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Study Suggests A Supernova Exploded Near Earth About 2.5 Million Years Ago, Possibly Causing An Extinction Event

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Supernovas are amazingly bright explosions of massive stars at the end of their lives. During the gravitational collapse, the outer layers of the star are pushed away, and chemical elements formed inside the dying star are released into space. This cosmic dust rains down onto the Earth continuously, eventually becoming part of sediments deposited in the sea.

Research published in the journal Physical Review Letters used the concentrations of elements formed in an exploding star and preserved in oceanic sediments to hypothesize that a supernova exploded near Earth just 2.5 million years ago.

The authors, led by Dr. Gunther Korschinek from the Technical University of Munich, focused their study on ferromanganese crusts collected in the Pacific Ocean. Ferromanganese crusts form on the bottom of the ocean by layers of iron- and manganese-oxides precipitating out of seawater. The studied samples started to grow some 20 million years ago at depths ranging from 5,200 feet to 3.18 miles (approximately 1.600 to 5.120 meters). The researchers measured the concentrations of iron-60 and manganese-53 isotopes in the hardened crust. They differ from Earth’s most common form of the elements by their varying number of neutrons in the atomic nucleus. Both isotopes are synthesized in large stars shortly before supernova explosions and are unstable, decaying completely after 4 to 15 million years. Their presence in sediment samples is evidence for Earth passing through a cloud of cosmic dust generated by an exploding star in – geologically speaking – recent times.

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Foundation to Fight H-ABC, University of Massachusetts Medical School and Yale University Initiate Gene Therapy Study Targeting Cure for Rare Disease

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ROCKVILLE, Md., Oct. 13, 2020 /PRNewswire/ — Foundation to Fight H-ABC, a non-profit organization dedicated to increasing awareness and driving development of a cure for the degenerative children’s disease, H-ABC, today announced a sponsored research agreement with the University of Massachusetts Medical School and Yale University to advance a targeted gene therapy for H-ABC.

“We have high hopes to quickly prove efficacy with this approach to move research forward and find a permanent cure for this devastating disease,” said Michele Sloan, Co-Founder, Foundation to Fight H-ABC.

H-ABC (hypomyelination with atrophy of the basal ganglia and cerebellum) belongs to a group of conditions called leukodystrophies, diseases that affect the white matter of the brain. These diseases disrupt the growth or maintenance of the myelin sheath, a protective layer that insulates nerve cells and allows for the transmission of messages between cells.

Caused by a mutation in the TUBB4A gene, H-ABC is a rare genetic disorder that affects certain parts of the brain—specifically the basal ganglia and the cerebellum, which control movement. H-ABC targets these important structures, reducing both their size and function. As a result, children who suffer from H-ABC often experience motor problems, cannot walk, talk, or sit on their own. Currently, there is no known cure for this disabling and life-threatening condition.

The teams of Dr. Guangping Gao (University of Massachusetts Medical School) and Dr. Karel Liem (Yale School of Medicine) will combine extensive expertise in the fields of Adeno-associated virus (AAV), a platform for gene delivery for the treatment of a variety of human diseases and H-ABC disease models, to develop AAV vectors to silence or outcompete the mutated TUBB4A gene.

“To date, AAV-based gene delivery system is the vector of choice for in vivo gene therapy of many currently untreatable rare diseases including H-ABC,” said Guangping Gao,

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Black hole-sized magnetic fields could be created on Earth, study says

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Scientists should be able to create magnetic fields on Earth that rival the strength of those seen in black holes and neutron stars, a new study suggests. 

Such strong magnetic fields, which would be created by blasting microtubules with lasers, are important for conducting basic physics, materials science and astronomy research, according to a new research paper authored by Osaka University engineer Masakatsu Murakami and colleagues. The paper was published Oct. 6 in the open-access journal Scientific Reports.

Most magnetic fields on Earth, even artificial ones, are not particularly strong. The magnetic resonance imaging (MRI) used in hospitals typically produces fields of around 1 tesla, or 10,000 gauss. (For comparison, the geomagnetic field that swings compass needles to the north registers between 0.3 and 0.5 gauss.) Some research MRI machines use fields as high as 10.5 tesla, or 105,000 gauss, and a 2018 lab experiment involving lasers created a field of up to about 1,200 tesla, or just over 1 kilotesla. But no one has successfully gone higher than that. 

Related: 9 cool facts about magnets

Now, new simulations suggest that generating a megatesla field — that is, a 1 million tesla field — should be possible. Murakami and his team used computer simulations and modeling to find that shooting ultra-intense laser pulses at hollow tubes just a few microns in diameter could energize the electrons in the tube wall and cause some to leap into the hollow cavity at the center of the tube, imploding the tube. The interactions of these ultra-hot electrons and the vacuum created as the tube implodes leads to the flow of electric current. The flow of electric charges is what creates a magnetic field. In this case, the current flow can amplify a pre-existing magnetic field by two to

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NASA delays commercial crew mission to study Falcon 9 engine issue

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WASHINGTON — NASA is delaying the launch of the first operational SpaceX commercial crew mission to the first half of November to provide more time to review a problem during a recent Falcon 9 launch attempt.

NASA announced Oct. 10 the Crew-1 mission, which was scheduled to launch on a Falcon 9 in the early morning hours of Oct. 31 from the Kennedy Space Center, will now launch no earlier than early to mid-November.

The delay, the agency said, will provide more time for SpaceX “to complete hardware testing and data reviews as the company evaluates off-nominal behavior of Falcon 9 first stage engine gas generators observed during a recent non-NASA mission launch attempt.” NASA did not identify the specific launch attempt in question, but an Oct. 2 launch of a Falcon 9 carrying a GPS 3 satellite was scrubbed just two seconds before liftoff because of SpaceX Chief Executive Elon Musk later described as an “unexpected pressure rise in the turbomachinery gas generator.”

“With the high cadence of missions SpaceX performs, it really gives us incredible insight into this commercial system and helps us make informed decisions about the status of our missions,” Kathy Lueders, NASA associate administrator for human exploration and operations, said in the agency statement. She said an investigation into the problem is ongoing “and we should be a lot smarter within the coming week.”

Both the Crew-1 and the GPS 3 missions are using new Falcon 9 first stages that have not previously launched. After the GPS 3 scrub, SpaceX successfully launched another Falcon 9 Oct. 6 carrying 60 Starlink satellites using a booster making its third flight. SpaceX has yet to reschedule the GPS 3 launch.

NASA said the issue with the Crew-1 mission will not delay another Falcon 9 launch, of the Sentinel-6

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Climate patterns linked in Amazon, North and South America, study shows

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amazon rainforest
Credit: CC0 Public Domain

University of Arkansas researchers have established a link between climate patterns in the Amazon and large parts of North and South America using their newly developed tree-ring chronology from the Amazon River basin.


The discovery helps researchers better understand large-scale climate extremes and the impact of the El Niño phenomenon.

Tree growth is a well-established climate proxy. By comparing growth rings in Cedrela odorata trees found in the Rio Paru watershed of the eastern Amazon River with hundreds of similar chronologies in North and South America, scientists have shown an inverse relationship in tree growth, and therefore precipitation patterns, between the areas. Drought in the Amazon is correlated with wetness in the southwestern United States, Mexico and Patagonia, and vice versa.

The process is driven by the El Niño phenomenon, which influences surface-level winds along the equator, researchers said. El Niño is the name given to a large-scale irregularly occurring climate pattern associated with unusually warm water in the Pacific Ocean.

“The new Cedrela chronologies from the Amazon, when compared with the hundreds of tree-ring chronologies in temperate North and South America, document this Pan American resonance of climate and ecosystem extremes in the centuries before widespread deforestation or human-caused climate change,” said Dave Stahle, Distinguished Professor of geosciences and first author of a study documenting the findings in the journal Environmental Research Letters.

Credit: University of Arkansas

The connection was not documented until researchers at the University of Arkansas Tree Ring Laboratory, along with colleagues from Brazil and Argentina, developed rainfall reconstructions from growth rings in Cedrela trees. Most rainfall records in the Amazon only date back about 70 years, but Cedrelas live for 200 to 300 years, providing valuable rainfall proxies that pre-date human-influenced climate change. Their work in the Amazon is documented

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