суббота, 20 апреля 2019 г.

Patterns of Transmission Tuberculosis (TB) affects about a…


Patterns of Transmission


Tuberculosis (TB) affects about a third of the world’s population. Seven lineages of the causative bacterium Mycobacterium tuberculosis (Mtb) are composed of different strains, which vary according to characteristics like drug sensitivity. A study of 124 TB patients in Brazil and the more than 700 individuals who’d been in close contact subdivided a lineage of Mtb into two strains, high (HT) and low (LT), according to how effectively they’d transmitted disease. Now the team has looked in mice at the lung damage the two strains cause. Immune cells called macrophages filled with lipid droplets are a hallmark of Mtb infection. In mice with Mtb-HT discrete collections of macrophages (granulomas) developed with fewer lipid droplets and containing fewer bacteria (the black squiggles seen here centrally) than the widespread inflammatory macrophages found with Mtb-LT. How the immune system interacts with Mtb apparently leads to distinct patterns of bacterial growth and damage, which in turn underlies the subsequent differences in infectiousness.


Written by Lindsey Goff



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2019 April 20 Falcon Heavy Launch Close Up Image Credit:…


2019 April 20


Falcon Heavy Launch Close Up
Image Credit: SpaceX


Explanation: Twenty seven Merlin rocket engines are firing in this close-up of the launch of a Falcon Heavy rocket. Derived from three Falcon 9 first stage rockets with nine Merlin rocket engines each, the Falcon Heavy left NASA’s Kennedy Space Center launch pad 39A on April 11. This second launch of a Falcon Heavy rocket carried the Arabsat 6A communications satellite to space. In February of 2018, the first Falcon Heavy launch carried Starman and a Tesla Roadster. Designed to be reusable, both booster stages and the central core returned safely to planet Earth, the boosters to Cape Canaveral Air Force Station landing zones. The core stage landed off shore on autonomous spaceport drone ship Of Course I Still Love You.


∞ Source: apod.nasa.gov/apod/ap190420.html


Scientists restore some functions in a pig’s brain hours after death

Circulation and cellular activity were restored in a pig’s brain four hours after its death, a finding that challenges long-held assumptions about the timing and irreversible nature of the cessation of some brain functions after death, Yale scientists report in the journal Nature.











Scientists restore some functions in a pig's brain hours after death
Immunofluorescent stains for neurons (NeuN; green), astrocytes (GFAP; red), and cell nuclei (DAPI, blue) in the
hippocampal CA3 region of brains either unperfused for 10 hours after death (left) or subjected to perfusion
with the BrainEx technology (right). After 10 hours postmortem, neurons and astrocytes normally undergo
cellular disintegration unless salvaged by the BrainEx system [Credit: Stefano G. Daniele
& Zvonimir Vrselja; Sestan Laboratory; Yale School of Medicine]

The brain of a postmortem pig obtained from a meatpacking plant was isolated and circulated with a specially designed chemical solution. Many basic cellular functions, once thought to cease seconds or minutes after oxygen and blood flow cease, were observed, the scientists report.


«The intact brain of a large mammal retains a previously underappreciated capacity for restoration of circulation and certain molecular and cellular activities multiple hours after circulatory arrest,» said senior author Nenad Sestan, professor of neuroscience, comparative medicine, genetics, and psychiatry.


However, researchers also stressed that the treated brain lacked any recognizable global electrical signals associated with normal brain function.


«At no point did we observe the kind of organized electrical activity associated with perception, awareness, or consciousness,» said co-first author Zvonimir Vrselja, associate research scientist in neuroscience. «Clinically defined, this is not a living brain, but it is a cellularly active brain.»


Cellular death within the brain is usually considered to be a swift and irreversible process. Cut off from oxygen and a blood supply, the brain’s electrical activity and signs of awareness disappear within seconds, while energy stores are depleted within minutes. Current understanding maintains that a cascade of injury and death molecules are then activated leading to widespread, irreversible degeneration.


However, researchers in Sestan’s lab, whose research focuses on brain development and evolution, observed that the small tissue samples they worked with routinely showed signs of cellular viability, even when the tissue was harvested multiple hours postmortem. Intrigued, they obtained the brains of pigs processed for food production to study how widespread this postmortem viability might be in the intact brain. Four hours after the pig’s death, they connected the vasculature of the brain to circulate a uniquely formulated solution they developed to preserve brain tissue, utilizing a system they call BrainEx. They found neural cell integrity was preserved, and certain neuronal, glial, and vascular cell functionality was restored.


The new system can help solve a vexing problem — the inability to apply certain techniques to study the structure and function of the intact large mammalian brain — which hinders rigorous investigations into topics like the roots of brain disorders, as well as neuronal connectivity in both healthy and abnormal conditions.


«Previously, we have only been able to study cells in the large mammalian brain under static or largely two-dimensional conditions utilizing small tissue samples outside of their native environment,» said co-first author Stefano G. Daniele, an M.D./Ph.D. candidate. «For the first time, we are able to investigate the large brain in three dimensions, which increases our ability to study complex cellular interactions and connectivity.»


While the advance has no immediate clinical application, the new research platform may one day be able to help doctors find ways to help salvage brain function in stroke patients, or test the efficacy of novel therapies targeting cellular recovery after injury, the authors say.


The research was primarily funded by the National Institutes of Health’s (NIH) BRAIN Initiative.


«This line of research holds hope for advancing understanding and treatment of brain disorders and could lead to a whole new way of studying the postmortem human brain,» said Andrea Beckel-Mitchener, chief of functional neurogenomics at the NIH’s National Institute of Mental Health, which co-funded the research.


The researchers said that it is unclear whether this approach can be applied to a recently deceased human brain. The chemical solution used lacks many of the components natively found in human blood, such as the immune system and other blood cells, which makes the experimental system significantly different from normal living conditions. However, the researcher stressed any future study involving human tissue or possible revival of global electrical activity in postmortem animal tissue should be done under strict ethical oversight.


«Restoration of consciousness was never a goal of this research,» said co-author Stephen Latham, director of Yale’s Interdisciplinary Center for Bioethics. «The researchers were prepared to intervene with the use of anesthetics and temperature-reduction to stop organized global electrical activity if it were to emerge. Everyone agreed in advance that experiments involving revived global activity couldn’t go forward without clear ethical standards and institutional oversight mechanisms.»


There is an ethical imperative to use tools developed by the Brain Initiative to unravel mysteries of brain injuries and disease, said Christine Grady, chief of the Department of Bioethics at the NIH Clinical Center.


«It’s also our duty to work with researchers to thoughtfully and proactively navigate any potential ethical issues they may encounter as they open new frontiers in brain science,» she said.


Author: Bill Hathaway | Source: Yale University [April 17, 2019]



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Researchers discover ‘ghostly’ signs of a mysterious new mineral

An international research team including Curtin University scientists has documented the ‘ghost’ of an undiscovered mineral at two ancient meteorite impact craters.











Researchers discover 'ghostly' signs of a mysterious new mineral
Monazite under a microscope showing the former presence of a new mineral
[Credit: Curtin University]

The new study, published in the journal Geology, is the first to document evidence of a new form of the mineral monazite, which only exists on Earth during the immense pressures exerted by meteorite impacts.


Study co-author Associate Professor Nick Timms, from Curtin’s Space Science and Technology Centre, said the international research team made their discovery by looking at tiny rock fragments from impact craters in Germany and Canada using a high-powered electron microscope.


«We found microscopic evidence that monazite, a rare earth element phosphate, transformed to another crystal structure under high pressure from a shockwave, similar to how graphite can turn into diamond under pressure,» Professor Timms said.


«However, the mineral reverted to its original crystal structure instead of maintaining this new structural form, and while the new mineral only existed for fractions of a second as the shockwave passed through the Earth close to ground zero, it left unique crystallographic clues to its existence.


«We are on the verge of discovering a new mineral, but there is a hitch because the mineral is not stable at the Earth’s surface and readily transforms back to monazite again. Therefore, we have really only seen, and will probably only ever see, its ‘ghost’.»


The evidence for the new mineral was found at two ancient meteorite impact craters – the Ries Crater in Germany and the Haughton impact structure in arctic Canada – but until the elusive mineral is found preserved in rocks, scientists cannot give it a proper name.


Source: Curtin University [April 17, 2019]



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Fish that outlived dinosaurs reveals secrets of ancient skull evolution

A new study into one of the world’s oldest types of fish, Coelacanth, provides fresh insights into the development of the skull and brain of vertebrates and the evolution of lobe-finned fishes and land animals, as published in Nature.











Fish that outlived dinosaurs reveals secrets of ancient skull evolution
Coelacanth off waters near South Africa [Credit: Laurent Ballista,
Gombessa expeditions, Andromede Oceanology Ltd]

Coelacanth (Latimeria chalumnae) is so rare it was thought to have gone extinct with dinosaurs over 65 million years ago. But the discovery of a living specimen off the coast of South Africa in 1938 prompted debate about whether this fish fits into our understanding about the evolution of land animals.


The skull of this fish also happens to be completely split in half a by special ‘intracranial joint’ and it’s brain is so ridiculously small, it remains only one percent the size of the cavity that houses it, which makes Coelacanth survival unique amongst all living vertebrates.


The new paper from an international team of researchers provides insights into the biology of the unique skull of this fish and its links to the evolution of vertebrate species, including humans.


How the coelacanth skull grows and why the brain remains so small has remained a secret for thousands of years but a team of researchers, led by Dr Hugo Dutel at the University of Bristol, have studied its brain cavity at different stages of development to understand when the skull divides to form a hinged brain case.











Fish that outlived dinosaurs reveals secrets of ancient skull evolution
Vertebrate family tree [Credit: Dr. Hugo Dutel, Bristol University]

Collaborator Professor John Long from Flinders University says the discovery provides a better understanding of why ancient fossil fish had hinged heads and suggests why four limbed animals later lost this joint between two parts of their skull.


«We think that formation of this special joint is probably caused by the unique development of the notochord (a tube extending below the brain and the spinal cord in the early stages of life).


«It usually degenerates into a small rod below the brain in some fishes. However, the notochord for Coelacanth expands dramatically to become 50 times bigger than the brain in the adult fish.»


«This process of brain growth is very unusual, especially compared to primates like us in which the brain expands dramatically. A mismatch between the brain and its cavity also exists in some other living and fossil fishes, but what is observed here is totally unequalled among vertebrates.»











Fish that outlived dinosaurs reveals secrets of ancient skull evolution
The overall anterolateral view of the skull of the Coelacanth’s foetus.
The brain is in yellow [Credit: Dutel et al. 2019]

Two species of primitive, slow-moving coelacanths still around today are often called «living fossils» because they remain physically unchanged.


The scientists used state-of-the-art imaging techniques to visualize the internal anatomy of the fish without damaging them.


They digitalized a 5 cm-long fetus, the earliest developmental stage available, with synchrotron X-ray at the European Synchrotron (ESRF).


The data was used to generate detailed 3D models, which allowed the team to analyse how the form of the skull, the brain and the notochord changes from a fetus to an adult.



Professor John Long explains new paper providing insights into the biology of the unique skull 


and brain of coelacanth [Credit: Flinders University]


«Coelacanths are iconic animals thought to be on the line to the first land animals or tetrapods, because of their strange hinged head,» says Professor Long.


«This new research shows the peculiar hinge in the skull was caused by persistence of the large cartilaginous rod, or notochord, preventing the skull form ossifying as one solid unit.»


The team also observed how these structures are positioned relative to each other at each stage, and compared their observations with what is known about the formation of the skull in other vertebrates.


Dr Hutel says These are very unique observations, but they represent only a tiny step forward compared to the amount we know on the development of other species.


«There are still more questions than answers! Latimeria still holds many clues for our understanding of vertebrate evolution, and it is important to protect this threatened species and its environment.»


Source: Flinders University [April 17, 2019]



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Argentinian researchers discover an extraordinary 220 million year old animal cemetery in...

It is a surprising accumulation of fossils that would belong to dinosaurs, giant crocodiles and mammalian ancestors. In this «bed of bones», there are skulls and dismembered parts of, at least, seven or eight individuals, although there could be many more.











Argentinian researchers discover an extraordinary 220 million year old animal cemetery in San Juan
The fossilised dinosaur remains discovered in western Argentina are believed
to be 220 million years old [Credit: CTyS-UNLaM Agency]

Dr. Ricardo Martínez, a researcher at the Institute and Museum of Natural Sciences of the University of San Juan (IMCN), highlighted the CTyS-UNLaM Agency that “it is a mass of almost bone against bone, there are no sediments; it is as if they had made a well and filled it with bones”.


In 2014, IMCN investigators had also released another bonebed, but that accumulation was not at all comparable to the one announced today. “This is something impressive; it’s as if, here, the carnivores had a well and were pulling the bones after the meal”, joked the paleontologist.


In times of re-releases of Pet Sematary, this finding is an increased remastering of the bed of bones found years ago in Balde de Leyes, which is another very important site located southeast of the province of San Juan. If you want, too, with an even more terrifying image.


Dr. Martinez compared: “What we find now is a true accumulation of bones, glued together, with skulls, jaws, of at least 10 different animals totally disarticulated, piled bone on bone”.











Argentinian researchers discover an extraordinary 220 million year old animal cemetery in San Juan
Scientists speculate the site was a former drinking hole at a time of great drought,
where the creatures died of weakness [Credit: CTyS-UNLaM Agency]

The diameter of this bone bed is King size, about two meters. Meanwhile, the depth may be much greater than that of a sommier. “So far, we have managed to dig about 50 centimeters and it continue down, so it could have a depth of a meter or two, we do not know, but, with what we have seen so far, it is already impressive», pondered the chief of the IMCN paleontology area. He added: «In addition, we verify that the diameter of the accumulation grows as we move forward with the excavation”.


Dr. Cecilia Apaldetti, researcher at IMCN and CONICET, explained that the finding was made in September of last year and, now, after the summer season in which there are no campaigns because of the high temperatures and the rains, they have returned with the intention to extract the entire block.


«However, this accumulation of bones is bigger than we thought, we still can not find the base and we will return to the site in these weeks with more people and more logistics, to be able to extract the entire block, for which we must make a concrete base and, of course, we will need a crane and adequate machinery to be able to achieve it”, Apaldetti told the CTyS-UNLaM Agency.


Beyond the fact that the famous Ischigualasto basin in San Juan always surprises, researchers claim never to have seen anything like it. «It is very difficult to find a cause to this tremendous accumulation of bones”, remarked Martinez, who directs this research.











Argentinian researchers discover an extraordinary 220 million year old animal cemetery in San Juan
Scientists preparing the fossil bed for transporation
[Credit: CTyS-UNLaM Agency]

The expert noted that, beyond the extraordinary that is this accumulation, the finding has an even greater scientific value, «because these bones belong to a time interval that is among the fauna of Los Colorados, in which there was a great abundance of herbivorous dinosaurs especially sauropodomorphs and, below, is the Ischigualasto formation that has the most primitive and ancient dinosaurs known in the world”.


But in this interval that would be about 220 million years old, many species were not known and here a lot of individuals have been found, at least seven or eight, although there may be many more.


Among these new species, there would be discinodes -predecessors of mammals the size of an ox- and other archosaurs that, surely, are unknown species that can be dinosaurs and the giant ancestors of crocodiles, for example.


The researchers run a hypothesis about the factors that would have allowed this surprising accumulation of bones worthy of the imagination of a Stephen King of the Triassic. «Our theory is that it could have been a time of great drought and there was a body of water, a small lake for example, in which the herbivores were piled up to drink and, as the water evaporated, they were weakening and they were dying in the place”.



Once dead, other animals trampled their bodies and also appeared predators that partially disintegrated their bones. «Many of the predators also died on the spot, either because of the scarcity of water or because this site became a kind of trap for them”, Martínez said. He added: «This is how we thought that this great accumulation of bones would have taken place that we do not yet know the depth and the extension that it has; We will know this as we move forward with the investigation”.


Source: CTyS-UNLaM Agency [April 18, 2019]



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Researchers hunt for 17th century ‘witch bottles’

A team of archaeologists and historians from MOLA and the University of Hertfordshire are calling on people who may have discovered 17th century ‘witch bottles’ during restoration work or know of examples curated at their places of work, to come forward.











Researchers hunt for 17th century 'witch bottles'
Credit: University of Hertfordshire

‘Witch bottles’ is the name given to 17th century stoneware and glass vessels believed to have served as objects for ritual protection or as the containers of a ‘prepared cure’ against witchcraft. Their contents most commonly include pins and nails, but sometimes also urine, nail clippings and thorns. They have been found deliberately concealed in a range of places: in hearths or beneath the floors of historic buildings, in churchyards, ditches and riverbanks, and on archaeological sites


MOLA Finds Specialist Nigel Jeffries, and Professor Owen Davies and Dr. Ceri Houlbrook from the University of Hertfordshire are conducting the most comprehensive synthesis of evidence relating to the much practice mythologised phenomenon of ‘witch bottles’ ever undertaken. Led by Jeffries, ‘Bottles concealed and revealed’ is a three year project funded by the Arts and Humanities Research Council.


For the first time, all known examples that survive in museums and other collections around Southern and Eastern England (the apparent geographical extent of the phenomenon) are to be surveyed first-hand or through literature review and critiqued along with their contents. Extensive research will also be done to explore the origins of the practice and to situate ‘witch bottles’ in their full historic and cultural context, perhaps debunking some myths along the way.


The team asks that anyone who believes they may have found a ‘witch bottle’ to treat it as an archaeological artefact, not move it, and report it to their local Finds Liaison Officer at the Portable Antiquities Scheme before notifying the ‘Bottles concealed team’ by email: witchbottles@mola.org.uk


Source: University of Hertfordshire [April 18, 2019]



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Daily grind: The biography of a stone axe

Tom Breukel analysed some 250 stone axes from the Caribbean and reconstructed their biographies, thus increasing our knowledge of production and trade in the period around the arrival of Columbus. His Ph.D. defence is on 18 April.











Daily grind: The biography of a stone axe
Credit: Tom Breukel

Breukel researched how the stone axes – a collective term in archaeology that also includes adzes and chisels – were produced, traded, and used in the Dominican Republic and the Windward Islands between 1200 and 1600. Previous research had already shown that there was intensive barter between the islands in that region: some axes ‘travelled’ as far as 1000 km to their final destination.
Breukel studied the axes and discovered that many were only partly finished before they were transported. He found unusual semi-finished products among the traded goods. «The buyers probably wanted to finish the stone axes themselves,» he says. «This may have helped them develop a close relationship with the object. Even today, the users in some indigenous communities in the Amazon have a personal relationship with an object, and that’s not as easy if you order a ready-made axe.»











Daily grind: The biography of a stone axe
Credit: Tom Breukel

In addition, Breukel concluded that the majority of the axes were actually used for the purpose for which they were made. He only found one that had never been used and thus may have primarily served ceremonial purposes. «Sometimes you find beautiful jade stones that have been polished until you can see your reflection in them. Then it’s tempting to think that the stone was only used as a talisman or pendant, but if you look closely, you nearly always find traces of wear.»
Breukel made his discoveries under a microscope. He studied the 250 stone axes by looking, one millimetre at a time, for wear traces and information about the type of stone and production method. This resulted in a biography for each individual object. «Each time the object is usedm traces are left behind that archaeologists can find later, even on a cup as you stir your tea,» he says as he holds a greenish axe. «You can read from the grooves in the stone or the residue left behind whether the tool has been used to grind, polish or hack.»











Daily grind: The biography of a stone axe
Credit: Tom Breukel

Another aspect of Breukel’s research was an experiment that involved reproducing how axes were used. He worked with fellow archaeologists and the local community to build a stone age house on Saint Vincent, using only stone tools. This allowed him to compare the traces on the experimental axe with traces on real stone age axes. «I spent two whole weeks hacking at posts with my stone axe – in the sun at least.»


Author: Merijn Van Nuland | Source: Leiden University [April 18, 2019]



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One Year Into Our Planet-Hunting TESS Mission

image

Our Transiting Exoplanet Survey Satellite (TESS), launched last year on April 18, is completing a year in space, surveying the skies to find the closest, most exciting planets outside our solar system for further study. Worlds that TESS is hunting for include super-Earths, rocky planets, gas giants, and maybe even some Earth-sized planets — and much, much more! TESS is scanning the whole sky one section at a time, monitoring the brightness of stars for periodic dips caused by planets transiting (that is, passing in front of) those stars. So far, TESS has found 548 candidates and 10 confirmed exoplanets.


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Since its launch, TESS has orbited Earth a total of 28 times. TESS has a unique elliptical orbit that circuits around Earth twice every time the Moon orbits. This allows TESS’s cameras to monitor each patch of sky continuously for nearly a month at a time. To get into this special orbit, TESS made a series of loops culminating in a lunar gravitational assist, which gave it the final push it needed.


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Did you know that TESS has some serious mileage? The spacecraft has traveled about 20 million miles so far, which works out to an average of about 2,200 miles per hour. That’s faster than any roadrunner we’ve ever seen! This would be four times faster than an average jet. You’d get to your destination in no time!


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TESS downloads data during its closest approach to Earth about every two weeks. So far, it has returned 12,000 gigabytes of data. That’s as if you streamed about 3,000 movies on Netflix. Get the popcorn ready! If you total all the pixels from every image taken using all four of the TESS cameras — which is about 600 full-frame images per orbit, you’d get about 805 billion pixels. This is like half a million iPhone screens put together!


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When the Kepler Space Telescope reached the end of its mission, it passed the planet-finding torch to TESS. Where Kepler’s view was deep — looking for planets as far away as 3,000 light-years — TESS’s view is wide, surveying nearly the entire sky over two years. Each sector TESS views is 20 times larger than Kepler’s field of view.


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TESS will continue to survey the sky and is expected to find about 20,000 exoplanets in the two years it’ll take to complete a scan of nearly the entire sky. Before TESS, several thousand candidate exoplanets were found, and more than 3,000 of these were confirmed. Some of these exoplanets are expected to range from small, rocky worlds to giant planets, showcasing the diversity of planets in the galaxy.


The TESS mission is led by MIT and came together with the help of many different partners. You can keep up with the latest from the TESS mission by following mission updates and keep track of the number of candidates and confirmed exoplanets.


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.


Sharp, upturned stones to provide a defensive perimeter barrier against horse riders,...

Sharp, upturned stones to provide a defensive perimeter barrier against horse riders, Castell Henllys Iron Age Settlement, Newport, Wales, 12.4.19.





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Lithium Detected in an Ancient Star Gives New Clues for Big Bang Nucleosynthesis



ISIS spectrum of J0023+0307, and J1029+1729, one of the most metal-poor stars known and shown for comparison. In red, the best model fit. Figure taken from Aguado et al., 2018. Large format: [PNG]


Researchers from the Instituto de Astrofísica de Canarias (Spain) and the University of Cambridge (UK) have detected lithium (Li) in the ancient star J0023+0307, a main-sequence extremely iron-poor dwarf star about 9,450 light years away in the Galactic halo.



The study of the most ancient stars in the Milky Way allows us to infer the early properties of the Galaxy, its chemical composition, and its assembly history. Metal-poor stars are invaluable messengers that carry information from early epochs, and are an important key to understand the primordial production of Li and the processes responsible for the possible «meltdown» of the Li plateau (a typical Li abundance of a metal-poor dwarf star which is related to the primordial lithium abundance). All stars with low metallicities and low Li abundances, significantly below A(Li)~2.2, are considered to have been likely affected by destruction of the Li in the stars.


New or poorly measured nuclear reaction resonances could affect the Li production predicted by the Standard Big Bang Nucleosynthesis (SBBN). Processes injecting neutrons at the relevant temperatures of the primordial plasma can also alter the primordial Li abundance. In addition, time-varying fundamental constants may lead to a significant Li lower value. Li observations in stars at the lowest metallicities are especially important to bring an insight into the processes of potential Li depletion in stars and, ultimately, to establish if any non-standard physics may have played a role during or after SBBN.


Stars that formed in the first or second generation are extremely rare objects, and only a few are known. The lack of metals in the gas available in the mini-halos, where the first stars formed, limits radiative cooling, increasing the Jeans mass and shifting the initial mass function to large masses, to the point that perhaps no low-mass stars were formed in the first generation. This picture has been challenged in recent years by the discovery of low-mass stars which show extremely low metallicity and low carbon and nitrogen abundances, suggesting that low-mass stars can form even at such low metallicities.


A year ago, astronomers using the ISIS spectrograph at the William Herschel Telescope (WHT) discovered the star J0023+0307, one of the most metal-poor stars known, with about a million times less iron than the Sun. J0023+0307 also shows very little carbon, an important element for the formation of low-mass stars in the low metallicity regime.


New data obtained using UVES, a high-resolution spectrograph at the Very Large Telescope (VLT) in Paranal Observatory (Chile), revealed a Li abundance with values consistent with the extended Li plateau at these low metallicities. However, the predicted Li abundance from the SBBN theory remains a factor of 3 higher than that of the Li plateau.


The presence of Li in this extremely iron-poor star has implications for the production of Li at the Big Bang, and strongly constrains any theory aiming at explaining the cosmological Li problem. The fact that no star in this large low-metallicity regime has been detected showing a Li abundance between that inferred from SBBN and the Li plateau, makes this upper boundary of Li abundance at low metallicities difficult to explain by destruction in the stars, and may support a lower primordial Li production, driven by non-standard nucleosynthesis processes.

More information:


D. S. Aguado, C. Allende Prieto, J. I. González Hernández, 2018, «J0023+0307: A mega metal-poor dwarf star from SDSS/BOSS», ApJ, 854, L34 [ ADS ]


D. S. Aguado, J. I. González Hernández, C. Allende Prieto, R. Rebolo, 2019, «Back to the Lithium Plateau with the [Fe/H] < -6 Star J0023+0307», ApJL, 874, L21 [ ADS ]

«Journey to the Big Bang through the lithium of a Milky Way star», IAC press release, 2 Apr 2019


Contact:  Javier Méndez  (Public Relations Officer) 





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InSight Sol 14 Panorama & Instrument Deployment Animation


NASA — Insight Mission patch.


April 19, 2019



(Click on the image for enlarge)

NASA’s InSight spacecraft captured this panorama of its landing site on Dec. 9, 2018, the 14th Martian day, or sol, of its mission. The 290-degree perspective surveys the rim of the degraded crater InSight landed in, nicknamed «Homestead Hollow.»


The panorama is made of 30 individual images that were taken by the spacecraft’s Instrument Deployment Camera, located on its robotic arm.


Raw Images Animation



Animation above: NASA’s InSight Mars lander acquired this image using its robotic arm-mounted, Instrument Deployment Camera (IDC) and Instrument Context Camera (ICC). The images was acquired between April 14 at April 18, 2019, Sol 135 where the local mean solar time.


JPL manages InSight for NASA’s Science Mission Directorate. InSight is part of NASA’s Discovery Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.


InSight Mars Lander: https://www.nasa.gov/mission_pages/insight/main/index.html


Image, Animation, Text, Credits: NASA/Tony Greicius/Orbiter.ch Aerospace/Roland Berga.


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Early chariot riders of Transcaucasia came from…

I’m finding it increasingly difficult nowadays to fully appreciate all of the ancient DNA samples that are accumulating in my dataset. But it’s not entirely my fault.
Among the hundreds of ancient samples published last year there was a couple of Middle Bronze Age (MBA) individuals from what is now Armenia labeled «Lchashen Metsamor» (see here). I wasn’t planning to do much with these samples because, even after reading the Nature paper that they came with a couple times over, I didn’t have a clue what they were about. But after some digging around, I now know that their people, those associated with the Lchashen Metsamor archeological culture, were among the earliest in Transcaucasia, and indeed the Near East, to use the revolutionary spoked-wheel horse chariot. How awesome is that?
The invention of the spoked-wheel chariot is generally credited to the Middle Bronze Age Sintashta culture of the Trans-Ural steppe in Central Asia, and its rapid spread is often associated with the early expansions of Indo-European languages deep into Asia. On the other hand, some have argued that this type of chariot was first developed in the Near East, and directly derived from solid-wheeled wagons pulled by donkeys.
It’s now obvious, thanks to ancient DNA, that the Sintashta people were by and large migrants to Central Asia from somewhere in Eastern Europe, and that they didn’t harbor any recent ancestry from the Near East. So if chariot technology spread into the steppes from the Near East, then it did so without any accompanying gene flow, which is possible but not entirely convincing. This begs the question of whether the Lchashen Metsamor population was of Sintashta-related origin, because if it was, then this would corroborate the consensus that spoked-wheel chariots were introduced into Transcaucasia from the steppes to the north.
Below is a Principal Component Analysis (PCA) of West Eurasian genetic variation. It does suggest that the Lchashen Metsamor pair (labeled Armenia_MBA_Lchashen), as well as most of the other currently available samples from what is now Armenia dating to the Middle to Late Bronze Age (MLBA), harbor some steppe ancestry. That’s because they appear to form a cline between samples associated with the Sintashta and Kura-Araxes cultures. Of course, the Kura-Araxes culture was a major Early Bronze Age (EBA) archeological phenomenon centered on Transcaucasia and surrounds, so its population can be reasonably assumed to have formed the genetic base of most subsequent populations in the region. The relevant PCA datasheet is available here.



To investigate the possibility of Sintashta-related admixture in Lchashen Metsamor with formal methods, I ran a series of mixture models with the qpAdm software. Here are the three statistically most sound outcomes that I was able to come up with for Lchashen Metsamor:



Armenia_MBA_Lchashen
CWC_Kuyavia 0.183±0.036
Kura-Araxes_Kaps 0.817±0.036
chisq 13.941
tail prob 0.378021
Full output
Armenia_MBA_Lchashen
Balkans_BA_I2163 0.193±0.045
Kura-Araxes_Kaps 0.807±0.045

chisq 14.780
tail prob 0.321267
Full output
Armenia_MBA_Lchashen
Kura-Araxes_Kaps 0.788±0.043
Sintashta_MLBA 0.212±0.043

chisq 14.871
tail prob 0.315451
Full output



I sorted the output by «tail prob», but the fact that Sintashta_MLBA is in third place isn’t a problem because the stats in all of these models are basically identical. Indeed, CWC_Kuyavia (Corded Ware culture samples from present-day Kuyavia, North-Central Poland) and Balkans_BA_I2163 (a Bronze Age singleton from what is now Bulgaria) are both very similar and probably closely related to each other and to the Sintashta samples.
Interestingly, and, I’d say, importantly, ancients from the steppe that are closest to Lchashen Metsamor in both space and time, but not particularly closely related to the Sintashta people, don’t work too well as a mixture source in such models.



Armenia_MBA_Lchashen
Kubano-Tersk 0.184±0.046
Kura-Araxes_Kaps 0.816±0.046

chisq 22.179
tail prob 0.0526526
Full output



A couple of months ago I suggested that populations associated with the Early to Middle Bronze Age (EMBA) Catacomb culture were the vector for the spread of steppe ancestry into what is now Armenia during the MLBA (see here). After taking a closer look at the Lchashen Metsamor samples, I now think that the peoples of the Sintashta and related cultures were also important in this process. If so, they may have moved from the steppe into Transcaucasia both from the west via the Balkans and the east via Central Asia, and brought with them spoked-wheel chariots. I don’t have a clue what language they spoke, but I’m guessing that it may have been something Indo-European.
See also…
The mystery of the Sintashta people
A potentially violent end to the Kura-Araxes Culture (Alizadeh et al. 2018)
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…

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How NASA Earth Data Aids America

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Today we roll out a new communications project that highlights some of the many ways that NASA’s Earth observations help people strengthen communities across the United States.


Space for U.S. features stories on how Earth science data is used to make informed decisions about public health, disaster response and recovery and environmental protection. By highlighting advanced technology from a global perspective, our data helps provide people achieve groundbreaking insights.


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For example, a family-owned coffee company in Maine used our sunlight, wind and temperature data to determine the placement of their power-generating solar wall.


Space for U.S. features 56 stories illustrating how our science has made an impact in every state in the nation as well as the District of Columbia, Puerto Rico and regions along the Atlantic, Pacific, Gulf of Mexico, and the Great Lakes.


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For six decades, we’ve used the vantage point of space to better understand our home planet and improve lives. Using Space for U.S., you can browse through stories about how applied Earth science either by state or by topics such as animals, disasters, energy, health, land and water. Each click brings you a story about how people are putting NASA data to work.


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Explore the true stories behind the innovative technology, groundbreaking insights, and extraordinary collaboration happening right here in the United States with Space for U.S.


Check out “Space for U.S.” today! www.nasa.gov/spaceforus


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For more information on NASA Earth, head to www.nasa.gov/Earth or https://appliedsciences.nasa.gov.


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.


Running Mates Exercise improves our health in many ways,…


Running Mates


Exercise improves our health in many ways, potentially even boosting our ability to produce more neurons. In mice, exercise causes an increase in stem cells known as neural precursor cells (NPCs), found in a part of the brain’s hippocampus, the dentate gyrus, which may give rise to new neurons during adulthood. Recent research suggests this is linked to changes in their blood, particularly their platelets, small blood cells responsible for blood clotting after injury. Mice given access to running wheels possessed more activated platelets, with different properties and protein content, than mice that had not exercised. In laboratory tests, blood serum from those active mice stimulated the multiplication of cultured NPCs (pictured, with cell nuclei in blue), while activated platelets even encouraged more cells to become neurons (in red). How exactly they do so remains unclear, but platelets may form an important link, passing the benefits of exercise onto the brain.


Written by Emmanuelle Briolat



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