22 research outputs found

    Notable shifts beyond pre-industrial streamflow and soil moisture conditions transgress the planetary boundary for freshwater change

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    Human actions compromise the many life-supporting functions provided by the freshwater cycle. Yet, scientific understanding of anthropogenic freshwater change and its long-term evolution is limited. Here, using a multi-model ensemble of global hydrological models, we estimate how, over a 145-year industrial period (1861–2005), streamflow and soil moisture have deviated from pre-industrial baseline conditions (defined by 5th–95th percentiles, at 0.5° grid level and monthly timestep over 1661–1860). Comparing the two periods, we find an increased frequency of local deviations on ~45% of land area, mainly in regions under heavy direct or indirect human pressures. To estimate humanity’s aggregate impact on these two important elements of the freshwater cycle, we present the evolution of deviation occurrence at regional to global scales. Annually, local streamflow and soil moisture deviations now occur on 18.2% and 15.8% of global land area, respectively, which is 8.0 and 4.7 percentage points beyond the ~3 percentage point wide pre-industrial variability envelope. Our results signify a substantial shift from pre-industrial streamflow and soil moisture reference conditions to persistently increasing change. This indicates a transgression of the new planetary boundary for freshwater change, which is defined and quantified using our approach, calling for urgent actions to reduce human disturbance of the freshwater cycle

    Family Firms and Firm Performance: Evidence from Japan

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    Corrigendum: Nature Structural and Molecular Biology 16 (12), 1331 (2009) doi:10.1038/nsmb1209-1331bInternational audienceThioredoxins (Trxs) are oxidoreductase enzymes, present in all organisms, that catalyze the reduction of disulfide bonds in proteins. By applying a calibrated force to a substrate disulfide, the chemical mechanisms of Trx catalysis can be examined in detail at the single-molecule level. Here we use single-molecule force-clamp spectroscopy to explore the chemical evolution of Trx catalysis by probing the chemistry of eight different Trx enzymes. All Trxs show a characteristic Michaelis-Menten mechanism that is detected when the disulfide bond is stretched at low forces, but at high forces, two different chemical behaviors distinguish bacterial-origin from eukaryotic-origin Trxs. Eukaryotic-origin Trxs reduce disulfide bonds through a single-electron transfer reaction (SET), whereas bacterial-origin Trxs show both nucleophilic substitution (SN2) and SET reactions. A computational analysis of Trx structures identifies the evolution of the binding groove as an important factor controlling the chemistry of Trx catalysis

    Quantifying Earth system interactions for sustainable food production via expert elicitation

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    Several safe boundaries of critical Earth system processes have already been crossed due to human perturbations; not accounting for their interactions may further narrow the safe operating space for humanity. Using expert knowledge elicitation, we explored interactions among seven variables representing Earth system processes relevant to food production, identifying many interactions little explored in Earth system literature. We found that green water and land system change affect other Earth system processes strongly, while land, freshwater and ocean components of biosphere integrity are the most impacted by other Earth system processes, most notably blue water and biogeochemical flows. We also mapped a complex network of mechanisms mediating these interactions and created a future research prioritization scheme based on interaction strengths and existing knowledge gaps. Our study improves the understanding of Earth system interactions, with sustainability implications including improved Earth system modelling and more explicit biophysical limits for future food production

    Operative tests of a new system for train traffic control

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    Tomorrow’s train traffic systems requires new strategies and solutions for efficient traintraffic control and utilization of track capacity, especially in traffic systems with a highdegree of deregulated and mixed traffic. There are many different goals associated withthe traffic control tasks and the work of the traffic controllers (dispatchers). Examples aresafety, efficiency of the traffic with regard to timeliness and energy consumption, goodservice and information to passengers and customers etc. Today’s traffic controlsystems and user interfaces do not efficiently support such goals. In earlier research wehave analyzed important aspects of the traffic controller’s tasks, strategies, decisionmaking, use of information and support systems etc. Based on this research we,together with Banverket (Swedish Rail Administration), have designed prototypesystems and interfaces that better can meet future goals and contribute to more optimaluse of infrastructure capacity. These prototype systems have now been developed into afully operational system which has been tested during 6 months, for control of train trafficin a section of the Swedish rail system. The evaluation shows that the system efficientlysupports control tasks and is well accepted by the involved traffic controllers

    Operative tests of a new system for train traffic control

    No full text
    Tomorrow’s train traffic systems requires new strategies and solutions for efficient traintraffic control and utilization of track capacity, especially in traffic systems with a highdegree of deregulated and mixed traffic. There are many different goals associated withthe traffic control tasks and the work of the traffic controllers (dispatchers). Examples aresafety, efficiency of the traffic with regard to timeliness and energy consumption, goodservice and information to passengers and customers etc. Today’s traffic controlsystems and user interfaces do not efficiently support such goals. In earlier research wehave analyzed important aspects of the traffic controller’s tasks, strategies, decisionmaking, use of information and support systems etc. Based on this research we,together with Banverket (Swedish Rail Administration), have designed prototypesystems and interfaces that better can meet future goals and contribute to more optimaluse of infrastructure capacity. These prototype systems have now been developed into afully operational system which has been tested during 6 months, for control of train trafficin a section of the Swedish rail system. The evaluation shows that the system efficientlysupports control tasks and is well accepted by the involved traffic controllers

    Operative tests of a new system for train traffic control

    No full text
    Tomorrow’s train traffic systems requires new strategies and solutions for efficient traintraffic control and utilization of track capacity, especially in traffic systems with a highdegree of deregulated and mixed traffic. There are many different goals associated withthe traffic control tasks and the work of the traffic controllers (dispatchers). Examples aresafety, efficiency of the traffic with regard to timeliness and energy consumption, goodservice and information to passengers and customers etc. Today’s traffic controlsystems and user interfaces do not efficiently support such goals. In earlier research wehave analyzed important aspects of the traffic controller’s tasks, strategies, decisionmaking, use of information and support systems etc. Based on this research we,together with Banverket (Swedish Rail Administration), have designed prototypesystems and interfaces that better can meet future goals and contribute to more optimaluse of infrastructure capacity. These prototype systems have now been developed into afully operational system which has been tested during 6 months, for control of train trafficin a section of the Swedish rail system. The evaluation shows that the system efficientlysupports control tasks and is well accepted by the involved traffic controllers
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