Ocean acidification and hypoxia alter organic carbon fluxes in marine soft sediments.

Anthropogenic stressors can alter the structure and functioning of infaunal communities, which are key drivers of the carbon cycle in marine soft sediments. Nonetheless, the compounded effects of anthropogenic stressors on carbon fluxes in soft benthic systems remain largely unknown. Here, we investigated the cumulative effects of ocean acidification (OA) and hypoxia on the organic carbon fate in marine sediments, through a mesocosm experiment. Isotopically labelled macroalgal detritus (13 C) was used as a tracer to assess carbon incorporation in faunal tissue and in sediments under different experimental conditions. In addition, labelled macroalgae (13 C), previously exposed to elevated CO2 , were also used to assess the organic carbon uptake by fauna and sediments, when both sources and consumers were exposed to elevated CO2 . At elevated CO2 , infauna increased the uptake of carbon, likely as compensatory response to the higher energetic costs faced under adverse environmental conditions. By contrast, there was no increase in carbon uptake by fauna exposed to both stressors in combination, indicating that even a short-term hypoxic event may weaken the ability of marine invertebrates to withstand elevated CO2 conditions. In addition, both hypoxia and elevated CO2 increased organic carbon burial in the sediment, potentially affecting sediment biogeochemical processes. Since hypoxia and OA are predicted to increase in the face of climate change, our results suggest that local reduction of hypoxic events may mitigate the impacts of global climate change on marine soft-sediment systems.

[Emotional robots in a nursing context : Empirical analysis of the present use and the effects of Paro and Pleo]. / Emotionale Roboter im Pflegekontext : Empirische Analyse des bisherigen Einsatzes und der Wirkungen von Paro und Pleo.

BACKGROUND: It has been questioned by researchers in robotics as well in the general public to what extent companion-type robots can support the elderly with the fulfillment of their psychological and social needs. Although these robots have already been used in care settings in Germany, research has referred little to this practical experience in order to analyze their impact and benefit. To start to close this gap, the current article reports on the current use of companion-type robots in care settings, on the effects reported by professional caregivers as well as on the role of psychosocial needs in the acceptance and use of companion-type robots by the elderly. MATERIAL AND METHODS: In the first study, 30 professional caregivers with experience in the use of the robot seal Paro in care settings were interviewed regarding Paro's application and the observed effects on their clients. In the second study, three case examples are presented from an interaction study in which vulnerable elderly persons had the robot dinosaur Pleo at their disposal for a maximum period of 15 days. RESULTS: Paro is used very flexibly in a variety of settings and with a broad range of user groups (study 1). The reported psychosocial effects were mainly positive but short term. The case examples (study 2) show that psychosocial needs can both foster or hinder robot acceptance and use. They also emphasize the important role of caregivers in the interaction between the elderly and emotional robots in the context of eldercare. CONCLUSION: The beneficial and ethical use of companion-type robots in care settings demands a high commitment on the part of the caregivers. Given this prerequisite, emotional robots can be a valuable therapeutic tool.

Biogeochemical consequences of a changing Arctic shelf seafloor ecosystem.

Unprecedented and dramatic transformations are occurring in the Arctic in response to climate change, but academic, public, and political discourse has disproportionately focussed on the most visible and direct aspects of change, including sea ice melt, permafrost thaw, the fate of charismatic megafauna, and the expansion of fisheries. Such narratives disregard the importance of less visible and indirect processes and, in particular, miss the substantive contribution of the shelf seafloor in regulating nutrients and sequestering carbon. Here, we summarise the biogeochemical functioning of the Arctic shelf seafloor before considering how climate change and regional adjustments to human activities may alter its biogeochemical and ecological dynamics, including ecosystem function, carbon burial, or nutrient recycling. We highlight the importance of the Arctic benthic system in mitigating climatic and anthropogenic change and, with a focus on the Barents Sea, offer some observations and our perspectives on future management and policy.