Earth

Researchers at the University of California San Diego have identified new mechanisms in neurons that cause Alzheimer's disease. In particular, they discovered that changes in the structure of chromatin, the tightly coiled form of DNA, trigger neurons to lose their specialized function and revert to an earlier cell state. This results in the loss of synaptic connections, an effect associated with memory loss and dementia.

The findings are published Nov. 13 in Science Advances.

The study was founded on the question: how do neurons in patients with Alzheimer's disease differ from neurons in healthy individuals?

"It's a fundamental question that would provide the framework and foundation for understanding Alzheimer's disease at the cellular level, and thus pave the path for novel therapeutic approaches," said Shankar Subramaniam, professor of bioengineering at the UC San Diego Jacobs School of Engineering.

Subramaniam worked with an interdisciplinary team of engineers and neuroscientists at UC San Diego to answer this question. They started by taking human induced pluripotent stem cells derived from patients with familial Alzheimer's disease, which is a hereditary form of Alzheimer's, and transformed them into neurons. They used next generation sequencing techniques to look at what genes are being expressed in these neurons and how gene expression is regulated, and then compared how they differ in neurons of healthy individuals.

They discovered that neurons derived from the patients de-differentiate to a precursor state.

"In other words, they cease to be neurons," Subramaniam said. "This is the key defect observed across a diversity of patients with distinct mutations. The consequences to the brain are dramatic, with loss of synaptic connections leading to cognitive decline."

The researchers observed other defects: neuronal genes are suppressed, so these cells no longer have any instructions telling them that they are neurons; they are in a precursor-like state, which means they can trigger cell growth and division--this is unusual because adult brains do not produce new neurons; and they have inflammation, which signals damage or stress.

The same defects were also observed in post-mortem human brain samples from patients with Alzheimer's disease. "This was validating for our findings because we weren't just seeing these mechanisms in the stem cells, but in actual brain samples as well," Subramaniam said.

The researchers traced all of these mechanisms back to changes in the structure of chromatin. Parts of this structure consist of open regions, where genes are expressed or regulated, and other parts consist of closed regions, where gene expression is repressed. In the diseased neurons, some regions that used to be open are now closed, and vice versa. As a consequence, the neurons are not behaving as they should be, Subramaniam explained.

The team is now working on developing drugs to inhibit these mechanisms.

Vibrations travel through our planet in waves, like chords ringing out from a strummed guitar. Earthquakes, volcanoes and the bustle of human activity excite some of these seismic waves. Many more reverberate from wind-driven ocean storms.

As storms churn the world's seas, wind-whipped waves at the surface interact in a unique way that produces piston-like thumps of pressure on the seafloor, generating a stream of faint tremors that undulate through Earth to every corner of the globe.

"There is an imprint of those three Earth systems in this ambient seismic data: atmosphere, Earth's rocky outer layers and ocean," said Stanford University geophysicist Lucia Gualtieri, lead author of a paper in Proceedings of the National Academy of Sciences that helps to resolve a decades-old conundrum over the physics of seismic waves related to ocean storms.

Known as secondary microseisms, the small seismic waves excited by rumbling oceans are so ubiquitous and chaotic that seismologists have long set the data aside. "When you record these waves, the seismic record looks like random noise because there are so many sources, one close to the other across the extended area of a storm. They're all acting at the same time, and the resulting wavefields interfere with each other," Gualtieri said. "You want to just discard it."

Yet over the last 15 years, researchers have found a way to extract meaning from this noisy data. By analyzing how quickly pairs of waves travel from one seismic station to another, they have begun to glean insights about the materials they're moving through. "We use seismic waves like X-rays in medical imaging for scanning the Earth," said Gualtieri, who is an assistant professor of geophysics in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth).

Love waves from the ocean floor

Unlike a single ocean wave rolling across the surface, which dies out before it reaches the deep sea, the chaotic interactions of waves traveling in opposite directions during a storm can create an up-and-down bobbing motion at the surface that pulses all the way to the solid Earth below. Vibrations known as Rayleigh waves then travel outward from the pulse, moving the ground up and down as they go.

For decades, scientists have understood the vertical component of ocean-storm microseisms, where Rayleigh waves dominate. But there is another set of vibrations recorded during ocean storms that are inexplicable in the accepted theories for how stormy seas generate movements in the solid Earth. These vibrations, named Love waves after their 20th-century discoverer, jostle underground rock particles side to side - perpendicular to their path forward - like a slithering snake. "These waves shouldn't be there at all," Gualtieri said. "We didn't know where they were coming from."

Scientists have presented two plausible explanations. One idea is that when the vertical force pumping down from colliding ocean waves encounters a slope on the seafloor, it splits and forms the two different surface wave types: Rayleigh and Love. "In that case, the source of Love waves would be very close to the source of Rayleigh waves, if not the same location," Gualtieri said.

But Gualtieri's research, co-authored with geoscientists from Princeton University, finds the slopes and inclines of the seafloor are not steep enough to generate the strong horizontal force necessary to produce the Love waves picked up by seismic recorders. Their results, published Nov. 9, support an alternative theory, in which Love waves originate within the Earth itself. It turns out that when windswept seas throttle pressure down to the seafloor, the patchwork structure of the solid Earth underneath answers with a thrum all its own.

"We understand how earthquakes create Love waves, but we've never exactly figured out how ocean waves create them," said ambient seismic noise expert Keith Koper, a professor of geology and geophysics and director of seismograph stations at the University of Utah, who was not involved with the study. "This is a little embarrassing because ocean-generated Love waves have been observed for over 50 years." The paper led by Gualtieri, he said, "provides conclusive evidence" for how ocean waves generate this particular kind of vibration in the Earth.

Simulating Earth

Using the Summit supercomputer at Oak Ridge National Laboratory, the researchers simulated the complex interactions that occur between storms, ocean waves and the solid Earth over three-hour periods. Accurate down to four seconds, each simulation included 230,400 pressure sources scattered across the entire globe. "We're using the computer as a lab, to let seismic waves propagate from realistic sources all over the world's oceans based on known physics about how and where seismic waves are generated by ocean storms, as well as how they move through the Earth," Gualtieri said.

One version of the model Earth represented the planet as a simplistic stratified world, where properties vary only with depth, like a layer cake. The other, more true-to-life model captured more of the three-dimensional variation in its underground terrain, like a chocolate chip cookie. For each version, the researchers switched underwater depth data on and off to test whether seafloor features like canyons, ravines and mountains - as opposed to the deeper structure - could produce Love waves.

The results show that Love waves are poorly generated in the layer-cake-like, one-dimensional Earth. Given about 30 minutes and a rumbling ocean, however, Love waves emanated from below the seafloor in the three-dimensional model. When Rayleigh waves and other seismic waves generated by ocean storms encounter hotter or cooler zones and different materials in their lateral journey through Earth, the study suggests their energy scatters and refocuses. In the process, a portion of the wavefield converts to Love waves. "If you apply those pressure sources from interfering ocean waves and you wait, the Earth will give you the entire wavefield," Gualtieri said. "It's the Earth itself that will generate the Love waves."

According to Gualtieri, better understanding of how these vibrations arise and propagate through Earth could help to fill in gaps in knowledge of not only our planet's interior but also its changing climate. Analog seismic recordings date back to before the satellite era, and high-quality digital data has been logged for several decades.

"This database holds information about environmental processes, and it's virtually untapped," she said.

Hybrid organic-inorganic perovskites (*1) have received much attention as potential next generation solar cells and as materials for light-emitting devices.

Kobe University's Associate Professor TACHIKAWA Takashi (of the Molecular Photoscience Research Center) and Dr. KARIMATA Izuru (previously a graduate student engaged in research at the Graduate School of Science) have succeeded in completely substituting the halide ions of perovskite nanocrystals while maintaining their morphology and light-emitting efficiency.

Furthermore, by using techniques such as single-particle photoluminescence imaging, the researchers were able to understand the momentary changes in light emission and the crystal structure, which in turn enabled them to develop a principle for controlling ion composition.

It is expected that these research results will contribute towards enabling the synthesis of perovskites of varying compositions and advancing the development of devices which utilize them. In addition, it is hoped that the flexibility of perovskite structures can be harnessed, allowing for them to be applied to devices and the creation of new functional materials.

These findings were published in the German academic journal 'Angewandte Chemie International Edition' on October 19, 2020.

Research Background

Hybrid organic-inorganic perovskites, such as organic lead halide perovskites (for example, CH3NH3PbX3 (X = Cl, Br, I)), have been receiving worldwide attention as a promising material for highly efficient solar cells (Figure 1). Furthermore, the color of the light that they emit can be controlled by altering the type and composition of the halide ions. Consequently, it is hoped that hybrid organic-inorganic perovskites can be applied to light-emitting devices such as displays and lasers.

However, the halide ions inside the crystals are known to move around even at room temperature, and this high flexibility causes issues such as reductions in both synthesis reproducibility and device durability.

Research Methodology

In this study, the researchers used a custom-made flow reactor (*3) to precisely control the exchange reaction between the CH3NH3PbI3 nanocrystals and Br- ions in solution. This enabled them to successfully convert the nanocrystals into CH3NH3PbBr3 nanocrystals while maintaining their morphology and light-emitting efficiency (Figure 2).

It is important to know what kind of reaction will occur inside the crystals in order to develop synthesis techniques. To understand this, the researchers used a fluorescence microscope to observe how each individual nanocrystal was reacting. From this observation, they understood that once the red light emitted by the CH3NH3PbI3 had completely disappeared, the green light originating from the CH3NH3PbBr3 was suddenly generated after an interval of 10s to 100s of seconds (upper portion of Figure 2). Based on the results of structural analysis using an x-ray beam, it was revealed that Br- ions replaced I- ions inside the crystal structure while a bromide-rich layer formed on the surface. Afterwards, the bromide on the surface layer gradually moved into the inner regions.

It is believed that the red light emissions became unobservable because the inner regions of the crystal structure were partially disordered during the ion transition, which led to the loss of energy necessary for light emission (bottom of Figure 2). Subsequently, CH3NH3PbBr3 crystal nuclei formed inside the nanocrystal particle and a cooperative transition to the green light generating state occurred.

From these results, it can be said that temporally separating the crystal structure transitions and the subsequent restructuring (that occurs on a nanometer scale) is one of the keys to the successful, precise synthesis of organic lead halide perovskites.

Further Developments

The structural transformation process observed in perovskite nanocrystals in this study is thought to be related to all modes of nanomaterial synthesis that are based on ion exchange, therefore future research could hopefully illuminate the underlying mechanism. Although researchers have a negative impression of organic halide perovskites' flexibility, it is hoped that this characteristic could be exploited and applied to the development of new materials and devices that can react to the environment and external stimuli.

FRANKFURT. The development of new drugs or innovative molecular materials with new properties requires specific modification of molecules. Selectivity control in these chemical transformations is one of the main goals of catalysis. This is particularly true for complex molecules with multiple reactive sites in order to avoid unnecessary waste for improved sustainability. The selective insertion of individual nitrogen atoms into carbon-hydrogen bonds of target molecules is, for instance, a particularly interesting goal of chemical synthesis. In the past, these kinds of nitrogen transfer reactions were postulated based on quantum-chemical computer simulations for molecular metal complexes with individual nitrogen atoms bound to the metal. These highly reactive intermediates have, however, previously escaped experimental observation. A closely entangled combination of experimental and theoretical studies is thus indispensable for detailed analysis of these metallonitrene key intermediates and, ultimately, the exploitation of catalytic nitrogen-atom transfer reactions.

Chemists in the groups of Professor Sven Schneider, University of Göttingen, and Professor Max Holthausen, Goethe University Frankfurt, in collaboration with the groups of Professor Joris van Slagern, University of Stuttgart and Professor Bas de Bruin, University of Amsterdam, have now been able for the first time to directly observe such a metallonitrene, measure it spectroscopically and provide a comprehensive quantum-chemical characterization. To this end, a platinum azide complex was transformed photochemically into a metallonitrene and examined both magnetometrically and using photo-crystallography. Together with theoretical modelling, the researchers have now provided a detailed report on a very reactive metallonitrene diradical with a single metal-nitrogen bond. The group was furthermore able to show how the unusual electronic structure of the platinum metallonitrene allows the targeted insertion of the nitrogen atom into, for example, C-H bonds of other molecules.

Professor Max Holthausen explains: "The findings of our work significantly extend the basic understanding of chemical bonding and reactivity of such metal complexes, providing the basis for a rational synthesis planning." Professor Sven Schneider says: "These insertion reactions allow the use of metallonitrenes for the selective synthesis of organic nitrogen compounds through catalyst nitrogen atom transfer. This work therefore contributes to the development of novel 'green' syntheses of nitrogen compounds."

A sphere and a cube can be deformed into one another without cuts or stitches. A mug and a glass cannot because, to deform the first into the second, the handle needs to be broken. Topology is the branch of mathematics that formalises this difference between mugs and glasses, extending it also to abstract spaces with many dimensions. A new theory developed by scientists at SISSA in Trieste has succeeded in establishing a new relationship between the presence or absence of "handles" in the space of the arrangements of atoms and molecules that make up a material, and the propensity of the latter to conduct electricity. According to this theory, the insulating materials "equipped with handles" can conduct electricity as well as metals, while retaining typical properties of insulators, such as transparency.

The research, which has just been published in the journal Physical Review X, has thrived in the fascinating world of topology, an abstract discipline that gives a potent handle (pun intended!) to some of the most exotic properties of matter. In this way, scientists at the School of Trieste have investigated how to estimate the charge transport and the currents in generic ionic fluids rigorously, in line with the quantum nature of the material.

They have thus developed a theory to explain physical phenomena which have been known for more than a century but which until now lacked a rigorous interpretative base and predictive framework, thereby laying the foundations for major technological developments, for example in the field of thermoelectric materials.

Metals and mineral water, reflection and transparency

"We usually divide materials into conductors and insulators according to their propensity to conduct electricity or not" explain the research authors Paolo Pegolo, Federico Grasselli and Stefano Baroni. "In a metal, which is a typical conductor, some electrons move freely within the ionic crystal lattice. However, some liquids, such as mineral water, also conduct electricity, thanks to the transport of charged ions that are dissolved in them. In this case, we speak of ionic conductors, which are transparent, while metals are reflective". Ionic fluids were the focus of the recent study. "We wanted to develop a theory based on the quantum nature of atoms and able to describe charge transport in this type of conductors" explain the scientists. "A sound explanation of the phenomenon could also be useful to create new materials with unprecedented electrical properties".

Topology at the service of physics

The scholars have borrowed the mathematical tools of topology. Pegolo, Grasselli and Baroni's theory has thus linked transport in ionic fluids with the existence in an abstract space of structures that present holes or handles. "If these structures exist, it is possible to transport electrons without moving the ions, thus significantly improving the electrical conduction properties of a material while leaving it non-metallic and therefore transparent. In the absence of holes or handles, the electrons remain bound to their atom and the conduction is less efficient". "These phenomena" continue the researchers "have been known in physics for at least one hundred years. Our research gives them an elegant and powerful mathematical foundation and a reliable theoretical support structure".

Possible technological developments

This theory finds application in the science of thermoelectric materials, which are all the more efficient the more they are able to guarantee the conduction of electricity without heating up. The researchers conclude, "The materials described in this theory do not have metallic properties and thus favour thermal insulation, but the presence of electrons that are sufficiently mobile to be transported increases their electrical conductivity. Both are important qualities which, at the technological level, could greatly contribute to the development of more efficient and advanced devices".

The science of electrolyte materials might also benefit from the results of this research, in that better understanding of conduction in absence of metallicity can lead to design batteries that are efficient and electrochemically stable.

Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich have identified the first mechanosensitive ion channel to be found in an intracellular vesicle system. It responds to concentration changes within the vesicle, and probably controls the initiation of immune reactions.

Small membrane vesicles, known as endosomes or lysosomes play a key role in the uptake, secretion and intracellular transport of proteins and ions. Various types of endosomes are involved in the transport of cargoes into and out of cells, while lysosomes degrade their contents in a controlled manner. Trafficking of substances between the various classes of vesicles is largely controlled by the ion channels located in their membranes. In cooperation with Martin Biel (Chair of Pharmacology at LMU) and Christian Wahl-Schott (Medical University Hannover), pharmacologist Christian Grimm at LMU's Walther Straub Institute of Pharmacology and Toxicology has now characterized an unusual ion channel in the endolysosomal system of cells called macrophages. This particular ion channel responds specifically to mechanical stimuli that are associated with deformation of the vesicle membrane and changes in the concentration of substances present within the vesicle. As the team reports in the online journal Science Advances, this mechanosensitive channel is probably involved in the secretion of signaling molecules that regulate the immune system, and may help to determine the system's reaction time.

The endolysosomal system comprises diverse types of vesicles, which interact with factors that are attached to the inner face of the cell's outer membrane (the plasma membrane). These interactions regulate the uptake of cargo by the vesicle, and determine its transport to, and processing by other vesicle types. Ultimately, these cargos are either recycled to the plasma membrane or delivered to vesicles known as lysosomes for degradation. These processes may also include morphological changes, such as the pinching-off of vesicles or their incorporation into the endoplasmic reticulum, which consists of a network of membrane tubules that controls membrane trafficking within the cell. Two types of vesicles are responsible for the recycling of cargoes to the plasma membrane. What are called 'fast' recycling endosomes secrete their contents across the plasma membrane within a matter of minutes. The mechanisms responsible for rapid recycling in macrophages have remained unclear.

Christian Grimm is a master of the endolysosomal patch-clamp technique, which can be used to determine the functional characteristics of the ion channels in the endolysosomal system. Thanks to recent refinements of this method, he was able to measure the biophysical properties of the TRPML2 channels, which are found in the membranes of fast recycling endosomes in macrophages. Macrophages form part of the innate immune system, which detects invasive bacteria and viruses, and triggers a rapid immune response designed to eliminate them.

The TRPML2 channel participates in the secretion of messenger molecules that regulate immune responses, as Grimm and his colleagues had shown in a previous study. "TRPML2 is particularly active in recycling endosomes," says Cheng-Chang Chen, lead author of the new paper. "We have now shown, for the first time, that the channel is activated by mechanical stimuli and alterations in osmolarity - a parameter that reflects the concentration of the dissolved substances in the vesicle." These stimuli come into play when, for example, vesicles are budded off from the tubular components of the endolysosomal system, owing to the accompanying alterations in the surface-to-volume ratio. "TRPML2 is the first ion channel found in intracellular membranes that has been shown to react to these stimuli. This property distinguishes it from all other endolysosomal channels," Grimm adds. He and his colleagues are convinced that this feature enables TRPML2-containing vesicles to promptly secrete their contents upon detection of invasive pathogens. The channel thus contributes to the rapid response of the innate immune system.

Unlike many other cell types, macrophages have no dedicated secretory organelles, apart from those derived from the endolysosomal system. The unconventional character of the stimulus to which TRPML2 responds could serve as a means of optimizing the function of specific transport pathways in macrophages. "In the case of an acute infection, the innate immune system cannot afford to wait 24 hours before synthesizing and secreting immunomodulators. They must be able to mount a quick response," says Grimm. In addition, the results suggest that changes in the surface-to-volume ratios of membrane tubules and vesiculation of endosomes are a prerequisite for the maintenance of the physiological functions of immune cells.

In a screening for a functional impact to the neuronal differentiation process, Danish researchers identified a specific circular RNA, circZNF827, which surprisingly "taps the brake" on neurogenesis. The results provide an interesting example of co-evolution of a circRNA, and its host-encoded protein product, that regulate each other's function, to directly impact the fundamental process of neurogenesis.

Correct timing and delicate control of neuronal differentiation is essential for development of a functional nervous system. These events establish a fine-tuned balance between the ability of stem cells to grow/divide and the neuronal progenitors to eventually exit the cell cycle and emerge as mature neurons. A variety of genes become up- or downregulated upon differentiation, giving rise to both neuron-specific proteins and ribonucleic acids (RNAs), including circular RNAs (circRNAs). This class of circRNAs has until recently escaped conventional detection, although these molecules are highly expressed in the mammalian brain. However, the functional roles of brain-expressed circRNAs remain virtually unknown.

In a study, spearheaded by postdoc Anne Kruse Hollensen and led by Associate Professor Christian Kroun Damgaard, Molecular Biology and Genetics, Aarhus University, thousands of circRNAs were identified when stem cells become differentiated into mature neurons. In a screening for a functional impact to the differentiation process, the authors identified a specific circRNA, circZNF827, which surprisingly "taps the brake" on neurogenesis.

Various biochemical and cell biological assays, revealed that circZNF827 mechanistically functions as a scaffold for a complex of RNA-binding proteins, including its own host-gene-encoded protein, ZNF827, and two known transcriptional regulators, hnRNP K and L (Figure 1). Despite being localized mostly to the cell cytoplasm, circZNF827 apparently "moonlights" in the nucleus, where it nucleates these transcription factors to specific neuronal genes (e.g. NGFR), and hence, repress their expression (Figure 1).

The results contribute to the molecular understanding of neurogenesis and in particular how abundant brain-specific circRNAs tap into this fundamental process.

The African continent is slowly separating into several large and small tectonic blocks along the diverging East African Rift System, continuing to Madagascar - the long island just off the coast of Southeast Africa - that itself will also break apart into smaller islands.

These developments will redefine Africa and the Indian Ocean. The finding comes in a new study by D. Sarah Stamps of the Department of Geosciences for the journal Geology. The breakup is a continuation of the shattering of the supercontinent Pangea some 200 million years ago.

Rest assured, though, this isn't happening anytime soon.

"The rate of present-day break-up is millimeters per year, so it will be millions of years before new oceans start to form," said Stamps, an assistant professor in the Virginia Tech College of Science. "The rate of extension is fastest in the north, so we'll see new oceans forming there first."

Geosciences doctoral student Tahiry Rajaonarison sets up a GPS instrument in northern Madagascar in this 2016 photograph. Behind Tahir is the Indian Ocean and a rock island. Photo credit: Rina Andrianasolo.

"Most previous studies suggested that the extension is localized in narrow zones around microplates that move independent of surrounding larger tectonic plates," Stamps said. The new GPS dataset of very precise surface motions in Eastern Africa, Madagascar, and several islands in the Indian Ocean reveal that the break-up process is more complex and more distributed than previously thought, according to the study, completed by Stamps with researchers from the University of Nevada-Reno, University of Beira Interior in Portugal, and the Institute and Observatory of Geophysics of Antananarivo at the University of Antananarivo in Madagascar itself.

In one region, the researchers found that extension is distributed across a wide area. The region of distributed extension is about 600 kilometers (372 miles) wide, spanning from Eastern Africa to whole parts of Madagascar. More precisely, Madagascar is actively breaking up with southern Madagascar moving with the Lwandle microplate -- a small tectonic block -- and a piece of central Madagascar is moving with the Somalian plate. The rest of the island is found to be deforming nonrigidly, Stamps added.

Also working on the paper was geosciences Ph.D. student Tahiry Rajaonarison, who previously was a master's student at Madagascar's University of Antananarivo. He assisted Stamps in 2012 in collecting GPS data that was used in this study. He joined Virginia Tech in 2015 and returned to Madagascar later to collect more data as the lead on a National Geographic Society grant. "Leading a team to collect GPS data in Madagascar in summer 2017 was an amazing field experience," Rajaonarison said.

The team used new surface motion data and additional geologic data to test various configurations of tectonic blocks in the region using computer models. Through a comprehensive suite of statistical tests, the researchers defined new boundaries for the Lwandle microplate and Somalian plate. This approach allowed for testing if surface motion data are consistent with rigid plate motion.

Final model for the East African Rift System.

Hashed lines indicate newly discovered broad deforming zone. Arrows represent predicted tectonic plate motions. ABFZ--Andrew Bain Fracture Zone; IFZ--Indomed Fracture Zone; RSZ--Ranotsara shear zone. Figure created by D.S. Stamps.

"Accurately defining plate boundaries and assessing if continents diverge along narrowly deforming zones or through wide zones of diffuse deformation is crucial to unraveling the nature of continental break-up," Stamps said. "In this work, we have redefined how the world's largest continental rift is extending using a new GPS velocity solution."

The discovery of the broad deforming zone helps geoscientists understand recent and ongoing seismic and volcanic activity happening in the Comoros Islands, located in the Indian Ocean between East Africa and Madagascar. The study also provides a framework for future studies of global plate motions and investigations of the forces driving plate tectonics for Stamps and her team.

When it came to naming a gene that could lead to new insights on a crucial feature of evolution, the Harvard Organismic and Evolutionary Biology alumna leading the project aimed for something rather tongue in cheek. She called it POPOVICH, after San Antonio Spurs coach and president Gregg Popovich.

Evangeline Ballerini, Ph.D. '10, an assistant professor of biological sciences at California State University, Sacramento, said she and her collaborators -- including Harvard's Elena Kramer -- settled on the name because the newly discovered gene calls the shots for floral nectar spurs the way Popovich does for his NBA team.

"I ended up choosing to name it after Gregg Popovich, in part, because the gene plays a regulatory role in spur development, kind of like a coach controls the development of their team," said Ballerini, who is a long-time Golden State Warriors fan and a part-time Celtics fan because of her time in the Boston area, but respects the Spurs and admires Popovich's leadership.

The work is described in a recently published study in PNAS.

Nectar spurs are the hollow tubes that bulge out from a number of flowers and are crucial to increasing biodiversity among flowering plants that have them. In many cases, species with nectar spurs are much more diverse than their close relative without this novel trait.

In the paper, the scientists identify the gene critical to controlling the development of these spurs in the common columbine, or Aquilegia. They found it acts as a master regulator that appears to control the creation of the spurs by regulating the activity of other genes, the way a coach decides who plays and when.

Aside from the quirky NBA reference, what really has evolutionary biologists excited about the discovery is that the findings have the potential to help them understand how organisms get their vast array of shapes and traits, and then how those traits evolve.

Nectar spurs are considered a key innovation in flowers, meaning they are considered a novel feature -- one that helps organisms make the greatest use of their environment and leads to a diversity boom. Animals that evolved to have wings, for instance, have spun off into number of different species over millions of years. Other key innovations are eyes or the backbone in mammals.

Most key innovations happened deep in the past, making identifying their origin increasingly difficult. In the group of plants the researchers studied, however, floral nectar spurs have only been around for about 5 to 7 million years.

"Given that the Aquilegia nectar spur evolved relatively recently and is formed by modifications to a single floral organ, it provides a unique opportunity to begin to dissect the developmental and genetic basis of a key innovation, which, in turn, will provide insight into its origin," the researchers wrote.

The researchers believe the gene is among the first key innovations for which scientists have identified the critical gene, opening the door to a number of areas in understanding how form and morphology are achieved in flowers and other living things.

"We're particularly interested in novel features that seem to be very important for promoting speciation events," said Kramer, Bussey Professor of Organismic and Evolutionary Biology and chair of the Department of Organismic and Evolutionary Biology. "In terms of a morphological trait, like the nectar spur, we're asking: How did development [of the species] change? ... It gives us, essentially, a handle, a starting place to try to start understanding this genetic network."

Researchers made the discovery using a combination of techniques that included genetic sequencing and crossing species, and gene expression analyses. One of the keys was using a species of the Aquilegia native to China and known to be the only member of that genus, out of 60 to 70 species, to lack nectar spurs.

The team started by repeating a 1960 study by the Russian geneticist W. Pra?mo that crossed the spurless flower with a spurred species and suggested that a single, recessive gene was responsible for spur loss. Unlike Pra?mo, they had the genetic tools to finish the job, and sequenced the genome of about 300 offspring. That narrowed the search to just over 1,000 genes. Further genetic sleuthing led them to POPOVICH, which they call POP for short, and confirmed it using a genetically modified virus that knocks down, or suppresses, targeted genes.

"We took a species that has spurs and normally has POP expression, and we downregulated the expression of POP," Kramer said. "We showed that it lost its spurs, and that result was the thing that ties it all together. Not only is this a gene that's specifically expressed in spurs, but when you knock it down, it loses its spurs."

While this is all strong evidence, more work is needed to confirm their findings.

"There are several directions that we'd like to go in, including trying to figure out how POP expression is controlled, which genes POP regulates the expression of, and what the POP gene is doing in the spurless relatives of Aquilegia," Ballerini said.

A drug that has shown promise for treating multiple sclerosis may actually make the debilitating disease worse, new research from the University of Virginia School of Medicine suggests.

The drug has not yet made it to human trials for MS, but the UVA scientists are warning their fellow researchers to proceed extremely cautiously. In addition to worsening the disease in mouse models, the drug also had unintended, off-target effects, they report.

"It was not at all what we expected," said MS researcher Alban Gaultier, PhD, of UVA's Department of Neuroscience and its Center for Brain Immunology and Glia (BIG). "The take-home message is that we should be very careful and do more fundamental research before we propose to take this to clinical trials."

About Multiple Sclerosis

Multiple sclerosis is a debilitating autoimmune disease that affects an estimated 1 million Americans. The disease causes the body's immune system to destroy myelin, the insulation that surrounds and protects our nerve fibers. This prevents the nerves from transmitting signals to the brain. The damage can create a wide range of symptoms, including muscle spasms, fatigue, difficulty moving, numbness and pain. These symptoms can vary from patient to patient.

Existing MS drugs carry unwanted side effects, such as impairing the body's ability to fight infections, so doctors are eager to develop better alternatives. One promising candidate is a small-molecule drug called TEPP-46. Originally developed to fight cancer, TEPP-46 targets what is known as "metabolic adaptation" - changes in how cells generate energy - that occurs in both cancer and MS.

In Gaultier's MS models, however, TEPP-46 worsened the disease, redirecting inflammation from the spinal cord into the brain. He and his collaborators determined the drug caused harmful changes in immune cells called T cells, though he and his team do not fully understand why. There were also unexpected "off-target" effects, meaning the drug affected other cellular processes than the one intended.

Gaultier notes his findings are at odds with other studies, and he says more research is needed before scientists move the drug into clinical trials in people with MS.

One upside to the new research is that it suggests that TEPP-46 could be used to create better mouse models of MS, helping scientists in their efforts to understand and treat the disease.

"It's something that could be very useful," Gaultier said. "In this animal model of MS, most of the inflammation takes places in the spinal cord. So by using that drug and reprogramming the immune cells, we were able to move the pathology from the spinal cord to the brain, which better mimics human disease."

Findings Published

The researchers have published their findings in the scientific journal Science Signaling. The research team consisted of Scott M. Seki, Kacper Posyniak, Rebecca McCloud, Dorian A Rosen, Anthony Ferna?ndez-Castan?eda, Rebecca M. Beiter, Vlad Serbulea, Sarah C. Nanziri, Nikolas Hayes, Charles Spivey, Lelisa Gemta, Timothy Bullock, Ku-Lung Hsu and Gaultier.

BUFFALO, N.Y. - If dispositional mindfulness can teach us anything about how we react to stress, it might be an unexpected lesson on its ineffectiveness at managing stress as it's happening, according to new research from the University at Buffalo.

When the goal is "not to sweat the small stuff," mindfulness appears to offer little toward achieving that end.

The findings, published in the journal Personality and Social Psychology Bulletin, which measured the cardiovascular responses of 1,001 participants during stressful performance tasks, run contrary to previous research and pop culture assertions of how being mindful offers stress relief and coping benefits.

Where earlier work in this area suggests how mindfulness may help people manage active stressors, the current paper finds evidence for an opposite response. In the midst of stress, mindful participants demonstrated cardiovascular responses consistent with greater care and engagement. Put another way, they actually were "sweating the small stuff."

Even more curiously, although the study's participants demonstrated no physiological signs associated with positive stress responses, they did report having a positive experience afterward.

"What's surprising, and particularly striking about our results, is that mindfulness didn't seem to affect whether people had a more positive stress response in the moment," said Thomas Saltsman, a researcher in UB's psychology department and the paper's lead author. "Did more mindful people actually feel confident, comfortable and capable while engaged in a stressful task? We didn't see evidence of that, despite them reporting feeling better about the task afterward."

Mindfulness does have benefits, but appears to be limited in what it can accomplish while people are actively engaged in stressful tasks, like taking a test, giving a speech or sitting for a job interview. Instead, being mindful may only benefit people's perception of their stress experience after it has ended.

"Although our findings seem to go against a wholesome holy grail of stress and coping benefits associated with dispositional mindfulness, we believe that they instead point to its possible limitations," says Saltsman. "Like an alleged holy grail of anything, its fruits are likely finite."

Saltsman describes dispositional mindfulness as having a focused attention on the present. It's a mindset that tries to avoid ruminating on past realities or considering future possibilities or consequences. It's about being non-judgmental and relaxing critical interpretations. Mindfulness can be approached with formal training, but people can also be dispositionally higher or lower in mindfulness, which was the focus of their study.

Those high in dispositional mindfulness report greater well-being. They tend not to dwell on past events, and claim to manage stress well.

"Although those benefits seem unambiguous, the specific ways in which mindfulness should impact people's psychological experiences during stress remain unclear," says Saltsman. "So we used cardiovascular responses to capture what people were experiencing in a moment of stress, when they're more or less dispositionally mindful."

By measuring cardiovascular responses, Saltsman and the other researchers, including Mark Seery, an associate professor of psychology at UB, can tap into participants' experiences during moments of stress -- in this case, giving a speech or taking a reasoning-ability test.

Those responses include heart rate and how hard the heart is pumping. When people care more about the task they are completing, Seery says, their heart rate increases and beats harder. Other measures, like how much blood the heart is pumping and the degree to which blood vessels dilate, indicate how confident or capable one feels during the task.

"One thing these results say to me, in terms of what the average person is expecting when they casually get into mindfulness, is that what it's actually doing for them could very well be mismatched from their expectations going in," says Seery. "And this is an impressively large sample of more than a thousand participants, which makes the results particularly convincing."

In 2018, a new aurora-like discovery struck the world. From 2015 to 2016, citizen scientists reported 30 instances of a purple ribbon in the sky, with a green picket fence structure underneath. Now named STEVE, or Strong Thermal Emission Velocity Enhancement, this phenomenon is still new to scientists, who are working to understand all its details. What they do know is that STEVE is not a normal aurora - some think maybe it's not an aurora at all - and a new finding about the formation of streaks within the structure brings scientists one step closer to solving the mystery.

"Often in physics, we build our understanding then test the extreme cases or test the cases in a different environment," Elizabeth MacDonald, a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, explains. "STEVE is different than the usual aurora, but it is made of light and it is driven by the auroral system. In finding these tiny little streaks, we may be learning something fundamentally new in how green auroral light can be produced."

These "tiny little streaks" are extraordinarily small point-like features within the green picket fence of STEVE. In a new paper for AGU Advances, researchers share their latest findings on these points. They suggest the streaks could be moving points of light - elongated in the images due to blur from the cameras. The tip of the streak in one image will line up with the end of the tail in the next image, contributing to this speculation from the scientists. However, there are still a lot of questions to be answered - determining whether the green light is a point or indeed a line, is one extra clue to help scientists figure out what causes green light.

"I'm not entirely sure about anything with respect to this phenomenon just yet," Joshua Semeter, a professor at Boston University and first author on the paper, said. "You have other sequences where it looks like there is a tube-shaped structure that persists from image to image and doesn't seem to conform to a moving point source, so we're not really sure about that yet."

STEVE as a whole is something that scientists are still working to label. Scientists tend to classify optical features in the sky into two categories: airglow and aurora. When airglow occurs at night, atoms in the atmosphere recombine and release some of their stored energy in the form of light, creating bright swaths of color. By studying the patterns in airglow, scientists can learn more about that area of the atmosphere, the ionosphere. To be classified as an aurora, on the other hand, that release of light must be caused by electron bombardment. These features are formed differently but also look different - airglow can occur across Earth, while auroras form in a broad ring around Earth's magnetic poles.

"STEVE in general appears to not conform well to either one of those categories," Semeter said. "The emissions are coming from mechanisms that we don't fully understand just yet."

STEVE's purple emissions are likely a result of ions moving at a supersonic speed. The green emissions seem to be related to eddies, like the ones you might see forming in a river, moving more slowly than the other water around it. The green features are also moving more slowly than the structures in the purple emissions, and scientists speculate they could be caused by turbulence in the space particles - a brew of charged particles and magnetic field, called plasma - at these altitudes.

"We know this kind of turbulence occurs. There are people who base their entire careers on studying turbulence in the ionospheric plasma formed by very rapid flows." Semeter said. "The evidence generally comes from radar measurements. We don't ever have an optical signature." Semeter suggests that when it comes to the appearance of STEVE, the flows in these instances are so extreme, that we can actually see them in the atmosphere.

"This paper is the tip of the iceberg in this new area of these tiny little pieces of the picket fence. Something we do in physics is try to chip away to increase our understanding," MacDonald said. "This paper establishes the altitude range and some of the techniques we can use to identify these features, then they can be better resolved in other observations."

To establish the altitude range and identify these features, the scientists extensively used photos and videos captured by citizen scientists.

"Citizen scientists are the ones who brought the STEVE phenomenon to the scientists' attention. Their photos are typically longer time lapse than our traditional scientific observations," MacDonald said. "Citizen scientists don't get into the patterns that scientists get into. They do things differently. They are free to move the camera around and take whatever exposure they want." However, to make this new discovery of the points within STEVE, photographers actually took shorter exposure photographs to capture this movement.

To get those photographs, citizen scientists spend hours in the freezing cold, late at night, waiting for an aurora - or hopefully STEVE - to appear. While data can indicate if an aurora will show up, indicators for STEVE haven't been identified yet. However, the aurora chasers show up and take pictures anyway.

Neil Zeller, a photographer and co-author on the paper, says he didn't originally plan to be a citizen scientist. "It was just for the beauty of it," Zeller explained. Zeller has been involved with the discovery of STEVE from the start. He showed a picture he took of STEVE to MacDonald years ago, sparking the first research into the phenomena. Now he's a co-author on this paper.

"It's an honor, it really is," Zeller said about contributing to this research. "I tend to take a step back from the scientists doing the work. I'm out there for the beauty of it and to capture these phenomena in the sky."

This paper also made use of another valuable citizen scientist contribution - a volunteer database of STEVE observations. Michael Hunnekuhl, another author on the paper, maintains this database and has contributed to STEVE findings in the past. Hunnekuhl noticed the streaks in the photographs independently of the scientists on the paper, and his detailed record and triangulation techniques were pivotal in this research.

Zeller and other citizen scientists plan to keep taking and examining those pictures, capturing the beauty of Earth's atmosphere, and MacDonald, Semeter, and other scientists will keep studying them, uncovering more about this new phenomenon.

De'Broski Herbert has a philosophy that's guided his career researching helminths, or parasitic worms, and their interaction with their hosts' immune systems: "Follow the worm."

"The mantra of my lab since its inception has been that parasitic worms manipulate their hosts in very interesting ways to maintain their survival," says Herbert, an associate professor of pathobiology in Penn's School of Veterinary Medicine. "SARS-CoV-2 doesn't care about staying in your body very long because it is transmitted so easily. Worms aren't spread so easily, so they have to figure out how to persist."

That focus has revealed a key insight about an immune signaling molecule, the cytokine IL-33, that is important not only in parasite infections, but in a range of other health conditions, such as asthma, obesity, and eczema. In a new study published in Science Immunology, Herbert and colleagues made insights that explain how IL-33 can both help defend the body against parasite infection, but also suppress chronic inflammation in diseases where the immune system is activated inappropriately and causes harmful pathology. A key discovery was that the activity of IL-33 depends upon which cell type is releasing it.

"Lots of people have been interested in IL-33 ever since two big genomic association studies implicated it and its receptor in the pathogenesis of asthma," Herbert says. "Other researchers have looked at it in the context of infections and others in the context of the brain and development. And everyone knew this protein was in the nucleus, but no one understood how it got out of the cell to accomplish all of these things.

"I'm excited for this work because not only do we find this cytokine in a cell type that nobody was expecting, but we also present a mechanism that no one was expecting for how it could come out."

IL-33 has been of major interest to immunologists focused on what are known as type 2 immune responses, typically associated with parasite infections or asthma and allergies. On the parasite front, researchers knew that IL-33 acted in part to "wake up" the immune system to the presence of a worm infection. In a mouse model, animals lacking IL-33 sustain worm infections much longer than those with IL-33 intact.

To find out whether it mattered which cell type was releasing the IL-33 signaling molecule, Herbert and colleagues used special mouse model in which only myeloid antigen-presenting cells (immune cells), or epithelial cells (those that line mucosal surfaces), failed to release IL-33.

"Sure enough, we found that when animals lacking the myeloid-derived IL-33 experienced a hookworm infection, they eliminated those hookworms quite fast," Herbert says. Mice lacking IL-33 in the epithelial cells, however, were not able to readily clear the infection. The same results held up in another rodent model, this one of roundworm infection.

Dendritic cells, a type of myeloid antigen-presenting cell, produce IL-33, and further experiments showed that the cytokine produced by these cells supported a specific population of regulatory T cells (Tregs), which are cells "whose whole purpose is to suppress the immune response," Herbert says.

Now understanding that dendritic cells were key to supporting Tregs, the researchers wanted to understand how the dendritic cells were delivering the IL-33. The team screened dendritic cells from mice with and without IL-33, identifying a protein called perforin-2 to be suppressed in expression from myeloid cells lacking IL-33.

Perforin-2, as its name suggests, forms a pore that spans the cell membrane, like a tunnel in a hillside, allowing the transport of proteins in and out. The find made complete sense to the researchers, providing an explanation for how dendritic cells could promote the release of IL-33 into the tissues to interact with Tregs. And when Herbert and colleagues experimentally eliminated perforin-2 from dendritic cells, they saw a subsequent lack of Treg growth.

To connect the findings in their animal model and lab dishes to humans, the team utilized patient samples from Penn otolaryngologist Noam Cohen. They found perforin-2 at the plasma membrane of cells from polyps removed from patients with chronic rhinosinusitis, suggesting that the significance of the findings extends to human health.

The study paves the way for even more translational work in immunology--and worms are to thank. "It's kind of the missing link," Herbert says. "It opens up a whole new direction for understanding how this cytokine could be involved in obesty, inflammatory bowel disease, Crohn's, asthma, and development."

Using NASA satellite imagery and software processing approaches, a group of geoscientists has discovered a landslide-generated tsunami threat in Barry Arm, Alaska, that will likely affect tourists and locals in the surrounding area in the next 20 years.

The Barry Arm Glacier has diminished rapidly in the last decade due to climate change, causing the surrounding terrain to become unstable. The researchers found that the mountainside near the Barry Arm Glacier has moved 394 feet (120 meters) over the seven-year period between 2010 to 2017. If that slow-moving landmass were to catastrophically fail - becoming what we typically think of as a landslide - it would fall 3,000 feet into the fjord below, sending tsunami waves toward nearby communities.

The researchers jumped into action after the discovery, writing an open letter to community stakeholders. The findings were published Oct. 29 in Geophysical Research Letters.

Chunli Dai, geophysics researcher at The Ohio State University in Columbus, worked with Bretwood Higman, geologist and co-founder of Ground Truth Alaska nonprofit, to analyze the slow-moving landslide near the Barry Arm Glacier. Their team tracked the landslide's horizontal movement using satellite imagery and measurements from NASA-U.S. Geological Survey's Landsat constellation, NASA's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), ESA's (the European Space Agency) Sentinel-1, Planet Labs, and DigitalGlobe. As the longest-running Earth-observing satellite program, Landsat provided the researchers with an archive of satellite imagery that allowed the team to see how the Arctic surface in that area has changed over time. Data from the Polar Geospatial Center's ArcticDEM project were also used to measure the elevation of the glacier to see how its height has changed over the years.

Dai and her team developed new and innovative tools that confirmed the threat from the landslide near the Barry Arm Glacier. The tools are sensitive enough to enable the team to detect signals associated with volcanic eruptions, changes in the surface due to permafrost melting, and landslides. These tools sort through massive topographic datasets to detect subtle changes in the land's surface over time - acting as one step toward better preparation for hazards on the changing Arctic.

The new finding came out of a large project studying the topography of the Arctic surface and how that landscape is changing. The project uses ArcticDEM digital elevation models and is funded by the NASA Earth Surface and Interior (ESI) program. This project intends to use global, high-resolution topographic measurements so that NASA may better understand natural hazards and changing environments, said Benjamin Phillips, lead for NASA's Earth Surface and Interior Focus Area. Partnering with the National Science Foundation, National Geospatial-Intelligence Agency, and others, NASA supports the development and distribution of new digital surface models of the globe, constructed from optical imagery acquired by the DigitalGlobe constellation.

As the Barry Arm Glacier retreats, 600 million cubic yards of rugged terrain that was once supported by the glacier is left unstable. During a landslide, rocks and debris act less like a collection of solids and more like a fluid. In the case of sudden landslide failure, this flow of rock and debris would likely fill the fjord, leaving several smaller lakes in place of the 450-foot deep body of water.

Barry Arm Fjord and the adjacent Harriman Fjord - 60 miles east of Anchorage on the southern coast of Alaska - are frequented by cruise ships, tour boats, fishing boats, kayakers, and hikers. Because of the immediate dangers posed by the potential the landslide and tsunami threat, Dai and the other scientists signed an open letter to local community stakeholders as soon as the hazard was identified so that they were aware of the implications that the landslide would likely generate a tsunami.

At the landslide's current elevation, its mass would trigger a tsunami with waves hundreds of feet tall in Barry Arm. Broader impacts of the tsunami include 30-foot waves hitting Whittier, Alaska. Prince William Sound may experience wave and current changes, and rock and debris from the landslide would be scattered in this area.

If the landslide were to fail all at once, the potential energy stored within the event is equivalent to a magnitude seven earthquake, nearly ten times greater than any of Alaska's largest tsunami-generating landslides in the last 70 years, said geoscientist Anna Liljedahl of Woods Hole Research Center in Homer, Alaska.

The resulting tsunami could travel up the opposite side of the fjord, harming wildlife, hikers and vegetation. Farther away from the source, bays throughout Prince William Sound act as amplifiers, meaning this tsunami would be less localized and more powerful even tens of miles from the source.

As a result of this discovery, the National Oceanic and Atmospheric Administration (NOAA), the agency responsible for tsunami alerts, is in the process of preliminary tsunami modeling. In early June, NOAA also assessed the fjord for wave height monitoring equipment, which could be installed and connected to their warning system network later this summer, said Liljedahl, who worked with Dai to assess the Barry Arm landslide threat.

Alaska's Division of Geological and Geophysical Surveys (DGGS) is also monitoring the Barry Arm region following the scientists' discovery. They completed an airborne lidar survey in mid-June to track the slide's movement and are working with the Alaska Earthquake Center to install a seismic station near the fjord that will help detect sudden landslide movements. Without new monitoring equipment, Whittier would only have 20 minutes warning to evacuate if the Barry Arm landslide were to suddenly fail.

"There are a lot of natural hazards that people in Alaska are used to - earthquakes, volcanoes, and fire hazards. We need to take that mindset and apply that to landslide-generated tsunamis," Liljedahl said.

In addition to current monitoring efforts, geoscientist Bretwood Higman said that having a GPS system on the landslide mass should be a high priority because it could give a better indication as to when the landslide will fail.

"Landslides sometimes accelerate just before they fail," he said. "If you have some way of measuring deformation - if we see something like that - we can say risk is much higher right now, let's get everyone out of the area."

The landslide's movement down the mountainside is strongly correlated to the nearby Barry Arm Glacier's retreat, as surrounding area becomes destabilized as the glacier melts. While a landslide-generated tsunami is not a certainty, knowledge of the risk informs the need to monitor and prepare for the possibility. "This is such a huge area and rare event, but the risk of it happening is just going up because we have this warming climate," Liljedahl said.

All too often, kids are given less information than they deserve when it comes to complex phenomena, like how a virus such as COVID-19 spreads, or how to confront deeply painful societal issues like racism. If you are a parent or adult who has struggled to talk about race with kids, you are certainly not alone.

"Parents are generally afraid that they don't have all the answers, and that has to go out the window," says Judith Scott, a Boston University School of Social Work assistant professor, whose research focuses on how parents can prepare kids to deal with racial discrimination, and how families and peers transmit messages about identity and culture to kids. "It's okay to say, 'I'm still learning myself,' and learn together with your children," Scott says.

Adults avoid conversations with their kids about race for a whole host of reasons--from feeling unqualified, or uncomfortable, or like they don't know enough. Now a recent study from Boston University researchers published in the Journal of Experimental Psychology finds there might be another reason parents hold off on talking about race with kids: adults assume children are too young to be aware of race.

The new data suggests that the majority of adults in the United States have false perceptions about how and when kids learn about race, says Evan Apfelbaum, a BU social psychologist and Questrom School of Business associate professor of management and organizations, who coauthored the study with assistant professors Leigh Wilton and Jessica Sullivan, social and developmental psychologists at Skidmore College.

"Regardless of whether [study participants] were a parent, regardless of whether they were white or Black, they had similar misconceptions about when kids first process race, which was very unexpected and surprising," Apfelbaum says.

To figure out adults' assumptions about the onset of children's racial processing, the study authors asked a demographically representative sample of US adults basic questions about childhood development milestones, children's processing of race, and what factors influence their ability to talk about race. On average, participants were off by about four and a half years when asked when they think kids start processing race, which can begin before one year old. Their data suggests that this misconception was the biggest reason why adults didn't want to talk about race with kids, even compared to other personal reasons, like feeling uncomfortable or afraid of inflicting racist views.

"I wouldn't say this is the only reason," Apfelbaum says. "But it's a surprisingly large factor, according to our data." As a follow-up to the survey, participants received a quick science lesson on childhood development and race. And after their lesson, the majority of people were more willing to talk about race with kids, possibly because they were more assured that the kids can handle it.

In their paper, Apfelbaum and his coauthors note that past research has found toddlers and children under the age of five can detect messages and ideas about race, while infants at six months old can notice differences in skin color. By five years old, kids begin to associate racial characteristics with traits, stereotypes, and social status, and start to internalize messages about race they have inferred from adults and people around them.

"I've had young kids, at four years old, who I've worked with come up to me and ask, 'Why are you brown and I'm white?'" says Scott. And in those situations, "parents freak out," she says, "because parents automatically associate race with racism."

With ongoing protests against police brutality, systemic racism, and racial injustice happening across the country since George Floyd was killed, Scott and Apfelbaum both agree that now is as good a time as ever to talk honestly about racism, since young kids and teens are very likely putting pieces together themselves, or possibly talking and sharing information on social media with their peers.

Even if children are a bit older, there's still time for parents and educators to start talking about race. "There's work to be done earlier, but kids start to develop a more sophisticated understanding about unfairness and inequality in society, and about how their actions will be perceived by others at around 10 years old," Apfelbaum says.

"Kids understand the nature of unfairness," says Scott. "And I think that foundation is a way to start having conversations about racism."

Netflix sci-fi series Raising Dion is a great example of why some parents have to start talking about racism, Scott says, because in one episode, Dion--who is a young Black boy with superpowers--is distressed after experiencing discrimination in school and his mother has to talk to him about racism for the first time. It's important to keep in mind that motivations for having these conversations differ; it could be triggered by something on the news, times that kids are hearing about racism issues at school or experiencing racial discrimination themselves, or talking about race with peers. Scott has found in her research that context is crucial when families decide how to talk about race and racism as issues or questions arise, since every situation and child is different.

Generally, when it comes to engaging kids and teens in conversations about racism, Scott emphasizes using the power of stories and positive examples. Such stories could be about young activists fighting against racist systems, like 13-year-old Mari Copeny--better known as "Little Miss Flint"--who spoke up about environmental racism with the ongoing water crisis in Flint, Mich.

"It's important for kids to understand that society is trying to do something about it, and people are fighting the fight," says Scott. The key is understanding your child, seeing if they want opportunities to engage in small or big ways, and to keep checking in.

"As kids get older, the information you give them about race and racism has a different meaning to them because of where they are developmentally or their experiences, and so if your child is 12 or 14 and the last conversation you had about race was when they were 8, that is not going to cut it," says Scott. Contributing with small actions, making signs, drawing positive messages or images on the sidewalk, or even attending a protest or organizing virtual events, are a few possibilities for kids who want to engage in antiracism work.

"For parents of color, people who have had bad experiences, it's important to--after those conversations--take care of yourself," says Scott. "Finding time to talk about these things when you're emotionally ready, and only if you're ready, is okay."