Brain

Almost all living organisms - from bacteria to humans - have gate-like protein complexes in their cell membranes that get rid of unwanted or life-threatening molecules. This is not always to human advantage, since in the case of bacteria or cancer cells these complexes, known as ABC transporters, are also responsible for resistance to antibiotics or chemotherapy. Researchers at Goethe University Frankfurt, together with the Max Planck Institute of Biophysics, which is also located in Frankfurt, have now succeeded in decrypting all the stages of the transport mechanism.

Over the past five years, the research group led by Robert Tampé at the Institute of Biochemistry of Goethe University Frankfurt has invested considerable effort in preparing samples of sensitive membrane protein complexes in such a way that they can be examined in membrane environment by means of cryo-electron microscopy. Cryo-electron microscopy delivers high-resolution images by freezing the molecules so that blurring is reduced to a minimum when they are in motion.

If the aim is not only to produce clear images of complex molecules, such as ABC transporters, but also to observe them at work, snapshots of different stages are required. The team of biochemists led by Tampé was able to trigger these stages deliberately by supplying the transporter with different concentrations of ATP and ADP. Without the energy supply of ATP, the transporter is unable to translocate molecules against the concentration gradient between the cell interior and its surroundings.

In the current issue of the journal Nature, Tampé and his colleagues show eight high-resolution conformations of an ABC export complex composed of two different protein subunits. The researchers were also able to make intermediate stages of the transport process visible for the first time. The publishers of Nature have selected this important discovery as the cover story for the current issue.

"Our work could lead to a paradigm shift in structural biology, since it was possible to display all the motions of a cellular machine in almost atomic resolution," explains Professor Tampé. "Thanks to this unexpected discovery, we can now answer questions about the transport mechanism of ABC transporters which were previously the subject of controversial debate and are highly relevant for medicine." In addition, the researchers were able to observe for the first time how the gates open inwards or outwards. The resolution of 2.8 Angstrom (1 Angstrom = a ten millionth of a millimeter) is the highest resolution ever achieved in the imaging of an ABC transporter structure with the help of cryo-electron microscopy.

LA JOLLA, CA – Like overpacked suitcases unloaded from the underbelly of a jet, molecular satchels called exosomes are continuously deployed from all cells in the body—each one brimming with an assortment of contents that another cell may unpack and use. By sending off these biological parcels, cells communicate with each other via shared proteins and genetic material. 

Once simply thought to be microscopic sacks of cellular “garbage,” exosomes are now understood to hold immense importance for our health. An outflowing of research in recent years has even shown they can transport molecules that are linked to the spread of cancer and neurodegenerative disorders such as Alzheimer’s. Yet, until recently, their role in brain development remained a mystery.

In new research published in Proceedings of the National Academy of Sciences, Hollis Cline, PhD, and her colleagues at Scripps Research begin to close that knowledge gap by showing that exosomes are not only integral to the development of neurons and neural circuits, but they can restore health to brain cells affected by developmental disease.

“During different stages of brain development, signaling between cells is absolutely essential,” says Cline, co-chair of the Department of Neuroscience at Scripps Research and director of the Dorris Neuroscience Center. “We found that exosomes are one of the ways cells communicate these signals.”

Our bodies use spherical containers called “vesicles” to traffic different materials within and among cells. Exosomes are a type of vesicle tasked specifically with transporting various biological cargo—lipids, proteins, RNA—from one cell to another. Cline’s research determined that proteins, in particular, were responsible for the cell-to-cell signaling capabilities of exosomes.

Her research team examined exosomes from healthy human neurons and those from a disease model of Rett syndrome, a genetically-driven developmental brain disorder that causes autism-like symptoms.

Pranav Sharma, PhD, a neuroscientist in Cline’s lab, designed experiments to clearly identify and compare exosome bioactivity from healthy neurons and diseased neurons. Through multiple cellular and functional assays, they found that the Rett-affected exosomes didn’t contain any harmful proteins, but also didn’t have essential signaling proteins found in healthy exosomes. “They did not have bad stuff, but lacked the good stuff,” Sharma says.

As part of the experiment, the team used CRISPR gene editing technology to correct the mutation that causes Rett syndrome, and then examined whether the signaling functions of the neural exosomes were restored as a result. “Fixing the mutation reversed the deficits,” Sharma says.

They also tested whether adding healthy exosomes to a culture-dish model of Rett syndrome would provide a therapeutic effect. It did.  

“That was perhaps our most exciting finding: that exosomes from healthy cells can indeed rescue neurodevelopmental deficiencies in cells with Rett syndrome,” Cline said. “We see this as very promising because of the many neurodevelopmental disorders in need of a treatment. These are disorders for which we already have a deep understanding of the underlying gene deficiencies but are still lacking a therapy to address the disease itself.”

Sharma says the study relied on human neurons derived from induced pluripotent stem cells (iPSCs) from Rett patients. For this aspect of the experiment, the team drew on the expertise of Alysson Muotri, PhD, a neuroscience and stem cell specialist at University of California, San Diego. To obtain the rich and quantifiable proteomic data needed to characterize the exosomes, the team collaborated with several others from Scripps Research, including mass spectrometry pioneer John Yates III, PhD, and scientist Daniel McClatchy, PhD, in the Yates lab.

“The brain is a very complicated organ, and neurons are more complex than normal cells,” Sharma says. “We didn’t want to get lost in the complexity, so we decided on a reductionist approach to test what these vesicles are capable of and what they contain.”

They also injected healthy exosomes into a mouse hippocampus—a brain region involved in learning and memory—and observed increased neuron proliferation. This in vivo facet of the study proved that the exosome bioactivity seen in cell cultures carried over to an animal model.

Armed with their remarkable findings, Cline and her team now intend to dig deeper into their results and explore a slew of new questions related to exosome bioactivity and potential clinical applications: Could exosomes be measured in a blood test to detect disease or treatment efficacy? Do these findings also apply to autism spectrum disorders (ASDs) and other neurodevelopmental diseases, such as Fragile X? Could exosome-based therapies one day help patients with brain disorders?

“This research has huge relevance for many diseases related to brain development,” Cline says. “It’s very interesting biology that has a lot of scientists excited about the possibilities.”

Volcanic eruptions eject sulfur dioxide gas high into the atmosphere, forming sulfate aerosol chemically and block the incoming sunlight like a parasol. This causes surface cooling globally, but the response of global monsoon rainfall is different following volcano eruptions at different latitudes, according to a quantitative research by Meng Zuo, a doctoral student from the Institute of Atmospheric Physics, Chinese Academy of Sciences, along with her mentors Prof. Tianjun Zhou and associate Prof. Wenmin Man.

This work is recently published in Journal of Climate.

Monsoon rainfall and volcano eruption

Monsoon rainfall imposes great impacts on society since it affects over two-thirds of the world's population. Insufficient monsoon rainfall brings drought and famines to many parts of the world, while too much rainfall causes floods.

Following tropical volcanic eruptions, the monsoon circulation weakens and rainfall decreases consequently. But when we take the latitude of eruptions into consideration, the monsoon rainfall response changes accordingly. This phenomenon has been found in previous studies but the physical mechanism still remains inconclusive. Also the knowledge of the monsoon rainfall response to volcanic eruptions is crucial for adaptation.

The dominant role of atmospheric circulation change

The researchers analyzed large sets of data and the climate model simulations to investigate the different impacts of northern, tropical and southern volcanic eruptions on the global monsoon rainfall. "In contrast to previous work, we used a diagnostic method to quantitatively analyze the factors determining rainfall response, which is helpful to understand the different physical processes of volcanoes at different latitudes affecting the monsoon rainfall", introduced Zuo.

The team found that both the proxy and observations show that monsoon rainfall in one hemisphere is reduced by the volcanic eruptions in the same hemisphere, but is enhanced by the volcanic forcing in the other hemisphere. Similar relationship is found in the model simulations.

They further put forward the underlying mechanism by using moisture budget analysis and moisture static energy budget analysis, which can decompose rainfall changes into water vapor change and circulation change. The changes in atmospheric circulation is found to play a dominant role in rainfall responses. The dry-wet changes are attributed to weakened monsoon circulation and enhanced hemispheric thermal contrast, respectively. They also found that the response of the extreme rainfall is consistent with that of the mean rainfall, but more sensitive over monsoon regions, which are related to drought and flood hazards.

"This work implies that future volcanic eruptions located in different latitudes will impact the monsoon rainfall differently through circulation changes, which implies that the rainfall response to volcanic eruptions at different hemispheres should be considered in the design of Decadal Climate Prediction Project (DCPP) experiments and the implementation of geoengineering activities", the corresponding author Tianjun Zhou, highlighted.

How well you manage your money in college may determine when you'll ultimately achieve "adult identity," according to a new study led by the University of Arizona.

Researchers tracked a group of students from their fourth year of college to five years post-graduation. Participants were asked at three different points to self-report on financial behaviors such as spending, saving, budgeting and borrowing. Those who had good financial habits in their fourth year of college, or who showed marked improvement in their habits over the course of the study, were more likely to see themselves as adults at the end of the study period, when they were 26 to 31 years old.

On the flip side, those whose financial behaviors in college weren't as good, or didn't improve over time, were less likely to see themselves as having reached adulthood five years after college.

"We found that financial behaviors during that fourth year of college continue to have positive implications for emerging adults more than half a decade later," said study co-author Melissa Curran, an associate professor in the UA's Norton School of Family and Consumer Sciences in the College of Agriculture and Life Sciences.

The research, published in the Journal of Applied Developmental Psychology, is based on data collected at three different time points over a six-year period, starting with students' fourth year of college in 2010 and five years post-college in 2016. All of the participants were originally UA students.

Although adult identity has traditionally been measured by milestones like getting married, having children and achieving financial independence, for this study researchers measured participants' perceived adult identity by asking them to rate, on a scale of 1 to 5, a series of statements, such as "I feel that I have matured fully."

"We asked them to reflect on whether they think they've already reached adulthood and whether others around them see and treat them as adults," said lead study author Xiaomin Li, a doctoral student in family studies and human development.

It wasn't just the young adults' own financial behaviors that impacted whether or not they considered themselves adults. Study participants who reported that their romantic partners had good financial habits also scored higher on measures of adult identity.

Researchers focused only on individuals who were in romantic relationships at each point of data collection, since research has shown that romantic partners play an increasingly important role in young adults' financial well-being as they transition into adulthood. About 80% of participants were married by the end of the study, and 20% had children.

"The emerging adults we focused on are at a special developmental phase, and in this period, they have the need for intimacy," Li said. "It's a stage when they become independent from the family but more dependent on their partner, so researchers need to regard intimate relationships' effects on development in this stage of emerging adulthood."

Li and Curran - along with their collaborators at Beijing Normal University in China, the University of Minnesota and the University of Wisconsin - identified two possible pathways through which financial behaviors may impact adult identity formation.

They found that those who practiced more responsible financial behaviors reported having fewer symptoms of depression and higher relationship satisfaction, both of which, in turn, seemed to promote the formation of adult identity.

While the study focused on college-educated students, future research should consider the implications of financial behavior on adult identity formation in non-college educated young adults, Li said.

Meanwhile, given the role that financial behaviors seem to play in college students' adult identity formation, it may be beneficial for colleges to focus on financial education, Li said.

"Other stakeholders should develop some programs to help young adults keep accumulating more responsible financial behaviors even after they've graduated from college," she said.

Adding canned laughter to the end of a punchline increases how funny we find a joke, but not as much as real laughter, finds a new UCL-led study.

The research, published in Current Biology, looked to establish whether the presence and intensity of laughter increased our perception of whether or not a joke was funny, or how funny it was.

In the study, 40 groan worthy 'dad jokes' were given a baseline humour rating of between one (not funny) and seven (hilarious). A professional comedian then recorded each of the jokes, and two versions were created adding short canned (or posed) laughter and short spontaneous (or real) laughter.

Researchers, based at the UCL Institute of Cognitive Neuroscience, then tested both versions of the jokes on two distinct participant groups: neurotypical and autistic.

Laughter may be processed differently in autism: typically developing children's enjoyment of cartoons is enhanced by laughter tracks, watching with another or simulating a smile; in contrast autistic children's enjoyment is not significantly modulated by such manipulations.

Commenting on the findings, lead author, Professor Sophie Scott (UCL Institute of Cognitive Neuroscience), said: "What this study shows is that adding laughter to a joke, increases the humour value, no matter how funny or unfunny the joke is.

"It also suggests we respond much better to spontaneous genuine laughter, rather than posed or canned laughter, showing the inherent human joy and value of a natural response."

The addition of laughter increased how funny the jokes were perceived to be.

There was a significant difference between the baseline ratings and the joke/laughter ratings in neurotypical adults, irrespective of the type of laughter.

The increase in humour was tempered by the kind of laughter; the addition of spontaneous laughs led to jokes being rated as funnier than with the addition of posed laughs.

There was no difference between neurotypical and autistic adult participants in the effect the different types of laughter had on the ratings of the jokes.

Both groups gave higher funniness ratings for jokes paired with spontaneous laughter than with posed laughter.

The only difference between the groups was that those with autism gave all the 40 dad jokes an increased funniness rating, when laughter was added. This may be because neurotypical adults were more aware these 'dad jokes' are considered childish and uncool, whereas autistic adults are more open to such jokes.

Professor Scott added: "Our data suggest that laughter may also influence how funny the comedy is perceived to be, and that people with autism are equally sensitive to this effect.

"This might suggest that comedy and laughter are more accessible to people with autism than typically considered to be."

Five jokes from the study:

What state has the smallest drinks? Mini-soda!

What does a dinosaur use to pay the bills? Tyrannosaurus cheques!

What's orange and sounds like a parrot? A carrot!

What do you call a man with a spade on his head? Dug!

Professor Scott added: "Historically, TV and radio programmes were always recorded in front of a live studio audience: this allowed those watching and listening to feel part of the performance.

"However, as the audience reaction was natural, certain 'comedy' programmes, which weren't overtly funny wouldn't get a long laugh, so TV and radio producers increasingly added canned laughter to prompt an audience reaction.

"This research shows that while canned laughter does elevate the humour of a comedy, adding real laughter would get a better response. This has been adopted in shows like Friends, which are recorded in front of an audience, with the real laughter amplified during editing for particular jokes that had been well received."

Some parasitic plants steal genetic material from their host plants and use the stolen genes to more effectively siphon off the host's nutrients. A new study led by researchers at Penn State and Virginia Tech reveals that the parasitic plant dodder has stolen a large amount of genetic material from its hosts, including over 100 functional genes. These stolen genes contribute to dodder's ability to latch onto and steal nutrients from the host and even to send genetic weapons back into the host. The new study appears July 22, 2019, in the journal Nature Plants.

"Horizontal gene transfer, the movement of genetic material from one organism into the genome of another species, is very common in microbes and is a major way that bacteria can acquire antibiotic resistance," said Claude dePamphilis, professor of biology at Penn State and senior author of the study. "We don't see many examples of horizontal gene transfer in complex organisms like plants, and when we do see it, the transferred genetic material isn't generally used. In this study, we present the most dramatic case known of functional horizontal gene transfer ever found in complex organisms."

Parasitic plants like dodder cannot live on their own by generating energy through photosynthesis. Instead, they use structures called haustoria to tap into a host plant's supply of water and nutrients. Dodder wraps itself around its host plant, growing into its vascular tissue, and often feeds on multiple plants at one time. It can parasitize many different species, wild plants as well as those of agricultural and horticultural importance.

"Parasitic plants live very intimately in connection with their host, extracting nutrients," said dePamphilis. "But they also get genetic material in the process, and sometimes they incorporate that material into their genome. Previous studies focused on single transferred genes. Here, we used genome-scale datasets about gene expression to determine whether the large amount of genetic material coming over through horizontal gene transfer is actually being used."

The research team identified 108 genes that have been added to dodder's genome by horizontal gene transfer and now seem to be functional in the parasite, contributing to haustoria structure, defense responses, and amino acid metabolism. One stolen gene even produces small segments of RNA known as micro RNAs that are sent back into the host plant, acting as weapons that may play a role in silencing host defense genes.

The team used rigorous criteria to determine whether the stolen genetic material was likely to be functional: The genes had to be full length, they had to contain all the necessary parts of a gene, they had to be transcribed into an RNA sequence that later builds proteins, and they had to be expressed in relevant structures. The team also explored the evolution of these transferred genes as additional support for functionality.

"We compare a gene's genetic sequence with closely related genes, and look for a special signature in how that sequence evolves to tell if it's likely to be functional," said dePamphilis. "Certain kinds of mutations in a gene do not affect the protein that the gene codes for and therefore do not impact the gene's function. When we see large amounts of these kinds of mutations, as opposed to mutations that might change or disrupt the gene's function, it is strong evidence that natural selection is acting to keep the proteins intact and useful."

Eighteen of the 108 genes appear in all dodder species, suggesting that these genes were originally stolen by the ancestral form of dodder and are maintained in modern species.

"This is the first time any study has seen evidence that horizontal gene transfers occurred early in the evolution of a parasitic group," said dePamphilis. "In this case, 18 of these genes were present in the common ancestor of all the living dodder species, which may have contributed to successful spread of these parasites."

The team also identified 42 regions in the dodder genome that appear to result from horizontal gene transfer, but do not have any functional genes.

"Because such a huge quantity of genetic material has come over through horizontal gene transfer, we suspect that the parasitic plants cannot filter what is coming in," said dePamphilis. "But natural selection is helping maintain the useful genes and filter out the less useful segments."

The researchers are currently investigating how exactly genetic material is being transferred from host to parasite. They would also like to explore whether this transfer is a one-way street, or if the host can obtain genetic material from its parasite.

"We'd love to know how extensive horizontal gene transfer really is," said dePamphilis. "We looked at just one of species of dodder, which is just one of over 4000 species of parasitic plants. Does horizontal gene transfer of functional genes happen to the same extent in other species? Is it possible in non-parasitic plants? In other complex organisms? This may be the tip of the iceberg."

In addition to dePamphilis the research team includes first author Zhenzhen Yang, a graduate student in the Plant Biology Graduate Program at Penn State at the time of the research, as well as Penn State researchers Eric Wafula, Saima Shahid, Paula Ralph, Prakash Timilsina, Wen-bin Yu, Elizabeth Kelley, Huiting Zhang, Thomas Nate Person, Naomi Altman, and Michal Axtell; Joel McNeal at Kennesaw State University; and Virginia Tech researchers Gunjune Kim and co-corresponding author James Westwood. This work was funded in part by the National Science Foundation and the United States and Department of Agriculture. Additional support was provided by the National Institute of Food and Agriculture, the Penn State Department of Biology, and the Penn State Huck Institutes of the Life Sciences.

ROCHESTER, Minn. -- A phase I clinical trial is the first research monitored by the Food and Drug Administration that demonstrates the potential of regenerative therapy for hypoplastic left heart syndrome (HLHS) through collecting, processing and injecting an infant's own stem cells directly into the heart at the time of surgery. A paper detailing the clinical trial was published in The Journal of Thoracic and Cardiovascular Surgery.

The study focused on the safety and feasibility of stem cell treatments designed to strengthen the heart muscle of children with hypoplastic left heart syndrome, a severe congenital heart disease. The research is funded by the Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome at Mayo Clinic and Mayo Clinic.

Hypoplastic left heart syndrome affects approximately 1,000 infants in the U.S. each year. In these babies, the left side of the heart is critically underdeveloped, requiring surgical intervention to support remaining function in the right side of the heart. Patients with hypoplastic left heart syndrome undergo three staged reconstructive surgeries. The Norwood surgery is typically performed within the first days of life. The Glenn surgery takes place within the first few months of age. And the Fontan operation is performed at 2 to 4 years of age.

Since HLHS is rare, no single hospital can treat enough of these patients to advance research with the scope, scale and pace provided by Mayo Clinic's HLHS Consortium, says Tim Nelson, M.D., Ph.D., senior author and director of the Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome. Within this growing collaboration, seven hospitals and an advocacy group work together to provide care for HLHS patients across the U.S. The combined efforts of treatment teams facilitate the sharing of care options and information that benefit patients, families and research.

The phase I clinical trial studied 10 babies diagnosed with hypoplastic left heart syndrome before birth, each enrolled in the ongoing Mayo Clinic Umbilical Cord Blood Collection Study. A minimum of 35 milliliters of cord blood was collected at the time of birth using a specialized collection kit. Then this blood was sent to Mayo Clinic for processing and storage. Mayo Clinic's Human Cellular Therapy Laboratories and ReGen Theranostics Inc. manufactured a highly concentrated specialized stem cell product that could be stored and then shipped back to the hospital to be directly thawed and injected into the heart muscle at the time of the baby's second surgery.

"The infrastructure is now in place to collect and process stem cells with this method for any HLHS baby born in the U.S.," Dr. Nelson says.

Each patient underwent the first surgery and then received his or her processed stem cells during the second operation. This study was a first for using a cell-based therapy by direct injection during heart surgery in children. The study team was required to gather three months of follow-up data from the first child before administering the injection to the second child, and likewise for the third.

All 10 patients successfully underwent the second surgery with injection of stem cells directly into the heart. There were no deaths, and none of the children had any significant safety concerns over six months following surgery.

"We now have a reproducible protocol to utilize stem cell therapy in babies with HLHS. Our hopes are that this groundbreaking research will lead to stem cell therapy strengthening these babies' hearts while delaying or even preventing the need for a heart transplant in some," says Harold Burkhart, M.D., a pediatric cardiothoracic surgeon at OU Medicine in Oklahoma and first author on the paper.

The HLHS Consortium is now conducting a larger phase IIb study with 50 infants. This study focuses on testing the ability of the stem cells to improve heart function. This study also is enrolling control patients who do not receive cell delivery because hypoplastic left heart syndrome was not diagnosed before birth or cord blood was not collected.

Black carbon, commonly known as soot, is a significant contributor to global warming and is strongly linked to adverse health outcomes. Produced by the incomplete combustion of fuels - emitted from large trucks, trains, and marine vessels - it is an air pollutant of particular concern to residents in urban areas. Sensors available on the market today are expensive, making black carbon difficult to track.

Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), collaborating with UC Berkeley, have developed a new type of sensor network that is much more affordable yet capable of tracking this particulate matter. With more than 100 custom-built sensors installed across West Oakland for 100 days, the team created the largest black carbon monitoring network to be deployed in a single city.

A full description of the 100×100 air quality network was published in the journal Environmental Science and Technology.

Generating a new technology to monitor air pollution

The project was launched to address a persistent concern in the community: the need for better tools to monitor black carbon across time and space. Expanding on prior research at Berkeley Lab, the team addressed this challenge by building the Aerosol Black Carbon Detector (ABCD). "We generated a technology that didn't exist to make this invisible problem visible," said Thomas Kirchstetter, who leads the Energy Analysis and Environmental Impacts Division at Berkeley Lab, and is an Adjunct Professor of Civil and Environmental Engineering at UC Berkeley.

Small and inexpensive, the ABCD is a compact air quality monitor that can measure the concentration of black carbon in an air sample. "We had to create a sensor that was as accurate as high-grade, expensive instrumentation, but low enough in cost that we could distribute 100 of them throughout the community," said Kirchstetter. Thanks to design innovations that coauthor Julien Caubel developed during his PhD research, which help the sensors withstand changes in temperature and humidity, the ABCD can produce reliable data when left outside for extended periods of time. The materials for each ABCD cost less than $500. In comparison, commercially available instruments that measure black carbon cost many thousands of dollars.

A well distributed network

The fleet of sensors was deployed throughout West Oakland, a fifteen-square-kilometer mixed-use residential/industrial neighborhood surrounded by freeways and impacted by emissions from the Port of Oakland and other industrial activities. Six land-use categories were designated for sensor placement: upwind, residential, industrial, near highway, truck route, and port locations. "It was important to build a well-distributed network across the neighborhood in order to capture pollution patterns," said coauthor Chelsea Preble, a Berkeley Lab affiliate and postdoctoral researcher at UC Berkeley. Through a collaboration with the West Oakland Environmental Indicators Project (WOEIP), Environmental Defense Fund, Bay Area Air Quality Management District, and Port of Oakland, the scientists recruited community members willing to host the black carbon sensors outside of their homes and businesses. "Our partnership with WOEIP, in particular working with Ms. Margaret Gordon and Brian Beveridge, was essential to the success of the study," said Preble.

To track the individual sensors in real time, including their operating status, and collect measurements, coauthor Troy Cados built a custom website and database. Every hour, the devices sent black carbon concentrations to the database using 2G, the mobile wireless network. The study produced approximately 22 million lines of data, yielding insights about the nature of air pollution on a local scale. Now available for download, the data is also being used by collaborators from UC Berkeley, the Bay Area Air Quality Management District, and other institutions to improve air pollution modeling tools.

Turning invisible pollutants into data

How did these devices work? The ABCD pulled air through a white filter, where black carbon particles were deposited. Optical components in the sensor periodically measured the amount of light transmitted through the darkening filter. Black carbon concentration in the air was based on how much the filter had darkened over time. This technique, developed several decades ago by Berkeley Lab and now commercially available, served as a foundation for the innovations in this study.

In West Oakland, the researchers found that black carbon varied sharply over distances as short as 100 meters and time spans as short as one hour. The highest and most variable levels were associated with truck activity along Maritime Street, typically low in the pre-dawn hours when the Port of Oakland was closed and peaking at the start of business, around eight in the morning. The lowest black carbon concentrations in the study area were recorded on Sundays, when truck activity is typically lowest, and at upwind sites near the bay, west of the freeways and the city's industrial activity. Most of the sensors were able to collect data sufficient to establish pollution patterns during the first 30 days of the study, suggesting that similar - and shorter - studies could provide other communities with valuable information about their air quality.

Partnering with communities to advance the science of monitoring

"This research is an example of how a national laboratory can have a meaningful impact by working with communities," said Kirchstetter. "We worked to address a concern that they've long had and provided data describing how pollution varies throughout the neighborhood, which can be used to advocate for cleaner air," he said. The team is currently working to advance this technology, making it more robust and easier to use so that it can be deployed for longer periods of time at other locations.

"We've long been involved in the generation of air pollution sensing technologies," said Kirchstetter, whose mentor, Tica Novakov, started the field of black carbon research and was an inspiration for this work. "Berkeley Lab has experts in air quality and materials sciences, and can further the science of sensors to continue this path forward," he said. Since the completion of the project, Cados and Caubel have founded a start-up to develop these techniques and make them more readily available.

Elementary schools tend to discipline black students more harshly than white students, leading to a considerable racial gap in expulsion and suspension. That's among the findings of a new data analysis led by researchers at Brown and Princeton universities.

The analysis found that teachers' different treatment of black and white students accounted for 46% of the racial gap in suspensions and expulsions from school among 5- to 9-year-old children. It showed that about 21% of the gap could be explained by differences in the characteristics of schools that black and white children attend predominantly, while differences in student behavior accounted for 9% of the gap.

The analysis was co-authored by Jayanti Owens, an assistant professor of sociology at the Watson Institute for International and Public Affairs at Brown, and published in the journal Social Forces.

The results come on the heels of a 2018 U.S. Government Accountability Office report showing that black K-12 students are 3.2 times more likely than white students to be suspended or expelled from school. The article also follows recent research showing a strong connection between high rates of suspension and expulsion and higher risk of poor school performance, school dropout, arrest, incarceration and unemployment.

Combined with previous research, the analysis provides evidence that different treatment of children as they enter school could play a large role in the early criminalization of black students, Owens said.

"The idea that you can have two kids of different races misbehaving in similar ways and receiving different forms of punishment -- one gets a slap on the wrist, say, and the other gets suspended -- is a really important thing to understand socially," Owens said. "Subconsciously, we all have racial biases in different ways. This is one way in which those biases are manifesting in the classroom."

According to Owens, who led the analysis with Sara McLanahan of Princeton, sociologists have long focused on two different explanations for the racial gap in school suspensions and expulsions. One explanation, often referred to as "between-school sorting," touches on the fact that schools serving mostly students of color and those from low-income families are more likely to adopt "zero tolerance" policies for misbehavior, penalizing students with suspension or expulsion after just one offense.

The other explanation for the racial gap focuses on demonstrated differences across reported race in children's behavior before they enter school. Such differences in behavior are well documented in research, Owens said, and there are several reasons why they might exist: Students of color are less likely to have prior formal education experience than their white peers, and they're more likely to have been exposed to a stressful home environment. Those and other factors, Owens said, could lead to misbehavior or misunderstandings at school.

Owens said she was interested in exploring a third explanation for the racial gap, one that has been investigated independently through lab experiments: that teachers and principals punish students of color differently than white students, even within the same schools.

"I'm interested in the ways that the same behaviors can be interpreted and perceived differently based on race, gender and social class," Owens said. "I wanted to look at groups of kids who behaved in the same way but came from different races, and ask, 'Is there a difference in the way they are treated?'"

Drawing on teacher and parent reports, school records, and survey data on children who attended elementary school from 2003 to 2009, Owens and McLanahan set out to study the racial gap through the lens of these three explanations altogether for the first time, focusing specifically on children between the ages of 5 and 9.

They found that the third explanation -- different treatment of black and white students, even those who attended the same school -- accounted for nearly half of the racial gap. They discovered that gap was prominent even among students who attended the same schools: Black students had anywhere from a 10 to 19 percentage-point higher likelihood of being suspended or expelled than their comparably-behaved white peers, depending on the severity of their behavior problems, as reported by teachers and parents.

"Not only were black children more likely to be suspended, but these racial differences were happening in the same schools," Owens said. "It shows that the categories teachers use as reasons for punishment, like 'defiance,' 'disrespect' and 'noncompliance,' are ripe for racial discrimination. What does it mean to be disrespectful? It would be easy for a teacher to read the behavior of a kid as disrespectful when it may not have been intended that way."

Owens said the findings not only emphasize the need for bias training among teachers and school administrators but also cast a critical eye on schools' use of suspension, expulsion and other exclusionary discipline tactics, which have increased by almost 50 percent over the last 40 years, according to previous research.

"Our findings really put a spotlight on processes within schools," she said. "There's been a huge movement toward decreasing the use of out-of-school suspensions in particular urban districts. Tutoring, counseling and trust-building initiatives between teachers and students of all races -- all of those things are likely to help close the racial gap."

Greenland's more than 860,000 square miles are largely covered with ice and glaciers, and its melting fuels as much as one-third of the sea level rise in Florida. That's why a team of University of South Florida geoscientists' new discovery of one of the mechanisms that allows Greenland's glaciers to collapse into the sea has special significance for the Sunshine State.

In research published in Nature Communications, a group of scientists led by USF Distinguished University Professor Tim Dixon, PhD, uncovered a process that can control the "calving" of glaciers - when large chunks of glacier ice collapse into the sea, forming icebergs like the one that sank the Titanic. The discovery by the team that included USF PhD student Surui Xie; David Holland, PhD, and Irena Vaková, PhD, at New York University (NYU) and NYU-Abu Dhabi Research Institute; and Denis Voytenko, PhD, formerly at NYU and now at Nielson Communications, will help the scientific community better model future Greenland ice loss and sea level rise.

Glacier calving is one of the more dramatic aspects of climate change. Depending on the height of the glacier, calving can be akin to an ice structure the size of a tall skyscraper falling into the sea. Dixon's team caught one such calving on video.

"Iceberg calving has been challenging to model," Dixon said. "One of the big unknowns in future sea level rise is how fast Greenland falls apart, and iceberg calving is one of the least understood mechanisms."

The team ventured to Greenland in the summer of 2016 to install a new radar system to better understand the process. In particular, they wanted to monitor formations known as pro-glacial "mélange" (from the French word for mixture), a combination of sea ice and icebergs in front of the glacier. The mélange can be tightly packed in the long, narrow fjords that front many of Greenland's glaciers that meet the sea.

Scientists have long known that mélange can impede glaciers as they move toward the sea, but they haven't had the data to fully understand the phenomenon.

Dixon's team developed a new radar-based approach to precisely measure elevations of the mélange in front of Jakobshavn Glacier , a major outlet glacier on Greenland's west side. Using analytical techniques developed by Xie, the scientists measured the height of the mélange. The scientists found a thick mélange wedge pressed up against the glacier in late spring and early summer.

During this period, no icebergs calved, the scientists observed. Once the wedge thinned and melted by mid-summer, calving began in earnest.

"On the surface, this mélange is a subtle thing - it appears almost flat- but underwater, there are huge variations," Dixon said. "It's really the underwater part that is pinning the glacier back and preventing it from calving. By precisely measuring the surface elevations, we were able to get a handle on the much bigger sub-surface variations, which define mélange thickness."

Earlier this spring, NASA scientists reported Jakobshavn Glacier, which has been Greenland's fastest -thinning glacier for the last 20 years, was slowing in its movement toward the ocean in what appears to be a cyclical pattern of warming and cooling. But because Jakobshavn is still giving up more ice than it accumulates each year, its sheer size makes it an important factor in sea level rise, the NASA scientists maintain.

"Our study helps understand the calving process," Dixon said. "We are the first to discover that mélange isn't just some random pile of icebergs in front of the glacier. A mélange wedge can occasionally 'hold the door' and keep the glacier from calving."

A new study has found that offering children a wide variety and large quantities of snack food
encourages them to eat more - and this practice may be contributing to Australia's weight problem.

The research*, led by the Murdoch Children's Research Institute and published in the latest
International Journal of Obesity, also found that how snacks are presented (in a large or small
container) has little influence on how much children snack.

Lead researcher Dr Jessica Kerr said their study found children weren't greatly affected by container
size, with food consumption mainly driven by the quantity/variety of snacks on offer.

"There has been a popular push by nutritionists and public health officials towards replacing large
dishware with smaller versions to nudge people towards healthier decisions," she said. "But we have
found dishware size has very little effect on the amount of food consumed."

Dr Kerr said while the overconsumption of snack foods is an important contributor to obesity, most people
do not recognise the impact it has on their calorie intake.

"Children and adults should only consume energy-dense snacks occasionally - they do not need to be
part of daily energy intake," she said. "But the reality is that Australians typically get around 30-40 per
cent of their energy intake from snack foods."

Dr Kerr said three times as many children in Australia are now overweight or obese compared to 30 years
ago.

"About 20 per cent (1 in 5) of children are overweight or obese," she said. "There are many complications
of children being overweight such as type 2 diabetes, orthopaedic and respiratory disorders, liver
problems and sleep apnoea."

Dr Kerr said until now studies into snacking behavior were limited by self-reported data or small sample
sizes.

"Past dietary studies have mostly focused on main meals," Dr Kerr said. "It is important to determine on
a larger scale how dishware size and the quantity, variety, and energy density of snacks affect both child
and adult snacking behavior when apart from each other outside of the family environment," she said.

For the study, participants ate during a 15-minute snack break between 20 other health assessments at
the Child Health CheckPoint, which looked at the health of 1800 children, aged 11-12 years, and their
parents across a variety of factors from physical activity to sleep.

The children and parents were given a snack box containing non-perishable items such as crackers,
cheese, a muesli bar, biscuits, a tub of peaches and chocolate.

The quantity/number and variety of snack food items and the container sizes that the food was presented
in varied. Children and parents ate separately and at different times.

Researchers recorded how much food each child and parent left in the box uneaten, and calculated the
total grams and kilojoules consumed.

"Children who were offered more snack items consumed considerably more energy and a slightly higher
food mass. Manipulating box/container size had little effect on consumption," she said.

The impact on adults was little, however Dr Kerr said adults were more aware that they were being
observed and this may have impacted their eating behaviour.

Dr Kerr said further research should be done with parents and community leaders to better understand
the use and purpose of snack food items in the face of time pressures, marketing, and child preferences.

"Although there is sometimes a place for snack items to bridge the gap between main meals, our results
reinforce calls to educate parents and schools about appropriate snack items and amounts of food to
offer children," she said.

"Our research indicates that more attention and resources should be directed to toward offering children
smaller amounts of food and, specifically, fewer and less variety of energy-dense foods and pre-packaged
items. Interventions should not solely invest in reducing dishware size in the expectation that this will lead
to reduced intake of snack foods."

A significant jump in preterm births to Latina mothers living in the U.S. occurred in the nine months following the November 8, 2016 election of President Donald Trump, according to a study led by a researcher at the Johns Hopkins Bloomberg School of Public Health.

The study, published July 19 in JAMA Network Open, was prompted by smaller studies that had suggested adverse, stress-related health effects among Latin Americans in the U.S. after the Trump election. The new analysis, based on U.S. government data on more than 33 million live births in the country, found an excess of 2,337 preterm births to U.S. Latinas compared to what would have been expected given trends in preterm birth in the years prior to the election. This is roughly 3.5 percent more preterm births than expected given projections from pre-election data.

Preterm birth, defined as birth before 37 weeks of gestation, is associated with a wide range of negative health consequences, from a greater risk of death in infancy to developmental problems later in life.

"The 2016 election, following campaign promises of mass deportation and the rollback of policies such as DACA, the Deferred Action for Childhood Arrivals program, may have adversely affected the health of Latinas and their newborns," says study first author Alison Gemmill, PhD, MPH, assistant professor in the Department of Population, Family and Reproductive Health at the Bloomberg School.

Researchers know that stress in pregnant women can bring an elevated risk of preterm birth. Prior studies also suggest that anti-immigrant policies or actions can stress immigrant women and/or make them less likely to seek prenatal care. Moreover, although most Latinas living in the U.S. are citizens or otherwise documented immigrants and would not be directly threatened by tighter policies for undocumented immigrants, they are very likely to have close friends or family members who would be threatened by such policies.

The new study was prompted by a smaller study in 2018 by other researchers, who found a moderately elevated rate of preterm births to foreign-born Latina women in New York City from September 1, 2015 to July 31, 2016 compared to January 1, 2017 to August 31, 2017. Gemmill and her colleagues decided to investigate this issue on a national level, using more rigorous methodology that would account, for example, for the slow rise in the national preterm rate that has been observed since 2014.

In their analysis, Gemmill and colleagues used a database from the Centers for Disease Control and Prevention that covers essentially all live births in the U.S. First, the researchers tracked preterm births to self-identified Latina women over the previous adminstration, January 2009 to October 2016. They then used those data to generate an estimate of expected preterm births during the following nine months, from November 2016 to July 2017. Next, the authors compared those expected numbers to the actual numbers of preterm births to Latina women during the nine months after the election. The researchers found there were 1,342 preterm births of male infants above the expected number of 36,828, and 995 preterm births of female infants above the expected 30,687.

The analysis also revealed peaks in excess preterm births in February and July of 2017 for both male and female infants, which hints that infants conceived or in the second trimester of gestation at the time of the election may have been particularly vulnerable to maternal stress.

"We've known that government policies, even when they're not health policies per se, can affect people's health, but it's remarkable that an election and the associated shift in presidential tone appears to have done so," says Gemmill.

Gemmill and her colleagues suggest that future research should be done to determine more precisely the mechanisms by which policies and government messages can negatively affect population health outcomes.

"Association of Preterm Births Among U.. Latina Women With the 2016 Presidential Election" was written by Alison Gemmill, Ralph Catalano, Joan Casey, Deborah Karasek, Héctor Alcalá, Holly Elser and Jacqueline M. Torres.

Argonne develops novel method to more clearly see complex materials physics in difficult-to-access environments.

With the right tools, scientists can have Superman-like X-ray vision that reveals hidden features buried within objects — but it’s highly complicated.

The Advanced Photon Source (APS), an Office of Science User Facility at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, gives scientists access to highly penetrating X-rays that can illuminate — at the atomic level — materials contained deep within other structures.

The next phase for the APS, the APS Upgrade, transforms today’s APS into a world-leading, storage-ring based, high-energy X-ray light source that equips scientists with a vastly more powerful tool for investigating and improving the materials and chemical processes that impact nearly every aspect of our lives. In particular, the Upgrade enables the use of lensless imaging methods with high-energy X-rays to overcome optics limitations for obtaining the highest spatial resolution deep within opaque samples.

“It’s similar to trying to determine the shape and size of a stone thrown into a pond by looking at the ripples the stone creates, except in three dimensions. If your pixel size is small enough … you can [actually] … obtain a three-dimensional picture of the object causing the scattering.” — Siddharth Maddali, Argonne postdoctoral researcher

However, using high-energy X-rays for deep penetration comes with a potential hitch — deeply penetrating X-rays can run into limitations with current detector technology.

“Essentially, the signal on the detector gets more and more compressed as we go to higher and higher X-ray energies,” said Argonne postdoctoral researcher Siddharth Maddali. “The price we pay for more penetrating X-rays is a loss of fidelity in the recorded data.”

In a new study, researchers at Argonne have found a novel way to overcome these limitations.

These limitations, according to Argonne X-ray physicist Stefan Vogt, are like using a low-resolution computer monitor to view a high-resolution digital photograph. “You cannot see the fidelity of the original image,” he said. 

The overall effect makes the image appear to be pixelated, said Maddali, an author of the study.

Because the distance from target to detector is relatively fixed, improving the resolution of a pixelated X-ray scattering image — in essence, sharpening it — requires computational algorithms that create subdivided “virtual pixels” that can redistribute the pixelated image. Then researchers can use a process called phase retrieval to reconstitute real-space information about the sample based on the scattered X-ray wavefronts.

“It’s similar to trying to determine the shape and size of a stone thrown into a pond by looking at the ripples the stone creates, except in three dimensions,” Maddali said. “If your pixel size is small enough so that you can see the ups and downs in the wave, you can computationally process those images and obtain a three-dimensional picture of the object causing the scattering.”

By using signal processing in this manner, scientists are able to effectively computationally correct an image  that would have otherwise required an experimentally impossible system of lenses to resolve.

Scientists could use this technique to gain better information about material interfaces, and thereby better understand and ultimately control the behavior of new materials.

Lower-income parents are less likely than their higher-income counterparts to involve their children in youth sports because of obstacles such as rising costs of these extracurricular activities, according to a new RAND Corporation study.

Researchers surveyed a pool of approximately 2,800 parents, public school administrators and community sports program leaders and found that financial costs and time commitments were barriers to sports participation for middle and high school youths.

Of those surveyed, 52% of parents from lower-income families reported that their children in grade 6-12 participated in sports, as compared to 66% of middle- and higher-income families. (Middle- and higher-income families had an annual household income of $50,000 or more.)

Though costs for sports activities has increased in the past five years, about 63% of public school administrators indicated that school funding for sports has either remained flat or is decreasing. As for why parents didn't involve their children in sports, about 35% of all families cited financial costs as a reason, while 42% of lower-income families reported the same.

"Most survey participants thought youth sports participation provided physical health, social and emotional and academic benefits," said Anamarie Whitaker, lead author of the report and a policy researcher at RAND, a nonprofit, nonpartisan research organization. "However, the increasing costs for such activities are often passed along to families, which has become more burdensome for those who are lower-income."

Researchers recommend that community-based organizations help reduce out-of-pocket costs for low-income families to increase their children's participation in sports. Providing equipment and transportation, while also minimizing parent time commitments, may have the greatest effect on increasing sports participation among youths from lower-income families, the study also noted.

Scientists have confirmed that viruses can kill marine algae called diatoms and that diatom die-offs near the ocean surface may provide nutrients and organic matter for recycling by other algae, according to a Rutgers-led study.

The study in the journal Nature Microbiology also revealed that environmental conditions can accelerate diatom mortality from viral infection, which is important for understanding how diatoms influence carbon cycling and respond to changes in the oceans, including warming waters from climate change. Diatoms, which are single-celled algae that generate about 20 percent of the Earth’s oxygen, help store carbon dioxide, a key greenhouse gas, in the oceans.

“To our knowledge, this is the first time different stages of infection have been diagnosed in natural diatom populations and suggests that diatom populations may be terminated by viruses,” said senior author Kim Thamatrakoln, associate research professor in the Department of Marine and Coastal Sciences at Rutgers University–New Brunswick. “Our study showed that when silicon levels in the ocean are low, diatoms can be more rapidly infected and killed by viruses and are then more likely to release their nutrients and other matter in the surface ocean instead of sinking.”

Since the Victorian era, diatoms have been known as the “glass houses of the sea” because of their beautiful cell walls made of silicon dioxide, or glass. Silicon is essential for diatom growth, but since glass is heavy, diatoms can sink to the deep ocean when they die. That makes all of their nutrients, carbon and organic matter unavailable for surface recycling by other algae that need sunlight only available in the upper ocean.

Diatoms are infected by the smallest viruses on Earth and were once believed to be immune because of their glass-based armor. Such viruses have long escaped detection by traditional methods and very little was known about how they affect diatoms. So, the scientists studied what drives and ends diatom blooms in the California Current, a Pacific Ocean current that flows southward along the coast. The scientists found distinct areas ranging from uninfected diatom populations to highly infected populations.

They also found that some populations had undergone a die-off and the level of silicon was the strongest predictor of viral infection. Diatoms take up dissolved silicon from the environment and turn it into glass for their cell walls. But most of the surface waters where diatoms live have low silicon levels, so these findings suggest viral infection may play an important role in controlling diatom populations globally.

The lead author is Chana F. Kranzler, a Simons Foundation post-doctoral fellow in Thamatrakoln’s lab. Co-authors include Rutgers undergraduate student William P. Biggs; Professor Kay D. Bidle in the Rutgers Department of Marine and Coastal Sciences; and scientists at Woods Hole Oceanographic Institution, the University of California and University of South Alabama.

Journal

Nature Microbiology

DOI

10.1038/s41564-019-0502-x