Science & TechnologyS


Bulb

Leg bone yields DNA secrets of man's Neanderthal 'Eve'


Guardian
Mon, 11 Aug 2008 14:50 UTC


Neanderthal
©Unknown

Some confusion has arisen over our account of Neanderthals, which said at one point that they are thought to have died out 30,000 years ago, but at another that this happened 40,000 years ago. Our correspondent's best judgment now is that they disappeared somewhere between these two dates. As to their height, which has also been disputed, that seems usually to have been between 5ft 4in and 5ft 7in.

Strands of DNA recovered from the fossilized leg bone of a Neanderthal have shed light on the fragility of the ancient population and pinpointed when they first split from what were to become modern humans.
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Cloud Lightning

Researchers track aerosol's effects on cloud control

Todd Morton
Ars Technica
Fri, 15 Aug 2008 00:17 UTC
The global climate is a complex system - something that isn't simply controlled by the concentration of a single greenhouse gas or one type of cloud in the sky. Researchers have completed a study on the effects of aerosol layers and their influence on cloud formation, a key parameter in understanding and controlling local climate. If you're a mad scientist bent on global weather domination, start taking notes now.
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Bulb

Big-brained animals evolve faster


University of Chicago Press Journals
Thu, 14 Aug 2008 16:22 UTC


Image
©Daniel Sol
Parrots have a big brain and are also one of the most evolutionarily diversified bird clades.

Ever since Darwin, evolutionary biologists have wondered why some lineages have diversified more than others. A classical explanation is that a higher rate of diversification reflects increased ecological opportunities that led to a rapid adaptive radiation of a clade. A textbook example is Darwin finches from Galapagos, whose ancestor colonized a competitors-free archipelago and rapidly radiated in 13 species, each one adapted to use the food resources in a different way.

This and other examples have led some to think that the progenitors of the major evolutionary radiations are those that happened to be in the right place and at the right time to take advantage of ecological opportunities. However, is it possible that biological diversification not only depends on the properties of the environment an ancestral species finds itself in, but also on the features of the species itself? Now a study supports this possibility, suggesting that possessing a large brain might have facilitated the evolutionary diversification of some avian lineages.
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Magnify

Galileo, Reconsidered - The first biography of Galileo Galilei resurfaces

Mike Price
The Smithsonian Magazine
Fri, 15 Aug 2008 13:59 UTC
The classic image of Galileo Galilei has the 16th century Italian scientist dropping two balls of differing weights from the Leaning Tower of Pisa and observing them hitting the ground at the same time. Though that scenario was probably no more than one of Galileo's thought experiments - his known tests involved rolling balls down inclines - it does illustrate his towering reputation as a scientific revolutionary. Galileo helped paved the way for classic mechanics and made huge technological and observational leaps in astronomy. Most famously, he championed the Copernican model of the universe, which put the sun at its center and the earth in orbit. The Catholic Church deemed Galileo's 1632 book Dialogue Concerning the Two Chief World Systems­ heresy, banned it, forced Galileo to recant his heliocentric views and condemned him to house arrest. He died in his Florence home in 1642.
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Question

Promising research may grow bee population

Laura Rillos
KVAL.com
Wed, 13 Aug 2008 13:10 UTC


flower_bee
©Unknown

Corvallis, Oregon -- From foraging techniques to pollen gathering patterens, bee behavior is the focus of many research projects at Oregon State University.

But the latest major discovery happened here by accident.
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Pharoah

Stone Age mass graves reveal green Sahara

Nora Schultz
New Scientist
Thu, 14 Aug 2008 16:49 UTC
One of the driest deserts in the world, the Saharan Tenere Desert, hosted at least two flourishing lakeside populations during the Stone Age, a discovery of the largest graveyard from the era reveals.

Image
©Mike Hettwer, courtesy Project Exploration
Dark skull, left: The skull of this mature Kiffian male was found at the cemetery at Gobero. Light Skull, right: This Tenerian male died in the prime of his life at about 18 years of age.

The archaeological site in Niger, called Gobero, was discovered by Paul Sereno at the University of Chicago, during a dinosaur-hunting expedition. It had been used as a burial site by two very different populations during the millennia when the Sahara was lush.

Careful examination of 67 graves - a third of the 200 plots on the site - has uncovered unprecedented details about the lifestyles of the people who inhabited the green Stone Age "desert", says Sereno.

"The first people who used the Gobero cemetery were Kiffian, hunter-gatherers who grew up to two metres tall," says Elena Garcea of the University of Cassino in Italy and one of the scientists on the team. The large stature of the Kiffian suggests that food was plentiful during their time in Gobero, 10,000 to 8,000 years ago.
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Robot

Robot With A Biological Brain


Science Daily
Thu, 14 Aug 2008 13:40 UTC
A multidisciplinary team at the University of Reading has developed a robot which is controlled by a biological brain formed from cultured neurons. This cutting-edge research is the first step to examine how memories manifest themselves in the brain, and how a brain stores specific pieces of data.

Cultured neurons from rats
©University of Reading
Cultured neurons from rats are placed onto a multi-electrode array -- a dish with approximately 60 electrodes which pick up the electrical signals generated by the cells.

The key aim is that eventually this will lead to a better understanding of development and of diseases and disorders which affect the brain such as Alzheimer's Disease, Parkinson's Disease, stoke and brain injury.

The robot's biological brain is made up of cultured neurons which are placed onto a multi-electrode array (MEA). The MEA is a dish with approximately 60 electrodes which pick up the electrical signals generated by the cells. This is then used to drive the movement of the robot. Every time the robot nears an object, signals are directed to stimulate the brain by means of the electrodes. In response, the brain's output is used to drive the wheels of the robot, left and right, so that it moves around in an attempt to avoid hitting objects. The robot has no additional control from a human or a computer, its sole means of control is from its own brain.
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Magnify

Maelstrom Quashes Jumping Genes


Medical News Today
Wed, 13 Aug 2008 11:27 UTC
Scientists have known for decades that certain genes (called transposons) can jump around the genome in an individual cell. This activity can be dangerous, however, especially when it arises in cells that produce eggs and sperm. Such changes can threaten the offspring and the success of a species. To ensure the integrity of these cells, nature developed a mechanism to quash this genetic scrambling, but how it works has remained a mystery. Now a team of scientists, including researchers at the Carnegie Institution's Department of Embryology, has identified a key protein that suppresses jumping genes in mouse sperm and found that the protein is vital to sperm formation.
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Magnify

Nanotechnology produces highly conductive, single-molecule junction between electrodes


Foresight Nanotech Institute
Thu, 14 Aug 2008 11:14 UTC
Nanotech has taken a major step along the road to molecular electronics with the demonstration that one molecule of benzene can form a highly conductive junction between two platinum electrodes. From an article on nanotechweb.org, written by Belle Dumé (requires free registration) "Ballistic breakthrough could lead to molecular logic gates":
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Clock

Signals seem to travel faster than light

Charles Q. Choi
LiveScience
Wed, 13 Aug 2008 13:05 UTC
Strange events that Einstein himself called "spooky" might happen at least 10,000 times the speed of light, according to the latest attempt to understand them.
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