Astronomers detect hydroxyl molecule signature in an exoplanet atmosphere

 An international collaboration of astronomers led by a researcher from the Astrobiology Center and Queen's University Belfast, and including researchers from Trinity College Dublin, has detected a new chemical signature in the atmosphere of an extrasolar planet (a planet that orbits a star other than our Sun).

The hydroxyl radical (OH) was found on the dayside of the exoplanet WASP-33b. This planet is a so-called 'ultra-hot Jupiter', a gas-giant planet orbiting its host star much closer than Mercury orbits the Sun and therefore reaching atmospheric temperatures of more than 2,500° C (hot enough to melt most metals).

The lead researcher based at the Astrobiology Center and Queen's University Belfast, Dr Stevanus Nugroho, said: "This is the first direct evidence of OH in the atmosphere of a planet beyond the Solar System. It shows not only that astronomers can detect this molecule in exoplanet atmospheres, but also that they can begin to understand the detailed chemistry of this planetary population."

In the Earth's atmosphere, OH is mainly produced by the reaction of water vapour with atomic oxygen. It is a so-called 'atmospheric detergent' and plays a crucial role in the Earth's atmosphere to purge pollutant gasses that can be dangerous to life (e.g., methane, carbon monoxide).

In a much hotter and bigger planet like WASP-33b, where astronomers have previously detected signs of iron and titanium oxide gas) OH plays a key role in determining the chemistry of the atmosphere through interactions with water vapour and carbon monoxide. Most of the OH in the atmosphere of WASP-33b is thought to have been produced by the destruction of water vapour due to the extremely high temperature.

"We see only a tentative and weak signal from water vapour in our data, which would support the idea that water is being destroyed to form hydroxyl in this extreme environment," explained Dr Ernst de Mooij from Queen's University Belfast, a co-author on this study.

To make this discovery, the team used the InfraRed Doppler (IRD) instrument at the 8.2-meter diameter Subaru Telescope located in the summit area of Maunakea in Hawai`i (about 4,200 m above sea level). This new instrument can detect atoms and molecules through their 'spectral fingerprints,' unique sets of dark absorption features superimposed on the rainbow of colours (or spectrum) that are emitted by stars and planets.

As the planet orbits its host star, its velocity relative to the Earth changes with time. Just like the siren of an ambulance or the roar of a racing car's engine changes pitch while speeding past us, the frequencies of light (e.g., colour) of these spectral fingerprints change with the velocity of the planet. This allows us to separate the planet's signal from its bright host star, which normally overwhelms such observations, despite modern telescopes being nowhere near powerful enough to take direct images of such 'hot Jupiter' exoplanets.

Dr Neale Gibson, Assistant Professor at Trinity College Dublin and co-author of this work, said: "The science of extrasolar planets is relatively new, and a key goal of modern astronomy is to explore these planets' atmospheres in detail and eventually to search for 'Earth-like' exoplanets -- planets like our own. Every new atmospheric species discovered further improves our understanding of exoplanets and the techniques required to study their atmospheres, and takes us closer to this goal."

By taking advantage of the unique capabilities of IRD, the astronomers were able to detect the tiny signal from hydroxyl in the planet's atmosphere. "IRD is the best instrument to study the atmosphere of an exoplanet in the infrared," adds Professor Motohide Tamura, one of the principal investigators of IRD, Director of the Astrobiology Center, and co-author of this work.

"These techniques for atmospheric characterisation of exoplanets are still only applicable to very hot planets, but we would like to further develop instruments and techniques that enable us to apply these methods to cooler planets, and ultimately, to a second Earth," says Dr Hajime Kawahara, assistant professor at the University of Tokyo and co-author of this work.

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Anesthesia doesn't simply turn off the brain, it changes its rhythms

In a uniquely deep and detailed look at how the commonly used anesthetic propofol causes unconsciousness, a collaboration of labs at The Picower Institute for Learning and Memory at MIT shows that as the drug takes hold in the brain, a wide swath of regions become coordinated by very slow rhythms that maintain a commensurately languid pace of neural activity. Electrically stimulating a deeper region, the thalamus, restores synchrony of the brain's normal higher frequency rhythms and activity levels, waking the brain back up and restoring arousal.

"There's a folk psychology or tacit assumption that what anesthesia does is simply 'turn off' the brain," said Earl Miller, Picower Professor of Neuroscience and co-senior author of the study in eLife. "What we show is that propofol dramatically changes and controls the dynamics of the brain's rhythms."

Conscious functions, such as perception and cognition, depend on coordinated brain communication, in particular between the thalamus and the brain's surface regions, or cortex, in a variety of frequency bands ranging from 4 to 100 Hz. Propofol, the study shows, seems to bring coordination among the thalamus and cortical regions down to frequencies around just 1 Hz.

Miller's lab, led by postdoc Andre Bastos and former graduate student Jacob Donoghue, collaborated with that of co-senior author Emery N. Brown, who is Edward Hood Taplin Professor of Medical Engineering and Computational Neuroscience and an anesthesiologist at Massachusetts General Hospital. The collaboration therefore powerfully unified the Miller lab's expertise on how neural rhythms coordinate the cortex to produce conscious brain function with the Brown lab's expertise in the neuroscience of anesthesia and statistical analysis of neural signals.

Brown said studies that show how anesthetics change brain rhythms can directly improve patient safety because these rhythms are readily visible on the EEG in the operating room. The study's main finding of a signature of very slow rhythms across the cortex offers a model for directly measuring when subjects have entered unconsciousness after propofol administration, how deeply they are being maintained in that state, and how quickly they may wake up once propofol dosing ends.

"Anesthesiologists can use this as a way to better take care of patients," Brown said.

Brown has long studied how brain rhythms are affected in humans under general anesthesia by making and analyzing measurements of rhythms using scalp EEG electrodes and to a limited extent, cortical electrodes in epilepsy patients. Because the new study was conducted in animal models of those dynamics, the team was able to implant electrodes that could directly measure the activity or "spiking" of many individual neurons and rhythms in the cortex and thalamus. Brown said the results therefore significantly deepen and extend his findings in people.

For instance, the same neurons that they measured chattering away with spikes of voltage 7-10 times a second during wakefulness routinely fired only once a second or less during propofol-induced unconsciousnesss, a notable slowing called a "down state." In all, the scientists made detailed simultaneous measurements of rhythms and spikes in five regions: two in the front of the cortex, two toward the back, and the thalamus.

"What's so compelling is we are getting data down to the level of spikes," Brown said. "The slow oscillations modulate the spiking activity across large parts of the cortex."

As much as the study explains how propofol generates unconsciousness, it also helps to explain the unified experience of consciousness, Miller said.

"All the cortex has to be on the same page to produce consciousness," Miller said. "One theory about how this works is through thalamo-cortical loops that allow the cortex to synchronize. Propofol may be breaking the normal operation of those loops by hyper synchronizing them in prolonged down states. It disrupts the ability of the cortex to communicate."

For instance, by making measurements in distinct layers of the cortex, the team found that higher frequency "gamma" rhythms, which are normally associated with new sensory information like sights and sounds, were especially reduced in superficial layers. Lower frequency "alpha" and "beta" waves, which Miller has shown tend to regulate the processing of the information carried by gamma rhythms, were especially reduced in deeper layers.

In addition to the prevailing synchrony at very slow frequencies, the team noted other signatures of unconsciousness in the data. As Brown and others have observed in humans before, alpha and beta rhythm power was notably higher in posterior regions of the cortex during wakefulness, but after loss of consciousness power at those rhythms flipped to being much higher in anterior regions.

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Exposure to high heat neutralizes SARS-CoV-2 in less than one second, study finds

Arum Han, professor in the Department of Electrical and Computer Engineering at Texas A&M University, and his collaborators have designed an experimental system that shows exposure of SARS-CoV-2 to a very high temperature, even if applied for less than a second, can be sufficient to neutralize the virus so that it can no longer infect another human host.

Applying heat to neutralize COVID-19 has been demonstrated before, but in previous studies temperatures were applied from anywhere from one to 20 minutes. This length of time is not a practical solution, as applying heat for a long period of time is both difficult and costly. Han and his team have now demonstrated that heat treatment for less than a second completely inactivates the coronavirus -- providing a possible solution to mitigating the ongoing spread of COVID-19, particularly through long-range airborne transmission.

The Medistar Corporation approached leadership and researchers from the College of Engineering in the spring of 2020 to collaborate and explore the possibility of applying heat for a short amount of time to kill COVID-19. Soon after, Han and his team got to work, and built a system to investigate the feasibility of such a procedure.

Their process works by heating one section of a stainless-steel tube, through which the coronavirus-containing solution is run, to a high temperature and then cooling the section immediately afterward. This experimental setup allows the coronavirus running through the tube to be heated only for a very short period of time. Through this rapid thermal process, the team found the virus to be completely neutralized in a significantly shorter time than previously thought possible. Their initial results were released within two months of proof-of-concept experiments.

Han said if the solution is heated to nearly 72 degrees Celsius for about half a second, it can reduce the virus titer, or quantity of the virus in the solution, by 100,000 times which is sufficient to neutralize the virus and prevent transmission.

"The potential impact is huge," Han said. "I was curious of how high of temperatures we can apply in how short of a time frame and to see whether we can indeed heat-inactivate the coronavirus with only a very short time. And, whether such a temperature-based coronavirus neutralization strategy would work or not from a practical standpoint. The biggest driver was, 'Can we do something that can mitigate the situation with the coronavirus?'"

Their research was featured on the cover of the May issue of the journal Biotechnology and Bioengineering.

Not only is this sub-second heat treatment a more efficient and practical solution to stopping the spread of COVID-19 through the air, but it also allows for the implementation of this method in existing systems, such as heating, ventilation and air conditioning systems.

It also can lead to potential applications with other viruses, such as the influenza virus, that are also spread through the air. Han and his collaborators expect that this heat-inactivation method can be broadly applied and have a true global impact.

"Influenza is less dangerous but still proves deadly each year, so if this can lead to the development of an air purification system, that would be a huge deal, not just with the coronavirus, but for other airborne viruses in general," Han said.

In their future work, the investigators will build a microfluidic-scale testing chip that will allow them to heat-treat viruses for much shorter periods of time, for example, tens of milliseconds, with the hope of identifying a temperature that will allow the virus to be inactivated even with such a short exposure time.

The lead authors of the work are electrical engineering postdoctoral researchers, Yuqian Jiang and Han Zhang. Other collaborators on this project are Professor Julian L. Leibowitz, and Associate Professor Paul de Figueiredo from the College of Medicine; biomedical postdoctoral researcher Jose A. Wippold; Jyotsana Gupta, associate research scientist in microbial pathogenesis and immunology; and Jing Dai, electrical engineering assistant research scientist.

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Analysis of famous fossil helps unlock when humans and apes diverged

 A long-awaited, high-tech analysis of the upper body of famed fossil "Little Foot" opens a window to a pivotal period when human ancestors diverged from apes, new USC research shows.

Little Foot's shoulder assembly proved key to interpreting an early branch of the human evolutionary tree. Scientists at the Keck School of Medicine of USC focused on its so-called pectoral girdle, which includes collarbones, shoulder blades and joints.

Although other parts of Little Foot, especially its legs, show humanlike traits for upright walking, the shoulder components are clearly apelike, supporting arms surprisingly well suited for suspending from branches or shimmying up and down trees rather than throwing a projectile or dangling astride the torso like humans.

The Little Foot fossil provides the best evidence yet of how human ancestors used their arms more than 3 million years ago, said Kristian J. Carlson, lead author of the study and associate professor of clinical integrative anatomical sciences at the Keck School of Medicine.

"Little Foot is the Rosetta stone for early human ancestors," he said. "When we compare the shoulder assembly with living humans and apes, it shows that Little Foot's shoulder was probably a good model of the shoulder of the common ancestor of humans and other African apes like chimpanzees and gorillas."

The apelike characteristics will likely attract considerable intrigue as science teams around the world have been examining different parts of the skeleton to find clues to human origins. The USC-led study, which also involved researchers at the University of Wisconsin, the University of Liverpool and the University of the Witwatersrand in South Africa, among others, was published today in the Journal of Human Evolution.

The journal devoted a special issue to Little Foot analyses from a global research group, which looked at other parts of the creature's skeleton. The process is somewhat akin to the story of blind men and the elephant, each examining one part in coordination with others to explain the whole of something that's not fully understood.

The Little Foot fossil is a rare specimen because it's a near-complete skeleton of an Australopithecus individual much older than most other human ancestors. The creature, probably an old female, stood about 4 feet tall with long legs suitable for bipedal motion when it lived some 3.67 million years ago. Called "Little Foot" because the first bones recovered consisted of a few small foot bones, the remains were discovered in a cave in South Africa in the 1990s. Researchers have spent years excavating it from its rock encasement and subjecting it to high-tech analysis.

While not as widely known as the Lucy skeleton, another Australopithecus individual unearthed in East Africa in the 1970s, Carlson said Little Foot is older and more complete.

The USC-led research team zeroed in on the shoulder assemblies because Little Foot provides the oldest and most intact example of this anatomy ever found. Those bones provide telltale clues of how an animal moves. In human evolution, he said, these parts had to change form before our ancestors could live life free of trees, walk the open savannah and use their arms for functions other than supporting the weight of the individual.

The scientists compared the creature's shoulder parts to apes, hominins and humans. Little Foot was a creature adapted to living in trees because the pectoral girdle suggests a creature that climbed trees, hung below branches and used its hands overhead to support its weight.

For example, the scapula, or shoulder blade, has a big, high ridge to attach heavy muscles similar to gorillas and chimpanzees. The shoulder joint, where the humerus connects, sits at an oblique angle, useful for stabilizing the body and lessening tensile loads on shoulder ligaments when an ape hangs beneath branches. The shoulder also has a sturdy, apelike reinforcing structure, the ventral bar. And the collarbone has a distinctive S-shaped curve commonly found in apes.

Those conclusions mean that the structural similarities in the shoulder between humans and African apes are much more recent, and persisted much longer, than has been proposed, Carlson said.

"We see incontrovertible evidence in Little Foot that the arm of our ancestors at 3.67 million years ago was still being used to bear substantial weight during arboreal movements in trees for climbing or hanging beneath branches," he said. "In fact, based on comparisons with living humans and apes, we propose that the shoulder morphology and function of Little Foot is a good model for that of the common ancestor of humans and chimpanzees 7 million to 8 million years ago."

The scientists were able to achieve remarkably clear images of the fossils. That's because the bones, painstakingly excavated for many years, are in good condition and uniquely complete. The scientists examined them using micro-CT scans, which can detect minute features on the surface of an object, peer deep inside a bone, measure the density of an object and generate a 3D model without harming the fossil.

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Seismicity on Mars full of surprises, in first continuous year of data

The SEIS seismometer package from the Mars InSight lander has collected its first continuous Martian year of data, revealing some surprises among the more than 500 marsquakes detected so far.

At the Seismological Society of America (SSA)'s 2021 Annual Meeting, Savas Ceylan of ETH Zürich discussed some of the findings from The Marsquake Service, the part of the InSight ground team that detects marsquakes and curates the planet's seismicity catalog.

Marsquakes differ from earthquakes in a number of ways, Ceylan explained. To begin with, they are much smaller than earthquakes, with the largest event recorded at teleseismic distances around magnitude 3.6. SEIS is able to detect these small events because the background seismic noise on Mars can be much lower than on Earth, without the constant tremor produced by ocean waves.

"For much of a Martian year, from around sunset until early hours, the Martian atmosphere becomes very quiet, so there is no local noise either," he said. "Additionally, our sensors are optimized and shielded for operating under severe Martian conditions, such as extremely low temperatures and the extreme diurnal temperature fluctuations on the red planet."

Marsquakes also come in two distinct varieties: low-frequency events with seismic waves propagating at various depths in the planet's mantle, and high-frequency events with waves that appear to propagate through the crust. "In terms of how the seismic energy decays over time, the low-frequency events appear to be more like earthquakes" in which the shaking dies away relatively quickly, Ceylan said, "while the high-frequency events are resembling moonquakes" in persisting for longer periods.

The vast majority of the events are high-frequency and occur at hundreds of kilometers of distance from the lander. "It is not quite clear to us how these events could be confined to only high frequency energy while they occur at such large distances," he said. "On top of that, the frequency of those events seems to vary over the Martian year, which is a pattern that we do not know at all from Earth."

Only a handful of marsquakes have clear seismic phase arrivals -- the order in which the different types of seismic waves arrive at a location -- which allows researchers to calculate the direction and distance the waves come from. All these marsquakes originate from a sunken area of the surface called Cerberus Fossae, about 1800 kilometers away from the InSight Lander.

Cerberus Fossae is one of the youngest geological structures on Mars, and may have formed from extensional faulting or subsidence due to dike emplacement. Recent studies suggest extension mechanism may be the source of the Cerberus Fossae quakes, Ceylan noted, "however, we have a long way in front of us to be able to explain the main tectonic mechanisms behind these quakes."

The biggest challenge for The Marsquake Service and InSight science team has been "adapting to unexpected signals in the data from a new planet," Ceylan said.

Although there were significant efforts to shield SEIS from non-seismic noise by covering it and placing it directly on the Martian surface, its data are still contaminated by weather and lander noise.

"We needed to understand the noise on Mars from scratch, discover how our seismometers behave, how the atmosphere of Mars affects seismic recordings, and find alternative methods to interpret the data properly," said Ceylan.

It took the Service a while to be "confident in identifying the different event types," he added, "discriminating these weak signals from the rich and varied background noise, and being able to characterize these novel signals in a systematic manner to provide a self-consistent catalog."

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New research uncovers continental crust emerged 500 million years earlier than thought

 The first emergence and persistence of continental crust on Earth during the Archaean (4 billion to 2.5 billion years ago) has important implications for plate tectonics, ocean chemistry, and biological evolution, and it happened about half a billion years earlier than previously thought, according to new research being presented at the EGU General Assembly 2021.

Once land becomes established through dynamic processes like plate tectonics, it begins to weather and add crucial minerals and nutrients to the ocean. A record of these nutrients is preserved in the ancient rock record. Previous research used strontium isotopes in marine carbonates, but these rocks are usually scarce or altered in rocks older than 3 billion years.

Now, researchers are presenting a new approach to trace the first emergence of old rocks using a different mineral: "barite."

Barite forms from a combination of sulfate coming from ocean water mixing with barium from hydrothermal vents. Barite holds a robust record of ocean chemistry within its structure, useful for reconstructing ancient environments. "The composition of the piece of barite we pick up in the field now that has been on Earth for three and a half billion years, is exactly the same as it was when it when it actually precipitated," says Desiree Roerdink, a geochemist at University of Bergen, Norway, and team leader of the new research. "So in essence, it is really a great recorder to look at processes on the early Earth."

Roerdink and her team tested six different deposits on three different continents, ranging from about 3.2 billion to 3.5 billion years old. They calculated the ratio of strontium isotopes in the barite, and from there, inferred the time where the weathered continental rock made its way to the ocean and incorporated itself into the barite. Based on the data captured in the barite, they found that weathering started about 3.7 billion years ago -- about 500 million years earlier than previously thought.

"That is a huge time period," Roerdink says. "It essentially has implications for the way that we think about how life evolved." She added that scientists usually think about life starting in deep sea, hydrothermal settings, but the biosphere is complex. "We don't really know if it is possible that life could have developed at the same time on land," she noted, adding "but then that land has to be there."

Lastly, the emergence of land says something about plate tectonics and the early emergence of a geodynamic Earth. "To get land, you need processes operating to form that continental crust, and form a crust that is chemically different from the oceanic crust," Roerdink says.

From Science Daily

3D holographic head-up display could improve road safety

Researchers have developed the first LiDAR-based augmented reality head-up display for use in vehicles. Tests on a prototype version of the technology suggest that it could improve road safety by 'seeing through' objects to alert of potential hazards without distracting the driver.

The technology, developed by researchers from the University of Cambridge, the University of Oxford and University College London (UCL), is based on LiDAR (light detection and ranging), and uses LiDAR data to create ultra high-definition holographic representations of road objects which are beamed directly to the driver's eyes, instead of 2D windscreen projections used in most head-up displays.

While the technology has not yet been tested in a car, early tests, based on data collected from a busy street in central London, showed that the holographic images appear in the driver's field of view according to their actual position, creating an augmented reality. This could be particularly useful where objects such as road signs are hidden by large trees or trucks, for example, allowing the driver to 'see through' visual obstructions. The results are reported in the journal Optics Express.

"Head-up displays are being incorporated into connected vehicles, and usually project information such as speed or fuel levels directly onto the windscreen in front of the driver, who must keep their eyes on the road," said lead author Jana Skirnewskaja, a PhD candidate from Cambridge's Department of Engineering. "However, we wanted to go a step further by representing real objects in as panoramic 3D projections."

Skirnewskaja and her colleagues based their system on LiDAR, a remote sensing method which works by sending out a laser pulse to measure the distance between the scanner and an object. LiDAR is commonly used in agriculture, archaeology and geography, but it is also being trialled in autonomous vehicles for obstacle detection.

Using LiDAR, the researchers scanned Malet Street, a busy street on the UCL campus in central London. Co-author Phil Wilkes, a geographer who normally uses LiDAR to scan tropical forests, scanned the whole street using a technique called terrestrial laser scanning. Millions of pulses were sent out from multiple positions along Malet Street. The LiDAR data was then combined with point cloud data, building up a 3D model.

"This way, we can stitch the scans together, building a whole scene, which doesn't only capture trees, but cars, trucks, people, signs, and everything else you would see on a typical city street," said Wilkes. "Although the data we captured was from a stationary platform, it's similar to the sensors that will be in the next generation of autonomous or semi-autonomous vehicles."

When the 3D model of Malet St was completed, the researchers then transformed various objects on the street into holographic projections. The LiDAR data, in the form of point clouds, was processed by separation algorithms to identify and extract the target objects. Another algorithm was used to convert the target objects into computer-generated diffraction patterns. These data points were implemented into the optical setup to project 3D holographic objects into the driver's field of view.

The optical setup is capable of projecting multiple layers of holograms with the help of advanced algorithms. The holographic projection can appear at different sizes and is aligned with the position of the represented real object on the street. For example, a hidden street sign would appear as a holographic projection relative to its actual position behind the obstruction, acting as an alert mechanism.

In future, the researchers hope to refine their system by personalising the layout of the head-up displays and have created an algorithm capable of projecting several layers of different objects. These layered holograms can be freely arranged in the driver's vision space. For example, in the first layer, a traffic sign at a further distance can be projected at a smaller size. In the second layer, a warning sign at a closer distance can be displayed at a larger size.

"This layering technique provides an augmented reality experience and alerts the driver in a natural way," said Skirnewskaja. "Every individual may have different preferences for their display options. For instance, the driver's vital health signs could be projected in a desired location of the head-up display.

"Panoramic holographic projections could be a valuable addition to existing safety measures by showing road objects in real time. Holograms act to alert the driver but are not a distraction."

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Can a newborn's brain discriminate speech sounds?

People's ability to perceive speech sounds has been deeply studied, specially during someone's first year of life, but what happens during the first hours after birth? Are babies born with innate abilities to perceive speech sounds, or do neural encoding processes need to age for some time?

Researchers from the Institute of Neurosciences of the University of Barcelona (UBNeuro) and the Sant Joan de Déu Research Institute (IRSJD) have created a new methodology to try to answer this basic question on human development.

The results, published in the Nature's open-access journal Scientific Reports, confirm that newborn neural encoding of voice pitch is comparable to the adults' sabilities after three years of being exposed to language. However, there are differences regarding the perception of spectral and temporal fine structures of sounds, which consists on the ability to distinguish between vocal sounds such as /o/ and /a/. Therefore, according to the authors, neural encoding of this sound aspect, recorded for the first time in this study, is not found mature enough after being born, but it needs a certain exposure to the language as well as stimulation and time to develop.

According to the researchers, knowing the level of development typical in these neural encoding processes from birth will enable them to make an "early detection of language impairments, which would provide an early intervention or stimulus to reduce future negative consequences."

The study is led by Carles Escera, professor of Cognitive Neuroscience at the Department of Clinical Psychology and Psychobiology of the UB, and has been carried out at the IRSJD, in collaboration with Maria Dolores Gómez Roig, head of the Department of Obstetrics and Gynecology of Hospital Sant Joan de Déu. The study is also signed by the experts Sonia Arenillas Alcón, first author of the article, Jordi Costa Faidella and Teresa Ribas Prats, all members of the Cognitive Neuroscience Research Group (Brainlab) of the UB.

Decoding the spectral and temporal fine structure of sound

In order to distinguish the neural response to speech stimuli in newborns, one of the main challenges was to record, using the baby's electroencephalogram, a specific brain response: the frequency-following response (FFR). The FFR provides information on the neural encoding of two specific features of sound: fundamental frequency, responsible for the perception of voice pitch (high or low), and the spectral and temporal fine structure. The precise encoding of both features is, according to the study, "fundamental for the proper perception of speech, a requirement in future language acquisition."

To date, the available tools to study this neural encoding enabled researchers to determine whether the newborn's baby was able to encode inflections in the voice pitch, but it did not when it came to the spectral and temporal fine structure. "Inflections in voice pitch contour are very important, especially in tonal variations like in Mandarin, as well as to perceive the prosody from speech that transmits emotional content of what is said. However, the spectral and temporal fine structure of sound is the most relevant aspect in language acquisition regarding non-tonal languages like ours, and the few existing studies on the issue do not inform about the precision with which a newborn's brain encodes it," note the authors.

The main cause of this lack of studies is the technical limitation caused by the type of sounds used to conduct these tests. Therefore, authors have developed a new stimulus (/oa/) whose internal structure (increasing change in voice pitch, two different vocals) allows them to evaluate the precision of the neural encoding of both features of the sound simultaneously using the FFR analysis.

An adapted test to the limitations of the hospital environment

One of the most highlighted aspects of the study is that the stimulus and the methodology are compatible to the typical limitations of the hospital environment in which the tests are carried out. "Time is essential in the FFR research with newborns. On the one hand, because recording time limitations determine the stimuli they can record. On the other hand, for the actual conditions of the situation of newborns in hospitals, where there is a frequent and continuous access to the baby and the mother so they receive the required care and undergo evaluations and routine tests to rule out health problems," authors add. Considering these restrictions, the responses of the 34 newborns that were part of the study were recorded in sessions that lasted between twenty and thirty minutes, almost half the time used in common sessions in studies on speech sound discrimination.

A potential biomarker of learning problems

After this study, the objective of the researchers is to characterize the development f neural encoding of the spectral and temporal fine structure of speech sounds over time. To do so, they are currently recording the frequency-following response in those babies that took part in the present study, who are now 21 months old. "Given that the two first years of life are a critical period of stimulation for language acquisition, this longitudinal evaluation of the development will enable us to have a global view on how these encoding skills mature over the first months of life," note the researchers.

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Experimental drug shows potential against Alzheimer's disease

Researchers at Albert Einstein College of Medicine have designed an experimental drug that reversed key symptoms of Alzheimer's disease in mice. The drug works by reinvigorating a cellular cleaning mechanism that gets rid of unwanted proteins by digesting and recycling them. The study was published online today in the journal Cell.

"Discoveries in mice don't always translate to humans, especially in Alzheimer's disease," said co-study leader Ana Maria Cuervo, M.D., Ph.D., the Robert and Renée Belfer Chair for the Study of Neurodegenerative Diseases, professor of developmental and molecular biology, and co-director of the Institute for Aging Research at Einstein. "But we were encouraged to find in our study that the drop-off in cellular cleaning that contributes to Alzheimer's in mice also occurs in people with the disease, suggesting that our drug may also work in humans." In the 1990s, Dr. Cuervo discovered the existence of this cell-cleaning process, known as chaperone-mediated autophagy (CMA) and has published 200 papers on its role in health and disease.

CMA becomes less efficient as people age, increasing the risk that unwanted proteins will accumulate into insoluble clumps that damage cells. In fact, Alzheimer's and all other neurodegenerative diseases are characterized by the presence of toxic protein aggregates in patients' brains. The Cell paper reveals a dynamic interplay between CMA and Alzheimer's disease, with loss of CMA in neurons contributing to Alzheimer's and vice versa. The findings suggest that drugs for revving up CMA may offer hope for treating neurodegenerative diseases.

Establishing CMA's Link to Alzheimer's

Dr. Cuervo's team first looked at whether impaired CMA contributes to Alzheimer's. To do so, they genetically engineered a mouse to have excitatory brain neurons that lacked CMA. The absence of CMA in one type of brain cell was enough to cause short-term memory loss, impaired walking, and other problems often found in rodent models of Alzheimer's disease. In addition, the absence of CMA profoundly disrupted proteostasis -- the cells' ability to regulate the proteins they contain. Normally soluble proteins had shifted to being insoluble and at risk for clumping into toxic aggregates.

Dr. Cuervo suspected the converse was also true: that early Alzheimer's impairs CMA. So she and her colleagues studied a mouse model of early Alzheimer's in which brain neurons were made to produce defective copies of the protein tau. Evidence indicates that abnormal copies of tau clump together to form neurofibrillary tangles that contribute to Alzheimer's. The research team focused on CMA activity within neurons of the hippocampus -- the brain region crucial for memory and learning. They found that CMA activity in those neurons was significantly reduced compared to control animals.

What about early Alzheimer's in people -- does it block CMA too? To find out, the researchers looked at single-cell RNA-sequencing data from neurons obtained postmortem from the brains of Alzheimer's patients and from a comparison group of healthy individuals. The sequencing data revealed CMA's activity level in patients' brain tissue. Sure enough, CMA activity was somewhat inhibited in people who had been in the early stages of Alzheimer's, followed by much greater CMA inhibition in the brains of people with advanced Alzheimer's.

"By the time people reach the age of 70 or 80, CMA activity has usually decreased by about 30% compared to when they were younger," said Dr. Cuervo. "Most peoples' brains can compensate for this decline. But if you add neurodegenerative disease to the mix, the effect on the normal protein makeup of brain neurons can be devastating. Our study shows that CMA deficiency interacts synergistically with Alzheimer's pathology to greatly accelerate disease progression."

A New Drug Cleans Neurons and Reverses Symptoms

In an encouraging finding, Dr. Cuervo and her team developed a novel drug that shows potential for treating Alzheimer's. "We know that CMA is capable of digesting defective tau and other proteins," said Dr. Cuervo. "But the sheer amount of defective protein in Alzheimer's and other neurodegenerative diseases overwhelms CMA and essentially cripples it. Our drug revitalizes CMA efficiency by boosting levels of a key CMA component."

In CMA, proteins called chaperones bind to damaged or defective proteins in cells of the body. The chaperones ferry their cargo to the cells' lysosomes -- membrane-bound organelles filled with enzymes, which digest and recycle waste material. To successfully get their cargo into lysosomes, however, chaperones must first "dock" the material onto a protein receptor called LAMP2A that sprouts from the membranes of lysosomes. The more LAMP2A receptors on lysosomes, the greater the level of CMA activity possible. The new drug, called CA, works by increasing the number of those LAMP2A receptors.

"You produce the same amount of LAMP2A receptors throughout life," said Dr. Cuervo. "But those receptors deteriorate more quickly as you age, so older people tend to have less of them available for delivering unwanted proteins into lysosomes. CA restores LAMP2A to youthful levels, enabling CMA to get rid of tau and other defective proteins so they can't form those toxic protein clumps." (Also this month, Dr. Cuervo's team reported in Nature Communications that, for the first time, they had isolated lysosomes from the brains of Alzheimer's disease patients and observed that reduction in the number of LAMP2 receptors causes loss of CMA in humans, just as it does in animal models of Alzheimer's.)

The researchers tested CA in two different mouse models of Alzheimer's disease. In both disease mouse models, oral doses of CA administered over 4 to 6 months led to improvements in memory, depression, and anxiety that made the treated animals resemble or closely resemble healthy, control mice. Walking ability significantly improved in the animal model in which it was a problem. And in brain neurons of both animal models, the drug significantly reduced levels of tau protein and protein clumps compared with untreated animals.

"Importantly, animals in both models were already showing symptoms of disease, and their neurons were clogged with toxic proteins before the drugs were administered," said Dr. Cuervo. "This means that the drug may help preserve neuron function even in the later stages of disease. We were also very excited that the drug significantly reduced gliosis -- the inflammation and scarring of cells surrounding brain neurons. Gliosis is associated with toxic proteins and is known to play a major role in perpetuating and worsening neurodegenerative diseases."

Treatment with CA did not appear to harm other organs even when given daily for extended periods of time. The drug was designed by Evripidis Gavathiotis, Ph.D.,, professor of biochemistry and of medicine and a co-leader of the study.

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Fearsome tyrannosaurs were social animals, study shows

The fearsome tyrannosaur dinosaurs that ruled the northern hemisphere during the Late Cretaceous period (66-100 million years ago) may not have been solitary predators as popularly envisioned, but social carnivores similar to wolves, according to a new study.

The finding, based on research at a unique fossil bone site inside Utah's Grand Staircase-Escalante National Monument containing the remains of several dinosaurs of the same species, was made by a team of scientists including Celina Suarez, University of Arkansas associate professor of geosciences.

"This supports our hypothesis that these tyrannosaurs died in this site and were all fossilized together; they all died together, and this information is key to our interpretation that the animals were likely gregarious in their behavior," Suarez said.

The research team also include scientists from the U.S. Bureau of Land Management, Denver Museum of Nature and Science, Colby College of Maine and James Cook University in Australia. The study examines a unique fossil bone site inside Grand Staircase-Escalante National Monument called the "Rainbows and Unicorns Quarry" that they say exceeded the expectations raised even from the site's lofty nickname.

"Localities [like Rainbows and Unicorns Quarry] that produce insights into the possible behavior of extinct animals are especially rare, and difficult to interpret," said tyrannosaur expert Philip Currie in a press release from the BLM. "Traditional excavation techniques, supplemented by the analysis of rare earth elements, stable isotopes and charcoal concentrations convincingly show a synchronous death event at the Rainbows site of four or five tyrannosaurids. Undoubtedly, this group died together, which adds to a growing body of evidence that tyrannosaurids were capable of interacting as gregarious packs."

In 2014, BLM paleontologist Alan Titus discovered the Rainbows and Unicorns Quarry site in Grand Staircase-Escalante National Monument and led the subsequent research on the site, which is the first tyrannosaur mass death site found in the southern United States. Researchers ran a battery of tests and analyses on the vestiges of the original site, now preserved as small rock fragments and fossils in their final resting place, and sandbar deposits from the ancient river.

"We realized right away this site could potentially be used to test the social tyrannosaur idea. Unfortunately, the site's ancient history is complicated," Titus said. "With bones appearing to have been exhumed and reburied by the action of a river, the original context within which they lay has been destroyed. However, all has not been lost." As the details of the site's history emerged, the research team concluded that the tyrannosaurs died together during a seasonal flooding event that washed their carcasses into a lake, where they sat, largely undisturbed until the river later churned its way through the bone bed.

"We used a truly multidisciplinary approach (physical and chemical evidence) to piece the history of the site together, with the end-result being that the tyrannosaurs died together during a seasonal flooding event," said Suarez.

Using analysis of stable carbon and oxygen isotopes and concentrations of rare earth elements within the bones and rock, Suarez and her then-doctoral student, Daigo Yamamura, were able to provide a chemical fingerprint of the site. Based on the geochemical work, they were able to conclusively determine that the remains from the site all fossilized in the same environment and were not the result of an attritional assemblage of fossils washed in from a variety of areas.

"None of the physical evidence conclusively suggested that these organisms came to be fossilized together, so we turned to geochemistry to see if that could help us. The similarity of rare earth element patterns is highly suggestive that these organisms died and were fossilized together," said Suarez.

Excavation of the quarry site has been ongoing since its discovery in 2014 and due to the size of the site and volume of bones found there the excavation will probably continue into the foreseeable future. In addition to tyrannosaurs, the site has also yielded seven species of turtles, multiple fish and ray species, two other kinds of dinosaurs, and a nearly complete skeleton of a juvenile (12-foot-long) Deinosuchus alligator, although they do not appear to have all died together like the tyrannosaurs.

"The new Utah site adds to the growing body of evidence showing that tyrannosaurs were complex, large predators capable of social behaviors common in many of their living relatives, the birds," said project contributor, Joe Sertich, curator of dinosaurs at the Denver Museum of Nature & Science. "This discovery should be the tipping point for reconsidering how these top carnivores behaved and hunted across the northern hemisphere during the Cretaceous."

Future research plans for the Rainbows and Unicorns Quarry fossils include additional trace element and isotopic analysis of the tyrannosaur bones, which paleontologists hope will determine with a greater degree of certainty the mystery of Teratophoneus' social behavior.

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