Life Sciences Commons^™

Zooplankton Trophic Ecology In The San Francisco Estuary During Summer As Determined By Stable Isotope Analysis, Kyla Bradylong, Steven Westbrook, Julien Moderan, Wim Kimmerer

STAR Program Research Presentations

Declines in the abundance of several pelagic fish species in the upper San Francisco Estuary have prompted investigation into food web interactions within the estuary and delta (the lower Sacramento and San Joaquin Rivers). This area is characterized by low primary production and pelagic food webs much longer and reticulated than previously thought, implying low efficiency in the energy transfers from primary producers to planktivorous fish. We determined the carbon and nitrogen stable isotope (SI) composition of zooplankton samples collected monthly between June 2012 and February 2013 at eight stations along the salinity gradient. As consumers SI composition reflects that …

Big Babies, Big Mammas?: Relationship Of Leatherback Hatchling Size And Mother Size, Shane Morales, Violet Campbell, Kelly Stewart

STAR Program Research Presentations

Individual leatherback hatchlings vary in size when compared to individuals from other nests, as well as individuals from the same nest. It is thought that many factors affect hatchling size but that one of the most influential factors is maternal size. Of all the aspects of a mother which could affect hatchling size, evidence for question concerning influence of mother size is determinable within the field using minimal tools and basic statistical analysis. If a direct correlation exists between mother size and hatchling size then the claim can be made that larger mothers produce larger offspring while smaller mothers produce …

Effects Of Composition And Separation Techniques On The Structure Of Aggregates In The Milk Fat Globular Membrane, Tristan Dilbeck, Jose Ibarra, Rafael Jimenez-Flores, Tracey Nguyen

STAR Program Research Presentations

The milk fat globular membrane (MFGM) is a complex structure composed mainly of phospholipids, sphingolipids, and membrane specific proteins. The composition and size of the MFGM differs based on the isolation, purification, and techniques used in analysis of the membrane as well as physiological, chemical, and mechanical factors present during its creation. The purpose of this experiment is to analyze the effects of separation techniques and composition of lipids and proteins on the structure of aggregates in the MFGM. The aggregates found in whey protein isolate (95% pure whey protein), whey buttermilk (whey protein and phospholipids), and sweet buttermilk (whey …

Abundance And Distribution Of Microplankton In The San Francisco Estuary, Carrie Ann Sharitt, Lindsay Sullivan, Wim Kimmerer

STAR Program Research Presentations

Microplankton are a diverse group of planktonic organisms ranging from 0.02 to 0.2 millimeters. Since the group is defined solely by size, it spans numerous taxonomic groups, including both heterotrophs and autotrophs. Microplankton are abundant in all aquatic ecosystems and are important prey for many organism, including bivalves, crustaceans, and fish. Little is known about the microplankton community in the San Francisco Estuary, and information on their abundance and distribution will help scientists better understand their role in local foodwebs. This research quantified the abundance and distribution of microplankton in the San Francisco Estuary from 2010 to 2012. Microplankton were …

Life Support: Long Term Storage Of Solid Waste In An Enclosed Membrane System, Emmy O. Trieu, Michael Flynn, Rocco Mancinelli

STAR Program Research Presentations

In deep space missions, maintaining life support is of the utmost priority. In such a closed system, human waste must be stored and treated. Simulated feces (ersatz) will be inoculated with microbes representing normal fecal flora, mixed with urine brine and shredded refuse of products typically used in space missions. Composting methods often use alternating layers of waste with scraps of carboniferous materials (finely shredded refuse). By preparing membrane bags with a homogenized ersatz and carboniferous refuse mixture and membrane bags with alternating layers of ersatz and carboniferous refuse, it may be possible to monitor anaerobic thermophillic digestion of the …

Identifying Molecular Markers Associated With Salt And Boron Tolerance In Poplar Trees, Darshanpreet Gill, Nathan Follen, Davis W. Cheng, Kyan Salehi, Gary Banuelos, James P. Prince

STAR Program Research Presentations

Standard irrigation practices promote salt and boron accumulation in soils on the Westside of Central California. The build-up of these inorganic salts leads to the degradation of arable land and reduction of crop production. Different clones of poplar trees have been shown to grow in salt- and boron-contaminated soils, and in doing so, gradually remove significant amounts of these inorganic salts from the soil. In an effort to identify molecular markers linked with salt and boron tolerance in poplars, 31 PCR primer pairs have been designed based on candidate genes identified from the literature, and an additional 31 PCR primer …

Testing Compounds As Sole Carbon Sources Of Strains Isolated From The Hot Lake Phototrophic Mat, Lyzbeth Becerra, Stephen Lindemann

STAR Program Research Presentations

Hot Lake is a meromictic, epsomitic lake. It has a phototrophic microbial mat that reassembles every year. The mat community is subjected to large fluctuations of salinity and solar irradiance. PNNL is interested in studying how these communities respond to the fluctuating environment conditions. To date, 70 isolates have been obtained from Hot Lake with the intention of characterizing their physiology to gain a better understanding of how they are naturally functioning in the Hot Lake mat community. I tested eight of these isolates in media designed to mimic the chemistry of Hot Lake with a selection of sugars, amino …

Creating A Package In R, Brit Schneiders, Eric Archer

STAR Program Research Presentations

In a time of increasingly efficient technology and data production, scientists are producing data faster than it can be analyzed. Therefore, user accessibility to data analysis is becoming more and more critical. In general, researchers have a set of raw data and want an efficient means to their final analysis. A package serves as that means by creating a set of functions and making them accessible to the user. Often, a user has a small piece of code to run (a single R script, for example), and that script requires the use of certain functions, which are contained in a …

Jellyfish Identification And Quantification In The San Francisco Estuary, Amalia Borson, Lindsay L. Sullivan, Wim Kimmerer

STAR Program Research Presentations

As potential predators and competitors of plankton-eating fish, jellyfish have the potential to negatively impact fish populations. Jellyfish were collected weekly with plankton tows from the RombergTiburonCenterpier in Tiburon, CA. Since some jellyfish were too small to identify, one tow was collected and preserved to record abundances, and a second tow was collected to rear jellyfish until distinguishing characteristics were visible enough for identification. Jellyfish in the preserved tows were then identified, measured, and counted, and their abundance (number m^-3) was calculated. Jellyfish from the second tows were reared in plastic buckets that were lightly bubbled using aquarium …

Preservation Of Biosignature Molecules In Potential Sample Return Container Of The Mars 2020 Mission, Kimberly E. Lykens, Fei Chen Ph.D

STAR Program Research Presentations

Preservation of Biosignature Molecules in Potential Sample Return Container of the Mars 2020 Mission

Kimberly Lykens¹ and Fei Chen²

¹Wittenberg University, Springfield, Ohio 45501 ²Jet Propulsion Laboratory, Pasadena, California, 91109

One requirement for sustainable life on terrestrial planets includes the presence of organic polymers, compounds that are essential for major biological functions such as replication and catalysis. An identified goal of the Mars mission in the year 2020 is to implement a sample-return to identify and validate signs of life on Mars through the discovery of biosignature molecules in Martian core samples. Martian core samples recovered …

Behavioral Variation Between Two Clades Of Leptasterias Spp., Ashley N. Contreras

STAR Program Research Presentations

Leptasterias spp. are six-rayed sea stars found along the rocky intertidal of the northeast Pacific Alaska to Santa Catalina Island, southern California. In central California, three clades of Leptasterias are found in separate or mixed populations, in diverse habitats that range from shallow pools of seagrass and algae to bare rock exposed to crashing waves. Initial field observations of two clades from different locations suggested that behavioral variation may relate to habitat differences among clades. To measure differences in activity, the righting response was timed at both field sites. As a result of behavioral variation observed in the field, more …

Temporal Variation In Larval Release In Botrylloides Violaceous, Damion J. Delton, Sarah Cohen

STAR Program Research Presentations

Despite Botrylloides violaceous being a globally invasive species in temperate marine habitats, little is known about it’s natural dispersal behavior. Previous work (Delton et al, 2011) suggests behavioral inferences based on a related and much more commonly studied species may not be appropriate, potentially due to a large size difference between the non-feeding larvae of these two species. Here, we consider factors that may affect dispersal potential. To study how light affects larval release, we measured timing of larval release in the field and compared larval size and time of release. Colonies were collected from floating docks in Richmond, CA …

Physiologically-Based Pharmacokinetic Modeling For Predicting Caffeine/Theophylline-Ciprofloxacin Interactions, David M. Ng, Ali Navid

STAR Program Research Presentations

Dynamics of interactions between the drugs caffeine, theophylline, and ciprofloxacin are predicted using physiologically-based pharmacokinetic (PBPK) modeling. Pharmacokinetic means the model determines where the drugs are distributed in the body over time. Physiologically-based means the anatomy and physiology of the human body are reflected in the structure and functioning of the model. Multiple drugs can interact to increase or decrease their beneficial and/or undesired effects. This is important because some common substances, such as caffeine in coffee, soft drinks, and energy drinks, are actually drugs that affect the body. Ciprofloxacin is an inhibitor of caffeine and theophylline metabolism; such inhibition …

Feeding Ecology Of Delta Smelt During A Seasonal Pulse Of Turbidity, William A. Hilton, Aaron Johnson, Wim Kimmerer

STAR Program Research Presentations

The delta smelt (Hypomesus transpacificus) is a small, pelagic fish endemic to the San Francisco Estuary (SFE) and protected under federal and state endangered species acts. This study examines the diet of adult delta smelt during their spawning migration in the winters of 2010 and 2012. Delta smelt and their zooplankton prey were sampled concurrently during a seasonal pulse of turbidity at sites along their migratory route from the low salinity zone in Suisun Bay to the fresher waters of the Sacramento/San Joaquin Delta. Gut contents were identified to the lowest possible taxon and counted, along with zooplankton …

Characterization Of Bacillus Bacterial Strains; Optimum Growth Temperature, Proteolytic And Lipolytic Activity, Jamie Anne Boring

STAR Program Research Presentations

Characterization of Bacillus bacterial strains is an important step in identifying and removing biofilms contaminating processing equipment. These biofilms lead to large amounts of spores in the final product. Strains that produce spoilage enzymes cause off-flavors, structural defects and reduced shelf life of milk products. Using four treatments, we determined the best growth protocol for each strain to use in future experiments. Treatment 1: 80 ^o C heat shock and 32 ^o C 24hr incubation, Treatment 2: 80^o C/ 55 ^o C, Treatment 3: 100 ^o C/ 32 ^o C, Treatment 4: 100 ^o C/ 55 ^o C. Our …

Leatherback Hatchling Fitness, Violet Campbell, Shane Morales, Kelly Stewart

STAR Program Research Presentations

Leatherback hatchling fitness on land is essential for their success in entering the ocean without being predated. Two ways fitness on land may be measured are by how fast hatchlings crawl as well as how fast their righting responses are when they are flipped onto their carapaces. Hatchlings from certain nests have slower righting response times along with slower crawl times, both of which would increase the odds of predation and hinder the success of hatchlings reaching the ocean.

Hatchling crawling speed was determined by timing 12 randomly selected hatchlings from each nest to crawl a distance of two meters. …

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR Program Research Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In the future, multivariable spatial correlations …

Rescuing Acetylcholinesterase From Nerve Agent Inhibition: Protein Dynamics Driven Drug Discovery, Aiyana M. Emigh, Brian Bennion

STAR Program Research Presentations

Severe morbidity and mortality consequences result from irreversible inhibition of human acetylcholinesterase by organophosphates (OPs). Oxime-based reactivators are currently the only available treatments but lack efficacy in the central nervous system (CNS) where the most damage occurs. Computational docking and molecular dynamics (MD) simulations reveal complex structural barriers that may reduce oxime efficacy. These results may guide future drug designs of more effective countermeasures.

Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan

STAR Program Research Presentations

Microbial fuel cells (MFC) utilize bacteria to generate an electrical current that can be used in the decomposition of sludge and human urine. In a MFC there is an anode (for oxidation of organic compounds), cathode (reduction of oxygen or carbon dioxide), and a proton exchange membrane (PEM, allows protons to migrate); reduction-oxidation reactions between the anode and cathode produce a measurable current. Bacteria that are found in sludge can be used to produce electrons in a voltaic cell, but optimizing conditions for harnessing the energy is crucial to making a MFC efficient. Research has shown that the ratios of …

Fishing For Peptides, Kevin Nguyen, Heather Brewer, Ljiljana Pasa-Tolic

STAR Program Research Presentations

In the field of proteomics, samples come from an unlimited variety of sources depending on what the research goals are. During preparation for analysis by mass spectrometry (MS), there is a need to separate peptides from other molecules used in the digestion process. Solid Phase Extraction (SPE) is a common cleanup step used to capture peptides, allowing the researcher to remove unwanted chemicals (e.g. salts, denaturants, surfactants) which results in a sample that can be effectively analyzed by MS. For our testing procedures we performed an in solution digest of Shewanella oneidensis with trypsin, mimicking the preparation for membrane-bound peptides …

Detection Of Viable Microorganisms Using Propidium Monoazide, Erik J. Mcfarland, Adrian Ponce Dr.

STAR Program Research Presentations

Propidium monoazide (PMA) is a molecular tool used to assess viability of microorganisms. Currently, PMA is thought to discern viability through membrane permeability; PMA enters only membrane compromised cells, irreversibly crosslinks to theirDNAand precipitates theDNAout of solution, preventing it from being amplified during polymerase chain reaction (PCR). Using PMA on a sample of live and dead microorganisms results in only theDNAof living organisms being amplified and identified. Therefore, a comparison ofPCRresults with and without PMA allows one to determine the live fraction and total population, respectively.

Current literature provides conflicting evidence as to the effectiveness of the technique. Our research …

Disocvering Ionic Liquid Resistant Genes, Bree Person, Douglass Higgins, Michael Thelen

STAR Program Research Presentations

: Plant biomass is a rich source of sugars that can be converted to biofuels by engineered microbes. However, because the lignocellulose in biomass is insoluble in aqueous conditions and recalcitrant to enzymatic degradation, thermochemical treatment is required to break apart the lignin and cellulose polymers before sugars can be released. The most effective chemicals for doing this are known as ionic liquids, which are salts that are molten at temperatures below 100° C. Although these solvents have many unique properties that are ideal for solubilizing lignocellulose, they have been found to inhibit the growth of bacterial strains used to …

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR Program Research Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on …