4,328 research outputs found

    A Software Suite for the Control and the Monitoring of Adaptive Robotic Ecologies

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    Adaptive robotic ecologies are networks of heterogeneous robotic devices (sensors, actuators, automated appliances) pervasively embedded in everyday environments, where they learn to cooperate towards the achievement of complex tasks. While their flexibility makes them an increasingly popular way to improve a system’s reliability, scalability, robustness and autonomy, their effective realisation demands integrated control and software solutions for the specification, integration and management of their highly heterogeneous and computational constrained components. In this extended abstract we briefly illustrate the characteristic requirements dictated by robotic ecologies, discuss our experience in developing adaptive robotic ecologies, and provide an overview of the specific solutions developed as part of the EU FP7 RUBICON Project

    Shear-Thinning Fluid Flow in Variable-Aperture Channels

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    Non-Newtonian fluid flow in a single fracture is a 3-D nonlinear phenomenon that is often averaged across the fracture aperture and described as 2-D. To capture the key interactions between fluid rheology and spatial heterogeneity, we adopt a simplified geometric model to describe the aperture variability, consisting of adjacent one-dimensional channels with constant aperture, each drawn from an assigned aperture distribution. The flow rate is then derived under the lubrication approximation for the two limiting cases of an external pressure gradient that is parallel/perpendicular to the channels; these two arrangements provide upper and lower bounds to the fracture conductance. The fluid rheology is described by the Prandtl–Eyring shear-thinning model. Novel closed-form results for the flow rate and hydraulic aperture are derived and discussed; different combinations of the parameters that describe the fluid rheology and the variability of the aperture field are considered. The flow rate values are very sensitive to the applied pressure gradient and to the shape of the distribution; in particular, more skewed distribution entails larger values of a dimensionless flow rate. Results for practical applications are compared with those valid for a power-law fluid and show the effects on the fracture flow rate of a shear stress plateau

    3D bioprinted human cortical neural constructs derived from induced pluripotent stem cells

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    Bioprinting techniques use bioinks made of biocompatible non-living materials and cells to build 3D constructs in a controlled manner and with micrometric resolution. 3D bioprinted structures representative of several human tissues have been recently produced using cells derived by differentiation of induced pluripotent stem cells (iPSCs). Human iPSCs can be differentiated in a wide range of neurons and glia, providing an ideal tool for modeling the human nervous system. Here we report a neural construct generated by 3D bioprinting of cortical neurons and glial precursors derived from human iPSCs. We show that the extrusion-based printing process does not impair cell viability in the short and long term. Bioprinted cells can be further differentiated within the construct and properly express neuronal and astrocytic markers. Functional analysis of 3D bioprinted cells highlights an early stage of maturation and the establishment of early network activity behaviors. This work lays the basis for generating more complex and faithful 3D models of the human nervous systems by bioprinting neural cells derived from iPSCs

    Ex-vivo recruitment and x-ray assessment of donor lungs in a challenging retrieval from a donor supported by lvad using the portable normothermic perfusion system: A case report

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    Lung transplantation (LTx) is limited by the shortage of suitable donors. To overcome this problem, many programs have begun to use donors with extended criteria (marginal donors). However, brain-dead patients with implanted mechanical circulatory support system have rarely been considered as potential lung donors. This case demonstrates the feasibility of lung transplantations from organ donors supported by a mechanical circulatory support system despite the possible difficulties of lung retrieval. CASE PRESENTATION: Our case presents a successful procurement and bilateral lung transplantation from a donor supported by a left ventricular assist device (LVAD) who experienced an intraoperatively haemodynamic complication. The use of portable normothermic perfusion device let us to reduce ischemic injury and assess these marginal donor lungs helping us to determine the clinical suitability for transplantation. Given our extensive experience with the device instrumentation and management, the EVLP process was uneventful with excellent post-transplant course. CONCLUSIONS: This case report demonstrates the feasibility of lung transplantations from organ donors supported by a mechanical circulatory support system using the portable normothermic perfusion platform to assess and preserve these donor lungs

    Multi-agent quality of experience control

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    In the framework of the Future Internet, the aim of the Quality of Experience (QoE) Control functionalities is to track the personalized desired QoE level of the applications. The paper proposes to perform such a task by dynamically selecting the most appropriate Classes of Service (among the ones supported by the network), this selection being driven by a novel heuristic Multi-Agent Reinforcement Learning (MARL) algorithm. The paper shows that such an approach offers the opportunity to cope with some practical implementation problems: in particular, it allows to face the so-called “curse of dimensionality” of MARL algorithms, thus achieving satisfactory performance results even in the presence of several hundreds of Agents

    Long Term Survival in Patients Suffering from Glio-blastoma Multiforme: A Single-Center Observational Cohort Study

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    Background: Glioblastomas (GBM) are generally burdened, to date, by a dismal prognosis, although long term survivors have a relatively significant incidence. Our specific aim was to determine the exact impact of many surgery-, patient- and tumor-related variables on survival parameters. Methods: The surgical, radiological and clinical outcomes of patients have been retrospectively reviewed for the present study. All the patients have been operated on in our institution and classified according their overall survival in long term survivors (LTS) and short term survivors (STS). A thorough review of our surgical series was conducted to compare the oncologic results of the patients in regard to: (1) surgical-(2) molecular and (3) treatment-related features. Results: A total of 177 patients were included in the final cohort. Extensive statistical analysis by means of univariate, multivariate and survival analyses disclosed a survival advantage for patients presenting a younger age, a smaller lesion and a better functional status at presentation. From the histochemical point of view, Ki67 (%) was the strongest predictor of better oncologic outcomes. A stepwise analysis of variance outlines the existence of eight prognostic subgroups according to the molecular patterns of Ki67 overexpression and epidermal growth factor receptor (EGFR), p53 and isocitrate dehydrogenase (IDH) mutations. Conclusions: On the grounds of our statistical analyses we can affirm that the following factors were significant predictors of survival advantage: Karnofsky performance status (KPS), age, volume of the lesion, motor disorder at presentation and/or a Ki67 overexpression. In our experience, LTS is associated with a gross total resection (GTR) of tumor correlated with EGFR and p53 mutations with regardless of localization, and poorly correlated to dimension. We suppose that performing a standard molecular analysis (IDH, EGFR, p53 and Ki67) is not sufficient to predict the behavior of a GBM in regards to overall survival (OS), nor to provide a deeper understanding of the meaning of the different genetic alterations in the DNA of cancer cells. A fine molecular profiling is feasible to precisely stratify the prognosis of GBM patients
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