Science + Logic + Reason

[Preciouslife1]

Unravelling A Cosmic Mystery: Scientists Discover The Universe's Strongest Magnetic Field

Scientists from The University of Exeter and the International University, Bremen have discovered what is thought to be the strongest magnetic field in the Universe.

(Credit: Daniel Price (U/Exeter) and Stephan Rosswog (Int. U/Bremen))
In a paper in the journal Science, Dr Daniel Price and Professor Stephan Rosswog show that violent collisions between neutron stars in the outer reaches of space create this field, which is 1000 million million times larger than our earth's own magnetic field. It's thought that these collisions could be behind some of the brightest explosions in the Universe since the Big Bang, so-called short Gamma-ray bursts.
Dr Daniel Price, of the School of Physics at The University of Exeter, said: " We have managed to simulate, for the first time, what happens to the magnetic field when neutron stars collide, and it seems possible that the magnetic field produced could be sufficient to spark the creation of Gamma-ray bursts. Gamma-ray bursts are the most powerful explosions we can detect but until recently little to nothing has been known about how they are generated.
It's thought that strong magnetic fields are essential in producing them, but until now no one has shown how fields of the required intensity could be created."
He continues: "What really surprised us was just how fast these tremendous fields are generated - within one or two milliseconds after the stars hit each other. "
Prof Stephan Rosswog, of the International University, Bremen, Germany, adds: "Even more incredible is that the magnetic field strengths reached in the simulations are just lower limits on the strengths that may be actually be produced in nature.
It has taken us months of nearly day and night programming to get this project running - just to calculate a few milliseconds of a single collision takes several weeks on a supercomputer."
The remnants of supernovae, neutron stars are formed when massive stars run out of nuclear fuel and explode, shedding their outer layers and leaving behind a small but extremely dense core.
When two neutron stars are left orbiting each other, they will spiral slowly together, resulting in these massive collisions.

amazing things happening in the science world..remember this great site for more interesting articles..http://www.sciencedaily.com/

PL1 on the Mark

[Preciouslife1]

A Bizarre Find in Egyptian Desert Caves

Ancient ships have been found in caves at the edge of the Egyptian desert. Yes, ships. In caves. In the desert! They are considered the oldest remains of seafaring ships in the world and also contain the cargo boxes they once hauled.

The cache was found in an area called Wadi Gawasis along a sand-covered bluff near the Red Sea by a team led by Florida State University anthropology professor Cheryl Ward. Wadi Gawasis is located about 13 miles south of the modern Egyptian city of Port Safaga.

The find suggests that ancient Egyptians sailed nearly 1,000 miles on rough waters to get treasures from a place they called God's Land, or Punt. The wooden planks found in the manmade caves are about 4,000 years old, making them the world's most ancient ship timbers. Shipworms that had tunneled into the planks indicated the ships had weathered a long voyage of a few months, likely to the fabled southern Red Sea trading center of Punt, a place referenced in hieroglyphics on empty cargo boxes found in the caves.

"The archaeological site is like a mothballed military base, and the artifacts there tell a story of some of the best organized administrators the world has ever seen," Ward, an expert on ancient shipbuilding, explained in a news release announcing the findings. "It's a site that has kept its secrets for 40 centuries."

Scholars have long known that Egyptians traveled to Punt, but they have debated its exact location and whether the Egyptians reached Punt by land or by sea. Some had thought the ancient Egyptians did not have the naval technology to travel long distances by sea, but the findings at the Wadi Gawasis confirm that Egyptians sailed a 2,000-mile round trip voyage to Punt, putting it in what is today Ethiopia or Yemen, Ward said.

The six rock-cut caves were used by the ancient Egyptians as work and storage rooms to protect their equipment from the harsh desert weather conditions. Along with timber and cargo boxes, the archaeologists found large stone anchors, shards of storage jars and more than 80 perfectly preserved coils of rope in the caves that had been sealed off until the next expedition--one that obviously never came. The team also found a stela, or limestone tablet, of Pharaoh Amenemhat III, who ruled between 1844-1797 B.C., inscribed with all five of his royal names. This discovery provided further evidence that the items date to Egypt's Middle Kingdom period.

The findings will be published in an upcoming issue of the International Journal of Nautical Archaeology.

PL1

[Preciouslife1]

Blue Ring Discovered Around Uranus

The outermost ring of Uranus, discovered just last year, is bright blue, making it only the second known blue ring in the solar system, according to a report this week in the journal Science.

A comparison of the outer rings of Saturn (at top) and Uranus, where each system has been scaled to a common planetary radius. The recently discovered outer ring of Uranus, like that of Saturn, is blue because the material in these rings is smaller than the material in the inner, red rings. (Credit: Imke de Pater, Heidi Hammel, Seran Gibbard, Mark Showalter, courtesy Science)
Perhaps not coincidentally, both blue rings are associated with small moons.
"The outer ring of Saturn is blue and has Enceladus right smack at its brightest spot, and Uranus is strikingly similar, with its blue ring right on top of Mab's orbit," said Imke de Pater, professor of astronomy at the University of California, Berkeley. "The blue color says that this ring is predominantly submicron-sized material, much smaller than the material in most other rings, which appear red."
The authors of the paper in the April 7 issue of Science are de Pater, Mark Showalter of the SETI Institute in Mountain View, Calif.; Heidi B. Hammel of the Space Science Institute in Boulder, Colo.; and Seran Gibbard of Lawrence Livermore National Laboratory in California.
The similarity between these outer rings implies a similar explanation for the blue color, according to the authors. Many scientists now ascribe Saturn's blue E ring to the small dust, gas and ice particles spewed into Enceladus' orbit by newly discovered plumes on that moon's surface. However, this is unlikely to be the case with Mab, a small, dead, rocky ball, about 15 miles across - one-twentieth the diameter of Enceladus.
Instead, the astronomers suspect both rings owe their blue color to subtle forces acting on dust in the rings that allow smaller particles to survive while larger ones are recaptured by the moon.
"We know now that there is at least one way to make a blue ring that doesn't involve plumes, because Mab is surely too small to be internally active," said Showalter. He and astronomer Jack Lissauer of NASA Ames Research Center in Mountain View, Calif., discovered Mab in Hubble Space Telescope images in 2003.
The likely scenario to explain Saturn's blue ring was proposed before plumes were discovered last November as the Cassini spacecraft flew by Enceladus. As modeled for the E ring, meteoroid impacts on the surface of Enceladus scatter debris into its orbit, probably in a broad range of sizes. While the larger pieces remain within the moon's orbit and eventually are swept up by the moon, smaller particles are subject to subtle forces that push them toward or away from the planet out of the moon's orbit. These forces include pressure from sunlight, magnetic torques acting on charged dust particles, and the influence of slight variations in gravity due to the equatorial bulge of Saturn.
The net result is a broad ring of smaller particles, most less than a tenth of a micron across - a thousandth the width of a human hair - that scatter and reflect predominantly blue light.
"This model can be transferred directly to what we now see in Uranus, although we still need to understand the details of the process," de Pater said.
All other rings - those around Jupiter, Saturn, Uranus and Neptune - are reddish. Though they contain particles of many sizes that reflect many wavelengths of light, red dominates not only because larger particles - many microns to meters across - are abundant, but also because the material itself may be reddish, perhaps from iron.
"Arguing by analogy, the two outermost rings, the two rings that have satellites embedded in them, are both the blue rings. That can't be coincidental, there has to be a common thread of dynamics that is causing both of these phenomena," Showalter said.
The discovery of the blue ring came after combining ground-based near-infrared observations by the Keck Telescope in Hawaii and visible-light photos taken by the Hubble Space Telescope. De Pater, Hammel and Gibbard have observed Uranus since 2000 with the second-generation NIRC2 infrared camera using the adaptive optics system on the Keck II telescope, and in August 2005 obtained 30 new images of the planet in hopes of seeing new features as the ring plane moves edge-on to Earth.
Showalter and Lissauer, on the other hand, captured numerous visible-light images of Uranus between 2003 and 2005 with Hubble's Advanced Camera for Surveys.
Neither team realized it had captured pictures of new rings until an extensive analysis, basically piling image upon image until faint features stood out from the background. In December 2005, as Showalter and Lissauer reported finding two new rings - Uranus's 12th and 13th - and two new moons, Mab and Cupid, numbers 26 and 27, de Pater, Hammel and Gibbard reported seeing the red, innermost of the two new rings but not the outermost. The blue ring peaks in brightness about 97,700 kilometers from the planet's center, exactly at Mab's orbit.
Further analysis proved to both teams that the outer ring seen in visible light was definitely not observable in the near-infrared, and so must be blue. The analysis also showed that Mab, which like its ring could not be seen in the infrared, is probably covered with water ice, like the other outer moons of Uranus, and is probably Uranus's smallest moon.
De Pater's research is supported by the National Science Foundation and the Technology Center for Adaptive Optics at UC Santa Cruz. Hammel is supported by NASA, while Gibbard is supported by the U.S. Department of Energy's National Nuclear Security Administration.
Showalter's work is supported by NASA through the Space Telescope Science Institute.

[Preciouslife1]

http://www.diserio.com/top15-skylines.html#top



The Top 15 Skylines in the World v3.0
All my years in studying Urban Planning helped me grow a greater appreciation for the dense downtown skyline of the big city. The downtown core of big cities across the Americas, Europe and Asia are the cultural pulse and economic engines of urban regions where millions of people live. All urban "life" begins and ends, each day and night under the watch of the city's tallest skyscrapers and most grand architectural structures. So kick back and appreciate the view that they have to offer...
1. Hong Kong, China
Hong Kong is number one on my list for many reasons: Hong Kong has a whopping 43 buildings over 200 metres tall, 30 of which were built in the year 2000 or later!!! It also boasts four of the 15 tallest buildings in the world… that's all in one city! Hong Kong’s skyline shows a large selection of distinct sky-reaching towers, with beautiful night lighting and reflection. This city exemplifies the post-modern skyscraper and skyline. Finally, the mountain backdrop makes this skyline (as you can clearly see) the greatest on the planet!
Metro/Urban Population: 6.9 million

2. Chicago, USA
Chicago is the birthplace of the modern skyscraper. When Chicago built its first steel high-rise in 1885, it was not the tallest structure in the world but the first example of a new form of engineering that would change nearly every city on earth. Chicago has 19 buildings over 200 metres tall (three of which are among the top 20 tallest buildings in the world, including the tallest in North America). Chicago has some of the finest mid-century architecture and examples of modern skyscrapers.
Metro/Urban Population: 9.5 million

3. Shanghai, China
Not to be mistaken for a space station, Shanghai is a real city! China's biggest and most advanced city, Shanghai was said to be the most cosmopolitan city in the beginning of the 20th century, but lost its glory during the “Mao era”. It is now quickly regaining its position as one of the biggest economic powerhouses in the world as well as a showcase of modern architecture. In Shanghai you’ll find 25 structures that are over 200 metres tall, one of which is the insanely tall, the 468m downtown Oriental Pearl TV Tower.
Metro/Urban Population: 13.1 million

4. New York City, USA
New York City has one of the densest and most diverse skylines, with a huge collection of buildings and building styles. Thanks to Hollywood’s obsession with the city, it is also the most easily recognizable skyline in the world. New York City has an amazing 47 buildings over 200 metres - the most in the world! The four tallest buildings in NYC were all built in the early 1930s! Home of the famous, (now tragically destroyed) World Trade Center Towers, the Empire State building, the Statue of Liberty and the United Nations, New York City is the financial capital of the western world! Upon the completion of the new "Freedom Tower" (built on the old site of the World Trade Centers), it may rank higher in this list.
Metro/Urban Population: 21.0 million
5. Tokyo, Japan
Tokyo is the world's most populated city. Its skyline has a number of unique characteristics that set it apart from other big city skylines, among them 15 structures at over 200 metres tall (including the Tokyo Tower which changes colors every night). But because of the density and vast size of the city, every corner appears to have its own skyline. With the height restrictions and the required red lights that flash atop all mid to tall-sized buildings make the city look spectacular at night. Tokyo is filled with neon lighting and unique, contemporary architecture, and like New York City is also often portrayed in movies for its aesthetic and eye-catching cityscapes. Interesting fact: Tokyo houses the world's largest fleet of helicopters to get around town if traffic gets too crazy.
Metro/Urban Population: 32.0 million

6. Singapore
One of the best (urban) planned and cleanliest metropolitan cities in the world, Singapore looks like an architectural model city come to life. The buildings cannot be higher than 280 metres due to air traffic control restrictions, but that has added a tall (but not too tall) and consistent building height and space pattern that makes this skyline unique: Three buildings are exactly 280 metres tall and 5 others (8 total) stand at just over 200 metres. The buildings are mostly light-coloured and there is a large expanse of greenery dotted around the city core. This South-Eastern city is definitely in a league of its own.
Metro/Urban Population: 3.8 million


7. Toronto, Canada
Toronto is a meeting place, a crossroads of many cultures and ethnicities. Toronto is downtown Canada, the biggest city in the country with a skyline to match. Toronto has 7 structures in its skyline that stand at over 200 metres, including the astonishingly tall 553 metre, CN Tower, which is often referred to as the tallest free-standing structure in the world. While mostly untrue (because there are taller TV masts in the world), the CN Tower possess the world's highest observation deck, making this city's skyline one of the most immediately identifiable.
Metro/Urban Population: 5.1 million


8. Kuala Lumpur, Malaysia
This is probably the most impressive city worldwide that has less than 2 million residents. Marvelous modern buildings reach the sky here, and while the skyline is not too dense, it does allow buildings to soar and stand out. Kuala Lumpar has three of the 25 tallest buildings worldwide, including the tallest twin buildings, the Petronas Towers (which are arguably the second and third tallest overall in the world) as well as the 420 metre Menara Kuala Lumpur Tower.
Metro/Urban Population: 1.5 million

9. Shenzhen, China
What was a tiny fishing village on the border of Hong Kong in 1970 is now a buzzing metropolis of over four million people. With 13 buildings at over 200 meters tall, including the Shun Hing Square (the 8th tallest building in the world), Shenzen is a marvel of lights after sunset. You can’t help but ask yourself if you are in a video game or in a real city.
Metro/Urban Population: 4.2 million
10. Seoul, South Korea
This city's skyscrapers are divided into many clusters, spread amongst the main businesses and residential districts. Most of the recent growth in Seoul's skyline, however, has been of residential towers over 60 storeys high that are shooting up like blades of grass! There are 10 buildings in Seoul over 200 meters tall and much of the mid-rise to high-rise structures are lined up in a linear fashion, creating a "wall" of buildings like no other. Seoul is where the ancient Eastern world meets the modern West.
Metro/Urban Population: 20.8 million

[Preciouslife1]

“What building did you say they lived in?” Finding it in the largest mass of condensed apartment buildings anywhere would be like finding a needle in a haystack. Sao Paolo has a population of over 18 million people! While the buildings are not super tall (with only a single structure at over 200 meters tall) this skyline is nevertheless stacked. Sao Paolo has a fleet of over 500 helicopters, the second largest helicopter fleet in the world.
Metro/Urban Population: 18.3 million


12. Sydney, Australia
Australia’s showcase city, Sydney has one of the most recognizable skylines due to its world-famous harbour, often referred to as the most beautiful natural harbour in the world. The Sydney Harbour has many bays, inlets and secondary harbours. It is spanned by the monumental Harbour Bridge, and the Opera House decorates the shoreline like a white flower. The Sydney skyline is world-class with hundreds of skyscrapers in the central business district and many more high-rise buildings in the outlying neighbourhoods. Sydney has 8 buildings over 200 metres tall.
Metro/Urban Population: 4.2 million


13. Frankfurt, Germany
Certainly one of Europe's most interesting cities in terms of skylines, Frankfurt is home to five structures that are over 200 metres tall. These modern skyscrapers are marvels compared to those other, mostly non-existent ones scattered across European cities. The contrast here is interesting: The city combines low-rise, high-density traditional European architecture (some of which is over 1,000 years old), with modern towers that stick out like sore thumbs, but are impressive nonetheless.
Metro/Urban Population: 4.1 million


14. Dubai, United Arab Emirates
Is this a mirage in the Middle East? Seemingly out of nowhere emerges a city in the middle of a desert. This is Dubai, a city that produces only the best modern architecture in the world. Already home of the world's tallest all-hotel building and the tallest all-residential building in the world, AND currently proposed to build the world's tallest building, this skyline might just leap to the number 1 spot in the near future. While the skyline is not so dense, each building is a marvel all on its own. As a skyline it probably can't compete with the larger cities, however the individual buildings in this city are by far the greatest examples of modern architectural accomplishments. All seven structures in this city at over 200 metres tall were built in 1999 or later - that's how new this city is.
Metro/Urban Population: 1.6 million

15. Seattle, USA
Seattle is the commercial, cultural and advanced technology hub of the Northwest USA and a major port city for Pacific and European trade. Home 4 buildings over 200m and the famous 184m Space Needle observation tower, Seattle is surrounded by mountains and water and offers some picture-perfect views. Seattle is commonly referred to as the Emerald City and renowned as a great social and corporate city with great planning.
Metro/Urban Population: 3.6 million

Honorable Mentions
16. Pittsburgh, USA
Although Pittsburgh only has two buildings over 200m tall, its skyline is very impressive nonetheless. Pittsburgh has nicknames like the "city of bridges", "the Burgh" or the "golden triangle" which outlines its true characteristics. It is surround by three rivers and the CBD is shaped in a triangle and surrounded by golden color bridges. The city is also surrounded by hills and valley's giving access to great views of the city. The city has not had a major skyscraper raised since 1988, but good planning and a scenic surrounding region still makes it a great skyline.
Metro/Urban Population: 2.4 million

17. Guangzhou, China
Guangzhou is a very modern city, yet it is called "the City of Flowers,” as each of its spectacular skyscrapers is surrounded by grand green spaces and flower beds. Although it only has six structures at over 200 metres tall, there are plenty of other high-rises, each displaying a design that stands out in its own respect. This includes the 391 metre, 80-floor, CITIC Plaza which appears transparent against the (usually) clear blue sky!
Metro/Urban Population: 4.1 million
18. Dallas, USA
The "Big D", is a major inland American city. The city and metropolitan area lies amidst vast, high, and varying rolling prairies - with hundreds of large & small lakes, rivers, creeks, waterways and meanders. But Dallas; downtown is the center of the Forth-Worth-Dallas Metro Region which is home to 5.9 million people. Dallas' skyline is home to 7 buildings over 200 meters and the 187m Reunion Tower which looks like huge sphere of light! The skyline is very distinctive at night as it building lighting is very colorful, particularly with lots of green.
Metro/Urban Population: 5.2 million

[Preciouslife1]

The Great Easter Egg Hunt: The Void's Incredible Richness

An image made of about 300 million pixels is being released by ESO, based on more than 64 hours of observations with the Wide-Field Camera on the 2.2m telescope at La Silla (Chile). The image covers an 'empty' region of the sky five times the size of the full moon, opening an exceptionally clear view towards the most distant part of our universe. It reveals objects that are 100 million times fainter than what the unaided eye can see.

Part of the Deep 3 Deep Public Survey field, showing the brightest galaxy in the field ESO 570-19 (upper left) and the brightest star UW Crateris. This red giant (upper right) is a variable star that is about 8 times fainter than what the unaided eye can see. An 'S'-shaped ensemble of galaxies is also visible in the lower part of the picture. (Image courtesy of European Southern Observatory)
Easter is in many countries a time of great excitement for children who are on the big hunt for chocolate eggs, hidden all about the places. Astronomers, however, do not need to wait this special day to get such an excitement: it is indeed daily that they look for faraway objects concealed in deep images of the sky. And as with chocolate eggs, deep sky objects, such as galaxies, quasars or gravitational lenses, come in the wildest variety of colours and shapes.
The image presented here is one of such very deep image of the sky. It is the combination of 714 frames for a total exposure time of 64.5 hours obtained through four different filters (B, V, R, and I)! It consists of four adjacent Wide-Field Camera pointings (each 33x34 arcmin), covering a total area larger than one square degree.
Yet, if you were to look at this large portion of the firmament with the unaided eye, you would just see... nothing. The area, named Deep 3, was indeed chosen to be a random but empty, high galactic latitude field, positioned in such a way that it can be observed from the La Silla observatory all over the year.
Together with two other regions, Deep 1 and Deep 2, Deep 3 is part of the Deep Public Survey (DPS), based on ideas submitted by the ESO community and covering a total sky area of 3 square degrees. Deep 1 and Deep 2 were selected because they overlapped with regions of other scientific interest. For instance, Deep 1 was chosen to complement the deep ATESP radio survey carried out with the Australia Telescope Compact Array (ATCA) covering the region surveyed by the ESO Slice Project, while Deep 2 included the CDF-S field. Each region is observed in the optical, with the WFI, and in the near-infrared, with SOFI on the 3.5-m New Technology Telescope also at La Silla.
Deep 3 is located in the Crater ('The Cup'), a southern constellation with very little interest (the brightest star is of fourth magnitude, i.e. only a factor six brighter than what a keen observer can see with the unaided eye), in between the Virgo, Corvus and Hydra constellations. Such comparatively empty fields provide an unusually clear view towards the distant regions in the Universe and thus open a window towards the earliest cosmic times. The deep imaging data can for example be used to pre-select objects by colour for follow-up spectroscopy with ESO's Very Large Telescope instruments.
But being empty is only a relative notion. True, on the whole image, the SIMBAD Astronomical database references less than 50 objects, clearly a tiny number compared to the myriad of anonymous stars and galaxies that can be seen in the deep image obtained by the Survey!
Among the objects catalogued is the galaxy visible in the top middle right (see also PR Photo 14b/06) and named ESO 570-19. Located 60 million light-years away, this spiral galaxy is the largest in the image. It is located not so far - on the image! - from the brightest star in the field, UW Crateris. This red giant is a variable star that is about 8 times fainter than what the unaided eye can see. The second and third brightest stars in this image are visible in the lower far right and in the lower middle left. The first is a star slightly more massive than the Sun, HD 98081, while the other is another red giant, HD 98507.
In the image, a vast number of stars and galaxies are to be studied and compared. They come in a variety of colours and the stars form amazing asterisms (a group of stars forming a pattern), while the galaxies, which are to be counted by the tens of thousands come in different shapes and some even interact or form part of a cluster.
The image and the other associated data will certainly provide a plethora of new results in the years to come. In the meantime, why don't you explore the image with the zoom-in facility, and start your own journey into infinity? Just be careful not to get lost. And remember: don't eat too many of these chocolate eggs!

PL1

[Preciouslife1]

Brain Communicates In Analog And Digital Modes Simultaneously

Contrary to popular belief, brain cells use a mix of analog and digital coding at the same time to communicate efficiently, according to a study by Yale School of Medicine researchers published this week in Nature.

This finding partially overturns a longstanding belief that each of the brain's 100 billion neurons communicate strictly by a digital code. Analog systems represent signals continuously, while digital systems represent signals in the timing of pulses. Traditionally, many human-designed circuits operate exclusively in analog or in digital modes.
"This study reveals that the brain is very sophisticated in its operation, using a code that is more efficient than previously appreciated," said David McCormick, professor in the Department of Neurobiology and senior author of the study. "This has widespread implications, not only for our basic understanding of how the brain operates, but also in our understanding of neuronal dysfunction."
"It's as if everyone thought communication in the brain was like a telegraph, but actually it turned out to be more similar to a telephone," he said.
Neurons receive input from other cells largely through synaptic contacts on their dendrites and cell bodies. The release of neurotransmitters at these synapses causes the voltage inside the cell receiving the transmitters to fluctuate continuously. Once this voltage passes a threshold, an action potential is generated. The action potential is a specialized waveform known to be able to travel down the axon, or output portion of the cell.
Due to its length and thinness, the nerve axon has been believed to be impassable to the smaller analog voltage deflections that gave rise to action potential. As this action potential reaches the synaptic terminals of the axon, it causes the release of a transmitter onto the next neurons in the chain. So, although signals in the cell body are represented in an analog fashion, they were thought to be transmitted between cells solely through the rate and timing of the action potentials that propagated down the axon, that is, in a digital fashion.
McCormick's group demonstrated that the analog signal present in the cell body also propagates down the axon and influences synaptic transmission onto other neurons. As the voltage on the sending cell becomes more positive, the amplitude of the subsequent transmission to the receiving cell, mediated by an action potential, is enhanced. This means that the waveform generated in the receiving neuron is not just determined by the digital pattern of action potentials generated, but also by the analog waveform occurring in the sending neuron.
For example, McCormick said, epileptic seizures and the aura of migraine headache both involve large changes in the voltage inside neurons. He said this study indicates that these abnormal patterns of activity may be directly communicated to nearby neurons, even in the absence of the generation of the digital code of action potential activity.
McCormick said future investigations and models of neuronal operation in the brain will need to take into account the mixed analog-digital nature of communication. Only with a thorough understanding of this mixed mode of signal transmission will a truly in depth understanding of the brain and its disorders be achieved, he said.
The first author is Yousheng Shu of Yale. Co-authors are Andrea Hasenstaub, Alvaro Duque and Yuguo Yu of Yale.

PL1

[Preciouslife1]

Ageing: Chromatin unbound

Abstract:
Sir2 proteins slow ageing in yeast by locking chromatin — the DNA and proteins in chromosomes — into a stable, silent state. Inactivating a Sir2 family protein in mice causes premature ageing and genome instability.

Genomes are exquisitely adapted to provide the information, at the right time and place, for cells to function. Loss of genome integrity has long been implicated in ageing: cancer, for example, occurs more frequently with age and can be caused by genome alterations. Writing in Cell, Mostoslavsky et al.1 now show that, in mice, inactivation of SIRT6 — a protein related to Sir2, which increases lifespan in yeast and worms when overexpressed — causes genome instability and premature ageing.
Ever since the discovery in the late 1940s that low, daily doses of radiation accelerated the signs of ageing in rodents2, loss of genome integrity has been proposed as a universal cause of ageing3. Under normal conditions, the most likely culprits for causing genome deterioration are the reactive oxygen species continually produced during ********************bolism. It comes as no surprise that the enzymatic systems that detect and repair DNA damage are widely considered candidate longevity mechanisms. Heritable defects in such genome maintenance processes are generally associated with premature ageing syndromes. Werner's syndrome, for example, is caused by lack of the WRN protein that is crucial for some forms of DNA repair and for maintaining the structural integrity of chromosome ends. In both humans and mice, WRN mutations and other defects in pathways that protect genome integrity cause premature ageing4.
Intriguing players in genome maintenance are the silent information regulator (SIR) proteins, which repress gene expression and genome instability in yeast by stabilizing chromatin. The founding member of this family, Sir2, promotes longevity in yeast by protecting regions in the genome that consist of repeated DNA sequences, which are inherently unstable. Moreover, extra copies of Sir2 increase the lifespan of fruitflies and nematodes5. Interestingly, in some species Sir2 has been connected to the 'pro-longevity' effect of both caloric restriction (that is, food deprivation without malnutrition) and the reduced insulin/insulin-like growth factor-1 (IGF-1) signalling that is a response to nutritional stress but can also occur as a consequence of mutations in genes acting in the insulin/IGF-1 cascade5.
The actions of Sir2 are not straightforward and there has been no direct evidence to link Sir2 with ageing in mammals. Its closest mammalian relative, SIRT1, regulates the tumour-suppressor protein p53 and FOXO3 (a gene regulatory factor that is negatively regulated by insulin/IGF-1 signalling) to suppress programmed cell death (apoptosis) and promote cell survival6. Inactivating SIRT1 in mice is mostly lethal, with the few live births dying within weeks from abnormalities that do not resemble ageing7.
Mostoslavsky et al.1 show that inactivation in mice of another Sir2 relative, SIRT6, quickly causes abnormalities that resemble some aspects of ageing, such as thinning of the skin due to loss of subcutaneous fat, and signs of osteoporosis. Cells from these mice showed impaired proliferation and increased genomic instability, possibly because of a defect in base excision repair (BER). This would be the first demonstration that accelerated ageing is associated with a defect in this DNA-repair pathway. BER is especially crucial for removing DNA damage caused by reactive oxygen species. It is unclear how SIRT6 promotes BER, but because Mostoslavsky et al. find that the protein is associated with chromatin, it may regulate accessibility of BER enzymes to the damaged site.
Premature ageing symptoms in mice with defects in DNA repair have been linked to cellular responses to the increased DNA damage, such as apoptosis and cellular senescence (the irreversible cessation of cell division)4. Mostoslavsky et al. found a dramatic increase in apoptosis of lymphocytes — cells active in the immune response — in SIRT6-deficient mice. This was the most likely cause of the severe lymphocyte depletion seen in the animals. Unexpectedly, however, bone marrow transplantation experiments indicated that the lymphocyte depletion was not cell-intrinsic but rather a response to a systemic defect. Analysis of the blood serum of SIRT6-deficient mice revealed extremely low levels of IGF-1, as compared with normal, control animals. IGF-1 strongly inhibits apoptosis in lymphocytes, and the age-related reduction in lymphocyte production by the thymus has been ascribed to a decline in IGF-1 levels with age8. This finding presents us with a paradox, because reduction of IGF-1 signalling is linked with a longer, not a shorter lifespan. How can these results be reconciled?
Life extension conferred by dampening IGF-1 signalling is likely to represent a ********************bolic switch in the use of resources, away from growth and reproduction with the inevitable side effect of DNA damage, towards increased maintenance and repair5. Although defects in insulin signalling in mammals cause diabetes, reduced IGF-1 signalling extends life in mice9. The attenuation of IGF-1 signalling in the SIRT6-deficient mice may indicate that this switch has been activated as a means to limit the onslaught of spontaneous DNA damage and to upregulate the apoptosis of severely damaged cells. Indeed, modulating IGF-1 signalling, possibly through members of the Sir2 family, may be a general mechanism for coping with environmental stress, including nutrient limitation and genotoxic stress. Interestingly, XpdTTD mutant mice, which harbour a defect in another form of DNA repair known as nucleotide excision repair, display characteristics of accelerated ageing and caloric restriction, suggesting that ********************bolism adjustment might be a general mechanism to deal with genotoxic stress (Fig. 1)10.
Figure 1: Balancing act.

The possible role of SIRT6 and genome maintenance in balancing ageing (blue) and longevity (pink). Although a mechanism is as yet unclear, SIRT6 may act in its pro-longevity role by promoting DNA repair, increasing stress resistance and maintaining ********************bolic homeostasis. The genotoxic stress resulting from its absence may cause a compensatory ********************bolic shift towards reduced insulin-like growth factor (IGF-1) signalling, thereby lowering the production of reactive oxygen species (ROS). The resulting increase in apoptosis could be a cause of the premature ageing symptoms observed by Mostoslavsky et al.1 in mice lacking SIRT6.
High resolution image and legend (90K)



PL1 end part #1

[Preciouslife1]

Part #2

So does SIRT6 connect BER to the IGF-1 signalling pathway? As yet, this is far from clear. For example, neither the nature of the SIRT6 enzymatic activity, nor its potential substrates, is known. Indeed, Mostoslavsky and colleagues' results only indirectly implicate SIRT6 in BER, so although it is reasonable to assume that SIRT6 promotes the access of repair enzymes through chromatin remodelling, there is no direct evidence for this. Also, it is not apparent if and how SIRT6 is involved in regulating the IGF-1 response. Finally, not all degenerative symptoms associated with reduced lifespan necessarily involve the causes that underlie natural ageing. Indeed, the degenerative symptoms observed in SIRT6-deficient mice are far from comprehensive and may well result from developmental defects.
Nonetheless, Mostoslavsky et al.1 provide a potential link in the chain connecting genome instability, ********************bolic effects and ageing. Ultimately, this may lead to ways of exploiting the role of Sir2 family members in genome maintenance to silence senescence.

PL1

[Preciouslife1]

Science Tells How Jesus Walked on Water?

The Bible says that Jesus walked on water, but a professor of oceanography at Florida State University in Tallahassee has developed a controversial theory: He claims Christ was actually walking on a floating piece of ice.
The sixth chapter of the Gospel of John tells the story familiar to Christians: When evening came, his disciples went down to the sea, got into a boat and started across the sea to Capernaum. It was now dark, and Jesus had not yet come to them. The sea became rough because a strong wind was blowing. When they had rowed about three or four miles, they saw Jesus walking on the sea and coming near the boat, and they were terrified. But he said to them: "It is I, do not be afraid." (John 6:16-20)
Reuters reports that FSU professor Doron Nof credits this miraculous act to an unusual combination of water and atmospheric conditions in what is now northern Israel that could have led to ice formation on the Sea of Galilee. Using statistical models to examine the dynamics of the Sea of Galilee (now known as Lake Kinneret) and records of surface temperatures of the Mediterranean Sea, Nof determined there was a period of cooler temperatures in the area between 1,500 and 2,600 years ago. He says this could have included the time in which Jesus lived.
Had the temperature dropped below freezing, it could have created ice to form in the freshwater lake that was then called the Sea of Galilee. And that ice would have been thick enough to support the weight of a man. What's more, it might have been impossible for distant observers--especially in the dark as the Gospel of John reports--to see that it was actually ice surrounded by water and not just water.
Nof calls this a "possible explanation" of how Jesus walked on water. "If you ask me if I believe someone walked on water, no, I don't," Nof told Reuters. "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."
Nof acknowledges he has received hate mail for espousing this theory. The study findings were published in the Journal of Paleolimnology.

PL1 ~ And not a religious nor political statement by me fyi.

[Preciouslife1]

Hubble Finds 'Tenth Planet' Is Slightly Larger Than Pluto

NASA's Hubble Space Telescope has resolved the "tenth planet," nicknamed "Xena" for the first time, and has found that it is only just a little larger than Pluto.

NASA's Hubble Space Telescope has resolved the "tenth planet," nicknamed "Xena," for the first time and has found that it is only just a little larger than Pluto. (Credit: NASA, ESA, and M. Brown (California Institute of Technology))
Polaris 60mm AZ-D Telescope. Get It Free By Completing Survey!
Telescope.Computer-Offer.com



Though previous ground-based observations suggested that Xena was about 30 percent greater in diameter than Pluto, Hubble observations taken on Dec. 9 and 10, 2005, yield a diameter of 1,490 miles (with an uncertainty of 60 miles) for Xena. Pluto's diameter, as measured by Hubble, is 1,422 miles.
"Hubble is the only telescope capable of getting a clean visible-light measurement of the actual diameter of Xena," said Mike Brown, planetary scientist at the California Institute of Technology in Pasadena, Calif. Brown's research team discovered Xena, and their results have been accepted for publication in the Astrophysical Journal.
It only required a couple of Hubble images to nail Xena's diameter. Located 10 billion miles away, but with a diameter that is a little more than half the width of the United States, the object is 1.5 pixels across in Hubble's view. That's enough to precisely make a size measurement.
Because Xena is smaller than earlier thought, but comparatively bright, it must be one of the most reflective objects in the solar system. The only object more reflective is Enceladus, a geologically active moon of Saturn whose surface is continuously recoated with highly reflective ice by active geysers.
Xena's bright reflectivity is possibly due to fresh methane frost overlying the surface. It is possible that Xena had an atmosphere when it was closer to the Sun, but "froze out" at its current large distance, and material settled on its surface as frost.
Another possibility is that Xena is also continuously leaking methane gas from its warmer interior. When this methane makes it to the cold surface it immediately freezes solid, covering craters and other features to make this Kuiper Belt object (KBO) uniformly bright to Hubble's telescopic eye.
Xena is officially catalogued as 2003 UB313. Its orbital period is about 560 years, and the KBO is now very close to aphelion (the point on its orbit that is farthest from the Sun).
Brown next plans to use Hubble and other telescopes to study other recently discovered KBOs that are almost as large as Pluto and Xena. The Kuiper Belt is a vast ring of primordial icy comets and larger bodies encircling Neptune's orbit.
Finding that the largest known KBO is a virtual twin to Pluto may only further complicate the debate about whether to categorize the large icy worlds that dwell in the Kuiper Belt as planets. If Pluto were considered to be the minimum size for a planet, then Xena would fulfill this criterion, too.

PL1

It is my opinion that science answers "how" while faith provides the "why." This is not to equate faith with religious zealotry; the two should not be confused, although admitedly there are too many who claim their motivation to be the former when indeed it is the latter. For myself, I have not run across any scientific breakthrough that cannot work into my own catholic faith so long as my focus is based on intelligent analysis of the design of the universe.

[Preciouslife1]

OHH Man, now what do we do now???

http://www.shibumi.org/eoti.htm








guess we have to go outside and act like "normal" people now!!!

PL1

[Preciouslife1]

Incredible sidewalk art not to be believed. I registered to the site and it was quick and easy, and is linked to the Davinci Institute too...

http://www.impactlab.com/modules.ph...rticle&sid=7567
__________________

PL1 on the Mark


Fear is the path to the dark side. Fear leads to anger. Anger leads to hate. Hate leads to suffering.”


Never believe that a few caring people can't change the world. For, indeed, that's all who ever have.~ Margaret Mead

[Preciouslife1]

Comet break-up puts on sky show

The comet is breaking into fragments. (Image: European Southern Observatory)

A comet is delighting astronomers with a marvellous night-time display as it makes a near pass of the Earth.
The ball of ice, rock and dust has broken up into more than 60 pieces; two of the larger fragments are visible through binoculars or small telescopes.
At its closest approach this weekend, the comet will be some 10 million km (six million miles) from the Earth.
Continued disintegration means this may be the last swing around the Sun for Comet 73P/Schwassmann-Wachmann 3.
Good chance
Dr Robert Massey, of the Royal Observatory, Greenwich, said the optimum time to see the comet in the UK was between 0000 and 0100 BST, away from the lights of the city.
He said observers should look East with binoculars and use a sky chart to get the best chance of a sighting.

Click here to see the comet's path across the sky

"It's a rare opportunity for members of the public to see what is a pretty dramatic phenomenon," he said.
"Watching a comet break up is not something the public gets to do that often."
Rapid demise
Comet 73P/Schwassmann-Wachmann 3 was discovered in 1930 by German astronomers. It orbits the Sun every 5.4 years.
It has an elongated path that swings out towards Jupiter then back towards the Earth and the Sun.
All periodic comets like this one are doomed to disintegrate and die. Astronomers first noticed in 1995 that Comet 73P had split into several chunks.
When it moved back towards the Sun in March this year, seven fragments were observed, of which two - B and C - were particularly bright. The break-up has continued apace.
Fragments B and C are expected to be visible between 11 and 14 May with binoculars and perhaps even the unaided eye.
If they fall apart still further - ejecting light-reflective material from the heart of the comet - they will be a magnificent sight in the night sky.
COMET 73P/SCHWASSMANN-WACHMANN 3 IN THE MAY SKY

To get the best view of the sky always move away from the city
The fragments are now moving across the Cygnus constellation
Look East and high with binoculars; fragment B has been brightest