cosmological timescale. In a half to one billion years the Sun will start to be too luminous and warm for water to exist in liquid form on Earth, leading to a runaway greenhouse effect in less than 2 billion years.

Repost from : http://io9.com

Read more »

We Could Be Discovering Earthlike Planets By 2013

There are probably billions of Earthlike planets in our galaxy alone, predicts scientist Alan Boss. With NASA launching the Kepler satellite, seeking other Earths, you can expect the first discoveries in a few years.


The Kepler satellite will use the same planet-finding method that's already found a few hundred planets outside our solar system: looking for subtle dips in stellar brightness. But it'll use more sensitive methods, looking for smaller, cooler planets that are closer to Earth and more hospitable to life.

Boss, who's just written a new book called The Crowded Universe, argues that Earthlike planets should be quite common:

First, if you talk to astronomers who look at young stars, they will tell you that when stars form, they tend to have a little bit of angular momentum, which means that they can't accrete all of their matter and they end up having a disk around them. Such disks are what planetary systems form out of, basically the leftovers from the star-formation process. Essentially all young stars have these disks, so we expect that these young stars at least have the possibility of having planetary systems.

Second, those who worry about planet-formation processes find that it's very hard to stop Earth-like planets, or some sort of large, rocky object, from forming. Earths in some sense are easier to build than Jupiters, but we already know from our extrasolar planet census that Jupiters exist around at least 10 percent, and probably around 20 percent, of stars. So Earths should be even more common than that.

Finally, and even more directly, the planetary searches are already beginning to find a new class of planets called super-Earths with masses maybe five, 10 or 15 times the mass of Earth that orbit a little closer to their star than our planet does. These guys occur on roughly one third of nearby solar-type stars. And these are sort of the oddballs in some sense, which I think are very much just the tip of the iceberg of the spectrum of Earth-like planets. In any theoretical model of planet formation that people talk about, there should be a ton of Earths compared to these oddball super-Earths, so when we do a complete census we should find a lot of Earths. If these oddballs are there 30 percent of the time and the Jupiters are there 20 percent of the time, that means the ones we can't quite see should be there essentially all the time. So it's a very compelling story, and all the evidence from several different directions points toward Earths being quite common.

He also believes that life is quite tenacious and it's likely that many of these planets have water on them, and comets dumping amino acids and other prebiotic chemicals, making life pretty likely. So many of these Earthlike worlds could turn out to have our alien cousins on them.

Read more »