Ecology and Evolution of Diseases
in Complex, Natural Systems
Wolf 926F in Yellowstone
Photo: Jort Vanderveen
Photo: Jort Vanderveen
Nicole Nova is a PhD candidate in Biology (Ecology and Evolution track), a Stanford Data Science Scholar and a Philanthropic Educational Organization (PEO) Scholar at Stanford University. She also recently earned an MS in Statistics from Stanford University. Nicole is co-advised by Prof. Erin Mordecai and Prof. Dmitri Petrov, and she is a member of the Program for Disease Ecology, Health and the Environment and the Program for Conservation Genomics.
Nicole is studying the ecology and evolution of (re)emerging infectious diseases in complex, natural systems. This includes vector-borne diseases and diseases that are transmitted among different species. Nicole combines mathematical modeling and complexity science with statistics and data science to study the ecology, evolution and emergence of infectious diseases in humans and wildlife. She uses approaches from disease ecology, population dynamics, phylodynamics, population genetics, eco-evolutionary dynamics, evolutionary and comparative genomics to study pathogen adaptation and cross-species transmission, i.e., spillover (COVID-19 is a novel spillover example). She also studies climate drivers of infectious disease dynamics, and environmental predictors of pathogen sharing across taxa.
In general, her research focuses on how anthropogenic change impacts environmental health, and gives rise to emerging infectious diseases threatening public health and wildlife conservation. The goal of her research is to find environmentally sustainable win-win solutions for health and conservation (based on the concept of EcoHealth, One Health, and Planetary Health). Nicole aims to protect and promote health, biodiversity, and conservation through research and policy.
Before Nicole enrolled at Stanford, she completed her undergraduate and graduate studies in dental surgery at Karolinska Institutet in Sweden. Nicole also conducted biomedical research, and completed a Master's thesis on the pathophysiology of chronic pain in rheumatoid arthritis. This was conducted in the Molecular Pain Lab in collaboration with the Department of Physiology and Pharmacology and the Department of Oral Physiology at Karolinska Institutet (more information can be found here).
Nicole also studied abroad for a semester at Queen Mary University of London as an EU Erasmus Mundus scholar, and completed a clinical summer internship at the Department of Head and Neck Surgery, Medical University of Vienna, Austria. She worked on several head and neck cancer cases and became interested in the development of cancer at the cell population level. That spark of interest led her to study ecology and evolutionary biology, and its useful applications in medicine, public health, and planetary health.
Nicole decided to pursue a career in research after her first forays into academic research at Karolinska Institutet, Harvard and MIT as a high school student. She also wanted to combine research with clinical practice as a surgeon to help advance medicine and improve health. In her early career as a surgeon, Nicole became frustrated that she and other clinicians were often treating cases that were (or ultimately became) beyond repair. Most medical treatments were temporary and often had side effects, whereas Nicole's desire was to prevent many diseases at their origin. For example, the underlying cause of cancer or an emerging infectious disease is the spontaneous mutation of a single cell or pathogen. The progression of the disease is driven by complex evolutionary and ecological processes inside the body and outside in the environment. Thus, Nicole decided to pursue PhD studies in ecology and evolutionary biology in order to seek sustainable solutions for disease prevention.
The study of complex evolutionary and ecological processes is highly quantitative. Throughout her life, Nicole developed a strong affinity for mathematics, and became fascinated by mathematical biology and its applications in medicine by modeling ecological and evolutionary processes. To strengthen her quantitative foundation, she completed coursework in mathematics and computer science at the Royal Institute of Technology in Sweden (here is a video of a robot that she and a team of engineering students built using Segway technology).
In 2014, Nicole started working in the Michor Lab at the Department of Data Science, Dana-Farber/Harvard Cancer Center (Dana-Farber Cancer Institute, Harvard Medical School and Harvard T.H. Chan School of Public Health). She worked on mathematical modeling of cancer development using theories from evolutionary dynamics and population genetics.
In 2015, Nicole started working as a Research Associate in the Koelle Research Group in the Department of Biology at Duke University. There she studied eco-evolutionary dynamics of infectious diseases. She formulated a mathematical model that captured the development of broadly neutralizing antibodies (BnAbs) in chronic HIV-infections. This allowed her to study the within-host co-evolution between BnAbs and HIV, which could potentially provide useful insights for developing effective HIV vaccines.
This journey led her to study the ecology and evolution of infectious diseases using mathematical and statistical modeling at Stanford. Over the years studying ecology and evolution, Nicole became more aware of the synergies between health and conservation. Climate change, habitat destruction, deforestation and poaching often threaten not only natural ecosystems, wildlife, and endangered species, but also human health. For example, spillover of emerging infectious diseases from wildlife to humans (e.g., SARS, Nipah, Hendra, MERS, and most recently, COVID-19) has increased over the years as a consequence of human encroachment into wild habitats, damaged ecosystems, species removal, illegal hunting, and/or poor living conditions of captive wild animals and domestic animals. Raised next to a horse farm and a nature preserve in the Swedish woods, Nicole has always been passionate about helping animals, and understands the value of preserving nature. Nicole's mission is to protect nature and prevent future pandemics via sustainable win-win solutions for public health and conservation of wildlife.
The overall research topic concerns ecological and evolutionary drivers of emerging infectious diseases in humans and wildlife. Dissertation chapters are described below. Other research projects can be found in publications. Due to the current pandemic, I also joined a team that developed a model for long-term intervention strategies for COVID-19 (for more information visit covid-measures.stanford.edu), and a team that built the How We Feel app for tracking self-reported symptoms, health conditions and test results of COVID-19.
This is a phylogenetic study of a multi-host pathogen, called canine distemper virus. It has caused several outbreaks in the wolf population in Yellowstone National Park since the wolf reintroduction in 1995 and 1996. This study investigates whether the viral strains that caused the different canine distemper outbreaks in Yellowstone are closely related or not, suggesting either endemic persistence of canine sitemper virus in Yellowstone, or new introductions of the virus from elsewhere. Canine distemper has spilled over across many different species (not humans, yet). Because of its high mortality and rapid transmission it poses a major threat to wild carnivores such as wolves, bears, and foxes (and also endangered species such as tigers and snow leopards).
This is a cross-species phylodynamic study of canine distemper virus in the Alaskan ecosystem. This study investigates the relatedness of different canine distemper virus strains across different carnivore species (grizzly bears, black bears, wolves, coyotes, and wolverines) and mesocarnivore species (Arctic foxes, red foxes, river otters) to predict potential transmission pathways and reservoir host species.
This is a project that determines when ecological factors (i.e., geography, host behavior, host life history, etc.) become more important for predicting parasite sharing between various host species than their phylogenetic relatedness (evolutionary factor). This is useful for predicting the most likely source of new emerging diseases threatening human health and the survival of endangered species.
This study uses an empirical dynamic modeling (EDM) approach to detect causality between ecological drivers and incidence in a complex vector-borne disease system: dengue dynamics in the Americas. Dengue is a mosquito-borne disease and the climate may affect mosquito survival, abundance, and thus disease transmission. EDM demonstrates that population dynamics (i.e., pool of susceptible individuals) modulates the climate effects (i.e., temperature and rainfall) on dengue incidence. This interdependency is important to consider when building models that forecast dengue epidemics for public health interventions. This study was published in Ecology Letters. doi:10.1111/ele.13652
* denotes co-first authorship
Glidden CK*, Nova N*, Kain MP, Lagerstrom KM, Skinner EB, Mandle L, Sokolow SH, Plowright RK, Dirzo R, De Leo GA, Mordecai EA. 2021.
Human-mediated impacts on biodiversity and the consequences for zoonotic disease spillover.
Current Biology. In press.
Authorea preprint
Nova N. 2021. Cross-species transmission of coronaviruses in humans and domestic mammals, what are the ecological mechanisms driving transmission, spillover, and disease emergence? Frontiers in Public Health. 9:717941. In press. Authorea preprint
doi:10.3389/fpubh.2021.717941
Childs ML*, Kain MP*, Harris MJ*, Kirk DG, Couper LI, Nova N, Delwel I, Ritchie J, Becker AD, Mordecai EA.
2021.
The impact of long-term non-pharmaceutical interventions on COVID-19 epidemic dynamics and control: the value and limitations of early models. Proceedings of the Royal Society B. 288(1957):20210811.
doi:10.1098/rspb.2021.0811
Couper LI, Farner JE, Caldwell JM, Childs ML, Harris MJ, Kirk DG, Nova N, Shocket MS, Skinner EB, Uricchio LH, Exposito-Alonso M, Mordecai EA.
2021.
How will mosquitoes adapt to climate warming?
eLife. 10:e69630.
doi:10.7554/eLife.69630
Hopkins SR, Sokolow SH, Buck JC, De Leo GA, Jones IJ, Kwong LH, LeBoa C, Lund AJ, MacDonald AJ, Nova N, Olson SH, Peel AJ, Wood CL, Lafferty KD. 2021. How to identify win–win interventions that benefit human health and conservation. Nature Sustainability. 4(4):298–304.
doi:10.1038/s41893-020-00640-z
Athni TS, Shocket MS, Couper LI, Nova N, Caldwell IR, Caldwell JM, Childress JN, Childs ML, De Leo GA, Kirk D, MacDonald AJ, Olivarius K, Pickel DG, Winokur OC, Young HS, Cheng J, Grant EA, Kurzner PM, Kyaw S, Lin BJ, López RC, Massihpour DS, Olsen EC, Roache M, Ruiz A, Schultz EA, Shafat M, Spencer RL, Bharti N, Mordecai EA. 2021. The influence of vector-borne disease on human history: socio-ecological mechanisms. Ecology Letters. 24(4):829–846.
doi:10.1111/ele.13675
Nova N, Deyle ER, Shocket MS, MacDonald AJ, Childs ML, Rypdal M, Sugihara G, Mordecai EA. 2021. Susceptible host availability modulates climate effects on dengue dynamics. Ecology Letters. 24(3):415–425.
doi:10.1111/ele.13652
Allen WE*, Altae-Tran H*, Briggs J*, Jin X*, McGee G*, Shi A*, Raghavan R, Kamariza M,
Nova N, Pereta A, Danford C, Kamel A, Gothe P, Milam E, Aurambault J, Primke T, Li W, Inkenbrandt J, Huynh T, Chen E, Lee C, Croatto M, Bentley H, Lu W, Murray R, Travassos M, Coull BA, Openshaw J, Greene CS, Shalem O, King G, Probasco R, Cheng DR, Silbermann B, Zhang F, Lin X. 2020. Population-scale longitudinal mapping of COVID-19 symptoms, behaviour and testing. Nature Human Behaviour. 4(9):972–982.
doi:10.1038/s41562-020-00944-2
Smith JR, Hendershot JN, Nova N, Daily GC. 2020. The biogeography of ecoregions: Descriptive power across regions and taxa. Journal of Biogeography. 47(7):1413–1426. doi:10.1111/jbi.13871
Sokolow SH, Nova N, Pepin MK, Peel AJ, Pulliam JRC, Manlove K, Cross PC, Becker DJ, Plowright RK, McCallum H, De Leo GA. 2019. Ecological interventions to prevent and manage zoonotic pathogen spillover. Philosophical Transactions of the Royal Society B. 374(1782):20180342. doi:10.1098/rstb.2018.0342
Childs ML, Nova N, Colvin J, Mordecai EA. 2019. Mosquito and primate ecology predict human risk of yellow fever virus spillover in Brazil. Philosophical Transactions of the Royal Society B. 374(1782):20180335. doi:10.1098/rstb.2018.0335
Nova N, Pagliara R, Gordon DM. Individual variation does not regulate foraging response to humidity in harvester ant colonies. Under review.
Leempoel K*, Nova N*, Meyer JM, Hebert T, Hadly EA. Return of an apex predator (Puma concolor) to a suburban preserve triggers a rapid behaviorally-mediated trophic cascade. In revision.
Sokolow SH, Jones IJ, Wood CL, Lafferty KD, Garchitorena A, Hopkins SR, Lund AJ, MacDonald AJ, Nova N, Le Boa C, Peel AJ, Mordecai EA, Chamberlin A, Howard ME, Buck JC, Lopez-Carr D, Barry M, Bonds M, De Leo GA. More than one third of global human infectious disease burden is environmentally mediated, with disproportionate effects in rural poor areas. In revision. The Lancet preprint
Hopkins SR, Lafferty KD, Wood CL, Olson SH, Buck JC, De Leo GA, Fiorella KJ, Fornberg J, Garchitorena A, Jones IJ, Kuris AM, Kwong LH, LeBoa C, Leon AE, Lund AJ, MacDonald AJ, Metz DCG, Nova N, Peel AJ, Remais JV, Stewart Merrill TE, Wilson M, Bonds MH, Dobson AP, Lopez Carr D, Howard ME, Mandle L, Sokolow SH. Diversity and evidence gaps among potential win–win solutions for conservation and human infectious disease control. Under review.
Kirk DG*, Skinner EB*, Shocket MS, Couper LI, Nova N, Athni TS, Pourtois JD, Farner JE, Childs ML, Nyathi S, Mordecai EA. Climate Change and Disease Ecology. In: Suzán G, Aguirre AA, Mills JM, editors. The Ecology of Infectious Diseases: Methods on Evolution, Biodiversity, and Environmental Interactions. Oxford University Press. In press.
Shocket MS, Anderson CB, Caldwell JM, Childs ML, Couper LI, Han S, Harris MJ, Howard ME, Kain MP, MacDonald AJ, Nova N, Mordecai EA. 2021. Environmental drivers of vector-borne diseases. In: Drake JM, Bonsall M, Strand M, editors. Population Biology of Vector-borne Diseases (Ecology and Evolution of Infectious Diseases Series).
Oxford University Press.
ISBN:9780198853244
Van Wert M, Nova N, Horowitz T, Wolfe J. 2008. What does performance on one visual search task tell you about performance on another? Journal of Vision. 8(6):312. doi:10.1167/8.6.312
Nova N, Alstergren P, Svensson C. 2012. Chronic inflammation and pain: Assessment of c-Fos and ATF-3 as markers of spinal neuronal activity in a pain model of rheumatoid arthritis. M.Sc. Thesis, Karolinska Institutet. PDF
Nicole is also a graphic designer and a scientific illustrator. Here is a piece named The Beauty of Mathematical Modeling in Biology that she created as a final project in CS 148: Introduction to Computer Graphics and Imaging at Stanford Univerity. Below is a sample portfolio of her artwork used for scientific publications, conference logos, or personal use. The silhouettes displayed on this website have also been created by Nicole.
RSI is a summer research program for high school students at Massachusetts Institute of Technology (MIT) and co-sponsored by the Center for Excellence in Education (CEE). Nicole attended RSI as a student in 2007 and she worked with Prof. Jeremy Wolfe in the Visual Attention Lab in the Department of Brain and Cognitive Sciences at Harvard Medical School and Brigham and Women's Hospital. She was investigating whether a simple search task (i.e., looking for a green line among red lines) was correlated with the search for objects in the real world, in particular, the search for weapons in airport security (X-ray images of luggage). The work was later published in the Journal of Vision. As an RSI alum, Nicole has been involved with the RSI program for several years and served as the Director of RSI in 2016, and a research mentor in 2020. For more information, see the CEE Alumni Spotlight press release page.
Rays is a summer research program for high school students, similar to Research Science Institute (RSI), but located in Sweden and it was founded in 2011. The first couple of years were run by Swedish RSI alumni (including Nicole), before Rays alumni could also hold staff positions. Mentorships are being held at various universities in Stockholm, such as Karolinska Institutet, Stockholm University and the Royal Institute of Technology. After a summer-long internship in a research lab, the Rays students present their projects in the Swedish Museum of Science and Technology.
