Friday, September 29, 2017

Gamers Have an Advantage in Learning

Video games are apparently better than their reputation.

The weather prediction task


Sabrina Schenk and Boris Suchan tested how well video gamers learn.
Credit: © RUB, Marquard

Video gamers better with high uncertainties


The analysis of the questionnaire revealed that the gamers had acquired more knowledge about the meaning of the card combinations than the control group. “Our study shows that gamers are better in analysing a situation quickly, to generate new knowledge and to categorise facts – especially in situations with high uncertainties,” says first author Sabrina Schenk.

This kind of learning is linked to an increased activity in the hippocampus, a brain region that plays a key role in learning and memory. “We think that playing video games trains certain brain regions like the hippocampus”, says Schenk. “That is not only important for young people, but also for older people; this is because changes in the hippocampus can lead to a decrease in memory performance. Maybe we can treat that with video games in the future.”

The study was conceived as part of Collaborative Research Centre 874, which has been funded since 2010 by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) to investigate memory formation and sensory processing.
Original publication

Contacts and sources:
Prof Dr Boris Suchan
Department of Clinical Neuropsychology
Institute for Cognitive Neuroscience
Faculty of Psychology
Ruhr-Universität Bochum

Citation: Sabrina Schenk, Robert K. Lech, Boris Suchan: Games people play: How video games improve probabilistic learning, in: Behavioral Brain Research, 2017, DOI: 10.1016/j.bbr.2017.08.027





Credit: University of Copenhagen


Yamna culture tomb in Volgograd oblast'
File:Yamna culture tomb.jpg
Credit: XVodolazx / Wikimedia Commons

Peas, beans, turnips and shrimps



Credit; University of Copenhagen



Contacts and sources:
Archaeologist Rune Iversen
University of Copenhagen

Linguist Guus Kroonen
Roots of Europe, University of Copenhagen


Thursday, September 28, 2017

Mapping the Thylacine's Mysterious Loss from Mainland

Ancient DNA extracted from fossil bones and museum specimens has shed new light on the mysterious loss of the Tasmanian tiger (thylacine) from Australia's mainland.

The University of Adelaide study, published in the Journal of Biogeography, traces the history of thylacine populations over the last 30,000 years.

The researchers from the University's Australian Centre for Ancient DNA (ACAD) found that a large and genetically diverse population of thylacines lived in western regions of Australia right up to their extinction from the mainland around 3000 years ago, separated from the eastern population.

These are Thylacine jaw bones kept in the Tasmanian Museum and Art Gallery.
Credit: University of Adelaide

They have concluded that climate change from about 4000 years ago, in particular more drought-prone seasons caused by the onset of the El Niño-Southern Oscillation, was the likely main cause of mainland extinction.

"The thylacine was a marsupial carnivore, now infamous for its recent human-driven extinction from Tasmania following the arrival of Europeans and their bounty hunting schemes," says project leader Associate Professor Jeremy Austin, Deputy Director of ACAD.

"Thylacines once lived across most of the Australian mainland, but by the time Europeans arrived in the late 1700s they were found only in Tasmania. They became extinct about 150 years later, with the last of the species dying in Hobart Zoo in 1936. But the reasons for their disappearance from mainland Australia and continuing survival in Tasmania has remained a mystery." Climate change, increased human activity and the introduction of the dingo are the three main causes debated.

The researchers generated 51 new thylacine mitrochondrial DNA genome sequences from fossil bones and museum specimens - the largest dataset of thylacine DNA to date.

This provided the first genetic evidence that mainland thylacines split into eastern and western populations in southern Australia before the last Ice Age peak of about 25,000 years ago.

"We wanted to understand why thylacines went extinct on the mainland, but survived in Tasmania," says lead author and PhD student Lauren White. "The ancient DNA tells us that the mainland extinction was rapid, and not the result of intrinsic factors such as inbreeding or loss of genetic diversity.

"We also found evidence of a population crash, reducing numbers and genetic diversity of thylacines in Tasmania around the same time," says Associate Professor Austin. "This mirrors what happened with another carnivorous marsupial, the Tasmanian devil, which still lives in Tasmania. Unlike the devil, however, it appears that the population of thylacines was expanding at the time of European arrival."

"Tasmania would have been somewhat shielded from the warmer, drier climate because of its higher rainfall but it appears that this population was also affected by the El Niño event before starting to recover."

 Contacts and sources:
Associate Professor Jeremy Austin
University of Adelaide 

Citation: Ancient mitochondrial genomes reveal the demographic history and phylogeography of the extinct, enigmatic thylacine (Thylacinus cynocephalus)
Authors: Lauren C. White, Kieren J. Mitchell, Jeremy J. Austin

Robots to Emulate Nature’s Perfect Pursuit

Although its name may not inspire fear and dread in the way of a great white shark, or Bengal tiger, the humble dragonfly is widely considered nature’s most effective predator.

This phenomenally talented aerialist is able to target, pursue and capture tiny flying prey in mid-air at speeds of up to 60 km/h—even if that target attempts to disappear within a seething swarm—with an incredible hit-rate of over 95%.

With such abilities having obvious application to human needs in the areas of defence and surveillance, along with health systems, environmental monitoring and manufacturing, researchers at the University of Adelaide recently set themselves the task of unlocking and harnessing the dragonfly’s secrets.

According to lead researcher and neuroscientist Dr Steven Wiederman, from the Adelaide Medical School, they’re succeeding.

“We’re delighted to say that we’ve been able to build an autonomous robot that, using computational models bio-inspired by the dragonfly’s neuronal processing, can effectively and efficiently pursue targets in unstructured environments,” says Steven.

The team, which also includes researchers in the fields of mechanical engineering and computer science, first investigated how the dragonfly was able to focus on a single moving target and shut out all else.

“We recorded the activity of dragonfly neurons, and discovered the first identified neuron in any animal that exhibits an ‘attentional spotlight’; selecting a single target amidst distracters.

“We also recorded from target-detecting neurons that predictively encode trajectory, enabling the dragonfly to estimate its target’s future location and ambush it.”

The processes displayed were then adapted into a unique algorithm to emulate the dragonfly’s visual tracking capability. When tested in various nature-mimicking virtual reality environments, the algorithm performed every bit as accurately as other state-of-the-art algorithms, but while running up to 20 times faster, so requiring less relative processing power.

“We’re very excited to continue our research now,” says Steven, “and further define the fundamental principles that underlie neuronal processing. Translating these principles into the development of advanced artificial vision systems could result in some incredibly effective autonomous robotics, drones, neuronal prosthetics, and many more applications.”

Contacts and sources:
The University of Adelaide

Perovskite Solar Cells Reach Record Long-Term Stability, Efficiency Over 20 Percent

Perovskite solar cells (PSCs) can offer high light-conversion efficiency with low manufacturing costs. But to be commercially viable, perovskite films must also be durable and not degrade under solar light over time. 

Ecole Polytechnique Fédérale de Lausanne (EPFL) scientists have now greatly improved the operational stability of PSCs, retaining more than 95% of their initial efficiencies of over 20 % under full sunlight illumination at 60oC for more than 1000 hours. The breakthrough, which marks the highest stability for perovskite solar cells, is published in Science.

Challenges of stability

Conventional silicon solar cells have reached a point of maturation, with efficiencies plateauing around 25% and problems of high-cost manufacturing, heavyweight, and rigidity has remained largely unresolved. On the contrary, a relatively new photovoltaic technology based on perovskite solar cells has already achieved more than 22% efficiency.

Structure of β-CuSCN and cross-sectional SEM micrograph of a complete solar cell.

Credit: M. Ibrahim Dar/EPFL

Given the vast chemical versatility, and the low-cost processability of perovskite materials, the PSCs hold the promise to lead the future of photovoltaic technology by offering cheap, light weight and highly efficient solar cells. But until now, only highly expensive, prototype organic hole-transporting materials (HTMs,selectively transporting positive charges in a solar cell) have been able to achieve power-conversion efficiencies over 20%. And by virtue of their ingredients, these hole-transporting materials adversely affect the long-term operational stability of the PSC.

Therefore, investigating cheap and stable hole transporters that produce equally high efficiencies is in great demand to enable large-scale deployment of perovskite solar cells. Among various inorganic HTMs, cuprous thiocyanate (CuSCN) stands out as a stable, efficient and cheap candidate ($0.5/gr versus $500 /gr for the commonly used spiro-OMeTAD). But previous attempts to use CuSCN as a hole transporter in perovskite solar cells have yielded only moderately stabilized efficiencies and poor device stability, due to problems associated with depositing a high-quality CuSCN layer atop of the perovskite film, as wells as the chemical instability of the CuSCN layer when integrated into a 
perovskite solar cell.

A stable solution

Now, researchers at Michael Grätzel's lab at EPFL, in a project led by postdocs Neha Arora and M. Ibrahim Dar, have introduced two new concepts that overcome the major shortcomings of CuSCN-based perovskite solar cells. First, they developed a simple dynamic solution-based method for depositing highly conformal, 60-nm thick CuSCN layers that allows the fabrication of perovskite solar cells with stabilized power-conversion efficiencies exceeding 20%. This is comparable to the efficiencies of the best performing, state-of-the-art spiro-OMeTAD-based perovskite solar cells.

Second, the scientists introduced a thin spacer layer of reduced graphene oxide between the CuSCN and a gold layer. This innovation allowed the perovskite solar cells to achieve excellent operational stability, retaining over 95% of their initial efficiency while operating at a maximum power point for 1000 hours under full-sun illumination at 60 °C. This surpasses even the stability of organic HTM-based perovskite solar cells that are heavily researched and have recently dominated the field.

The researchers also discovered that the instability of the perovskite devices originates from the degradation of CuSCN/gold contact during the solar cell's operation.

"This is a major breakthrough in perovskite solar-cell research and will pave the way for large-scale commercial deployment of this very promising new photovoltaic technology," says Michael Grätzel. "It will benefit the numerous scientists in the field that have been intensively searching for a material that could replace the currently used, prohibitively expensive organic hole-transporters," adds M. Ibrahim Dar.

Contacts and sources:
Nik Papageorgiou /Professor Michael Grätzel /Dr M. Ibrahim Dar 
Ecole Polytechnique Fédérale de Lausanne (EPFL)

Citation: Neha Arora, M. Ibrahim Dar, Alexander Hinderhofer, Norman Pellet, Frank Schreiber, Shaik Mohammed Zakeeruddin, Michael Grätzel. Perovskite solar cells with CuSCN hole extraction layers yield stabilized efficiencies >20%. Science 28 September 2017.

Chimpanzees Figure Out How to Make and Use Tools Without Observing Others

New observations have lead researchers to believe that chimpanzees can use tools spontaneously to solve a task, without needing to watch others first.

The evidence of chimpanzees (Pan troglodytes) spontaneously using sticks to scoop food from water surfaces is published in the open-access journal PeerJ.

Researchers from the University of Birmingham, UK, and University of Tübingen, Germany, looked for the spontaneous re-occurrence of a tool-use behaviour practiced in wild chimpanzees where sticks are used to 'scoop' algae from the top of water surfaces.

Credit:  University of Birmingham

Chimpanzees at Twycross Zoo, UK, were provided with a container of water with pieces of floating food. The tested chimpanzees successfully used the sticks, and moreover, spontaneously showed the same underlying action pattern (a scooping action of the stick) as their wild cousins do.

The results challenge the accepted belief that chimpanzees need to learn from each other how to use tools, and instead suggest that some (if not all) forms of tool-use are instead within their pre-existing behavioural repertoire (what the authors call "latent solutions").

Elisa Bandini explained, "The commonly held belief is that chimpanzee behaviour is cultural, much like how human culture has been passed between groups. But if that was the case, the same behaviours should never re-occur in naïve subjects. Nobody, for example, could accurately reinvent extinct languages on the spot."

Due to the close genetic ties between humans and chimpanzees, it is likely that naïve individuals also spontaneously invented some forms of early human material culture.

Dr Claudio Tennie added, "Given these results, the long-held assumption that apes must observe one another in order to show these behaviours may have been due to an illusion of cultural transmission - created by the apes arriving at the same behaviour independently."

The University of Birmingham and Twycross Zoo has a Memorandum of Understanding (MoU), which promotes teaching, research and other activities for the mutual benefit of both parties. This research was conducted under the MoU agreement, using Twycross' extensive history with, and in caring for, primates.


Contacts and sources:
Luke Harrison
University of Birmingham

Unprecedented: Hundreds of Species Surfed 2011 Tsunami To Hawaii and American West Coast from Japan

The 2011 Japanese tsunami set the stage for something unprecedented. For the first time in recorded history, scientists have detected entire communities of coastal species crossing the ocean by floating on makeshift rafts. Nearly 300 species have appeared on the shores of Hawaii and the U.S. West Coast attached to tsunami debris, marine biologists from the Smithsonian Environmental Research Center, Williams College and other institutions reported in the journal Science on Thursday.

The tsunami formed March 11, 2011, triggered by an earthquake of 9.0 moment magnitude that struck Japan the same day. At its tallest point, the tsunami towered 125 feet over Japan's Tohoku coast and swept millions of objects out to sea, from small pieces of plastic to fishing boats and docks. These kinds of objects, scientists said, helped the species attached to them complete the transoceanic journey.


Credit: John Chapman


Scientists began finding tsunami debris washing up in Hawaii and western North America in 2012, with living organisms still attached. From 2012 to 2017, they continued to find debris, including buoys, crates, vessels and docks. In total, they detected 289 living species on tsunami debris originating from Japan, and they suspect there are far more that escaped their notice. While the arrivals have slowed down, they have not stopped. The team was still finding new species when the study period ended in 2017.

Mollusks such as mussels occurred most frequently of all invertebrate groups. Worms, hydroids (sea anemone and jellyfish relatives), crustaceans and bryozoans that form branch-like underwater colonies were not far behind. Nearly two-thirds of the species had never been seen on the U.S. West Coast. None of the species were known--or expected--to survive a transoceanic rafting voyage between continents, largely because the open ocean is considered to be a harsher environment for creatures used to more hospitable waters of the coasts. However, the slower speed of ocean rafts (1 or 2 knots, compared to 20 or more knots for commercial ships) may have allowed species to gradually adjust to their new environments. The sluggish pace of these "floating islands" may also have made it easier for some species to reproduce and for their larvae to attach to the debris.

A vessel carried by the Japanese tsunami washed ashore in Oregon, coated in gooseneck barnacles that colonized the boat as it floated across the North Pacific. Several Japanese species also survived the voyage, in the crevices inside and underneath the boat.

Credit: John Chapman

The increase in marine plastics and other more durable debris also made survival easier, according to the researchers. Much of the debris the scientists found rafted ashore was made of fiberglass or other plastic materials that do not decompose and could easily survive six or more years at sea. These materials started becoming common in the mid-20th century, and their dominance is only expected to rise.

"There is huge potential for the amount of marine debris in the oceans to increase significantly," said lead author James Carlton, an invasive species expert with the Maritime Studies Program of Williams College and Mystic Seaport in Connecticut. According to a 2015 report in Science, over 10 million tons of plastic waste enter the ocean each year, and that figure may increase 10 times by 2025. Hurricanes and typhoons, which scientists also expect to become more frequent due to climate change, also can sweep debris out into the ocean.

So far, no new species are known to have colonized the West Coast directly due to the 2011 tsunami. However, it can take years after a nonnative species first arrives to detect a newly established population. This provides a window of time for action, although the full consequences of the tsunami-driven rafting are still uncertain.

"This has turned out to be one of the biggest, unplanned, natural experiments in marine biology, perhaps in history," said co-author John Chapman of Oregon State University.

However, scientists largely agree that prevention is the most effective way to combat invasive species. Since preventing tsunamis is not an option, Ruiz suggested the main focus should be managing plastic.


Moss Landing Marine Laboratories, the Oregon Institute of Marine Biology and Portland State University also contributed to this report.

Supersonic Gas Streams Left Over from The Big Bang Drive Massive Black Hole Formation

An international team of researchers has successfully used a super-computer simulation to recreate the formation of a massive black hole from supersonic gas streams left over from the Big Bang. Their study, published in this week's Science, shows this black hole could be the source of the birth and development of the largest and oldest super-massive black holes recorded in our Universe.


Recent discoveries of these super-massive black holes located 13 billion light years away, corresponding to when the universe was just five per cent of its present age, pose a serious challenge to the theory of black hole formation and evolution. The physical mechanisms that form black holes and drive their growth are poorly understood.

These are projected density distributions of dark matter (background and top panel) and gas (bottom three panels) components when the massive star forms. The stellar cradle is extremely assymmetry as a wide wedge-shaped structure (middle panel) due to the initial supersonic gas motions left over from the Big Bang. The circle in the right panel indicates the gravitationally unstable region with mass of 26,000 solar-masses.

Credit: Shingo Hirano

Theoretical studies have suggested these black holes formed from remnants of the first generation of stars, or from a direct gravitational collapse of a massive primordial gas cloud. However, these theories either have difficulty in forming super-massive black holes fast enough, or require very particular conditions.

Yoshida and JSPS Overseas Research Fellow Shingo Hirano, currently at the University of Texas at Austin, identified a promising physical process through which a massive black hole could form fast enough. The key was incorporating the effect of supersonic gas motions with respect to dark matter.

This is the gas density distribution around the new-born protostar. The left-to-right supersonic gas motion results in the non-spherical, compressed density structure. The collapsed inner cloud also shows the turbulated object, which can rapidly accrete onto the central protostar and cause a fast mass growth of it.

Credit:  Shingo Hirano



This the evolution of the temperature and density structure in the protostellar accretion phase after the protostar formation. The rapid accretion of dense gas cloud (white contour) constricts an expansion of the photoionized region (red) which is possible to shut off the gas accretion.

Credit: Takashi Hosokawa


The result from this study will be important for future research into the growth of massive black holes. Especially with the increased number of black hole observations in the far universe that are expected to be made when NASA's James Webb Space Telescope is launched next year.

This research was published in Science on September 28.

Aterui, one of the supercomputers this work used, is operated by the Center for Computational Astrophysics (CfCA) of the National Astronomical Observatory of Japan (NAOJ).

Contacts and sources:
Motoko Kakubayashi 
 Kavli Institute for the Physics and Mathematics of the Universe

Earliest Evidence for Domesticated Sorghum in Africa


Credit: Drawing by Dorian Q. Fuller




Contacts and sources:
Frank Winchell
The University of Chicago Press

Citation: Evidence for Sorghum Domestication in Fourth Millennium BC Eastern Sudan: Spikelet Morphology from Ceramic Impressions of the Butana Group
Current Anthropology  published by The University of Chicago Press and sponsored by the Wenner-Gren Foundation for Anthropological Research.

Rewriting Prehistory: Stone Age Child Reveals Modern Humans Emerged More Than 300,000 Years Ago

South Africa is well-known for its hominin fossil record. But this time, results from a study of ancient DNA presented in the September 28th First Release early online issue of Science show that the 2000-year-old remains of a boy found at Ballito Bay in KwaZulu-Natal during the 1960s, helped to rewrite human history.

Marlize Lombard, Professor of Stone Age archaeology at the University of Johannesburg, initiated collaboration with geneticists from Uppsala University in Sweden and the University of the Witwatersrand, who put together a team of experts at the Uppsala laboratory.

They reconstructed the full genome of the Ballito Bay child, together with the genomes of six other individuals from KwaZulu-Natal who lived between 2300 and 300 years ago.

This is Marlize Lombard (University of Johannesburg) excavating at Sibudu Cave (under the direction of Prof Lyn Wadley, University of the Witwatersrand), about 40 km southeast of Ballito Bay where the boy was found. The cave was intermittently occupied by humans from at least 77 000 years ago who might have been ancestral to the Ballito boy.
Photograph: Lyn Wadley, University of the Witwatersrand.

Three Stone Age individuals who lived between 2300 and 1800 years ago were found to be genetically related to the descendants of Khoe-San groups living in southern Africa today. The remains of the other four individuals who lived 500-300 years ago during the Iron Age, were genetically related to present-day South Africans of West African descent.

Because the boy from Ballito Bay was of hunter-gatherer descent, living at a time before migrants from further north in Africa reached South African shores, his DNA could be used to estimate the split between modern humans and earlier human groups as occurring between 350 000 and 260 000 years ago. "This means that modern humans emerged earlier than previously thought", says Mattias Jakobsson, population geneticist at Uppsala University, who headed the project together with Marlize Lombard from the University of Johannesburg.

This image shows the new demographic model of African population history and estimated divergences resulting from the ancient DNA study on hunter-gatherer remains from South Africa presented in the Sept. 28th (early online) issue of Science.

Credit: Uppsala University

The 350 000 to 260 000 years estimate also coincides with the Florisbad skull, who was a contemporary of the small-brained Homo naledi in South Africa. "It now seems that at least two or three Homo species occupied the southern African landscape during this time, which also represents the early phases of the Middle Stone Age", says Lombard.

Cumulatively, the fossil, ancient DNA and archaeological records indicate that the transition from archaic to modern humans might not have occurred in only one place in Africa. Instead, regions including southern and northern Africa (as recently reported) probably played a role. "Thus, both palaeo-anthropological and genetic evidence increasingly points to multiregional origins of anatomically modern humans in Africa, i.e. Homo sapiens did not originate in one place in Africa, but might have evolved from older forms in several places on the continent with gene flow between groups from different places", says Carina Schlebusch.

This is Dr. Helena Malmström (Uppsala University) sampling in South Africa for ancient human DNA.

Photograph: Mattias Jakobsson (Uppsala University)






Of the Iron Age individuals, three carry at least one Duffy null allele, protecting against malaria, and two have at least one sleeping-sickness-resistance variant in the APOL1 gene. The Stone Age individuals do not carry these protective alleles. "This tells us that Iron Age farmers carried these disease-resistance variants when they migrated to southern Africa", says co-first author Helena Malmström, archaeo-geneticist at Uppsala University.



"It is remarkable that we can now sequence entire genomes of ancient human remains from tropical areas, such as the southeast coast of South Africa", says Helena Malmström. This is promising for our several ongoing investigations in Africa.

Contacts and sources:
Prof Marlize Lombard, University of Johannesburg
Mattias Jakobsson Uppsala University


K2 Incoming: The Most Primitive Comet Ever Seen, Still 1.5 Billion Miles Away





Since we’re seeing it so far away, past the orbit of Saturn, K2 is still in its early phase of activity, likely making it the most primitive comet anyone has ever seen.

Video: NASA, STScI, and Goddard Space Flight Center/K. Jackson;
Music: “Space Cake” by Donn Wilerson [BMI] and Lance Sumner [BMI]; Killer Tracks BMI; Killer Tracks Production Music.


This illustration shows the orbit of comet C/2017 K2 PANSTARRS (K2) on its maiden voyage into the solar system. The Hubble Space Telescope observed K2 when it was 1.5 billion miles from the Sun, halfway between the orbits of Saturn and Uranus. The observations revealed a fuzzy cloud of dust, called a coma, surrounding the icy visitor, evidence that the frozen comet is being warmed by the Sun and releasing material. K2 is the farthest active inbound comet ever observed.

K2 has been traveling toward the Sun for millions of years from its home in the Oort Cloud, a spherical region at the edge of our solar system. The graphic shows the comet in its inbound journey, high above the plane of the major planets' orbits. The orbits of the giant planets, from Jupiter to Neptune, are also shown in the diagram. The farthest object from the Sun depicted here is the dwarf planet Pluto, which resides in the Kuiper Belt, a vast rim of primordial debris encircling our solar system.
Schematic of Comet C/2017 K2's Approach to the Solar System
Credits:  NASAESA, and D. Jewitt (UCLA)

Based on the Hubble observations of K2's coma, Jewitt suggests that sunlight is heating frozen volatile gases - such as oxygen, nitrogen, carbon dioxide, and carbon monoxide - that coat the comet's frigid surface. These icy volatiles lift off from the comet and release dust, forming the coma. Past studies of the composition of comets near the Sun have revealed the same mixture of volatile ices.











Contacts and sources:
Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore, Maryland

David Jewitt
University of California, Los Angeles, California

Wednesday, September 27, 2017

New Light on How Earth and Mars Were Created




Massive planetary bodies impacting at several kilometers per second generate substantial heat which, in turn, produces magma oceans and temporary atmospheres of vaporized rock.


Credit: Philip J. Carter










The main findings are three-fold:





Contacts and sources:
Shona East
\University of Bristol'


Researchers Develop Wearable Solar Thermoelectric Generator



Credit:  UNIST




Credit: UNIST






Credit: UNIST

Contacts and sources:
  JooHyeon Heo 
Ulsan National Institute of Science and Technology (UNIST)

Citation: Yeon Soo Jung et al., “Wearable solar thermoelectric generator driven by unprecedentedly high temperature difference.” Nano Energy, (2017).

This Material Obscures Supermassive Black Holes

Black holes appear to play a fundamental role in how galaxies evolve throughout their life during a phase in which they are active and consume material from the galaxy itself. During this phase, the galaxy hosts an active galactic nucleus (AGN), and the effect that this nuclear activity produces in the galaxy is known as AGN feedback. This feedback can take place in different forms: the AGN can heat, disrupt, consume and remove the gas available to form new stars, preventing further galaxy growth.

In fact, AGN feedback is now required by simulations of galaxy formation to explain the observations of massive galaxies at cosmological distances. "If AGN feedback is not accounted for in the simulations", explains Cristina Ramos, "the predicted number of massive galaxies when the universe was younger is much higher than those that are observed".

Galaxy NGC 1068 can be seen in close-up in this view from NASA's Hubble Space Telescope. This active black hole -shown as an illustration in the zoomed-in inset- is one of the most obscured known, as it is surrounded by extremely thick clouds of gas and dust that can be characterized using infrared and X-ray observations.
Click to enlarge image
Credit: NASA/JPL-Caltech.

Directly studying the influence of nuclear activity on galaxy evolution is challenging because of the different spatial scales and timescales involved in the two processes. Massive galaxies host extremely compact supermassive black holes of millions or even billions of solar masses in their nuclei. It is estimated that the phases of nuclear activity last for a short period of time, between one and a hundred million years, whereas galaxy evolution processes, such as bulge growth or bar formation last much longer. Thus, in order to study the connection between the AGN and the host galaxy, "we need," explains Claudio Ricci, "to look at the nucleus of galaxies, where the material that links them is found. This material consists mainly of gas and dust, which are normally studied in the infrared and X-ray band."

In this review, Cristina Ramos Almeida, researcher at the Instituto de Astrofísica de Canarias (IAC), and Claudio Ricci, astrophysicist at the Institute of Astronomy of the Universidad Católica de Chile, tried to give a comprehensive view of the current understanding, thanks to infrared and X-ray studies, of nuclear obscuration in AGN. This has greatly improved in the last decade thanks to observing facilities such as CanariCam on the Gran Telescopio CANARIAS (GTC), located at the Roque de los Muchachos Observatory (Garafía, La Palma) and the Very Large Array Interferometer (VLTI) in the infrared range, as well as X-ray satellites like NuSTAR, Swift/BAT and Suzaku.

"We now know", adds Cristina Ramos, "that this nuclear material is more complex and dynamic than we thought a few years ago: it is very compact, formed by gas and dusty clouds orbiting the black hole and its properties depend on the AGN luminosity and accretion rate. Moreover, it is not an isolated structure but appears connected with the galaxy via outflows and inflows of gas, like streams of material flowing as part of a cycle. This gas flow cycle keeps feeding the black hole and regulates the formation of new stars in the galaxy".

Very recently, the Atacama Large Millimeter/submillimeter Array (ALMA) has recently imaged for the first time the nuclear obscuring material in an active galaxy. ALMA operates in the millimiter and sub-millimeter range, and the latter traces the coolest dust and gas surrounding AGN. In the case of the galaxy NGC 1068, ALMA has shown that this material is distributed in a very compact disc-like shape of 7-10 parsecs (pc) diameter and, in addition to the regular rotation of the disk, there are non-circular motions that correspond to high-velocity gas outflowing from the galaxy nucleus. "Over the next decade, the new generation of infrared and X-ray facilities will contribute greatly to our understanding of the structure and physical properties of the nuclear material", concludes Claudio Ricci.

Contacts and sources:  
Elena Mora
Instituto de Astrofísica de Canarias (IAC)

Strange Blades of Ice the Size of Skyscrapers Found on Pluto







An example of the penitentes from the southern end of the Chajnantor plain in Chile. Though these ice formations only reach a few feet in height, while Pluto’s bladed terrain reaches hundreds of feet, they both have similar sharp ridges.'

Credits: Wikimedia Commons/ESO





The maps above are from New Horizons’ data on the topography (top) and composition (bottom) of Pluto’s surface. In the high-resolution topographical map, the highlighted red region is high in elevation. The map below, showing the composition, indicates the same section also contains methane, color-coded in orange. One can see the orange features spread into the fuzzier, lower-resolution data that covers the rest of the globe, meaning those areas, too, are high in methane, and therefore likely to be high in elevation.



Mapping Pluto’s Surface




Contacts and sources:
Author: Frank Tavares, NASA's Ames Research Center
 Darryl Waller, NASA's Ames Research Center

Graphene Pyramid Takes 2-D Material into 3-D



Graphene pyramid: A similar structure was made experimentally by using laser irradiation in a process called "optical forging."
Credit: Academy of Finland






Contacts and sources:
Suomen Akatemia (Academy of Finland)

Citation: Andreas Johansson, Pasi Myllyperkiö, Pekka Koskinen, Jukka Aumanen, Juha Tapio Koivistoinen, Hung-Chieh Tsai, Chia-Hao Chen, Lo-Yueh Chang, Vesa-Matti Hiltunen, Jyrki Manninen, Wei-Yen Woon, and Mika Pettersson, Optical Forging of Graphene into Three-Dimensional Shapes. Nano Lett., DOI: 10.1021/acs.nanolett.7b03530

Discovery May Revolutionize Dieting

Dieting could be revolutionized, thanks to the ground-breaking discovery by the University of Warwick of the key brain cells which control our appetite.




Tanycyte cells reacting to a puff of the amino acid arginine
Credit: Professor Nicholas Dale/Greta Lazutkaite

These amino acids are found in high concentration in foods such as pork shoulder, beef sirloin steak, chicken, mackerel, plums, apricots, avocadoes, lentils and almonds – so eating those foods will activate the tanycytesand make you feel less hungry quicker.








It is funded by the Biotechnology and Biological Sciences Research Council.

Contacts and sources:
Luke Walton
University of Warwick

Citation: ‘Amino Acid Sensing in Hypothalamic Tanycytes via Umami Taste Receptors’, will be published inMolecular Metabolism. Authors: Greta Lazutkaite, Alice Soldà, Kristina Lossow, Wolfgang Meyerhof, Nicholas Dale

Middle Age Fattens You Up If You Do Not Increase Your Physical Activity

The Faculty of Sport and Health Sciences at the University of Jyväskylä has examined how changes in the daily step count are related to changes in the body mass index (BMI).

During the four-year follow-up period, especially women increased their daily step count significantly. Approximately 25% of the research participants increased their step count with more than 2,000 steps, whereas approximately 19% decreased their step count during the follow-up.

The participants were grouped into increasers, decreasers and maintainers according to the total of their steps. The changes in the groups’ BMI were compared to the changes in their step count, and the comparison of the step counts was proportioned to the time the step counter had been kept on.

Image result for middle aged weight gain
Credit: Wikipedia

During the research period, there was growth in both the women’s and the men’s BMI. Almost half of the participants maintained the amount of their daily aerobic steps at the same level and approximately one-fourth increased their daily step count with over 1,000 steps during the research period.

The test participants whose total step count grew by more than 2,000 steps during the follow-up period, maintained their BMI at the same level throughout the years. In contrast, BMI increased for those whose step count stayed at the same level or decreased.

- The trend in physical activity looks good. International studies have shown that physical activity generally decreases along with age, but here it increased, Professor Mirja Hirvensalo states. Even though step counts in general look good, it should be noted that the amount of passive people who take less than 5,000 steps per day did not change significantly during the research period.

The researchers remind everyone about the significance of incidental activity.

- The steps accumulate on many instances during the day, if you give it a chance. One does not necessarily need to go for a walk every day to increase the daily step count. Instead, attention should be paid to choices in everyday life. Does every trip need to be made by car or could some of them be done by foot, or could the stairs be taken instead of the elevator, Postdoctoral Researcher Kasper Salin reminds us.

The Cardiovascular Risk in Young Finns Study has been monitoring over 3,000 Finns regularly from 1980 onwards. One part of the study considers physical activity, and during the last two measurings it was monitored with step counters. During the four-year follow-up period, the step count data and the required background variables were gathered from a total of 1,033 participants. During the follow-up period, the examinees were from 34 to 49 years of age. The recommended daily step count for adults is 10,000 steps.

The research was executed as a part of The Cardiovascular Risk in Young Finns Study led by professor Olli Raitakari. The study is funded by the Ministry of Education and Culture and the Finnish Cultural Foundation.

Contacts and sources:
University of Jyväskylä

Citation:  Salin, K., Hirvensalo, M., Magnussen, CG., Telama, R., Hutri-Kähönen, N., Viikari, J., Raitakari, O., & Tammelin, T. (2017). Changes in daily steps and body mass index and waist to height ratio during four year follow-up in adults: Cardiovascular Risk in Young Finns Study.

Oxygen-Deficient Dwarf Galaxy Hints at Makings of Early Universe




The faint Lynx constellation requires the eye of a lynx to see.
Credit: University of Virginia







Contacts and sources: 
Fariss Samarrai
University of Virginia 

Coconut-Cracking Giant Rat Discovered in Solomon Islands




This is an illustration of the new species, Uromys vika.

Credit: Velizar Simeonovski, The Field Museum




This is a skull of new species Uromys vika.
Courtesy of Tyrone Lavery, The Field Museum





Courtesy of Tyrone Lavery, The Field Museum.





Contacts and sources:
Kate Golembiewski
The Field Museum

The Strange Structures of the Saturn Nebula

The spectacular planetary nebula NGC 7009, or the Saturn Nebula, emerges from the darkness like a series of oddly-shaped bubbles, lit up in glorious pinks and blues. This colourful image was captured by the powerful MUSE instrument on ESO’s Very Large Telescope (VLT), as part of a study which mapped the dust inside a planetary nebula for the first time. The map — which reveals a wealth of intricate structures in the dust, including shells, a halo and a curious wave-like feature — will help astronomers understand how planetary nebulae develop their strange shapes and symmetries.

The Saturn Nebula is located approximately 5000 light years away in the constellation of Aquarius (The Water Bearer). Its name derives from its odd shape, which resembles everyone’s favourite ringed planet seen edge-on.

Annotated image showing features in the Saturn Nebula
Credit: ESO/J. Walsh

But in fact, planetary nebulae have nothing to do with planets. The Saturn Nebula was originally a low-mass star, which expanded into a red giant at the end of its life and began to shed its outer layers. This material was blown out by strong stellar winds and energized by ultraviolet radiation from the hot stellar core left behind, creating a circumstellar nebula of dust and brightly-colored hot gas. At the heart of the Saturn Nebula lies the doomed star, visible in this image, which is in the process of becoming a white dwarf [1].

Credit: ESO

In order to better understand how planetary nebulae are moulded into such odd shapes, an international team of astronomers led by Jeremy Walsh from ESO used the Multi Unit Spectroscopic Explorer (MUSE) to peer inside the dusty veils of the Saturn Nebula. MUSE is an instrument installed on one of the four Unit Telescopes of the Very Large Telescopeat ESO’s Paranal Observatory in Chile. It is so powerful because it doesn’t just create an image, but also gathers information about the spectrum — or range of colors — of the light from the object at each point in the image.

This view shows how the MUSE instrument on ESO’s Very Large Telescope gives a three-dimensional depiction of the Saturn Nebula. For each part of this spectacular nebula, the light has been split up into its component colours — revealing in detail the chemical and physical properties of each pixel.  During the subsequent analysis the astronomer can move through the data and study different views of the object at different wavelengths, just like tuning a television to different channels at different frequencies.
Three-dimensional MUSE view of the Saturn Nebula
Credit: ESO/J. Walsh

The team used MUSE to produce the first detailed optical maps of the gas and dust distributed throughout a planetary nebula [2]. The resulting image of the Saturn Nebula reveals many intricate structures, including an elliptical inner shell, an outer shell, and a halo. It also shows two previously imaged streams extending from either end of the nebula’s long axis, ending in bright ansae (Latin for “handles”).


Credit: ESO/J. Walsh/L.Calçada

Intriguingly, the team also found a wave-like feature in the dust, which is not yet fully understood. Dust is distributed throughout the nebula, but there is a significant drop in the amount of dust at the rim of the inner shell, where it seems that it is being destroyed. There are several potential mechanisms for this destruction. The inner shell is essentially an expanding shock wave, so it may be smashing into the dust grains and obliterating them, or producing an extra heating effect that evaporates the dust.

Mapping the gas and dust structures within planetary nebulae will aid in understanding their role in the lives and deaths of low mass stars, and it will also help astronomers understand how planetary nebulae acquire their strange and complex shapes.


Credit: ESO/Digitized Sky Survey 2/N. Risinger ( Music: Astral Electronic

But MUSE’s capabilities extend far beyond planetary nebulae. This sensitive instrument can also study the formation of stars and galaxies in the early Universe, as well as map the dark matter distribution in galaxy clusters in the nearby Universe. MUSE has also created the first 3D map of the Pillars of Creation in the Eagle Nebula (eso1518) and imaged a spectacular cosmic crash in a nearby galaxy (eso1437).

[1] Planetary nebulae are generally short-lived; the Saturn Nebula will last only a few tens of thousands of years before expanding and cooling to such an extent that it becomes invisible to us. The central star will then fade as it becomes a hot white dwarf.

[2] The NASA/ESA Hubble Space Telescope has previously provided a spectacular image of the Saturn Nebula — but, unlike MUSE, it cannot reveal the spectrum at each point over the whole nebula.

Contacts and sources:
Richard Hook