Publications

Since the replication standard was proposed for political science research, more journals have required or encouraged authors to make data available, and more authors have shared their data. The calls for continuing this trend are more persistent than ever, and the agreement among journal editors in this Symposium continues this trend. In this article, I offer a vision of a possible future of the replication movement. The plan is to implement this vision via the Virtual Data Center project, which – by automating the process of finding, sharing, archiving, subsetting, converting, analyzing, and distributing data – may greatly facilitate adherence to the replication standard.

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The delicate balance of the major global biogeochemical cycles greatly depends on the transformation of Earth materials at or near its surface. The formation and degradation of rocks, minerals, and organic matter are pivotal for the balance, maintenance, and future of many of these cycles. Microorganisms also play a crucial role, determining the transformation rates, pathways, and end products of these processes. While most of Earth's crust is oceanic rather than terrestrial, few studies have been conducted on ocean crust transformations, particularly those mediated by endolithic (rock-hosted) microbial communities. The biology and geochemistry of deep-sea and sub-seafloor environments are generally more complicated to study than in terrestrial or near-coastal regimes. As a result, fewer, and more targeted, studies usually homing in on specific sites, are most common. We are studying the role of endolithic microorganisms in weathering seafloor crustal materials, including basaltic glass and sulfide minerals, both in the vicinity of seafloor hydrothermal vents and off-axis at unsedimented (young) ridge flanks. We are using molecular phylogenetic surveys and laboratory culture studies to define the size, diversity, physiology, and distribution of microorganisms in the shallow ocean crust. Our data show that an unexpected diversity of microorganisms directly participate in rock weathering at the seafloor, and imply that endolithic microbial communities contribute to rock, mineral, and carbon transformations.

Gravitational lensing is a powerful tool for the study of thedistribution of dark matter in the Universe. The cold-dark-matter modelof the formation of large-scale structures (that is, clusters ofgalaxies and even larger assemblies) predicts the existence of quasarsgravitationally lensed by concentrations of dark matter so massive thatthe quasar images would be split by over 7arcsec. Numerous searches forlarge-separation lensed quasars have, however, been unsuccessful. All ofthe roughly 70 lensed quasars known, including the first lensed quasardiscovered, have smaller separations that can be explained in terms ofgalaxy-scale concentrations of baryonic matter. Although gravitationallylensed galaxies with large separations are known, quasars are moreuseful cosmological probes because of the simplicity of the resultinglens systems. Here we report the discovery of a lensed quasar, SDSSJ1004 + 4112, which has a maximum separation between the components of14.62arcsec. Such a large separation means that the lensing object mustbe dominated by dark matter. Our results are fully consistent withtheoretical expectations based on the cold-dark-matter model.