Science & TechnologyS


Chalkboard

Atomic-Resolution View of a Receptor Reveals How Stomach Bacterium Avoids Acid


ScienceDaily
Fri, 15 Jun 2012 17:02 UTC
Image
© Ímage courtesy of University of OregonAtomic-resolution view of a receptor reveals how stomach bacterium avoids acid.
University of Oregon scientists have discovered how the bacterium Helicobacter pylori navigates through the acidic stomach, opening up new possibilities to inactivate its disease-causing ability without using current strategies that often fail or are discontinued because of side effects.

Their report -- online ahead of regular publication July 3 in the journal Structure -- unveils the crystal structure of H. pylori's acid receptor TlpB. The receptor has an external protrusion, identified as a PAS domain, bound by a small molecule called urea and is poised to sense the external environment. TlpB is the first bacterial chemoreceptor of known function shown by crystallography to contain an extracellular PAS domain, the researchers reported.

"It is a beautiful structure, and this domain has never been seen before in this class of proteins," said co-author S. James Remington, professor of physics and member of the UO Institute of Molecular Biology. Captured at the atomic resolution of 1.38 angstroms, it is the first new, significant structural view in 20 years of the class of receptors used by bacteria to navigate their chemical environment.
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Sun

Solar storms on the way

Alan Boyle
MSNBC
Thu, 14 Jun 2012 20:00 UTC
Image
© AIA/LMSAL/NASAA color-coded image from the Atmospheric Imaging Assembly on NASA's Solar Dynamics Observatory highlights the solar flare thrown off from the sun's disk today in shades of gold and yellow.
For the second day in a row, the sun has sent a blast of electrically charged particles toward Earth - and according to SpaceWeather.com, that means we're in for a double shot of geomagnetic activity early Saturday. But not to worry: The most noticeable effect of the twin M-class blasts should be heightened auroral displays.

Both of the coronal mass eruptions, or CMEs, originated in a sunspot region known as AR1504, which is currently pointing in Earth's direction. AR1504 has been shooting off a series of flares in recent days, including an M1.2-class flare on Wednesday and an M1.5 today. None of the flares have approached the X-class level, which would have the potential for significant disruptions in power grids or satellite-based communication.
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SpaceWeather.com projects that the CMEs thrown off by those two flares will merge into one wave of particles that's due to hit Earth's magnetic field around 6:16 a.m. ET Saturday. The National Oceanic and Atmospheric Administration's Space Weather Prediction Center, meanwhile, predicts that the CME will arrive "late on 16 June." The prediction center noted that today's flare sparked a minor radio blackout and "has the potential" to produce more such storms.

Comment: Is Solar and Cosmic Radiation Playing Havoc With Life on Planet Earth?

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Satellite

Humanity escapes the solar system: Voyager 1 signals that it has reached the edge of interstellar space - 11billion miles away

Eddie Wrenn
Daily Mail
Thu, 14 Jun 2012 16:53 UTC
With absolutely no attempt at hyperbole at all, it is fair to say that this is one of - if not the - biggest achievement of the human race.
Image
© UnknownThe probe is still detecting 'spikes' in the intensity of cosmic ray electrons - which lead scientists to think it's still within the 'heliosheath', the very outer edge of our solar system.
For, as we speak, an object conceived in the human mind, and built by our tools, and launched from our planet, is sailing out of the further depths of our solar system - and will be the first object made by man to sail out into interstellar space.

The Voyager 1, built by Nasa and launched in 1977 has spent the last 35 years steadily increasing its distance from Earth, and is now now 17,970,000,000km - or 11,100,000,000miles - away, travelling at 10km a second.

Indications over the last week implies that Voyager 1 is now leaving the heliosphere - the last vestige of this solar system.
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Sun

2nd Coronal Mass Ejection Heading Our Way June 16


Spaceweather.com
Thu, 14 Jun 2012 15:38 UTC
On June 14th, for the second day in a row, sunspot AR1504 erupted and hurled a CME toward Earth. The fast-moving (1360 km/s) cloud is expected to hit our planet's magnetic field on June 16th at 14:00 UT, possibly sparking a geomagnetic storm. High-latitude sky watchers should be alert for auroras.
Image
© SOHO
Active sunspot AR1504 erupted on June 13th at 1319 UT, producing a long-duration M1-flare and hurling a CME into space. According to analysts at the Goddard Space Weather Lab, the cloud will deliver a glancing blow to three planets: Venus on June 15th, Earth on June 16th, and Mars on June 19th. This animation shows the likely progression of the cloud.

Animation
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Question

Were Neanderthals Europe's First Cave Artists?

Stephanie Pappas
LiveScience
Thu, 14 Jun 2012 13:00 UTC
Cave Paintings
© Pedro SauraThe Panel of Hands at El Castillo Cave in Spain. Researchers have now dated one of these hand stencils back to 37,300 years ago.

A series of cave paintings in Spain are thousands of years older than scientists realized, raising speculation - but no proof - that Neanderthals could have been the earliest wall artists in Europe.

The oldest image, a large red disk on the wall of El Castillo cave in northern Spain, is more than 40,800 years old, according to an advanced method that uses natural deposits on the surfaces of the paintings to date their creation. The new findings, detailed in the June 15 issue of the journal Science, make the paintings the oldest reliably dated wall paintings ever.

They also push the art back into a time when early modern humans, who looked anatomically like us, co-existed with their Neanderthal cousins in Europe. Some researchers think the paintings may predate European Homo sapiens, suggesting that the art may not be the work of modern humans at all.

"It would not be surprising if the Neanderthals were indeed Europe's first cave artists," said study researcher Joao Zilhao, a professor at the Institució Catalana de Recerca i Estudis Avançats (ICREA) at the University of Barcelona.
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Telescope

Ghostly Evidence: Does this picture show traces of a universe that existed before the Big Bang?

Eddie Wrenn
Daily Mail
Mon, 11 Jun 2012 11:26 UTC
A renowned scientist says he has spotted evidence that a universe existed before the Big Bang.

Professor Roger Penrose from Oxford University says concentric circles discovered in the background microwaves of the universe provides evidence of events that took place before the universe came into being.

The cosmic microwave offers us a ghostly look at the the universe just 300,000 years after the Big Ban' - a microscopic amount of time compared to the universe's estimated age of 13.7billion years.

The research by Penrose, who was awarded the 1988 Wolf Prize along with Stephen Hawkings for adding to our cosmic knowledge, adds evidence to the theory that the universe has expanded ('the Big Bang') and contracted ('the Big Crunch') many times.

big bang astronomy
© UnknownA map of the cosmic background radiation (CMB) in the universe with circles which may signify events that took place before the Big Bang
The cosmic radiation background (CMB) is believed to have cooled to a temperature of -270C in the near 14 billion years since the birth of the universe.

Stars and galaxies started to form around 300 million years later. Our Sun was born around five billion years ago, and life first appeared on the Earth around 3.7 billion years ago.
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Fish

Where Humans Split from Sharks: Common Ancestor Comes Into Focus


Science Daily
Thu, 14 Jun 2012 04:41 UTC
Humans and Sharks
© Megan Doherty/University of ChicagoThese are various latex molds taken from the fossil of Acanthodes bronni.
The common ancestor of all jawed vertebrates on Earth resembled a shark, according to a new analysis of the braincase of a 290-million-year-old fossil fish that has long puzzled paleontologists.

New research on Acanthodes bronni, a fish from the Paleozoic era, sheds light on the evolution of the earliest jawed vertebrates and offers a new glimpse of the last common ancestor before the split between the earliest sharks and the first bony fishes -- the lineage that would eventually include human beings.

"Unexpectedly, Acanthodes turns out to be the best view we have of conditions in the last common ancestor of bony fishes and sharks," said Michael Coates, PhD, professor of organismal biology and anatomy at the University of Chicago and senior author of the study published in Nature. "Our work is telling us that the earliest bony fishes looked pretty much like sharks, and not vice versa. What we might think of as shark space is, in fact, general modern jawed vertebrate space."
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Better Earth

Conundrum: 10m years ago there was less CO2 - but the Earth was WARMER

Lewis Page
The Register
Thu, 07 Jun 2012 17:37 UTC
Miocene Mammals
© UnknownMiocene mammals
Warmth and carbon 'decoupled': 'A surprising finding'

Scientists are puzzled today by the discovery that millions of years ago levels of carbon dioxide in the atmosphere were lower - and yet, temperatures were higher than today's.

The revelations come in a new paper just published by hefty boffinry mag Nature, in which geoscientists probed the temperatures experienced by the Earth during the Miocene era - the period from 12 to 5 million years ago. The boffins write:
Comparatively little is known about the climate of the late Miocene (~12 - 5 Myr ago), an interval with pCO2 values of only 200 - 350 parts per million by volume but nearly ice-free conditions in the Northern Hemisphere and warmer-than-modern temperatures on the continents.
Today CO2 stands at 390 parts per million, well up on Miocene levels, and yet the planet - and in particular its oceans, engines of the climate - are significantly cooler. This wasn't known until now, as it is only recently that the team led by Jonathan P LaRiviere of UC Santa Cruz have looked into the matter. A statement from San Francisco State uni, where another of the scientists works, explains the methods used:
They used an organic compound called unsaturated alkenone as their "fossil thermometers." The compound is produced by tiny phytoplankton and preserved in cores of ocean sediment drawn from the mid-latitude Pacific Ocean basin. Ratios of the compound preserve a record of the water temperature in which the plankton lived.
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Meteor

Bright Near-Earth Asteroid 2012 LZ1

Nick Howes, Ernesto Guido & Giovanni Sostero
Remanzacco Observatory
Wed, 13 Jun 2012 17:42 UTC
M.P.E.C. 2012-L30 issued on 2012, June 12 announces the discovery of a new Near-Earth object (discovery magnitude 15.1) by R. H. McNaught in the course of the Siding Spring Survey on CCD images taken with the 0.5-m Uppsala Schmidt. This new asteroid has been designated 2012 LZ1.

2012 LZ1 is a large Near-Earth Object (NEO) approximately 300-700 metres in size (H=19.7) and it has been classified as a PHA (Potentially Hazardous Asteroid). PHA are asteroids larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.

2012 LZ1 will be at its closest approach with Earth at ~14 lunar-distances (0.036 AU) on June 14, 23:10 UT.

We have been able to follow-up this object from the Haleakala-Faulkes Telescope North on 2012, June 13.5, through a 2.0-m f/10.0 Ritchey-Chretien + CCD.

At the moment of our images from FTN, "2012 LZ1" was moving at about ~33.64 "/min and its magnitude was ~14.2. At the moment of its close approach it will be bright as magnitude ~13.9 and moving at ~38.80 "/min. Anyway, for the following days, it will be bright enough to be imaged by most amateur telescopes. In fact it will drop below magnitude 17 on June 23.

Below you can see a 10-second exposure of 2012 LZ1 obtained with the FTN. The asteroid is slighlty trailed in the image due to its fast speed. Click on it for a bigger version.

Asteroid 2012 LZ1_1
© Remanzacco Observatory
Here you can see an animation showing the motion of 2012 LZ1. Each frame is a 10-second exposure through the FTN 2.0-m telescope.
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Meteor

Huge Asteroid to Fly by Earth Thursday

Mike Wall
Space.com
Wed, 13 Jun 2012 14:01 UTC
Asteroid 2012 LZ1
© Slooh Space CameraA look at where near-Earth asteroid 2012 LZ1 will appear in the sky on the evening of June 14, 2012.
An asteroid the size of a city block is set to fly by Earth Thursday (June 14), and you may be able to watch it happen live.

The near-Earth asteroid 2012 LZ1, which astronomers think is about 1,650 feet (500 meters) wide, will come within 14 lunar distances of Earth Thursday evening. While there's no danger of an impact on this pass, the huge space rock may come close enough to be caught on camera.

That's what the team running the Slooh Space Camera thinks, anyway. The online skywatching service will train a telescope on the Canary Islands on 2012 LZ1 and stream the footage live, beginning at 8:00 p.m. EDT Thursday (0000 GMT Friday).

You can watch the asteroid flyby on Slooh's website, found here.

2012 LZ1 just popped onto astronomers' radar this week. It was discovered on the night of June 10-11 by Rob McNaught and his colleagues, who were peering through the Uppsala Schmidt telescope at Siding Spring Observatory in Australia.
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