Breakthrough in understanding cosmic forces that shape Earth's heliosphere

A multi-institutional team of astrophysicists headquartered at Boston University, led by BU astrophysicist Merav Opher, has made a breakthrough discovery in our understanding of the cosmic forces that shape the protective bubble surrounding our solar system -- a bubble that shelters life on Earth and is known by space researchers as the heliosphere.

Astrophysicists believe the heliosphere protects the planets within our solar system from powerful radiation emanating from supernovas, the final explosions of dying stars throughout the universe. They believe the heliosphere extends far beyond our solar system, but despite the massive buffer against cosmic radiation that the heliosphere provides Earth's life-forms, no one really knows the shape of the heliosphere -- or, for that matter, the size of it.

"How is this relevant for society? The bubble that surrounds us, produced by the sun, offers protection from galactic cosmic rays, and the shape of it can affect how those rays get into the heliosphere," says James Drake, an astrophysicist at University of Maryland who collaborates with Opher. "There's lots of theories but, of course, the way that galactic cosmic rays can get in can be impacted by the structure of the heliosphere -- does it have wrinkles and folds and that sort of thing?"

Opher's team has constructed some of the most compelling computer simulations of the heliosphere, based on models built on observable data and theoretical astrophysics. At BU, in the Center for Space Physics, Opher, a College of Arts & Sciences professor of astronomy, leads a NASA DRIVE (Diversity, Realize, Integrate, Venture, Educate) Science Center that's supported by $1.3 million in NASA funding. That team, made up of experts Opher recruited from 11 other universities and research institutes, develops predictive models of the heliosphere in an effort the team calls SHIELD (Solar-wind with Hydrogen Ion Exchange and Large-scale Dynamics).

Since BU'S NASA DRIVE Science Center first received funding in 2019, Opher's SHIELD team has hunted for answers to several puzzling questions: What is the overall structure of the heliosphere? How do its ionized particles evolve and affect heliospheric processes? How does the heliosphere interact and influence the interstellar medium, the matter and radiation that exists between stars? And how do cosmic rays get filtered by, or transported through, the heliosphere?

"SHIELD combines theory, modeling, and observations to build comprehensive models," Opher says. "All these different components work together to help understand the puzzles of the heliosphere."

And now a paper published by Opher and collaborators in Astrophysical Journal reveals that neutral hydrogen particles streaming from outside our solar system most likely play a crucial role in the way our heliosphere takes shape.

In their latest study, Opher's team wanted to understand why heliospheric jets -- blooming columns of energy and matter that are similar to other types of cosmic jets found throughout the universe -- become unstable. "Why do stars and black holes -- and our own sun -- eject unstable jets?" Opher says. "We see these jets projecting as irregular columns, and [astrophysicists] have been wondering for years why these shapes present instabilities."

Similarly, SHIELD models predict that the heliosphere, traveling in tandem with our sun and encompassing our solar system, doesn't appear to be stable. Other models of the heliosphere developed by other astrophysicists tend to depict the heliosphere as having a comet-like shape, with a jet -- or a "tail" -- streaming behind in its wake. In contrast, Opher's model suggests the heliosphere is shaped more like a croissant or even a donut.

The reason for that? Neutral hydrogen particles, so-called because they have equal amounts of positive and negative charge that net no charge at all.

"They come streaming through the solar system," Opher says. Using a computational model like a recipe to test the effect of 'neutrals' on the shape of the heliosphere, she "took one ingredient out of the cake -- the neutrals -- and noticed that the jets coming from the sun, shaping the heliosphere, become super stable. When I put them back in, things start bending, the center axis starts wiggling, and that means that something inside the heliospheric jets is becoming very unstable."

Instability like that would theoretically cause disturbance in the solar winds and jets emanating from our sun, causing the heliosphere to split its shape -- into a croissant-like form. Although astrophysicists haven't yet developed ways to observe the actual shape of the heliosphere, Opher's model suggests the presence of neutrals slamming into our solar system would make it impossible for the heliosphere to flow uniformly like a shooting comet. And one thing is for sure -- neutrals are definitely pelting their way through space.

Drake, a coauthor on the new study, says Opher's model "offers the first clear explanation for why the shape of the heliosphere breaks up in the northern and southern areas, which could impact our understanding of how galactic cosmic rays come into Earth and the near-Earth environment." That could affect the threat that radiation poses to life on Earth and also for astronauts in space or future pioneers attempting to travel to Mars or other planets.

"The universe is not quiet," Opher says. "Our BU model doesn't try to cut out the chaos, which has allowed me to pinpoint the cause [of the heliosphere's instability]…. The neutral hydrogen particles."

Specifically, the presence of the neutrals colliding with the heliosphere triggers a phenomenon well known by physicists, called the Rayleigh-Taylor instability, which occurs when two materials of different densities collide, with the lighter material pushing against the heavier material. It's what happens when oil is suspended above water, and when heavier fluids or materials are suspended above lighter fluids. Gravity plays a role and gives rise to some wildly irregular shapes. In the case of the cosmic jets, the drag between the neutral hydrogen particles and charged ions creates a similar effect as gravity. The "fingers" seen in the famous Horsehead Nebula, for example, are caused by the Rayleigh-Taylor instability.

Read more at Science Daily

Beads of glass in meteorites help scientists piece together how solar system formed

Ever since scientists started looking at meteorites with microscopes, they've been puzzled -- and fascinated -- by what's inside. Most meteorites are made of tiny beads of glass that date back to the earliest days of the solar system, before the planets were even formed.

Scientists with the University of Chicago have published an analysis laying out how these beads, which are found in many meteorites, came to be -- and what they can tell us about what happened in the early solar system.

"These are big questions," said UChicago alum Nicole Xike Nie, PhD'19, a postdoctoral fellow at the Carnegie Institution for Science and first author of the study. "Meteorites are snapshots that can reveal the conditions this early dust experienced -- which has implications for the evolution of both Earth and other planets."

'This question goes back 50 years'

The beads of glass inside these meteorites are called chondrules. Scientists think they are bits of rock left over from the debris that was floating around billions of years ago, which eventually coalesced into the planets we now know and love. These are immensely useful to scientists, who can get their hands on pieces of the original stuff that comprised the solar system -- before the constant churn of volcanoes and tectonic plates of Earth changed all the rock we can find on the planet itself.

But what exactly caused the formation of these chondrules remains unclear.

"We have the same theories we had 50 years ago," said study co-author and UChicago postdoctoral researcher Timo Hopp. "Even though there have been advances in many other areas, this one has been stubborn."

Scientists can find clues about the early days of the solar system by looking at the types of a given element in a rock. Elements can come in several different forms, called isotopes, and the proportion in each rock varies according to what happened when that rock was born -- how hot it was, whether it cooled slowly or was flash-frozen, what other elements were around to interact with it. From there, scientists can piece together a history of likely events.

To try and understand what had happened to the chondrules, Nie, Hopp and other scientists at the Dauphas Origins Lab at UChicago tried applying a unique angle to the isotopes.

First, Nie took extremely rigorous, precise measurements of the concentrations and isotopes of two elements that are depleted in meteorites, potassium and rubidium, which helped narrow down the possibilities of what could have happened in the early solar system.

From this information, the team pieced together what must have been happening as the chondrules formed. The elements would have been part of a clump of dust that got hot enough to melt, and then to vaporize. Then, as the material cooled, some of that vapor coalesced back into chondrules.

"We can also tell you how fast it cooled, because it was fast enough that not everything condensed," said Nicolas Dauphas, Professor of Geophysical Sciences at UChicago. "That must mean the temperature was dropping at a rate of around 500 degrees Celsius per hour, which is really fast."

Based on these constraints, scientists can theorize what kind of event would have been sudden and violent enough to cause this extreme heating and cooling. One scenario that fits would be massive shockwaves passing through the early nebula. "Large planetary bodies nearby can create shocks, which would have heated and then cooled the dust as it passed through," Dauphas said.

Over the past half-century, people have proposed different scenarios to explain the formation of the chondrules -- lightning, or collisions between rocks -- but this new evidence tips the balance toward shockwaves as an explanation.

This explanation may be the key to understanding a persistent finding that has bedeviled scientists for decades, involving a category of elements that are "moderately volatile," including potassium and rubidium. The Earth has less of these elements than scientists would expect, based on their general understanding of how the solar system formed. They knew the explanation could be traced to some complex chain of heating and cooling, but no one know the exact sequence. "It's a huge question in the field of cosmochemistry." said Dauphas.

Now, finally, the team is happy to have put a significant dent in the mystery.

"We know other processes happened -- this is just one part of the story -- but this really solves one step in the formation of planets," said Hopp.

Nie agreed: "It's really cool to be able to say quantitatively, this is what happened."

Read more at Science Daily

Immune system-stimulating nanoparticle could lead to more powerful vaccines

A common strategy to make vaccines more powerful is to deliver them along with an adjuvant -- a compound that stimulates the immune system to produce a stronger response.

Researchers from MIT, the La Jolla Institute for Immunology, and other institutions have now designed a new nanoparticle adjuvant that may be more potent than others now in use. Studies in mice showed that it significantly improved antibody production following vaccination against HIV, diphtheria, and influenza.

"We started looking at this particular formulation and found that it was incredibly potent, better than almost anything else we had tried," says Darrell Irvine, the Underwood-Prescott Professor with appointments in MIT's departments of Biological Engineering and Materials Science and Engineering; an associate director of MIT's Koch Institute for Integrative Cancer Research; and a member of the Ragon Institute of MGH, MIT, and Harvard.

The researchers now hope to incorporate the adjuvant into an HIV vaccine that is currently being tested in clinical trials, in hopes of improving its performance.

Irvine and Shane Crotty, a professor at the Center for Infectious Disease and Vaccine Research at the La Jolla Institute for Immunology, are the senior authors of the study, which appears today in Science Immunology. The lead authors of the paper are Murillo Silva, a former MIT postdoc, and Yu Kato, a staff scientist at the La Jolla Institute.

More powerful vaccines

Although the idea of using adjuvants to boost vaccine effectiveness has been around for decades, there are only a handful of FDA-approved vaccine adjuvants. One is aluminum hydroxide, an aluminum salt that induces inflammation, and another is an oil and water emulsion that is used in flu vaccines. A few years ago, the FDA approved an adjuvant based on saponin, a compound derived from the bark of the Chilean soapbark tree.

Saponin formulated in liposomes is now used as an adjuvant in the shingles vaccine, and saponins are also being used in a cage-like nanoparticle called an immunostimulatory complex (ISCOM) in a Covid-19 vaccine that is currently in clinical trials.

Researchers have shown that saponins promote inflammatory immune responses and stimulate antibody production, but how they do that is unclear. In the new study, the MIT and La Jolla team wanted to figure out how the adjuvant exerts its effects, and to see if they could make it more potent.

They designed a new type of adjuvant that is similar to the ISCOM adjuvant but also incorporates a molecule called MPLA, which is a toll-like receptor agonist. When these molecules bind to toll-like receptors on immune cells, they promote inflammation. The researchers call their new adjuvant SMNP (saponin/MPLA nanoparticles).

"We expected that this could be interesting because saponin and toll-like receptor agonists are both adjuvants that have been studied separately and shown to be very effective," Irvine says.

The researchers tested the adjuvant by injecting it into mice along with a few different antigens, or fragments of viral proteins. These included two HIV antigens, as well as diphtheria and influenza antigens. They compared the adjuvant to several other approved adjuvants and found that the new saponin-based nanoparticle elicited a stronger antibody response than any of the others.

One of the HIV antigens that they used is an HIV envelope protein nanoparticle, which presents many copies of the gp120 antigen that is present on the HIV viral surface. This antigen recently completed initial testing in phase 1 clinical trials. Irvine and Crotty are part of the Consortium for HIV/AIDS Vaccine Development at the Scripps Research Institute, which ran that trial. The researchers now hope to develop a way to manufacture the new adjuvant at large scale so it can be tested along with an HIV envelope trimer in another clinical trial beginning next year. Clinical trials that combine envelope trimers with the traditional vaccine adjuvant aluminum hydroxide are also underway.

"Aluminum hydroxide is safe but not particularly potent, so we hope that (the new adjuvant) would be an interesting alternative to elicit neutralizing antibody responses in people," Irvine says.

Rapid flow

When vaccines are injected into the arm, they travel through lymph vessels to the lymph nodes, where they encounter and activate B cells. The research team found that the new adjuvant speeds up the flow of lymph to the nodes, helping the antigen to get there before it starts to break down. It does this in part by stimulating immune cells called mast cells, which previously were not known to be involved in vaccine responses.

"Getting to the lymph nodes quickly is useful because once you inject the antigen, it starts slowly breaking down. The sooner a B cell can see that antigen, the more likely it's fully intact, so that B cells are targeting the structure as it will be present on the native virus," Irvine says.

Additionally, once the vaccine reaches the lymph nodes, the adjuvant causes a layer of cells called macrophages, which act as a barrier, to die off quickly, making it easier for the antigen to get into the nodes.

Another way that the adjuvant helps boost immune responses is by activating inflammatory cytokines that drive a stronger response. The TLR agonist that the researchers included in the adjuvant is believed to amplify that cytokine response, but the exact mechanism for that is not known yet.

This kind of adjuvant could also be useful for any other kind of subunit vaccine, which consists of fragments of viral proteins or other molecules. In addition to their work on HIV vaccines, the researchers are also working on a potential Covid-19 vaccine, along with J. Christopher Love's lab at the Koch Institute. The new adjuvant also appears to help stimulate T cell activity, which could make it useful as a component of cancer vaccines, which aim to stimulate the body's own T cells to attack tumors.

Read more at Science Daily

Daytime meals may reduce health risks linked to night shift work

A small clinical trial supported by the National Institutes of Health has found that eating during the nighttime -- like many shift workers do -- can increase glucose levels, while eating only during the daytime might prevent the higher glucose levels now linked with a nocturnal work life. The findings, the study authors said, could lead to novel behavioral interventions aimed at improving the health of shift workers -- grocery stockers, hotel workers, truck drivers, first responders, and others -- who past studies show may be at an increased risk for diabetes, heart disease, and obesity.

The new study, which the researchers noted is the first to demonstrate the beneficial effect of this type of meal timing intervention in humans, appears online in the journal Science Advances. It was funded primarily by the National Heart, Lung, and Blood Institute (NHLBI), part of NIH.

"This is a rigorous and highly controlled laboratory study that demonstrates a potential intervention for the adverse metabolic effects associated with shift work, which is a known public health concern," said Marishka Brown, Ph.D., director of the NHLBI's National Center on Sleep Disorders Research. "We look forward to additional studies that confirm the results and begin to untangle the biological underpinnings of these findings."

For the study, the researchers enrolled 19 healthy young participants (seven women and 12 men). After a preconditioning routine, the participants were randomly assigned to a 14-day controlled laboratory protocol involving simulated night work conditions with one of two meal schedules. One group ate during the nighttime to mimic a meal schedule typical among night workers, and one group ate during the daytime.

The researchers then evaluated the effects of these meal schedules on their internal circadian rhythms. That's the internal process that regulates not just the sleep-wake cycle, but also the 24-hour cycle of virtually all aspects of your bodily functions, including metabolism.

The researchers found that nighttime eating boosted glucose levels -- a risk factor for diabetes -- while restricting meals to the daytime prevented this effect. Specifically, average glucose levels for those who ate at night increased by 6.4% during the simulated night work, while those who ate during the daytime showed no significant increases.

"This is the first study in humans to demonstrate the use of meal timing as a countermeasure against the combined negative effects of impaired glucose tolerance and disrupted alignment of circadian rhythms resulting from simulated night work," said study leader Frank A.J.L. Scheer, Ph.D., professor of medicine at Harvard Medical School and director of the Medical Chronobiology Program at Brigham & Women's Hospital in Boston.

The researchers said that the mechanisms behind the observed effects are complex. They believe that the nighttime eating effects on glucose levels during simulated night work are caused by circadian misalignment. That corresponds to the mistiming between the central circadian "clock" (located in the brain's hypothalamus) and behavioral sleep/wake, light/dark, and fasting/eating cycles, which can influence peripheral "clocks" throughout the body. The current study shows that, in particular, mistiming of the central circadian clock with the fasting/eating cycles plays a key role in boosting glucose levels. The work further suggests the beneficial effects of daytime eating on glucose levels during simulated night work may be driven by better alignment between these central and peripheral "clocks."

Read more at Science Daily

Stellar cocoon with organic molecules at the edge of our galaxy

For the first time, astronomers have detected a newborn star and the surrounding cocoon of complex organic molecules at the edge of our Galaxy, which is known as the extreme outer Galaxy. The discovery, which revealed the hidden chemical complexity of our Universe, appears in a paper in The Astrophysical Journal.

The scientists from Niigata University (Japan), Academia Sinica Institute of Astronomy and Astrophysics (Taiwan), and the National Astronomical Observatory of Japan, used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe a newborn star (protostar) in the WB89-789 region, located in the extreme outer Galaxy. A variety of carbon-, oxygen-, nitrogen-, sulfur-, and silicon-bearing molecules, including complex organic molecules containing up to nine atoms, were detected. Such a protostar, as well as the associated cocoon of chemically-rich molecular gas, were for the first time detected at the edge of our Galaxy.

The ALMA observations reveal that various kinds of complex organic molecules, such as methanol (CH3OH), ethanol (C2H5OH), methyl formate (HCOOCH3), dimethyl ether (CH3OCH3), formamide (NH2CHO), propanenitrile (C2H5CN), etc., are present even in the primordial environment of the extreme outer Galaxy. Such complex organic molecules potentially act as the feedstock for larger prebiotic molecules.

Interestingly, the relative abundances of complex organic molecules in this newly discovered object resemble remarkably well what is found in similar objects in the inner Galaxy. The observations suggest that complex organic molecules are formed with similar efficiency even at the edge of our Galaxy, where the environment is very different from the solar neighborhood.

It is believed that the outer part of our Galaxy still harbors a primordial environment that existed in the early epoch of galaxy formation. The environmental characteristics of the extreme outer Galaxy, e.g., low abundance of heavy elements, small or no perturbation from Galactic spiral arms, are very different from those seen in the present-day solar neighborhood. Because of its unique characteristics, the extreme outer Galaxy is an excellent laboratory to study star formation and the interstellar medium in the past Galactic environment.

"With ALMA we were able to see a forming star and the surrounding molecular cocoon at the edge of our Galaxy," says Takashi Shimonishi, an astronomer at Niigata University, Japan, and the paper's lead author. "To our surprise, a variety of abundant complex organic molecules exists in the primordial environment of the extreme outer Galaxy. The interstellar conditions to form the chemical complexity might have persisted since the early history of the Universe," Shimonishi adds.

"These observations have revealed that complex organic molecules can be efficiently formed even in low-metallicity environments like the outermost regions of our Galaxy. This finding provides an important piece of the puzzle to understand how complex organic molecules are formed in the Universe," says Kenji Furuya, an astronomer at the National Astronomical Observatory of Japan, and the paper's co-author.

Read more at Science Daily

Combined heat and power as a platform for clean energy systems

The state of Georgia could dramatically reduce its greenhouse gas emissions, while creating new jobs and a healthier public, if more of its energy-intensive industries and commercial buildings were to utilize combined heat and power (CHP), according to the latest research from Georgia Tech's School of Public Policy.

The paper, digitally available now and in print on December 15 in the journal Applied Energy, finds that CHP -- or cogeneration -- could measurably reduce Georgia's carbon footprint while creating green jobs. Georgia ranks 8th among all 50 states for total net electricity generation and 11th for total carbon dioxide emissions, according to data from the U.S. Energy Information Administration.

"There is an enormous opportunity for CHP to save industries money and make them more competitive, while at the same time reducing air pollution, creating jobs and enhancing public health," said principal investigator Marilyn Brown, Regents and Brook Byers professor of Sustainable Systems at Georgia Tech's School of Public Policy.

Benefiting the Environment, Economy, and Public Health

The research finds that if Georgia added CHP systems to the 9,374 sites that are suitable for cogeneration, it could reduce carbon emissions in Georgia by 13%. Bringing CHP to just 34 of Georgia's industrial plants, each with 25 megawatts of electricity capacity, could reduce greenhouse gas emissions by 2%. The study authors, using modeling tools they developed, note that this "achievable" level of CHP adoption could add 2,000 jobs to the state; full deployment could support 13,000 new jobs.

According to Brown, CHP systems can be 85 to 90% efficient, compared with 45 to 60% efficiency of traditional heat and power systems. CHP has advantages over renewable electricity from solar and wind, which only offers intermittent power.

CHP technologies co-produce electricity useful for heat and cooling, resulting in ultra-high system efficiencies, cleaner air, and more affordable energy. Georgia industries that would profit from CHP include chemical, textile, pulp and paper, and food production. Large commercial buildings, campuses, and military bases also could benefit from CHP. By utilizing both electricity and heat from a single source onsite, the energy system if more reliable, resilient, and efficient.

CHP can meet the same needs at higher efficiency using less overall energy, while reducing peak demand on a region's utility-operated power grid, Brown explained. In addition, if there is an outage or disruption in a community's power grid, companies with their own onsite electricity sources can continue to have power.

Calculating CHP Costs and Benefits per Plant

The research used a database of every Georgia industrial site to determine which facilitates operated or could operate a CHP system. They then identified the appropriate type of CHP system for plants without one. To help assess if a CHP system was a financially sound investment, they developed a model to estimate the benefits and costs of each CHP system, factoring in the cost to install the equipment, operations and maintenance, fuel expenses, and financing. The result was an estimated "net present value" of each system that reflected the present value of future costs and benefits, Brown explained.

The paper also used data analytics to predict economic and health benefits of CHP for Georgians. Plants converting to cogeneration could boost the state's clean energy workforce by 2,000 to 13,000 depending on how widely it's adopted, Brown said. Currently, the state has about 2,600 jobs in electric vehicle manufacturing and less than 5,000 in the solar industry, according to the 11th Annual National Solar Jobs Census 2020.

In addition to job growth, CHP adoption could lead to dramatic health benefits for the state's more vulnerable residents, Brown emphasized. "We're displacing more polluting electricity when companies generate their own from waste heat," she noted.

The study estimates nearly $150 million in reduced health costs and ecological damages in 2030 in the "achievable" scenario for CHP, with nearly $1 billion in health and ecological benefits if every Georgia plant identified in the study adopted CHP.

"The public health improvements are gigantic -- that's a lot of lives saved, as well as childhood asthma and heart problems avoided," Brown said.

Georgia Tech's research was sponsored by Drawdown Georgia, a statewide initiative focused on scaling market-ready, high-impact climate solutions in Georgia this decade. The organization has identified a roadmap of 20 solutions, including electricity solutions such as CHP.

The impact of CHP could be dramatic considering that electricity generation accounts for nearly 37% of Georgia's energy-related carbon dioxide emissions, according to findings Brown and other researchers published earlier this year in the journal, Environmental Management.

Identifying Ideal CHP Sites

Georgia Tech researchers identified numerous different industrial sites in Georgia that could use combined heat and power. Ideal locations include established universities or military bases, and large industrial sites such as paper making, chemical sites, and food processing facilities. Georgia's number-one industry is agriculture, with chemicals and wood products among the state's top manufacturers.

"I find Georgia's potential to take advantage of existing industrial and commercial facilities to build CHP plants very interesting," said study co-author Valentina Sanmiguel, a 2020 master's graduate of the School of Public Policy in sustainable energy and environmental management. "I hope both industries and policymakers in Georgia realize the benefits that cogeneration has on the environment, the economy and society and take action to implement CHP in the state at a greater scale."

Dissecting Hurdles to Adoption

Despite the advantages of CHP, there remains hurdles to its adoption -- for one, establishing these facilities is capital-intensive, ranging from tens of millions for a campus CHP plant to hundreds of millions for a large plant at an industrial site. Once built, these facilities require their own workforce to operate, explained Brown.

"The cost-competitiveness of CHP systems depends significantly on two factors -- whether they are customer or utility-owned, and the type of rate tariff they operate under," said Brown.

In the paper, Georgia Tech cited three ways to improve the business case for CHP: clean energy portfolio standards, regulatory reform, and financial incentives such as tax credits.

Those approaches have worked well in North Carolina, noted Isaac Panzarella, director of the Department of Energy Southeast CHP Technical Assistance Partnership, and the assistant director for Technical Services for the North Carolina's Clean Energy Technology Center at North Carolina State University. North Carolina State University, where Panzarella is based, recently installed its second CHP facility on campus.

North Carolina, he added, has a policy that supports the use of renewable energy. Along with solar and wind, North Carolina embraced converting waste from swine and poultry-feeding operations into renewable energy.

"It's taken a long time, but finally there are more and more of these digester or biomass operations, using CHP to generate electricity and thermal energy from those waste resources," he said.

While Georgia Tech is not yet operating a CHP system, the Campus Sustainability Committee is currently examining options for lessening their energy footprint.

"Georgia Tech seeks to leverage Dr. Brown's important research, and the deep faculty expertise at Georgia Tech in climate solutions, as we advance the development of a campus-wide Carbon Neutrality Plan and Campus Master Plan in 2022," said Anne Rogers, associate director, Office of Campus Sustainability. "The Campus Master and Carbon Neutrality Plan will provide a roadmap to implementing sustainable infrastructure solutions to advance Georgia Tech's strategic goals."

Read more at Science Daily

Most dog breeds highly inbred

Dog breeds are often recognized for distinctive traits -- the short legs of a dachshund, wrinkled face of a pug, spotted coat of a Dalmatian. Unfortunately, the genetics that give various breeds their particular attributes are often the result of inbreeding.

In a recent study published in Canine Medicine and Genetics, an international team of researchers led by University of California, Davis, veterinary geneticist Danika Bannasch show that the majority of canine breeds are highly inbred, contributing to an increase in disease and health care costs throughout their lifespan.

"It's amazing how inbreeding seems to matter to health," Bannasch said. "While previous studies have shown that small dogs live longer than large dogs, no one had previously reported on morbidity, or the presence of disease. This study revealed that if dogs are of smaller size and not inbred, they are much healthier than larger dogs with high inbreeding."

Inbreeding affects health

The average inbreeding based on genetic analysis across 227 breeds was close to 25%, or the equivalent of sharing the same genetic material with a full sibling. These are levels considered well above what would be safe for either humans or wild animal populations. In humans, high levels of inbreeding (3-6%) have been associated with increased prevalence of complex diseases as well as other conditions.

"Data from other species, combined with strong breed predispositions to complex diseases like cancer and autoimmune diseases, highlight the relevance of high inbreeding in dogs to their health," said Bannasch, who also serves as the Maxine Adler Endowed Chair in Genetics at the UC Davis School of Veterinary Medicine.

The researchers partnered with Wisdom Health Genetics, a world leader in pet genetics, to obtain the largest sample size possible for analysis. Wisdom Health's database is the largest dog DNA database in the world, helping researchers collect data from 49,378 dogs across 227 breeds -- primarily from European sources.

Some breeds more inbred

So, what makes a dog breed more inbred than others? Bannasch explained that it's often a combination of a small founding population followed by strong selection for particular traits in a breed -- often based on looks rather than purpose. While she has always had an interest in the population structure of some of these breeds, she became particularly interested in the Danish-Swedish farmdog several years ago. She fell in love with their compact size, disposition and intelligence, and ended up importing one from Sweden.

Bannasch discovered that Danish-Swedish farmdogs have a low level of inbreeding based on their history of a relatively large founding population of 200, and being bred for function, rather than a strong artificial selection for looks. And according to the insurance health data on breeds collected from Agria Insurance Sweden and hosted online by the International Partnership for Dogs, the farmdog is one of the healthiest breeds.

The study also revealed a significant difference in morbidity between brachycephalic (short skull and snout) and non-brachycephalic breeds. While that finding wasn't unexpected, the researchers removed brachycephalic breeds from the final analysis on effects of inbreeding on health.

Preserving genetic diversity

In the end, Bannasch said she isn't sure there is a way out of inbred breeds. People have recognized that creating matches based solely on pedigrees is misleading. The inbreeding calculators don't go back far enough in a dog's genetic line, and that method doesn't improve overall high levels of population inbreeding.

There are other measures that can be taken to preserve the genetic diversity and health of a breed, she said. They include careful management of breeding populations to avoid additional loss of existing genetic diversity, through breeder education and monitoring of inbreeding levels enabled by direct genotyping technologies.

Outcrosses are being proposed or have already been carried out for some breeds and conditions as a measure to increase genetic diversity, but care must be taken to consider if these will effectively increase overall breed diversity and therefore reduce inbreeding, Bannasch said. In particular, in the few breeds with low inbreeding levels, every effort should be made to maintain the genetic diversity that is present.

Read more at Science Daily

Whether people inform themselves or remain ignorant is due to three factors

People choose whether to seek or avoid information about their health, finances and personal traits based on how they think it will make them feel, how useful it is, and if it relates to things they think about often, finds a new study by UCL researchers.

Most people fall into one of three 'information-seeking types': those that mostly consider the impact of information on their feelings when deciding whether to get informed, those that mostly consider how useful information will be for making decisions, and those that mostly seek information about issues they think about often, according to the findings published in Nature Communications.

Co-lead author Professor Tali Sharot (UCL Psychology & Language Sciences and Max Planck UCL Centre for Computational Psychiatry and Ageing Research) said: "Vast amounts of information are now available to individuals. This includes everything from information about your genetic make-up to information about social issues and the economy. We wanted to find out: how do people decide what they want to know? And why do some people actively seek out information, for example about COVID vaccines, financial inequality and climate change, and others don't?

"The information people decide to expose themselves to has important consequences for their health, finance and relationships. By better understanding why people choose to get informed, we could develop ways to convince people to educate themselves."

The researchers conducted five experiments with 543 research participants, to gauge what factors influence information-seeking.

In one of the experiments, participants were asked how much they would like to know about health information, such as whether they had an Alzheimer's risk gene or a gene conferring a strong immune system. In another experiment, they were asked whether they wanted to see financial information, such as exchange rates or what income percentile they fall into, and in another one, whether they would have liked to learn how their family and friends rated them on traits such as intelligence and laziness.

Later, participants were asked how useful they thought the information would be, how they expected it would make them feel, and how often they thought about each subject matter in question.

The researchers found that people choose to seek information based on these three factors: expected utility, emotional impact, and whether it was relevant to things they thought of often. This three-factor model best explained decisions to seek or avoid information compared to a range of other alternative models tested.

Some participants repeated the experiments a couple of times, months apart. The researchers found that most people prioritise one of the three motives (feelings, usefulness, frequency of thought) over the others, and their specific tendency remained relatively stable across time and domains, suggesting that what drives each person to seek information is 'trait-like'.

In two experiments, participants also filled out a questionnaire to gauge their general mental health. The researchers found that when people sought information about their own traits, participants who mostly wanted to know about traits they thought about often, reported better mental health.

Co-lead author, PhD student Christopher Kelly (UCL Psychology & Language Sciences and Max Planck UCL Centre for Computational Psychiatry and Ageing Research) said: "By understanding people's motivations to seek information, policy makers may be able to increase the likelihood that people will engage with and benefit from vital information. For example, if policy makers highlight the potential usefulness of their message and the positive feelings that it may elicit, they may improve the effectiveness of their message.

Read more at Science Daily

Lunar radar data uncovers new clues about moon’s ancient past

The dusty surface of the moon -- immortalized in images of Apollo astronauts' lunar footprints -- formed as the result of asteroid impacts and the harsh environment of space breaking down rock over millions of years. An ancient layer of this material, covered by periodic lava flows and now buried under the lunar surface, could provide new insight into the Moon's deep past, according to a team of scientists.

"Using careful data processing, we found interesting new evidence that this buried layer, called paleoregolith, may be much thicker than previously expected," said Tieyuan Zhu, assistant professor of geophysics at Penn State. "These layers have been undisturbed since their formation and could be important records for determining early asteroid impact and volcanic history of the moon."

The team, led by Zhu, conducted new analysis of radar data collected by China's Chang'e 3 mission in 2013, which performed the first direct ground radar measurements on the moon.

The researchers identified a thick layer of paleoregolith, roughly 16 to 30 feet, sandwiched between two layers of lava rock believed to be 2.3 and 3.6 billion years old. The findings suggest the paleoregolith formed much faster than previous estimates of 6.5 feet per billion years, the scientists said.

The moon has experienced volcanic activity throughout its history, depositing lava rock on the surface. Over time, the rock breaks down into dust and soil, called regolith, with repeated asteroid impacts and space weathering, only to be buried by subsequent lava flows, the scientists said.

"Lunar scientists count craters on the moon and use computer models to determine the rate that regolith is produced," Zhu said. "Our findings provide a constraint on what happened between two and three billion years ago. This is the very unique contribution of this work."

Previous studies have examined the dataset, created when the Yutu rover sent electromagnetic pulses into the lunar underground and listened as they echoed back. Zhu said his team developed a four-step data processing flow to enhance the signal and suppress noise in the data.

The scientists observed changes in polarity as the electromagnetic pulses traveled down through the dense lava rock and the paleoregolith, allowing the team to distinguish between the different layers.

"Our paper is really providing the first geophysical evidence to see this electromagnetic permittivity changed from a small value for the paleoregolith to a large value for the lava flows," Zhu said. "We discovered this polarity change in the data and created a detailed geophysical image of the subsurface up to a few hundred meters depth."

The results may indicate higher meteoric activity in the solar system during this period billions of years ago, according to the team, who recently reported their findings in the journal Geophysical Research Letters.

Zhu said the data processing tools may have use for interpreting similar data collected during future missions to the moon, Mars or elsewhere in the solar system. His team is now working with machine learning technology to further improve the findings.

Read more at Science Daily

Climate modeling confirms historical records showing rise in hurricane activity

When forecasting how storms may change in the future, it helps to know something about their past. Judging from historical records dating back to the 1850s, hurricanes in the North Atlantic have become more frequent over the last 150 years.

However, scientists have questioned whether this upward trend is a reflection of reality, or simply an artifact of lopsided record-keeping. If 19th-century storm trackers had access to 21st-century technology, would they have recorded more storms? This inherent uncertainty has kept scientists from relying on storm records, and the patterns within them, for clues to how climate influences storms.

A new MIT study published today in Nature Communications has used climate modeling, rather than storm records, to reconstruct the history of hurricanes and tropical cyclones around the world. The study finds that North Atlantic hurricanes have indeed increased in frequency over the last 150 years, similar to what historical records have shown.

In particular, major hurricanes, and hurricanes in general, are more frequent today than in the past. And those that make landfall appear have grown more powerful, carrying more destructive potential.

Curiously, while the North Atlantic has seen an overall increase in storm activity, the same trend was not observed in the rest of the world. The study found that the frequency of tropical cyclones globally has not changed significantly in the last 150 years.

"The evidence does point, as the original historical record did, to long-term increases in North Atlantic hurricane activity, but no significant changes in global hurricane activity," says study author Kerry Emanuel, the Cecil and Ida Green Professor of Atmospheric Science in MIT's Department of Earth, Atmospheric, and Planetary Sciences. "It certainly will change the interpretation of climate's effects on hurricanes -- that it's really the regionality of the climate, and that something happened to the North Atlantic that's different from the rest of the globe. It may have been caused by global warming, which is not necessarily globally uniform."

Chance encounters

The most comprehensive record of tropical cyclones is compiled in a database known as the International Best Track Archive for Climate Stewardship (IBTrACS). This historical record includes modern measurements from satellites and aircraft that date back to the 1940s. The database's older records are based on reports from ships and islands that happened to be in a storm's path. These earlier records date back to 1851, and overall the database shows an increase in North Atlantic storm activity over the last 150 years.

"Nobody disagrees that that's what the historical record shows," Emanuel says. "On the other hand, most sensible people don't really trust the historical record that far back in time."

Recently, scientists have used a statistical approach to identify storms that the historical record may have missed. To do so, they consulted all the digitally reconstructed shipping routes in the Atlantic over the last 150 years and mapped these routes over modern-day hurricane tracks. They then estimated the chance that a ship would encounter or entirely miss a hurricane's presence. This analysis found a significant number of early storms were likely missed in the historical record. Accounting for these missed storms, they concluded that there was a chance that storm activity had not changed over the last 150 years.

But Emanuel points out that hurricane paths in the 19th century may have looked different from today's tracks. What's more, the scientists may have missed key shipping routes in their analysis, as older routes have not yet been digitized.

"All we know is, if there had been a change (in storm activity), it would not have been detectable, using digitized ship records," Emanuel says "So I thought, there's an opportunity to do better, by not using historical data at all."

Seeding storms

Instead, he estimated past hurricane activity using dynamical downscaling -- a technique that his group developed and has applied over the last 15 years to study climate's effect on hurricanes. The technique starts with a coarse global climate simulation and embeds within this model a finer-resolution model that simulates features as small as hurricanes. The combined models are then fed with real-world measurements of atmospheric and ocean conditions. Emanuel then scatters the realistic simulation with hurricane "seeds" and runs the simulation forward in time to see which seeds bloom into full-blown storms.

For the new study, Emanuel embedded a hurricane model into a climate "reanalysis" -- a type of climate model that combines observations from the past with climate simulations to generate accurate reconstructions of past weather patterns and climate conditions. He used a particular subset of climate reanalyses that only accounts for observations collected from the surface -- for instance from ships, which have recorded weather conditions and sea surface temperatures consistently since the 1850s, as opposed to from satellites, which only began systematic monitoring in the 1970s.

"We chose to use this approach to avoid any artificial trends brought about by the introduction of progressively different observations," Emanuel explains.

He ran an embedded hurricane model on three different climate reanalyses, simulating tropical cyclones around the world over the past 150 years. Across all three models, he observed "unequivocal increases" in North Atlantic hurricane activity.

"There's been this quite large increase in activity in the Atlantic since the mid-19th century, which I didn't expect to see," Emanuel says.

Within this overall rise in storm activity, he also observed a "hurricane drought" -- a period during the 1970s and 80s when the number of yearly hurricanes momentarily dropped. This pause in storm activity can also be seen in historical records, and Emanuel's group proposes a cause: sulfate aerosols, which were byproducts of fossil fuel combustion, likely set off a cascade of climate effects that cooled the North Atlantic and temporarily suppressed hurricane formation.

Read more at Science Daily