четверг, 10 мая 2018 г.

HiPOD (10 May 2018) Hydrothermal Silica in a Volcanic Unit   –…

HiPOD (10 May 2018) Hydrothermal Silica in a Volcanic Unit

   – 296 km above the surface (Less than 5 km across).

NASA/JPL/University of Arizona


Ash from Kilauea Eruption Viewed by NASA’s MISR

NASA – EOS Terra Mission patch.

May 10, 2018

On May 3, 2018, a new eruption began at a fissure of the Kilauea volcano on the Island of Hawaii. Kilauea is the most active volcano in the world, having erupted almost continuously since 1983. Advancing lava and dangerous sulfur dioxide gas have forced thousands of residents in the neighborhood of Leilani Estates to evacuate. A number of homes have been destroyed, and no one can say how soon the eruption will abate and evacuees can return home.

On May 6, 2018, at approximately 11 a.m. local time, the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra satellite captured this view of the island as it passed overhead. Much of the island was shrouded by clouds, including the fissure on its eastern point. However, an eruption plume is visible streaming southwest over the ocean. The MISR instrument is unique in that it has nine cameras that view Earth at different angles: one pointing downward, four at various angles in the forward direction, and four in the backward direction. This image shows the view from one of MISR’s forward-pointing cameras (60 degrees), which shows the plume more distinctly than the near-vertical views.

The information from the images acquired at different view angles is used to calculate the height of the plume, results of which are superimposed on the right-hand image. The top of the plume near the fissure is at approximately 6,500 feet (2,000 meters) altitude, and the height of the plume decreases as it travels south and west. These relatively low altitudes mean that the ash and sulfur dioxide remained near the ground, which can cause health issues for people on the island downwind of the eruption. The “Ocean View” air quality monitor operated by the Clean Air Branch of the State of Hawaii Department of Health recorded a concentration of 18 μg/m3 of airborne particles less than 2.5 micrometers in diameter at 11 a.m. local time. This amount corresponds to an air quality rating of “moderate” and supports the MISR results indicating that ash was most likely present at ground level on this side of the island.

EOS Terra satellite. Image Credit: NASA

These data were acquired during Terra orbit 97780. The smoke plume height calculation was performed using the MISR INteractive eXplorer (MINX) software tool, which is publicly available at https://github.com/nasa/MINX. The MISR Plume Height Project maintains a database of global smoke plume heights, accessible at https://www-misr.jpl.nasa.gov/getData/accessData/MisrMinxPlumes2/.

MISR was built and is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, for NASA’s Science Mission Directorate in Washington. The Terra spacecraft is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, Virginia. JPL is a division of Caltech in Pasadena.

Related article:

NASA Satellite detects Kilauea Fissures

For more information about Terra satellite, visit:

Terra Satellite: http://www.nasa.gov/mission_pages/terra/index.html

Images, Text, Credits: NASA/Tony Greicius/MISR.

Greetings, Orbiter.ch Archive link


Switzerland Alps

Switzerland Alps

Source Ancient Origins All about archaeology, human evolution, mythologies and legends from all around the world.

Yotvingians – Mighty Warriors of the Baltic Sea

The Yotvingians were one of the most influential tribes to live near the Baltic Sea. Their name is known from the first historical books of the world. Despite their centuries of domination in the area of modern-day Poland and some of the surrounding area, they appear to modern people as mysterious and are often misunderstood.

Read more…

Source Ancient Origins All about archaeology, human evolution, mythologies and legends from all around the world.

400 years proof of Russian Empire in ancient Bulgaria

A Gospel Book in Bulgarian which is almost 400 years old, and was printed in the Cyrillic alphabet in Vilnius, then in the Polish-Lithuanian Commonwealth, has been found among the belongings of a deceased priest who served in a church in the town of Voynezha, near Veliko Tarnovo, Central North Bulgaria.

Between 1596 and 1705, a total of 74 books in Cyrillic were published by the printing house of the “Descent of the Holy Spirit” in Vilnius, “an impressive publishing output”, according to the Museum.

“The book… is richly decorated with dyes and ornate initials, the font is large and solemn, the pages are framed with decorative elements. Apparently, the book was actively used for religious services and reading: many of the pages have traces of candle wax, and the lower edges where the pages are turned are stained and worn out,
The Bulgarian Gospel from Vilnius has been passed on from priest to priest in the town of Voynezha over the past almost 400 years. Photos: http://www.historymuseum.org/en/

A Gospel Book in Bulgarian which is almost 400 years old, and was printed in the Cyrillic alphabet in Vilnius, then in the Polish-Lithuanian Commonwealth, has been found among the belongings of a deceased priest who served in a church in the town of Voynezha, near Veliko Tarnovo, Central North Bulgaria.

The Gospel Book, Evangelion, or Book of the Gospels

The Gospel Book, Evangelion, or Book of the Gospels (Greek: Εὐαγγέλιον, Evangélion) is a codex or bound volume containing one or more of the four Gospels of the Christian New Testament — normally all four. The term is also used of the liturgical book, also called the Evangeliary, from which are read the portions of the Gospels used in the Mass and other services, arranged according to the order of the liturgical calendar.

The book is written in the ancient Russian Cyrillic language, which confirms that the Bulgarians around 500 years ago, as all Slavic peoples spoke in general Cyrillic language.

The source reports that this ancient Bulgarian language, but it’s a hoax.

Bulgarians at that time before the wars and revolutions were Russian ethnic group and speak the Slavic language.


Astronaut Journal Entry – Pre-Launch

Currently, six humans are living and working on the International Space Station, which orbits 250 miles above our planet at 17,500mph. Below you will find a real journal entry written by NASA astronaut Scott Tingle.

To read more entires from this series, visit our Space Blogs on Tumblr.


Our crew just finished the final training event before the launch. Tomorrow, at 13:20 local time (Baikonur), we will strap the Soyuz MS-07 spacecraft to our backs and fly it to low Earth orbit. We will spend 2.5 days in low Earth orbit before docking to the MRM-1 docking port on the International Space Station (ISS). There we will begin approximately 168 days of maintenance, service and science aboard one of the greatest engineering marvels that humans have ever created.


Today was bittersweet. Ending a 2-year process of intense training was welcomed by all of us. We are very tired. Seeing our families for the last time was difficult. I am pretty lucky, though. My wife, Raynette, and the kids have grown up around military service and are conditioned to endure the time spent apart during extended calls-to-duty. We are also very much anticipating the good times we will have upon my return in June. Sean and Amy showed me a few videos of them mucking it up at Red Square before flying out to Baikonur. Eric was impressed with the Russian guards marching in to relieve the watch at Red Square. Raynette was taking it all in stride and did not seem surprised by any of it. I think I might have a family of mutants who are comfortable anywhere. Nice! And, by the way, I am VERY proud of all of them!


Tomorrow’s schedule includes a wake-up at 04:00, followed by an immediate medical exam and light breakfast. Upon returning to our quarters, we will undergo a few simple medical procedures that should help make the 2.5-day journey to ISS a little more comfortable. I’ve begun prepping with motion sickness medication that should limit the nausea associated with the first phases of spaceflight. I will continue this effort through docking. This being my first flight, I’m not sure how my body will respond and am taking all precautions to maintain a good working capability. The commander will need my help operating the vehicle, and I need to not be puking into a bag during the busy times. We suit up at 09:30 and then report to the State Commission as “Готовы к Полёту”, or “Ready for Flight”. We’ll enter the bus, wave goodbye to our friends and family, and then head out to the launch pad. Approximately 2 kilometers from the launch pad, the bus will stop. 


The crew will get out, pee on the bus’s tire, and then complete the last part of the drive to the launch pad. This is a traditional event first done by Yuri Gagarin during his historic first flight and repeated in his honor to this day. We will then strap in and prepare the systems for launch. Next is a waiting game of approximately 2 hours. Ouch. The crew provided five songs each to help pass the time. My playlist included “Born to Run” (Springsteen), “Sweet Child O’ Mine” (Guns and Roses), “Cliffs of Dover” (Eric Johnson), “More than a Feeling” (Boston), and “Touch the Sky” (Rainbow Bridge, Russian). Launch will happen precisely at 13:20.


I think this sets the stage. It’s 21:30, only 6.5 hours until duty calls. Time to get some sleep. If I could only lower my level of excitement!

Find more ‘Captain’s Log’ entries HERE.

Follow NASA astronaut Scott Tingle on Instagram and Twitter.

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


Prague archaeologists shed light on Medieval city

The City of Prague Museum has published the results of two unique archaeological digs carried out in the centre of the city. Among the discoveries are everyday objects from Wenceslas Square dating to back to Medieval Times which shed light on everyday life. They also include a rare statuette of a Madonna.

Prague archaeologists shed light on Medieval city
St. Valentines Gate [Credit: Petr Starec, Jiří Vidman, Martin Frouz/City of Prague Museum]

Examinations also focused on the St. Valentines Gate in Prague’s Old Town. During research of what used to be the ramparts, archaeologists discovered an even older gate that used to stand in its place. Analysis of the old wooden doorstep determined it was made of an oak that could have been felled around the year 1239. That enabled them to specify the age of the Prague’s fortifications there to the mid-13th century.

The City of Prague Museum has also continued its archaeological research on Wenceslas Square. Petr Starec was the head archaeologist:

“Most of the objects discovered here are linked to the life in the market of a medieval city from the mid-14th to the end of 16th century.

“Wenceslas Square used to be called the Horse Market and it was one of the three main markets of the New City of Prague, intended for trading horses and the sale of agricultural products and crafts.

“As a result there were piles of waste both from the market and from households.”

Once in a while, the waste was covered with pebbles from the Vltava River. Today, all sorts of fragments from medieval households can be discovered in the layers of waste, including animal bones from kitchens, fragments of ceramic tableware, and horseshoes. All that helps architects to shed more light on life in medieval Prague.

Prague archaeologists shed light on Medieval city
Statuette of a Madonna [Credit: CTK]

Petr Starec once again: “Thanks to the collections of animal bones from different layers of the market, we get an idea what the townspeople had on their plates. We know that at least one third of the meat they ate was from cattle, sheep and goats.

“The ceramic fragments can give us an impression of what life in the kitchen was like.”

The most recent excavations on Wenceslas Square have also yielded a more unusual discovery, a statuette of a Madonna engraved from an animal horn:

“The statue is about three centimetres tall and depicts the Virgin Mary holding little Jesus in her arms. We haven’t determined yet which animal it was made from.

“There is a little metal device on her back, so it was probably attached to some object, perhaps a home altar. It could have been possessed by a wealthy townsman and it was most probably lost, because people would not throw away something like this.”

The newly discovered objects, including the statuette of a Madonna, will now be processed and classified before going on display.

Some of the earlier excavations from Wenceslas Square have already been showcased at the City Museum of Prague’s permanent exhibition at the House at the Golden Ring.

Author: Ruth Fraňková | Source: Radio Praha [May 03, 2018]




Warning signs: how early humans first began to paint animals

Visual culture – and the associated forms of symbolic communication, are regarded by palaeo-anthropologists as perhaps the defining characteristic of the behaviour of Homo sapiens. One of the great mysteries of archaeology is why figurative art, in the form of the stunningly naturalistic animal depictions, appeared relatively suddenly around 37,000 years ago in the form of small sculpted objects and drawings and engravings on cave and rock shelter walls.

Warning signs: how early humans first began to paint animals
Painting from El Castillo cave (Cantabria, Spain). Early Upper Palaeolithic or older
[Credit: Becky Harrison and courtesy Gobierno de Cantabria., Author provided]

Since the discovery and authentication of such Palaeolithic art more than a century ago, theories have abounded as to what this meant to its Ice Age hunter-gatherer creators. But theories often say more about modern preconceptions regarding the function of art – how can we tell if we’re on the right track to understanding the remote and alien societies that created the first images?

In a radical new approach to the issue, we applied recent findings from visual neuroscience, perceptual psychology and the archaeology of cave art, that begin to make sense of the intriguing representations and forward what we hope can be tested scientifically.

Hands down

The first clue to their provenance came from the ancient hand marks (positive prints and negative stencils), which predate the earliest animal depictions by a considerable period. Recent dating shows that they were created by Neanderthals more than 64,000 years ago. The second clue came from the widespread inclusion of natural cave features – such as ledges and cracks – as parts of animal depictions. The final clue relates to the environment in which Upper Palaeolithic hunter-gatherers, along with other predators, were stalking the large herbivores – such as bison, deer and horses – that formed their prey and which often lay hidden in camouflage in the tundra environment.

Warning signs: how early humans first began to paint animals
This hand stencil has been deliberately placed so its left side matches with a natural crack in the wall of El Castillo cave
[Credit: Paul Pettitt and courtesy Gobierno de Cantabria., Author provided]

We argue that hand marks initially supplied the idea to archaic humans that a graphic mark could act as a representation, however basic it was. This was a beginning of sorts – but how could hand marks give rise to the more complex animal depictions? We needed to be able to explain how that gap was bridged.

Seeing the unseen

Fortunately, the way hunters relate to the environment has changed little since early times in that they remain acutely sensitive to particular animal contours. So much so, that in challenging lighting situations – and where prey might be well camouflaged – the hunter becomes hypersensitive to such features.

Warning signs: how early humans first began to paint animals
The interior of the cave at Castillo in Spain [Credit: Gabinete de Prensa del Gobierno de Cantabria, CC BY-SA]

In such ambiguous circumstances, it’s better to “see” an animal when it’s not there – to mistake a rock for a bear – than not see it. Such better-safe-than-sorry hair-trigger cues are cognitive adaptations that promote survival. In dangerous conditions, the human visual system becomes increasingly aroused and is even more easily triggered into accepting the slightest cue as an animal.

In short, we are preconditioned to interpret ambiguous shapes as animals. Recent evidence from visual neuroscience shows that when individuals are conditioned to see particular objects – faces, say – they are more likely to see them in ambiguous patterns. Upper Palaeolithic hunters conditioned themselves due to the need to detect animals, but this effect was reinforced by the suggestive features of the caves.

Warning signs: how early humans first began to paint animals
In El Castillo cave, this natural stalagmite column bears a boss in the shape of an upright bison, which has been
elaborated by painting in black pigment [Credit: Marc Groenen and courtesy Gobierno de Cantabria]

Caves are full of suggestive cues. They are dangerous places, often inhabited by predators, thereby stimulating increased arousal levels. Hunters entering the caves with an overactive visual system will have regularly “mistaken” the natural cave features for animals. The cave walls also simulated the outdoor environment, where hunters regularly had to be able to spot their prey in camouflage.

All the hunter needed to do to “complete” a depiction was to add one or two graphic marks to the suggestive natural features based on the visual imagery in their “mind’s eye”. A typical example of this can be seen at Chauvet cave where two giant deer (Megaloceros) are depicted by complementing the natural wall fissures (highlighted in brown) with lines (highlighted in black) painted onto the cave wall to complete the animal outlines. This potentially explains how the very first representational depictions arose.

Corroborating evidence

We’ve tried to combine our respective expertise in visual psychology and Palaeolithic art and, unlike many other theories, our approach is open to refutation. For example, if someone finds depictions of animals or similar that predate the first hand marks, this would overturn our main proposition. Similarly, if earlier figurative depictions come to light that do not derive from natural features, this would also challenge our theory.

Warning signs: how early humans first began to paint animals
Image based on: Relevé de La Niche Au Petit Ours by Carole Fritz et Gilles Tosello
 – CNRS – Équipe Chauvet –Ministère de la Culture et de la Communication.

But as we were making the final touches to our academic paper, valuable corroborative evidence came to light supporting the theory. Namely, the dating of a negative hand stencil and a geometric mark from the Monte Castillo cave art complex in Spain dating to a minimum of 64,000 years ago and almost certainly made by Neanderthals.

When later humans entered the same caves and saw these, the Neanderthals may literally have “handed on” to our own species the notion that a graphic mark could act as a figurative representation. Thanks to the primed visual system of the later hunter-gatherers – and the suggestive environment of the caves – it was Homo sapiens who took the final step creating the first complex figurative representations, with all the ramifications that followed for art and culture.

Authors: Derek Hodgson And Paul Pettitt | Source: The Conversation [May 04, 2018]

This article was originally published on The Conversation. Read the original article.




Large predators once hunted to near-extinction are showing up in unexpected places

Alligators on the beach. Killer whales in rivers. Mountain lions miles from the nearest mountain. In recent years, sightings of large predators in places where conventional wisdom says they “shouldn’t be” have increased, in large part because local populations, once hunted to near-extinction, are rebounding — thanks to conservation.

Large predators once hunted to near-extinction are showing up in unexpected places
Credit: Brian Silliman, Duke University

Many observers have hypothesized that as these populations recover the predators are expanding their ranges and colonizing new habitats in search of food. A Duke University-led paper published today in the journal Current Biology suggests otherwise.

It finds that, rather than venturing into new and alien habitats for the first time, alligators, sea otters and many other large predators — marine and terrestrial species alike — are re-colonizing ecosystems that used to be prime hunting grounds for them before humans decimated their populations and well before scientists started studying them.

“We can no longer chock up a large alligator on a beach or coral reef as an aberrant sighting,” said Brian Silliman, Rachel Carson Associate Professor of Marine Conservation Biology at Duke’s Nicholas School of the Environment. “It’s not an outlier or short-term blip. It’s the old norm, the way it used to be before we pushed these species onto their last legs in hard-to-reach refuges. Now, they are returning.”

By synthesizing data from recent scientific studies and government reports, Silliman and his colleagues found that alligators, sea otters, river otters, gray whales, gray wolfs, mountain lions, orangutans and bald eagles, among other large predators, may now be as abundant or more abundant in “novel” habitats than in traditional ones.

Large predators once hunted to near-extinction are showing up in unexpected places
Credit: Brian Silliman, Duke University

Their successful return to ecosystems and climatic zones long considered off-limits or too stressful for them upends one of the most widely held paradigms of large animal ecology, Silliman said.

“The assumption, widely reinforced in both the scientific and popular media, is that these animals live where they live because they are habitat specialists. Alligators love swamps; sea otters do best in saltwater kelp forests; orangutans need undisturbed forests; marine mammals prefer polar waters. But this is based on studies and observations made while these populations were in sharp decline. Now that they are rebounding, they’re surprising us by demonstrating how adaptable and cosmopolitan they really are,” Silliman said.

For instance, marine species such as sting rays, sharks, shrimps, horseshoe crabs and manatees now make up 90 percent of alligators’ diet when they’re in seagrass or mangrove ecosystems, showing that gators adapt very well to life in a saltwater habitat.

The unanticipated adaptability of these returning species presents exciting new conservation opportunities, Silliman stressed.

Large predators once hunted to near-extinction are showing up in unexpected places
Credit: Brian Silliman, Duke University

“It tells us these species can thrive in a much greater variety of habitats. Sea otters, for instance, can adapt and thrive if we introduce them into estuaries that don’t have kelp forests. So even if kelp forests disappear because of climate change, the otters won’t,” he said. “Maybe they can even live in rivers. We will find out soon enough.”

As top predators return, the habitats they re-occupy also see benefits, he said. For instance, introducing sea otters to estuarine seagrass beds helps protect the beds from being smothered by epiphytic algae that feed on excess nutrient runoff from inland farms and cities. The otters do this by eating Dungeness crabs, which otherwise eat too many algae-grazing sea slugs that form the bed’s front line of defense.

“It would cost tens of millions of dollars to protect these beds by re-constructing upstream watersheds with proper nutrient buffers,” Silliman said, “but sea otters are achieving a similar result on their own, at little or no cost to taxpayers.”

Source: Duke University [May 07, 2018]





The Earth — with its myriad shifting atmospheric, oceanic, land and ice components — presents an extraordinarily complex system to simulate using computer models.

Argonne scientists helped create a comprehensive new model that draws on supercomputers
to simulate how various aspects of the Earth – its atmosphere, oceans, land, ice – move
[Credit: E3SM.org]

But a new Earth modeling system, the Energy Exascale Earth System Model (E3SM), is now able to capture and simulate all these components together. Released on April 23, after four years of development, E3SM features weather-scale resolution — i.e., enough detail to capture fronts, storms and hurricanes — and uses advanced computers to simulate aspects of the Earth’s variability. The system can help researchers anticipate decadal-scale changes that could influence the U.S. energy sector in years to come.

“With this new system, we’ll be able to more realistically simulate the present, which gives us more confidence to simulate the future.” — David Bader, computational scientist at Lawrence Livermore National Laboratory and overall E3SM project lead.

The E3SM project is supported by the U.S. Department of Energy’s (DOE) Office of Biological and Environmental Research. “One of E3SM’s purposes is to help ensure that DOE’s climate mission can be met — including on future exascale systems,” said Robert Jacob, a computational climate scientist in the Environmental Science division of DOE’s Argonne National Laboratory and one of 15 project co-leaders.

To support this mission, the project’s goal is to develop an Earth system model that increases prediction reliability. This objective has historically been limited by constraints in computing technologies and uncertainties in theory and observations. Enhancing prediction reliability requires advances on two frontiers: (1) improved simulation of Earth system processes by developing new models of physical processes, increasing model resolution and enhancing computational performance; and (2) representing the two-way interactions between human activities and natural processes more realistically, especially where these interactions affect U.S. energy needs.

“This model adds a much more complete representation between interactions of the energy system and the Earth system,” said David Bader, a computational scientist at Lawrence Livermore National Laboratory and overall E3SM project lead. “With this new system, we’ll be able to more realistically simulate the present, which gives us more confidence to simulate the future.”

The long view

Simulating the Earth involves solving approximations of physical, chemical and biological governing equations on spatial grids at the highest resolutions possible.

In fact, increasing the number of Earth-system days simulated per day of computing time at varying levels of resolution is so important that it is a prerequisite for achieving the E3SM project goal. The new release can simulate 10 years of the Earth system in one day at low resolution or one year of the Earth system at high resolution in one day (a sample movie is available at the project website). The goal is for E3SM to support simulation of five years of the Earth system on a single computing day at its highest possible resolution by 2021.

This objective underscores the project’s heavy emphasis on both performance and infrastructure — two key areas of strength for Argonne. “Our researchers have been active in ensuring that the model performs well with many threads,” said Jacob, who will lead the infrastructure group in Phase II, which — with E3SM’s initial release — starts on July 1. Singling out the threading expertise of performance engineer Azamat Mametjanov of Argonne’s Mathematics and Computer Science division, Jacob continued: “We’ve been running and testing on Theta, our new 10-petaflop system at Argonne’s Leadership Computing Facility, and will conduct some of the high-res simulations on that platform.”

Researchers using the E3SM can employ variable resolution on all model components (atmosphere, ocean, land, ice), allowing them to focus computing power on fine-scale processes in different regions. The software uses advanced mesh-designs that smoothly taper the grid-scale from the coarser outer region to the more refined region.

Adapting for exascale

E3SM’s developers — more than 100 scientists and software engineers — have a longer-term aim: to use the exascale machines that the DOE Advanced Scientific Computing Research Office expects to procure over the next five years. Thus, E3SM development is proceeding in tandem with the Exascale Computing Initiative. (Exascale refers to a computing system capable of carrying out a billion [1018] calculations per second — a thousand-fold increase in performance over the most advanced computers from a decade ago.)

Another key focus will be on software engineering, which includes all of the processes for developing the model; designing the tests; and developing the required infrastructure, including input/output libraries and software for coupling the models. E3SM uses Argonne’s Model Coupling Toolkit (MCT), as do other leading climate models (e.g., Community Earth System Model [CESM]) to couple the atmosphere, ocean and other submodels. (A new version of MCT [2.10] was released along with E3SM.)

Additional Argonne-specific contributions in Phase II will center on:

– Crop modeling: Efforts will focus on better emulating crops such as corn, wheat and soybeans, which will improve simulated influences of crops on carbon, nutrient, energy and water cycles, as well as capturing the implications of human-Earth system interactions

– Dust and aerosols: These play a major role in the atmosphere, radiation and clouds, as well as various chemical cycles.

Collaboration among – and beyond – national laboratories

The E3SM project has involved researchers at multiple DOE laboratories including Argonne, Brookhaven, Lawrence Livermore, Lawrence Berkeley, Los Alamos, Oak Ridge, Pacific Northwest and Sandia national laboratories, as well as several universities.

The project also benefits from collaboration within DOE, including with the Exascale Computing Project and programs in Scientific Discovery through Advanced Computing, Climate Model Development and Validation, Atmospheric Radiation Measurement, Program for Climate Model Diagnosis and Intercomparison, International Land Model Benchmarking Project, Community Earth System Model and Next-Generation Ecosystem Experiments for the Arctic and the Tropics.

Author: Andrea Manning | Source: Argonne National Laboratory [May 07, 2018]




Understanding how DNA is selectively tagged with ‘do not use’ marks

Not all of your genome needs to be active at any given time. Some regions are prone to hopping around the genome in problematic ways if left unchecked; others code for genes that need to be turned off in certain cells or at certain times. One way that cells keep these genetic elements under control is with the chemical equivalent of a “do not use” sign. This chemical signal, called DNA methylation, is known to vary in different cell types or at different stages of cellular development, but the details of how cells regulate exactly where to put DNA methylation marks have remained unclear.

Understanding how DNA is selectively tagged with 'do not use' marks
Salk Assistant Professor Julie Law and Research Associate Ming Zhou, pictured with their
Arabidopsis thaliana plants in a Salk greenhouse [Credit: Salk Institute]

Salk scientists studying plants discovered a small family of proteins that control where in the genome DNA methylation marks are added. Their work on this aspect of genetic regulation is highly relevant for processes that range from normal development to cellular defects and diseases, which can arise due to erroneous DNA methylation patterns in plants and/or humans, respectively. Their paper is published in Nature Genetics.

“If we want to understand how differences in DNA methylation patterns can cause developmental defects in plants, or diseases like cancer in humans, we need to understand how DNA methylation is targeted to specific regions of the genome under normal conditions,” says Salk Assistant Professor Julie Law, senior author of the paper. “Until now, factors able to control methylation in such a precise manner have been elusive.”

Law studies an easy-to-grow weed, Arabidopsis thaliana, the first plant to have its genome sequenced. In the ensuing years, scientists, including Law, have been working to characterize and understand the plant’s DNA methylation patterns, which affect gene activity without changing the DNA code itself. This process is similar in plants and animals, but investigating DNA methylation in Arabidopsis is much easier because plants can tolerate methylation defects better than animals, where global changes in methylation are often lethal.

Law was interested in understanding how the pathways that control DNA methylation are regulated not only to control global patterns of methylation but also to enable the regulation of individual regions–a critical step in generating different patterns of DNA methylation within a given organism.

Previously, it was known that a protein complex called RNA polymerase IV (Pol-IV) played a global role in establishing DNA methylation patterns. This polymerase makes small molecular messages called siRNAs that act like a molecular GPS system, indicating all the locations within the genome where methylation should be targeted. However, how this polymerase might be regulated to control DNA methylation at individual genomic locations was unclear.

To address this question, Law’s lab used a combined genetic-genomic approach to investigate the functions of four related proteins, the CLASSY family, that they thought might regulate Pol-IV. It turned out that disruption of each CLASSY gene resulted in different sets of genomic regions–in different locations–losing their siRNA signals, resulting in reduced DNA methylation levels. More dramatically, when all four CLASSY genes were disrupted, the siRNA signals and DNA methylation were lost throughout the entire genome.

“In the CLASSY quadruple mutants, the Pol-IV signal completely disappears–essentially no siRNAs are made,” says Ming Zhou, a Salk research associate and the paper’s first author. “This is very strong evidence that CLASSYs are required for Pol-IV function.”

When Law’s team probed further, they discovered that the DNA methylation defects in the CLASSY mutants caused some genes to be erroneously turned on and resulted in global decreases in methylation at mobile DNA elements, increasing their potential to move around and disrupt essential gene activity.

“The CLASSYs are a part of a large superfamily that is common to both plants and animals,” adds Law, who holds the Hearst Foundation Development Chair. “We hope that by understanding how specific methylation patterns are generated in plants, we can provide insights into how DNA methylation is regulated in other organisms.”

Knowledge of this mechanism for regulating DNA methylation could help scientists develop strategies for correcting epigenetic defects that are associated with reduced yields in crops, or diseases–such as cancer–in humans. In the future, the lab is interested in exploring how DNA methylation patterns are controlled during development and in response to the environment.

Source: Salk Institute [May 07, 2018]




Stomata – the plant pores that give us life – arise thanks to a gene called...

Plants know how to do a neat trick. Through photosynthesis, they use sunlight and carbon dioxide to make food, belching out the oxygen that we breathe as a byproduct. This evolutionary innovation is so central to plant identity that nearly all land plants use the same pores — called stomata — to take in carbon dioxide and release oxygen.

Stomata - the plant pores that give us life - arise thanks to a gene called MUTE
Close-up images of the epidermis of Arabidopsis. seedlings, taken using a microscope. (A) and (C): Seedlings with typical
arrangement of stomata across the surface. (B) and (D): Seedlings that artificially produce a lot of the MUTE protein,
 and have many stomata as a result. Scale bars are 50 micrometers [Credit: Soon-Ki Han/Xingyun Qi]

Stomata are tiny, microscopic and critical for photosynthesis. Thousands of them dot on the surface of the plants. Understanding how stomata form is critical basic information toward understanding how plants grow and produce the biomass upon which we thrive.

In a paper published in the journal Developmental Cell, a University of Washington-led team describes the delicate cellular symphony that produces tiny, functional stomata. The scientists discovered that a gene in plants known as MUTE orchestrates stomatal development. MUTE directs the activity of other genes that tell cells when to divide and not to divide — much like how a conductor tells musicians when to play and when to stay silent.

“The MUTE gene acts as a master regulator of stomatal development,” said senior author Keiko Torii, a UW professor of biology and investigator at the Howard Hughes Medical Institute. “MUTE exerts precision control over the proper formation of stomata by initiating a single round of cell division — just one — in the precursor cell that stomata develop from.”

Stomata resemble doughnuts — a circular pore with a hole in the middle for gas to enter or leave the plant. The pore consists of two cells — each known as a guard cell. They can swell or shrink to open or close the pore, which is critical for regulating gas exchange for photosynthesis, as well as moisture levels in tissues.

“If plants cannot make stomata, they are not viable — they cannot ‘breathe,'” said Torii, who also is a professor at Nagoya University in Japan.

Stomata - the plant pores that give us life - arise thanks to a gene called MUTE
Without MUTE, Arabidopsis plants cannot produce stomata, and do not develop past the seedling stage
[Credit: Soon-Ki Han/ Xingyun Qi]

Torii and her team investigated which genes governed stomata formation in Arabidopsis thaliana, a small weed that is one of the most widely studied plants on the planet. Past research by Torii’s team and other researchers had indicated that, in Arabidopsis, MUTE plays a central role in the formation of stomata. The MUTE gene encodes instructions for a cellular protein that can control the “on” or “off” state of other plant genes.

The researchers created a strain of Arabidopsis that can artificially produce a lot of the MUTE protein, so they could easily identify which genes the MUTE protein turned on or off. They discovered that many of the activated genes control cell division — a process that is critical for stomatal development.

In Arabidopsis, as in nearly all plants, stomata form from precursor cells known as guard mother cells, or GMCs. To form a working stoma — singular for stomata — a GMC divides once to yield to paired guard cells. Since their data showed that MUTE proteins switched on genes that regulated cell division, Torii and her team wondered if MUTE is the gene that activates this single round of cell division. If so, it would have to be a tightly regulated process. The genetic program would have to switch on cell division in the GMC, and then quickly switch it right back off to ensure that only a single round of division occurs.

Torii’s team showed that one of the genes activated by the MUTE protein to its DNA is CYCD5;1, a gene that causes the GMC to divide. The researchers also found that MUTE proteins turn on two genes called FAMA and FOUR LIPS. This was an important discovery because, while CYCD5;1 turns on cell division of the GMC, FAMA and FOUR LIPS turn off — or repress — the cell division program.

“Our experiments showed that MUTE was turning on both activators of cell division and repressors of cell division, which seemed counterintuitive — why would it do both?” said Torii. “That made us very interested in understanding the temporal regulation of these genes in the GMC and the stomata.”

Stomata - the plant pores that give us life - arise thanks to a gene called MUTE
MUTE is a master regulator of the development of stomata in Arabidopsis
[Credit: Keiko Torii and her daughter Erika]

Through precise experiments, they gathered data on the timing MUTE activation of these cell division activators and repressors. They incorporated this information into a mathematical model, which simulated how MUTE acts to both activate and repress cell division in the GMC. First, MUTE turns on the activator CYCD5;1 — which triggers one round of cell division. Then, FAMA and FOUR LIPS act to prevent further cell division, yielding one functional stomata consisting of two guard cells.

“Like a conductor at the podium, MUTE appears to signal its target genes — each of which has specific, and even opposite, parts to play in the ensuing piece,” said Torii. “The result is a tightly coupled sequence of activation and repression that gives rise to one of the most ancient structures on land plants.”

Author: James Urton | Source: University of Washington [May 07, 2018]




The Last of the Welsh Lords: Llywelyn Ap Gruffydd

Father, fighter, and final, Llywelyn ap Gruffydd was born around 1223 AD and was the last Welsh ruler of Wales. The second son of Gruffydd ap Llywelyn Fawr (himself the illegitimate son of Llywelyn the Great), Llywelyn ap Gruffydd is remembered primarily for his role (albeit unintentional) as the loss of the moniker “Prince of Wales” from his family lineage. Further, his death marked the conquest of Wales by England, thus encompassing the region into (what is now called) the United Kingdom.

Division of Gwynedd

Division of Gwynedd ( CC BY-SA 3.0 ) In 1247 following the succession of the brothers Owain (whose lands are shown in dark green) and Llywelyn (light green) ap Gruffudd. The Commote of Cymydmaen (gold) was granted to Dafydd ap Gruffudd by Owain when he reached majority in 1252 (Source: J. Beverley Smith) 

Llywelyn as the Ruler of Gwynedd

The way in which Llywelyn became ruler of Gwynedd in 1258 is as convoluted as the loss of his title due to the dissonance between his father and his uncles. Although Gruffydd was the eldest son of Llywelyn the Great, his illegitimate status made him unable to take control of Gwynedd. Further, Gruffydd’s father and younger brother Dafydd ap Llywelyn imprisoned Gruffydd and Gruffydd’s eldest son Owain in Criccieth Castle to ensure neither could attempt to claim control upon Llywelyn the Great’s death.

During this imprisonment, Gruffydd was passed from Dafydd’s castle to the Tower of London under Henry III of England, and subsequently died during an escape attempt in 1244. The lands of Gwynedd eventually passed to Llywelyn ap Gruffydd around 1258 following Uncle Dafydd’s death and the former’s subsequent “removal” of his older brother, Owain, and younger brother, also called Dafydd, from positions of power.

Llywelyn ap Gruffudd at Cardiff City Hall.

Llywelyn ap Gruffudd at Cardiff City Hall. ( Public Domain )

Throughout his reign, Edward I of England was Llywelyn’s constant enemy. Though he married Edward’s cousin, it was not without animosity. Edward had declared Llywelyn a rebel in 1276, one year after marrying Eleanor de Montfort, daughter of Earl Simon and the granddaughter of John of England and Isabella of Angoulême, by proxy.

However, on her journey from France to meet her new husband, Edward I himself ensured Eleanor’s capture by pirates to punish Llywelyn, and she remained jailed in Windsor Castle until 1277/1278. It is believed that Eleanor’s father Earl Simon had arranged for Llywelyn to marry Eleanor before Simon’s death, but an official ceremony did not take place until three years later, with the consent of Edward I and after Llywelyn conceded to Edward’s demands. Among those demands were acknowledging Edward I as the proper English king.

Portrait in Westminster Abbey, thought to be of Edward I.

Portrait in Westminster Abbey, thought to be of Edward I. ( Public Domain )

The Battle of Orewin Bridge

Tragically, though not uncommon in the 13th century, Eleanor died giving birth to her daughter in 1282, just seven years after marrying Llywelyn. Only six months later, Llywelyn also perished, murdered by the English in the Battle of Orewin Bridge. The Battle of Orewin Bridge was preempted by a war against Edward I in 1277 in which Llywelyn lost and was forced to hand over significant parts of Wales to Edward, thereby condensing his own region to a small portion of Wales.

The Battle of Orewin Bridge occurred on a hill near the Irfon River. Llywelyn was not present at the initial start of the war, but arrived after a local had tricked the Welsh into removing their defenses from the bridge. Llywelyn was slain far from the center of the battle, perhaps by a soldier named Stephen de Frankton.

The Llywelyn Monument at Cilmeri which marks the battle of Orewin Bridge.

The Llywelyn Monument at Cilmeri which marks the battle of Orewin Bridge. ( Public Domain )

Admittedly, details of the battle are scarce, and the way in which Llywelyn died may be mere conjecture. A later 15th century poem claims that Llywelyn was returning from a nightly tryst before being called into battle—one can only imagine what actually happened just prior to Llywelyn’s death. It is believed he was decapitated after he fell, his head placed on a lance to show the final English defeat of the Welsh forces. Again, this was not an uncommon practice.

Moon below Venus on January




Tonight – January 29, 2017 – look westward after sunset to view the two brightest luminaries of nighttime, the moon and Venus. Be sure to catch the moon as soon as darkness falls. The slender waxing crescent moon will sit rather low in the sky, and will follow the sun beneath the horizon by early evening.

Day by day, you’ll see a wider waxing crescent moon higher up in the sky at sunset and staying out longer after dark. That’s because the moon is presently moving away from the setting sun and toward the planet Venus on the sky’s dome. Tomorrow – after sunset on January 30 – look for the moon to be closer to Venus in the evening twilight sky.

The moon always goes westward (toward the sunset) each day, due to the Earth’s spinning motion from west-to-east on its rotational axis. Yet, the moon is actually moving eastward with respect to the background stars and planets of the zodiac, due to its motion in orbit around Earth. As you watch the moon’s change of position over several days, as depicted on the sky chart above, you can begin to get a sense of the moon’s orbital motion around Earth.

That motion causes the moon to move eastward by about 1/2 degree (the moon’s own apparent diameter) in one hour, or 12o eastward per day, with respect to the sun. In contrast, the moon travels about 13o eastward per day as measured by the backdrop stars.

Or, to put it another way, the moon goes full circle relative to the backdrop stars of the zodiac in about 27.3 days and full circle relative to the sun in about 29.5 days.

The 27.3-day lunar cycle is called the sidereal month, while the 29.5-day cycle of the phases is called the lunar or synodic month.

Click here for an illustration of the synodic month

Bottom line: Beginning on January 29, 2017, watch as the waxing crescent moon sweeps past Venus and then Mars on the sky’s dome. You’ll find them all in the west at nightfall.

Source earthsky

Discovered a Black Hole 40 Billion Times More Massive than Our Sun

S5 0014+81 is a distant, compact, hyperluminous, broad-absorption line quasar or blazar located near the high declination region of the constellation Cepheus, near the North Equatorial Pole.

The object is a blazar, in fact an FSRQ (Flat Spectrum Radio Quasar) quasar, the most energetic subclass of objects known as active galactic nuclei, produced by the rapid accretion of matter by a central supermassive black hole, changing the gravitational energy to light energy that can be visible in cosmic distances. In the case of S5 0014+81 it is one of the most luminous quasars known, with a total luminosity of over 1041 watts, equal to an absolute bolometric magnitude of -31.5.

If the quasar were at a distance of 280 light-years from Earth, it would give as much energy per square meter as the Sun despite being 18 million times more distant. The quasar’s luminosity is therefore about 3 x 1014 (300 trillion) times the Sun,or over 25,000 times as luminous as all the 100 to 400 billion stars of the Milky Way Galaxy combined, making it one of the most powerful objects in the universe. However, because of its huge distance of 12.1 billion light-years it can only be studied by spectroscopy. The central black hole of the quasar devours an extremely huge amount of matter, equivalent to 4,000 solar masses of material every year.

The quasar is also a very strong source of radiation, from gamma-rays and X-rays down to radio waves. The quasar is located at a distance where the observed redshift of quasars and stars are extremely similar, making the two objects difficult to distinguish using the standard spectroscopic redshift and the photometric redshift determination, and hence must be treated by other special techniques to successfully determine the nature of the object.

The quasar’s designation, S5, is from the Fifth Survey of Strong Radio Sources, 0014+81 was its coordinates in epoch B1950.0. It also has the other designation 6C B0014+8120 from the Sixth Cambridge Survey of radio sources by Cambridge University.

The host galaxy of S5 0014+81 is a giant elliptical starburst galaxy, with the apparent magnitude of 24.

Supermassive black hole 


(adsbygoogle = window.adsbygoogle || []).push({});

The host galaxy S5 0014+81 is an FSRQ blazar, a giant elliptical galaxy that hosts a supermassive black hole in its center, which may be responsible for the intense activity of this blazar.

In 2009, a team of astronomers using the Swift Spacecraft used the luminosity output of S5 0014+81 to measure the mass of the central black hole. To their surprise, they found out that the central black hole of S5 0014+81 is actually 10,000 times more massive than the black hole at the center of our galaxy, or equivalent to 40 billion solar masses. This makes it one of the most massive black holes ever discovered, more than six times the value of the black hole of Messier 87, which was thought to be the largest black hole for almost 60 years, and was coined to be an “ultramassive” black hole.

The Schwarzschild radius of this black hole is 118.35 billion kilometers. So, this black hole has an external horizon showing a diameter of 236.7 billion kilometers, 1,600 astronomical units, or 37.4 times the diameter of Pluto‘s orbit, and shows a mass equivalent to four Large Magellanic Clouds. What is even more astounding is that the monstrous black hole exists so early in the universe, at only 1.6 billion years after the Big Bang. This suggests that supermassive black holes grow up very quickly.

However, there are some cautions about the study. First, the method used was actually an indirect method of calculation, and not Keplerian orbital estimation; the latter being a more precise estimate. It is unlikely for a quasar as luminous as S5 0014+81, which will just outshine the stars within its vicinity, thereby making estimates very inaccurate. Second, the spectra used is actually a long spectra, not accounting for the observed parameters.

Third, the quasar is surrounded by a large accretion disc, a few parsecs in size, and it shines at 40% of its Eddington luminosity, the maximum luminosity through which radiation pressure is strong enough to blow up the disc away from the gravitational influence of the central black hole, so the observed characteristics are unknown due to intervening dust and gases. However, the possibility of an ultramassive black hole has not been ruled out entirely, since only a black hole of that mass can account for the observed power output of the quasar.

Evolution models based on the mass of S5 0014+81’s supermassive black hole predict that it will live for roughly 1.342×1099 years (near the end of the Black Hole Era of the Universe, when it is more than 1088 times its current age), before it dissipates by the Hawking radiation. However, it is undergoing accretion, so it may take longer than the stated time for it to dissipate.

Source Sci-Tech Universe

MUFON Case 41918, 45899: 5:20 a.m., July 14, 2012

Денежный фонтан в Италии

Туристическая достопримечательность

На счастье или чтобы загадать желание туристы каждую недели

бросают в фонтан 25.000 долларов, монетами евро.

Работникни муниципалитета Рима часто осушают фонтан, собирают монеты и под конвоем отвозят деньги в банк.

Муниципалитет тратит деньги на помощь бедным и бездомным по официальному заявлению

Последнее озеро с рыбой



Weeds take over kelp in high CO2 oceans

Weedy plants will thrive and displace long-lived, ecologically valuable kelp forests under forecast ocean acidification, new research from the University of Adelaide shows.

Weeds take over kelp in high CO2 oceans
Kelp, Channel Islands, California [Credit: Shutterstock]

Published in the journal Ecology, the researchers describe how kelp forests are displaced by weedy marine plants in high CO2 conditions, equivalent to those predicted for the turn of the century.

Carbon emissions will fuel the growth of small weedlike species, but not kelps – allowing weeds to take over large tracts of coastal habitats, the researchers say.

“Carbon emissions might boost plant life in the oceans, but not all plant life will benefit equally,” says project leader Professor Sean Connell, from the University of Adelaide’s Environment Institute. “Weedy species are quicker to capitalise on nutrients, such as carbon, and can grow faster than their natural predators can consume them.

“Unfortunately, the CO2 that humans are pumping into the atmosphere by burning fossil fuels gets absorbed by the ocean and favours weedy turfs, which replace kelp forests that support higher coastal productivity and biodiversity.”

Led by the University of Adelaide, the international team from Europe, Canada, USA, Hong Kong used natural volcanic CO2 seeps to compare today’s growth of weeds and kelps with levels of CO2 that are predicted for the turn of the century.

“In our study, we found that while elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2,” says Professor Connell.

Fellow researchers Dr Zoe Doubleday and Professor Ivan Nagelkerken, from the University’s Southern Seas Ecology Laboratories, visited the volcanic vents with Professor Connell.

“We could clearly see the effect of CO2 on promoting the dominance of weedy species and the suppression of their natural predators,” says Dr Doubleday.

Professor Nagelkerken says: “Under the level of acidification we will find in oceans in a few decades, marine life is likely to be dominated by fast-growing and opportunistic species at the expense of longer-lived species with specialist lifestyles, unless we can set some change in place.

“We need to consider how natural enemies might be managed so that those weedy species are kept under control,” Professor Nagelkerken says.

Source: University of Adelaide [May 03, 2018]




Tracing cerebral cortex evolution

Our cerebral cortex, a sheet of neurons, connections and circuits, comprises “ancient” regions such as the hippocampus and “new” areas such as the six-layered “neocortex”, found only in mammals and most prominently in humans. But when in evolution did the components of cerebral cortex arise and how did they evolve? Scientists at the Max Planck Institute for Brain Research in Frankfurt am Main studied gene expression in the neurons of the cortex of turtles and lizards, and found unexpected similarities and differences with the mammalian cortex. These results are a milestone towards reconstructing the evolution of the vertebrate brain.

Tracing cerebral cortex evolution
Snapshot of the turtle three-layered cortex (left) and distinct types of neurons in the turtle dorsal cortex (right).
The neurons are labeled with fluorescent in situ hybridization for two genes expressed
in the two neuronal types [Credit: MPI f. Brain Research]

We are, in many ways, our cerebral cortex. Its circuits serve to shape our perception of the world, store our memories and plan our behavior. A cerebral cortex, with its typical layered organization, is found only among mammals, including humans, and non-avian reptiles such as lizards and turtles. Mammals, reptiles and birds originate from a common ancestor that lived some 320 million years ago. Neuroscientists believe that this ancestor had a small cortex with three layers, because a similar structure is found today in the hippocampus of mammals and in all cortices of modern reptiles: these three-layered cortices likely correspond to their common ancestral cortex.

By comparing the cortex of today’s reptiles to the old and new cortices of today’s mammals (such as hippocampus and neocortex, respectively), we can search for similarities, potential ancestral traits, and differences – resulting from their independent evolutions – and thus reconstruct the main features of cortical evolution. Comparisons were, until now, based on developmental and anatomical features. This new study, based on the molecular characterization of individual reptilian neurons, provides unprecedented data to help reconstruct cortex evolution.

For decades, the anatomical differences between reptilian and mammalian brains have fueled many disputes about cortical evolution. People argued on whether this part of the reptilian brain corresponds to that part of the mammalian brain, or whether the many layers found in mammalian neocortex actually exist also in reptiles, but in a form that is not detectable with traditional methods. Gilles Laurent and his group at the Max Planck Institute for Brain Research took a different approach and focused on the molecular characterization of the myriad neuronal types that make up cortical circuits.

Transcriptome sequenced

Neuronal “types” differ, among others, by their morphology, neurotransmitters, connections and functional properties. These features all result from the expression of different sets of genes; hence individual neurons can be classified (or typed) by measuring the messenger RNA molecules they contain (their “transcriptome”). Maria Antonietta Tosches, the first author of this study, and her colleagues sequenced the transcriptomes of turtle and lizard cells after capturing them, one by one, in microscopic water droplets using specialized microfluidics platforms.

Using these gene expression profiles, the scientists could categorize thousands of neurons. From each type they could identify diagnostic marker genes, and use them to assess the position of the cell types in the brain. Imagine a picture of the cortex, uniform until then, suddenly transformed into a collage of colored zones, with each zone containing one or several characteristic cell types.

The authors could now compare reptilian molecular maps to those of mammalian brains directly, find one-to-one correspondences and even draw hypotheses about the brain of their common ancestor of 320 million years ago (now extinct).

Forced to fold

“Our results tremendously clarify our understanding of the reptilian brain and thus, of brain evolution”, Tosches says. These new molecular maps show, for example, that reptiles have neuron types that correspond to those found in the mammalian hippocampus, a structure involved in spatial orientation and in the formation of memories. In reptiles, the hippocampus is found towards the center of the brain, but unlike its folded-up mammalian counterpart, looks like a single sheet. “It is as if, in early mammals, the ancestral hippocampus had been pushed by an increasingly dominant neocortex and forced to fold onto itself, to acquire its signature mammalian architecture”, Laurent adds.

The non-hippocampal reptilian cortex, by contrast, revealed the intricate history of mammalian neocortex. Inhibitory neurons, for example, express similar sets of genes in reptiles and mammals, indicating a common ancestry. Excitatory neurons, however, differ substantially across these two groups. “The mammalian six-layered neocortex is a fascinating mosaic of ancient and new neuronal types”, says Tosches. The scientists can now point to the true novelty of the mammalian neocortex, that is, the emergence of new types of excitatory neurons after profound changes of gene expression programs.

This study opens up many new questions. Do ancient neuronal types have the same functions in reptilian and mammalian cortical circuits? And can these molecular similarities and differences inform us on the evolution of brain function and animal behavior? “There is a lot more to explore from these new molecular maps” says Laurent: “this is only the beginning”.

The findings are published in Science.

Source: Max Planck Society [May 04, 2018]





Полет на параплане с обрыва на мысу Куяльницкого лимана, соленого озера. Экстремальный развлекательный полет проводится для любителей. ...