She's been making her mark in all three since enrolling in 2016 in the UC Davis Department of Entomology and Nematology's Ph.D. program, with a designated emphasis in the biology of vector-borne diseases.
Winokur, who studies with major advisor Christopher Barker, associate professor, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, is a newly selected fellow of Professors for the Future (PFTF).
This is a program sponsored by UC Davis Graduate Studies “to recognize and develop the leadership skills of outstanding graduate students and postdoctoral scholars who have demonstrated their commitment to professionalism, integrity, and academic service.”
As a fellow, she will receive a stipend of $3000. Traditionally, approximately 12 fellows annually are selected to participate in the yearlong program, launched in 1992.
The PFTF program is designed to prepare UC Davis doctoral students and postdoctoral scholars “for an increasingly competitive marketplace and a rapidly changing university environment,” according to PFTF co-directors Ellen Hartigan-O'Connor, acting associate dean of UC Davis Graduate Studies, and Teresa Dillinger, academic administrator.
During the year, the fellows will receive formal training-in-teaching methods and course design; participate in a seminar course on ethics and professionalism, and meet regularly for roundtable panel discussions to promote their professional development, intellectual growth and leadership skills, the directors said.
The fellows will work on projects of their own design to enhance their graduate or postdoctoral experience and professional development of their colleagues. They summarize their projects in end-of-the-year reports. (See 2019-2020 fellows.)
Winokur titled her successful proposal, “Addressing Financial Barriers to Participation in STEM (Science, Technology, Engineering and Mathematics).”
“Graduate students perform many roles as researchers, mentors, educators, communicators, service leaders, and humans,” wrote Winokur, who is president of the UC Davis Entomology Graduate Student Association. “Financial insecurity affects students' abilities to perform these roles well, and provides a leg up to students with financial support beyond a graduate student stipend. We know that diversity is important in academia; cultivating talent from folks across the social spectrum leads to innovative and appropriate solutions.”
“Addressing financial barriers to participation in STEM graduate programs will lead to more diverse and inclusive programs,” she wrote. “Further, financial insecurity affects those who enters graduate school in the first place; research experience is often required to be considered for acceptance into graduate school, which unfortunately is often offered in the form of unpaid research internships. This can filter out low-income students early, making academia even more elite than it already is.”
Winokur will collaborate with existing resources on campus to set up a series of workshops to address the issues, focusing on three points: (1) creative ways to fund your research (2) how to support your research mentees—why unpaid labor filters low income and other disadvantaged students, and (3) making your teaching cheaper—how to make education more accessible for low-income and other disadvantaged students.
“I've been interested in applying to the Professors for the Future program for a couple years,” she said. “This year, I feel that I am at a good point in my graduate career to develop my skills through the PFTF coursework and to contribute to the graduate student community through a PFTF project.”
Since 2016, the UC Davis doctoral student has developed her teaching, mentoring, course development, and leadership skills through various courses and programs, “which has led to a basic understanding of my teaching philosophy and pedagogy.” She aims to develop her skills to “further align with my core values of diversity, equity, and inclusion in the classroom and laboratory.”
Olivia grew up in Laguna Niguel, Calif. where she focused on science at the Dana Hills High School Health and Medical Occupations Academy. She holds a bachelor's degree, 2015, from Cornell University, where she majored in interdisciplinary studies, focusing on the environmental effects on human health. While at Cornell, she worked as an intern for the National Institutes of Health, working on climate change initiatives for the National Institute of Environmental Health Sciences and the Fogarty International Center.
Winokur holds a National Science Foundation Graduate Research Fellowship. She is a two-time recipient of the Bill Hazeltine Memorial Research Award, given annually to an outstanding UC Davis graduate student studying vector-borne diseases.
Winokur, who researches Aedes aegypti mosquitoes, is the co-author of research published in several journals, including PLOS Neglected Tropical Diseases. Her first first-author paper, “Impact of Temperature on the Extrinsic Incubation Period of Zika Virus in Aedes aegypti” was just published in March.
Since 2017, she has served as a volunteer with the California Department of Public Health's Vector-Borne Disease Section, assisting with hantavirus and plague surveillance by rodent trapping and testing.
Winokur mentors undergraduate students in the UC Davis Research Scholars Program in Insect Biology (RSPIB), founded and directed by faculty members Jay Rosenheim, Joanna Chiu and Louie Yang, UC Davis Department of Entomology and Nematology.
Active in STEM projects, Winokur co-founded GOALS (Girls' Outdoor Adventure in Leadership and Science) in 2017, a program that develops and runs free two-week summer science programs for high school girls and gender expansive youth from backgrounds underrepresented in STEM fields. The girls learn science, outdoor skills and leadership hands-on while backpacking in Sequoia National Park./span>
- Walter Leal, distinguished professor, Department of Molecular and Cellular Biology and former chair of the Department of Entomology (now the Department of Entomology and Nematology
- Cristina Davis, the Warren and Leta Geidt Endowed Professor and Chair, Department of Mechanical and Aerospace Engineering
NIA honors and encourages academic inventions that benefit society. Between the two UC Davis faculty members, they hold 42 patents: Davis with 12; and Leal with 28 Japanese and 2 U.S. patents.
Davis is a world leader in trace chemical sensing, while Leal is a leading global scientist in the field of insect olfaction and communication, investigating how insects detect odors, how they detect host and nonhost plant matter, and how they communicate within their species.
Leal's research, spanning three decades, focuses on insects that carry mosquito-borne diseases as well as agricultural pests, such as the Asian citrus psyllid and the orange navelworm. He and his lab drew international attention with their discovery of the mode of action of DEET, the gold standard of insect repellents.
We remember when Leal and a group of 18 students hosted a Zika Public Awareness Symposium in 2016 on the UC Davis campus. It was an amazing symposium that drew attention to Aedes aeqytpi, which transmits the disease. Soon thereafter, Brazilian-born Leal and his colleagues in Brazil, detected the Zika virus in wild-caught Culex quinquefasciatus mosquitoes in Recife, the epicenter of the Zika epidemic.
We also remember when Leal identified the sex pheromones of the navel orangeworm (Amyelois transitella), a pest of almonds, figs, pomegranates and walnuts, the major hosts. This led to practical applications of pest management techniques in the fields.
Those are just several examples of the work he does. And still, he found time to co-chair the 2016 International Congress of Entomology meeting, "Entomology Without Borders," in Orlando, Fla., that drew the largest delegation of scientists and experts in the history of the discipline: 6682 attendees from 102 countries.
We're not sure how Leal can find the time to do all this (see news story on the UC Davis Department of Entomology and Nematology). We figure he must have a clone! Make that multiple clones!
At any rate, Leal is the second faculty member affiliated with the entomology department to be selected an NIA fellow. The other scientist: Bruce Hammock, distinguished professor, who holds a joint appointment in the Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center. Hammock is the co-founder and chief executive officer of EicOsis LLC, a Davis-based company that is developing a non-opiate drug to relieve inflammatory pain in companion animals and target chronic neuropathic pain in humans and horses.
As Hammock said: “When Walter Leal reached UC Davis (in 2000), he came with the reputation of being a 'one man army in research.' This reputation was well deserved. I know of no one at UC Davis who matches Walter in taking his remarkable fundamental advances in science and translating them to increase the safety and magnitude of world food production.”
Wait, there's more! "Not So Heartless: Functional Integration of the Immune and Circulatory Systems of Mosquitoes."
This may not be the proverbial heart-stopping seminar, but it promises to be an eye opener by a medical entomologist and captivating speaker.
Julián Hillyer, associate professor of biological sciences, Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tenn., will deliver that seminar at 4:10 p.m., Wednesday, Oct. 23, in 122 Briggs Hall, as part of the weekly UC Davis Department of Entomology and Nematology seminars.
"Mosquitoes--like all other animals--live under constant threat of infection," Hillyer says in his abstract. "Viral, bacterial, fungal, protozoan and metazoan pathogens infect mosquitoes through breaches in their exoskeleton and following ingestion. Because these pathogens pose a threat to their survival, mosquitoes have evolved a powerful immune system."
In his seminar, Hillyer will present his laboratory's work characterizing the circulatory and immune systems of the African malaria mosquito, Anopheles gambiae. "Specifically," he says. "the talk will describe the structural mechanism of hemolymph (insect blood), circulation in different mosquito life stages, and the role that immune cells, called hemocytes play in the killing of pathogens by phagocytosis, melanization and lysis. Then I will describe the functional integration of the circulatory and immune systems a process that is manifested differently in larvae and adults. Specifically, the infection of an adult mosquito induces the aggregation of hemocytes at the abdominal ostia (valves) of the heart--where they sequester and kill pathogens in areas of high hemolymph flow--whereas the hemocytes of larvae aggregate instead on respiratory structures that flank the posterior in current openings of the heart."
"This research," Hillyer explains, "informs on the physiological interaction between two major organ systems and uncovers parallels between how the organ systems of invertebrate and vertebrate animals interact during the course of an infection."
What does the mosquito heart look like? Check out former Vanderbilt graduate student Jonas King's prize-winning image--a fluorescent image of the heart of a mosquito. It won first place in Nikon's "Small World'" photomicrography competition in 2010. King's image shows a section of the tube-like mosquito heart magnified 100 times. At the time he was a member of Hillyer's research group and is now an assistant professor at Mississippi State University.
In a piece by David Salisbury of Vanderbilt News, Hillyer related that "Surprisingly little is known about the mosquito's circulatory system despite the key role that it plays in spreading the malaria parasite. Because of the importance of this system, we expect better understanding of its biology will contribute to the development of novel pest- and disease-control strategies.”
"The mosquito's heart and circulatory system is dramatically different from that of mammals and humans," wrote Salisbury in the Oct. 15, 2010 piece. "A long tube extends from the insect's head to tail and is hung just under the cuticle shell that forms the mosquito's back. The heart makes up the rear two-thirds of the tube and consists of a series of valves within the tube and helical coils of muscle that surround the tube. These muscles cause the tube to expand and contract, producing a worm-like peristaltic pumping action. Most of the time, the heart pumps the mosquito's blood—a clear liquid called hemolymph—toward the mosquito's head, but occasionally it reverses direction. The mosquito doesn't have arteries and veins like mammals. Instead, the blood flows from the heart into the abdominal cavity and eventually cycles back through the heart."
“The mosquito's heart works something like the pump in a garden fountain,” Hillyer told Salisbury.
Hillyer was a Vanderbilt Chancellor Faculty Fellow (2016-2018) and was awarded the 2015 Henry Baldwin Ward Medal by the America Society of Parasitologists. He was elected to the Council of the American Society of Parasitologists, serving from 2012-2016. Other recent awards: the 2011 Jeffrey Nordhous Award for Excellence in Undergraduate Teaching and the 2012 Recognition Award in Insect Physiology, Biochemistry and Toxicology from the Southeastern Branch of the Entomological Society of America.
Hillyer received his master's degree and doctorate from the University of Wisconsin-Madison under the mentorship of Ralph Albrecht and Bruce Christensen, respectively. He completed a postdoctoral fellowship under the mentorship of Kenneth Vernick at the University of Minnesota, now with Institut Pasteur. In 2007, Hillyer moved to Nashville, Tenn. to establish Vanderbilt University's mosquito immunology and physiology laboratory. (See more.)
The Hillyer Lab is interested in basic aspects of mosquito immunology and physiology, focusing on the mechanical and molecular bases of hemolymph (blood) propulsion, and the immunological interaction between mosquitoes and pathogens in the hemocoel (body cavity)," according to his website. "Given that chemical and biological insecticides function in the mosquito hemocoel, and that disease-causing pathogens traverse this compartment prior to being transmitted, we expect that our research will contribute to the development of novel pest and disease control strategies."
Host is Olivia Winokur, doctoral student in the Chris Barker lab. Community ecologist Rachel Vannette, assistant professor, Department of Entomology and Nematology, coordinates the weekly seminars. (See list of seminars)
Nine speakers are booked for the fall quarter seminars sponsored by the UC Davis Department of Entomology and Nematology. The seminars begin Wednesday, Sept. 25 and continue through Wednesday, Dec. 5.
Coordinated by assistant professor and community ecologist Rachel Vannette, the seminars will take place at 4:10 p.m., every Wednesday in Room 122 of Briggs Hall except on Nov. 20 (no seminar due to the Entomological Society of America meeting in St. Louis, Mo).
James Nieh, professor, Section of Ecology, Behavior and Evolution, Department of Biological Sciences, UC San Diego
Topic: "Animal Information Warfare: How Sophisticated Communication May Arise from the Race to Find an Advantage in a Deadly Game Between Honey Bees and their Predators" (See lab website)
Host: Brian Johnson, associate professor, Department of Entomology and Nematology
Nathan Schroeder, assistant professor, Department of Crop Sciences, University of Illinois, Urbana-Champaign
Topic: "Stem Cells and Neurobiology of Nematodes"
Host: Shahid Saddique, assistant professor, Department of Entomology and Nematology
John Mola, doctoral candidate, Neal Williams lab, Graduate Group in Ecology
Exit seminar: "Bumble Bee Movement Ecology and Response to Wildfire." Mola specializes in bee biology, pollinator ecology and population genetics.
Host: Neal Williams, professor, Department of Entomology and Nematology
Rebecca Irwin, professor, applied ecology, North Carolina State University, Raleigh, N.C.
Topic: (to be announced; she specializes in the ecology and evolution of multiple-species interactions, pollination biology, and species invasions)
Host: Rachel Vannette, assistant professor, Department of Entomology and Nematology
Julián Hillyer, director of the program in career development and associate professor of biological sciences, Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, Tenn.
Topic: "Not So Heartless: Functional Integration of the Immune and Circulatory Systems of Mosquitoes"
Host: Olivia Winokur, graduate student, Chris Barker lab
Takato Imaizumi, professor, Department of Biology, University of Washington, Seattle
Topic: Circadian Timing Mechanisms in Plant-Pollinator Interaction"
Host: Joanna Chiu, associate professor and vice chair of the Department of Entomology and Nematology
Brock Harpur, assistant professor, Department of Entomology, Purdue University
Topic: "Caste Differentiation in Honey Bees from the Bottom Up"
Host: Santiago Ramirez, associate professor, UC Davis Department of Evolution and Ecology, College of Biological Sciences
Allison Hansen, assistant professor, Department of Entomology, UC Riverside
Topic: Insect Herbivore-Microbe Interactions
Host: Clare Casteeel, assistant professor, UC Davis Department of Plant Pathology
No seminar (meeting of Entomological Society of America in St. Louis, Mo.)
Jackson Audley, doctoral candidate, Louie Yang lab and Steve Seybold lab
Exit seminar (topic to be announced). Audley studies the walnut twig beetle, Pityophthorus juglandis, which in association with the fungus, Geosmithia morbida, causes the insect-pathogen complex known as thousand cankers disease.)
Host: Steve Seybold, lecturer, forest entomology, UC Davis Department of Entomology and Nematology and forest entomologist and chemical ecologist with the Pacific Southwest Research Station, USDA Forest Service, Davis
The seminars are free and open to all interested persons. Some will be recorded for later viewing on YouTube. More information on the fall seminars or schedule is available from Vannette at email@example.com.
They manage to find us, don't they? Even when we're doing our best to try to avoid them!
It's not so well-known that mosquitoes, both male and female, frequent plants to feed on nectar for energy.
And now UC Davis chemical ecologist Walter Leal and scientists Fangfang Zen and Pingxi Xu of the Leal lab have discovered that the odorant receptors from the southern house mosquito, Culex quinquefasciatus, and the yellow fever mosquito Aedes aegypti, are sensitive to floral compounds.
The manuscript: "Odorant Receptors from Culex quinquefasciatus and Aedes aegypti Sensitive to Floral Compounds."
The team, led by Leal, a distinguished professor in the Department of Molecular and Cellular Biology and a former chair of the UC Davis Department of Entomology, cloned the genes of several odorant receptors from the mosquitoes and tested them, using egg cells of Xenopus toads. They exposed the cloned receptors to different scent chemicals.
"We are delighted to find out how mosquitoes smell plant-derived compounds and are repelled by them," Leal said. "These findings may lead to the discovery of better repellents from natural sources."
"Mosquitoes rely heavily on the olfactory system to find a host for a bloodmeal, plants for a source of energy and suitable sites for oviposition," the scientists explained in their abstract. "Here, we examined a cluster of 8 odorant receptors (ORs), which includes one OR, CquiOR1, previously identified to be sensitive to plant-derived compounds. We cloned 5 ORs from Culex quinquefasciatus and 2 ORs from Aedes aegypti, ie, CquiOR2, CquiOR4, CquiOR5, CquiOR84, CquiOR85, AaegOR14, and AaegOR15 and then deorphanized these receptors using the Xenopus oocyte recording system and a large panel of odorants. 2-Phenylethanol, phenethyl formate, and phenethyl propionate were the best ligands for CquiOR4 somewhat resembling the profile of AaegOR15, which gave the strongest responses to phenethyl propionate, phenethyl formate, and acetophenone. In contrast, the best ligands for CquiOR5 were linalool, PMD, and linalool oxide. CquiOR4 was predominantly expressed in antennae of nonblood fed female mosquitoes, with transcript levels significantly reduced after a blood meal. 2-Phenylethanol showed repellency activity comparable to that of DEET at 1%. RNAi experiments suggest that at least in part 2-phenylethanol-elicited repellency is mediated by CquiOR4 activation."
Meanwhile, Leal is gearing up for the 2019 Entomological Society of America (ESA) meeting in St. Louis, Mo., where he will deliver the Founders' Memorial Award Lecture on “Tom Eisner — An Incorrigible Entomophile and Innovator Par Excellence,” at the awards breakfast on Tuesday, Nov. 19.
ESA officials selected Leal, an ESA fellow and internationally recognized chemical ecologist, for the global honor. Leal is the first UC Davis scientist selected to present the Founders' Memorial Lecture, although medical entomologist Shirley Luckhart of the University of Idaho, formerly of UC Davis, delivered the lecture in 2018.
The 7000-member ESA is the world's largest organization serving the professional and scientific needs of entomologists and people in related disciplines. ESA, founded in 1889, is headquartered in Annapolis, Md.