[ROBERT]

" Wasp performs roach-brain-surgery to make zombie slave-roaches

Ampulex compressa is a wasp that has evolved to tackle roaches, insert a stinger into their brains and disable their escape reflexes. This lets the wasp use the roach's antennae to steer the roach to its lair, where it can lay its egg in it. "Parasite Rex" author Carl Zimmer tells the story in gooey, graphic detail:
The wasp slips her stinger through the roach's exoskeleton and directly into its brain. She apparently use sensors along the sides of the stinger to guide it through the brain, a bit like a surgeon snaking his way to an appendix with a laparoscope. She continues to probe the roach's brain until she reaches one particular spot that appears to control the escape reflex. She injects a second venom that influences these neurons in such a way that the escape reflex disappears.
From the outside, the effect is surreal. The wasp does not paralyze the cockroach. In fact, the roach is able to lift up its front legs again and walk. But now it cannot move of its own accord. The wasp takes hold of one of the roach's antennae and leads it--in the words of Israeli scientists who study Ampulex--like a dog on a leash. "

http://www.boingboing.net/2006/02/03/wasp_performs_roachb.html

[ariel]

Old-World Primates Evolved Color Vision To Better See Each Other Blush, Study Reveals

Your emotions can easily be read by others when you blush--at least by others familiar with your skin color. What's more, the blood rushing out of your face when you're terrified is just as telling. And when it comes to our evolutionary cousins the chimpanzees, they not only can see color changes in each other's faces, but in each other's rumps as well.
Now, a team of California Institute of Technology researchers has published a paper suggesting that we primates evolved our particular brand of color vision so that we could subtly discriminate slight changes in skin tone due to blushing and blanching. The work may answer a long-standing question about why trichromat vision (that is, color via three cone receptors) evolved in the first place in primates.
"For a hundred years, we've thought that color vision was for finding the right fruit to eat when it was ripe," says Mark Changizi, a theoretical neurobiologist and postdoctoral researcher at Caltech. "But if you look at the variety of diets of all the primates having trichromat vision, the evidence is not overwhelming."
Reporting in the current issue of the journal Biology Letters, Changizi and his coauthors show that our color cones are optimized to be sensitive to subtle changes in skin tone due to varying amounts of oxygenated hemoglobin in the blood.
The spectral sensitivity of the color cones is somewhat odd, Changizi says. Bees, for example, have four color cones that are evenly spread across the visible spectrum, with the high-frequency end extending into the ultraviolet. Birds have three color cones that are also evenly distributed in the visible spectrum.
The old-world primates, by contrast, have an "S" cone at about 440 nanometers (the wavelength of visible light roughly corresponding to blue light), an "M" cone sensitive at slightly less than 550 nanometers, and an "L" cone sensitive at slightly above 550 nanometers.
"This seems like a bad idea to have two cones so close together," Changizi says. "But it turns out that the closeness of the M and L cone sensitivities allows for an additional dimension of sensitivity to spectral modulation. Also, their spacing maximizes sensitivity for discriminating variations in blood oxygen saturation." As a result, a very slight lowering or rising of the oxygen in the blood is easily discriminated by any primate with this type of cone arrangement.
In fact, trichromat vision is sensitive not only for the perception of these subtle changes in color, but also for the perception of the absence or presence of blood. As a result, primates with trichromat vision are not only able to tell if a potential partner is having a rush of emotion due to the anticipation of mating, but also if an enemy's blood has drained out of his face due to fear.
"Also, ecologically, when you're more oxygenated, you're in better shape," Changizi adds, explaining that a naturally rosy complexion might be a positive thing for purposes of courtship.
Adding to the confidence of the hypothesis is the fact that the old-world trichromats tend to be bare-faced and bare-butted as well. "There's no sense in being able to see the slight color variations in skin if you can't see the skin," Changizi says. "And what we find is that the trichromats have bare spots on their faces, while the dichromats have furry faces."
"This could connect up with why we're the 'naked ape,'" he concludes. The few human spots that are not capable of signaling, because they are in secluded regions, tend to be hairy-such as the top of the head, the armpits, and the crotch. And when the groin occasionally does tend to exhibit bare skin, it occurs in circumstances in which a potential mate may be able to see that region.
"Our speculation is that the newly bare spots are for color signaling."

http://www.sciencedaily.com/releases/2006/03/060320221839.htm


ariel

[neilep (OP)]

Mass extinctions – a threat from outer space or our own planet's detox?


University of Leicester scientists suggest extraterrestrial theories are flawed and that more down to earth factors could have accounted for past mass extinctions
Earth history has been punctuated by several mass extinctions rapidly wiping out nearly all life forms on our planet. What causes these catastrophic events? Are they really due to meteorite impacts? Current research suggests that the cause may come from within our own planet – the eruption of vast amounts of lava that brings a cocktail of gases from deep inside the Earth and vents them into the atmosphere.
University of Leicester geologists, Professor Andy Saunders and Dr Marc Reichow, are taking a fresh look at what may actually have wiped out the dinosaurs 65 million years ago and caused other similarly cataclysmic events, aware they may end up exploding a few popular myths.

The idea that meteorite impacts caused mass extinctions has been in vogue over the last 25 years, since Louis Alverez's research team in Berkeley, California published their work about an extraterrestrial iridium anomaly found in 65-million-year-old layers at the Cretaceous-Tertiary boundary. This anomaly only could be explained by an extraterrestrial source, a large meteorite, hitting the Earth and ultimately wiping the dinosaurs – and many other organisms - off the Earth's surface.

Professor Saunders commented: "Impacts are suitably apocalyptic. They are the stuff of Hollywood. It seems that every kid's dinosaur book ends with a bang. But are they the real killers and are they solely responsible for every mass extinction on earth? There is scant evidence of impacts at the time of other major extinctions e.g., at the end of the Permian, 250 million years ago, and at the end of the Triassic, 200 million years ago. The evidence that has been found does not seem large enough to have triggered an extinction at these times."

Flood basalt eruptions are – he says - an alternative kill mechanism. These do correspond with all main mass extinctions, within error of the techniques used to determine the age of the volcanism. Furthermore, they may have released enough greenhouse gases (SO2 and CO2) to dramatically change the climate. The largest flood basalts on Earth (Siberian Traps and Deccan Traps) coincide with the largest extinctions (end-Permian, and end-Cretaceous). "Pure coincidence?", ask Saunders and Reichow.

While this is unlikely to be pure chance, the Leicester researchers are interested in precisely what the kill mechanism may be. One possibility is that the gases released by volcanic activity lead to a prolonged volcanic winter induced by sulphur-rich aerosols, followed by a period of CO2-induced warming.

Professor Andy Saunders and Dr. Marc Reichow at Leicester, in collaboration with Anthony Cohen, Steve Self, and Mike Widdowson at the Open University, have recently been awarded a NERC (Natural Environment Research Council) grant to study the Siberian Traps and their environmental impact.

The Siberian Traps are the largest known continental flood basalt province. Erupted about 250 million years ago at high latitude in the northern hemisphere, they are one of many known flood basalts provinces - vast outpourings of lava that covered large areas of the Earth's surface. A major debate is underway concerning the origin of these provinces –including the Siberian Traps - and their environmental impact.

Using radiometric dating techniques, they hope to constrain the age and, combined with geochemical analysis, the extent, of the Siberian Traps. Measuring how much gas was released during these eruptions 250 million years ago is a considerable challenge. The researchers will study microscopic inclusions trapped in minerals of the Siberian Traps rocks to estimate the original gas contents. Using these data they hope to be able to assess the amount of SO2 and CO2 released into the atmosphere 250 million years ago, and whether or not this caused climatic havoc, wiping out nearly all life on earth. By studying the composition of sedimentary rocks laid down at the time of the mass extinction, they also hope to detect changes to seawater chemistry that resulted from major changes in climate.

From these data Professor Saunders and his team hope to link the volcanism to the extinction event. He explained: "If we can show, for example, that the full extent of the Siberian Traps was erupted at the same time, we can be confident that their environmental effects were powerful. Understanding the actual kill mechanism is the next stage….watch this space."

SOURCE: EUREKALERT.ORG



Men are the same as women, just inside out !

[neilep (OP)]

Mars meteorite similar to bacteria-etched Earth rocks
OREGON STATE UNIVERSITY NEWS RELEASE
Posted: March 28, 2006

A new study of a meteorite that originated from Mars has revealed a series of microscopic tunnels that are similar in size, shape and distribution to tracks left on Earth rocks by feeding bacteria.

And though researchers were unable to extract DNA from the Martian rocks, the finding nonetheless adds intrigue to the search for life beyond Earth.

Results of the study were published in the latest edition of the journal Astrobiology.

Martin Fisk, a professor of marine geology in the College of Oceanic and Atmospheric Sciences at Oregon State University and lead author of the study, said the discovery of the tiny burrows do not confirm that there is life on Mars, nor does the lack of DNA from the meteorite discount the possibility.

"Virtually all of the tunnel marks on Earth rocks that we have examined were the result of bacterial invasion," Fisk said. "In every instance, we've been able to extract DNA from these Earth rocks, but we have not yet been able to do that with the Martian samples.

"There are two possible explanations," he added. "One is that there is an abiotic way to create those tunnels in rock on Earth, and we just haven't found it yet. The second possibility is that the tunnels on Martian rocks are indeed biological in nature, but the conditions are such on Mars that the DNA was not preserved."

More than 30 meteorites that originated on Mars have been identified. These rocks from Mars have a unique chemical signature based on the gases trapped within. These rocks were "blasted off" the planet when Mars was struck by asteroids or comets and eventually these Martian meteorites crossed Earth's orbit and plummeted to the ground.

One of these is Nakhla, which landed in Egypt in 1911, and provided the source material for Fisk's study. Scientists have dated the igneous rock fragment from Nakhla - which weighs about 20 pounds - at 1.3 billion years in age. They believe that the rock was exposed to water about 600 million years ago, based on the age of clay found inside the rocks.

"It is commonly believed that water is a necessary ingredient for life," Fisk said, "so if bacteria laid down the tunnels in the rock when the rock was wet, they may have died 600 million years ago. That may explain why we can't find DNA - it is an organic compound that can break down."

Other authors on the paper include Olivia Mason, an OSU graduate student; Radu Popa, of Portland State University; Michael Storrie-Lombardi, of the Kinohi Institute in Pasadena, Calif.; and Edward Vicenci, from the Smithsonian Institution.

Fisk and his colleagues have spent much of the past 15 years studying microbes that can break down igneous rock and live in the obsidian-like volcanic glass. They first identified the bacteria through their signature tunnels then were able to extract DNA from the rock samples - which have been found in such diverse environments on Earth as below the ocean floor, in deserts and on dry mountaintops.

They even found bacteria 4,000 feet below the surface in Hawaii that they reached by drilling through solid rock.

In all of these Earth rock samples that contain tunnels, the biological activity began at a fracture in the rock or the edge of a mineral where the water was present. Igneous rocks are initially sterile because they erupt at temperatures exceeding 1,000 degrees C. - and life cannot establish itself until the rocks cool. Bacteria may be introduced into the rock via dust or water, Fisk pointed out.

"Several types of bacteria are capable of using the chemical energy of rocks as a food source," he said. "One group of bacteria in particular is capable of getting all of its energy from chemicals alone, and one of the elements they use is iron - which typically comprises 5 to 10 percent of volcanic rock."

Another group of OSU researchers, led by microbiologist Stephen Giovannoni, has collected rocks from the deep ocean and begun developing cultures to see if they can replicate the rock-eating bacteria. Similar environments usually produce similar strains of bacteria, Fisk said, with variable factors including temperature, pH levels, salt levels, and the presence of oxygen.

The igneous rocks from Mars are similar to many of those found on Earth, and virtually identical to those found in a handful of environments, including a volcanic field found in Canada.

One question the OSU researchers hope to answer is whether the bacteria begin devouring the rock as soon as they are introduced. Such a discovery would help them estimate when water - and possibly life - may have been introduced on Mars

SOURCE: SPACEFLIGHTNOW.COM


Men are the same as women, just inside out !

[neilep (OP)]

Preserved in crystal

Scientists at the Weizmann Institute of Science recently discovered a new source of well-preserved ancient DNA in fossil bones. Their findings were published in the Proceedings of the National Academy of Sciences (PNAS).
Fossil DNA is a potential source of information on the evolution, population dynamics, migrations, diets and diseases of animals and humans. But if it is not well preserved or becomes contaminated by modern DNA, the results are uninterpretable.

The scientists, Prof. Steve Weiner and Michal Salamon of the Institute's Structural Biology Department, working in collaboration with Profs. Baruch Arensburg, Tel Aviv University, and Noreen Tuross, Harvard University, may have found a way to overcome these problems.

It was in 1986 that Weiner first reported the existence of crystal clusters in fresh bones. Even when these bones are ground up and treated with sodium hypochlorite – a substance that removes all traces of organic matter – the clusters of crystals remain intact and the organic material embedded in them is unaffected. Now, almost 20 years later, Weiner and Salamon have returned to these findings, reasoning that fossil bones might possess such crystal structures containing preserved ancient DNA.

After treating two modern and six fossil animal bones with the sodium hypo-chlorite, they found that DNA could be extracted from most of these crystal aggregates that is better preserved and contains longer fragments than DNA from untreated ground bone. The technique for reading the DNA worked better, as well, and the use of sodium hypochlorite reduces the possibility of modern contamination.

The crystal aggregates act as a "privileged niche in fossil bone," protecting the DNA from hostile environments and leaving it relatively undamaged over time. The team's findings suggest that the DNA in these aggregates should be preferred, whenever possible, over DNA from untreated bone.

This method holds much promise for the future analysis of ancient DNA in bones in yielding more reliable and authentic results than has previously been possible, and may help in unearthing the mysteries of our ancestral past.


SOURCE: EUREKALERT.ORG

Men are the same as women, just inside out !

[neilep (OP)]

XXL from Too Few Zs? Skimping on sleep might cause obesity, diabetes
Ben Harder

Widespread sleep deprivation could partly explain the current epidemics of both obesity and diabetes, emerging data suggest.

Too little sleep may contribute to long-term health problems by changing the concentrations of hormones that control appetite, increasing food intake, and disrupting the biological clock, according to Eve Van Cauter of the University of Chicago.

Van Cauter and other researchers discussed possible links between sleep deprivation, expanding waistlines, and obesity-related problems this week in Washington, D.C., at a meeting titled A Scientific Workshop on Sleep Loss and Obesity: Interacting Epidemics.

Researchers have observed that people who sleep less than 7 to 8 hours a night have elevated rates of obesity and diabetes. In late 2004, Karine Spiegel of the Free University of Brussels in Belgium and Van Cauter conducted experiments in healthy men showing that forced sleep restriction for 2 days increased appetite and triggered changes in the appetite-related hormones ghrelin and leptin.The observed ghrelin elevation and leptin suppression may have encouraged food intake, Spiegel says.

Before that pivotal study, tests had demonstrated that obesity could disrupt sleep, but few experiments had investigated whether lack of sleep could contribute to obesity.

Preliminary results close in on an independent relationship between sleep loss and diabetes. Spiegel, Van Cauter, and their colleagues collected data from 13 volunteers who habitually sleep about 5 hours per night and from 14 others who sleep about 8 hours per night. The groups had similar body weights and ages.

Spiegel reported at the conference that the people who sleep less produce markedly elevated quantities of the hormone insulin. Their high insulin production reflects a state, called insulin resistance, that can be a harbinger of diabetes, Spiegel says.

In another new study reported at the conference, Emmanuel Mignot of Stanford University Medical School and his colleagues tested about 2,000 employees of Wisconsin government agencies. Obesity was common in that population, and volunteers who slept either significantly less or more than the overall average tended to be heavier than people getting a moderate amount of sleep, Mignot reports. Compared with people who slept 8 hours a night, those who slept 5 hours had 16 percent lower leptin concentrations and 15 percent higher ghrelin concentrations in their blood.

Mignot and his colleagues have launched a yearlong trial that will test whether prescribing extra sleep can make some obese people lose weight. He hypothesizes that an extra 1.5 hours of sleep per night might produce weight losses of 3 to 4 percent.

But Van Cauter says that when her team previously asked patients to increase nightly sleep for extended periods of time, the changes in behavior lasted only a few days.

Short sleep might encourage overeating independent of its hormonal effects, says Mignot. "When people sleep less, they have more time for eating," he notes.


SOURCE: SCIENCENEWS.ORG

Oh Joy !!..lucky me !!...though the conclusion that if you're awake more means you'll eat more is obvious isn't it ?

Men are the same as women, just inside out !

[neilep (OP)]

Google to advertise on the moon
VNUnet Saturday April 1, 09:00 AM

 
By Arif Pollo

In the most wide-scale advertising attempt ever known,Google plans to brand itslogo into the surface of the moon so that it is visible from Earth.

The search giant will pay the US government an estimated $1bn for the rightsto the lunar land.

"You've heard of GoogleMars and GoogleEarth, where we show you maps of those planets? Well this is Google Moon,where we become the world's biggest brand," said an unnamed source at thecompany.

The Americans were the first to lay claim to the moon back in July 1969 whenNeilArmstrong took "one small step for a man, one giant leap for mankind".

Planting the flag on the Moon's surface has always been considered a gestureof being there first, but that claim has now paid off in real money terms forthe US government.

Google announced this week that it would sell afurther 5.3 billion shares to raise $2.1bn.

Google's official filing to theSecurities and ExchangeCommission said that the sale of shares was designed to raise additionalcapital for future acquisitions, but the company declined to be morespecific about any current agreements or commitments.

Analysts speculated at the time that the company must have a major purchasein mind and it is now clear where the funds will be heading.

SOURCE: YAHOO.

Men are the same as women, just inside out !

[ariel]

Study claims ice, not water, kept Jesus afloat


University professor attempts to explain miracles with science


Tuesday, April 4, 2006; Posted: 6:54 p.m. EDT (22:54 GMT)

MIAMI, Florida (Reuters) -- The New Testament says that Jesus walked on water, but a Florida university professor believes there could be a less miraculous explanation -- he walked on a floating piece of ice.

Professor Doron Nof also theorized in the early 1990s that Moses's parting of the Red Sea had solid science behind it.

Nof, a professor of oceanography at Florida State University, said on Tuesday that his study found an unusual combination of water and atmospheric conditions in what is now northern Israel could have led to ice formation on the Sea of Galilee.

Nof used records of the Mediterranean Sea's surface temperatures and statistical models to examine the dynamics of the Sea of Galilee, which Israelis know now as Lake Kinneret.

The study found that a period of cooler temperatures in the area between 1,500 and 2,600 years ago could have included the decades in which Jesus lived.

A drop in temperature below freezing could have caused ice -- thick enough to support a human -- to form on the surface of the freshwater lake near the western shore, Nof said. It might have been nearly impossible for distant observers to see a piece of floating ice surrounded by water.

Nof said he offered his study -- published in the April edition of the Journal of Paleolimnology -- as a "possible explanation" for Jesus' walk on water.

"If you ask me if I believe someone walked on water, no, I don't," Nof said. "Maybe somebody walked on the ice, I don't know. I believe that something natural was there that explains it."

"We leave to others the question of whether or not our research explains the biblical account."

When he offered his theory 14 years ago that wind and sea conditions could explain the parting of the Red Sea, Nof said he received some hate mail, even though he noted that the idea could support the biblical description of the event.

And as his theory of Jesus' walk on ice began to circulate, he had more hate mail in his e-mail inbox.

"They asked me if I'm going to try next to explain the resurrection," he said.



http://www.cnn.com/2006/TECH/science/04/04/jesus.science.reut/index.html

ariel

[DoctorBeaver]

Oh bugger, he's sussed me [!]

Brand new forum at
http://beaverlandforum.d4a.com
More than just science

[JimBob]

I bow in awe and reverence.

Jim

The mind is like a parachute. It works best when open.  -- A. Einstein

[ROBERT]

" Testicle cells may aid research  
 
Stem cells hold the promise of many new treatments
Scientists believe the human testicle may provide a less controversial source of cells for stem cell research.
Stem cells hold great promise for new treatments for many conditions as they have the ability to become many different types of adult tissue.

But at present the most flexible type is found in human embryos - and their use is mired in controversy.

A German team describes in the journal Nature how it isolated cells from mice testes that seem equally useful.

  The possibility of using cells from the testes as an alternative to embryonic stem cells for therapy is intriguing

Scientists already knew certain cells in the testes of newborn mice were able, like embryonic stem cells, to generate numerous different tissue types.

But until now they had not been able to show the same cells existed in adults."

http://news.bbc.co.uk/1/hi/health/4841786.stm

[JimBob]

From http://www.eurekalert.org/pub_releases/2006-04/iodp-spf041906.php

Public release date: 20-Apr-2006

Contact: Nancy Light
nlight@iodp.org
202-465-7511
Integrated Ocean Drilling Program Management International

Scientists penetrate fossil magma chamber beneath intact ocean crust

-- achieving scientific 'first'
PACIFIC OCEAN, approximately 800 km west of Costa Rica¡ªAn international team of scientists aboard the research drilling ship JOIDES Resolution has¡--for the first time¡--recovered black rocks known as gabbros from intact ocean crust. Supported by the Integrated Ocean Drilling Program (IODP), the scientists drilled through the volcanic rock that forms the Earth's crust to reach a fossil magma chamber lying 1.4 kilometers beneath the seafloor.

"By sampling a complete section of the upper oceanic crust, we've achieved a goal scientists have pursued for over 40 years, since the days of Project MoHole," says Damon Teagle, National Oceanography Centre, University of Southampton, UK, and co-chief scientist of this drilling expedition. "Our accomplishment will ultimately help science answer the important question, 'how is new ocean crust formed?'"

Formation of ocean crust is a key process in the cycle of plate tectonics; it constantly 'repaves' the Earth's surface, builds mountains, and leads to earthquakes and volcanoes. Project MoHole, begun in the 1950s, aimed to drill all the way through the ocean crust, into the Earth's mantle.

Jeffrey Alt of the University of Michigan and co-chief scientist on an earlier leg of this mission, explains that "having this sample from the deep fossil magma chamber allows us to compare its composition to the overlying lavas. It will help explain," he says, "whether ocean crust, which is about six- to seven- kilometers thick, is formed from one high-level magma chamber, or from a series of stacked magma lenses." He emphasizes that "the size and geometry of the melt lens affects not only the composition and thermal structure of the ocean crust, but also the vigor of hydrothermal circulation of seawater through the crust." Alt states that such systems lead to spectacular black-smoker vents--modern analogs of ancient copper deposits and deep-ocean oases that support exotic life.

IODP Program Director James Allan at the U.S. National Science Foundation, which co-funds IODP research with Japan, further clarifies what the expedition's discovery represents. "These results," he says, "coming from the structural heart of Pacific crust, confirm ideas from seismologic interpretation about how fast-spreading oceanic crust is built. They refine our understanding of the relationship between seismic velocity and crustal rock composition, and open new vistas for investigating the origin of lower oceanic crust, best addressed by deeper drilling." NSF and Japan each provide a scientific drilling vessel to IODP for research teams.

Geophysical theories have long projected that oceanic magma chambers freeze to form coarse-grained, black rocks known as gabbros, commonly used for facing stones on buildings and kitchen countertops. Although gabbros have been sampled elsewhere in the oceans, where faulting and tectonic movement have brought them closer to the seafloor, this is the first time that gabbros have been recovered from intact ocean crust.

"Drilling this deep hole in the eastern Pacific is a rare opportunity to calibrate remote geophysical measurements such as seismic travel time or magnetic field with direct observations of real rocks," says geophysicist Doug Wilson, University of California, Santa Barbara. Co-chief scientist on an earlier expedition to the same drilling site, Wilson was instrumental in helping to select the site drilled. His contributed to the research mission thorough study of the ocean crust's magnetic properties.

"Finding the right place to drill was probably key to our success," Wilson asserts. The research team identified a 15-million-year-old region of the Pacific Ocean that formed when the East Pacific Rise was spreading at a 'superfast' rate (more than 200 millimeters per year), faster than any mid-ocean ridge on Earth today. "We planned to exploit a partially tested geophysical observation that magma chambers should be closest to the Earth's surface, in crust formed at the fastest spreading rate. If that theory were to be correct," reasoned Wilson, "then we should only need to drill a relatively shallow hole--compared to anywhere else--to reach gabbros." Wilson and colleagues proved the theory correct.

Following three years of research and multiple trips to the site in question, the borehole that rendered the magma chamber is now more than 1,500 meters deep; it took nearly five months at sea to drill. Twenty-five hardened steel and tungsten carbide drill bits were used before the scientists' work was complete. The rocks directly above the frozen magma chamber were extremely hard because they had been baked by the underlying magmas, much like tempered steel.

IODP scientists want to return to the site of the unearthed magma chamber to explore deeper, in hopes of finding more secrets hidden deep within the ocean's crust.

###

The Integrated Ocean Drilling Program (IODP) is an international marine research program dedicated to advancing scientific understanding of the Earth, the deep biosphere, climate change, and Earth processes by sampling and monitoring sub-seafloor environments. IODP is supported by two lead agencies: the U.S. National Science Foundation, and Japan's Ministry of Education, Culture, Sports, Science, and Technology, with support from a European consortium of 17 countries, and the People's Republic of China. IODP's U.S.-sponsored drilling operations are conducted by the JOI Alliance; comprised of the Joint Oceanographic Institutions, Texas A & M University Research Foundation, and Lamont-Doherty Earth Observatory of Columbia University.

To access a list of research participants on IODP Expedition 312 and the countries they represent, or to see photos from the expedition, go to http://iodp.tamu.edu/scienceops/expeditions/exp312.html.

Note to Editors: A paper authored by the IODP research party is to be published online in Science Express on April 20, 2006. To obtain a copy of the embargoed paper, contact AAAS Office of Public Programs, +1-202-326-6440 or scipak@aaas.org

CONTACTS:

Nancy Light, IODP Management International
Tel: 202-465-7511, 202-361-3325

Jon Corsiglia, Joint Oceanographic Institutions, JOI Alliance
Tel: 202-232-3900 ext. 1644

Cheryl Dybas, U.S. National Science Foundation
Tel: 703-292-7734



The mind is like a parachute. It works best when open.  -- A. Einstein

[Ophiolite]

As you can tell from my user name JimBob, this interests me. Thank you for posting it.

Observe; collate; conjecture; analyse; hypothesise; test; validate; theorise. Repeat until complete.

[elegantlywasted]

MRI helps spot problems before birth
21/04/2006 3:59:24 PM  

Some infants and their families in Alberta are benefiting from the use of MRIs to catch problems before birth.

"An ultrasound just has limits on the type of detailed picture it can obtain," said Dr. Radha Chari, a professor at the University of Alberta's faculty of medicine. "The MRI seems better for us to define things a little bit better."

Chari uses MRIs to help prepare for births that are high-risk.

In the case of six-month-old Taliesin Schultz, doctors in the rural community of Barrhead first spotted a problem with his lungs when his mother had an ultrasound.

She was sent to Edmonton's Royal Alexandra Hospital for an MRI, which allowed the medical team to take a closer look at the spot on the lungs.

"There was a few times that we were considering the fact that we might not ever be able to see him," recalled Taliesin's father, Rick Shultz.

MRI is particularly useful for monitoring how the lungs of a fetus are developing.

For Taliesin, radiologist Dr. Ravi Bhargava was able to determine what was causing the mass in the baby's chest. Taliesin's lungs repaired themselves and he was born without complications.

But if the cyst is larger or the abnormality is different then a child may need surgery after birth, the doctor said.

Knowing what treatment the baby will need ahead of time allows doctors to prepare resources for the child's family, such as counselling or the services of a specialist.

Parents may also learn the location of delivery and its timing beforehand.

Chari and Bhargava first started using the technology several years ago as part of a study on fetal lung development. MRIs are now used for about one in 100 high-risk pregnancies at the hospital.

The results of the study helped to set new standards for lung development for 16- to 40-week-old fetuses, which were published in the journal Radiology.

http://www.cbc.ca

My Question to you is- Isnt radiology (Xrays) toxic to a developing feuts? Why subjec high risk babies to more risks??

-Meg

[ROBERT]

quote:Originally posted by elegantlywasted

MRI helps spot problems before birth
21/04/2006 3:59:24 PM  

Some infants and their families in Alberta are benefiting from the use of MRIs to catch problems before birth.

http://www.cbc.ca

My Question to you is- Isnt radiology (Xrays) toxic to a developing feuts? Why subjec high risk babies to more risks??

-Meg

Hi Meg,
MRIs do not use X-rays, they use radio waves and a strong magnetic field:-

"  The Basic Idea
If you have ever seen an MRI machine, you know that the basic design used in most is a giant cube. The cube in a typical system might be 7 feet tall by 7 feet wide by 10 feet long (2 m by 2 m by 3 m), although new models are rapidly shrinking. There is a horizontal tube running through the magnet from front to back. This tube is known as the bore of the magnet. The patient, lying on his or her back, slides into the bore on a special table. Whether or not the patient goes in head first or feet first, as well as how far in the magnet they will go, is determined by the type of exam to be performed. MRI scanners vary in size and shape, and newer models have some degree of openness around the sides, but the basic design is the same. Once the body part to be scanned is in the exact center or isocenter of the magnetic field, the scan can begin.
In conjunction with radio wave pulses of energy, the MRI scanner can pick out a very small point inside the patient's body and ask it, essentially, "What type of tissue are you?" The point might be a cube that is half a millimeter on each side. The MRI system goes through the patient's body point by point, building up a 2-D or 3-D map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models. "
http://electronics.howstuffworks.com/mri1.htm

 
 

[neilep (OP)]

Hominid fossils from Ethiopia link ape-men to more distant human ancestors

Berkeley -- New fossils discovered in the Afar desert of eastern
Ethiopia are a missing link between our ape-man ancestors some 3.5
million years ago and more primitive hominids a million years older,
according to an international team led by the University of
California, Berkeley, and Los Alamos National Laboratory in New
Mexico.


The fossils are from the most primitive species of Australopithecus,
 known as Au. anamensis, and date from about 4.1 million years ago,
 said Tim White, a UC Berkeley professor of integrative biology and
one of the team's leaders. The hominid Australopithecus has often
been called an ape-man because, though short-statured, small-brained
and big-toothed, it walked on two legs unlike the great apes.


More primitive hominids in the genus Ardipithecus date from between
4.4 million and 7 million years ago and were much more ape-like,
though they, too, walked on two legs.


"This new discovery closes the gap between the fully blown
Australopithecines and earlier forms we call Ardipithecus," White
said. "We now know where Australopithecus came from before 4 million
years ago."


The fossil finds and an analysis of the hominid's habitat and
evolutionary position are reported by White and co-authors from
Ethiopia, Japan, France and the United States in the April 13 issue
of Nature.


Since the first Australopithecus skull, the famous Taung child, was
discovered in South Africa 82 years ago by Raymond Dart, fossils of
this hominid have been found all over eastern Africa spanning a 3-
million-year time period. Seven separate species have been named,
including the most primitive, Au. anamensis, which dates from 4.2
million years ago, and Au. africanus, Dart's find. The most
specialized species, Au. boisei, died out about 1.2 million years
ago, long after the genus Homo had spread throughout the Old World.


The most famous of the Australopithecine fossils was "Lucy," a 3.5-
foot adult skeleton discovered in the Afar depression in 1974. Her
analytical team included White. Subsequently named Au. afarensis,
this hominid, which lived between 3.6 and 3 million years ago, was
also discovered in the Middle Awash study area, where the new Au.
anamensis fossils were found.


Ardipithecus, on the other hand, was discovered by White and his
team in 1992, based on fossils from Aramis, a village in the Awash
Valley of Ethiopia's Afar rift. White and his team named the 4. 4
million-year-old fossils Ardipithecus ramidus.


The relationship between Australopithecus and Ardipithecus remained
unclear, however, because of a million-year gap between these two
genera. The new fossil finds, jawbones and teeth from each of two
localities, bridge that gap. With Ardipithecus in older rocks and
Au. afarensis in overlying rocks, the newly announced fossils are
intermediate in time and anatomy.


The teeth tell a story about the organism's diet, White said.
Australopithecus's large cheek teeth - anthropologists refer to the
hominid as a megadont, meaning large-toothed - allowed it to subsist
on a broader diet of tough, fibrous plants. The teeth of
Ardipithecus were smaller, restricting it to a diet of softer, less
abrasive food, White said.


"Australopithecus became a superior omnivore, able to eat tubers and
roots with more fiber and grit, adapting it better to times of
scarcity during periods of extended drought," he said. "They may
have been small brained, but they stuck around a long time, fully
half of our zoological family's 6-million-year existence on the
planet."


White and his Middle Awash team are cautious about claiming that the
new fossils are closely related to the most recent member of the
genus Ardipithecus, Ar. ramidus, since the two are separated by only
300,000 years. While Au. anamensis could have rapidly evolved from
Ar. ramidus, contemporary fossils may yet be found. Nevertheless,
White said, the new fossils show clear descent from the genus
Ardipithecus, two species of which have been identified over the
genus's 2 million years of existence. The fact that fossils of Ar.
ramidus, Au. anamensis and Au. afarensis have been found in
successive sediment layers in the same area of the Middle Awash site
also indicates an evolutionary sequence, said White.


"It is fair to say that some species of Ardipithecus gave rise to
Australopithecus," he said.


The first of the newly reported fossils, an upper jawbone with
teeth, was discovered in November 1994 at Aramis, the site of
earlier fossil finds of Au. anamensis. In 2000, 2003 and again in
both January and December 2005, the team found additional teeth and
jaw fragments at Asa Issie, about 10 kilometers west of Aramis. Many
of the teeth were completely shattered, but by water-sieving the
surface sediments, they were able to collect nearly all the
fragments, which White painstakingly reassembled.


In all, teeth and jawbones of eight individuals were found at Asa
Issie, all from about 4.1 million years ago as dated by
paleomagnetic and argon-argon methods by a team led by geologist
Paul Renne, UC Berkeley adjunct professor of earth and planetary
science and director of the independent Berkeley Geochronology
Center. A partial thigh bone and hand and foot bones were very
similar to the Lucy bones found 60 kilometers away in Hadar and
dating from 3 million to 3.4 million years ago. The large, thick
-enameled teeth were judged by the research team to be closest to
Au. anamensis, and ancestral to Au. afarensis.


Hundreds of mammal fossils also were found, allowing the team to
reconstruct the habitat as closed woodland with lots of colobus
monkeys, kudus, pigs, birds and rodents, as well as a collection of
carnivores, primarily hyenas and big cats.


"The abundance of monkeys, kudus and other mammals, and petrified
wood found both at Aramis and Asa Issie shows that a closed, wooded
habitat type persisted over a long period in this part of the Afar
and was favored by early hominids between 4 and 6 million years
ago," said Giday WoldeGabriel of Los Alamos National Laboratory, a
geologist and co-leader of the Middle Awash project.


The Middle Awash team, consisting of 60 scientists from 17
countries, brings expertise in geology, archaeology, paleontology
and evolutionary biology to the study of fossils unearthed in
Ethiopia spanning nearly 6 million years of evolution - from the
first hominids that split from chimpanzees to modern humans, Homo
sapiens sapiens. The team continues to unearth fossils from what
White describes as "the world's best window on human evolution."


SOURCE:EUREKERALERT.ORG

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Apollo lunar rocks suggest meteorite shower
OREGON STATE UNIVERSITY NEWS RELEASE


New age measurements of lunar rocks returned by the Apollo space missions have revealed that a surprising number of the rocks show signs of melting about 3.9 billion years ago, suggesting that the moon - and its nearby neighbor Earth - were bombarded by a series of large meteorites at that time.

The idea that meteorites have hammered the moon's surface isn't news to scientists. The lunar surface is pock-marked with large craters carved out by the impact of crashing asteroids and meteorites, said Robert Duncan, a professor and associate dean in the College of Oceanic and Atmospheric Sciences at Oregon State University.

But the narrow range of the impact dates suggests to researchers that a large spike in meteorite activity took place during a 100-million year interval - possibly the result of collisions in the asteroid belt with comets coming from just beyond our solar system.

Results of the study are being published in Geochimica et Cosmochimica Acta, the journal of the international Meteoritical Society. Co-authors with Duncan are Marc Norman of the Australian National University and John Huard, also an oceanographer at OSU. The study was funded by NASA.

Tiny melted fragments from the lunar rocks were dated at the noble gas geochronology laboratory at Oregon State. Duncan and Huard were able to use radiometric dating techniques to determine when the rocks had melted after being struck by meteorites. What is particularly intriguing, Duncan says, is that this apparent spike in meteorite activity took place about 3.8 to 4 billion years ago - an era that roughly coincides with when scientists believe life first began on Earth, as evidenced by the fossil record of primitive one-cell bacteria.

It is possible that life was introduced to Earth from one of these meteorites, Duncan said. Or it could have developed spontaneously once the bombardment subsided, or developed beneath the ocean near life-nurturing hydrothermal vents. The lack of evidence on Earth makes the analysis of moon rocks much more compelling. The meteorite activity that bombarded the moon likely struck our planet as well.

"Unfortunately, we haven't found many very old rocks on Earth because of our planet's surface is constantly renewed by plate tectonics, coupled with erosion," Duncan said. "By comparison, the moon is dead, has no atmosphere and provides a record of meteorite bombardment that we can only assume is similar to that on Earth."

When the solar system was formed, scientists say, it spun away from the sun like a huge, hot disk that subsequently condensed into planets. At least nine planets survived, sucking in loose space matter from around them. Those planets closer to the sun were more solid, while those farther away were comprised primarily of gases.

Over time, the space debris has lessened, either being gravitationally collected into the planets, or smashed into cosmic dust through collisions with other objects. The discovery of this apparent spike in meteorite activity suggests to the authors that a major event took place.

"We may have had a 10th and 11th planet that collided," Duncan said, "or it's possible that the outward migration of Neptune may have scattered comets and small planet bodies, inducing collisions in the asteroid belt. The close passing of a neighboring star could have had a similar effect."

Duncan and his colleagues examined about 50 different rock samples scooped up by astronauts on the Apollo missions. All but a few of them produced ages close to 3.9 billion years and they exhibited different chemical "fingerprints," indicating that they had melted from different meteorites and lunar surface rocks.

"The evidence is clear that there was repeated bombardment by meteorites," Duncan said.

When meteorites collide with the moon, the surface rock and the meteorites partially melt, and then turn to glass. After the glasses quenched, they slowly began to accumulate argon gas that scientists can measure and calculate from the known isotopic decay rate (from potassium) to determine age.

"The formation of glass from the melting is like starting a clock," Duncan said. "It resets the time for us to determine billions of years later."

Duncan and his colleagues say the intense bombardment ended about 3.85 billion years ago, and there has been a slowly declining pattern of meteorite activity since. Many of the prominent craters found on the moon date back to that era, including Imbrium, at 3.84 billion years; Serenitatis, 3.89 billion years; and Nectaris, 3.92 billion years.

Many of the moon's craters are 10 to 100 kilometers across and scientists say that meteorites of that size or larger may have struck the Earth in the past. Such meteorites impacts may have been responsible for the extinction of dinosaurs 65 million years ago, and a mass extinction that wiped out an estimated 75 percent of the Earth's plant and animal species 250 million years ago.

However, Duncan said, these mass extinctions could also be linked to climate, disease and volcanism - or a combination of such factors.

"It is clear that there was a spike of meteorite activity on the moon about 3.9 billion years ago, and that it lasted for roughly 100 million years," Duncan said. "The moon provides important information about the early history of our solar system that is missing from the Earth's geologic record."

SOURCE: SPACEFLIGHTNOW.COM

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Mobile DNA part of evolution's toolbox
The repeated copying of a small segment of DNA in the genome of a primeval fish may have been crucial to the transition of ancient animals from sea to land, or to later key evolutionary changes in land vertebrates. The discovery is "tantalizing evidence" that copied DNA elements known as retroposons could be an important source of evolutionary innovations, says the director of the research, Howard Hughes Medical Institute investigator David Haussler.
"The big question is whether this is a special case or whether it's the tip of the iceberg," says Haussler, who is at the University of California, Santa Cruz. A report on the research is published in the May 4, 2006, issue of the journal Nature.

Haussler and his colleagues were led to the discovery through their work on what they call "ultraconserved elements" -- segments of DNA hundreds of nucleotides long that are almost exactly the same in a wide variety of vertebrate organisms. Haussler and postdoctoral fellow Gill Bejerano discovered the ultraconserved elements in 2003, and since then they have been trying to figure out how they arose and what function they serve.

One ultraconserved element in particular caught their eye. "We were very interested in this sequence, because it had a number of copies elsewhere in the genome," says Bejerano, who is the first author of the study. Close copies of the sequence were ubiquitous in amphibians, birds, and mammals, indicating that it served an important function. "We found it in every species for which we have genomes, from frogs to humans," says Bejerano.

Comparing the sequence to other species also turned up a big surprise. When the researchers compared the human ultraconserved element to all the DNA sequences in the public database GenBank, the closest match was to DNA from the coelacanth -- an ancient fish thought to have gone extinct millions of years ago until a live specimen was caught in 1938 off the east coast of South Africa. The coelacanth is a descendant of the ancient marine organism that gave rise to the terrestrial vertebrates more than 360 million years ago. Humans are therefore separated from the coelacanth by hundreds of millions of years of evolution, yet the two organisms still share critical DNA sequences.

In the coelacanth, the ultraconserved segments were produced by a retroposon known as a short interspersed repetitive element, or SINE, which is a piece of DNA that can make copies of itself and insert those copies elsewhere in an organism's genome. Haussler and his colleagues called this SINE the LF-SINE, where LF stands for lobe-finned fishes--the group of fishes that gave rise to both the coelacanth and terrestrial vertebrates.

The LF-SINE was very active in the evolutionary lineage leading to the terrestrial vertebrates, but much less active after animals moved onto land. Humans have 245 recognizable copies of the LF-SINE, most or all of which probably were in place before the origins of the mammals. But in the lineage leading to the coelacanth, the LF-SINE remained active, so that the coelacanth genome is now estimated to contain hundreds of thousands of copies of the sequence.

The close copies of the ultraconserved element scattered around vertebrate genomes have changed less than would be expected over evolutionary time, indicating that they are functionally important. But relatively few of the copies contain parts that code for proteins, which suggests they instead are helping to regulate when genes are turned on and off. Furthermore, when Bejerano analyzed the locations of the copies, he found that they tended to be near genes that control the development of the brain.

Haussler and his colleagues then looked at a particular example -- a copy of the ultraconserved element that is near a gene called Islet 1 (ISL1). ISL1 produces a protein that helps control the growth and differentiation of motor neurons. In the laboratory of Edward Rubin at the University of California, Berkeley, postdoctoral fellow Nadav Ahituv combined the human version of the LF-SINE sequence with a "reporter" gene that would produce an easily recognizable protein if the LF-SINE were serving as its on-off switch. He then injected the resulting DNA into the nuclei of fertilized mouse eggs. Eleven days later, he examined the mouse embryos to see whether and where the reporter gene was switched on. Sure enough, the gene was active in the embryos' developing nervous systems, as would be expected if the LF-SINE copy were regulating the activity of ISL1.

The discoverer of mobile DNA elements, Barbara McClintock, suggested in 1950 that they might play a role in the regulation of genes -- a hypothesis that was more fully developed by Roy Britten and Eric Davidson in about 1970, when it was discovered that more than half of the human genome consists of remnants of mobile elements. But the mechanisms underlying this process remained obscure. Haussler's work provides direct evidence that even when they land at some distance from a gene, mobile elements like SINEs can be adapted to serve as regulatory elements that have powerful effects in their new locations. "When you activate a gene in a new context," Bejerano points out, "you get processes that did not occur before."

Bejerano and Haussler's results support the hypothesis that the movement of retroposons can generate evolutionary experiments by adding new regulatory modules to genes. Most of these experiments will have no effects or will harm an organism. But every once in a while, the movement of a regulatory element will give an organism an evolutionary advantage. "And to the extent that [such changes] improve the fitness of an organism," says Haussler, "they eventually will become fixed in a population."

"This suggests a lot of exciting evolutionary avenues," says Haussler, "but we don't yet know how prevalent this kind of evolution is." Other labs have found similar examples of mobile elements that have changed the regulation of genes, and Haussler expects the number of reports to grow. "It's a very exciting time to be looking at the human genome, because there's an enormous amount of DNA that we know is important, but we don't yet know what it's doing."

SOURCE: EUREKALERT


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World-leading microscope shows more detail than ever


A unique 3-dimensional microscope that works in a new way is giving unprecedented insight into microscopic internal structure and chemical composition. It is revealing how materials are affected, over time, by changes in temperature, humidity, weight load and other conditions.
The device could lead to advances in a range of areas, such as healthcare (in furthering, for instance, the understanding of conditions such as osteoporosis), the development of better construction materials, improved oil extraction methods and even the study of fossils.

Like a number of other microscopes, the new microscope harnesses X-rays to provide information about an object's internal structure down to micron scale. (A micron is a millionth of a metre.) What makes it unique, however, is its innovative use of a technique called 'time delay integration', which enables it to generate much better images of larger objects than any other device. This means that microscopic structure can be studied with greater accuracy.

With EPSRC funding, a multi-disciplinary team drawn from six UK universities has been developing and utilising the microscope, which, although similar to the CT scanners used in healthcare, can view things in much greater detail.

X-ray microscopes can produce 3-d internal pictures of an object by taking a large number of 2-d images from different angles – this is known as X-ray microtomography. However, the new microscope's combining of this technique with time delay integration is completely unique. Through averaging out imperfections in the image across all pixels, this approach enables the microscope to produce clearer and bigger pictures than previously possible (see 'Notes for Editors').

Some of the microscope's many potential uses include:

Studying how bone and tooth tissue behave in conditions such as osteoporosis, osteoarthritis and tooth decay. By improving understanding of these conditions, the microscope could aid prevention, earlier diagnosis and more effective treatment.
Observing how crude oil is held in sandstone pores. This knowledge could assist the development of more efficient ways of exploiting both offshore and onshore oil resources.
Investigating the mechanical behaviour of metals at a microscopic level. This could contribute to development of more reliable, more resilient and lower weight materials for use in construction, aviation and the storage & transportation of dangerous substances.
Detailed study of fossils embedded in rocks without having to remove and risk damaging them.
Professor Jim Elliott of Queen Mary, University of London led the project. "As well as developing these microscopes to study subtle variations in internal structure, a main aim of ours is to work with the wider scientific community to identify problems where they could make a real contribution," he says. "There's no limit to what it would be useful or interesting to look at."

The microscope looks set to be a valuable research tool that many different organisations in a wide range of sectors could benefit from using. The team is currently planning to seek funding to support the development of a radical new design that could be even more effective.

SOURCE: EUREKALERT


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Man may have caused pre-historic extinctions

New research shows that pre-historic horses in Alaska may have been hunted into extinction by man, rather than by climate change as previously thought.

The discovery by Andrew Solow of Woods Hole Oceanographic Institute, US, David Roberts of the Royal Botanic Garden, Kew and Karen Robbirt of the University of East Anglia (UEA) is published this week in Proceedings of the National Academy of Sciences (PNAS).

The accepted view had previously been that the wild horses became extinct long before the extinction of mammoths and the arrival of humans from Asia - ruling out the possibility that they were over-hunted by man. One theory had been that a period of climate cooling wiped them out.

However, the researchers have discovered that uncertainties in dating fossil remains and the incompleteness of fossil records mean that the survival of the horse beyond the arrival of humans cannot be ruled out.

The PNAS paper develops a new statistical method to help resolve the inherent problems associated with dating fossils from the Pleistocene period. The aim is to provide a far more accurate timetable for the extinction of caballoid horses and mammoths and, ultimately, the cause.

"This research is exciting because it throws open the debate as to whether climate change or over-hunting may have led to the extinction of pre-historic horses in North America," said UEA's Karen Robbirt.

The Pleistocene period refers to the first epoch of the Quarternary period between 1.64 million and 10,000 years ago. It was characterised by extensive glaciation of the northern hemisphere and the evolution of modern man around 100,000 years ago.

It is known that the end of the Pleistocene period was a time of large-scale extinctions of animals and plants in North America and elsewhere but the factors responsible have remained open to question, with climate change and over-hunting by humans the prime suspects. Ends

SOURCE: EUREKALERT.

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