2015년 1월 29일 목요일

ScienceDaily: Top Science News

Posted: 28 Jan 2015 01:05 PM PST
Paleontologists have discovered a new species of a long-necked dinosaur from a skeleton found in China. The new species belongs to a group of dinosaurs called mamenchisaurids, known for their extremely long necks sometimes measuring up to half the length of their bodies. Most sauropods, or long-necked dinosaurs, have necks only about one third the length of their bodies.
    
Posted: 28 Jan 2015 01:05 PM PST
Two phenomena known to inhibit the potential habitability of planets -- tidal forces and vigorous stellar activity -- might instead help chances for life on certain planets orbiting low-mass stars, astronomers have found.
    
Posted: 28 Jan 2015 12:22 PM PST
Gullies carved into impact craters on Mars provide a window into climate change on the Red Planet. A new analysis suggests Mars has undergone several ice ages in the last several million years. The driver of these climate swings is likely the Red Planet's wobbly axis tilt.
    
Posted: 28 Jan 2015 12:21 PM PST
From the subarctic Pacific to the Chilean margins, extreme oxygen loss is stretching from the upper ocean to about 3,000 meters deep. In some oceanic regions, such loss occurred within 100 years or less, according to a new study.
    
Posted: 28 Jan 2015 11:16 AM PST
A new study shows genomic differences in head and neck cancers caused by infection with the human papillomavirus. In addition, researchers have uncovered new smoking-related cancer subtypes and potential new drug targets, and found numerous genomic similarities with other cancer types. Together, this study's findings may provide detailed explanations of how HPV infection and smoking play roles in head and neck cancer risk and disease development, and offer potential diagnostic and treatment directions.
    
Posted: 28 Jan 2015 11:16 AM PST
Ever since Einstein proposed his special theory of relativity in 1905, physics and cosmology have been based on the assumption that space looks the same in all directions -- that it's not squeezed in one direction relative to another. A new experiment by physicists used partially entangled atoms -- identical to the qubits in a quantum computer -- to demonstrate more precisely than ever before that this is true: to one part in a billion billion.
    
Posted: 28 Jan 2015 11:16 AM PST
Earth's magnetic field shields the life on our planet's surface from cosmic rays. It is generated by turbulent motions of liquid iron in Earth's core. Iron is a metal, which means it can easily conduct a flow of electrons. New findings show that a missing piece of the traditional theory explaining why metals become less conductive when they are heated was needed to complete the puzzle of this field-generating process.
    
Posted: 28 Jan 2015 11:14 AM PST
Women whose bodies have high levels of chemicals found in plastics, personal-care products, common household items and the environment experience menopause two to four years earlier than women with lower levels of these chemicals, according to a new study.
    
Posted: 28 Jan 2015 10:13 AM PST
The discovery of a 55,000-year-old partial skull in Northern Israel provides new insights into the migration of modern humans out of Africa. A key event in human evolution was the expansion of modern humans of African origin across Eurasia, replacing all other forms of hominin (humans and their predecessors), around 40,000-60,000 years ago. However, due to the scarcity of human fossils from this period, these ancestors of all present-day non-African modern populations have largely remained a mystery. Now, researchers describe a partial skull that dates to around 55,000, which was found at Manot Cave in Israel's Western Galilee.
    
Posted: 28 Jan 2015 09:54 AM PST
The two hemispheres of Mars are more different from any other planet in our solar system. Non-volcanic, flat lowlands characterize the northern hemisphere, while highlands punctuated by countless volcanoes extend across the southern hemisphere. Although theories and assumptions about the origin of this so-called and often-discussed Mars dichotomy abound, there are very few definitive answers. Geophysicists are now providing a new explanation.
    
Posted: 28 Jan 2015 08:40 AM PST
Genetic variations associated with some modern maladies are extremely old, scientists have discovered, predating the evolution of Neanderthals, Denisovans (another ancient hominin) and contemporary humans.
    
Posted: 28 Jan 2015 06:35 AM PST
How do you make an optical fiber transmit light only one way? Researchers have experimentally demonstrated, for the first time, the phenomenon of Brillouin Scattering Induced Transparency (BSIT), which can be used to slow down, speed up, and block light in an optical waveguide. The BSIT phenomenon permits light to travel in the forward direction while light traveling in the backward direction is strongly absorbed. This non-reciprocal behavior is essential for building isolators and circulators.
    
Posted: 28 Jan 2015 06:34 AM PST
Researchers have made a surprising discovery in the aquifers beneath the Western Australian desert, which challenges the traditional Darwinian view of evolution. They have discovered that a species of blind predatory water beetles -- living underground for millions of years -- express vision genes (opsin) which are usually only found in species with eyes.
    
Posted: 27 Jan 2015 07:03 AM PST
Stimulation of the hypothalamus completely reverses learning and memory deficits caused by brain lesions in rats, according to a first time discovery. The research has also served to study the mechanisms through which this recovery occurs, suggesting that the stimulation of the hypothalamus activates several regions of the brain, especially the memory systems, which offer compensatory effects.
    
Posted: 21 Jan 2015 10:51 AM PST
It's not surprising that our memories of highly emotional events, such as 9/11 or the birth of a child, are quite strong. But can these events change our memories of the past? Researchers report that emotional learning can lead to the strengthening of older memories.
    





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