Meet the world’s only immortal animal

Meet God, immortal creator of the universe, cleverly disguised. The Flying Spaghetti Monster people were close. It turns out God is more of a Swimming Spaghetti Monster.

If you’re thinking McLeod, you couldn’t be further from the truth. What you have to do is think small; not microscopic, just big enough to see with your naked eye. Turritopsis nutricula is a hydrozoan, and it’s considered by scientists to be the only animal that cheated death.

Solitary organisms are (according to current belief) doomed to die, after they completed their life cycle. Hydrozoa are a huge class of predatory animals that live mostly in saltwater, closely related to jellyfish and corals. Eggs and sperm from an adult jellyfish (medusa) and they then develop into polyp stage. Medusae evolve asexually from polyps.

Still, our Turritopsis nutricula (could we call it Joe??) managed to find a way to beat that. What these little folks do is they revert completely to a sexually immature, colonial stage after they reach sexual maturity. They’re even cooler than that. When they’re young they’ve got only several tentacles, but at a mature stage, they get to 80-90 of them.

They’re able to return to polyp stage due to a cell change in the external screen (Exumbrella), which allows them to bypass death. As far as scientists have been able to find out, this change renders the hydrozoa virtually immortal.

via Meet the world’s only immortal animal | ZME Science.

If sexual immaturity was the key to immortality … (INSERT JOKE HERE). But seriously ladies and polyps, this is one of the most amazing discoveries ever … if it is true.  First, we need to get our population down to something sustainable, but then … we should figure this out and use it to bypass death.

Turritopsis nutricula is a hydrozoan with a life cycle in which it reverts to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage (Piraino et al. 1996, p. 302). It does this through the cell development process of transdifferentiation. Theoretically, this cycle can repeat indefinitely, rendering it effectively immortal. – wiki

Transdifferentiation in biology takes place when a non-stem cell transforms into a different type of cell, or when an already differentiated stem cell creates cells outside its already established differentiation. … Transdifferentiation takes place in nature in a few specific cases. For example, in salamanders and chickens when the lens of the eye is removed, cells of the iris turn into lens cells. Still, such naturally occurring cases, or even ones created in the laboratory are rare. … Evidence for transdifferentiation in adult humans is given by Barrett’s metaplasia in which epithelieal cells of the esophagus switch to intestinal mucin-secreting goblet cells. Barrett’s metaplasia predisposes people to adenocarcinoma, with an 80% mortality rate. – wiki

Some more detail. Seems to be true.

Hydrozoan cnidarians usually have a complex life cycle, wherein a colonial stage leads to the sexually mature, solitary, adult stage. Eggs and sperm from solitary, sexual, adult medusa (jellyfish) develop into an embryo and planula larva, and they then form the colonial polyp stage. Medusae are formed asexually from polyps. These medusae have a limited lifespan and die shortly after releasing their gametes

… The hydrozoan Turritopsis nutricula has evolved a remarkable variation on this theme, and in so doing appears to have achieved immortality. The solitary medusa of this species can revert to its polyp stage after becoming sexually mature (Bavestrello et al., 1992; Piraino et al., 1996). In the laboratory, 100% of these medusae regularly undergo this change. Thus, it is possible that organismic death does not occur in this species!

How does Turritopsis accomplish this feat? It can do this because it can alter the differentiated state of a cell, transforming it into another cell type. Such a phenomenon is called transdifferentiation, and it is usually seen only when parts of an organ regenerate. However, it appears to occur normally in the Turritopsis life cycle (Figure 2). In this transdifferentiation process, the medusa is transformed into the stolons and polyps of a hydroid colony. First, the umbrella everts and the tentacles and mesoglea (the middle layer) are resorbed. The everted medusa attach to the substrate by the end that had been at the opposite end of the umbrella, and spawning occurs shortly thereafter. The cnidarian then secretes a perisarc (stolon covering) and stolons. Two days after the stolons are first seen, polyps differentiate. These polyps feed on zooplankton and soon are budding off new medusae.

… Turritopsis nutricula is the first case in which a metazoan is capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. Thus, it appears that it has cheated death and is a potentially immortal, solitary metazoan. – devbio

“Renegade” Stars Tearing Across Universe, Hubble Shows

… As they careen through the cosmos, the stars’ winds slam against nearby gas, creating enormous bow shocks billions or even a trillion miles wide.

So far astronomers have found 14 of these rogue stars using images from the Hubble Space Telescope. But study leader Raghvendra Sahai, of NASA’s Jet Propulsion Laboratory in Pasadena, California, thinks the stellar interlopers will turn out to be common in the universe. Sahai unveiled his results Wednesday at the American Astronomical Society meeting in Long Beach, California.

…

Sahai and colleages discovered the odd stars while peering at images taken between October 2005 and July 2006. They were looking for what they thought was a subclass of dying stars near the Milky Way’s galactic plane, the flattened region where most of the galaxy’s stars lie. Sahai’s team found objects that shared some of the same characteristics of the dying stars they sought, but closer inspection revealed 14 of the 38 suspect objects as stellar renegades instead.

“We accidentally stumbled across a new class of objects,” Sahai said. …

The stars may be the ousted members of two-star systems that were ejected when their partners exploded as supernovae. It’s also possible that a binary star system would collide with another binary set or a single star and the interaction would fling one of the stars into space. In either scenario, the ousted stars go shooting away to follow their own unique paths, Sahai said. Based on the shapes of the wakes, the researchers have dubbed the strange objects with names such as “The Flying Wedge,” “The Whirlygig,” and “The Cropduster.”

… “We think the massive runaway stars observed before were just the tip of the iceberg,” Sahai said in a statement.

The group is planning future studies using the Arizona Radio Observatory’s 10- and 12-meter telescopes, and the National Radio Astronomy Observatory’s radio arrays in New Mexico and West Virginia.

via “Renegade” Stars Tearing Across Universe, Hubble Shows.

INTERACTIVE TIMELINE: Unemployment rate – Economy in Turmoil

INTERACTIVE TIMELINE: Unemployment rate – Economy in Turmoil – MSNBC.com.

Danger ahead as the Sun goes quiet

THE sun’s ability to shield the solar system from harmful cosmic rays could falter in the early 2020s, just in time to threaten the health of NASA astronauts as they return to the moon.

As well as the 11-year cycle of sunspots and solar flares, the sun’s activity experiences longer-term shifts lasting several decades. The sun is currently in a long-term high, having been relatively active for nearly a century, but it is not known when this will end.

To find out, a team led by Jose Abreu of the Swiss Federal Institute of Aquatic Science and Technology in Duebendorf analysed 66 long-term highs from the past 10,000 years, as recorded in fluctuating levels of rare isotopes such as beryllium-10 in ice cores from Greenland. These are produced when cosmic rays break down the nuclei of oxygen and nitrogen atoms in the Earth’s atmosphere. Production of these isotopes peaks when the sun is inactive, as the weaker solar wind lets more cosmic rays enter the solar system, which hit the Earth.

Based on the duration of past highs, and the fact that the current one has already lasted 80 years, the team has calculated that its most likely total lifetime is between 95 and 116 years, and they suspect the high will probably end at the shorter end of this range (Geophysical Research Letters, DOI: 10.1029/2008GL035442).

Records of the sun’s brightness during the 20th century show that it gets slightly dimmer when it is less active, so could a long-term reduction in activity help to offset global warming? No such luck, says Nigel Weiss from the University of Cambridge, who is a member of Abreu’s team. While there is a rough correspondence between a period of very low activity from 1645 to 1715 and the middle of a period of lower average global temperatures lasting from the late 16th to mid 19th century, leading some to suggest a causal link, this correlation could be a coincidence, Weiss says.

Weiss also points out that the sun’s brightness changes only slightly with variations in activity. If the sun does dim slightly in the coming decades, he says, this would only reduce the warming expected due to human-induced climate change by 0.1 °C. “It might be discernible, but it would be a blip rather than a major change,” he says. “It is nothing [compared] with the global warming that is now being produced through pumping of greenhouse gases into the atmosphere.” …

via Danger ahead as the Sun goes quiet – space – 07 January 2009 – New Scientist.

Habitable Exoplanets Could Be Common in Our Galaxy | Wired Science from Wired.com

Earth-like planets may in fact be common in the galaxy, increasing the likelihood of extraterrestrial life.

By observing the remains of smashed up asteroids around dead stars, astronomers were able to deduce their chemical composition. They found that the dust of many chewed-up asteroids resembles the materials inside Earth and the other small, rocky inner planets of our solar system.

“We found evidence that this asteroid dust is similar to rocks on Earth,” said UCLA astronomer Michael Jura in a press conference today at the American Astronomical Society meeting in Long Beach, California. “This strengthens suspicions that Earth-like planets are common.”

Asteroids and planets are made from the same stuff: the dusty material that circles around

young stars in disks. Eventually some of the dust clumps together and grows into planets, while asteroids represent the detritus left over. Because asteroids are formed from the same material as planets, observing asteroids around other stars can tell us crucial information about what ingredients are available to form planets around those stars.

“Asteroids are leftover building blocks that didn’t get incorporated into the planets,” Jura said. “What we have now is a tool to measure the bulk composition of planets.”

Jura and his team used NASA’s Spitzer Space Telescope to observe six dead white-dwarf stars that were coated with the debris of shredded asteroids that had collided into them. By viewing the stars through a spectrograph, which separates out light from different wavelengths, the scientists were able to observe the telltale signatures of certain chemicals in the light. Since that starlight is passing through the film of the asteroid debris, the light picked up signatures of the asteroids’ composition, too.

The team found that the asteroid dust contains a glassy silicate mineral similar to minerals commonly found on Earth. They also detected a lack of carbon in the dust, which again echoes the solar system’s rocky planets and asteroids, which also have no carbon.

Finding planets similar to our own is a priority for scientists yearning for a hint that we are not alone, because Earth-like worlds may be the likeliest place for extraterrestrial life.

via Habitable Exoplanets Could Be Common in Our Galaxy | Wired Science from Wired.com.

Women Can Smell a Man’s Intentions

…Scientists have long debated whether humans, like animals, use chemical signals called pheromones to communicate sexual interest to potential mates. Problem is, the effects of pheromones are thought to be subconscious — meaning that if we do communicate using them, we sure don’t know it. It’s also hard to know what these pheromones might be and how we sense them, so researchers understand little about them.

But if human pheromones are going to be anywhere, they’re going to be in sweat, right? Denise Chen, a psychologist at Rice University in Houston, and her colleagues devised an experiment to compare how women respond to different forms of male sweat — sweat produced in everyday situations versus that produced when a man is turned on.

The researchers speculated that if humans do produce and respond to sweat pheromones, then a woman should respond to a guy’s sexual sweat differently than she does to his normal sweat.

Chen and her colleagues asked 20 heterosexual guys to stop wearing deodorant and scented products for a few days. Then they told the men to put small pads in their armpits as they watched pornographic videos and became aroused (the researchers confirmed, using electrodes, that the images did the job). Later, the guys were asked to exchange those pads for fresh pads to collect the sweat they produced when they weren’t aroused.

Then the researchers recruited 19 brave women to smell the men’s pads while undergoing brain scans.

The investigators used functional magnetic resonance imaging (fMRI), a technique that reveals the brain regions a person is using at any given time — even if their brain activity is subconscious.

Sure enough, the women’s brains responded very differently depending on which sweat they sniffed. (And no, none of them passed out.) The sexual sweat, but not the normal sweat, activated the right orbitofrontal cortex and the right fusiform cortex, brain areas that help us recognize emotions and perceive things, respectively. Both regions are in the right hemisphere, which is generally involved in smell, social response, and emotion. …

via Women Can Smell a Man’s Intentions | LiveScience.

I assume that if you wear deodorant then no one can read your mind via your armpits?

Black holes sprout galaxies, not vice versa

Astronomers think they have finally solved the cosmic chicken-and-egg problem of what came first — the giant black holes lying at the center of many big galaxies or the galaxies that feed them?

The answer: the black holes.

The finding, which surprised even the scientists involved, implies that black holes grow the galaxies surrounding them, like a garden springing from a single seed or a man growing a suit of clothes.

The problem with that idea, according to the scientific team that presented the findings Wednesday at the American Astronomical Society meeting in Long Beach, is that nobody has come up with an explanation for how a black hole could sprout a galaxy.

“That is hard to imagine,” said Chris Carilli of the National Radio Astronomy Observatory.

A black hole is the remains of a giant star that has collapsed — typically after exploding in a supernova — to what is known as a singularity, in which the gravity is so extreme that nothing, not even light, can escape. The researchers based their work on past studies showing that for any given galaxy there is a constant ratio between the masses of a central black hole and the “bulge” of stars and gas relatively close to the galaxy’s center.

In the nearby universe, that ratio is the same for black holes ranging from a few million times the mass of the sun to behemoths billions of times its mass, as is the case with the gigantic black hole at the heart of our own Milky Way galaxy.

“The big question,” according to Caltech astronomer Dominik Riechers, “has been whether one grows before the other or if they grow together.”

To find out, Carilli, Riechers and others on their team used telescopes that capture radio waves instead of visible light to study the first galaxies in the universe. Those date to the time when the universe, which is now 13.7 billion years old, was less than 1 billion years old.

They found these ancient galaxies by studying the degree to which their light was shifted toward the red end of the spectrum. The greater the redshift, which is a measure of how fast the galaxy is speeding away from us, the older the galaxy.

Next, they weighed the black hole and the galaxy’s bulge, a challenging calculation that is done by observing the movements of the galaxy’s clouds of gas, which are influenced by gravity. In four early galaxies — which are so distant that they appear to us in their youth — the ratio between the black hole and the galaxy bulge was different from what was expected, the scientists said.

“The black holes in these young galaxies are much more massive compared to the bulges than those seen in the nearby universe,” according to Fabian Walter of the Max Planck Institute for Radio Astronomy in Germany and another member of the team.

That, according to the scientists, means the black holes started growing first.

via Black holes sprout galaxies, not vice versa – Los Angeles Times.

Cool your brain, save your mind

BRIDGET HARRIS lies on a hospital bed with a nylon hood covering her head. As cold air streams from the hood and over her scalp, her lips gradually turn blue and her speech slows. Within an hour, her core body temperature has dropped by 0.5 °C, but she remains comfortable. “The airflow is almost relaxing,” she says. “It sounds like white noise.”

Harris, a PhD student at the University of Edinburgh, UK, is testing her own invention: a cooling helmet designed to induce mild hypothermia.

We all know that a cool cloth applied to the forehead can ease a headache, but now researchers like Harris are investigating whether technologies that cool the brain itself could prevent brain damage following a stroke or cardiac arrest. Similar techniques could also protect the heart and kidneys from damage during surgery.

For some time, doctors have observed that cooling patients following a heart attack can reduce brain damage. Although they are not yet sure of the mechanism behind this effect, researchers suspect that cooling the brain by 4 °C, to around 33 °C, reduces the metabolism of brain cells, reducing their hunger for oxygen for the crucial moments during which blood is in short supply. Damage seems to be reduced even if the brain is only cooled once the heart has been restarted, suggesting that cooling may also slow the release of toxic chemicals from neurons and glial cells – a process called the ischaemic cascade, which triggers further brain-cell death up to 24 hours after a cardiac arrest or stroke.

Previously, doctors have induced “therapeutic hypothermia” by applying ice packs or cooling blankets to the whole body, or injecting cold saline solution into the veins. However, cooling the whole body can increase the risk of infection and pneumonia, so researchers are now building targeted devices that chill the brain directly.

Harris’s hood, for example – developed with her supervisor Peter Andrews and medical technology company KCI of San Antonio, Texas – exploits the dense network of blood vessels on the scalp that carries blood to the brain. The device consists of two nylon sheets that fit around the head, one on top of the other, with small perforations in the layer closest to the skin. When cold air is blown between the two sheets, these perforations allow it to penetrate to the skin at regular intervals across the scalp, cooling the blood vessels. “It’s a bit like a hairdryer hood – it doesn’t cover the face and one lies with one’s head inside it,” says Harris. …

via Cool your brain, save your mind – tech – 07 January 2009 – New Scientist.

Climate warming means food shortages, study warns

The warming climate is likely to put stress on crops and livestock alike and could cause serious food shortages for half the world’s population, U.S. researchers predicted on Thursday.

The worst effects will be in the regions where the poorest people already live — the tropics and subtropics, the researchers wrote in the journal Science. But temperate regions will see very warm average temperatures, they added.

“In temperate regions, the hottest seasons on record will represent the future norm in many locations,” David Battisti, a University of Washington atmospheric sciences professor, and Rosamond Naylor, director of Food Security and the Environment at California’s Stanford University, wrote in their report.

The two combined direct observations with data from 23 global climate models.

They found a greater than a 90 percent probability that by 2100, growing-season low temperatures in the tropics and subtropics will be higher than the highest current temperatures.

“We are taking the worst of what we’ve seen historically and saying that in the future it is going to be a lot worse unless there is some kind of adaptation,” Naylor said.

There have been some recent tastes of what is to come, such as a heat wave that struck Europe in summer 2003 and resulted in deaths and reduced food production, they said.

Record temperatures hurt key crops including maize and fruit and accelerated crop ripening by 10 to 20 days. Livestock were stressed, the soil was dryer and more water was used in agriculture, they said.

Italy experienced a record drop in maize yields of 36 percent from a year earlier, and in France maize and fodder production fell by 30 percent, fruit harvests declined by 25 percent and wheat harvests declined by 21 percent, they wrote.

“I think what startled me the most is that when we looked at our historic examples there were ways to address the problem within a given year. People could always turn somewhere else to find food,” Naylor said. “But in the future there’s not going to be any place to turn unless we rethink our food supplies.”

Battisti said 3 billion people live in the areas that will be worst affected. The researchers urged investment in development of crop varieties that can withstand higher heat.

“You are talking about hundreds of millions of additional people looking for food because they won’t be able to find it where they find it now,” he said. …

via Climate warming means food shortages, study warns | Environment | Reuters.

BBC NEWS | Middle East | Mummy of female pharaoh uncovered

Egyptologists have discovered the remains of a mummy thought to belong to a queen who ruled 4,300 years ago, Egypt’s antiquities chief has said.

The body of Queen Seshestet was found in a recently-discovered pyramid in Saqqara, Zahi Hawass announced.

She was mother of King Teti, founder of the Sixth Dynasty of pharaonic Egypt. Her name was not found but “all the signs indicate that she is Seshestet”.

Such old royal mummies are rare. Most date from dynasties after 1800 BC.

Historians believe Queen Seshestet ruled Egypt for 11 years – making her one a small number of women pharaohs.

It took five hours to lift the lid of a sarcophagus, according to a statement by Mr Hawass.

It contained a skull, legs, pelvis, other body parts wrapped in linen, pottery and gold finger wrappings.

The burial chamber was raided in antiquity by grave robbers who stole everything, including most valuables from inside the sarcophagus.

via BBC NEWS | Middle East | Mummy of female pharaoh uncovered.