89 research outputs found

    Precision is in the Eye of the Beholder: Application of Eye Fixation-Related Potentials to Information Systems Research

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    This is the final version. Available from Association for Information Systems via the DOI in this recordThis paper introduces the eye-fixation related potential (EFRP) method to IS research. The EFRP method allows one to synchronize eye tracking with electroencephalographic (EEG) recording to precisely capture users’ neural activity at the exact time at which they start to cognitively process a stimulus (e.g., event on the screen). This complements and overcomes some of the shortcomings of the traditional event related potential (ERP) method, which can only stamp the time at which a stimulus is presented to a user. Thus, we propose a method conjecture of the superiority of EFRP over ERP for capturing the cognitive processing of a stimulus when such cognitive processing is not necessarily synchronized with the time at which the stimulus appears. We illustrate the EFRP method with an experiment in a natural IS use context in which we asked users to read an industry report while email pop-up notifications arrived on their screen. The results support our proposed hypotheses and show three distinct neural processes associated with 1) the attentional reaction to email pop-up notification, 2) the cognitive processing of the email pop-up notification, and 3) the motor planning activity involved in opening or not the email. Furthermore, further analyses of the data gathered in the experiment serve to validate our method conjecture about the superiority of the EFRP method over the ERP in natural IS use contexts. In addition to the experiment, our study discusses important IS research questions that could be pursued with the aid of EFRP, and describes a set of guidelines to help IS researchers use this method.Social Sciences and Humanities Research Council of Canada (SSHRC)Natural Sciences and Engineering Research Council of CanadaFonds Québécois pour la Recherche sur la Société et la Culture (FQRSC)Fonds de recherche Nature et Technologies (FQRNT

    Mobile health use in low- and high-income countries: an overview of the peer-reviewed literature.

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    The evolution of mobile phone technology has introduced new possibilities to the field of medicine. Combining technological advances with medical expertise has led to the use of mobile phones in all healthcare areas including diagnostics, telemedicine, research, reference libraries and interventions. This article provides an overview of the peer-reviewed literature, published between 1 August 2006 and 1 August 2011, for the application of mobile/cell phones (from basic text-messaging systems to smartphones) in healthcare in both resource-poor and high-income countries. Smartphone use is paving the way in high-income countries, while basic text-messaging systems of standard mobile phones are proving to be of value in low- and middle-income countries. Ranging from infection outbreak reporting, anti-HIV therapy adherence to gait analysis, resuscitation training and radiological imaging, the current uses and future possibilities of mobile phone technology in healthcare are endless. Multiple mobile phone based applications are available for healthcare workers and healthcare consumers; however, the absolute majority lack an evidence base. Therefore, more rigorous research is required to ensure that healthcare is not flooded with non-evidence based applications and is maximized for patient benefit

    Dural lymphatics regulate clearance of extracellular tau from the CNS

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    BackgroundAlzheimer's disease is characterized by two main neuropathological hallmarks: extracellular plaques of amyloid- (A) protein and intracellular aggregates of tau protein. Although tau is normally a soluble monomer that bind microtubules, in disease it forms insoluble, hyperphosphorylated aggregates in the cell body. Aside from its role in AD, tau is also involved in several other neurodegenerative disorders collectively called tauopathies, such as progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), some forms of frontotemporal dementia, and argyrophilic grain disease (AGD). The prion hypothesis suggests that after an initial trigger event, misfolded forms of tau are released into the extracellular space, where they spread through different brain regions, enter cells, and seeding previously normal forms. Thus understanding mechanisms regulating the clearance of extracellular tau from the CNS is important. The discovery of a true lymphatic system in the dura and its potential role in mediating A pathology prompted us to investigate its role in regulating extracellular tau clearance.MethodsTo study clearance of extracellular tau from the brain, we conjugated monomeric human tau with a near-infrared dye cypate, and injected this labeled tau in the parenchyma of both wild-type and K14-VEGFR3-Ig transgenic mice, which lack a functional CNS lymphatic system. Following injection we performed longitudinal imaging using fluorescence molecular tomography (FMT) and quantified fluorescence to calculate clearance of tau from the brain. To complement this, we also measured tau clearance to the periphery by measuring plasma tau in both groups of mice.ResultsOur results show that a significantly higher amount of tau is retained in the brains of K14-VEGFR3-Ig vs. wild type mice at 48 and 72h post-injection and its subsequent clearance to the periphery is delayed. We found that clearance of reference tracer human serum albumin (HSA) was also significantly delayed in the K14-VEGFR3-Ig mice.ConclusionsThe dural lymphatic system appears to play an important role in clearance of extracellular tau, since tau clearance is impaired in the absence of functional lymphatics. Based on our baseline characterization of extracellular tau clearance, future studies are warranted to look at the interaction between tau pathology and efficiency of lymphatic function.Peer reviewe

    STRESS AND MAGNETO-OPTICAL STUDIES ON TETRAHEDRAL AND TETRAGONAL F CENTRES IN SrCl2 AND BaCIF

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    Nous rapportons nos résultats de dichroïsme circulaire magnétique et de dichroïsme linéaire sous contrainte du centre F tétraédrique dans SrCl2 et des centres F tétragonaux dans BaCIF. Dans tous les cas le facteur de Landé orbital de l'état excité est proche de zéro et la constante de couplage spin orbite est déterminée. L'analyse des moments d'ordre supérieur des courbes d'absorption et de dichroïsme permet d'atteindre certains paramètres de couplage électron-réseau.Results of magneto-optical and stress linear dichroism on tetrahedral F centre in SrCl2 and tetragonal F centres in BaCIF are presented. In both cases, the excited state Landé factor is found to be close to zero and the spin orbit splitting is determined. The analysis of higher order moments of absorption and dichroism curves leads to the determination of some electron lattice coupling parameters

    Addition, addition répétée, multiplication : un trajet éclairé par les schèmes d’action

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    International audienceDans le texte sur les erreurs en division écrite (Brun et al, 1993), il a été montré comment la notion de schème (Inhelder et Cellérier, 1992 ; Vergnaud, 1990) permet de comprendre les erreurs des élèves. Ces erreurs témoigneraient de coordinations de schèmes conduisant à la formation d’un schème-algorithme pour la division. Parmi ces schèmes, le schème « partager/distribuer » est central. Nous poursuivons l’examen de son fonctionnement et de sa coordination à d’autres schèmes, dans le contexte de problèmes sur les relations additives et multiplicatives

    Indikatoren

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