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According to Analytical Graphics, Inc. (AGI), the Center for Space Standards and Innovation (CSSI) has determined that on January 22, 2013 debris from the Chinese FENGYUN 1C collided with Russia's BLITS satellite. The FENGYUAN 1C is the satellite that was destroyed by China on January 11, 2007 in a test of an anti-satellite missile. The collision changed the orbit of the Russian satellite, along with its spin velocity and attitude. The animation above is from AGI and it depicts the event.
The collision wasn't reported until February 4, 2013 when engineers at the Institute for Precision Instrument Engineering (IPIE) in Moscow reported to CSSI a significant change in the orbit for their BLITS satellite. BLITS is tracked to high precision by the International Laser Ranging Service (ILRS), and IPIE had detected a sudden decrease of 120 meters in the semi-major axis of its orbit and a change in its spin velocity and attitude.
© Shutterstock
According to The Huffington Post, the study demonstrated that melittin, a toxin found in the venom, can help smaller particles penetrate the protective envelope around HIV, and subsequently destroy it.
"We are attacking an inherent physical property of HIV," said research instructor Dr. Joshua L. Hood, one of the study's authors, in a release. "Theoretically, there isn't any way for the virus to adapt to that. The virus has to have a protective coat, a double-layered membrane that covers the virus."
© Stuart N. Thomson/UA department of geosciencesThis 3-D reconstruction of the topography hidden under Antarctica's two-mile-thick coating of ice was made using data from radar surveys.
Like Alaska's mighty Yukon, a broad river once flowed across Antarctica, following a gentle valley shaped by tectonic forces at a time before the continent became encased in ice. Understanding what happened when rivers of ice later filled the valley could solve certain climate and geologic puzzles about the southernmost continent.
The valley is Lambert Graben in East Antarctica, now home to the world's largest glacier. Trapped beneath the ice, the graben (which is German for ditch or trench) is a stunning, deep gorge. But before Antarctica's deep freeze 34 million years ago, the valley was relatively flat and filled by a lazy river, leaving a riddle for geologists to decode: How did Lambert Graben get so steep, and when was it carved?
© UNSWProfessor Merlin Crossley is dean of science at University of New South Wales.
Professor Merlin Crossley, of the University of New South Wales, and his international team studied the blood-clotting disorder, hemophilia B Leyden, which is unusual because symptoms improve after puberty.
The results, published in The American Journal of Human Genetics, explain how more than half of the cases of this rare, hereditary bleeding disorder occur, and could help improve understanding of other conditions such as thrombosis.
The find also demonstrates the importance of curiosity-driven research, says Crossley, who is dean of science at UNSW.
"Science is advanced by people who get caught up in puzzles that are important to them and they never forget them. Curious investigators never give up," he says.
Crossley spotted the final genetic clue two years ago, when he was on an aeroplane, marking a young researcher's PhD project. Data in the thesis reminded him of his own PhD project on hemophilia B Leyden, carried out at the University of Oxford in the late 1980s.
1 of the most commonly studied animals may shed light on how the brain controls social interactions.
Sniffing, a common behavior in dogs, cats and other animals, has been observed to also serve as a method for rats to communicate - a fundamental discovery that may help scientists identify brain regions critical for interpreting communications cues and what brain malfunctions may cause some complex social disorders.
Researchers have long observed how animals vigorously sniff when they interact, a habit usually passed off as simply smelling each other. But Daniel W. Wesson, PhD, of Case Western Reserve University School of Medicine, whose research is published in Current Biology, found that rats sniff each other to signal a social hierarchy and prevent aggressive behavior.
Wesson, who drew upon previous work showing that, similar to humans, rodents naturally form complex social hierarchies, used wireless methods to record and observe rats as they interacted. He found that, when two rats approach each other, one communicates dominance by sniffing more frequently, while the subordinate signals its role by sniffing less. Wesson found that if the subordinate didn't do so, the dominant rat was more likely to become aggressive to the other.
Sniffing, a common behavior in dogs, cats and other animals, has been observed to also serve as a method for rats to communicate - a fundamental discovery that may help scientists identify brain regions critical for interpreting communications cues and what brain malfunctions may cause some complex social disorders.
Researchers have long observed how animals vigorously sniff when they interact, a habit usually passed off as simply smelling each other. But Daniel W. Wesson, PhD, of Case Western Reserve University School of Medicine, whose research is published in Current Biology, found that rats sniff each other to signal a social hierarchy and prevent aggressive behavior.
Wesson, who drew upon previous work showing that, similar to humans, rodents naturally form complex social hierarchies, used wireless methods to record and observe rats as they interacted. He found that, when two rats approach each other, one communicates dominance by sniffing more frequently, while the subordinate signals its role by sniffing less. Wesson found that if the subordinate didn't do so, the dominant rat was more likely to become aggressive to the other.
© L.A. Cicero
It's easy to forget that these brain images aren't real snapshots of brain activity. Instead, each picture is the result of many layers of analysis and interpretation, far removed from raw data.
"It's just one representation of brain activity," said Matthew Sacchet, a PhD student in the Neurosciences Program at the Stanford School of Medicine. "As you process the data, it can change."
Sacchet works in the lab of Stanford psychology Associate Professor Brian Knutson, who studies reward processing in a small area of the brain known as the nucleus accumbens. Precisely how that structure activates is at the heart of an ongoing debate about reward circuits - a subject that holds relevance for our understanding of everything from addiction to financial risk-taking.
Unfortunately, according to a paper from Knutson and Sacchet, hundreds of research papers on this circuit may be unintentionally biased. When the labs processed their fMRI findings, many used a one-size-fits-all strategy that skewed which regions of the brain appeared to be activating.
"I honestly think most people want good data," said Knutson. "I'm excited that we can make this kind of research more rigorous."
The paper appeared in the journal NeuroImage.
Something unexpected is happening on the sun. 2013 is supposed to be the year of Solar Max, the peak of the 11-year sunspot cycle. Yet 2013 has arrived and solar activity is relatively low. Sunspot numbers are well below their values in 2011, and strong solar flares have been infrequent for many months.
The quiet has led some observers to wonder if forecasters missed the mark. Solar physicist Dean Pesnell of the Goddard Space Flight Center has a different explanation:
The quiet has led some observers to wonder if forecasters missed the mark. Solar physicist Dean Pesnell of the Goddard Space Flight Center has a different explanation:
"This is solar maximum," he suggests. "But it looks different from what we expected because it is double peaked."
© Hyelim ChoThe white arrows highlight infected cells in a mouse brain. Scientists at Washington University School of Medicine in St. Louis have discovered that genetic programming makes some brain cells more resistant to infection.
"The cells that a pathogen infects can be a major determinant of the seriousness of brain infections," says senior author Michael Diamond, MD, PhD, professor of medicine. "To understand the basis of disease, it is important to understand which brain regions are more susceptible and why."
While some brain infections are caused by bacteria, fungi or parasites, often the cause is a virus, such as West Nile virus, herpesvirus or enteroviruses.
For their study, now available online in Nature Medicine, the researchers focused on granule cell neurons, a cell type that rarely becomes infected. They compared gene profiles in granule cells from the cerebellum with the activity in cortical neurons in the cerebral cortex, which are more vulnerable to infection.
The comparison revealed many differences, including a number of genes in cortical neurons that were less well-expressed - meaning that for those specific genes there were fewer copies of mRNA, the molecules that relay genetic information from DNA to the cell's protein-making mechanisms.
The solar system's small bodies have been often in the news lately. There are currently two bright comets in the southern sky, one of which, Comet C/2011 L4 (PANSTARRS) will soon be moving into the northern sky. An asteroid named 2012 DA14 recently passed close to the Earth. There have been two bright meteors in the past month, one in Russia and one in California. But these types of bodies aren't the smallest relics of the solar system visible from here on Earth. A rare and hard to spot phenomenon called the Zodiacal Light, made from tiny solar system dust particles, can only be sighted under the best conditions. And a good time to view it is coming up soon.
© European Southern Observatory/Flickr
© X-ray: NASA/CXC/Rutgers/G.Cassam-Chenaï, J.Hughes et al.; Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell; Optical: Middlebury College/F.Winkler, NOAO/AURA/NSF/CTIO Schmidt & DSS
Researchers with the Harvard-Smithsonian Center for Astrophysics (CfA) have announced in a new paper that one such event has been discovered.
Supernovae are split into sub-types. While some of them can be traced to the collapse of massive stars, others arise from the accretion of mass onto a tiny white dwarf, barely more massive than our Sun, yet far more dense. The exact manner in which the supernova proceeds can further subdivide supernovae into different classes.
One of the rarest classes is known as Type Ibn. Only five previous events have ever been seen and they were all found in galaxies similar to the Milky Way - young spiral systems with significant ongoing star formation.
The working theory is that such supernovae are the result of the collapse of massive stars that had ejected massive amounts of helium prior to their collapse. The catch is such high mass stars - those on the order of 100 solar masses - do not live very long. Because of the immense gravitational pressure on their cores, the rate of fusion needed to sustain hydrostatic equilibrium is immense and they quickly burn through their nuclear fuel.
Comment: It's interesting that they don't even entertain the possibility that a space rock might have collided with the Russian satellite, especially since they state that "the predicted distance would seem to preclude a collision". Given that fireballs are currently raining down on our planet and given that the International Space Station was hit by a small space rock last year, shouldn't cometary debris at least be on their radar of possible explanations for what happened to these satellites?