Individual organisms on land and in the ocean sequester massive amounts of the carbon emitted into the atmosphere by humans. Yet the role of ecosystems as a whole in modulating this uptake of carbon is less clear. Here, we study several different mechanisms by which climate change and ecosystems could interact. We show that climate change could cause changes in ecosystems that reduce their capacity to take up carbon, further accelerating climate change. More research on – and better governance of – interactions between climate change and ecosystems is urgently required.

OBJECTIVES/SPECIFIC AIMS: To fulfill the Indiana Clinical and Translational Sciences Institute’s (Indiana CTSI) Community Health Partnerships’ (CHeP) mission of improving the health of Indiana residents through community-university partnerships, CHeP engaged with community partners to develop and implement a pilot award program for community-based participatory research, the Trailblazer Award (TA). The objective is to describe the engagement processes throughout the pilot program timeline and as the pilot program evolved over the 6-year period since the program started. METHODS/STUDY POPULATION: Though a process of engagement with community stakeholders, we assessed the process for each year of the TA, noting what changes occurred and how they occurred. Engagement for the TA process occurred during the following phases: RFA development, review, active project support, dissemination of project results, and project/partnership follow-up. RESULTS/ANTICIPATED RESULTS: During the RFA development phase, we decided to focus the award on health equity for 5 years; and we implemented structural changes to encourage new partnerships in underrepresented and rural areas. During the review phase, we incorporated both community and university reviewers and co-moderators. To increase capacity among our reviewer pool, we offered webinars and repeated opportunities to serve as reviewers. During the project support phase, we added the following: community-based CITI training; opportunities for networking with peer awardee teams; and community and academic co-led sessions on addressing recruitment barriers, grant writing, and dissemination to a community audiences. Through our active engagement of the CHeP Advisory Board, one Board member (from Indiana State Department of Health) leveraged matching funds for the TA, effectively doubling the number of projects supported each year. DISCUSSION/SIGNIFICANCE OF IMPACT: Whereas previous work has reported on engagement during the review process of pilot award applications, we discuss ways to extend engagement to include other aspects of a pilot program both before and after the review process. In our process, several key partners offered insightful changes that have resulted in a more engaged program.

The study of extremely metal-poor (EMP; [Fe/H] <−3.0) and ultra metal-poor (UMP; [Fe/H] <−4.0) stars is crucial for better understanding first-star nucleosynthesis and constraining the initial mass function in the early Universe. However, UMP stars discovered in the past 25 years only number ~25. A few recent theoretical studies have pointed out that there is likely to exist large numbers of EMP and UMP stars in the periphery of the Galactic halo, at distances exceeding 30-50 kpc. We present identifications of several new EMP/UMP stars and introduce a survey to expedite discovering hundreds to thousands of EMP/UMP stars in the outermost halo (as well as in the local volume) over the next few years, which could revolutionize chemical-evolution studies of the Galaxy.

The AAOmega Evolution of Galactic Structure (AEGIS) survey (P.I. Keller) was a moderate scale (45 nights) spectroscopic survey carried out with the AAOmega multi-fiber spectrograph at the Anglo-Australian Telescope. The input catalogue for the spectroscopic observations was derived from photometry of approximately 200 two-degree diameter fields obtained during the commissioning of the SkyMapper survey. The data consists of medium-resolution (R ~ 2,000) spectroscopy for approximately 70,000 thick disk and halo stars spanning a survey footprint of 4,900 square degrees. We plan to use the AEGIS data to further characterize the properties of the disk and halo systems and better constrain the assembly history of the Galaxy based on the behavior of the CEMP-no and CEMP-s stars in the sample.

The RAVE survey obtains moderate-resolution (R ~ 7500) spectroscopy of relatively bright stars in the region of the Ca triplet, and derives estimates of stellar atmospheric parameters (Teff, log g, and [Fe/H]) and abundance estimates for a limited number of elements. The RAVE sample is selected on apparent magnitude, effectively removing the biases typically associated with searches for metal-poor stars such as metallicity, evolutionary status, or Galactic population membership. For the past several years, we have been obtaining medium-resolution (R ~ 1800) spectroscopy over a much wider wavelength range, from 3700 Å to 5500 Å, for RAVE stars with estimated metallicities from the RAVE pipeline of [Fe/H] < −1.8.

Based on these observations, we use the well-tested n-SSPP pipeline to obtain atmospheric parameter estimates, as well as measurements of [C/Fe], for over 1,700 metal-poor star candidates. We present an analysis of the distribution of carbon-enhancement in the relatively local volume of the Galaxy as a function of metallicity, location, and kinematics. Our results are useful to test the RAVE parameter estimates, and add to the growing number of known carbon-enhanced metal-poor (CEMP) stars for future high-resolution follow-up.

Studies of stellar populations have been reinvigorated during the last decade by the advent of large-area sky surveys such as SDSS, 2MASS, RAVE, and others. These data, together with theoretical and modeling advances, are revolutionizing our understanding of the nature of the Milky Way, and galaxy formation and evolution in general. The abundance of substructure in the multi-dimensional space of various observables, such as position, kinematics, and metallicity, is by now proven beyond doubt, and demonstrates the importance of mergers in the growth of galaxies. Unlike smooth models that involve simple components, the new data reviewed here clearly exhibit many irregular structures, such as the Sagittarius dwarf tidal stream and the Virgo and Pisces overdensities in the halo, and the Monoceros stream closer to the Galactic plane. These recent developments have made it clear that the Milky Way is a complex and dynamic structure, one that is still being shaped by the merging of neighboring smaller galaxies. Here we summarize developments over the last decade in our mapping of the stellar content of the Milky Way, as well as recent attempts to map the dark matter halo by Loebman et al. (2012) and ISM dust distribution by Berry et al. (2012). We also briefly discuss the next generation of wide-field sky surveys, exemplified by Gaia and LSST, which will improve measurement precision manyfold, and comprise billions of individual stars.