Amazon Rainforest Foliage Gases Affect the Earth’s Atmosphere

PNNL Earth scientist Manish Shrivastava and his team identified an atmospheric process that creates a type of fine particle over the Amazon rainforest. Through the process, semi-volatile gases, which are natural carbon-based chemical compounds that can easily condense to form fine particles in the upper atmosphere, are emitted throughout the Amazon rainforest by previously unrecognized in-plant and surface chemistry processes.
Illustration by Nathan Johnson | Pacific Northwest National Laboratory

Plant-foliage-derived gases drive a previously unknown atmospheric phenomenon over the Amazon rainforest, according to a recent study by researchers at Pacific Northwest National Laboratory (PNNL).

The findings have important applications for atmospheric science and for climate change modeling.

“The tropical Amazon rainforest constitutes the lungs of the Earth, and this study connects natural processes in the forest to aerosols, clouds, and the Earth’s radiative balance in ways that have not been previously recognized,” said Manish Shrivastava, Earth scientist at PNNL and principal investigator of the study.

The findings were recently published in ACS Earth and Space Chemistry.

Filling the missing data gap

Shrivastava and his team were studying fine particles in the upper atmosphere when they discovered a large disparity between their measurements and what would have been expected based on current understanding in atmospheric models. Through further study, the team found that there was key forest–atmosphere interactions missing from current atmospheric models that govern the number of fine particles in the upper atmosphere.

Researchers unravel mummy bird mystery

Carol Anne Barsody scans the mummy bird for a 3D model that will be included in a multisensory exhibition she is planning to hold in October.
Credit: Ryan Young/Cornell University

Over the last several months, a certain bird – believed to be a sacred ibis – has been drawing a lot of attention, and covering a lot of ground, from the College of Arts and Sciences to the College of Veterinary Medicine, College of Engineering and, later, the Lab of Ornithology.

Not bad for an animal that has been dead and mummified for more than 1,500 years.

The so-called “mummy bird” has had help getting around. Carol Anne Barsody, a master’s student in archaeology, has been trying to learn everything she can about the artifact, which is part of the Anthropology Collections in the College of Arts and Sciences, by consulting an array of researchers from across the university.

“One of the things I love about this project is that it incorporates expertise from across Cornell, all working together on a common goal,” Barsody said. “Where else but Cornell can you speak with a curator of vertebrates about a skeleton, and then call the vet school and have it X-rayed? There are so many different resources that students can utilize. And interdisciplinary projects make for stronger research.”

What began as a passion project, and grew into an independent study and then a proposed master’s thesis, has become a cross-campus fascination that encompasses everything from ancient burial rituals to the lost history of donated artifacts, the totemic power of animals, the ways museums can better engage the public, and even Egyptian beer.

Vegetarian birds are more sociable than insect eaters

The lesser masked weaver builds its nests in large colonies and has several partners per breeding season.
Credit: Chao Zhao

Weaver birds that eat seeds flock together and nest in colonies more commonly than those species that eat insects, suggests new research by an international team of scientists led by the Milner Centre for Evolution at the University of Bath. For the first time, the study statistically supports an influential ecological hypothesis on social behavior first proposed 58 years ago.

Weaver birds are a family of 118 songbird species that live mostly in sub-Saharan Africa and are so-called because of the elaborate construction of their nests.

Whilst some species live on the savannah feeding on seeds, other species live in the forest and mostly dine on insects.

The researchers looked at data collected from previously published studies of many weaver species to investigate the relationships between diet, habitat and social behavior.

They observed that birds living in the open savannah tended to flock together, foraging in groups to help find the best sources of seeds. The same birds also nested in large colonies and often had a polygamous breeding behavior, pairing with multiple mates during each season.

In contrast, the species living in the forest tended to be solitary foragers and nesters that did not flock together or live in colonies. These birds tended to be monogamous breeders with a single mate per season.

New Polymer Membrane Tech Improves Efficiency of CO2 Capture

Image credit: Chris Robert.

Researchers have developed a new membrane technology that allows for more efficient removal of carbon dioxide (CO2) from mixed gases, such as emissions from power plants.

“To demonstrate the capability of our new membranes, we looked at mixtures of CO2 and nitrogen, because CO2/nitrogen dioxide mixtures are particularly relevant in the context of reducing greenhouse gas emissions from power plants,” says Rich Spontak, co-corresponding author of a paper on the work. “And we’ve demonstrated that we can vastly improve the selectivity of membranes to remove CO2 while retaining relatively high CO2 permeability.”

“We also looked at mixtures of CO2 and methane, which is important to the natural gas industry,” says Spontak, who is a Distinguished Professor of Chemical and Biomolecular Engineering and Professor of Materials Science & Engineering at North Carolina State University. “In addition, these CO2-filtering membranes can be used in any situation in which one needs to remove CO2 from mixed gases – whether it’s a biomedical application or scrubbing CO2 from the air in a submarine.”

Membranes are an attractive technology for removing CO2 from mixed gases because they do not take up much physical space, they can be made in a wide variety of sizes, and they can be easily replaced. The other technology that is often used for CO2 removal is chemical absorption, which involves bubbling mixed gases through a column that contains a liquid amine – which removes CO2 from the gas. However, absorption technologies have a significantly larger footprint, and liquid amines tend to be toxic and corrosive.

‘Flash Droughts’ Coming on Faster, Global Study Shows

A map of drought conditions across the United States in mid-July 2012, the peak of a flash drought that decimated crops in the Midwest.
Credit: Richard Heim/ NCEI/NOAA

Just like flash floods, flash droughts come on fast — drying out soil in a matter of days to weeks. These events can wipe out crops and cause huge economic losses. And according to scientists, the speed at which they dry out the landscape has increased.

Researchers at The University of Texas at Austin, The Hong Kong Polytechnic University and Texas Tech University found that although the number of flash droughts has remained stable during the past two decades, more of them are coming on faster. Globally, the flash droughts that come on the fastest — sending areas into drought conditions within just five days — have increased by about 3%-19%. And in places that are especially prone to flash droughts — such as South Asia, Southeast Asia and central North America — that increase is about 22%-59%.

Rising global temperatures are probably behind the faster onset, said co-author and UT Jackson School Professor Zong-Liang Yang, who added that the study’s results underscore the importance of understanding flash droughts and preparing for their effects.

“Every year, we are seeing record-breaking warming episodes, and that is a good precursor to these flash droughts,” he said. “The hope and purpose [of this research] is to minimize the detrimental effects.”

Does this artificial intelligence think like a human?

MIT researchers developed a method that helps a user understand a machine-learning model’s reasoning, and how that reasoning compares to that of a human.
Credits: Christine Daniloff, MIT

In machine learning, understanding why a model makes certain decisions is often just as important as whether those decisions are correct. For instance, a machine-learning model might correctly predict that a skin lesion is cancerous, but it could have done so using an unrelated blip on a clinical photo.

While tools exist to help experts make sense of a model’s reasoning, often these methods only provide insights on one decision at a time, and each must be manually evaluated. Models are commonly trained using millions of data inputs, making it almost impossible for a human to evaluate enough decisions to identify patterns.

Now, researchers at MIT and IBM Research have created a method that enables a user to aggregate, sort, and rank these individual explanations to rapidly analyze a machine-learning model’s behavior. Their technique, called Shared Interest, incorporates quantifiable metrics that compare how well a model’s reasoning matches that of a human.

Shared Interest could help a user easily uncover concerning trends in a model’s decision-making — for example, perhaps the model often becomes confused by distracting, irrelevant features, like background objects in photos. Aggregating these insights could help the user quickly and quantitatively determine whether a model is trustworthy and ready to be deployed in a real-world situation.

Carbon flow through inland and coastal waterways, implications for climate

A recent study by an international team of scientists including Raymond Najjar, professor of oceanography at Penn State, found that the flows of carbon through the complex network of water bodies that connect land and ocean has often been overlooked and that ignoring these flows overestimates the carbon storage in terrestrial ecosystems and underestimates sedimentary and oceanic carbon storage.
Credit: Pixabay

Terrestrial and marine ecosystems have a powerful influence on the Earth’s climate by regulating the level of atmospheric carbon dioxide. A recent study found that the flows of carbon through the complex network of water bodies that connect land and ocean has often been overlooked and that ignoring these flows overestimates the carbon storage in terrestrial ecosystems and underestimates sedimentary and oceanic carbon storage.

Carbon storage by the ocean and by land is usually quantified separately and does not fully consider the land-to-ocean transport of carbon through inland waters, estuaries, tidal wetlands and continental shelf waters — referred to as the land-to-ocean aquatic continuum or LOAC. In a detailed analysis of the LOAC, researchers from Belgium, the United States and France provide a perspective on the global carbon cycle and identify key knowledge gaps that have significant implications for enforcing the carbon calculations that are part of international climate accords. They reported their findings in the journal Nature.

“There are scientists who develop terrestrial models and scientists who develop marine models, and the continuum between them is poorly represented in global earth system models,” said Raymond Najjar, professor of oceanography at Penn State and co-author on the paper. “There are different communities of scientists studying land and ocean. Our assessment indicates that more attention needs to be paid to the LOAC, and that our models need to better represent it.”

Smart but stressful

Intelligent personal assistants accompany people worldwide every day.
Credit: RUB, Kramer

Intelligent personal assistants make everyday work easier. If you use them intensively and over a longer period of time, they can also create stress.

Siri, delete the light! Alexa, what does the weather forecast say? Nowadays, so-called intelligent personal assistants such as loudspeakers with speech recognition are hard to imagine in our everyday life. But do they only have a positive effect on us? What does the long-term human-assistant relationship look like?? Prof. also asked himself these questions. Dr. Sascha Alavi, chair holder at the Sales Management Department of RUB, and his research colleagues Prof. Dr. Valéry Bezençon and Ertuğrul Uysal from the University of Neuchâtel. In their joint study, published in the Journal of the Academy of Marketing Science, economists show that personal assistance systems can also have damaging effects on users in the long term.

“Previous studies have primarily and exclusively dealt with the advantages of intelligent assistance systems, highlighted their benefits for the world of work, for companies, especially from a commercial point of view. We were also interested in the potentially damaging consequences for consumers,” reports Alavi. To this end, he carried out surveys with his colleagues with more than 1,000 users of intelligent language assistants as well as qualitative in-depth interviews with eleven users.

“Tree of life” could help slow climate change

Mauritia palm fruit are vital to the local economy
Credit: Dael Sassoon

Changing the way fruit is gathered from a “tree of life” could have hugely positive environmental and financial impacts in Amazonia, according to a new study.

An international research team, jointly led by the University and the Peruvian Amazon Research Institute (Instituto de Investigaciones de la Amazonia; IIAP) has shown for the first time the widespread harm caused in Peru by cutting down the palm tree Mauritia flexuosa in order to harvest its fruit.

The scientists examined where and why the trees were felled, producing detailed maps and analysis to reveal the extent of the environmental and economic damage caused by cutting down the palms.

Study lead author Gabriel Hidalgo, who conducted the research as a postgraduate student at Leeds’ School of Geography while based at IIAP, said: “Cutting down female palm trees to harvest the fruit has halved the total production of fruit of this palm that is available to local communities.

“This is a clear example of the impact of humans on natural resource levels, in an ecosystem that, on first look, appears undamaged.

“However, changing the way the fruit is harvested can increase both the number of fruit-bearing palms trees, and the value of these Amazonian peatland ecosystems to people.”

Scientists discover genetic variants that speed up and slow down brain aging

Researchers from a USC-led consortium have discovered 15 “hot spots” in the genome that either speed up brain aging or slow it down — a finding that could provide new drug targets to resist developmental delays, Alzheimer’s disease and other degenerative brain disorders.

The research appeared online Tuesday in Nature Neuroscience.

“The big game-changer here is discovering locations on the chromosome that speed up or slow down brain aging in worldwide populations. These can quickly become new drug targets,” said Paul Thompson of USC, a lead author on the study and the co-founder and director of the ENIGMA Consortium. “Through our AI4AD [Artificial Intelligence for Alzheimer’s Disease] initiative we even have a genome-guided drug repurposing program to target these and find new and existing drugs that help us age better.”

ENIGMA is working group based at USC that is exploring a vast trove of brain data and has published some of the largest-ever neuroimaging studies of schizophrenia, major depression, bipolar disorder, epilepsy, Parkinson’s disease, and even HIV infection.

To discover the hot spots, or genomic loci, more than 200 ENIGMA-member scientists from all over the world looked for people whose brains were scanned twice with MRI. The scans provided a measure of how fast their brains were gaining or losing tissue in regions that control memory, emotion and analytical thinking.