Culture

Scientists from Tohoku University have developed a new fluorine-free calcium (Ca) electrolyte based on a hydrogen (monocarborane) cluster that could potentially realize rechargeable Ca batteries.

The researchers say the new material, achieved by designing the coordination structure of Ca cation with a weakly coordinating anion and mixed solvents, shows markedly improved electrochemical performances such as high conductivity and high electrochemical stabilities.

Current lithium-ion (Li-ion) batteries have some drawbacks. They are approaching their demand limits of theoretical energy density and cost, and lithium is not naturally plentiful.

Calcium, however, is the fifth most abundant element in Earth's crust and its metal anode has low reduction potential (-2.87 V vs. standard hydrogen electrode (SHE)) and volumetric capacities of 2072 mAh cm-3, giving it comparable cell voltage and energy density to those of Li. Calcium batteries are therefore cost effective and possess high battery performance, making them a suitable substitute for Li-batteries.

Still, many challenges remain before Ca batteries can be realized due to a lack of suitable electrolytes which possess reductive/oxidative stabilities and high ionic conductivities. Moreover, realizing a fluorine-free system is desirable for practical Ca electrolytes because a fluorine-containing electrolyte intrinsically induces CaF2 formation on the electrode, which hinders Ca diffusion as well as the Ca plating and stripping processes.

The Tohoku University research team, which was led by Kazuaki Kisu and Shin-ichi Orimo from the Advanced Institute for Materials Research (AIMR), utilized the hydrogen cluster anion because of its high reductive and oxidative stability, which allows for a wide potential window and demonstrates excellent stability against metal anodes such as Li, Na, and Mg.

"A design that incorporates a hydrogen cluster into a Ca electrolyte had not been proposed yet," said Kisu. "We were pleased that this turned out suitable for a Ca battery."

The team, which also included Kim Sangryun from the Institute of Materials Research and Kun Zhao and Andreas Züttel from École Polytechnique Fédérale de Lausanne (EPFL) as part of Tohoku University's Core Research Cluster for Materials Science, envisions this new Ca electrolyte with robust electrochemical performances to be a breakthrough for Ca batteries.

"We expect the development of a promising electrolyte candidate based on complex hydrides compatible with Ca batteries will create future opportunities for exploring other related complex hydride compounds such as multivalent electrolytes," added Kisu.

A total of 108 women participated in the research from the first weeks of pregnancy to delivery, having recorded their stress levels before, during, and after conception (via the concentration of cortisol in hair) and performed different psychological tests

A study carried out by scientists from the University of Granada (UGR) has revealed that women who experience stress both before becoming pregnant and during conception are almost twice as likely to have a girl as a boy.

Researchers from the Mind, Brain and Behaviour Research Centre (CIMCYC), the Department of Pharmacology (Faculty of Pharmacy), and the Faculty of Psychology have analysed the levels of cortisol (a steroid hormone that is released in response to stress) in the hair of pregnant women in the period spanning from before conception to week 9 of pregnancy, to determine whether there was any link with the sex of the baby.

A total of 108 women were monitored from the first weeks of pregnancy through to delivery, to record their stress levels before, during, and after conception via the concentration of cortisol in their hair and various psychological tests. The measurement of cortisol in hair samples taken approximately in week 8-10 of pregnancy showed the concentration of cortisol in the pregnant woman for the previous three months (one month per centimetre of hair growth), meaning that it covered the period preceding and after conception. Subsequently, the UGR scientists recorded different variables relating to the birth and the sex of the baby.

María Isabel Peralta Ramírez, the main author of this work and researcher at the UGR's Department of Personality, Evaluation and Psychological Treatment explains: "The results we found were surprising, as they showed that the women who had given birth to girls presented higher concentrations of hair cortisol in the weeks before, during, and after the point of conception than those who had boys." In fact, these cortisol concentrations in the hair of mothers who subsequently had girls were almost double those who had boys.

Consequences of stress

There is ample scientific evidence demonstrating the impact of stress on the mother in the processes of pregnancy, birth, and even infant neurodevelopment. "Specifically, our research group has shown in numerous publications how psychological stress in the mother generates a greater number of psychopathological symptoms during pregnancy, postpartum depression, a greater likelihood of assisted delivery, an increase in the time taken for lactation to commence (lactogenesis), or inferior neurodevelopment of the baby six months after birth," says Peralta.

All of the existing research tells us about the effect of stress when pregnancy has already occurred. However, few studies have shown the link between stress and the mother-to-be before or during the conception of the baby, the present study being a rare exception. Its findings were recently published in the prestigious Journal of Developmental Origins of Health and Disease.

One possible explanation for the results would be that the activation of the "stress system"--the hypothalamus-pituitary-adrenal gland system--which involves an increase in cortisol secretion, modifies the concentrations of sex hormones at the time of conception. However, the mechanisms underlying this modification are not clear, because, on the one hand, there is evidence that testosterone could influence the determination of the baby's sex, since the higher the levels of prenatal stress, the higher the levels of female testosterone.

On the other hand, there is scientific evidence that sperm carrying the X chromosome (which determines that the baby will be female) perform better at passing through the cervical mucus in circumstances of adversity. Therefore, due to the hormonal changes associated with stress in the mother, these sperm are more likely to be successful in reaching the egg than sperm carrying the Y chromosome (which determines that the baby will be male).

"There are other possible hypotheses that attempt to explain this phenomenon. Among the strongest theories is the idea that there are more terminations of male foetuses on medical grounds during the first weeks of gestation in situations of severe maternal stress. That said, in light of the design of these studies, it is recommended that the results are corroborated in greater depth," observes Peralta.

The effect of stress on the foetus

What does appear to be clear-- and this has been shown in several studies--is that foetuses are vulnerable to the effect of stress, since it plays a key role in their development. An example of this is the proven fact that male (XY) foetuses mature more slowly than female (XX) foetuses; they tend to be associated with more complications in pregnancy and premature delivery; and, at birth, they are more likely to have shorter telomeres. This renders XY foetuses more vulnerable to adverse prenatal environments, suggesting that women who experience high levels of stress around the time of conception may be less likely to give birth to a boy.

Cuckoo wasps - also called emerald wasps - are some of the most beautiful insects we have, with colourful exteriors that shine like jewels. However, these beauties have also created a lot of headaches.

"Normally we distinguish insects from each other by their appearance, but cuckoo wasps are so similar to each other that it makes it difficult," says Frode Ødegaard.

Ødegaard is an insect researcher at the NTNU (Norwegian University of Science and Technology) University Museum and belongs to the European research group that has now described thia recent contribution to species diversity. The new species is very rare, and is only a single specimen has been found on the Lista peninsula in Agder county in Norway.

For more than 200 years, insect researchers have struggled to sort cuckoo wasps into the right "species boxes," and to determine which characteristics are variations within a species and which are species-specific differences.

In the last 10 years, DNA barcoding has brought about a major breakthrough by making it possible to distinguish different species of cuckoo wasps from each other by looking at the differences in their genetic material.

"But it's not always that easy, either. In this case, we had two cuckoo wasps with microscopic differences in appearance and very small differences in DNA," Ødegaard says.

"The next step was to look at the language of each of the wasps to find out if they belonged to different species," he says.

Insects communicate with each other through pheromones - in other words, they have a chemical language. Very closely related species often have completely different languages to prevent them from interbreeding.

The cuckoo wasp is an insect with above-average linguistic abilities. They are parasites, which means that they behave like cuckoos and lay their eggs in the nests of other bees and wasps. The larvae grow quickly and hatch before the host's eggs. Then they eat the eggs, the larvae and the food supply that the host has arranged in the nest.

"When you live as a parasite, it's important not to be discovered, and therefore the cuckoo wasp has also learned the language of its host," says Ødegaard.

By conducting an ever-so-small language study, the researchers were able to discover that the two almost identical cuckoo wasps did indeed belong to different species. They use different hosts - and that means that they also speak completely different languages.

"The evolutionary development associated with sponging off another species happens very fast. That's why you can have two species that are really similar genetically but still belong to different species," says Ødegaard.

When a new species is described it has to be given a name, and Frode Ødegaard had the good fortune to receive the honour of naming the newcomer.

"A naming competition was announced among researchers in Europe who work with cuckoo wasps, and then the proposals that came in were voted on. It turned out my proposal actually got the most votes!" Ødegaard says.

"As mentioned, the new wasp is very similar to another species called Chrysis brevitarsis, so the new species was named Chrysis parabrevitarsis, which means 'the one standing next to brevitarsis'."

Ødegaard was also responsible for giving the species its slightly simpler Norwegian name of sporegullveps. He makes no secret of the fact that he found it great to be able to name a new species.

"In a way, you place yourself in the perspective of eternity, because that species will always have that name. There's something very fundamental about it."

The only known specimen of this cuckoo wasp has been captured and pinned in an insect collection. So it may seem both morally reprehensible and unnecessary that this one lone individual was stuck onto a needle.

"Even with today's advanced methods, using live animals for studies like this isn't possible, but collecting individual specimens fortunately has no impact on the population," Ødegaard says.

"The insects have enormous reproductive potential, and the size and quality of the habitats are what determine the viability of the population, not whether any specimens are eaten by birds or collected by an insect researcher."

He adds that the collected insects are absolutely crucial for researchers to be able to map and describe their diversity and thus take care of viable populations for posterity.

New research suggests Ireland's increasing populations of Sika deer may be linked to local outbreaks of TB infection in cattle.

Although TB infection rates have decreased in general in recent decades, county-level data shows a correlation between higher Sika numbers and higher local TB infections - with County Wicklow a particular hotspot.

The research, conducted by researchers from Trinity College Dublin and the National Parks and Wildlife Service and supported by the Department of Agriculture, Food and the Marine, has major implications for controlling TB. It has just been published in the journal, Frontiers in Veterinary Science.

First author of the journal article, Dr David Kelly, from Trinity's School of Natural Sciences, said:

"Irish farmers have been aware of the effects of bovine TB for well over 70 years. Its incidence has steadily diminished in Ireland, from 3% in 1960 to 0.3% some 50 years later. In the mid-1980s it became clear European badgers were a TB wildlife host. Since then, badger populations have been controlled around farms with TB outbreaks whenever those outbreaks cannot be linked to cattle.

In recent years, however, it has become clear that controlling TB in badger populations cannot rely on culling alone. Along with this change in thinking, there has been a steady shift away from culling and towards badger vaccination. Unfortunately, while the management of one TB wildlife host has made great advances, another wildlife TB host has appeared on the radar: deer."

The number of deer in Ireland has been rising steadily during the 21st century, and studies in Europe and the USA have shown that deer, at higher densities, can sustain TB in their herds. Indeed, recent research has identified Sika deer in County Wicklow as one such maintenance host of TB.

The researchers behind the current study used county-level population densities (taken between 2000 and 2018) to track the three known maintenance hosts of TB in Ireland: cattle, badgers, and Sika deer.

They then considered how variations in local densities compared with the variation in bovine TB infection across the country (and also at county-level).

Dr Kelly said:

"Our analyses show that while there have been general reductions in TB infection, there is a correlation between increasing Sika deer density and higher local TB infection. This pattern has emerged in recent years and has major implications for TB control within Ireland.

"Now, when attempting to manage TB in wildlife, Sika deer will need to be considered as well as badgers. Our analyses suggest Sika deer are currently of greatest concern in County Wicklow but if numbers continue to rise in other counties they may also pose problems elsewhere."

New Orleans, LA - A study led by Edward Wojcik, PhD, Associate Professor of Biochemistry & Molecular Biology at LSU Health New Orleans School of Medicine, identified how microcephaly (abnormally small heads) and blindness may develop in Zika-infected fetuses, as well as a new way to potentially prevent these neurodevelopmental defects. The results are published online in iScience, available here.

The mechanism by which Zika virus disrupts neuronal development and results in congenital Zika syndrome was unknown. Because of similarities between Zika syndrome and a recognized congenital genetic disease (Kinesin-5) known to cause microcephaly and retinopathies in developing infants, the research team studied both, looking for similarities. They discovered a direct link, the first molecular and cellular evidence supporting a direct connection between the two.

"We had a hunch that the microcephaly and blindness that results from Kinesin-5 genetic disease could be linked to Zika infection, and the hunch paid off," notes Dr. Wojcik. "Our experiments identify a molecular motor as a target for degradation by an encoded Zika virus protein (Zika protease). The molecular motor is Kinesin-5, and it is required for cell division in humans. Our data identify Kinesin-5 as a target for the virus and links the infection to microcephaly."

The researchers observed that Zika protease cuts Kinesin-5 during cell division, disrupting the process and causing a loss of function. They also suggest a way to prevent it.

The Zika protease can degrade only a target protein it can reach. Since the protease is part of the endoplasmic reticulum (ER) membrane, only target proteins that come in direct contact with the ER can be degraded. In this way, the protease acts in a spatially restricted manner in the cell; target proteins are degraded only in certain regions of the cell volume and not in others. So, the research team proposes a drug that would affect only the Zika protease instead of drugs that would affect all target proteins in a cell.

"We predict and hope that potential drugs that inhibit Zika protease may be effective in preventing microcephaly and blindness from developing within Zika-infected fetuses," Dr. Wojcik concludes.

Comparison of coda waves, the scattered waves that arrive after the direct waves of a seismic event, can be used to determine the relative locations of two underground explosions, according to a new study published in the open-access journal The Seismic Record.

The technique, called coda wave interferometry, was tested on explosions conducted as part of the Source Physics Experiment (SPE). Lawrence Livermore National Laboratory researchers Sean Ford and Bill Walter report that coda wave interferometry can also put a limit on the extent of damage caused by an explosion.

The findings suggest the technique could be used to improve the estimates of the relative locations of larger explosions, such as the series of announced nuclear tests conducted by the Democratic People's Republic of Korea over the past two decades.

"Based on the size and frequency scaling that we were able to employ in the paper and successes at SPE," said Ford, "a conclusion point is that this technique could be used for larger explosions at larger separations recorded at more distant stations" such as those used to monitor North Korean testing.

Unlike the direct and strong P- and S-seismic waves produced by an earthquake or explosion event, coda waves arrive later and are more sensitive to scattering by the rock that they pass through. Any changes in the scattering structure--from rocks pushed or crushed by an explosion, for example--"will show up in how these later arriving waves have bounced around in that medium over a greater duration," Ford explained.

In the new study, Ford and Walter used data from the SPE, an ongoing multi-institutional project involving Lawrence Livermore, Los Alamos and Sandia National Laboratories at the former Nevada nuclear test site. The SPE conducts chemical explosions to better understand the seismic waves they produce and to refine explosion detection techniques, using the analyses to improve monitoring of global nuclear explosions.

The researchers used coda wave interferometry to determine the known relative location of two chemical explosions that took place during Phase I of the SPE. The first explosion, SPE-1, was equivalent to 87.9 kilograms of TNT. The second explosion, SPE-2, was equivalent to 997 kilograms of TNT.

Their analysis concluded that the two explosions were located between 6 and 18 meters apart, and most likely 9.2 meters apart. The known separation between the two explosions is about 9.4 meters apart.

Previous research by seismologists David Robinson and coworkers, showed that coda wave interferometry could precisely locate earthquakes separated by hundreds of meters. "We were confident that the approach would work for chemical explosions, but the question for us was whether it could work for such small and closely located explosions," said Ford.

Ford and Walter also used the technique to better characterize the underground damage caused by SPE-2, comparing its coda waves with those produced by the 905-kilogram TNT equivalent SPE-3 that was later detonated in the same spot as SPE-2.

The details of the damage "can't be seen from the direct waves arriving at the [1-kilometer or more] distant stations that we're used to, so we thought perhaps we could see it in these more sensitive scattered waves, the coda waves," Ford explained

Based on the analysis, the damage caused by SPE-2 must have been confined to a spherical region with a radius less than 10 meters, the researchers concluded.

"We thought there would be much more damage, or at least more of an effect on the outgoing waves, but now there is evidence against that hypothesis, so this points us in other directions to explain the observed P- and S-waves," Ford said.

The study is the first research paper published in The Seismic Record, a new short-form, open-access journal from the Seismological Society of America.

Using samples of small cell lung tumours, a research team led by biologist Dr Silvia von Karstedt has discovered two new ways to induce tumour cell death. One of two subsets of tumour cells can be targeted by activating ferroptosis: iron-dependent cell death caused by oxidative stress. In the second subtype, oxidative stress - and hence cell death - can also be induced in a different way. Both types of cell death must be triggered simultaneously by drugs to kill the majority of the tumour mass. The results of the study have been published in Nature Communications.

Despite many advances in treatment, a diagnosis of small cell lung cancer means a particularly poor prognosis. In Germany, up to 8000 new cases of small cell lung cancer (SCLC) are diagnosed each year. At the time of diagnosis, cancer has already found many loopholes to escape the body's immune system. 'Traditional' cell death mechanisms, such as regulated cell death by apoptosis, are usually already inactivated at this stage. That way, tumour cells can continue to divide and spread almost unperturbed.

A high cell division rate is characteristic of small cell lung cancer, which initially promises a good response to chemotherapy. 'Unfortunately, in many cases the success of chemotherapy is short-lived because tumour cells rapidly develop resistance to therapy. In addition, a tumour consists not only of one, but of several cell types - the so-called subtypes - each of which uses unique strategies to escape lethal therapy,' said von Karstedt, research group leader at the CECAD Cluster of Excellence for Aging Research, the Department of Translational Genomics at the University of Cologne and the Center for Molecular Medicine Cologne (CMMC). This is where her research comes in. The biologist explores which cell death mechanisms are already inactivated in cancer cells and which ones can still be targeted by therapies to kill the tumour.

The research team used patient samples taken at the time of diagnosis, thus depicting the treatment-naïve tumour. To find out which pathways of cell death are still available, the scientists compared gene activity between patient cells taken inside and outside the tumour. Signalling pathways important for traditional cell death mechanisms were already switched off inside the tumour at this early stage, before therapy. In contrast, genes important for the activation of iron-dependent cell death by oxidative damage (ferroptosis) were strongly activated in the cancer cells.

Put in simple terms, small cell lung cancer cells can be divided into two subtypes: neuroendocrine cells and non-neuroendocrine cells. In the neuroendocrine cell subtype, more genes are active which are otherwise typically found in nerve cells that produce hormones. Cells belonging to the other subtype do not have this property and are therefore grouped as non-neuroendocrine cells. 'Several experiments showed that cells of the non-neuroendocrine type can be killed using buthionine sulfoximine, which induces ferroptosis. In cells belonging to the neuroendocrine subtype, we found that they protect themselves from oxidative stress - and thus cell death - by producing antioxidants. However, by adding the antioxidant inhibitor Auranofin, we were able to kill these cells as well,' explains doctoral researcher Christina Bebber, the lead author of the paper.

Regarding a possible application of these findings to the therapy of small cell lung cancer, the biologists made an important observation: When targeting just one of the two pathways - i.e., either activating ferroptosis or inhibiting antioxidant production - in a tumour consisting of cells of both subtypes, cancer cells were able to evade the lethal therapy. They did so by adjusting their gene expression to switch to the subtype that could resist the respective single pathway-targeting treatment. 'When we applied a combination therapy, we took away this route of escape. What is also special about the study is that we used drugs that have already been tested in extensive clinical trials or even approved for the treatment of other diseases,' von Karstedt explained. Buthionine sulfoximine, which triggers ferroptosis, is already in clinical trials for cancer treatment. The gold salt Auranofin, which blocks the production of protective antioxidants in cancer cells, has been in use for decades to treat rheumatoid arthritis.

Future clinical studies using this combined therapy will clarify to what extent this targeted therapy option will improve the prognosis of small cell lung cancer patients.

DURHAM, N.C. -- Some guys have it all: the muscle, the power, the high social status, the accelerated aging.

But wait. Faster aging? Who wants that? For male baboons, it's the price they pay to be at the top.

New research appearing April 6 in eLife by Jenny Tung, associate professor of evolutionary anthropology and biology at Duke University, and her colleagues shows that male baboons that climb the social ladder age faster than males with lower social standing. If a male drops in social status, his estimated rate of aging drops as well.

Using blood samples from 245 wild baboons in the Amboseli ecosystem in Kenya, the team analyzed chemical modifications to DNA known as DNA methylation marks.

"These marks change with age in a clock-like fashion," Tung said. "However, environmental stressors can make the clock tick faster." This would make an individual appear older than they really are, and, research in humans suggests, can put them at a higher risk of aging-related disease.

Since this cohort of baboons is one of the most intensively studied wild mammal populations in the world, the researchers already knew not only each baboon's age, but also the environment in which they grew up, their exposure to early life adversity, and a great deal about their adult environment, especially the aspects that predict how long they live and how many offspring they leave behind.

"We used DNA methylation to compare the baboons known ages to their 'biological ages,'" said Jordan Anderson, a graduate student in the Tung lab who co-led the work. These methylation markers are found across the genome, so the team first needed to measure a large number of these sites - about 400,000 of them - and then, through statistical methods and models, whittle the number of sites down to about 500 that best predicted age.

Interestingly, for males, early life adversity didn't affect how fast their biological clocks tick.

Adult social status was the strongest factor that affected aging. "Male baboons who compete successfully for high social status appear to age faster," Tung said. "We repeatedly sampled some of these males and were able to show that the clock can speed up or slow down as males move up or down the social ladder."

This is contrary to what we see in humans. Typically, high social status in humans predicts better health, not worse. The most wealthy and powerful humans have access to and can afford the best houses, schools, healthcare and more. Those who live in poverty and have lower socioeconomic status are at increased risk and have higher rates of disease, cancer and all-cause mortality.

Male baboons, though, have to fight for their social status. Because of this, it's common to see male-male competition on a regular basis, where baboon observers can see a clear winner and a clear loser.

To maintain their social status, males at the top regularly have to hold their ground and defend themselves physically. Because of this, male baboons at the top tend to have more muscle mass and better body condition than lower ranking baboons. But as their physicality starts to diminish with age, a new, younger, stronger male may overcome them for the top spot.

High ranking males also spend a lot of time mate-guarding females. Around ovulation, they follow females closely and ward off other males. Mate-guarding constrains a male's other activities, and Tung and her team think it is likely to be energetically costly -- perhaps helping to explain their accelerated aging result.

So why do these males work so hard to achieve a high stress social status? It's simple: to have offspring.

"If male baboons are going to have babies, they need to achieve high rank," Tung said. "They will have very little chance to leave offspring if they don't achieve high rank, which creates a powerful evolutionary motivation."

This study highlights one way that the social environment can influence aging. "Our research shows that the manner in which social status is attained and maintained is crucial to understanding its consequences," Tung said.

TAMPA, Fla. -- Tumors are genetically diverse with different mutations arising at different times throughout growth and development. Many models have tried to explain how genetic heterogeneity arises and what impact these alterations have on tumor growth. In a new article published in Nature Communications, Moffitt Cancer Center researchers show how the location of the tumor and spatial constraints put on it by the surrounding tissue architecture impact genetic heterogeneity of tumors.

Genetic differences are apparent among tumors from different patients, as well as within different regions of the same tumor of an individual patient. Some of these mutations may benefit the tumor and become selected for, such as mutations that allow the tumor to grow faster and spread to other sites. This type of tumor evolution is known as Darwinian evolution. Alternatively, other cellular mutations may have no immediate impact on the tumor but still accumulate over time, known as neutral evolution. Researchers in Moffitt's Center of Excellence for Evolutionary Therapy wanted to determine how the surrounding tissue architecture impacts these different types of tumor evolution patterns and genetic heterogeneity.

The team used mathematical modeling to determine how spatial constraints impact tumor evolution with a focus on the three-dimensional architecture of ductal carcinoma of the breast. They used a well-studied model of tumor evolution and altered variables related to spatial constraints and cell mixing and demonstrated that the surrounding tissue architecture greatly affects the genetic heterogeneity of tumors over time. For example, the ductal network of breast tissue is similar to the trunk and branches of a tree. A tumor that forms within the wider region of the base of the duct has less spatial constraints placed on it compared to a tumor that initially forms in the smaller ductal branches. As a result, a tumor near the base tends to acquire mutations over an extended time and will have more genetic heterogeneity due to neutral evolution. On the other hand, a tumor within the smaller ductal regions tends to undergo accelerated genetic changes that result in one mutation becoming dominant due to Darwinian evolution, - also known as clonal sweep.

"Two otherwise identical tumors may realize dramatic differences in ?tness depending on constraints imposed by tissue architecture," said Sandy Anderson, Ph.D., study author and director of the Center of Excellence for Evolutionary Therapy at Moffitt. "On the cell scale, any given subclone may have a selective advantage. Yet, the effective outcome of this subclonal advantage depends on the surrounding competitive context of that cell. In other words, cell-speci?c phenotypic behavior can be 'overridden' by the tissue architecture, allowing the tumor to realize increased ?tness."

The study sheds light on the important role that tumor location has in the development and progression of cancer and helps explain the wide variety of mutational patterns observed among different patients.

"Our approach adds clarity to the debate of neutral tumor evolution by exploring a key mechanism behind both interpatient and intratumoral tumor heterogeneity: competition for space," said Jeffrey West, Ph.D., study co-author and postdoctoral fellow in the Integrated Mathematical Oncology Department at Moffitt.

NASA's Hubble Space Telescope is "seeing double." Peering back 10 billion years into the universe's past, Hubble astronomers found a pair of quasars that are so close to each other they look like a single object in ground-based telescopic photos, but not in Hubble's crisp view.

The researchers believe the quasars are very close to each other because they reside in the cores of two merging galaxies. The team went on to win the "daily double" by finding yet another quasar pair in another colliding galaxy duo.

A quasar is a brilliant beacon of intense light from the center of a distant galaxy that can outshine the entire galaxy. It is powered by a supermassive black hole voraciously feeding on inflating matter, unleashing a torrent of radiation.

"We estimate that in the distant universe, for every 1,000 quasars, there is one double quasar. So finding these double quasars is like finding a needle in a haystack," said lead researcher Yue Shen of the University of Illinois at Urbana-Champaign.

The discovery of these four quasars offers a new way to probe collisions among galaxies and the merging of supermassive black holes in the early universe, researchers say.

Quasars are scattered all across the sky and were most abundant 10 billion years ago. There were a lot of galaxy mergers back then feeding the black holes. Therefore, astronomers theorize there should have been many dual quasars during that time.

"This truly is the first sample of dual quasars at the peak epoch of galaxy formation with which we can use to probe ideas about how supermassive black holes come together to eventually form a binary," said research team member Nadia Zakamska of Johns Hopkins University in Baltimore, Maryland.

The team's results appeared in the April 1 online issue of the journal Nature Astronomy.

Shen and Zakamska are members of a team that is using Hubble, the European Space Agency's Gaia space observatory, and the Sloan Digital Sky Survey, as well as several ground-based telescopes, to compile a robust census of quasar pairs in the early universe.

The observations are important because a quasar's role in galactic encounters plays a critical part in galaxy formation, the researchers say. As two close galaxies begin to distort each other gravitationally, their interaction funnels material into their respective black holes, igniting their quasars.

Over time, radiation from these high-intensity "light bulbs" launch powerful galactic winds, which sweep out most of the gas from the merging galaxies. Deprived of gas, star formation ceases, and the galaxies evolve into elliptical galaxies.

"Quasars make a profound impact on galaxy formation in the universe," Zakamska said. "Finding dual quasars at this early epoch is important because we can now test our long-standing ideas of how black holes and their host galaxies evolve together."

Astronomers have discovered more than 100 double quasars in merging galaxies so far. However, none of them is as old as the two double quasars in this study.

The Hubble images show that quasars within each pair are only about 10,000 light-years apart. By comparison, our Sun is 26,000 light-years from the supermassive black hole in the center of our galaxy.

The pairs of host galaxies will eventually merge, and then the quasars also will coalesce, resulting in an even more massive, single solitary black hole.

Finding them wasn't easy. Hubble is the only telescope with vision sharp enough to peer back to the early universe and distinguish two close quasars that are so far away from Earth. However, Hubble's sharp resolution alone isn't good enough to find these dual light beacons.

Astronomers first needed to figure out where to point Hubble to study them. The challenge is that the sky is blanketed with a tapestry of ancient quasars that flared to life 10 billion years ago, only a tiny fraction of which are dual. It took an imaginative and innovative technique that required the help of the European Space Agency's Gaia satellite and the ground-based Sloan Digital Sky Survey to compile a group of potential candidates for Hubble to observe.

Located at Apache Point Observatory in New Mexico, the Sloan telescope produces three-dimensional maps of objects throughout the sky. The team pored through the Sloan survey to identify the quasars to study more closely.

The researchers then enlisted the Gaia observatory to help pinpoint potential double-quasar candidates. Gaia measures the positions, distances, and motions of nearby celestial objects very precisely. But the team devised a new, innovative application for Gaia that could be used for exploring the distant universe. They used the observatory's database to search for quasars that mimic the apparent motion of nearby stars. The quasars appear as single objects in the Gaia data. However, Gaia can pick up a subtle, unexpected "jiggle" in the apparent position of some of the quasars it observes.

The quasars aren't moving through space in any measurable way, but instead their jiggle could be evidence of random fluctuations of light as each member of the quasar pair varies in brightness. Quasars flicker in brightness on timescales of days to months, depending on their black hole's feeding schedule.

This alternating brightness between the quasar pair is similar to seeing a railroad crossing signal from a distance. As the lights on both sides of the stationary signal alternately flash, the sign gives the illusion of "jiggling."

When the first four targets were observed with Hubble, its crisp vision revealed that two of the targets are two close pairs of quasars. The researchers said it was a "light bulb moment" that verified their plan of using Sloan, Gaia, and Hubble to hunt for the ancient, elusive double powerhouses.

Team member Xin Liu of the University of Illinois at Urbana-Champaign called the Hubble confirmation a "happy surprise." She has long hunted for double quasars closer to Earth using different techniques with ground-based telescopes. "The new technique can not only discover dual quasars much further away, but it is much more efficient than the methods we've used before," she said.

Their Nature Astronomy article is a "proof of concept that really demonstrates that our targeted search for dual quasars is very efficient," said team member Hsiang-Chih Hwang, a graduate student at Johns Hopkins University and the principal investigator of the Hubble program. "It opens a new direction where we can accumulate a lot more interesting systems to follow up, which astronomers weren't able to do with previous techniques or datasets."

The team also obtained follow-up observations with the National Science Foundation NOIRLab's Gemini telescopes. "Gemini's spatially-resolved spectroscopy can unambiguously reject interlopers due to chance superpositions from unassociated star-quasar systems, where the foreground star is coincidentally aligned with the background quasar," said team member Yu-Ching Chen, a graduate student at the University of Illinois at Urbana-Champaign.

Although the team is convinced of their result, they say there is a slight chance that the Hubble snapshots captured double images of the same quasar, an illusion caused by gravitational lensing. This phenomenon occurs when the gravity of a massive foreground galaxy splits and amplifies the light from the background quasar into two mirror images. However, the researchers think this scenario is highly unlikely because Hubble did not detect any foreground galaxies near the two quasar pairs.

Galactic mergers were more plentiful billions of years ago, but a few are still happening today. One example is NGC 6240, a nearby system of merging galaxies that has two and possibly even three supermassive black holes. An even closer galactic merger will occur in a few billion years when our Milky Way galaxy collides with neighboring Andromeda galaxy. The galactic tussle would likely feed the supermassive black holes in the core of each galaxy, igniting them as quasars.

Future telescopes may offer more insight into these merging systems. NASA's James Webb Space Telescope, an infrared observatory scheduled to launch later this year, will probe the quasars' host galaxies. Webb will show the signatures of galactic mergers, such as the distribution of starlight and the long streamers of gas pulled from the interacting galaxies.

Breast cancer survivors with a higher risk of cancer recurrence based on genomic testing may experience greater fear of their cancer returning, according to a new study led by researchers at NYU Rory Meyers College of Nursing. However, psychological factors such as anxiety are the best predictors of survivors' fear of their cancer recurring.

"Although genomic test results were associated with fear of cancer recurrence, our findings highlight that distressing, but treatable, psychological factors fuel cancer survivors' fear of recurrence," said Maurade Gormley, PhD, RN, an assistant professor and faculty fellow at NYU Meyers and the lead author of the study, which was published in the journal Psycho-Oncology.

For breast cancer survivors, fear and worry that their cancer will return is a significant, unmet psychological need. Over half of breast cancer survivors experience moderate to severe levels of fear of cancer recurrence; this grows to up to 70 percent among younger breast cancer survivors.

The Oncotype Dx® test is a genomic test that is used to predict the likelihood of cancer recurring in women with early-stage hormone receptor-positive breast cancer, the most common form of breast cancer. It analyzes breast cancer cells after surgery or biopsy to predict the 10-year risk of recurrence, creating a "recurrence score" that is divided into three risk categories: low, intermediate, and high. The genomic test can also be used to plan breast cancer treatment, including whether a patient will benefit from chemotherapy in addition to hormone therapy.

"We wanted to address the question of whether women with a history of breast cancer have greater fear of recurrence when they are told they are at high risk from genomic testing," said Gormley.

In the study, Gormley and her colleagues studied 110 breast cancer survivors to explore associations between the genomic test's recurrence score and its relationship to a range of factors: fear of cancer recurrence, distress, anxiety, depression, health-related quality of life, including pain and fatigue, and perceived risk of cancer recurring and spreading. They also measured women's beliefs about their illness, including their emotional response to it, perceived consequences of cancer on their lives, whether they believe they have control over their illness, and whether they perceive their cancer to be chronic.

The researchers found that breast cancer survivors with high recurrence scores reported higher overall fear and greater perceived consequences of their cancer compared to those with low recurrence scores. A greater fear of cancer recurrence was associated with higher distress, anxiety, depression, lower quality of life, and certain beliefs about their cancer, including worse perceived consequences and greater emotional response to illness.

The duration of time since breast cancer diagnosis was not associated with fear of cancer recurrence or perceived risk. However, younger women had greater fear of recurrence and worse psychosocial outcomes.

Further analyses revealed that the best predictors of whether someone was at high risk for fear of cancer recurrence were actually modifiable factors--anxiety, greater emotional response to cancer, and perceived consequences of illness--and not unchangeable factors like genomic test results and age. The modifiable, psychological factors explained 58 percent of the variance in fear of cancer recurrence.

"These findings are important because they illustrate that an individual's understanding of and response to their illness may explain who is at greatest risk for developing fear of cancer recurrence," said Gormley. "This could pave the way for developing targeted support--for instance, mental health interventions like cognitive behavioral skills--to address maladaptive beliefs about illness that occur among many breast cancer survivors."

Battling other male baboons to achieve high social status comes with physiological costs that accelerate aging, according to study published today in eLife.

The findings suggest that current life circumstances may be more important contributors to premature aging than early life hardship, at least in baboons.

Chemical changes to DNA, also called epigenetic changes, can be used as a kind of 'clock' to measure aging. While these epigenetic changes usually correspond with age, they can also be used to detect signs of premature aging.

"Environmental stressors can make the clock tick faster, so that some individuals appear biologically older than their actual age and experience a higher risk of age-related disease," explains co-first author Jordan Anderson, a PhD student in Evolutionary Anthropology at Duke University, Durham, North Carolina, US. "We sought to answer what social or early life experiences contribute to accelerated aging in baboons."

The team measured aging in 245 wild baboons from a well-studied population in Kenya using the epigenetic clock and other methods. They found that the epigenetic clock was a good predictor of chronological age overall. But contrary to what they expected, early life adversity was not a good predictor of accelerated aging in the animals.

Instead, they found that the highest-ranking males showed signs of accelerated aging. Higher body mass index, which is associated with having more lean muscle mass in baboons, was also associated with accelerated aging, likely because of the physical demands of maintaining high status. The team was also able to show that the epigenetic clock sped up as the animals climbed the social ladder and slowed down as they moved down it.

"Our results argue that achieving high rank for male baboons - the best predictor of reproductive success in these animals - imposes costs that are consistent with a 'live fast, die young,' life history strategy," says co-first author Rachel Johnston, Postdoctoral Associate in Evolutionary Anthropology at Duke University.

"While the findings reveal how social pressures can influence aging for males, we don't see the same effect of rank in female baboons, who are born into their social rank rather than having to fight for it," adds senior author Jenny Tung, Associate Professor in the Departments of Evolutionary Anthropology and Biology at Duke University, and a Faculty Associate of the Duke University Population Research Institute.

"Our results have important implications for research on the social determinants of health in humans and other animals because they show that 'high status' can mean very different things in different contexts. They also highlight the importance of examining the effects of both early life and current life environments on biological aging," Tung concludes.

HOUSTON - (April 6, 2021) - Runoff from Houston's 2016 Tax Day flood and 2017's Hurricane Harvey flood carried human waste onto coral reefs more than 100 miles offshore in the Flower Garden Banks National Marine Sanctuary, according to a Rice University study.

"We were pretty shocked," said marine biologist Adrienne Correa, co-author of the study in Frontiers in Marine Science. "One thing we always thought the Flower Garden Banks were safe from was terrestrial runoff and nutrient pollution. It's a jolt to realize that in these extreme events, it's not just the salt marsh or the seagrass that we need to worry about. Offshore ecosystems can be affected too."

The Flower Garden Banks sit atop several salt domes near the edge of the continental shelf about 100 miles from the Texas and Louisiana coast. Rising several hundred feet from the seafloor, the domes are topped with corals, algae, sponges and fish. Each bank, or dome-topped ecosystem, is separated by miles of open ocean. The Flower Garden Banks National Marine Sanctuary, which was recently expanded, protects 17 banks.

Correa and colleagues sampled sponges at the sanctuary in 2016, 2017 and 2018. They showed samples collected after extreme storm flooding in 2016 and 2017 contained E. coli and other human fecal bacteria. They also used a catalog of E. coli genetic markers contributed by Rice environmental engineer and co-author Lauren Stadler to show that E. coli on sponges in 2017 came from Harvey floodwaters.

Lead author Amanda Shore, who conducted the research while a Rice Academy Postdoctoral Fellow in Correa's lab, said many studies have shown nearshore reefs can be harmed by pollutants that are washed into the ocean by rainfall over land. But marine biologists generally assume ecosystems far from shore are safe from such dangers.

"This shows perhaps they aren't protected from severe events," said Shore, an assistant professor of biology at Farmingdale State College in New York. "And these events are increasing in frequency and intensity with climate change."

Correa said, "That's the other piece of this. There actually was a massive flooding event in 2015 with the Memorial Day flood. Dips in salinity after that event were detected at surface buoys offshore, but nobody looked or sampled out at the Flower Garden Banks. Nobody imagined you would see something like this 160 kilometers out."

In April 2016, widespread flooding occurred in the Houston area when a severe storm dropped more than 17 inches of rain in some places in less than 24 hours. Three months after the flood, recreational divers reported murky waters and dead and dying organisms at East Flower Garden Bank. Marine biologists, including study co-author Sarah Davies of Boston University, arrived two weeks later to investigate.

Shore and co-authors Carsten Grupstra, a Rice graduate student, and Jordan Sims, a Rice undergraduate, analyzed samples from the expedition, including tissue collected from sponges. Shore said sponges are indicators of water quality because they "are basically filtering seawater to catch organic material to use as food."

She said previous studies have shown sponges have a microbiome, a population of bacteria that normally live in and on these animals. In this study, Shore characterized the microbiomes on two species: giant barrel sponges, or Xestospongia muta, and orange elephant ear sponges, or Agelas clathrodes. It was the first time the species' microbiomes had been assayed at Flower Garden Banks, and Correa said that was one reason it took so long to understand what happened in the flood years.

Correa said, "In 2016, we saw differences between sponge bacteria at a location that showed signs of death and a location that didn't show signs of death, but we couldn't get at the cause of the differences because we had no baseline data. We thought we'd be able to get the baseline data -- the normal year -- the next year in 2017. But then there was another disaster. We couldn't get a normal sample in a no-flood year until 2018."

Shore joined Correa's lab in 2018, helped collect samples that year and analyzed the microbiomes from each year.

Correa said, "There was a big change in community composition, a shift of the team players, on the sponges that were most affected in 2016. Then, following Harvey in 2017 there was also a shift, but less water made it out there that year, and we think it was less stressful. We didn't see dead and dying organisms like we had the previous year."

Harvey, the most intense rainfall event in U.S. history, dropped an estimated 13 trillion gallons of rain over southeast Texas in late August 2017. The researchers said Harvey posed a greater potential threat to the Flower Garden Banks, by far, than the 2016 flood. So why did reefs fare better in 2017?

"Because we got lucky with ocean currents," Shore said. "Instead of going straight out from Galveston Bay and over the Flower Garden Banks, the water ended up turning a bit and going down the Texas coast instead."

Harvey's runoff still sideswiped the banks. Research buoys at the reefs measured a 10% drop in salinity in less than a day on Sept. 28, and Correa's team found genetic evidence that fecal pollution gathered from the banks in October originated in Harvey floodwaters in Houston.

Correa said the story in 2016 was more complicated.

"There was an upwelling event that brought nutrients and cooler waters up from the deep to the top part of the Flower Garden Banks," she said. "Fresh water is less dense than salt water, and we think the floodwaters came at the surface and sort of sat there like a lens on top of the salt water and kept oxygen from mixing in from the top. The combination of this surface event and the nutrients coming up from the bottom contributed to a bacterial bloom that drew down so much oxygen that things just asphyxiated."

The big question is whether pollution from extreme storms poses a long-term threat to the Flower Garden Banks. Correa said the answer could come from an investment in research that follows the health and microbiomes of individual sponges and corals on the reef over time. She said her group at Rice and her collaborators are committed to learning as much as they can about the reefs, and they are determined to support efforts to conserve and protect them.

Boron nitride is a technologically interesting material because it is very compatible with other two-dimensional crystalline structures. It therefore opens up pathways to artificial heterostructures or electronic devices built on them with fundamentally new properties.

About a year ago, a team from the Institute of Physics at Julius-Maximilians-Universität (JMU) Wuerzburg in Bavaria, Germany, succeeded in creating spin defects, also known as qubits, in a layered crystal of boron nitride and identifying them experimentally.

Recently, the team led by Professor Vladimir Dyakonov, his PhD student Andreas Gottscholl and group leader PD Dr. Andreas Sperlich, succeeded in taking an important next step: the coherent control of such spin defects, and that even at room temperature. The researchers report their findings in the impactful journal Science Advances. Despite the pandemic, the work was carried out in an intensive international collaboration with groups from the University of Technology Sydney in Australia and Trent University in Canada.

Measuring local electromagnetic fields even more precisely

"We expect that materials with controllable spin defects will allow more precise measurements of local electromagnetic fields once they are used in a sensor", explains Vladimir Dyakonov, "and this is because they are, by definition, at the border to the surrounding world, which needs to be mapped. Conceivable areas of application are imaging in medicine, navigation, everywhere where contactless measurement of electromagnetic fields is necessary, or in information technology.

"The research community's search for the best material for this is not yet complete, but there are several potential candidates," adds Andreas Sperlich. "We believe we found a new candidate that stands out because of its flat geometry, which offers the best integration possibilities in electronics."

Limits of spin coherence times trickily overcome

All spin-sensitive experiments with the boron nitride were carried out at JMU. "We were able to measure the characteristic spin coherence times, determine their limits and even trickily overcome these limits," says a delighted Andreas Gottscholl, PhD student and first author of the publication. Knowledge of spin coherence times is necessary to estimate the potential of spin defects for quantum applications, and long coherence times are highly desirable as one eventually wants to perform complex manipulations.

Gottscholl explains the principle in simplified terms: "Imagine a gyroscope that rotates around its axis. We have succeeded in proving that such mini gyroscopes exist in a layer of boron nitride. And now we have shown how to control the gyroscope, i.e., for example, to deflect it by any angle without even touching it, and above all, to control this state."

Coherence time reacts sensitively to neighboring atomic layers

The contactless manipulation of the "gyroscope" (the spin state) was achieved through the pulsed high-frequency electromagnetic field, the resonant microwaves. The JMU researchers were also able to determine how long the "gyroscope" maintains its new orientation. Strictly speaking, the deflection angle should be seen here as a simplified illustration of the fact that a qubit can assume many different states, not just 0 and 1 like a bit.

What does this have to do with sensor technology? The direct atomic environment in a crystal influences the manipulated spin state and can greatly shorten its coherence time. "We were able to show how extremely sensitive the coherence reacts to the distance to the nearest atoms and atomic nuclei, to magnetic impurities, to temperature and to magnetic fields - so the environment of the qubit can be deduced from the measurement of the coherence time," explains Andreas Sperlich.

Goal: Electronic devices with spin decorated boron nitride layers

The JMU team's next goal is to realize an artificially stacked two-dimensional crystal made of different materials, including a spin-bearing component. The essential building blocks for the latter are atomically thin boron nitride layers containing optically active defects with an accessible spin state.

"It would be particularly appealing to control the spin defects and their surroundings in the 2D devices not only optically, but via the electric current. This is completely new territory," says Vladimir Dyakonov.

New York, NY--April 6, 2021--The digital revolution is built on a foundation of invisible 1s and 0s called bits. As decades pass, and more and more of the world's information and knowledge morph into streams of 1s and 0s, the notion that computers prefer to "speak" in binary numbers is rarely questioned. According to new research from Columbia Engineering, this could be about to change.

A new study from Mechanical Engineering Professor Hod Lipson and his PhD student Boyuan Chen proves that artificial intelligence systems might actually reach higher levels of performance if they are programmed with sound files of human language rather than with numerical data labels. The researchers discovered that in a side-by-side comparison, a neural network whose "training labels" consisted of sound files reached higher levels of performance in identifying objects in images, compared to another network that had been programmed in a more traditional manner, using simple binary inputs.

VIDEO: https://youtu.be/Iq2YjHCAPRQ

PROJECT WEBSITE: https://www.creativemachineslab.com/label-representation.html
https://engineering.columbia.edu/faculty/hod-lipson

"To understand why this finding is significant," said Lipson, James and Sally Scapa Professor of Innovation and a member of Columbia's Data Science Institute, "It's useful to understand how neural networks are usually programmed, and why using the sound of the human voice is a radical experiment."

When used to convey information, the language of binary numbers is compact and precise. In contrast, spoken human language is more tonal and analog, and, when captured in a digital file, non-binary. Because numbers are such an efficient way to digitize data, programmers rarely deviate from a numbers-driven process when they develop a neural network.

Lipson, a highly regarded roboticist, and Chen, a former concert pianist, had a hunch that neural networks might not be reaching their full potential. They speculated that neural networks might learn faster and better if the systems were "trained" to recognize animals, for instance, by using the power of one of the world's most highly evolved sounds--the human voice uttering specific words.

One of the more common exercises AI researchers use to test out the merits of a new machine learning technique is to train a neural network to recognize specific objects and animals in a collection of different photographs. To check their hypothesis, Chen, Lipson and two students, Yu Li and Sunand Raghupathi, set up a controlled experiment. They created two new neural networks with the goal of training both of them to recognize 10 different types of objects in a collection of 50,000 photographs known as "training images."

One AI system was trained the traditional way, by uploading a giant data table containing thousands of rows, each row corresponding to a single training photo. The first column was an image file containing a photo of a particular object or animal; the next 10 columns corresponded to 10 possible object types: cats, dogs, airplanes, etc. A "1" in any column indicates the correct answer, and nine 0s indicate the incorrect answers.

The team set up the experimental neural network in a radically novel way. They fed it a data table whose rows contained a photograph of an animal or object, and the second column contained an audio file of a recorded human voice actually voicing the word for the depicted animal or object out loud. There were no 1s and 0s.

Once both neural networks were ready, Chen, Li, and Raghupathi trained both AI systems for a total of 15 hours and then compared their respective performance. When presented with an image, the original network spat out the answer as a series of ten 1s and 0s--just as it was trained to do. The experimental neural network, however, produced a clearly discernible voice trying to "say" what the object in the image was. Initially the sound was just a garble. Sometimes it was a confusion of multiple categories, like "cog" for cat and dog. Eventually, the voice was mostly correct, albeit with an eerie alien tone (see example on website).

At first, the researchers were somewhat surprised to discover that their hunch had been correct--there was no apparent advantage to 1s and 0s. Both the control neural network and the experimental one performed equally well, correctly identifying the animal or object depicted in a photograph about 92% of the time. To double-check their results, the researchers ran the experiment again and got the same outcome.

What they discovered next, however, was even more surprising. To further explore the limits of using sound as a training tool, the researchers set up another side-by-side comparison, this time using far fewer photographs during the training process. While the first round of training involved feeding both neural networks data tables containing 50,000 training images, both systems in the second experiment were fed far fewer training photographs, just 2,500 apiece.

It is well known in AI research that most neural networks perform poorly when training data is sparse, and in this experiment, the traditional, numerically trained network was no exception. Its ability to identify individual animals that appeared in the photographs plummeted to about 35% accuracy. In contrast, although the experimental neural network was also trained with the same number of photographs, its performance did twice as well, dropping only to 70% accuracy.

Intrigued, Lipson and his students decided to test their voice-driven training method on another classic AI image recognition challenge, that of image ambiguity. This time they set up yet another side-by-side comparison but raised the game a notch by using more difficult photographs that were harder for an AI system to "understand." For example, one training photo depicted a slightly corrupted image of a dog, or a cat with odd colors. When they compared results, even with more challenging photographs, the voice-trained neural network was still correct about 50% of the time, outperforming the numerically-trained network that floundered, achieving only 20% accuracy.

Ironically, the fact their results went directly against the status quo became challenging when the researchers first tried to share their findings with their colleagues in computer science. "Our findings run directly counter to how many experts have been trained to think about computers and numbers; it's a common assumption that binary inputs are a more efficient way to convey information to a machine than audio streams of similar information 'richness,'" explained Boyuan Chen, the lead researcher on the study. "In fact, when we submitted this research to a big AI conference, one anonymous reviewer rejected our paper simply because they felt our results were just 'too surprising and un-intuitive.'"

When considered in the broader context of information theory however, Lipson and Chen's hypothesis actually supports a much older, landmark hypothesis first proposed by the legendary Claude Shannon, the father of information theory. According to Shannon's theory, the most effective communication "signals" are characterized by an optimal number of bits, paired with an optimal amount of useful information, or "surprise."

"If you think about the fact that human language has been going through an optimization process for tens of thousands of years, then it makes perfect sense, that our spoken words have found a good balance between noise and signal;" Lipson observed. "Therefore, when viewed through the lens of Shannon Entropy, it makes sense that a neural network trained with human language would outperform a neural network trained by simple 1s and 0s."

The study, to be presented at the International Conference on Learning Representations conference on May 3, 2021, is part of a broader effort at Lipson's Columbia Creative Machines Lab to create robots that can understand the world around them by interacting with other machines and humans, rather than by being programed directly with carefully preprocessed data.

"We should think about using novel and better ways to train AI systems instead of collecting larger datasets," said Chen. "If we rethink how we present training data to the machine, we could do a better job as teachers."

One of the more refreshing results of computer science research on artificial intelligence has been an unexpected side effect: by probing how machines learn, sometimes researchers stumble upon fresh insight into the grand challenges of other, well-established fields.

"One of the biggest mysteries of human evolution is how our ancestors acquired language, and how children learn to speak so effortlessly," Lipson said. "If human toddlers learn best with repetitive spoken instruction, then perhaps AI systems can, too."