U Presidential Scholar

2022 U Presidential Scholar


Luisa Whittaker-Brooks

Luisa Whittaker-Brooks named 2022 U presidential scholar.

As an associate professor in the Department of Chemistry who organized a research program with national prominence, Luisa Whittaker-Brooks has been called a “trailblazing role model.” Whittaker-Brooks’ program focuses on the synthesis of organic and inorganic materials for energy conversion and storage, among other things. Whittaker-Brooks’ research results have appeared in premier journals of chemistry and materials science, and she has received numerous awards for her work, including being selected as a Department of Energy Career awardee, a Cottrell Scholar and a Scialog Fellow.

Four new associate professors have been named as Presidential Scholars at the University of Utah. Each of the scholars will be recognized as a Presidential Scholar for three academic years, from 2022 to 2025.

The annual awards recognize excellence and achievement for faculty members at the assistant or associate professor level, and come with $10,000 in annual funding for three years to support their scholarship and enrich their research activities. The program is made possible by a donor who wishes to remain anonymous.

The 2022 recipients are Ashley Spear, associate professor in the Department of Mechanical Engineering; Lauri Linder, associate professor in the Acute and Chronic Care Division of the College of Nursing; Luisa Whittaker-Brooks, associate professor in the Department of Chemistry; and Marcel Paret, associate professor in the Department of Sociology.

“I am so proud of the work these scholars are doing in the classroom, and in their field of study,” said Interim Senior Vice President for Academic Affairs Martell Teasley. “As educators at the U, they are positioned to guide their students and impact our whole community. I’m excited to see what the future holds.”

 

by Amy Choate-Nielsen, first published @theU

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Crystal Su

Crystal Su


A new paper in Current Biology describes the development of a novel, synthetic insect-bacterial symbiosis.

The symbiotic bacteria express a red fluorescent protein that is visible through the insect cuticle, facilitating characterization of the mechanics of infection and transmission in insect tissues and cells. In addition, Su et al. engineered the bacteria to modify their ability to synthesize aromatic amino acids, which are used by the insect host to fuel cuticle strengthening. Correspondingly, insects maintaining bacteria that overproduce these nutrients exhibited stronger cuticles, signifying mutualistic function. The establishment of this synthetic symbiosis will facilitate detailed molecular genetic analysis of symbiotic interactions and presents a foundation for the use of genetically-modified symbionts in the engineering of insects that transmit diseases of medical and agricultural importance. The paper is titled “Rational engineering of a synthetic insect-bacterial mutualism.”

Red fluorescent proteins in a weevil.

Broader context
SBS Professor and Principal Investigator Colin Dale says, “the work described in the paper was catalyzed and conducted by Crystal Su, an extremely brave and dedicated graduate student in SBS, who took on this very high risk and transformative project and pushed through numerous roadblocks, doggedly refusing to take no for an answer.” Su engaged three additional labs–Golic, Rog and Gagnon–in SBS to assist with specialist techniques, highlighting the utility of interdisciplinary science and the breadth of talent and collaborative spirit that exists in SBS.

Dale views Su’s work as a “bucket list” accomplishment, “something I dreamed about while playing cricket games at Bristol University Vet School during my Ph.D. While Crystal dedicated six years of her life to bring this novel new biology to life, it’s also the product of foundational work by SBS graduate students in the decade prior, involving the identification, characterization, culture and development of genetic tools for proto-symbionts free-living bacteria that have the capability to establish stable, maternally-transmitted associations with insects.”

Synthetic Biology
Synthetic Biology focuses on utilizing engineering approaches to design and fabricate organisms (including associations and communities) that do not exist in the natural world. It can yield practical solutions for a wide range of problems in medicine, agriculture, materials and environmental sciences. In addition, it can be used to investigate the functions of natural systems, via replication and manipulation, as highlighted in the Su et al. paper. To understand its potential, it is useful to think of the contribution of synthetic approaches to other disciplines in science, most notably in chemistry, says Dale who also serves in the School of Biological Sciences as Section Head, Genetics and Evolution.

 

Read the paper in Current Biology
Read the article on Undergraduate Research in the Dale Lab

 

by David Pace, first published @biology.utah.edu

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Ants of the World

Ants of the World


Seeing the world through ants.

Known affectionately as “Ant Man” in the School of Biological Sciences at the University of Utah and beyond, John “Jack” Longino is part of a globe-spanning initiative called the Ants of the World Project that aims to generate the most complete phylogenetic tree of the ant family (Formicidae) to date.

Part of that project is Ant Course, a regularly-occurring field course on ant biology and identification. After three years of accommodating the pandemic, this year the group, involving multiple research universities, is convening in Vietnam August 1-13. During the course, the world’s ant identification experts get together to teach 24 students all about ants. Beginning in 2001, the course has been staged in the United States, Costa Rica, Venezuela, French Guiana, Peru, Uganda, Mozambique, Borneo, and Australia.

“These courses have become famous,” says Longino, “with generations of students being shaped and connected by their Ant Course experience.” The Ants of the World project, he explains, integrates teaching and research. The initiative funds three new Ant Courses in locations that are poorly known, training new generations of ant biologists while they learn about the ants of these regions.

 

John “Jack” Longino

"These courses have become famous," says Longino, "with generations of students being shaped and connected by their Ant Course experience."

 

“After a long delay due to COVID, we are finally offering our first Ant Course, in Vietnam,” says Longino of their field site in Cúc Phương National Park, just south of Hanoi. “I’m really looking forward to meeting this new group of students, interacting with Asian colleagues, and experiencing first-hand the ant fauna of Southeast Asia.” Situated in the foothills of the northern Annamite Range, the national park consists of verdant karst mountains and lush valleys with an elevation that varies from 150 meters (500 feet) to 656 m (2,152 feet) at the summit of May Bac Mountain, or Silver Cloud Mountain.

It’s all part of Ants of the World Project’s attempt to survey nearly all ant genera and just under half the described species using advanced genome reduction techniques. The result will be a comprehensive evolutionary tree of ants, out to the smallest branch tips.

The resulting data set will help researchers answer questions: Are there predictable patterns of intercontinental dispersal and diversification? Following dispersal to a new region, is there accelerated filling of morphological and climate space? How have biotas responded to climate shifts in the past? Can we predict how ants will respond to current rapid climate change?

Eurhopalothrix semicapillum, named for the hairy patches on its face.

Longino and Elaine Tan, a graduate student in the Longino lab, will be meeting up with 34 other ant specialists and ant specialists-to-be. Along with “Ant Man,” course faculty include the other principal investigators of the Ants of the World Project: Michael Branstetter (USDA-ARS), Bonnie Blaimer (Museum für Naturkunde in Berlin, Germany), Brian Fisher (California Academy of Sciences) and Philip Ward (UC Davis).

Ants of the World is a collaboration of four different institutions, including the School of Biological Sciences. Ant Course is organized and run by the California Academy of Science and is designed for scholars to share information and discover together the ants of a particular region. It applies ant biology to established areas of inquiry but also encourages students to ask new questions.

Zahra Saifee is a University of Utah intern who will be accompanying the team as a scientific communications specialist. She says of Ant Course, “it really is about the ants, what new species there are in [a particular region and] where species overlap. The team discusses their observations of what they’re doing with others across the world. The core is bringing diverse people to ‘nerd out’ about it for two weeks.”

A lot of the time in Vietnam, says Saifee, is set up just to explore and see what people will find. “Curiosity is at a premium, bringing observations to the group as a sounding board. People can bring to the group ‘rough drafts’ of research and ideas.”

This open-door approach to discovery was transformative for Rodolfo Probst, PhD, a member of the Longino lab who successfully defended his dissertation just this month. His 2013 Ant Course experience in Borneo connected him to a year’s work back east following his graduation from college before he settled into graduate school as part of Longino’s lab.

Ants are the focus of that lab’s research but it’s not just about ants. The research goals of the Longino lab involve “reciprocal illumination,” in which the latest evolutionary concepts of species formation, combined with the latest genetic tools, allow the construction of a detailed “biodiversity map” of ants. The patterns revealed in the map then inform general concepts of biological diversification.

The research has the additional benefit of allowing other researchers, like those students participating in Ant Course, to more easily identify ants. To this end, Longino helps curate a large on-line specimen and image database (Antweb.org), a major resource for ant researchers worldwide.

To study the way ants network can potentially speak to the design and character of larger eco-systems, Saifee suggests, making the study of ants more than a niche science. It propels one to look at the larger picture of life—not just its wonders, but its changes and adaptations. In short, its ecology and evolution. “There are a lot of different species [of ants] and how we organize data is key to new scientific discoveries,” concludes Saifee.

Making new discoveries about ants is important because, as subject models, they are on par with vertebrates and vascular plants as key taxa for ecology, evolutionary biology, biogeography, conservation biology, and public interest. Having a solid phylogenetic history opens entire new worlds of biological exploration, and has been achieved for vertebrates and many plants. With a little more effort, much of which is being addressed by the NSF-funded Ants of the World project, the same can be true for ants.

Ant Course in Vietnam is currently at the center of that ambition. Follow the Ant Course blog and on Twitter @AntsProject. Read the profile of graduate student Elaine Tan, who is accompanying Jack Longino to Vietnam here.

 

First published at biology.utah.edu

 

N.S.F. Director

National Science Foundation


The National Science Foundation has announced a 2-to-4-year appointment of Denise Dearing as Director for the Division of Integrative Organismal Systems.

The Division of Integrative Organismal Systems (IOS) is one of four divisions within the Directorate of Biological Sciences at the NSF. The Division Director provides vision and leadership, and contributes to NSF’s mission by supporting fundamental research to advancing our understanding of organisms as integrated units of biological organization. The Division Director also provides guidance to program officers and administrative and support staff, and assesses needs and trends, develops breakthrough opportunities, implements overall strategic planning, and policy setting.

Both the NSF and the UU are supportive of Denise continuing to participate in her on-going research program and provide mechanisms and resources to enable the research in her group to continue and advance during her time at the NSF.

Dearing is Distinguished Professor in Biology at the University of Utah and a two-term former chair of the department which was made a School in 2018 after which she became director. The research in the Dearing lab focuses on understanding how small mammals overcome challenges related to diet and disease. “Our work draws on approaches from many disciplines (e.g., physiology, ecology, pharmacology, genetics, biochemistry, ethology) and combines field and laboratory studies,” says Dearing whose research website features three current projects: Understanding the genetic underpinnings that enable ingestion of poisonous diets; Investigating the role of gut microbes in facilitating the ingestion of dietary toxins; and Rules of Resilience: Modeling impacts of host-microbe interactions during perturbations.

Dearing earned her B.S. in Biology from Eastern Connecticut State University, 1985 an M.S. in Biology from the University of Vermont in 1988, and a Ph.D. in Biology from the University of Utah in 1995. She served as Associate Dean, College of Science between 2012 and 2014.

Among her awards and honors are the 2018 Joseph Grinnell Award (American Society of Mammalogist); the 2014 C. Hart Merriam Award (American Society of Mammalogists); a 2008 Graduate Student and Postdoctoral Scholar Distinguished Mentor Award; and a 2008 Distinguished University Teaching Award (University of Utah).

 

by David Pace, first published @biology.utah.edu

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Hollywood Dinosaurs

Hollywood Dinosaurs


Cinematic dinosaur representation. Accurate?

Have you ever wondered if “Jurassic Park” is realistic? Jeff Goldblum’s sexual magnetism is most certainly accurate, but what of the dinosaurs?

Enter Mark Loewen, a paleontologist at the Natural History Museum of Utah and associate professor in the Department of Geology and Geophysics at the U. In June, Loewen critiqued the accuracy of Hollywood’s depictions of dinosaurs for Vanity Fair in a video that has racked up nearly 2.5 million views on YouTube. You can watch the video below.

Mark Loewen

“I view myself as an evangelist for science. Movies are a sneaky way of showing students how cool these concepts are. I mean, isn’t this one of the most awesome classes you could take? Get a science credit to watch movies and learn about the science!”

 

“I love these movies—some of them are horrible, but I still love them,” said Loewen. “Before being a paleontologist, I became a geologist because I wanted to time travel. By looking at rocks, you can literally see what past worlds looked like! Seeing dinosaurs reconstructed in movies is the same thing. It’s fun to see how we can use fossils to imagine what these animals could have looked like.”

Loewen is uniquely suited for the job. In the early 2000s, he and his mentor Scott Sampson created a class called World of Dinosaurs, GEO 1040, where students watched movie clips and analyzed the veracity of dino representation. He expanded this idea to create Science and Cinema, GEO 1000, a non-majors science class that analyzes science in movies. By studying the dinosaurs, natural disasters and science fiction presented on screen, students learn science fundamentals while having fun celebrating—or berating—various motion pictures.

An alum of the Science of Cinema class now works at Vanity Fair and recommended Loewen for the video series, which coincides with the release of “Jurassic World: Dominion” (2022). A professional film crew shot his interview in the paleontology collections at the museum. If you watch the video closely, you can see specimens of dinosaurs that Loewen himself has discovered and named. U students can use their UCard to visit the museum for free, and during the museum’s annual Behind-the-Scenes event you can tour the collections and see fossils and specimens not displayed on the main floor.

“I’ve named 13 dinosaurs, and many of them are in the museum,” Loewen said, “My favorite is Lythronax, an earlier cousin of the T-Rex. Lythronax means ‘King of Gore’ or ‘Gore King.’ It’s a big, bloody dinosaur on its way to becoming a T-Rex.”

Loewen cites the Disney classic “Fantasia” (1940) segment, “Extinction of the Dinosaurs,” as an early catalyst for his love of dinosaurs. He analyzes the scene in the Vanity Fair video and gives it props for being the first movie to show dinosaurs living in their ecosystem. He calls it an important movie because it “sets the stage of dinosaurs being these iconic beasts of the past.” However, he explains that the animation reflected people’s understanding of the creatures in the 40s—the animals were sluggish and dragged their tails while moving around. It wasn’t until much later that we understood that many dinosaurs were agile and fearsome hunters.

For all y’all older millennials out there, be relieved–Loewen confirms that fossils of baby long-necked dinosaurs such as Little Foot in “The Land Before Time” (1988) did have big, puppy eyes and delicate little beaks—so they really were as cute as the cartoon. However, Sara the Triceratops and Little Foot the Brontosaurus didn’t co-exist at the same time, so would never have met to become friends.

He also critiques some aspects of the original "Jurassic Park.” However, Loewen does applaud the movie for being accurate based on our understanding in the early 90s.

“’Jurassic Park’ was one of the first accurate depictions of dinosaurs. They’re not acting like lizards. They’re acting like ferocious birds of prey,” said Loewen. “But when it came out, we didn’t know that dinosaurs had feathers. At the time, lots of scientists would have told you that dinosaurs didn’t become birds. Forty years later, 100% of dinosaur paleontologists will tell you that birds are actually dinosaurs, and we have evidence of feathers for almost every type of dinosaur. In the new movies, most of the dinosaurs have feathers.”

Editor’s note on conflict of interest: The author’s favorite movie is “Jurassic Park.”

 

by Lisa Potter, first published in @theU. Video first published by Vanity Fair.

 

Cellular Crosslinking

Cellular Crosslinking


Structural signatures of Escherichia coli chemoreceptor signaling states revealed by cellular crosslinking

Motile bacteria are capable of swimming efficiently toward favorable chemical environments and away from inhospitable ones. This behavior–called “chemotaxis”–is frequently used by unicellular organisms for finding food.

Not surprisingly, such behaviors play important roles in establishing beneficial host symbioses and pathogenic infections. The value of understanding in detail this mechanism of directed cell migration in response to extracellular chemical signals cannot be over-stated, and Escherichia coli, commonly referred to as E. coli, has become the paradigm molecular model.

“Despite their tiny size, bacteria have evolved amazingly sophisticated protein machines for detecting and responding to changes in their environment,” says John “Sandy” Parkinson, principal investigator in the School of Biological Sciences. Caralyn Flack, a research associate in the Parkinson Lab, developed a technique for monitoring the behavior of living bacteria before and after she changed the structure of a critical signaling protein inside the cell.

Flack’s new findings were recently published in Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS). The paper, titled “Structural signatures of Escherichia coli chemoreceptor signaling states revealed by cellular crosslinking,” makes an important advance in elucidating the molecular mechanism(s) of signal propagation through chemoreceptor molecules.

Caralyn Flack

"This new cellular crosslinking approach delivers unprecedented insight into receptor structural properties as the receptors function within cells"

 

“Bacteria are amazing at sensing and responding quickly to changes in their environment,” states Flack. “This makes them a great model for trying to understand transmembrane signaling.” But it turns out that changes that accompany signaling events in chemoreceptors are difficult to follow with traditional structural methods, and those techniques that do work cannot replicate the native cellular environment. To remedy that, the technique Flack developed does three things. First, it assesses behavior. Second, it changes the structure of a protein inside living bacteria, and third, it then watches the signaling behavior change in real-time. The technique, which involves “crosslinking,” she says, has proven to be “really powerful for structure-function analyses of signaling proteins.”

In essence, what Flack did was create receptor proteins with a special amino acid at a position of interest. That amino acid, cysteine, has unique chemical properties that, under the right conditions, allow it to form a covalent bond (to “crosslink”) to a nearby cysteine in the same protein or in another protein. Such crosslinks constrain the structural movements of the proteins and can change its behavior. This is how Flack was able to change the structure, and in consequence, the function of a receptor within a living cell.

The crosslinking reporter sites “enabled us to evaluate receptor output states before and after crosslink formation,” she writes. This new cellular crosslinking approach “delivers unprecedented insight into receptor structural properties as the receptors function within cells” stated one reviewer of the PNAS manuscript. Flack suggests that “similar crosslinking approaches could serve to follow signal transmission in other regions of the chemoreceptor molecule and perhaps in other signaling proteins, as well.”

Work on those topics is ongoing.

Photo: Colorized scanning electron micrograph of Escherichia coli, grown in culture and adhered to a cover slip by NIAID on Flickr

 

by David Pace, first published in biology.utah.edu.

 

Biomimetic Cephalopods

Biomimetic Cephalopods


Bringing ancient animals back to life—as robots.

In a university swimming pool, scientists and their underwater cameras watch carefully as a coiled shell is released from a pair of metal tongs. The shell begins to move under its own power, giving the researchers a glimpse into what the oceans might have looked like millions of years ago when they were full of these ubiquitous animals.

This isn’t Jurassic Park, but it is an effort to learn about ancient life by recreating it. In this case, the recreations are 3-D-printed robots designed to replicate the shape and motion of ammonites, marine animals that both preceded and were contemporaneous with the dinosaurs.

 

David Peterman

"Evolution dealt them a very unique mode of locomotion after liberating them from the seafloor with a chambered, gas-filled conch. These animals are essentially rigid-bodied submarines propelled by jets of water."

 

The robotic ammonites allowed the researchers to explore questions about how shell shapes affected swimming ability. They found trade-offs between stability in the water and maneuverability, suggesting that the evolution of ammonite shells explored different designs for different advantages rather than converged toward a single best design.

“These results reiterate that there is no single optimum shell shape,” says David Peterman, a postdoctoral fellow in the University of Utah’s Department of Geology and Geophysics.

The study is published in Scientific Reports and supported by the National Science Foundation.

Bringing ammonites to “life”

For years, Peterman and Kathleen Ritterbush, assistant professor of geology and geophysics, have been exploring the hydrodynamics, or physics of moving through the water, of ancient shelled cephalopods, including ammonites. Cephalopods today include octopuses and squid, with only one group sporting an external shell—the nautiluses.

Before the current era, cephalopods with shells were everywhere. Although their rigid coiled shells would have impacted their free movement through the water, they were phenomenally successful evolution-wise, persisting for hundreds of millions of years and surviving every mass extinction.

“These properties make them excellent tools to study evolutionary biomechanics,” Peterman says, “the story of how benthic (bottom-dwelling) mollusks became among the most complex and mobile group of marine invertebrates. My broader research goal is to provide a better understanding of these enigmatic animals, their ecosystem roles, and the evolutionary processes that have shaped them.”

Peterman and Ritterbush previously built life-sized 3-D weighted models of cone-shaped cephalopod shells and found, through releasing them in pools, that the ancient animals likely lived a vertical life, bobbing up and down through the water column to find food. These models’ movements were governed solely by buoyancy and the hydrodynamics of the shell.

But Peterman has always wanted to build models more similar to living animals.

Diagram of a Biometic Cehalapod.

“I have wanted to build robots ever since I developed the first techniques to replicate hydrostatic properties in physical models, and Kathleen strongly encouraged me as well,” Peterman says. “On-board propulsion enables us to explore new questions regarding the physical constraints on the life habits of these animals.”

Buoyancy became Peterman’s chief challenge. He needed the models to be neutrally buoyant, neither floating nor sinking. He also needed the models to be water-tight, both to protect the electronics inside and to prevent leaking water from changing the delicate buoyancy balance.

But the extra work is worth it. “New questions can be investigated using these techniques,” Peterman says, “including complex jetting dynamics, coasting efficiency, and the 3-D maneuverability of particular shell shapes.”

Three kinds of shells

The researchers tested robotic ammonites with three shell shapes. They’re partially based on the shell of a modern Nautilus and modified to represent the range of ancient ammonites’ shell shapes. The model called a serpenticone had tight whorls and a narrow shell, while the sphaerocone model had few thick whorls and a wide, almost spherical shell. The third model, the oxycone, was somewhere in the middle: thick whorls and a narrow, streamlined shell. You can think of them occupying a triangular diagram, representing “end-members” of different shell characteristics.

“Every planispiral cephalopod to ever exist plots somewhere on this diagram,” Peterman says, allowing the properties for in-between shapes to be estimated.

Once the 3-D-printed models were built, rigged and weighted, it was time to go to the pool. Working first in the pool of Geology and Geophysics professor Brenda Bowen and later in the U’s Crimson Lagoon, Peterman and Ritterbush set up cameras and lights underwater and released the robotic ammonites, tracking their position in 3-D space throughout around a dozen “runs” for each shell type.

No perfect shell shape

By analyzing the data from the pool experiments, the researchers were looking for the pros and cons associated with each shell characteristic.

“We expected there to be various advantages and consequences for any particular shapes,” Peterman says. “Evolution dealt them a very unique mode of locomotion after liberating them from the seafloor with a chambered, gas-filled conch. These animals are essentially rigid-bodied submarines propelled by jets of water.” That shell isn’t great for speed or maneuverability, he says, but coiled-shell cephalopods still managed remarkable diversity through each mass extinction.

“Throughout their evolution, externally shelled cephalopods navigated their physical limitations by endlessly experimenting with variations on the shape of their coiled shells,” Peterman says.

So, which shell shape was the best?

David Peterman

“The idea that one shape is better than another is meaningless without asking the question—‘better at what?’” Peterman says. Narrower shells enjoyed less drag and more stability while traveling in one direction, improving their jetting efficiency. But wider, more spherical shells could more easily change directions, spinning on an axis. This maneuverability may have helped them catch prey or avoid slow predators (like other shelled cephalopods).

Peterman notes that some interpretations consider many ammonite shells as hydrodynamically “inferior” to others, limiting their motion too much.

“Our experiments, along with the work of colleagues in our lab, demonstrate that shell designs traditionally interpreted as hydrodynamically ‘inferior’ may have had some disadvantages but are not immobile drifters,” Peterman says. “For externally shelled cephalopods, speed is certainly not the only metric of performance.” Nearly every variation in shell design iteratively appears at some point in the fossil record, he says, showing that different shapes conferred different advantages.

“Natural selection is a dynamic process, changing through time and involving numerous functional tradeoffs and other constraints,” he says, “Externally-shelled cephalopods are perfect targets to study these complex dynamics because of their enormous temporal range, ecological significance, abundance, and high evolutionary rates.”

Find the full study @ Nature.com.

 

by Paul Gabrielsen, first published in @TheU.

 

Mass Spectrometry

The John B. Fenn Award


Armentrout receives ASMS Award for Distinguished Contributions In Mass Spectrometry.

Peter B. Armentrout the Henry Eyring Presidential Endowed Chair of Chemistry at the University of Utah is the 2021 recipient of the John B. Fenn Award for Distinguished Contribution in Mass Spectrometry.

Armentrout is receiving this award for the development of robust experimental and statistical techniques for the determination of accurate thermochemistry. He developed the guided ion beam threshold dissociation approach to provide insights into the thermochemistry, kinetics, and dynamics of simple and complex chemical reactions. In addition, he developed a suite of software programs for statistically modeling the energy dependence of product formation for most reactive processes.

 

Armentrout in the lab

"These developments have allowed nearly 2500 distinct bond energies to be measured during his career. The impact of these fundamental measurements has been felt over many fields, including catalysis, biochemistry, surface chemistry, organometallic chemistry, and plasma chemistry."

 

He shared both the instrumentation designs and the software with laboratories around the world to enable the greater scientific community to study thermochemical processes. These developments have allowed nearly 2500 distinct bond energies to be measured during his career. The impact of these fundamental measurements has been felt over many fields, including catalysis, biochemistry, surface chemistry, organometallic chemistry, and plasma chemistry.

Professor Armentrout is a member of the editorial advisory boards of the Journal of the American Society of Mass Spectrometry and the International Journal of Mass Spectrometry and Ion Processes, and formerly of the Journal of the American Chemical Society, Journal of Physical Chemistry, Journal of Chemical Physics, Organometallics, and the Journal of Cluster Science (charter member).

He is a member of the American Chemical Society, American Physical Society (fellow), American Society for Mass Spectrometry, and the American Association for the Advancement of Science (fellow). He presently has nearly 500 research publications that have appeared in the literature. Thirty-six students have received their Ph.D.s with Professor Armentrout.

Talley Fenn, Sara Rockow, Peter B. Armentrout, Brandon C. Stevenson, David Loertscher

The ASMS Award for Distinguished Contribution in Mass Spectrometry is named to honor the memory of John B. Fenn who shared the 2002 Nobel Prize for the development of electrospray Ionization. Fenn joined ASMS in 1986 and remained an active member until his passing in 2010. The award in his name recognizes a focused or singular achievement in fundamental or applied mass spectrometry in contrast to awards that recognize lifetime achievement.

 

First published at ASMS.org

 

Moiré Magic

Moiré Magic


Highly tunable composite materials—with a twist.

The above animation shows the patterns created as two circles move across each other. Those patterns, created by two sets of lines offset from each other, are called moiré (pronounced mwar-AY) effects. As optical illusions, moiré patterns create neat simulations of movement. But at the atomic scale, when one sheet of atoms arranged in a lattice is slightly offset from another sheet, these moiré patterns can create some exciting and important physics with interesting and unusual electronic properties.

Mathematicians at the University of Utah have found that they can design a range of composite materials from moiré patterns created by rotating and stretching one lattice relative to another. Their electrical and other physical properties can change—sometimes quite abruptly, depending on whether the resulting moiré patterns are regularly repeating or non-repeating. Their findings are published in Communications Physics.

The mathematics and physics of these twisted lattices applies to a wide variety of material properties, says Kenneth Golden, distinguished professor of mathematics. “The underlying theory also holds for materials on a large range of length scales, from nanometers to kilometers, demonstrating just how broad the scope is for potential technological applications of our findings.”

 

Ken Golden

"We observe a geometry-driven localization transition that has nothing to do with wave scattering or interference effects, which is a surprising and unexpected discovery."

 

With a twist

Before we arrive at these new findings, we’ll need to chart the history of two important concepts: aperiodic geometry and twistronics.

Aperiodic geometry means patterns that don’t repeat. An example is the Penrose tiling pattern of rhombuses. If you draw a box around a part of the pattern and start sliding it in any direction, without rotating it, you’ll never find a part of the pattern that matches it.

Aperiodic patterns designed over 1000 years ago appeared in Girih tilings used in Islamic architecture. More recently, in the early 1980s, materials scientist Dan Shechtman discovered a crystal with an aperiodic atomic structure. This revolutionized crystallography, since the classic definition of a crystal includes only regularly repeating atomic patterns, and earned Shechtman the 2011 Nobel Prize in Chemistry.

Okay, now onto twistronics, a field that also has a Nobel in its lineage. In 2010, Andre Geim and Konstantin Novoselov won the Nobel Prize in Physics for discovering graphene, a material that’s made of a single layer of carbon atoms in a lattice that looks like chicken wire. Graphene itself has its own suite of interesting properties, but in recent years physicists have found that when you stack two layers of graphene and turn one slightly, the resulting material becomes a superconductor that also happens to be extraordinarily strong. This field of study of the electronic properties of twisted bilayer graphene is called “twistronics.”

Two-phase composites

In the new study, Golden and his colleagues imagined something different. It’s like twistronics, but instead of two layers of atoms, the moiré patterns formed from interfering lattices determine how two different material components, such as a good conductor and a bad one, are arranged geometrically into a composite material. They call the new material a “twisted bilayer composite,” since one of the lattices is twisted and/or stretched relative to the other. Exploring the mathematics of such a material, they found that moiré patterns produced some surprising properties.

“As the twist angle and scale parameters vary, these patterns yield myriad microgeometries, with very small changes in the parameters causing very large changes in the material properties,” says Ben Murphy, co-author of the paper and adjunct assistant professor of mathematics.

Twisting one lattice just two degrees, for example, can cause the moiré patterns to go from regularly repeating to non-repeating—and even appear to be randomly disordered, although all the patterns are non-random.  If the pattern is ordered and periodic, the material can conduct electrical current very well or not at all, displaying on/off behavior similar to semiconductors used in computer chips. But for the aperiodic, disordered-looking patterns, the material can be a current-squashing insulator, “similar to the rubber on the handle of a tool that helps to eliminate electrical shock,” says David Morison, lead author of the study who recently finished his Ph.D. in Physics at the University of Utah under Golden’s supervision.

This kind of abrupt transition from electrical conductor to insulator reminded the researchers of yet another Nobel-winning discovery: the Anderson localization transition for quantum conductors. That discovery, which won the 1977 Nobel Prize in Physics, explains how an electron can move freely through a material (a conductor) or get trapped or localized (an insulator), using the mathematics of wave scattering and interference. But Golden says that the quantum wave equations Anderson used don’t work on the scale of these twisted bilayer composites, so there must be something else going on to create this conductor/insulator effect. “We observe a geometry-driven localization transition that has nothing to do with wave scattering or interference effects, which is a surprising and unexpected discovery,” Golden says.

The electromagnetic properties of these new materials vary so much with just tiny changes in the twist angle that engineers may someday use that variation to precisely tune a material’s properties and select, for example, the visible frequencies of light (a.k.a. colors) that the material will allow to pass through and the frequencies it will block.

“Moreover, our mathematical framework applies to tuning other properties of these materials, such as magnetic, diffusive and thermal, as well as optical and electrical,” says professor of mathematics and study co-author Elena Cherkaev, “and points toward the possibility of similar behavior in acoustic and other mechanical analogues.”

Find the full study in Communications Physics.

 

by Paul Gabrielsen, first published in @TheU.

 

Living Legend

Toto Gets Stamped!


Filipino stamp of "Toto"

Distinguished Professor Baldomero Olivera is featured in the Filipino Postal Office’s “Living Legends” commemorative stamp series.

Affectionately referred to as “Toto,” Olivera has pioneered research on marine cone snails, demonstrating the therapeutic potential of their venom, already resulting in an FDA-approved drug. The University of Utah’s biochemistry and pharmacy departments (UofU Health) are currently expanding on some of this work.

His early research contributions include the discovery and biochemical characterization of E. coli DNA ligase, a key enzyme of DNA replication and repair that is widely used in recombinant DNA technology.

In a 2018 profile, Olivera was described as unconventional: “Not every molecular biologist would think to look in cone snail venom for potential therapeutics. But a long-held interest in the biological environment that surrounded him while growing up in the Philippines — and a habit of making unconventional choices — led Baldomero ‘Toto’ Olivera to do just that.”

After completing his Ph.D. at the California Institute of Technology and postdoctoral research at Stanford University, Olivera returned to the Philippines to establish his independent research program. Now at the School of Biological Sciences at the University of Utah, Olivera has discovered several peptides in snail venom that have reached human clinical trials. One has been approved for the treatment of severe pain.

 

Baldomero Olivera

“I didn’t make choices that were conventionally considered wise at the time. The things that didn’t seem so wise at the time turned out to be okay.”

 

While building a productive research program, he also was developing new ways to educate and inspire future generations of scientists in the U.S. and the Philippines. As a Howard Hughes Medical Institute Professor, he has developed hands-on curricula that draw young students to science by teaching them about scientific principles they can observe in the organisms they see every day.

When Olivera was selected as one in the series of “Living Legends” commemorative stamps, graduate student Paula Florez Salcedo in the Olivera lab tweeted “He is a living legend, and I can’t believe I get to learn from him!”

When asked by an interviewer to list something that Olivera knows now in his career as a scientist that he wished he’d known earlier, he says,

“I didn’t make choices that were conventionally considered wise at the time. When I was going back to the Philippines, everyone was saying ‘Why are you doing that? You’re ruining your scientific career.’ But that turned out to be very good for my scientific career because I started working with cone shells. So I really have no major regrets, I must say. The things that didn’t seem so wise at the time turned out to be okay.”

In science and technology, the post office selected to honor national scientist and physician Ernesto Domingo along with the internationally recognized Olivera.

“They have dedicated their lives and talents to the Filipino people,” Postmaster General Norman Fulgencio said in February when the announcement was made. “They deserve to be immortalized in our stamps to inspire not only Filipinos, but every nationality who will see our stamps.”

The post office turned over to representatives of the honorees the framed stamps in tribute to them. “The stamps we issued today are not only meant for delivery of letters, but more importantly to deliver hope,” Fulgencio said.

Furthermore, the stamps “symbolize what Filipinos are capable of — wherever we are, whoever we are up against and whatever it takes,” he said.

 

by David Pace, first published at biology.utah.edu.