311 research outputs found

    Gaze and Gestures in Telepresence: multimodality, embodiment, and roles of collaboration

    Full text link
    This paper proposes a controlled experiment to further investigate the usefulness of gaze awareness and gesture recognition in the support of collaborative work at a distance. We propose to redesign experiments conducted several years ago with more recent technology that would: a) enable to better study of the integration of communication modalities, b) allow users to freely move while collaborating at a distance and c) avoid asymmetries of communication between collaborators.Comment: Position paper, International Workshop New Frontiers in Telepresence 2010, part of CSCW2010, Savannah, GA, USA, 7th of February, 2010. http://research.microsoft.com/en-us/events/nft2010

    Generation and annihilation time of magnetic droplet solitons

    Get PDF
    Magnetic droplet solitons were first predicted to occur in materials with uniaxial magnetic anisotropy due to a long-range attractive interaction between elementary magnetic excitations, magnons. A non-equilibrium magnon population provided by a spin-polarized current in nanocontacts enables their creation and there is now clear experimental evidence for their formation, including direct images obtained with scanning x-ray transmission microscopy. Interest in magnetic droplets is associated with their unique magnetic dynamics that can lead to new types of high frequency nanometer scale oscillators of interest for information processing, including in neuromorphic computing. However, there are no direct measurements of the time required to nucleate droplet solitons or their lifetime-experiments to date only probe their steady-state characteristics, their response to dc spin-currents. Here we determine the timescales for droplet annihilation and generation using current pulses. Annihilation occurs in a few nanoseconds while generation can take several nanoseconds to a microsecond depending on the pulse amplitude. Micromagnetic simulations show that there is an incubation time for droplet generation that depends sensitively on the initial magnetic state of the nanocontact. An understanding of these processes is essential to utilizing the unique characteristics of magnetic droplet solitons oscillators, including their high frequency, tunable and hysteretic response

    Multiple magnetic droplet soliton modes

    Full text link
    Droplet solitons are large amplitude localized spin-wave excitations that can be created in magnetic thin films with uniaxial anisotropy by a spin-polarized current flowing through an electrical nanocontact. Here, we report a low-temperature (4 K) experimental study that shows there are multiple and, under certain conditions, combinations of droplet modes, each mode with a distinct high-frequency spin precession (tens of gigahertz). Low-frequency (1 GHz) voltage noise is used to assess the stability of droplet modes. It is found that droplets are stable only in a limited range of applied field and current, typically near the current and field at which they nucleate, in agreement with recent predictions. Applied fields in the film plane favor multiple droplet modes, whereas fields perpendicular to the film plane tend to stabilize a single droplet mode. Micromagnetic simulations are used to show that spatial variation in the energy landscape in the nanocontact region (e.g., spatial variation of magnetic anisotropy or magnetic field) can lead to quantized droplet modes and low-frequency mode modulation, characteristics observed in our experiments

    Territories of Confluence: a Socio-Eco-Aesthetic Approach to the Ecologies of the Llobregat River Delta

    Get PDF
    [EN] The Llobregat River Delta is a biodiverse yet fragile ecosystem located a few kilometers from the center of Barcelona. This network of wetlands constitutes the main habitat for different species of protected flora and fauna, and also represents the most important periurban agricultural area of the Barcelona metropolitan area. The ecological balances of this complex biotope have been severely affected by the urban transformations that have taken place in recent decades in and around the Catalan capital. The expansion of infrastructures such as the port and airport of Barcelona, together with the unregulated development of the urban fabric and the creation of a network of roads and railroads, have fragmented the territory, causing a severe habitat loss, as well as profound changes in land use. The Working Group on Hybrid Ecologies of the Llobregat Delta studies this naturcultural ecosystem as a space where the multiple criticalities of the neoliberal model and its predatory relationship with the environment become visible. Referring to the notions of ecosophy (Guattari, 1996), situated knowledge (Haraway, 1998) and interspecies care (Puig de la Bellacasa, 2017), the group proposes an experiential approach to this place through projects of artistic creation, cultural mediation and curatorship. Based on collaborative and transdisciplinary methodologies, the group seeks to offer perceptions that are capable of transforming sensitivity, formulate stories based on multispecies justice, and develop strategies of eco-social commitment to the territory. This paper describes the research processes that led to the creation of the art installation entitled Observatory of the Llobregat River Delta: Patterns of Complexity, shown in the context of the exhibition Multispecies Imaginaries. The art of living in a world of contingency and uncertainty (February-April 2022) at La Capella Art Center, Barcelona, delving into the ideas, methods and techniques that have driven this inquiry as well as its aesthetic configuration.[ES] El Delta del río Llobregat es un ecosistema biodiverso pero a la vez frágil, situado a pocos kilómetros del centro de Barcelona. Esta red de humedales constituye el hábitat principal para diferentes especies de flora y fauna protegidas, y representa también la zona agrícola periurbana más importante del área metropolitana de Barcelona. Los equilibrios ecológicos de este complejo biotopo se han visto gravemente afectados por las transformaciones urbanísticas que han tenido lugar en las últimas décadas en la capital catalana y sus alrededores. La ampliación de infraestructuras como el puerto y el aeropuerto de Barcelona junto al desarrollo incontrolado del tejido urbano y de una red de carreteras y ferrocarriles, han fragmentado el territorio generando una dramática reducción del hábitat, así como unos profundos cambios en los usos del suelo.El Grupo de trabajo de las ecologías híbridas del Delta del Llobregat estudia esta “zona de sacrificio” como un ecosistema naturcultural donde se hacen visibles las múltiples criticidades que caracterizan el modelo neoliberal y su relación predatoria con el medio ambiente. Haciendo referencia a las nociones de ecosofía (Guattari, 1996) y cura interespecie (Puig de la Bellacasa, 2017), el grupo propone un acercamiento perceptivo a este lugar a través de proyectos de creación artística, mediación cultural y comisariado. Basándose en metodologías colaborativas y transdisciplinares, el colectivo busca formular otras narraciones para encontrar nuevos significados y estrategias de compromiso ecosocial con el territorio.Esta comunicación recoge los procesos de investigación que se han plasmado en la instalación titulada Observatorio naturcultural del Delta del río Llobregat: patrones de complejidad, realizada en el contexto de la exposición Imaginarios multiespecies. El arte de vivir en un mundo de contingencia e incertidumbre (febrero-abril de 2022) en la Capella, Barcelona, ahondando en las reflexiones teóricas que han impulsado esta indagación así como en su formalización estética.Alonso Madrid, C.; Lega Lladós, F.; Sgaramella, C. (2022). Territorios de confluencia: una aproximación socio-eco-estética a las ecologías del Delta del río Llobregat. Editorial Universitat Politècnica de València. 510-516. https://doi.org/10.4995/ANIAV2022.2022.15458OCS51051

    Investigation and management of residual sleepiness in CPAP-treated patients with obstructive sleep apnoea: the European view

    Get PDF
    Excessive daytime sleepiness (EDS) is a major symptom of obstructive sleep apnoea (OSA), defined as the inability to stay awake during the day. Its clinical descriptors remain elusive, and the pathogenesis is complex, with disorders such as insufficient sleep and depression commonly associated. Subjective EDS can be evaluated using the Epworth Sleepiness Scale, in which the patient reports the probability of dozing in certain situations; however, its reliability has been challenged. Objective tests such as the multiple sleep latency test or the maintenance of wakefulness test are not commonly used in patients with OSA, since they require nocturnal polysomnography, daytime testing and are expensive. Drugs for EDS are available in the United States but were discontinued in Europe some time ago. For European respiratory physicians, treatment of EDS with medication is new and they may lack experience in pharmacological treatment of EDS, while novel wake-promoting drugs have been recently developed and approved for clinical use in OSA patients in the USA and Europe. This review will discuss 1) the potential prognostic significance of EDS in OSA patients at diagnosis, 2) the prevalence and predictors of residual EDS in treated OSA patients, and 3) the evolution of therapy for EDS specifically for Europe

    Three-dimensional-printed patient-specific instrumentation is an accurate tool to reproduce femoral bone tunnels in multiple-ligament knee injuries

    Get PDF
    Altres ajuts: acords transformatius de la UABMultiple-ligament knee reconstruction techniques often involve the creation of several bone tunnels for various reconstruction grafts. A critical step in this procedure is to avoid short tunnels or convergences among them. Currently, no specific template guide to reproduce these angulations has been reported in the literature, and the success of the technique still depends on the experience of the surgeon. The aim of this study is to analyze the accuracy and reliability of 3D-printed patient-specific instrumentation (PSI) for lateral and medial anatomical knee reconstructions. Ten cadaveric knees were scanned by computed tomography (CT). Using specific computer software, anatomical femoral attachments were identified: (1) on the lateral side the lateral collateral ligament (LCL) and the popliteal tendon (PT) and (2) on the medial side the medial collateral ligament (MCL) and the posterior oblique ligament (POL). Four bone tunnels were planned for each knee, and PSI with different directions were designed as templates to reproduce the planned tunnels during surgery. Twenty 3D-printed PSI were used: ten were tailored to the medial side for reconstructing MCL and POL tunnels, and the other ten were tailored to the lateral side for reconstructing LCL and PT tunnels. Postoperative CT scans were made for each cadaveric knee. The accuracy of the use of 3D-printed PSI was assessed by superimposing post-operative CT images onto pre-operative images and analyzing the deviation of tunnels performed based on the planning, specifically the entry point and the angular deviations. The median entry point deviations for the tunnels were as follows: LCL tunnel, 1.88 mm (interquartile range (IQR) 2.2 mm); PT tunnel, 2.93 mm (IQR 1.17 mm); MCL tunnel, 1.93 mm (IQR 4.26 mm); and POL tunnel, 2.16 mm (IQR 2.39). The median angular deviations for the tunnels were as follows: LCL tunnel, 2.42° (IQR 6.49°); PT tunnel, 4.15° (IQR 6.68); MCL tunnel, 4.50° (IQR 6.34°); and POL tunnel, 4.69° (IQR 3.1°). No statistically significant differences were found in either the entry point or the angular deviation among the different bone tunnels. The use of 3D-printed PSI for lateral and medial anatomical knee reconstructions provides accurate and reproducible results and may be a promising tool for use in clinical practice

    Incidence of Hepatocellular Carcinoma in Patients With Nonalcoholic Fatty Liver Disease: A Systematic Review, Meta-analysis, and Meta-regression.

    Get PDF
    Background & Aims Nonalcoholic fatty liver disease (NAFLD) may be a risk factor for hepatocellular carcinoma (HCC), but the extent of this association still needs to be addressed. Pooled incidence rates of HCC across the disease spectrum of NAFLD have never been estimated by meta-analysis. Methods In this systematic review, we searched Web of Science, Embase, PubMed, and the Cochrane Library from January 1, 1950 through July 30, 2020. We included studies reporting on HCC incidence in patients with NAFLD. The main outcomes were pooled HCC incidences in patients with NAFLD at distinct severity stages. Summary estimates were calculated with random-effects models. Sensitivity analyses and meta-regression analyses were carried out to address heterogeneity. Results We included 18 studies involving 470,404 patients. In patients with NAFLD at a stage earlier than cirrhosis, the incidence rate of HCC was 0.03 per 100 person-years (95% confidence interval [CI], 0.01–0.07; I2 = 98%). In patients with cirrhosis, the incidence rate was 3.78 per 100 person-years (95% CI, 2.47–5.78; I2 = 93%). Patients with cirrhosis undergoing regular screening for HCC had an incidence rate of 4.62 per 100 person-years (95% CI, 2.77–7.72; I2 = 77%). Conclusions Patients with NAFLD-related cirrhosis have a risk of developing HCC similar to that reported for patients with cirrhosis from other etiologies. Evidence documenting the risk in patients with nonalcoholic steatohepatitis or simple steatosis is limited, but the incidence of HCC in these populations may lie below thresholds used to recommend a screening. Well-designed prospective studies in these subpopulations are needed. The protocol for this systematic review is registered in the Prospero database (registration number CRD42018092861)

    Comparative analysis of tools to predict rapid progression in autosomal dominant polycystic kidney disease

    Get PDF
    Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease and shows a wide phenotype. Only patients with rapid progression (RP) are included in clinical trials or are approved to receive disease-modifying drugs. This study aims at comparing different available predictive tools in ADPKD with the Mayo classification (MC) identification of rapid progressors based on high total kidney volume (TKV) according to age. Methods: A total of 164 ADPKD patients were recruited retrospectively from a single centre. The performance of diverse tools to identify RP defined as being in MC categories 1C-1E was assessed. Results: A total of 118 patients were MC 1C-1E. The algorithm developed by the European Renal Association-European Dialysis and Transplant Association Working Group on Inherited Kidney Disorders/European Renal Best Practice had a low sensitivity in identifying MC 1C-1E. The sensitivity and specificity of TKV to predict RP depend on the cut-off used. A kidney length of >16.5 cm before age 45 years has high specificity but low sensitivity. Assessing the MC by ultrasonography had high levels of agreement with magnetic resonance imaging (MRI) data, especially for 1A, 1D and 1E. The estimated glomerular filtration rate (eGFR) decline was very sensitive but had low specificity. In contrast, the Predicting Renal Outcome in Polycystic Kidney Disease (PROPKD) score was very specific but had poor sensitivity. Having hypertension before 35 years of age is a good clinical predictor of MC 1C-1E. Family history can be of help in suggesting RP, but by itself it lacks sufficient sensitivity and specificity. Conclusions: The MC by ultrasonography could be an option in hospitals with limited access to MRI as it performs well generally, and especially at the extremes of the MC, i.e. classes 1A, 1D and 1E. The eGFR decline is sensitive but not very specific when compared with the MC, whereas the PROPKD score is very specific but has low sensitivity. Integrating the different tools currently available to determine RP should facilitate the identification of rapid progressors among patients with ADPKD
    corecore