The common idea of global water supply is rain falling on the earth’s surface and then stored in aquifers, lakes, and rivers. This idea is usually used to assess water security and the risk of water scarcity. However, a new study published in Nature Water shows how the water risks are dependent on governance and environmental conditions present upwind, which means the areas where the moisture for rain comes from.

“Water supply really originates beforehand, with moisture evaporated from land or in the ocean traveling in the atmosphere before falling as rain. This upwind moisture is commonly overlooked when assessing water availability,” says Fernando Jaramillo, associate professor in physical geography at Stockholm University and responsible for the study.

When a lake or river is shared between different countries or authorities, assessments and regulations mainly apply an upstream perspective, considering conditions in the direction upriver from the water body. Instead, an upwind perspective considers the area where evaporated water is transported before ending up as rain. The area is known as a precipitationshed and can cover large areas of the earth’s surface.

“For instance, in tropical South America, most of the Amazon basin is downstream of the Andes mountain range, whereas large areas of the Andes are in themselves downwind of the Amazon rainforest and depending on it, which makes these two regions dependent on each other for water supply,” says Fernando Jaramillo.

The study examined 379 hydrological basins worldwide, revealing that risks to water security are significantly higher when considering the upwind origin of water.

“With this approach, we see that 32,900 km3/year of water requirements worldwide face very high risk, a near 50 percent increase, compared to the 20,500 km3/year resulting from the more traditional upstream focus,” says José Posada, former doctoral student at Stockholm University and main author of the study.

Political control can have major consequences

Since a large amount of water is evaporated from plants, changes in land use can affect downwind water availability. If deforestation and agricultural development are predominant in upwind areas, the amount of moisture vegetation provides may decrease, reducing rainfall downwind and increasing the risk to water security.

“For coastal countries such as the Philippines, most of the rain comes from the sea, which means that land-use changes pose very little risk to water security. Rainfall in inland countries such as Niger, on the other hand, comes mainly from moisture that evaporates in neighboring countries such as Nigeria and Ghana . This puts many land-locked countries at high risk regarding how water security is affected by changes in land use,” says Fernando Jaramillo.

In other words, political factors such as environmental management and regulations in areas where moisture first evaporates can affect water safety in completely different areas.

“For instance, the Congo River basin, heavily reliant on moisture from neighboring countries with low environmental performance and governance according to global indicators, faces considerable risks due to potential deforestation and unregulated land use changes in neighboring areas,” says Lan Wang-Erlandsson, researcher at the Stockholm Resilience Centre at Stockholm University and co-author of the study.

Environmental regulation requires an upwind perspective.

The study reveals why the lack of governability and environmental performance in a country upwind may be relevant to the water supply of a country downwind. It stresses the codependence between upstream/downwind and downstream/upwind countries.

“It is not possible to ignore the interdependence between countries. In the end, all water is connected, so we should not only mind how we manage our water resources within a region or country but also how our neighboring countries do,” says Lan Wang-Erlandsson.

“We hope that the findings of this study can help identify where and to whom cooperation strategies and efforts can be directed to mitigate the causes of water-related tensions, including atmospheric water flows in transboundary decision-making and water governance frameworks. We stress the need for international cooperation to effectively manage upwind moisture sources,” concludes Fernando Jaramillo.

The findings, reported Sept. 1 at the European Society of Cardiology meeting and published in the Journal of the American College of Cardiology, provide inconclusive data about whether atrial fibrillation screening lowers stroke rates. The COVID pandemic led to an early halt of the study before fully enrolling, so it did not have enough participants to establish definitive results about stroke.

“Atrial fibrillation is often undiagnosed and can increase the risk of ischemic stroke, which is largely reversible by oral anticoagulation,” said lead author Renato Lopes, M.D., Ph.D., a professor of medicine and member of the Duke Clinical Research institute.

“We still need definitive evidence that diagnosis of atrial fibrillation through systematic screening can lead to subsequent treatment with oral anticoagulation and therefore, lower stroke risk,” Lopes said.

The study enrolled approximately 12,000 patients in the U.S. who were at least 70 years old with no history of atrial fibrillation. Roughly half the patients were randomly assigned to receive a long-term (14 days) continuous monitoring device, and the other half usual care.

Over a median of 15 months of follow-up, the study reported a 52% increase in the number of cases of atrial fibrillation diagnosed among the device-wearers compared to those in usual care. There was no increase in rates of hospitalization for bleeding, and no significant reduction in the rate of hospitalizations for all stroke compared with usual care.

The study was originally designed to enroll 52,000 patients, which would have given it the power to determine whether screening reduces the numbers of strokes. A large study population is needed because strokes occur in a subset of patients with atrial fibrillation.

“Despite the inconclusive results, we have a lot of lessons learned that might inform future studies” Lopes said. He said the study’s design, which enabled patients to be enrolled and screened online in a virtual format with self-applied patch devices in their homes with only remote support, could be duplicated in future studies.

In addition to Lopes, study authors include Steven J. Atlas, Alan S. Go, teven A. Lubitz, David D. McManus, Rowena J. Dolor, Ranee Chatterjee, Michael B. Rothberg, David R. Rushlow, Lori A. Crosson, Ronald S. Aronson, Michael Patlakh, Dianne Gallup, Donna J. Mills, Emily C. O’Brien, and Daniel E. Singer.

The study received funding support from the Bristol-Myers Squibb/Pfizer Alliance.

Precisely howbutterflies are able to generate the vibrant patterns and colors on their wings has fascinated biologists for centuries. The genetic code contained within the cells of developing butterfly wings dictates the specific arrangement of the color on the wing’s scales — the microscopic tiles that form wing patterns — similar to the arrangement of colored pixels to form a digital image. Cracking this code is fundamental to understanding how our own genes build our anatomy. In the lab, researchers can manipulate that code in butterflies with gene-editing tools and observe the effect on visible traits, such as coloration on a wing.

Scientists have long known that protein-coding genes are crucial to these processes. These types of genes create proteins that can dictate when and where a specific scale should generate a particular pigment. When it comes to black pigments, researchers thought this process would be no different, and initially implicated a protein-coding gene. The new research, however, paints a different picture.

The team discovered a gene that produces an RNA molecule — not a protein — controls where dark pigments are made during butterfly metamorphosis. Using the genome-editing technique CRISPR, the researchers demonstrated that when you remove the gene that produces the RNA molecule, butterflies completely lose their black pigmented scales, showing a clear link between RNA activity and dark pigment development.

“What we found was astonishing,” said Livraghi, a postdoctoral scientist at GW. “This RNA molecule directly influences where the black pigment appears on the wings, shaping the butterfly’s color patterns in a way we hadn’t anticipated.”

The researchers further explored how the RNA molecule functions during wing development. By examining its activity, they observed a perfect correlation between where the RNA is expressed and where black scales form.

“We were amazed that this gene is turned on where the black scales will eventually develop on the wing, with exquisite precision” said Arnaud Martin, associate professor of biology at GW. “It is truly an evolutionary paintbrush in this sense, and a creative one, judging by its effects in several species.”

The researchers examined the newly discovered RNA in several other butterflies whose evolutionary history diverged around 80 million years ago. They found that in each of these species, the RNA had evolved to control new placements in the patterns of dark pigments.

“The consistent result obtained from CRISPR mutants in several species really demonstrate that this RNA gene is not a recent invention, but a key ancestral mechanism to control wing pattern diversity,” said Riccardo Papa, professor of biology at the University of Puerto Rico — Río Piedras.

“We and others have now looked at this genetic trait in many different butterfly species, and remarkably we are finding that this same RNA is used again and again, from longwing butterflies, to monarchs and painted lady butterflies,” said Joe Hanly, a postdoctoral scientist and visiting fellow at GW. “It’s clearly a crucial gene for the evolution of wing patterns. I wonder what other, similar phenomena biologists might have been missing because they weren’t paying attention to the dark matter of the genome.”

The findings not only challenge long-standing assumptions about genetic regulation but also open up new avenues for studying how visible traits evolve in animals.