727 research outputs found

    New practices in science communication: Roles of professionals in science and technology development

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    Currently, Science Communication (SC) professionals who are working in the context of science and technology development, have various jobs at universities, government agencies, NGOs and industry. Their positions have changed in recent years, due to developments in science and technology and to social trends. Increasingly, SC practitioners play a role as mediator in participatory processes, or facilitator of stakeholder meetings. These roles require decisions in difficult to manage processes and in situations that are hard to overlook. A decision support system would be able to help them. In this paper we describe the changing role of SC practitioners and the context in which they make decisions. Then we argue which requirements decision support systems must meet in order to support SC practitioners in their decision making processes. Our paper is based on a literature review on professionalization and in-depth interviews with science communication professionals. Our main conclusion is that a decision support system should not only support the SC practitioner‟s instrumental decisions, but shoul

    Biogeochemistry of Norwegian cold-water coral reef sediments

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    Cold-water coral ecosystems may constitute a geologically significant fraction (>1%) of global carbonate production (Lindberg and Mienert, 2005). Thriving cold-water coral reefs are also considered to be hot-spots of diversity and biomass production. Nevertheless, the impacts of these ecosystems on the adjacent sediment and associated geochemical processes including carbonate preservation are poorly understood.Here we present the first data quantifying the biogeochemical processes in modern (post-glacial) cold-water coral reef sediments. This work integrates organoclastic sulfate reduction rates, multi-element pore-water profiles and solid-phase analyses of gravity cores (8 sites at two reefs) retrieved during R/V Polarstern expedition ARKXXII/1a to the mid-Norwegian cold-water coral reefs in June 2007.The reef sediments are comprised of coral fragments embedded in loose silt or clay and biogenic debris (of 0,5 to 3,2 m thickness). The base of the coral-bearing reef sediments consists of highly compacted glacial clays. High carbonate contents (up to 75 %) and low organic carbon contents (~0,5 %) characterize the reef sediments. Porewater Ca2+, Mg2+ and Sr2+ profiles indicate that on-going carbonate precipitation dominates any carbonate dissolution. Overall microbial activity in these sediments is low; measured sulfate reduction rates are less than 1 nmol S cm-3 d-1. Pore-water analyses reveal elevated Fe2+ and Mn2+ concentrations suggesting that Fe and Mn reduction occurs. This may be the result of sulfide reacting with the available reactive iron pool to form Fe-sulfides indicated by the absence of sulfide in the pore water. Fe and Mn reduction may also be attributed to dissimilatory microbial metal reduction. Iron reduction linked to microbial sulfate reduction may enhance diagenetic carbonate precipitation and coral preservation in these sediments as suggested for the older coldwater coral mound systems drilled in IODP Expedition 307 (Ferdelman et al., 2006). Extremely low methane concentrations (<0,5 µM) were found at all depths and sites along the Norwegian margin. This argues against a linkage between coral reef distribution and the appearance of hydrocarbon seepage as formulated by Hovland et al. (1998)

    Beyond Speculative Robot Ethics

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    In this article we develop a dialogue model for robot technology experts and designated users to discuss visions on the future of robotics in long-term care. Our vision assessment study aims for more distinguished and more informed visions on future robots. Surprisingly, our experiment also lead to some promising co-designed robot concepts in which jointly articulated moral guidelines are embedded. With our model we think to have designed an interesting response on a recent call for a less speculative ethics of technology by encouraging discussions about the quality of positive and negative visions on the future of robotics.

    Sulfur cycling in an iron oxide-dominated, dynamic marine depositional system: The Argentine continental margin

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    The interplay between sediment deposition patterns, organic matter type and the quantity and quality of reactive mineral phases determines the accumulation, speciation, and isotope composition of pore water and solid phase sulfur constituents in marine sediments. Here, we present the sulfur geochemistry of siliciclastic sediments from two sites along the Argentine continental slope—a system characterized by dynamic deposition and reworking, which result in non-steady state conditions. The two investigated sites have different depositional histories but have in common that reactive iron phases are abundant and that organic matter is refractory—conditions that result in low organoclastic sulfate reduction rates (SRR). Deposition of reworked, isotopically light pyrite and sulfurized organic matter appear to be important contributors to the sulfur inventory, with only minor addition of pyrite from organoclastic sulfate reduction above the sulfate-methane transition (SMT). Pore-water sulfide is limited to a narrow zone at the SMT. The core of that zone is dominated by pyrite accumulation. Iron monosulfide and elemental sulfur accumulate above and below this zone. Iron monosulfide precipitation is driven by the reaction of low amounts of hydrogen sulfide with ferrous iron and is in competition with the oxidation of sulfide by iron (oxyhydr)oxides to form elemental sulfur. The intervals marked by precipitation of intermediate sulfur phases at the margin of the zone with free sulfide are bordered by two distinct peaks in total organic sulfur (TOS). Organic matter sulfurization appears to precede pyrite formation in the iron-dominated margins of the sulfide zone, potentially linked to the presence of polysulfides formed by reaction between dissolved sulfide and elemental sulfur. Thus, SMTs can be hotspots for organic matter sulfurization in sulfide-limited, reactive iron-rich marine sedimentary systems. Furthermore, existence of elemental sulfur and iron monosulfide phases meters below the SMT demonstrates that in sulfide-limited systems metastable sulfur constituents are not readily converted to pyrite but can be buried to deeper sediment depths. Our data show that in non-steady state systems, redox zones do not occur in sequence but can reappear or proceed in inverse sequence throughout the sediment column, causing similar mineral alteration processes to occur at the same time at different sediment depths

    Development and implementation of a new service delivery model for children with disabilities : implications for DCD

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    There is a general consensus that new service delivery models are needed for children with developmental coordination disorder (DCD). Emerging principles to guide service delivery include the use of graduated levels of intensity and evidence-based services that focus on function and participation. Interdisciplinary, community-based service delivery models based on best practice principles are needed. In this case report, we propose the Apollo model as an example of an innovative service delivery model for children with DCD. We describe the context that led to the creation of a program for children with DCD, describe the service delivery model and services, and share lessons learned through implementation. The Apollo model has 5 components: first contact, service delivery coordination, community-, group- and individual-interventions. This model guided the development of a streamlined set of services offered to children with DCD, including early-intake to share educational information with families, community interventions, inter-disciplinary and occupational therapy groups and individual interventions. Following implementation of the Apollo model, waiting times decreased and numbers of children receiving services increased, without compromising service quality. Lessons learned are shared to facilitate development of other practice models to support children with DCD

    Pain in patients with pancreatic cancer: prevalence, mechanisms, management and future developments

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    Pain affects approximately 80% of patients with pancreatic cancer, with half requiring strong opioid analgesia, namely: morphine-based drugs on step three of the WHO analgesic ladder (as opposed to the weak opioids: codeine and tramadol). The presence of pain is associated with reduced survival. This article reviews the literature regarding pain: prevalence, mechanisms, pharmacological, and endoscopic treatments and identifies areas for research to develop individualized patient pain management pathways. The online literature review was conducted through: PubMed, Clinical Key, Uptodate, and NICE Evidence. There are two principal mechanisms for pain: pancreatic duct obstruction and pancreatic neuropathy which, respectively, activate mechanical and chemical nociceptors. In pancreatic neuropathy, several histological, molecular, and immunological changes occur which correlate with pain including: transient receptor potential cation channel activation and mast cell infiltration. Current pain management is empirical rather etiology-based and is informed by the WHO analgesic ladder for first-line therapies, and then endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) in patients with resistant pain. For EUS-CPN, there is only one clinical trial reporting a benefit, which has limited generalizability. Case series report pancreatic duct stenting gives effective analgesia, but there are no clinical trials. Progress in understanding the mechanisms for pain and when this occurs in the natural history, together with assessing new therapies both pharmacological and endoscopic, will enable individualized care and may improve patients’ quality of life and survival

    Mineralogical and geochemical analysis of Fe-phases in drill-cores from the Triassic Stuttgart Formation at Ketzin CO₂ storage site before CO₂ arrival

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    Reactive iron (Fe) oxides and sheet silicate-bound Fe in reservoir rocks may affect the subsurface storage of CO2 through several processes by changing the capacity to buffer the acidification by CO2 and the permeability of the reservoir rock: (1) the reduction of three-valent Fe in anoxic environments can lead to an increase in pH, (2) under sulphidic conditions, Fe may drive sulphur cycling and lead to the formation of pyrite, and (3) the leaching of Fe from sheet silicates may affect silicate diagenesis. In order to evaluate the importance of Fe-reduction on the CO2 reservoir, we analysed the Fe geochemistry in drill-cores from the Triassic Stuttgart Formation (Schilfsandstein) recovered from the monitoring well at the CO2 test injection site near Ketzin, Germany. The reservoir rock is a porous, poorly to moderately cohesive fluvial sandstone containing up to 2–4 wt% reactive Fe. Based on a sequential extraction, most Fe falls into the dithionite-extractable Fe-fraction and Fe bound to sheet silicates, whereby some Fe in the dithionite-extractable Fe-fraction may have been leached from illite and smectite. Illite and smectite were detected in core samples by X-ray diffraction and confirmed as the main Fe-containing mineral phases by X-ray absorption spectroscopy. Chlorite is also present, but likely does not contribute much to the high amount of Fe in the silicate-bound fraction. The organic carbon content of the reservoir rock is extremely low (<0.3 wt%), thus likely limiting microbial Fe-reduction or sulphate reduction despite relatively high concentrations of reactive Fe-mineral phases in the reservoir rock and sulphate in the reservoir fluid. Both processes could, however, be fuelled by organic matter that is mobilized by the flow of supercritical CO2 or introduced with the drilling fluid. Over long time periods, a potential way of liberating additional reactive Fe could occur through weathering of silicates due to acidification by CO2

    Volcanic CO2 output at the Central American subduction zone inferred from melt inclusions in olivine crystals from mafic tephras

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    The volatile contents of olivine‐hosted (Fo89–71) melt inclusion glasses in rapidly quenched mafic tephras from volcanic front volcanoes of the Central American Volcanic Arc (CAVA) in Guatemala, Nicaragua, and Costa Rica, were analyzed by secondary ion mass spectrometry (SIMS) in order to derive the minimum eruptive output of CO2, along with H2O, Cl, and S. Details of the analytical method are provided that establish melt inclusion CO2 analyses with the Cameca ims6f at the Helmholtz Centre Potsdam. The highest CO2 concentrations (up to 1800 mg/g) are observed in Nicaraguan samples, while melt inclusions from Guatemala and Costa Rica have CO2 contents between 50 and 500 mg/g. CO2 does not positively covary with sediment/slab fluid tracers such as Ba/La, Ba/Th, or U/La. Instead, the highest CO2 concentrations occur in the inclusions with the most depleted incompatible element compositions and low H2O, approaching the composition of mid‐ocean ridge basalts (MORBs), whereas the most H2O‐rich inclusions are relatively CO2‐poor (<800 mg/g). This suggests that CO2 degassing was more extensive in the melts with the highest slab contribution. CO2/Nb ratios in the least degassed CAVA melt inclusions are similar to those of primitive MORBs. These are interpreted here as recording a minimum CO2 output rate from the mantle wedge, which amounts to 2.8 × 104 g/s for the ∼1100 km long CAVA. Previously published estimates from quiescent degassing and numerical modeling, which also encompassed the slab contribution, are 3 times higher. This comparison allows us to estimate the proportion of the total CO2 output derived from the mantle wedge

    Biogeochemical cycling in the Bering Sea over the onset of major Northern Hemisphere glaciation

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    The Bering Sea is one of the most biologically productive regions in the marine system and plays a key role in regulating the flow of waters to the Arctic Ocean and into the subarctic North Pacific Ocean. Cores from IODP Expedition 323 to the Bering Sea provide the first opportunity to obtain reconstructions from the region that extend back to the Pliocene. Previous research at Bowers Ridge, south Bering Sea, has revealed stable levels of siliceous productivity over the onset of major Northern Hemisphere Glaciation (NHG) (c. 2.85-2.73 Ma). However, diatom silica isotope records of oxygen (δ18Odiatom) and silicon (δ30Sidiatom) presented here demonstrate that this interval was associated with a progressive increase in the supply of silicic acid to the region, superimposed on shift to a more dynamic environment characterized by colder temperatures and increased sea ice. This concluded at 2.58 Ma with a sharp increase in diatom productivity, further increases in photic zone nutrient availability and a permanent shift to colder sea surface conditions. These transitions are suggested to reflect a gradually more intense nutrient leakage from the subarctic northwest Pacific Ocean, with increases in productivity further aided by increased sea-ice and wind-driven mixing in the Bering Sea. In suggesting a linkage in biogeochemical cycling between the south Bering Sea and subarctic Northwest Pacific Ocean, mainly via the Kamchatka Strait, this work highlights the need to consider the inter-connectivity of these two systems when future reconstructions are carried out in the region
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