вторник, 26 февраля 2019 г.

2019 February 26 Simulation TNG50: A Galaxy Cluster Forms Video…


2019 February 26


Simulation TNG50: A Galaxy Cluster Forms
Video Credit: IllustrisTNG Project; Visualization: Dylan Nelson (Max Planck Institute for Astrophysics) et al.
Music: Symphony No. 5 (Ludwig van Beethoven), via YouTube Audio Library


Explanation: How do clusters of galaxies form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. A recent effort is TNG50 from IllustrisTNG, an upgrade of the famous Illustris Simulation. The first part of the featured video tracks cosmic gas (mostly hydrogen) as it evolves into galaxies and galaxy clusters from the early universe to today, with brighter colors marking faster moving gas. As the universe matures, gas falls into gravitational wells, galaxies forms, galaxies spin, galaxies collide and merge, all while black holes form in galaxy centers and expel surrounding gas at high speeds. The second half of the video switches to tracking stars, showing a galaxy cluster coming together complete with tidal tails and stellar streams. The outflow from black holes in TNG50 is surprisingly complex and details are being compared with our real universe. Studying how gas coalesced in the early universe helps humanity better understand how our Earth, Sun, and Solar System originally formed.


∞ Source: apod.nasa.gov/apod/ap190226.html


Past and future generations of stars in NGC 300



Past and future generations of stars in NGC 300


Copyright: ESA/XMM-Newton (X-rays); MPG/ESO (optical); NASA/Spitzer (infrared)

Acknowledgement: S. Carpano, Max-Planck Institute for Extraterrestrial Physics



 JPG – (1.48 MB) / PNG – (7.99 MB)




This swirling palette of colours portrays the life cycle of stars in a spiral galaxy known as NGC 300.

Located some six million light-years away, NGC 300 is relatively nearby. It is one of the closest galaxies beyond the Local Group – the hub of galaxies to which our own Milky Way galaxy belongs. Due to its proximity, it is a favourite target for astronomers to study stellar processes in spiral galaxies.


The population of stars in their prime is shown in this image in green hues, based on optical observations performed with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at La Silla, Chile. Red colours indicate the glow of cosmic dust in the interstellar medium that pervades the galaxy: this information derives from infrared observations made with NASA’s Spitzer space telescope, and can be used to trace stellar nurseries and future stellar generations across NGC 300.


A complementary perspective on this galaxy’s composition comes from data collected in X-rays by ESA’s XMM-Newton space observatory, shown in blue. These represent the end points of the stellar life cycle, including massive stars on the verge of blasting out as supernovas, remnants of supernova explosions, neutron stars, and black holes. Many of these X-ray sources are located in NGC 300, while others – especially towards the edges of the image – are foreground objects in our own Galaxy, or background galaxies even farther away.


The sizeable blue blob immediately to the left of the galaxy’s centre is especially interesting, featuring two intriguing sources that are part of NGC 300 and shine brightly in X-rays.

One of them, known as NGC 300 X-1, is in fact a binary system, consisting of a Wolf-Rayet star – an ageing hot, massive and luminous type star that drives strong winds into its surroundings – and a black hole, the compact remains of what was once another massive, hot star. As matter from the star flows towards the black hole, it is heated up to temperatures of millions of degrees or more, causing it to shine in X-rays.


The other source, dubbed NGC 300 ULX1, was originally identified as a supernova explosion in 2010. However, later observations prompted astronomers to reconsider this interpretation, indicating that this source also conceals a binary system comprising a very massive star and a compact object – a neutron star or a black hole – feeding on material from its stellar companion.


Data obtained in 2016 with ESA’s XMM-Newton and NASA’s NuSTAR observatories revealed regular variations in the X-ray signal of NGC 300 ULX1, suggesting that the compact object in this binary system is a highly magnetized, rapidly spinning neutron star, or pulsar.

The large blue blob in the upper left corner is a much more distant object: a cluster of galaxies more than one billion light years away, whose X-ray glow is caused by the hot diffuse gas interspersed between the galaxies.

Explore NGC 300 in ESASky





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ALMA Differentiates Two Birth Cries from a Single Star



ALMA image of the protostar MMS5/OMC-3. The protostar is located at the center and the gas streams are ejected to the east and west (left and right). The slow outflow is shown in orange and the fast jet is shown in blue. It is obvious that the axes of the outflow and jet are misaligned. Credit: ALMA (ESO/NAOJ/NRAO), Matsushita et al. Hi-res image





Artist’s impression of the baby star MMS5/OMC-3. ALMA observations identified two gas streams from the protostar, a collimated fast jet and a wide-angle slow outflow, and found that the axes of the two gas flows are misaligned. Credit: NAOJ. Hi-res image


Astronomers have unveiled the enigmatic origins of two different gas streams from a baby star. Using ALMA, they found that the slow outflow and the high speed jet from a protostar have misaligned axes and that the former started to be ejected earlier than the latter. The origins of these two flows have been a mystery, but these observations provide telltale signs that these two streams were launched from different parts of the disk around the protostar.


Stars in the Universe have a wide range of masses, ranging from hundreds of times the mass of the Sun to less than a tenth of that of the Sun. To understand the origin of this variety, astronomers study the formation process of the stars, that is the aggregation of cosmic gas and dust.


Baby stars collect the gas with their gravitational pull, however, some of the material is ejected by the protostars. This ejected material forms a stellar birth cry which provides clues to understand the process of mass accumulation.


Yuko Matsushita, a graduate student at Kyushu University and her team used ALMA to observe the detailed structure of the birth cry from the baby star MMS5/OMC-3 and found two different gaseous flows: a slow outflow and a fast jet. There have been a handful of examples with two flows seen in radio waves, but MMS5/OMC-3 is exceptional.


“Measuring the Doppler shift of the radio waves, we can estimate the speed and lifetime of the gas flows,” said Matsushita, the lead author of the research paper that appeared in the Astrophysical Journal. “We found that the jet and outflow were launched 500 years and 1300 years ago, respectively. These gas streams are quite young.”


More interestingly, the team found that the axes of the two flows are misaligned by 17 degrees. The axis of the flows can be changed over long time periods due to the precession of the central star. But in this case, considering the extreme youth of the gas streams, researchers concluded that the misalignment is not due to precession but is related to the launching process.


There are two competing models for the formation mechanism of the protostellar outflows and jets. Some researchers assume that the two streams are formed independently in different parts of the gas disk around the central baby star, while others propose that the collocated jet is formed first, then it entrains the surrounding material to form the slower outflows. Despite extensive research, astronomers had not yet reached a conclusive answer.


A misalignment in the two flows could occur in the ‘independent model,’ but is difficult in the ‘entrainment model.’ Moreover, the team found that the outflow was ejected considerably earlier than the jet. This clearly backs the ‘independent model.’


“The observation well matches the result of my simulation,” said Masahiro Machida, a professor at Kyushu University. A decade ago, he performed pioneering simulation studies using a supercomputer operated by the National Astronomical Observatory of Japan. In the simulation, the wide-angle outflow is ejected from the outer area of the gaseous disk around a prototar, while the collimated jet is launched independently from the inner area of the disk. Machida continues, “An observed misalignment between the two gas streams may indicate that the disk around the protostar is warped.”


“ALMA’s high sensitivity and high angular resolution will enable us to find more and more young, energetic outflow-and-jet-systems like MMS 5/OMC-3,” said Satoko Takahashi, an astronomer at the National Astronomical Observatory of Japan and the Joint ALMA Observatory and co-author of the paper. “They will provide clues to understand the driving mechanisms of outflows and jets. Moreover studying such objects will also tell us how the mass accretion and ejection processes work at the earliest stage of star formation.”



Additional Information


These observation results were published as Matsushita et al. “Very Compact Extremely High Velocity Flow toward MMS 5 / OMC-3 Revealed with ALMA” in the Astrophysical Journal issued in February 2019.

The research team members are:


Yuko Matsushita (Kyushu University), Satoko Takahashi (Joint ALMA Observatory/National Astronomical Observatory of Japan/SOKENDAI), Masahiro Machida (Kyushu University), and Koji Tomisaka (National Astronomical Observatory of Japan/SOKENDAI)

This research was supported by JSPS KAKENHI (No. 17K05387, 17H06360, 17H02869, 15K05032) and the Science Visitor Program of the Joint ALMA Observatory.



The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.




Contacts


Valeria Foncea
Education and Public Outreach Officer
Joint ALMA Observatory Santiago – Chile
Phone: +56 2 2467 6258
Cell phone: +56 9 7587 1963
Email: valeria.foncea@alma.cl


Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
Observatory
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp


Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USAv 
Phone: +1 434 296 0314
Cell phone: +1 202 236 6324
Email: cblue@nrao.edu


Calum Turner
ESO Assistant Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: calum.turner@eso.org









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NASA Study Reproduces Origins of Life on Ocean Floor


NASA logo.


Feb. 25, 2019



Image above: An image of Saturn’s moon Enceladus backlit by the Sun, taken by the Cassini mission. The false color tail shows jets of icy particles and water that spray into space from an ocean that lies deep below the moon’s icy surface. Future missions could search for the ingredients for life in an ocean on an icy moon like Enceladus. Image Credits: NASA/JPL/Space Science Institute.


Scientists have reproduced in the lab how the ingredients for life could have formed deep in the ocean 4 billion years ago. The results of the new study offer clues to how life started on Earth and where else in the cosmos we might find it.


Astrobiologist Laurie Barge and her team at NASA’s Jet Propulsion Laboratory in Pasadena, California, are working to recognize life on other planets by studying the origins of life here on Earth. Their research focuses on how the building blocks of life form in hydrothermal vents on the ocean floor.



Animation above: A time-lapse video of a miniature hydrothermal chimney forming in the lab, as it would in early Earth’s ocean. Natural vents can continue to form for thousands of years and grow to tens of yards (meters) in height. Animation Credits: NASA/JPL-Caltech/Flores.


To re-create hydrothermal vents in the lab, the team made their own miniature seafloors by filling beakers with mixtures that mimic Earth’s primordial ocean. These lab-based oceans act as nurseries for amino acids, organic compounds that are essential for life as we know it. Like Lego blocks, amino acids build on one another to form proteins, which make up all living things.


“Understanding how far you can go with just organics and minerals before you have an actual cell is really important for understanding what types of environments life could emerge from,” said Barge, the lead investigator and the first author on the new study, published in the journal <a href=”https://www.pnas.org/content/early/2019/02/19/1812098116″>Proceedings of the National Academy of Sciences</a>. “Also, investigating how things like the atmosphere, the ocean and the minerals in the vents all impact this can help you understand how likely this is to have occurred on another planet.”


Found around cracks in the seafloor, hydrothermal vents are places where natural chimneys form, releasing fluid heated below Earth’s crust. When these chimneys interact with the seawater around them, they create an environment that is in constant flux, which is necessary for life to evolve and change. This dark, warm environment fed by chemical energy from Earth may be the key to how life could form on worlds farther out in our solar system, far from the heat of the Sun.


“If we have these hydrothermal vents here on Earth, possibly similar reactions could occur on other planets,” said JPL’s Erika Flores, co-author of the new study.


Barge and Flores used ingredients commonly found in early Earth’s ocean in their experiments. They combined water, minerals and the “precursor” molecules pyruvate and ammonia, which are needed to start the formation of amino acids. They tested their hypothesis by heating the solution to 158 degrees Fahrenheit (70 degrees Celsius) — the same temperature found near a hydrothermal vent — and adjusting the pH to mimic the alkaline environment. They also removed the oxygen from the mixture because, unlike today, early Earth had very little oxygen in its ocean. The team additionally used the mineral iron hydroxide, or “green rust,” which was abundant on early Earth.


The green rust reacted with small amounts of oxygen that the team injected into the solution, producing the amino acid alanine and the alpha hydroxy acid lactate. Alpha hydroxy acids are byproducts of amino acid reactions, but some scientists theorize they too could combine to form more complex organic molecules that could lead to life.



Lau Basin – SRoF 2012 – Q328 Black smokers

Video above: Hydrothermal vents are places in the seafloor where warm water from under the Earth’s crust mixes with near-freezing seawater. These vents form natural chimneys, which play host to all kinds of ocean life. Video Credits: MARUM/University of Bremen/NOAA-Pacific Marine Environmental Laboratory.


“We’ve shown that in geological conditions similar to early Earth, and maybe to other planets, we can form amino acids and alpha hydroxy acids from a simple reaction under mild conditions that would have existed on the seafloor,” said Barge.


Barge’s creation of amino acids and alpha hydroxy acids in the lab is the culmination of nine years of research into the origins of life. Past studies looked at whether the right ingredients for life are found in hydrothermal vents, and how much energy those vents can generate (enough to power a light bulb). But this new study is the first time her team has watched an environment very similar to a hydrothermal vent drive an organic reaction. Barge and her team will continue to study these reactions in anticipation of finding more ingredients for life and creating more complex molecules. Step by step, she’s slowly inching her way up the chain of life.



Image above: Laurie Barge, left, and Erika Flores, right, in JPL’s Origins and Habitability Lab in Pasadena, California. Image Credits: NASA/JPL-Caltech.


This line of research is important as scientists study worlds in our solar system and beyond that may host habitable environments. Jupiter’s moon Europa and Saturn’s moon Enceladus, for example, could have hydrothermal vents in oceans beneath their icy crusts. Understanding how life could start in an ocean without sunlight would assist scientists in designing future exploration missions, as well as experiments that could dig under the ice to search for evidence of amino acids or other biological molecules. 


Future Mars missions could return samples from the Red Planet’s rusty surface, which may reveal evidence of amino acids formed by iron minerals and ancient water. Exoplanets — worlds beyond our reach but still within the realm of our telescopes — may have signatures of life in their atmospheres that could be revealed in the future.


“We don’t have concrete evidence of life elsewhere yet,” said Barge. “But understanding the conditions that are required for life’s origin can help narrow down the places that we think life could exist.”


This research was supported by the NASA Astrobiology Institute, JPL Icy Worlds team.


For more information on astrobiology at NASA, please visit: https://astrobiology.nasa.gov/


Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Arielle Samuelson.


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U.S. Cargo Ship Completes Mission and Deployment of Several Satellites after Departure...


Northrope Grumman – Cygnus NG-10 Mission patch.


Feb. 25, 2019


Following completion of its primary mission to deliver more than 7,400 pounds of science and supplies to the International Space Station, a Northrop Grumman Cygnus cargo spacecraft then spent more than two weeks on a new commercial mission to deploy several small satellites into multiple orbits.


This is a first-of-its-kind use of a space station commercial resupply spacecraft beyond the primary mission and demonstrates continued commercialization of low-Earth orbit enabled by the microgravity outpost.


After Cygnus, named the SS John Young, departed the orbital laboratory Feb. 8, its thrusters fired to move the spacecraft a safe distance from the station before Northrop Grumman flight controllers in Dulles, Virginia, took over to adjust the vehicle to a higher altitude where the Slingshot CubeSat Deployer deployed two CubeSats and hosted an additional payload. The NanoRacks External Cygnus Deployer then released two more CubeSats.



Cygnus NG-10

Cygnus then moved to a lower orbit to deploy a third CubeSat via the NanoRacks deployer, carrying 100 tiny satellites called femtosatellites. These satellites are even smaller than the already-small 3-Unit CubeSat, with each including a power, sensor, and communication system on a printed circuit board that measures 3.5 by 3.5 cm at a thickness of a few millimeters and a mass of less than three and a half ounces. They are part of the KickSat-2 mission to demonstrate the capabilities of even smaller, more cost-effective satellites.


Having completed this bonus commercial mission, Cygnus re-entered Earth’s atmosphere on Feb. 25 and burned up harmlessly over the Pacific Ocean.


The primary focus of this Commercial Resupply Services contract mission was to deliver dozens of new and existing investigations to contribute to some of the hundreds of science and research studies the Expedition 58 crew will facilitate during their time in space. Highlights from the new experiments include a demonstration of 3D printing and recycling technology and simulating the creation of celestial bodies from stardust.


The Refabricator is the first 3D printer and recycler integrated into one user-friendly machine. Once installed in the space station, it will demonstrate recycling of waste plastic and previously 3D printed parts already on-board into high-quality filament, or 3D printer “ink.” This recycled filament will be fed into the printer as stock to make new tools and parts on-demand in space. This technology could enable closed-loop, sustainable fabrication, repair and recycling on long-duration space missions, and greatly reduce the need to continually launch large supplies of new material and parts for repairs and maintenance. The demonstration, which NASA’s Space Technology Mission and Human Exploration and Operations Directorates co-sponsored, is considered a key enabling technology for in-space manufacturing. NASA awarded a Small Business Innovation Research contract valued to Tethers Unlimited Inc. to build the recycling system.


The Experimental Chondrule Formation at the International Space Station (EXCISS) investigation will explore how planets, moons and other objects in space formed by simulating the high-energy, low-gravity conditions that were present during formation of the early solar system. Scientists plan to zap a specially formulated dust with an electrical current, and then study the shape and texture of the resulting pellets.


The Crystallization of LRRK2 Under Microgravity Conditions-2 (PCG-16) investigation grows large crystals of an important protein, leucine-rich repeat kinase 2 (LRRK2), in microgravity for analysis back on Earth. This protein is implicated in development of Parkinson’s disease, and improving our knowledge of its structure may help scientists better understand the pathology of the disease and develop therapies to treat it. LRRK2 crystals grown in gravity are too small and too compact to study, making microgravity an essential part of this research.  This investigation is sponsored by the International Space Station U.S. National Laboratory, which Congress designated in 2005 to maximize its use for improving quality of life on Earth.



NG CRS-10- SS John Young Cygnus departure

This was the seventh flight of an enhanced Cygnus spacecraft, and the fourth using Northrop Grumman’s upgraded Antares 230 launch vehicle featuring new RD-181 engines that provide increased performance and flexibility.


The spacecraft for this mission was named in honor of astronaut John Young. Young was selected for NASA’s second astronaut class and flew during the Gemini, Apollo and Space Shuttle programs. He walked on the Moon during Apollo 16 in 1972 and commanded the first space shuttle mission in 1981. Young died in January 2018.


Cygnus launched Nov. 17, 2018, on an Antares 230 rocket from Virginia Mid-Atlantic Regional Spaceport’s Pad 0A at Wallops, and arrived at the station Nov. 19 for the company’s 10th NASA-contracted commercial resupply mission to the station. Ground controllers used the space station’s Canadarm2 robotic arm to detach Cygnus at 11:16 a.m. EST on Friday, Feb. 8 from the Earth-facing side of the station’s Unity module and maneuver the spacecraft into its release position. Expedition 58 Flight Engineers Anne McClain of NASA and David Saint-Jacques of the Canadian Space Agency sent the command to release the spacecraft.


Related links:


Northrop Grumman Cygnus: https://www.nasa.gov/mission_pages/station/structure/launch/northrop-grumman.html


KickSat-2: https://www.nasa.gov/mission_pages/station/research/experiments/2374.html


Refabricator: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html


Small Business Innovation Research: http://sbir.nasa.gov/


EXCISS: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html


PCG-16: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html


International Space Station U.S. National Laboratory: https://www.iss-casis.org/


Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html


Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Image, Video, Text, Credits: NASA/Gary Jordan/NASA Tv/SciNews.


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Midmar Kirk Recumbent Stone Circle, nr Echt, Aberdeenshire, 20.2.19.










Midmar Kirk Recumbent Stone Circle, nr Echt, Aberdeenshire, 20.2.19.


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Easter Aquhorthies Recumbent Stone Circle, Aberdeenshire, 22.2.19.

Easter Aquhorthies Recumbent Stone Circle, Aberdeenshire, 22.2.19.












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Excavations at Kunal village open up more doors to pre-Harappan period

The three successive seasons of excavation at prominent pre-Harappan site in Kunal, a sleepy village in Ratia Tehsil of Haryana’s Fatehabad district, including the ongoing digging for the last one month, have led to the discovery of a wide variety of artefacts. Wares, beads, bangles, stamps and copper objects with the evidence of a furnace and a workshop giving insights into the Harappan Civilization were unearthed from this historic site.











Excavations at Kunal village open up more doors to pre-Harappan period
Credit: The Hindu

Though excavated earlier in the 1980s and 1990s as well, the site at Kunal is spread over an area of around 15-20 acre with over 4 million thick habitation. The site has been dug up thrice since 2017 following a Memorandum of Understanding signed between the Department of Archaeology and Museums, Haryana; the Indian Archaeological Society, New Delhi and National Museum, New Delhi. The present excavation work started on January 9 and is expected to go on till the end of March.


Objectives of the excavation


Speaking about the purpose of excavations since 2017, Technical Assistant, Shuvam Malik said there was enough information available about the structural phases from the previous excavations in 80s and 90s at this site. But there was no background information about the identity of the occupants as to who they were and when and where did they come from. “The main objective during these three seasons of digging was, therefore, to see the origin of Hakra culture and to find out as to who were the earliest occupants of the site and where did they come from,” he said. He added that their team also attempted to know about the craft-specialisation of pre-Harappan people, their behaviour and ceramic traditions through the recent diggings.


A large variety of Hakra ware, red ware, black-on-red ware, black-and-red ware and painted grey ware has been found in considerable quantity and in various shapes at Kunal during the three seasons. Besides this, terracotta cakes, terracotta beads, bangles, gamesmen, steatite beads, seals, stamps, terracotta animal figurines, including one with pasted steatite beads, semi-precious stone beads, copper objects and other antiquities were also discovered.


Artefacts unearthed


Excavation co-director, Banani Bhattacharyya, said the activity areas of craftsmanship having evidence of furnace and workshop for making steatite beads, different ornaments, ceramics were noticed with evidences of finished and unfinished products. “Mud brick walls and floors and multiple floors have also been found during the excavation. A large number of precious antiquities like silver objects and gold beads in early Harappan fabric pot were revealed by the excavators. Copper smelting furnace was also found along with a large number of copper objects and also typical classical Harappan crucible [terracotta] was found,” said Dr. Bhattacharyya.


Mr. Malik pointed out that Kunal had the richest ceramic repertoire among the pre-Harappan sites in the region and the entire Indus Valley Civilization and there was a “lot of variation and variety in ceramic tradition”. He added that they also found interesting antiquities and gold beads, but the bone and copper artefacts were found in abundance during the diggings.











Excavations at Kunal village open up more doors to pre-Harappan period
Credit: The Hindu

The excavators have also found a lot of pit activity at the site and the bones of the mammals, a majority of them charred. The bones are found in the context of the pits. “We are trying to classify the pits found. The charred bones found are of mammals such as antelopes, gazelle and nilgai. These remains will be tested by geologists to find out if they are of wild or domesticated variety. It also hints at some kind of ritual to sacrifice animals,” said Mr. Malik.
“In Kunal, we stumbled upon dwelling pits not usually found in early-Harappan context. It is unique. Bricks are used along with these dwelling pits. The moulded bricks make lining of the pits with thatched roofs,” said Mr. Malik.


Mr. Malik said that the discovery of marine shells at Kunal, whose nearest possible source can be Arabian Sea, hinted at possibilities of trade between these people and other socio-cultural groups.


Cultural chronology


The digging at the site is being done vertically using the Wheeler-Kenyon method to ascertain the chronological sequence of the habitation. The chronology of cultural sequence found at the site is: Period I A- Stage I (Pre-Harappan), Period I B- Stage II (Early Harappan), Period II A- Stage III (Transitional phase), Period II B- Stage IV (Harappan) and Period III – painted grey ware.


As per the Wheeler-Kenyon method, the mound has been divided into grids measuring 10 m x10 m and each grid is further divided into four quadrants. “After digging, the soil along with cultural material is sent for sieving. All cultural material is sorted during the sieving. Ceramics are sent for washing. Bones and rest of antiquities are sorted out from the soil during sieving and labelled. We also maintain pottery yard at the site where we sort all the ceramics in the sequence of digging of each and every quadrant. It help us understand the pattern emerging in the ceramic culture of the society,” said another Technical Assistant Ravi Kant.


The labourers hired for the digging are mostly the local villagers, who are imparted training before being engaged for the job. “The villagers are excited about the digging work as for them it is an opportunity to get work. We engaged 80 labourers, though more than 200 had turned up for hiring,” said the photographer in the team, Darbar Singh.


The staff involved in the digging has been staying put at the site and a makeshift kitchen and other facilities are put in place for them.


Kunal is an excavation site protected by Department of Archaeology and Museums, Haryana and is fenced and guarded by a security guard.


During the first season of digging in 2016-17, the eastern part of the mound, which is low-lying, was dug up. In the next season, the team dug up South-eastern slope and discovered some good structural deposit results, including a white platform, and also got evidence of the deposit of industrial dump. “So to expand the region, we have dug up adjacent to it this year,” said Mr. Malik.


Findings for the three seasons of digging are likely to be published by year-end.


Author: Ashok Kumar | Source: The Hindu [February 19, 2019]



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Complex structural organisation studied in slime mould

Researchers in Japan think they have found an answer to the fundamental biological question of how individual cells know which way to position themselves within a complex, multicellular body. Depending on a cell’s purpose in the larger structure, contact or diffuse chemical signals direct it to its final destination.











Complex structural organisation studied in slime mould
Slime moulds are unicellular organisms that can form multicellular structures like the ones seen here
[Credit: Akihiko Nakajima]

The journey from egg and sperm to a fully grown body requires more than just multiplication. Plants, animals, and people are all made of trillions of cells, carefully organized into larger structures like tissues and organs. Somehow, each cell knows where it belongs — the left side of the heart, the inner lining of the colon, and so on — and generally stays put.


“It’s close to impossible to dissect what’s happening while cells position themselves in multicellular organisms because there are so many players: different cell types, different molecules inside cells, different chemical signals outside the cells, cell growth, programmed cell death,” said Professor Satoshi Sawai from the University of Tokyo, an expert in biological physics, a field that uses the principles of physics to understand living systems.


The slime mould system


Slime moulds provide a simpler system to understand cell positioning. Slime moulds are amoebas, but are similar in size and shape to human white blood cells and share the fundamental aspects of cell dynamics, such as migration and engulfment of disease-causing pathogens.


Individual cells of the slime mould Dictyostelium discoideum can exist independently, living freely in the soil and eating bacteria and fungi. When food is scarce, independent slime mould cells clump together and function as a multicellular organism.


When slime mould cells clump together, sometimes 100 cells, other times 10,000 cells, they differentiate into two distinct types.


The first type, pre-stalk cells, eventually forms a column that supports a sphere composed of the second type, pre-spore cells. Researchers call this two-part structure a fruiting body. The pre-stalk cells will die as the pre-spore cells eventually float off in the wind to a better environment where they can grow and divide again as independent amoebas.


Pre-stalk cells (green) and pre-spore cells (magenta) of Dictyostelium discoideum respond to physical or diffuse


 chemical signals while organizing themselves in a multicellular structure called the fruiting body 


[Credit: Fujimori et al. PNAS 2019]


Inside the clump, before the fruiting body takes shape, cells attach to form long trains and swirl around, immersed in a chemical signal that they secrete. First identified in the 1970s, this diffusive chemical, called cAMP, attracts cells.


Traditionally, the degree of attraction to cAMP signals was thought to separate the cells into pre-stalk and pre-spore cells. More recent genetic experiments revealed, however, that molecules related to adhesion, or cell-to-cell touch, may also be important.


“What’s great about slime mould is that you can take individual cells out of the larger structure and they still do their thing by behaving naturally in a relatively simple setup that mimics the multicellular environment,” said Sawai.


Two types of signals


In their new experiments, the researchers took cells out of a multicellular clump and tracked how the individual cells migrate in response to artificial touch and cAMP signals.


When cell trains formed, the leader cell moved in the direction of cAMP. The follower cells were not pulled along, but rather actively pushed leader cells forward.


“Cell-cell contact activates processes for cell movement. The follower cells are the engine and the leader cells are the steering wheel, always pointing in the direction of the chemical signal,” said Sawai.


Researchers also placed individual pre-stalk or pre-spore cells with beads coated with an adhesion molecule that appears to function in the tail end of cells. All cells attached to follow the bead as in a cell train. Researchers then added cAMP to the experiment. Pre-stalk cells released the bead and moved towards the cAMP source. Pre-spore cells, however, ignored cAMP and held fast to the bead.


Sawai’s research team demonstrated that head-to-tail touch between cells directs their migration, but cAMP somehow overrides this contact only in pre-stalk cells.


“Many people think you have to go to Mars to look for the fundamental rules of what makes life. But we can look at all the still-unexplored branches of the tree of life here on Earth. Slime mould gives us hints at what to look for to understand the mechanistic logics underlying more complex species,” said Sawai.


This discovery of the importance of cell-cell contact to activate cell movement and organization will open new possibilities to study cell-pattern formation in events such as embryo development or spread of breast cancer.


The results are published in the Proceedings of the National Academy of Sciences.


Source: University of Tokyo [February 20, 2019]



TANN



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New twist in evolution’s ‘Big Bang’ theory

Animal life’s evolutionary ‘Big Bang’ ended much sooner than previously thought, a new study has found.











New twist in evolution's ‘Big Bang’ theory
An example of a typical Cambrian trilobite: the 499 million-year-old species, Cedaria minor, from Utah, USA;
body length: 12mm [Credit: John Paterson (University of New England)]

An international team of scientists led by Professor John Paterson at University of New England in Australia, says the Cambrian explosion of life was over surprisingly quickly – possibly in the brief span of 20 million years.


The Cambrian ‘Explosion’ is one of the most important evolutionary events in the history of life and is connected to the ‘sudden’ appearance of numerous and diverse animals.


The fossil record shows that near the start of the Cambrian Period (up to 541 million years ago), a huge burst of evolution commenced, generating all the modern animal groups (phyla) we see today, from worms to insects to humans.


Scientists have long assumed that this Big Bang of evolution extended for some time, at least across much of the Cambrian Period, which lasted 56 million years.


To address this issue, the team studied one of the most diverse and abundant fossil groups of this time period, the trilobites – an extinct group of marine arthropods distantly related to crustaceans, insects, spiders and kin.


Using features preserved in the trilobites’ fossilised skeletons and their geological ages, the team reconstructed a highly detailed evolutionary tree from which rates of evolution could be calculated.











New twist in evolution's ‘Big Bang’ theory
Trilobites (Estaingia), the strange-yet-familiar evolutionary products of the Cambrian Period, are exquisitely preserved
in famous fossil sites around the world, such as the Burgess Shale in Canada and Chengjiang in China.
[Credit: John Paterson, UNE, Australia]

Lead author Professor Paterson says the new research indicates the Cambrian Explosion was “shorter and sharper than we imagined”.


“Our results show that animal evolution’s Big Bang was over a lot earlier than expected: 521 million years ago, within 20 million years after the beginning of the Cambrian,” says Professor Paterson.


Co-author Professor Michael Lee, a Matthew Flinders Fellow at Flinders University and South Australian Museum, says it now looks as though “modern animal groups evolved, diversified and completely re-engineered our planet in a much shorter time frame than previously thought.”


The earliest Cambrian fossil record is patchy, dominated by burrows and trackways rather than shells and skeletons, and things only start to improve from about 521 million years ago, when fossil sites such as the famous Burgess Shale in Canada start to appear.


“Our results give a new framework for palaeontologists trying to understand the earliest history of animal life on Earth”, says the other co-author Dr Greg Edgecombe, from the Natural History Museum in London.


“The Cambrian Explosion is already over by the time the ‘normal’ shelly fossil record kicks in,” says Dr Edgecombe.











New twist in evolution's ‘Big Bang’ theory
Cambrian seascape off South Australia, dominated by large (Redlichia) and small (Estaingia) trilobites
[Credit: Katrina Kenny]

More than 100 anatomical traits of more than 100 species from the Cambrian Period were used to estimate the animals’ evolutionary rates. Multiple statistical models revealed uniform evolutionary rates throughout the entire time interval.


The findings suggest that evolution can fill even huge ecological vacuums extremely rapidly, the scientists say.


The paper is published in the Proceedings of the National Academy of Sciences.


Source: Flinders University [February 20, 2019]



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Unique medieval burial found in Sicily

In medieval Sicily, a man was stabbed multiple times in the back, buried in a really weird way and ostensibly lost to history.











Unique medieval burial found in Sicily
This medieval man’s skeleton, bearing marks of stab wounds, was found facedown in a shallow pit in Sicily
[Credit: Emanuele Canzonieri; Roberto Micciche. et al. 2019]

Now, hundreds of years later, archaeologists have excavated evidence of this ancient crime in the Piazza Armerina, Sicily. The researchers found the man’s skeleton lying face-down in a shallow pit, empty of any funerary objects typical of ancient burials. The body was buried in a position that was unusual for that time period, they reported last month in the International Journal of Osteoarchaeology.


The evidence suggests that the man, lived in the 11th century and was between 30 and 40 years old when he died. Using CT scans and 3D reconstructions, the researchers set out to determine how he died and why his burial was so unusual.


According to the report, there was evidence of six cuts on the individual’s sternum (breastbone) that were indicative of stab wounds likely inflicted by a knife or dagger. On the right side of his sternum, the researchers found a chop mark where a piece of the bone had been removed, likely by a twisting motion from the weapon.


There was no evidence of other injuries on the man’s vertebrae or ribs that would suggest that the man was involved in some kind of “uncontrolled” fight, said lead author Roberto Miccichè, an archaeologist at the University of Palermo in Italy.


The goal of the man’s killer, it seems, was to attack the victim in a “very effective and rapid way,” Miccichè said; in addition, the assailant likely knew human anatomy “very well.” In fact, the cuts were so clean and smooth, that the man may have been immobilized, perhaps with binding, Miccichè said. The man’s feet were also squished together in the burial space, which further supports the idea that his feet were bound together.


Using CT scans, the researchers were able to determine the the angle and size of the man’s stab wounds, information that the investigators then used to create a 3D reconstruction of where the sharp object dug into the sternum and chest cage.


Because the blade of the knife would have entered the man’s upper back at an angle, the researchers think that the man was kneeling on the ground at the time of the stabbing, Miccichè said. Since the knife pierced through the thorax (the part of the body between the neck and the abdomen) and into the man’s breastbone, Miccichè said the weapon likely punctured the man’s lung and heart repeatedly — so he probably died very quickly. And then there’s the weirdness of the burial — the first, well-documented case of a deviant burial in Sicily.


“The burial is atypical because [it] does not follow any religious prescription in the arrangement of the body,” Miccichè said. During this time in Sicily, three major monotheistic religions coexisted: Judaism, Christianity and Islam. Each had different traditions in burying its dead — Jews and Christians of the Middle Ages buried their dead face-up, while Muslims buried the body lying on its right side, so that the head faced southeast, toward Mecca. This skeleton, on the other hand, was buried face-down.


Atypical burials tend to be the result of superstitious beliefs (such as if people think the dead person is a vampire or has returned from the dead) or an indication that the person was an outlaw, Miccichè said. He said he thinks, in this case, that it’s the latter. If in “his life, the individual was not aligned to the social order of the community, [his] burial should reflect this lack of conformity in death,” Miccichè said.


All of this is to say that the man was likely an exile of sorts who was executed. What’s more, this was a time of “crisis and social reorganization” that occurred right after the Norman conquest of Sicily in 1061. “As everywhere and anytime during a period of sociopolitical rearrangement, it is possible to note an increase in violent acts among people,” Micciché said.


Now, Miccichè and his team are looking through medieval archaeological records to find evidence of weapons that could be compatible with the marks on the skeleton and move a step closer to solving this ancient game of Clue.


Author: Yasemin Saplakoglu | Source: LiveScience [February 19, 2019]



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Researchers create DNA-like molecule to aid search for alien life

In a research breakthrough funded by NASA, scientists have synthesized a molecular system that, like DNA, can store and transmit information. This unprecedented feat suggests there could be an alternative to DNA-based life, as we know it on Earth – a genetic system for life that may be possible on other worlds.











Researchers create DNA-like molecule to aid search for alien life
This illustration shows the structure of a new synthetic DNA molecule, dubbed hachimoji DNA, which uses the four
informational ingredients of regular DNA (green, red, blue, yellow) in addition to four new ones
(cyan, pink, purple, orange) [Credit: Indiana University School of Medicine]

This new molecular system, which is not a new life form, suggests scientists looking for life beyond Earth may need to rethink what they are looking for. The research appears in Science Magazine.


DNA is a complex molecule that stores and transmits genetic information, is passed from parent to offspring in all living organisms on Earth, and its components include four key ingredients called nucleotides – all standard for life as we know it. But, what about life on other worlds?


“Life detection is an increasingly important goal of NASA’s planetary science missions, and this new work will help us to develop effective instruments and experiments that will expand the scope of what we look for,” said Lori Glaze, acting director of NASA’s Planetary Science Division.


One way to imagine the kinds of foreign structures found on other worlds is to try to create something foreign on Earth. A team of researchers, led by Steven Benner at the Foundation for Applied Molecular Evolution in Alachua, Florida, successfully achieved the fabrication of a new informational molecular system that is like DNA, except in one key area: The new molecule has eight informational ingredients instead of four.


The synthetic DNA includes the four nucleotides present in Earth life – adenine, cytosine, guanine, and thymine – but also four others that mimic the structures of the informational ingredients in regular DNA. The result is a double-helix structure that can store and transfer information.


Benner’s team, which collaborated with laboratories at the University of Texas in Austin, Indiana University Medical School in Indianapolis, and DNA Software in Ann Arbor, Michigan, dubbed their creation “hachimoji” DNA (from the Japanese “hachi,” meaning “eight,” and “moji,” meaning “letter”). Hachimoji DNA meets all the structural requirements that allow our DNA to store, transmit and evolve information in living systems.


Crystyal structure of a hachimoji double helix built from four naturally-occurring bases, G (green), A (red), 


C (blue), T (yellow), and four synthetic bases, B (cyan), S (pink), P (purple), and Z (orange). 


Notable is the geometric regularity of the pairs, a requirement for evolution 


[Credit: Millie Georgiadis, Indiana University School of Medicine]


“By carefully analyzing the roles of shape, size and structure in hachimoji DNA, this work expands our understanding of the types of molecules that might store information in extraterrestrial life on alien worlds,” said Benner.


Scientists have much more to do on the question of what other genetic systems could serve as the foundation for life, and where such exotic organisms could be found. However, this study opens the door to further research on ways life could structure itself in environments that we consider inhospitable, but which might be teeming with forms of life we haven’t yet imagined. 


“Incorporating a broader understanding of what is possible in our instrument design and mission concepts will result in a more inclusive and, therefore, more effective search for life beyond Earth,” said Mary Voytek, senior scientist for Astrobiology at NASA Headquarters.


One of NASA’s goals is to search for life on other planets like Mars, where there was once flowing water and a thick atmosphere, or moons of the outer solar system like Europa and Enceladus, where vast water oceans churn under thick layers of ice. What if life on those worlds doesn’t use our DNA? How could we recognize it? This new DNA may be the key to answering these questions and many more.


This work also interests those interested in information as part of life.


“The discovery that DNA with eight nucleotide letters is suitable for storing and transmitting information is a breakthrough in our knowledge of the range of possibilities necessary for life,” said Andrew Serazin, president of Templeton World Charity Foundation in Nassau, The Bahamas, which also supported this work. “This makes a major contribution to the quest supported by Templeton World Charity Foundation to understand the fundamental role that information plays in both physics and biology.”


Source: NASA [February 21, 2019]



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Rules of inheritance rewritten in worms

The idea that children inherit half of their DNA from each parent is a central tenet of modern genetics. But a team led by KAUST’s Christian Frøkjær-Jensen has re-engineered this heredity pattern in roundworms, a commonly used model organism in biology, and created animals with an unusual pedigree that are beginning to help scientists better understand nongenetic modes of inheritance and molecular signaling events between tissues and genomes.











Rules of inheritance rewritten in worms
The presence of red and green fluorescence in the muscles of the worm pharynx provides an easy visual readout
of atypical chromosome sorting [Credit: © 2018 Karen Lynn Artiles]

“Being able to produce such populations is a game changer for developmental and genetic studies,” says KAUST geneticist Frøkjær-Jensen. “We expect these tools to be of substantial interest to the worm research community, as well as to many colleagues working on other model systems for which this approach may provide paradigm and guidance.”
Frøkjær-Jensen and his colleagues describe an easy and reliable way of making these worms. Their method builds on the 2016 work of researchers in Germany, who made a simple tweak to the cytoskeletal structure that forms during cell division. They overexpressed just one gene, GPR-1, which induced faulty sorting of chromosomes in the earliest stage of embryonic development.


This led to mosaic offspring in which certain tissues contained DNA only from mom while other tissues contained DNA only from dad–but the protocol was finicky and unreliable. GPR-1 expression was often lost over time, and the microscopic detailing needed to confirm whether atypical chromosome sorting had occurred was tedious, making it hard to take advantage of the genetic tool.











Rules of inheritance rewritten in worms
Over-expression of just a single gene (gpr-1) in the early embryo of the roundworm C. elegans allows a fundamental
rewriting of Mendelian inheritance. Instead of all cells containing maternal and paternal DNA, the first cell division
leads to maternal and paternal DNA being split into two different cells. Germ cells are generated from only
one of these cells resulting in grandchildren with DNA exclusively from one of the original parents.
Such a system allows us to question fundamental assumptions about inheritance
[Credit: ©  2019 Karen Artiles, Andrew Fire and Christian Frøkjaer-Jensen]

Frøkjær-Jensen worked with Nobel Prize-winning geneticist Andrew Fire and his lab manager at Stanford University to improve and simplify the German team’s technique. They modified the GPR-1 gene to prevent it from being turned off by genomic defense mechanisms, and they developed a more easily tractable system for visually identifying whether worms were mosaic or not.
The researchers created a library of fluorescently marked, GPR-1-overexpressing strains that offer a platform for interrogating the function of any genes of interest. As a proof of concept, they used these toolkit strains to generate worms containing almost no genetic material from their maternal lineage. Only the DNA found in the mitochondria, the subcellular power plants, came from the maternal lineage, while all nuclear DNA came from the paternal lineage–a departure from the way heredity is supposed to work.


In his KAUST lab, Frøkjær-Jensen is now using the strains to design worms with recoded genomes for applications in synthetic biology. As part of the KAUST Environmental Epigenetics Research Program, his lab is also studying how chemical marks that impact gene expression can be passed from one generation to the next, a phenomenon known as transgenerational epigenetic inheritance.


The findings are published in Developmental Cell.


Source: King Abdullah University of Science and Technology [February 21, 2019]



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Mini Models To study skyscraper design or aeroplane flight…


Mini Models


To study skyscraper design or aeroplane flight dynamics, you might make a small model before tinkering with the real thing. Researchers take a similar approach to studying our organs. Clusters of cells resembling miniature organs are used to mimic conditions like cancer on a safe and manageable scale demonstrating how they take hold in our body. For example, scientists studying oesophageal cancers have been hampered by a lack of experimental options, but have now produced organoids that replicate the molecular, physiological and genetic environment of the disease. These organoids – pictured at 3, 7, 14 and 21 days of development from a tumour-derived starting point – provide a new realistic platform for testing drugs and other treatments, as well as observing disease progression, without endangering human or animal test subjects.


Written by Anthony Lewis



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All quiet on the eastern front

I put together this quick and dirty qpGraph tree just to double check what the Eneolithic trio from the Piedmont steppe (Piedmont_Eneolithic) were roughly made of, and how they related to some of the other populations from the eastern half of ancient West Eurasia. The relevant graph file is available here.



Yep, the tree basically lines up with scientific literature. In other words, Piedmont_Eneolithic appears to be a two-way mixture of populations very closely related to Caucasus and Eastern European Hunter-Gatherers (CHG and EHG, respectively). Good to know.
See also…
On Maykop ancestry in Yamnaya
Big deal of 2018: Yamnaya not related to Maykop
Yamnaya isn’t from Iran just like R1a isn’t from India

Source


Lligwy Prehistoric Burial Chamber, Watercolour and Ink Sketch, February 2019.

Lligwy Prehistoric Burial Chamber, Watercolour and Ink Sketch, February 2019.



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Tealing Iron Age Earthhouse or Soutterrain, Dundee, Scotland, 19.2.19.

Tealing Iron Age Earthhouse or Soutterrain, Dundee, Scotland, 19.2.19.












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