346 research outputs found
Cannabis use as a predictor and outcome of positive and negative affect in college students: An ecological momentary assessment study
Cannabis use as a predictor and outcome of positive and negative affect in college students: An ecological momentary assessment study
Rethinking Safety and Security of the Energy System for a Green Future
Nations across the world are transitioning their energy systems from fossil fuels to renewable sources at a rapidly accelerating pace. This has huge consequences for how we balance supply and demand in our electricity grid. The shift to renewables also entails a shift from highly centralised production, in large-scale fossil fuel power plants, to vastly distributed renewable sources at scales ranging from photovoltaic home systems to huge offshore wind farms. We argue that this transition requires us to radically rethink the safety and security of the energy grids and the whole supply chain that our modern society depends on. We will move from a well-understood heavily centralised infrastructure to one that is much harder to control, because of physical remoteness (e.g., offshore windfarms), the vast amount of decentralised assets, and because of a much more volatile and dynamic energy production level. This vastly increases our dependence on digital Operational Technology (OT) to control and monitor production for supply and demand balancing, and to, e.g., sense disruptions that require maintenance crews to be sent to remote locations. Couple that with a required change in behaviour of large consumers (industry) and small prosumers (households) to deal with a much more dynamic energy market and it is clear that we face big challenges in safety and security for the energy transition. In this position paper, we argue the need for a research agenda for rethinking how we manage the safety and security of our energy infrastructure
Impacts of Ocean Acidification on Sediment Processes in Shallow Waters of the Arctic Ocean
International audienceDespite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO 2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in subtropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO 2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study
The enabling and constraining connections between trust and digitalisation in incumbent value chains
Digitalisation is a disruptive socio-technical process that goes beyond digital technologies and their use within an
organisation, and involves besides (in many cases radical) technological change, social, institutional and economic
change. This creates uncertainties for value chain actors and the trust relationships between them. In this
paper we aim to understand the connections between trust and digitalisation. We investigate how trust relations
affect digitalisation, and how digitalisation affects trust relations among value chain actors, using the Dutch
flower sector as a case study. Our findings show that the sector has a high level of interpersonal trust, but limited
institutional trust, as the relationships between companies are highly competitive and transactional. In this
context, limited trust hinders digitalisation in multiple and mutually reinforcing ways, inducing a vicious cycle
whereby existing distrust or limited trust results in limited digitalisation, which in turn causes more distrust due
to uncertainties around the digitalisation process, further increased by existing (technological) path dependencies.
Hence there is a need for 1) awareness of mutually reinforcing (dis)trust dynamics and vicious (or
virtuous) cycles in relation to digitalisation are needed; 2) higher levels of understanding of what digitalisation
entails and 3) joint strategy building and foresighting in the value chain
The pathophysiological basis of pharmacological interventions in CAVD
Calcific aortic valve disease (CAVD) results in aortic valve stenosis and is one of the most common cardiac diseases in both Western and developing countries. The burden of this disease is expected to increase rapidly in the future, but there are still no relevant pharmacological therapies available and aortic valve replacement remains the sole definite therapy. This review presents an overview of the most common causes of CAVD, followed by current debates and trials related to the onset and progression of this disease. Several differences and similarities between the different causes of CAVD are presented. Additionally, stages of CAVD are compared with stages in atherosclerosis. Finally, future directions for research on CAVD will be discussed
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