Saturday, October 19, 2019

Stormy Cluster Weather Could Unleash Black Hole Power and Explain Lack of Cosmic Cooling



“Weather” in clusters of galaxies may explain a longstanding puzzle, according to a team of researchers at the University of Cambridge. The scientists used sophisticated simulations to show how powerful jets from supermassive black holes are disrupted by the motion of hot gas and galaxies, preventing gas from cooling, which could otherwise form stars. The team publish their work in the journal Monthly Notices of the Royal Astronomical Society.

Typical clusters of galaxies have several thousand member galaxies, which can be very different to our own Milky Way and vary in size and shape. These systems are embedded in very hot gas known as the intracluster medium (ICM), all of which live in an unseen halo of so-called ‘dark matter’.

An artist’s impression of the jet launched by a supermassive black hole, which inflates lobes of very hot gas that are distorted by the cluster weather. 
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Credit Institute of Astronomy, University of Cambridge

A large number of galaxies have supermassive black holes in their centres, and these often have high speed jets of material stretching over thousands of light years that can inflate very hot lobes in the ICM.

The researchers, based at the Kavli Institute for Cosmology and the Institute of Astronomy, performed state-of-the-art simulations looking at the jet lobes in fine detail and the X-rays emitted as a result. The model captures the birth and cosmological evolution of the galaxy cluster, and allowed the scientists to investigate with unprecedented realism how the jets and lobes they inflate interact with a dynamic ICM.

They found that the mock X-ray observations of the simulated cluster revealed the so-called “X-ray cavities” and “X-ray bright rims” generated by supermassive black hole-driven jets, which itself is distorted by motions in the cluster, remarkably resemble those found in observations of real galaxy clusters.

The left hand panel shows an actual observation of the galaxy cluster MS 0735.6+7421, while on the right the background Hubble image has instead been overlaid with a mock observation of the jet (pink) and X-ray emission (blue) made from the simulation. Both images show cavities excavated by the lobe inflation surround by X-ray bright rims of dense gas (blue), which are filled by distorted jet material (pink).


Credit: NASA, ESA, CXC, STScI, and B. McNamara (University of Waterloo); Very Large Array Telescope Image: NRAO, and L. Birzan and team (Ohio University); Simulated Data: M. A. Bourne (University of Cambridge)


Dr Martin Bourne of the Institute of Astronomy in Cambridge led the team. He commented: “We have developed new computational techniques, which harness the latest high-performance computing technology, to model for the first time the jet lobes with more than a million elements in fully realistic clusters. This allows us to place the physical processes that drive the liberation of the jet energy under the microscope.”

As galaxies move around in the cluster, the simulation shows they create a kind of ‘weather’, moving, deforming and destroying the hot lobes of gas found at the end of the black hole jets. The jet lobes are enormously powerful and if disrupted, deliver vast amounts of energy to the ICM.

The Cambridge team believe that this cluster weather disruption mechanism may solve an enduring problem: understanding why ICM gas does not cool and form stars in the cluster centre. This so-called “cooling flow” puzzle has plagued astrophysicists for more than 25 years.

The simulations performed provide a tantalising new solution that could solve this problem. Dr Bourne commented: “The combination of the huge energies pumped into the jet lobes by the supermassive black hole and the ability of cluster weather to disrupt the lobes and redistribute this energy to the ICM provides a simple and yet elegant mechanism to solve the cooling flow problem.”

A series of next generation X-ray space telescopes will launch into orbit over the next decade. These advanced instruments should help settle the debate – and if intergalactic weather really does stop the birth of stars.


Contacts and sources:
Dr Robert Massey
Royal Astronomical Society

Dr Martin Bourne
Institute of Astronomy
Cambridge








Mars Once Had Salt Lakes Similar To Earth



Mars once had salt lakes that are similar to those on Earth and has gone through wet and dry periods, according to an international team of scientists that includes a Texas A&M University College of Geosciences researcher.

Marion Nachon, a postdoctoral research associate in the Department of Geology and Geophysics at Texas A&M, and colleagues have had their work published in the current issue of Nature Geoscience.

The team examined Mars’ geological terrains from Gale Crater, an immense 95-mile-wide rocky basin that is being explored with the NASA Curiosity rover since 2012 as part of the MSL (Mars Science Laboratory) mission.

A color image from NASA’s Curiosity rover’s Mast Camera shows part of the wall of Gale Crater, the location on Mars where the rover landed August 5, 2012 on Mars.
Mars Gale Crater
Credit: NASA

The results show that the lake that was present in Gale Crater over 3 billion years ago underwent a drying episode, potentially linked to the global drying of Mars.

Gale Crater formed about 3.6 billion years ago when a meteor hit Mars and created its large impact crater.

“Since then, its geological terrains have recorded the history of Mars, and studies have shown Gale Crater reveals signs that liquid water was present over its history, which is a key ingredient of microbial life as we know it,” Nachon said. “During these drying periods, salt ponds eventually formed. It is difficult to say exactly how large these ponds were, but the lake in Gale Crater was present for long periods of time – from at least hundreds of years to perhaps tens of thousands of years,” Nachon said.

So what happened to these salt lakes?

Nachon said that Mars probably became dryer over time, and the planet lost its planetary magnetic field, which left the atmosphere exposed to be stripped by solar wind and radiation over millions of years.

“With an atmosphere becoming thinner, the pressure at the surface became lesser, and the conditions for liquid water to be stable at the surface were not fulfilled anymore,” Nachon said. “So liquid water became unsustainable and evaporated.”

The salt ponds on Mars are believed to be similar to some found on Earth, especially those in a region called Altiplano, which is near the Bolivia-Peru border.

Nachon said the Altiplano is an arid, high-altitude plateau where rivers and streams from mountain ranges “do not flow to the sea but lead to closed basins, similar to what used to happen at Gale Crater on Mars,” she said. “This hydrology creates lakes with water levels heavily influenced by climate. During the arid periods Altiplano lakes become shallow due to evaporation, and some even dry up entirely. The fact that the Atliplano is mostly vegetation free makes the region look even more like Mars,” she said.”

Nachon added that the study shows that the ancient lake in Gale Crater underwent at least one episode of drying before “recovering.” It’s also possible that the lake was segmented into separate ponds, where some of the ponds could have undergone more evaporation.

Because up to now only one location along the rover’s path shows such a drying history, Nachon said it might give clues about how many drying episodes the lake underwent before Mars’s climate became as dry as it is currently.

“It could indicate that Mars’s climate ‘dried out’ over the long term, on a way that still allowed for the cyclical presence of a lake,” Nachon said. “These results indicate a past Mars climate that fluctuated between wetter and drier periods. They also tell us about the types of chemical elements (in this case sulphur, a key ingredient for life) that were available in the liquid water present at the surface at the time, and about the type of environmental fluctuations Mars life would have had to cope with, if it ever existed.”



Contacts and sources:
Keith RandallTexas A&M University

Citation:






What Happens under the Yellowstone Volcano



Yellowstone National Park in the US is a major attraction for tourists with its geysers and hot springs. Especially in times of low news, however, the media focus is often on the super volcano Yellowstone, which erupted for the last time around 630,000 years ago.

 At the latest then the question of the underlying geological structures is asked. A recent study by Bernhard Steinberger from the German GeoForschungsZentrum and colleagues in the USA helps to better understand the processes in the Earth's interior. The work will soon be published in the journal "Geochemistry, Geophysics, Geosystems" of the American Geophysical Union. It is based on the modeling of the mantle.

The model results show a high similarity with interpretations from seismic waves. The circles mark remnants of the ancient Yellowstone crater (Calderen), suggesting that the continental crust has moved westward. The "Mantel Plume" under the Hot Spot is tilted and has its origin under the Baja California 
Credit; CC BY 3.0: Bernhard Steinberger).


Thus, there is a so-called mantle Plume under the Yellowstone volcano: a structure similar to a chimney, which stretches thousands of miles deep to the border of the earth's core and mantle. The origin of the plume lies under the "Baja California", more than a thousand kilometers southwest of the national park. Evaluations of earthquake waves had already suggested such a thing, but the idea of ​​such a "mantle plume" did not match the movement of the lithospheric plates.

The model results show high similarity with interpretations from seismic waves. The mantle plume below the hot spot is tilted with its origin below Baja California. (CCBY 3.0: Steinberger/GFZ)
Credit: Steinberger et al.

It is clear that Yellowstone is a so-called intraplate volcano. Most volcanoes in the world are at the boundaries of continental plates, either where material is swelling up from the Earth's interior, as in the Mid-Atlantic Ridge, or where one continental plate dips and melts beneath the other, as it does along the entire South American west coast is. In contrast to plate-edge volcanism, intraplate volcanism goes back to "hotspots" beneath the earth's crust. This can be imagined as a welding torch, which melts the rock plate from below - where a hole is blown, a volcano grows. That's how Hawaii, for example, came into being.

However, the seismic data for Yellowstone did not provide a clear picture for a long time. This has been changed by new data and refined measurement methods, which allowed the deeper part of the plume to be imaged in a tomographic image. However, there were gaps in the upper mantle. The data was not so clear here. The study from the GFZ now fills these gaps with a modeling result that depicts the cloak Plume consistently with the observation data. 

Accordingly, there are movements of the viscoplastic rock in the lower mantle, which move relative to the surface to the south-southwest. Like the plume of a steamer, the plume drifts from the Baja California to the north-northeast to the Yellowstone volcano. Bernhard Steinberger: "Our study contributes to a better understanding of intraplate volcanism and supports the hypothesis of a deep mantle plume. But for the risk assessment of the Yellowstone volcano this has no effect. "

Original study: B. Steinberger PL Nelson, SP Grand, W. Wang, 2019: "Yellowstone plume conduit tilt caused by large-scale mantle flow". Geochemistry, Geophysics, Geosystems; DOI: 10.1029 / 2019GC008490 (accepted and reviewed version, in print) http://dx.doi.org/10.1029/2019GC008490







Contacts and sources:
Josef ZensJosef ZensHelmholtz Center Potsdam German Research Center for Geosciences GFZ

Dr. Bernhard Steinberger
Section Geodynamic Modeling
Helmholtz Center Potsdam German Research Center for Geosciences GFZ









Lifestyle Is a Threat to Gut Bacteria: Ötzi Proves It

A joint study by UniTrento and Eurac Research in Bolzano/Bozen that was published in Cell Host & Microbe explored for the first time the variation and evolution of Prevotella copri, a common human gut microbe.

Ötzi, the Iceman
Credit:  ©South Tyrol Museum of Archaeology_Eurac Research - Marion Lafogler

The intestinal microbiome is a delicate ecosystem made up of billions and billions of microorganisms, bacteria in particular, that support our immune system, protect us from viruses and pathogens, and help us absorb nutrients and produce energy.

The industrialization process in Western countries had a huge impact on its content.

This was confirmed by a study on the bacteria found in the intestine of Ötzi, the Iceman who, in 1991, emerged from the ice of the Ötztal Alps, where Italy borders with Austria.


File:Ötzi Museum Bozen - panoramio.jpg
Credit: Andre, Schade / Wikimedia Commons

Scientists of Eurac Research examined samples of the mummy's bacteria, confirming the findings of the researchers of the University of Trento who had analyzed the genome of intestinal microorganisms of over 6500 individuals from all continents.

Previous studies by the University of Trento had demonstrated that there is a connection between the microbiome's bacterial content and the increase, in Western countries, of obesity, autoimmune and gastrointestinal diseases, allergies and other complex conditions.

In the study that appeared today in Cell Host & Microbe, researchers from Cibio of the University of Trento and Eurac in Bolzano/Bozen demonstrated that the differences between Western and non-Western or prehistoric microbiome lie in the decrease of some types of bacteria that process complex and vegetal fibers in the intestine.

That may have been caused by the Westernization process. Changes in diet, which is now higher in fat and low in fibers, a sedentary lifestyle in an urban setting, the development of new hygiene habits and the widespread use of antibiotics and other medical products have, with no doubt, made our life safer, but impacted the delicate balance of our microbiome.

About the study
The scientists of Eurac Research in Bolzano/Bozen sequenced the Iceman's DNA and were able to identify his set of bacteria, while the researchers of the University of Trento compared it with the microbiome of contemporary non-Westernized populations (from Tanzania and Ghana in particular), which are not used to processed food and have non-Westernized hygiene practices and lifestyle. Their findings were surprising.
The study focused, in particular, on Prevotella copri, a microbe that, when is found in our intestine, is usually the most represented. Prevotella copri is present in 30% of Western individuals.

The study is the result of close collaboration with the research group of Albert Zink and Frank Maixner at Eurac Research in Bolzano/Bozen. Their team was responsible for the collection and pre-analysis of the Iceman's DNA samples.


Contacts and sources:
Università di Trento
Citation: The Prevotella copri complex comprises four distinct clades underrepresented in Westernised populations, Adrian Tett, Kun D. Huang, Francesco Asnicar, Hannah Fehlner-Peach, Edoardo Pasolli, Nicolai Karcher, Federica Armanini, Paolo Manghi, Kevin Bonham, Moreno Zolfo, Francesca De Filippis, Cara Magnabosco, Richard Bonneau, John Lusingu, John Amuasi, Karl Reinhard, Thomas Rattei, Fredrik Boulund, Lars Engstrand, Albert Zink, Maria Carmen Collado, Dan R. Littman, Daniel Eibach, Danilo Ercolini, Omar Rota-Stabelli, Curtis Huttenhower, Frank Maixner, Nicola Segata. Cell Host & Microbe, 2019; DOI: 10.1016/j.chom.2019.08.018






Friday, October 18, 2019

Stranded Whales Detected from Space


A new technique for analyzing satellite images may help scientists detect and count stranded whales from space. Researchers tested a new detection method using Very High Resolution (VHR) satellite images from Maxar Technologies of the biggest mass stranding of baleen whales yet recorded. It is hoped that in the future the technique will lead to real-time information as stranding events happen.

Satellite image of a stranded whale



The study, published this week in the journal PLoS ONE by scientists from British Antarctic Survey and four Chilean research institutes, could revolutionise how stranded whales, that are dead in the water or beached, are detected in remote places.

In 2015, over 340 whales, most of them sei whales, were involved in a mass-stranding in a remote region of Chilean Patagonia. The stranding was not discovered for several weeks owing to the remoteness of the region. Aerial and boat surveys assessed the extent of the mortality several months after discovery.

The researchers studied satellite images covering thousands of kilometers of coastline, which provided an early insight into the extent of the mortality. They could identify the shape, size and colour of the whales, especially after several weeks when the animals turned pink and orange as they decomposed. A greater number of whales were counted in the images captured soon after the stranding event than from the local surveys.

Many coastal nations have mammal stranding networks recognizing that this is a crucial means to monitor the health of the local environment, especially for providing first notice of potential marine contamination and harmful algal blooms.

\Deceased stranded sei whale in Chile
Credit: BAS 


Author and whale biologist Dr Jennifer Jackson at British Antarctic Survey says: “The causes of marine mammal strandings are poorly understood and therefore information gathered helps understand how these events may be influenced by overall health, diet, environmental pollution, regional oceanography, social structures and climate change.

“As this new technology develops, we hope it will become a useful tool for obtaining real-time information. This will allow local authorities to intervene earlier and possibly help with conservation efforts.”

Lead author, remote sensing specialist Dr Peter Fretwell at British Antarctic Survey says:


“This is an exciting development in monitoring whales from space. Now we have a higher resolution ‘window’ on our planet, satellite imagery may be a fast and cost-effective alternative to aerial surveys allowing us to assess the extent of mass whale stranding events, especially in remote and inaccessible areas.”

Using remote sensing to detect whale strandings in remote areas: the case of sei whales mass mortality in Chilean Patagonia by Peter T. Fretwell1*, Jennifer A. Jackson1, Mauricio J. Ulloa Encina2, Vreni Häussermann 3, Maria J. Perez Alvarez4,5,6, Carlos Olavarría7, Carolina S.Gutstein8, 9 is published in the journal PLoS ONE.


Contacts and sources:
British Antarctic Survey (BAS)







Surveying Solar Storms by Ancient Assyrian Astronomers



Scientists at the University of Tsukuba study ancient cuneiform records for evidence of unusual solar activity 2,700 years ago, and identify three possible magnetic storms by matching the dates with tree-ring radioisotope data

 A research team led by the University of Tsukuba combined observations from ancient cuneiform tablets that mention unusual red skies with radioisotope data to identify solar storms that likely occurred around 679 to 655 BCE, prior to any previously datable events. This work may help modern astronomers predict future solar flares or coronal mass ejections that can damage satellite and terrestrial electronic devices.


Credit; MikeDrago.cz/Shutterstock

Humans have been looking to the skies for as long as we have been around. Some of the observations made by ancient Assyrian and Babylonian astrologers more than two millennia ago survive in the form of cuneiform records. These rectangular clay tablets were messages from professional scholars to kings who had commissioned astrological observations for the purpose of discerning omens—including comets, meteors, and planetary motions.

Now, a team led by the University of Tsukuba has matched three of these ancient tablets that mention an unusual red glow in the sky with the carbon-14 concentrations in tree rings and demonstrate how they are evidence of solar magnetic storms. These observations were made approximately 2,700 years ago in Babylon and the Assyrian city of Nineveh, both of which are mentioned contemporaneously in the Bible. For example, one tablet says, “red covers the sky,” while another mentions a “red cloud.” 

These were probably manifestations of what we call today stable auroral red arcs, consisting of light emitted by electrons in atmospheric oxygen atoms after being excited by intense magnetic fields. While we usually think of aurorae as confined to northern latitudes, during periods of strong magnetic activity, as with a solar mass ejection, they may be observed much further south. Moreover, because of changes in the Earth’s magnetic field over time, the Middle East was closer to the geomagnetic pole during this period in history.

“Although the exact dates of the observations are not known, we were able to narrow the range considerably by knowing when each astrologer was active,” senior author Yasuyuki Mitsuma says. Based on tree-ring samples, there was a rapid rise in radioactive carbon-14 in the environment during this time, which is associated with increased solar activity.

“These findings allow us to recreate the history of solar activity a century earlier than previously available records,” explains Mitsuma. “This research can assist in our ability to predict future solar magnetic storms, which may damage satellites and other spacecraft.”





Contacts and sources:
University of Tsukuba

Citation: “The Earliest Candidates of Auroral Observations in Assyrian Astrological Reports: Insights on Solar Activity around 660 BCE.” The Astrophysical Journal Letters (DOI: 10.3847/2041-8213/ab42e4)

A Secret in Our Saliva: Food and Germs Helped Humans Evolve into Unique Member of Great Apes

Two million years of eating meat and cooked food may have helped humans shift further from other great apes on the evolutionary tree. The evidence is in our saliva, according to new research from the University at Buffalo.

The research discovered that the human diet — a result of increased meat consumption, cooking and agriculture — has led to stark differences in the saliva of humans compared to that of other primates.

Human saliva is unique in that it is waterier and contains a different mix of proteins. The findings came as a big surprise to the researchers, since humans are known to be genetically close relatives of the great apes, chimpanzees and gorillas.

Close-up view of a man cutting off a piece of steak.
Credit: University of Buffalo

“Salivary proteins in humans and other primates could be overlooked hotbeds of evolutionary activity,” said Stefan Ruhl, DDS, PhD, lead investigator and professor of oral biology in the UB School of Dental Medicine. “We knew already that evolutionary adaptations to a human-specific diet have resulted in obvious changes to jaws and teeth, as well as the oral microbiome. Our findings now open up the possibility that dietary differences and pathogenic pressures may have also shaped a distinct saliva in humans.”

The study published yesterday evening, Oct. 15 in Molecular Biology and Evolution.

Beyond spitting distance

Saliva is a crucial bodily secretion in humans. The fluid helps digest food, protects tooth enamel, polices microbes in the mouth, and forms a first line of defense against pathogens. Saliva plays an important role in speech and taste as well.

Spit’s many functions can be credited to the salivary proteome, which are the thousands of proteins within the fluid. These proteins may also reveal clues to how humanity diverged from the great apes throughout its evolution.

The researchers compared the salivary proteins of humans and our closest evolutionary relatives: gorillas and chimpanzees. Macaques — who share a common, more distant ancestor with humans and great apes — were examined as well.

Figure showing the differences between proteins in human, chimpanzee and gorilla saliva using three different staining methods

Photo: Stefan Ruhl.


Key findings include:
  • Humans have waterier saliva than great apes. The overall protein content in human saliva was less than half of the amount found in chimpanzee, gorilla and macaque saliva.
  • Human saliva is more adept at breaking down starch, modifying fat, and detecting key flavors in human diet. The investigators discovered in humans higher amounts of amylase (an enzyme key to digesting starch into sugars) and carbonic anhydrase VI (an enzyme involved in taste perception) than was present in great apes. The saliva of humans and chimpanzees also contained more zinc-alpha-2-glycoprotein, a protein that aids in fat metabolism, than the spit of gorillas.
  • Losing our fur has led to the lack of latherin in human saliva. Latherin, a detergent-like protein that helps fluids become frothy, was only found in the saliva of the great apes. The researchers believe that humans, who no longer grow fur coats and don’t engage in social grooming, lost the need to produce the protein.

All major proteins detected in human saliva were also present in chimpanzee and gorilla saliva. The range of proteins detectable in saliva of humans matched that of the great apes. However, drastic differences in protein quantity and structure were found. "The later may in part be due to different glycans — complex sugar molecules — attached to the proteins", says Ruhl.

“Did human salivary glands evolve to produce a more watery saliva to accommodate a diet which drastically differs from that of great apes?” asks Supaporn “Nina” Thamadilok, PhD, PharmD candidate at the Massachusetts College of Pharmacy and Health Sciences and former post-doctoral research associate in Ruhl’s lab. “Great apes and Old World monkeys chew on their fiber-rich food for longer periods of time, while humans swallow food faster, an ability that is arguably supported by the cooking of food. A watery consistency of saliva could aid in faster digestion of dry food in the mouth, and easier swallowing.

“It might also be advantageous to keep the mouth moist in arid savannah-like environments where early humans evolved, or be important to facilitate human speech and vocalization. Of course, those possibilities remain speculative.”

Co-investigator Omer Gokcumen added, “The study's findings provide a necessary basis for future studies to assess whether the differences in human salivary proteins were caused by natural selection.”

“The challenge will be to decipher the genetic underpinnings of these changes and understand the evolutionary mechanisms that caused them. For some of the genes, we have a good idea, for most of the others however, we still have to find out,” said Gokcumen, PhD, associate professor of biological sciences in the UB College of Arts and Sciences

Differences shaped by disease

Differences between the saliva of humans and great apes were also found in proteins involved in defense against disease.

The saliva of chimpanzees, gorillas and macaques possessed greater amounts of parotid secretory protein than human spit. Human and chimpanzee saliva contained higher levels of secretory immunoglobulin components than gorilla saliva. Each of the proteins play a role in defense against disease.

“Besides diet, pathogenic pressure is another important driving force for evolutionary adaptation,” said Ruhl. “Whether any of the salivary proteins that show human-specific features were driven to change by diseases that came along with the evolution of humans into a top predator and the later shift towards agriculture and breeding livestock is an intriguing question worth examining.

“Little is known about the degree to which human saliva has adapted to dietary, technological (pounding, cutting and cooking), environmental and microbial pressures. Hopefully, other labs will join with their expertises, and help us answer those fundamental questions.”

About the study

Additional investigators include Kyoung-Soo Choi, an associate consultant biologist at Eli Lilly and Company and a former research technologist at Roswell Park Comprehensive Cancer Center; Lorenz Ruhl, a senior associate at Putnam Associates and a former summer research student at Roswell Park Comprehensive Cancer Center; Latif Kazim, PhD, emeritus faculty at Roswell Park Comprehensive Cancer Center; and Fabian Schulte, PhD, research fellow, and Markus Hardt, PhD, assistant member of the staff, both at The Forsyth Institute.

The research was supported by the National Institute of Dental and Craniofacial Research and the National Cancer Institute, both within the National Institutes of Health, as well as by Roswell Park Comprehensive Cancer Center.



Contacts and sources:
Marcene Robinson
University at Buffalo


Citation: Human and Non-Human Primate Lineage-Specific Footprints in the Salivary Proteome.
Supaporn Thamadilok, Kyoung-Soo Choi, Lorenz Ruhl, Fabian Schulte, A Latif Kazim, Markus Hardt, Omer Gokcumen, Stefan Ruhl. Molecular Biology and Evolution, 2019; DOI: 10.1093/molbev/msz223




Warehouses a Future Thing of the Past? Highest-Throughput 3D Printer Is Future of Manufacturing

Northwestern University researchers have developed a new, futuristic 3D printer that is so big and so fast it can print an object the size of an adult human in just a couple of hours.

HARP prints vertically, using projected UV light to cure liquid resins into hardened plastic
harp 3d printer
Credit: Northwestern University

Called HARP (high-area rapid printing), the new technology enables a record-breaking throughput that can manufacture products on demand. Over the last 30 years, most efforts in 3D printing have been aimed at pushing the limits of legacy technologies. Often, the pursuit of larger parts has come at the cost of speed, throughput and resolution. With HARP technology, this compromise is unnecessary, enabling it to compete with both the resolution and throughput of traditional manufacturing techniques.

The prototype HARP technology is 13-feet tall with a 2.5 square-foot print bed and can print about half a yard in an hour — a record throughput for the 3D printing field. This means it can print single, large parts or many different small parts at once.

Chad A. Mirkin
Credit: Northwestern University

“3D printing is conceptually powerful but has been limited practically,” said Northwestern’s Chad A. Mirkin, who led the product’s development. “If we could print fast without limitations on materials and size, we could revolutionize manufacturing. HARP is poised to do that.”

Mirkin predicts that HARP will be available commercially in the next 18 months.

The work will be published Oct. 18 in the journal Science. Mirkin is the George B. Rathmann Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences and director of the International Institute of Nanotechnology. David Walker and James Hedrick, both researchers in Mirkin’s laboratory, coauthored the paper.

Keeping it cool

HARP uses a new, patent-pending version of stereolithography, a type of 3D printing that converts liquid plastic into solid objects. HARP prints vertically and uses projected ultraviolet light to cure the liquid resins into hardened plastic. This process can print pieces that are hard, elastic or even ceramic. These continually printed parts are mechanically robust as opposed to the laminated structures common to other 3D-printing technologies. They can be used as parts for cars, airplanes, dentistry, orthotics, fashion and much more.

A major limiting factor for current 3D printers is heat. Every resin-based 3D printer generates a lot of heat when running at fast speeds — sometimes exceeding 180 degrees Celsius. Not only does this lead to dangerously hot surface temperatures, it also can cause printed parts to crack and deform. The faster it is, the more heat the printer generates. And if it’s big and fast, the heat is incredibly intense.

This problem has convinced most 3D printing companies to remain small. “When these printers run at high speeds, a great deal of heat is generated from the polymerization of the resin,” Walker said. “They have no way to dissipate it.”
‘Liquid Teflon’

The Northwestern technology bypasses this problem with a nonstick liquid that behaves like liquid Teflon. HARP projects light through a window to solidify resin on top of a vertically moving plate. The liquid Teflon flows over the window to remove heat and then circulates it through a cooling unit.

“Our technology generates heat just like the others,” Mirkin said. “But we have an interface that removes the heat.”

“The interface is also nonstick, which keeps the resin from adhering to the printer itself,” Hedrick added. “This increases the printer’s speed by a hundredfold because the parts do not have to be repeatedly cleaved from the bottom of the print-vat.”

Goodbye, warehouses

Current manufacturing methods can be cumbersome processes. They often require filling pre-designed molds, which are expensive, static and take up valuable storage space. Using molds, manufacturers print parts in advance — often guessing how many they might need — and store them in giant warehouses.

Although 3D printing is transitioning from prototyping to manufacturing, current 3D printers’ size and speed have limited them to small-batch production. HARP is the first printer that can handle large batches and large parts in addition to small parts.

“When you can print fast and large, it can really change the way we think about manufacturing,” Mirkin said. “With HARP, you can build anything you want without molds and without a warehouse full of parts. You can print anything you can imagine on-demand.”
Largest in its class

While other print technologies have slowed down or reduced their resolution to go big, HARP does not make such concessions.

“Obviously there are many types of 3D printers out there — you see printers making buildings, bridges and car bodies, and conversely you see printers that can make small parts at very high resolutions,” Walker said. “We’re excited because this is the largest and highest throughput printer in its class.”

Printers on the scale of HARP often produce parts that must be sanded or machined down to their final geometry. This adds a large labor cost to the production process. HARP is in a class of 3D printers that uses high-resolution light-patterning to achieve ready-to-use parts without extensive post-processing. The result is a commercially viable route to the manufacturing of consumer goods.
Nano goes big

A world-renowned expert in nanotechnology, Mirkin invented the world’s smallest printer in 1999. Called dip-pen nanolithography, the technology uses a tiny pen to pattern nanoscale features. He then transitioned this to an array of tiny pens that channels light through each pen to locally generate features from photo-sensitive materials. The special nonstick interface used in HARP originated while working to develop this technology into a nanoscale 3D printer.

“From a volumetric standpoint, we have spanned over 18 orders of magnitude,” Mirkin said.

Mirkin also is a professor of biomedical engineering, materials science and engineering, and chemical and biological engineering in the McCormick School of Engineering; professor of medicine in the Feinberg School of Medicine; and a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.



Contacts and sources:
Amanda Morris
Northwestern University

Citation: Rapid, large-volume, thermally controlled 3D printing using a mobile liquid interface.
David A. Walker, James L. Hedrick, Chad A. Mirkin. Science, 2019; 366 (6463): 360 DOI: 10.1126/science.aax1562

Ancient Stars Shed Light on Earth’s Similarities to Other Planets and Likely Abundant Cousins



Earth-like planets may be common in the universe, a new UCLA study implies. The team of astrophysicists and geochemists presents new evidence that the Earth is not unique. The study was published in the journal Science on Oct. 18.

“We have just raised the probability that many rocky planets are like the Earth, and there’s a very large number of rocky planets in the universe,” said co-author Edward Young, UCLA professor of geochemistry and cosmochemistry.

An artist’s rendering shows a white dwarf star with a planet in the upper right.
Artist’s rendering of a white dwarf
Credit: Mark Garlick

The scientists, led by Alexandra Doyle, a UCLA graduate student of geochemistry and astrochemistry, developed a new method to analyze in detail the geochemistry of planets outside of our solar system. Doyle did so by analyzing the elements in rocks from asteroids or rocky planet fragments that orbited six white dwarf stars.

“We’re studying geochemistry in rocks from other stars, which is almost unheard of,” Young said.

“Learning the composition of planets outside our solar system is very difficult,” said co-author Hilke Schlichting, UCLA associate professor of astrophysics and planetary science. “We used the only method possible — a method we pioneered — to determine the geochemistry of rocks outside of the solar system.”

White dwarf stars are dense, burned-out remnants of normal stars. Their strong gravitational pull causes heavy elements like carbon, oxygen and nitrogen to sink rapidly into their interiors, where the heavy elements cannot be detected by telescopes. The closest white dwarf star Doyle studied is about 200 light-years from Earth and the farthest is 665 light-years away.

“By observing these white dwarfs and the elements present in their atmosphere, we are observing the elements that are in the body that orbited the white dwarf,” Doyle said. The white dwarf’s large gravitational pull shreds the asteroid or planet fragment that is orbiting it, and the material falls onto the white dwarf, she said. “Observing a white dwarf is like doing an autopsy on the contents of what it has gobbled in its solar system.”

The data Doyle analyzed were collected by telescopes, mostly from the W.M. Keck Observatory in Hawaii, that space scientists had previously collected for other scientific purposes.

“If I were to just look at a white dwarf star, I would expect to see hydrogen and helium,” Doyle said. “But in these data, I also see other materials, such as silicon, magnesium, carbon and oxygen — material that accreted onto the white dwarfs from bodies that were orbiting them.”

When iron is oxidized, it shares its electrons with oxygen, forming a chemical bond between them, Young said. “This is called oxidation, and you can see it when metal turns into rust,” he said. “Oxygen steals electrons from iron, producing iron oxide rather than iron metal. We measured the amount of iron that got oxidized in these rocks that hit the white dwarf. We studied how much the metal rusts.”

Rocks from the Earth, Mars and elsewhere in our solar system are similar in their chemical composition and contain a surprisingly high level of oxidized iron, Young said. “We measured the amount of iron that got oxidized in these rocks that hit the white dwarf,” he said.

The sun is made mostly of hydrogen, which does the opposite of oxidizing — hydrogen adds electrons.

The researchers said the oxidation of a rocky planet has a significant effect on its atmosphere, its core and the kind of rocks it makes on its surface. “All the chemistry that happens on the surface of the Earth can ultimately be traced back to the oxidation state of the planet,” Young said. “The fact that we have oceans and all the ingredients necessary for life can be traced back to the planet being oxidized as it is. The rocks control the chemistry.”

Until now, scientists have not known in any detail whether the chemistry of rocky exoplanets is similar to or very different from that of the Earth.

How similar are the rocks the UCLA team analyzed to rocks from the Earth and Mars?

“Very similar,” Doyle said. “They are Earth-like and Mars-like in terms of their oxidized iron. We’re finding that rocks are rocks everywhere, with very similar geophysics and geochemistry.”

“It’s always been a mystery why the rocks in our solar system are so oxidized,” Young said. “It’s not what you expect. A question was whether this would also be true around other stars. Our study says yes. That bodes really well for looking for Earth-like planets in the universe.”

White dwarf stars are a rare environment for scientists to analyze.

The researchers studied the six most common elements in rock: iron, oxygen, silicon, magnesium, calcium and aluminum. They used mathematical calculations and formulas because scientists are unable to study actual rocks from white dwarfs. “We can determine the geochemistry of these rocks mathematically and compare these calculations with rocks that we do have from Earth and Mars,” said Doyle, whose background is in geology and mathematics. “Understanding the rocks is crucial because they reveal the geochemistry and geophysics of the planet.”

“If extraterrestrial rocks have a similar quantity of oxidation as the Earth has, then you can conclude the planet has similar plate tectonics and similar potential for magnetic fields as the Earth, which are widely believed to be key ingredients for life,” Schlichting said. “This study is a leap forward in being able to make these inferences for bodies outside our own solar system and indicates it’s very likely there are truly Earth analogs.”

Young said his department has both astrophysicists and geochemists working together.

“The result,” he said, “is we are doing real geochemistry on rocks from outside our solar system. Most astrophysicists wouldn’t think to do this, and most geochemists wouldn’t think to ever apply this to a white dwarf.”

Co-authors are Benjamin Zuckerman, a UCLA professor of physics and astronomy, and Beth Klein, a UCLA astronomy researcher.

The research was funded by NASA.




Contacts and sources:
Stuart Wolpert
University of California - Los Angeles
Citation: Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets. Alexandra E. Doyle, Edward D. Young, Beth Klein, Ben Zuckerman, Hilke E. Schlichting. Science, 2019 DOI: 10.1126/science.aax3901


Daily Exposure to Blue Light May Accelerate Aging, Even If It Doesn’t Reach Your Eyes, Study Suggests



Prolonged exposure to blue light, such as that which emanates from your phone, computer and household fixtures, could be affecting your longevity, even if it’s not shining in your eyes.

New research at Oregon State University suggests that the blue wavelengths produced by light-emitting diodes damage cells in the brain as well as retinas.

The study, published today in Aging and Mechanisms of Disease, involved a widely used organism, Drosophila melanogaster, the common fruit fly, an important model organism because of the cellular and developmental mechanisms it shares with other animals and humans.

Credit: Oregon State University

Jaga Giebultowicz, a researcher in the OSU College of Science who studies biological clocks, led a research collaboration that examined how flies responded to daily 12-hour exposures to blue LED light – similar to the prevalent blue wavelength in devices like phones and tablets – and found that the light accelerated aging.

Flies subjected to daily cycles of 12 hours in light and 12 hours in darkness had shorter lives compared to flies kept in total darkness or those kept in light with the blue wavelengths filtered out. The flies exposed to blue light showed damage to their retinal cells and brain neurons and had impaired locomotion – the flies’ ability to climb the walls of their enclosures, a common behavior, was diminished.

Some of the flies in the experiment were mutants that do not develop eyes, and even those eyeless flies displayed brain damage and locomotion impairments, suggesting flies didn’t have to see the light to be harmed by it.

“The fact that the light was accelerating aging in the flies was very surprising to us at first,” said Giebultowicz, a professor of integrative biology. “We’d measured expression of some genes in old flies, and found that stress-response, protective genes were expressed if flies were kept in light. We hypothesized that light was regulating those genes. Then we started asking, what is it in the light that is harmful to them, and we looked at the spectrum of light. It was very clear cut that although light without blue slightly shortened their lifespan, just blue light alone shortened their lifespan very dramatically.”

Natural light, Giebultowicz notes, is crucial for the body’s circadian rhythm – the 24-hour cycle of physiological processes such as brain wave activity, hormone production and cell regeneration that are important factors in feeding and sleeping patterns.

“But there is evidence suggesting that increased exposure to artificial light is a risk factor for sleep and circadian disorders,” she said. “And with the prevalent use of LED lighting and device displays, humans are subjected to increasing amounts of light in the blue spectrum since commonly used LEDs emit a high fraction of blue light. But this technology, LED lighting, even in most developed countries, has not been used long enough to know its effects across the human lifespan.”

Giebultowicz says that the flies, if given a choice, avoid blue light.

“We’re going to test if the same signaling that causes them to escape blue light is involved in longevity,” she said.

Eileen Chow, faculty research assistant in Giebultowicz’s lab and co-first author of the study, notes that advances in technology and medicine could work together to address the damaging effects of light if this research eventually proves applicable to humans.

“Human lifespan has increased dramatically over the past century as we’ve found ways to treat diseases, and at the same time we have been spending more and more time with artificial light,” she said. “As science looks for ways to help people be healthier as they live longer, designing a healthier spectrum of light might be a possibility, not just in terms of sleeping better but in terms of overall health.”

In the meantime, there are a few things people can do to help themselves that don’t involve sitting for hours in darkness, the researchers say. Eyeglasses with amber lenses will filter out the blue light and protect your retinas. And phones, laptops and other devices can be set to block blue emissions.

“In the future, there may be phones that auto-adjust their display based on the length of usage the phone perceives,” said lead author Trevor Nash, a 2019 OSU Honors College graduate who was a first-year undergraduate when the research began. “That kind of phone might be difficult to make, but it would probably have a big impact on health.”

Contacts and sources:
Steve Lundeberg
Oregon State University



Thursday, October 17, 2019

Fingerprints of Earth's Original Building Blocks Discovered in Diamond-Bearing Rocks

Primordial chemical signatures discovered in modern kimberlites trace back 2 billion years

Scientists have detected primordial chemical signatures preserved within modern kimberlites, according to new research by a multi-national team involving a University of Alberta scientist. The results provide critical insight for understanding the formation of Earth.

"Knowing the chemical signature of Earth's original building blocks is the holy grail of geochemistry," said Graham Pearson, author on the study. "This knowledge can help us understand the formation of the planets in the solar system as well as their relationship to each other."

Kimberlite sample from the Cumberland Peninsula on Baffin Island, Nunavut, Canada.
Credit: Subarcticmike / Wikimedia Commons

The research team analyzed kimberlites--a type of rock formed by cooling magma that sometimes carries diamonds--from around the world, including many from Canada.

"We found that kimberlites' chemical signatures are remarkably uniform and very like the chondritic building blocks thought to have formed the Earth 4.55 billion years ago," added Pearson, professor in the Department of Earth and Atmospheric Sciences, Henry Marshall Tory Chair, and Canada Excellence Research Chair Laureate. "We think this is the cleanest signal of this primordial signature 
found in any group of rocks on Earth."

Credit: Black Tusk / Wikimedia Commons

Never-ending cycle

The interior of our planet is constantly cycling, as minerals at Earth's surface are continually returned to great depths through movement of the tectonic plates. "This mixing makes it very difficult to detect the starting ingredients--a bit like trying to detect the brand of flour that was used by tasting an over-cooked cake," explained Pearson. "The final twist is that in the last 200 million years, these signatures became more scarce, likely due to events associated with the breakup of the supercontinent, Pangaea."
 
The discovery of these ancient, primordial signatures suggest that reflect the melting of deep, isolated regions of pristine material within the Earth that have remained untouched by billions of years of tectonic plate recycling--revealing a glimpse of the holy grail that will shed new light on how Earth, and planets like it, formed.

Contacts and sources:
Katie Willis
University of Alberta

Citation: "Kimberlites reveal 2.5-billion-year evolution of a deep, isolated mantle reservoir," was published in Nature (doi: 10.1038/s41586-019-1574-8).



The Blistering Speed of the World's Fastest Ants



According to Noël Coward, mad dogs and Englishmen are the only creatures that go out in the midday sun, but Harald Wolf from the University of Ulm, Germany, would add another animal: Saharan silver ants (Cataglyphis bombycina). 

Venturing from their nests to scavenge the corpses of less-fortunate creatures at the peak of the day - when the sand can reach 60°C - these resilient ants had always fascinated Wolf. 'Even among desert ants, the silver ants are special', he says, explaining that the insects were reputed to hit speeds approaching 1 m s/1. But little was known about how the ants scamper at such blistering speeds across the sand. 


These are Saharan silver ant (Cataglyphis bombycina) workers in the desert at Douz, Tunisia.


Credit: Harald Wolf

During an earlier trip to the salt pans of Tunisia - to study the silver ant's cousin, Cataglyphis fortis - Wolf, Sarah Pfeffer, Verena Wahl and Matthias Wittlinger had taken a detour to Douz to search for the enigmatic desert dwellers. After finding silver ants thriving in the dunes, the team returned in 2015 to film them in action. The team publishes their discover that Saharan silver ants are the fastest ants ever recorded, reaching speeds of 0.855m/s (855mm/s) by swinging their legs at speeds of up to 1300mm/s in Journal of Experimental Biology at http://jeb.biolgists.org.

Pfeffer recalls that locating the inconspicuous nests was far from easy: 'We had to look for digging ants or follow a foraging ant back home', she explains. However, once the team had located a nest, it was simply a matter of connecting an aluminium channel to the entrance and placing a feeder at the end to lure the ants out. 'After the ants have found the food - they love mealworms - they shuttle back and forth in the channel and we mounted our camera to film them from the top', smiles Pfeffer. In addition, the team excavated a nest, returning with it to Germany, to record the insects running more slowly at cooler temperatures.

Calculating the insects' top speeds, Pfeffer and Wahl were impressed to find the animals hit an extraordinary 0.855m/s (that is, 855mm/s or 108 times their own body length per second) during the hottest part of the desert day, falling to 0.057m/s at 10°C in the lab. In contrast, larger Cataglyphis fortis only get up to 0.62m/s (only 50body lengths/s), making C. bombycina the world's fastest ant and placing them close to the top of the list of world record-breaking creatures, alongside Australian tiger beetles (171body lengths/s) and California coastal mites (377body lengths/s).

The scientists also compared the leg lengths of the two species and it was evident that the swift silver ants are doing something remarkable. Their limbs are almost 20% shorter than those of their leggier cousins. Wondering how the smaller ants outstrip their larger Cataglyphis relatives, the team focused on the ants' footwork.

Analysing the silver ant's manoeuvres, the team realised that the insects were swinging their 4.3-6.8mm long legs at speeds of up to 1300mm/s, taking up to 47strides/s - around a third faster than their larger relatives. And when they scrutinised the ants' stride lengths, they quadrupled from 4.7mm to 20.8mm as the ants shifted up through the gears. The team also discovered that instead of simply running, the ants switched to a gallop, with all six feet off the ground simultaneously at speeds above 0.3m/s.

 In addition, they analysed the ants' coordination and were impressed by how well the ants synchronised their feet - tightly coordinating the movements of the three legs that work together forming tripods as they walk - while each foot only contacted the ground for as little as 7 milliseconds before initiating the next stride.

'These features may be related to the sand dune habitat', says Wolf, adding, '[they] could prevent the animal's feet from sinking too deeply into the soft sand'. He is also keen to find out more about how these desert dwellers pull off their high-speed feats, which he suspects must require muscle contraction speeds close to physiological limits.



Contacts and sources:
Kathryn KnightThe Company of Biologists

Citation: Pfeffer, S. E., Wahl, V. L., Wittlinger, M. and Wolf, H. (2019). High-speed locomotion in the Saharan silver ant, Cataglyphis bombycina. Journal of Experimental Biology 222, jeb198705  https://jeb.biologists.org/content/222/20/jeb198705



Cascades Of Gas Around Young Star Indicate Early Stages Of Planet Formation



What does a gestating baby planet look like? New research in Nature by a team including Carnegie's Jaehan Bae investigated the effects of three planets in the process of forming around a young star, revealing the source of their atmospheres.

In their youth, stars are surrounded by a rotating disk of gas and dust from which planets are born. Studying the behavior of the material that makes up these disks can reveal new details about planet formation, and about the evolution of a planetary system as a whole.

An artist’s conception of the disk of gas and dust rotating around the young star HD 163296. Gas can be seen cascading into gaps in the disk—likely indicating the formation of baby planets in these locations.
Image is by Robin Dienel, courtesy of the Carnegie Institution for Science.

The disk around a young star called HD 163296 is known to include several rings and gaps. Using 3-D visualizations taken by the Atacama Large Millimeter/submillimeter Array, or ALMA—a radio telescope made up of 66 antennas—Bae teamed with University of Michigan’s Richard Teague and Ted Bergin to determine the velocities of some of the gas spinning in this disk.
"We were struck by how dynamic the disk is," Bae said. "There's a lot going on around this star."

They found three areas on either side of which the gas appears to be cascading into gaps in the disk, a good indication that planets could be forming in these locations. They were spotted at 87, 140, and 237 astronomical units, or AUs, from the star, with an AU being the distance between the Earth and our Sun.

They tested these findings by creating a computational model of the stellar system and inserting three planets--one half Jupiter's mass, one equivalent to Jupiter, and one twice Jupiter's mass--at the same distances from HD 163296 as the gas disturbances found by ALMA. Their simulation indicated that the observed cascades of disk gas could be well explained by the existence of the three planets.

Last year, Teague, Bae, and Bergin were part of a team that used one-dimensional measurements of the velocity of gas in the same disk to demonstrate a new technique for finding young planets. This latest paper takes that tool to the next level, enabling even deeper understanding of the planet-formation process.

"This gives us a much more complete picture of planet formation than we ever dreamed," said Bergin.

Their efforts also confirmed a long-standing theory about how planets acquire their atmospheres.

"Planets form in the middle layer of the disk, the so-called midplane. This is a cold place, shielded from radiation from the star," explained lead author Teague. "We think that the gaps caused by planets bring in warmer gas from the more chemically active outer layers of the disk, and that this gas will form the atmosphere of the planet."

The next step is to determine the chemical composition of the gas added to planets' atmospheres during this formative period.

"Looking ahead, analyzing the movement of material in a disk around a young star could help us find exoplanets while they are still in their most-formative stages," Bae concluded. "This could really help us understand how the architecture of a planetary system comes to be and maybe even unlock mysteries about the evolution of our own Solar System."

This work was supported, in part, by NASA.

ALMA is a partnership of European Southern Observatory, the U.S. National Science Foundation, and the Japanese National Institutes of Natural Sciences, together with the Canadian National Research Council, the Academia Sinica Institute of Astronomy and Astrophysics inTaiwan, and the Korea Astronomy and Space Science Institute, in cooperation with Chile. The Joint ALMA Observatory is operated by ESO, Associated Universities, Inc/National Radio Astronomy Observatory, and National Astronomical Observatory of Japan. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Computing resources provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing Division at Ames Research Center and by the Extreme Science and Engineering Discovery Environment, which is supported by the U.S. National Science Foundation.




Contacts and sources:
Jaehan BaeThe Carnegie Institution for Science





Halo of Dark Matter Spins Super Spirals Faster




You’ve probably never noticed it, but our solar system is moving along at quite a clip. Stars in the outer reaches of the Milky Way, including our Sun, orbit at an average speed of 130 miles per second. But that’s nothing compared to the most massive spiral galaxies. “Super spirals,” which are larger, brighter, and more massive than the Milky Way, spin even faster than expected for their mass, at speeds up to 350 miles per second.

Their rapid spin is a result of sitting within an extraordinarily massive cloud, or halo, of dark matter – invisible matter detectable only through its gravity. The largest “super spiral” studied here resides in a dark matter halo weighing at least 40 trillion times the mass of our Sun. The existence of super spirals provides more evidence that an alternative theory of gravity known as Modified Newtonian Dynamics, or MOND, is incorrect.

Mosaic of Super Spirals: The top row of this mosaic features Hubble images of three spiral galaxies, each of which weighs several times as much as the Milky Way. The bottom row shows three even more massive spiral galaxies that qualify as “super spirals,” which were observed by the ground-based Sloan Digital Sky Survey. Super spirals typically have 10 to 20 times the mass of the Milky Way. The galaxy at lower right, 2MFGC 08638, is the most massive super spiral known to date, with a dark matter halo weighing at least 40 trillion Suns.

Astronomers have measured the rotation rates in the outer reaches of these spirals to determine how much dark matter they contain. They found that the super spirals tend to rotate much faster than expected for their stellar masses, making them outliers. Their speed may be due to the influence of a surrounding dark matter halo, the largest of which contains the mass of at least 40 trillion suns.

Mosaic of Super Spiral galaxies
CREDITS:Top row: NASA, ESA, P. Ogle and J. DePasquale (STScI). Bottom row: SDSS, P. Ogle and J. DePasquale (STScI

When it comes to galaxies, how fast is fast? The Milky Way, an average spiral galaxy, spins at a speed of 130 miles per second (210 km/sec) in our Sun’s neighborhood. New research has found that the most massive spiral galaxies spin faster than expected. These “super spirals,” the largest of which weigh about 20 times more than our Milky Way, spin at a rate of up to 350 miles per second (570 km/sec).

Super spirals are exceptional in almost every way. In addition to being much more massive than the Milky Way, they’re also brighter and larger in physical size. The largest span 450,000 light-years compared to the Milky Way’s 100,000-light-year diameter. Only about 100 super spirals are known to date. Super spirals were discovered as an important new class of galaxies while studying data from the Sloan Digital Sky Survey (SDSS) as well as the NASA/IPAC Extragalactic Database (NED).

“Super spirals are extreme by many measures,” says Patrick Ogle of the Space Telescope Science Institute in Baltimore, Maryland. “They break the records for rotation speeds.”

Ogle is first author of a paper that was published October 10, 2019 in the Astrophysical Journal Letters. The paper presents new data on the rotation rates of super spirals collected with the Southern African Large Telescope (SALT), the largest single optical telescope in the southern hemisphere. Additional data were obtained using the 5-meter Hale telescope of the Palomar Observatory, operated by the California Institute of Technology. Data from NASA’s Wide-field Infrared Survey Explorer (WISE) mission was crucial for measuring the galaxy masses in stars and star formation rates.

Referring to the new study, Tom Jarrett of the University of Cape Town, South Africa says, “This work beautifully illustrates the powerful synergy between optical and infrared observations of galaxies, revealing stellar motions with SDSS and SALT spectroscopy, and other stellar properties — notably the stellar mass or ‘backbone’ of the host galaxies — through the WISE mid-infrared imaging."

Theory suggests that super spirals spin rapidly because they are located within incredibly large clouds, or halos, of dark matter. Dark matter has been linked to galaxy rotation for decades. Astronomer Vera Rubin pioneered work on galaxy rotation rates, showing that spiral galaxies rotate faster than if their gravity were solely due to the constituent stars and gas. An additional, invisible substance known as dark matter must influence galaxy rotation. A spiral galaxy of a given mass in stars is expected to rotate at a certain speed. Ogle’s team finds that super spirals significantly exceed the expected rotation rate.

Super spirals also reside in larger than average dark matter halos. The most massive halo that Ogle measured contains enough dark matter to weigh at least 40 trillion times as much as our Sun. That amount of dark matter would normally contain a group of galaxies rather than a single galaxy.

“It appears that the spin of a galaxy is set by the mass of its dark matter halo,” Ogle explains.

The fact that super spirals break the usual relationship between galaxy mass in stars and rotation rate is a new piece of evidence against an alternative theory of gravity known as Modified Newtonian Dynamics, or MOND. MOND proposes that on the largest scales like galaxies and galaxy clusters, gravity is slightly stronger than would be predicted by Newton or Einstein. This would cause the outer regions of a spiral galaxy, for example, to spin faster than otherwise expected based on its mass in stars. MOND is designed to reproduce the standard relationship in spiral rotation rates, therefore it cannot explain outliers like super spirals. The super spiral observations suggest no non-Newtonian dynamics is required.

Despite being the most massive spiral galaxies in the universe, super spirals are actually underweight in stars compared to what would be expected for the amount of dark matter they contain. This suggests that the sheer amount of dark matter inhibits star formation. There are two possible causes: 1) Any additional gas that is pulled into the galaxy crashes together and heats up, preventing it from cooling down and forming stars, or 2) The fast spin of the galaxy makes it harder for gas clouds to collapse against the influence of centrifugal force.

“This is the first time we’ve found spiral galaxies that are as big as they can ever get,” Ogle says.

Despite these disruptive influences, super spirals are still able to form stars. Although the largest elliptical galaxies formed all or most of their stars more than 10 billion years ago, super spirals are still forming stars today. They convert about 30 times the mass of the Sun into stars every year, which is normal for a galaxy of that size. By comparison, our Milky Way forms about one solar mass of stars per year.

Ogle and his team have proposed additional observations to help answer key questions about super spirals, including observations designed to better study the motion of gas and stars within their disks. After its 2021 launch, NASA’s James Webb Space Telescope could study super spirals at greater distances and correspondingly younger ages to learn how they evolve over time. And NASA’s WFIRST mission may help locate more super spirals, which are exceedingly rare, thanks to its large field of view.

The Space Telescope Science Institute is expanding the frontiers of space astronomy by hosting the science operations center of the Hubble Space Telescope, the science and operations center for the James Webb Space Telescope, and the science operations center for the future Wide Field Infrared Survey Telescope (WFIRST). STScI also houses the Mikulski Archive for Space Telescopes (MAST) which is a NASA-funded project to support and provide to the astronomical community a variety of astronomical data archives, and is the data repository for the Hubble, Webb, Kepler, K2, TESS missions and more.



KEYWORDS:GALAXIES SPIRAL GALAXIES

CONTACT:Christine Pulliam
Space Telescope Science Institute

Contacts and sources:

Citation:



Rewriting History: Scientists Find Evidence that Early Human Moved through the Mediterranean Much Earlier than Believed



An international research team led by scientists from McMaster University has unearthed new evidence in Greece proving that the island of Naxos was inhabited by Neanderthals and earlier humans at least 200,000 years ago, tens of thousands of years earlier than previously believed.



The findings, published today in the journal Science Advances, are based on years of excavations and challenge current thinking about human movement in the region—long thought to have been inaccessible and uninhabitable to anyone but modern humans.

The new evidence is leading researchers to reconsider the routes our early ancestors took as they moved out of Africa into Europe and demonstrates their ability to adapt to new environmental challenges.


Credit: McMaster University

“Until recently, this part of the world was seen as irrelevant to early human studies but the results force us to completely rethink the history of the Mediterranean islands,” says Tristan Carter, an associate professor of anthropology at McMaster and lead author on the study. He conducted the work with Dimitris Athanasoulis, head of archaeology at the Cycladic Ephorate of Antiquities within the Greek Ministry of Culture.

While Stone Age hunters are known to have been living on mainland Europe for more than 1 million years, the Mediterranean islands were previously believed to be settled only 9,000 years ago, by farmers, the idea being that only modern humans – Homo sapiens – were sophisticated enough to build seafaring vessels.

Scholars had believed the Aegean Sea, separating western Anatolia (modern Turkey) from continental Greece, was therefore impassable to the Neanderthals and earlier hominins, with the only obvious route in and out of Europe was across the land bridge of Thrace (southeast Balkans).

The authors of this paper suggest that the Aegean basin was in fact accessible much earlier than believed. At certain times of the Ice Age the sea was much lower exposing a land route between the continents that would have allowed early prehistoric populations to walk to Stelida, and an alternative migration route connecting Europe and Africa.

Researchers believe the area would have been attractive to early humans because of its abundance of raw materials ideal for toolmaking and for its fresh water.

At the same time however, “in entering this region the pre-Neanderthal populations would have been faced with a new and challenging environment, with different animals, plants and diseases, all requiring new adaptive strategies,” says Carter.

In this paper, the team details evidence of human activity spanning almost 200,000 years at Stelida, a prehistoric quarry on the northwest coast of Naxos. Here early Homo sapiens, Neanderthals and earlier humans used the local stone (chert) to make their tools and hunting weapons, of which the team has unearthed hundreds of thousands.


Credit: McMaster University

Reams of scientific data collected at the site add to the ongoing debate about the importance of coastal and marine routes to human movement. While present data suggests that the Aegean could be crossed by foot over 200,000 years ago, the authors also raise the possibility that Neanderthals may also have fashioned crude seafaring boats capable of crossing short distances.

This research is part of the Stelida Naxos Archeological Project, a larger collaboration involving scholars from all over the world. They have been working at the site since 2013.



Contacts and sources:
Michelle Donovan
McMaster University

Citation: Earliest occupation of the Central Aegean (Naxos), Greece: Implications for hominin and Homo sapiens’ behavior and dispersals. Tristan Carter, Daniel A. Contreras, Justin Holcomb, Danica D. Mihailović, Panagiotis Karkanas, Guillaume Guérin, Ninon Taffin, Dimitris Athanasoulis, Christelle Lahaye. Science Advances, 2019; 5 (10): eaax0997 DOI: 10.1126/sciadv.aax0997


New Understanding of the Evolution of Cosmic Electromagnetic Fields



Next year is the 200 years anniversary of the discovery of electromagnetism by the Danish physicist H.C. Ørsted. Even 200 years after its discovery, the existence of electromagnetism still brings up new puzzles pertaining to their origin.

One such mystery is the origin of electro magnetic fields on the very largest scale in the universe.

While researchers have believed for some time that magnetic fields of femto-Gauss strength extend to the largest scales in the universe — to scales larger than the largest clusters of galaxies — it is an unresolved mystery how such magnetic fields can have been created in the early universe.

Credit: NASA/JPL-Caltech/J. Bally (Univ. of Colo.)

The very early universe

One logical possibility is that the magnetic fields were enhanced by the primordial period of inflation, which is needed also to solve the flatness and horizon problem in the standard Big-Bang model, if the magnetic fields in this period had some new non-standard interactions with the inflaton particle. The inflaton particle is responsible for driving the period of primordial inflation.

But the problem is that magnetic fields generated during inflation have been believed to quickly be washed away by the subsequent ordinary expansion of the universe making successful inflationary magnetogenesis a challenge.

Recently the researchers Takeshi Kobayashi from International Centre for Theoretical Physics in Italy and Martin S. Sloth from University of Southern Denmark (the university in the region were H.C. Ørsted was born) have shown that due to Faraday’s law of induction, the assumed evolution of electromagnetic fields after inflation is different than previously assumed if there are also strong primordial electric fields.

The work has been published in the journal Physical Review D.

“This opens a new door to our understanding of the origin of cosmic magnetic fields”, says Martin S. Sloth, professor, CP3-Origins, Center for Cosmology and Particle Physics Phenomenology, University of Southern Denmark.


Contacts and sources:
Birgitte Svennevig
University of Southern Denmark.

Citation: Early cosmological evolution of primordial electromagnetic fields. Takeshi Kobayashi, Martin S. Sloth. Physical Review D, 2019; 100 (2) DOI: 10.1103/PhysRevD.100.023524


Wednesday, October 16, 2019

A Breath Test of Opiods



A test to detect opioid drugs in exhaled breath has been developed by engineers and physicians at the University of California, Davis. A breath test could be useful in caring for chronic pain patients as well as for checking for illegal drug use.

“There are a few ways we think this could impact society,” said professor Cristina Davis, chair of the Department of Mechanical and Aerospace Engineering at UC Davis, who led the research along with Professor Michael Schivo from the UC Davis Medical Center. The work is described in a paper published in the Journal of Breath Research Oct. 3.

A table full of fentanyl and other designer drugs seized by CBP sit on display at the International Mail Facility
File:Opiod Epidemic (23882642067).jpg
Credit: U.S. Customs and Border Protection

Doctors and nurses treating chronic pain may need to monitor patients to make sure they are taking their drugs correctly, that their prescribed drugs are being metabolized properly and that they are not taking additional medications. Blood tests are the gold standard: a reliable, noninvasive test would be a useful alternative. 

Collecting droplets from breath

For the test developed by postdoctoral researcher Eva Borras, Davis and colleagues, subjects breathe normally into a specialized collection device. Droplets in breath condense and are stored in a freezer until testing. Davis’ lab uses mass spectrometry to identify compounds in the samples.

The researchers tested the technique in a small group of patients receiving infusions of pain medications including morphine and hydromorphone, or oral doses of oxycodone, at the UC Davis Medical Center. They were therefore able to compare opioid metabolites in breath with both blood samples and the doses given to patients.

“We can see both the original drug and metabolites in exhaled breath,” Davis said.

Fully validating the breath test will require more data from larger groups of patients, she said. Davis’ laboratory is working toward real-time, bedside testing.

Other authors on the paper include graduate student Andy Cheng, UC Davis forensic science program; Ted Wun, Department of Internal Medicine; Kristen Reese and Matthias Frank, Lawrence Livermore National Laboratory; and Michael Schivo, UC Davis School of Medicine and VA Northern California Health System.

Davis’ laboratory is working on a variety of applications for detecting small amounts of chemicals, especially in air and exhaled breath. Other projects include diagnosing influenza in people and citrus greening disease in fruit trees.

The work was supported by grants from the UC Davis Medical Center’s Collaborative for Diagnostic Innovation, the U.S. Department of Energy and the NIH.

Contacts and sources:
Andy Fell
UC Davis

Citation:



Accelerating Global Agricultural Productivity Growth Is Critical to Feed 10 Billion by 2050

The Global Agricultural Productivity Index tracks global progress toward the sustainable production of food, feed, fiber, and bioenergy for 10 billion people in 2050.


The 2019 Global Agricultural Productivity Report, "Productivity Growth for Sustainable Diets, and More," released today by Virginia Tech’s College of Agriculture and Life Sciences, shows agricultural productivity growth – increasing output of crops and livestock with existing or fewer inputs – is growing globally at an average annual rate of 1.63 percent.

According to the report’s Global Agricultural Productivity Index, global agricultural productivity needs to increase at an average annual rate of 1.73 percent to sustainably produce food, feed, fiber, and bioenergy for 10 billion people in 2050.

Productivity growth is strong in China and South Asia, but it is slowing in the agricultural powerhouses of North America, Europe, and Latin America.

The report calls attention to the alarmingly low levels of productivity growth in low-income countries, where there also are high rates of food insecurity, malnutrition, and rural poverty.

Agricultural productivity growth in low-income countries is rising at an average annual rate of just 1 percent. The UN Sustainable Development Goals call for doubling the productivity of the lowest-income farmers by 2030.

The GAP Report was released at the World Food Prize in Des Moines, Iowa. Speakers at the GAP Report Launch event included Tim Sands, president of Virginia Tech; Miguel Garcia Winder, undersecretary for agriculture for Mexico; Rose Mwonya, vice chancellor of the Egerton University in Kenya; and Alan Grant, dean of Virginia Tech’s College of Agriculture and Life Sciences.

The report calls for a strong focus on countries with high rates of population growth, persistent low levels of agricultural productivity, and significant shifts in consumption patterns — the primary drivers of unsustainable agricultural practices, such as converting forests to crop and rangeland.

“These productivity gaps, if they persist, will have serious ramifications for environmental sustainability, the economic vitality of the agriculture sector, and the prospects for reducing poverty, malnutrition, and obesity,” said Ann Steensland, author of the 2019 GAP Report and coordinator of the GAP Report Initiative at Virginia Tech.

The 2019 GAP Report examines the pivotal role of agricultural productivity in achieving global goals for environmental sustainability, economic development, and improved nutrition.

“Decades of research and experience tell us that by accelerating productivity growth, it is possible to improve environmental sustainability, while ensuring that consumers have access to the foods they need and want,” said Tom Thompson, associate dean and director of global programs for the Virginia Tech College of Agriculture and Life Sciences.

Productivity growth is generated by such innovations as precision agriculture technology and improved seeds and best practices for nutrient management and animal health. Attention to ecosystem services, such as pollination and erosion prevention, can increase and sustain productivity gains over time.

The GAP Report looks at the powerful combination of agricultural technology, best farm management practices, and attention to ecosystem services in supporting productivity growth, sustainability, and resilience.

Historically, productivity growth has been strongest in high-income countries, such as the U.S, with significant environmental benefits.

Due to widespread adoption of improved agricultural technologies and best farm management practices, especially in high-income countries, global agricultural output has increased by 60 percent, while global cropland has increased by just 5 percent during the past 40 years.

Between 1980 and 2015, productivity gains led to a 41 percent decrease in the amount of land used in U.S. corn production, irrigation water use declined 46 percent, greenhouse gas emissions declined 31 percent, and soil erosion declined (tons of soil loss per acre) by 58 percent.

Animal agriculture in the U.S. has experienced similar productivity gains, dramatically reducing the environmental footprint of the livestock production. According to Robin White, assistant professor of animal and poultry science at Virginia Tech, if livestock production in the U.S. was eliminated, total U.S. greenhouse gas emissions would decline by only 2.9 percent.

The Global Agricultural Productivity Index tracks global progress toward sustainably producing food, feed, fiber, and bioenergy for 10 billion people in 2050.

In the absence of further productivity gains in Total Factor Productivity, more land and water will be needed to increase food and agriculture production, straining a natural resource base already threatened by climate change.

Unable to afford higher-priced nutrient-dense foods, such as animal proteins and fruits and vegetables, consumers will rely on foods made from cheaper cereal grains for most of their calories, exacerbating skyrocketing obesity rates in adults and children.

The GAP Report describes six strategies for accelerating productivity growth: investing in public agricultural R&D and extension, embracing science- and information-based technologies, improving infrastructure and market access, cultivating partnerships for sustainable agriculture and nutrition, expanding regional and global trade, and reducing post-harvest loss and food waste.

Beginning this year, the GAP Report was produced by Virginia Tech’s College of Agriculture and Life Sciences. The GAP Report brings together expertise from Virginia Tech and other universities, the private sector, NGOs, conservation and nutrition organizations, and global research institutions. The report is part of the Global Programs Office unit within the College of Agriculture and Life Sciences that builds partnerships and creates global opportunities for students and faculty.

Productivity data for the GAP Index are provided by the USDA Economic Research Service. The GAP Report is available to view and download at www.globalagriculturalproductivity.org.

Agricultural productivity, measured as Total Factor Productivity, increases when the output of crops and livestock increases using existing, or less, land, labor, fertilizer, capital, and livestock.

The GAP Report is supported by the Virginia Tech College of Agriculture and Life Sciences and its supporting partners: Bayer Crop Science, Corteva Agriscience, John Deere, The Mosaic Company, and Smithfield Foods.

The GAP Report’s consultative partners are ACDI/VOCA, Congressional Hunger Center, Farm Foundation, Global Alliance for Improved Nutrition, HarvestPlus, Inter-American Institute for Cooperation on Agriculture, International Potato Center, The Nature Conservancy, New Markets Lab, Purdue Center for Global Food Security, Supporters of Agricultural Research Foundation, Tanager, and the Daugherty Water for Food Global Institute.


Contacts and sources:
Virginia Tech




New Calcium Batteries as Sustainable Energy Storage Systems



Calcium-based batteries promise to reach a high energy density at low manufacturing costs. This lab-scale technology has the potential for replacing lithium-ion technology in future energy storage systems. Using the electrolytes available, however, it has been impossible so far to charge calcium batteries at room temperature. In the Energy & Environmental Science journal, researchers of Karlsruhe Institute of Technology (KIT) now present a promising electrolyte class, with which this will be possible. (DOI: 10.1039/c9ee01699f)

Efficient, large, and low-cost energy storage systems will facilitate nationwide transition to zero-emission mobility and power supply. Today’s predominant lithium-ion technology, however, cannot fulfill this task on a global scale, says Professor Maximilian Fichtner of KIT, Director of the research platform CELEST (Center for Electrochemical Energy Storage Ulm & Karlsruhe). Here, calcium batteries and other storage technologies are studied. 

Zhirong Zhao-Karger (left) and Zhenyou Li (right) from the POLiS (Post Lithium Storage) Cluster of Excellence succeeded in producing promising electrolytes for calcium batteries. 
Photo: Markus Breig/KIT

“In the medium term, lithium-ion batteries will reach their limits in terms of performance and some of the resources used for their manufacture. This will prevent their future use wherever that would be reasonable for the energy transition. Availability of resources needed for manufacture, such as cobalt, nickel, and lithium, is limited.” 

At the Helmholtz Institute Ulm (HIU) established by KIT in cooperation with Ulm University, Fichtner and his team focus on alternative battery technologies instead. These technologies are based on more abundant resources. Calcium is a promising candidate, because it can release and accept two electrons per atom contrary to lithium and because it supplies a voltage similar to that of lithium: “Calcium is the fifth most abundant element in the Earth’s crust. It is distributed homogeneously on Earth and it is safe, non-toxic, and inexpensive.”

Search for a Suitable Electrolyte

Still, there has been a big obstacle in calcium battery development so far: In contrast to the established lithium-ion technology or more recent sodium or magnesium technologies, practicable electrolytes to produce rechargeable calcium batteries have been lacking so far. “For a few years now, experimental electrolytes and, hence, prototypes of the calcium battery have been available,” say Dr. Zhenyou Li, first author of the study, and Dr. Zhirong Zhao-Karger, who heads the project. 

Both are working in the POLiS (Post Lithium Storage) Cluster of Excellence of KIT that is embedded in CELEST. “But these electrolytes enable charging at temperatures beyond 75 degrees Celsius only and additionally they are susceptible to undesired side reactions.”

The researchers have now succeeded in synthesizing a class of new electrolytes based on special organic calcium salts. These electrolytes enable charging at room temperature. Using the new electrolyte calcium tetrakis[hexafluoroisopropyloxy]borate, the researchers demonstrated feasibility of calcium batteries of high energy density, storage capacity, and quick-charging capability. Their results are reported in the journal Energy & Environmental Science.

Calcium Batteries as Sustainable Energy Storage Systems

The new class of electrolytes is an important basis for transferring calcium batteries from the laboratory to application. In electric vehicles, mobile electronic devices, and stationary storage systems, they might replace the presently predominating lithium-ion battery one day. But this may take a while: “The new electrolytes are a first important step,” Fichtner emphasizes. “There still is a far way to go to the mature calcium battery.”


Contacts and sources:
Karlsruhe Institute of Technology


Citation: Towards stable and efficient electrolytes for room-temperature rechargeable calcium batteries. Zhenyou Li, Olaf Fuhr, Maximilian Fichtner, Zhiron Zhao-Karger: Energy & Environmental Science, 2019. DOI: 10.1039/c9ee01699f.
https://pubs.rsc.org/en/content/articlelanding/2019/EE/C9EE01699F#!divAbstract