New capybara fossil changes the forecast for the ancient Atacama region
Capybaras like their habitats wet. These large rodents thrive in low-elevation wetlands, migrating along creeks and rivers to nibble on foliage and flowers. That’s why researchers were surprised to find an 8.8 million-year-old fossilized capybara tooth in northern Chile’s Atacama Desert, one of the driest regions on Earth. In a paper published Sept. 5 in Scientific Reports, researchers postulate that the Atacama Desert must have had a wetter climate during the Miocene epoch, based on this discovery. This is the first time a capybara species has ever been seen in the Atacama region of Chile — today these creatures reside in the marshy lowlands across Venezuela, Colombia, Argentina and Uruguay. Researchers had at one time assumed that the Andean mountain chain on the eastern side of Chile would have prevented these short-legged rodents from ever entering the Atacama region. With this discovery, the authors propose that capybaras were able to follow a wetland trail along the northern part of South America, trekking from Bolivia to Peru into northern Chile. In addition to capybaras, the ancient Atacama region also likely had palms and other flowering plants, according to plant fossils analyzed by a UW scientist for the study. These findings challenge the idea that the Atacama was just always a desert, and can help researchers better understand how shifts in climate can drastically affect the environment.
For more information, contact co-author Caroline Strömberg, UW professor of biology, at caestrom@uw.edu.
A full list of co-authors and funding is included in the paper. Adapted from a release from the University of Arizona.
Multitasking gives marine microbes an edge when nutrients are scarce
The world’s oceans teem with tiny organisms that are difficult to study yet critical to account for. The organisms that make up this microscopic community, many of which are protists, have evolved over time to help keep marine ecosystems balanced. A UW study published Sept. 11 in the ISME Journal, found that organisms that can both photosynthesize and eat to generate energy do better in nutrient-limited environments, which includes warmer water. This flexibility may help them cope with changing conditions and could help researchers gauge how marine ecosystems will respond to future warming. Gathering more data from the bottom of the food web is important for understanding the ecosystem-wide impacts of environmental change. The study also debuted a new genetic method for studying energy production versus consumption that may make it easier to study protists. Samples in this study were collected from the North Pacific, near Hawaii and about 1,000 miles north, but the researchers hope to continue expanding the radius to improve global ocean models.
For more information, contact Sacha Coesel, UW research scientist and engineer of biological oceanography at coesel@uw.edu.
The UW co-authors are Shiri Graff van Creveld, Francois Ribalet and Virginia Armbrust. A full list of co-authors and funding is included in the paper.
UW engineers capture behavior of ‘edge waves’ on beaches, putting popular wave models to the test
Coastal engineers and oceanographers often think of the motion of water on beaches as “one dimensional”: waves propagating directly onto the beach from offshore. These simplified wave models are used widely from designing shoreline infrastructure to forecasting coastal flooding. However, some waves propagate along the coast rather than crashing into it, and may push an additional meter of water depth onto the beach. For decades, these “edge waves” have not been accounted for in the one-dimensional models commonly used to understand wave behavior. To find out how edge waves might be impacting model accuracy, researchers at the UW and UC San Diego deployed an array of pressure and velocity sensors along a beach in Southern California for 60 days. In a paper published Sept. 4 in JGR Oceans, the researchers describe a model they built to tease out the influence of edge waves in the larger system. While edge waves contributed a significant amount of energy, the team found that ultimately the one-dimensional models that exclude edge waves remain accurate enough for predicting total water levels at the shoreline.
For more information, contact Cassandra Henderson, a postdoctoral scholar of civil and environmental engineering, at cshender@uw.edu.
A full list of co-authors and funding is included with the paper.
How Colombian environmentalists use law and democracy to redefine mountain landscapes
In 2013 and 2017, Colombian voters in two towns backed a legal effort to stop a large-scale gold mining project. In doing so, they are making the mountainous areas where they live more visible and politically relevant. The decision allowed environmental advocates to organize around a larger area defined by elevation, massive volume, and subterranean and arboreal features. Ángela Castillo Ardila, UW assistant professor of anthropology, recently published a research article in the journal Anthropological Forum that examines how the effort used legal tools for citizen participation to not only voice their opinions on extractive projects, but also reconfigure space in unprecedented ways. The case shows that democratic participation can have far-reaching consequences for how landscapes are defined and lived. The article appears in a special issue, called “Ethnographies of Vertical and Volumetric Worlds,” which was co-edited by Ardila and Steven Schwartz of the University of Rochester.
For more information, contact Castillo at acastil@uw.edu.
Funding information is included in the paper.
Researchers develop new way to measure how blood clots form
A wound stops bleeding because tiny blood cell fragments called platelets clump together to form a clot. Researchers know that platelets generate forces that help compact and strengthen clots. However, they’ve struggled to understand how blood clots form in real time. To better understand this system, UW mechanical engineers created a device that measures how platelet forces and stiffness evolve together during the first minutes of clot formation. In a paper published recently in Advanced Healthcare Materials, the research team used the device to apply magnetic forces to clumps of platelets, causing them to strengthen and stiffen through a process called “mechanotransduction” in which cells convert mechanical forces into biological responses. These findings could be used to study how new drugs affect clot formation, how platelets respond to signals when disease is present, and how blood clotting biomechanics contribute to cardiovascular disorders.
For more information, contact Nate Sniadecki, a UW professor of mechanical engineering, at nsniadec@uw.edu.
The UW co-authors are Nikita Taparia, Ava Obenaus, Yoeur-Man Mach and Nakul Sridhar. A full list of co-authors and funding is included with the paper. Adapted from a story by UW mechanical engineering.
UW researchers probe superconducting materials that defy expectations
Most materials resist the flow of electricity to some degree, but unusual materials known as superconductors can carry an electric current with no resistance at all. Superconductors offer a unique window into the physics of materials at tiny scales, and they could one day revolutionize electronics. In recent years, researchers have discovered new forms of superconductivity in stacks of atomically thin materials such as graphene. Resistance typically drops to zero as these materials are cooled, but in some cases it mysteriously levels off at a small finite value, which contradicts expectations of superconductor behavior. In a paper published Sept. 23 in Nature, UW materials scientists tested this behavior with a device consisting of several layers of graphene stacked in a staircase-like pattern. By adjusting voltages applied to the device, the researchers could control whether the graphene exhibited true superconductivity or the more peculiar “failed” form, providing clear evidence that failed superconductivity is real. The team is now working to uncover the origin of this mysterious behavior.
For more information, contact Matthew Yankowitz, a UW associate professor of both physics and materials science and engineering, at myank@uw.edu..
The UW co-authors are Anna Okounkova, Abigail Sohm, Manish Kumar and Derek Waleffe. A full list of co-authors and funding is included with the paper.