Sunday, April 23, 2017

Watershed Stewards Program

Watershed Stewards Program (WSP), a natural resources program, is currently recruiting 48 Members to serve in our 10.5 month program throughout California.

WSP offers exceptional training and hands-on experience for individuals interested in natural resources and watershed protection. The mission of WSP is to conserve, restore, and enhance anadromous watersheds for future generations by linking education with high quality scientific practices.

I have attached position descriptions for the Member and Team Leader position for our 24th program year. Please visit our website at to learn more.

Earth Sciences Colloquium | Rob Eagle Tripati from UCLA

Rob Tripati (UCLA) will be coming tomorrow to speak about "Cross-disciplinary approaches to understand the response of marine organisms to changing oceanic conditions in a high CO2 world”.

Abstract: The growth response of calcium carbonate mineralizing organisms to elevated CO2 conditions is extremely diverse. Some organisms are negatively influenced by CO2-induced seawater carbonate system perturbations and associated pH decline, producing less calcium carbonate in their shells or skeletons. Yet, other organisms are resilient and positive growth response for some species has been observed in culture experiments. Many organisms produce their shells and skeletons from an internal fluid pool that is chemically distinct from seawater. Here we address the hypothesis that an organism’s ability to regulate the pH and carbonate chemistry of their internal calcification fluid and their ability to buffer internal pH from changes in external seawater chemistry is a significant factor in the observed diversity of organismal responses to increasing CO2 conditions. To address this we combine approaches from geochemistry and cellular biology, using measurements of δ11B and pH microelectrodes to probe the calcification site pH of a range of different marine calcifying organisms cultured across a range of CO2 levels. Our data shows an extremely diverse range of isotopic and microelectrode signatures. In some cases this diversity is coupled to net calcification response, suggesting a primary internal pH control over shell growth, and in other cases it is decoupled suggesting additional complexity in organismal calcification responses to CO2.

Monday, April 17, 2017

2016-17 BISC Honors Luncheon Program

Please note: We are no longer accepting RSVPs for this event.

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PBK Scholarship available to final year international graduate students

Two awards, in the amount of $2,000, are available from the Phi Beta Kappa Alumni Association for international students who will be in the “final year of their program and seeking degrees which are considered “terminal” in their field,” i.e. PhD or MFA.

Completed copies of the attached application should be uploaded to as a single PDF by Friday, May 5, 2017. Two letters of recommendation should be sent to by the end of the day on Friday, May 5, 2017.

Please contact Kate Tegmeyer at if there are any questions.

Sunday, April 9, 2017

MEMS and Microfluidics Technologies for Plant Phenomics and Sustainable Agriculture and Environment

Housing available to Grad Students

Minimizing cheating through course design

MEB Seminar Series | Grad Student Presentations | 4/11, 12 PM, AHF Torrey Webb Room

Jayme Smith, PhD Candidate
PI: Dr. David Caron
Title: "Dissolved Algal Toxins in Southern California Waters"
Abstract: Harmful algal blooms (HABs) have been increasing globally, particularly along the North American west coast, threatening marine wildlife, human health, and commercial fisheries. HAB species of particular concern in southern California waters include those of the dinoflagellate genus Alexandrium (saxitoxin producer) and Dinophysis (okadaic acid producer), and diatom genus Pseudo-nitzchia (domoic acid producer). Toxic strains of these species produce toxins that cause illness and sometimes death in humans and marine wildlife. We utilized a new technique called Solid Phase Adsorption Toxin Tracking (SPATT) to monitor dissolved algal toxins at several locations along the southern California coast. SPATT has the advantage of integrating dissolved algal toxins present in the water throughout the deployment period, providing information about events that may occur between discrete sampling periods. We utilized SPATT for short studies at Catalina Island and on temporary offshore moorings, as well as a long-term study at our Newport Beach Pier HAB monitoring station. SPATT samples were analyzed for saxitoxin, and domoic acid and a subset of samples were tested for okadaic acid. Our data revealed the regular occurrence of at least one algal toxin at all study sites. Algal toxins were present in at least 64% of samples from our long-term site. Perhaps more concerning, we found that multiple toxins often co-occurred, presenting an increased risk to human and wildlife health.
Xiaoshen Yin, PhD Candidate
PI: Dr. Dennis Hedgecock
Title: "Mapping genes determining Type-III survivorship in the Pacific oyster Crassostrea gigas"
Abstract: The Pacific oyster Crassostrea gigas has a high mortality during its early life stages (type III survivorship). Previous mapping of genetic factors affecting viability (quantitative trait loci, vQTL) has revealed ~7-13 vQTL in each family of Pacific oysters. Estimated genetic inviability caused by vQTL ranges from 96% to 99%, which accounts for the high early mortality in the Pacific oyster. However, these previous studies used low-density linkage maps, which make it hard to pinpoint genomic regions containing vQTL accurately. To resolve this issue, I constructed high-density linkage maps with single nucleotide polymorphism markers (SNPs), generated from Illumina sequencing (genotyping-by-sequencing, GBS). The linkage map has an average interval between markers of 0.65 cM, about 12 times denser than previous linkage maps. Using these high-density linkage maps, I discovered 9-14 vQTL in six F2 families and estimated cumulative genetic mortality to be 96%-99%, which is consistent with previous studies. High-density linkage maps, on the other hand, more narrowly localize vQTL peaks caused by recessive viability mutations than did low-density maps, improving the accuracy of vQTL mapping. Finally, high-density linkage maps are effective in teasing apart multiple deleterious mutations and their genetic effects under broad vQTL peaks.

Saturday, April 1, 2017

Faculty Fast Five: Ian Ehrenreich

Ian Ehrenreich

What is your favorite book?

James Joyce, A portrait of the artist as a young man. This book helped me think a lot about my own process of discovering who I am and what I care about.

Do you remember your first classroom science experiment as a child?

No. But I do remember I greatly enjoyed gardening and that working with plants when I was young made me think more about the biological world.

What's your favorite scientific discovery in history?

Tie. Mendel and Darwin respectively recognizing the basic principles of heredity and evolutionary diversification by natural selection. 

What excites you about science today?

Two amazing technologies really excite me right now. These are CRISPR/Cas9, which allows us to genetically modify organisms with ease, and long read DNA sequencing, which enables us to determine the genomic sequence of nearly any species. These technologies are transforming our making it possible to pursue genetic and genomics research in any species. 

If you would describe a day in your life at USC by using a character (preferably Scientist) from a movie who would it be?

Honestly, I rarely am able to do experiments any more because I wear so many hats. As a professor, my job is more so to inspire students to discover what they care about and make the most of their opportunities in education and life. In this way, maybe my job is similar to Robin Williams' character in Dead Poets Society.