"Is the water safe to swim in ?" That's the question that crossed the minds of Annie Chang and Daisy Chen, two 9th graders from Woodbridge High School, Irvine, and brother-sister team Hari and Anita Garg from University High School, Irvine after observing the confluence of pets, toddlers and river effluent at one of our local beaches last summer. They wondered whether certain sites in our local watershed harbor high concentrations of coliform bacteria that might elevate risks to human health. So they set out to find some answers. But what initially had seemed like a straight forward question, they quickly came to realize was a complex problem with no easy answers and no simple single methodology.
Under mentorship from Dr. Felix Grün (CCBS) and Dr. Michelle Digman (BME) they spent last summer collecting water samples along the ocean coastline, at river outlets and throughout Newport Bay, and analysing them for bacterial contaminants using a variety of quantitative laboratory techniques including bacterial colony forming plate and growth assays, species-specific qPCR, and applying a novel sensitive fluorescence particle counting instrument developed at UCI's Laboratory of Fluorescence Dynamics. Quantitative data on bacterial levels - along with real time weather, tidal and water flow data - were then used as input parameters for a research grade hydrodynamic and biogeochemical computational simulator (ELCOM-CAEDYM, Centre for Water Research, UWA) able to model the three-dimensional temporal and spatial dynamics of complex water transport processes and their ecological responses.
Annie and Daisy's modeling results, together with Hari and Anita's surveys, highlighted the highly dynamic (and sometimes surprising) interactions throughout our watershed. Notable was the distribution of high coliform counts in the Upper Bay around areas of freshwater input sources, e.g. runoff from marshes and golf courses, that were also subject to inefficient tidal flushing, and the rapid decline in viable bacterial counts at most ocean locations due to dilution effects and inhospitable growth conditions. So appearances aren't everything: the Upper Newport Bay ecological preserve might look tempting but is not a good place for a swim; swimming close to the Santa Ana river outlet ... well that depends on the time, tide and weather events.
Annie and Daisy won 1st Prize in Environmental Science for their project entitled "Multimethod Analysis and Spatial Modeling of Bacterial Dynamics in the Newport Bay Watershed" at the Orange County Science & Engineering Fair in April and took 4th place at the California statewide competition held at the Staples Center, Los Angeles in May. Their work also received recognition with additional awards from the Irvine Ranch Water District, Orange County Sea and Sage Audobon Society and the California Shore and Beach Preseveration Association. Hari and Anita Garg also excelled with their project entilted "Pathogen Detection in Southern California Water Using a Particle Counter" being recognized by a special IRWD award, a 3rd Place in the Biological Products section of the OCSEF and also going on to compete at the California statewide competition. Congratulations to all !
Congratulations to Assistant Professor Jun Allard (Department of Mathematics and Physics & Astronomy) for receiving a 5-year NSF Career Award on the topic of "Mathematical Framework for Elucidating Mechanics at Immune Cell Interfaces."
Dr. Allard's work will focus on developing mathematical models of the physical interactions at cell-cell interfaces, with particular emphasis on immune cells that need to decipher information - relevant to self and non-self recognition and disease processes - from transient dynamic cellular contacts. The dynamics at these interfaces involve an interplay between transport, mechanics and chemical kinetics, and play out over a range of length and time-scales, necessitating a combination of mathematical techniques, including systems of elliptic, parabolic and stochastic differential equations; computational fluid dynamics of liquid-structure interactions; Brownian dynamics; as well as Bayesian statistics that leverages quantitative experimental data. This work therefore aims to provide a deeper understanding of how cells overcome and exploit physical constraints to cell-cell contact, by developing a model that integrates motion of the intracellular and extracellular fluid, Brownian motion of molecules embedded in the cell's membranes and active forces. Dr. Allard will also explore the mechanism and evolutionary advantages of molecular clustering, and develop, validate and apply mesoscale models of large flexible biomolecules to decipher their mechanical properties and biological role. These mesoscale models are suitable to exploring timescales that all-atom molecular dynamics cannot, while capturing details that particle-based simulations miss.
Results from the work will have direct implications for understanding immune function, impacting research on autoimmune disease and immunotherapy. Students recruited to these projects will have the opportunity to gain exposure to contemporary work at the interface of mathematics, biology and physics.
Anna Kicheva et al. Science (2014), 345, 1254927; DOI: 10.1126/science.
The Mitochondrial Special Interest Group will be meeting next on Friday, March 13 from 3:30 - 5:00 pm in NatSci II, Rm 2201.
Dr. Chris Kenney and Dr. Pinar Coskun will be presenting on "mtDNA."
Please contact Susanne Rafelski for additional program information and to be added to the email list.