859 research outputs found

    On Grasp Quality Measures: Grasp Robustness and Contact Force Distribution in Underactuated and Compliant Robotic Hands

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    The availability of grasp quality measures is fundamental for grasp planning and control, and also to drive designers in the definition and optimization of robotic hands. This work investigates on grasp robustness and quality indexes that can be applied to power grasps with underactuated and compliant hands. When dealing with such types of hands, there is the need of an evaluation method that takes into account the forces that can be actually controlled by the hand, depending on its actuation system. In this paper, we study the potential contact robustness and the potential grasp robustness (PCR, PGR) indexes. They both consider main grasp properties: contact points, friction coefficient, etc., but also hand degrees of freedom and consequently, the directions of controllable contact forces. The PCR comes directly from the classical grasp theory and can be easily evaluated, but often leads to too conservative solutions, particularly when the grasp has many contacts. The PGR is more complex and computationally heavier, but gives a more realistic, even if still conservative, estimation of the overall grasp robustness, also in power grasps. We evaluated the indexes for various simulated grasps, performed with underactuated and compliant hands, and we analyzed their variations with respect to the main grasp parameters

    Modeling and Simulation of Robotic Grasping in Simulink Through Simscape Multibody

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    Grasping and dexterous manipulation remain fundamental challenges in robotics, above all when performed with multifingered robotic hands. Having simulation tools to design and test grasp and manipulation control strategies is paramount to get functional robotic manipulation systems. In this paper, we present a framework for modeling and simulating grasps in the Simulink environment, by connecting SynGrasp, a well established MATLAB toolbox for grasp simulation and analysis, and Simscape Multibody, a Simulink Library allowing the simulation of physical systems. The proposed approach can be used to simulate the grasp dynamics in Simscape, and then analyse the obtained grasps in SynGrasp. The devised functions and blocks can be easily customized to simulate different hands and objects

    Endovascular Interventional Radiology of the Urogenital Tract

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    Interventional radiology of the male urogenital system includes percutaneous and endovascular procedures, and these last consist mostly of transcatheter arterial embolizations. At the kidney level, arterial embolizations are performed mainly for palliative treatment of parenchymal tumors, for renal traumas and, less frequently, for arteriovenous fistulas and renal aneurysms and pseudoaneurysms. These latter may often require emergency intervention as they can cause renal or peri-renal hematomas or significant hematuria. Transcatheter arterial embolization is also an effective therapy for intractable severe bladder hematuria secondary to a number of neoplastic and inflammatory conditions in the pelvis, including unresectable bladder cancer and radiation-induced or cyclophosphamide-induced hemorrhagic cystitis. Endovascular interventional procedures for the penis are indicated for the treatment of post-traumatic priapism. In this article, we review the main endovascular radiological interventions of the male urogenital system, describing the technical aspects, results, and complications of each procedure at the various anatomical districts

    Analysis of postures for handwriting on touch screens without using tools

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    The act of handwriting affected the evolutionary development of humans and still impacts the motor cognition of individuals. However, the ubiquitous use of digital technologies has drastically decreased the number of times we really need to pick a pen up and write on paper. Nonetheless, the positive cognitive impact of handwriting is widely recognized, and a possible way to merge the benefits of handwriting and digital writing is to use suitable tools to write over touchscreens or graphics tablets. In this manuscript, we focus on the possibility of using the hand itself as a writing tool. A novel hand posture named FingerPen is introduced, and can be seen as a grasp performed by the hand on the index finger. A comparison with the most common posture that people tend to assume (i.e. index finger-only exploitation) is carried out by means of a biomechanical model. A conducted user study shows that the FingerPen is appreciated by users and leads to accurate writing traits

    Fare rete per affrontare le sfide della ricerca sul "Technology Enhanced Learning"

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    The paper analyses the case of the Theme Teams, i.e. one of the instruments used by the STELLAR Network of Excellence to contribute to the achievement of its aims, i.e. overcoming the fragmentation of the Technology Enhanced Learning research field and drawing the road map for future research. Qualitative and quantitative data about the way this instrument worked show how even a rather limited budget can be fruitfully used to promote the integration of researchers of different countries, with different backgrounds and approaches and thus overcome the traditional discipline fragmentation.Questo contributo analizza il caso dei Theme Team, uno degli strumenti usati dalla Rete di Eccellenza STELLAR per raggiungere i suoi obiettivi, che includono in particolare il superamento della frammentazione del settore del Technology Enhanced Learning, l\u27identificazione delle principali sfide e la prefigurazione di percorsi per la ricerca futura

    Ricolinostat, a selective HDAC6 inhibitor, shows anti-lymphoma cell activity alone and in combination with bendamustine

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    Histone deacetylase inhibitors (HDACis) have emerged as a new class of anticancer agents, targeting the biological process including cell cycle and apoptosis. We investigated and explained the anticancer effects of an HDAC6 inhibitor, ricolinostat alone and in combination with bendamustine in lymphoma cell lines. Cell viability was measured by MTT assay. Apoptosis, reactive oxygen species (ROS) generation, Bcl-2 protein expression, cell cycle progression and tubuline expression were determined by flow cytometry. The effects of ricolinostat alone and in combination on the caspases, PI3K/Akt, Bcl-2 pathways, ER stress and UPR were assessed by immunoblotting. Ricolinostat shows anti lymphoma activity when used as single agent and its capability to induce apoptosis is synergistically potentiated by the bendamustine in lymphoma cell lines. Drug combination reduced the proportion of cells in the G0/G1and S phases and caused an increase of âsub-G0/G1â peak. The synergistic effect accompanied with the increased ROS, activation of caspase-8, -9, and -3, the cleavage of PARP and modulated by Bcl-2 proteins family. In addition, the exposure of ricolinostat induced the acetylation level of α-tubulin, the extend of which was not further modified by bendamustine. Finally, the apoptosis effect of ricolinostat/bendamustine may be mediated by a corresponding effect on microtubule stabilization. Our data suggest that ricolinostat in combination with bendamustine may be a novel combination with potential for use as an antitumor agent in lymphoma

    The Distant Horizon: investigating the relationship between social sciences academic research and game development

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    Research in the social sciences devotes a great amount of attention to investigating the impact of video games on the individual and on society. However, results generated by this research often fail to inform game development. The present study investigated the outreach of research conducted by the academic community by interviewing 30 game developers and 14 researchers, highlighting critical aspects in the relationship between game research and game industry. Specifically, we found that the difference in priorities, speed cycles, and dissemination practices between these two contexts hinder communication. Subsequently, we carried out a focus group for a set of developers and researchers (N=6) with the aim of eliciting recommendation for improving communication between academics and developers. Among the recommendations to emerge were calls to diversify dissemination channels, promote joint conferences and develop research-production partnerships. It was felt such measures could strengthen the influence of research results outside the academic community

    Pericardiectomy for Pleuropericardial Effusion Complicating Bacterial Pneumonia

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    Severe pericardial effusion is a rare complication of bacterial pneumonia and it usually disappears under medical treatment. Herein we report a case of a girl with a congenital immunodeficient syndrome and bacterial pneumonia, who developed recurrent and life-threatening pericardial effusion refractory to medical treatment. She was finally treated with pericardiectomy

    Juan Carlos Sager: home polifacètic, avançat al seu temps

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    Juan Carlos Sager deixa un gran llegat no només de publicacions, sinó també de molts altres elements, igual d’importants. I els records d’aquests perduren en la memòria de tothom que el va conèixer i admirar
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