Wednesday, June 26, 2019

Raikoke Volcano on the Kuril Islands Eruption Seen from Space

Unlike some of its perpetually active neighbors on the Kamchatka Peninsula, Raikoke Volcano on the Kuril Islands rarely erupts. The small, oval-shaped island most recently exploded in 1924 and in 1778.

The dormant period ended around 4:00 a.m. local time on June 22, 2019, when a vast plume of ash and volcanic gases shot up from its 700-meter-wide crater. Several satellites—as well as astronauts on the International Space Station—observed as a thick plume rose and then streamed east as it was pulled into the circulation of a storm in the North Pacific.

Raikoke Erupts

On the morning of June 22, astronauts shot a photograph (above) of the volcanic plume rising in a narrow column and then spreading out in a part of the plume known as the umbrella region. That is the area where the density of the plume and the surrounding air equalize and the plume stops rising. The ring of clouds at the base of the column appears to be water vapor.

“What a spectacular image. It reminds me of the classic Sarychev Peak astronaut photograph of an eruption in the Kuriles from about ten years ago,” said Simon Carn, a volcanologist at Michigan Tech. “The ring of white puffy clouds at the base of the column might be a sign of ambient air being drawn into the column and the condensation of water vapor. Or it could be a rising plume from interaction between magma and seawater because Raikoke is a small island and flows likely entered the water.”

June 22, 2019JPEG

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired the second image on the morning of June 22. At the time, the most concentrated ash was on the western edge of the plume, above Raikoke. The third image, an oblique, composite view based on data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP, shows the plume a few hours later. After an initial surge of activity that included several distinct explosive pulses, activity subsided and strong winds spread the ash across the Pacific. By the next day, just a faint remnant of the ash remained visible to MODIS.

Since ash contains sharp fragments of rock and volcanic glass, it poses a serious hazard to aircraft. The Tokyo and Anchorage Volcanic Ash Advisory Centers have been tracking the plume closely and have issued several notes to aviators indicating that ash had reached an altitude of 13 kilometers (8 miles). Meanwhile, data from the CALIPSO satelliteindicate that parts of the plume may have reached 17 kilometers (10 miles).

In addition to tracking ash, satellite sensors can also track the movements of volcanic gases. In this case, Raikoke produced a concentrated plume of sulfur dioxide (SO2) that separated from the ash and swirled throughout the North Pacific as the plume interacted with the storm.

“Radiosonde data from the region indicate a tropopause altitude of about 11 kilometers, so altitudes of 13 to 17 kilometers suggest that the eruption cloud is mostly in the stratosphere,” said Carn. “The persistence of large SO2 amounts over the last two days also indicates stratospheric injection.”

June 22, 2019JPEG

Volcanologists watch closely for plumes that reach the stratosphere because they tend to stay aloft for longer than those that remain within the troposphere. That is why plumes that reaches the stratosphere typically have the greatest effects on aviation and climate.

NASA Earth Observatory images by Joshua Stevens, using MODIS and VIIRS data from NASA EOSDIS/LANCE and GIBS/Worldview and the Suomi National Polar-orbiting Partnership. Astronaut photograph ISS059-E-119250 was acquired on June 22, 2019, with a Nikon D5 digital camera and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 59 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. Story by Adam Voiland, with information from Erik Klemetti (Denison University), Simon Carn (Michigan Tech), and Andrew Prata (Barcelona Supercomputing Center).

Ancient Levän­luhta Jew­ellery Links Finland to a European Exchange Network

The Levänluhta water burial site, dating back to the Iron Age (300-800 CE), is one of Finland's most famous archaeological sites. Nearly one hundred individuals, mainly women or children, were buried in a lake located at Isokyrö in SW Finland, during the Iron Age. Some of the deceased were accompanied by arm rings and necklaces made out of copper alloy, bronze or brass.

Style of jewellery domestic but material from abroad

"The origin of the metals used in these pieces of jewellery was determined on the basis of the objects' geochemical and lead isotope compositions. The jewellery of the deceased is stylistically typical Finnish Iron Age jewellery, making it probable that they were cast in local workshops. However, the metals used to make these objects are unlikely to be originally from the region, since copper ores had not yet been discovered here during the Iron Age," says Elisabeth Holmqvist-Sipilä, a postdoctoral researcher.

Archaeological findings of Levänluhta in the Finnish National Museum's exhibition. In the front arm rings and necklaces found from the burial site, made out of copper alloy.

Credit: Elisabeth Holmqvist-Sipilä

Up to now, archaeologists have assumed that copper used in the Iron Age came mainly from the copper ores discovered in southern Scandinavia. However, this interpretation has in recent years been called into question, since the copper found in archaeological metal discoveries in Sweden has also been determined to be imported.

In a study conducted in collaboration between archaeologists at the University of Helsinki and the Geological Survey of Finland, the origin of the bronze and brass jewellery found at Levänluhta was investigated by comparing their geochemical composition and lead isotope ratios to known copper ores in Finland, Sweden and elsewhere in Europe. The study was published in the Journal of Archaeological Science: Reports.

Copper tracks lead to southern Europe

"The results demonstrate that the copper used in the objects was not from Finland or the nearby regions; rather, it has travelled to Finland along extensive exchange networks, most likely from southern Europe," says Holmqvist-Sipilä.

Based on the lead isotope ratios, the copper in the objects has its origins in the copper ores found in Greece and Bulgaria. These regions produced a large quantity of copper in the Bronze and Iron Age, which spread around Europe as various object forms, distributed as presents, loot and merchandise. Metals were also recycled by melting old objects into raw material for new casts. It may be possible that metals that ended up in Finland during the Bronze Age were recycled in the Levänluhta region.

The findings of this project, funded by the Emil Aaltonen Foundation, demonstrate that products of the copper exchange network of continental Europe also reached Finland across the Baltic Sea, thus making it possible to link the region with the extensive copper exchange system known to have extended throughout Europe. The results also illustrate the temporally and technologically multi-layered nature of prehistoric metal artefacts: raw materials found their way here through a number of hands, most likely over a long period of time and across very great distances. In domestic artisan workshops, these metals of international origin were manufactured into pieces of jewellery in domestic Iron Age fashion, perhaps embodying the local identity and place of residence of the bearer.

Contacts and sources:
Elisabeth Holmqvist-Sipilä, postdoctoral researcher, Helsinki Collegium for Advanced Studies
Anna Wessman, docent, Department of Cultures, leader of the Levänluhta project
University of Helsinki

Tuesday, June 25, 2019

Cyanide Compounds Discovered in Meteorites May Hold Clues to the Origin of Life

Cyanide and carbon monoxide are both deadly poisons to humans, but compounds containing iron, cyanide, and carbon monoxide discovered in carbon-rich meteorites by a team of scientists at Boise State University and NASA may have helped power life on early Earth. The extraterrestrial compounds found in meteorites resemble the active site of hydrogenases, which are enzymes that provide energy to bacteria and archaea by breaking down hydrogen gas (H2). Their results suggest that these compounds were also present on early Earth, before life began, during a period of time when Earth was constantly bombarded by meteorites and the atmosphere was likely more hydrogen-rich.

Artist’s concept of meteors impacting ancient Earth. Some scientists think such impacts may have delivered water and other molecules useful to emerging life on Earth.

Credits: NASA's Goddard Space Flight Center Conceptual Image Lab

“When most people think of cyanide, they think of spy movies – a guy swallowing a pill, foaming at the mouth and dying, but cyanide was probably an essential compound for building molecules necessary for life,” explained Dr. Karen Smith, senior research scientist at Boise State University, Boise, Idaho. Cyanide, a carbon atom bound to a nitrogen atom, is thought to be crucial for the origin of life, as it is involved in the non-biological synthesis of organic compounds like amino acids and nucleobases, which are the building blocks of proteins and nucleic acids used by all known forms of life.

Smith is lead author of a paper on this research published June 25 in Nature Communications. Smith, along with Boise State assistant professor Mike Callahan, a co-author on the paper, developed new analytical methods to extract and measure ancient traces of cyanide in meteorites. They found that the meteorites containing cyanide belong to a group of carbon-rich meteorites called CM chondrites. Other types of meteorites tested, including a Martian meteorite, contained no cyanide.

“Data collected by NASA’s OSIRIS-REx spacecraft of asteroid Bennu indicate that it is related to CM chondrites,” said co-author Jason Dworkin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “OSIRIS-REx will deliver a sample from Bennu to study on Earth in 2023. We will search for these very compounds to try to connect Bennu to known meteorites and to understand the potential delivery of prebiotic compounds such as cyanide, which may have helped start life on the early Earth or other bodies in the solar system.”

Cyanide has been found in meteorites before. However, in the new work, Smith and Callahan were surprised to discover that cyanide, along with carbon monoxide (CO), were binding with iron to form stable compounds in the meteorites. They identified two different iron cyano-carbonyl complexes in the meteorites using high-resolution liquid chromatography-mass spectrometry. “One of the most interesting observations from our study is that these iron cyano-carbonyl complexes resemble portions of the active sites of hydrogenases, which have a very distinct structure,” Callahan said.

Meteorites contain metal-organic compounds that resemble portions of enzymes found in bacteria and archaea. CN is cyanide, CO is carbon monoxide, Fe is iron, Ni is nickel.

Credits: Smith et al. Nature Communications, 2019

Hydrogenases are present in almost all modern bacteria and archaea and are widely believed to be ancient in origin. Hydrogenases are large proteins, but the active site – the region where chemical reactions take place – happens to be a much smaller metal-organic compound contained within the protein, according to Callahan. It is this compound that resembles the cyanide-bearing compounds the team discovered in meteorites.

An enduring mystery regarding the origin of life is how biology could have arisen from non-biological chemical processes. The similarities between the active sites in hydrogenase enzymes and the cyanide compounds the team found in meteorites suggests that non-biological processes in the parent asteroids of meteorites and on ancient Earth could have made molecules useful to emerging life.

“Cyanide and carbon monoxide attached to a metal are unusual and rare in enzymes. Hydrogenases are the exception. When you compare the structure of these iron cyano-carbonyl complexes in meteorites to these active sites in hydrogenases, it makes you wonder if there was a link between the two,” Smith added. “It’s possible that iron cyano-carbonyl complexes may have been a precursor to these active sites and later incorporated into proteins billions of years ago. These complexes probably acted as sources of cyanide on early Earth as well.”

The research was funded by the NASA Emerging Worlds Program, NASA Astrobiology Institute, and the NASA Earth and Space Science Fellowship. The team included Smith, Callahan, and colleagues at Penn State University, University of Maryland and the NASA Goddard Space Flight Center. NASA Goddard provides overall mission management, systems engineering and safety and mission assurance for OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer). Dante Lauretta is the mission's principal investigator at the University of Arizona. Lockheed Martin Space Systems in Denver is building the spacecraft. OSIRIS-REx is the third mission in NASA's New Frontiers Program. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages New Frontiers for the agency's Science Mission Directorate in Washington. NASA is exploring our Solar System and beyond, uncovering worlds, stars, and cosmic mysteries near and far with our powerful fleet of space and ground-based missions.

Contacts and sources:
Bill Steigerwald / Nancy Jones
NASA Goddard Space Flight Center, Greenbelt, Maryland

Cienna Madrid
Boise State University

Minute Lasting Gamma Ray Glows Coming from Thunderclouds, Linked to Lightning

University of Tokyo graduate student Yuuki Wada with colleagues from Japan discover a connection between lightning strikes and two kinds of gamma-ray phenomena in thunderclouds. The research suggests that in certain conditions, weak gamma-ray glows from thunderclouds may precede lightning bolts and their accompanying gamma-ray flashes.

A thundercloud can carry over 1 billion volts of electricity.

Credit: 2019 Yuuki Wada


In the city of Kanazawa, Ishikawa Prefecture, in central Japan, Wada and colleagues work with local schools and businesses to install radiation monitors onto buildings. These radiation monitors are not there due to some worry about local radiation levels, though. They form a network, the purpose of which is to detect radiation coming from the sky. It may surprise some, but it's been known for around 30 years that thunderstorms can bring with them gamma-ray activity.

"Forever, people have seen lightning and heard thunder. These were the ways we could experience this power of nature," said Wada. "With the discovery of electromagnetism, scientists learned to see lightning with radio receivers. But now we can observe lightning in gamma rays - ionizing radiation. It's like having four eyes to study the phenomena."

A thundercloud over the city of Kanazawa. The gamma-ray glow terminated abruptly around location B. The lightning struck between locations A and B.
Credit: 2019 Yuuki Wada

There are two known kinds of gamma-ray phenomena associated with thunderclouds: gamma-ray glows, weak emissions which last about a minute, and short-lived terrestrial gamma-ray flashes (TGFs), which occur as lightning strikes and are much more intense than gamma-ray glows. Both occur in regions of thunderclouds sandwiched between layers of varying charge. The charged regions accelerate electrons to near the speed of light. At these speeds, referred to as relativistic, electrons that stray very close to the nuclei of nitrogen atoms in the air slow down a little and emit a telltale gamma ray. This is called bremsstrahlung radiation.

"During a winter thunderstorm in Kanazawa, our monitors detected a simultaneous TGF and lightning strike. This is fairly common, but interestingly we also saw a gamma-ray glow in the same area at the same time," continued Wada. "Furthermore, the glow abruptly disappeared when the lightning struck. We can say conclusively the events are intimately connected and this is the first time this connection has been observed."

The mechanism underlying lightning discharge is highly sought after and this research may offer previously unknown insights. Wada and team intend to further their investigation to explore the possibility that gamma-ray glows don't just precede lightning strikes, but may in fact cause them. Radiation levels of the gamma-ray flashes are quite low, approximately a tenth the level one may receive from a typical medical X-ray.

"Our finding marks a milestone in lightning research and we will soon double our number of radiation sensors from 23 to about 40 or 50. With more sensors, we could greatly improve predictive models," explained Wada. "It's hard to say right now, but with sufficient sensor data, we may be able to predict lightning strikes within about 10 minutes of them happening and within around 2 kilometers of where they happen. I'm excited to be part of this ongoing research."

Further investigations will likely still take place in Kanazawa as the area has rare and ideal meteorological conditions for this kind of work. Most radiation observations in storms come from airborne or mountain-based stations as thunderclouds are generally very high up. But winter storms in Kanazawa bring thunderclouds surprisingly close to the ground, ideal for study with the low-cost portable monitors developed by the research team.

Gamma-ray glow preceding gamma-ray flash.

Credit:  2019 Yuuki Wada and Hayanon's Science Manga Studio

The researchers created these unique portable radiation monitors in part with technology derived from space-based satellite observatories designed for astrophysics experiments. This is appropriate as the data from this kind of research could be useful for those who research astrophysics and in particular solar physics in the context of particle acceleration. But there is a more down-to-earth offshoot as well.

"Paleontologists who study life from the last 50,000 years or so use a technique called carbon-14 dating to determine the age of a sample. The technique relies on knowledge of the levels of two kinds of carbon, carbon-12 and carbon-14," said Wada. "It's commonly thought carbon-14 is created by cosmic rays at a roughly constant rate, hence the predictive power of the technique. But there's a suggestion thunderstorms may alter the ratio of carbon-12 to carbon-14, which may slightly change the accuracy of or calibration required for carbon-14 dating to work."

Wada and colleagues will continue to unpick the mysteries of lightning, one of nature's most captivating and iconic phenomena. An upcoming collaborative project based in France will launch a dedicated satellite for worldwide lightning observations from space.

Contacts and sources:
Yuuki WadaUniversity of Tokyo

Citation: Gamma-ray glow preceding downward terrestrial gamma-ray flash Yuuki Wada, Teruaki Enoto, Yoshitaka Nakamura, Yoshihiro Furuta, Takayuki Yuasa, Kazuhiro Nakazawa, Takeshi Morimoto, Mitsuteru Sato, Takahiro Matsumoto, Daisuke Yonetoku, Tatsuya Sawano, Hideo Sakai, Masashi Kamogawa, Tomoo Ushio, Kazuo Makishima & Harufumi Tsuchiya Communications Physicsvolume 2, Article number: 67 (2019) 

'Flying Salt Shakers of Death:' Fungal-Infected Zombie Cicadas

Cicadas can carry a fungus similar to those found in hallucinogenic mushrooms, making them zombie-like fliers.

If cicadas made horror movies, they'd probably study the actions of their counterparts plagued by a certain psychedelic fungus.

West Virginia University researchers have discovered that a cicada fungus called Massopora contains chemicals similar to those found in hallucinogenic mushrooms.

The fungus causes cicadas to lose their limbs and eccentric behavior sets in: Males try to mate with everything they encounter, although the fungus has consumed their genitals and butts.

A cicada clings to a blade of grass.
Credit: Matt Kasson

Despite the horrid physical state of infected cicadas, they continue to roam around freely as if nothing's wrong, dousing other cicadas with a dose of their disease.

You've heard of "The Walking Dead." This is "The Flying Dead."

"They are only zombies in the sense that the fungus is in control of their bodies," said Matt Kasson, assistant professor of forest pathology and one of the study's authors.

Cicadas first encounter the fungus underground where they spend 13 to 17 years before emerging to the surface as adults, Kasson said. Within seven to 10 days above ground, the abdomen begins to slough off revealing the fungal infection at the end of the cicada, he continued.

It's quite the coming out party.

"Infected adults maintain or accelerate normal host activity during sporulation, enabling rapid and widespread dispersal prior to host death," Kasson said. "They also engage in hypersexual behaviors."

Joining Kasson on this research published in Fungal Ecology are his Davis College of Agriculture, Natural Resources and Design colleagues Greg Boyce, Kasson's former Ph.D. student in the Division of Plant and Soil Sciences; and Daniel Panaccione, professor of plant and soil sciences.

The impetus of the study came in 2016 when billions of cicadas ascended upon the northeast United States. Two of Kasson's students loved cicadas. One, Matt Berger, convinced the professor to study the fungus. Another student, Angie Macias, coined a creative, heavy metal sounding name for the cicadas: "flying salt shakers of death."

a bug sits in the green grass
Credit: Matt Kasson

Initially, the research team tried infecting the cicadas in a lab but that method did not work. But they managed to examine enough infected cicadas from the wild to make the new discovery.

For those of you wondering if you can get "high" from the psychedelic chemicals in a Massospora-infected cicada, Kasson's answer is "maybe, if you're motivated enough."

"Here is the thing," he said. "These psychoactive compounds were just two of less than 1,000 compounds found in these cicadas. Yes, they are notable but there are other compounds that might be harmful to humans. I wouldn't take that risk."

Kasson and his team are buzzing along on additional cicada research. They recently collected cicadas from this year's emergence in Pennsylvania and West Virginia. They plan to resequence the genome of the fungus and analyze the gene expression in both healthy and infected cicadas to better understand the genetic aspects of the discovery.

And beyond the discovery being downright creepy and fascinating, it may lead to someday benefiting the greater society instead of serving as nightmare fuel.

"We anticipate these discoveries will foster a renewed interest in early diverging fungi and their pharmacologically important secondary metabolites, which may serve as the next frontier for novel drug discovery.

"I love them (cicadas). They still scare me when they fall down my shirt or walk up my neck but I can appreciate something that spends almost two decades underground for six weeks of bliss, with or without the fungus."

Contacts and sources:
Jake StumpWest Virginia University

Citation: Psychoactive plant- and mushroom-associated alkaloids from two behavior modifying cicada pathogens!

Solving the Mystery of Nighttime Water Loss in Plantz

Plant scientists have been awarded funding to find out why wheat loses water during the night and develop new ways for growers to identify and develop plants that maintain yields under rising global temperatures.

During the day, plants lose water by evaporating it through their leaves via tiny pores known as stomata. Opening in response to sunlight, these stomata cool the leaf and allow CO2 to enter for photosynthesis. However, it has been discovered that stomata can remain open at night; facilitating water loss without any CO2 uptake for photosynthesis.

Discovering why this happens is vital as climate change and a growing global population is forcing farmers to grow crops with higher yields and less water. This new project - supported by £550k investment from the Newton fund and led by the University of Nottingham - will aim to solve this problem by discovery of wheat traits for increased water-use efficiency and high temperature tolerance.

Credit: University of Nottingham

Wheat is the most widely grown cereal crop in the world, with over 35% of humans reliant on it as a staple food source. An increasing population and pressures on land use mean there is a continual need to improve the 'genetic gain' of wheat to maintain and increase yields. These annual yield gains are increasingly threatened by the dual impact of rising atmospheric temperatures and lowered water availability caused by climate change. Vulnerable wheat producing regions, including Mexico, face lowered productivity and economic difficulties if wheat yields decline or fail as a result of adverse temperatures or water availability.

“It is known that wheat leaves can lose a substantial amount of water at night via transpiration, even under drought, and that there is genetic variation for this trait. During this project, we will apply methods for manipulating nocturnal temperatures of experimental crops in the field in the Sonoran region. Work done in this project will produce novel techniques for night time screening of promising wheat germplasm for night time transpiration under representative Sonoran field conditions and under high nocturnal temperatures.”says Professor Erik Murchie

Improving water use efficiency

The project team, which includes postdoctoral fellow Dr Lorna McAusland (UoN), collaborating wheat researchers in NW Mexico (Sonora Institute of Technology) and the Earlham Institute in Norwich (Professor Anthony Hall), will generate novel genetic and physiological information that is necessary to improve water use efficiency and heat tolerance of wheat in North-Western (NW) Mexico. High temperature and water availability have a clear negative relationship. Temperature is also a regulator of plant and crop processes, being central to the regulation of development and growth. High temperatures can be a major source of stress, affecting many of the plants processes including; photosynthesis, respiration, photorespiration and the generation of damaging active oxygen.

Prof Murchie continues: “Water is important for wheat yields in Mexico, with up to 84% of wheat requiring irrigation. There is also strong evidence that the mean daytime temperatures in NW Mexico are rapidly rising. However, it is also becoming clear that the minimum (night time) temperatures are contributing to yield decline in cereals. Despite this, most work has focussed on the effect of day time temperatures while very little is known about nocturnal traits and their genetic regulation. Here we focus on the puzzle of night time water loss and its relationship with increasing night time temperatures. This project will be of immediate benefit to growers in this region and will be a substantial contribution to 'climate-proof' agriculture and the local economy.”

Contacts and sources:
Jane Icke
University of Nottingham

Electric Buckyballs Discovered in Space

Scientists using NASA's Hubble Space Telescope have confirmed the presence of electrically-charged molecules in space shaped like soccer balls, shedding light on the mysterious contents of the interstellar medium (ISM) - the gas and dust that fills interstellar space.

Since stars and planets form from collapsing clouds of gas and dust in space, "The diffuse ISM can be considered as the starting point for the chemical processes that ultimately give rise to planets and life," said Martin Cordiner of the Catholic University of America, Washington. "So fully identifying its contents provides information on the ingredients available to create stars and planets." Cordiner, who is stationed at NASA's Goddard Space Flight Center in Greenbelt, Maryland, is lead author of a paper on this research published April 22nd in the Astrophysical Journal Letters.

The molecules identified by Cordiner and his team are a form of carbon called "Buckminsterfullerene," also known as "Buckyballs," which consists of 60 carbon atoms (C60) arranged in a hollow sphere. C60 has been found in some rare cases on Earth in rocks and minerals, and can also turn up in high-temperature combustion soot.

This is an artist's concept depicting the presence of buckyballs in space. Buckyballs, which consist of 60 carbon atoms arranged like soccer balls, have been detected in space before by scientists using NASA's Spitzer Space Telescope. The new result is the first time an electrically charged (ionized) version has been found in the interstellar medium.

Credit: NASA/JPL-Caltech

C60 has been seen in space before. However, this is the first time an electrically charged (ionized) version has been confirmed to be present in the diffuse ISM. The C60 gets ionized when ultraviolet light from stars tears off an electron from the molecule, giving the C60 a positive charge (C60+). "The diffuse ISM was historically considered too harsh and tenuous an environment for appreciable abundances of large molecules to occur," said Cordiner. "Prior to the detection of C60, the largest known molecules in space were only 12 atoms in size. Our confirmation of C60+ shows just how complex astrochemistry can get, even in the lowest density, most strongly ultraviolet-irradiated environments in the Galaxy."

Life as we know it is based on carbon-bearing molecules, and this discovery shows complex carbon molecules can form and survive in the harsh environment of interstellar space. "In some ways, life can be thought of as the ultimate in chemical complexity," said Cordiner. "The presence of C60 unequivocally demonstrates a high level of chemical complexity intrinsic to space environments, and points toward a strong likelihood for other extremely complex, carbon-bearing molecules arising spontaneously in space."

Most of the ISM is hydrogen and helium, but it's spiked with many compounds that haven't been identified. Since interstellar space is so remote, scientists study how it affects the light from distant stars to identify its contents. As starlight passes through space, elements and compounds in the ISM absorb and block certain colors (wavelengths) of the light. When scientists analyze starlight by separating it into its component colors (spectrum), the colors that have been absorbed appear dim or are absent. Each element or compound has a unique absorption pattern that acts as a fingerprint allowing it to be identified. However, some absorption patterns from the ISM cover a broader range of colors, which appear different from any known atom or molecule on Earth. These absorption patterns are called Diffuse Interstellar Bands (DIBs). Their identity has remained a mystery ever since they were discovered by Mary Lea Heger, who published observations of the first two DIBs in 1922.

A DIB can be assigned by finding a precise match with the absorption fingerprint of a substance in the laboratory. However, there are millions of different molecular structures to try, so it would take many lifetimes to test them all.

"Today, more than 400 DIBs are known, but (apart from the few newly attributed to C60+), none has been conclusively identified," said Cordiner. "Together, the appearance of the DIBs indicate the presence of a large amount of carbon-rich molecules in space, some of which may eventually participate in the chemistry that gives rise to life. However, the composition and characteristics of this material will remain unknown until the remaining DIBs are assigned."

Decades of laboratory studies have failed to find a precise match with any DIBs until the work on C60+. In the new work, the team was able to match the absorption pattern seen from C60+ in the laboratory to that from Hubble observations of the ISM, confirming the recently claimed assignment by a team from University of Basel, Switzerland, whose laboratory studies provided the required C60+ comparison data. The big problem for detecting C60+ using conventional, ground-based telescopes, is that atmospheric water vapor blocks the view of the C60+ absorption pattern. However, orbiting above most of the atmosphere in space, the Hubble telescope has a clear, unobstructed view. Nevertheless, they still had to push Hubble far beyond its usual sensitivity limits to stand a chance of detecting the faint fingerprints of C60+.

The observed stars were all blue supergiants, located in the plane of our Galaxy, the Milky Way. The Milky Way's interstellar material is primarily located in a relatively flat disk, so lines of sight to stars in the Galactic plane traverse the greatest quantities of interstellar matter, and therefore show the strongest absorption features due to interstellar molecules.

The detection of C60+ in the diffuse ISM supports the team's expectations that very large, carbon-bearing molecules are likely candidates to explain many of the remaining, unidentified DIBs. This suggests that future laboratory efforts measure the absorption patterns of compounds related to C60+, to help identify some of the remaining DIBs.

The team is seeking to detect C60+ in more environments to see just how widespread buckyballs are in the Universe. According to Cordiner, based on their observations so far, it seems that C60+ is very widespread in the Galaxy.

This work was funded by NASA under a grant from the Space Telescope Science Institute. The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. NASA is exploring our Solar System and beyond, uncovering worlds, stars, and cosmic mysteries near and far with our powerful fleet of space and ground-based missions.

Contacts and sources:
Claire Andreoli NASA's Goddard Space Flight Center

Citation: Confirming Interstellar C60 + Using the Hubble Space Telescope M. A. Cordiner, H. Linnartz, N. L. J. Cox, J. Cami, F. Najarro, C. R. Proffitt, R. Lallement, P. Ehrenfreund, B. H. Foing, T. R. Gull1, P. J. Sarre, and S. B. Charnley The American Astronomical Society. All rights reserved. The Astrophysical Journal Letters, Volume 875, Number 2

Santorini Volcano Has Analog on Mars

One of the great attractions of the island of Santorini, in Greece, lies in its spectacular volcanic landscape, which also contains places similar to those of Mars. A team of European and U.S. scientists has discovered it after analyzing basaltic rocks collected in one of its coves.

The Greek island of Santorini is now one of the most popular tourist destinations in the Mediterranean, but 3,600 years ago it suffered one of the largest volcanic eruptions recorded in history. Among the material that has been exposed, scientists have now found rocks similar to those of Mars.

On the island of Santorini, basaltic rocks similar to those located by the Curiosity rover in the crater Gale de Marte have been found.

Credit: NASA/JPL-Caltech/MSSS

"In the Balos Cove -located to the south of the island - we have discovered basalts such as those that have been identified by the rovers on Mars and with properties similar to those of certain meteorites from the red planet and those of terrestrial rocks classified as Martian analogues," points out Ioannis Baziotis, a researcher at the Agricultural University of Athens and co-author of the study, recently published in Icarus journal.

More specifically, the authors have confirmed that this basaltic material is equivalent to that located by the Spirit and Curiosity rovers in the Gusev and Gale craters of the red planet, and that its chemical and mineralogical composition resembles that of genuinely Martian meteorites (olivine-phyric shergottites) and similar Martian samples included in The International Space Analogue Rockstore (ISAR), a collection of terrestrial rocks used to test and calibrate instruments that will fly on space missions.

"The basalts of this cove and other, similar ones that we have also found in two areas northeast of Santorini are quite abundant," explains Baziotis, "so they can serve as an accessible and low-cost resource for experiments, instead of using the rare and expensive olivine-phyric shergottites collected on Earth or material laboriously prepared from synthetic mixes".

"Optical microscopy and geochemical analyses show that the basalts of Balos Cove are viable analogues for characterizing geological processes and chemical and mineralogical properties of materials present on the Martian surface," says another author, Anezina Solomonidou, a researcher at the European Space Astronomy Centre (ESAC) run by the European Space Agency (ESA) near Madrid.

"In addition -she adds-, this area of the island is easily accessible and offers excellent logistics for sampling, testing and calibration instruments, field training and other activities related to current and future Mars exploration."

Along with its tourist relevance, Santorini has thus become an excellent destination for comparative planet studies, a field which, according to Solomonidou, "plays an important role both in characterising geologically distant exotic worlds, such as planets and moons, and in better understanding our own planet."

Beside researchers from Agricultural University of Athens and ESA, this study has involved scientists from NASA, California Institute of Technology (Caltech) and various Greek institutions, in addition to the collaboration of the Spanish geologist Jesús Martínez Frías to improve the scientific content of the paper.

Contacts and sources:
Enrique Sacristán
FECYT - Spanish Foundation for Science And Technology

Citation:  "Santorini volcano as a potential Martian analogue: The Balos Cove Basalts". A. Pantazidis, I. Baziotis, A. Solomonidou, E. Manoutsoglou, D. Palles, E. Kamitsos, A. Karageorgis, G. Profitiliotis, M. Kondoyanni, S. Klemme, J. Berndt, D. Ming, P. D. Asimow.Icarus 325: 128-140, June 2019.

Coffee Fights Fat, Stimulates "Brown Fat"

A new study finds that drinking a cup of coffee could have a direct effect on the body's brown fat functions

Scientists from the University of Nottingham have discovered that drinking a cup of coffee can stimulate ‘brown fat’, the body’s own fat-fighting defenses, which could be the key to tackling obesity and diabetes.
Credit: University of Nottingham

The pioneering study, published today in the journal Scientific Reports, is one of the first to be carried out in humans to find components which could have a direct effect on ‘brown fat’ functions, an important part of the human body which plays a key role in how quickly we can burn calories as energy.

Brown adipose tissue (BAT), also known as brown fat, is one of two types of fat found in humans and other mammals. Initially only attributed to babies and hibernating mammals, it was discovered in recent years that adults can have brown fat too. Its main function is to generate body heat by burning calories (opposed to white fat, which is a result of storing excess calories).

People with a lower body mass index (BMI) therefore have a higher amount of brown fat.

Professor Michael Symonds, from the School of Medicine at the University of Nottingham who co-directed the study said: “Brown fat works in a different way to other fat in your body and produces heat by burning sugar and fat, often in response to cold. Increasing its activity improves blood sugar control as well as improving blood lipid levels and the extra calories burnt help with weight loss. However, until now, no one has found an acceptable way to stimulate its activity in humans.

This is the first study in humans to show that something like a cup of coffee can have a direct effect on our brown fat functions. The potential implications of our results are pretty big, as obesity is a major health concern for society and we also have a growing diabetes epidemic and brown fat could potentially be part of the solution in tackling them.”Professor Michael Symonds

The team started with a series of stem cell studies to see if caffeine would stimulate brown fat. Once they had found the right dose, they then moved on to humans to see if the results were similar.

The team used a thermal imaging technique, which they’d previously pioneered, to trace the body’s brown fat reserves. The non-invasive technique helps the team to locate brown fat and assess its capacity to produce heat.

“From our previous work, we knew that brown fat is mainly located in the neck region, so we were able to image someone straight after they had a drink to see if the brown fat got hotter,” said Professor Symonds.

“The results were positive and we now need to ascertain that caffeine as one of the ingredients in the coffee is acting as the stimulus or if there’s another component helping with the activation of brown fat. We are currently looking at caffeine supplements to test whether the effect is similar. Once we have confirmed which component is responsible for this, it could potentially be used as part of a weight management regime or as part of glucose regulation programme to help prevent diabetes.”

A full copy of the report can be found here.

Contacts and sources:
Professor Michael Symonds
Charlotte Anscombe
University of Nottingham

Commonly Prescribed Drug Likely Increases of Dementia

The study, carried out by experts from the University of Nottingham and funded by the NIHR School for Primary Care Research, found that there was nearly a 50% increased risk of dementia among patients aged 55 and over who had used strong anticholinergic medication daily for three years or more.

Anticholinergic drugs help to contract and relax muscles. They work by blocking acetylcholine, a chemical that transmits messages in the nervous system.

Credit: University of Nottingham

Doctors prescribe the drugs to treat a variety of conditions, including chronic obstructive pulmonary disease, bladder conditions, allergies, gastrointestinal disorders and symptoms of Parkinson's disease.

These medicines can have short-term side effects, including confusion and memory loss, but it is less certain whether long-term use increases the risk of dementia.

The research, published in the JAMA Internal Medicine journal and led by Professor Carol Coupland from the University's Division of Primary Care, looked at the medical records of 58,769 patients with a diagnosis of dementia and 225,574 patients without a diagnosis of dementia, all aged 55 and over and registered with UK GPs contributing data to the QResearch database, between 1 January 2004 and 31 January 2016.

The study findings showed increased risks of dementia for anticholinergic drugs overall and specifically for the anticholinergic antidepressants, antipsychotic drugs, antiparkinsons drugs, bladder drugs and epilepsy drugs after accounting for other risk factors for dementia.

No increased risks were found for the other types of anticholinergic drug studied such as antihistamines and gastrointestinal drugs.

Professor Tom Dening, Head of the Centre for Dementia at the University of Nottingham and a member of the research study team, said: "This study provides further evidence that doctors should be careful when prescribing certain drugs that have anticholinergic properties. However, it's important that patients taking medications of this kind don't just stop them abruptly as this may be much more harmful. If patients have concerns, then they should discuss them with their doctor to consider the pros and cons of the treatment they are receiving."

The 58,769 patients with dementia had an average age of 82 and 63% were women. Each dementia case was matched to five control patients of the same age, sex, and general practice.

Anticholinergic drug exposure was assessed using prescription information over a complete period of 10 years from 1 to 11 years before diagnosis of dementia or the equivalent dates in control patients, and was compared between the two patient groups. Further analysis looked at prescriptions for anticholinergic drugs up to 20 years before diagnosis of dementia.

This is an observational study so no firm conclusions can be drawn about whether these anticholinergic drugs cause dementia, and it is possible that the drugs were being prescribed for very early symptoms of dementia.

Professor Coupland said: "Our study adds further evidence of the potential risks associated with strong anticholinergic drugs, particularly antidepressants, bladder antimuscarinic drugs, anti-Parkinson drugs and epilepsy drugs.

"The risks of this type of medication should be carefully considered by healthcare professionals alongside the benefits when the drugs are prescribed and alternative treatments should be considered where possible, such as other types of antidepressants or alternative types of treatment for bladder conditions. These findings also highlight the importance of carrying out regular medication reviews.

"We found a greater risk for people diagnosed with dementia before the age of 80 which indicates that anticholinergic drugs should be prescribed with caution in middle-aged people as well as in older people."

These results, along with those of a similar study published in 2018 help to clarify which types of anticholinergic drug are associated with the highest risks of dementia.

In the 1-11 years before the dementia diagnosis date or equivalent in controls, nearly 57% of cases and 51% of controls were prescribed at least one strong anticholinergic drug, with an average of six prescriptions in cases and 4 in controls. The most frequently-prescribed types of drugs were antidepressants, anti-vertigo and bladder antimuscarinic drugs - which are used to treat an overactive bladder.

The increased risk associated with these drugs indicates that if the association is causal around 10% of dementia diagnoses could be attributable to anticholinergic drug exposure, which would equate to around 20,000 of the 209,600 new cases of dementia per year in the UK.

This is a sizeable proportion and is comparable with other modifiable risk factors for dementia, including 5% for midlife hypertension, 3% for diabetes, 14% for later life smoking and 6.5% for physical inactivity.

Contacts and sources:
Charlotte AnscombeUniversity of Nottingham


Stellar Heavyweight Champion of Dying Stars

Dying stars that cast off their outer envelopes to form the beautiful yet enigmatic "planetary nebulae" (PNe) have a new heavy-weight champion, the innocuously named PNe "BMP1613-5406". Massive stars live fast and die young, exploding as powerful supernovae after only a few million years. 

However, the vast majority of stars, including our own Sun, have much lower mass and may live for many billions of years before going through a short lived but glorious PNe phase. PNe form when only a tiny fraction of unburnt hydrogen remains in the stellar core. Radiation pressure expels much of this material and the hot stellar core can shine through. This ionizes the previously ejected shroud creating a PNe and providing a visible and valuable fossil record of the stellar mass loss process (PNe have nothing to do with planets but acquired this name because their glowing spheres of ionized gas around their hot central stars resembled planets to early observers).

This is a 30 x 30 arcminute image of NGC6067 & BMP1613-5406. North-East is top left. The image is a B,R,H-alpha tri-colour RGB image (extracted from the online UK Schmidt Telescope SuperCOSMOS H-alpha Survey H-alpha, short-Red (SR) and broad-band 'B' images.
Credit: @The University of Hong Kong

PNe theoretically derive from stars in the range 1-8 times the mass of the Sun, representing 90% of all stars more massive than the sun. However, until now, PNe have been proven to derive from stars born with only 1-3 times the mass of our Sun. Professor Quentin Parker, Department of Physics and Director of The Laboratory for Space Research, The University of Hong Kong and his PhD student Miss Fragkou Vasiliki, in collaboration with University of Manchester and South African Astronomical Observatory, have now officially smashed this previous limit and grabbed the proof that a PNe has emerged from a star born with 5.5 times the mass of our Sun. Their journal paper "A high-mass planetary nebula in a Galactic open cluster" has just been published on the Nature Astronomy's website.

But why is this important?

Firstly, PNe provide a unique window into the soul of late stage stellar evolution revealed by their rich emission line spectra that are excellent laboratories for plasma physics. PNe are visible to great distances where their strong lines permit determination of the size, expansion velocity and age of the PN, so probing the physics and timescales of stellar mass loss. They can also be used to derive luminosity, temperature and mass of their central remnant stellar cores, and the chemical composition of the ejected gas.

Secondly, and key here, is that this is an unprecedented example of a star whose proven original "progenitor" mass is close to the theoretical lower limit of core-collapse supernova formation. Our results are the first solid evidence confirming theoretical predictions that 5+ solar mass stars can actually form PNe. This unique case therefore provides the astronomical community with an important tool for fresh insights into stellar and Galactic chemical evolution.

A VPHAS+ combined u g r multi-band 'RGB' color image centred on the planetary nebula central star (CS) candidate. The image is 55 x 55 arcseconds in size and the CS is obvious as the sole blue star in the middle of field, located at RA:16h13m02.1s and DEC:-54o06'32.3" (J2000).
Credit: @The University of Hong Kong

But how did the team from The University of Hong Kong and the University of Manchester claim the heavyweight crown?

The key was the discovery of the PNe in a young, Galactic open cluster called NGC6067. Finding a PNe residing in an open cluster is an extremely rare event. Indeed, only one other PNe, "PHR1615-6555" has ever been previously proven to reside on an open cluster but whose progenitor star had considerably lower mass. Interestingly, this was an earlier discovery from the same led team as here. The proven location of a PN in a cluster provides key and important data that is difficult to acquire otherwise. This includes an accurate distance and a cluster "turn off" mass estimate (i.e. the mass a star must have had when it was born to now be seen evolving off the main sequence in the cluster of known age). High confidence in the PN-cluster association comes from their highly consistent radial velocities (to better tan 1km/s) in a sight-line with a steep velocity-distance gradient, common distances, common reddening and projected and close physical proximity of the PN to the cluster centre.

A current plot from cluster WDs for the latest IFMR estimates from Cummings et al (2018), together with our estimated point for BMP1613-5406 plotted as a red circle. The only other point from a known OC PN is plotted as a yellow circle (Parker et al 2011). The errors attached to our point reflect the errors in the adopted cluster parameters and the spread of the estimated CS magnitudes.
Credit: @The University of Hong Kong

In summary our exciting results are solid evidence confirming theoretical predictions that 5+ solar mass stars can form planetary nebulae and are, as expected, Nitrogen rich. The PN's cluster membership provides fresh and tight constraints on the lower mass limit for the progenitor mass of core-collapse supernovae and also for the intermediate to high mass end of the white dwarf Initial to Final Mass Relation (IFMR). It also provides an empirical benchmark for evaluating nucleosynthetic (element creation) predictions for intermediate-mass stars. PN BMPJ1613-5406 and its cluster NGC6067 will provide the astronomical community with important insights into stellar and Galactic (chemical) evolution.

Contacts and sources:
Cindy ChanThe University of Hong Kong

Citation: A high-mass planetary nebula in a Galactic open cluster V. Fragkou, Q. A. Parker, A. A. Zijlstra, L. Crause & H. Barker Nature Astronomy (2019)

How Trees Affect the Weather and Intensify Droughts

Nature, said Ralph Waldo Emerson, is no spendthrift. Unfortunately, he was wrong.

New research led by University of Utah biologists William Anderegg, Anna Trugman and David Bowling find that some plants and trees are prolific spendthrifts in drought conditions--"spending" precious soil water to cool themselves and, in the process, making droughts more intense. The findings are published in Proceedings of the National Academy of Sciences.

"We show that the actual physiology of the plants matters," Anderegg says. "How trees take up, transport and evaporate water can influence societally important extreme events, like severe droughts, that can affect people and cities."

Credit: Sémhur / Wikimedia Commons

Functional traits

Anderegg studies how tree traits affect how well forests can handle hot and dry conditions. Some plants and trees, he's found, possess an internal plumbing system that slows down the movement of water, helping the plants to minimize water loss when it's hot and dry. But other plants have a system more suited for transporting large quantities of water vapor into the air--larger openings on leaves, more capacity to move water within the organism. Anderegg's past work has looked at how those traits determine how well trees and forests can weather droughts. But this study asks a different question: How do those traits affect the drought itself?

"We've known for a long time that plants can affect the atmosphere and can affect weather," Anderegg says. Plants and forests draw water out of the soil and exhale it into the atmosphere, affecting the balance of water and heat at our planet's surface, which fundamentally controls the weather. In some cases, like in the Amazon rainforest, all of that water vapor can jumpstart precipitation. Even deforestation can affect downwind weather by leaving regions drier than before.

Anderegg and his colleagues used information from 40 sites around the world, in sites ranging from Canada to Australia. At each site, instruments collected data on the flows of heat, water and carbon in and out of the air, as well as what tree species were prevalent around the instrumentation. Comparing that data with a database of tree traits allowed the researchers to draw conclusions about what traits were correlated with more droughts becoming more intense.

Two traits stuck out: maximum leaf gas exchange rate and water transport. The first trait is the rate at which leaves can pump water vapor into the air. The second describes how much water the tree can move to the leaves. The results showed that in cool regions, plants and trees slowed down their water use in response to declining soil moisture. But in hot climates, some plants and trees with high water transport and leaf gas exchange rates cranked up the AC, so to speak, when the soil got dry, losing more and more water in an effort to carry out photosynthesis and stay cool while depleting the soil moisture that was left.

"You end up getting to these conditions that are hotter and drier much faster with those plants than with other plants," Anderegg says.

More drought to come

It's true that hot and dry regions tend to have more plants and trees that are adapted to dry conditions. But regardless of the climate some species with water-intensive traits, such as oaks in a Mediterranean climate, can still exacerbate a drought.

Anderegg says that understanding the relationship between a tree's traits and drought conditions helps climate scientists and local leaders to plan for future drought effects on communities.

"Failing to account for this key physiology of plants would give us less accurate predictions for what climate change is going to mean for drought in a lot of regions," he says.

Drought is always on Anderegg's mind, even during the recent wet spring. "Just because we're having a good water year in the U.S. and in Utah this year doesn't get us off the hook," he says. "We need to remember that we're going to see a lot more droughts in the future."

Contacts and sources:
Paul Gabrielsen
University of Utah

Monday, June 24, 2019

'Bathtub Rings' around Titan's Lakes May Be Alien Crystals

The frigid lakeshores of Saturn’s moon Titan might be encrusted with strange, unearthly minerals, according to new research being presented here.

Scientists re-creating Titan-esque conditions in their laboratory have discovered new compounds and minerals not found on Earth, including a co-crystal made of solid acetylene and butane.

A false-color, near infrared view of Titan’s northern hemisphere collected by NASA’s Cassini spacecraft showing the moon’s seas and lakes. Orange areas near some of them may be deposits of organic evaporite minerals left behind by receding liquid hydrocarbon.

Credit: NASA / JPL-Caltech / Space Science Institute

Acetylene and butane exist on Earth as gases and are commonly used for welding and camp stove fuel. On Titan, with its extremely cold temperatures, acetylene and butane are solid and combine to form crystals, the new research found.

The new mineral might be responsible for the bathtub rings that are suspected to exist around Titan’s hydrocarbon lakes, according to Morgan Cable of NASA’s Jet Propulsion Laboratory at the California Institute of Technology, who will present the new researchMonday at the 2019 Astrobiology Science Conference.

Titan’s lakes are filled with liquid hydrocarbons. Previous research using images and data gathered during the Cassini mission has shown that lakes in the moon’s dry regions near the equator contain signs of evaporated material left behind, like rings on a bathtub.

To create Titan-like conditions in the laboratory, the researchers started with a custom-built cryostat, an apparatus to keep things cold. They filled the cryostat with liquid nitrogen to bring the temperature down. They then warmed the chamber slightly, so the nitrogen turned to gas, which is mostly what Titan’s atmosphere contains. Next, they threw in what abounds on Titan, methane and ethane, as well as other carbon-containing molecules, and looked for what formed.

The first things to drop out of their Titan hydrocarbon soup were benzene crystals. Benzene is perhaps best known as a component of gasoline and is a snowflake-shaped molecule made out of a hexagonal ring of carbon atoms. But Titan benzene held a surprise: The molecules rearranged themselves and allowed ethane molecules inside, creating a co-crystal.

The researchers then discovered the acetylene and butane co-crystal, which is probably a lot more common on Titan than benzene crystals, based on what’s known about the moon’s composition, Cable said.

In the moon’s cold climate, the acetylene-butane co-crystals might form rings around the moon’s lakes as the liquid hydrocarbons evaporate and the minerals drop out – in the same way that salts can form crusts on the shores of Earth’s lakes and seas, according to Cable.

To confirm whether Titan has bathtub rings of co-crystals and other, undiscovered, hydrocarbon crystals, scientists will have to wait until a spacecraft can visit the shorelines of this moon, Cable said.

“We don’t know yet if we have these bathtub rings,” Cable said. “It’s hard to see through Titan’s hazy atmosphere.”

Contacts and sources:
Liza LesterAmerican Geophysical Union

Poster: “The acetylene-butane co-crystal: A potentially abundant molecular mineral on Titan “

Big Data Says Food Is Too Sweet

Text-mining analysis of Amazon customer reviews suggests foods are over-sweetened.
New research from the Monell Center analyzed nearly 400,000 food reviews posted by Amazon customers to gain real-world insight into the food choices that people make. The findings reveal that many people find the foods in today’s marketplace to be too sweet.

File:20150303-RD-LSC-0259 (16849295900).jpg
Credit: Lance Cheung / Wikimedia Commons

“This is the first study of this scale to study food choice beyond the artificial constraints of the laboratory,” said study lead author Danielle Reed, PhD, a behavioral geneticist at Monell. “Sweet was the most frequently mentioned taste quality and the reviewers definitively told us that human food is over-sweetened.”

The study used data posted on an open-source data science site to examine 393,568 unique food reviews of 67,553 products posted by 256,043 Amazon customers over a 10-year period. Using a sophisticated statistical modeling program to identify words related to taste, texture, odor, spiciness, cost, health, and customer service, the scientists computed the number of reviews that mentioned each of these categories.

“Reading and synthesizing almost 400,000 reviews would essentially be impossible for a human team, but recent developments in machine learning gave us the ability to understand both which words are present and also their underlying semantic meaning,” said study coauthor Joel Mainland, PhD, an olfactory neurobiologist at Monell.

The focus on product over-sweetness was striking, as almost one percent of product reviews, regardless of food type, used the phrase “too sweet.” When looking at reviews that referred to sweet taste, the researchers found that over-sweetness was mentioned 25 times more than under-sweetness.

The findings, published online in advance of print in Physiology & Behavior, indicated that over 30 percent of the Amazon food product reviews mentioned “taste,” making it the most frequently-used word.

Drilling down, the scientists found that sweet taste was mentioned in 11 percent of product reviews, almost three times more often than bitter. Saltiness was rarely mentioned, a somewhat surprising finding in light of public health concerns about excess salt consumption.

Seeking to better understand individual differences in how people respond to a given food, the scientists also looked at responses to the 10 products that received the widest range of ratings, as defined by the variability in the number of stars the product received. They identified two factors that tended to account for polarizing reviews related to a product: product reformulation and differing perspectives on the product’s taste. With regard to taste, people often rated the sweetness of a product differently. Response to a product’s smell also contributed to differences in opinion about a particular product.

“Genetic differences in taste or olfactory receptor sensitivity may help account for the extreme reactions that some products get,” said Reed. “Looking at the responses to polarizing foods could be a way to increase understanding of the biology of personal differences in food choice.”

Together, the findings illustrate the potential uses of big-data approaches and consumer reviews to advance sensory nutrition, an emerging field that integrates knowledge from sensory science with nutrition and dietetics to improve health. Moving forward, similar methods may inform approaches to personalized nutrition that can match a person’s sensory responses to inform healthier food choices.

Also contributing to the research, which was funded by institutional funds from the Monell Center, was Charles Arayata of Monell.

Contacts and sources:
Danielle Reed, PhD,  Joel Mainland, PhD
Monell Chemical Senses Center

Citation: “Sensory nutrition: The role of taste in the reviews of commercial food products,” by D.R. Reed, J.D. Mainland, and C.J. Arayata. Physiology & Behavior, in press. DOI: 10.1016/j.physbeh.2019.112579

Mood Neurons Mature During Adolescence, May Play Role in Emotional Development, Mood Disorders

Immature amygdala neurons (green and red) in a 13-year-old brain. As the brain's mood circuits mature during adolescence, most of these cells would be replaced by mature neurons (blue).
Immature amygdala neurons
 Image credit: Alvarez-Buylla lab / UCSF

Researchers have discovered that a mysterious group of neurons in the amygdala – a key center for emotional processing in the brain – remain in an immature, prenatal developmental state throughout childhood. Most of these cells mature rapidly during adolescence, suggesting a key role in the brain’s emotional development, but some stay immature throughout life, suggesting new ideas about how the brain keeps its emotional responses flexible throughout life.

Shawn Sorrells, PhD. 
Photo courtesy of Shawn Sorrells

“Most brain cells have matured far beyond this stage by the time you are born,” said study lead author Shawn Sorrells, PhD, a former UCSF researcher who is now assistant professor of neuroscience at the University of Pittsburgh. “It’s fascinating that these are some of the very last cells to mature in the human brain, and most do so during puberty, precisely when huge developments in emotional intelligence are going on.”

The amygdala is an almond-shaped brain structure located deep in the brain’s temporal lobes (you actually have two, one on each side of the brain) that plays a key role in learning appropriate emotional responses to our environment. During childhood and adolescence – long after most of the rest of the human brain is finished growing – the amygdala continues to expand by as many as two million neurons, a late growth spurt that researchers believe is likely to play a key role in human emotional development, and which may go awry in neurodevelopmental disorders. For example, this expansion is absent in children with autism, and mood disorders that frequently emerge in adolescence, such as depression, anxiety, bipolar disorder, and post-traumatic stress disorder (PTSD), have also been linked to problems with amygdala development.

Recent studies had detected a unique group of immature neurons in a region of the amygdala called the paralaminar nuclei (PL), which could help explain the amygdala’s rapid growth, but researchers had little idea where these cells came from or what role they play in mature brain circuits – even whether they are excitatory or inhibitory, the two main functional classes of neurons.

Arturo Alvarez-Buylla, PhD.
 Photo by Cindy Chew

In the new study, published June 21, 2019, in Nature Communications, researchers from the lab of Arturo Alvarez-Buylla, PhD, the Heather and Melanie Muss Endowed Chair and Professor of Neurological Surgery and a member of the Eli and Edyth Broad Center of Regeneration Medicine and Stem Cell Research at UCSF, set out to understand the identity of these cells and their role in the amygdala’s rapid growth during childhood.

The researchers examined postmortem human amygdala tissue from 49 human brains – ranging in age from 20 gestational weeks to 78 years of age. Using both anatomical and molecular techniques to classify individual neurons’ maturity and function within neural circuits, they found that the percentage of immature cells in the PL region of the amygdala remains high throughout childhood, but declines rapidly during adolescence: from birth to age 13, the number of immature cells declines from approximately 90 percent to just under 70 percent, but by the end of adolescence, only about 20 percent of PL cells remain immature.

Based on quantification of neurons in different stages of development coupled with analysis of gene expression patterns in individual neurons extracted from PL, the researchers showed that as the immature cells disappear, they are replaced by mature excitatory neurons – suggesting that the cells have taken their place in the amygdala’s maturing emotion processing circuitry. Since this is the first time these neurons have been clearly studied, scientists don’t know exactly what function the neurons serve, but the timing of their maturation suggests they may play a role in the rapid emotional development that occurs during human adolescence.

Researchers found that the percentage of immature cells in a region of the amygdala remains high throughout childhood, but declines rapidly during adolescence. Immature (green and blue) and mature (red) amygdala neurons in a 13-year-old brain. 
Image credit: Alvarez Buylla lab / UCSF

“Anyone who’s met a teenager knows that they are going through a rapid and sometimes tumultuous process of emotional learning about how to respond to stress, how to form positive social bonds, and so on,” Sorrells said. “At the same time, adolescence is when many psychiatric disorders known to involve the amygdala first manifest, suggesting that perhaps something has gone wrong with the normal process of emotional and cognitive development – though whether these cells are involved is a matter for future study."

Notably, the researchers also found that some immature neurons appear to remain in the amygdala throughout life, and were even found in one 77-year-old brain. These results were in stark contrast to the hippocampus – a nearby structure in which the authors recently found that newborn and immature neurons decline to undetectable levels by adolescence.

“This is consistent with what we have seen before: that immature neurons are vanishingly rare in the adult hippocampus, but they do appear to persist in the amygdala,” Alvarez-Buylla said. “As far as we can tell, these cells aren’t being born throughout life, but seem to be maintained in an immature state from birth, though we can’t say this for sure given the techniques we’ve used here.”

In other animals, such as mice, new neurons continue to be born throughout life in the memory-forming hippocampus – and possibly at low rates in the amygdala – which researchers believe allows the brain to continuously rewire neural circuits to adapt to new experiences and environments. Following on the authors’ 2018 study showing that the birth of new neurons declines in the human brain during childhood and is very rare or absent in adults, the new study suggests that the human brain may maintain reserves of immature neurons throughout life, using these “Peter Pan” cells in a similar manner to the neurogenesis seen in other species – as new cells to be called on as needed to keep the brain’s emotional responses flexible and adaptable into old age.

“You could imagine these immature cells let the brain continue to sculpt the structure of neural circuits and their growth once you are out in the world experiencing what it’s like,” Sorrells said. “Of course, that’s just speculation at this point – one of the fascinating questions these findings open up for future study.”

Neurogenesis Debate: New or Long-Lived Immature Neurons?

Whether new neurons are born in the adult primate or human brain remains controversial. In 2018, Alvarez-Buylla, Sorrells and colleagues published results of the most rigorous search yet for new neurons in the human hippocampus, and they found that the birth of new neurons declined rapidly in childhood and was undetectable in adults.

Subsequently, other groups published data that appears to show newborn neurons in the adult human hippocampus, but Alvarez-Buylla and colleagues believe these studies rely too strongly on a small number of molecular markers for newborn neurons. They have shown that these markers can also be found in fully mature neurons and in non-neuronal cells called glia – which are known to continue dividing throughout life.

“Identifying new neurons is technically very challenging,” Alvarez-Buylla said. “It’s easy to forget that the molecular markers we use to identify particular molecules are not produced for our benefit – cells are using these molecules for their own biological needs, which are always going to be messy from the perspective of someone looking for simple classification. This is why we have endeavored to examine as many lines of evidence as possible – not just molecular markers but also cells’ shape and appearance – to make sure we are confident in what types of cells we are actually looking at in these analyses.”

The new study in the amygdala uses comprehensive single-cell gene expression techniques to sensitively detect immature neurons based on multiple lines of molecular evidence, and reinforces the group’s earlier findings in the hippocampus – showing that the precursors that divide to give birth to new neurons disappear within the first two years of life in the human amygdala, and that most immature neurons disappear during adolescence.

“Single-cell sequencing not only clearly identifies these long-lived immature neurons, but also shows that they express many developmental genes involved in axon development, synaptogenesis, dendrite morphogenesis, and even neuronal migration,” Sorrells said. “These cells could be erroneously assumed to be newborn neurons, but based on our developmental perspective, and the fact that we see few dividing cells present nearby, it looks as though they are already present at birth and decline throughout life.”

Authors: Additional authors on the paper were Mercedes F. Paredes, Dmitry Velmeshev, Kadellyn Sandoval, Simone Mayer, Edward F. Chang, Arnold R. Kriegstein, John R. Rubenstein, Eric J. Huang of UCSF; Jose Manuel Garcia-Verdugo of the University of Valencia, Spain; Vicente Herranz-Pérez of the University of Valencia and Universitat Jaume I, Spain; and Ricardo Insausti of the University of Castilla-La Mancha, Spain.

Funding: The researchers were supported by the US National Institutes of Health (NIH) (P01 NS083513, R01 NS028478, F32 MH103003, K08 NS091537), the German Research Foundation (DFG, MA 7374/1-1), and a gift from the John G. Bowes Research Fund.

Disclosures: Alvarez Buylla and co-authors Kriegstein and Rubenstain are co-founders and serve on the scientific advisory board of Neurona Therapeutics.

Contacts and sources:Nicholas Weller
University of California - San Francisco

Citation: Immature excitatory neurons develop during adolescence in the human amygdala.
Shawn F. Sorrells, Mercedes F. Paredes, Dmitry Velmeshev, Vicente Herranz-Pérez, Kadellyn Sandoval, Simone Mayer, Edward F. Chang, Ricardo Insausti, Arnold R. Kriegstein, John L. Rubenstein, Jose Manuel Garcia-Verdugo, Eric J. Huang, Arturo Alvarez-Buylla. Nature Communications, 2019; 10 (1) DOI: 10.1038/s41467-019-10765-1

Awe Filled State of Mind Can Set You Free

An induced feeling of awe, or state of wonder, may be the best strategy yet for alleviating the discomfort that comes from uncertain waiting. Research shows a sense of wonderment can alleviate the worry of waiting for uncertain news.
Credit: Blackpack_rider / Wikimedia Commons

Kate Sweeny’s research explores the most excruciating form of waiting: the period during which one awaits uncertain news, the outcome of which is beyond one’s control. It’s waiting for news from a biopsy, or whether you aced — or tanked — the exam. That’s distinguished from waiting periods such as when looking for a new job, when you have at least some control over the outcome.

Kate Sweeny  previously demonstrated that meditation and "flow" activities relieve stress.
Credit: University of California - Riverside

Her research has found some clues for alleviating those difficult periods. Meditation helps, as does engaging in “flow” activities — those that require complete focus, such as a video game.

“However, meditation is not for everyone, and it can be difficult to achieve a state of flow when worry is raging out of control,” Sweeny and her team assert in their latest related research, published recently in The Journal of Positive Psychology.

Sweeny, a professor of psychology at UC Riverside, has discovered what may be the best strategy yet to alleviate the most uncomfortable purgatory of waiting. That is, awe, defined in the research as a state of wonder, a transportive mindset brought on by beautiful music, or a deeply affecting film.

The research drew from two studies, for a total of 729 participants. In the first test, participants took a faux intelligence assessment. In the second test, participants believed they were awaiting feedback on how other study participants perceived them.

In both cases, they watched one of three movies that inspired varying levels of awe. The first was an “awe induction” video, a high-definition video of a sunrise with instrumental music. The second was a positive control video meant to elicit happy feelings, but not awe. The video was of cute animal couples. The third was a neutral video. In this case, about how padlocks are made.

Researchers found that those exposed to the awe-induction video experienced significantly greater positive emotion and less anxiety during the period waiting for IQ test results and peer assessments.

“Our research shows that watching even a short video that makes you feel awe can make waiting easier, boosting positive emotions that can counteract stress in those moments,” Sweeny said.

Sweeny said the research can be used to devise strategies for maximizing positive emotion and minimizing anxiety during the most taxing periods of waiting. Because the concept of awe has only received recent attention in psychology, the research also is the first to stress its beneficial effects during stressful waiting periods, opening new opportunities for study.

“Now that we know we can make people feel better through brief awe experiences while they’re waiting in the lab, we can take this knowledge out into the real world to see if people feel less stressed when they watch “Planet Earth” or go to an observatory, for example, while they’re suffering through a difficult waiting period,” Sweeny said.

Aside from Sweeny, other authors in the study, “Awe-full uncertainty: Easing discomfort during waiting periods,” include UCR doctoral candidate Kyla Rankin and former UCR graduate student Sara E. Andrews.

Contacts and sources:
J.D. Warren
University of California - Riverside

Citation: Awe-full uncertainty: Easing discomfort during waiting periods.
Kyla Rankin, Sara E. Andrews, Kate Sweeny. The Journal of Positive Psychology, 2019; 1 DOI: 10.1080/17439760.2019.1615106

Screams Are Personal: a 'Calling Card' for the Vocalizer's Identity

Screams are very personal. 

Human screams convey a level of individual identity that may help explain their evolutionary origins, finds a study by scientists at Emory University.

"Our findings add to our understanding of how screams are evolutionarily important," says Emory psychologist Harold Gouzoules, senior author of the paper. 
Credit: Emory University

PeerJ published the research, showing that listeners can correctly identify whether pairs of screams were produced by the same person or two different people — a critical prerequisite to individual recognition.

“Our findings add to our understanding of how screams are evolutionarily important,” says Harold Gouzoules, senior author of the paper and an Emory professor of psychology. “The ability to identify who is screaming is likely an adaptive mechanism. The idea is that you wouldn’t respond equally to just anyone’s scream. You would likely respond more urgently to a scream from your child, or from someone else important to you.”

Jonathan Engelberg is first author of the paper and Jay Schwartz is a co-author. They are both Emory PhD candidates in Gouzoules’ Bioacoustics Lab.

The ability to recognize individuals by distinctive cues or signals is essential to the organization of social behavior, the authors note, and humans are adept at making identity-related judgements based on speech — even when the speech is heavily altered. Less is known, however, about identity cues in nonlinguistic vocalizations, such as screams.

Gouzoules first began researching monkey screams in 1980, before becoming one of the few scientists studying human screams about 10 years ago.

“The origin of screams was likely to startle a predator and make it jump, perhaps allowing the prey a small chance to escape,” Gouzoules says. “That’s very different from calling out for help.”

He theorizes that as some species became more social, including monkeys and other primates, screams became a way to recruit help from relatives and friends when someone got into trouble.

Previous research by Gouzoules and others suggests that non-human primates are able to identify whether a scream is coming from an individual that is important to them. Some researchers, however, have disputed the evidence, arguing that the chaotic and inconsistent nature of screams does not make them likely conduits for individual recognition.

Gouzoules wanted to test whether humans could determine if two fairly similar screams were made by the same person or a different person. His Bioacoustics Lab has amassed an impressive library of high-intensity, visceral sounds — from TV and movie performances to the screams of non-actors reacting to actual events on YouTube videos.

For the PeerJ paper, the lab ran experiments that included 104 participants. The participants listened to audio files of pairs of screams on a computer, without any visual cues for context. Each pair was presented two seconds apart and participants were asked to determine if the screams came from the same person or a different person.

In some trials, the two screams came from two different callers, but were matched by age, gender and the context of the scream. In other trials, the screams came from the same caller but were two different screams matched for context. And in a third trial, the stimulus pairs consisted of a scream and a slightly modified version of itself, to make it longer or shorter than the original.

For all three of the experiments, most of the participants were able to correctly judge most of the time whether the screams were from the same person or not.

“Our results provide empirical evidence that screams carry enough information for listeners to discriminate between different callers,” Gouzoules says. “Although screams may not be acoustically ideal for signaling a caller’s identity, natural selection appears to have adequately shaped them so they are good enough to do the job.”

The PeerJ paper is part of an extensive program of research into screams by Gouzoules. In previous work, his lab has found that listeners cannot distinguish acted screams from naturally occurring screams.

In upcoming papers, he is zeroing in on how people determine whether they are hearing a scream or some other vocalization and how they perceive the emotional context of a scream — judging whether it’s due to happiness, anger, fear or pain.

Contacts and sources:
Carol Clark
Emory Health Sciences

Citation: Do human screams permit individual recognition?
Jonathan W. M. Engelberg, Jay W. Schwartz, Harold Gouzoules. PeerJ, 2019; 7: e7087 DOI: 10.7717/peerj.7087