Building the BRIDGE: closing the gap on digital exclusion

Access to products, services and government is increasingly reliant on people being able to use information and communications technologies: from computers to mobile phones. Whilst there are many obvious benefits to those already familiar with the technology, those that do not have the skills or inclination to interact through such technology can get excluded and this may eventually lead to a permanent disadvantage. These groups within society can be very large according to the UK government, with 70% of over 65s reported as never having used the Internet (www.statistics.gov.uk, 2008). As companies grow in scale and design products and services for global rather than local markets it becomes harder to track these partially excluded groups. This is reported as a growing 'psychic distance' between the designers of technologies and the prospective users of those technologies, with a risk that those excluded from the market today will become effectively invisible to designers of future products. Such users' requirements of technology no longer inform the design process and create a digital divide that is socially constructed rather than economically constrained. This is neither good for society nor business, where such exclusion may alienate, as well as prevent business from identifying and engaging with latent demand for their products and services. This project aims to build a 'Bridge' from the needs of technologically excluded users to the capabilities of suppliers of products and services. This will be achieved through exploration of users' expectations, desires and needs and by building design guidelines to help address them. The project will extrapolate the results of this work to wider markets. In order to realise these goals, a combination is needed of qualitative research methods to deliver a detailed picture of user needs, and quantitative methods to map that to the data that large global corporations would typically hold about their current customers and markets. User needs identified through qualitative methods need to be related to behavioural characteristics observed through data analysis and modelling of demand within global markets. This element of the project builds on direct engagement with industry, both with designers, and their existing customers, as well as the organisational processes and data that relate one to the other and informs the designer's view of their users. Through direct engagement with users, designers and producers, BRIDGE will contribute to the design of new products, services and interfaces. As design improves and becomes more socially inclusive, better and more sustainable relationships can be established with consumers. This knowledge can be used to identify opportunities for expansion within global markets for UK industry and hence has the potential to benefit individuals, society and the economy overall

Reconnection-controlled decay of magnetohydrodynamic turbulence and the role of invariants

We present a new theoretical picture of magnetically dominated, decaying turbulence in the absence of a mean magnetic field. We demonstrate that such turbulence is governed by the reconnection of magnetic structures, and not by ideal dynamics, as has previously been assumed. We obtain predictions for the magnetic-energy decay laws by proposing that turbulence decays on reconnection timescales, while respecting the conservation of certain integral invariants representing topological constraints satisfied by the reconnecting magnetic field. As is well known, the magnetic helicity is such an invariant for initially helical field configurations, but does not constrain non-helical decay, where the volume-averaged magnetic-helicity density vanishes. For such a decay, we propose a new integral invariant, analogous to the Loitsyansky and Saffman invariants of hydrodynamic turbulence, that expresses the conservation of the random (scaling as $\mathrm{volume}^{1/2}$) magnetic helicity contained in any sufficiently large volume. Our treatment leads to novel predictions for the magnetic-energy decay laws: in particular, while we expect the canonical $t^{-2/3}$ power law for helical turbulence when reconnection is fast (i.e., plasmoid-dominated or stochastic), we find a shallower $t^{-4/7}$ decay in the slow `Sweet-Parker' reconnection regime, in better agreement with existing numerical simulations. For non-helical fields, for which there currently exists no definitive theory, we predict power laws of $t^{-10/9}$ and $t^{-20/17}$ in the fast- and slow-reconnection regimes, respectively. We formulate a general principle of decay of turbulent systems subject to conservation of Saffman-like invariants, and propose how it may be applied to MHD turbulence with a strong mean magnetic field and to isotropic MHD turbulence with initial equipartition between the magnetic and kinetic energies.Comment: 30 pages, 15 figures, accepted by Phys. Rev.

Cosmic-void observations reconciled with primordial magnetogenesis

It has been suggested that the weak magnetic field hosted by the intergalactic medium in cosmic voids could be a relic from the early Universe. However, accepted models of turbulent magnetohydrodynamic decay predict that the present-day strength of fields originally generated at the electroweak phase transition (EWPT) without parity violation would be too low to explain the observed scattering of γ-rays from TeV blazars. Here, we propose that the decay is mediated by magnetic reconnection and conserves the mean square fluctuation level of magnetic helicity. We find that the relic fields would be stronger by several orders of magnitude under this theory than was indicated by previous treatments, which restores the consistency of the EWPT-relic hypothesis with the observational constraints. Moreover, efficient EWPT magnetogenesis would produce relics at the strength required to resolve the Hubble tension via magnetic effects at recombination and seed galaxy-cluster fields close to their present-day strength

Cosmic-void observations reconciled with primordial magnetogenesis

It has been suggested that the weak magnetic field hosted by the intergalactic medium in cosmic voids could be a relic from the early Universe. However, accepted models of turbulent magnetohydrodynamic decay predict that the present-day strength of fields originally generated at the electroweak phase transition (EWPT) without parity violation would be too low to explain the observed scattering of γ-rays from TeV blazars. Here, we propose that the decay is mediated by magnetic reconnection and conserves the mean square fluctuation level of magnetic helicity. We find that the relic fields would be stronger by several orders of magnitude under this theory than was indicated by previous treatments, which restores the consistency of the EWPT-relic hypothesis with the observational constraints. Moreover, efficient EWPT magnetogenesis would produce relics at the strength required to resolve the Hubble tension via magnetic effects at recombination and seed galaxy-cluster fields close to their present-day strength

Emergence of long-range correlations and thermal spectra in forced turbulence

Recent numerical studies have shown that forced, statistically isotropic turbulence develops a ‘thermal equilibrium’ spectrum, E(k) ∝ k 2 , at large scales. This behaviour presents a puzzle, as it appears to imply the growth of a non-zero Saffman integral, which would require the longitudinal velocity correlation function, χ(r), to satisfy χ(r → ∞) ∝ r −3 . As is well known, the Saffman integral is an invariant of decaying turbulence, precisely because non-local interactions (i.e., interactions via exchange of pressure waves) are too weak to generate such correlations. Subject to certain restrictions on the nature of the forcing, we argue that the same should be true for forced turbulence. We show that long-range correlations and a k 2 spectrum arise as a result of the turbulent diffusion of linear momentum, and extend only up to a maximum scale that grows slowly with time. This picture has a number of interesting consequences. First, if the forcing generates eddies with significant linear momentum (as in so-called Saffman turbulence), a thermal spectrum is not reached—instead, a shallower spectrum develops. Secondly, the energy of turbulence that is forced for a while and then allowed to decay obeys Saffman’s decay laws for a period that is much longer than the duration of the forcing stage

Effects of oilseed meal and grain-urea supplements fed infrequently on digestion in sheep: 1. Low quality grass hay diets

An experiment examined intake, growth response and rumen digestion of young sheep fed ad libitum low quality grass hay alone or supplemented with approximately isonitrogenous amounts of barley grain and urea (Bar/N), safflower meal (SAF) or linseed meal (LIN) provided at 3 days intervals. Supplements comprised 13–20% of total DM intake. Sheep fed grass hay alone consumed 60.2gDM/kgLW0.75/day of hay and an estimated 6.09MJ metabolizable energy (ME)/day, and were in liveweight (LW) maintenance. Hay intake was decreased (P<0.05) by the Bar/N supplement with a substitution rate of 0.9, but was not changed by the oilseed meal supplements. Each of the supplements increased (P<0.05) estimated ME intake to a similar extent, but LW gain and wool growth were lower (P<0.05) in sheep supplemented with Bar/N than those supplemented with LIN. Rumen degradabilities of the SAF and LIN CP were estimated to be 0.72 and 0.62, respectively. Rumen ammonia concentrations in sheep fed hay alone (average 97mgNH3/l) were expected to be adequate for microbial activity. Fractional outflow rate (FOR) of liquid from the rumen measured with Co-EDTA (mean 0.109h−1) was greater than that of Cr-mordanted supplements (mean 0.056h−1), which was in turn greater than the FOR of Cr-mordanted hay (mean 0.031h−1). Diet did not affect these FOR. Supplemented sheep accommodated increased DM intake on Day 1 of the 3 day supplementation cycle by increasing rumen digesta load rather than by increasing rate of passage of digesta. Results show that the LW gain of young sheep fed low quality hay was increased more by either oilseed meal than by equivalent amounts of barley grain/urea supplement, apparently due to more efficient utilization of ME for LW gain

Mental template matching is a potential cultural transmission mechanism for New Caledonian crow tool manufacturing traditions

Cumulative cultural evolution occurs when social traditions accumulate improvements over time. In humans cumulative cultural evolution is thought to depend on a unique suite of cognitive abilities, including teaching, language and imitation. Tool-making New Caledonian crows show some hallmarks of cumulative culture; but this claim is contentious, in part because these birds do not appear to imitate. One alternative hypothesis is that crows' tool designs could be culturally transmitted through a process of mental template matching. That is, individuals could use or observe conspecifics' tools, form a mental template of a particular tool design, and then reproduce this in their own manufacture - a process analogous to birdsong learning. Here, we provide the first evidence supporting this hypothesis, by demonstrating that New Caledonian crows have the cognitive capacity for mental template matching. Using a novel manufacture paradigm, crows were first trained to drop paper into a vending machine to retrieve rewards. They later learnt that only items of a particular size (large or small templates) were rewarded. At test, despite being rewarded at random, and with no physical templates present, crows manufactured items that were more similar in size to previously rewarded, than unrewarded, templates. Our results provide the first evidence that this cognitive ability may underpin the transmission of New Caledonian crows' natural tool designs.Tis study was supported by the NZ Marsden fund (RDG), a Rutherford Discovery Fellowship and the 2015 Prime Ministers MacDiarmid Emerging Scientist prize (AHT). SAJ thanks the ERC (Grant Agreement No. 3399933) for funding