Former Brown-MBL student Dr. Pedro Flombaum recently published a new journal article entitled Interactions among resource partitioning, sampling effect, and facilitation on the biodiversity effect: a modeling approach. Pedro was a 2008 graduate student in the Brown University EEB Program and a former student of Dr. Ed Rastetter at MBL. He now works at the Centro de Investigaciones del Mar y de la Atmósfera (CIMA) in Buenos Aires, Argentina. His journal article can be found here.
Cassandra Bilogan successfully defended her dissertation on August 5th, 2013 at Brown University in Providence, RI. Cassandra described her doctoral research that was completed in Dr. Marko Horb’s lab at the MBL’s Bell Center for Regenerative Biology and Tissue Engineering. Cassandra’s research focused on elucidating the molecular mechanisms involved in endoderm development and pancreatic organogenesis in Xenopus laevis. Specifically, she identified a novel role for a well-conserved RNA-binding protein during endoderm development. This research provided new insights into a previously unappreciated role of the spatial-temporal regulation of germ layer patterning during gastrulation. During her graduate studies Cassandra published two first author papers and a second author review paper.
Cassandra is also the first Ph.D. student to graduate from the Bell Center. Her research was supported by grants to Dr. Horb from the National Institutes of Health and a Canadian Institute of Health Research fellowship to Bilogan.
In October, Cassandra will start a postdoctoral fellowship at the Cleveland Clinic in the lab of Dr. Takuya Sakaguchi.
For more information on Cassandra click here
Agricultural activities are changing globally in response to increased demand for foods and other goods, but how are these changes occurring and affecting people and ecosystems differently across the planet?
From 14-16 January 2013, postdoc Rebecca Ryals of the Marine Biological Lab (MBL) and the Brown Environmental Change Initiative (ECI) convened a workshop at MBL for faculty, researchers and graduate students working in Brazil, Africa, China and North America to share recent findings from research on agricultural change, spanning natural and social science fields. Participants hailed from numerous ECI-affiliated departments at Brown, including Ecology and Evolutionary Biology, Geological Sciences, and Sociology, the Marine Biological Laboratory (MBL), the Woods Hole Research Center (WHRC) and institutions across the country, including The Earth Institute at Columbia University and the Cary Institute of Ecosystem Studies in New York, and the University of Virginia.
Researchers presented projects on facets of agricultural intensification from Brazil, East Africa, North America and China. For Brazil, presented research showed surprising dynamics of the fate and transport of fertilizer-added nitrogen and phosphorus through soils, differing seasonal variations in soil moisture across land use areas, impacts of riparian forest buffers on stream water quality, innovative satellite remote sensing techniques for studying extents and patterns of double-cropping, and relationships between national currency valuation, markets, social dynamics and agricultural production. For East Africa, preliminary results demonstrated relationships between seasonal patterns in nitrogen transport dynamics through soils , new multi-satellite-based approaches for mapping land cover in complex, small land-holder dominated landscapes, and impacts of fertilizer use on soil microbial diversity. Research in North America focused on range and livestock management impacts for watershed biogeochemistry, and web tools for increasing public awareness of how personal food choices connect to ecosystem nitrogen losses. Research in North America and China highlighted relationships between fertilizer rates, and CO2 and N2O losses from soils to the atmosphere.
Together, presentations highlighted that agricultural intensification, the increased use of technology (e.g. fertilizers, mechanization, new cultivars) to improve crop yields per unit area, has progressed in starkly contrasting patterns between places such as Brazil and East Africa. Environmental and social consequences such as fertilizer-applied nitrogen losses and local food security were shown to matter differently across continents. Discussions stressed that factors from a region’s economic development status before intensification occurs, to soil texture, must be considered integrally for scientists across disciplines to pursue appropriate future research. The workshop produced outlines for interdisciplinary research papers, watershed-scale research projects, conference proposals, and new senses of camaraderie among participants.
Brown-MBL Student Research on Phosphorous Budgets in Soybean Agriculture in Bioscience and Science Daily
Brown-MBL student Shelby Hayhoe-Riskin’s work on phosphorous uptake and release in soils and associated environmental impacts in the three largest soybean growing regions of the world will be published in an upcoming issue of Bioscience. Brown-MBL joint faculty Stephen Porder and Chris Neill are co-authors on the paper as are Meagan Schipanski of Pennsylvania State University and Elena Bennett of McGill University. Science Daily reported on the research on December 17th. Read more…
On December 5, 2012, Brown-MBL Graduate Student, Anupriya Dutta, successfully defended her PhD dissertation, ‘Recognizing microRNAs (miRNAs) in Microinvertebrates and Confirming their Absence.’
Bdelloid rotifers are aquatic microinvertebrates that have several outstanding qualities among metazoans. They make up the only ancient asexual animal lineage. Bdelloid rotifers are also incredibly robust to DNA damage, which is a necessary adaptation for life in desiccation-prone environments. During desiccation, they are capable of incorporating foreign DNA into their genome. An investigation of a class of noncoding small RNAs, called microRNAs (miRNAs), reveals that the unique characteristics of bdelloid rotifers are reflected in their miRNA repertoire. miRNAs are involved in post-transcriptional gene regulation and have been implicated in numerous cellular processes. Some miRNAs are believed to be indispensable due to their integration into many gene regulatory networks. For this reason, many miRNAs are easy to identify across diverse animal phyla. However, the conserved miRNA repertoire of bdelloid rotifers is exceptional in this regard. The surprising miRNA repertoire of bdelloid rotifers not only provides important clues to understanding the asexual evolution of bdelloid rotifers, but also reveals new insights into miRNA evolution in animals.
Speaking to a live audience in Providence and over videolink to Woods Hole, Susanna Theroux defended her dissertation on November 28th, 2012. Theroux described her doctoral research that was completed in collaboration between the labs of Dr. Yongsong Huang at Brown University’s Department of Geological Sciences and Dr. Linda Amaral-Zettler at the MBL’s Bay Paul Center.
Theroux’s research focused on haptophyte algae that produce organic biomarkers used for paleoclimate reconstruction. Specifically, she identified novel species of haptophyte algae in lake environments that were responsible for producing alkenone lipids that record the temperature of the lake water going back through time. By combining field studies in Greenland and North Dakota, culture studies and DNA sequencing in Woods Hole and organic analyses in Providence, the project was able to identify novel species of algae and their individual lipid signatures. This research also provided new insights into haptophyte bloom dynamics in lake environments and will impact how future geologic records of haptophyte biomarkers are interpreted. This research was supported by grants to Huang and Amaral-Zettler from the National Science Foundation and the Brown SEED fund and an American Association of University Women fellowship to Theroux.
In January, Theroux will be starting a postdoctoral fellowship at the Department of Energy’s Joint Genome Institute.
Catherine Luria is finishing her second year in the Brown-MBL Graduate Program, advised by Hugh Ducklow (Ecosystems Center, MBL) and Jeremy Rich (Dept. of Ecology and Evolutionary Biology, Brown University). She recently returned from her first field season on the Antarctic Peninsula, where she participated in the Palmer Station Long Term Ecological Research (LTER) Project.
The peninsular region is one of the most rapidly warming regions on earth, with a 4-6°C increase in midwinter temperatures over the last 50 years and a 40% decline in winter sea ice extent. These changes are having profound impacts on all levels of the ecosystem, from marine diatoms to Adelie penguins.
Catherine is examining not only how microbial communities in this region change across study sites, seasons, and years, but also what factors drive microbial seasonal succession against a backdrop of rapid climate change. She is particularly interested in the effects of annual sea ice advance and retreat on microbial communities. As sea ice forms during the austral fall, bacteria and phytoplankton are entrained in the ice and often persist through the winter. In the spring, the sea ice melts releasing organic matter as well as bacteria and phytoplankton. This water column “seeding” may have dramatic impacts on microbial community composition within the water column and trigger phytoplankton blooms that help support this productive ecosystem. Although previous studies have examined the effects of sea ice extent and duration on primary production, zooplankton, and seabirds, little is known about the impact of sea ice advance and retreat on microbes and how microbes will respond to climate-driven declines in sea ice extent and duration. Catherine is exploring this question through a combination of environmental sampling and incubation experiments. She is excited to return to the Antarctic in September 2012 for further research.
by Catherine Luria, May 2012
Brown-MBL PhD student Xi Yang and colleagues recently reported in the Journal of Geophysical Research that the New England spring, as measured by plant phenological changes, arrives as much as a week earlier today than it did fifty years ago. Yang and his colleagues at the MBL Ecosystems Center, Brown University’s Department of Geological Sciences, and the University of Minnesota’s Department of Soil, Water Climate used remotely-sensed phenology and metereological data to assess the accuracy of three different species-level budburst phenology models and one senescence model, and then used the best of the budburst models, the Spring Warming Model, and the Delpierre Senescence Model, to reconstruct plant phenology in New England between 1960 and 2010. They determined that New England has experienced a statistically significant advance in the start of season between 1960 and 2010, averaging 0.143 days per year or a more than seven day advance over the 50 year period studied. In addition to showing a significant change in start of season over recent decades, the researchers also demonstrated that phenology models can be useful for both reconstructing and predicting plant phenological changes at the regional level over time.
June 5, 2012
Our IGERT and PIRE graduate training grants are in full swing. These programs, in reverse ecology and African agriculture, cut across multiple departments at Brown and the Bay Paul and Ecosystems Centers at MBL. The IGERT project addresses the question at the boundary of genomics and ecosystem science—how does the make-up of microbial communities influence key ecosystem processes such as sediment recycling of mineral nitrogen cycling or the production of methane. The PIRE tries to evaluate how a rapid increase in the amount of fertilizer in African agriculture can help farmers but at the same time lead to environmental problems. Four Brown-MBL IGERT and PIRE students are now developing doctoral research projects advised by combinations of Brown and MBL scientists.
The Partnership now hosts 20 PhD students. They continue to do innovative and exciting science. Shelby Hayhoe-Riskin was the latest to defend her dissertation, on May 30. Shelby compared multiple small watersheds in forest and in soybean fields to understand how the expansion of soybean agriculture in the Amazon is affecting both the amount of water that runs off into streams and the export of soil nutrients in streamwater.
The Partnership also involves a growing number of undergraduates. A record ten Brown undergraduate students are working in MBL laboratories and on MBL projects this summer, including two Beckman Foundation scholars. The Partnership also helps to support two post-doctoral scholars who work on joint Brown-MBL research projects in microbial ecology and tropical biogeochemistry and a third will arrive at the end of the summer. MBL and Brown faculty collaborated to teach eight new courses since 2010.
The common denominator in all of this work is that the collaboration across MBL and Brown, in teaching and research, allows scientists to tackle problems in innovative ways and to break new scientific ground that would not be possible at one institution alone.
Managing the biosphere and safeguarding human health in the face of accelerating environmental change will take new ways of thinking about problems across disciplines, new analytical tools brought to bear on big questions, and new ways of collaborating across the US and across the nations of the world. Partnership students and research projects are rising to those challenges.
Christopher Neill, Director
Brown MBL Partnership