52 research outputs found

    Metal–organic complexation in the marine environment

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    We discuss the voltammetric methods that are used to assess metal–organic complexation in seawater. These consist of titration methods using anodic stripping voltammetry (ASV) and cathodic stripping voltammetry competitive ligand experiments (CSV-CLE). These approaches and a kinetic approach using CSV-CLE give similar information on the amount of excess ligand to metal in a sample and the conditional metal ligand stability constant for the excess ligand bound to the metal. CSV-CLE data using different ligands to measure Fe(III) organic complexes are similar. All these methods give conditional stability constants for which the side reaction coefficient for the metal can be corrected but not that for the ligand. Another approach, pseudovoltammetry, provides information on the actual metal–ligand complex(es) in a sample by doing ASV experiments where the deposition potential is varied more negatively in order to destroy the metal–ligand complex. This latter approach gives concentration information on each actual ligand bound to the metal as well as the thermodynamic stability constant of each complex in solution when compared to known metal–ligand complexes. In this case the side reaction coefficients for the metal and ligand are corrected. Thus, this method may not give identical information to the titration methods because the excess ligand in the sample may not be identical to some of the actual ligands binding the metal in the sample

    How external and internal resources influence user action: the case of infusion devices

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    Human error can have potentially devastating consequences in contexts such as healthcare, but there is a rarely a simple dichotomy between errors and correct behaviour. Furthermore, there has been little consideration of how the activities of users (erroneous and otherwise) relate to the conceptual fit between user and device, despite the fact that healthcare technologies are becoming increasingly prevalent and complex. In this article, we present a study in which nurses’ conceptions of infusion device practice were elicited to identify misfits. By focusing on key concepts that users work with when setting up infusions and the extent to which the system supports them, our analysis highlights how actions are influenced by the different resources available to users including: the device itself; supporting artefacts; the conceptual understanding of the user; and the community of practice the user is part of. The findings reveal the ways in which users are resourceful in their day-to-day activities and also suggest potential vulnerabilities within the wider system that could threaten patient safety. Our approach is able to make previously under-explored aspects of practice visible, thus enabling insight into how users act and why

    Repeated successful surgical rescues of early and delayed multiple ruptures of ventricular septum, right ventricle and aneurysmal left ventricle following massive biventricular infarction

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    A 58 year old man underwent 6 surgical interventions for various complications of massive biventricular myocardial infarction over a period of 2 years following acute occlusion of a possibly "hyperdominant" left anterior descending coronary artery. These included concomitant repair of apicoanterior post-infarction VSD and right ventricular free wall rupture, repeat repair of recurrent VSD following inferoposterior extension of VSD in the infarcted septum 5 weeks later, repair of delayed right ventricular free wall rupture 4 weeks subsequently, repair of a bleeding left ventricular aneurysm eroding through left chest wall 16 months thereafter, repair of right upper lobe lung tear causing massive anterior mediastinal haemorrhage, mimicking yet another cardiac rupture, 2 months later, followed, at the same admission, 2 weeks later, by sternal reconstruction for dehisced and infected sternum using pedicled myocutaneous latissimus dorsi flap. 5 years after the latissimus myoplasty, the patient remains in NYHA class 1 and is leading a normal life

    Why so serious? Theorising playful model-driven group decision support with situated affectivity

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    This is the author accepted manuscript. The final version is available from Springer via the DOI in this record.An integrative approach to theorising behavioural, affective and cognitive processes in modeldriven group decision support (GDS) interventions is needed to gain insight into the (micro-)processes by which outcomes are accomplished. This paper proposes that the theoretical lens of situated affectivity, grounded in recent extensions of scaffolded mind models, is suitable to understand the performativity of affective micro-processes in model-driven GDS interventions. An illustrative vignette of a humorous micro-moment in a group decision workshop is presented to reveal the performativity of extended affective scaffolding processes for group decision development. The lens of situated affectivity constitutes a novel approach for the study of interventionist practice in the context of group decision making (and negotiation). An outlook with opportunities for future research is offered to facilitate an integrated approach to the study of cognitive-affective and behavioural micro-processes in model-driven GDS interventions.This work was supported in part by the EU FP7-ENERGY- SMARTCITIES-2012 (314277) project STEEP (Systems Thinking for Comprehensive City Efficient Energy Planning

    Knowledge-to-action processes in SHRTN collaborative communities of practice: A study protocol

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    <p>Abstract</p> <p>Background</p> <p>The Seniors Health Research Transfer Network (SHRTN) Collaborative is a network of networks that work together to improve the health and health care of Ontario seniors. The collaborative facilitates knowledge exchange through a library service, knowledge brokers (KBs), local implementation teams, collaborative technology, and, most importantly, Communities of Practice (CoPs) whose members work together to identify innovations, translate evidence, and help implement changes.</p> <p>This project aims to increase our understanding of knowledge-to-action (KTA) processes mobilized through SHRTN CoPs that are working to improve the health of Ontario seniors. For this research, KTA refers to the movement of research and experience-based knowledge between social contexts, and the use of that knowledge to improve practice. We will examine the KTA processes themselves, as well as the role of human agents within those processes. The conceptual framework we have adopted to inform our research is the Promoting Action on Research Implementation in Health Services (PARIHS) framework.</p> <p>Methods/design</p> <p>This study will use a multiple case study design (minimum of nine cases over three years) to investigate how SHRTN CoPs work and pursue knowledge exchange in different situations. Each case will yield a unique narrative, framed around the three PARIHS dimensions: evidence, context, and facilitation. Together, the cases will shed light on how SHRTN CoPs approach their knowledge exchange initiatives, and how they respond to challenges and achieve their objectives. Data will be collected using interviews, document analysis, and ethnographic observation.</p> <p>Discussion</p> <p>This research will generate new knowledge about the defining characteristics of CoPs operating in the health system, on leadership roles in CoPs, and on the nature of interaction processes, relationships, and knowledge exchange mechanisms. Our work will yield a better understanding of the factors that contribute to the success or failure of KTA initiatives, and create a better understanding of how local caregiving contexts interact with specific initiatives. Our participatory design will allow stakeholders to influence the practical usefulness of our findings and contribute to improved health services delivery for seniors.</p

    Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK): Explanation and Elaboration

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    The REMARK “elaboration and explanation” guideline, by Doug Altman and colleagues, provides a detailed reference for authors on important issues to consider when designing, conducting, and analyzing tumor marker prognostic studies
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