101 research outputs found
Understanding Business Travel Time and Its Place in the Working Day
This article argues that there is a need to understand business travel time in the context of the wider organization of work time. It considers why travel time use is potentially changing with the use of mobile technologies by the increasing number of individuals engaged in âknowledge workâ, and examines existing evidence that indicates that travel time use is part of a wider work-related âtaskscapeâ. However, it not only considers material productive output, but suggests that travel time as âtime outâ from work-related activities also plays a vital role for employees. It also suggests that business travel time use that is not of benefit to the employer may not be at the employer's expense. This is contrasted with the assumptions used in UK transport appraisal. Data gathered from the autumn 2004 wave of the National Rail Passenger Survey (GB) is used to illustrate some key issues concerning productivity and âanti-activityâ. A case study of an individual business traveller then points towards the need for a new approach to exploring the role played by travel time in the organization of work practices to be considered. © 2008, Sage Publications. All rights reserved
Consensus and ordering in language dynamics
We consider two social consensus models, the AB-model and the Naming Game
restricted to two conventions, which describe a population of interacting
agents that can be in either of two equivalent states (A or B) or in a third
mixed (AB) state. Proposed in the context of language competition and
emergence, the AB state was associated with bilingualism and synonymy
respectively. We show that the two models are equivalent in the mean field
approximation, though the differences at the microscopic level have non-trivial
consequences. To point them out, we investigate an extension of these dynamics
in which confidence/trust is considered, focusing on the case of an underlying
fully connected graph, and we show that the consensus-polarization phase
transition taking place in the Naming Game is not observed in the AB model. We
then consider the interface motion in regular lattices. Qualitatively, both
models show the same behavior: a diffusive interface motion in a
one-dimensional lattice, and a curvature driven dynamics with diffusing
stripe-like metastable states in a two-dimensional one. However, in comparison
to the Naming Game, the AB-model dynamics is shown to slow down the diffusion
of such configurations.Comment: 7 pages, 6 figure
The role of sulfoglucuronosyl glycosphingolipids in the pathogenesis of monoclonal IgM paraproteinemia and peripheral neuropathy
In IgM paraproteinemia and peripheral neuropathy, IgM M-protein secretion by B cells leads to a T helper cell response, suggesting that it is antibody-mediated autoimmune disease involving carbohydrate epitopes in myelin sheaths. An immune response against sulfoglucuronosyl glycosphingolipids (SGGLs) is presumed to participate in demyelination or axonal degeneration in the peripheral nervous system (PNS). SGGLs contain a 3-sulfoglucuronic acid residue that interacts with anti-myelin-associated glycoprotein (MAG) and the monoclonal antibody anti-HNK-1. Immunization of animals with sulfoglucuronosyl paragloboside (SGPG) induced anti-SGPG antibodies and sensory neuropathy, which closely resembles the human disease. These animal models might help to understand the disease mechanism and lead to more specific therapeutic strategies. In an in vitro study, destruction or malfunction of the blood-nerve barrier (BNB) was found, resulting in the leakage of circulating antibodies into the PNS parenchyma, which may be considered as the initial key step for development of disease
Hierarchy of Scales in Language Dynamics
Methods and insights from statistical physics are finding an increasing variety of applications where one seeks to understand the emergent properties of a complex interacting system. One such area concerns the dynamics of language at a variety of levels of description, from the behaviour of individual agents learning simple artificial languages from each other, up to changes in the structure of languages shared by large groups of speakers over historical timescales. In this Colloquium, we survey a hierarchy of scales at which language and linguistic behaviour can be described, along with the main progress in understanding that has been made at each of them â much of which has come from the statistical physics community. We argue that future developments may arise by linking the different levels of the hierarchy together in a more coherent fashion, in particular where this allows more effective use of rich empirical data sets
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 Mâ) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e †0.3 at 16.9 Gpcâ3 yrâ1 at the 90% confidence level
Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO
The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages
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