Tuesday, June 25, 2019

Commonly Prescribed Drug Likely Increases of Dementia



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

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

Credit: University of Nottingham

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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


Contacts and sources:
Charlotte AnscombeUniversity of Nottingham

Citation:




Stellar Heavyweight Champion of Dying Stars



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

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

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

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

But why is this important?

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

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

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

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

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

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

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


Contacts and sources:
Cindy ChanThe University of Hong Kong

Citation: A high-mass planetary nebula in a Galactic open cluster V. Fragkou, Q. A. Parker, A. A. Zijlstra, L. Crause & H. Barker Nature Astronomy (2019) https://www.nature.com/articles/s41550-019-0796-x http://dx.doi.org/10.1038/s41550-019-0796-x




How Trees Affect the Weather and Intensify Droughts



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

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

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



Credit: Sémhur / Wikimedia Commons

Functional traits

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

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

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

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

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

More drought to come

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

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

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

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



Contacts and sources:
Paul Gabrielsen
University of Utah





Monday, June 24, 2019

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

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

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


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


Credit: NASA / JPL-Caltech / Space Science Institute

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

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

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

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

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

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

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

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

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


Contacts and sources:
Liza LesterAmerican Geophysical Union

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


Big Data Says Food Is Too Sweet

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

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

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

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

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

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

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

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

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

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

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

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


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

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




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

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

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


Shawn Sorrells, PhD. 
Photo courtesy of Shawn Sorrells

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

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

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

Arturo Alvarez-Buylla, PhD.
 Photo by Cindy Chew

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

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

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

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

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

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

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

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

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

Neurogenesis Debate: New or Long-Lived Immature Neurons?

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

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

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

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

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

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

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

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




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

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



Awe Filled State of Mind Can Set You Free

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

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

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

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

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

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

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

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

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

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

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

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

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


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


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




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

Screams are very personal. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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



Contacts and sources:
Carol Clark
Emory Health Sciences


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



Electrolytic Robot Blood Powers Robofish

Untethered robots suffer from a stamina problem. A possible solution: a circulating liquid – “robot blood” – to store energy and power its applications for sophisticated, long-duration tasks.
Humans and other complex organisms manage life through integrated systems. Humans store energy in fat reserves spread across the body, and an intricate circulatory system transports oxygen and nutrients to power trillions of cells.
But crack open the hood of an untethered robot and things are much more segmented: Over here is the solid battery and over there are the motors, with cooling systems and other components scattered throughout.
robot fish
Credit: Cornell University
Cornell researchers have created a synthetic vascular system capable of pumping an energy-dense hydraulic liquid that stores energy, transmits force, operates appendages and provides structure, all in an integrated design.
“In nature we see how long organisms can operate while doing sophisticated tasks. Robots can’t perform similar feats for very long,” said Rob Shepherd, associate professor of mechanical and aerospace engineering. “Our bio-inspired approach can dramatically increase the system’s energy density while allowing soft robots to remain mobile for far longer.”
Shepherd, director of the Organic Robotics Lab, is senior author of “Electrolytic Vascular Systems for Energy Dense Robots,” which published June 19 in Nature. Doctoral student Cameron Aubin is lead author.
Engineers rely on lithium-ion batteries for their dense energy-storage potential. But solid batteries are bulky and present design constraints. Alternatively, redox flow batteries (RFB) rely on a solid anode and highly soluble catholyte to function. The dissolved components store energy until it is released in a chemical reduction and oxidation, or redox, reaction.
Soft robots are mostly fluid – up to around 90% fluid by volume, and many times use hydraulic liquid. Using that fluid to store energy offers the possibility of increased energy density without added weight.
The researchers tested the concept by creating an aquatic soft robot inspired by a lionfish, designed by co-author James Pikul, a former postdoctoral researcher now an assistant professor at the University of Pennsylvania. Lionfish use undulating fanlike fins to glide through coral-reef environments (In one sacrifice to verisimilitude, the researchers opted not to add venomous fins like the robots’ living counterparts).
Silicone skin on the outside and flexible electrodes and an ion separator membrane within allow the robot to bend and flex. Interconnected zinc-iodide flow cell batteries power onboard pumps and electronics through electrochemical reactions. The researchers achieved energy density equal to about half that of a Tesla Model S lithium-ion battery.
The robot swims using power transmitted to the fins from the pumping of the flow cell battery. The initial design provided enough power to swim upstream for more than 36 hours.
Current RFB technology is typically used in large, stationary applications, such as storing energy from wind and solar sources. RFB design has historically suffered from low power density and operating voltage. The researchers overcame those issues by wiring the fan battery cells in series, and maximized power density by distributing electrodes throughout the fin areas.
“We want to take as many components in a robot and turn them into the energy system. If you have hydraulic liquids in your robot already, then you can tap into large stores of energy and give robots increased freedom to operate autonomously,” Shepherd said.
Underwater soft robots offer tantalizing possibilities for research and exploration. Since aquatic soft robots are supported by buoyancy, they don’t require an exoskeleton or endoskeleton to maintain structure. By designing power sources that give robots the ability to function for longer stretches of time, Shepherd thinks autonomous robots could soon be roaming Earth’s oceans on vital scientific missions and for delicate environmental tasks like sampling coral reefs. These devices could also be sent to extraterrestrial worlds for underwater reconnaissance missions.
The work was supported by the Office of Naval Research. Co-authors include Lynden Archer, the James A. Friend Family Distinguished Professor of Engineering in the Smith School of Chemical and Biomolecular Engineering; Snehashis Choudhury, M.Eng. ’14, Ph.D. ’18, currently a postdoctoral researcher at Stanford; and doctoral candidate Rhiannon Jerch.


Contacts and sources:
Matt Hayes
Cornell University


Citation: Electrolytic vascular systems for energy-dense robots
Cameron A. Aubin, Snehashis Choudhury, Rhiannon Jerch, Lynden A. Archer, James H. Pikul, Robert F. Shepherd. . Nature, 2019; DOI: 10.1038/s41586-019-1313-1




Gigantic Fresh Water Aquifer Discovered Off U.S. Northeast Coast

An undersea aquifer as large as Ogallala Aquifer has been found under the sea off the  US Northeast coast.

Scientists have mapped a huge aquifer off the US Northeast (hatched area). Solid yellow or white lines with triangles show ship tracks. Dotted white line near shore shows edge of the glacial ice sheet that melted about 15,000 years ago. Further out, dark blue, the continental shelf drops off into the Atlantic abyss.

Credit: Gustafson et al., Scientific Reports, 2019


In a new survey of the sub-seafloor off the U.S. Northeast coast, scientists have made a surprising discovery: a gigantic aquifer of relatively fresh water trapped in porous sediments lying below the salty ocean. It appears to be the largest such formation yet found in the world. The aquifer stretches from the shore at least from Massachusetts to New Jersey, extending more or less continuously out about 50 miles to the edge of the continental shelf. 

If found on the surface, it would create a lake covering some 15,000 square miles. The study suggests that such aquifers probably lie off many other coasts worldwide, and could provide desperately needed water for arid areas that are now in danger of running out.

The researchers employed innovative measurements of electromagnetic waves to map the water, which remained invisible to other technologies. “We knew there was fresh water down there in isolated places, but we did not know the extent or geometry,” said lead author Chloe Gustafson, a PhD. candidate at Columbia University’s Lamont-Doherty Earth Observatory. “It could turn out to be an important resource in other parts of the world.” The study appears this week in the journal Scientific Reports.

The first hints of the aquifer came in the 1970s, when companies drilled off the coastline for oil, but sometimes instead hit fresh water. Drill holes are just pinpricks in the seafloor, and scientists debated whether the water deposits were just isolated pockets or something bigger. Starting about 20 years ago, study coauthor Kerry Key, now a Lamont-Doherty geophysicist, helped oil companies develop techniques to use electromagnetic imaging of the sub-seafloor to look for oil. More recently, Key decided to see if some form of the technology could also be used also to find fresh-water deposits.

 In 2015, he and Rob L. Evans of Woods Hole Oceanographic Institution spent 10 days on the Lamont-Doherty research vessel Marcus G. Langseth making measurements off southern New Jersey and the Massachusetts island of Martha’s Vineyard, where scattered drill holes had hit fresh-water-rich sediments.

An electromagnetic receiver used in the study being deployed off the research vessel Marcus Langseth.

 (Courtesy Kerry Key)

They dropped receivers to the seafloor to measure electromagnetic fields below, and the degree to which natural disruptions such as solar winds and lightning strikes resonated through them. An apparatus towed behind the ship also emitted artificial electromagnetic pulses and recorded the same type of reactions from the subseafloor. 

Both methods work in a simple way: salt water is a better conductor of electromagnetic waves than fresh water, so the freshwater stood out as a band of low conductance. Analyses indicated that the deposits are not scattered; they are more or less continuous, starting at the shoreline and extending far out within the shallow continental shelf — in some cases, as far as 75 miles. For the most part, they begin at around 600 feet below the ocean floor, and bottom out at about 1,200 feet.

The consistency of the data from both study areas allowed to the researchers to infer with a high degree of confidence that fresh water sediments continuously span not just New Jersey and much of Massachusetts, but the intervening coasts of Rhode Island, Connecticut and New York. They estimate that the region holds at least 670 cubic miles of fresh water. If future research shows the aquifer extends further north and south, it would rival the great Ogallala Aquifer, which supplies vital groundwater to eight Great Plains states, from South Dakota to Texas.

The water probably got under the seabed in one of two different ways, say the researchers. Some 15,000 to 20,000 years ago, toward the end of the last glacial age, much of the world’s water was locked up in mile-deep ice; in North America, it extended through what is now northern New Jersey, Long Island and the New England coast. Sea levels were much lower, exposing much of what is now the underwater U.S. continental shelf. When the ice melted, sediments formed huge river deltas on top of the shelf, and fresh water got trapped there in scattered pockets. Later, sea levels rose. Up to now, the trapping of such “fossil” water has been the common explanation for any fresh water found under the ocean.

But the researchers say the new findings indicate that the aquifer is also being fed by modern subterranean runoff from the land. As water from rainfall and water bodies percolates through onshore sediments, it is likely pumped seaward by the rising and falling pressure of tides, said Key. He likened this to a person pressing up and down on a sponge to suck in water from the sponge’s sides. Also, the aquifer is generally freshest near the shore, and saltier the farther out you go, suggesting that it mixes gradually with ocean water over time. Terrestrial fresh water usually contains less than 1 part per thousand salt, and this is about the value found undersea near land. By the time the aquifer reaches its outer edges, it rises to 15 parts per thousand. (Typical seawater is 35 parts per thousand.)

If water from the outer parts of the aquifer were to be withdrawn, it would have to be desalinated for most uses, but the cost would be much less than processing seawater, said Key. “We probably don’t need to do that in this region, but if we can show there are large aquifers in other regions, that might potentially represent a resource” in places like southern California, Australia, the Mideast or Saharan Africa, he said. His group hopes to expand its surveys.




Contacts and sources:
Kevin Krajick
Columbia University’s Lamont-Doherty Earth Observatory

Citation: Aquifer systems extending far offshore on the U.S. Atlantic margin Chloe Gustafson, Kerry Key & Rob L. Evans Scientific Reportsvolume 9, Article number: 8709 (2019) https://www.nature.com/articles/s41598-019-44611-7 http://dx.doi.org/10.1038/s41598-019-44611-7



Sunday, June 23, 2019

Don't Forget the Microbes with Changing Climate



A brown layer of ice algae coats the flanks of sea ice in Antarctica. These microbes thrive in sea ice ‘houses’ and are the beginning of many food webs, which branch out to feed all larger lifeforms. Melting sea ice affects ice algae, which means a diminished food web and greater risk of a starving ocean life. 
ice flow with algae
Photo courtesy of Rick Cavicchioli, University of New South Wales, Australia


Scientists are rightly focused on anticipating and preventing the major impacts that climate change will have on humans, plants and animals. But they shouldn’t forget the effect on Earth’s microbes, on which everything else depends, warns a group of 33 biologists from around the globe.

“Bacteria, viruses and other microorganisms support the existence of all higher lifeforms and will shape the response of plants and animals to climate change,” says Britt Koskella, an evolutionary biologist and assistant professor of integrative biology at UC Berkeley who collaborated on the consensus statement published today in the journal Nature Reviews Microbiology. “Microbes are themselves also profoundly affected by climate change, but are rarely the focus of climate change research, education or policy.”

While the researchers hope their statement will raise awareness about the role and vulnerability of microbes, they also are calling for the integration of microbial research into frameworks, such as climate models, for addressing climate change.

The group points out that Earth’s ‘unseen majority’ play critical functions in animal and human health, agriculture, the global food web and industry.

In our oceans, for example, where 90 percent of life is microbial, phytoplankton play the role that green plants play on land, fueling animal life from krill on up to the fish, sea birds and large mammals such as whales that feed on krill. Climate change could adversely affect the productivity of these marine microbes, threatening the stability of the food web that also supplies human food.


Climate change is altering natural and agricultural ecosystems in ways that can exacerbate zoonotic – diseases that move from animals into humans – and foodborne diseases.

UC Berkeley photo by Justin Remais

On land, climate change is causing an increase of emissions of important greenhouse gases from microbes to the atmosphere, accelerating changes to the climate system.

Such changes could have major effects on agriculture, infectious disease and human and animal health, says another coauthor of the statement, Justin Remais, associate professor and head of the Division of Environmental Health Sciences in UC Berkeley’s School of Public Health.

“Climate change influences the viability and virulence of pathogenic microbes,” Remais says. “There is robust evidence that there will be adverse consequences of climate change on the health of domesticated animals, plants and people.”

Changes to climate are already affecting infectious diseases of domesticated animals and is intensifying the spread of certain environmental pathogens among people, such as those that cause diarrheal diseases—a major global killer of children under 5 years old.

“We know that variation in environmental conditions can affect the transmission of waterborne diseases, and can expand the number and geographic range of vectors that carry pathogens, such as mosquitos or small mammals,” Remais says. “The end result can be more intense or distant spread of disease.”

The group also argues that more resources are needed to support educators seeking to teach students about the impact of climate change on microbial life and the role of microbial life as an important determinant of climate change.

“We need to build literacy, both within the scientific community and throughout society, for our mutual dependence on microorganisms and a stable climate,” Koskella said. “That will require a commitment to greater inclusion and diversity in science education, and an emphasis on microbiology as an important lens for understanding the drivers and implications of climate change.”

Contacts and sources:
Robert Sanders
University of California Berkeley

“Warm” Glow of Uranus’s Rings Seen

The rings of Uranus are invisible to all but the largest telescopes — they weren’t even discovered until 1977 — but they’re surprisingly bright in new heat images of the planet taken by two large telescopes in the high deserts of Chile.

Composite image of Uranus’s atmosphere and rings at radio wavelengths, taken with the ALMA array in December 2017. The image shows thermal emission, or heat, from the rings of Uranus for the first time, enabling scientists to determine their temperature: a frigid 77 Kelvin (-320 F). Dark bands in Uranus’s atmosphere at these wavelengths show the presence of molecules that absorb radio waves, in particular hydrogen sulfide gas. Bright regions like the north polar spot (yellow spot at right, because Uranus is tipped on its side) contain very few of these molecules

. (UC Berkeley image by Edward Molter and Imke de Pater)

The thermal glow gives astronomers another window onto the rings, which have been seen only because they reflect a little light in the visible, or optical, range and in the near-infrared. The new images taken by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Telescope (VLT) allowed the team for the first time to measure the temperature of the rings: a cool 77 Kelvin, or 77 degrees above absolute zero — the boiling temperature of liquid nitrogen and equivalent to 320 degrees below zero Fahrenheit.

The observations also confirm that Uranus’s brightest and densest ring, called the epsilon ring, differs from the other known ring systems within our solar system, in particular the spectacularly beautiful rings of Saturn.

“Saturn’s mainly icy rings are broad, bright and have a range of particle sizes, from micron-sized dust in the innermost D ring, to tens of meters in size in the main rings,” said Imke de Pater, a UC Berkeley professor of astronomy. “The small end is missing in the main rings of Uranus; the brightest ring, epsilon, is composed of golf ball-sized and larger rocks.”

By comparison, Jupiter’s rings contain mostly small, micron-sized particles (a micron is a thousandth of a millimeter). Neptune’s rings are also mostly dust, and even Uranus has broad sheets of dust between its narrow main rings.

“We already know that the epsilon ring is a bit weird, because we don’t see the smaller stuff,” said graduate student Edward Molter. “Something has been sweeping the smaller stuff out, or it’s all glomming together. We just don’t know. This is a step toward understanding their composition and whether all of the rings came from the same source material, or are different for each ring.”

Rings could be former asteroids captured by the planet’s gravity, remnants of moons that crashed into one another and shattered, the remains of moons torn apart when they got too close to Uranus, or debris remaining from the time of formation 4.5 billion years ago.

Near-infrared image of the Uranian ring system taken with the adaptive optics system on the 10-meter Keck telescope in Hawaii in July 2004. The image shows reflected sunlight. In between the main rings, which are composed of centimeter-sized or larger particles, sheets of dust can be seen. The epsilon ring seen in new thermal images is at the bottom.


 (UC Berkeley image by Imke de Pater, Seran Gibbard and Heidi Hammel, 2006)

The new data were published this week in The Astronomical Journal. De Pater and Molter led the ALMA observations, while Michael Roman and Leigh Fletcher from the University of Leicester in the United Kingdom led the VLT observations.

“The rings of Uranus are compositionally different from Saturn’s main ring, in the sense that in optical and infrared, the albedo is much lower: they are really dark, like charcoal,” Molter said. “They are also extremely narrow compared to the rings of Saturn. The widest, the epsilon ring, varies from 20 to 100 kilometers wide, whereas Saturn’s are 100’s or tens of thousands of kilometers wide.”

The lack of dust-sized particles in Uranus’s main rings was first noted when Voyager 2 flew by the planet in 1986 and photographed them. The spacecraft was unable to measure the temperature of the rings, however.

To date, astronomers have counted a total of 13 rings around the planet, with some bands of dust between the rings. The rings differ in other ways from those of Saturn.

“It’s cool that we can even do this with the instruments we have,” he said. “I was just trying to image the planet as best I could and I saw the rings. It was amazing.”

Both the VLT and ALMA observations were designed to explore the temperature structure of Uranus’ atmosphere, with VLT probing shorter wavelengths than ALMA.

“We were astonished to see the rings jump out clearly when we reduced the data for the first time,” Fletcher said.

This presents an exciting opportunity for the upcoming James Webb Space Telescope, which will be able provide vastly improved spectroscopic constraints on the Uranian rings in the coming decade.


Images of the Uranian ring system captured at different wavelengths by the ALMA and VLT telescopes. The planet itself is masked since it is very bright compared to the rings

. (Images by Edward Molter, Imke de Pater, Michael Roman and Leigh Fletcher, 2019)

The Berkeley research was funded by the National Aeronautics and Space Administration (NNX16AK14G). Work at the University of Leicester was supported by the European Research Council (GIANTCLIMES) under the European Union’s Horizon 2020 research and innovation program (723890)..





Contacts and sources:
Robert Sanders
University of California Berkeley

Researchers Use Facial Quirks to Unmask ‘Deepfakes’

Researchers at UC Berkeley and USC are racing to create new techniques to detect deepfakes of political leaders. This video shows two examples of deepfakes, “face swap” and “lip-sync,” which were produced by USC computer scientists for research purposes, and a new technique the team has developed for spotting them. 
(UC Berkeley video by Roxanne Makasdjian and Stephen McNally)

After watching hours of video footage of former President Barack Obama delivering his weekly address, Shruti Agarwal began to notice a few quirks about the way Obama speaks.

“Every time he says ‘Hi, everybody,’ he moves his head up to the left or the right, and then he purses his lips,” said Agarwal, a computer science graduate student at UC Berkeley.

Agarwal and her thesis advisor Hany Farid, an incoming professor in the Department of Electrical Engineering and Computer Science and in the School of Information at UC Berkeley, are racing to develop digital forensics tools that can unmask “deepfakes,” hyper-realistic AI-generated videos of people doing or saying things they never did or said.

Seeing these patterns in the real Obama’s speech gave Agarwal an idea.

“I realized that there is one thing common among all these deepfakes, and that is that they tend to change the way a person talks,” Agarwal said.

Agarwal’s insight led her and Farid to create the latest weapon in the war against deepfakes: a new forensic approach that can use the subtle characteristics of how a person speaks, such as Obama’s distinct head nods and lip purses, to recognize whether a new video of that individual is real or a fake.

Their technique, which Agarwal presented this week at the Computer Vision and Pattern Recognitionconference in Long Beach, CA, could be used to help journalists, policy makers, and the public stay one step ahead of bogus videos of political or economic leaders that could be used to swing an election, destabilize a financial market, or even incite civil unrest and violence.

“Imagine a world now, where not just the news that you read may or may not be real — that’s the world we’ve been living in for the last two years, since the 2016 elections — but where the images and the videos that you see may or may not be real,” said Farid, who begins his tenure at UC Berkeley on July 1. “It is not just about these latest advances in creating fake images and video. It is the injection of these techniques into an ecosystem that is already promoting fake news, sensational news and conspiracy theories.”


On the left, Saturday Night Live star Kate McKinnon impersonates Elizabeth Warren during a skit, and on the right, face swap deepfake technology has been used to superimpose Warren’s face onto that of McKinnon.

(UC Berkeley photo by Stephen McNally)

The new technique works because all three of the most common deepfake techniques — known as “lip-sync,” “face swap,” and “puppet-master,” — involve combining audio and video from one source with an image from another source, creating a disconnect that may be uncovered by a keen viewer — or a sophisticated computer model.

Using the “face swap” technique, for example, one could create a deepfake of Donald Trump by superimposing Trump’s face onto a video of Alec Baldwin doing an impersonation of Trump, so that it is almost as if Baldwin is wearing a skin-tight Trump mask. But Baldwin’s facial expressions will still show through the mask, Agarwal said.

“The new image that is created will have the expressions and facial behavior of Alec Baldwin, but the face of Trump,” Agarwal said.

Likewise, in a “lip-sync” deepfake, AI algorithms take an existing video of a person talking, and alter the lip movements in the video to match that of a new audio, where the audio may be an older speech taken out of context, an impersonator speaking, or synthesized speech. Last year, actor and director Jordan Peele used this technique to create a viral video of Obama saying inflammatory things about president Trump.

But in these videos, only the lip movements are changed, so the expressions on the rest of the face may no longer match the words being spoken.

To test the idea, Agarwal and Farid gathered video footage of five major political figures – Hillary Clinton, Barack Obama, Bernie Sanders, Donald Trump and Elizabeth Warren – and ran them through the open-source facial behavior analysis toolkit OpenFace2, which picked out facial tics like raised brows, nose wrinkles, jaw drops and pressed lips.

They then used the outputs to create what the team calls “soft biometric” models, which correlate facial expressions and head movements for each political leader. They found each leader had a distinct way of speaking and, when they used these models to analyze real videos and deepfakes created by their collaborators at the University of Southern California, they found the models could accurately tell the real from the fake between 92 and 96 percent of the time, depending on the leader and length of the video.


OpenFace tracking software analyzes a real video of President Obama on the left, and a “lip-sync” deepfake on the right.

 (UC Berkeley photo by Stephen McNally)

“The basic idea is we can build these soft biometric models of various world leaders, such as 2020 presidential candidates, and then as the videos start to break, for example, we can analyze them and try to determine if we think they are real or not,” Farid said.

Unlike some digital forensics techniques, which identify fakes by spotting image artifacts left behind during the fabrication process, the new method can still recognize fakes that have been altered through simple digital processing like resizing or compressing.

But it’s not foolproof. The technique works well when applied to political figures giving speeches and formal addresses because they tend to stick to well-rehearsed behaviors in these settings. But it might not work as well for videos of these people in other settings: for example, Obama may not give his same characteristic head nod when greeting his buddies.

Deepfake creators could also become savvy to these speech patterns and learn to incorporate them into their videos of world leaders, the researchers said.

Agarwal says she hopes the new approach will help buy a little time in the ever-evolving race to spot deepfakes.

“We are just trying to gain a little upper-hand in this cat and mouse game of detecting and creating new deepfakes,” Agarwal said.


Contacts and sources:
Kara Manke
University of California Berkeley






Spiders Risk Everything for Love

Spiders put it all on the line for love say biologists. 

Extravagant courtship dances make wolf spiders susceptible to predators, a UC study finds.


Credit: Gecko gr / Wikimedia Commons

University of Cincinnati biologist George Uetz long suspected the extravagant courtship dance of wolf spiders made them an easy mark for birds and other predators.

But it was only when he and colleague Dave Clark from Alma College teamed up with former University of Minnesota researcher Tricia Rubi and her blue jays that he could prove it.

For a study published in May in the journal Behavioural Processes, Rubi trained a captive colony of blue jays to peck at buttons to indicate whether or not they saw wolf spiders (Schizocosa ocreata) on video screens.

A blue jay from the experiment at the University of Minnesota.

 Photo/Tricia Rubi


Clark made videos superimposing images of courting, walking and stationary male spiders on a leaf-litter background. Rubi presented the videos to blue jays on a flat display screen on the ground.


Wolf spiders are brindled black and brown like a painted dog. And they have a median stripe that breaks up their body outline. When viewed from above, they disappear amid the dead leaves.

For the experiment, one set of males was their natural black and brown color while another was altered to be even more camouflaged.

The jays had trouble finding spiders that stayed motionless in the videos. This confirmed the adaptive value of the anti-predator “freeze” behavior. The jays had less trouble seeing spiders that walked in the video. But the jays were especially quick to find male spiders engaged in ritual courtship behavior, in which they wave their furry forelegs in the air like overzealous orchestra conductors. The jays spotted courting spiders regardless of the experiment’s changes to their color.


UC biology professor George Uetz in his biology lab, featuring a poster of spiders.

 Photo/Andrew Higley/UC Creative Services


The study demonstrates UC's commitment to research as described in its strategic direction called Next Lives Here.

“By courting the way they do, spiders are clearly putting themselves at risk of bird predation,” UC's Uetz said.

His lab studies the complementary methods spiders employ to communicate with each other, called multimodal communication. Female spiders leave a pheromone trail behind them in their silk and when they rub their abdomens on the ground, Uetz said.

And when male spiders come into visual range, they bounce and rattle their legs on the leaf litter to create vibrations that can travel some considerable distance to the legs of potential mates. The males also wave their front legs in a unique pattern to captivate females.




 Photo/Provided


The males of the species have especially furry front legs that look like black woolen leg warmers. The combination of thick fur and vigorous dancing are indicators that the male is fit and healthy, Uetz said.


“The displays and the decorations show off male quality,” Uetz said. “The males that display vigorous courtship and robust leg tufts are showing off their immune competence and overall health. They, in turn, will have sons that have those qualities.”


UC professor George Uetz discusses his research in his lab.

Photo/Andrew Higley/UC Creative Services


That is, if they live so long. Many birds, including blue jays, find spiders to be tasty. And a chemical called taurine found in spiders is especially important for the neurological development of baby birds, he said.


“The birds selectively feed on spiders in early days of nestling development because spiders contain significantly more taurine than insects do,” Uetz said. “And taurine is associated with the development of spatial memory in the hippocampus of developing birds.”


Spatial memory helps birds recall where they cached food or built their nest.

Spiders instinctively fear predatory birds. In previous studies, Uetz, Clark and UC student Anne Lohrey determined that wolf spiders would freeze in place when they detected the sharp, loud calls of blue jays, cardinals and other insect-eating birds. By comparison, they ignored the calls of seed-eating birds such as mourning doves along with background forest noises such as the creak of katydids.


“They clearly recognized these birds as some kind of threat,” Uetz said. “Robins will hunt them on the ground. Lots of other birds do, too. Turkeys will snap them up.”


Before the spider study, Rubi was using a captive colony of blue jays at the University of Minnesota to explore how birds distinguish good prey choices from bad ones such as monarch butterflies.


“Monarchs are toxic, so blue jays that eat them will get very sick. They learn to avoid them,” she said.

Rubi wanted to know whether the birds recognized a toxic insect’s bold colors or its distinctive geometric pattern. She found out that jays used both.


“In the wild, a butterfly’s colors could be hard to see in dim light. Or they could be in the thick foliage where color is more important,” she said. “So having the ability to use both color and pattern is advantageous.”

When Uetz proposed a spider experiment, it wasn’t hard to train the blue jays, Rubi said. The jays quickly learned to peck at different buttons when they either observed a spider or didn’t see one on a video screen.

“Birds are super visual. They have excellent color vision and good visual acuity. It’s not surprising they would have no trouble seeing spiders in motion,” she said.

Rubi now studies genetic evolution at the University of Victoria in British Columbia.


UC professor George Uetz, left, talks to biology student Emmanuel Bagirov in front of a laser doppler vibrometer researchers use to study vibratory communication between wolf spiders.

Photo/Andrew Higley/UC Creative Services


If natural selection means the most avid courting spiders are also most likely to get eaten, why does this behavior persist across generations? Wouldn’t meeker spiders survive to pass along their genes?

Rubi said the explanation lies in another selective force.

“Natural selection is selection for survival, which would lead to spiders that are less conspicuous to predators,” she said. “But sexual selection is driven by females. And they select for a more conspicuous display.”

In genetic terms, Rubi said, fitness is measured in the number of healthy offspring produced. So while staying alive by minimizing risk is a good strategy for the individual, it’s not a viable strategy for the species.

UC student Emmanuel Bagirov uses a tube to scoop up pinhead crickets to feed wolf spiders in a UC biology lab.


 Photo/Andrew Higley/UC Creative Services


“The longest-lived male can still have a fitness of ‘zero’ if he never mates,” Rubi said. “So there appears to be a trade-off between being safe and being sexy. That balance is what shapes these courtship displays.


Uetz said female wolf spiders can be very choosy about the qualities they value in a mate.

“The tufts on their forelegs are very important. Their size and symmetry play a big role,” he said. “They’re so tiny and have brains the size of a poppy seed. You wouldn’t think they could discriminate, but they do.”

And at least for successful male wolf spiders living in a hostile world, this means love wins over fear.




Did you find it? If so, you are better than a blue jay. UC's experiment found that jays had trouble spotting spiders that froze. They had far less trouble finding spiders engaged in courtship behaviors. Photo/Provided




Contacts and sources:
Michael Miller
University of Cincinnati









Salt-Tolerant Bacteria in Brine Have Implications for Life on Mars

Salt-tolerant bacteria grown in brine were able to revive after the brine was put through a cycle of drying and rewetting. The research has implications for the possibility of life on Mars, as well as for the danger of contaminating Mars and other planetary bodies with terrestrial microbes. The research is presented at ASM Microbe 2019, the annual meeting of the American Society for Microbiology.

“Ours is the first demonstration of microbes surviving and growing after being dried and then re-wetted with humidity only,” said Mark Schneegurt, PhD, Professor of Biological Sciences at Wichita State University, Wichita, KS.


Credit: Frontiers in Microbiology

While parched, Mars’ surface has abundant sulfate salts of calcium, iron, and magnesium which could form saturated brines—even at some of the frigid temperatures that prevail on the red planet’s surface—that could be compatible with terrestrial microorganisms, or that could harbor Martian microbes.

Despite the red planet’s apparent aridity, humidity is thought to reach 80% to 100% at night and then plummet during the daytime as temperatures rise.

“The likelihood is high that at times surface salts may be able to attract sufficient water to form brines that can support microbial growth,” said Dr. Schneegurt. “The current research may also help redefine what constitutes a habitable zone, broadening the search for life to other icy worlds.”

In the study, the investigators grew species of Halomonas and Marinococcus obtained from Hot Lake, in Washington, and Great Salt Plains, in Oklahoma, in media containing 50% magnesium sulfate and 50% water. They took small drops of the grown culture and dried them in a container with water-absorbing chemicals under a vacuum, which takes about two hours. The dried drops were locked in a Mason jar with some water or a salt solution, and the jar fills with humidity. Within a day, the salts in the dried culture absorb enough water to make a liquid brine, at which point the bacterial cells revive. While there is modest cell death with each cycle—typically less than 50%—a substantial proportion of cells survive.

Halomonas 

Credit: Image Courtesy of Expedition Zone. / Microwiki
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In experiments where water was not added directly to the dried cultures, the investigators maintained the cultures in a sealed jar, above a layer of water or a salt solution. The dry, water-attracting magnesium sulfate formed a saturated brine in less than a day by absorbing moisture from the air inside the jar. Surviving cells revived, and began to grow, reaching high culture densities.

“Liquid water is key to life,” said Dr. Schneegurt. “Liquid water on Mars is likely saturated with salts. We work at the limits of life to demonstrate microbial tolerances to high salts and low temperatures.”


“Understanding how microbes can grow on Mars relates directly to the risks of contaminating Mars or other celestial bodies with organisms that can potentially grow on these worlds. This also speaks to the definition of habitable zones and the search for life on Mars and the icy worlds,” said Dr. Schneegurt.

ASM Microbe is the annual meeting of the American Society for Microbiology, held June 20th through 24th in San Francisco, California.


Contacts and sources:
Aleea KhanThe American Society for Microbiology







The Solution to Antibiotic Resistance Could Be in Your Kitchen Sponge



Researchers from the New York Institute of Technology (NYIT) have discovered bacteriophages, viruses that infect bacteria, living in their kitchen sponges. As the threat of antibiotic resistance increases, bacteriophages, or phages for short, may prove useful in fighting bacteria that cannot be killed by antibiotics alone. The research is presented at ASM Microbe, the annual meeting of the American Society for Microbiology.

A kitchen sponge is exposed to all kinds of different microbes, which form a vast microbiome of bacteria. Phages are the most abundant biological particles on the planet and are typically found wherever bacteria reside. With this understanding, kitchen sponges seemed a likely place to find them.
Credit: Wikimedia Commons

Students in a research class isolated bacteria from their own used kitchen sponges and then used the bacteria as bait to find phages that could attack it. Two students successfully discovered phages that infect bacteria living in their kitchen sponges. "Our study illustrates the value in searching any microbial environment that could harbor potentially useful phages," said Brianna Weiss, a Life Sciences student at New York Institute of Technology.

The researchers decided to "swap" these two phages and see if they could cross-infect the other person's isolated bacteria. Consequently, the phages did kill the other's bacteria. "This led us to wonder if the bacteria strains were coincidentally the same, even though they came from two different sponges," said Weiss.

The researchers compared the DNA of both isolated strains of bacteria and discovered that they were both members of the Enterobacteriaceae family. These bacteria belong to a rod-shaped group of microbes commonly found in feces, where some cause infections in hospital settings. Although the strains are closely related, when performing biochemical testing they found chemical variations between them.

"These differences are important in understanding the range of bacteria that a phage can infect, which is also key to determining its ability to treat specific antibiotic-resistant infections," said Weiss. "Continuing our work, we hope to isolate and characterize more phages that can infect bacteria from a variety of microbial ecosystems, where some of these phages might be used to treat antibiotic-resistant bacterial infections."

This project began as part of an undergraduate research class with seven students at the New York Institute of Technology (NYIT) in Old Westbury, New York. The course was funded through internal grants provided by (NYIT), which also supported our later work to further characterize the isolated bacteria and bacteriophages. This second phase of our work will be presented on a poster at ASM Microbe on Sunday, June 23rd.





Contacts and sources:
Aleea Khan
The American Society for Microbiology