125 research outputs found

    Guidance on noncorticosteroid systemic immunomodulatory therapy in noninfectious uveitis: fundamentals of care for uveitis (focus) initiative

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    Topic: An international, expert-led consensus initiative to develop systematic, evidence-based recommendations for the treatment of noninfectious uveitis in the era of biologics. Clinical Relevance: The availability of biologic agents for the treatment of human eye disease has altered practice patterns for the management of noninfectious uveitis. Current guidelines are insufficient to assure optimal use of noncorticosteroid systemic immunomodulatory agents. Methods: An international expert steering committee comprising 9 uveitis specialists (including both ophthalmologists and rheumatologists) identified clinical questions and, together with 6 bibliographic fellows trained in uveitis, conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic reviewof the literature (English language studies from January 1996 through June 2016; Medline [OVID], the Central Cochrane library, EMBASE,CINAHL,SCOPUS,BIOSIS, andWeb of Science). Publications included randomized controlled trials, prospective and retrospective studies with sufficient follow-up, case series with 15 cases or more, peer-reviewed articles, and hand-searched conference abstracts from key conferences. The proposed statements were circulated among 130 international uveitis experts for review.Atotal of 44 globally representativegroupmembersmet in late 2016 to refine these guidelines using a modified Delphi technique and assigned Oxford levels of evidence. Results: In total, 10 questions were addressed resulting in 21 evidence-based guidance statements covering the following topics: when to start noncorticosteroid immunomodulatory therapy, including both biologic and nonbiologic agents; what data to collect before treatment; when to modify or withdraw treatment; how to select agents based on individual efficacy and safety profiles; and evidence in specific uveitic conditions. Shared decision-making, communication among providers and safety monitoring also were addressed as part of the recommendations. Pharmacoeconomic considerations were not addressed. Conclusions: Consensus guidelines were developed based on published literature, expert opinion, and practical experience to bridge the gap between clinical needs and medical evidence to support the treatment of patients with noninfectious uveitis with noncorticosteroid immunomodulatory agents

    Low-density star cluster formation: Discovery of a young faint fuzzy on the outskirts of the low-mass spiral galaxy NGC 247

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    The classical globular clusters found in all galaxy types have half-light radii of rh ~2-4 pc, which have been tied to formation in the dense cores of giant molecular clouds. Some old star clusters have larger sizes, and it is unclear if these represent a fundamentally different mode of low-density star cluster formation. We report the discovery of a rare, young \u27faint fuzzy\u27 star cluster, NGC 247-SC1, on the outskirts of the low-mass spiral galaxy NGC 247 in the nearby Sculptor group, and measure its radial velocity using Keck spectroscopy. We use Hubble Space Telescope imaging to measure the cluster half-light radius of rh ≃ 12 pc and a luminosity of LV ≃ 4 × 105Lθ. We produce a colour-magnitude diagram of cluster stars and compare to theoretical isochrones, finding an age of ≃300 Myr, a metallicity of [Z/H] ~-0.6 and an inferred mass of M∗ ≃ 9 × 104Mθ. The narrow width of blue-loop star magnitudes implies an age spread of ≲50 Myr, while no old red-giant branch stars are found, so SC1 is consistent with hosting a single stellar population, modulo several unexplained bright \u27red straggler\u27 stars. SC1 appears to be surrounded by tidal debris, at the end of an ∼2 kpc long stellar filament that also hosts two low-mass, low-density clusters of a similar age. We explore a link between the formation of these unusual clusters and an external perturbation of their host galaxy, illuminating a possible channel by which some clusters are born with large sizes

    Evaluation of fluid trajectory in time-resolved PIV

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    A new time-resolved PIV (TR-PIV) method is introduced by integrating both two concepts, the fluid parcel tracking [1] and the ensemble averaged correlation [2, 3]. The dynamic range is extended by applying the polynomial trajectory as the fluid motion [1]. The tracking procedure is not performed by using individual locations of the fluid parcel along the time, but the ensemble averaged cross-correlation value of the trajectory. The random errors caused by the crosscorrelation maps could be then reduced. Each polynomial coefficient is considered individually for economizing the computational cost by introducing the V-cycle search [4]. To taking into account the curved fluid motion, a new iterative corrector based on the shear rate of deformed image according to the trajectory is proposed for stabilizing the process. Not only the present method, but also the state-of-the-art TR-PIV methods, such as the trajectory correlation method [1] and the multi-frame pyramid correlation method [3] are carried out for the comparison. The quantitative evaluations are performed by analyzing synthetic image sequences of translation and rotation motions. An experimental image sequence of the flow around an airfoil is obtained by the High Rate-PIV measurement system, and used to evaluate the performances of the methods. The material acceleration from each methods is also calculated from the trajectory profile or the spatial velocity derivatives with respect to the measurement grid

    Evolved interactions stabilize many coexisting phases in multicomponent liquids

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    Phase separation has emerged as an essential concept for the spatial organization inside biological cells. However, despite the clear relevance to virtually all physiological functions, we understand surprisingly little about what phases form in a system of many interacting components, like in cells. Here we introduce a numerical method based on physical relaxation dynamics to study the coexisting phases in such systems. We use our approach to optimize interactions between components, similar to how evolution might have optimized the interactions of proteins. These evolved interactions robustly lead to a defined number of phases, despite substantial uncertainties in the initial composition, while random or designed interactions perform much worse. Moreover, the optimized interactions are robust to perturbations, and they allow fast adaption to new target phase counts. We thus show that genetically encoded interactions of proteins provide versatile control of phase behavior. The phases forming in our system are also a concrete example of a robust emergent property that does not rely on fine-tuning the parameters of individual constituents.BN/Liedewij Laan La

    Direct experimental comparison between tomo-PIV and scanning tomo-PIV: Wake flow behind a half-cylinder

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    In this paper, a direct experimental comparison ismade between scanning and tomo-PIV, on an unsteady wake flow behind a half-cylinder. Several seeding densities are used in order to demonstrate the capacities and limitations of both techniques. For the scanning technique, the effect of particles elongation is investigated and the influence of the seeding density on the volume reconstruction for tomo-PIV is examinated. The results of the two techniques are compared in terms of volume and velocity fields

    Assessment of the statistical relevance of TR-PIV datasets

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    The increasing interest for high repetition rate global optical measurement techniques such as Time-Resolved Particle Image Velocimetry (TR-PIV) raises a number of questions concerning their ability to provide relevant statistical and spectral quantities. In an effort to address this issue, complementary TR-PIV and Laser Doppler Velocimetry (LDV) measurements have been carried out. An application to the analysis of the detached flow over a NACA 0015 airfoil at a Reynolds number Re=105 in a water tunnel is proposed

    Loads and pressure evaluation of the flow around a flapping wing

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    An extension of nonintrusive approach based on an integral form of the momentum equation is proposed to evaluate instantaneous loads of a NACA0012 airfoil in flapping motion at Re = 1000 (The Reynolds number is based on the chord length and the velocity at 2/3 of the wingspan) in the case of the three-dimensional PIV measurements. Two major difficulties of this approach in 3D are the quality of the time-resolved volumic velocity fields and the estimation of the pressure field on the surface of the control volume. This last step needs a good spatial and temporal resolution of the velocity fields. Experimental data are issued from a scanning tomography PIV technique for a flapping wing in revolving motion. The volumes of particles are reconstructed using the 100 images of the acquisition, and the three-dimensional velocity fields around the airfoil are evaluated with an adaptive 3D cross-correlation. Phase-averaged velocity fields are estimated from the 25 velocity fields and are used by an iterative algorithm based on Navier-Stokes equations to deduce the pressure on the surfaces of the control volume. A special interest on the accuracy of the method is achieved. The results of the pressure fields and the load evaluation demonstrate the feasibility of the method and will provide new sets of data to better understand the effects of the 3D vortex structures on the wing lift in flapping motion

    Learning Mixed Strategies in Trajectory Games

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    In multi-agent settings, game theory is a natural framework for describing the strategic interactions of agents whose objectives depend upon one another’s behavior. Trajectory games capture these complex effects by design. In competitive settings, this makes them a more faithful interaction model than traditional “predict then plan” approaches. However, current game-theoretic planning methods have important limitations. In this work, we propose two main contributions. First, we introduce an offline training phase which reduces the online computational burden of solving trajectory games. Second, we formulate a lifted game which allows players to optimize multiple candidate trajectories in unison and thereby construct more competitive “mixed” strategies. We validate our approach on a number of experiments using the pursuit-evasion game “tag.”Learning & Autonomous Contro

    Probabilistic Online Robot Learning via Teleoperated Demonstrations for Remote Elderly Care

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    Daily household tasks involve manipulation in cluttered and unpredictable environments and service robots require complex skills and adaptability to perform such tasks. To this end, we developed a teleoperated online learning approach with a novel skill refinement method, where the operator can make refinements to the initially trained skill by a haptic device. After a refined trajectory is formed, it is used to update a probabilistic trajectory model conditioned to the environment state. Therefore, the initial model can be adapted when unknown variations occur and the method is able to deal with different object positions and initial robot poses. This enables human operators to remotely correct or teach complex robotic manipulation skills. Such an approach can help to alleviate shortages of caretakers in elderly care and reduce travel time between homes of different elderly to reprogram the service robots whenever they get stuck. We performed a human factors experiment on 18 participants teaching a service robot how to empty a dishwasher, which is a common daily household task performed by caregivers. We compared the developed method against three other methods. The results show that the proposed method performs better in terms of how much time it takes to successfully adapt a model and in terms of the perceived workload.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Human-Robot Interactio
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