Anyone who takes a walk through a coniferous forest and enjoys the tangy, refreshing air is inhaling α-pinene. This is one of the volatile organic compounds in the oils of conifer trees, and it also occurs in eucalyptus and rosemary. The smell triggers pleasant feelings in most people. Less pleasant is that the compound changes in the atmosphere, under the influence of radicals, into other compounds, so-called highly oxidised organic molecules. Some of these are reactive, to some extent harmful substances. They have only recently come under scrutiny by atmospheric researchers, and their role, for example in cloud formation, is not yet understood.

These highly oxidized organic molecules are less volatile than the starting substance α-pinene and therefore condense easily. Together with dust particles and other solid and liquid substances in the air, they form what we call particulate matter or aerosols.

“Up to now it was thought that such molecules are protected from further transformations once they have landed in particulate matter,” says Andre Prévôt of the Laboratory of Atmospheric Chemistry at PSI. “It was believed that they then would not change any more, but would simply spread out over the atmosphere and eventually rain down.”

This widespread opinion does not correspond to reality, however, as Prévôt and his fellow researchers at PSI showed: “The reactions continue, even in the particulate matter.” The molecules remain reactive and either react with each other to form larger particles or disassociate, thereby releasing for example formic acid. This common compound is found not only in ants and stinging nettles, but also in the atmosphere, where it is an important indicator of air pollution.

The PSI researchers’ observations should help to improve simulation models, such as those for cloud formation and air pollution. The models simulate what happens in the atmosphere to predict, for example, how a reduction in certain emissions will affect air quality.

From the aerosol into the measuring device

For the first time, PSI researchers analysed chemical compounds directly in particulate matter under atmospheric conditions. For this they used the PSI smog chamber, in which processes in the atmosphere can be simulated. The researchers injected a droplet of α-pinene into the chamber and caused the compound to react with ozone. Over a period of 15 hours, they observed which chemical compounds formed from α-pinene and which disappeared again afterwards.

This was made possible by a new analytic device for atmospheric measurements that the researchers developed in cooperation with the company Tofwerk in Thun, Switzerland: a so-called EESI-TOF (extractive electrospray ionisation time-of-flight mass spectrometer). “It also detects larger molecules directly in the aerosol,” explains atmospheric chemist Urs Baltensperger. “Previous measurement methods, on the other hand, chop up the molecules into smaller fragments at high temperatures.” The new device ionises without fragmentation. “We can record each molecule separately.”

Tofwerk has now brought the device to market with the help of PSI, so that other atmospheric researchers can also benefit from the new method.

Measurements in Zurich

The new analytic method can be used not only in the laboratory, but also directly on site.

During the winter of 2018/19 and the summer of 2019, PSI researchers used it to investigate aerosols in the air in Zurich.

As it turned out, a good third of Zurich’s particulate matter in summer consists solely of reaction products of α-pinene and similar molecules. In winter, however, emissions from wood-burning systems and their reaction products come to the fore.

The researchers have planned further measurement campaigns in China and India. There they want to analyse which molecules form in the air of a city with more than a million inhabitants.

The research results are being published on 13 March 2020 in the journal Science Advances.

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Materials provided by Paul Scherrer Institute. Original written by Brigitte Osterath. Note: Content may be edited for style and length.

Spiral galaxies, like our own Milky Way, make up approximately 70 percent of the galaxies in the nearby Universe. In many of these galaxies the difference in brightness between the winding arms and the inter-arm regions is very subtle, making it challenging for automated methods to measure. Even bright foreground stars can skew the automated analysis of a galaxy. Additionally, patterns in spiral galaxies are easily seen and followed by people but computer algorithms have a harder time determining where spirals begin and end, especially if they aren’t continuous.

The Spiral Graph project takes advantage of a time-honored short cut common in art classes — tracing. Ian Hewitt, Research Adjunct at the NC Museum of Natural Sciences, and Patrick Treuthardt, Assistant Head of the Museum’s Astronomy & Astrophysics Research Lab, tested their tracing method on a set of simple model images of spiral galaxies with known windings. They then traced out the spiral structure and measured the winding of the tracings with their own specially designed software, P2DFFT. When they compared their results against other approaches that involved an artificial intelligence program, fitting observed structure with mathematical models, or even directly inputting images into their own measurement software, none produced results as precise and accurate as their tracing method. A paper detailing this comparison appeared online on March 9, 2020. Spiral Graph is available on the Zooniverse.org platform for citizen science projects.

“These human-generated tracings give our software a boost so it can accurately measure how tightly wrapped the structure is,” Treuthardt says. “The degree of wrapping of the spiral arms is called the pitch angle. If a spiral pattern has very tightly wrapped arms, it has a small pitch angle. If it the spiral pattern is very open, it has a large pitch angle.” Why is pitch angle important? Because it relates to other parameters of the host galaxy that are more difficult and time consuming to measure, such as the mass of the black hole found in the nucleus, or dark matter content of the galaxy. “If we know the pitch angle we can quickly and easily estimate these parameters and identify interesting galaxies for more detailed, follow-up telescope observations,” Treuthardt adds.

Hewitt’s work on this study, and the Spiral Graph citizen science project, is especially rewarding since he started out as a volunteer working with Treuthardt. Although a long-time amateur astronomer, Hewitt retired from a career in industry to pursue astronomy full time. He later completed a degree in astronomy and began teaching and working on programming projects in the Museum’s Astronomy & Astrophysics Research Lab. “It’s been really exciting to get a chance to participate in this kind of research, but even better to have a part in enabling others to contribute to the efforts to better understand our Universe,” says Hewitt. And with an estimated 6,000 galaxies in their study, enlisting citizen scientists is a must.

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Materials provided by North Carolina Museum of Natural Sciences. Note: Content may be edited for style and length.

A multicenter team led by current and former investigators from the Salk Institute is reporting new details about how plants respond to a hormone called jasmonic acid, or jasmonate. The findings, which were published in Nature Plants on March 13, 2020, reveal a complex communication network. This knowledge could help researchers, such as members of Salk’s Harnessing Plants Initiative, develop crops that are hardier and more able to withstand assault, especially in an era of rapid climate change.

“This research gives us a really detailed picture of how this hormone, jasmonic acid, acts at many different levels,” says Professor Joseph Ecker, co-corresponding author and Howard Hughes Medical Institute investigator. “It enables us to understand how environmental information and developmental information is processed, and how it ensures proper growth and development.”

The plant used in the study was Arabidopsis thaliana, a small flowering plant in the mustard family. Because its genome has been well characterized, this plant is a popular model system. Scientists can take what they learn in A. thaliana and apply it to other plants, including those grown for food. Jasmonic acid is found not only in A. thaliana but throughout the plant kingdom.

“Jasmonic acid is particularly important for a plant’s defense response against fungi and insects,” says co-first author Mark Zander, a staff researcher in Ecker’s lab. “We wanted to precisely understand what happens after jasmonic acid is perceived by the plant. Which genes are activated and deactivated, which proteins are produced and which factors are in control of these well-orchestrated cellular processes?”

The researchers started with plant seeds grown in petri dishes. They kept the seeds in the dark for three days to mimic the first few days of a seed’s life, when it is still underground. “We know this growth stage is super important,” says co-first author and co-corresponding author Mathew Lewsey, an associate professor at La Trobe University in Melbourne, Australia, who previously worked in Ecker’s lab. The first few days in the soil are a challenging time for seedlings, as they face attacks from insects and fungi. “If your seeds don’t germinate and successfully emerge from the soil, then you will have no crop,” Lewsey adds.

After three days, the plants were exposed to jasmonic acid. The researchers then extracted the DNA and proteins from the plant cells and employed specific antibodies against their proteins of interest to capture the exact genomic location of these regulators. By using various computational approaches, the team was then able to identify genes that are important for the plant’s response to jasmonic acid and, moreover, for the cellular cross-communication with other plant hormone pathways.

Two genes that rose to the top in their degree of importance across the system were MYC2 and MYC3. These genes code for proteins that are transcription factors, which means that they regulate the activity of many other genes — or thousands of other genes in this case.

“In the past, the MYC genes and other transcription factors have been studied in a very linear fashion,” Lewsey explains. “Scientists look at how one gene is connected to the next gene, and the next one, and so on. This method is inherently slow because there are a lot of genes and lots of connections. What we’ve done here is to create a framework by which we can analyze many genes at once.”

“By deciphering all of these gene networks and subnetworks, it helps us to understand the architecture of the whole system,” Zander says. “We now have this very comprehensive picture of which genes are turned on and off during a plant’s defense response. With the availability of CRISPR gene editing, these kinds of details can be useful for breeding crops that are able to better withstand attacks from pests.”

Another noteworthy aspect of this work is that all of the data from the research has been made available on Salk’s website. Researchers can use the site to search for more information about genes they study and find ways to target them.

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Materials provided by Salk Institute. Note: Content may be edited for style and length.

Writing in the British Medical Journal, researchers from the University of East Anglia (UEA), London School of Hygiene & Tropical Medicine (LSHTM) and Samson Institute for Ageing Research (SIFAR), Cape Town, lead calls for an age perspective to be included explicitly in national and global planning on covid-19, as well as the urgent formation of an expert group on older people to support with guidance and response to the virus.

In their editorial, Prof Peter Lloyd-Sherlock of UEA, Prof Shah Ebrahim and Prof Martin McKee of LSHTM, and Dr Leon Geffen at SIFAR note that the largest numbers of deaths will occur among older people in low and middle-income countries (LMICs). These countries contain 69 per cent of the global population aged 60 and over, and health systems which are less extensive and less focussed on the needs of older people than in high-income countries.

Prof Lloyd-Sherlock, professor of social policy and international development at UEA, said: “The global response to coronavirus must be directed towards those groups who will face the most devastating consequences. So far, this has not happened. We are facing an unprecedented and enormous wave of mortality among older people in these countries.”

In LMICs the risk of infection for older people will be high because living arrangements are often cramped and overcrowded. Increasing numbers of older people in LMICs live in nursing homes or similar facilities, where conditions are often poor and regulation weak.

The researchers say social distancing policies must consider the already precarious existence of many older people, particularly those living alone or dependent on others for care and support. These people may face barriers to obtaining food and other essential supplies if quarantine conditions become more widespread.

As in high-income countries, the risk of dying from covid-19 in LMICs increases sharply with age and the vast majority of deaths observed are in people over the age of 60, especially those with chronic conditions such as cardiovascular disease.

The capacity of health systems in LMICs to screen, let alone treat, the virus will be very limited: in South Africa each test costs around US$75 -this exceeds total annual government per capita health spending in many LMICs. Even before covid-19 emerged, older people already faced significant barriers of access to health services and support, including affordability, and age based discrimination.

The researchers add: “It will not be easy to deal with these problems, especially in settings where there is often weak public health infrastructure, a lack of gerontological expertise at all levels of the health system, and limited trust in government.

“However, a first step would be to recognise that these problems exist. An age perspective should be included explicitly in the development of national and global planning for covid-19, and a global expert group on older people should be formed to support with guidance and response to the virus in both residential facilities and home settings.

“As new knowledge emerges, this group can identify and evaluate cost effective therapies and interventions that respond to the particular needs of older people in LMICs living in challenging settings, where formal health service infrastructure is limited.”

They conclude: “Previously, some of the authors have argued that global health priority setting is institutionally ageist. Covid-19 offers an opportunity to prove us wrong.”

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Materials provided by University of East Anglia. Note: Content may be edited for style and length.