Human behaviour is influenced by many things, most of which remain unconscious to us. One of these is a phenomenon known among perception psychologists as "pseudo-neglect." This refers to the observation that healthy people prefer their left visual field to their right and therefore devide a line regularly left of centre.
A study published on Friday, January 10, in the online magazine PLOS ONE now shows for the first time what effect this inconspicuous deviation had in the prehistoric past. A Slovak-German research team has investigated the alignment of early Neolithic houses in Central and Eastern Europe. Scientists of the Collaborative Research Centre (CRC) "Scales of Transformation" of Kiel University (CAU) and the Slovakian Academy of Sciences were able to prove that the orientation of newly built houses deviated by a small amount from that of existing buildings and that this deviation was regularly counterclockwise.
Archaeologist Dr. Nils Müller-Scheeßel, who coordinated the study within the CRC, says: "Researchers have long assumed that early Neolithic houses stood for about a generation, i.e. 30 to 40 years, and that new houses had to be built next to existing ones at regular intervals. By means of age determination using the radiocarbon method, we can now show that the new construction was associated with a barely perceptible rotation of the house axis counterclockwise. We see "Pseudoneglect" as the most likely cause of this."
This insight was made possible by the interpretation of one of the fastest growing archaeological data sets at present, namely the results of geophysical magnetics measurements. Differences in the earth's magnetic field are used to visualise archaeological features lying underground. Early Neolithic house ground plans belong to the best identifiable types of features.
"In recent years, we have discovered hundreds of Early Neolithic houses in our field of work in southwestern Slovakia using geophysical prospection methods. Excavating all these houses is neither possible nor desirable for reasons of monument conservation. The possibility of using "Pseudoneglect" to bring the houses into a relative sequence without excavation and thus to break down the settlement activity of an entire small region raises our research to a completely new level," says Mister Müller-Scheeßel enthusiastically. "Absolute dating using scientific methods must of course confirm the basic trend in every case."
Read more at Science Daily
Jan 11, 2020
African grey parrots spontaneously 'lend a wing'
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| African grey parrots |
"We found that African grey parrots voluntarily and spontaneously help familiar parrots to achieve a goal, without obvious immediate benefit to themselves," says study co-author Désirée Brucks of the Max Planck Institute for Ornithology, Germany.
Parrots and crows are known for having large brains relative to the size of their bodies and problem-solving skills to match. For that reason, they are sometimes considered to be "feathered apes," explain Brucks and study co-author Auguste von Bayern.
However, earlier studies showed that, despite their impressive social intelligence, crows don't help other crows. In their new study, Brucks and von Bayern wondered: what about parrots?
To find out, they enlisted several African grey parrots and blue-headed macaws. Both parrot species were eager to trade tokens with an experimenter for a nut treat. But, their findings show, only the African grey parrots were willing to transfer a token to a neighbor parrot, allowing the other individual to earn a nut reward.
"Remarkably, African grey parrots were intrinsically motivated to help others, even if the other individual was not their friend, so they behaved very 'prosocially,'" von Bayern says. "It surprised us that 7 out of 8 African grey parrots provided their partner with tokens spontaneously -- in their very first trial -- thus without having experienced the social setting of this task before and without knowing that they would be tested in the other role later on. Therefore, the parrots provided help without gaining any immediate benefits and seemingly without expecting reciprocation in return."
Importantly, she notes, the African grey parrots appeared to understand when their help was needed. When they could see the other parrot had an opportunity for exchange, they'd pass a token over. Otherwise, they wouldn't.
The parrots would help out whether the other individual was their "friend" or not, she adds. But, their relationship to the other individual did have some influence. When the parrot in need of help was a "friend," the helper transferred even more tokens.
The researchers suggest the difference between African greys and blue-headed macaws may relate to differences in their social organization in the wild. Despite those species differences, the findings show that helping behavior is not limited to humans and great apes but evolved independently also in birds.
Read more at Science Daily
Jan 10, 2020
Global warming is the kindling that caused extensive wildfire
In November of last year, the wildfire that started in California, U.S.A burned areas that amount about the size of Seoul and destructed over 500 buildings for two weeks. In 2018, six fires started simultaneously in southern California and spread out to the neighboring areas, burning total of 405 km2 with 86 fatalities and 200,000 victims for three days. Also, large-scale wildfires often occur in the northern inland of Russia. The forest fire occurred in July 2018 burned the total area of 3,211 km2 which is 5.3 times bigger than the city of Seoul and, the wildfire, in May 2019, started to spread out and burned down even greater land. So far, extensive wildfires such as the mentioned events are believed to be mostly caused by dry wind, however, the recent study explains that global warming is the kindling that starts such fires.
Jong-Seong Kug, a professor of Division of Environmental Engineering at POSTECH and Jin-Soo Kim, a postdoctoral researcher of University of Edinburgh jointly collaborated with Su-Jong Jeong of Seoul National University, Hotaek Park of Japan Agency for Marine-Earth Science and Technology, and Gabriela Schaepman-Strub of University of Zurich and, they identified a cause of wildfires in the permafrost region of southeastern Siberia which is related to the Artic Oscillation. Their research is published on the international journal, Science Advances on the 8th of January.
Permafrost area, where ground remains frozen for two years straight, spans widely in Siberia, Alaska, and North Europe and it takes about 24% of Northern Hemisphere. It is predicted that permafrost was formed in the end of Ice Age, 11 thousand years ago and believed to have bones of ancient animals, plant roots and five hundred billion tons of carbons buried in it. For this reason, carbon release in this region is as important as the carbon release from human's use of fossil fuels when predicting climate change.
The research team analyzed the relationship between the changes in weather conditions and forest fires occurred in the permafrost region of southeastern Siberia. In result, they discovered a fact that the atmospheric ring-like structure at the Arctic pole is disrupted and high pressure in this region abnormally increases temperature in winter which brings snowmelt earlier and dried surface, resulting in fire spreading.
Also, they analyzed large-scale atmospheric conditions of southeastern Siberia where most frequent forest fires occur in the Arctic regions. As a result, they found that the amount of burned area is larger one to two months before the Arctic Oscillation than the peak fire activity season in spring (April to May).
Even bigger problem exists when wildfire occurs in the permafrost area. It releases even more amount of carbon than fires in other regions and this increases the amount of carbon in atmosphere which accelerates Arctic warming. This will raise temperature in the Arctic, causing dried surface which then brings fire spreading and the vicious cycle of wildfire begins again.
In addition, one of the critical emissions of Siberian fire is aerosol such as fine dust. When large-scale wildfire occurs in this region, rapidly increased aerosol transports by westerlies and it impacts on air quality in Canada.
There had been reports describing a correlation between the Arctic Oscillation and the Siberian fire activity, however, there was no research that explained precise principle and mechanism before their research. Furthermore, their study can predict spring fire activities by measuring the Arctic Oscillation index in winter which then can help prevent wildfires.
Read more at Science Daily
Jong-Seong Kug, a professor of Division of Environmental Engineering at POSTECH and Jin-Soo Kim, a postdoctoral researcher of University of Edinburgh jointly collaborated with Su-Jong Jeong of Seoul National University, Hotaek Park of Japan Agency for Marine-Earth Science and Technology, and Gabriela Schaepman-Strub of University of Zurich and, they identified a cause of wildfires in the permafrost region of southeastern Siberia which is related to the Artic Oscillation. Their research is published on the international journal, Science Advances on the 8th of January.
Permafrost area, where ground remains frozen for two years straight, spans widely in Siberia, Alaska, and North Europe and it takes about 24% of Northern Hemisphere. It is predicted that permafrost was formed in the end of Ice Age, 11 thousand years ago and believed to have bones of ancient animals, plant roots and five hundred billion tons of carbons buried in it. For this reason, carbon release in this region is as important as the carbon release from human's use of fossil fuels when predicting climate change.
The research team analyzed the relationship between the changes in weather conditions and forest fires occurred in the permafrost region of southeastern Siberia. In result, they discovered a fact that the atmospheric ring-like structure at the Arctic pole is disrupted and high pressure in this region abnormally increases temperature in winter which brings snowmelt earlier and dried surface, resulting in fire spreading.
Also, they analyzed large-scale atmospheric conditions of southeastern Siberia where most frequent forest fires occur in the Arctic regions. As a result, they found that the amount of burned area is larger one to two months before the Arctic Oscillation than the peak fire activity season in spring (April to May).
Even bigger problem exists when wildfire occurs in the permafrost area. It releases even more amount of carbon than fires in other regions and this increases the amount of carbon in atmosphere which accelerates Arctic warming. This will raise temperature in the Arctic, causing dried surface which then brings fire spreading and the vicious cycle of wildfire begins again.
In addition, one of the critical emissions of Siberian fire is aerosol such as fine dust. When large-scale wildfire occurs in this region, rapidly increased aerosol transports by westerlies and it impacts on air quality in Canada.
There had been reports describing a correlation between the Arctic Oscillation and the Siberian fire activity, however, there was no research that explained precise principle and mechanism before their research. Furthermore, their study can predict spring fire activities by measuring the Arctic Oscillation index in winter which then can help prevent wildfires.
Read more at Science Daily
Scientists find oldest-known fossilized digestive tract -- 550 million years
A 550 million-year-old fossilized digestive tract found in the Nevada desert could be a key find in understanding the early history of animals on Earth.
Over a half-billion years ago, life on Earth was comprised of simple ocean organisms unlike anything living in today's oceans. Then, beginning about 540 million years ago, animal structures changed dramatically.
During this time, ancestors of many animal groups we know today appeared, such as primitive crustaceans and worms, yet for years scientists did not know how these two seemingly unrelated communities of animals were connected, until now. An analysis of tubular fossils by scientists led by Jim Schiffbauer at the University of Missouri provides evidence of a 550 million-year-old digestive tract -- one of the oldest known examples of fossilized internal anatomical structures -- and reveals what scientists believe is a possible answer to the question of how these animals are connected.
The study was published in Nature Communications, a journal of Nature.
"Not only are these structures the oldest guts yet discovered, but they also help to resolve the long-debated evolutionary positioning of this important fossil group," said Schiffbauer, an associate professor of geological sciences in the MU College of Arts and Science and director of the X-ray Microanalysis Core facility. "These fossils fit within a very recognizable group of organisms -- the cloudinids -- that scientists use to identify the last 10 to 15 million years of the Ediacaran Period, or the period of time just before the Cambrian Explosion. We can now say that their anatomical structure appears much more worm-like than coral-like."
The Cambrian Explosion is widely considered by scientists to be the point in history of life on Earth when the ancestors of many animal groups we know today emerged.
In the study, the scientists used MU's X-ray Microanalysis Core facility to take a unique analytical approach for geological science -- micro-CT imaging -- that created a digital 3D image of the fossil. This technique allowed the scientists to view what was inside the fossil structure.
Read more at Science Daily
Over a half-billion years ago, life on Earth was comprised of simple ocean organisms unlike anything living in today's oceans. Then, beginning about 540 million years ago, animal structures changed dramatically.
During this time, ancestors of many animal groups we know today appeared, such as primitive crustaceans and worms, yet for years scientists did not know how these two seemingly unrelated communities of animals were connected, until now. An analysis of tubular fossils by scientists led by Jim Schiffbauer at the University of Missouri provides evidence of a 550 million-year-old digestive tract -- one of the oldest known examples of fossilized internal anatomical structures -- and reveals what scientists believe is a possible answer to the question of how these animals are connected.
The study was published in Nature Communications, a journal of Nature.
"Not only are these structures the oldest guts yet discovered, but they also help to resolve the long-debated evolutionary positioning of this important fossil group," said Schiffbauer, an associate professor of geological sciences in the MU College of Arts and Science and director of the X-ray Microanalysis Core facility. "These fossils fit within a very recognizable group of organisms -- the cloudinids -- that scientists use to identify the last 10 to 15 million years of the Ediacaran Period, or the period of time just before the Cambrian Explosion. We can now say that their anatomical structure appears much more worm-like than coral-like."
The Cambrian Explosion is widely considered by scientists to be the point in history of life on Earth when the ancestors of many animal groups we know today emerged.
In the study, the scientists used MU's X-ray Microanalysis Core facility to take a unique analytical approach for geological science -- micro-CT imaging -- that created a digital 3D image of the fossil. This technique allowed the scientists to view what was inside the fossil structure.
Read more at Science Daily
Plant life expanding in the Everest region
Plant life is expanding in the area around Mount Everest, and across the Himalayan region, new research shows.
Scientists used satellite data to measure the extent of subnival vegetation -- plants growing between the treeline and snowline -- in this vast area.
Little is known about these remote, hard-to-reach ecosystems, made up of short-stature plants (predominantly grasses and shrubs) and seasonal snow, but the study reveals they cover between 5 and 15 times the area of permanent glaciers and snow.
Using data from 1993 to 2018 from NASA's Landsat satellites, University of Exeter researchers measured small but significant increases in subnival vegetation cover across four height brackets from 4,150-6,000 metres above sea level.
Results varied at different heights and locations, with the strongest trend in increased vegetation cover in the bracket 5,000-5,500m.
Around Mount Everest, the team found a significant increase in vegetation in all four height brackets. Conditions at the top of this height range have generally been considered to be close to the limit of where plants can grow.
Though the study doesn't examine the causes of the change, the findings are consistent with modelling that shows a decline in "temperature-limited areas" (where temperatures are too low for plants to grow) across the Himalayan region due to global warming.
Other research has suggested Himalayan ecosystems are highly vulnerable to climate-induced vegetation shifts.
"A lot of research has been done on ice melting in the Himalayan region, including a study that showed how the rate of ice loss doubled between 2000 and 2016," said Dr Karen Anderson, of the Environment and Sustainability Institute on Exeter's Penryn Campus in Cornwall.
"It's important to monitor and understand ice loss in major mountain systems, but subnival ecosystems cover a much larger area than permanent snow and ice and we know very little about them and how they moderate water supply.
"Snow falls and melts here seasonally, and we don't know what impact changing subnival vegetation will have on this aspect of the water cycle -- which is vital because this region (known as 'Asia's water towers') feeds the ten largest rivers in Asia."
Dr Anderson said "some really detailed fieldwork" and further validation of these findings is now required to understand how plants in this high-altitude zone interact with soil and snow.
Dominic Fawcett, who coded the image processing, said: "These large-scale studies using decades of satellite data are computationally intensive because the file sizes are huge. We can now do this relatively easily on the cloud by using Google Earth Engine, a new and powerful tool freely available to anyone, anywhere."
Read more at Science Daily
Scientists used satellite data to measure the extent of subnival vegetation -- plants growing between the treeline and snowline -- in this vast area.
Little is known about these remote, hard-to-reach ecosystems, made up of short-stature plants (predominantly grasses and shrubs) and seasonal snow, but the study reveals they cover between 5 and 15 times the area of permanent glaciers and snow.
Using data from 1993 to 2018 from NASA's Landsat satellites, University of Exeter researchers measured small but significant increases in subnival vegetation cover across four height brackets from 4,150-6,000 metres above sea level.
Results varied at different heights and locations, with the strongest trend in increased vegetation cover in the bracket 5,000-5,500m.
Around Mount Everest, the team found a significant increase in vegetation in all four height brackets. Conditions at the top of this height range have generally been considered to be close to the limit of where plants can grow.
Though the study doesn't examine the causes of the change, the findings are consistent with modelling that shows a decline in "temperature-limited areas" (where temperatures are too low for plants to grow) across the Himalayan region due to global warming.
Other research has suggested Himalayan ecosystems are highly vulnerable to climate-induced vegetation shifts.
"A lot of research has been done on ice melting in the Himalayan region, including a study that showed how the rate of ice loss doubled between 2000 and 2016," said Dr Karen Anderson, of the Environment and Sustainability Institute on Exeter's Penryn Campus in Cornwall.
"It's important to monitor and understand ice loss in major mountain systems, but subnival ecosystems cover a much larger area than permanent snow and ice and we know very little about them and how they moderate water supply.
"Snow falls and melts here seasonally, and we don't know what impact changing subnival vegetation will have on this aspect of the water cycle -- which is vital because this region (known as 'Asia's water towers') feeds the ten largest rivers in Asia."
Dr Anderson said "some really detailed fieldwork" and further validation of these findings is now required to understand how plants in this high-altitude zone interact with soil and snow.
Dominic Fawcett, who coded the image processing, said: "These large-scale studies using decades of satellite data are computationally intensive because the file sizes are huge. We can now do this relatively easily on the cloud by using Google Earth Engine, a new and powerful tool freely available to anyone, anywhere."
Read more at Science Daily
A stripped helium star solves the massive black hole mystery
Stellar black holes form when massive stars end their life in a dramatic collapse. Observations have shown that stellar black holes typically have masses of about ten times that of the Sun, in accordance with the theory of stellar evolution. Recently, a Chinese team of astronomers claimed to have discovered a black hole as massive as 70 solar masses, which, if confirmed, would severely challenge the current view of stellar evolution. The publication immediately triggered theoretical investigations as well as additional observations by other astrophysicists. Among those to take a closer look at the object was a team of astronomers from the Universities of Erlangen-Nürnberg and Potsdam. They discovered that it may not necessarily be a black hole at all, but possibly a massive neutron star or even an 'ordinary' star.
The putative black hole was detected indirectly from the motion of a bright companion star, orbiting an invisible compact object over a period of about 80 days. From new observations, a Belgian team showed that the original measurements were misinterpreted and that the mass of the black hole is, in fact, very uncertain. The most important question, namely how the observed binary system was created, remains unanswered. A crucial aspect is the mass of the visible companion, the hot star LS V+22 25. The more massive this star is, the more massive the black hole has to be to induce the observed motion of the bright star. The latter was considered to be a normal star, eight times more massive than the Sun.
A team of astronomers from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Potsdam had a closer look at the archival spectrum of LS V+22 25, taken by the Keck telescope at Mauna Kea, Hawaii. In particular, they were interested in studying the abundances of the chemical elements on the stellar surface. Interestingly, they detected deviations in the abundances of helium, carbon, nitrogen, and oxygen compared to the standard composition of a young massive star. The observed pattern on the surface showed ashes resulting from the nuclear fusion of hydrogen, a process that only happens deep in the core of young stars and would not be expected to be detected at its surface.
'At first glance, the spectrum did indeed look like one from a young massive star. However, several properties appeared rather suspicious. This motivated us to have a fresh look at the archival data', said Andreas Irrgang, the leading scientist of this study and a member of the Dr. Karl Remeis-Observatory in Bamberg, the Astronomical Institute of FAU.
The authors concluded that LS V+22 25 must have interacted with its compact companion in the past. During this episode of mass-transfer, the outer layers of the star were removed and now the stripped helium core is visible, enriched with the ashes from the burning of hydrogen.
However, stripped helium stars are much lighter than their normal counterparts. Combining their results with recent distance measurements from the Gaia space telescope, the authors determined a most likely stellar mass of only 1.1 (with an uncertainty of +/-0.5) times that of the Sun. This yields a minimum mass of only 2-3 solar masses for the compact companion, suggesting that it may not necessarily be a black hole at all, but possibly a massive neutron star or even an 'ordinary' star.
Read more at Science Daily
The putative black hole was detected indirectly from the motion of a bright companion star, orbiting an invisible compact object over a period of about 80 days. From new observations, a Belgian team showed that the original measurements were misinterpreted and that the mass of the black hole is, in fact, very uncertain. The most important question, namely how the observed binary system was created, remains unanswered. A crucial aspect is the mass of the visible companion, the hot star LS V+22 25. The more massive this star is, the more massive the black hole has to be to induce the observed motion of the bright star. The latter was considered to be a normal star, eight times more massive than the Sun.
A team of astronomers from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Potsdam had a closer look at the archival spectrum of LS V+22 25, taken by the Keck telescope at Mauna Kea, Hawaii. In particular, they were interested in studying the abundances of the chemical elements on the stellar surface. Interestingly, they detected deviations in the abundances of helium, carbon, nitrogen, and oxygen compared to the standard composition of a young massive star. The observed pattern on the surface showed ashes resulting from the nuclear fusion of hydrogen, a process that only happens deep in the core of young stars and would not be expected to be detected at its surface.
'At first glance, the spectrum did indeed look like one from a young massive star. However, several properties appeared rather suspicious. This motivated us to have a fresh look at the archival data', said Andreas Irrgang, the leading scientist of this study and a member of the Dr. Karl Remeis-Observatory in Bamberg, the Astronomical Institute of FAU.
The authors concluded that LS V+22 25 must have interacted with its compact companion in the past. During this episode of mass-transfer, the outer layers of the star were removed and now the stripped helium core is visible, enriched with the ashes from the burning of hydrogen.
However, stripped helium stars are much lighter than their normal counterparts. Combining their results with recent distance measurements from the Gaia space telescope, the authors determined a most likely stellar mass of only 1.1 (with an uncertainty of +/-0.5) times that of the Sun. This yields a minimum mass of only 2-3 solar masses for the compact companion, suggesting that it may not necessarily be a black hole at all, but possibly a massive neutron star or even an 'ordinary' star.
Read more at Science Daily
Jan 9, 2020
The Vikings erected a runestone out of fear of climate catastrophe
Several passages on the Rök stone -- the world's most famous Viking Age runic monument -- suggest that the inscription is about battles and for over a hundred years, researchers have been trying to connect the inscription with heroic deeds in war. Now, thanks to an interdisciplinary research project, a new interpretation of the inscription is being presented. The study shows that the inscription deals with an entirely different kind of battle: the conflict between light and darkness, warmth and cold, life and death.
The Rök runestone, erected in Östergötland around 800 CE, is the world's most famous runestone from the Viking Age, but has also proven to be one of the most difficult to interpret. This new interpretation is based on a collaboration between researchers from several disciplines and universities.
"The key to unlocking the inscription was the interdisciplinary approach. Without these collaborations between textual analysis, archaeology, history of religions and runology, it would have been impossible to solve the riddles of the Rök runestone," says Per Holmberg, professor in Swedish at the University of Gothenburg, who led the study.
A previous climate catastrophe
The study is based on new archaeological research describing how badly Scandinavia suffered from a previous climate catastrophe with lower average temperatures, crop failures, hunger and mass extinctions. Bo Gräslund, professor in Archaeology at Uppsala University, points to several reasons why people may have feared a new catastrophe of this kind:
"Before the Rök runestone was erected, a number of events occurred which must have seemed extremely ominous: a powerful solar storm coloured the sky in dramatic shades of red, crop yields suffered from an extremely cold summer, and later a solar eclipse occurred just after sunrise. Even one of these events would have been enough to raise fears of another Fimbulwinter," says Bo Gräslund.
Nine riddles
According to the researchers' new interpretation now being published, the inscription consists of nine riddles. The answer to five of these riddles is "the Sun." One is a riddle asking who was dead but now lives again. The remaining four riddles are about Odin and his warriors.
Olof Sundqvist, professor in History of Religions at Stockholm University, explains the connection:
"The powerful elite of the Viking Age saw themselves as guarantors for good harvests. They were the leaders of the cult that held together the fragile balance between light and darkness. And finally at Ragnarök, they would fight alongside Odin in the final battle for the light."
Parallels with other Old Norse texts
According to the researchers, several points in the inscription have clear parallels with other Old Norse texts that no one has previously noted.
"For me, it's been almost like discovering a new literary source from the Viking Age. Sweden's answer to the Icelandic Poetic Edda!" says Henrik Williams, professor in Scandinavian Languages with a specialty in Runology at Uppsala University.
Read more at Science Daily
The Rök runestone, erected in Östergötland around 800 CE, is the world's most famous runestone from the Viking Age, but has also proven to be one of the most difficult to interpret. This new interpretation is based on a collaboration between researchers from several disciplines and universities.
"The key to unlocking the inscription was the interdisciplinary approach. Without these collaborations between textual analysis, archaeology, history of religions and runology, it would have been impossible to solve the riddles of the Rök runestone," says Per Holmberg, professor in Swedish at the University of Gothenburg, who led the study.
A previous climate catastrophe
The study is based on new archaeological research describing how badly Scandinavia suffered from a previous climate catastrophe with lower average temperatures, crop failures, hunger and mass extinctions. Bo Gräslund, professor in Archaeology at Uppsala University, points to several reasons why people may have feared a new catastrophe of this kind:
"Before the Rök runestone was erected, a number of events occurred which must have seemed extremely ominous: a powerful solar storm coloured the sky in dramatic shades of red, crop yields suffered from an extremely cold summer, and later a solar eclipse occurred just after sunrise. Even one of these events would have been enough to raise fears of another Fimbulwinter," says Bo Gräslund.
Nine riddles
According to the researchers' new interpretation now being published, the inscription consists of nine riddles. The answer to five of these riddles is "the Sun." One is a riddle asking who was dead but now lives again. The remaining four riddles are about Odin and his warriors.
Olof Sundqvist, professor in History of Religions at Stockholm University, explains the connection:
"The powerful elite of the Viking Age saw themselves as guarantors for good harvests. They were the leaders of the cult that held together the fragile balance between light and darkness. And finally at Ragnarök, they would fight alongside Odin in the final battle for the light."
Parallels with other Old Norse texts
According to the researchers, several points in the inscription have clear parallels with other Old Norse texts that no one has previously noted.
"For me, it's been almost like discovering a new literary source from the Viking Age. Sweden's answer to the Icelandic Poetic Edda!" says Henrik Williams, professor in Scandinavian Languages with a specialty in Runology at Uppsala University.
Read more at Science Daily
Planet WASP-12b is on a death spiral, say scientists
Earth is doomed -- but not for 5 billion years. Our planet will be roasted as our sun expands and becomes a red giant, but the exoplanet WASP-12b, located 600 light-years away in the constellation Auriga, has less than a thousandth of that time left: a comparatively paltry 3 million years.
A Princeton-led team of astrophysicists has shown that WASP-12b is spiraling in toward its host star, heading toward certain destruction. Their paper appears in the Dec. 27, 2019, issue of the Astrophysical Journal Letters.
WASP-12b is known as a "hot Jupiter," a giant gaseous planet like our neighbor planet Jupiter, but which is very close to its own star, orbiting its sun in just 26 hours. (By contrast, we take 365 days to orbit, and even Mercury, the innermost planet of our solar system, takes 88 days.)
"Ever since the discovery of the first 'hot Jupiter' in 1995 -- a discovery that was recognized with this year's Nobel Prize in Physics -- we have wondered how long such planets can survive," said Joshua Winn, a professor of astrophysical sciences at Princeton and one of the authors of the paper. "We were pretty sure they could not last forever. The strong gravitational interactions between the planet and the star should cause the planet to spiral inward and be destroyed, but nobody could predict how long this takes. It might be millions of years, it might be billions or trillions. Now that we have measured the rate, for at least one system -- it's millions of years -- we have a new clue about the behavior of stars as fluid bodies."
The problem is that as WASP-12b orbits its star, the two bodies exert gravitational pulls on each other, raising "tides" like the ocean tides raised by the moon on Earth.
Within the star, these tidal waves cause the star to become slightly distorted and to oscillate. Because of friction, these waves crash and the oscillations die down, a process that gradually converts the planet's orbital energy into heat within the star.
The friction associated with the tides also exerts a gravitational torque on the planet, causing the planet to spiral inward. Measuring how quickly the planet's orbit is shrinking reveals how quickly the star is dissipating the orbital energy, which provides astrophysicists clues about the interior of stars.
"If we can find more planets like WASP-12b whose orbits are decaying, we'll be able to learn about the evolution and eventual fate of exoplanetary systems," said first author Samuel Yee, a graduate student in astrophysical sciences. "Although this phenomenon has been predicted for close-in giant planets like WASP-12b in the past, this is the first time we have caught this process in action."
One of the first people to make that prediction that was Frederic Rasio, the Joseph Cummings Professor of Physics and Astronomy at Northwestern University, who was not involved in Yee and Winn's work. "We've all been waiting nearly 25 years for this effect to be detected observationally," Rasio said. "The implications of the short timescale measured for orbital decay are also very important. In particular it means that there must be many more hot Jupiters that have already gone all the way. When they get to the Roche limit -- the tidal disruption limit for an object on a circular orbit -- their envelopes might get stripped, revealing a rocky core that looks just like a super-Earth (or maybe a mini-Neptune if they can retain a bit of their envelope)."
Rasio also edits Astrophysical Journal Letters, the journal in which the new paper appears. The researchers had originally submitted their paper to a less-prestigious sister journal also published by the American Astronomical Society, but Rasio redirected it to ApJ Letters because of the "especially great significance" of the research. "Part of my job is to ensure that all major new discoveries presented in manuscripts submitted to the AAS Journals are considered for publication in ApJ Letters," he said. "In this case it was a no-brainer."
WASP-12b was discovered in 2008 through the transit method, in which astronomers observe a small dip in a star's brightness as the planet passes in front of it, each time it completes an orbit. Since its discovery, the interval between successive dips has shortened by 29 milliseconds per year -- an observation that was first noted in 2017 by co-author Kishore Patra, then an undergraduate at the Massachusetts Institute of Technology.
That slight shortening could suggest that the planet's orbit is shrinking, but there are other possible explanations: If WASP-12b's orbit is more oval-shaped than circular, for example, the apparent changes in the orbital period could be caused by the changing orientation of the orbit.
The way to be sure if the orbit is actually shortening is to watch the planet disappear behind its star, known as occultation. If the orbit is just changing its direction, the actual orbital period doesn't change, so if transits occur more quickly than expected, occultations should occur more slowly. But if the orbit is truly decaying, the timing of both transits and occultations should shift in the same direction.
Over the last two years, the researchers have collected more data, including new occultation observations made with the Spitzer Space Telescope.
"These new data strongly support the orbital decay scenario, allowing us to firmly say that the planet is indeed spiraling toward its star," said Yee. "This confirms the long-standing theoretical predictions and indirect data suggesting that hot Jupiters should eventually be destroyed through this process."
This discovery will help theorists understand the internal workings of stars and interpret other data relating to tidal interactions, said Winn. "It also tells us about the lifetimes of hot Jupiters, a clue that might help shed light on the formation of these strange and unexpected planets."
Read more at Science Daily
A Princeton-led team of astrophysicists has shown that WASP-12b is spiraling in toward its host star, heading toward certain destruction. Their paper appears in the Dec. 27, 2019, issue of the Astrophysical Journal Letters.
WASP-12b is known as a "hot Jupiter," a giant gaseous planet like our neighbor planet Jupiter, but which is very close to its own star, orbiting its sun in just 26 hours. (By contrast, we take 365 days to orbit, and even Mercury, the innermost planet of our solar system, takes 88 days.)
"Ever since the discovery of the first 'hot Jupiter' in 1995 -- a discovery that was recognized with this year's Nobel Prize in Physics -- we have wondered how long such planets can survive," said Joshua Winn, a professor of astrophysical sciences at Princeton and one of the authors of the paper. "We were pretty sure they could not last forever. The strong gravitational interactions between the planet and the star should cause the planet to spiral inward and be destroyed, but nobody could predict how long this takes. It might be millions of years, it might be billions or trillions. Now that we have measured the rate, for at least one system -- it's millions of years -- we have a new clue about the behavior of stars as fluid bodies."
The problem is that as WASP-12b orbits its star, the two bodies exert gravitational pulls on each other, raising "tides" like the ocean tides raised by the moon on Earth.
Within the star, these tidal waves cause the star to become slightly distorted and to oscillate. Because of friction, these waves crash and the oscillations die down, a process that gradually converts the planet's orbital energy into heat within the star.
The friction associated with the tides also exerts a gravitational torque on the planet, causing the planet to spiral inward. Measuring how quickly the planet's orbit is shrinking reveals how quickly the star is dissipating the orbital energy, which provides astrophysicists clues about the interior of stars.
"If we can find more planets like WASP-12b whose orbits are decaying, we'll be able to learn about the evolution and eventual fate of exoplanetary systems," said first author Samuel Yee, a graduate student in astrophysical sciences. "Although this phenomenon has been predicted for close-in giant planets like WASP-12b in the past, this is the first time we have caught this process in action."
One of the first people to make that prediction that was Frederic Rasio, the Joseph Cummings Professor of Physics and Astronomy at Northwestern University, who was not involved in Yee and Winn's work. "We've all been waiting nearly 25 years for this effect to be detected observationally," Rasio said. "The implications of the short timescale measured for orbital decay are also very important. In particular it means that there must be many more hot Jupiters that have already gone all the way. When they get to the Roche limit -- the tidal disruption limit for an object on a circular orbit -- their envelopes might get stripped, revealing a rocky core that looks just like a super-Earth (or maybe a mini-Neptune if they can retain a bit of their envelope)."
Rasio also edits Astrophysical Journal Letters, the journal in which the new paper appears. The researchers had originally submitted their paper to a less-prestigious sister journal also published by the American Astronomical Society, but Rasio redirected it to ApJ Letters because of the "especially great significance" of the research. "Part of my job is to ensure that all major new discoveries presented in manuscripts submitted to the AAS Journals are considered for publication in ApJ Letters," he said. "In this case it was a no-brainer."
WASP-12b was discovered in 2008 through the transit method, in which astronomers observe a small dip in a star's brightness as the planet passes in front of it, each time it completes an orbit. Since its discovery, the interval between successive dips has shortened by 29 milliseconds per year -- an observation that was first noted in 2017 by co-author Kishore Patra, then an undergraduate at the Massachusetts Institute of Technology.
That slight shortening could suggest that the planet's orbit is shrinking, but there are other possible explanations: If WASP-12b's orbit is more oval-shaped than circular, for example, the apparent changes in the orbital period could be caused by the changing orientation of the orbit.
The way to be sure if the orbit is actually shortening is to watch the planet disappear behind its star, known as occultation. If the orbit is just changing its direction, the actual orbital period doesn't change, so if transits occur more quickly than expected, occultations should occur more slowly. But if the orbit is truly decaying, the timing of both transits and occultations should shift in the same direction.
Over the last two years, the researchers have collected more data, including new occultation observations made with the Spitzer Space Telescope.
"These new data strongly support the orbital decay scenario, allowing us to firmly say that the planet is indeed spiraling toward its star," said Yee. "This confirms the long-standing theoretical predictions and indirect data suggesting that hot Jupiters should eventually be destroyed through this process."
This discovery will help theorists understand the internal workings of stars and interpret other data relating to tidal interactions, said Winn. "It also tells us about the lifetimes of hot Jupiters, a clue that might help shed light on the formation of these strange and unexpected planets."
Read more at Science Daily
Cancer mortality continues steady decline, driven by progress against lung cancer
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| Medical report. |
The steady 26-year decline in overall cancer mortality is driven by long-term drops in death rates for the four major cancers -- lung, colorectal, breast, and prostate, although recent trends are mixed. The pace of mortality reductions for lung cancer -- the leading cause of cancer death -- accelerated in recent years (from 2% per year to 4% overall) spurring the record one-year drop in overall cancer mortality. In contrast, progress slowed for colorectal, breast, and prostate cancers. The article appears early online in CA: A Cancer Journal for Clinicians, and is accompanied by a consumer version, Cancer Facts & Figures 2020.
Overall cancer death rates dropped by an average of 1.5% per year during the most recent decade of data (2008-2017), continuing a trend that began in the early 1990s and resulting in the 29% drop in cancer mortality in that time. The drop translates to approximately 2.9 million fewer cancer deaths than would have occurred had mortality rates remained at their peak. Continuing declines in cancer mortality contrast with a stable trend for all other causes of death combined, reflecting a slowing decline for heart disease, stabilizing rates for cerebrovascular disease, and an increasing trend for accidents and Alzheimer disease.
Lung cancer death rates have dropped by 51% (since 1990) in men and by 26% (since 2002) in women, with the most rapid progress in recent years. For example, reductions in mortality accelerated from 3% per year during 2008-2013 to 5% per year during 2013-2017 in men and from 2% to almost 4% in women. However, lung cancer still accounts for almost one-quarter of all cancer deaths, more than breast, prostate, and colorectal cancers combined.
The most rapid declines in mortality occurred for melanoma of the skin, on the heels of breakthrough treatments approved in 2011 that pushed one-year survival for patients diagnosed with metastatic disease from 42% during 2008-2010 to 55% during 2013-2015. This progress is likewise reflected in the overall melanoma death rate, which dropped by 7% per year during 2013-2017 in people ages 20 to 64, compared to declines during 2006-2010 (prior to FDA approval of ipilimumab and vemurafenib) of 2%-3% per year in those ages 20 to 49 and 1% per year in those ages 50 to 64. Even more striking are the mortality declines of 5% to 6% in individuals 65 and older, among whom rates were previously increasing.
"The news this year is mixed," said Rebecca Siegel, MPH, lead author of the report. "The exciting gains in reducing mortality for melanoma and lung cancer are tempered by slowing progress for colorectal, breast, and prostate cancers, which are amenable to early detection. It's a reminder that increasing our investment in the equitable application of existing cancer control interventions, as well as basic and clinical research to further advance treatment, would undoubtedly accelerate progress against cancer."
Highlights from the report:
- The death rate for breast cancer dropped by 40% from 1989 to 2017.
- The death rate for prostate cancer dropped by 52% from 1993 to 2017.
- The death rate for colorectal cancer dropped by 53% from 1980 to 2017 among males and by 57% from 1969 to 2017 among females.
- Decades-long rapid increases in liver cancer mortality appear to be abating in both men and women.
- Cervical cancer, which is almost completely preventable, caused ten premature deaths per week in women ages 20-39 in 2017.
Other highlights:
- In 2020, 1,806,590 new cancer cases and 606,520 cancer deaths are projected to occur in the United States.*
- Progress for hematopoietic and lymphoid malignancies (leukemias and lymphomas) has been especially rapid due to improvements in treatment protocols, including the development of targeted therapies. The 5-year relative survival rate for chronic myeloid leukemia increased from 22% in the mid-1970s to 70% for those diagnosed during 2009 through 2015, and most patients treated with tyrosine kinase inhibitors now experience nearly normal life expectancy.
- The overall cancer incidence rate in men declined rapidly from 2007 to 2014, but stabilized through 2016, reflecting slowing declines for colorectal cancer and stabilizing rates for prostate cancer.
- The overall cancer incidence rate in women has remained generally stable over the past few decades because lung cancer declines have been offset by a tapering decline for colorectal cancer and increasing or stable rates for other common cancers in women.
- The slight rise in breast cancer incidence rates (by approximately 0.3% per year) since 2004 has been attributed at least in part to continued declines in the fertility rate and increased obesity, factors that may also contribute to increasing incidence for uterine cancer (1.3% per year from 2007-2016).
- Lung cancer incidence continues to decline twice as fast in men as in women, reflecting historical differences in tobacco uptake and cessation.
- In contrast, colorectal cancer incidence patterns are generally similar in men and women, with the rapid declines noted during the 2000s in the wake of widespread colonoscopy uptake appearing to taper in more recent years.
- Incidence continues to increase for cancers of the kidney, pancreas, liver, and oral cavity and pharynx (among non-Hispanic whites) and melanoma of the skin. Liver cancer is increasing most rapidly, by 2% to 3% annually during 2007 through 2016, although the pace has slowed from previous years.
- The 5-year relative survival rate for all cancers combined diagnosed during 2009 through 2015 was 67% overall, 68% in whites, and 62% in blacks.
- Cancer survival has improved since the mid-1970s for all of the most common cancers except cervical and uterine cancers. Stagnant survival rates for these cancers largely reflect a lack of major treatment advances for patients with recurrent and metastatic disease.
"The accelerated drops in lung cancer mortality as well as in melanoma that we're seeing are likely due at least in part to advances in cancer treatment over the past decade, such as immunotherapy," said William G. Cance, M.D., chief medical and scientific officer for the American Cancer Society. "They are a profound reminder of how rapidly this area of research is expanding, and now leading to real hope for cancer patients."
Read more at Science Daily
Pathways that extend lifespan by 500 percent identified
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| Caenorhabditis elegans |
The increase in lifespan would be the equivalent of a human living for 400 or 500 years, according to one of the scientists.
The research draws on the discovery of two major pathways governing aging in C. elegans, which is a popular model in aging research because it shares many of its genes with humans and because its short lifespan of only three to four weeks allows scientists to quickly assess the effects of genetic and environmental interventions to extend healthy lifespan.
Because these pathways are "conserved," meaning that they have been passed down to humans through evolution, they have been the subject of intensive research. A number of drugs that extend healthy lifespan by altering these pathways are now under development. The discovery of the synergistic effect opens the door to even more effective anti-aging therapies.
The new research uses a double mutant in which the insulin signaling (IIS) and TOR pathways have been genetically altered. Because alteration of the IIS pathways yields a 100 percent increase in lifespan and alteration of the TOR pathway yields a 30 percent increase, the double mutant would be expected to live 130 percent longer. But instead, its lifespan was amplified by 500 percent.
"Despite the discovery in C. elegans of cellular pathways that govern aging, it hasn't been clear how these pathways interact," said Hermann Haller, M.D., president of the MDI Biological Laboratory. "By helping to characterize these interactions, our scientists are paving the way for much-needed therapies to increase healthy lifespan for a rapidly aging population."
The elucidation of the cellular mechanisms controlling the synergistic response is the subject of a recent paper in the online journal Cell Reports entitled "Translational Regulation of Non-autonomous Mitochondrial Stress Response Promotes Longevity." The authors include Jarod A. Rollins, Ph.D., and Aric N. Rogers, Ph.D., of the MDI Biological Laboratory.
"The synergistic extension is really wild," said Rollins, who is the lead author with Jianfeng Lan, Ph.D., of Nanjing University. "The effect isn't one plus one equals two, it's one plus one equals five. Our findings demonstrate that nothing in nature exists in a vacuum; in order to develop the most effective anti-aging treatments we have to look at longevity networks rather than individual pathways."
The discovery of the synergistic interaction could lead to the use of combination therapies, each affecting a different pathway, to extend healthy human lifespan in the same way that combination therapies are used to treat cancer and HIV, Pankaj Kapahi, Ph.D., of the Buck Institute, has said. Kapahi is a corresponding author of the paper with Rogers and Di Chen, Ph.D., of Nanjing University.
The synergistic interaction may also may explain why scientists have been unable to identify a single gene responsible for the ability of some people to live to extraordinary old ages free of major age-related diseases until shortly before their deaths.
Read more at Science Daily
Jan 8, 2020
100 million years in amber: Researchers discover oldest fossilized slime mold
Most people associate the idea of creatures trapped in amber with insects or spiders, which are preserved lifelike in fossil tree resin. An international research team of palaeontologists and biologists from the Universities of Göttingen and Helsinki, and the American Museum of Natural History in New York has now discovered the oldest slime mould identified to date. The fossil is about 100 million years old and is exquisitely preserved in amber from Myanmar. The results have been published in the journal Scientific Reports.
Slime moulds, also called myxomycetes, belong to a group known as 'Amoebozoa'. These are microscopic organisms that live most of the time as single mobile cells hidden in the soil or in rotting wood, where they eat bacteria. However, they can join together to form complex, beautiful and delicate fruiting bodies, which serve to make and spread spores.
Since fossil slime moulds are extremely rare, studying their evolutionary history has been very difficult. So far, there have only been two confirmed reports of fossils of fruiting bodies and these are just 35 to 40 million years old. The discovery of fossil myxomycetes is very unlikely because their fruiting bodies are extremely short-lived. The researchers are therefore astounded by the chain of events that must have led to the preservation of this newly identified fossil. "The fragile fruiting bodies were most likely torn from the tree bark by a lizard, which was also caught in the sticky tree resin, and finally embedded in it together with the reptile," says Professor Jouko Rikkinen from the University of Helsinki. The lizard detached the fruiting bodies at a relatively early stage when the spores had not yet been released, which now reveals valuable information about the evolutionary history of these fascinating organisms.
The researchers were surprised by the discovery that the slime mould can easily be assigned to a genus still living today. "The fossil provides unique insights into the longevity of the ecological adaptations of myxomycetes," explains palaeontologist Professor Alexander Schmidt from the University of Göttingen, lead author of the study.
"We interpret this as evidence of strong environmental selection. It seems that slime moulds that spread very small spores using the wind had an advantage," says Rikkinen. The ability of slime moulds to develop long-lasting resting stages in their life cycle, which can last for years, probably also contributes to the remarkable similarity of the fossil to its closest present-day relatives.
From Science Daily
Slime moulds, also called myxomycetes, belong to a group known as 'Amoebozoa'. These are microscopic organisms that live most of the time as single mobile cells hidden in the soil or in rotting wood, where they eat bacteria. However, they can join together to form complex, beautiful and delicate fruiting bodies, which serve to make and spread spores.
Since fossil slime moulds are extremely rare, studying their evolutionary history has been very difficult. So far, there have only been two confirmed reports of fossils of fruiting bodies and these are just 35 to 40 million years old. The discovery of fossil myxomycetes is very unlikely because their fruiting bodies are extremely short-lived. The researchers are therefore astounded by the chain of events that must have led to the preservation of this newly identified fossil. "The fragile fruiting bodies were most likely torn from the tree bark by a lizard, which was also caught in the sticky tree resin, and finally embedded in it together with the reptile," says Professor Jouko Rikkinen from the University of Helsinki. The lizard detached the fruiting bodies at a relatively early stage when the spores had not yet been released, which now reveals valuable information about the evolutionary history of these fascinating organisms.
The researchers were surprised by the discovery that the slime mould can easily be assigned to a genus still living today. "The fossil provides unique insights into the longevity of the ecological adaptations of myxomycetes," explains palaeontologist Professor Alexander Schmidt from the University of Göttingen, lead author of the study.
"We interpret this as evidence of strong environmental selection. It seems that slime moulds that spread very small spores using the wind had an advantage," says Rikkinen. The ability of slime moulds to develop long-lasting resting stages in their life cycle, which can last for years, probably also contributes to the remarkable similarity of the fossil to its closest present-day relatives.
From Science Daily
Surprise! TESS shows ancient north star undergoes eclipses
Astronomers using data from NASA's Transiting Exoplanet Survey Satellite (TESS) have shown that Alpha Draconis, a well-studied star visible to the naked eye, and its fainter companion star regularly eclipse each other. While astronomers previously knew this was a binary system, the mutual eclipses came as a complete surprise.
"The first question that comes to mind is 'how did we miss this?'" said Angela Kochoska, a postdoctoral researcher at Villanova University in Pennsylvania who presented the findings at the 235th meeting of the American Astronomical Society in Honolulu on Jan. 6. "The eclipses are brief, lasting only six hours, so ground-based observations can easily miss them. And because the star is so bright, it would have quickly saturated detectors on NASA's Kepler observatory, which would also mask the eclipses."
The system ranks among the brightest-known eclipsing binaries where the two stars are widely separated, or detached, and only interact gravitationally. Such systems are important because astronomers can measure the masses and sizes of both stars with unrivaled accuracy.
Alpha Draconis, also known as Thuban, lies about 270 light-years away in the northern constellation Draco. Despite its "alpha" designation, it shines as Draco's fourth-brightest star. Thuban's fame arises from a historical role it played some 4,700 years ago, back when the earliest pyramids were being built in Egypt.
At that time, it appeared as the North Star, the one closest to the northern pole of Earth's spin axis, the point around which all of the other stars appear to turn in their nightly motion. Today, this role is played by Polaris, a brighter star in the constellation Ursa Minor. The change happened because Earth's spin axis performs a cyclic 26,000-year wobble, called precession, that slowly alters the sky position of the rotational pole.
TESS monitors large swaths of the sky, called sectors, for 27 days at a time. This long stare allows the satellite to track changes in stellar brightness. While NASA's newest planet hunter mainly seeks dimmings caused by planets crossing in front of their stars, TESS data can be used to study many other phenomena as well.
A 2004 report suggested that Thuban displayed small brightness changes that cycled over about an hour, suggesting the possibility that the system's brightest star was pulsating.
To check this, Timothy Bedding, Daniel Hey, and Simon Murphy at the University of Sydney, Australia, and Aarhus University, Denmark, turned to TESS measurements. In October, they published a paper that described the discovery of eclipses by both stars and ruling out the existence of pulsations over periods less than eight hours.
Now Kochoska is working with Hey to understand the system in greater detail.
"I've been collaborating with Daniel to model the eclipses and advising on how to bring together more data to better constrain our model." Kochoska explained. "The two of us took different approaches to modeling the system, and we hope our efforts will result in its full characterization."
As known from earlier studies, the stars orbit every 51.4 days at an average distance of about 38 million miles (61 million kilometers), slightly more than Mercury's distance from the Sun. The current preliminary model shows that we view the system about three degrees above the stars' orbital plane, which means neither star completely covers the other during the eclipses. The primary star is 4.3 times bigger than the Sun and has a surface temperature around 17,500 degrees Fahrenheit (9,700 C), making it 70% hotter than our Sun. Its companion, which is five times fainter, is most likely half the primary's size and 40% hotter than the Sun.
Kochoska says she is planning ground-based follow-up observations and anticipating additional eclipses in future TESS sectors.
"Discovering eclipses in a well-known, bright, historically important star highlights how TESS impacts the broader astronomical community," said Padi Boyd, the TESS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "In this case, the high precision, uninterrupted TESS data can be used to help constrain fundamental stellar parameters at a level we've never before achieved."
Read more at Science Daily
"The first question that comes to mind is 'how did we miss this?'" said Angela Kochoska, a postdoctoral researcher at Villanova University in Pennsylvania who presented the findings at the 235th meeting of the American Astronomical Society in Honolulu on Jan. 6. "The eclipses are brief, lasting only six hours, so ground-based observations can easily miss them. And because the star is so bright, it would have quickly saturated detectors on NASA's Kepler observatory, which would also mask the eclipses."
The system ranks among the brightest-known eclipsing binaries where the two stars are widely separated, or detached, and only interact gravitationally. Such systems are important because astronomers can measure the masses and sizes of both stars with unrivaled accuracy.
Alpha Draconis, also known as Thuban, lies about 270 light-years away in the northern constellation Draco. Despite its "alpha" designation, it shines as Draco's fourth-brightest star. Thuban's fame arises from a historical role it played some 4,700 years ago, back when the earliest pyramids were being built in Egypt.
At that time, it appeared as the North Star, the one closest to the northern pole of Earth's spin axis, the point around which all of the other stars appear to turn in their nightly motion. Today, this role is played by Polaris, a brighter star in the constellation Ursa Minor. The change happened because Earth's spin axis performs a cyclic 26,000-year wobble, called precession, that slowly alters the sky position of the rotational pole.
TESS monitors large swaths of the sky, called sectors, for 27 days at a time. This long stare allows the satellite to track changes in stellar brightness. While NASA's newest planet hunter mainly seeks dimmings caused by planets crossing in front of their stars, TESS data can be used to study many other phenomena as well.
A 2004 report suggested that Thuban displayed small brightness changes that cycled over about an hour, suggesting the possibility that the system's brightest star was pulsating.
To check this, Timothy Bedding, Daniel Hey, and Simon Murphy at the University of Sydney, Australia, and Aarhus University, Denmark, turned to TESS measurements. In October, they published a paper that described the discovery of eclipses by both stars and ruling out the existence of pulsations over periods less than eight hours.
Now Kochoska is working with Hey to understand the system in greater detail.
"I've been collaborating with Daniel to model the eclipses and advising on how to bring together more data to better constrain our model." Kochoska explained. "The two of us took different approaches to modeling the system, and we hope our efforts will result in its full characterization."
As known from earlier studies, the stars orbit every 51.4 days at an average distance of about 38 million miles (61 million kilometers), slightly more than Mercury's distance from the Sun. The current preliminary model shows that we view the system about three degrees above the stars' orbital plane, which means neither star completely covers the other during the eclipses. The primary star is 4.3 times bigger than the Sun and has a surface temperature around 17,500 degrees Fahrenheit (9,700 C), making it 70% hotter than our Sun. Its companion, which is five times fainter, is most likely half the primary's size and 40% hotter than the Sun.
Kochoska says she is planning ground-based follow-up observations and anticipating additional eclipses in future TESS sectors.
"Discovering eclipses in a well-known, bright, historically important star highlights how TESS impacts the broader astronomical community," said Padi Boyd, the TESS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "In this case, the high precision, uninterrupted TESS data can be used to help constrain fundamental stellar parameters at a level we've never before achieved."
Read more at Science Daily
Cosmic bubbles reveal the first stars
Astronomers using the Mayall telescope at Kitt Peak National Observatory, a program of NSF's National Optical-Infrared Astronomy Research Laboratory, have identified several overlapping bubbles of hydrogen gas ionized by the stars in early galaxies, a mere 680 million years after the Big Bang. This is the earliest direct evidence from the period when the first generation of stars formed and began reionizing the hydrogen gas that permeated the Universe.
There was a period in the very early Universe -- known as the "cosmic dark ages" -- when elementary particles, formed in the Big Bang, had combined to form neutral hydrogen but no stars or galaxies existed yet to light up the Universe. This period began less than half a million years after the Big Bang and ended with the formation of the first stars. While this stage in the evolution of our Universe is indicated by computer simulations, direct evidence is sparse.
Now, astronomers using the infrared imager NEWFIRM on the 4-meter Mayall Telescope at the Kitt Peak National Observatory of NSF's National Optical-Infrared Astronomy Research Laboratory (OIR Lab), have reported imaging a group of galaxies, known as EGS77, that contains these first stars. Their results were announced at a press conference held today at the 235th meeting of the American Astronomical Society (AAS) in Honolulu, Hawai'i.
"The young Universe was filled with hydrogen atoms, which so attenuate ultraviolet light that they block our view of early galaxies," said James Rhoads at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who presented the findings at the AAS press conference. "EGS77 is the first galaxy group caught in the act of clearing out this cosmic fog."
The team began with an imaging survey designed to detect high redshift galaxies and combined these data with corresponding images taken by the Hubble Space Telescope. This enabled the team to compute what is known as a photometric redshift, a proxy for estimating distance. At these redshifts, a galaxy's light is shifted completely out of the range of wavelengths to which the human eye is sensitive (the visible spectrum) to longer (infrared) wavelengths. The criteria for selecting distant galaxy candidates included a clear detection of them in the special infrared narrowband filters used with NEWFIRM on the Mayall 4-meter telescope and a complete non-detection in the shorter wavelength optical filter bands used by Hubble. "The discovery of the two fainter galaxies in the group was only possible because of the special narrowband filter used with NEWFIRM," said team leader Vithal Tilvi, a researcher at Arizona State University in Tempe.
"Intense light from galaxies can ionize the surrounding hydrogen gas, forming bubbles that allow starlight to travel freely," said Tilvi. "EGS77 has formed a large bubble that allows its light to travel to Earth without much attenuation. Eventually, bubbles like these grew around all galaxies and filled intergalactic space, clearing the way for light to travel across the Universe."
EGS77 was discovered as part of the Cosmic Deep And Wide Narrowband (Cosmic DAWN) survey, for which Rhoads serves as principal investigator. The team imaged a small area in the constellation of Boötes using a custom-built filter on the National Optical Astronomy Observatory's Extremely Wide-Field InfraRed imager (NEWFIRM). Ron Probst, a DAWN team member who also helped to develop NEWFIRM, adds, "These results show the value of maintaining instruments at our national observatories that are powerful and can flexibly adapt to pursue new scientific questions, questions that may not have been in mind when an instrument was originally built."
Once identified, the distances and hence the ages of these galaxies were confirmed with spectra taken with the MOSFIRE spectrograph at the Keck I telescope at the W. M. Keck Observatory on Maunakea in Hawai'i. All three galaxies show strong emission lines of hydrogen Lyman alpha at a redshift (z = 7.7), which means we are seeing them at about 680 million years after the Big Bang. The size of the ionized bubble around each was derived from computer modeling. These bubbles overlap spatially, but are large enough (about 2.2 million light-years) that Lyman alpha photons are redshifted before they reach the boundary of the bubble and can thus escape unscathed, allowing astronomers to detect them.
Read more at Science Daily
There was a period in the very early Universe -- known as the "cosmic dark ages" -- when elementary particles, formed in the Big Bang, had combined to form neutral hydrogen but no stars or galaxies existed yet to light up the Universe. This period began less than half a million years after the Big Bang and ended with the formation of the first stars. While this stage in the evolution of our Universe is indicated by computer simulations, direct evidence is sparse.
Now, astronomers using the infrared imager NEWFIRM on the 4-meter Mayall Telescope at the Kitt Peak National Observatory of NSF's National Optical-Infrared Astronomy Research Laboratory (OIR Lab), have reported imaging a group of galaxies, known as EGS77, that contains these first stars. Their results were announced at a press conference held today at the 235th meeting of the American Astronomical Society (AAS) in Honolulu, Hawai'i.
"The young Universe was filled with hydrogen atoms, which so attenuate ultraviolet light that they block our view of early galaxies," said James Rhoads at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who presented the findings at the AAS press conference. "EGS77 is the first galaxy group caught in the act of clearing out this cosmic fog."
The team began with an imaging survey designed to detect high redshift galaxies and combined these data with corresponding images taken by the Hubble Space Telescope. This enabled the team to compute what is known as a photometric redshift, a proxy for estimating distance. At these redshifts, a galaxy's light is shifted completely out of the range of wavelengths to which the human eye is sensitive (the visible spectrum) to longer (infrared) wavelengths. The criteria for selecting distant galaxy candidates included a clear detection of them in the special infrared narrowband filters used with NEWFIRM on the Mayall 4-meter telescope and a complete non-detection in the shorter wavelength optical filter bands used by Hubble. "The discovery of the two fainter galaxies in the group was only possible because of the special narrowband filter used with NEWFIRM," said team leader Vithal Tilvi, a researcher at Arizona State University in Tempe.
"Intense light from galaxies can ionize the surrounding hydrogen gas, forming bubbles that allow starlight to travel freely," said Tilvi. "EGS77 has formed a large bubble that allows its light to travel to Earth without much attenuation. Eventually, bubbles like these grew around all galaxies and filled intergalactic space, clearing the way for light to travel across the Universe."
EGS77 was discovered as part of the Cosmic Deep And Wide Narrowband (Cosmic DAWN) survey, for which Rhoads serves as principal investigator. The team imaged a small area in the constellation of Boötes using a custom-built filter on the National Optical Astronomy Observatory's Extremely Wide-Field InfraRed imager (NEWFIRM). Ron Probst, a DAWN team member who also helped to develop NEWFIRM, adds, "These results show the value of maintaining instruments at our national observatories that are powerful and can flexibly adapt to pursue new scientific questions, questions that may not have been in mind when an instrument was originally built."
Once identified, the distances and hence the ages of these galaxies were confirmed with spectra taken with the MOSFIRE spectrograph at the Keck I telescope at the W. M. Keck Observatory on Maunakea in Hawai'i. All three galaxies show strong emission lines of hydrogen Lyman alpha at a redshift (z = 7.7), which means we are seeing them at about 680 million years after the Big Bang. The size of the ionized bubble around each was derived from computer modeling. These bubbles overlap spatially, but are large enough (about 2.2 million light-years) that Lyman alpha photons are redshifted before they reach the boundary of the bubble and can thus escape unscathed, allowing astronomers to detect them.
Read more at Science Daily
Correcting vaccine misinformation is a difficult process, study shows
The number of girls receiving HPV vaccines in Denmark plummeted after vaccine misinformation spread through Danish media outlets from 2013 to 2016. Health officials launched a campaign in 2017 aiming to correct the misinformation and encourage girls to get vaccinated.
New research from the University of North Carolina at Chapel Hill shows that, despite substantial progress, about 26,000 Danish girls remain unvaccinated as a result of vaccine misinformation. About 33,000 girls are born annually in Denmark. Among the unvaccinated girls, researchers expect to see as many as 180 avoidable cases of cervical cancer and 45 deaths.
The researchers found that misinformation in Danish media outlets from 2013-2016 led to vaccinations dropping by 50.4%. An information campaign geared toward concerned parents helped increase vaccine uptake again, but uptake is still below the level before misinformation began, showing how difficult it is to undo the damages misinformation causes.
The study results were published Jan. 7 in Vaccine. The paper's lead author is UNC-Chapel Hill Latané Distinguished Professor of Economics Peter R. Hansen. Hansen worked with Noel Brewer, professor of health behavior at Carolina and Lineberger Comprehensive Cancer Center member, and Matthias Schmidblaicher, graduate student in the Department of Economics at the European University Institute, on the research.
"Denmark is a good case study to see how a country deals with vaccine misinformation. By using anecdotal stories, media can create a false equivalence between outrageous claims and scientific facts," Hansen said. "The media stories that include inaccurate information cut HPV vaccine uptake in half. Recovery has been slow and costly. Resources are being used to combat misinformation instead of being used for healthcare benefits."
The HPV vaccine is safe and can prevent six cancers, including up to 90% of cervical cancers. Receiving the vaccine at 11- or 12-years-old is important because the vaccine is most effective at that time and infections often begin at 13-years-old.
The Danish Health Agency, Danish Cancer Society and Danish Medical Association partnered on the information campaign, which was funded by the Danish Parliament's Health and Senior Citizen's Committee and the Danish Cancer Society. The campaign cost about $1 million USD in taxpayer funds, and aimed to provide information to people hesitant about the vaccine, as opposed to people unwilling to get the vaccine for their children, who likely wouldn't change their minds, the study said. The campaign focused on sharing personal stories from women with cervical cancer on social media and digital platforms.
Read more at Science Daily
New research from the University of North Carolina at Chapel Hill shows that, despite substantial progress, about 26,000 Danish girls remain unvaccinated as a result of vaccine misinformation. About 33,000 girls are born annually in Denmark. Among the unvaccinated girls, researchers expect to see as many as 180 avoidable cases of cervical cancer and 45 deaths.
The researchers found that misinformation in Danish media outlets from 2013-2016 led to vaccinations dropping by 50.4%. An information campaign geared toward concerned parents helped increase vaccine uptake again, but uptake is still below the level before misinformation began, showing how difficult it is to undo the damages misinformation causes.
The study results were published Jan. 7 in Vaccine. The paper's lead author is UNC-Chapel Hill Latané Distinguished Professor of Economics Peter R. Hansen. Hansen worked with Noel Brewer, professor of health behavior at Carolina and Lineberger Comprehensive Cancer Center member, and Matthias Schmidblaicher, graduate student in the Department of Economics at the European University Institute, on the research.
"Denmark is a good case study to see how a country deals with vaccine misinformation. By using anecdotal stories, media can create a false equivalence between outrageous claims and scientific facts," Hansen said. "The media stories that include inaccurate information cut HPV vaccine uptake in half. Recovery has been slow and costly. Resources are being used to combat misinformation instead of being used for healthcare benefits."
The HPV vaccine is safe and can prevent six cancers, including up to 90% of cervical cancers. Receiving the vaccine at 11- or 12-years-old is important because the vaccine is most effective at that time and infections often begin at 13-years-old.
The Danish Health Agency, Danish Cancer Society and Danish Medical Association partnered on the information campaign, which was funded by the Danish Parliament's Health and Senior Citizen's Committee and the Danish Cancer Society. The campaign cost about $1 million USD in taxpayer funds, and aimed to provide information to people hesitant about the vaccine, as opposed to people unwilling to get the vaccine for their children, who likely wouldn't change their minds, the study said. The campaign focused on sharing personal stories from women with cervical cancer on social media and digital platforms.
Read more at Science Daily
Jan 7, 2020
Ooh là là! Music evokes 13 key emotions: Scientists have mapped them
The "Star-Spangled Banner" stirs pride. Ed Sheeran's "The Shape of You" sparks joy. And "ooh là là!" best sums up the seductive power of George Michael's "Careless Whispers."
Scientists at the University of California, Berkeley, have surveyed more than 2,500 people in the United States and China about their emotional responses to these and thousands of other songs from genres including rock, folk, jazz, classical, marching band, experimental and heavy metal.
The upshot? The subjective experience of music across cultures can be mapped within at least 13 overarching feelings: Amusement, joy, eroticism, beauty, relaxation, sadness, dreaminess, triumph, anxiety, scariness, annoyance, defiance, and feeling pumped up.
"Imagine organizing a massively eclectic music library by emotion and capturing the combination of feelings associated with each track. That's essentially what our study has done," said study lead author Alan Cowen, a UC Berkeley doctoral student in neuroscience.
The findings are set to appear this week in the journal Proceedings of the National Academy of Sciences.
"We have rigorously documented the largest array of emotions that are universally felt through the language of music," said study senior author Dacher Keltner, a UC Berkeley professor of psychology.
Cowen translated the data into an interactive audio map, where visitors can move their cursors to listen to any of thousands of music snippets to find out, among other things, if their emotional reactions match how people from different cultures respond to the music.
Potential applications for these research findings range from informing psychological and psychiatric therapies designed to evoke certain feelings to helping music streaming services like Spotify adjust their algorithms to satisfy their customers' audio cravings or set the mood.
While both U.S. and Chinese study participants identified similar emotions -- such as feeling fear hearing the "Jaws" movie score -- they differed on whether those emotions made them feel good or bad.
"People from different cultures can agree that a song is angry, but can differ on whether that feeling is positive or negative," said Cowen, noting that positive and negative values, known in psychology parlance as "valence," are more culture-specific.
Furthermore, across cultures, study participants mostly agreed on general emotional characterizations of musical sounds, such as angry, joyful and annoying. But their opinions varied on the level of "arousal," which refers in the study to the degree of calmness or stimulation evoked by a piece of music.
For the study, more than 2,500 people in the United States and China were recruited via Amazon Mechanical Turk's crowdsourcing platform.
First, volunteers scanned thousands of videos on YouTube for music evoking a variety of emotions. From those, the researchers built a collection of audio clips to use in their experiments.
Next, nearly 2,000 study participants in the United States and China each rated some 40 music samples based on 28 different categories of emotion, as well as on a scale of positivity and negativity, and for levels of arousal.
Using statistical analyses, the researchers arrived at 13 overall categories of experience that were preserved across cultures and found to correspond to specific feelings, such as being "depressing" or "dreamy."
To ensure the accuracy of these findings in a second experiment, nearly 1,000 people from the United States and China rated over 300 additional Western and traditional Chinese music samples that were specifically intended to evoke variations in valence and arousal. Their responses validated the 13 categories.
Vivaldi's "Four Seasons" made people feel energized. The Clash's "Rock the Casbah" pumped them up. Al Green's "Let's Stay Together" evoked sensuality and Israel Kamakawiwo?ole's "Somewhere over the Rainbow" elicited joy.
Meanwhile, heavy metal was widely viewed as defiant and, just as its composer intended, the shower scene score from the movie "Psycho" triggered fear.
Researchers acknowledge that some of these associations may be based on the context in which the study participants had previously heard a certain piece of music, such as in a movie or YouTube video. But this is less likely the case with traditional Chinese music, with which the findings were validated.
Cowen and Keltner previously conducted a study in which they identified 27 emotions in response to evocative YouTube video clips. For Cowen, who comes from a family of musicians, studying the emotional effects of music seemed like the next logical step.
"Music is a universal language, but we don't always pay enough attention to what it's saying and how it's being understood," Cowen said. "We wanted to take an important first step toward solving the mystery of how music can evoke so many nuanced emotions."
Read more at Science Daily
Scientists at the University of California, Berkeley, have surveyed more than 2,500 people in the United States and China about their emotional responses to these and thousands of other songs from genres including rock, folk, jazz, classical, marching band, experimental and heavy metal.
The upshot? The subjective experience of music across cultures can be mapped within at least 13 overarching feelings: Amusement, joy, eroticism, beauty, relaxation, sadness, dreaminess, triumph, anxiety, scariness, annoyance, defiance, and feeling pumped up.
"Imagine organizing a massively eclectic music library by emotion and capturing the combination of feelings associated with each track. That's essentially what our study has done," said study lead author Alan Cowen, a UC Berkeley doctoral student in neuroscience.
The findings are set to appear this week in the journal Proceedings of the National Academy of Sciences.
"We have rigorously documented the largest array of emotions that are universally felt through the language of music," said study senior author Dacher Keltner, a UC Berkeley professor of psychology.
Cowen translated the data into an interactive audio map, where visitors can move their cursors to listen to any of thousands of music snippets to find out, among other things, if their emotional reactions match how people from different cultures respond to the music.
Potential applications for these research findings range from informing psychological and psychiatric therapies designed to evoke certain feelings to helping music streaming services like Spotify adjust their algorithms to satisfy their customers' audio cravings or set the mood.
While both U.S. and Chinese study participants identified similar emotions -- such as feeling fear hearing the "Jaws" movie score -- they differed on whether those emotions made them feel good or bad.
"People from different cultures can agree that a song is angry, but can differ on whether that feeling is positive or negative," said Cowen, noting that positive and negative values, known in psychology parlance as "valence," are more culture-specific.
Furthermore, across cultures, study participants mostly agreed on general emotional characterizations of musical sounds, such as angry, joyful and annoying. But their opinions varied on the level of "arousal," which refers in the study to the degree of calmness or stimulation evoked by a piece of music.
For the study, more than 2,500 people in the United States and China were recruited via Amazon Mechanical Turk's crowdsourcing platform.
First, volunteers scanned thousands of videos on YouTube for music evoking a variety of emotions. From those, the researchers built a collection of audio clips to use in their experiments.
Next, nearly 2,000 study participants in the United States and China each rated some 40 music samples based on 28 different categories of emotion, as well as on a scale of positivity and negativity, and for levels of arousal.
Using statistical analyses, the researchers arrived at 13 overall categories of experience that were preserved across cultures and found to correspond to specific feelings, such as being "depressing" or "dreamy."
To ensure the accuracy of these findings in a second experiment, nearly 1,000 people from the United States and China rated over 300 additional Western and traditional Chinese music samples that were specifically intended to evoke variations in valence and arousal. Their responses validated the 13 categories.
Vivaldi's "Four Seasons" made people feel energized. The Clash's "Rock the Casbah" pumped them up. Al Green's "Let's Stay Together" evoked sensuality and Israel Kamakawiwo?ole's "Somewhere over the Rainbow" elicited joy.
Meanwhile, heavy metal was widely viewed as defiant and, just as its composer intended, the shower scene score from the movie "Psycho" triggered fear.
Researchers acknowledge that some of these associations may be based on the context in which the study participants had previously heard a certain piece of music, such as in a movie or YouTube video. But this is less likely the case with traditional Chinese music, with which the findings were validated.
Cowen and Keltner previously conducted a study in which they identified 27 emotions in response to evocative YouTube video clips. For Cowen, who comes from a family of musicians, studying the emotional effects of music seemed like the next logical step.
"Music is a universal language, but we don't always pay enough attention to what it's saying and how it's being understood," Cowen said. "We wanted to take an important first step toward solving the mystery of how music can evoke so many nuanced emotions."
Read more at Science Daily
Need to control blood sugar? There's a drink for that
With more people with diabetes and pre-diabetes looking for strategies to help control blood sugar, new research from UBC's Okanagan campus suggests that ketone monoester drinks -- a popular new food supplement -- may help do exactly that.
"There has been a lot of excitement and interest in ketone drinks and supplements, which have really only been on the market and available to consumers for the last couple of years," says Jonathan Little, associate professor at UBC Okanagan's School of Health and Exercise Sciences and study lead author. "Because they're so new, there's very little research on how they can influence metabolism and we're among the first to look at their use in non-athletes."
Little says that Type 2 diabetes is a disease whereby the body is unable to control the level of sugar in the blood because defects in the functioning of a hormone called insulin.
"It's a disease that's becoming alarmingly common in Canada and approaching what many would consider epidemic levels," he says. "While Type 2 diabetes can be controlled with medications or injectable insulin, many people are looking to options that don't require taking pills every day or that are less invasive."
Ketone supplements are proving fertile ground for research into Type 2 diabetes because, according to Little, ketones are the natural fuel source of the body when it's in ketosis -- the metabolic byproduct of consuming a low carbohydrate, ketogenic diet.
"There is mounting evidence that a low carbohydrate ketogenic diet is very effective in controlling blood sugar and even reversing Type 2 diabetes," says Little. "We wanted to know what would happen if artificial ketones were given to those with obesity and at risk for Type 2 diabetes but who haven't been dieting."
To test the idea, Little and his team asked 15 people to consume a ketone drink after fasting overnight. After 30 minutes, they were then asked to drink a fluid containing 75 grams of sugar while blood samples were taken.
"It turns out that the ketone drink seemed to launch participants into a sort of pseudo-ketogenic state where they were better able to control their blood sugar levels with no changes to their insulin," explains Little. "It demonstrates that these supplements may have real potential as a valuable tool for those with Type 2 diabetes."
Little is quick to point out that ketone supplements are not a magic bullet in managing the disease.
"There are a number of problems that we still have to work out, including the fact that we still don't know what the long-term effects of consuming ketones are," he says. "And not to mention that the drink itself tastes absolutely terrible."
Read more at Science Daily
"There has been a lot of excitement and interest in ketone drinks and supplements, which have really only been on the market and available to consumers for the last couple of years," says Jonathan Little, associate professor at UBC Okanagan's School of Health and Exercise Sciences and study lead author. "Because they're so new, there's very little research on how they can influence metabolism and we're among the first to look at their use in non-athletes."
Little says that Type 2 diabetes is a disease whereby the body is unable to control the level of sugar in the blood because defects in the functioning of a hormone called insulin.
"It's a disease that's becoming alarmingly common in Canada and approaching what many would consider epidemic levels," he says. "While Type 2 diabetes can be controlled with medications or injectable insulin, many people are looking to options that don't require taking pills every day or that are less invasive."
Ketone supplements are proving fertile ground for research into Type 2 diabetes because, according to Little, ketones are the natural fuel source of the body when it's in ketosis -- the metabolic byproduct of consuming a low carbohydrate, ketogenic diet.
"There is mounting evidence that a low carbohydrate ketogenic diet is very effective in controlling blood sugar and even reversing Type 2 diabetes," says Little. "We wanted to know what would happen if artificial ketones were given to those with obesity and at risk for Type 2 diabetes but who haven't been dieting."
To test the idea, Little and his team asked 15 people to consume a ketone drink after fasting overnight. After 30 minutes, they were then asked to drink a fluid containing 75 grams of sugar while blood samples were taken.
"It turns out that the ketone drink seemed to launch participants into a sort of pseudo-ketogenic state where they were better able to control their blood sugar levels with no changes to their insulin," explains Little. "It demonstrates that these supplements may have real potential as a valuable tool for those with Type 2 diabetes."
Little is quick to point out that ketone supplements are not a magic bullet in managing the disease.
"There are a number of problems that we still have to work out, including the fact that we still don't know what the long-term effects of consuming ketones are," he says. "And not to mention that the drink itself tastes absolutely terrible."
Read more at Science Daily
A fast radio burst tracked down to a nearby galaxy
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| Gemini telescopes, Mauna Kea, Hawaii. |
In results published in the January 9 edition of Nature, the European VLBI Network (EVN) used eight telescopes spanning locations from the United Kingdom to China to simultaneously observe the repeating radio source known as FRB 180916.J0158+65. Using a technique known as Very Long Baseline Interferometry (VLBI), the researchers achieved a level of resolution high enough to localize the FRB to a region approximately seven light years across -- a feat comparable to an individual on Earth being able to distinguish a person on the Moon.
A 'very different' location for an FRB
With that level of precision, the research team was able to train an optical telescope onto the location to learn more about the environment from which the burst emanated. What they found has added a new chapter to the mystery surrounding the origins of FRBs.
"We used the eight-metre Gemini North telescope in Hawaii to take sensitive images that showed the faint spiral arms of a Milky-Way-like galaxy and showed that the FRB source was in a star-forming region in one of those arms," said co-author Shriharsh Tendulkar, a former McGill University postdoctoral researcher who co-led the optical imaging and spectroscopic analyses of the FRB's location.
"This is a very different environment for a repeating FRB, compared to the dwarf galaxy in which the first repeating FRB 121102 was discovered to reside."
CHIME team's hypotheses in line with observed data
The discovery lined up with a number of ideas CHIME/FRB researchers had put forward following their initial detection of the burst in 2018.
"The FRB is among the closest yet seen and we even speculated that it could be a more conventional object in the outskirts of our own galaxy," said co-author Mohit Bhardwaj, a McGill University doctoral student and CHIME team member.
"However the EVN observation proved that it's in a relatively nearby galaxy, making it still a puzzling FRB, but close enough to now study using many other telescopes."
Zooming in on the radio sky
Since it began operation in the summer of 2018, CHIME has detected dozens of fast radio bursts, greatly accelerating the rate of discovery of these transient astrophysical phenomena. With over 1,000 antennas, CHIME's large field of view gives it a much greater chance of picking up fleeting bursts than conventional radio telescopes that are able to observe only a small area of the sky at a time.
When it came to pinpointing FRB 180916, the CHIME/FRB team worked closely with their EVN colleagues to determine exactly where to point the VLBI telescopes.
"By recording and processing the raw signal from each of the antenna elements that make up CHIME, we were able to refine the source position to a level close enough for EVN to successfully observe and localize multiple bursts from this FRB source," said co-author Daniele Michilli, a McGill University postdoctoral researcher and CHIME/FRB team member.
FRB's proximity opens the way for further study
At half-a-billion light years from Earth, the source of FRB 180916 is around seven times closer than the only other repeating burst to have been localized, and more than 10 times closer than any of the few non-repeating FRBs scientists have managed to pinpoint. That's exciting for astronomers because it will enable more detailed study that may help narrow down the possible explanations for FRBs.
"We have a new chance to perhaps detect emissions at other wavelengths -- x-ray or visible light, for instance," said McGill University astrophysicist Victoria Kaspi, a leading member of the CHIME/FRB collaboration. "And if we did, that would be hugely constraining of the models."
Read more at Science Daily
NASA planet hunter finds Earth-size habitable-zone world
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| This illustration of TOI 700 d is based on several simulated environments for an ocean-covered version of the planet. |
TOI 700 d is one of only a few Earth-size planets discovered in a star's habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA's Kepler Space Telescope.
"TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars," said Paul Hertz, astrophysics division director at NASA Headquarters in Washington. "Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS. Confirming the planet's size and habitable zone status with Spitzer is another win for Spitzer as it approaches the end of science operations this January."
TESS monitors large swaths of the sky, called sectors, for 27 days at a time. This long stare allows the satellite to track changes in stellar brightness caused by an orbiting planet crossing in front of its star from our perspective, an event called a transit.
TOI 700 is a small, cool M dwarf star located just over 100 light-years away in the southern constellation Dorado. It's roughly 40% of the Sun's mass and size and about half its surface temperature. The star appears in 11 of the 13 sectors TESS observed during the mission's first year, and scientists caught multiple transits by its three planets.
The star was originally misclassified in the TESS database as being more similar to our Sun, which meant the planets appeared larger and hotter than they really are. Several researchers, including Alton Spencer, a high school student working with members of the TESS team, identified the error.
"When we corrected the star's parameters, the sizes of its planets dropped, and we realized the outermost one was about the size of Earth and in the habitable zone," said Emily Gilbert, a graduate student at the University of Chicago. "Additionally, in 11 months of data we saw no flares from the star, which improves the chances TOI 700 d is habitable and makes it easier to model its atmospheric and surface conditions."
Gilbert and other researchers presented the findings at the 235th meeting of the American Astronomical Societyin Honolulu, and three papers -- one of which Gilbert led -- have been submitted to scientific journals.
The innermost planet, called TOI 700 b, is almost exactly Earth-size, is probably rocky and completes an orbit every 10 days. The middle planet, TOI 700 c, is 2.6 times larger than Earth -- between the sizes of Earth and Neptune -- orbits every 16 days and is likely a gas-dominated world. TOI 700 d, the outermost known planet in the system and the only one in the habitable zone, measures 20% larger than Earth, orbits every 37 days and receives from its star 86% of the energy that the Sun provides to Earth. All of the planets are thought to be tidally locked to their star, which means they rotate once per orbit so that one side is constantly bathed in daylight.
A team of scientists led by Joseph Rodriguez, an astronomer at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts, requested follow-up observations with Spitzer to confirm TOI 700 d.
"Given the impact of this discovery -- that it is TESS's first habitable-zone Earth-size planet -- we really wanted our understanding of this system to be as concrete as possible," Rodriguez said. "Spitzer saw TOI 700 d transit exactly when we expected it to. It's a great addition to the legacy of a mission that helped confirm two of the TRAPPIST-1 planets and identify five more."
The Spitzer data increased scientists' confidence that TOI 700 d is a real planet and sharpened their measurements of its orbital period by 56% and its size by 38%. It also ruled out other possible astrophysical causes of the transit signal, such as the presence of a smaller, dimmer companion star in the system.
Rodriguez and his colleagues also used follow-up observations from a 1-meter ground-based telescope in the global Las Cumbres Observatory network to improve scientists' confidence in the orbital period and size of TOI 700 c by 30% and 36%, respectively.
Because TOI 700 is bright, nearby, and shows no sign of stellar flares, the system is a prime candidate for precise mass measurements by current ground-based observatories. These measurements could confirm scientists' estimates that the inner and outer planets are rocky and the middle planet is made of gas.
Future missions may be able to identify whether the planets have atmospheres and, if so, even determine their compositions.
While the exact conditions on TOI 700 d are unknown, scientists can use current information, like the planet's size and the type of star it orbits, to generate computer models and make predictions. Researchers at NASA's Goddard Space Flight Center in Greenbelt, Maryland, modeled 20 potential environments of TOI 700 d to gauge if any version would result in surface temperatures and pressures suitable for habitability.
Their 3D climate models examined a variety of surface types and atmospheric compositions typically associated with what scientists regard to be potentially habitable worlds. Because TOI 700 d is tidally locked to its star, the planet's cloud formations and wind patterns may be strikingly different from Earth's.
One simulation included an ocean-covered TOI 700 d with a dense, carbon-dioxide-dominated atmosphere similar to what scientists suspect surrounded Mars when it was young. The model atmosphere contains a deep layer of clouds on the star-facing side. Another model depicts TOI 700 d as a cloudless, all-land version of modern Earth, where winds flow away from the night side of the planet and converge on the point directly facing the star.
When starlight passes through a planet's atmosphere, it interacts with molecules like carbon dioxide and nitrogen to produce distinct signals, called spectral lines. The modeling team, led by Gabrielle Englemann-Suissa, a Universities Space Research Association visiting research assistant at Goddard, produced simulated spectra for the 20 modeled versions of TOI 700 d.
"Someday, when we have real spectra from TOI 700 d, we can backtrack, match them to the closest simulated spectrum, and then match that to a model," Englemann-Suissa said. "It's exciting because no matter what we find out about the planet, it's going to look completely different from what we have here on Earth."
TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA's Ames Research Center in California's Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT's Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.
The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.
Read more at Science Daily
Jan 6, 2020
Astronomers find wandering massive black holes in dwarf galaxies
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| Artist's conception of a dwarf galaxy, its shape distorted, most likely by a past interaction with another galaxy, and a massive black hole in its outskirts (pullout). The black hole is drawing in material that forms a rotating disk and generates jets of material propelled outward. |
These dwarf galaxies, more than 100 times less massive than our own Milky Way, are among the smallest galaxies known to host massive black holes. The scientists expect that the black holes in these smaller galaxies average about 400,000 times the mass of our Sun.
"We hope that studying them and their galaxies will give us insights into how similar black holes in the early Universe formed and then grew, through galactic mergers over billions of years, producing the supermassive black holes we see in larger galaxies today, with masses of many millions or billions of times that of the Sun," said Amy Reines of Montana State University.
Reines and her colleagues used the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to make the discovery, which they are reporting at the American Astronomical Society's meeting in Honolulu, Hawaii.
Reines and her collaborators used the VLA to discover the first massive black hole in a dwarf starburst galaxy in 2011. That discovery was a surprise to astronomers and spurred a radio search for more.
The scientists started by selecting a sample of galaxies from the NASA-Sloan Atlas, a catalog of galaxies made with visible-light telescopes. They chose galaxies with stars totalling less than 3 billion times the mass of the Sun, about equal to the Large Magellanic Cloud, a small companion of the Milky Way. From this sample, they picked candidates that also appeared in the National Radio Astronomy Observatory's Faint Images of the Radio Sky at Twenty centimeters (FIRST) survey, made between 1993 and 2011.
They then used the VLA to make new and more sensitive, high-resolution images of 111 of the selected galaxies.
"The new VLA observations revealed that 13 of these galaxies have strong evidence for a massive black hole that is actively consuming surrounding material. We were very surprised to find that, in roughly half of those 13 galaxies, the black hole is not at the center of the galaxy, unlike the case in larger galaxies," Reines said
The scientists said this indicates that the galaxies likely have merged with others earlier in their history. This is consistent with computer simulations predicting that roughly half of the massive black holes in dwarf galaxies will be found wandering in the outskirts of their galaxies.
"This work has taught us that we must broaden our searches for massive black holes in dwarf galaxies beyond their centers to get a more complete understanding of the population and learn what mechanisms helped form the first massive black holes in the early Universe," Reines said.
Read more at Science Daily
Study finds dopamine, biological clock link to snacking, overeating and obesity
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| Clock and eating concept. |
Coinciding with this increase in weight are ever-rising rates of heart disease, diabetes, cancer and health complications caused by obesity, such as hypertension. Even Alzheimer's disease may be partly attributable to obesity and physical inactivity.
"The diet in the U.S. and other nations has changed dramatically in the last 50 years or so, with highly processed foods readily and cheaply available at any time of the day or night," Ali Güler, a professor of biology at the University of Virginia, said. "Many of these foods are high in sugars, carbohydrates and calories, which makes for an unhealthy diet when consumed regularly over many years."
In a study published Thursday in the journal Current Biology, Güler and his colleagues demonstrate that the pleasure center of the brain that produces the chemical dopamine, and the brain's separate biological clock that regulates daily physiological rhythms, are linked, and that high-calorie foods -- which bring pleasure -- disrupt normal feeding schedules, resulting in overconsumption. Using mice as study models, the researchers mimicked the 24/7 availability of a high-fat diet, and showed that anytime snacking eventually results in obesity and related health problems.
Güler's team found that mice fed a diet comparable to a wild diet in calories and fats maintained normal eating and exercise schedules and proper weight. But mice fed high-calorie diets laden with fats and sugars began "snacking" at all hours and became obese.
Additionally, so-called "knockout" mice that had their dopamine signaling disrupted -- meaning they didn't seek the rewarding pleasure of the high-fat diet -- maintained a normal eating schedule and did not become obese, even when presented with the 24/7 availability of high-calorie feeds.
"We've shown that dopamine signaling in the brain governs circadian biology and leads to consumption of energy-dense foods between meals and during odd hours," Güler said.
Other studies have shown, Güler said, that when mice feed on high-fat foods between meals or during what should be normal resting hours, the excess calories are stored as fat much more readily than the same number of calories consumed only during normal feeding periods. This eventually results in obesity and obesity-related diseases, such as diabetes.
Speaking of the modern human diet, Güler said, "The calories of a full meal may now be packed into a small volume, such as a brownie or a super-size soda. It is very easy for people to over-consume calories and gain excessive weight, often resulting in obesity and a lifetime of related health problems.
"Half of the diseases that affect humans are worsened by obesity. And this results in the need for more medical care and higher health care costs for individuals, and society."
Güler said the human body, through thousands of years of evolution, is hard-wired to consume as much food as possible as long as it's available. He said this comes from a long earlier history when people hunted or gathered food and had brief periods of plenty, such as after a kill, and then potentially lengthy periods of famine. Humans also were potential prey to large animals and so actively sought food during the day, and sheltered and rested at night.
"We evolved under pressures we no longer have," Güler said. "It is natural for our bodies as organisms to want to consume as much as possible, to store fat, because the body doesn't know when the next meal is coming.
"But, of course, food is now abundant, and our next meal is as close as the kitchen, or the nearest fast-food drive-through, or right here on our desk. Often, these foods are high in fats, sugars, and therefore calories, and that's why they taste good. It's easy to overconsume, and, over time, this takes a toll on our health."
Additionally, Güler said, prior to the advent of our electricity-powered society, people started the day at dawn, worked all day, often doing manual labor, and then went to sleep with the setting of the sun. Human activity, therefore, was synchronized to day and night. Today, we are working, playing, staying connected -- and eating -- day and night. This, Guler said, affects our body clocks, which were evolved to operate on a sleep-wake cycle timed to daytime activity, moderate eating and nighttime rest.
Read more at Science Daily
Animal life thriving around Fukushima
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| Fukushima, Japan map. |
The camera study, published in the Journal of Frontiers in Ecology and the Environment, reports that over 267,000 wildlife photos recorded more than 20 species, including wild boar, Japanese hare, macaques, pheasant, fox and the raccoon dog -- a relative of the fox -- in various areas of the landscape.
UGA wildlife biologist James Beasley said speculation and questions have come from both the scientific community and the general public about the status of wildlife years after a nuclear accident like those in Chernobyl and Fukushima.
This recent study, in addition to the team's research in Chernobyl, provides answers to the questions.
"Our results represent the first evidence that numerous species of wildlife are now abundant throughout the Fukushima Evacuation Zone, despite the presence of radiological contamination," said Beasley, associate professor at the Savannah River Ecology Laboratory and the Warnell School of Forestry and Natural Resources.
Species that are often in conflict with humans, particularly wild boar, were predominantly captured on camera in human-evacuated areas or zones, according to Beasley.
"This suggests these species have increased in abundance following the evacuation of people."
The team, which included Thomas Hinton, professor at the Institute of Environmental Radioactivity at Fukushima University, identified three zones for the research.
Photographic data was gathered from 106 camera sites from three zones: humans excluded due to the highest level of contamination; humans restricted due to an intermediate level of contamination; and humans inhabited, an area where people have been allowed to remain due to "background" or very low levels of radiation found in the environment.
The researchers based their designations on zones previously established by the Japanese government after the 2011 Fukushima Daiichi accident.
For 120 days, cameras captured over 46,000 images of wild boar. Over 26,000 of those images were taken in the uninhabited area, compared to approximately 13,000 in the restricted and 7,000 in the inhabited zones.
Other species seen in higher numbers in the uninhabited or restricted zones included raccoons, Japanese marten and Japanese macaque or monkeys.
Anticipating questions about physiological condition of the wildlife, Hinton said their results are not an assessment of an animal's health.
"This research makes an important contribution because it examines radiological impacts to populations of wildlife, whereas most previous studies have looked for effects to individual animals," said Hinton.
The uninhabited zone served as the control zone for the research.
The scientists said although there is no previous data on wildlife populations in the evacuated areas, the close proximity and similar landscape of the human-inhabited zone made the area the ideal control for the study.
The team evaluated the impact of other variables: distance to road, time of activity as captured by the cameras' date-time stamps, vegetation type and elevation.
"The terrain varies from mountainous to coastal habitats, and we know these habitats support different types of species. To account for these factors, we incorporated habitat and landscape attributes such as elevation into our analysis," Beasley said.
"Based on these analyses, our results show that level of human activity, elevation and habitat type were the primary factors influencing the abundance of the species evaluated, rather than radiation levels."
The study's results indicate the activity pattern of most species aligned with their well-known history or behavior patterns. Raccoons, who are nocturnal, were more active during the night, while pheasants, which are diurnal animals, were more active during the day. However, wild boar inside the uninhabited area were more active during the day than boar in human-inhabited areas, suggesting they may be modifying their behavior in the absence of humans.
One exception to these patterns was the Japanese serow, a goat-like mammal. Normally far-removed from humans, they were most frequently seen on the camera footage in rural human-inhabited upland areas. The researchers suggest this might be a behavioral adjustment to avoid the rapidly growing boar population in the evacuated zone.
Read more at Science Daily
Some genetic sequencing fail to analyze large segments of DNA
Children who undergo expansive genetic sequencing may not be getting the thorough DNA analysis their parents were expecting, say experts at UT Southwestern Medical Center.
A review of clinical tests from three major U.S. laboratories shows whole exome sequencing routinely fails to adequately analyze large segments of DNA, a potentially critical deficiency that can prevent doctors from accurately diagnosing potential genetic disorders, from epilepsy to cancer.
The reanalysis by UT Southwestern shows each lab on average adequately examined less than three-quarters of the genes -- 34, 66, and 69 percent coverage -- and had startlingly wide gaps in their ability to detect specific disorders.
Researchers say they conducted the study because they believe vast differences in testing quality are endemic in clinical genetic sequencing but have not been well documented or shared with clinicians.
"Many of the physicians who order these tests don't know this is happening," says Jason Park, M.D., Ph.D., associate professor of pathology at UT Southwestern. "Many of their patients are young kids with neurological disorders, and they want to get the most complete diagnostic test. But they don't realize whole exome sequencing may miss something that a more targeted genetic test would find."
Whole exome sequencing, a technique for analyzing protein-producing genes, is increasingly used in health care to identify genetic mutations that cause disease -- mostly in children but also in adults with rare or undiagnosed diseases. However, Park says the process of fully analyzing the approximately 18,000 genes in an exome is inherently difficult and prone to oversights. About half the tests do not pinpoint a mutation.
The new study published in Clinical Chemistry gives insight into why some analyses may be coming back negative.
Researchers re-analyzed 36 patients' exome tests conducted between 2012 and 2016 -- 12 from each of the three national clinical laboratories -- and found starkly contrasting results and inconsistency with which genes were completely analyzed. A gene was not considered completely analyzed unless the lab met an industry-accepted threshold for adequate analysis of all DNA that encodes protein, which is defined as sequencing that segment at least 20 times per test.
Notably, less than 1.5 percent of the genes were completely analyzed in all 36 samples. A review of one lab's tests showed 28 percent of the genes were never adequately examined and only 5 percent were always covered. Another lab consistently covered 27 percent of the genes.
"And things really start to fall apart when you start thinking about using these tests to rule out a disease," Park says. "A negative exome result is meaningless when so many of the genes are not thoroughly analyzed."
For example, the chances of detecting an epileptic disorder from any of the 36 tests varied widely depending on which genes were analyzed. One lab conducted several patient tests that fully examined more than three quarters of the genes associated with epilepsy, but the same lab had three other patient samples in which less than 40 percent were completely analyzed.
Three tests from another lab came in at under 20 percent.
"When we saw this data we made it a regular practice to ask the labs about coverage of specific genes," says Garrett Gotway, M.D., Ph.D., a clinical geneticist at UT Southwestern who is the corresponding author of the study. "I don't think you can expect complete coverage of 18,000 genes every time, but it's fair to expect 90 percent or more."
The findings build upon previous research that showed similar gaps and disparities in whole genome sequencing, a technique that examines all types of genes, regardless of whether they produce proteins.
Gotway says he hopes the findings will prompt more physicians to ask labs about which genes were covered and push for improved consistency in testing quality. He also encourages physicians -- even before ordering the test -- to consider whether whole exome sequencing is the best approach for the patient.
"Clinical exomes can be helpful in complex cases, but you probably don't need one if a kid has epilepsy and doesn't have other complicating clinical problems," Gotway says. "There's a decent chance the exome test will come back negative and the parents are still left wondering about the genetic basis for their child's disease."
Read more at Science Daily
A review of clinical tests from three major U.S. laboratories shows whole exome sequencing routinely fails to adequately analyze large segments of DNA, a potentially critical deficiency that can prevent doctors from accurately diagnosing potential genetic disorders, from epilepsy to cancer.
The reanalysis by UT Southwestern shows each lab on average adequately examined less than three-quarters of the genes -- 34, 66, and 69 percent coverage -- and had startlingly wide gaps in their ability to detect specific disorders.
Researchers say they conducted the study because they believe vast differences in testing quality are endemic in clinical genetic sequencing but have not been well documented or shared with clinicians.
"Many of the physicians who order these tests don't know this is happening," says Jason Park, M.D., Ph.D., associate professor of pathology at UT Southwestern. "Many of their patients are young kids with neurological disorders, and they want to get the most complete diagnostic test. But they don't realize whole exome sequencing may miss something that a more targeted genetic test would find."
Whole exome sequencing, a technique for analyzing protein-producing genes, is increasingly used in health care to identify genetic mutations that cause disease -- mostly in children but also in adults with rare or undiagnosed diseases. However, Park says the process of fully analyzing the approximately 18,000 genes in an exome is inherently difficult and prone to oversights. About half the tests do not pinpoint a mutation.
The new study published in Clinical Chemistry gives insight into why some analyses may be coming back negative.
Researchers re-analyzed 36 patients' exome tests conducted between 2012 and 2016 -- 12 from each of the three national clinical laboratories -- and found starkly contrasting results and inconsistency with which genes were completely analyzed. A gene was not considered completely analyzed unless the lab met an industry-accepted threshold for adequate analysis of all DNA that encodes protein, which is defined as sequencing that segment at least 20 times per test.
Notably, less than 1.5 percent of the genes were completely analyzed in all 36 samples. A review of one lab's tests showed 28 percent of the genes were never adequately examined and only 5 percent were always covered. Another lab consistently covered 27 percent of the genes.
"And things really start to fall apart when you start thinking about using these tests to rule out a disease," Park says. "A negative exome result is meaningless when so many of the genes are not thoroughly analyzed."
For example, the chances of detecting an epileptic disorder from any of the 36 tests varied widely depending on which genes were analyzed. One lab conducted several patient tests that fully examined more than three quarters of the genes associated with epilepsy, but the same lab had three other patient samples in which less than 40 percent were completely analyzed.
Three tests from another lab came in at under 20 percent.
"When we saw this data we made it a regular practice to ask the labs about coverage of specific genes," says Garrett Gotway, M.D., Ph.D., a clinical geneticist at UT Southwestern who is the corresponding author of the study. "I don't think you can expect complete coverage of 18,000 genes every time, but it's fair to expect 90 percent or more."
The findings build upon previous research that showed similar gaps and disparities in whole genome sequencing, a technique that examines all types of genes, regardless of whether they produce proteins.
Gotway says he hopes the findings will prompt more physicians to ask labs about which genes were covered and push for improved consistency in testing quality. He also encourages physicians -- even before ordering the test -- to consider whether whole exome sequencing is the best approach for the patient.
"Clinical exomes can be helpful in complex cases, but you probably don't need one if a kid has epilepsy and doesn't have other complicating clinical problems," Gotway says. "There's a decent chance the exome test will come back negative and the parents are still left wondering about the genetic basis for their child's disease."
Read more at Science Daily
Jan 5, 2020
Researchers learn more about teen-age T.Rex
Without a doubt, Tyrannosaurus rex is the most famous dinosaur in the world. The 40-foot-long predator with bone crushing teeth inside a five-foot long head are the stuff of legend. Now, a look within the bones of two mid-sized, immature T. rex allow scientists to learn about the tyrant king's terrible teens as well.
In the early 2000s, the fossil skeletons of two comparatively small T. rex were collected from Carter County, Montana, by Burpee Museum of Natural History in Rockford, Illinois. Nicknamed "Jane" and "Petey," the tyrannosaurs would have been slightly taller than a draft horse and twice as long.
The team led by Holly Woodward, Ph.D., from Oklahoma State University Center for Health Sciences studied Jane and Petey to better understand T. rex life history.
The study "Growing up Tyrannosaurus rex: histology refutes pygmy 'Nanotyrannus' and supports ontogenetic niche partitioning in juvenile Tyrannosaurus" appears in the peer-reviewed journal Science Advances.
Co-authors include Jack Horner, presidential fellow at Chapman University; Nathan Myhrvold, founder and CEO of Intellectual Ventures; Katie Tremaine, graduate student at Montana State University; Scott Williams, paleontology lab and field specialist at Museum of the Rockies; and Lindsay Zanno, division head of paleontology at the North Carolina Museum of Natural Sciences. Supplemental histological work was conducted at the Diane Gabriel Histology Labs at Museum of the Rockies/Montana State University.
"Historically, many museums would collect the biggest, most impressive fossils of a dinosaur species for display and ignore the others," said Woodward. "The problem is that those smaller fossils may be from younger animals. So, for a long while we've had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception."
The smaller size of Jane and Petey is what make them so incredibly important. Not only can scientists now study how the bones and proportions changed as T. rex matured, but they can also utilize paleohistology -- the study of fossil bone microstructure -- to learn about juvenile growth rates and ages. Woodward and her team removed thin slices from the leg bones of Jane and Petey and examined them at high magnification.
"To me, it's always amazing to find that if you have something like a huge fossilized dinosaur bone, it's fossilized on the microscopic level as well," Woodward said. "And by comparing these fossilized microstructures to similar features found in modern bone, we know they provide clues to metabolism, growth rate, and age."
The team determined that the small T. rex were growing as fast as modern-day warm-blooded animals such as mammals and birds. Woodward and her colleagues also found that by counting the annual rings within the bone, much like counting tree rings, Jane and Petey were teenaged T.rex when they died; 13 and 15 years old, respectively.
There had been speculation that the two small skeletons weren't T. rex at all, but a smaller pygmy relative Nanotyrannus. Study of the bones using histology led the researchers to the conclusion that the skeletons were juvenile T. rex and not a new pygmy species.
Instead, Woodward points out, because it took T. rex up to twenty years to reach adult size, the tyrant king probably underwent drastic changes as it matured. Juveniles such as Jane and Petey were fast, fleet footed, and had knife-like teeth for cutting, whereas adults were lumbering bone crushers. Not only that, but Woodward's team discovered that growing T. rex could do a neat trick: if its food source was scarce during a particular year, it just didn't grow as much. And if food was plentiful, it grew a lot.
"The spacing between annual growth rings record how much an individual grows from one year to the next. The spacing between the rings within Jane, Petey, and even older individuals is inconsistent -- some years the spacing is close together, and other years it's spread apart," said Woodward.
Read more at Science Daily
In the early 2000s, the fossil skeletons of two comparatively small T. rex were collected from Carter County, Montana, by Burpee Museum of Natural History in Rockford, Illinois. Nicknamed "Jane" and "Petey," the tyrannosaurs would have been slightly taller than a draft horse and twice as long.
The team led by Holly Woodward, Ph.D., from Oklahoma State University Center for Health Sciences studied Jane and Petey to better understand T. rex life history.
The study "Growing up Tyrannosaurus rex: histology refutes pygmy 'Nanotyrannus' and supports ontogenetic niche partitioning in juvenile Tyrannosaurus" appears in the peer-reviewed journal Science Advances.
Co-authors include Jack Horner, presidential fellow at Chapman University; Nathan Myhrvold, founder and CEO of Intellectual Ventures; Katie Tremaine, graduate student at Montana State University; Scott Williams, paleontology lab and field specialist at Museum of the Rockies; and Lindsay Zanno, division head of paleontology at the North Carolina Museum of Natural Sciences. Supplemental histological work was conducted at the Diane Gabriel Histology Labs at Museum of the Rockies/Montana State University.
"Historically, many museums would collect the biggest, most impressive fossils of a dinosaur species for display and ignore the others," said Woodward. "The problem is that those smaller fossils may be from younger animals. So, for a long while we've had large gaps in our understanding of how dinosaurs grew up, and T. rex is no exception."
The smaller size of Jane and Petey is what make them so incredibly important. Not only can scientists now study how the bones and proportions changed as T. rex matured, but they can also utilize paleohistology -- the study of fossil bone microstructure -- to learn about juvenile growth rates and ages. Woodward and her team removed thin slices from the leg bones of Jane and Petey and examined them at high magnification.
"To me, it's always amazing to find that if you have something like a huge fossilized dinosaur bone, it's fossilized on the microscopic level as well," Woodward said. "And by comparing these fossilized microstructures to similar features found in modern bone, we know they provide clues to metabolism, growth rate, and age."
The team determined that the small T. rex were growing as fast as modern-day warm-blooded animals such as mammals and birds. Woodward and her colleagues also found that by counting the annual rings within the bone, much like counting tree rings, Jane and Petey were teenaged T.rex when they died; 13 and 15 years old, respectively.
There had been speculation that the two small skeletons weren't T. rex at all, but a smaller pygmy relative Nanotyrannus. Study of the bones using histology led the researchers to the conclusion that the skeletons were juvenile T. rex and not a new pygmy species.
Instead, Woodward points out, because it took T. rex up to twenty years to reach adult size, the tyrant king probably underwent drastic changes as it matured. Juveniles such as Jane and Petey were fast, fleet footed, and had knife-like teeth for cutting, whereas adults were lumbering bone crushers. Not only that, but Woodward's team discovered that growing T. rex could do a neat trick: if its food source was scarce during a particular year, it just didn't grow as much. And if food was plentiful, it grew a lot.
"The spacing between annual growth rings record how much an individual grows from one year to the next. The spacing between the rings within Jane, Petey, and even older individuals is inconsistent -- some years the spacing is close together, and other years it's spread apart," said Woodward.
Read more at Science Daily
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