NASA finds Neptune moons locked in 'dance of avoidance'

Screenshot of animation illustrating how the odd orbits of Neptune's inner moons Naiad and Thalassa enable them to avoid each other as they race around the planet.

Even by the wild standards of the outer solar system, the strange orbits that carry Neptune's two innermost moons are unprecedented, according to newly published research.

Orbital dynamics experts are calling it a "dance of avoidance" performed by the tiny moons Naiad and Thalassa. The two are true partners, orbiting only about 1,150 miles (1,850 kilometers) apart. But they never get that close to each other; Naiad's orbit is tilted and perfectly timed. Every time it passes the slower-moving Thalassa, the two are about 2,200 miles (3,540 kilometers) apart.

In this perpetual choreography, Naiad swirls around the ice giant every seven hours, while Thalassa, on the outside track, takes seven and a half hours. An observer sitting on Thalassa would see Naiad in an orbit that varies wildly in a zigzag pattern, passing by twice from above and then twice from below. This up, up, down, down pattern repeats every time Naiad gains four laps on Thalassa.

Although the dance may appear odd, it keeps the orbits stable, researchers said.

"We refer to this repeating pattern as a resonance," said Marina Brozović, an expert in solar system dynamics at NASA's Jet Propulsion Laboratory in Pasadena, California, and the lead author of the new paper, which was published Nov. 13 in Icarus. "There are many different types of 'dances' that planets, moons and asteroids can follow, but this one has never been seen before."

Far from the pull of the Sun, the giant planets of the outer solar system are the dominant sources of gravity, and collectively, they boast dozens upon dozens of moons. Some of those moons formed alongside their planets and never went anywhere; others were captured later, then locked into orbits dictated by their planets. Some orbit in the opposite direction their planets rotate; othersswap orbits with each otheras if to avoid collision.

Neptune has 14 confirmed moons. Neso, the farthest-flung of them, orbits in a wildly elliptical loop that carries it nearly 46 million miles (74 million kilometers) away from the planet and takes 27 years to complete.

Naiad and Thalassa are small and shaped like Tic Tacs, spanning only about 60 miles (100 kilometers) in length. They are two of Neptune's seven inner moons, part of a closely packed system that is interwoven with faint rings.

So how did they end up together -- but apart? It's thought that the original satellite system was disrupted when Neptune captured its giant moon, Triton, and that these inner moons and rings formed from the leftover debris.

"We suspect that Naiad was kicked into its tilted orbit by an earlier interaction with one of Neptune's other inner moons," Brozović said. "Only later, after its orbital tilt was established, could Naiad settle into this unusual resonance with Thalassa."

Brozović and her colleagues discovered the unusual orbital pattern using analysis of observations by NASA's Hubble Space Telescope. The work also provides the first hint about the internal composition of Neptune's inner moons. Researchers used the observations to compute their mass and, thus, their densities -- which were close to that of water ice.

"We are always excited to find these co-dependencies between moons," said Mark Showalter, a planetary astronomer at the SETI Institute in Mountain View, California, and a co-author of the new paper. "Naiad and Thalassa have probably been locked together in this configuration for a very long time, because it makes their orbits more stable. They maintain the peace by never getting too close."

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Tool for studying decision-making is ineffective for training better behavior

A two-step task commonly used to study people's decision-making behaviors does not appear to be effective for training people to rely more on goal-oriented behaviors and less on habitual behaviors. Elmar Grosskurth of Inselspital University Hospital Bern, Switzerland, and colleagues present these findings in PLOS Computational Biology.

Some psychiatric disorders, such as addiction and obsessive-compulsive disorder, heavily rely on habitual behaviors at the expense of goal-oriented behaviors. Many studies have used a two-step experimental approach to investigate these behaviors. In the new study, Grosskurth and colleagues tested whether the two-step task could also be used to train people to engage in more goal-oriented strategies. Such a training would be beneficial for the above-mentioned psychiatric disorders to reduce habitual behaviors and enhance goal-directed decisions.

The researchers recruited 33 healthy participants who each completed 1005 trials of the two-step task over five weeks. In the first step of each trial, the participant chose between two different shapes on a computer screen. That choice was associated with a probability that influenced whether one or another of two new pairs of shapes now appeared. The participant then chose a shape from the second pair and received a small monetary reward or not, depending on their choice.

As usual for the two-step task, the participants showed a mix of goal-directed versus habitual behaviors in making their choices. However, analysis of their choices across five weeks of intensive training suggests that the training had no effect on goal-directed or habitual behavior, nor on the balance between the two. Neuroimaging of brain circuits thought to underlie these behaviors supported these findings, showing that the training did not affect brain activity.

"Our findings suggest that the two-step task in its current form has methodological drawbacks which are not suitable for training purposes," says Lisa Holper, the senior author of the study. This result was observed in healthy people and may be different under psychiatric conditions.

The authors suggest that future work could focus on developing a more sophisticated version of the two-step task that could be used for psychiatric patients to train goal-directed behaviors while reducing habitual behavior.

From Science Daily

DNA data offers scientific look at 500 years of extramarital sex in Western Europe

These days it's easy to resolve questions about paternity with over-the-counter test kits. Now, researchers have put DNA evidence together with long-term genealogical data to explore similar questions of biological fatherhood on a broad scale among people living in parts of Western Europe over the last 500 years.

The findings reported in Current Biology on November 14 yielded some surprises. While the number of so-called extra-pair paternity (EPP) events overall was (not surprisingly) fairly low, their frequency varied considerably among people depending on their circumstances. Specifically, evidence of EPP events turned up much more often in people of lower socioeconomic status who lived in densely populated cities in the 19th century.

"Of course, extra-pair paternity, especially due to adultery, is a popular topic in gossip, jokes, TV series, and literature," said Maarten Larmuseau of KU Leuven and Histories, Belgium. "But scientific knowledge on this phenomenon is still highly limited, especially regarding the past.

"Our research shows that the chance of having extra-pair paternity events in your family history really depends on the social circumstances of your ancestors. If they lived in cities and were of the lower socioeconomic classes, the chances that there were EPP events in your family history are much higher than if they were farmers."

Evolutionarily speaking, it's clear that remaining faithful to one's partner isn't always the most advantageous strategy. Males may benefit from straying by siring extra offspring; females may benefit by mating with superior males. But in human societies over time, how often has EPP really happened?

In the new study, Larmuseau's team took the first broad look at this question to find that social context really matters. Their study covered a time period of several centuries during which there were dramatic changes in the human social environment, including the rapid urbanization that accompanied the Industrial Revolution in 19th century Western Europe. To estimate historical EPP rates among married couples, they identified 513 pairs of contemporary adult males living in Belgium and the Netherlands who, based on genealogical evidence, shared a common paternal ancestor and therefore -- barring an EPP event -- should have carried the same Y chromosome.

The evidence showed no significant difference in EPP rates between countries despite key religious differences, they report. But they varied widely with socioeconomic status and population density. The EPP rate was much lower among farmers and more well-to-do craftsmen and merchants (about 1%) than among lower class laborers and weavers (about 4%).

EPP rates also rose with population density. Putting the two together, the researchers report that the estimated EPP rates for the families varied by more than one order of magnitude, from about 0.5% among the middle to high classes and farmers living in the most sparsely populated towns to almost 6% for the low socioeconomic classes living in the most densely populated cities.

The researchers say the findings support evolutionary theories suggesting that individual incentives and opportunities for seeking or preventing extra-pair mating should depend on the social context. They also debunk the notion that EPP rates in Western society are generally high, they say, noting that the evidence puts average rates at around 1%.

Read more at Science Daily

Ancient Egyptians gathered birds from the wild for sacrifice and mummification

Ibis

In ancient Egypt, Sacred Ibises were collected from their natural habitats to be ritually sacrificed, according to a study released November 13, 2019 in the open-access journal PLOS ONE by Sally Wasef of Griffith University, Australia and colleagues.

Egyptian catacombs are famously filled with the mummified bodies of Sacred Ibises. Between around 664BC and 250AD, it was common practice for the birds to be sacrificed, or much more rarely worshipped in ritual service to the god Thoth, and subsequently mummified. In ancient sites across Egypt, these mummified birds are stacked floor to ceiling along kilometers of catacombs, totaling many millions of birds. But how the Egyptians got access to so many birds has been a mystery; some ancient texts indicate that long-term farming and domestication may have been employed.

In this study, Wasef and colleagues collected DNA from 40 mummified Sacred Ibis specimens from six Egyptian catacombs dating to around 2500 years ago and 26 modern specimens from across Africa. 14 of the mummies and all of the modern specimens yielded complete mitochondrial genome sequences. These data allowed the researchers to compare genetic diversity between wild populations and the sacrificed collections.

If the birds were being domesticated and farmed, the expected result would be low genetic diversity due to interbreeding of restricted populations, but in contrast, this study found that the genetic diversity of mummified Ibises within and between catacombs was similar to that of modern wild populations. This suggests that the birds were not the result of centralized farming, but instead short-term taming. The authors suggest the birds were likely tended in their natural habitats or perhaps farmed only in the times of year they were needed for sacrifice.

The authors add: "We report the first complete ancient genomes of the Egyptian Sacred Ibis mummies, showing that priests sustained short-term taming of the wild Sacred Ibis in local lakes or wetlands contrary to centralised industrial scale farming of sacrificial birds."

From Science Daily

Experts unlock key to photosynthesis, a find that could help us meet food security demands

Green leaf in sunlight.

Scientists have solved the structure of one of the key components of photosynthesis, a discovery that could lead to photosynthesis being 'redesigned' to achieve higher yields and meet urgent food security needs.

The study, led by the University of Sheffield and published today in the journal Nature, reveals the structure of cytochrome b6f -- the protein complex that significantly influences plant growth via photosynthesis.

Photosynthesis is the foundation of life on Earth providing the food, oxygen and energy that sustains the biosphere and human civilisation.

Using a high-resolution structural model, the team found that the protein complex provides the electrical connection between the two light-powered chlorophyll-proteins (Photosystems I and II) found in the plant cell chloroplast that convert sunlight into chemical energy.

Lorna Malone, the first author of the study and a PhD student in the University of Sheffield's Department of Molecular Biology and Biotechnology, said: "Our study provides important new insights into how cytochrome b6f utilises the electrical current passing through it to power up a 'proton battery'. This stored energy can then be then used to make ATP, the energy currency of living cells. Ultimately this reaction provides the energy that plants need to turn carbon dioxide into the carbohydrates and biomass that sustain the global food chain."

The high-resolution structural model, determined using single-particle cryo-electron microscopy, reveals new details of the additional role of cytochrome b6f as a sensor to tune photosynthetic efficiency in response to ever-changing environmental conditions. This response mechanism protects the plant from damage during exposure to harsh conditions such as drought or excess light.

Dr Matt Johnson, reader in Biochemistry at the University of Sheffield and one of the supervisors of the study added: "Cytochrome b6f is the beating heart of photosynthesis which plays a crucial role in regulating photosynthetic efficiency.

"Previous studies have shown that by manipulating the levels of this complex we can grow bigger and better plants. With the new insights we have obtained from our structure we can hope to rationally redesign photosynthesis in crop plants to achieve the higher yields we urgently need to sustain a projected global population of 9-10 billion by 2050."

The research was conducted in collaboration with the Astbury Centre for Structural Molecular Biology at the University of Leeds.

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Extinct giant ape directly linked to the living orangutan

Modern-day orangutan

By using ancient protein sequencing, researchers have retrieved genetic information from a 1.9 million year old extinct, giant primate that used to live in a subtropical area in southern China. The genetic information allows the researchers to uncover the evolutionary position of Gigantopithecus blacki, a three-meter tall and may be up to 600 kg heavy primate, revealing the orangutan as its closest, living relative.

It is the first time that genetic material this old has been retrieved from a warm, humid environment. The study is published in the scientific journal Nature, and the results are groundbreaking within the field of evolutionary biology, according to Frido Welker, Postdoc at the Globe Institute at the Faculty of Health and Medical Sciences and first author of the study.

'Primates are relatively close to humans, evolutionary speaking. With this study, we show that we can use protein sequencing to retrieve ancient genetic information from primates living in subtropical areas even when the fossil is two million years old. Until now, it has only been possible to retrieve genetic information from up to 10,000-year-old fossils in warm, humid areas. This is interesting, because ancient remains of the supposed ancestors of our species, Homo sapiens, are also mainly found in subtropical areas, particularly for the early part of human evolution. This means that we can potentially retrieve similar information on the evolutionary line leading to humans', says Frido Welker.

Today, scientists know that the human and the chimpanzee lineages split around seven or eight million years ago. With the previous methodologies though, they could only retrieve human genetic information not older than 400,000 years. The new results show the possibility to extend the genetic reconstruction of the evolutionary relationships between our species and extinct ones further back in time, at least up to two million years -- covering a much larger portion of the entire human evolution.

Analyzing ancient dental enamel proteins using mass spectrometry-based proteomics

In a recent study, also published on Nature, Enrico Cappellini, Associate Professor at the Globe Institute and senior author on this study, initially demonstrated, together with an international team of colleagues, the massive potential of ancient protein sequencing.

'By sequencing proteins retrieved from dental enamel about two million years old, we showed it is possible to confidently reconstruct the evolutionary relationships of animal species that went extinct too far away in time for their DNA to survive till now. In this study, we can even conclude that the lineages of orangutan and Gigantopithecus split up about 12 million years ago', says Enrico Cappellini.

Sequencing protein remains two million years old was made possible by stretching to its limits the technology at the base of proteomic discovery: mass spectrometry. State of the art mass spectrometers and the top palaeoproteomics expertise needed to get the best out of such sophisticated instrumentation are key resources deriving from the decade-long strategic collaboration with Jesper Velgaard Olsen, Professor at Novo Nordisk Foundation Center for Protein Research and co-author on this study.

The mystery of Gigantopithecus

The fossil evidence attributed to Gigantopithecus was initially discovered in southern China in 1935, and it is currently limited to just a few lower jaws and lots of teeth. No complete skull and no other bone from the rest of the skeleton has been found so far. As a result, there has been a lot of speculation about the physical appearance of this mysterious animal.

'Previous attempts to understand which could be the living organism most similar to Gigantopithecus could only be based on the comparison of the shape of the fossils with skeletal reference material from living great apes. Ancient DNA analysis was not an option, because Gigantopithecus went extinct approximately 300,000 years ago, and in the geographic area Gigantopithecus occupied no DNA older than approximately 10,000 years has been retrieved so far. Accordingly, we decided to sequence dental enamel proteins to reconstruct its evolutionary relation with living great apes, and we found that orangutan is Gigantopithecus' closest living relative', says Enrico Cappellini.

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Spot the difference: Two identical-looking bird species with very different genes

New research by the Milner Centre for Evolution academics in collaboration with Sun Yat-sen University in Guangzhou (China) shows that Southern and Northern breeding populations of plovers in China are in fact two distinct species: Kentish plover (Charadrius alexandrinus) in the North and white-faced plover (Charadrius dealbatus) in the South.

Using state-of-the-art genomics analysis, the team revealed that the Kentish plover and white-faced plover diverged approximately half a million years ago due to cycling sea level changes between the Eastern and Southern China Sea causing intermittent isolation of the two regional populations.

The results show that despite looking very similar, the two plover species have high levels of genetic divergence on their sex chromosomes, (Z chromosome) than on other chromosomes, indicating that sexual selection might play a role to in the evolution of the two species.

Dr Yang Liu, a visiting scholar from Sun Yat-sen University at the Milner Centre for Evolution, led the work. He said: "The initial divergence of the two plovers was probably triggered by the geographical isolation.

"However, other factors, such as ecological specialisations, behavioural divergence, and sexual selection could also contribute to the speciation of the two species.

"In future studies, we wish to understand how these factors operate on plover populations."

Dr Araxi Urrutia, Senior Lecturer from the Milner Centre for Evolution at the University of Bath, said: "Speciation -- the process by which new species evolve -- is the basis of all biodiversity around us, yet our understanding of how new species arise is still limited.

"By studying recent divergence patterns, where the two species still able to reproduce with each other, we can better understand the conditions on which all species, including our own species, have evolved."

The team have published their findings in two papers. The first paper revealed small to moderate differences between Kentish and white-faced plover in their appearance (morphology), diet and behaviour. The second study produced the first genome of the Kentish plover, one of the few published genomes from shorebirds.

Dr Liu said: "The genomic resources generated by our team will help investigate other important evolutionary questions, such as genetic basis of local adaptation, migration and mating system variation."

Led by Dr Liu, the research team also included Dr Araxi Urrutia, Professor Tamás Székely and a former NERC funded PhD student Dr Kathryn Maher.

The research is part of a long-term study on the Kentish plover that has been running for over 30 years, led by Professor Székely.

He said: "Plovers are excellent model systems to understand breeding system evolution.

"These small, drab shorebirds have worldwide distribution, and they are amenable to field studies.

Read more at Science Daily

At future Mars landing spot, scientists spy mineral that could preserve signs of past life

Next year, NASA plans to launch a new Mars rover to search for signs of ancient life on the Red Planet. A new study shows that the rover's Jezero crater landing site is home to deposits of hydrated silica, a mineral that just happens to be particularly good at preserving biosignatures.

"Using a technique we developed that helps us find rare, hard-to-detect mineral phases in data taken from orbiting spacecraft, we found two outcrops of hydrated silica within Jezero crater," said Jesse Tarnas, a Ph.D. student at Brown University and the study's lead author. "We know from Earth that this mineral phase is exceptional at preserving microfossils and other biosignatures, so that makes these outcrops exciting targets for the rover to explore."

The research is published in Geophysical Research Letters.

NASA announced late last year that its Mars 2020 rover would be headed to Jezero, which appears to have been home to an ancient lake. The star attraction at Jezero is a large delta deposit formed by ancient rivers that fed the lake. The delta would have concentrated a wealth of material from a vast watershed. Deltas on Earth are known to be good at preserving signs of life. Adding hydrated silica to the mix at Jezero increases that preservation potential, the researchers say. One of the silica deposits was found on the edge of the delta at low elevation. It's possible that the minerals formed in place and represent the bottom layer of the delta deposit, which is a great scenario for preserving signs of life.

"The material that forms the bottom layer of a delta is sometimes the most productive in terms of preserving biosignatures," said Jack Mustard, a professor at Brown and study co-author. "So if you can find that bottomset layer, and that layer has a lot of silica in it, that's a double bonus."

For the study, researchers used data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument that flies aboard NASA's Mars Reconnaissance Orbiter. The technique applied to the CRISM data used big data analysis methods to tease out the weak spectral signature of the silica deposits.

While the geologic context of the deposits suggests they could have formed at the base of the delta, it's not the only possibility, the researchers say. The minerals could have formed upstream in the watershed that fed Jezero and been washed subsequently into the crater, by volcanic activity or later episodes of water saturation in the Jezero crater lake. The rover should be able to isolate the real source, the researchers say.

"We can get amazing high-resolution images and compositional data from orbit, but there's a limit on what we can discern in terms of how these minerals formed," Tarnas said. "Given instruments on the rover, however, we should be able to constrain the origin of these deposits."

The rover will be able to perform fine-scale chemical analysis of the deposits and provide a close-up view of how the deposits are situated in relation to surrounding rock units. It will also have a sensor similar to CRISM to link orbital and lander data. That will go a long way to determining how the deposits formed. What's more, one instrument aboard the rover is able to look for complex organic material. If the silica deposits have high concentrations of organics, it would be an especially intriguing find, the researchers say.

And in addition to the work the rover does on site, it will also cache samples to be returned to Earth by future missions.

Read more at Science Daily

The smell of old books could help preserve them

Old books give off a complex mélange of odors, ranging from pleasant (almonds, caramel and chocolate) to nasty (formaldehyde, old clothes and trash). Detecting early signs of paper degradation could help guide preservation efforts, but most techniques destroy the very paper historians want to save. Now, researchers reporting in ACS Sensors have developed an electronic nose that can non-destructively sniff out odors emitted by books of different paper compositions, conditions and ages.

Paper is made primarily of cellulose, along with other plant components, and additives that improve the paper's properties. Cellulose is resistant to ageing, but the other paper components are much more vulnerable to degradation by heat, humidity and UV light. Before 1845, paper was made mainly from cotton and linen rags, which were relatively pure forms of cellulose and therefore quite stable. Then, in 1845, inventors developed a process to make paper from wood-pulp fibers. This paper is less durable than that made from cotton, but wood is cheaper and more readily available. In 1980, the advent of acid-free paper was a boon to preservationists because it degrades much more slowly than acidic wood-pulp paper. Marta Veríssimo, M. Teresa Gomes and colleagues wanted to develop an electronic nose that could non-destructively detect early signs of paper degradation from the volatile organic compounds (VOCs) books emit.

The researchers collected 19 books published from 1567 to 2016. They classified the books by time period, paper composition, color and visible state. Then, the researchers collected VOCs released from the books and detected the gases with an electronic nose containing six sensors that selectively bound different VOCs. The electronic nose clearly distinguished between paper from cotton or linen rags and paper from wood, as well as among books from three different time periods. Unexpectedly, some books published after 1990 still contained acidic paper, which the sensor discriminated from books with acid-free paper. And finally, the device sniffed out yellowing books, and new and used books from the same time period. The sensitive new method could help identify books in need of preservation, as well as help protect books from VOCs emitted by their neighbors on a shelf.

From Science Daily

Distant worlds under many suns

Illustration of exoplanet with two suns.

Is Earth the only habitable planet in the universe or are there more worlds somewhere out there that are capable of supporting life? And if there are, what might they look like? In a bid to answer these fundamental questions, scientists are searching space for exoplanets: distant worlds that orbit other stars outside our solar system.

More than 4,000 exoplanets are known to date, most of them orbiting single stars like our Sun. Now astrophysicist Dr Markus Mugrauer of Friedrich Schiller University Jena, Germany, has discovered and characterised many new multiple star systems that contain exoplanets. The findings confirm assumptions that the existence of several stars influences the process by which planets are formed and develop. The study by Mugrauer, of the Astrophysical Institute and University Observatory of the University of Jena, has now been published in the specialist journal Monthly Notices of the Royal Astronomical Society.

Space telescope provides precise data

"Multiple star systems are very common in our Milky Way," explains Mugrauer. "If such systems include planets, they are of particular interest to Astrophysics, because the planetary systems in them can differ from our solar system in fundamental ways." To find out more about these differences, Mugrauer searched more than 1,300 exoplanet host stars with exoplanets orbiting them to see whether they have companion stars. To this end, he accessed the precise observation data of the Gaia space telescope, which is operated by the European Space Agency (ESA).

In this way, he succeeded in demonstrating the existence of around 200 companion stars to planetary host stars that are up to 1,600 light years away from the Sun. With the help of the data, Mugrauer was also able to characterise the companion stars and their systems in more detail. He found that there are both tight systems with distances of only 20 astronomical units (au) -- which in our solar system corresponds approximately to the distance between the Sun and Uranus -- as well as systems with stars that are over 9,000 au from each other.

Red and white dwarfs

The companion stars also vary as to their mass, temperature and stage of evolution. The heaviest among them weigh 1.4 times more than our Sun, while the lightest have only 8 per cent of the Sun's mass. Most of the companion stars are low-mass, cool dwarf stars that glow faintly red. However, eight white dwarfs were also identified among the faint stellar companions. A white dwarf is the burnt-out core of a sun-like star, which is only about as big as our Earth, but half as heavy as our Sun. These observations show that exoplanets can indeed survive the final evolutionary stage of a nearby sun-like star.

Double, triple and quadruple star systems with exoplanets

The majority of the star systems with exoplanets identified in the study have two stars. However, some two dozen hierarchical triple star systems and even a quadruple star system were detected. In the range of distances investigated, of between approximately 20 and 10,000 astronomical units, a total of 15 per cent of the stars studied have at least one companion star. This is only about half the frequency expected in general for solar-like stars. In addition, the companion stars detected show distances about five times greater than in ordinary systems.

"These two factors taken together could indicate that the influence of several stars in a star system disrupts the process of planet formation as well as the further development of their orbits," says Mugrauer. The cause of this could be first the gravitational impact of a stellar companion on the gas and dust disc in which planets form around their host star. Later, the gravitation of the stellar companion influences the motion of the planets around their host star.

Read more at Science Daily

A runaway star ejected from the galactic heart of darkness

Astronomers have spotted an ultrafast star, traveling at a blistering 6 million km/h, that was ejected by the supermassive black hole at the heart at the Milky Way five million years ago.

The discovery of the star, known as S5-HVS1, was made by Carnegie Mellon University Assistant Professor of Physics Sergey Koposov as part of the Southern Stellar Stream Spectroscopic Survey (S5). Located in the constellation of Grus -- the Crane -- S5-HVS1 was found to be moving ten times faster than most stars in the Milky Way.

"The velocity of the discovered star is so high that it will inevitably leave the galaxy and never return," said Douglas Boubert from the University of Oxford, a co-author on the study.

Astronomers have wondered about high velocity stars since their discovery only two decades ago. S5-HVS1 is unprecedented due to its high speed and close passage to the Earth, "only" 29 thousand light years away. With this information, astronomers could track its journey back into the center of the Milky Way, where a four million solar mass black hole, known as Sagittarius A*, lurks.

"This is super exciting, as we have long suspected that black holes can eject stars with very high velocities. However, we never had an unambiguous association of such a fast star with the galactic center," said Koposov, the lead author of this work and member of Carnegie Mellon's McWilliams Center for Cosmology. "We think the black hole ejected the star with a speed of thousands of kilometers per second about five million years ago. This ejection happened at the time when humanity's ancestors were just learning to walk on two feet."

Superfast stars can be ejected by black holes via the Hills Mechanism, proposed by astronomer Jack Hills thirty years ago. Originally, S5-HSV1 lived with a companion in a binary system, but they strayed too close to Sagittarius A*. In the gravitational tussle, the companion star was captured by the black hole, while S5-HVS1 was thrown out at extremely high speed.

"This is the first clear demonstration of the Hills Mechanism in action," said Ting Li from Carnegie Observatories and Princeton University, and leader of the S5 Collaboration. "Seeing this star is really amazing as we know it must have formed in the galactic center, a place very different to our local environment. It is a visitor from a strange land."

The discovery of S5-HVS1 was made with the 3.9-meter Anglo-Australian Telescope (AAT) near Coonabarabran, NSW, Australia, coupled with superb observations from the European Space Agency's Gaia satellite, that allowed the astronomers to reveal the full speed of the star and its journey from the center of the Milky Way.

"The observations would not be possible without the unique capabilities of the 2dF instrument on the AAT," said Daniel Zucker, an astronomer at Macquarie University in Sydney, Australia, and a member of the S5 executive committee. "It's been conducting cutting-edge research for over two decades and still is the best facility in the world for our project."

These results were published on November 4 online in the Monthly Notices of the Royal Astronomical Society, and the S5 collaboration unites astronomers from the United States, United Kingdom, Australia and Chile.

Read more at Science Daily

With Mars methane mystery unsolved, Curiosity serves scientists a new one: Oxygen

For the first time in the history of space exploration, scientists have measured the seasonal changes in the gases that fill the air directly above the surface of Gale Crater on Mars. As a result, they noticed something baffling: oxygen, the gas many Earth creatures use to breathe, behaves in a way that so far scientists cannot explain through any known chemical processes.

Over the course of three Mars years (or nearly six Earth years) an instrument in the Sample Analysis at Mars (SAM) portable chemistry lab inside the belly of NASA's Curiosity rover inhaled the air of Gale Crater and analyzed its composition. The results SAM spit out confirmed the makeup of the Martian atmosphere at the surface: 95% by volume of carbon dioxide (CO2), 2.6% molecular nitrogen (N2), 1.9% argon (Ar), 0.16% molecular oxygen (O2), and 0.06% carbon monoxide (CO). They also revealed how the molecules in the Martian air mix and circulate with the changes in air pressure throughout the year. These changes are caused when CO2 gas freezes over the poles in the winter, thereby lowering the air pressure across the planet following redistribution of air to maintain pressure equilibrium. When CO2 evaporates in the spring and summer and mixes across Mars, it raises the air pressure.

Within this environment, scientists found that nitrogen and argon follow a predictable seasonal pattern, waxing and waning in concentration in Gale Crater throughout the year relative to how much CO2 is in the air. They expected oxygen to do the same. But it didn't. Instead, the amount of the gas in the air rose throughout spring and summer by as much as 30%, and then dropped back to levels predicted by known chemistry in fall. This pattern repeated each spring, though the amount of oxygen added to the atmosphere varied, implying that something was producing it and then taking it away.

"The first time we saw that, it was just mind boggling," said Sushil Atreya, professor of climate and space sciences at the University of Michigan in Ann Arbor. Atreya is a co-author of a paper on this topic published on November 12 in the Journal of Geophysical Research: Planets.

As soon as scientists discovered the oxygen enigma, Mars experts set to work trying to explain it. They first double- and triple-checked the accuracy of the SAM instrument they used to measure the gases: the Quadrupole Mass Spectrometer. The instrument was fine. They considered the possibility that CO2 or water (H2O) molecules could have released oxygen when they broke apart in the atmosphere, leading to the short-lived rise. But it would take five times more water above Mars to produce the extra oxygen, and CO2 breaks up too slowly to generate it over such a short time. What about the oxygen decrease? Could solar radiation have broken up oxygen molecules into two atoms that blew away into space? No, scientists concluded, since it would take at least 10 years for the oxygen to disappear through this process.

"We're struggling to explain this," said Melissa Trainer, a planetary scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland who led this research. "The fact that the oxygen behavior isn't perfectly repeatable every season makes us think that it's not an issue that has to do with atmospheric dynamics. It has to be some chemical source and sink that we can't yet account for."

To scientists who study Mars, the oxygen story is curiously similar to that of methane. Methane is constantly in the air inside Gale Crater in such small quantities (0.00000004% on average) that it's barely discernable even by the most sensitive instruments on Mars. Still, it's been measured by SAM's Tunable Laser Spectrometer. The instrument revealed that while methane rises and falls seasonally, it increases in abundance by about 60% in summer months for inexplicable reasons. (In fact, methane also spikes randomly and dramatically. Scientists are trying to figure out why.)

With the new oxygen findings in hand, Trainer's team is wondering if chemistry similar to what's driving methane's natural seasonal variations may also drive oxygen's. At least occasionally, the two gases appear to fluctuate in tandem.

"We're beginning to see this tantalizing correlation between methane and oxygen for a good part of the Mars year," Atreya said. "I think there's something to it. I just don't have the answers yet. Nobody does."

Oxygen and methane can be produced both biologically (from microbes, for instance) and abiotically (from chemistry related to water and rocks). Scientists are considering all options, although they don't have any convincing evidence of biological activity on Mars. Curiosity doesn't have instruments that can definitively say whether the source of the methane or oxygen on Mars is biological or geological. Scientists expect that non-biological explanations are more likely and are working diligently to fully understand them.

Trainer's team considered Martian soil as a source of the extra springtime oxygen. After all, it's known to be rich in the element, in the form of compounds such as hydrogen peroxide and perchlorates. One experiment on the Viking landers showed decades ago that heat and humidity could release oxygen from Martian soil. But that experiment took place in conditions quite different from the Martian spring environment, and it doesn't explain the oxygen drop, among other problems. Other possible explanations also don't quite add up for now. For example, high-energy radiation of the soil could produce extra O2 in the air, but it would take a million years to accumulate enough oxygen in the soil to account for the boost measured in only one spring, the researchers report in their paper.

"We have not been able to come up with one process yet that produces the amount of oxygen we need, but we think it has to be something in the surface soil that changes seasonally because there aren't enough available oxygen atoms in the atmosphere to create the behavior we see," said Timothy McConnochie, assistant research scientist at the University of Maryland in College Park and another co-author of the paper.

The only previous spacecraft with instruments capable of measuring the composition of the Martian air near the ground were NASA's twin Viking landers, which arrived on the planet in 1976. The Viking experiments covered only a few Martian days, though, so they couldn't reveal seasonal patterns of the different gases. The new SAM measurements are the first to do so. The SAM team will continue to measure atmospheric gases so scientists can gather more detailed data throughout each season. In the meantime, Trainer and her team hope that other Mars experts will work to solve the oxygen mystery.

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Good noise, bad noise: White noise improves hearing

Noise is not the same as noise -- and even a quiet environment does not have the same effect as white noise. With a background of continuous white noise, hearing pure sounds becomes even more precise, as researchers from the University of Basel have shown in a study in Cell Reports. Their findings could be applied to the further development of cochlear implants.

Despite the importance of hearing in human communication, we still understand very little of how acoustic signals are perceived and how they are processed to allow us to make sense of them. One thing is clear though: the more precisely we can distinguish sound patterns, the better our hearing is. But how does the brain manage to distinguish between relevant and less relevant information -- especially in an environment with background noise?

Exploring the "auditory brain"

Researchers led by Prof. Dr. Tania Rinaldi Barkat from the Department of Biomedicine at the University of Basel have investigated the neuronal foundation of sound perception and sound discrimination in a challenging sound environment. The focus was on research into the auditory cortex -- the "auditory brain," that is, the area of the brain that processes acoustic stimuli. The resulting activity patterns stem from measurements in a mouse brain.

As is well known, the distinction between sounds becomes more difficult the closer they are in the frequency spectrum. Initially, the researchers assumed that additional noise could make such a hearing task even more difficult. However, the opposite was observed: The team was able to demonstrate that the brain's ability to distinguish subtle tone differences improved when white noise was added to the background. Compared to a quiet environment, the noise thus facilitated auditory perception.

Noise reduces neuronal activity

The data of the research group showed that white noise significantly inhibited the activity of the nerve cells in the auditory cortex. Paradoxically, this suppression of the neuronal excitation led to a more precise perception of the pure tones. "We found that less overlap occurred between populations of neurons during two separate tone representations," explains Professor Tania Barkat. "As a result, the overall reduction in neuronal activity produced a more distinct tone representation."

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Bacteria may contribute more to climate change as planet heats up

Salt lake at Coorong National Park, South Australia.

As bacteria adapt to hotter temperatures, they speed up their respiration rate and release more carbon, potentially accelerating climate change.

By releasing more carbon as global temperatures rise, bacteria and related organisms called archaea could increase climate warming at a faster rate than current models suggest. The new research, published today in Nature Communications by scientists from Imperial College London, could help inform more accurate models of future climate warming.

Bacteria and archaea, collectively known as prokaryotes, are present on every continent and make up around half of global biomass -- the total weight of all organisms on Earth.

Most prokaryotes perform respiration that uses energy and releases carbon dioxide -- just like we do when we breathe out. The amount of carbon dioxide released during a given time period depends on the prokaryote's respiration rate, which can change in response to temperature.

However, the exact relationship between temperature, respiration rate and carbon output has been uncertain. Now, by bringing together a database of respiration rate changes according to temperature from 482 prokaryotes, researchers have found the majority will increase their carbon output in response to higher temperatures to a greater degree than previously thought.

Lead researcher Dr Samraat Pawar, from the Department of Life Sciences at Imperial, said: "In the short term, on a scale of days to hours, individual prokaryotes will increase their metabolism and produce more carbon dioxide. However, there is still a maximum temperature at which their metabolism becomes inefficient.

"In the longer term, over years, these prokaryote communities will evolve to be more efficient at higher temperatures, allowing them to further increase their metabolism and their carbon output.

"Rising temperatures therefore cause a 'double whammy' effect on many prokaryote communities, allowing them to function more efficiently in both the short and long term, and creating an even larger contribution to global carbon and resulting temperatures."

The researchers compiled prokaryote responses to temperature changes from across the world and in all different conditions -- from salty Antarctic lakes below 0°C to thermal pools above 120°C.

They found that prokaryotes that usually operate in a medium temperature range -- below 45°C -- show a strong response to changing temperature, increasing their respiration in both the short term (days to weeks) and long term (months to years).

Prokaryotes that operate in higher temperature ranges -- above 45°C -- did not show such a response, but since they operate at such high temperatures to begin with, they are unlikely to be impacted by climate change.

The short-term responses of medium-temperature prokaryotes to warming were larger than those reported for eukaryotes -- organisms with more complex cells, including all plants, fungi and animals.

The team built a mathematical model that predicted how these respiration rate changes would affect the carbon output of prokaryote communities. This revealed that short- and long-term changes to respiration rate would combine to create a larger-than-expected rise in carbon output, which is currently unaccounted for in ecosystem and climate models.

Lead author of the new research, PhD student Thomas Smith from the Department of Life Sciences, said: "Most climate models assume that all organisms' respiration rates respond to temperature in the same way, but our study shows that bacteria and archaea are likely to depart from the 'global average'.

"Given that these micro-organisms are likely to be significant contributors to total respiration and carbon output in many ecosystems, it's important for climate models to take into account their higher sensitivity to temperature change at both short and long timescales.

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Specific neurons that map memories now identified in the human brain

Brain-map overlay concept illustration.

An important aspect of human memory is our ability to conjure specific moments from the vast array of experiences that have occurred in any given setting. For example, if asked to recommend a tourist itinerary for a city you have visited many times, your brain somehow enables you to selectively recall and distinguish specific memories from your different trips to provide an answer.

Studies have shown that declarative memory -- the kind of memory you can consciously recall like your home address or your mother's name -- relies on healthy medial temporal lobe structures in the brain, including the hippocampus and entorhinal cortex (EC). These regions are also important for spatial cognition, demonstrated? by the Nobel-Prize-winning discovery of "place cells" and "grid cells" in these regions -- neurons that activate to represent specific locations in the environment during navigation (akin to a GPS). However, it has not been clear if or how this "spatial map" in the brain relates to a person's memory of events at those locations, and how neuronal activity in these regions enables us to target a particular memory for retrieval among related experiences.

A team led by neuroengineers at Columbia Engineering has found the first evidence that individual neurons in the human brain target specific memories during recall. They studied recordings in neurosurgical patients who had electrodes implanted in their brains and examined how the patients' brain signals corresponded to their behavior while performing a virtual-reality (VR) object-location memory task. The researchers identified "memory-trace cells" whose activity was spatially tuned to the location where subjects remembered encountering specific objects. The study is published today in Nature Neuroscience.

"We found these memory-trace neurons primarily in the entorhinal cortex (EC), which is one of the first regions of the brain affected by the onset of Alzheimer 's disease," says Joshua Jacobs, associate professor of biomedical engineering, who directed the study. "Because the activity of these neurons is closely related to what a person is trying to remember, it is possible that their activity is disrupted by diseases like Alzheimer's, leading to memory deficits. Our findings should open up new lines of investigation into how neural activity in the entorhinal cortex and medial temporal lobe helps us target past events for recall, and more generally how space and memory overlap in the brain."

The team was able to measure the activity of single neurons by taking advantage of a rare opportunity: invasively recording from the brains of 19 neurosurgical patients at several hospitals, including the Columbia University Irving Medical Center. The patients had drug-resistant epilepsy and so had already had recording electrodes implanted in their brains for their clinical treatment. The researchers designed experiments as engaging and immersive VR computer games and the bedridden patients used laptops and handheld controllers to move through virtual environments. In performing the task, subjects first navigated through the environment to learn the locations of four unique objects. Then the researchers removed the objects and asked patients to move through the environment and mark the location of one specific object on each trial.

The team measured the activity of neurons as the patients moved through the environment and marked their memory targets. Initially, they identified purely spatially tuned neurons similar to "place cells" that always activated when patients moved through specific locations, regardless of the subjects' memory target. "These neurons seemed only to care about the person's spatial location, like a pure GPS," says Salman E. Qasim, Jacobs' PhD student and lead author of the study.

But the researchers also noticed that other neurons only activated in locations relevant to the memory the patient was recalling on that trial -- whenever patients were instructed to target a different memory for recall, these neurons changed their activity to match the new target's remembered location. What especially excited Jacobs and Qasim is that they could actually decode the specific memory a patient was targeting based on the activity of these neurons.

"Our study demonstrates that neurons in the human brain track the experiences we are willfully recalling, and can change their activity patterns to differentiate between memories. They're just like the pins on your Google map that mark the locations you remember for important events," Qasim says. "This discovery might provide a potential mechanism for our ability to selectively call upon different experiences from the past and highlights how these memories may influence our brain's spatial map."

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Ancient gas cloud reveals universe's first stars formed quickly

The discovery of a 13 billion-year-old cosmic cloud of gas enabled a team of Carnegie astronomers to perform the earliest-ever measurement of how the universe was enriched with a diversity of chemical elements. Their findings reveal that the first generation of stars formed more quickly than previously thought. The research, led by recent Carnegie-Princeton fellow Eduardo Bañados and including the Carnegie's Michael Rauch and Tom Cooper, is published by the Astrophysical Journal.

The Big Bang started the universe as a hot, murky soup of extremely energetic particles that was rapidly expanding. As this material spread out, it cooled, and the particles coalesced into neutral hydrogen gas. The universe stayed dark, without any luminous sources, until gravity condensed matter into the first stars and galaxies.

All stars, including this first generation, act as chemical factories, synthesizing almost all of the elements that make up the world around us. When the original stars exploded as supernovae, they spewed out the elements that they created, seeding the surrounding gas. Subsequent generations of stars incorporated these elements and steadily increased the chemical abundances of their surroundings.

But the first stars formed in a still pristine, cold universe. Consequently these initial stars produced elements in different proportions than those synthesized by younger stars, which were formed in an environment that was already enriched by earlier generations.

"Looking back in time far enough, one may expect cosmic gas clouds to show the tell-tale signature of the peculiar element ratios made by the first stars," said Rauch. "Peering even further back, we may ultimately witness the disappearance of most elements and the emergence of pristine gas."

Astronomers have long used quasars to learn about the chemical composition of cosmic gas over time, showing how different generations of stars enrich their surroundings.

"We found this ancient gas cloud when following up on an inventory of very distant quasars using the Magellan telescopes at Carnegie's Las Campanas Observatory in Chile," explained Bañados, who is now a group leader at the Max-Planck Institute in Heidelberg.

Quasars are tremendously luminous objects comprised of enormous black holes accreting matter at the centers of massive galaxies. Because the gas cloud exists between the quasar and us on Earth, the quasar's incredibly bright light must pass through it to get to us and astronomers can take advantage of this to understand the cloud's chemistry. This discovery presented an unprecedented opportunity to characterize a gas cloud from the first billion years of cosmic history.

The team found that the cloud's chemical makeup was quite modern, and not as primitive as expected if dominated by the first stars. Although it formed only 850 million years after the Big Bang, its chemical abundances were already as high as those typically seen in cosmic gas clouds that were formed several billion years later.

"Apparently, the first generation of stars had already expired by the time the cloud formed," Rauch explained. "This shows that the universe was rapidly swamped by the chemical products of later generations of stars, even before most of the present-day galaxies were in place."

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Free Internet access should be a basic human right: Study

Free internet access must be considered as a human right, as people unable to get online -- particularly in developing countries -- lack meaningful ways to influence the global players shaping their everyday lives, according to a new study.

As political engagement increasingly takes place online, basic freedoms that many take for granted including free expression, freedom of information and freedom of assembly are undermined if some citizens have access to the internet and others do not.

New research reveals that the internet could be a key way of protecting other basic human rights such as life, liberty, and freedom from torture -- a means of enabling billions of people to lead 'minimally decent lives'.

Dr. Merten Reglitz, Lecturer in Global Ethics at the University of Birmingham, has published his findings -- the first study of its kind -- in the Journal of Applied Philosophy.

"Internet access is no luxury, but instead a moral human right and everyone should have unmonitored and uncensored access to this global medium -- provided free of charge for those unable to afford it," commented Dr Reglitz.

"Without such access, many people lack a meaningful way to influence and hold accountable supranational rule-makers and institutions. These individuals simply don't have a say in the making of the rules they must obey and which shape their life chances."

He added that exercising free speech and obtaining information was now heavily dependent on having internet access. Much of today's political debate took place online and politically relevant information is shared on the internet -- meaning the relative value these freedoms held for people 'offline' had decreased.

Dr. Reglitz's research attributes to the internet unprecedented possibilities for protecting basic human rights to life, liberty and bodily integrity.

Whilst acknowledging that being online does not guarantee these rights, he cites examples of internet engagement that helped hold Government and institutions to account. These examples include:

• The 'Arab Spring'- new ways of global reporting on government atrocities.
• Documenting unjustified police violence against African Americans in the US.
• #MeToo campaign -- helping to 'out' sexual harassment of women by powerful men.

Dr. Reglitz defines 'moral human rights' as based on universal interests essential for a 'minimally decent life'. They must also be of such fundamental importance that if a nation is unwilling or unable to uphold these rights, the international community must step in.

The study points to a number of important political institutions which have committed to ensuring universal access for their populations, convinced that this goal is affordable:

• The Indian state of Kerala has declared universal internet access a human right and aims to provide it for its 35 million people by 2019.
• The European Union has launched the WiFi4EU initiative to provide 'every European village and city with free wireless internet access around main centres of public life by 2020.
• Global internet access is part of the UN Sustainable Development Goals, with the UN demanding states help to deliver universal Internet access in developing nations.

Dr Reglitz outlines the size of the challenge posed in providing universal internet access, noting that the UN's International Telecommunication Union estimated that, by the end of 2018, 51 percent of the world's population of 7 billion people had access to the Internet.

Many people in poorer parts of the world are still without internet access, but their number is decreasing as technology becomes cheaper. However, internet expansion has slowed in recent years, suggesting universal access will not occur without intentional promotion.

"Universal internet access need not cost the earth -- accessing politically important opportunities such as blogging, obtaining information, joining virtual groups, or sending and receiving emails does not require the latest information technology," commented Dr Reglitz.

"Web-capable phones allow people to access these services and public internet provision, such as public libraries, can help get people online where individual domestic access is initially too expensive."

He added that the human right to internet access was similar to the global right to health, which cannot require globally the highest possible medical treatment, as many states are too poor to provide such services and thus would face impossible demands.

Instead, poor states are called upon to provide basic medical services and work toward providing higher quality health care delivery. Similarly, such states should initially offer locations with public Internet access and develop IT infrastructure that increases access.

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Humans' ability to read dogs' facial expressions is learned, not innate

Dogs were the first domesticated animal, with humans and dogs sharing more than 40,000 years of social interactions and life together. According to the co-domestication hypothesis, this process allowed humans and dogs to evolve special emotional signals and cognitive skills that favor mutual understanding. We know, for example, that over the millennia, dogs have evolved the ability to understand human words, iconic signs, and other gestures, and research has shown that dogs can even use tone of voice and facial expressions to recognize human emotions. Beyond personal testimony from dog lovers, however, little attention has been paid to how well humans can understand their canine counterparts.

In the current study, led by Federica Amici of the Max Planck Institute for Evolutionary Anthropology and Juliane Bräuer of the Max Planck Institute for the Science of Human History, the researchers set out to understand how well humans can understand the emotional displays of dogs, and where that understanding comes from.

How well do we understand our species' best friend?

In order to test how well humans can understand the emotions behind dog facial expressions, researchers collected photographs of dogs, chimpanzees, and humans displaying either happy, sad, angry, neutral, or fearful emotions as substantiated by the photographers. They then recruited 89 adult participants and 77 child participants and categorized them according to their age, the dog-positivity of their cultural context, and the participants' personal history of dog ownership.

Each participant was presented with photographs of dogs, chimps, and humans, and asked to rate how much the individual in the picture displayed happiness, sadness, anger, or fear. Adults were also asked to determine the context in which the picture had been taken (e.g., playing with a trusted conspecific partner; directly before attacking a conspecific). The results of the study showed that, while some dog emotions can be recognized from early on, the ability to reliably recognize dog emotions is mainly acquired through age and experience. In adults, the probability of recognizing dog emotions was higher for participants who grew up in a cultural context with a positive attitude towards dogs, regardless of whether they owned a dog themselves.

Without a dog-positive context, we could be barking up the wrong tree

A dog-postive cultural background, one in which dogs are closely integrated into human life and considered highly important, may result in a higher level of passive exposure and increased inclination and interest in dogs, making humans better at recognizing dogs' emotions even without a history of personal dog ownership. "These results are noteworthy," says Amici, "because they suggest that it is not necessarily direct experience with dogs that affects humans' ability to recognize their emotions, but rather the cultural milieu in which humans develop."

The researchers also found that regardless of age or experience with dogs, all participants were able to identify anger and happiness reliably. While these results may suggest an innate ability favored by the co-domestication hypothesis, it is also possible that humans learn to recognize these emotions quickly, even with limited exposure. Other than anger and happiness, the children in the study were not good at identifying dog emotions. They recognized anger and happiness more reliably in dogs than in chimps, but otherwise identified dog emotions as poorly as they did chimpanzee emotions, suggesting that the ability to understand how dogs are feeling is not innate.

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Antibiotics: New substances break bacterial resistance

Researchers at the Martin Luther University Halle-Wittenberg (MLU) have developed a new, promising class of active ingredients against resistant bacteria. In initial tests in cell cultures and insects, the substances were at least as effective as common antibiotics. The new compounds target a special enzyme that only appears in bacteria in this specific form and that was not previously the target of other antibiotics. This is why bacteria have not yet developed any resistance to it. The team reported on its work in the journal Antibiotics.

Whether staphylococcus or the dreaded MRSA germs: resistant bacteria are a problem for physicians and patients worldwide. Only a few weeks ago, several large pharmaceutical companies also announced that they were further cutting back their own research work on new antibiotics. "However, in order to be able to treat infectious diseases reliably and in the long run, we need new active substances against which bacteria have not yet developed resistances," says Professor Andreas Hilgeroth from the Institute of Pharmacy at MLU. Together with researchers from the University of Greifswald and the Julius Maximilian University of Würzburg, he is working on these new active substances in a research project funded by the Federal Ministry of Education and Research.

The scientists have developed new active ingredients that attack a special enzyme that only appears in this form in pathogenic bacteria: the so-called pyruvate kinase. It plays an important role in metabolic processes. The idea: If the metabolism of the bacteria is obstructed, this ultimately renders them harmless. "The pyruvate kinase is an ideal target for new active ingredients. In the best case, the new substances only affect the bacterial enzyme and therefore the bacteria. If so, there should be only a few side effects. In addition, this new target structure can be used to break existing antibiotic resistance," Hilgeroth continues.

In cell experiments and initial tests on the larvae of the greater wax moth, a model organism used in life sciences, the researchers were able to confirm the efficacy of their new substances. The best compounds achieved at least as good results as conventional antibiotics. A patent application has also been filed for these active ingredients. "These initial results give us confidence that we are on the right track," Hilgeroth says. However, the ingredients still have to undergo numerous other tests before they can be tested in large-scale clinical trials on humans. Thus it may take more than ten years before the substances of the scientists from Halle, Würzburg and Greifswald become a marketable drug.

From Science Daily

How Human Population came from our ability to cooperate

Humans may owe their place as Earth's dominating species to their ability to share and cooperate with each other, according to a new study published in the Journal of Anthropological Research.

In "How There Got to Be So Many of Us: The Evolutionary Story of Population Growth and a Life History of Cooperation," Karen L. Kramer explores the deep past to discover the biological and social underpinnings that allowed humans to excel as reproducers and survivors. She argues that the human tendency to bear many children, engage in food sharing, division of labor, and cooperative childcare duties, sets us apart from our closest evolutionary counterparts, the apes.

In terms of population numbers, few species can compare to the success of humans. Though much attention on population size focuses on the past 200 years, humans were incredibly successful even before the industrial revolution, populating all of the world's environments with more than a billion people. Kramer uses her research on Maya agriculturalists of Mexico's Yucatan Peninsula and the Savanna Pumé hunter-gatherers of Venezuela to illustrate how cooperative childrearing increases the number of children that mothers can successfully raise and -- in environments where beneficial -- even speed up maturation and childbearing. Kramer argues that intergenerational cooperation, meaning that adults help support children, but children also share food and many other resources with their parents and other siblings, is at the center of humans' demographic success. "Together our diet and life history, coupled with an ability to cooperate, made us really good at getting food on the table, reproducing, and surviving," Kramer writes.

During her time with the Maya, Kramer constructed a demographic model that considered how much household members consume, as the family grows and matures across a mother's reproductive career, balanced against how much a mother, father, and their children contribute. She found that Maya children contributed a substantial amount of work to the family's survival, with those aged 7-14 spending on average 2 to 5 hours working each day, and children aged 15-18 spending as much as their parents, about 6.5 hours a day. Labor type varied, with younger children doing much of the childcare, older children and fathers fill in much of the day-today cost of growing and processing food and running the household. "If mothers and juveniles did not cooperate, mothers could support far fewer children over their reproductive careers," Kramer writes. "It is the strength of intergenerational cooperation that allows parents to raise more children than they would otherwise be able to on their efforts alone."

Kramer's second research population were the Savanna Pumé, hunter-gatherers in west-central Venezuela. The Savanna Pumé live in a high-mortality environment, with challenges such as seasonal undernutrition, high immunological stress, chronic intestinal parasite loads, endemic malaria, and no access to healthcare or immunization. Despite all this -- or perhaps, in part, because of it -- Savanna Pumé girls mature quickly and begin childbearing in their mid-teens. This pattern conforms with theoretic predictions that fast maturation optimizes fitness in a high-mortality environment. Early childbearing is also, however, associated with a higher probability of mothers losing their firstborn.

Kramer found that intergenerational cooperation mitigated these risks. "In this challenging environment, young Pumé females are buffered against seasonal fluctuations because food is shared with them, she writes. "If young Pumé mothers relied solely on their own efforts, they would have to delay childbearing until they matured as foragers and caretakers.

Humans' ability to reproduce more successfully than other great apes can be traced to differences in evolutionary strategy: humans bear more children, at a faster rate. They also provision food for juveniles, whereas other great apes stop helping children find food as soon as they have been weaned. Humans are able to shoulder the greater childcare burden through cooperation.

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Brains of girls and boys are similar, producing equal math ability

In 1992, Teen Talk Barbie was released with the controversial voice fragment, "Math class is hard." While the toy's release met with public backlash, this underlying assumption persists, propagating the myth that women do not thrive in science, technology, engineering and mathematic (STEM) fields due to biological deficiencies in math aptitude.

Jessica Cantlon at Carnegie Mellon University led a research team that comprehensively examined the brain development of young boys and girls. Their research shows no gender difference in brain function or math ability. The results of this research are available online in the November 8 issue of the journal Science of Learning.

"Science doesn't align with folk beliefs," said Cantlon, the Ronald J. and Mary Ann Zdrojkowski Professor of Developmental Neuroscience at CMU's Dietrich College of Humanities and Social Sciences and senior author on the paper. "We see that children's brains function similarly regardless of their gender so hopefully we can recalibrate expectations of what children can achieve in mathematics."

Cantlon and her team conducted the first neuroimaging study to evaluate biological gender differences in math aptitude of young children.

Her team used functional MRI to measure the brain activity in 104 young children (3- to 10-years-old; 55 girls) while watching an educational video covering early math topics, like counting and addition. The researchers compared scans from the boys and girls to evaluate brain similarity. In addition, the team examined brain maturity by comparing the children's scans to those taken from a group of adults (63 adults; 25 women) who watched the same math videos.

After numerous statistical comparisons, Cantlon and her team found no difference in the brain development of girls and boys. In addition, the researchers found no difference in how boys and girls processed math skills and were equally engaged while watching the educational videos. Finally, boys' and girls' brain maturity were statistically equivalent when compared to either men or women in the adult group.

"It's not just that boys and girls are using the math network in the same ways but that similarities were evident across the entire brain," said Alyssa Kersey, postdoctoral scholar at the Department of Psychology, University of Chicago and first author on the paper. "This is an important reminder that humans are more similar to each other than we are different."

The researchers also compared the results of the Test of Early Mathematics Ability, a standardized test for 3- to 8-year-old children, from 97 participants (50 girls) to gauge the rate of math development. They found that math ability was equivalent among the children and did not show a difference in gender or with age. Nor did the team find a gender difference between math ability and brain maturity.

This study builds on the team's previous work that found equivalent behavioral performance on a range of mathematics tests between young boys and girls.

Cantlon said she thinks society and culture likely are steering girls and young women away from math and STEM fields. Previous studies show that families spend more time with young boys in play that involves spatial cognition. Many teachers also preferentially spend more time with boys during math class, predicting later math achievement. Finally, children often pick up on cues from their parent's expectations for math abilities.

"Typical socialization can exacerbate small differences between boys and girls that can snowball into how we treat them in science and math," Cantlon said. "We need to be cognizant of these origins to ensure we aren't the ones causing the gender inequities."

This project is focused on early childhood development using a limited set of math tasks. Cantlon wants to continue this work using a broader array of math skills, such as spatial processing and memory, and follow the children over many years.

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