воскресенье, 18 ноября 2018 г.

Link of the Week standing in for the Image of the Week –…


Link of the Week standing

in for the Image of the Week – November 19, 2018


Our friends over at

Technology Networks have created a Spectacular Cell Images flipbook of cell

images they found at the Cell Image Library. 


Check it out here http://go.technologynetworks.com/spectacular-cell-images

or here https://www.technologynetworks.com/tn/lists/spectacular-cell-images-311644.


Have you seen other great

uses of images from the Cell Image Library? Have you used images from the Cell

Image Library? Let us know in the comments.


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Junction Box Millions of times a day we turn our thoughts into…


Junction Box


Millions of times a day we turn our thoughts into actions – at neuromuscular junctions where electrical signals from motor neurons feed into our muscles. Amyotrophic lateral sclerosis (ALS) gradually weakens these connections for thousands of people around the world – but here’s a vital step towards new treatments. Inside a sort of lab-in-a-box called a microfluidic device, a bundle of nerve cells (artificially-coloured green with nuclei in blue) is reaching out tiny finger-like neurites towards muscle cells (purple) – creating a living 3D model of a neuromuscular junction. The neurons are modified to be optogenetic – they respond to pulses of laser light by pulling at the muscle cells, revealing weaker forces in cells grown from ALS sufferers. The next job is to bathe the diseased cells in different combinations of drugs, looking for clues to restoring neuromuscular junctions to full strength, in the hope of treating ALS as well as other conditions affecting the nervous system.


Written by John Ankers



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Prehistoric Avebury, Wiltshire, 17.11.18.The mother of all UK prehistoric sites…











Prehistoric Avebury, Wiltshire, 17.11.18.


The mother of all UK prehistoric sites…


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Climate, life and the movement of continents: New connections…


Climate, life and the movement of continents: New connections http://www.geologypage.com/2018/11/climate-life-and-the-movement-of-continents-new-connections.html


2018 November 18 Creature Aurora Over Norway Image Credit &…


2018 November 18


Creature Aurora Over Norway
Image Credit & Copyright: Ole C. Salomonsen (Arctic Light Photo)


Explanation: It was Halloween and the sky looked like a creature. Exactly which creature, the astrophotographer was unsure but (possibly you can suggest one). Exactly what caused this eerie apparition in 2013 was sure: one of the best auroral displays in recent years. This spectacular aurora had an unusually high degree of detail. Pictured here, the vivid green and purple auroral colors are caused by high atmospheric oxygen and nitrogen reacting to a burst of incoming electrons. Birch trees in Tromsø, Norway formed an also eerie foreground. Recently, new photogenic auroras have accompanied new geomagnetic storms.


∞ Source: apod.nasa.gov/apod/ap181118.html


What happened to Maykop?

The Maykop culture was probably the result of migration waves of settlers from Transcaucasia and beyond into the Northwest Caucasus during the Eneolithic and Early Bronze Age. Its peak lasted for roughly 700 years, from about 3700 BC to 3000 BC, after which it seems to have vanished suddenly. Why? Are there any decent papers on the topic?
The currently rather popular idea that Maykop gave rise to the Yamnaya culture is likely false. It was probably somehow involved in the rise of the contemporaneous Steppe Maykop culture in the steppes abutting the North Caucasus. But, thanks to ancient DNA, we now know that the people associated with this culture were distinct from those associated with Yamnaya.
In fact, when Steppe Maykop disappeared, Yamnaya spread into much of its former territory, and this turnover registers clearly in the time transect of ancient genomic data from the North Caucasus steppes (see here).
My view is that Maykop was generally an alien entity to the indigenous peoples of the steppes. These natives may have emulated it in some ways, much like the Amerindians sometimes emulated the European colonizers of the Americas. But there’s no need, I’d say, to go as far as to assume that Maykop was the vector for the spread of Indo-European languages into the Pontic-Caspian steppe.
Indeed, it seems to me that when the technological and economic advantages of Maykop over the steppe peoples eventually eroded, it couldn’t hold its ground on the edge of a vastly different and perhaps largely hostile world, and quickly disappeared.
Here’s a quote from a recent paper by Trifonov et al. on Maykop jewellery that I found very enlightening in regards to these issues (emphasis is mine):



These deep-rooted Near East traditions of ritualization of the production and use of jewellery pieces made of gold, silver and gemstones in the Maykop culture, on the one hand, maintained familiar canons of ritual behaviour and, on the other, made perception of sophisticated symbolism of gemstones more difficult for neighbouring cultures with different living standards, levels of social development and value systems to understand. The jewellery traditions of the Maykop culture had no successors in the Caucasus or the adjacent steppes. In the third millennium BC , the goldsmiths of Europe and Asia had to reinvent the technique of making thin-walled jointless gold beads from scratch (Born et al. 2009).



I do wonder, in fact, if the language spoken by the Maykop people was even part of a still existing language group, let alone if it belonged to the Indo-European language family.
See also…
Big deal of 2018: Yamnaya not related to Maykop

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A Galaxy-scale Fountain of Cold Molecular Gas Pumped by a Black Hole


An image of the bright cluster galaxy Abell 2597 in the X-ray (blue), hydrogen line emission (red), and optical (yellow). Astronomers using multi-wavelength observations from the millimeter to the X-ray have concluded, in agreement with predictions, that this galaxy is both accreting gas from its surroundings and ejecting material out from its supermasssive black hole, thus acting like a cosmic fountain. Credit: X-ray: NASA/CXC/Michigan State Univ/G.Voit et al; Optical: NASA/STScI & DSS; H-alpha: Carnegie Obs./Magellan/W.Baade Telescope/U.Maryland/M.McDona


Most galaxies lie in clusters containing from a few to thousands of other galaxies. Our Milky Way, for example, belongs to the Local Group cluster of about fifty galaxies whose other large member, the Andromeda galaxy, is about 2.3 million light-years away. Clusters are the most massive gravitationally bound objects in the universe and form (according to current ideas) in a “bottoms-up” fashion with smaller structures developing first and with dark matter playing an important role. Exactly how they grow and evolve, however, depends on several competing physical processes including the behavior of the hot intracluster gas.


The galaxy Abell 2597 lies near the center of a cluster about one billion light-years away in the midst of a hot nebula (tens of millions of degrees) of cluster gas. Astronomers have long theorized that intergalactic matter like the plasma around Abell 2597 can fall onto galaxies, cool, and provide fresh material for the galaxy’s star formation. They have, however, also discovered the opposite activity: galaxies’ central supermassive black holes are ejecting jets of material back out into the hot intracluster medium. CfA astronomers Grant Tremblay, Paul Nulsen, Esra Bulbul, Laurence David, Bill Forman, Christine Jones, Ralph Kraft, Scott Randall, and John ZuHone led a large team of colleagues studying the behavior of the hot gas and these competing processes in Abell 2597 using a wide range of observations including new and archival ALMA millimeter observations, optical spectroscopy, and deep Chandra X-Ray Observatory images.


The sensitive and wide-ranging datasets enabled the scientists to probe the thermodynamic character and motions of the hot gas (including both infall and outflow streams), the cold, star forming dust clouds in the galaxy, and the relative spatial arrangement of all these ingredients. They find detailed support for the models, including both infall of hot material into the galaxy and its subsequent conversion into new stars and as well the outflow of gas driven by jets from the central supermassive black hole. They show that the warm and cold material are actually found together in this galaxy (although they are of different densities), with clouds of cold gas likely feeding the black hole and apparently coupling to the powerful jets ejected from the nucleus. The result is that the molecular and ionized nebula at the heart of Abell 2597 is what they term a galaxy-scale “fountain:” cold gas drains into the reservoir created by the presence of the black hole at the center, and this powers outflowing jets that, in turn, later cool and sink, raining back down. Because the outflowing material does not move quickly enough to escape the galaxy’s gravity, they conclude that this dramatic galactic fountain seems likely to be long-lived. It may also be a common occurrence in these massive clusters, helping to explain the cosmic evolution of galaxies.

Reference(s):

“A Galaxy-scale Fountain of Cold Molecular Gas Pumped by a Black Hole,” G. R. Tremblay et al. ApJ 865, 13, 2018.






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Exploding Stars Make Key Ingredient in Sand, Glass



This image of supernova remnant G54.1+0.3 includes radio, infrared and X-ray light. 


Credit: NASA/JPL-Caltech/CXC/ESA/NRAO/J. Rho (SETI Institute)› Full image and caption

We are all, quite literally, made of star dust. Many of the chemicals that compose our planet and our bodies were formed directly by stars. Now, a new study using observations by NASA’s Spitzer Space Telescope reports for the first time that silica – one of the most common minerals found on Earth – is formed when massive stars explode.


Look around you right now and there’s a good chance you will see silica (silicon dioxide, SiO2) in some form. A major component of many types of rocks on Earth, silica is used in industrial sand-and-gravel mixtures to make concrete for sidewalks, roads and buildings. One form of silica, quartz, is a major component of sand found on beaches along the U.S. coasts. Silica is a key ingredient in glass, including plate glass for windows, as well as fiberglass. Most of the silicon used in electronic devices comes from silica.


In total, silica makes up about 60 percent of Earth’s crust. Its widespread presence on Earth is no surprise, as silica dust has been found throughout the universe and in meteorites that predate our solar system. One known source of cosmic dust is AGB stars, or stars with about the mass of the Sun that are running out of fuel and puff up to many times their original size to form a red giant star. (AGB stars are one type of red giant star.) But silica is not a major component of AGB star dust, and observations had not made it clear if these stars could be the primary producer of silica dust observed throughout the universe.


The new study reports the detection of silica in two supernova remnants, called Cassiopeia A and G54.1+0.3. A supernova is a star much more massive than the Sun that runs out of the fuel that burns in its core, causing it to collapse on itself. The rapid in-fall of matter creates an intense explosion that can fuse atoms together to create “heavy” elements, like sulfur, calcium and silicon.


Chemical Fingerprints


To identify silica in Cassiopeia A and G54.1+0.3, the team used archival data from Spitzer’s IRS instrument and a technique called spectroscopy, which takes light and reveals the individual wavelengths that compose it. (You can observe this effect when sunlight passes through a glass prism and produces a rainbow: The different colors are the individual wavelengths of light that are typically blended together and invisible to the naked eye.)


Chemical elements and molecules each emit very specific wavelengths of light, meaning they each have a distinct spectral “fingerprint” that high-precision spectrographs can identify. In order to discover the spectral fingerprint of a given molecule, researchers often rely on models (typically done with computers) that re-create the molecule’s physical properties. Running a simulation with those models then reveals the molecule’s spectral fingerprint.


But physical factors can subtly influence the wavelengths that molecules emit. Such was the case with Cassiopeia A. Although the spectroscopy data of Cassiopeia A showed wavelengths close to what would be expected from silica, researchers could not match the data with any particular element or molecule.


Jeonghee Rho, an astronomer at the SETI Institute in Mountain View, California, and the lead author on the new paper, thought that perhaps the shape of the silica grains could be the source of the discrepancy, because existing silica models assumed the grains were perfectly spherical.


She began building models that included some grains with nonspherical shapes. It was only when she completed a model that assumed all the grains were not spherical but, rather, football-shaped that the model “really clearly produced the same spectral feature we see in the Spitzer data,” Rho said.


Rho and her coauthors on the paper then found the same feature in a second supernova remnant, G54.1+0.3. The elongated grains may tell scientists something about the exact processes that formed the silica.


The authors also combined the observations of the two supernova remnants from Spitzer with observations from the European Space Agency’s Herschel Space Observatory in order to measure the amount of silica produced by each explosion. Herschel detects different wavelengths of infrared light than Spitzer. The researchers looked at the entire span of wavelengths provided by both observatories and identified the wavelength at which the dust has its peak brightness. That information can be used to measure the temperature of dust, and both brightness and temperature are necessary in order to measure the mass. The new work implies that the silica produced by supernovas over time was significant enough to contribute to dust throughout the universe, including the dust that ultimately came together to form our home planet.


The study was published on Oct. 24, 2018, in the Monthly Notices of the Royal Astronomical Society, and it confirms that every time we gaze through a window, walk down the sidewalk or set foot on a pebbly beach, we are interacting with a material made by exploding stars that burned billions of years ago.


NASA’s Herschel Project Office is based at NASA’s Jet Propulsion Laboratory in Pasadena, California. The NASA Herschel Science Center, part of IPAC, supports the U.S. astronomical community. Caltech manages JPL for NASA.


The JPL 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, California. Spacecraft operations are based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech.


For more information about Herschel and Spitzer, visit:


http://www.herschel.caltech.edu  http://www.spitzer.caltech.edu  https://www.nasa.gov/spitzer



News Media Contact

Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.
626-808-2469
calla.e.cofield@jpl.nasa.gov


Rebecca McDonald
Director of Communications, SETI Institute
650-960-4526
rmcdonald@seti.org





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HiPOD (17 November 2018): Where the Nights are Cold and Lonely …



HiPOD (17 November 2018): Where the Nights are Cold and Lonely


   – This observation features an impact crater, about 80-meters in diameter, alone in the North Polar layered deposits. (Alt: 319 km. Black and white is less than 5 km across and the color is at full resolution, less than 1 km.)


NASA/JPL/University of Arizona


Losing Contacts Like detectives piecing together the moments…


Losing Contacts


Like detectives piecing together the moments leading up to a crime, researchers have unpicked the events that result in the destruction of nerves in the muscle wasting disease amyotrophic lateral sclerosis (ALS). Connections between muscles and the nerves that stimulate them called neuromuscular junctions (NMJs) are lost early on in ALS. And in this study the team probed whether this is down to entire nerves suddenly dying or the dismantling of nerve branches along which the NMJs reside. They used fluorescent microscopy to repeatedly image the nerves, muscle fibres (pictured in red and green) and NMJs of normal (left) and ALS mice (right) revealing that NMJ loss was due to individual branches disassembling before total nerve degeneration. This presents a window of time, between the first signs of disease with NMJ loss and eventual nerve death, for targeting efforts to treat ALS.


Written by Lux Fatimathas



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jason-1971: West kennet Long Barrow ,Wilkshire (at West Kennet…


jason-1971:



West kennet Long Barrow ,Wilkshire (at West Kennet Long Barrow)
https://www.instagram.com/p/BqSeAf9lCYy/?utm_source=ig_tumblr_share&igshid=dm1ozjry71dk



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