Reposted from impact.science.oregonstate.edu

A senior’s gut decision in high school to major in physics holds steady four years later

Looking back on his gut decision in high school to major in physics after taking a class in it, graduating senior Abe Teklu remains somewhat mystified. “I guess I was just really confident,” he laughs.
Abe grew up around numbers and changing locations, moving from Ethiopia to Arizona at age six when his father got an engineering job at Intel, and then moving to Colorado before his family settled outside of Portland when he was 12.
His family is mathematically inclined. His mom is an accountant and his dad, who not so secretly yearned to be a mathematician, is an engineer who reads calculus books and earned a master’s degree in fluid dynamics. This home field advantage explains some of Abe’s youthful confidence (he “loved math” even as a child) but since then Abe has carried the ball all on his own.
At Oregon State as an Honors physics student, Abe has remained confident – at least most of the time – as well as comfortable with numbers and shifting contexts. He has had three research internships. The first was the summer after his sophomore year when he had a paid internship at Northwestern University’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) in Evanston, Illinois, in a rather niche but fascinating area of speculative research called astrobiology. There Abe analyzed mathematical models of theoretical predator-prey systems not limited to planet Earth.
The summer before his junior year, Abe headed down to San Diego for another paid internship, this time at the U.S. Department of Energy’s DIII-D National Fusion Facility. The facilty consists of a tokamak, a magnetic fusion device which Abe describes as “a big metal donut spinning plasma to get fusion energy.” Abe used magnetohydrodynamics (MHD) theory to model plasma confinement, with the goal of understanding which conditions better spread heat flux in the divertor region.
In his third research experience, Abe spent more than two years working in physics department head Heidi Schellman’s Particle Physics Research Group, analyzing neutrino-antineutrino data as part of the MINERvA, a major international research effort exploring matter-antimatter differences in neutrino physics. This involved aiming a beam of neutrinos from Illinois to South Dakota. Specifically, Abe worked on the recoil energies recorded when the rare neutrino-antineutrino reactions hit parallel strips of the scintillator, each of which is connected to a photomultiplier tube that determines how much energy is deposited in a strip.
Abe’s research experiences beyond the classroom gave him many advantages. For one, the DIII-D fusion internship formed the basis for his senior thesis. He also learned valuable lessons about the nature of scientific work.
“Unlike class, where there is always an answer, research is open-ended. It was difficult for me at first, but I came to appreciate that even if you don’t solve a problem, you are contributing to a much larger research effort with scientists around the world that will one day lead to a solution.”
Throughout his four years at OSU, community and relationships were key to Abe’s success, a sentiment reflected in his two top pieces of advice for new students.
“Have as much fun as you can freshman year. Talk toeveryone. You will have the most free time this year and so it’s a great time to meet new people and make friends. It gets harder after that.”
As an Honors College freshman, Abe enjoyed meeting friends in his dorm, Cauthorne, and also hung out in West so often that he was mistaken as a resident. He was and is “surprised by the amount of really smart people here. So many amazing people – and it’s so cool now to see all of my friends going off to exciting new destinations next year, from MIT to Brown to AI research!”
His second piece of advice?
“Talk to professors. Go to office hours. Not just to talk about academics, but just to talk about life. It’s helped me out a lot.”
Some of his favorite professors to hang out with are physicists Corinne Monogue, who he calls a “great teacher and person to talk to about anything at all” and Heidi Schellman. Abe suggests another good reason to talk with professors:  It’s a “great way to start research sooner.”
To wit, when Abe visited to Schellman during her office hours, she began describing her research and Abe just jumped in and asked if he could help.
“That day she gave me a key to her lab and I started doing research!” Two years later, Abe still has a coveted seat in Schellman’s Lab and is currently mentoring a new student to take his place after graduation.
Despite his success at OSU, Abe has faced his share of rejection and challenging times. Before joining the Schellman Lab, he was turned down as a freshman for research positions. The fall of his senior year was a really difficult time. After an intense summer working at the fusion facility DIII-D in San Diego, he returned to campus for a nonstop term which on top of his usual demanding coursework included studying for the Physics GRE, applying to graduate schools, writing his senior thesis and dealing with the inevitable “personal stuff.”
“I was overwhelmed and my confidence was shaken. Was I good enough? I had imposter syndrome. The only thing that got me out of it,” Abe reflects, “was just to endure. I just kept going step by step, every single day. I had to keep going and I did and it finally got better.”
It certainly did. Abe was accepted into the physics Ph.D. program at Stonybrook University in Long Island, New York, remarking with great enthusiasm upon the fact that there are no less than “60-70 physics researchers there!” Not wasting any time, he will jumpstart his graduate research this summer at CERN in Geneva, Switzerland, working on a yet-to-be-defined research project with his graduate advisor.
Abe is grateful for the science education he has received at Oregon State and was not surprised when he heard that the Department of Physics recently received a national award for improving undergraduate physics education.
“All of my professors were great,” he said. The junior-year Paradigms in Physics series in particular, which was redesigned to include interactive pedagogies and real-world applications to better reflect how professional physicists think, was a real game-changer for Abe.
“[The junior-year Paradigms in Physics] was hard, but it was great and everyone in the class bonded together. We came out feeling that we could do anything!”
Abe’s gratitude extends to the many scholarships he received that helped cement his choice to go to Oregon State. He received the university’s four-year Academic Achievement award as well as a freshman year Honors College scholarship, a Kenneth S. Krane Scholarship in Physics and a David B. Nicodemus Scholarship in Physics.

The Ostroverkhova group’s work on bee vision had attracted a lot of attention!

Ostroverkhova et al examined responses of wild bees to traps designed to selectively stimulate either the blue or the green photoreceptor using sunlight-induced fluorescence in the 420-480 nm or 510-540 nm region. Image credit: Rebekka D.

KATU has an interview with Oksana Ostroverkhova at: https://katu.com/news/local/wild-bees-are-attracted-to-blue-fluorescent-light-oregon-state-university-research-finds

Sci-news has an article http://www.sci-news.com/biology/bees-blue-fluorescent-light-06121.html

and there is a press release to go with their recent paper in Journal of Comparative Physiology A. https://link.springer.com/article/10.1007/s00359-018-1269-x

CORVALLIS, Ore. – Researchers at Oregon State University have learned that a specific wavelength range of blue fluorescent light set bees abuzz.

The research is important because bees have a nearly $15 billion dollar impact on the U.S. economy – almost 100 commercial crops would vanish without bees to transfer the pollen grains needed for reproduction.

“The blue fluorescence just triggered a crazy response in the bees, told them they must go to it,” said the study’s corresponding author, Oksana Ostroverkhova. “It’s not just their vision, it’s something behavioral that drives them.”

The findings are a powerful tool for assessing and manipulating bee populations – such as, for example, if a farmer needed to attract large numbers of bees for a couple of weeks to get his or her crop pollinated.

“Blue is broad enough wavelength-wise that we needed to figure out if it mattered to the bees if the light emitted by the sunlight-illuminated trap was more toward the purple end or the green end, and yes, it mattered,” Ostroverkhova said. “What’s also important is now we’ve created traps ourselves using stage lighting filters and fluorescent paint – we’re not just reliant on whatever traps come in a box. We’ve learned how to use commercially available materials to create something that’s very deployable.”

Fluorescent light is what’s seen when a fluorescent substance absorbs ultraviolet rays or some other type of lower-wavelength radiation and then immediately emits it as higher-wavelength visible light – think about a poster whose ink glows when hit by the UV rays of a blacklight.

Like humans, bees have “trichromatic” vision: They have three types of photoreceptors in their eyes.

Both people and bees have blue and green receptors, but the third type for people is red while the third kind for bees is ultraviolet – electromagnetic energy of a lower wavelength that’s just outside the range of human vision.

Flowers’ vibrant colors and patterns – some of them detectable only with UV sight – are a way of helping pollinators like bees find nectar, a sugar-rich fluid produced by plants. Bees get energy from nectar and protein from pollen, and in the process of seeking food they transfer pollen from a flower’s male anther to its female stigma.

Building on her earlier research, Ostroverkhova, a physicist in OSU’s College of Science, set out to determine if green fluorescence, like blue, was attractive to bees. She also wanted to learn whether all wavelengths of blue fluorescence were equally attractive, or if the drawing power tended toward the green or violet edge of the blue range.

In field conditions that provided the opportunity to use wild bees of a variety of species – most bee-vision studies have been done in labs and used captive-reared honeybees – Ostroverkhova designed a collection of bee traps – some non-fluorescent, others fluorescent via sunlight – that her entomology collaborators set up in the field.

Under varying conditions with a diverse set of landscape background colors, blue fluorescent traps proved the most popular by a landslide.

Researchers examined responses to traps designed to selectively stimulate either the blue or the green photoreceptor using sunlight-induced fluorescence with wavelengths of 420 to 480 nanometers and 510 to 540 nanometers, respectively.

They found out that selective excitation of the green photoreceptor type was not attractive, in contrast to that of the blue.

“And when we selectively highlighted the blue photoreceptor type, we learned the bees preferred blue fluorescence in the 430- to 480-nanometer range over that in the 400-420 region,” Ostroverkhova said.

Findings were recently published in the Journal of Comparative Physiology A. The Agricultural Research Foundation and OSU supported this research.

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Editor’s note: Images are available at http://bit.ly/2JO7ypl and http://bit.ly/2MA4080

The Ostraverkhova group’s work on xylindein, an organic semiconductor produced naturally by fungi, has been featured in a press release.

http://today.oregonstate.edu/news/fungi-produced-pigment-shows-promise-semiconductor-material

June 5, 2018
CORVALLIS, Ore. – Researchers at Oregon State University are looking at a highly durable organic pigment, used by humans in artwork for hundreds of years, as a promising possibility as a semiconductor material.
Findings suggest it could become a sustainable, low-cost, easily fabricated alternative to silicon in electronic or optoelectronic applications where the high-performance capabilities of silicon aren’t required.
Optoelectronics is technology working with the combined use of light and electronics, such as solar cells, and the pigment being studied is xylindein.
“Xylindein is pretty, but can it also be useful? How much can we squeeze out of it?” said Oregon State University physicist Oksana Ostroverkhova. “It functions as an electronic material but not a great one, but there’s optimism we can make it better.”
Xylindien is secreted by two wood-eating fungi in the Chlorociboria genus. Any wood that’s infected by the fungi is stained a blue-green color, and artisans have prized xylindein-affected wood for centuries.
The pigment is so stable that decorative products made half a millennium ago still exhibit its distinctive hue. It holds up against prolonged exposure to heat, ultraviolet light and electrical stress.
“If we can learn the secret for why those fungi-produced pigments are so stable, we could solve a problem that exists with organic electronics,” Ostroverkhova said. “Also, many organic electronic materials are too expensive to produce, so we’re looking to do something inexpensively in an ecologically friendly way that’s good for the economy.”
With current fabrication techniques, xylindein tends to form non-uniform films with a porous, irregular, “rocky” structure.
“There’s a lot of performance variation,” she said. “You can tinker with it in the lab, but you can’t really make a technologically relevant device out of it on a large scale. But we found a way to make it more easily processed and to get a decent film quality.”
Ostroverkhova and collaborators in OSU’s colleges of Science and Forestry blended xylindein with a transparent, non-conductive polymer, poly(methyl methacrylate), abbreviated to PMMA and sometimes known as acrylic glass. They drop-cast solutions both of pristine xylindein and a xlyindein-PMMA blend onto electrodes on a glass substrate for testing.
They found the non-conducting polymer greatly improved the film structure without a detrimental effect on xylindein’s electrical properties. And the blended films actually showed better photosensitivity.
“Exactly why that happened, and its potential value in solar cells, is something we’ll be investigating in future research,” Ostroverkhova said. “We’ll also look into replacing the polymer with a natural product – something sustainable made from cellulose. We could grow the pigment from the cellulose and be able to make a device that’s all ready to go.
“Xylindein will never beat silicon, but for many applications, it doesn’t need to beat silicon,” she said. “It could work well for depositing onto large, flexible substrates, like for making wearable electronics.”
This research, whose findings were recently published in MRS Advances, represents the first use of a fungus-produced material in a thin-film electrical device.
“And there are a lot more of the materials,” Ostroverkhova said. “This is just first one we’ve explored. It could be the beginning of a whole new class of organic electronic materials.”
The National Science Foundation supported this research.
About the OSU College of Science:  As one of the largest academic units at OSU, the College of Science has seven departments and 12 pre-professional programs. It provides the basic science courses essential to the education of every OSU student, builds future leaders in science, and its faculty are international leaders in scientific research.

 

Rebecca Grollman, Graham Founds, Rick Wallace and  Oksana Ostroverkhova’s paper “Simultaneous fluorescence and surface charge measurements on organic semiconductor-coated silica microspheres” has been featured by Advances in Engineering  as a key scientific article contributing to excellence in science and engineering research.  See

https://advanceseng.com/simultaneous-fluorescence-surface-charge-measurements/

for a short summary of the paper and a short video highlighting the result.

Model predictions for flux vs time(solid lines) compared to observations (symbols).
GW170817, detected on August 17, 2017, was the first multi-messenger astronomical source, seen in gravitational waves and across the whole electromagnetic spectrum. Much of the physics of this source has been understood thanks to the high quality data collected for months after the initial detection. We now know that it was due to the collision between two neutron stars, a class of very massive and compact stars that were in orbit around each other and eventually merged forming a black hole. During the collision material was flung out in all directions. Most of the material was sent in the equatorial direction, where new atoms – such as gold and platinum – were formed through rapid neutron capture. Some material was sent in the polar direction, but exactly how much and with what energy is not known, since our observing geometry is far from the polar axis. For that reason, it had been impossible to ascertain whether a short gamma-ray burst also took place with the star collision.
Short gamma-ray bursts are some of the brightest explosions recorded in present day universe. They are produced when extremely fast outflows are sent in our direction by leftover material that accretes onto a newly formed black hole. Scientists believe they should be caused by a neutron star collision, but direct evidence is not yet available. When we detect  the burst directly, it is so bright that outshines all the signs of the neutron star collision. Groundbreaking research performed by the astrophysics group led by Dr. Lazzati and accepted for publication in Physical Review Letters, however, has shown that the unusual increase of the luminosity of GW170817 over time is a sign that a short GRB did happen right after the merger, albeit along a different direction. The figure displays the model predictions (solid lines) along with the observations (symbols), showing the excellent agreement of the model with the data.

Just a reminder that our annual Yunker Lecture is this Friday the 20th.

Laura Greene (center) in her natural habitat

 

330 PM in Weniger 328 is a reception/poster show

500 PM in Weniger 151 is the lecture by Prof. Laura Green, Chief Scientist at the National Magnetic Field Laboratory and past president of the American Physical Society.

http://impact.oregonstate.edu/2018/04/yunker-lecture-explores-dark-energy-quantum-materials/  has a longer description.  One correction is that the reception is now in Weniger 328 instead of 379.

 

Prof. Janet Tate has been named one of three Oregon State University’s 2018 Distinguished Professor honorees for 2018

From the press release:

Janet Tate setting up her superconducting demonstration.

The university has presented the Distinguished Professor award annually since 1988 to active OSU faculty members who have achieved extraordinary national and/or international stature for their contributions in research and creative work, education, outreach and engagement, and service.

Professor Tate’s research focuses on creating new semiconductors with transparent circuits with electrical and optical properties that help solve problems such as the efficient conversion of solar energy and efficient light emission. Her research stimulated the invention of the transparent oxide transistor, the enabling technology for the Retina 5K display now found in many Apple products. Tate’s contributions in the classroom earned her the Frederick H. Horne Award for Sustained Excellence in Teaching Science in 2002 and two OSU Mortar Board top professor awards.

For more information regarding the 2018 Distinguished Professors, please visit the OSU news release on the award recipients here.

 

 

Molecular motor mystery solved: Novel protein rounds out plant cells’ machinery

A research team led by Prof. Weihong Qiu and collaborators from University of California, Davis has discovered a novel motor protein that significantly expands current understanding of the evolution and design principle of motor proteins.

White arrowheads indicate the microtubule plus end, and red and yellow arrowheads indicate the leading ends of two different actin filaments.

The findings of the research team, led by of the OSU College of Science and Bo Liu ­of UC Davis, were published today in Nature Communications.

Read the full OSU announcement at: http://today.oregonstate.edu/news/molecular-motor-mystery-solved-novel-protein-rounds-out-plant-cells%E2%80%99-machinery

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Trio Receives Prestigious Scialog Award To Study Collective Cancer Cell Dynamics

A cancerous tumor has cells that act as leaders as the tumor invades and degrades the body’s extracellular matrix, a collection of molecules secreted by healthy cells that provides for their structural and biochemical support. Little is known about how cancer cells become leader cells or how a hierarchy is established as the invasion moves forward.

Three scientists — Michelle Digman, University of California Irvine, Steve Pressé, Arizona State University, and Bo Sun, Oregon State University – have formed a collaboration to screen novel metabolic and rheological (i.e., flow) markers within an invading group of cancer cells. Specifically they aim to determine the probabilities of a cell belonging to a certain type within the invading tumor, and also determine how to eliminate leading cells, as well how new leaders are “elected.”

Among the three scientists, who have not worked together before, there is considerable expertise in live cell imaging and analysis, mathematical analysis and statistical modeling, and tumor patterning and cancer migration.

Digman, Presse and Sun formed their collaboration at the most recent Scialog: Molecules Come to Life conference organized by the private foundation Research Corporation for Science Advancement (RCSA).
Scialog is a combination of “science” plus “dialog.” The unique conference encourages early career scientists to form multidisciplinary teams to identify and tackle critical research challenges. The program is designed to fund highly innovative, but untested, ideas with the potential for high impact on challenges of global significance.

“Funding early stage, potentially high-impact research of this nature can be riskier than funding well-established lines of research,” notes RCSA Senior Program Director Richard Wiener, “but it represents an approach to accelerating the pace of breakthrough scientific discoveries.”

The $168,750 in funding for the trio’s research is provided by the Gordon and Betty Moore Foundation, which is co-sponsoring Scialog: Molecules Come to Life.

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About Research Corporation for Science Advancement (RCSA):
Founded in 1912, Research Corporation for Science Advancement (www.rescorp.org) is the second-oldest foundation in the United States (after the Carnegie Corporation) and the oldest foundation for science advancement. RCSA is a leading advocate for the sciences and a major funder of scientific innovation and of research in America’s colleges and universities.

Media Contact:
Research Corporation for Science Advancement
Dan Huff
520-571-7817
dhuff@rescorp.org

The work of OSU physics graduate student Lee Aspitarte was featured as a Scientific Highlight on the American Institute of Physics website. Lee’s recent experiments in Ethan Minot’s lab provide new insights about nanoscale pn-junctions. Nanoscale pn-junctions are a promising technology for maximizing the efficiency of light-to-electricity conversion.