вторник, 11 декабря 2018 г.

In 2013, researchers published a shape model of asteroid Bennu…

In 2013, researchers published a shape model of asteroid Bennu based on years of observations from Puerto Rico’s Arecibo Observatory. Their model depicted a rough diamond shape. Five years later, the OSIRIS-REx spacecraft has reached the asteroid, and data obtained from spacecraft’s cameras corroborate those ground-based telescopic observations of Bennu. 

The original model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination and overall shape presented almost exactly as projected! This video shows the new shape model created using data from OSIRIS-REx’s approach to the asteroid.

One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated it to be at least 33 feet (10 meters) in height. Preliminary calculations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).

Also during the approach phase, OSIRIS-REx revealed water locked inside the clays that make up Bennu. The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study. Get all the details about this discovery HERE.

Learn more about OSIRIS-REx’s journey at nasa.gov/osirisrex

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Jupiter’s North Equatorial Belt

NASA – JUNO Mission logo.

Dec. 10, 2018

Colorful swirling clouds in Jupiter’s North Equatorial Belt practically fill this image from NASA’s Juno spacecraft. This is the closest image captured of the Jovian clouds during this recent flyby of the gas giant planet.

The color-enhanced image was taken at 2:08 p.m. PDT (5:08 p.m. EDT) on Oct. 29, 2018 as the spacecraft performed its 16th close flyby of Jupiter. At the time, Juno was about 2,100 miles (3,400 kilometers) from the planet’s cloud tops, at approximately 14 degrees north latitude. In other words, the spacecraft was about as close to Jupiter as San Francisco is to Chicago, which is quite close when racing over a planet that’s 11 times wider than Earth.

Juno spacecraft orbiting Jupiter

Citizen scientist Björn Jónsson created this image using data from the spacecraft’s JunoCam imager.

JunoCam’s raw images are available for the public to peruse and to process into image products at: http://missionjuno.swri.edu/junocam.  

More information about Juno is at: http://www.nasa.gov/juno and http://missionjuno.swri.edu.

Image, Animation, Text, Credits: NASA/Tony Greicius/JPL-Caltech/SwRI/MSSS/Björn Jónsson.

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Columbite-(Mn) with Rhodizite | #Geology #GeologyPage…

Columbite-(Mn) with Rhodizite | #Geology #GeologyPage #Mineral

Locality: Tetezantsio pegmatites, Madagascar

Crystal size:6 mm wide

Overall size: 85mm x 50 mm x 40 mm

Photo Copyright © Minservice

Geology Page



Scepter Quartz on Dolomite | #Geology #GeologyPage…

Scepter Quartz on Dolomite | #Geology #GeologyPage #Mineral

Locality: Maggiana, frazione di Mandello del Lario (LC), Lombardy, Italy

Crystal size:5 mm

Overall size: 50mm x 27 mm x 20 mm

Photo Copyright © Minservice

Geology Page



Chrysoberyl | #Geology #GeologyPage #Mineral Locality: Lac…

Chrysoberyl | #Geology #GeologyPage #Mineral

Locality: Lac Alaotra Chrysoberyl Pegmatites, Ambatondrazaka District, Alaotra-Mangoro Region, Toamasina Province, Madagascar

Overall size: 14mm x 1 mm x 18 mm

Photo Copyright © Minservice

Geology Page



Cacoxenite | #Geology #GeologyPage #Mineral Locality:…

Cacoxenite | #Geology #GeologyPage #Mineral

Locality: Capoterra, Cagliari, Sardegna, Italy

Crystal size:sub.mm

Overall size: 38mm x 30 mm x 34 mm

Photo Copyright © Minservice

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2018 December 11 Arp 188 and the Tadpole’s Tail Image…

2018 December 11

Arp 188 and the Tadpole’s Tail
Image Credit: Hubble Legacy Archive, ESA, NASA; Processing: Faus Márquez (AAE)

Explanation: Why does this galaxy have such a long tail? In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation of the Dragon (Draco). Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 – from right to left in this view – and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy’s stars, gas, and dust forming the spectacular tail. The intruder galaxy itself, estimated to lie about 300 thousand light-years behind the, can be seen through foreground spiral arms at the upper right. Following its terrestrial namesake, the Tadpole Galaxy will likely lose its tail as it grows older, the tail’s star clusters forming smaller satellites of the large spiral galaxy.

∞ Source: apod.nasa.gov/apod/ap181211.html

HiPOD (10 December 2017) The Enduring Charm of Martian…

HiPOD (10 December 2017) The Enduring Charm of Martian Spiders

Araneiform terrain (colloquially: spider-like terrain) is located in the south polar region of Mars and evolves in appearance over the spring and summer. In the season shown here, the thin bright lines on the surface (the spider legs) are troughs and many of these features have dark fan-shaped markings emanating from them.

Our current theory for how these patterns are formed is that during winter a carbon dioxide ice layer develops over the surface. When sun rays strike this surface, this carbon dioxide ice acts in a similar way to our atmosphere: it allows the sun light to penetrate but traps the infrared radiation creating a greenhouse-like effect.

The trapped heat transforms the ice at the bottom of the layer to gas, building up pressure until it bursts through. When that happens, the gas flows out in geyser-like fashion and carries dust with it, which falls back to the surface to form the dark fans.

NASA/JPL/University of Arizona

How did Y-haplogroup N1c get to Bolshoy Oleni Ostrov?

Y-haplogroup N1c probably entered Europe from Siberia during the Bronze Age or a little earlier. It first appears in the European ancient DNA record in two samples from a burial site at Bolshoy Oleni Ostrov, in the Kola Peninsula, dated to 1523±87 calBCE (see here). These individuals also show significant genome-wide Siberian ancestry, but it’s possible that this is in large part a coincidence, and that N1c spread into the Kola Peninsula from the south in a population of overwhelmingly European ancestry.
Crazy, huh? Not really. Consider the qpAdm mixture models below for BOO002 and BOO004, the two males from the Bolshoy Oleni Ostrov site belonging to N1c, and BOO006, a female and the most Siberian-admixed individual from the same site. Although BOO002 and BOO004 show a lot of Nganasan-related and thus Siberian ancestry, they also require significant input from a source closely related to Baltic_BA, a fully European Bronze Age population from the East Baltic region. On the other hand, BOO006 doesn’t need Baltic_BA for a successful model.

Baltic_BA 0.124±0.029
EHG 0.406±0.032
Nganasan 0.469±0.017
chisq 10.847
tail prob 0.286316
Full output
Baltic_BA 0.065±0.043
EHG 0.265±0.084
Nganasan 0.517±0.033
West_Siberia_N 0.152±0.074
chisq 8.847
tail prob 0.355397
Full output
EHG 0.367±0.049
Nganasan 0.544±0.031
West_Siberia_N 0.089±0.063
chisq 9.878
tail prob 0.360451
Full output

Keep in mind that N1c is very common in the East Baltic today in populations with minimal Siberian genome-wide ancestry. Indeed, Latvians and Lithuanians can often be modeled with no Siberian input. Thus, it’s likely that by the time N1c arrived in the East Baltic, probably during the late Bronze Age or early Iron Age, it did so with populations with heavily diluted Siberian genome-wide ancestry. Such groups may also have taken N1c north of the Baltic and into the Kola Peninsula.
See also…
On the trail of the Proto-Uralic speakers (work in progress)


NASA’s Voyager 2 Probe Enters Interstellar Space

NASA – Voyager 1 & 2 Mission patch.

Dec. 10, 2018

Image above: This illustration shows the position of NASA’s Voyager 1 and Voyager 2 probes, outside of the heliosphere, a protective bubble created by the Sun that extends well past the orbit of Pluto. Image Credits: NASA/JPL-Caltech.

For the second time in history, a human-made object has reached the space between the stars. NASA’s Voyager 2 probe now has exited the heliosphere – the protective bubble of particles and magnetic fields created by the Sun.

Members of NASA’s Voyager team will discuss the findings at a news conference at 11 a.m. EST (8 a.m. PST) today at the meeting of the American Geophysical Union (AGU) in Washington. The news conference will stream live on the agency’s website.

NASA’s Voyager 2 Enters Interstellar Space

Comparing data from different instruments aboard the trailblazing spacecraft, mission scientists determined the probe crossed the outer edge of the heliosphere on Nov. 5. This boundary, called the heliopause, is where the tenuous, hot solar wind meets the cold, dense interstellar medium. Its twin, Voyager 1, crossed this boundary in 2012, but Voyager 2 carries a working instrument that will provide first-of-its-kind observations of the nature of this gateway into interstellar space.

Voyager 2 now is slightly more than 11 billion miles (18 billion kilometers) from Earth. Mission operators still can communicate with Voyager 2 as it enters this new phase of its journey, but information – moving at the speed of light – takes about 16.5 hours to travel from the spacecraft to Earth. By comparison, light traveling from the Sun takes about eight minutes to reach Earth.

The most compelling evidence of Voyager 2’s exit from the heliosphere came from its onboard Plasma Science Experiment (PLS), an instrument that stopped working on Voyager 1 in 1980, long before that probe crossed the heliopause. Until recently, the space surrounding Voyager 2 was filled predominantly with plasma flowing out from our Sun. This outflow, called the solar wind, creates a bubble – the heliosphere – that envelopes the planets in our solar system. The PLS uses the electrical current of the plasma to detect the speed, density, temperature, pressure and flux of the solar wind. The PLS aboard Voyager 2 observed a steep decline in the speed of the solar wind particles on Nov. 5. Since that date, the plasma instrument has observed no solar wind flow in the environment around Voyager 2, which makes mission scientists confident the probe has left the heliosphere.

In addition to the plasma data, Voyager’s science team members have seen evidence from three other onboard instruments – the cosmic ray subsystem, the low energy charged particle instrument and the magnetometer – that is consistent with the conclusion that Voyager 2 has crossed the heliopause. Voyager’s team members are eager to continue to study the data from these other onboard instruments to get a clearer picture of the environment through which Voyager 2 is traveling.

Image above: The set of graphs on the left illustrates the drop in electrical current detected in three directions by Voyager 2’s plasma science experiment (PLS) to background levels. They are among the key pieces of data that show that Voyager 2 entered interstellar space in November 2018. Image Credits: NASA/JPL-Caltech/MIT.

“There is still a lot to learn about the region of interstellar space immediately beyond the heliopause,” said Ed Stone, Voyager project scientist based at Caltech in Pasadena, California.

Together, the two Voyagers provide a detailed glimpse of how our heliosphere interacts with the constant interstellar wind flowing from beyond. Their observations complement data from NASA’s Interstellar Boundary Explorer (IBEX), a mission that is remotely sensing that boundary. NASA also is preparing an additional mission – the upcoming Interstellar Mapping and Acceleration Probe (IMAP), due to launch in 2024 – to capitalize on the Voyagers’ observations.

“Voyager has a very special place for us in our heliophysics fleet,” said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. “Our studies start at the Sun and extend out to everything the solar wind touches. To have the Voyagers sending back information about the edge of the Sun’s influence gives us an unprecedented glimpse of truly uncharted territory.”

While the probes have left the heliosphere, Voyager 1 and Voyager 2 have not yet left the solar system, and won’t be leaving anytime soon. The boundary of the solar system is considered to be beyond the outer edge of the Oort Cloud, a collection of small objects that are still under the influence of the Sun’s gravity. The width of the Oort Cloud is not known precisely, but it is estimated to begin at about 1,000 astronomical units (AU) from the Sun and to extend to about 100,000 AU. One AU is the distance from the Sun to Earth. It will take about 300 years for Voyager 2 to reach the inner edge of the Oort Cloud and possibly 30,000 years to fly beyond it.

The Voyager probes are powered using heat from the decay of radioactive material, contained in a device called a radioisotope thermal generator (RTG). The power output of the RTGs diminishes by about four watts per year, which means that various parts of the Voyagers, including the cameras on both spacecraft, have been turned off over time to manage power.

“I think we’re all happy and relieved that the Voyager probes have both operated long enough to make it past this milestone,” said Suzanne Dodd, Voyager project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “This is what we’ve all been waiting for. Now we’re looking forward to what we’ll be able to learn from having both probes outside the heliopause.”

Voyager 2 launched in 1977, 16 days before Voyager 1, and both have traveled well beyond their original destinations. The spacecraft were built to last five years and conduct close-up studies of Jupiter and Saturn. However, as the mission continued, additional flybys of the two outermost giant planets, Uranus and Neptune, proved possible. As the spacecraft flew across the solar system, remote-control reprogramming was used to endow the Voyagers with greater capabilities than they possessed when they left Earth. Their two-planet mission became a four-planet mission. Their five-year lifespans have stretched to 41 years, making Voyager 2 NASA’s longest running mission.

The Voyager story has impacted not only generations of current and future scientists and engineers, but also Earth’s culture, including film, art and music. Each spacecraft carries a Golden Record of Earth sounds, pictures and messages. Since the spacecraft could last billions of years, these circular time capsules could one day be the only traces of human civilization.

Voyager’s mission controllers communicate with the probes using NASA’s Deep Space Network (DSN), a global system for communicating with interplanetary spacecraft. The DSN consists of three clusters of antennas in Goldstone, California; Madrid, Spain; and Canberra, Australia.

The Voyager Interstellar Mission is a part of NASA’s Heliophysics System Observatory, sponsored by the Heliophysics Division of NASA’s Science Mission Directorate in Washington. JPL built and operates the twin Voyager spacecraft. NASA’s DSN, managed by JPL, is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions. The Commonwealth Scientific and Industrial Research Organisation, Australia’s national science agency, operates both the Canberra Deep Space Communication Complex, part of the DSN, and the Parkes Observatory, which NASA has been using to downlink data from Voyager 2 since Nov. 8.

Related article:

NASA’s Voyager 1 Explores Final Frontier of Our ‘Solar Bubble’

Related links:

Interstellar Boundary Explorer (IBEX): https://www.nasa.gov/mission_pages/ibex/index.html

Interstellar Mapping and Acceleration Probe (IMAP): https://www.nasa.gov/press-release/nasa-selects-mission-to-study-solar-wind-boundary-of-outer-solar-system

Deep Space Network (DSN): https://www.nasa.gov/directorates/heo/scan/services/networks/dsn

For more information about the Voyager mission, visit: https://www.nasa.gov/voyager

More information about NASA’s Heliophysics missions is available online at: https://www.nasa.gov/sunearth

Images (mentioned), Animations, Video, Text, Credits: NASA/Dwayne Brown/Karen Fox/Sean Potter/JPL/Calla Cofield.

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NASA’s Newly Arrived OSIRIS-REx Spacecraft Already Discovers Water on Asteroid

NASA – OSIRIS-REx Mission patch.

Dec. 10, 2018

Image above: This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on Dec. 2 by the OSIRIS-REx spacecraft from a range of 15 miles (24km). Image Credits: NASA/Goddard/University of Arizona.

Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.

During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.

Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.

OSIRIS-REx arrival at Bennu. Animation Credit: NASA

“The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”

Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.

One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).

Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.

3D Shape Model of Asteroid Bennu

Video above: This preliminary shape model of asteroid Bennu was created from a compilation of images taken by OSIRIS-REx’s PolyCam camera during the spacecraft’s approach toward Bennu during the month of November. This 3D shape model shows features on Bennu as small as six meters. Video Credits: NASA/Goddard/University of Arizona.

“Our initial data show that the team picked the right asteroid as the target of the OSIRIS-REx mission. We have not discovered any insurmountable issues at Bennu so far,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “The spacecraft is healthy and the science instruments are working better than required. It is time now for our adventure to begin.”

The mission currently is performing a preliminary survey of the asteroid, flying the spacecraft in passes over Bennu’s north pole, equator, and south pole at ranges as close as 4.4 miles (7 km) to better determine the asteroid’s mass. The mission’s scientists and engineers must know the mass of the asteroid in order to design the spacecraft’s insertion into orbit because mass affects the asteroid’s gravitational pull on the spacecraft. Knowing Bennu’s mass will also help the science team understand the asteroid’s structure and composition.

This survey also provides the first opportunity for the OSIRIS-REx Laser Altimeter (OLA), an instrument contributed by the Canadian Space Agency, to make observations, now that the spacecraft is in proximity to Bennu.

The spacecraft’s first orbital insertion is scheduled for Dec. 31, and OSIRIS-REx will remain in orbit until mid-February 2019, when it exits to initiate another series of flybys for the next survey phase. During the first orbital phase, the spacecraft will orbit the asteroid at a range of 0.9 miles (1.4 km) to 1.24 miles (2.0 km) from the center of Bennu — setting new records for the smallest body ever orbited by a spacecraft and the closest orbit of a planetary body by any spacecraft.

Goddard provides overall mission management, systems engineering and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space Systems in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the agency’s New Frontiers Program for the Science Mission Directorate in Washington.

For more information about OSIRIS-REx, visit: https://www.nasa.gov/osiris-rex

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Dwayne Brown/JoAnna Wendel/Katherine Brown/GSFC/Nancy Jones/University of Arizona/Erin Morton.

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LHC prepares for new achievements

CERN – European Organization for Nuclear Research logo.

Dec. 10, 2018

After an outstanding performance, the Large Hadron Collider (LHC), the accelerator complex and the experiments are now stopping for two years for major improvements and upgrading.

Image above: The Superconducting Magnets and Circuits Consolidation project which took place during the first Long Shutdown (LS1) (Image: Maximilien Brice/CERN).

Geneva, 3 December 2018. Early this morning, operators of the CERN Control Centre turned off the Large Hadron Collider (LHC), ending the very successful second run of the world’s most powerful particle accelerator. CERN’s accelerator complex will be stopped for about two years to enable major upgrade and renovation works.

During this second run (2015–2018), the LHC performed beyond expectations, achieving approximately 16 million billion proton-proton collisions at an energy of 13 TeV and large datasets for lead-lead collisions at an energy of 5.02 TeV. These collisions produced an enormous amount of data, with more than 300 petabytes (300 million gigabytes) now permanently archived in CERN’s data centre tape libraries. This is the equivalent of 1000 years of 24/7 video streaming! By analysing these data, the LHC experiments have already produced a large amount of results, extending our knowledge of fundamental physics and of the Universe.

“The second run of the LHC has been impressive, as we could deliver well beyond our objectives and expectations, producing five times more data than during the first run, at the unprecedented energy of 13 TeV,” says Frédérick Bordry, CERN Director for Accelerators and Technology. “With this second long shutdown starting now, we will prepare the machine for even more collisions at the design energy of 14 TeV.”

“In addition to many other beautiful results, over the past few years the LHC experiments have made tremendous progress in the understanding of the properties of the Higgs boson,” adds Fabiola Gianotti, CERN Director-General. “The Higgs boson is a special particle, very different from the other elementary particles observed so far; its properties may give us useful indications about physics beyond the Standard Model.”

A cornerstone of the Standard Model of particle physics – the theory that best describes the elementary particles and the forces that bind them together – the Higgs boson was discovered at CERN in 2012 and has been studied ever since. In particular, physicists are analysing the way it decays or transforms into other particles, to check the Standard Model’s predictions. Over the last three years, the LHC experiments extended the measurements of rates of Higgs boson decays, including the most common, but hard-to-detect, decay into bottom quarks, and the rare production of a Higgs boson in association with top quarks. The ATLAS and CMS experiments also presented updated measurement of the Higgs boson mass with the best precision to date.

Besides the Higgs boson, the LHC experiments produced a wide range of results and hundreds of scientific publications, including the discovery of exotic new particles such as Ξcc++ and pentaquarks with the LHCb experiment, and the unveiling of so-far unobserved phenomena in proton–proton and proton-lead collisions at ALICE.

During the two-year break, Long Shutdown 2 (LS2), the whole accelerator complex and detectors will be reinforced and upgraded for the next LHC run, starting in 2021, and the High-Luminosity LHC (HL-LHC) project, which will start operation after 2025. Increasing the luminosity of the LHC means producing far more data.

“The rich harvest of the second run enables the researchers to look for very rare processes,” explains Eckhard Elsen, Director for Research and Computing at CERN. “They will be busy throughout the shutdown examining the huge data sample for possible signatures of new physics that haven’t had the chance to emerge from the dominant contribution of the Standard Model processes. This will guide us into the HL-LHC when the data sample will increase by yet another order of magnitude.”

Large Hadron Collider (LHC)

Several components of the accelerator chain (injectors) that feed the LHC with protons will be renewed to produce more intense beams. The first link in this chain, the linear accelerator Linac2, will be replaced by Linac4. The new linear accelerator will accelerate H- ions, which are later stripped to protons, allowing the preparation of brighter beams. The second accelerator in the chain, the Proton Synchrotron Booster, will be equipped with completely new injection and acceleration systems. The Super Proton Synchrotron (SPS), the last injector before the LHC, will have new radio frequency power to accelerate higher beam intensities, and will be connected to upgraded transfer lines.

Some improvements of the LHC are also planned during LS2. The bypass diodes – the electrical components that protect the magnets in case of quench – will be shielded, as a prerequisite for extending the LHC beam energy to 7 TeV after the LS2, and more than 20 main superconducting magnets will be replaced. Moreover, civil engineering works for the HL-LHC that started in June 2018 will continue, new galleries will be connected to the LHC tunnel, and new powerful magnet and superconducting technologies will be tested for the first time.

All the LHC experiments will upgrade important parts of their detectors in the next two years. Almost the entire LHCb experiment will be replaced with faster detector components that will enable the collaboration to record events at full proton-proton rate. Similarly, ALICE will upgrade the technology of its tracking detectors. ATLAS and CMS will undergo improvements and start to prepare for the big experiments’ upgrade for HL-LHC.

Proton beams will resume in spring 2021 with the LHC’s third run.


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Higgs boson: https://home.cern/science/physics/higgs-boson

ATLAS paper: https://arxiv.org/pdf/1806.00242.pdf

CMS paper: https://arxiv.org/abs/1706.09936

High-Luminosity LHC (HL-LHC) project: https://home.cern/science/accelerators/high-luminosity-lhc

Linac2: https://home.cern/news/news/accelerators/so-long-linac2-and-thanks-all-protons

Large Hadron Collider (LHC): https://home.web.cern.ch/fr/topics/large-hadron-collider

ATLAS: https://home.web.cern.ch/about/experiments/atlas

CMS: https://home.web.cern.ch/about/experiments/cms

ALICE: https://home.web.cern.ch/about/experiments/alice

LHCb: https://home.web.cern.ch/about/experiments/lhcb

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Image, Animation, Text, Credit: CERN.

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Improved Membrane Technology Creates Tiny Pores with Big Impact

ISS – International Space Station logo.

Dec. 10, 2018

Membranes – thin barriers that allow some things to pass through, but stop others – occur naturally in cells and tissues. Artificial membranes modeled after natural ones are used in a number of applications, including separating and removing carbon dioxide (CO2) from waste gases released in energy production.

An investigation on the International Space Station looks at whether making artificial membranes in microgravity can help reduce greenhouse gas emissions on Earth.

Image above: Cemsica calcium silicate nanoparticles, which have diameters as small as a few nanometers. Image Credits: Cemsica.

The Cemsica investigation uses particles of calcium-silicate to make membranes with openings or pores smaller than 100 nanometers, known as nanoporous membranes, to separate carbon dioxide molecules from air and other gases. These membranes are as thin as a human hair. Membranes already represent one of the most energy-efficient and cost-effective technologies for separating and removing CO2 from waste gases.

The investigation takes its name from Houston-based Cemsica, LLC, a company that is commercializing this gas separation membrane technology. “Our technology not only controls the shape and size of the membrane pores,” said Negar Rajabi, principal investigator and Cemsica founder and CEO. “It also creates an affinity to certain gases such as CO2, meaning those gases are drawn to the membrane.” That gives the membranes significantly greater separation capability.

Creating these membranes in microgravity may resolve current challenges in the technology, including high-cost and manufacturing difficulties, Rajabi added. Resolving those challenges could lead to development of lower-cost membranes with improved performance and stability, as well as improved manufacturing techniques.

Large gaps or separation of the calcium-silicate particles and substrate material adversely affect membrane performance. Microgravity minimizes these problems since calcium-silicate crystals grow larger and in more organized structures in space, creating organized, defect-free pores and higher surface area.

Image above: The rise of carbon dioxide in the atmosphere. In 2013, CO2 levels surpassed 400 ppm for the first time in recorded history. Image Credits: National Oceanic and Atmospheric Administration.

Surface area plays a key role in gas separation in microgravity, where separation occurs only through diffusion. The higher surface area remains a significant factor in improved gas separation even in Earth’s gravity because it creates higher surface tension that facilitates affinity-based gas separation.

This investigation was sponsored by the International Space Station U.S. National Laboratory. “Cemsica’s novel approach to gas separation membranes in microgravity conditions provides the energy community a new avenue for evaluating unique ways to reduce the effects of CO2 emissions on our planet,” said Patrick O’Neill with the National Lab. “The project also could reduce energy consumption while improving the chemical stability of products on Earth.”

Lessons learned from the investigation may enable Earth-based production of membranes that can separate and capture CO2 from fossil-fuel power plants using half the energy of current methods. Roughly 40 percent of CO2 emissions in the U.S. come from these power plants. Other potential applications include oil and gas production and water treatment.

These membrane pores may be tiny, but they have very big potential.

Related links:

Cemsica, LLC: http://www.cemsica.com/

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

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

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

Images (mentioned), Text, Credits: NASA/Michael Johnson/JSC/International Space Station Program Science Office/Melissa Gaskill.

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NASA Provides New Look at Puerto Rico Post-Hurricane Maria

NASA – Suomi NPP Mission patch.

Dec. 10, 2018

When Hurricane Maria struck Puerto Rico head-on as a Category 4 storm with winds up to 155 miles per hour in September 2017, it damaged homes, flooded towns, devastated the island’s forests and caused the longest electricity black-out in U.S. history.

Image above: On Sept. 21, 2017, NASA-NOAA’s Suomi NPP satellite provided this thermal image of Hurricane Maria after it moved off the coast of Puerto Rico. Image Credit: NOAA/NASA Goddard Rapid Response Team.

Two new NASA research efforts delve into Hurricane Maria’s far-reaching effects on the island’s forests as seen in aerial surveys and on its residents’ energy and electricity access as seen in data from space. The findings, presented Monday at the American Geophysical Union meeting in Washington, illustrate the staggering scope of Hurricane Maria’s damage to both the natural environment and communities.

An Island Gone Dark

At night, Earth is lit up in bright strings of roads dotted with pearl-like cities and towns as human-made artificial light takes center stage. During Hurricane Maria, Puerto Rico’s lights went out.

In the days, weeks and months that followed, research physical scientist Miguel Román at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and his colleagues developed neighborhood-scale maps of lighting in communities across Puerto Rico. To do this, they combined daily satellite data of Earth at night from the NASA/NOAA Suomi National Polar-orbiting Partnership satellite with USGS/NASA Landsat data and OpenStreetMap data. They monitored where and when the electricity grid was restored, and analyzed the demographics and physical attributes of neighborhoods longest affected by the power outages.

NASA’s Black Marble Maps Puerto Rico’s Energy Use After Hurricane Maria

Video above: Credits: NASA’s Goddard Space Flight Center.

A disproportionate share of long-duration power failures occurred in rural communities. The study found that 41 percent of Puerto Rico’s rural municipalities experienced prolonged periods of outage, compared to 29 percent of urban areas. When combined, power failures across Puerto Rico’s rural communities accounted for 61 percent of the estimated cost of 3.9 billion customer-interruption hours, six months after Hurricane Maria. These regions are primarily rural in the mountainous interior of the island where residents were without power for over 120 days. However, even more heavily populated areas had variable recovery rates between neighborhoods, with suburbs often lagging behind urban centers.

The difference between urban and rural recovery rates is in part because of the centralized set-up of Puerto Rico’s energy grid that directs all power to prioritized locations rather than based on proximity to the nearest power plant, Román said. Areas were prioritized, in part, based on their population densities, which is a disadvantage to rural areas. Within cities, detached houses and low-density suburban areas were also without power longer.

“It’s not just the electricity being lost,” Román said. “Storm damage to roads, high-voltage power lines and bridges resulted in cascading failures across multiple sectors, making many areas inaccessible to recovery efforts. So people lost access to other basic services like running water, sanitation, and food for extended time periods.”

The absence of electricity as seen in the night lights data offers a new way to visualize storm impacts to vulnerable communities across the entirety of Puerto Rico on a daily basis. It’s an indicator visible from space that critical infrastructure, beyond power, may be damaged as well, including access to fuel and other necessary supplies. The local communities with long-duration power outages also correspond to areas that reported lack of access to medical resources.

The next step for Román when looking at future disasters is to go beyond night lights data and sync it up with updated information on local infrastructure – roads, bridges, internet connectivity, clean water sources – so that when the lights are out, disaster responders can cross-reference energy data with other infrastructure bottlenecks that needs to be solved first, which would help identify at-risk communities and allocate resources.

The Buzz-Cut Forest

Hurricane Maria’s lashing rain and winds also transformed Puerto Rico’s lush tropical rainforest landscape. Research scientist Doug Morton of Goddard was part of the team of NASA researchers who had surveyed Puerto Rico’s forests six months before the storm. The team used Goddard’s Lidar, Hyperspectral, and Thermal (G-LiHT) Airborne Imager, a system designed to study the structure and species composition of forests. Shooting 600,000 laser pulses per second, G-LiHT produces a 3D view of the forest structure in high resolution, showing individual trees in high detail from the ground to treetop. In April 2018, post-Maria, the team went back and surveyed the same tracks as in 2017.

Comparing the before and after data, the team found that 40 to 60 percent of the tall trees that formed the canopy of the forest were damaged, either snapped in half, uprooted by strong winds or lost large branches.

3-D Views of Puerto Rico’s Forests After Hurricane Maria

Video above: Credits: NASA’s Goddard Space Flight Center.

“Maria gave the island’s forests a haircut,” said Morton. “The island lost so many large trees that the overall height of forests was shortened by one-third. We basically saw 60 years’ worth of what we would otherwise consider natural treefall disturbances happen in one day.”

The extensive damage to Puerto Rico’s forests had far-reaching effects, Morton said. Fallen trees that no longer stabilize soil on slopes with their roots as well as downed branches can contribute to landslides and debris flows, increased erosion, and poor water quality in streams and rivers where sediments build up.

In addition, the lidar surveys across the island corroborate findings presented at AGU by ecologist Maria Uriarte at Columbia University in New York City, who looked at tree death and damage rates in ground plots at the National Science Foundation Luquillo Long-Term Ecological Research site. Uriarte found certain tree species were more susceptible to the high wind damage, while others such as the palms, survived at higher rates, along with shrubs and shorter trees in the understory.

Morton and Uriarte will continue to follow the fate of Puerto Rican forests as they recover from hurricane damages using laser technology from the ground to make detailed measurements of forest regrowth.

Related articles:

NASA Measures Hurricane Maria’s Torrential Rainfall, Sees Eye Re-open

NASA Looks Within Category 5 Hurricane Maria Before and After First Landfall

NASA Sees Maria Intensify into a Major Hurricane

NASA Finds Very Heavy Rainfall in Hurricane Maria

NASA Infrared Data Targets Maria’s Strongest Side

For more information on NASA’s Black Marble data, visit: https://viirsland.gsfc.nasa.gov/Products/NASA/BlackMarble.html

For more information on NASA’s G-LiHT data: https://gliht.gsfc.nasa.gov/

Suomi NPP (National Polar-orbiting Partnership): http://www.nasa.gov/mission_pages/NPP/main/index.html

Image (mentioned), Videos (mentioned), Text, Credits: NASA/Sara Blumberg/Earth Science News Team, by Ellen Gray.

Greetings, Orbiter.chArchive link

More Glaciers in East Antarctica Are Waking Up

NASA – IceSat-2 Mission patch / NASA – Operation IceBridge patch.

Dec. 10, 2018

East Antarctica has the potential to reshape coastlines around the world through sea level rise, but scientists have long considered it more stable than its neighbor, West Antarctica. Now, new detailed NASA maps of ice velocity and elevation show that a group of glaciers spanning one-eighth of East Antarctica’s coast have begun to lose ice over the past decade, hinting at widespread changes in the ocean.

Image above: A group of four glaciers in an area of East Antarctica called Vincennes Bay, west of the massive Totten Glacier, have lowered their surface height by about 9 feet since 2008, hinting at widespread changes in the ocean. The data used for this map is an early version of the NASA MEaSUREs ITS_LIVE project and was produced by Alex Gardner, NASA-JPL. Image Credits: NASA Earth Observatory/Joshua Stevens.

In recent years, researchers have warned that Totten Glacier, a behemoth that contains enough ice to raise sea levels by at least 11 feet, appears to be retreating because of warming ocean waters. Now, researchers have found that a group of four glaciers sitting to the west of Totten, plus a handful of smaller glaciers farther east, are also losing ice.

“Totten is the biggest glacier in East Antarctica, so it attracts most of the research focus,” said Catherine Walker, a glaciologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who presented her findings at a press conference on Monday at the American Geophysical Union meeting in Washington. “But once you start asking what else is happening in this region, it turns out that other nearby glaciers are responding in a similar way to Totten.”

For her research, Walker used new maps of ice velocity and surface height elevation that are being created as part of a new NASA project called Inter-mission Time Series of Land Ice Velocity and Elevation, or ITS_LIVE. Researchers with ITS_LIVE will be launching a new initiative in early 2019 to track the movement of the world’s ice, which includes the creation of a 30-year record of satellite observations of changes in the surface elevation of glaciers, ice sheets and ice shelves, and a detailed record of variations in ice velocity starting in 2013.

Walker found that four glaciers west of Totten, in an area called Vincennes Bay, have lowered their surface height by about 9 feet since 2008 – before that year, there had been no measured change in elevation for these glaciers. Farther east, a collection of glaciers along the Wilkes Land coast have approximately doubled their rate of lowering since around 2009, and their surface is now going down by about 0.8 feet every year.

Image above: This map shows the flow of the Antarctic ice sheet as measured from the tracking of subtle surface features across millions of Landsat repeat image pairs. The “donut hole” marks the maximum latitude visible by the Landsat satellites. The data used for this map is an early version of the NASA MEaSUREs ITS_LIVE project and was produced by Alex Gardner, NASA-JPL. Image Credits: NASA Earth Observatory/Joshua Stevens.

These levels of ice loss are small when compared to those of glaciers in West Antarctica. But still, they speak of nascent and widespread change in East Antarctica.

“The change doesn’t seem random; it looks systematic,” said Alex Gardner, a glaciologist with NASA’s Jet Propulsion Laboratory in Pasadena, California, lead of ITS_LIVE and a participant in the press conference. “And that systematic nature hints at underlying ocean influences that have been incredibly strong in West Antarctica. Now we might be finding clear links of the ocean starting to influence East Antarctica.”

Walker used simulations of ocean temperature from a model and compared them to actual measurements from sensor-tagged marine mammals. She found that recent changes in winds and sea ice have resulted in an increase to the heat delivered by the ocean waters to the glaciers in Wilkes Land and Vincennes Bay.

“Those two groups of glaciers drain the two largest subglacial basins in East Antarctica, and both basins are grounded below sea level,” Walker said. “If warm water can get far enough back, it can progressively reach deeper and deeper ice. This would likely speed up glacier melt and acceleration, but we don’t know yet how fast that would happen. Still, that’s why people are looking at these glaciers, because if you start to see them picking up speed, that suggests that things are destabilizing.”

Image above: A glacier in East Antarctica, as seen during an Operation IceBridge flight in November 2013. Image Credits: NASA/Michael Studinger.

There is a lot of uncertainty about how a warming ocean might affect these glaciers, due to how little explored that remote area of East Antarctica is. The main unknowns have to do with the topography of the bedrock below the ice and the bathymetry (shape) of the ocean floor in front of and below the ice shelves, which govern how ocean waters circulate near the continent and bring ocean heat to the ice front.

For example, if it turned out that the terrain beneath the glaciers sloped upward inland of the grounding line –the point where glaciers reach the ocean and begin floating over sea water forming an ice shelf— and featured ridges that provided friction, this configuration would slow down the flow and loss of ice. This type of landscape would also limit the access of warm circumpolar deep ocean waters to the ice front.

A much worse scenario for ice loss would be if the bedrock under the glaciers sloped downward inland of the grounding line. In that case, the ice base would get deeper and deeper as the glacier retreated and, as ice calved off, the height of the ice face exposed to the ocean would increase. That would allow for more melt at the front of the glacier and also make the ice cliff more unstable, increasing the rate of iceberg release. This kind of terrain would make it easier for warm circumpolar deep water to reach the ice front, sustaining high melt rates near the grounding line.

“Heightened attention needs to be given to these glaciers: We need to better map the topography and we need to better map the bathymetry,” Gardner said. “Only then can we be more conclusive in determining whether, if the ocean warms, these glaciers will enter a phase of rapid retreat or stabilize on upstream topographic features.”

Related Links:

NASA’s AGU website: https://www.nasa.gov/topics/earth/agu/index.html

NASA’s Earth Portal: https://www.nasa.gov/topics/earth/index.html

IceBridge: http://www.nasa.gov/mission_pages/icebridge/index.html

ICESat-2: http://www.nasa.gov/content/goddard/icesat-2

Images (mentioned), Text, Credits: NASA/Sara Blumberg/Earth Science News Team, by Maria-José Viñas.

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Wintertime Arctic sea ice growth slows long-term decline

New NASA research has found that increases in the rate at which Arctic sea ice grows in the winter may have partially slowed down the decline of the Arctic sea ice cover.

Wintertime Arctic sea ice growth slows long-term decline
The sun setting over the Arctic sea ice pack, as observed during the Beaufort Gyre Exploration Project
in October 2014 [Credit: NASA/Alek Petty]

As temperatures in the Arctic have warmed at double the pace of the rest of the planet, the expanse of frozen seawater that blankets the Arctic Ocean and neighboring seas has shrunk and thinned over the past three decades. The end-of-summer Arctic sea ice extent has almost halved since the early 1980s. A recent NASA study found that since 1958, the Arctic sea ice cover has lost on average around two-thirds of its thickness and now 70 percent of the sea ice cap is made of seasonal ice, or ice that forms and melts within a single year.

But at the same time that sea ice is vanishing quicker than it has ever been observed in the satellite record, it is also thickening at a faster rate during winter. This increase in growth rate might last for decades, a new study accepted for publication in Geophysical Research Letters found.

This does not mean that the ice cover is recovering, though. Just delaying its demise.

“This increase in the amount of sea ice growing in winter doesn’t overcome the large increase in melting we’ve observed in recent decades,” said Alek Petty, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study. “Overall, thickness is decreasing. Arctic sea ice is still very much in decline across all seasons and is projected to continue its decline over the coming decades. “

Petty and his team used climate models and observations of sea ice thickness from the European Space Agency’s CryoSat-2 satellite to explore sea ice growth variability across the Arctic. The climate model results compared well both with CryoSat-2’s measurements and the results of another commonly used Arctic sea ice model, giving the authors confidence in the climate model’s ability to capture Arctic sea ice variability.

“The global climate model seems to do a good job of capturing the Arctic sea ice state and shows that most of the thickness change in the central Arctic is from thermodynamics, that is, ice formation and ice melt, although around the Arctic sea ice edge dynamics, which is ice transport, can play a bigger role,” Petty said.

These model simulations showed that in the 1980s, when Arctic sea ice was on average 6.6 feet thick in October, about 3.3 extra feet of ice would form over the winter. That rate of growth has increased and may continue to do so for several more decades in some regions of the Arctic; in the coming decades, we could have an ice pack that would on average be only around 3.3 feet thick in October, but could experience up to 5 feet of ice growth over the winter.

It seems counterintuitive: how does a weakening ice cover manage to grow at a faster rate during the winter than it did when the Arctic was colder and the ice was thicker and stronger?

“Our findings highlight some resilience of the Arctic sea ice cover,” Petty said. “If we didn’t have this negative feedback, the ice would be declining even faster than it currently is. Unfortunately, the positive feedback loop of summer ice melt and increased solar absorption associated with summer ice melting still appears to be dominant and continue to drive overall sea ice declines.”

Nonetheless, the increased rate of sea ice thickening in winter has other implications. As ice forms at the ocean surface, it releases a lot of the salty and dense water from which it originated, which sinks and increases the mixing of waters in the upper ocean. The more ice formation that takes place, the more mixing we expect to see in the upper ocean. Increases in this ice formation and mixing during winter may help mitigate the strong freshening of the Arctic Ocean’s surface waters that has been observed in recent decades due to increased summer melt.

“This is altering the seasonal balance and the salinity distribution of the upper ocean in the Arctic; it’s changing when we have fresh water, when we have salty water and how deep and seasonal that upper oceanic mixed layer is,” Petty said. “And that’s all going to mean that local micro-organisms and ecosystems have to adapt to these rapidly evolving conditions.”

Petty’s projections found that, by the middle of the century, the strong increases in atmospheric and oceanic temperatures will outweigh the mechanism that allows ice to regrow faster, and the Arctic sea ice cover will decline further. The study predicted that the switch will happen once the sea ice is less than 1.6 feet thick at the beginning of winter, or its concentration -the percentage of an area that is covered in sea ice- is less than 50 percent.

“This negative feedback mechanism increasing ice growth is unlikely to be sufficient in preventing an ice-free Arctic this century,” Petty and his colleagues concluded.

Author: Maria-José Viñas | Source: NASA’s Goddard Space Flight Center [December 06, 2018]



Parrot genome analysis reveals insights into longevity, cognition

Parrots are famously talkative, and a blue-fronted Amazon parrot named Moises – or at least its genome – is telling scientists volumes about the longevity and highly developed cognitive abilities that give parrots so much in common with humans. Perhaps someday, it will also provide clues about how parrots learn to vocalize so well.

Parrot genome analysis reveals insights into longevity, cognition
This photograph shows an Amazona aestiva taking care of the nest in Pantanal
[Credit: Glaucia Seixas]

Morgan Wirthlin, a BrainHub post-doctoral fellow in Carnegie Mellon University’s Computational Biology Department and first author of a report to appear in the journal Current Biology, said she and her colleagues sequenced the genome of the blue-fronted Amazon and used it to perform the first comparative study of parrot genomes.
By comparing the blue-fronted Amazon with 30 other long- and short-lived birds — including four additional parrot species — she and colleagues at Oregon Health and Science University (OHSU), the Federal University of Rio de Janeiro and other entities identified a suite of genes previously not known to play a role in longevity that deserve further study. They also identified genes associated with longevity in fruit flies and worms.

“In many cases, this is the first time we’ve connected those genes to longevity in vertebrates,” she said.

Parrot genome analysis reveals insights into longevity, cognition
This photograph shows Amazona aestiva chicks in Pantanal
[Credit: Glaucia Seixas]

Wirthlin, who began the study while a Ph.D. student in behavioral neuroscience at OHSU, said parrots are known to live up to 90 years in captivity — a lifespan that would be equivalent to hundreds of years for humans. The genes associated with longevity include telomerase, responsible for DNA repair of telomeres (the ends of chromosomes), which are known to shorten with age. Changes in these DNA repair genes can potentially turn cells malignant. The researchers have found evidence that changes in the DNA repair genes of long-lived birds appear to be balanced with changes in genes that control cell proliferation and cancer.
The researchers also discovered changes in gene-regulating regions of the genome — which seem to be parrot-specific — that were situated near genes associated with neural development. Those same genes are also linked with cognitive abilities in humans, suggesting that both humans and parrots evolved similar methods for developing higher cognitive abilities.

Parrot genome analysis reveals insights into longevity, cognition
This photograph shows an Amazona aestiva taking care of the nest in Pantanal
[Credit: Glaucia Seixas]

“Unfortunately, we didn’t find as many speech-related changes as I had hoped,” said Wirthlin, whose research is focused on the evolution of vocal behaviors, including speech. Animals that learn songs or speech are relatively rare — parrots, hummingbirds, songbirds, whales, dolphins, seals and bats — which makes them particularly interesting to scientists, such as Wirthlin, who hope to gain a better understanding of how humans evolved this capacity.
“If you’re just analyzing genes, you hit the end of the road pretty quickly,” she said. That’s because learned speech behaviors are thought be more of a function of gene regulation than of changes in genes themselves. Doing comparative studies of these “non-coding” regulatory regions, she added, is difficult, but she and Andreas Pfenning, assistant professor of computational biology, are working on the computational and experimental techniques that may someday reveal more of their secrets.

Author: Byron Spice | Source: Carnegie Mellon University [December 06, 2018]



Double the stress slows down evolution

Like other organisms, bacteria constantly have to fight to survive in hostile living conditions. Together with colleagues in Finland, researchers at the Max Planck Institute for Evolutionary Biology in Plön have discovered that bacteria adapt to their environment more slowly and less efficiently as soon as they are exposed to two stress factors rather than one. This is due to mutations in different genes. The slower rate of evolution led to smaller population sizes. This means that evolution can take divergent paths if an organism is exposed to several stress factors.

Double the stress slows down evolution
The single-cell organism Tetrahymena thermophila (green) with its bacterial prey (purple)
[Credit: Matti Jalasvuori]

Bacteria rarely live alone; they are usually part of a community of species that is exposed to various stress factors. They can often react to these factors by adapting to new environmental conditions with astonishing speed. Antibiotics that enter soil and water via waste water and accumulate there in low concentrations can trigger the evolution of resistance in bacteria – even though these concentrations are so low that they inhibit bacterial growth only slightly or not at all. However, bacteria do not only have to fight antibiotics; they also have to deal with predators. This is why they often grow in large colonies that cannot be consumed by predatory organisms.
Typically, scientists investigate the effects that a single stress factor has on an organism. Researchers at the Max Planck Institute for Evolutionary Biology in Plön and the Universities of Helsinki and Jyväskylä, Finland, have now investigated the question of how microorganisms behave when they are confronted with more than one stress factor. “We simulated natural environmental conditions in the lab and exposed bacteria to both predators and antibiotics. This allows us to estimate how likely it is to find evolution of resistance to antibiotics outdoors,” explains study leader Lutz Becks.

Antibiotics and predators

In the scientists’ laboratory, the bacterium Pseudomonas fluorescence had to cope with both antibiotics and the predatory single-cell organism Tetrahymena thermophila. After just a short time, the team of researchers noticed that the bacterial population was changing: the bacteria were much slower and less effective in developing resistance and protecting themselves from being consumed than others of the species that were only exposed to one of these factors. Moreover, resistance against the antibiotic was much less common. “The bacteria were clearly unable to optimize both attributes at the same time,” says Becks.

In the next step, the scientists analysed the genetic basis of these adaptations. Their results show that mutations for improved protection from predators appear in the same numbers and at the same places in the bacterial genome if only the predatory ciliates are present. The same applies to mutations that cause resistance to antibiotics. However, other mutations occur as soon as both stress factors influence the bacteria and the bacteria have to fight both predators and antibiotics. This causes both the bacteria’s protection against predators and resistance to antibiotics to evolve more slowly and be less efficient.

Because the bacteria are less able to protect themselves from predators if they are confronted by the predatory ciliates and antibiotics simultaneously, their numbers are fewer than when they only have to defend themselves from predators. Several stress factors therefore appear to have a strong influence on whether and how often resistance to antibiotics develops and how large the population of bacteria can become.

“Microbial populations – whether in a lake or in the gut – are complex communities in which many species have to compete for resources. The various stress factors to which microbes are exposed have an enormous effect on their evolution and survival rate. It will take some time until we fully understand the interaction of all these factors and the influence of antibiotics and pesticides,” explains Becks.

The study is published in Nature Ecology & Evolution.

Source: Max Planck Society [December 06, 2018]



Researchers discover information about a gene that helps define us as humans

University of Otago researchers have discovered information about a gene that sets primates—great apes and humans—apart from other mammals, through the study of a rare developmental brain disorder.

Researchers discover information about a gene that helps define us as humans
Brain organoids, or “mini-brains” growing in culture [Credit: Dr Adam O’Neill]

Dr. Adam O’Neill carried out the research as part of his Ph.D. at the University of Otago, under the supervision of Professor Stephen Robertson, discovering that the PLEKHG6 gene has qualities that drives aspects of brain development differently in primates compared to other species.

“Broadly speaking, this gene can be thought of as one of the genetic factors that make us human in a neurological sense,” Dr. O’Neill who now works in the Department of Physiological Genomics at Ludwig Maximilian Universität in Munich, Germany, explains.

Professor Robertson says the research, just published in international journal Cell Reports, aimed to address the idea that there must be genes that humans have that have made our brains bigger and better functioning in some respects than other animals. However, that increased complexity could come at a cost, potentially predisposing humans to the development of a whole suite of neurological or psychiatric conditions.

“Such genes have been hard to find, but using an approach where we studied children with a certain brain malformation called periventricular nodular heterotopia, we found a ‘damaged’ genomic element in a child that had the attributes of such a primate specific genetic factor,” he explains. In this particular condition a subset of neurons in the developing brain fail to take up their correct position resulting in a variety of symptoms including epilepsy and delayed development.

Dr. O’Neill and research collaborators from Max Planck Institute of Psychiatry, Germany, then set forth to test the point that the gene drives aspects of brain development that are unique to primates. Some amazing data was found using a novel approach through studying human “mini-brains” in culture. It is now possible to take a skin cell and transform it using a set of genetic tricks, so that it can be triggered to form a tiny brain-like structure in culture in the lab.

Their results showed that the particular genetic change that disabled a component of this gene (PLEKHG6) altered its ability to support the growth and proliferation of specialised stem cells in the developing brain. In addition, some of these cells also failed to migrate to their correct position in the growing “mini-brain” during the first few weeks of brain development.

Professor Robertson says it has been known for a while that these stem cells behave differently between primates/humans and other animals, but understanding what genes regulate these differences has been a mystery.

“Adam’s achievement has been to show that this particular component of the PLEKHG6 gene is one such regulator that humans have ‘acquired’ very recently in their evolution to make their brains ‘exceptional’.”

Dr. O’Neill says there are very few genetic elements that are primate specific in our genome, so this discovery adds to a very short list of genetic factors that, at least in one sense, make us human.

“Such an understanding positions us to better understand how a brain builds itself- knowledge that will add to our ability to design strategies to repair the damaged brain, especially early in infancy where there are still lots of stem cells around,” Dr. O’Neill says.

The work also helps provide more information about the list of genes that are altered to cause this particular type of brain malformation.

“Personally, I also think it does underscore how it is very subtle nuanced differences that separate us from other animals. Our anthropocentrism could be a whole lot more humble,” Dr. O’Neill says.

Source: University of Otago [December 06, 2018]




    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...