вторник, 5 февраля 2019 г.

Hearing Loss Found Every sound we hear is the result of sound…

Hearing Loss Found

Every sound we hear is the result of sound waves in the air wobbling tiny hairs found on specialised cells inside the ear. There are two layers of hair cells – inner (stained green) and outer (red) – which turn that physical information into electrical impulses that go to the brain where they are interpreted as sounds. Unfortunately, these delicate hair cells can become damaged over time, leading to age-related hearing loss – a condition that is expected to affect more than 900 million people worldwide by 2050. By focusing on the complex biological processes that control the development and maturation of hair cells, researchers have discovered that a molecule called helios is responsible for converting immature outer hair cells into functional, grown-up ones. Understanding these pathways and learning how to manipulate them could lead to new ways to regenerate hair cells in the ear, potentially providing a way to reverse age-related hearing loss.

Written by Kat Arney

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Colliding Exoplanets

The figure shows one frame from the middle of a hydrodynamical simulation of a high-speed head-on collision between two 10 Earth-mass planets. The temperature range of the material is represented by four colors grey, orange, yellow and red, where grey is the coolest and red is the hottest. Such collisions eject a large amount of the silicate mantle material leaving a high-iron content, high-density remnant planet similar to the observed characteristics of Kepler-107c. Credit: Zoe Leinhardt and Thomas Denman, University of Bristol. High Resolution (jpg) Low Resolution (jpg)

The video shows a hydrodynamical simulation of a high-speed head-on collision between two 10 Earth-mass planets. The temperature range of the material is represented by four colors grey, orange, yellow and red, where grey is the coolest and red is the hottest. Such collisions eject a large amount of the silicate mantle material leaving a high-iron content, high-density remnant planet similar to the observed characteristics of Kepler-107c.  Credit: Zoe Leinhardt and Thomas Denman, University of Bristol. Watch Video

Cambridge, MA – There are currently about 2000 confirmed exoplanets with radii less than about three Earth-radii, and measurements of their densities reveal an astonishing diversity. Some have densities lower than Neptune which is made mostly of volatiles (materials less dense than metal and rock, but Neptune has almost four times the Earth’s radius), while others appear to have rock-like densities, as high as the Earth’s or higher. Such a wide range of compositions may be the product of the different initial conditions in the planet-formation process, or it could be because something dramatic happens to the planet to alter its initial properties as it evolves.

In a new paper in Nature Astronomy, Istituto Nazionale Di Astrofisica (INAF) astronomers Aldo S. Bonomo and Mario Damasso and Center for Astrophysics | Harvard & Smithsonian (CfA) astrophysicist Li Zeng, along with a large team of colleagues, report that a giant collision must have occurred in the exoplanetary system Kepler-107. While there is some observational evidence for the collisional process in our own solar system, so far there has been no unambiguous finding in support of the impact scenario among exoplanets.

Astronomers used to think that low-density planets, like the giants Jupiter, Saturn, Uranus and Neptune, form from cold ices and gas in the outer regions of a young star’s protoplanetary disk; the inner zone builds planets from rocky elements like silicates and iron whose particulates can survive in the hotter environment. Today the picture has become more complicated with hundreds of low-density giant exoplanets discovered orbiting close to their stars. In the case of evolutionary effects, two processes are thought most likely to affect a planet’s density: mass loss from the planet’s atmosphere and/or surface due to evaporation by the host star’s radiation, or a giant collision between planets.

Of the four known planets in Kepler-107, the two innermost ones have nearly identical radii of 1.536 and 1.597 Earth-radii, respectively, (the uncertainty of each is only about 0.2%). Their periods are also similar at 3.18 and 4.90 days, meaning that they orbit relatively nearby each other. Using the HARPS-N spectrograph at the Telescopio Nazionale Galileo in La Palma, the team determined the planet masses, and hence their densities. The observations are surprising — their densities are very different: 5.3 and 12.65 grams per cubic centimeter, respectively. For comparison, water’s density is 1 grams per cubic centimeter and the Earth’s is 5.5 grams per cubic centimeter. The fact that one of the planets has a density more than twice the other cannot be easily explained by stellar radiation effects which should have affected them both in the same way. Moreover, it is the outer one that is denser than the inner one. The astronomers argue instead that a giant impact on one planet, Kepler-107c (the denser planet), stripped off part of its initial silicate mantle, leaving it dominated by its dense iron core. They support this hypothesis with theoretical calculations.

The CfA’s Li Zeng notes: “This is one out of many interesting exoplanet systems that the Kepler space telescope has discovered and characterized. This discovery has confirmed earlier theoretical work suggesting that giant impact between planets has played a role during planet formation. The TESS mission is expected to find more of such examples.”

If catastrophic disruptions occur frequently in planetary systems, then astronomers predict finding many other examples like Kepler-107 as an increasing number of exoplanet densities are determined precisely.

Mercedes Lopez-Morales, Andrew Vanderburg, John Johnson, Dave Latham, Chantanelle Nava, David Phillips and Dimitar Sasselov are other CfA members of the team. Li Zeng is also affiliated with the Harvard Origins of Life Initiative and the Department of Earth & Planetary Sciences.

Headquartered in Cambridge, Mass., the Center for Astrophysics | Harvard & Smithsonian (CfA) is a collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

For more information, contact:

Tyler Jump
Public Affairs
Center for Astrophysics | Harvard & Smithsonian
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2019 February 5 Perijove 16: Passing Jupiter Video Credit…

2019 February 5

Perijove 16: Passing Jupiter
Video Credit & License: NASA, Juno, SwRI, MSSS, Gerald Eichstadt;
Music: The Planets, IV. Jupiter (Gustav Holst); USAF Heritage of America Band (via Wikipedia)

Explanation: Watch Juno zoom past Jupiter again. NASA’s robotic spacecraft Juno is continuing on its 53-day, highly-elongated orbits around our Solar System’s largest planet. The featured video is from perijove 16, the sixteenth time that Juno has passed near Jupiter since it arrived in mid-2016. Each perijove passes near a slightly different part of Jupiter’s cloud tops. This color-enhanced video has been digitally composed from 21 JunoCam still images, resulting in a 125-fold time-lapse. The video begins with Jupiter rising as Juno approaches from the north. As Juno reaches its closest view – from about 3,500 kilometers over Jupiter’s cloud tops – the spacecraft captures the great planet in tremendous detail. Juno passes light zones and dark belt of clouds that circle the planet, as well as numerous swirling circular storms, many of which are larger than hurricanes on Earth. As Juno moves away, the remarkable dolphin-shaped cloud is visible. After the perijove, Jupiter recedes into the distance, now displaying the unusual clouds that appear over Jupiter’s south. To get desired science data, Juno swoops so close to Jupiter that its instruments are exposed to very high levels of radiation.

∞ Source: apod.nasa.gov/apod/ap190205.html

Retreating Snow Line Reveals Organic Molecules around Young Star

False-color image of V883 Ori taken with ALMA. The distribution of dust is shown in orange and the distribution of methanol, an organic molecule, is shown in blue. Credit: ALMA (ESO/NAOJ/NRAO), Lee et al. Hi-res image

Artist’s impression of the protoplanetary disk around a young star V883 Ori. The outer part of the disk is cold and dust particles are covered with ice. ALMA detected various complex organic molecules around the snow line of water in the disk. Credit: National Astronomical Observatory of Japan. Hi-res image

Schematic illustration of the composition of protoplanetary disks in normal state and outburst phase. V883 Ori is experiencing an FU Orionis outburst and the increase in disk temperature pushes the snow line outward, causing various molecules contained in ice to be released into gas. Credit: National Astronomical Observatory of Japan. Hi-res image

Astronomers using ALMA have detected various complex organic molecules around the young star V883 Ori. A sudden outburst from this star is releasing molecules from the icy compounds in the planet forming disk. The chemical composition of the disk is similar to that of comets in the modern Solar System. Sensitive ALMA observations enable astronomers to reconstruct the evolution of organic molecules from the birth of the Solar System to the objects we see today.

The research team led by Jeong-Eun Lee (Kyung Hee University, Korea) used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect complex organic molecules including methanol (CH3OH), acetone (CH3COCH3), acetaldehyde (CH3CHO), methyl formate (CH3OCHO), and acetonitrile (CH3CN). This is the first time that acetone was unambiguously detected in a planet forming region or protoplanetary disk.

Various molecules are frozen in ice around micrometer-sized dust particles in protoplanetary disks. V883 Ori’s sudden flare-up is heating the disk and sublimating the ice, which releases the molecules into gas. The region in a disk where the temperature reaches the sublimation temperature of the molecules is called the “snow line.” The radii of snow lines are about a few astronomical units (au) around normal young stars, however, they are enlarged almost 10 times around bursting stars.

“It is difficult to image a disk on the scale of a few au with current telescopes,” said Lee. “However, around an outburst star, ice melts in a wider area of the disk and it is easier to see the distribution of molecules. We are interested in the distribution of complex organic molecules as the building blocks of life.”

Ice, including frozen organic molecules, could be closely related to the origin of life on planets. In our Solar System, comets are the focus of attention because of their rich icy compounds. For example, the European Space Agency’s legendary comet explorer Rosetta found rich organic chemistry around the comet Churyumov-Gerasimenko. Comets are thought to have been formed in the outer colder region of the proto-Solar System, where the molecules were contained in ice. Probing the chemical composition of ice in protoplanetary disks is directly related to probing the origin of organic molecules in comets, and the origin of the building blocks of life.

Thanks to ALMA’s sharp vision and the enlarged snow line due to the flare-up of the star, the astronomers obtained the spatial distribution of methanol and acetaldehyde. The distribution of these molecules has a ring-like structure with a radius of 60 au, which is twice the size of Neptune’s orbit. The researchers assume that inside of this ring the molecules are invisible because they are obscured by thick dusty material, and are invisible outside of this radius because they are frozen in ice.

“Since rocky and icy planets are made from solid material, the chemical composition of solids in disks is of special importance. An outburst is a unique chance to investigate fresh sublimates, and thus the composition of solids.” says Yuri Aikawa at the University of Tokyo, a member of the research team.

V883 Ori is a young star located at 1300 light-years away from the Earth. This star is experiencing a so-called FU Orionis type outburst, a sudden increase of luminosity due to a bursting torrent of material flowing from the disk to the star. These outbursts last only on the order of 100 years, therefore the chance to observe a burst is rather rare. However, since young stars with a wide range of ages experience FU Ori bursts, astronomers expect to be able to trace the chemical composition of ice throughout the evolution of young stars.

Note: Another ALMA observation (van’t Hoff et al. 2018, ApJL, 864, 23) also detected CH3OH emissions from V883 Ori. However, the sensitivity and resolution of the observations were not enough to resolve the structure inside the water snow line.

Additional Information

These observation results are published as Lee et al. “The ice composition in the disk around V883 Ori revealed by its stellar outburst” in Nature Astronomy on February 4, 2019.

The research team members are:

Jeong-Eun Lee (Kyung Hee University), Seokho Lee (Kyung Hee University), Giseon Baek (Kyung Hee University), Yuri Aikawa (The University of Tokyo), Lucas Cieza (Universidad Diego Prtales), Sung-Yong Yoon (Kyung Hee University), Gregory Herczeg (Peking University), Doug Johnstone (NRC Herzberg Astronomy and Astrophysics), Simon Casassus (Universidad de Chile)

This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (grant No. NRF-2018R1A2B6003423), the Korea Astronomy and Space Science Institute under the R&D program supervised by the Ministry of Science, ICT and Future Planning, JSPS KAKENHI (No. 16K13782 and 18H05222), the general grant (No. 11473005) by the National Science Foundation of China, National Research Council of Canada, and NSERC Discovery Grant.


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Amethyst | #Geology #GeologyPage #Mineral Locality: Jacksons…

Amethyst | #Geology #GeologyPage #Mineral

Locality: Jacksons Crossroads, Wilkes Co., Georgia, USA

Size: 5.2 x 4.8 x 4.5 cm

Photo Copyright © Saphira Minerals

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Captioned Image Spotlight (4 February 2019): Exposing the Rock…

Captioned Image Spotlight (4 February 2019): Exposing the Rock in Impact Craters

In this complex crater (about 44-kilometers in diameter), we see bedrock in several locations from different depths in the crust. The central uplift exposes large fragments of green-toned bedrock that possibly originated from several kilometers beneath the surface.

To the south of the crater, we see more of this bedrock along with material that was excavated and thrown out after the impact. In craters of this size, the rim is unstable and collapses inwards forming terraces, which occasionally exposes more bedrock that would have originated from close to the surface than the rocks exposed within the uplift itself. Central uplifts have better exposures of bedrock, but in this example the terraces steal the show, displaying beautiful green- and light-toned bedrock at multiple locations.

NASA/JPL/University of Arizona

Earthquake with magnitude 7.5 in Indonesia—an unusual and steady…

Earthquake with magnitude 7.5 in Indonesia—an unusual and steady speed http://www.geologypage.com/2019/02/earthquake-with-magnitude-7-5-in-indonesia-an-unusual-and-steady-speed.html

InSight’s Seismometer Now Has a Cozy Shelter on Mars

NASA – InSight Mission patch.

Feb. 4, 2019

Image above: NASA’s InSight lander deployed its Wind and Thermal Shield on Feb. 2 (Sol 66). The shield covers InSight’s seismometer, which was set down onto the Martian surface on Dec. 19. Image Credits: NASA/JPL-Caltech.

For the past several weeks, NASA’s InSight lander has been making adjustments to the seismometer it set on the Martian surface on Dec. 19. Now it’s reached another milestone by placing a domed shield over the seismometer to help the instrument collect accurate data. The seismometer will give scientists their first look at the deep interior of the Red Planet, helping them understand how it and other rocky planets are formed.

The Wind and Thermal Shield helps protect the supersensitive instrument from being shaken by passing winds, which can add “noise” to its data. The dome’s aerodynamic shape causes the wind to press it toward the planet’s surface, ensuring it won’t flip over. A skirt made of chain mail and thermal blankets rings the bottom, allowing it to settle easily over any rocks, though there are few at InSight’s location.

An even bigger concern for InSight’s seismometer — called the Seismic Experiment for Interior Structure (SEIS) — is temperature change, which can expand and contract metal springs and other parts inside the seismometer. Where InSight landed, temperatures fluctuate by about 170 degrees Fahrenheit (94 degrees Celsius) over the course of a Martian day, or sol.

“Temperature is one of our biggest bugaboos,” said InSight Principal Investigator Bruce Banerdt of NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL leads the InSight mission and built the Wind and Thermal Shield. “Think of the shield as putting a cozy over your food on a table. It keeps SEIS from warming up too much during the day or cooling off too much at night. In general, we want to keep the temperature as steady as possible.”

 InSight lander deploying its Wind and Thermal Shield. Animation Credits: NASA//JPL-Caltech

On Earth, seismometers are often buried about four feet (1.2 meters) underground in vaults, which helps keep the temperature stable. InSight can’t build a vault on Mars, so the mission relies on several measures to protect its seismometer. The shield is the first line of defense.

A second line of defense is SEIS itself, which is specially engineered to correct for wild temperature swings on the Martian surface. The seismometer was built so that as some parts expand and contract, others do so in the opposite direction to partially cancel those effects. Additionally, the instrument is vacuum-sealed in a titanium sphere that insulates its sensitive insides and reduces the influence of temperature.

But even that isn’t quite enough. The sphere is enclosed within yet another insulating container — a copper-colored hexagonal box visible during SEIS’s deployment. The walls of this box are honeycombed with cells that trap air and keep it from moving. Mars provides an excellent gas for this insulation: Its thin atmosphere is primarily composed of carbon dioxide, which at low pressure is especially slow to conduct heat.

With these three insulating barriers, SEIS is well-protected from thermal “noise” seeping into the data and masking the seismic waves that InSight’s team wants to study. Finally, most additional interference from the Martian environment can be detected by InSight’s weather sensors, then filtered out by mission scientists.

With the seismometer on the ground and covered, InSight’s team is readying for its next step: deploying the heat flow probe, called the Heat Flow and Physical Properties Package (HP3), onto the Martian surface. That’s expected to happen next week.

About InSight

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

A number of European partners, including France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES and the Institut de Physique du Globe de Paris (IPGP) provided the Seismic Experiment for Interior Structure (SEIS) instrument, with significant contributions from the Max Planck Institute for Solar System Research (MPS) in Germany, the Swiss Federal Institute of Technology (ETH Zurich) in Zurich, Switzerland, Imperial College London and Oxford University in the United Kingdom, and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain’s Centro de Astrobiología (CAB) supplied the wind sensors.

Related article & link:

InSight Places First Instrument on Mars – New Images

Experiment for Interior Structure (SEIS): https://mars.nasa.gov/insight/spacecraft/instruments/seis/

For more information about InSight, visit: https://mars.nasa.gov/insight/

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.

Greetings, Orbiter.chArchive link

First discovered fossil feather did not belong to iconic bird…

First discovered fossil feather did not belong to iconic bird Archaeopteryx http://www.geologypage.com/2019/02/first-discovered-fossil-feather-did-not-belong-to-iconic-bird-archaeopteryx.html

Researchers solve the riddle of a unique fish

A great mystery around a unique fish species has been solved by researchers at The Australian National University (ANU).

Researchers solve the riddle of a unique fish
Lungfish scales [Credit: Fallon SJ, et al. 2019]

Scientists knew Lungfish shared some traits with humans — such as the ability to breathe air through lungs — but a new study proves they also have a similar life span, potentially up to 80 years.

Dr Stewart Fallon from the Research School of Earth Sciences said Lungfish have been on the threatened species list in Australia for decades, but this new research could help change that.

“One of the main issues is no one knew their longevity,” Dr Fallon said.

“A lot of fish have what’s called an Otolith — basically a solid stone in their inner ear. As the fish grows, the stone grows as well and there’s usually little annual marker bands on there, so we can count them and know how old the fish is — but the lungfish doesn’t have that stone.

The other main issue is that to get an ear stone you usually have to kill the fish — so obviously you wouldn’t want to do that to a threatened species.”

Dr Fallon and his team, in collaboration with Griffith University, Seqwater, the Queensland Department of Natural Resources, Mines and Energy, and the Queensland Department of Agriculture and Fisheries, came up with a new approach.

Their technique involves measuring the amount of Carbon 14 in Lungfish scales to pinpoint how old the fish is.

The group discovered they were able to place the fish on the “bomb curve,” which is used to chart the amount of carbon 14 in the atmosphere.

The curve has a distinct shape, starting to rise in the mid-50s with the advent of nuclear weapons and peaking in 1963, when the Nuclear Test Ban Treaty came into effect.

“That carbon’s been basically mixing in with all the carbon in the Earth since then,” Dr Fallon said.

“So we have this distinct curve, and when we tested the fish we were able to reproduce that curve, and tell when the fish was born.”

The ANU team did around 1200 radio carbon measurements over several years and found fish aged from around three years to 78.

It’s an important breakthrough, as previously researchers had struggled to find any evidence of juvenile fish, leading to concerns there was an ageing population and the fish would eventually just disappear.

“People have been doing research on these fish for 80 years or more. There’s anecdotes about some of the fish in the Brisbane River being translocated from one of the other rivers in the early 1900s because they were already worried about the population then,” Dr Fallon said.

Dr Fallon and his colleagues also noticed there were long time periods where no fish were born at all.

“For example in the Mary River in the 1970s and 80s we didn’t see many fish born.”

“I actually don’t know how they’ve survived in Australia for so long. They like to lay their eggs in the shallow parts of the river where there are plants for the eggs to cling onto. Whenever we have big floods it just wipes everything away, so in these time periods we may find there were big floods just beforehand, and then it takes several years for the plants to grow back.

“If you’re trying to understand a certain population this kind of information is pretty critical and gives us a whole nice background of information that wasn’t there before.”

The research has been published in the journal PLOS ONE.

Source: Australian National University [January 31, 2019]



Prostate’s Progress What turns normal cells in the prostate…

Prostate’s Progress

What turns normal cells in the prostate (stained green) into cancer cells (red and white)? Why are some prostate cancers slow growing and don’t need immediate treatment, while others quickly become life-threatening? And which therapy will work best for a particular patient? To answer these questions, researchers are trawling through DNA from hundreds of tumour samples, using high-powered computer programmes to sift all this genetic information in search of clues. After crunching all the data, they discovered that prostate cancers can be classified into a number of different groups based on their genetic makeup and patterns of gene activity, enabling them to predict which tumours are more likely to grow fast and need urgent treatment and which will take a more leisurely path. The programme can also identify treatments that are more likely to work for each individual patient, leading to more personalised therapy that could make a difference to survival.

Today is World Cancer Day 2019

Written by Kat Arney

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