Shallow Rupture Propagation of Pleistocene Earthquakes Along the Hurricane Fault, UT, Revealed by Hematite (U-Th)/He Thermochronometry and Textures

The material properties and distribution of faults above the seismogenic zone promote or inhibit earthquake rupture propagation. We document the depths and mechanics of fault slip along the seismically active Hurricane fault, UT, with scanning and transmission electron microscopy and hematite (U-Th)/He thermochronometry. Hematite occurs as mm-scale, striated patches on a \u3e10 m2 thin, mirror-like silica fault surface. Hematite textures include bulbous aggregates and cataclasite, overlain by crystalline Fe-oxide nanorods and an amorphous silica layer at the slip interface. Textures reflect mechanical, fluid, and heat-assisted amorphization of hematite and silica-rich host rock that weaken the fault and promote rupture propagation. Hematite (U-Th)/He dates document episodes of mineralization and fault slip between 0.65 and 0.36 Ma at ∼300 m depth. Data illustrate that some earthquake ruptures repeatedly propagate along localized slip surfaces in the shallow crust and provide structural and material property constraints for in models of fault slip

Building Bridges with Boats: Preserving Community History through Intra- and Inter-Institutional Collaboration

This chapter discusses Launching through the Surf: The Dory Fleet of Pacific City, a project which documents the historical and contemporary role of dory fishers in the life of the coastal village of Pacific City, Oregon, U.S. Linfield College’s Department of Theatre and Communication Arts, its Jereld R. Nicholson Library, the Pacific City Arts Association, the Pacific City Dorymen\u27s Association, and the Linfield Center for the Northwest joined forces to engage in a collaborative college and community venture to preserve this important facet of Oregon’s history. Using ethnography as a theoretical grounding and oral history as a method, the project utilized artifacts from the dory fleet to augment interview data, and faculty/student teams created a searchable digital archive available via open access. The chapter draws on the authors’ experiences to identify a philosophy of strategic collaboration. Topics include project development and management, assessment, and the role of serendipity. In an era of value-added services where libraries need to continue to prove their worth, partnering with internal and external entities to create content is one way for academic libraries to remain relevant to agencies that do not have direct connections to higher education. This project not only developed a positive “town and gown” relationship with a regional community, it also benefited partner organizations as they sought to fulfill their missions. The project also serves as a potential model for intra- and inter-agency collaboration for all types of libraries

The NANOGrav 11-Year Data Set: Limits on Gravitational Waves from Individual Supermassive Black Hole Binaries

Observations indicate that nearly all galaxies contain supermassive black holes (SMBHs) at their centers. When galaxies merge, their component black holes form SMBH binaries (SMBHBs), which emit low-frequency gravitational waves (GWs) that can be detected by pulsar timing arrays (PTAs). We have searched the recently-released North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 11-year data set for GWs from individual SMBHBs in circular orbits. As we did not find strong evidence for GWs in our data, we placed 95\% upper limits on the strength of GWs from such sources as a function of GW frequency and sky location. We placed a sky-averaged upper limit on the GW strain of $h_0 < 7.3(3) \times 10^{-15}$ at $f_\mathrm{gw}= 8$ nHz. We also developed a technique to determine the significance of a particular signal in each pulsar using ``dropout' parameters as a way of identifying spurious signals in measurements from individual pulsars. We used our upper limits on the GW strain to place lower limits on the distances to individual SMBHBs. At the most-sensitive sky location, we ruled out SMBHBs emitting GWs with $f_\mathrm{gw}= 8$ nHz within 120 Mpc for $\mathcal{M} = 10^9 \, M_\odot$, and within 5.5 Gpc for $\mathcal{M} = 10^{10} \, M_\odot$. We also determined that there are no SMBHBs with $\mathcal{M} > 1.6 \times 10^9 \, M_\odot$ emitting GWs in the Virgo Cluster. Finally, we estimated the number of potentially detectable sources given our current strain upper limits based on galaxies in Two Micron All-Sky Survey (2MASS) and merger rates from the Illustris cosmological simulation project. Only 34 out of 75,000 realizations of the local Universe contained a detectable source, from which we concluded it was unsurprising that we did not detect any individual sources given our current sensitivity to GWs.Comment: 10 pages, 11 figures. Accepted by Astrophysical Journal. Please send any comments/questions to S. J. Vigeland ([email protected]

Ornamental plants: annual reports and research reviews

Ohio State University Extension Nursery, Landscape, and Turf Team Directory: 1998 / Jack Kerrigan -- Floriculture Industry Roundtable of Ohio: 1998 / Charles Behnke -- Ohio State University Extension Buckeye Yard and Garden Line / James A. Chatfield, Pamela J. Bennett, Joseph F. Boggs, Gary Y. Gao, Jane C. Martin, David J. Shetlar and Randall H. Zondag -- Environmental and cultural problems of ornamental plants in Ohio: 1997 / Pamela J. Bennett and Jane C. Martin -- Insect and mite activity noted in Ohio nurseries and landscapes: 1997 / Joseph F. Boggs, David J. Shetlar, Jane C. Martin, Pamela J. Bennett, James A. Chatfield, Gary Y. Gao and Chris Carlson -- Summary of ornamental diseases in Ohio: 1997 / James A. Chatfield, Nancy J. Taylor, Stephen N. Nameth, Chris Carlson, Joseph F. Boggs, Jane C. Martin, Dan Balser and David Madison -- Weed problems in Ohio landscapes and nurseries: 1997 / Gary Y. Gao, Joseph F. Boggs, Pamela J. Bennett, Jane C. Martin, Mary Ann Rose, Joseph W. Rimelspach, Randall H. Zondag and William E. Pound -- Wildlife problems in Ohio landscapes: 1997 / Gary Y. Gao, Joseph F. Boggs, Jane C. Martin, Charles T. Behnke and James A. Chatfield -- Summary of turf cultural and disease problems in 1997 / Gary Y. Gao, Joseph F. Boggs, Pamela J. Bennett, Jane C. Martin, Joseph W. Rimelspach and James A. Chatfield -- Master Gardeners serve Ohio / Marianne Riofrio -- The greening of Poland's nurseries / Kenneth D. Cochran and Wojtek Grabczewski -- The marketing potential of Ginkgo biloba in the United States / Kenneth D. Cochran -- Composts in the Landscape: Effects on Soil pH and plant growth / Mary Ann Rose and Hao Wang -- How to optimize disease control using composts / Harry A. J. Hoitink, Wei-Zheng Zhang, David Y. Han, Alexandra G. Stone, Matthew S. Krause and Warren A. Dick -- The flowering sequence of ornamental plants as a tool for predicting the phenology of insect pests / Daniel A. Herms -- Reducing maintenance costs may mean selecting plants with the fewest flaws / T. Davis Sydnor-- Comprehensive aesthetic evaluations of crabapples at Secrest Arboretum in Wooster: 1993-1997 / Erik A. Draper, James A. Chatfield, Kenneth D. Cochran, Peter W. Bristol and David E. Allen -- Precision control of microirrigation for container-grown mini-roses / Robert C. Hansen, Ted H. Short, C. C. Pasian and R. Peter Fynn -- Red thread (Laetisaria fuciformis) control study on perennial ryegrass / Joseph W. Rimelspach, Kerry Kline, Karl Danneberger and Michael Boehm-- Red thread (Laetisaria fuciformis) control study on Kentucky bluegrass / Joseph W. Rimelspach, Kerry Kline, Karl Danneberger and Michael Boehm -- Red thread - from novelty to nuisance / Joseph W. Rimelspach -- Chrysanthemum cultivars differ in response to photoperiod when grown under far-red absorbing filters / M. J. McMahon -- Improving fuchsia cutting performance by grafting / D. M. Napier and M. J. McMahon -- Paint/paclobutrazol mix on the inside surface of rooting wedge cells to control poinsettia cutting height / Claudio C. Pasian -- Response of poinsettias to paclobutrazol in paint applications / Claudio C. Pasian and Daniel K. Struve -- Dynamic transpiration of highly stressed container-grown Acer rubrum / Ted H. Short, Ahmet Irvem and Robert C. Hansen -- Effects of temperature on the development of Asiatic Lilies / J. Steininger and C. C. Pasian-- New publications for 1997-199

The NANOGrav 11 Year Data Set: Pulsar-timing Constraints on the Stochastic Gravitational-wave Background

We search for an isotropic stochastic gravitational-wave background (GWB) in the newly released 11 year data set from the North American Nanohertz Observatory for Gravitational Waves (NANOGrav). While we find no evidence for a GWB, we place constraints on a population of inspiraling supermassive black hole (SMBH) binaries, a network of decaying cosmic strings, and a primordial GWB. For the first time, we find that the GWB constraints are sensitive to the solar system ephemeris (SSE) model used and that SSE errors can mimic a GWB signal. We developed an approach that bridges systematic SSE differences, producing the first pulsar-timing array (PTA) constraints that are robust against SSE errors. We thus place a 95% upper limit on the GW-strain amplitude of A GWB < 1.45 × 10−15 at a frequency of f = 1 yr−1 for a fiducial f −2/3 power-law spectrum and with interpulsar correlations modeled. This is a factor of ~2 improvement over the NANOGrav nine-year limit calculated using the same procedure. Previous PTA upper limits on the GWB (as well as their astrophysical and cosmological interpretations) will need revision in light of SSE systematic errors. We use our constraints to characterize the combined influence on the GWB of the stellar mass density in galactic cores, the eccentricity of SMBH binaries, and SMBH–galactic-bulge scaling relationships. We constrain the cosmic-string tension using recent simulations, yielding an SSE-marginalized 95% upper limit of Gμ < 5.3 × 10−11—a factor of ~2 better than the published NANOGrav nine-year constraints. Our SSE-marginalized 95% upper limit on the energy density of a primordial GWB (for a radiation-dominated post-inflation universe) is ΩGWB(f) h 2 < 3.4 × 10−10

The NANOGrav 11-year Data Set: High-precision Timing of 45 Millisecond Pulsars

We present high-precision timing data over time spans of up to 11 years for 45 millisecond pulsars observed as part of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) project, aimed at detecting and characterizing low-frequency gravitational waves. The pulsars were observed with the Arecibo Observatory and/or the Green Bank Telescope at frequencies ranging from 327 MHz to 2.3 GHz. Most pulsars were observed with approximately monthly cadence, and six high-timing-precision pulsars were observed weekly. All were observed at widely separated frequencies at each observing epoch in order to fit for time-variable dispersion delays. We describe our methods for data processing, time-of-arrival (TOA) calculation, and the implementation of a new, automated method for removing outlier TOAs. We fit a timing model for each pulsar that includes spin, astrometric, and (for binary pulsars) orbital parameters; time-variable dispersion delays; and parameters that quantify pulse-profile evolution with frequency. The timing solutions provide three new parallax measurements, two new Shapiro delay measurements, and two new measurements of significant orbital-period variations. We fit models that characterize sources of noise for each pulsar. We find that 11 pulsars show significant red noise, with generally smaller spectral indices than typically measured for non-recycled pulsars, possibly suggesting a different origin. A companion paper uses these data to constrain the strength of the gravitational-wave background

The International Pulsar Timing Array: First data release

International audienceThe highly stable spin of neutron stars can be exploited for a variety of (astro)physical investigations. In particular, arrays of pulsars with rotational periods of the order of milliseconds can be used to detect correlated signals such as those caused by gravitational waves. Three such 'pulsar timing arrays' (PTAs) have been set up around the world over the past decades and collectively form the 'International' PTA (IPTA). In this paper, we describe the first joint analysis of the data from the three regional PTAs, i.e. of the first IPTA data set. We describe the available PTA data, the approach presently followed for its combination and suggest improvements for future PTA research. Particular attention is paid to subtle details (such as underestimation of measurement uncertainty and long-period noise) that have often been ignored but which become important in this unprecedentedly large and inhomogeneous data set. We identify and describe in detail several factors that complicate IPTA research and provide recommendations for future pulsar timing efforts. The first IPTA data release presented here (and available on-line) is used to demonstrate the IPTA's potential of improving upon gravitational-wave limit

From spin noise to systematics:stochastic processes in the first International Pulsar Timing Array data release

We analyse the stochastic properties of the 49 pulsars that comprise the first International Pulsar Timing Array (IPTA) data release. We use Bayesian methodology, performing model selection to determine the optimal description of the stochastic signals present in each pulsar. In addition to spin-noise and dispersion-measure (DM) variations, these models can include timing noise unique to a single observing system, or frequency band. We show the improved radio-frequency coverage and presence of overlapping data from different observing systems in the IPTA data set enables us to separate both system and band-dependent effects with much greater efficacy than in the individual pulsar timing array (PTA) data sets. For example, we show that PSR J1643-1224 has, in addition to DM variations, significant band-dependent noise that is coherent between PTAs which we interpret as coming from time-variable scattering or refraction in the ionized interstellar medium. Failing to model these different contributions appropriately can dramatically alter the astrophysical interpretation of the stochastic signals observed in the residuals. In some cases, the spectral exponent of the spin-noise signal can vary from 1.6 to 4 depending upon the model, which has direct implications for the long-term sensitivity of the pulsar to a stochastic gravitational-wave (GW) background. By using a more appropriate model, however, we can greatly improve a pulsar's sensitivity to GWs. For example, including system and band-dependent signals in the PSR J0437-4715 data set improves the upper limit on a fiducial GW background by similar to 60 per cent compared to a model that includes DM variations and spin-noise only

Extended self-knowledge

We aim to move the externalism and self-knowledge debate forward by exploring two novel sceptical challenges to the prospects of self-knowledge of a paradigmatic sort, both of which result from ways in which our thought content, cognitive processes and cognitive successes depend crucially on our external environments. In particular, it is shown how arguments from extended cognition (e.g., Clark A, Chalmers D. Analysis 58:7–19 (1998); Clark A. Supersizing the mind: Embodiment, action, and cognitive extension. Oxford: Oxford University Press (2008)) and situationism (e.g., Alfano M. The Philosophical Quarterly 62:223–249 (2012), Alfano M. Expanding the situationist challenge to reliabilism about inference. In Fairweather A (ed) Virtue epistemology naturalized, Springer, Dordrecht, pp 103–122 (2014); Doris JM. Noûs 32:504–530 (1998), Doris JM. Lack of character: Personality and moral behavior. Cambridge University Press, Cambridge (2002); Harman G. Proceedings of the Aristotelian Society. 99:315–331 (1999), Harman G. Proceedings of the Aristotelian Society 100:223–226 (2000)) pose hitherto unexplored challenges to the prospects of self-knowledge as it is traditionally conceived. It is shown, however, that, suitably understood, these apparent challenges in fact only demonstrate two ways in which our cognitive lives can be dependent on our environment. As such, rather than undermining our prospects for attaining self-knowledge, they instead illustrate how self-knowledge can be extended and expanded