Science & TechnologyS


Bulb

"End of Men" Discovery? Scientists create test-tube sperm

Jeremy Laurance
The Independent
Thu, 09 Jul 2009 03:38 UTC
Dr Karim Nayernia
© PADr Karim Nayernia, Newcastle University Professor of Stem Cell Biology
Scientists have created human sperm in the laboratory for the first time. The extraordinary development, which until a few years ago belonged in the realms of science fiction, raises hopes that infertile men may one day be able to father their own biological children.

The sperm were created in a test tube, from stem cells derived from a five-day-old male embryo. The advance raises ethical questions over the safety of the procedure and the threat it poses to the future role of men. It was also challenged by experts who claimed the sperm-like cells produced in the experiment were not genuine sperm.

If the finding is confirmed, a single male embryo could, in theory, yield a stem-cell line which when stored could provide an unlimited supply of sperm. Once the stem-cell line was established, there would be no further reproductive need for men. In a briefing on the research, the scientists at Newcastle University and the NorthEast England Stem Cell Institute, led by Professor Karim Nayernia, raise the question of whether their discovery means "the end of men".
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Better Earth

Ancient volcano caused 10-year winter


United Press International
Wed, 08 Jul 2009 01:45 UTC
U.S. scientists said they have determined the eruption of Indonesia's Toba volcano about 74,000 years ago triggered a decade-long severe winter.

Previous studies suggested the massive eruption produced a 1,000-year episode of ice sheet advance, as well as a "volcanic winter," which most likely would have drastically reduced the human population at the time.

To investigate additional mechanisms that might have enhanced and extended the effects of the Toba eruption, Rutgers University Professor Alan Robock and colleagues conducted six climate model computer simulations using state-of-the-art models that include vegetation death effects and stratospheric chemistry feedback that might affect the lifetime of the volcanic cloud.
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Magnify

Contaminated Site Remediation: Are Nanomaterials the Answer?


Environmental Health Perspectivess
Thu, 09 Jul 2009 00:13 UTC
A new review article appearing in Environmental Health Perspectives (EHP) co-authored by Dr. Todd Kuiken, a research associate for the Project on Emerging Nanotechnologies (PEN), focuses on the use of nanomaterials for environmental cleanup. It provides an overview of current practices; research findings; societal issues; potential environment, health, and safety implications; and possible future directions for nanoremediation. The authors conclude that the technology could be an effective and economically viable alternative for some current site cleanup practices, but potential risks remain poorly understood.
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Info

Faster, more cost-effective DNA test for crime scenes, disease diagnosis

Michael Woods
American Chemical Society
Thu, 09 Jul 2009 00:06 UTC
Scientists in Japan are reporting development of a faster, less expensive version of the fabled polymerase chain reaction (PCR) a DNA test widely used in criminal investigations, disease diagnosis, biological research and other applications. The new method could lead to expanded use of PCR in medicine, the criminal justice system and elsewhere, the researchers say. Their study is scheduled for the July 15 issue of Analytical Chemistry, a semi-monthly journal.
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Laptop

Computer learns sign language by watching TV

Colin Barras
New Scientist
Wed, 08 Jul 2009 21:47 UTC
It's not only humans that can learn from watching television. Software developed in the UK has worked out the basics of sign language by absorbing TV shows that are both subtitled and signed.

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Sherlock

Kublai Khan's Xanadu Unearthed in China


Indo-Asian News Service
Wed, 08 Jul 2009 19:00 UTC
Xanadu, the city built by Mongol emperor Kublai Khan and mentioned by Italian traveller Marco Polo, has been unearthed by Chinese archaeologists who have sketched its layout.

"The most exciting findings are the layout of the moat in front of the Mingde Gate to the royal capital in the three-month excavation," said Yang Xingyu, a senior archaeologist.

Xanadu, also spelled Shangdu, was built in 1256 under the command of Kublai Khan, the first emperor of Yuan or Mongol Dynasty (1206-1368). It became the summer capital of Mongol emperors of China after the Yuan Dynasty moved its capital to what is now Beijing.
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Blackbox

What can DNA tell us? Place your bets now

Lewis Wolpert and Rupert Sheldrake
New Scientist
Wed, 08 Jul 2009 21:04 UTC
Image
© Chad Baker / GettyCan DNA predict the details of an organism that develops from it?
From Newton to Hawking, scientists love wagers. Now Lewis Wolpert has bet Rupert Sheldrake a case of fine port that: "By 1 May 2029, given the genome of a fertilised egg of an animal or plant, we will be able to predict in at least one case all the details of the organism that develops from it, including any abnormalities." If the outcome isn't obvious, then the Royal Society will be asked to adjudicate.

Lewis Wolpert

I have entered into this wager with Rupert Sheldrake because of my interest in the details of how embryos develop, and how our understanding of this process will progress. In my latest book, How We Live and Why We Die, I suggest that it will one day be possible to predict from an embryo's genome how it will develop, and I believe it is possible for this to happen in the next 20 years.

I am, in fact, being a little over-keen because 40 years is a more likely time frame for such a breakthrough. Cells and embryos are extremely complicated: for their size, embryonic cells are the most complex structures in the universe.

Animals develop from a single cell, a fertilised egg, which divides to produce cells that will form the embryo. How that egg develops into an embryo and newborn animal is controlled by genes in the chromosomes. These genes are passive: they do nothing, just provide the code for proteins. It is proteins that determine how cells behave. While the DNA in every cell contains the code for all the proteins in all the cells, it is the particular proteins produced in particular cells that determine how those cells behave.
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Magnify

11-Billion-Year-Old Giant Supernovae Farthest Ever Detected


PhysOrg
Wed, 08 Jul 2009 20:49 UTC
Supernova
© NASAEta Carinae, a star in the Milky Way galaxy that is 7,500 light years from Earth, will become a supernova similar to those detected by Jeff Cooke and colleagues.
UC Irvine cosmologists have found two supernovae farther away than any previously detected by using a new technique that could help find other dying stars at the edge of the universe.

This method has the potential to allow astronomers to study some of the very first supernovae and will advance the understanding of how galaxies form, how they change over time and how Earth came to be.

"When stars explode, they spew matter into space. Eventually, gravity collapses the matter into a new star, which could have planets such as Earth around it," said Jeff Cooke, McCue Postdoctoral Fellow in physics & astronomy, who reports his findings July 9 in the journal Nature.
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Telescope

Phantom menace to dark matter theory

Marcus Chown
New Scientist
Wed, 08 Jul 2009 20:48 UTC
Image
© NASAThe answer to the riddle of dark matter could be found in our own solar system
A subtle anomaly in the orbit of the planets in our solar system could prove a controversial idea that goes beyond Einstein.

The orbit of the innermost planet, Mercury, departs from what it should be under Newton's laws. A century ago, when Einstein explained this anomaly, it confirmed his theory of gravity - the general theory of relativity.

Now an Israeli physicist predicts that a similar but far more subtle anomaly in the orbits of the planets, if detected, might prove his own theory, known as modified Newtonian dynamics, or MOND. This provides an alternative theory to dark matter to explain why stars orbiting at the edge of spiral galaxies are not flung out into space. These stars are travelling at speeds too fast for conventional gravity from the mass at the heart of a spiral galaxy to hold them in their orbits, so something else must be keeping them on track.

One theory is that invisible dark matter provides that extra pull. But an alternative is MOND, devised in the early 1980s by Mordehai Milgrom, now at the Weizmann Institute of Science in Rehovot, Israel.
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Magic Wand

Device makes objects invisible in certain light conditions


ScienceDaily.com
Wed, 08 Jul 2009 06:38 UTC
A group of researchers from the Department of Physics at UAB have designed a device, called a dc metamaterial, which makes objects invisible under certain light - very low frequency electromagnetic waves - by making the inside of the magnetic field zero but not altering the exterior field. The device, which up to date has only been studied in theoretical works, thus acts as an invisibility cloak, making the object completely undetectable to these waves.

The research is based on an initial idea of the British Ben Wood and John Pendry - the latter considered the father of metamaterials - and is a step forward in the race to create devices which could make objects invisible at visible light frequencies.
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