Rotation measure variations for 20 millisecond pulsars

We report on variations in the mean position angle of the 20 millisecond pulsars being observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is found that the observed variations are dominated by changes in the Faraday rotation occurring in the Earth's ionosphere. Two ionospheric models are used to correct for the ionospheric contribution and it is found that one based on the International Reference Ionosphere gave the best results. Little or no significant long-term variation in interstellar RM was found with limits typically about 0.1 rad m$^{-2}$ yr$^{-1}$ in absolute value. In a few cases, apparently significant RM variations over timescales of a few 100 days or more were seen. These are unlikely to be due to localised magnetised regions crossing the line of sight since the implied magnetic fields are too high. Most probably they are statistical fluctuations due to random spatial and temporal variations in the interstellar electron density and magnetic field along the line of sight.Comment: Accepted for publication in Astrophysics & Space Scienc

The Right Place at the Right Time: Creative Spaces in Libraries

Purpose This essay explores the recent trend in libraries: that of the establishment of spaces specifically set aside for creative work. The rise of these dedicated creative spaces is owed to a confluence of factors that happen to be finding their expression together in recent years. This essay examines the history of these spaces and explores the factors that gave rise to them and will fuel them moving forward. Design/Methodology/Approach A viewpoint piece, this essay combines historical research and historical/comparative analyses to examine the ways by which libraries have supported creative work in the past and how they may continue to do so into the 21st century. Findings The key threads brought together include a societal recognition of the value of creativity and related skills and attributes; the philosophies, values, and missions of libraries in both their longstanding forms and in recent evolutions; the rise of participatory culture as a result of inexpensive technologies; improved means to build community and share results of efforts; and library experience and historical practice in matters related to creativity. The chapter concludes with advice for those interested in the establishment of such spaces, grounding those reflections in the author’s experiences in developing a new creative space at Virginia Commonwealth University. Originality/value While a number of pieces have been written that discuss the practicalities of developing certain kinds of creative spaces, very little has been written that situates these spaces in larger social and library professional contexts; this essay begins to fill that gap

Rethinking Cultural Relations and Exchange in the Critical Zone

Chapter for Managing Culture: Reflecting on Exchange in our Global Times, book edited by Raphaela Henze and Victoria Durrer, to be published by Palgrave: Sociology of the Arts

The short term debt vs. long term debt puzzle: a model for the optimal mix

This paper argues that the existing finance literature is inadequate with respect to its coverage of capital structure of small and medium sized enterprises (SMEs). In particular it is argued that the cost of equity (being both conceptually ill defined and empirically non quantifiable) is not applicable to the capital structure decisions for a large proportion of SMEs and the optimal capital structure depends only on the mix of short and long term debt. The paper then presents a model, developed by practitioners for optimising the debt mix and demonstrates its practical application using an Italian firm's debt structure as a case study

Discovery and Physical Characterization of a Large Scattered Disk Object at 92 au

We report the observation and physical characterization of the possible dwarf planet 2014. UZ224 ("DeeDee"), a dynamically detached trans-Neptunian object discovered at 92 au. This object is currently the second-most distant known trans-Neptunian object with reported orbital elements, surpassed in distance only by the dwarf planet Eris. The object was discovered with an r-band magnitude of 23.0 in data collected by the Dark Energy Survey between 2014 and 2016. Its 1140 year orbit has (a, e, i)=(109 au, 0.65, 26 degrees.8). It will reach its perihelion distance of 38 au in the year 2142. Integrations of its orbit show it to be dynamically stable on Gyr timescales, with only weak interactions with Neptune. We have performed follow-up observations with ALMA, using 3 hr of on-source integration time to measure the object's thermal emission in the Rayleigh-Jeans tail. The signal is detected at 7 sigma significance, from which we determine a V-band albedo of 13.1(-2.4)(+3.3)(stat)sys percent and a diameter of 635(-61)(+57)(stat)(-39)(+32)(sys) km assuming a spherical body with uniform surface properties

Extreme sensitivity of the spin-splitting and 0.7 anomaly to confining potential in one-dimensional nanoelectronic devices

Quantum point contacts (QPCs) have shown promise as nanoscale spin-selective components for spintronic applications and are of fundamental interest in the study of electron many-body effects such as the 0.7 x 2e^2/h anomaly. We report on the dependence of the 1D Lande g-factor g* and 0.7 anomaly on electron density and confinement in QPCs with two different top-gate architectures. We obtain g* values up to 2.8 for the lowest 1D subband, significantly exceeding previous in-plane g-factor values in AlGaAs/GaAs QPCs, and approaching that in InGaAs/InP QPCs. We show that g* is highly sensitive to confinement potential, particularly for the lowest 1D subband. This suggests careful management of the QPC's confinement potential may enable the high g* desirable for spintronic applications without resorting to narrow-gap materials such as InAs or InSb. The 0.7 anomaly and zero-bias peak are also highly sensitive to confining potential, explaining the conflicting density dependencies of the 0.7 anomaly in the literature.Comment: 23 pages, 7 figure

Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

A Discourse Analysis of Pilgrimage Reviews

This paper is the first to provide an account of the discursive features of online consumer reviews of pilgrimage sites. Drawing from pilgrimage studies and narrativity theory in consumer research, we explore how consumers communicate the spiritual and material aspects of pilgrimage experiences by examining a corpus of 833 consumer reviews on TripAdvisor of the most sacred pilgrimage sites of the world’s major five faith groups. Pilgrims include analytical discursive features to communicate the material aspect of their consumption experience. They reserve narration for spiritual transformation and the experience of strong emotions. Moreover, review ratings are only reflective of the spiritual aspect of their consumption experience. As such, our research complements previous studies by highlighting the material, physical aspect of this extraordinary consumption experience

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011