1,796 research outputs found

    Investigation of Smart Responses of Human Serum Albumin in Fever Condition: An In Vitro Approach

    Get PDF
    To move real objects, our hand needs to get in direct physical contact with the object. However, this is not necessarily the case when interacting with virtual objects, for example when displacing objects on tablets by swipe movements. Here, we performed two experiments to study the behavioral strategies of these movements, examining how visual information about the virtual object is mapped into a swipe that moves the object into a goal location. In the first experiment, we investigated how swiping behavior depends on whether objects were located within or outside the swiping workspace. Results show that participants do not start the swipe movement by placing their finger on the virtual object, as they do when reaching to real objects, but rather keep a systematic distance between the object location and the initial swipe location. This mismatch, which was experimentally imposed by placing the object outside the workspace, also occurred when the object was within the workspace. In the second experiment, we investigated which factors determine this mismatch by systematically manipulating the initial hand location, the location of the object and the location of the goal. Dimensionality reduction of the data showed that three factors are taken into account when participants choose the initial swipe location: the expected total movement distance, the distance between their finger on the screen and the object, and a preference not to cover the object. The weight given to each factor differed among individuals. These results delineate, for the first time, the flexibility of visuomotor associations in the virtual world

    Licorice consumption as a cause of posterior reversible encephalopathy syndrome: a case report

    Get PDF
    INTRODUCTION: A 49-year-old woman was admitted to our hospital because of thunderclap headache and blurred vision. At the time of presentation, her blood pressure was 219/100 mmHg, her arterial pH was 7.64 and her potassium level was 2.7 mM/l. METHODS: The combination of sequential computed tomography (CT) and the triad of hypertension, hypokalemia and metabolic alkalosis in this patient suggested the diagnosis. Supplementary anamnesis and long-term follow-up confirmed it. RESULTS: Brain computed tomography imaging showed minor bleeding in the left Sylvian fissure and bilateral occipital edema, suggestive of posterior reversible encephalopathy syndrome (PRES). Repeated brain CT after 10 days showed a complete resolution of radiological signs. The patient informed us that she had quit smoking 2 weeks ago and had started consuming large amounts of licorice instead of smoking. After she abandoned licorice consumption, her blood pressure normalized. Her latest blood pressure reading was 106/60 mmHg without the use of any antihypertensive drugs. CONCLUSIONS: To the best of our knowledge, this is the first case report describing licorice consumption as a cause of PRES. Glycyrrhizic acid, a component of licorice, inhibits 11β-hydroxysteroid dehydrogenase and subsequently causes mineralocorticoid excess. Mineralocorticoid excess in turn causes high blood pressure and ultimately gives rise to malignant hypertension. Physicians should remember that licorice use is a very easy-to-treat cause of hypertension, hypertensive encephalopathy and PRES

    How does our motor system determine its learning rate?

    Get PDF
    Motor learning is driven by movement errors. The speed of learning can be quantified by the learning rate, which is the proportion of an error that is corrected for in the planning of the next movement. Previous studies have shown that the learning rate depends on the reliability of the error signal and on the uncertainty of the motor system’s own state. These dependences are in agreement with the predictions of the Kalman filter, which is a state estimator that can be used to determine the optimal learning rate for each movement such that the expected movement error is minimized. Here we test whether not only the average behaviour is optimal, as the previous studies showed, but if the learning rate is chosen optimally in every individual movement. Subjects made repeated movements to visual targets with their unseen hand. They received visual feedback about their endpoint error immediately after each movement. The reliability of these error-signals was varied across three conditions. The results are inconsistent with the predictions of the Kalman filter because correction for large errors in the beginning of a series of movements to a fixed target was not as fast as predicted and the learning rates for the extent and the direction of the movements did not differ in the way predicted by the Kalman filter. Instead, a simpler model that uses the same learning rate for all movements with the same error-signal reliability can explain the data. We conclude that our brain does not apply state estimation to determine the optimal planning correction for every individual movement, but it employs a simpler strategy of using a fixed learning rate for all movements with the same level of error-signal reliability

    Optimal Distinctiveness: The Role of Platform Size and Identity

    Get PDF
    Recent theoretical advances hold that platforms comprise a second strategic dimension next to size, called identity, which describes the platform’s techno-logical and market scope. Letting go of platform size as the main criterion for platform value opens the possibility for platforms to pursue differentiation strategies with a distinct market positioning. The concept of optimal distinctiveness (OD) implies that differentiation can be optimized so that it maximizes performance. In this paper, we draw on recent OD research in and outside of the field of platforms and elaborate on the role of platform size within the distinctiveness framework. We discuss platform size and identity in the context of OD and suggest propositions for future research. The paper contributes to the management of platforms and OD in platform markets by showing how a platform’s distinctiveness strategy may depend on its size. We contribute to platform management across various platform sizes and to research on OD in platform markets

    What’s the tally? An Investigation into the Field(s) of Dominant Designs and Platforms

    Get PDF
    Dominant designs and platforms are two distinct scientific fields in the analysis of innovation of and competition between technologies. Responding to calls for more synthesis in management research, we study the commonalities and differences between the fields surrounding these concepts. To this end, we develop a framework for the comparison of concepts and apply it to dominant designs and platforms. We show that dominant designs and platforms differ most prominently regarding their central mechanisms, their unit and level of analysis, and the timeframe. We will elaborate how they are complementary by developing a research agenda

    Prevalence and management of iron overload in pyruvate kinase deficiency: report from the Pyruvate Kinase Deficiency Natural History Study

    Get PDF
    Pyruvate kinase (PK) deficiency is the most common red cell glycolytic enzyme defect causing hereditary non-spherocytic hemolytic anemia. Current treatments are mainly supportive and include red cell transfusions and splenectomy.11 Regular red cell transfusions are known to result in iron overload; however, the prevalence and spectrum of transfusion-independent iron overload in the overall PK deficient population has not been well defined. This analysis describes the prevalence and clinical characteristics of iron overload in patients enrolled in the PK Deficiency Natural History Study (NHS) with a focus on those patients who are not regularly transfused.

    Reframing the future: the role of reflexivity in governance networks in sustainability transitions

    Get PDF
    Contains fulltext : 183569.pdf (Publisher’s version ) (Open Access)30 november 201

    Samenvatting Monitoring Nulsituatie-Rapport Resultaten meetronde 2005-2006

    Get PDF
    Eind 2004 is door het Hoofdproductschap Akkerbouw (HPA), het Productschap Tuinbouw (PT) en LTO Nederland het initiatief genomen om de aaltjesproblemen gezamenlijk aan te pakken. Hiervoor is het actieplan aaltjesbeheersing gelanceerd. Eén van de projecten binnen dit actieplan was het monitoren van de nulsituatie. Dit project is uitgevoerd door een consortium van Blgg BV, NAK AGRO BV, en PPO-AGV. Binnen het project zijn tussen 2005 en 2006 425 akkerbouwbedrijven grondmonsters genomen. Deze zijn geanalyseerd op de meest bekende plantenparasitaire aaltjes. Daarnaast is aan de deelnemers gevraagd mee te werken aan een enquête over hun bedrijfsvoering en hun ervaringen met aaltje

    Spatially valid proprioceptive cues improve the detection of a visual stimulus

    Get PDF
    Vision and proprioception are the main sensory modalities that convey hand location and direction of movement. Fusion of these sensory signals into a single robust percept is now well documented. However, it is not known whether these modalities also interact in the spatial allocation of attention, which has been demonstrated for other modality pairings. The aim of this study was to test whether proprioceptive signals can spatially cue a visual target to improve its detection. Participants were instructed to use a planar manipulandum in a forward reaching action and determine during this movement whether a near-threshold visual target appeared at either of two lateral positions. The target presentation was followed by a masking stimulus, which made its possible location unambiguous, but not its presence. Proprioceptive cues were given by applying a brief lateral force to the participant’s arm, either in the same direction (validly cued) or in the opposite direction (invalidly cued) to the on-screen location of the mask. The d′ detection rate of the target increased when the direction of proprioceptive stimulus was compatible with the location of the visual target compared to when it was incompatible. These results suggest that proprioception influences the allocation of attention in visual spac
    corecore