Digital Archive Policies and Trusted Digital Repositories

The MIT Libraries, the San Diego Supercomputer Center, and the University of California San Diego Libraries are conducting the PLEDGE Project to determine the set of policies that affect operational digital preservation archives and to develop standardized means of recording and enforcing them using rules engines. This has the potential to allow for automated assessment of "trustworthiness" of digital preservation archives. We are also evaluating the completeness of other efforts to define policies for digital preservation such as the RLG/NARA Trusted Digital Repository checklist and the PREMIS metadata schema. We present our results to date.National Archives and Records Administration (US) under NSF cooperative agreement 0523307 through a supplement to SCI 0438741 and the NSF grant ITR 0427196

Policymaking During Crises : How Diversity and Disagreement Can Help Manage the Politics of Expert Advice

Political leaders drawing on expertise in a crisis face two temptations: one is to dismiss unwelcome expert claims as politically motivated; another is to mask expert disagreement altogether. We show that protecting and promoting open disagreement among diverse sets of expert advisers can both improve the quality of expert advice and make it harder for political leaders to blur the lines between expert advice and political judgments. We highlight the importance of institutional design in managing the politics of expert advice

Locations of marine animals revealed by carbon isotopes

Knowing the distribution of marine animals is central to understanding climatic and other environmental influences on population ecology. This information has proven difficult to gain through capture-based methods biased by capture location. Here we show that marine location can be inferred from animal tissues. As the carbon isotope composition of animal tissues varies with sea surface temperature, marine location can be identified by matching time series of carbon isotopes measured in tissues to sea surface temperature records. Applying this technique to populations of Atlantic salmon (Salmo salar L.) produces isotopically-derived maps of oceanic feeding grounds, consistent with the current understanding of salmon migrations, that additionally reveal geographic segregation in feeding grounds between individual philopatric populations and age-classes. Carbon isotope ratios can be used to identify the location of open ocean feeding grounds for any pelagic animals for which tissue archives and matching records of sea surface temperature are available

Hydrodynamic electron flow and Hall viscosity

The authors acknowledge support from the Emergent Phenomena in Quantum Systems initiative of the Gordon and Betty Moore Foundation (T. S.) and NSF DMR-1507141 and a Simons Investigatorship (J. E. M.). We also acknowledge the support of the Max Planck Society and the UK Engineering and Physical Sciences Research Council under Grant No. EP/I032487/1.In metallic samples of small enough size and sufficiently strong momentum-conserving scattering, the viscosity of the electron gas can become the dominant process governing transport. In this regime, momentum is a long-lived quantity whose evolution is described by an emergent hydrodynamical theory. Furthermore, breaking time-reversal symmetry leads to the appearance of an odd component to the viscosity called the Hall viscosity, which has attracted considerable attention recently due to its quantized nature in gapped systems but still eludes experimental confirmation. Based on microscopic calculations, we discuss how to measure the effects of both the even and odd components of the viscosity using hydrodynamic electronic transport in mesoscopic samples under applied magnetic fields.PostprintPeer reviewe

Democratic Non-Participation

The idea that there might be democratic forms of non-participation has been largely overlooked in the theoretical and empirical literature on democracy. Non-participation has variously been seen as a threat to the proper functioning of democracy, a rational choice, or (more rarely) as potentially beneficial at the systems level. We argue that there are forms of non-participation that may be justified on democratic grounds. Our main theoretical move is to distinguish between reflectivity (or thoughtfulness) and participation. We argue that the normative value of both participation and non-participation is conditioned by reflectivity, such that there may be democratically desirable forms of reflective non-participation. To support our claims, we provide examples of how non-participation can help support democratic goods — such as inclusion, influence, and legitimacy — that are normally associated only with democratic participation

A Classification and Characterization of Two-Locus, Pure, Strict, Epistatic Models for Simulation and Detection

BackgroundThe statistical genetics phenomenon of epistasis is widely acknowledged to confound disease etiology. In order to evaluate strategies for detecting these complex multi-locus disease associations, simulation studies are required. The development of the GAMETES software for the generation of complex genetic models, has provided the means to randomly generate an architecturally diverse population of epistatic models that are both pure and strict, i.e. all n loci, but no fewer, are predictive of phenotype. Previous theoretical work characterizing complex genetic models has yet to examine pure, strict, epistasis which should be the most challenging to detect. This study addresses three goals: (1) Classify and characterize pure, strict, two-locus epistatic models, (2) Investigate the effect of model ‘architecture’ on detection difficulty, and (3) Explore how adjusting GAMETES constraints influences diversity in the generated models

Geometric effects on T-breaking in p+ip and d+id superconductors

Superconducting order parameters that change phase around the Fermi surface modify Josephson tunneling behavior, as in the phase-sensitive measurements that confirmed $d$ order in the cuprates. This paper studies Josephson coupling when the individual grains break time-reversal symmetry; the specific cases considered are $p \pm ip$ and $d \pm id$, which may appear in Sr$_2$RuO$_4$ and Na$_x$CoO$_2 \cdot$(H$_2$O)$_y$ respectively. $T$-breaking order parameters lead to frustrating phases when not all grains have the same sign of time-reversal symmetry breaking, and the effects of these frustrating phases depend sensitively on geometry for 2D arrays of coupled grains. These systems can show perfect superconducting order with or without macroscopic $T$-breaking. The honeycomb lattice of superconducting grains has a superconducting phase with no spontaneous breaking of $T$ but instead power-law correlations. The superconducting transition in this case is driven by binding of fractional vortices, and the zero-temperature criticality realizes a generalization of Baxter's three-color model.Comment: 8 page