2,098 research outputs found

    Are newspapers heading towards post-print obscurity? A case study of The Independent’s transition to online-only

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    With print circulations in decline and the print advertising market shrinking, newspapers in many countries are under pressure. Some—like Finland’s Taloussanomat and Canada’s La Presse—have decided to stop printing and go online-only. Others, like the Sydney Morning Herald, are debating whether to follow. Those newspapers that have made the switch often paint a rosy picture of a sustainable and profitable digital future. This study examines the reality behind the spin via a case study of The Independent, a general-interest UK national newspaper that went digital-only in March 2016. We estimate that, although its net British readership did not decline in the year after it stopped printing, the total time spent with The Independent by its British audiences fell 81%, a disparity caused by huge differences in the habits of online and print readers. This suggests that when newspapers go online-only they may move back into the black, but they also forfeit much of the attention they formerly enjoyed. Furthermore, although The Independent is serving at least 50% more overseas browsers since going online-only, the relative influence on that growth of internal organizational change and external factors—such as the “Trump Bump” in news consumption—is difficult to determine

    Observing biogeochemical cycles at global scales with profiling floats and gliders: prospects for a global array

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    Chemical and biological sensor technologies have advanced rapidly in the past five years. Sensors that require low power and operate for multiple years are now available for oxygen, nitrate, and a variety of bio-optical properties that serve as proxies for important components of the carbon cycle (e.g., particulate organic carbon). These sensors have all been deployed successfully for long periods, in some cases more than three years, on platforms such as profiling floats or gliders. Technologies for pH, pCO2, and particulate inorganic carbon are maturing rapidly as well. These sensors could serve as the enabling technology for a global biogeochemical observing system that might operate on a scale comparable to the current Argo array. Here, we review the scientific motivation and the prospects for a global observing system for ocean biogeochemistry

    Studies of opinion stability for small dynamic networks with opportunistic agents

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    There are numerous examples of societies with extremely stable mix of contrasting opinions. We argue that this stability is a result of an interplay between society network topology adjustment and opinion changing processes. To support this position we present a computer model of opinion formation based on some novel assumptions, designed to bring the model closer to social reality. In our model, the agents, in addition to changing their opinions due to influence of the rest of society and external propaganda, have the ability to modify their social network, forming links with agents sharing the same opinions and cutting the links with those they disagree with. To improve the model further we divide the agents into `fanatics' and `opportunists', depending on how easy is to change their opinions. The simulations show significant differences compared to traditional models, where network links are static. In particular, for the dynamical model where inter-agent links are adjustable, the final network structure and opinion distribution is shown to resemble real world observations, such as social structures and persistence of minority groups even when most of the society is against them and the propaganda is strong.Comment: Revised version accepted by International Journal of Modern Physics C Added analysis, references and a new figur

    Catalysis and chemical mechanisms of calcite dissolution in seawater

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    Near-equilibrium calcite dissolution in seawater contributes significantly to the regulation of atmospheric CO_2 on 1,000-y timescales. Despite many studies on far-from-equilibrium dissolution, little is known about the detailed mechanisms responsible for calcite dissolution in seawater. In this paper, we dissolve ^(13)C-labeled calcites in natural seawater. We show that the time-evolving enrichment of ÎŽ^(13)C in solution is a direct measure of both dissolution and precipitation reactions across a large range of saturation states. Secondary Ion Mass Spectrometer profiles into the ^(13)C-labeled solids confirm the presence of precipitated material even in undersaturated conditions. The close balance of precipitation and dissolution near equilibrium can alter the chemical composition of calcite deeper than one monolayer into the crystal. This balance of dissolution–precipitation shifts significantly toward a dissolution-dominated mechanism below about Ω= 0.7. Finally, we show that the enzyme carbonic anhydrase (CA) increases the dissolution rate across all saturation states, and the effect is most pronounced close to equilibrium. This finding suggests that the rate of hydration of CO_2 is a rate-limiting step for calcite dissolution in seawater. We then interpret our dissolution data in a framework that incorporates both solution chemistry and geometric constraints on the calcite solid. Near equilibrium, this framework demonstrates a lowered free energy barrier at the solid–solution interface in the presence of CA. This framework also indicates a significant change in dissolution mechanism at Ω= 0.7, which we interpret as the onset of homogeneous etch pit nucleation

    Carbon export and regeneration in the coastal upwelling system of Monterey Bay, central California

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    In order to quantify the role of coastal upwelling regions as source or sink areas for carbon, the relationships between particulate organic carbon (POC) production, export, remineralization, and accumulation were examined in Monterey Bay from 1989 through 1992. During a normal upwelling year (1989–90), a high positive correlation (r = 0.91) is observed between biweekly primary production and POC export at 450 m. Primary production values range from 500 mgC m−2 d−1 during the winter, to 2600 mgC m−2 d−1 in the spring and summer upwelling months. Corresponding deep-water (450 m) POC fluxes vary from a minimum of 10 mgC m−2 d−1 in December, to 120 mgC m−2 d−1 in May. In contrast, the mid-1991 through 1992 data sets obtained during the \u2791–92 El Nino period, show a relatively poor correlation (r = 0.23) between productivity and carbon export. Calculated ratios of POC export to POC production (defined as e-ratios) display a trend for the three-year data sets in which the e-ratio values are greatest during periods of low productivity and decrease to minimal values when surface production is high. Upwelling-induced, offshore Ekman transport of organic matter and probable seasonal changes in the planktonic community structure are the mechanisms likely to be responsible for the e-ratio trends. Based on the data sets reported from this work, a simple box model of the annual export and regeneration of particulate organic carbon is presented for the Monterey Bay region. An appreciable advective and/or recycling “loss” from the euphotic zone of 362.8 gC m−2 y−1 is estimated, representing primarily algal material transported offshore and/or recycled within the upper 100 m of the water column. Annual mid-water (≈100– 450 m) and deep-water (\u3e450 m) POC remineralization rates of 71.8 gC m−2 y−1 of 7.2 gC m−2 y−1, respectively, are reported for Monterey Bay. The average POC rain rate to the underlying slope sediments is sufficient to satisfy reported benthic utilization requirements without invoking an additional input source of POC via deep lateral advection and/or the downslope movement of particulate material
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